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Medical pcb manufacturing process

04/17/2024 in /by

As technology rapidly advances, the medical industry’s demand for electronic products is also growing. Among the various electronic components, PCBs undoubtedly play an indispensable role in medical devices. However, the requirements and standards for PCBs in the medical industry far exceed those in other sectors. Why is this so? This article will explore the high demands and standards of the medical industry for PCBs. In this article, we will discuss the manufacturing process of medical PCBs.

Importance of PCBAs in Medical Devices

  1. Precision: Medical devices require a high level of precision to ensure accurate diagnosis and effective treatment. Any defects or errors in the circuit board could lead to equipment failure or provide incorrect information, posing serious risks to patients’ health.
  2. Reliability: Medical devices often need to operate in continuous working environments, placing high demands on the reliability of the circuit boards. Sudden equipment failures could result in surgery interruptions, data loss, or other medical accidents.
  3. Safety: Medical devices are directly related to patients’ lives and health, so the design and manufacturing of their circuit boards must comply with strict safety standards. This includes, but is not limited to, electromagnetic compatibility, overheat protection, and fire prevention.
  4. Miniaturization: With technological advancements, many medical devices are pursuing smaller sizes and higher levels of integration. This requires circuit board designs to be more compact, with finer connections between components.

Material Selection and Performance

In the surface mounting process of medical device PCBA, the selection of PCB materials is crucial. Commonly used PCB materials include FR-4 (glass fiber reinforced epoxy resin), metal substrates (such as aluminum substrates), ceramic substrates, and so on. Different materials have different performance characteristics, and it is necessary to choose the appropriate materials according to the operating environment and requirements of medical devices.

▶ Thermal Stability: Medical devices may operate in high-temperature environments, so the thermal stability of PCBs is crucial to avoid performance issues caused by thermal expansion and contraction in high-temperature environments.

▶ Mechanical Strength: PCBs need to have sufficient mechanical strength to prevent breakage during transportation, installation, or use, ensuring the stability and durability of medical devices.

Hierarchy Structure and Design Layout

Medical devices typically require high integration, so the hierarchy structure and design layout of PCBs are particularly important. A reasonable hierarchy structure and layout design can minimize signal interference, improve circuit stability, and reliability to the maximum extent.

▶ Layered Design: For complex medical devices, multi-layer PCBs can be used to distribute different functional modules on different layers, reducing signal interference and improving the circuit’s anti-interference ability.

▶ Reasonable Wiring: A reasonable wiring design can reduce signal transmission paths, decrease signal delay, increase signal transmission speed, and avoid interference caused by signal cross-talk.

Pad Design and Process Requirements

The design of pads on the PCB and the process requirements for surface mounting are closely related. Proper pad design and process can ensure a good connection between surface-mount components and the PCB, preventing soldering defects and cold joints.

▶ Pad Size and Spacing: Different sizes and types of surface-mount components require pads of appropriate size and spacing to ensure soldering stability and reliability.

▶ Pad Shape: Different shapes of pads are suitable for different types of soldering processes, such as Surface Mount Technology (SMT) and through-hole soldering technology. Choosing the appropriate pad shape can improve soldering efficiency and quality.

Medical PCB manufacturing

Manufacturing Process of Medical PCBA

  1. PCB Design: Engineers use professional software to design the circuit board according to the requirements and specifications of the device. Once the design is completed, the PCB manufacturer produces the bare board based on the design.

  2. Component Procurement: The procurement team purchases the required electronic components based on the Bill of Materials (BOM). These components may include resistors, capacitors, inductors, ICs (integrated circuits), etc.

  3. SMT Mounting: Electronic components are precisely mounted onto the PCB using a pick-and-place machine. This process is automated to ensure speed and accuracy.

  4. Soldering: Components are soldered onto the PCB using reflow soldering or other soldering methods.

  5. Testing and Inspection: The completed PCBA undergoes quality inspection and functional testing using AOI (Automated Optical Inspection) equipment and other testing tools to ensure it meets design requirements and quality standards.

  6. Assembly and Encapsulation: The tested and qualified PCBA is assembled with other components (such as displays, batteries, etc.) to form a complete medical device.

Challenges and Trends in Medical Device PCBA

  1. Technological Challenges: With the continuous advancement of medical technology, the requirements for circuit boards in devices are also increasing. For example, many advanced imaging systems require processing large amounts of data, placing high demands on the transmission speed and processing capabilities of circuit boards.

  2. Regulatory Compliance: The medical device market is subject to strict regulatory oversight, and manufacturers must ensure that their products comply with various safety and performance standards. This requires PCBA manufacturers to have a high sense of responsibility and expertise.

  3. Supply Chain Management: Due to the uncertainty of the global supply chain and issues of component shortages, medical device manufacturers need to pay more attention to supply chain management and optimization to ensure production stability and cost-effectiveness.

  4. Sustainable Development: With the increasing environmental awareness, manufacturers need to consider sustainability issues in the manufacturing process, such as using environmentally friendly materials and reducing waste generation.

Medical  PCBA is closely related to patient health, so it is essential to maintain the accuracy and stability of the equipment. Therefore, when choosing a medical PCB manufacturer, it is necessary to consider multiple factors. If you need medical PCBs, you can choose LST, with 16 years of experience in medical PCB manufacturing and a professional team worthy of trust.

Development board manufacturing and application guide

04/15/2024 in /by

Development boards are circuit boards used for embedded system development, comprising a series of hardware components including central processing units, memory, input devices, output devices, data pathways/buses, and external resource interfaces. Typically, developers of embedded systems customize development boards according to their development needs, or users can design them on their own. Development boards serve as a means for beginners to understand and learn about both the hardware and software of systems. Additionally, some development boards provide basic integrated development environments, software source code, and hardware schematics. Common types of development boards include 51, ARM, FPGA, and DSP development boards.

The role of development boards:

Development boards serve as integrated platforms that facilitate embedded system development while reducing the barriers and risks associated with it. They play the following roles:

  1. Prototyping and validation: Development boards allow developers to quickly build prototypes of embedded systems and perform joint software and hardware debugging and testing to validate the functionality and performance of the system. They also simulate real-world environments, reducing uncertainties and risks during the development process.

  2. Application development: Development boards provide different hardware platforms and software support for various application needs, making it convenient for developers to create applications. They typically offer abundant peripheral interfaces and software libraries, enabling quick implementation of various application functions.

  3. Education and training: Development boards are also used for education and training, helping students and beginners understand the principles and development methods of embedded systems. They often have low costs and are easy to use, making them suitable for practical learning and experimentation.

  4. Enhancing learning efficiency: In terms of learning, development boards can effectively improve learning efficiency and shorten the development process.

Advantages of development boards:

  1. Rapid prototyping: Development boards assist developers in quickly designing prototypes and validating their designs efficiently.
  2. Easy portability: Development boards are highly versatile and can be easily ported to other hardware platforms.
  3. Abundant peripherals: Development boards typically offer a rich array of peripherals and interfaces, catering to diverse application scenarios.
  4. Cost-saving: Compared to designing and manufacturing hardware prototypes from scratch, using development boards can save on development costs.
  5. Default system and software support: Many development boards come with default system and software support, reducing the workload for developers.

Development board-4

Components of a Development Board

A development board is a complex assembly of multiple electronic components, each of which serves a specific purpose. The primary elements can be divided into several categories:

Microcontroller/Microprocessor
This component is the development board’s brain, running software programs and controlling other peripherals.

Memory
It includes both volatile (RAM) and non-volatile (Flash, EEPROM) storage for program code storage and execution.

Input/ Output (I/O) Interfaces
These make it possible for the board to communicate with other devices or parts. Examples include digital I/O, analog inputs, and communication interfaces such as USB, UART, and SPI.

Manufacturing Process of Development Circuit Boards

  1. Determine the requirements and functionalities of the development board: Before making a development board, it’s essential to clarify its requirements and functionalities, including the needed interfaces, operating frequency, processor type, etc. Only with a clear understanding of the board’s functions and requirements can the subsequent design and manufacturing proceed.

  2. Design the circuit schematic: Once the requirements and functionalities of the development board are determined, the circuit schematic needs to be designed. When designing the schematic, considerations must include the connection methods between various circuit modules, specific parameters of circuit modules, etc. Professional circuit design software like Altium Designer, Protel, etc., is typically used for this process.

  3. PCB layout design: After completing the circuit schematic design, the PCB layout design follows. PCB layout design involves arranging components and traces from the circuit schematic onto the actual circuit board. Factors to consider during layout design include the board’s dimensions, distances between components, trace routing, etc. Professional PCB design software like PADS, Altium Designer, etc., is used for this process.

  4. PCB board fabrication: Once the PCB layout design is completed, the designed PCB board needs to be fabricated. PCB board fabrication usually involves techniques like photolithography, etching, etc., and the process needs to be conducted in a clean laboratory environment. The fabricated PCB board needs to undergo quality testing to ensure there are no issues like copper leaks, short circuits, etc.

  5. Component soldering: After the PCB board fabrication, various components need to be soldered onto the PCB board. Soldering requires attention to factors like temperature, duration, etc., to ensure soldering quality. After soldering, testing is conducted to ensure good joint quality.

  6. Software programming: Once the hardware is completed, software programming is required. Software programming typically involves using programming languages like C, assembly language, etc., to write programs controlling various modules of the development board. The written programs need testing to ensure correctness and stability.

  7. Debugging and testing: After software programming, debugging and testing are conducted. This process involves using professional testing instruments and tools like oscilloscopes, logic analyzers, etc., to ensure the normal operation of the development board’s modules.

  8. Encapsulation and production: After completing debugging and testing, the development board can be encapsulated and put into production. Encapsulation involves placing the development board into a casing to protect it from external environmental influences. Production involves mass manufacturing of the development board to meet market demand.

Summary:

Development circuit boards play a crucial role in the electronics manufacturing field, offering excellent solutions to challenges in electronic design. If you need development circuit boards, please contact us.

The application and technical characteristics of LTCC PCB

04/11/2024 in /by

LTCC (Low Temperature Co-fired Ceramic) refers to a process where multiple layers of ceramic green sheets, printed with conductive metal patterns and interconnected vias, are stacked together after precise alignment and then co-fired at temperatures below 900°C to form a monolithic multilayer interconnect structure.

This technology allows for increased wiring density and shorter interconnect distances, as well as the independent design of circuits on each layer of the substrate, enabling the realization of circuits with three-dimensional structures.

Additionally, the surface of the multilayer ceramic substrate can be used to mount bare chips by cavity mounting or to install other circuit components by surface mounting, utilizing inter-layer vias and internal circuits for connectivity. This greatly enhances the assembly density of circuits, meeting the requirements of electronic devices for circuit miniaturization, high density, multifunctionality, high reliability, and high transmission rates.

Applications of LTCC PCB

LTCC PCBs are widely used in various applications that require high performance, reliability, and operation in harsh environments. Some key application areas include:

  1. Aerospace and Defense: LTCC multilayer ceramics are used in aerospace electronic systems, radar systems, missile guidance systems, and other military applications that require high reliability, resistance to harsh environments, and high-frequency performance.

  2. Automotive Electronics: The excellent thermal performance and reliability of LTCC PCBs make them suitable for automotive applications, such as engine control units, sensors, and Advanced Driver Assistance Systems (ADAS).

  3. Telecommunications: LTCC technology is widely used in high-frequency applications in the telecommunications industry, such as RF front-end modules, power amplifiers, and antenna arrays for cellular base stations and satellite communications.

  4. Medical Devices: The biocompatibility and hermetic sealing capability of LTCC PCBs make them suitable for implantable medical devices, such as pacemakers, cochlear implants, and neurostimulators.

  5. Industrial Sensors and Controls: LTCC multilayer ceramics are used in various industrial applications due to their ruggedness and tolerance to extreme temperatures, vibrations, and chemicals. This includes pressure sensors, flow meters, and harsh environment monitoring systems.

Manufacturing Process of LTCC PCB

The production process of Low Temperature Co-fired Ceramic (LTCC) PCB typically involves the following steps:

  1. Film Removal: Remove the film layer on the surface of the glass fiber board, usually done using an alkaline solution.

  2. Drilling: Punch holes on the ceramic board according to the requirements of the circuit diagram.

  3. Shaping: Mold solder pads and component positions on the ceramic board according to the requirements of the PCB.

  4. Coating: Apply coating on the surface of the shaped PCB to enhance its mechanical strength.

  5. Sintering: Subject the coated PCB to high-temperature sintering to achieve ceramicization and hardening of the PCB.

  6. Processing: Perform processes such as adhesive application and cleaning.

Material Selection for LTCC PCB

The materials used in the fabrication of LTCC PCBs include circuit layers, inner layer vias, hook holes, solder resist films, ceramic powders, silicon nitride, etc. Among them, ceramic powder is the primary raw material for making LTCC PCBs. The quality and performance of the selected ceramic powder determine the reliability and stability of the PCB. It is recommended to choose high-purity ceramic powder to ensure that the produced PCB has sufficient mechanical strength and durability.

Testing Specifications for LTCC PCB

The produced LTCC PCBs need to undergo relevant tests to ensure their quality and stability. The main testing specifications include:

  1. Solderability Test: Assessing the soldering quality of solder pads and wires on the PCB.

  2. Insulation Resistance Test: Measuring whether the insulation resistance of the PCB meets specified requirements.

  3. Metal Adhesion Test: Evaluating the adhesion between the conductive layer on the PCB surface and the ceramic substrate.

  4. Thermal Shock Test: Assessing the stability and reliability of the PCB under rapid temperature changes.

  5. Low-Temperature Constant Stress Test: Evaluating the stability and reliability of the PCB under specified temperature and stress conditions.

LTCC pcb-2

Advantages of LTCC Integration Technology

Technological Advantages:

  1. Ceramic materials possess excellent high-frequency, high-speed transmission, and wide bandwidth characteristics. Depending on the composition, the dielectric constant of LTCC materials can vary within a wide range. When combined with high-conductivity metal materials as conductors, it helps improve the quality factor of the circuit system, increasing the flexibility of circuit design.

  2. LTCC can meet the requirements of high current and high temperature resistance, and it has better thermal conductivity than ordinary PCB circuit substrates. This greatly optimizes the thermal design of electronic devices, enhances reliability, and can be applied in harsh environments, extending their service life.

  3. It can produce circuit boards with a high number of layers, and multiple passive components can be embedded within them, eliminating the cost of packaging components. On high-layer three-dimensional circuit boards, integration of passive and active components facilitates increased circuit assembly density, further reducing volume and weight.

  4. It has good compatibility with other multilayer wiring technologies. For example, combining LTCC with thin-film wiring technology can achieve hybrid multilayer substrates and hybrid multi-chip components with higher assembly density and better performance.

  5. Discontinuous production processes facilitate quality inspection of each layer of wiring and interconnection holes before final product assembly. This helps improve the yield and quality of multilayer boards, shorten production cycles, and reduce costs.

  6. Energy saving, material saving, green, and environmental protection have become irresistible trends in the component industry, and LTCC meets this development demand. It minimizes environmental pollution caused by raw materials, waste, and production processes to the greatest extent.

Application Advantages:

  1. Easy to achieve more wiring layers, increasing assembly density.

  2. Convenient for embedding components internally, enhancing assembly density and achieving multifunctionality.

  3. Facilitates quality inspection of each layer of wiring and interconnection holes before substrate firing, which is beneficial for improving the yield and quality of multilayer boards, shortening production cycles, and reducing costs.

  4. Exhibits excellent high-frequency and high-speed transmission characteristics.

  5. Easy to form various structures of cavities, thus enabling the realization of high-performance multifunctional microwave MCMs (Multichip Modules).

  6. Possesses good compatibility with thin-film multilayer wiring technology. Combining the two can achieve hybrid multilayer substrates and hybrid multichip components (MCM-C/D) with higher assembly density and better performance.

  7. Easy to realize integration of multilayer wiring and packaging, further reducing volume and weight, and improving reliability.

Technical Features:

Utilizing LTCC for the fabrication of chip-type passive integrated devices and modules offers several advantages:

  1. Ceramic materials exhibit excellent high-frequency and high Q-factor characteristics.

  2. The use of high-conductivity metal materials as conductor materials helps improve the quality factor of the circuit system.

  3. It can adapt to high current and high-temperature requirements and possesses better thermal conductivity than ordinary PCB circuit boards.

  4. Passive components can be embedded into multilayer circuit boards, facilitating increased circuit assembly density.

  5. It has favorable temperature characteristics, such as a small coefficient of thermal expansion and a small temperature coefficient of dielectric constant, allowing for the production of extremely high-layer circuit boards and structures with line widths smaller than 50μm. Additionally, the discontinuous production process allows for inspections of the green substrate, thereby enhancing yield and reducing production costs.

The future development trends of LTCC technology, as an advanced passive component miniaturization technique, will focus on further enhancing integration, miniaturization, high-frequency capability, and reliability. With the increasing demand for high-performance and high-reliability electronic products in fields such as electronics, communications, and automotive industries, LTCC technology is expected to play a crucial role in more application scenarios, driving sustained and stable market growth. Additionally, with technological advancements, the layer count of LTCC technology may further increase, enabling more efficient circuit designs and superior performance.

Inspection standard for PCBA processing

04/09/2024 in /by

Printed Circuit Board Assembly (PCBA) inspection is a crucial process in electronic device manufacturing. It involves examining the quality of PCBs and their components to ensure they meet necessary specifications and standards. PCBA inspection is a vital aspect of quality control as it helps prevent defects and failures in the final product. In this article, we will discuss in detail the inspection and acceptance criteria for PCBA boards.

PCBA Inspection Process

The PCBA inspection process typically involves a combination of automated and manual checks. The first step of the process is visual inspection, which includes examining the PCB for any physical defects such as cracks, scratches, or damage to solder mask layers. This is usually manually performed by trained inspectors using magnifying glasses or microscopes.

The next step is Automated Optical Inspection (AOI), which uses cameras and software to detect defects such as missing components, misaligned components, and soldering defects. AOI is a fast and accurate inspection method capable of detecting defects that may be difficult for humans to identify.

Following AOI, the circuit board may undergo X-ray inspection, which is used to detect defects in hidden areas such as solder joints beneath surface-mounted components. X-ray inspection is particularly useful for detecting defects like voids in solder joints, which may be challenging to detect using other methods.

PCBA Component Design and Inspection Specifications

Inspection Preparation: Inspectors must wear anti-static gloves and wristwatches and prepare tools such as calipers, electrical performance parameter instruments, etc.

  1. Technical Requirements

1.1 PCBA component boards must use materials with a flame retardancy rating of 94-V0 or above, with corresponding UL yellow cards.

1.2 The appearance of PCBA component boards should be free of rough burrs, poor cutting, and layer cracking.

1.3 The dimensions, apertures, and margins of PCBA component boards must comply with the engineering drawings’ requirements, with a tolerance of ±0.1mm unless otherwise specified. The thickness of the boards should be 1.6±0.1mm unless otherwise specified.

1.4 PCBA components must print the production (design) date, UL symbol, certificate number, 94V-0 character, factory logo, and product model. If the PCBA component consists of multiple PCB boards, the rest of the PCB boards should also print the above content.

1.5 The printed symbols and font sizes should be clear and distinguishable.

1.6 If PCBA components use resistor-capacitor voltage reduction circuits, they must use half-wave rectification circuits to improve circuit safety and stability.

1.7 If PCBA components use switch-mode power supply circuits, the standby power consumption must be less than 0.5W.

1.8 European products using PCBA must have standby power consumption less than 1W. For the US version of PCBA, if customers have special requirements, standby power consumption should be executed according to technical requirements.

1.9 Except for power indicator lights using φ5 amber high-brightness scattering, the rest should use full green or full red φ3 high-brightness scattering.

1.10 PCBA components specify the live wire (ACL), neutral wire (ACN), relay common terminal wire (ACL1), high-grade or continuous wire (HI), and low-grade wire (LO).

1.11 The solder fuse and CBB capacitor (resistor-capacitor circuit) of PCBA components must be on the live wire (ACL).

1.12 ACL1 must be connected to the live wire, HI or LO must be connected to one end of the heating body each, and the common terminal of the heating body must be connected to the neutral wire.

1.13 The solder joints of PCBA components must not have virtual soldering, continuous soldering, or desoldering. The solder joints should be clean, uniform, and free of bubbles, pinholes, etc.

  1. Component Selection

2.1 PCBA component elements should be prioritized from reputable brand manufacturers, followed by manufacturers that meet international or industry standards; manufacturers with proprietary standards should not be used.

2.2 Integrated circuit (IC) components should be industrial-grade ICs.

2.3 Connector plugs and terminals must have UL certification and provide certificates.

2.4 Resistor components should use metal film resistors with clear color bands, and manufacturers should meet industry standards.

2.5 Electrolytic capacitor components should use explosion-proof capacitors with a working temperature of -40 to 105°C, and manufacturers should meet industry standards.

2.6 Crystal oscillator components should use crystal elements; RC or chip-embedded options are not recommended. Manufacturers should meet international standards.

2.7 Diodes or transistors should be selected from reputable domestic brands that meet industry standards.

2.8 Tilt switches should use infrared photoelectric types and avoid mechanical types.

2.9 Specified component surfaces must be printed with clear and visible UL/VDE/CQC symbols, trademarks, parameters, etc.

2.10 Relevant wires must have UL/VDE symbols, wire specifications, certification numbers, manufacturer names, etc., clearly visible.

  1. Testing and Inspection

3.1 PCBA components are mounted on the corresponding test fixtures, and voltage frequency parameters are adjusted accordingly.

3.2 Verify whether the self-check function of the PCBA components meets the requirements of the functional specifications. Check for abnormal sounds in relay outputs and uniform brightness in fully lit LEDs.

3.3 Verify whether the placement of the tilt device and the output function during tilting comply with the functional specifications.

3.4 Check whether the output function and fault indication of the PCBA components meet the functional specifications when the temperature probe is disconnected or shorted.

3.5 Verify whether the output of each button function of the PCBA components meets the requirements of the functional specifications.

3.6 Check whether the temperature indicated by the environmental temperature indication LED or digital display of the PCBA components complies with the functional specifications.

3.7 Verify whether the power status indication LED of the PCBA components meets the functional specifications.

3.8 Check whether the smart control operation mode of the PCBA components complies with the functional specifications.

3.9 Verify whether the continuous operation mode of the PCBA components complies with the functional specifications.

3.10 Check whether the standby power consumption of the PCBA components complies with the functional specifications.

3.11 Adjust the voltage to 80% of the rated voltage, and check for abnormal sounds in relay outputs and uniform brightness in LEDs.

3.12 Adjust the voltage to 1.24 times the rated voltage, and check for abnormal sounds in relay outputs and uniform brightness in LEDs.

PCBA General Appearance Inspection specification

  1. Solder Joint Contact Angle Defect: The wetting angle between the angle solder fillet and the terminal pad graphic endpoint exceeds 90°.

  2. Standing: One end of the component is raised or standing up from the solder pad.

  3. Short Circuit: The solder between two or more solder joints that should not be connected, or the solder of the solder joint is connected to adjacent wires.

  4. Open Solder: The component leads are not soldered to the PCB solder pads.

  5. False Solder: The component leads are seemingly connected to the PCB solder pads but are not actually connected.

  6. Cold Solder: The solder paste at the solder joint is not fully melted or does not form a metal alloy.

  7. Insufficient Solder (Insufficient Fill): The solder area or height of the component terminal and PAD does not meet the requirements.

  8. Excessive Solder (Excessive Fill): The solder area or height of the component terminal and PAD exceeds the requirements.

  9. Solder Joint Blackening: The solder joint is blackened and lacks luster.

  10. Oxidation: Chemical reaction has occurred on the surface of components, circuits, PADs, or solder joints, resulting in colored oxides.

  11. Displacement: The component deviates from the predetermined position in the plane of the solder pad horizontally, vertically, or rotationally (based on the centerline of the component and the centerline of the solder pad).

  12. Polarity Reversal: The orientation or polarity of components with polarity does not match the requirements of documents (BOM, ECN, component position diagram, etc.).

  13. Float Height: There is a gap or difference in height between the component and the PCB.

  14. Wrong Part: The specifications, models, parameters, and forms of the components do not match the requirements of documents (BOM, samples, customer data, etc.).

  15. Solder Tip: The component solder joint is not smooth and has a pulled tip condition.

  16. Multiple Parts: The positions of parts that should not be mounted according to the BOM, ECN, or samples, or there are surplus parts on the PCB.

  17. Missing Parts: The positions on the PCB where parts should be mounted according to the BOM and ECN or samples, but no parts are present.

  18. Misalignment: The position of the component or component pin has shifted to other PADs or pin positions.

  19. Open Circuit: PCB circuit is disconnected.

  20. Side Mounting: Sheet-like components with differences in width and height are mounted sideways.

  21. Reverse Side (Upside Down): Two symmetrical faces of components with differences are swapped (e.g., faces with silk screen markings are inverted vertically), common in chip resistors.

  22. Solder Ball: Small solder points between component pins or outside PADs.

  23. Bubbles: There are bubbles inside solder joints, components, or PCBs.

  24. Soldering (Solder Climb): The solder height of the component solder joint exceeds the required height.

  25. Solder Cracking: The solder joint has a cracked condition.

  26. Hole Plugging: PCB plug-in holes or vias are blocked by solder or other substances.

  27. Damage: Components, board bottom, board surface, copper foil, circuits, vias, etc., have cracks, cuts, or damage.

  28. Unclear Silk Screen: The text or silk screen on the component or PCB is blurry or has broken lines, making it unrecognizable or unclear.

  29. Dirt: The board surface is unclean, with foreign objects or stains, etc.

  30. Scratches: Scratches or exposed copper foil on the PCB or buttons, etc.

  31. Deformation: The component or PCB body or corners are not on the same plane or are bent.

  32. Bubbling (Delamination): PCB or components delaminate from the copper plating and have gaps.

  33. Glue Overflow (Excess Glue): Excessive amount of red glue (or overflow) exceeds the required range.

  34. Insufficient Glue: The amount of red glue is insufficient or does not meet the required range.

  35. Pinhole (Concavity): There are pinholes or concavities on PCBs, PADs, solder joints, etc.

  36. Burr (Peak): The edge or burr of the PCB board exceeds the required range or length.

  37. Gold Finger Impurities: There are dots, tin spots, or solder resist oil abnormalities on the surface of the gold finger plating.

  38. Gold Finger Scratches: There are scratch marks or exposed copper on the surface of the gold finger plating.

How to help box build assembly manufacturers assemble products

04/07/2024 in /by

Box build assembly is an essential production method for electronic products. Manufacturers meticulously assemble various electronic components, modules, and parts according to specific designs and process requirements, precisely fitting them inside a casing to create a complete and fully functional electronic enclosure structure. During the assembly process, customers must provide certain assistance to the manufacturer to ensure the swift completion of the box assembly. In this article, we will discuss the assistance that customers should provide. Here are the details:

What is box build assembly?

Box build assembly refers to the process of fitting electronic components, including printed circuit boards (PCBs) and cables, into a fully enclosed chassis or housing. Precision and stability are crucial in electronic box assembly. Assembly personnel must strictly adhere to process requirements to ensure that each component is correctly and accurately installed in its designated position, and that all connections are securely reliable.

Benefits of Box Build Assembly

Some key benefits of utilizing box build assembly services:

▶Faster time-to-market – Using an experienced contract manufacturer speeds up product development and launch.
▶Focus on core competencies – Brands can focus on design and innovation while the EMS provider handles manufacturing.
▶Cost savings – Specialized manufacturers enjoy economies of scale in procurement and production.
▶Quality and reliability – Established EMS providers have robust quality control and testing capabilities.
▶Flexibility and scalability – Production volumes can be rapidly scaled up or down.
▶One-stop-shop – The EMS provider handles sourcing, assembly, testing, logistics, repairs, etc.

Industries Using Box Build Manufacturing

Some common industries that rely on box build assembly services:

▶Consumer electronics – Game consoles, home theaters, smart speakers
▶Industrial equipment – Power supplies, motor drives, automation controls, test instruments.
▶Telecom/networking – Routers, switches, servers, base stations.
▶Medical devices – Imaging systems, analyzers, monitors.
▶Automotive – Navigation systems, EV charging stations, auto infotainment.
▶Kiosks and vending – Self-checkout, ticketing kiosks, vending machines.
▶Defense and aerospace – Ruggedized electronics, avionics boxes.

How to help box build manufacturers

In the process of box assembly for electronic products, manufacturers and customers need to collaborate closely to produce high-quality products. In this section, we will discuss the assistance that customers can provide to manufacturers.

  1. Demand Feedback and Market Insights:
  • Customers can provide specific requirements for box assembly products, helping manufacturers better understand market trends and customer needs.
  • Sharing usage experiences, improvement suggestions, and potential market opportunities regarding box assembly products can assist manufacturers in adjusting product designs and marketing strategies.
  1. Technical Support and R&D Collaboration:
  • If customers have expertise in relevant fields, they can offer technical support to help manufacturers solve technical challenges or optimize product designs.
  • In terms of new product development, customers can act as partners, jointly investing resources in research and development to achieve technological innovation and product upgrades.
  1. Providing Schematic Diagrams and Layouts of the Enclosure Structure:
  • Providing schematic diagrams and layouts aims to give manufacturers a clear understanding of the appearance inside the cabinet, enabling them to engage in the work more efficiently.
  1. Providing Quality Control and Inspection Standards:
  • Customers can provide stringent quality control requirements and inspection standards to help manufacturers improve product quality and reliability.
  • By participating in the product testing phase, customers can promptly identify potential issues and provide improvement suggestions, ensuring that the product meets market and customer expectations.
  1. Supply Chain Optimization and Raw Material Recommendations:
  • Customers can share their supply chain management experience to help manufacturers optimize processes such as raw material procurement, inventory management, and logistics.
  • Recommending reliable raw material suppliers or providing information on alternative materials can help manufacturers reduce costs and improve production efficiency.

LST（leadsin technology）participated in ITES Shenzhen Industrial Exhibition

03/29/2024 in /by

The 25th ITES Shenzhen Industrial Exhibition was launched on March 28 at the Baoan International Convention and Exhibition Center. This exhibition focuses on two cores: high -end equipment industry cluster and advanced manufacturing technology industry cluster. The exhibition content of manufacturing creates a professional display and efficient exchange platform, bringing the latest technological achievements throughout the precision manufacturing industry chain to the audience.

As a part of the 2200+ exhibitors, Lingxin Tech also sent a super lineup. The project team and the sales team went together to make a detailed introduction to the customers who came to visit.

Shenzhen Lingxin Special Technology is a service provider with one -stop electronic product solutions for enterprises. We focus on the hardware design, software development, PCB manufacturing assembly, PCB test, finished product assembly and other businesses. The company was founded in 2011 with 23 million registered funds; industrial factories with more than 8,000 square meters of facilities, 7 fully automatic SMT production lines, 3 DIP back -end production lines; 2 assembly and testing production lines, more than 250 in -service staff; posts post; posts; The actual Nissan capacity of the film is 50 million points, and the plug -in is 2 million pieces; it can be installed with QFN and BGA packaging chips with components above 0201 or foot spacing of 0.3mm.

ITES

Four major industries focusing on the future development direction of the PCB industry

1. Automobile field

The development of the new energy vehicle industry will bring new growth points to the PCB industry. According to data released by the China Automobile Industry Association: In 2023, my country’s new energy vehicle production and sales were 9.587 million and 9.495 million, respectively, an increase of 35.8%and 37.9%year -on -year. It is expected that the production and sales of new energy vehicles in 2024 will reach about 11.5 million vehicles. Growth is about 20%. With the deepening of the degree of electronics of automobiles, and the continuous progress of the advanced driving assistance system (ADAS), autonomous driving technology and networking of the car, the demand for car PCB will increase rapidly, bringing a new round of growth momentum to the PCB industry.

2. intelligent medical care

Intelligent medical care refers to the use of new technologies such as artificial intelligence, the Internet of Things, and cloud computing to realize the intelligent, digital, and networked medical model of medical services. It has the advantages of efficient, convenient and personalized. It is the development direction of the future medical industry. Essence The realization of intelligent medical care requires a large number of intelligent medical equipment, intelligent medical platforms, and smart medical terminals. These devices and terminals require high -precision, highly reliable, and integrated circuit boards to support. It is estimated that the market size of smart medical circuit board will reach US $ 10 billion. The demand for intelligent medical care will grow rapidly, and the design and manufacturing of the circuit board also put forward higher challenges.

3. 5G communication

The commercialization of 5G technology has promoted the miniaturization and integration of communication equipment, and puts forward higher requirements for the miniaturization and high density of PCB. PCB has a wide range of application prospects in the fields of 5G base stations, mobile phones, IoT devices.

4.new energy module

The new energy field represented by the photovoltaic industry is also the focus of the future development of the PCB industry. With the increasing attention of renewable energy around the world, the solar panel industry is undergoing unprecedented rapid development. The prospects of the solar panel industry look very bright, and it will continue to become an important role in the field of clean energy in the next decades.

As a leading company in the circuit board industry, LST has been committed to providing customers with high -quality circuit board products and technical solutions. In this exhibition, we brought a variety of representative PCBAs. Smart charging modules in the automotive field, nuclear magnetic resonance systems in the medical field, smart home appliance modules in the smart home field, and photovoltaic inverters, energy storage systems, intelligent alarms in the security field, and so on.

We follow the direction of the industry, grasp the context of the industry, and continue to carry out technological innovation to bring new vitality to the entire industry. We will also continue to forge innovation toughness and continuously transport the technological achievements to Innovate and develop, empower thousands of industries to “new”, and take effect with “quality”.

What is PCB HS Code ？

03/26/2024 in /by

“HS Code” is based on the code number set by the International Convention on the “Commodity Name and Code Coordination System” (HS Convention), which is used to classify various imports and exports in international trade. Each cargo is assigned a unique classification number so that the type of cargo can be clearly identified. HS coding is critical to international trade, and it is closely related to the determination of tariffs. With the implementation of free trade agreements such as TPP and EPA, the demand for the “origin certificate” is increasing, and the formulation of the original place of origin depends on the HS encoding. Therefore, accurate understanding and using HS coding are particularly important in international trade.

HS coding is a code number, which gives the sole category number to various goods that import and export, so that you can understand what the goods look like in the world. It is an HS code because it is a code number defined by the HS Convention. The HS Convention is an international convention about the name of the product name and the coding coordination system.

The above HS Treaty is managed by the World Customs Organization (WCO), and 158 countries including China and the European Union are members of the HS Treaty. Some countries /regions use HS encoding, so more than 200 countries /regions use HS encoding.

What is PCB HS Code?

Printing circuit boards are a very frequent product in the world today. Understanding the HS code of PCB is particularly important to related trade. The customs code of the printing circuit board is 8534,0000. 8534 is the coding class number of the product, and 0000 represents the sub -category number under the product. In the actual customs declaration, the corresponding sub -classification number is required according to the specific classification standards of the printing circuit board.

Break Down of PCB HS Code

The specific HS Code for PCBs is 8534.00.00. This code consists of six digits, with each digit serving a specific purpose in product classification. Let’s break down the PCB HS Code to understand its significance:

85: The first two digits, 85, represent the broader category of electrical machinery and equipment. This category includes a wide range of electrical and electronic products, making it essential to narrow down the classification further.

34: The next two digits, 34, specify the subcategory of printed circuit boards. This subcategory is more specific and directs customs officials to the realm of PCBs within the broader electrical machinery and equipment category.

00: The final two digits, 00, provide additional details and differentiation within the subcategory. While these digits might seem generic, they help customs authorities identify the specific type of PCB being imported or exported, allowing for accurate customs procedures and tariff determination.

Printed Circuit Board Assembly, often referred to as PCBA, are the backbone of modern electronic devices. They serve as the foundation for connecting and supporting various electronic components like microchips, capacitors, and resistors. PCBs come in various shapes, sizes, and configurations, making it essential to have a specific HS Code for them.

The HS Code for PCBs, 8534.00.00, simplifies the process of customs clearance when shipping or receiving these crucial electronic components across international borders. Customs authorities can quickly identify and classify PCBs, ensuring that the appropriate import duties and tariffs are applied.

What does the PCB HS code do?

PCB HS code plays a very important role in international trade. Specifically, the role of PCB HS code is mainly reflected in the following aspects:

1. Commodity classification and categorization: HS code is a standardized system for the classification of international trade commodities, which allows customs to accurately classify and categorize commodities. For PCB, its HS code can help the customs identify and categorize this particular electronic product.

2. Customs tariff collection: HS code is an important basis for customs to collect tariffs. According to the HS code of PCB, customs can determine the corresponding tariff rate, so as to carry out the collection of tariffs.

3. Trade statistics: HS code is also used in international trade statistics. Customs of all countries according to the HS code of import and export commodities statistics, which helps to reflect the national import and export trade conditions, for the government to formulate trade policy to provide data support.

4. Trade control: HS code helps to implement trade control measures, such as quotas, licenses, bans and restrictions. Through HS codes, it can be determined whether PCBs are subject to trade control measures, thus ensuring trade compliance.

5. Transportation and Logistics: During the transportation and logistics of goods, HS codes can help transportation and logistics companies accurately identify goods and improve transportation and logistics efficiency. For electronic products such as PCBs, the correct HS code helps ensure their safety and efficiency during transportation.

PCB declaration requirements

When the declaration of the printing circuit board, you need to pay attention to the following requirements:

1. Code accurately. Select the sub -classification number corresponding to the printing circuit board according to the actual situation to avoid punishment or retention caused by incorrect coding errors.

2. Provide a complete production process. In the declaration form, the production process of printing circuit boards is required, including the procurement, production, processing, and testing of materials to facilitate the customs of the customs to check the printing circuit board.

3. Apply for accurate materials and technical parameters. In the declaration form, the substrate material, copper foil thickness, plate thickness, diamond diameter, line width, line distance, and line distance of the printing circuit board are required to accurately declare.

4. The replacement of the leading production process must be reorganized. If you replace the leading production process, you need to report to the customs and re -produce the customs declaration form.

5. Comply with relevant national quality standards. Printing circuit boards need to meet national quality standards, such as ISO, UL, etc.

Summarize

The PCB HS code plays a vital role in international trade. It is not only the key to customs identification and classification of import and export products, but also an important for customs to determine the tariff rate, impose import tariffs, regulatory trade measures, and implementing regional protectionist policies. in accordance with. Therefore, when conducting PCB import and export trade activities, the relevant HS codes must be declared correctly to ensure the smooth progress of trade and compliance.

Military PCB design and manufacturing

03/22/2024 in /by

Military PCB is a printed circuit board for military products. Because of its high requirements in terms of environment, stability and reliability, its design is relatively complicated and the design requirements are more stricter. How to ensure the quality of military PCB is a very critical issue. In this article, we will introduce the processes and requirements of military PCB manufacturing in detail.

The importance of military circuit board

Military circuit board is part of the core component of military electronic equipment. It is responsible for connecting and supporting various electronic components to realize the function of the circuit. In many military applications, such as communication, navigation, control, detection, etc., they need to rely on military circuit boards to ensure the stability of the equipment’s normal operation and signal transmission. Without a stable and reliable circuit board, these equipment will not be able to work effectively, which will affect the performance and security of the entire military system.

Military circuit boards have high reliability and durability. In military applications, equipment often needs to face harsh working environment, such as high temperature, low temperature, high humidity, strong vibration, etc. Military circuit boards are specially designed and manufactured, and can operate stably under these extreme conditions to ensure that the equipment can work for a long time and fail to fail. This is essential for ensuring the smooth completion of military tasks.

Military PCB design requirements

Components Selection:

Select high-quality printed circuit board materials that are best suited for military and defense applications. Use materials that meet the required standards for thermal management, chemical resistance, and PCB mechanical strength.

Abiding by Standards:

Military, aerospace, and law enforcement systems often hold specific standards and certifications that must be adhered to. For example, mention the standards and certifications of MIL-PFR-31032 (PCB HDI) and IPC-A-610 (acceptability of electronics assembled). Check and make sure that the PCB manufacturing process is according to these standards.

Durability and Functionality:

Military systems and their environment can be rigorous, facing extreme temperatures, increased humidity, and vibration. PCB must be designed very efficiently to adhere the required condition to ensure better functionality.

Confidentiality and Security Factor:

Military and security defense applications usually hold sensitive and confidential information. So, the security and keeping secret the design and manufacturing process of military PCB is very crucial to preventing unauthorized and unknown individuals from obtaining it.

PCB Traceability, Testing and Evaluation:

Design a strong traceability system for all materials to be used in military PCB manufacturing and assembly. It is essential to identify any malfunctions, errors, or defects throughout the military application lifecycle.

Apply a thorough testing and evaluation process to in the design and manufacturing of all components from beginning to the final military application.

Testing methods include visual testing, X-ray inspections, automated optical inspections (AOI), etc. which can help identify any malfunctions and defects produced in the early military PCB manufacturing process. Regarding the microscope magnification requirements for military PCB board inspection, it is generally required to use a microscope of more than 40 times for inspection.

The implementation of all these design and manufacturing considerations for military PCB is very important, as the military and law enforcement sectors need strict obedience to standards and regulations. Which enhances the required specifications for PCB manufacturing, such as working precision, functionality, and security throughout the PCB assembly and manufacturing process. Extreme

Thermal Management:

Military PCBs are subjected to extreme temperature conditions, so this factor should be critically considered in designing military systems and applications.

Electromagnetic Interference(EMI):

Military and defense sector environments often consist of electrical noise, which can interrupt sensitive electronics applications. Military PCBs should be properly shielded and designed to avoid any EMI issues.

PCB Corrosion:

Moisture exposure of PCB and severe chemicals can affect a printed circuit board with corrosion. Hence, military printed circuit boards must be covered with specialized components to resist and avoid corrosion.

Military PCB material

For military PCB, the reliability and stability of the material are very important. In extreme environments, under bad conditions such as high temperature, low temperature, and humidity, PCB needs to maintain good performance and working status. The commonly used materials are as follows:

1.FR-4

FR-4 is a glass fiber widely used in PCB to enhance epoxy resin materials, which has high mechanical strength and excellent insulation performance. It is widely used in the field of military industry, mainly because of its high stability and relatively low price, and is suitable for most military equipment.

2.PTFE

PTFE has excellent high temperature resistance and chemical stability. PTFE’s applications in military PCB are widely used, especially in some areas that have strict requirements on high -frequency performance, such as radar, communication and other systems, PTFE’s PCB can provide better signal transmission performance.

3. Metal substrate

The metal substrate has good heat dissipation performance and mechanical strength, which can effectively reduce the working temperature of electronic components and improve the reliability and stability of the system. In some military equipment with high heat dissipation, metal substrates are often adopted.

The characteristics of military PCB

Military PCB has the following characteristics:
1. High reliability
In military applications, reliability is crucial. Military PCB must be able to ensure stability in extreme environments to ensure the smooth completion of military tasks. The high reliability of the military PCB is mainly manifested in the control of the thickness of the copper of the hole wall or avoiding welding repairs or cutting circuit supplementation to ensure the performance and safety of the circuit board.

2. High -intensity
The high strength of military PCB refers to its ability to withstand high -intensity use environments, including high temperature, low temperature, high radiation, vibration, etc., while ensuring the stability and reliability of the circuit. This high -intensity is determined by military PCB materials and structural design to ensure that it can work normally in harsh environments and meet the special needs of military applications.

3. high heat dissipation properties
The military PCB’s high heat dissipation properties refer to their good thermal conductivity and heat dissipation capabilities, which can quickly pass and distribute the heat generated during the work of the circuit to ensure the stability and reliability of the circuit. This high heat dissipation is determined by the military PCB materials and structural design to meet the needs of military applications under high load and long -term work.

4.high confidentiality
The high confidentiality of military PCB refers to its good electromagnetic shielding and information security performance, which can prevent electromagnetic leakage and information leakage, to ensure the confidentiality and security of military equipment. This high secret is determined by military PCB materials and structural design to meet the special needs of military applications in information security.

5. high durability
The high durability of military PCB refers to its good mechanical strength and stability, and can work for a long time in harsh environments to ensure the reliability and service life of military equipment. This high durability is determined by military PCB materials and structural design to meet the special needs of military applications in a complex and changeable environment.

The testing standards for military-grade boards

There are different electrical test requirements as per MIL-PRF-55110 and MIL-PRF-31032 standards.

Electrical test requirements as per MIL-PRF-31032 standard
➤Continuity should be less than 10 Ω.
➤Isolation should be more than 2 mΩ and can be managed up to more than 10 mΩ for stringent requirements.
➤Voltage should be at least 40 volts unless otherwise specified.

Subject to all group A testing per C=0 sampling plan:
The following tests should be performed on a monthly basis on thermally stressed cross-section of every panel in X and Y direction.

➤Solderability
➤Ionic contamination
➤Dimensional & hole sizes
➤Plating adhesion test
➤Solder mask adhesion testing
➤Legend adhesion
➤Surface finish thickness – XRF
➤Bow and twist
➤Electrical testing (continuity and isolation)
➤Copper tensile and elongation should be tested monthly

Electrical test requirements as per MIL-PRF-55110 standard

➤Continuity should be less than 10Ω.
➤Isolation should be more than 10mΩ, including metal core jobs.
➤Voltage should be at least 40 volts unless otherwise specified.

Subject to all group A testing per C=0 sampling plan: The following tests should be performed on a monthly basis on thermally stressed cross-section of every panel in X and Y direction.

➤Solderability
➤Ionic contamination
➤Dimensional & hole sizes
➤Plating adhesion test
➤Solder mask adhesion testing
➤Legend adhesion
➤Surface finish thickness – XRF
➤Bow and twist
➤Electrical testing (continuity and isolation)
➤Copper tensile and elongation

Military PCB application

Military PCB (printing circuit board) is widely used in the military field, and its high reliability, stability and excellent performance make it an indispensable core component in military electronic equipment. The following are the main application areas of military PCB:

1. Missile system: Military PCB plays a key role in the guidance, control and communication systems of missiles to ensure that the missile can perform the task accurately and stably.

2. Aircraft and spacecraft: In the aerospace system, communication system, and navigation systems of aircraft and spacecraft, military PCB is responsible for connecting and supporting various electronic components to ensure the safe and stable flight of aircraft and spacecraft.

3. Chariot and ships: Military PCB plays an important role in the control system, communication system and weapon system of chariots and ships to improve combat effectiveness and survivability.

4. Radar and electronic warfare systems: radar and electronic warfare systems are key technologies in the military field. Military PCB undertakes tasks such as signal transmission, data processing and communication connection to ensure the stable operation of the system and efficient operations.

Application of 1.2K Ohm resistor

03/20/2024 in /by

1.2K resistor is a very common resistor. It is widely used and is an important part of the precision circuit. It can do surprising things. If you want to know more about the resistor, please authenticate this article.

What is a 1.2K Resistor?

1.2k ohm resistor refers to the resistance value of a resistor 1.2k ohm. The resistance is the physical quantity that indicates the size of the conductor to the current hindering the current, and its unit is Om (ω). In the circuit, the resistance can limit the size of the current, separate pressure or diversion. It can also be used as a matching between circuit components to ensure the correct transmission of signals or energy.

1.2k ohm resistor is a resistor with a specific resistance value. It can be a fixed resistor, variable resistor, or special type of resistor (such as thermal resistance, optical resistance, etc.), depending on application requirements. In the circuit, it can limit the current, adjust the voltage, or implement other specific functions according to the design requirements of the circuit.

When selecting a 1.2k ohm resistor, in addition to the resistance itself, it is necessary to consider parameters such as power capacity, accuracy, and temperature coefficient. The power capacity determines the maximum power that the resistor can bear safely, while the accuracy affects the accuracy of the resistance value, while the temperature coefficient describes the condition where the resistance value changes with temperature.

What Is The Color Code Of The 1.2K Resistor?

A 1.2K resistor has a color code of brown, red, red, and gold. Here’s how to interpret the color code:

The first band is brown, which represents the number 1. The second band is red, which represents the number 2. The third band is also red, which means there is an additional zero that needs to be added to the number. So the actual value of the resistor is 12 with one zero added, which is 1.2 in scientific notation.

The fourth band is gold, which represents the tolerance of the resistor. Therefore, a 1.2K resistor with a tolerance of +/- 5 percent would have the color code of brown, red, red, and gold.

1.2k ohm resistor application

1.1.2K Ohm’s resistance value is applied in multiple fields, depending on the design and needs of the circuit or system. The following are some possible application scenarios:

2. Electronic circuit: In the electronic circuit, the resistance is used to limit the matching of current, voltage, diversion or as a match between circuit components. 1.2K Ohm resistor can be used for these purposes according to the needs of the circuit.

3. Sensor: some types of sensors (such as photoresistid resistance, thermistor, etc.) may have 1.2k ohm’s resistor value or its nearby resistance range. These sensors can detect environmental parameters (such as light intensity, temperature, etc.) and convert them to resistance changes, and then convert them into measuring signals through circuits.

4. Measurement and calibration: In electrical measurement, accurate resistance is used to calibrate the measurement equipment or as a reference resistance. 1.2K Ohm’s resistors may be used in such applications, especially in calibration and measurement tasks that require medium resistance range.

5. Safety and protection: In certain circuits, the resistance is used to limit the current to protect the circuit component from the damage to the large current. 1.2K Ohm’s resistor may be used for such purposes, especially in circuits that require medium current restrictions.

6. Communication and signal processing: In the communication system and signal processing circuit, the resistance is used to match the radio impedance, attenuation signals, or perform other signal processing tasks. 1.2K Ohm’s resistors may play a role in these applications.

7. Power and battery management: In the power supply and battery management system, the resistance is used in the functions of current sampling, overcurrent protection or battery power detection. 1.2K Ohm resistor may be used for these purposes to achieve precise management of power or battery.

1.2K resistor

The role of 1.2k ohm resistor in the switch circuit

● Flow limit effect: When there is an inductance or capacitance in the circuit, they will generate an inductance or capacitor response when switching, thereby generating instantaneous changes in voltage and current. These instantaneous changes may cause damage to the components and switch tubes in the circuit. In this case, the 1.2 ohm resistor can be used as a restricted resistance to limit the instantaneous changes of the current, thereby protecting the components and switch tubes in the circuit.

● Stabilization: When the load changes in the circuit, it may cause the voltage change. The change in this voltage may cause other components in the circuit to be affected. In this case, 1.2 Ohm resistor can be used as a voltage resistance, which is to reduce the output voltage of the stable circuit by generating a constant voltage.

● Current detection function: 1.2 Ohm resistor can also be used as current detection resistance. By detecting the voltage drop at both ends of the resistance, the current in the circuit can be calculated.

Precautions for using 1.2k ohm resistor

●Make sure the power rating of the 1.2K resistor is sufficient for the circuit. Exceeding the power rating can cause the resistor to overheat and possibly fail.

●Verify the resistor’s tolerance: Resistors have a tolerance, which specifies how close the actual resistance value can be to the nominal resistance value. Make sure the resistor’s tolerance is acceptable for your circuit’s requirements.

●Make sure the resistor is installed in the correct orientation. Otherwise, you may encounter unexpected results.

●Make sure the resistor is not exposed to any high temperatures, humidity, or other environmental conditions.
Frequently Asked Questi

Summarize

1.2K Ohm resistor is one of the indispensable basic elements in the electronic circuit. Its accurate resistance and extensive application make it play an important role in various circuit design. In practical applications, the appropriate resistance types and parameters should be selected according to the specific circuit design requirements and performance requirements.

Design and Manufacturing Guidelines for 6-Layer Printed Circuit Boards

03/13/2024 in /by

The 6 -layer PCB (printed circuit board) is a printed circuit board with a multi -layer conductive layer. Its basic structures include the internal and external copper foil layers and the intermediate isolation layer. Among them, the first and 6th layers are the signal layer. Signal. This design allows more functions and higher performance in a limited space.

6-layer PCB application

The 6 -layer PCB (printed circuit board) plays a key role in modern electronic manufacturing, and its application is wide and diverse. The following are the main application areas of the 6 -layer circuit board:

1. In the field of communication equipment, the application of 6 layers of PCB is very common. For example, communication devices such as mobile phones and routers need to use this type of PCB. Due to the large amount of data processing of communication equipment and high requirements for circuit boards, the 6 -layer PCB can provide higher data transmission rate and lower signal interference, thereby ensuring the normal operation of the equipment.

2. In the field of industrial control equipment, the 6 -layer PCB also plays an important role. Industrial control equipment usually requires a large amount of data and complex control tasks, which have high requirements for the stability and reliability of the circuit board. The high stability and high reliability of the 6 -layer PCB can ensure the stable operation of the industrial control equipment, thereby improving production efficiency.

3. In the field of medical instruments, 6 -layer PCB is also widely used. For example, the ECG monitor and ultrasonic diagnostic instrument in medical equipment need to use this type of PCB. Because medical instruments have high requirements for data accuracy and stability, the 6 -layer PCB can provide high -precision signal transmission and stable working environment, thereby improving the work efficiency and diagnosis accuracy of medical equipment.

4.6 layers of PCB also have a wide range of application prospects in data centers and high -speed communication. Its high -density design can achieve smaller size and higher integration, saving space and cost for electronic products. At the same time, due to the characteristics of its high signal transmission rate and low signal loss, the 6 -layer PCB can meet the needs of high -speed communication and data centers.

Benefits of Using 6 Layer Printed Circuit Board

The six-layer printed circuit board incorporated within the multilayer board offers unmatched benefits. These exceptional advantages and specific characteristics of the six-layer printed circuit board are delineated in more detail hereinafter.

Firstly, a diminished size and surface area. The inclusion of additional layers provides ample room for diminishing the footprint of the printed circuit board. Consequently, one defining characteristic of the six-layer circuit board lies in its ability to minimize the overall area occupied by the end product while facilitating more intricate functionalities. This stands as one of the key motivators behind the utilization of six-layer printed circuit boards on an increasing scale currently. Reflecting the escalating demands for the portability of electronic gadgets, these attributes align flawlessly with prevailing market trends.

Secondly, superior electrical performance. With the escalating complexity of products, semiconductor DC, AC, rectification currents, diverse frequencies, and powers, encompassing high-grade ICs, elevated voltages, ADC conversion rates, precision, and so forth, the electrical performance benchmarks of components utilized for printed circuit boards invariably rise. This enhanced electrical reliability of six-layer printed circuit boards renders the interaction among components more reliable, offering a distinct edge over single- and double-layer printed circuit boards.

Thirdly, enhanced durability. Comparative to single-sided and double-layer printed circuit boards, six-layer printed circuit boards incorporate multiple insulation layers, thus enhancing PCB robustness for optimized prevention of PCB shorts, thereby prolonging PCB lifespan and product longevity.

Fourthly, superior connectivity, reduced weight. In contrast to conventional single-sided printed circuit boards and double-sided printed circuit boards, the elaborate circuitry of the six-layer printed circuit board simplifies component connections, thereby minimizing the usage of interconnection components and subsequently, reducing the total weight of the PCBA assembled product. As such, this represents a compact, yet lightweight solution ideal for portable electronics.

Lastly, the intricate stacking arrangement delivers a more robust structure and effectiveness. Design considerations related to stacking arrangements play a pivotal role in PCBs. Six-layer PCBs exhibit a more intricate stacking array compared to single-sided PCBs and double-layer PCBs. However, this increasingly complex configuration also enhances PCB application potential, ensuring quality and stability guarantees.

Which material does the 6 -layer PCB use?

The materials used in the 6 -layer PCB (printed circuit board) mainly include conductive materials, insulation materials and substrate materials. The following is a detailed introduction to the main materials used in 6 layers of PCB:

1. conductive material:
▶ Copper foil: The outer copper foil layer is a layer of metal foil on the surface of the PCB board. It will be processed into the required line pattern for connecting each component. The inner copper foil layer is located between the inner signal layer and is also used for the connection and transmission of the circuit.
▶ Gold plating, silver plating, etc.: Under certain specific needs, in order to improve the performance of electrical conductivity or prevent oxidation, metals such as gold -plated and silver plating may be used as conductive materials.

2. Insulation material:
▶ Prepreg: This is a thin piece of insulation material, which is used for adhesion materials and insulation materials for the inner conductive graphics of the multi -layer printing board. During the layer pressure, the semi -curing epoxy resin is squeezed away to form a reliable insulator.
▶ Polymidamine (PI), Polytesterafluoroethylene (PTFE), etc.: These high -performance insulation materials are also often used in 6 layers of PCB to improve insulation and high temperature resistance.

3. substrate material:
▶ FR-4: This is a glass fiber-covered copper plate with good insulation performance and mechanical strength. It is a substrate material commonly used in 6 layers of PCB. FR-4 contains flame retardants, so it is also called FR (flame retardant) layer.
▶ Other FR layer boards: In addition to the FR-4, there are FR-2 (paper-based phenolic resin layer plates), FR-6 (polyester resin glass fiber layer plate), etc. FR layer boards can also be used for 6-layer PCB manufacturing , But they may be different in certain performance or processing.

What Makes up a 6 Layer PCB Stackup?

A 6 layer PCB stackup comprises different layers. The ground plane, power plane, and signal layers make up a 6 layer PCB stackup. Each of these layers has its functions. However, it is important to understand how these layers play a significant role in the functionality of this stackup.

Ground plane
The ground plane functions as a return path for current from various components on the circuit. It is a layer of copper foil that connects to the ground point of the circuit. This separate layer is so large that it covers the whole board. The ground plane allows the PCB manufacturer to ground components easily.

Power plane
This is a plane of copper that connects to a power supply. The power plane provides a supply of voltage to the circuit board. This layer is often seen in multilayer stackups since these stackups use an even number of layers. A power plane reduces the operating temperature of a board as it can handle more current.

Signal layers
These layers include the bottom layer, top layer, and inner layer. All these layers have electrical connections.

▶Bottom signal layer: This layer is primarily for soldering and wiring. For a multilayer board, manufacturers can place components.
▶Top signal layer: It is also referred to as thecomponent layer. This layer is used to arrange copper or wires.
▶Inner signal layer: This layer is connected to power and ground planes. It has electrical connections and consists of an entire piece of the copper film. The inner signal layer can only be seen in multilayer boards.

6 -layer PCB stack design rules

The rules of the 6 -layer PCB stack design are mainly based on the performance requirements of the circuit board, signal integrity, the layout of the power supply and the formation, and the shielding effect. The following are some key stack design rules:

1. The tight coupling between the formation and the signal layer: the distance between the formation and the power layer should be as small as possible, and the thickness of the medium should be as small as possible to increase the capacitance between the power layer and the power efficiency.

2. Isolation between the signal layer: Try not to be adjacent directly between the two signal layers to prevent signal stringing and ensure that the performance of the circuit is stable.

3. Use the internal electrical layer to block: For the multi -layer circuit board, the signal layer should be adjacent to a internal electric layer (formation or power layer) as much as possible. The role of effectively avoids the skewers between the signal layer.

4. The layout of the high -speed signal layer: The high -speed signal layer should generally be between the two internal electrical layers. Small interference to other signal layers.

5. Symmetry of layered structure: During the design process, the symmetry of layering structure needs to be considered, which helps ensure the stability and reliability of the circuit board.

6. Use multiple ground electrical layers: This can effectively reduce ground impedance and improve the performance of the circuit board.

7. The use of even layers: It is generally recommended to use the even layer of PCB to avoid the odd number layer, because the strange number layer circuit board is easy to bend.

Factors To Consider In The Design Of 6-Layer PCB Stack-Up

Several factors need to be considered while designing the 6-layered PCB stack-up:

Signal Integrity Considerations
The electrical signal transmission through PCB is the result of signal integrity. Thus, trace lengths are planned carefully to prevent signal delays and distortions. On the other hand, impedance matching involves designing traces and terminations to match the characteristic impedance of the transmission lines, minimizing signal reflections. Additionally, minimizing crosstalk between adjacent traces is essential to avoid interference and ensure signal integrity. The design can maintain the desired signal quality and prevent data errors or signal degradation by addressing these factors.

Power and Ground Plane Design
A PCB’s overall performance depends heavily on the design of the power and ground planes. Several advantages to power and ground plane distribution can be realized. Noise reduction is one of the benefits. The planes serve as a shield, shielding the circuitry from outside noise. Another crucial element is stable power distribution, which guarantees that each component receives a steady supply of clean power. This helps prevent voltage swings and potential issues. Moreover, careful attention must be given to the placement and routing of power and ground traces to minimize the loop area, which reduces electromagnetic interference and improves signal integrity. These considerations collectively contribute to the efficient and reliable operation of the PCB.

Impedance Control and Routing Guidelines
Impedance control and routing guidelines are essential for maintaining consistent signal characteristics and preventing signal degradation. These guidelines dictate trace widths, spacing, and layer stack-up to achieve desired impedance values. Adhering to these guidelines helps minimize reflections and signal distortion.

EMI/EMC Considerations
EMI/EMC considerations are crucial for minimizing electromagnetic interference and ensuring compliance with electromagnetic compatibility standards. Shielding techniques, proper grounding, and strategic component placement are key to reducing EMI/EMC issues and ensuring the PCB functions reliably in its intended environment.

Materials
Standard substrate materials or aluminum cores are used to make single-layer PCBs. However, for the multilayer stack-ups, it should be clear that the aluminum core PCBs are not available. This is because multilayer aluminum PCBs are challenging to manufacture.

Thermal Management Techniques
Thermal management techniques are vital to prevent overheating and ensure the longevity and reliability of the PCB. This involves incorporating heat sinks, thermal vias, and proper component placement to dissipate heat efficiently. Thermal simulations and calculations can help identify potential hotspots and guide the selection of suitable cooling strategies.

6 Layer PCB Fabrication

Edit the schematic diagram
The 6 layer PCB can feature two layers of the ground plane in the circuit board. This means that the manufacturer can separate the digital and analog grounds. Involve the signal’s minimum return path in EMI. Ensure you check for any errors after creating the schematic diagram.

Create a new PCB file
After the manufacturer has created a new PCB file, the schematic netlist can be imported into that file. The manufacturer then sets the layer structure and adds layers. The next thing is to add the power and ground layers. During a 6 layer PCB fabrication, you must couple the main ground layer and the power layer. This should be at a distance of 5 ml.

Layout
Layout is very important in the fabrication of a 6 layer PCB stackup. The primary principle of layout is to ensure good partition. Moreso, the partition of digital and analog devices can help to minimize interference. Digital signals generate large interference and a strong anti-interference.

You need to check out the components layout with various operating voltages. Ensure that devices having large voltage differences are far apart. In principle, the best configuration type features 3 power layers and 3 signal layers. The ground plane is the second and fifth layers. The third and fourth layers are power and inner signal layers.

Ground plane production
In a 6 layer PCB fabrication, there are two layers of ground. They are DGND and AGND. The DGND is placed on the fourth layer while the AGND is placed on the second layer. The manufacturer uses wires to lead out the pins of the ground and top components. Then you use the via hole to connect the pins to the corresponding network. Ensure you use a few pads during the connection process. This is because the pads will increase interference.

Power plane production
You need to divide the power layer. This is because the 6 layer PCB will not feature one working voltage value. Follow these procedures for segmentation during a 6 layer PCB fabrication;

●Figure out a voltage network
●Change to the inner power layer    
●Draw a closed graph using a line
●Use wires to lead out the pins of the ground and top layer
●Create connection to the inner power layer via the pad
●Design the next power network.

Routing
Ensure the ground layer and power layer are made well. After this, route the signal lines. Routing during a 6 layer PCB fabrication requires serious attention. The manufacturer should ensure that the vital high-speed signal line goes to the inner signal layer. The signal can also move on its ground layer.

For instance, if analog signals are mostly on the top layer, the second layer should be set to AGND. Furthermore, you need to adjust the component layout appropriately to enhance wiring. The routing method for the inner signal layer is wire-pad –inner electric layer.

DRC Inspection
This is an important step for a 6 layer PCB fabrication. DRC simply means design rule check. After the manufacturer has drawn the board, the inspection must take place. Carrying out a DRC helps to enhance the fabrication yields of a 6 layer PCB.