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How to Quickly Create PCB Prototypes

The concept of PCB prototyping refers to the process in electronic product design where circuit diagrams or design files are transformed into tangible, functional circuit boards using specific techniques and materials. This process is typically employed to verify the correctness, functionality, and feasibility of the circuit design, allowing for necessary adjustments and optimizations before mass production. This article will focus on how to quickly create PCB prototypes, as detailed below.

How to Quickly Create PCB Prototype ?

The method for quickly creating PCB prototypes can be divided into several clear steps:

  1. Mechanical Engraving: Use physical engraving techniques with a milling machine or high-power laser to separate the traces and pads on the PCB from the unwanted copper. This method is suitable for special substrate circuit boards, such as ceramic substrate PCBs and aluminum substrate PCBs.

  2. Chemical Etching: Cover the traces and pads that need to be retained using methods such as exposure, heat transfer, inkjet printing, or hand drawing with an oil pen. Then, use chemical etching to remove the excess copper, forming a usable PCB. This includes using pre-coated photosensitive PCB boards, laser printers to print on transfer paper, specially modified inkjet printers to print directly on the PCB, or drawing with an oil-based marker.

  3. Design Using Professional Software:

    • Use professional PCB design software like Altium Designer or Eagle to create a new project, including schematics, PCB layout, schematic libraries, and PCB footprint libraries.
    • Draw the schematic diagram for the required components of the project.
    • Draw the footprints of the components as per the project needs and match them with the components in the schematic.
  4. Drawing the PCB:

    • Draw the PCB outline on the mechanical layer based on actual needs and cut the PCB shape using specific tools (such as shortcut keys DSD).
    • Update the schematic content to the PCB and set PCB rules and constraints.
  5. Rapid Verification and Testing:

    • Perform functional verification and testing as soon as the PCB prototype is completed to ensure the PCB’s performance and functionality meet the design requirements.
  6. Optimization and Iteration:

    • Optimize and iterate the circuit design and PCB prototype based on test results and feedback to improve the performance and reliability of the circuit board.
  7. Using Rapid Manufacturing Services:

    • If resources are limited or time is tight, consider using professional PCB rapid manufacturing services. These services typically offer quick design review, manufacturing, and testing services, helping designers quickly obtain PCB prototypes.

When quickly creating PCB prototypes, pay attention to the following:

  • Ensure the methods, materials, and equipment used for board fabrication meet the design requirements.
  • Carefully check and verify the correctness and completeness of the circuit design.
  • Pay attention to the rationality of layout and routing when drawing the PCB to avoid potential interference and faults.
  • During testing and verification, ensure the test environment and methods are correct.

By following these steps and considerations, you can create PCB prototypes more quickly and accurately, verifying the correctness and functionality of the circuit design.

Finding a Suitable PCB Manufacturer

Finding a suitable PCB manufacturer is crucial for successfully producing a PCB prototype. LST is a good choice; with 18 years of experience in PCB production and assembly, we have the technology, quality, and capability to meet customer needs. Contact us for consultation!

Advantages and Types of BGA Packaging Technology

In the electronics industry, packaging technology is crucial for the performance, stability, and cost of semiconductor devices. With the ongoing trend towards miniaturization, ultra-thin designs, and high performance, Ball Grid Array (BGA) packaging technology has emerged to meet market demands. This article provides a comprehensive overview of BGA packaging technology in PCB assembly, exploring its applications and future trends.

Overview of BGA Packaging

BGA packaging is a surface-mount technology that connects the chip to the circuit board using solder balls, facilitating signal transmission. Compared to traditional Quad Flat Package (QFP) technology, BGA packaging offers higher I/O (input/output) density and experiences less stress from differences in thermal expansion coefficients, thereby improving device stability and reliability.

The Advantages of BGA PCB Assembly

BGA PCB assembly offers many advantages that have solidified its position as a preferred packaging technology in the world of electronics. In this section, we’ll look into the specific benefits that BGA assembly brings to the table, shaping the way modern devices are designed, manufactured, and operated.

Increased Packaging Density
One of the standout advantages of BGA PCB assembly is its ability to pack more connections into a smaller footprint. Traditional packaging methods, with their protruding leads, limit the number of connections that can be accommodated in each space. BGA packages, with their compact arrangement of solder balls beneath the chip, enable a higher pin count while minimizing the overall size of the package. This is particularly vital in applications where space optimization is critical, such as in medical implants, IoT devices, and portable electronics.

Enhanced Thermal Performance
The efficient dissipation of heat is paramount in modern electronics, especially as devices become more powerful and compact. BGA technology excels in thermal management due to its structure. The solder balls beneath the package serve as pathways for heat to escape from the integrated circuit, reducing the risk of overheating and thermal stress. As a result, BGA PCBs are often favoured in applications that demand high processing power, such as gaming consoles, servers, and high-performance computing systems.

Improved Electrical Performance
BGA PCB assembly offers superior electrical performance compared to traditional packaging methods. The short and direct connections between the chip and the PCB minimize signal interference and impedance issues. This leads to improved signal integrity, reduced signal degradation, and enhanced data transfer rates. BGA packages are thus favored for applications requiring high-speed data processing and transmission, including networking equipment, graphics cards, and communication devices.

Reduced Signal Noise
Signal noise and crosstalk can compromise the accuracy and reliability of electronic devices. BGA technology’s minimized lead lengths and closely spaced solder balls contribute to lower inductance and reduced noise levels. This is especially advantageous in devices that require precision and sensitivity, such as medical imaging equipment, test and measurement instruments, and scientific research tools.

Mechanical Stability
Traditional packages with leads extending from the sides are susceptible to mechanical stress, bending, and vibration-related failures. BGA packages, on the other hand, offer enhanced mechanical stability due to their solder ball arrangement. This makes them highly suitable for applications subjected to physical stress or harsh environments, including automotive electronics, industrial automation systems, and aerospace components.

Higher Pin Counts for Complex Applications
As technology advances, the demand for higher computational power and greater functionality grows. BGA PCB assembly addresses this need by allowing a larger number of connections to be integrated into a single package. This makes BGAs the go-to choice for microprocessors, memory modules, and programmable logic devices (FPGAs) used in complex computing systems and advanced electronic devices.

bga Packaging

What is The Role of BGA in PCB Assembly?

The same ball grid array is created under the BGA package (component) and over the BGA PCB. These balls provide the connection of the component with the PCB board. The balls are made from the soldering material so that they can connect with the board.

The BGA component is a special type of surface mount component. These components are also mounted on the surface of the PCB without the requirement of holes. However, their connection with the board is not visible as the balls are present under the component.

BGA components look clean on the PCB board as their connections are hidden, and they offer dozens of advantages over Quad Flat Pack (QFP) components. Due to the constraints of the other types of SMD, BGA components are preferred for better performance in places where other SMDs cannot work or are unreliable.

Types of BGA Packaging

BGA (Ball Grid Array) packaging comes in various types, classified by the arrangement of solder balls: perimeter, staggered, and full array. The main types based on the substrate include PBGA, CBGA, FCBGA, and TBGA.

PBGA Packaging

PBGA (Plastic Ball Grid Array) is the most commonly used BGA packaging form, utilizing plastic materials and processes. The substrate used is typically PCB substrate material (BT resin/glass laminate). The bare chip is bonded and connected to the top of the substrate and lead frame using WB (Wire Bonding) technology, followed by injection molding (epoxy resin plastic compound) to form the complete package.

CBGA Packaging

CBGA (Ceramic Ball Grid Array) involves mounting the bare chip on the top surface of a ceramic multilayer substrate carrier. A metal lid is soldered to the substrate to protect the chip, leads, and pads. The package undergoes hermetic sealing to enhance reliability and physical protection. CBGA uses a multilayer ceramic wiring substrate, high-melting-point 90Pb10Sn eutectic solder balls, and low-temperature eutectic solder 63Sn37Pb for the solder ball-to-package connection. It employs a lid plus glass hermetic seal, falling under the category of hermetic packaging.

FCBGA Packaging

FCBGA (Flip Chip Ball Grid Array) is the primary packaging format for graphic accelerator chips. This packaging replaces traditional pins with small solder balls to connect the processor, requiring 479 balls with a diameter of 0.78 mm each, providing the shortest external connection distance. FCBGA uses flip chip technology to achieve interconnection with the substrate, with the bare chip facing downwards, distinguishing it from PBGA.

TBGA Packaging

TBGA (Tape Ball Grid Array), also known as Tape Automated Bonding, is a relatively novel BGA packaging form. The substrate used is a PI (polyimide) multilayer wiring substrate, with high-melting-point solder alloy for the solder balls. Low-melting-point solder alloy is used during the soldering process.

Conclusion

BGA packaging is widely used in the electronics industry due to its high I/O density, excellent heat dissipation, high reliability, and self-alignment capabilities. However, challenges such as inspection difficulties, high repair complexity, and relatively high production costs remain. In the future, through technological innovations and the application of advanced manufacturing equipment, BGA packaging is expected to further optimize to meet the demands for size, performance, and reliability in electronic products.

Functions and Differences of Tin Paste and Solder Paste

In the process of PCB assembly, tin paste and solder paste are essential auxiliary materials, each serving different functions and roles. This article will introduce the specific roles and differences of tin paste and solder paste in PCB assembly.

What is Tin Paste?

Tin paste is a new type of soldering material, mainly composed of solder powder, flux, surface-active agents, thixotropic agents, and other additives mixed into a paste. It is primarily used in the SMT (Surface Mount Technology) industry for soldering resistors, capacitors, ICs, and other electronic components onto PCB surfaces. The composition and properties of tin paste make it indispensable in SMT assembly. It is applied through stencil printing on the PCB surface, and during reflow soldering, it melts to form alloy connections between the component leads or terminals and the PCB pads, ensuring reliable connections.

Functions of Tin Paste

Tin paste plays a crucial role in electronic manufacturing, especially in SMT. Here are its main functions:

  1. Electrical Connection: The primary function of tin paste is to form electrical connections between the leads or terminals of electronic components (such as chips, resistors, capacitors) and the PCB pads after melting during heating. This is fundamental to the functioning of electronic devices.

  2. Mechanical Fixation: In addition to electrical connections, tin paste also provides mechanical fixation. Once melted and cooled, it forms solid solder joints that securely hold electronic components in place on the PCB, preventing movement or detachment during use.

  3. Heat Dissipation: The metal connections formed by solder joints have good thermal conductivity, helping to dissipate the heat generated by electronic components during operation. This enhances the stability and reliability of electronic devices.

  4. Compensation for Component Placement Errors: In the SMT process, there might be slight errors in the placement and angle of components. The flow and wetting properties of tin paste can compensate for these errors to a certain extent, ensuring accurate formation of solder joints.

  5. Oxidation and Corrosion Resistance: The flux in tin paste removes oxides and impurities from metal surfaces, preventing further oxidation and corrosion during soldering. This ensures the quality and reliability of the soldering process.

  6. Increased Production Efficiency: Through automated equipment and precise application techniques, tin paste enables efficient and accurate SMT soldering, thereby improving production efficiency and product quality.

What is Solder Paste?

Solder paste is a crucial material used in the electronics manufacturing industry, especially in surface mount technology (SMT). It is a homogeneous paste primarily composed of metal alloy powder (typically tin-based alloys such as tin-silver-copper) and flux. The selection and use of solder paste are critical for the success of the SMT process. Different types of solder paste have varying metal alloy compositions, flux types, and melting points to suit different soldering needs and process conditions. Additionally, the storage, use, and management of solder paste must adhere to strict standards to ensure its quality, stability, and consistency.

Functions of Solder Paste

Solder paste plays a vital role in the electronics manufacturing industry, particularly in SMT. Here are its primary functions:

  1. Electrical Connection: The main function of solder paste is to melt during the heating process and form an electrical connection between the leads or terminals of electronic components and the pads on the printed circuit board (PCB). This ensures the smooth transmission of current and signals between various electronic components, which is fundamental to the functionality of electronic devices.

  2. Mechanical Fixation: After cooling and solidifying, solder paste provides mechanical fixation, securing electronic components to the PCB and preventing them from moving or detaching during use. This mechanical stability is crucial for the reliability and stability of electronic devices.

  3. Thermal Conduction: The metal connections formed by solder joints have excellent thermal conductivity. They effectively transfer heat generated by electronic components to the PCB and dissipate it through heatsinks or other cooling mechanisms, maintaining the components within an optimal working temperature range.

  4. Compensation for Placement Errors: Due to possible errors in the placement position and angle of components, the flow and wetting properties of solder paste can compensate for these errors to a certain extent, ensuring accurate and reliable formation of solder joints.

  5. Removal of Oxides and Impurities: The flux in solder paste removes oxides and impurities from metal surfaces, ensuring clean and uncontaminated metal surfaces during the soldering process, thereby improving the quality and reliability of the solder joints.

  6. Increased Production Efficiency: Precise application of solder paste and automated soldering techniques can significantly enhance the production efficiency of the SMT process, reduce production costs, and improve the quality and reliability of the final products.

By understanding the roles and differences of tin paste and solder paste, manufacturers can optimize their PCB assembly processes, ensuring high-quality and reliable electronic products.

Differences Between Solder Paste and Solder Flux

Solder paste and solder flux differ significantly in several aspects. Below is a detailed breakdown of their differences:

  1. Composition:

    • Solder Paste: Composed mainly of tin, silver, copper, and other auxiliary materials. It is a soft, malleable soldering material.
    • Solder Flux: A homogeneous mixture made of alloy solder powder, paste-like flux, and various additives. Its main components are flux and a base material, with fluxes being either organic or inorganic.
  2. Usage:

    • Solder Paste: Primarily used in surface mount technology (SMT) and printed circuit board (PCB) manufacturing. Before soldering, solder paste is applied to the PCB pads. Through heating, it melts, creating a connection between electronic components and the PCB. Solder paste ensures a uniform soldering contact surface on the PCB, improving the quality and reliability of the solder joints.
    • Solder Flux: Mainly used in circuit board manufacturing and repair to fix electronic components and connect points between circuits. Its good flexibility allows it to cool quickly after heating, ensuring the quality of the soldering.
  3. Performance and Application Scenarios:

    • Solder Paste: Plays a critical role in SMT soldering processes, including placement and reflow soldering. It reduces oxidation of the solder, ensuring the stability of the solder joints.
    • Solder Flux: Due to its homogeneous and stable mixture characteristics, it can initially adhere electronic components to their designated positions at room temperature and achieve interconnection between components and pads when heated.

In summary, solder paste and solder flux differ in composition, usage, performance, and application scenarios. Solder paste is mainly used in SMT and PCB manufacturing, while solder flux is more widely applied in circuit board manufacturing and repair. The choice between the two depends on specific soldering needs and process requirements.

The application of 3D printing technology in PCB manufacturing

In the electronics industry, the design and production of PCBs (Printed Circuit Boards) is a complex and crucial process. Traditional methods often struggle to keep pace with the rapidly changing market demands and technological advancements. However, with the development of 3D printing technology, this is beginning to change. 3D printed PCBs offer greater flexibility in design and production, enabling optimal performance and efficiency. This article explores the application of 3D printing technology in PCB manufacturing.

What is 3D Printing?

3D printing, also known as additive manufacturing, is a type of rapid prototyping technology. It is a technique that constructs objects by adding material layer by layer based on a digital 3D model. Using powdered metal, plastic, or other bonding materials, 3D printers can create complex shapes and structures.

Typically, 3D printing is carried out using digital material printers. Initially used in mold manufacturing and industrial design to create models, it has gradually expanded into direct manufacturing of products, including components made with this technology. 3D printing finds applications in various industries such as jewelry, footwear, industrial design, architecture, engineering and construction (AEC), automotive, aerospace, dental and medical, education, geographic information systems, civil engineering, firearms, and more.

What is a 3D Print PCB Board?

3D print PCB is circuit board manufacturing using 3D printing technology. It uses a 3D printer instead of traditional manufacturing methods of etching copper traces on a flat substrate.

Let’s break down the 3D Print PCB in a more simple way of understanding:

Imagine a flat, rigid board that has copper traces etched on it. There are types of traditional circuit boards that connect the electronic components.

Whereas 3D printing is the technology that uses 3D objects by layering the materials on each other. Thus, a 3D Printed PCB uses a 3D printer with special conductive materials like filaments with metal particles or inks that print the circuit directly on the board. 3D-printed PCB boards are a new and exciting technology. It offers various benefits as compared to traditional methods. For example, it provides design freedom and faster prototypes for the modern electronics world.

Core Technologies of 3D Printed Circuit Boards

  1. Conductive Materials:

    One of the core technologies for 3D printed circuit boards is the selection and development of conductive materials. Researchers have successfully developed materials with conductive properties, such as conductive polymers and nanoparticles. These materials can be used as wires or circuit elements during the 3D printing process.

  2. Printing Techniques:

    The printing techniques used for 3D printed circuit boards typically include inkjet printing, extrusion printing, and laser sintering. These techniques allow for the precise deposition, accumulation, and curing of conductive materials, thereby constructing the structure and components of the circuit board layer by layer.

  3. Design Software and Model Creation:

    Professional design software is essential for circuit layout and model creation in 3D printed circuit boards. This software converts the designed circuit layout into instructions that the printer can understand and generates the model files necessary for printing.

  4. Printing Parameter Optimization:

    The success of 3D printed circuit boards also depends on the optimization of printing parameters. This includes adjusting key parameters such as printing speed, temperature control, and layer height to ensure print quality and circuit performance.

Advantages and Disadvantages of 3D Printed Circuit Boards

Compared to traditionally manufactured circuit boards, 3D printed PCBs offer significant advantages but also have practical limitations. Therefore, this technology may not yet be ideal for all purposes.

Advantages

  1. Cost-Effectiveness: While some PCB 3D printers are expensive, they can quickly provide a return on investment. 3D printed PCBs use fewer materials and eliminate transportation and outsourcing costs, significantly reducing the cost of circuit prototyping.

  2. Production Speed: With 3D printers, PCB production time is measured in hours. They can expedite the entire process, including circuit design, prototyping, iteration, final production, and market launch.

  3. Design Freedom: PCBs produced with 3D printers can be any shape and can even be printed with flexible materials. This increased design freedom allows engineers to focus on developing lighter, smaller, and more efficient products.

  4. Reduced Waste: Traditional manufacturing methods generate a lot of waste. 3D printed PCBs can make circuits more compact and complex in shape, saving materials.

  5. On-Demand Production: 3D printing enables the production of circuit boards as needed, without maintaining large inventories. It also eliminates the risk of supply chain disruptions by not relying on large orders from third-party manufacturers.

  6. High Precision: 3D printers can achieve higher precision in PCB production compared to traditional methods. Some printers can even place components, further reducing the possibility of human errors during production.

  7. More Layers: When using additive manufacturing systems for multilayer PCBs, the geometry of your circuit board can be more complex.

Disadvantages

  1. Limited Materials: As a relatively new technology, 3D PCB printing does not yet offer a wide range of materials. Many printers can only use one or two materials provided by the manufacturer, increasing costs and limiting design options.

  2. Lower Conductivity: Despite ongoing advancements in PCB 3D printing, the performance of some conductive printing materials is not yet on par with traditional materials.

  3. Limited Board Size: 3D printers can only produce PCBs within the dimensions of their print chambers. For many applications, this is not an issue, but many PCB 3D printers have relatively small print chambers, making them unsuitable for producing large circuit boards.

  4. Lack of Options: Similar to materials, few companies currently produce commercial PCB 3D printers. As the technology matures, this is likely to improve, but for now, there is not a wide range of options available.

Applications of 3D Printed Circuit Boards

3D printed PCBs have found widespread applications across various industries, from education to advanced aerospace equipment. Here are some key areas of application:

  1. Prototyping and Design Verification: 3D printing technology allows for the rapid production of PCB prototypes, enabling quick iteration and design validation. This is crucial for circuit design and optimization, significantly enhancing design efficiency.

  2. Custom PCB Manufacturing: 3D printing can create custom PCBs tailored to specific device requirements. This customization can enhance circuit layout compactness, reduce board size and weight, and improve overall performance.

  3. Electronics in Aerospace Manufacturing: In the aerospace sector, 3D printing is used for prototyping, part production, and model making. Engineers can quickly produce complex prototypes to validate the feasibility and precision of their designs. This technology also improves product quality and performance while reducing manufacturing costs.

  4. Medical Industry: 3D printed PCBs are widely used in the medical field for manufacturing medical devices, aiding surgical procedures, and producing artificial organs. For instance, 3D printing can create patient-specific models to assist surgeons in planning and simulating operations. It can also manufacture artificial organs like livers and hearts, addressing organ transplant challenges.

  5. Manufacturing Industry: In general manufacturing, 3D printed PCBs offer faster production speeds and broader applications, enabling the production of more complex circuits at significantly reduced costs. Specialized 3D printers for PCBs can manufacture boards faster than traditional methods, and even regular desktop FDM 3D printers with conductive filament can be used for production.

Conclusion

3D printed circuit boards are poised to revolutionize the world in a manner similar to the impact of integrated circuits, which triggered a technological revolution. Investing in this future technology is essential to fully automate and harness the potential of 3D printed PCBs.

Characteristics and Applications of Aluminum PCBs

Aluminum PCBs are a type of metal-based copper-clad laminate known for their excellent heat dissipation properties. A typical single-sided aluminum PCB consists of three layers: the circuit layer (copper foil), the insulation layer, and the metal base layer. For high-end applications, double-sided designs are also available, featuring a structure of circuit layer, insulation layer, aluminum base, insulation layer, and another circuit layer. In rare cases, multilayer boards are used, combining standard multilayer boards with insulation layers and aluminum bases.

Advantages of Aluminum PCBs

  1. Eco-Friendly: Aluminum is non-toxic and recyclable. Its ease of assembly also contributes to energy savings. For PCB suppliers, using aluminum supports environmental sustainability.

  2. Heat Dissipation: High temperatures can severely damage electronic components, so using materials that aid in heat dissipation is prudent. Aluminum effectively transfers heat away from critical components, minimizing its detrimental impact on the circuit board.

  3. Enhanced Durability: Aluminum provides a level of strength and durability that ceramic or fiberglass substrates cannot. It serves as a robust base material, reducing the likelihood of accidental damage during manufacturing, handling, and everyday use.

  4. Lightweight: Despite its remarkable durability, aluminum is surprisingly lightweight. It adds strength and resilience without adding significant weight.

Applications of Aluminum PCBs

  1. LED Lighting: The primary application of aluminum PCBs is in LED lighting. LEDs generate significant heat during operation, and the excellent heat dissipation properties of aluminum PCBs ensure the stable functioning of LEDs, thereby enhancing the lifespan and reliability of the lighting fixtures.

  2. Automotive Electronics: With the increasing degree of automotive electrification, the number and density of electronic components in vehicles are rising. The lightweight nature, excellent thermal management, and electrical performance of aluminum PCBs make them an ideal choice for automotive electronics.

  3. Renewable Energy: Aluminum PCBs play a crucial role in renewable energy sectors like solar and wind power. For example, solar panels need to efficiently convert solar energy into electrical energy, and the superior heat dissipation of aluminum PCBs helps maintain the stable operation of solar cells.

  4. Power Electronics: In power electronic devices such as inverters and converters, the use of aluminum PCBs ensures stable operation under high power densities.

  5. Industrial Automation: In industrial automation control systems, the high reliability, stability, and excellent electrical performance of aluminum PCBs make them the preferred material for critical components.

Applications of Aluminum PCBs

Manufacturing Process of Aluminum PCBs

  1. Mechanical Processing:

    • Drilling: While aluminum PCBs can be drilled, any burrs on the edges of the holes are unacceptable as they can affect the withstand voltage test.
    • Milling the Outline: Milling the outline is challenging. Punching the outline requires high-quality molds, which is a critical aspect of aluminum PCB production.
    • Punching: After punching the outline, the edges must be very neat, free of any burrs, and the solder mask layer on the edges should remain intact. Punching involves intricate techniques such as using a blanking die, ensuring the board does not warp more than 0.5% after the process.
  2. Avoid Scratches on the Aluminum Base:

    • The aluminum base must remain untouched throughout the process to prevent discoloration or blackening due to chemical exposure or handling. Any damage to the aluminum base is unacceptable, as re-polishing is often not permitted by customers. Protective measures, like passivation or applying protective films before and after hot air leveling (HASL), are essential to prevent damage.
  3. High Voltage Testing:

    • Aluminum PCBs for communication power supplies require 100% high voltage testing. Customers may specify either DC or AC testing, with voltages typically around 1500V or 1600V for durations of 5 to 10 seconds. Any dirt, burrs on holes or edges, jagged lines, or damage to the insulating layer can cause fires, leakage, or breakdowns during these tests. Issues such as delamination or bubbling during high voltage testing are grounds for rejection.

Aluminum PCB Manufacturing Specifications

  1. Copper Foil Thickness:

    • Aluminum PCBs are often used for power devices with high power densities, so the copper foil is typically thicker. For copper foil thicknesses of 3oz or more, the etching process requires precise line width compensation in the engineering design to ensure that the etched line width remains within tolerance.
  2. Protection of the Aluminum Base:

    • During the PCB manufacturing process, the aluminum base must be protected with a protective film to prevent damage from chemical exposure, which can tarnish the surface. This protective film is prone to damage, requiring careful handling and placement of the boards in racks throughout the process.
  3. Milling Tools:

    • Milling tools used for fiberglass boards (FR-4) have lower hardness, whereas those for aluminum PCBs require higher hardness. The milling speed for fiberglass boards is relatively high, but it must be reduced by at least two-thirds when milling aluminum PCBs.
  4. Cooling During Milling:

    • For milling fiberglass boards, the machine’s built-in cooling system is typically sufficient. However, when milling aluminum PCBs, additional cooling, such as applying alcohol to the milling bit, is necessary to dissipate heat effectively.

Difference between high speed pcb and high frequency pcb.

PCB, or printed circuit board, is an indispensable component in electronic products. Different PCBs used in various applications have distinct characteristics and advantages. Among them, high-frequency PCBs and high-speed PCBs are two special types, each with unique applications and benefits. In this article, we will introduce the differences and features of high-speed PCBs and high-frequency PCBs.

What are high-speed PCBs?

High-speed PCBs are printed circuit boards designed and manufactured considering factors such as signal transmission speed, transmission distance, and signal integrity. They are typically used in applications requiring high-frequency, high-speed, and high-precision data transmission, such as communication equipment, computer hardware, and medical devices.

What are high-frequency PCBs?

High-frequency PCBs are specifically designed for handling high-frequency signals. Their design, manufacturing, and material selection are optimized for the characteristics of high-frequency signal transmission to ensure stability, integrity, and low loss during transmission. High-frequency PCBs are commonly used in wireless communication, microwave communication, satellite communication, radar systems, and other fields where high demands are placed on signal transmission speed and stability. Therefore, the performance of high-frequency PCBs directly impacts the overall performance of the system.

The Differences Between High-Speed PCBs and High-Frequency PCBs:

  1. Different Applications:

High-Frequency PCBs: Primarily used in applications such as wireless communication and radar systems that require transmission of high-frequency signals, with high demands for signal fidelity and stability.

High-Speed High-Frequency PCBs: Commonly found in computer motherboards, network devices, etc., supporting high-speed data transmission and processing to ensure signal integrity during transmission on the PCB, avoiding signal distortion and interference.

  1. Different Materials Used:

High-Frequency PCBs: Utilize substrates made from various dielectric constant materials, such as glass fiber and its derivatives, known for low dielectric loss and stable electrical properties.

High-Speed High-Frequency PCBs: Employ materials with low dielectric constants to ensure signal transmission speed, while also focusing on dielectric stability and absorption performance.

  1. Different Design Requirements:

High-Frequency PCBs: Design considerations include signal transmission performance factors such as crosstalk, attenuation, harmonics, as well as factors like board thickness, substrate pressure, and precision.

High-Speed High-Frequency PCBs: Design focuses on characteristics of transmission lines, impedance, balance of differential transmission lines, port signal integrity, crosstalk, and anti-interference measures to ensure stable and rapid signal transmission.

  1. Differences in Manufacturing Processes:

High-Frequency PCBs: Require strict control of circuit loss, electromagnetic radiation, etc., using high-quality materials and processes, such as special material selection, fine line width and spacing, electromagnetic shielding, etc.

High-Speed High-Frequency PCBs: Manufacturing processes involve complex design and techniques to ensure rapid and stable signal transmission, including routing, signal layer layout, grounding design, signal integrity analysis, etc.

  1. Differences in Testing and Validation:

High-Frequency PCBs require specialized testing equipment to verify signal integrity and impedance matching across various frequency ranges. High-Speed PCBs require the use of advanced equipment for extensive signal integrity testing to validate performance at high data rates. Testing of multilayer PCBs focuses on general circuit functionality and performance.

Conclusion

With the continuous evolution of 5G communication technology, the requirements for PCB boards in high-frequency products are increasing. On one hand, high-frequency signal transmission demands smaller dielectric loss (Df) and dielectric constant (Dk) to ensure stable signal transmission. On the other hand, as products move towards miniaturization and standardization, PCB boards are inevitably moving towards high-layer and even HDI directions, placing higher demands on material processability. Therefore, whether from the perspective of high-frequency or high-speed materials, polyphenylene ether (PPO or PPE) resin shows promising development prospects and will become an important direction for future high-frequency and high-speed PCB board materials.

What is pcb flying probe testing?

Printed circuit board testing is a critical aspect of PCB assembly, allowing us to identify major circuit issues and address them promptly. There are various methods for PCBA testing, including flying probe testing, AOI testing, fixture testing, etc. This article will delve into the details of flying probe testing for PCBs.

What is Flying Probe Testing?

Flying probe testing is an electronic circuit testing method primarily used for testing printed circuit boards (PCBs). It employs a movable probe system that essentially “flies” over the PCB, making electrical contact with specific test points on the PCB. Ultimately, it identifies defects and verifies the electrical performance of the circuit. The flying probe testing system consists of several key components, including the probes themselves, test fixtures used to secure the PCB in place, and control software to manage the testing process.

Structural Features of PCB Flying Probe Testing

The flying probe tester is an improvement over traditional bed-of-nails testers, utilizing probes instead of a bed of nails. It features four heads with a total of eight testing probes that can move independently at high speeds on an X-Y mechanism, with a minimum testing gap of 0.2mm. During operation, the unit under test (UUT) is conveyed into the testing machine via belts or other UUT transfer systems, where the probes are then fixed to make contact with test pads and vias on the PCB, thereby testing individual components on the UUT. The testing probes are connected to drivers (signal generators, power supplies, etc.) and sensors (digital multimeters, frequency counters, etc.) via a multiplexing system to test components on the UUT. While one component is being tested, other components on the UUT are electrically shielded by the probes to prevent reading interference. The flying probe tester can detect short circuits, open circuits, and component values. Additionally, a camera is used during flying probe testing to aid in locating missing components and inspecting components with clear directional shapes, such as polarized capacitors.

Flying Probe Testing Capabilities

While flying probe testing can easily detect short circuits and open circuits, equipping them with special drivers enables them to test more complex parameters as well. Advanced probes can simultaneously probe and test both sides of multilayer boards, reducing the time needed for separate single-sided testing. Different architectures of flying probes can be used for various solutions, such as:

Signal Integrity Testing: Utilizing Time Domain Reflectometry (TDR) or Time Domain Reflectometer probes along with specialized instruments, various characteristics of PCB traces used for carrying high-speed and high-frequency signals can be tested. This setup typically captures and measures signals in both time and frequency domains to characterize defects in signal paths.

Phase Difference Measurement: Using specially designed probes to send high-frequency signals between reference traces and signal traces, the phase difference between them can be measured. This test eliminates the need for separate isolation testing to measure crosstalk between traces on the PCB.

High Voltage Stress Testing: PCBs may have insulation defects that conventional electrical tests may not detect. The insulation resistance between two traces on a PCB may be high enough to pass conventional resistance testing but still lower than the requirements in specifications. To detect this, high voltage stress testing is required, using a high voltage generator, appropriate probes, and high resistance meters.

Micro Short Circuit Detection: The presence of tiny whiskers can lead to micro short circuits on the PCB. Sometimes, they may burn off during high voltage stress testing, leaving behind carbonized residues on the PCB surface, forming high-resistance conductive paths. Micro short circuit detection probes apply low voltage to check the resistance between two traces on the PCB, gradually increasing the voltage to a level suitable for testing.

Kelvin DC Measurement: This is a highly precise DC measurement technique required for testing BGA and similar densely packed PCB patterns. It involves a force and sense pin in the flying probe. Kelvin connections compensate for losses in the testing probe.

Flying probe testing systems come in different sizes, with the main variable being the number of connectors the system uses. For example, a tester can have up to 16 connector heads, with 8 on the top and 8 on the bottom of the PCB. Of course, the cost of the system increases proportionally with the number of connectors it utilizes.

Advantages of Flying Probe Testing

Compared to traditional bed-of-nails or ICT fixtures, flying probe testing offers several advantages:

No Fixtures Required:Unlike bed-of-nails fixtures, flying probe testing doesn’t necessitate fixture setup. This saves the cost and time typically required for setting up ICT fixtures. In fact, manufacturers can set up flying probes immediately after the PCBs come off the production line, as they have access to Gerber data. On the other hand, designing and installing ICT fixtures can take weeks.

Short and Fast Program Development: Since netlists and CAD data form the basis for generating flying probe test programs, and there are multiple open-source programs to translate this information, program development time is short and requires minimal setup time. This also means that design changes can be easily integrated.

Process Flexibility: Unlike ICT’s bed-of-nails fixtures, flying probe setups are applicable to any PCB, whereas ICT’s bed-of-nails fixtures are specific to individual PCBs and useless for another. Simple modifications to internal programs are all that’s needed to adapt them to another board.

No Need for Test Points: Since flying probe testing is conducted on bare boards, probes can utilize component pads without the need for additional test points.

Controlled Probe Contact: Flying probes can achieve precise connections at closer intervals compared to bed-of-nails. For instance, high-precision flying probes can achieve testing gaps as small as 5 micrometers, while ICT’s minimum gap is 0.5 millimeters. This makes them highly useful for densely populated circuit boards or for achieving broader coverage on small PCBs.

Variable Testing Solutions and Methods: Flying probe systems can offer more testing solutions than ICT or bed-of-nails. This is possible because with programmable integrated test systems, various types of flying test probes can be utilized.

High Measurement Accuracy: Specific flying probes are employed for different tests, with precise probe positioning and complementary test instruments, ensuring high measurement accuracy.

Quick Feedback: Since flying probe test results can be obtained on-site, transmitting information to the production line can help them quickly make appropriate process adjustments. Similarly, PCB designers can receive rapid feedback during prototype design, enabling them to make necessary changes before production.

How Flying Probe Testing Works

Flying probe testing (FPT) is typically the preferred method for small batch and prototype circuit board testing as well as PCB assembly due to its cost-effectiveness and convenience for these smaller quantities.

The main advantage lies in the ability to complete testing at speeds ranging from a few days to a few hours, depending on the complexity of the circuit board, even for larger quantities, and with high coverage of testing.

Let’s break down its operation into steps:

  1. Creating an FPT Test Program

The design aims to test the entire circuit board and is usually completed using an offline computer with an FTP test program generator application. This typically requires Gerbers, BOMs, and ECAD files. On a machine with a motherboard, define the values of the components to be tested, test points, component formats, offsets, debugging, etc., and ultimately finalize the design of the test program.

  1. Uploading the Program to the FTP Tester

The components of the circuit board to be tested are placed on a conveyor belt within the FTP tester and transported to the area where the probes are operated.

  1. Application of Electrical and Power Test Signals

These tests are conducted at probe points and then readings are taken. This process determines whether specific sections of the PCB meet the expected results (components). Any failures or deviations from the established plan and expectations indicate defects within the unit, resulting in a test failure.

Flying probe testing is a crucial technology in the electronics industry, ensuring the quality and functionality of electronic components and systems. These tests utilize specialized equipment to perform various contact and non-contact electrical tests on printed circuit boards (PCBs), printed wiring boards (PWBs), PCB assemblies (PCBAs), individual components, and entire systems. By providing a flexible and efficient method to identify defects and validate performance, flying probe testing has become an essential tool for manufacturers and engineers.

What are the colors of PCB?

The color of a PCB typically refers to the hue of the solder mask on the board’s surface. PCB board staining pigments are a type of hardened resin, with the primary resin being colorless or nearly transparent. Green, as with other colors, is achieved through the addition of pigments.

We employ silk-screen printing to apply colors onto the PCB. PCBs come in various colors such as green, black, blue, yellow, purple, red, and brown. Some manufacturers have ingeniously developed PCBs in multiple colors like white and pink.

Physical Properties of PCB Colors

When selecting a PCB color, one must consider the physical properties of the PCB material. Typically composed of fiberglass and epoxy resin, PCB materials have densities, thermal conductivity coefficients, coefficients of thermal expansion, tensile strengths, and other physical attributes that directly impact performance and reliability. Different-colored PCBs may utilize varied production processes and materials, thereby exhibiting differing physical properties.

Chemical Properties of PCB Colors

In addition to physical properties, the color of a PCB also influences its chemical characteristics. PCB boards undergo heating and chemical treatments during production, and PCBs of different colors may require distinct chemical processes. This affects properties such as annealing temperature, acid and alkali resistance, and corrosion resistance. Some colored PCBs may employ more complex production processes and materials, resulting in enhanced chemical corrosion resistance.

Yellow PCB

Characteristics of Different Colored PCBs

  1. Green PCB

Green PCBs are the most popular color choice, enhancing clarity by providing a sharp contrast with white text, thus improving readability. Additionally, the surface treatment of green PCBs reflects less light, aiding in reducing glare.

  1. White PCB

White PCBs present a clean and neat appearance in various settings, gaining popularity. However, due to their tendency to obscure traces, white PCBs are not the top choice. Yet, the contrast with black silk-screen printing is notably distinct on white PCBs.

  1. Yellow PCB

Yellow PCBs cater swiftly to diverse requirements such as style, cleanliness, and visibility. However, a significant drawback of yellow PCBs is their poor contrast with traces and silk-screen printing.

  1. Blue PCB

Blue PCBs are considered thick boards suitable for labeling due to their significant contrast in silk-screen printing. While not as attention-grabbing as green, black, or white PCBs, blue PCBs are preferred for their excellent aesthetic appeal. Installing blue PCBs on LCDs is preferable as they avoid sharp contrast edges and bright background colors.

  1. Red PCB

Due to its advantages, many PCB manufacturers are keen on adopting red PCBs. Red PCBs offer excellent visibility and clearly define the contrast of traces, planes, and blank areas. Silk-screen printing appears particularly elegant against the backdrop of red PCBs.

  1. Black PCB

Black PCBs are as popular as white PCBs. Both colors produce low contrast, facilitating easy labeling of critical components. However, the primary drawbacks of black and white PCBs are the potential focal points and minor shadows, making tracing difficult. Therefore, black PCBs are unsuitable for various high-temperature applications as they may cause silk-screen printing to discolor. Moreover, black PCBs are a blend of cobalt and carbon, potentially resulting in poor conductivity.

Black PCB

How pcb colors are made

The color of a PCB (Printed Circuit Board) is primarily achieved by applying a layer of special solder mask during the manufacturing process. Here are the general steps involved in producing PCB colors:

  1. During the manufacturing process of a PCB, a thin layer of copper foil is first laid on the substrate, forming the conductive layer of the PCB. If producing a double-sided or multilayer board, both sides or multiple layers of the PCB substrate will be covered with copper foil.

  2. Next, the designed PCB circuit pattern is “printed” onto the metal conductor using a technique called subtractive transfer. In this process, the entire surface is covered with a layer of copper foil, and excess copper foil is removed through etching techniques to form the desired circuit pattern.

  3. After forming the circuit pattern, to separate the soldering and non-soldering parts of the PCB during soldering and prevent copper oxidation (pure copper surfaces quickly undergo oxidation reactions when exposed to air, and oxidized copper becomes a poor conductor of electricity, greatly damaging the electrical performance of the entire PCB), engineers apply a layer of solder mask on the surface of the PCB. This solder mask layer blocks the contact between copper and air, protecting the copper layer from oxidation.

  4. The color of the solder mask can be adjusted as needed. Since small text needs to be printed on the PCB, engineers typically add various colors to the solder mask to create different PCB colors. For example, black, red, blue, dark green, and dark brown are common PCB colors.

  5. After applying the solder mask, a series of post-processing steps such as hot air leveling, milling the outline, electrical testing, final inspection, etc., are required to ensure that the quality and performance of the PCB meet the requirements.

Why are most PCB green now?

The prevalence of green PCBs stems from several factors:

  1. Glass Epoxy Resin Material:

    • Historically, green was the standard color for the solder mask made from glass epoxy resin, which is commonly used in PCB manufacturing. While other colors have been introduced, green remains the preferred choice.
  2. Contrast with White Printed Text:

    • Green PCBs offer simplicity and time efficiency for assembly workers, as scanning them is straightforward and quick due to their familiarity with the color. Additionally, green creates less eye strain during scanning compared to other colors and provides contrast with white printed text on the circuit board.
  3. Military Applications:

    • Military standards have a significant influence on the preference for green PCBs. Many believe that green is highly effective for military purposes, leading to a demand for green PCBs from suppliers who also serve other clients. Consequently, green PCBs become surplus products for military suppliers, further reinforcing their acceptance.
  4. Exposure Rate of Solder Mask:

    • While other colors like blue, white, or brown exist, they may not offer a higher solder mask exposure rate compared to green. Darker colors tend to have higher pigment deposition, resulting in darker solder masks. White and black solder masks have high exposure rates, but green provides adequate shading for worker exposure and design tolerances.
  5. Better Machine Recognition:

    • During PCB manufacturing processes such as board fabrication and surface-mount component soldering, visual inspection is crucial. Green PCBs offer better visibility in yellow-lit environments, aiding machine recognition and calibration for tasks like solder paste application and automated optical inspection (AOI).
  6. Comfort for Workers:

    • In some manual inspection processes (although increasingly replaced by automated testing), workers may observe PCBs under strong lighting. Green PCBs are more comfortable for the eyes in such conditions.
  7. Cost Reduction:

    • Green PCBs have widespread use, enabling economies of scale in production and procurement. Standardizing on one color reduces production line costs, as bulk purchasing of the same-color solder mask lowers procurement costs. Consequently, green solder mask is advantageous in terms of manufacturing costs and lead times.
  8. Relative Environmental Friendliness:

    • Green PCBs are relatively environmentally friendly, as they do not release toxic gases during high-temperature recycling of waste boards. Other PCB colors, such as blue and black, contain cobalt and carbon, which pose risks of short circuits due to weaker conductivity.

Additionally, darker-colored PCBs, such as those in black, purple, or blue, may increase difficulty in board inspection and present challenges in manufacturing control.

The influence of PCB color on circuit boards is multifaceted. It affects not only the cost and appearance of the PCB but also directly impacts the physical and chemical properties of the PCB materials, thereby influencing the performance and reliability of the PCB. Therefore, when selecting PCB colors, it is necessary to consider a comprehensive range of factors such as the application environment, requirements, and costs of the product. Meanwhile, manufacturers need to enhance the quality and performance of PCBs through more sophisticated production processes and materials to meet the production needs of PCBs in different colors.

The status of packaging substrate in the PCB industry

If the PCB industry were a pyramid, undoubtedly, the substrate would be the gleaming jewel perched at its apex.

 

Firstly, it holds immense importance.

The substrate is the core material in the chip packaging process, characterized by its high density, precision, performance, miniaturization, and thinness. It, along with the die and leads, forms the chip after packaging and testing. The IC substrate not only provides support, heat dissipation, and protection for the chip but also serves as the electronic connection between the chip and the PCB, playing a pivotal “linking and enabling” role, and can even embed passive or active devices to achieve certain system functions.

 

Secondly, its barriers are exceptionally high.

According to the minutes of the investor survey by Xinsen Technology, newcomers in the substrate field require at least 2 to 3 years to establish a team, acquire land and build factories, complete decoration and debugging, pass large customer certifications, and ramp up production capacity. Looking at the recent projects of domestic manufacturers in substrate production, the construction phase alone takes up to 2 years, with several more years needed for capacity ramp-up. Moreover, projects involving high-end substrates like FC-BGA require even higher investment amounts due to the exorbitant equipment prices. Just consider, any random substrate project easily surpasses 2 billion yuan in investment, making it a “fighter jet” in the industry’s “burning money” battle.

Aside from raising the investment threshold, the high processing difficulty is also a core barrier in substrate production. From the perspectives of product layers, board thickness, line width and spacing, and minimum annular width, substrates tend to lean towards precision and miniaturization. Moreover, with a unit size smaller than 150*150 mm, they represent a higher-end category of PCBs. Among them, the line width/spacing is the core differentiation, with the minimum line width/spacing of substrates ranging from 10 to 130 micrometers, far smaller than the 50 to 1000 micrometers of ordinary multilayer rigid PCBs. Ordinary PCB factories cannot handle such high-difficulty technical tasks.

 

Thirdly, its market prospects are incredibly vast.

With the rapid advancement of technology in the electronics industry, terminal application products are trending towards miniaturization, intelligence, and customization, making the demand for high-end PCB products more prominent. Moreover, driven by a new wave of computational power, China’s substrate supply fails to meet the robust market demand, presenting the industry chain with expansive market space.

From the global demand perspective of IC substrates, these products are primarily applied in fields such as CPUs, GPUs, and high-end servers.

In recent years, with the widespread application of technologies like 5G, AI, and cloud computing, the demand for high-computational chips has been continuously increasing, thereby propelling the growth of substrate production value. This trend has stimulated a significant growth in the demand for chips and advanced packaging in the electronics industry, indirectly promoting the development of the global substrate industry.

In terms of market size, the Chinese substrate market reached 20.1 billion yuan in 2022, a year-on-year increase of 1.5%. According to forecasts from the China Industry Research Institute, by 2023, this market size will reach 20.7 billion yuan, with a growth rate of 3%. Simultaneously, the production volume of Chinese substrates has been increasing year by year. In 2022, the production reached 1.381 million square meters, an 11.73% increase year-on-year. It is expected to reach 1.515 million square meters by 2023, with a growth rate of 9.7%.

Looking at the medium to long term, the IC substrate market is expected to maintain rapid growth. According to Prismark’s forecast, by 2027, the market size of IC substrates will reach 22.286 billion US dollars, with a compound annual growth rate (CAGR) of 5.10% between 2022 and 2027. It is estimated that by 2027, the overall size of China’s IC substrate industry will reach 4.387 billion US dollars, with a CAGR of 4.60% between 2022 and 2027.

The recent surge in Chiplet packaging technology has injected new vitality into the growth of IC substrates. The rapid growth in the market size of Chiplet processor chips will drive the demand for ABF substrates. Advanced packaging technologies will increase the consumption of ABF substrates, and the introduction of 2.5/3D IC high-end technologies into products may enter mass production in the future, inevitably bringing greater growth momentum.

 

Fourthly, its players are industry giants.

Currently, IC substrate companies from Japan, South Korea, and the Taiwanese region hold absolute leading positions. According to statistics from the Taiwan Printed Circuit Association, the top ten global substrate suppliers and their market shares in 2022 were as follows: Unimicron (17.7%), Nan Ya Printed Circuit Board (10.3%), Ibiden (9.7%), Samsung Electro-Mechanics (9.1%), Shinko Electric Industries (8.5%), JCET Group (7.3%), LG Innotek (6.5%), AT&S (6.1%), Daeduck Electronics (4.9%), and Compeq Manufacturing (4.7%).

The top five global BT substrate manufacturers were LG Innotek (14.2%), Samsung Electro-Mechanics (11.9%), Compeq Manufacturing (10.3%), JCET Group (9.5%), and Unimicron (7.7%). The top five global ABF substrate manufacturers were Unimicron (26.6%), Ibiden (14.6%), Nan Ya Printed Circuit Board (13.5%), Shinko Electric Industries (12.8%), and AT&S (8.0%).

Although China’s IC substrate industry started relatively late, strong players have emerged continuously. Major suppliers include Shennan Circuit, Xinsen Technology, and Zhuhai Youya, which primarily possess mass production capabilities for BT substrates. Furthermore, since 2019, some manufacturers primarily engaged in PCB products have also begun investing in IC substrate projects, indicating a quietly evolving industrial landscape.

In conclusion, factors such as technological difficulty, industry players, investment barriers, market prospects, and critical roles have firmly established substrates at the forefront of the industry, rightfully earning them the title of the gleaming jewel atop the PCB pyramid.

Wave soldering operation guide for pcb assembly

What is wave soldering?

Wave soldering refers to the process of forming a solder wave of melted solder alloy, typically using an electric pump or an electromagnetic pump, to achieve the desired solder wave height. Alternatively, nitrogen gas can be injected into the solder pot to create the wave. During wave soldering, a printed circuit board (PCB) with pre-mounted components passes through the solder wave, forming a specific shape of solder fillet on the liquid solder surface. This process, in which the PCB with components is passed through the solder wave at a specific angle and with a certain immersion depth to achieve solder joint connections, is called wave soldering.

Historical Development of Wave Soldering

  1. Origin of Manual Wave Soldering Wave soldering, as an electronic soldering technology, originated in the early 1960s. At that time, manually operated wave soldering equipment was widely used. Due to its simple structure, complex operation, and low efficiency, the application of manual wave soldering equipment was somewhat limited.

  2. Automation Control of Wave Soldering Equipment In the early 1970s, wave soldering equipment began to transition towards automation control. With the continuous development of electronic technology, the equipment gradually achieved automation control, greatly improving production efficiency. During this period, various automatic control systems for wave soldering equipment, including PLCs and microcontrollers, began to appear.

  3. Digitization of Wave Soldering Equipment Since the 21st century, wave soldering equipment has been advancing towards digitization. The application of digital technology has enabled wave soldering equipment to achieve higher precision, more stable quality, increased production efficiency, and reduced production costs. In particular, the application of CAD technology in wave soldering equipment has resulted in more stable and consistent soldering effects.

The working principle of wave soldering

The fundamental principle of wave soldering is to utilize molten solder to form a wave on the soldering surface. The soldering material is heated and melted as it passes through the wave, then contacts the soldering surface to create a solder joint. The key to wave soldering lies in controlling the temperature and flowability of the solder to ensure joint quality.

  1. Formation of molten solder: Initially, molten solder is formed in the solder pot through pump pressure, creating a specific shape of solder wave on its surface.

  2. Transport of circuit board: The circuit board is conveyed through the wave soldering machine on a chain conveyor, passing through the preheating zone to ensure temperature control during soldering.

  3. Soldering process: As the circuit board passes through the solder wave at a certain angle, its pins pick up solder from the liquid solder, which solidifies during cooling to form solder joints. The solder wave wets the soldering area and extends to fill, facilitating the soldering process.

  4. Soldering quality: Wave soldering technology is suitable for soldering a variety of metals and non-metals, including aluminum, copper, steel, as well as plastics, ceramics, and other non-metallic materials. It is widely used in electronics, machinery, automotive manufacturing, and other fields, providing efficient, fast, and precise soldering to meet high-precision, high-reliability, and high-quality soldering requirements.

The Process of Wave Soldering

The wave soldering process involves the following steps:

  1. Preparation: Ensure the quality of the PCB and electronic components to be soldered, and perform necessary surface treatments such as cleaning and oxide removal.

  2. Application of solder paste: Apply solder paste to the appropriate soldering areas on the PCB, typically covering the contact surfaces of component pins and PCB pads.

  3. Component placement: Precisely mount electronic components onto the PCB at predetermined locations. This can be done using automated pick-and-place machines or manual methods.

  4. Wave soldering machine setup: Configure the wave soldering machine according to the soldering requirements and specifications, including soldering temperature, wave height, preheating zone, and soldering speed.

  5. Soldering process: Move the assembled PCB through the conveyor system to the solder wave area. The molten solder in the wave area makes contact with the PCB pads and component pins, forming solder joints.

  6. Cooling and solidification: Once the PCB exits the solder wave area, the solder joints are rapidly cooled and solidified through a cooling process, establishing stable solder connections.

  7. Inspection and quality control: Inspect and perform quality control checks on the soldered PCB, including visual inspection, X-ray testing, and solder joint reliability testing, to ensure that the soldering quality meets the requirements.

Operation Guide for Wave Soldering Equipment

  1. Preparing for Wave Soldering

(1) Turn on the main power switch according to the equipment’s operating schedule and control the solder pot switch time via the time electromagnetic valve.

(2) Check if the solder pot temperature indicator is functioning properly: Measure the temperature around 15mm below and above the solder pot’s liquid level with a thermometer, and ensure that the actual set temperature remains within a range of ±5°C.

(3) Check the operation of the lead cutter: Adjust the height of the cutter head based on the thickness of the PCBA, aiming for component pin lengths between 1.4 to 2.0mm.

(4) Verify the normal supply of flux: Pour flux into the fluxer, adjust the air inlet valve, and activate the fluxer to check for foaming or spraying of flux. Adjust the flux ratio to meet the requirements.

(5) Check the solder level height; if it is below 12-15mm from the solder pot, add solder promptly. Add solder in batches, not exceeding 10 kilograms each time.

(6) Clean the solder dross from the solder surface, and add anti-oxidant after cleaning.

(7) Adjust the angle of the transport rail: Adjust the total width of the rail according to the total width of the PCBAs to be soldered, ensuring moderate clamping force. Adjust the rail slope based on the pin density of the soldered components.

 

  1. Startup Process for Wave Soldering

(1) Turn on the flux switch, adjusting the foam adjusting plate thickness to half of “l” during foaming. For spraying, ensure the board is symmetrical, with moderate spray volume, preferably avoiding spraying on component surfaces.

(2) Adjust the air knife airflow to allow excess flux on the board to drip back into the foam groove, preventing drips on the preheater that could cause a fire.

(3) Turn on the transport switch and adjust the transport speed to the desired value.

(4) Turn on the cooling fans.

 

  1. Post-Wave Soldering Procedure

(1) Turn off the switches for the preheater, solder pot wave, fluxer, transport, cooling fans, and lead cutter.

(2) During operation, replace the flux in the foam groove every two weeks and measure it regularly.

(3) After shutdown, clean the wave soldering machine and claws thoroughly, soaking the nozzles in a cleaning solvent.

Wave soldering

Advantages and Disadvantages of Wave Soldering

Advantages:

High Efficiency: Wave soldering can simultaneously solder a large number of through-hole components, increasing production efficiency and output.

Welding Quality: Through strict control of welding parameters such as temperature, soldering time, and solder flux flow, wave soldering ensures stable welding quality.

Low Cost: Wave soldering can use standardized components and equipment, reducing production costs.

Disadvantages:

Component Limitations: Wave soldering can only solder through-hole components and cannot solder surface mount components.

Large Size Limitations: Wave soldering requires the PCB to be tilted on the soldering pallet, so there are certain limitations on the size and shape of the PCB.

Maintenance Difficulty: Wave soldering machines require regular maintenance and cleaning, which can be challenging.

Applications of Wave Soldering

Wave soldering technology has been widely applied in various electronic products, including consumer electronics, communication equipment, computers, and more. Here are the main application areas of wave soldering:

● Household Appliances: Wave soldering has become the primary welding technology in the manufacturing of household appliances, including TVs, DVDs, stereos, and more.

● Automotive Electronics: Wave soldering technology has been applied in automotive electronic products, including in-vehicle entertainment systems, safety control systems, etc., enhancing the reliability and safety of automotive electronic products.

● Communication Equipment: Wave soldering technology has been widely used in communication equipment such as base stations, routers, etc., enabling high-density and high-speed circuit designs.

● Industrial Control: Wave soldering technology has been applied in the field of industrial control, including PLCs, industrial computers, etc., improving the reliability and stability of equipment.

Future Development of Wave Soldering

With the trend of miniaturization and high-density electronic products, wave soldering technology is continuously innovating and developing. Here are the future development directions of wave soldering:

● Increased Automation: The automation level of wave soldering machines will continue to increase, including automation of component feeding and solder liquid supply.

● Improved Welding Quality: The welding quality of wave soldering machines will continue to improve, including more precise control of welding parameters such as temperature, welding time, solder flux flow, etc.

● Innovation in Welding Materials: With the growing environmental awareness, the welding materials used in wave soldering machines will continue to innovate and improve, including the adoption of lead-free solder and other environmentally friendly materials.

● Expansion of Application Areas: Wave soldering technology will be applied in more electronic products, including smart homes, the Internet of Things (IoT), etc.

In summary, as an important electronic component welding technology, wave soldering has been widely applied in various electronic products. With continuous technological innovation and development, it will play an increasingly important role in the future.