What are the processes of electric vehicle PCB assembly?

What are the processes of electric vehicle PCB assembly?

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In the automotive intelligence, electrification process accelerated today, automotive electronic circuit boards PCBA as the core carrier of the automotive electronic system, the processing process is precise and complex, any one of the links are related to the performance, reliability and safety of automotive electronic equipment. This article we will give you a detailed introduction to the electric car pcba assembly process, all-round control of the quality of electric car pcba.

The role of pcb in electric vehicles

PCB is the backbone of electronic equipment, providing a physical platform for installing and interconnecting various electronic components. In electric vehicles, pcb has a wide range of uses, including.

Battery Management System (BMS):The BMS monitors and manages the state of the battery to ensure optimal performance and safety. The system contains complex circuitry that requires high quality PCBs to efficiently handle power and data signals.
Power electronics: These include inverters, converters and chargers that manage the current between the battery and the motor. High-performance PCBs are essential to handle high currents and voltages.
Infotainment Systems:Modern electric vehicles are equipped with advanced infotainment systems that provide navigation, entertainment and connectivity. These systems rely on PCBs to seamlessly integrate various functions.
Advanced Driver Assistance Systems (ADAS): Technologies such as adaptive cruise control, lane keeping assist and collision avoidance require reliable PCBs to process data from sensors and cameras in real time.

Electric Vehicle PCBA Assembly Process


Raw material preparation

Circuit board substrate procurement: first of all, according to the specific needs of automotive electronics, select the appropriate circuit board substrate materials. In view of the harsh environment inside the car, large temperature changes, strong vibration and electromagnetic interference, usually with high heat resistance, high mechanical strength, good electromagnetic compatibility of the substrate, such as special modified FR-4 board or high-performance flexible board. These substrates should meet strict industry standards to ensure stable operation under complex working conditions.

Selection and procurement of electronic components: According to the design of the automotive electronic circuit, we accurately screen all kinds of electronic components, including resistors, capacitors, inductors, chips, etc. The quality of the components directly determines the quality of the PC. The quality of the components directly determines the quality of the PCBA, so we must use products that meet the automotive-grade standards, with high reliability, wide temperature range adaptability and other characteristics. Purchased components need to undergo strict factory inspection to check the integrity of the appearance, the accuracy of the electrical parameters, to prevent defective products from entering the production line.

SMT Processing

Solder Paste Printing: Solder paste is printed onto the circuit board pads through high-precision stencils to ensure sufficient quantity and accuracy to avoid soldering defects. The stencil is laser cut or etched, and different pads correspond to different mesh holes in order to meet the packaging requirements of the components.

SMD: The components are quickly and accurately mounted onto the pads using high-precision mounting machines to ensure that tiny components such as 0201, BGA chips, etc. are accurately aligned and pasted with solder paste.

Reflow Soldering: After the placement is completed, the temperature profile is precisely controlled through a multi-temperature zone reflow oven to ensure that the solder paste melts and solidifies uniformly, forming a high-quality solder joint, avoiding damage to components, and ensuring the reliability of the soldering.

THT Insert Processing (if required)

Some of the automotive electronics PCBA also involves through-hole technology (THT) processing link. For some larger power, high mechanical strength requirements or not applicable to SMT components, such as large electrolytic capacitors, relays, etc., need to use THT technology.

Insertion: Workers will insert the pins of the components into the pre-drilled holes in the circuit board, requiring the insertion of the right depth, straight pins, to ensure a good connection with the circuit board and the inner layer of the line. This process requires manual operation combined with auxiliary tooling to ensure the accuracy and consistency of the plug-in.

Wave soldering: After the plug-in is completed, the wave soldering equipment is utilized for soldering. Liquid solder to form a wave-like shape, the circuit board from the wave through the peak, so that the component pins and circuit board pads are fully infiltrated welding. The key to wave soldering is to control the solder temperature, wave height and soldering speed to ensure that the solder joints are full, no false soldering, while avoiding short circuits and other problems caused by too much solder.

Inspection and debugging

Appearance Inspection: Comprehensively inspect the PCBA appearance, check the missing components, offset, damage and defective solder joints and other issues, with the help of magnifying glass and other tools to ensure the quality of the appearance, to avoid potential safety hazards.

Electrical performance test: use professional equipment to test the PCBA electrical parameters, to confirm that the circuit connectivity, power module output and signal integrity in line with the design requirements.

Functional test: simulate the actual automotive environment, verify the actual working performance of PCBA through the test tooling to ensure its stable and reliable performance under various working conditions.


Three-proof processing

Considering the complexity of the automobile driving environment, automobile electronic PCBAs usually need three-proof (moisture-proof, mildew-proof, salt spray-proof) treatment. Special three-proof paint is used to form a protective film on the surface of PCBA by spraying, dipping or brushing to isolate the external moisture, mold, salt spray and other unfavorable factors and prolong the service life of PCBA.

EV PCB assembly

PCB Manufacturing and Assembly Considerations for Electric Vehicles

Thermal Management: The power electronics in electric vehicles generate a lot of heat. To prevent overheating, manufacturers need to use high thermal conductivity materials (e.g. copper, aluminum substrates) and advanced cooling technologies (heat sinks, hot channels, liquid cooling, etc.), and manage the coefficients of thermal expansion between different materials to avoid damages triggered by temperature changes.

High reliability: EVs are often exposed to harsh environments such as vibration, temperature differences, moisture and dust, and PCBs must be highly reliable and durable. Manufacturers need to follow IPC standards (e.g. IPC-A-600, IPC-A-610) and take protective measures such as conformal coating and encapsulation, and perform rigorous testing (temperature cycling, vibration, humidity, etc.) to ensure quality.

Miniaturization: PCBs are becoming increasingly miniaturized to fit compact vehicle designs, using HDI technology for microfabrication and multilayer stacking. Precision assembly and 3D PCB design software ensure compact layouts and stable signal and power distribution.

High power density: The high power requirements of electric vehicles require PCBs that support high currents, using thick copper layers and wide alignments to ensure stability and minimize losses in the power layer. Effective grounding, shielding, insulation and safe distance design are also critical to ensure safety and EMI suppression.

Cost and Scalability: While pursuing high performance, manufacturers need to control costs and increase production flexibility. Automated production (e.g., AOI, SMT) can reduce labor costs and improve consistency. However, there is still a need to balance innovation, cost and scale in the context of rapidly evolving technology.

Compliance with industry standards: Manufacturers must follow industry standards such as ISO 16750, IPC, and others to ensure that PCBs meet requirements for safety and performance. Compliance requires complete documentation, validation and process adjustments to adapt to changing regulations.

The Future of PCB Assembly for Electric Vehicles

The future of EV PCB assembly is bright, and the following trends are driving change in the industry:

Convergence of AI and IoT: As Artificial Intelligence (AI) and the Internet of Things (IoT) are increasingly used in EVs, the demand for high-performance PCBs increases. These advanced technologies require powerful processing and connectivity capabilities, driving the continued evolution of PCB design and assembly towards greater integration and intelligence.

Sustainable Manufacturing: Sustainability is increasingly in the spotlight, and environmentally friendly PCB manufacturing processes are gaining more attention. Lead-free soldering, recyclable substrates, and energy-efficient production processes are all important initiatives to promote green manufacturing.

Growing demand for customization: The increasing diversity of electric vehicle models and features is increasing the demand for customized PCBs. Manufacturers need to provide flexible and customized solutions to meet the specialized requirements of different platforms and application scenarios.

Collaboration and standardization: Collaboration between OEMs, electronics manufacturers and industry standards organizations is driving standardization in PCB design and production. Standardization helps streamline production processes and ensures interconnectivity and compatibility between systems.

leadsintec’s excellent pcba partner for automotive electronics

LST specializes in automotive electronic circuit board PCBA processing field, with advanced production equipment, from high-precision solder paste printing machine, top-class mounter to precision reflow oven, professional testing instruments, to ensure that each processing step can meet the automotive quality standards. The company’s technical team is experienced and familiar with the automotive electronics industry specifications, providing one-stop PCBA processing services. At the same time, strict quality control system throughout the production process, through multiple rounds of testing and debugging, to ensure the delivery of each piece of automotive electronics PCBA has a high degree of reliability, for the booming development of the automotive industry escort.