Printing circuit boards are important in automotive electronics and car-embedded systems. With the continuous innovation of the automotive industry, to provide the best technical support and performance, the work of PCB assembly has become more and more important. This trend reflects the continuous evolution of automotive electronic systems and develops from traditional mechanical systems to digitalization, intelligence, and interconnection. By continuously improving PCB assembly technology, higher performance, more reliable connection, more compact design, and higher efficiency can be achieved, thereby improving the function and performance of automotive electronic equipment. Therefore, the further development and optimization of PCB assembly and service work will bring more innovation and development opportunities to the automotive industry and can improve the driving experience.
● Circuit Traces
The conductivity on the PCB is used to connect to each electronic component. In the car PCBA designs the Motor control unit, vehicle electronic system, and other key components to ensure that they can communicate and coordinate effectively. So that the current can flow.
● Dielectric Layer
The dielectric layer is located between the line and the graph, and is usually composed of non -conductive materials (such as glass fiber or epoxy resin). Its function is to isolate the circuit between different levels, provide mechanical support, and protect the line from the impact of the external environment.
● Vias
The holes connect the lines of different layers so that the current can flow between different layers of the circuit board. The holes can be through different types such as Through Hole or Blind Via and Buried Via. These holes enable the current in the automotive electronic system to flow between different layers, connecting key components such as the car control unit, sensor, and actuator.
● Solder Mask
The welding ink is covered on the surface of the PCB, which is very important in the car environment. Protecting the PCB surface to avoid the impact of chemicals, moisture, and temperature changes, ensuring the stability of the automotive electronic system And reliability, according to different techniques, it is divided into green oil, red oil, and blue oil.
● Silkscreen
Silk printing is a text, symbol, or logo printed on the PCB surface. It is used to identify the location, and parameters, and use instructions of each component in the car electronics system, which provides convenience for maintenance and maintenance.
● Surface Finish
A layer of materials applied on the circuit board's surface protects the PCBA lines and pads of the car, prevents oxidation and corrosion, and provides good welding performance to cope with various environmental challenges during vehicle driving. Essence The protection methods include tin spray, gold, silver, tin, and organic welds.
The component layout is significant to automotive electronic systems' performance, reliability, and safety. It is necessary to comprehensively consider the vehicle's driving environment and system functional requirements to ensure the best design layout.
● Reasonable layout of conventional components
It is necessary to prioritize the layout of components that are closely matched with the vehicle structure, such as power sockets, indicator lights, switches in the vehicle safety system, connectors and interfaces in the vehicle electric drive system, etc. The reasonable layout of these components can ensure the convenience of their operation and maintenance.
● Layout of special components
Such as large components, heavy components, and heat-generating components in the vehicle driving assistance system, the reasonable layout of these components can optimize the heat dissipation effect to the greatest extent and ensure the system's stability under a high load and high-temperature environment. For example, heat-generating components should be evenly distributed to facilitate the heat dissipation of vehicle boards and the whole machine; other temperature-sensitive components except temperature detection components should be kept away from components with high heat generation to ensure their accuracy and stability.
● Wiring
When laying out components, wiring issues should be considered, and designs that are conducive to wiring should be selected as much as possible. For example, in the automotive lighting control system, the layout of components should be ensured to facilitate circuit wiring, thereby minimizing circuit complexity and power consumption.
● IC placement
The crystal oscillator should be placed as close to the IC as possible in the automotive electronic system to ensure the stability and reliability of clock signal transmission. The layout of the IC decoupling capacitor should be as close to the IC power pin as possible, and the loop formed between it and the automotive power supply and ground should be as short as possible to reduce the interference of voltage noise on the IC.
During the wiring process, priority should be given to the wiring of power lines and ground lines to ensure the stability and reliability of the PCB printing and assembly, which is crucial for the normal operation of automotive electronic systems.
● Keep high-speed signal routing as short as possible
This includes routing related to key signals such as automotive pressure sensing detection systems to ensure signal stability and reliability.
● Control the number of vias
Do not make too many vias in a routing, no more than two vias, to reduce signal interference and electromagnetic radiation.
● Corner design
The routing corner should be greater than 90 degrees as much as possible, avoid corners below 90 degrees, and use 90-degree corners as little as possible to reduce signal reflection and loss.
● When wiring double-sided boards
The wires should be perpendicular, oblique or curved to each other, avoid parallelism to reduce parasitic coupling, suitable for applications such as vehicle safety systems.
● Routing of audio input lines
Keep equal length, place close together, and include ground lines to ensure the transmission quality of audio signals, suitable for automotive driving assistance systems, etc.
● Routing of crystal capacitor ground wire
Try to use short wires to connect to the GND pin closest to the crystal oscillator, and minimize vias to ensure the stability of the clock signal, which is suitable for timing control in automotive electronic systems, etc.
● Routing of power lines and USB charging inputs
Thick wires should be used and widened, and copper should be laid on both sides of the vias, and more vias should be made at the copper laying to ensure the stability and reliability of the power supply, which is suitable for the power management part of the automotive electronic system.
