PCB Technical - Automotive electronic PCB and R&D direction

Nowadays, the topic of smart car development continues to be hot, especially after EV (Electric Vehicle) all-electric vehicles have set off a green transportation boom, immediately stimulating the demand for electronic design such as autonomous driving, connected cars, active and passive car safety, not only the development of new technologies Mature, and the demand for automotive PCBs required to realize the design is also increasing.

Smart cars, electric cars stimulate the use of PCBs for cars

* And Taiwan’s global printed circuit board manufacturing technology should be in the * position, the actual output will be mainly for consumer electronics substrates, and the investment in the automotive electronics industry is still less than the demand for consumer electronics. However, as the markets for smart cars, autonomous vehicles, and all-electric vehicles become more active, the number of companies developing automotive PCB products or specific technologies will gradually increase.

For a PCB, it is basically a carrier board that carries various electronic components and is connected to application modules in series. It is a support platform for electronic components. Among them, key electronic components are connected through metal thin films that etch conductive circuits.

From the perspective of traditional PCBs, printing methods are often used to reserve the reserved circuits, and use chemicals to etch away unnecessary metal foils to form the conductive circuits and graphics required by the circuit board. Therefore, it is called a printed circuit board. In the pursuit of miniaturization of the first generation of electronic products, the circuit board design must also reduce the volume area. Therefore, the new generation of small circuit boards or high-density carrier boards are manufactured using more precise processes, using a type of printing with etching resists attached. Use exposure and development treatment, and then carry out a finer circuit etching process.

Automotive PCB material requirements and verification standards are higher

Although the circuit boards and electronic component carrier boards used in general consumer electronics can be used directly for automotive electronics and can maintain normal operation, they cannot be directly replaced in practice because automotive electronics depends on the installation location, use, and stability requirements of the subsystems. Different, the material and process requirements of the circuit board will be very different.

Used in in-vehicle electronic equipment such as driving information systems and general leisure-use in-vehicle communications, the use of highly reliable and reliable 1.6mm thick PCBs can achieve the use of general in-vehicle electronic equipment with smaller materials and process adjustments. Require.

In addition, for car images and engine power control units that are related to car safety, the PCB itself must add more environmental conditions verification methods, such as cold and heat shock tests, high temperature * humidity conditions, and deviation tests to find out. PCB materials that can withstand higher environmental changes, to avoid circuit failures or material variations that affect the correct operation of electronic components due to changes in environmental conditions.

Self-driving cars and smart cars need high-frequency circuit boards

Another development direction is for the needs of wireless transmission and Internet of Vehicles applications required by various smart cars and electric vehicles, and the production requirements of PCBs for vehicles, especially high-frequency and high-frequency applications required for antenna applications of millimeter wave radars. Automotive PCB used in the frequency band.

For the high-frequency application conditions of automotive PCBs, the technical indicators concerned not only require the product to withstand large changes in environmental conditions, but also have higher requirements for transmission loss, special substrates, and composite structure processes. However, it is not easy to meet the low-cost requirements of mass production under complicated conditions.

In addition, for safety subsystems such as brakes and various control subsystems in the engine room. For automotive electronic circuits that are used all year round, in addition to various thermal shock tests and high humidity tests, the PCB verification must also be inspected and controlled. The crack state of the shear must be limited to the required condition value range, and at the same time, it can also ensure that the electronic components can be maintained in a normal and stable joint state under the severe operating environment.

For high power and high temperature, special car PCB blessing is required

Some high-end or more severe application conditions may use automotive PCB materials such as ceramics or other special substrates, but in fact products made of such special substrates are not cheap, in order to reduce costs and The weight of the carrier board, how to make the carrier board based on organic materials can also achieve the characteristic performance of the special substrate circuit board, while maintaining low cost and weight optimization is quite difficult.

In the advanced and high-end automotive circuit boards, the fine through-hole specifications are used to cope with the possibility of connecting small BGA components and maintaining better conditions of use. In order to reduce the volume of the electronic control module, the automotive PCB adopts a multi-layer board design. It is also quite common. For example, 6-layer boards are used, and the conditions of use are not lower than the requirements of general consumer electronics. The actual situation is that the verification and retest standards for vehicle carrier boards will be higher.

For the increasing demand for electric vehicles and all-electric vehicles for automotive electronics, the chances of integrating a large number of power components or high heating components in the battery high power and high power control module or related electronic subsystems are quite high. In order to make the PCB itself It can also achieve the effect of heat dissipation. This special application of automotive PCB also has different methods to improve the heat dissipation effect of the overall subsystem. For example, by embedding copper in the inner layer of the PCB (Cu Inlay PCB), it is combined with the traditional PCB itself. The auxiliary effect of heat dissipation provided by the material substrate is more obvious than optimization.