The topic of intelligent vehicle development continues to be hot, especially after the green transportation boom of all-electric EV vehicles, and the demand for electronic design, such as autonomous driving, networked vehicles, and active/passive vehicle safety, is stimulated. Not only is the development of new technologies maturing, but the demand for automotive electronic PCB required for design is increasing.
Electric vehicles and smart cars can be said to be the key industry trends to promote the vigorous development of automotive electronics. Especially in the direction of environmental protection and intelligence, most of the electronic control functions or components of vehicles play a very important role. Apart from a large number of sensors deployed inside and outside the vehicle, the vehicle can really grasp the driving dynamics and the peripheral information of the vehicle. While expanding the intelligent or electric functions of the vehicle, it also brings a great opportunity for the vehicle to upgrade and expand towards the electronic application system.
With the increase of automobile electronic control function, the consumption of automobile PCB also increases simultaneously.
However, configuring a large number of electronic sensors and electronic function modules for vehicles, these key subsystems will actually increase the usage of vehicle PCB. However, after all, vehicles are different from conventional electronic equipment applications, and they may climb mountains, wade in water, and be parked outdoors to be exposed to high temperature for a long time, or even in a long night’s low temperature environment. When vehicles are transported and driven, they must maintain the optimal running state of subsystems. These strict requirements of application and production also make vehicle PCB have higher product requirements, and even the corresponding safety inspection conditions are much higher than those of general consumer electronics.
Especially the active/passive safety modules developed for vehicle safety issues, and even the automatic driving modules with high safety requirements. In addition, for automotive electronic applications such as entertainment systems and landscape projection with relatively low safety requirements, these system modules must be integrated by connecting key components with PCB, and complicated verification requirements must be carried out together with the whole vehicle, meeting the management verification specifications of various countries. Compared with the product verification of consumer electronics, the relevant requirements of automotive PCB will only be more stringent.
Intelligent vehicles and electric vehicles stimulate PCB consumption of vehicles.
Taiwan Province’s manufacturing technology of printed circuit boards should be in the leading position in the world, and the actual output will be mainly the carrier boards for consumer electronics. Compared with the demand for consumer electronics, the investment in automotive electronics industry is still less. However, with the booming market of smart cars, self-driving cars and all-electric vehicles, the number of manufacturers developing automotive PCB products or specific technologies will gradually increase.
For PCB, basically, it is a carrier board for carrying various electronic components and connecting application modules in series, and it is a supporting platform for electronic components, in which 10 key electronic components are connected by etching the metal film of the conductive circuit.
As for the traditional PCB, it is often called printed circuit board (PCB) by using the printing method to reserve the reserved circuit and etching away the unnecessary metal foil with chemical agents. With the pursuit of miniaturization design of new generation electronic products, the design of PCB must also reduce the volume and area. Therefore, the new generation of small-sized PCB or high-density carrier board is manufactured by using more precise processes, and then the etching process is carried out by exposure and development of the type printed with etching resist.
The requirements and verification standards of automotive PCB materials are higher.
Although the circuit boards and electronic component carrier boards used in general consumer electronics can be directly used for automotive electronics, they can also maintain normal operation, but they can’t be directly replaced in practice, because the requirements for the materials and processes of the circuit boards will be greatly different depending on the installation position, purpose and stability requirements of the subsystems of automotive electronics.
It can be used for in-vehicle electronic equipment such as driving information system, car information communication for general entertainment, etc. Using 1.6mm thick PCB with high reliability can meet the use requirements of general in-vehicle electronic equipment with minimal material and process adjustment.
On the other hand, for vehicle images and engine power control units related to vehicle safety, PCB itself must add more environmental condition verification means, such as cold and hot shock test, deviation test in high temperature/high humidity environment, etc., so as to find out the performance of PCB materials that can withstand higher environmental changes, and avoid the circuit failure or material variation that will affect the correct operation of electronic components because the function of the circuit board is changed by environmental conditions.
Self-driving cars and smart cars need high-frequency circuit boards.
Another development direction is to meet the requirements of wireless transmission and vehicle networking applications required by various smart cars and electric vehicles, and the production requirements of vehicle PCB, especially the vehicle PCB used in high-frequency and high-frequency application frequency bands required by millimeter-wave radar antenna applications.
According to the high-frequency application conditions of automotive PCB, the technical indexes concerned not only require the tolerance of products to huge environmental conditions, but also have higher requirements for transmission loss, special base materials 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 used all the year round, in PCB verification, it is necessary to check and control that the crack state of welding shears must be limited to the required condition value range, and at the same time, it can ensure that the electronic components can maintain a normal and stable joint state in harsh operating environment.
Special vehicle PCB blessing for high power and high temperature
In some high-level or more application conditions, the material of automotive PCB may be used as ceramics or other special substrates, but in fact, the products made of such special substrates are not cheap. In order to reduce the cost and weight of the carrier board, it is quite difficult to make the carrier board based on organic materials achieve the characteristics of the special substrate circuit board, while maintaining the optimization of low cost and weight.
In advanced and high-end automotive circuit boards, the specification of fine through holes is used. In response to the possibility of connecting BGA components under small size and maintaining better service conditions, it is quite common for automotive PCB to adopt multi-layer board design in order to reduce the volume of electronic control module. Using 6-layer board, for example, the service conditions are not lower than those of general consumer electronics. The only difference is that the verification and retest standards of automotive carrier boards are higher.
With the increasing demand of automotive electronics for the production of electric vehicles and all-electric vehicles, there is a high chance that a large number of power components or high-heating components will be integrated into the circuit board in the battery high-power control module or related electronic subsystem. In order to make the PCB itself achieve the heat dissipation effect, this special application automotive PCB also has different ways to improve the heat dissipation effect of the whole subsystem. For example, by embedding “copper” in the PCB inner layer (Cu inlay PCB), the auxiliary heat dissipation effect provided by the composite substrate with the traditional PCB itself will be optimized.
