• High-frequency substrate board
Automotive collision-resistance/predictive braking safety system plays a role as a military radar device. Since automotive PCBs are responsible for transmitting microwave high-frequency signals, substrate with low dielectric loss needs to be applied with the ordinary substrate material to be PTFE. Different from FR4 material, PTFE or similar high-frequency substrate materials require special drilling speed and feeding speed during drilling.
• Thick copper PCB
Automotive electronics brings more heat energy owing to high density and power and hybrid power and electromotives tend to require more advancing electric power transmission system and more electronic functions, which leads to more requirements on heat dissipation and large current.
It’s relatively easy to fabricate thick copper double-layer PCBs while it’s much more difficult to fabricate thick copper multi-layer PCBs. The key point lies in thick copper image etching and thickness vacant filling.
Inner routes of thick copper multi-layer PCB are all thick copper and therefore and graphic transfer photo-induced dry film is also relatively thick, requiring extremely tremendous etch resistance. Thick copper graphic etching time will be long and etching equipment and technical condition in the best state so as to ensure complete routings of thick copper.
• Component embedment
Component embedded PCBs were massively applied in mobile phones in order to increase assembly density and decrease component size, which is acquired by other electronic equipment as well. Therefore, component embedded PCBs are also applied in automotive electronic equipment.
According to different component embedment methods, there are numerous manufacturing methods for component embedded PCBs. Component embedded PCBs for automotive electronics have mainly 4 manufacturing methods
• HDI technology
One of the key functions for automotive electronics lies in entertainment and communication among which smart phones and tablet PCs require HDI PCBs. Thus, technologies contained in HDI PCBs such as micro via drilling & plating and lamination positioning are applied in automotive PCB manufacturing.
What are the performances attributes of automotive PCB?
• Multiple categories of automotive PCBs
Automobiles combine machinery and electronic equipment. Modern automobile technology integrates traditional technique and advancing scientific technology, such as manual inner decorating parts and advancing GPS. In modern automobiles, there is electronic equipment with different functions at different positions and different functions derive from different types of PCBs.
According to substrate materials, automotive PCBs can be classified into two main categories: inorganic ceramic-based PCB and organic resin-based PCB. Ceramic-based PCB features high temperature resistance and excellent size stability, making it directly applied in motor system with high temperature. However, it features bad ceramic manufacturability and high cost. At present, with the development of resin substrate material in terms of its heat resistance capability, resin-based PCB has been widely applied in automobiles with substrate material with different performances applied in different positions.
• Different reliability requirements for PCBs at different positions
Concerned with public security, automobiles belong to high-reliability product category, so automotive PCBs have to pass some reliability tests apart from ordinary requirements such as dimension, size, mechanical and electric performance.
a. Thermal Cycling Test (TCT)
Five grades classified according to different positions of automobiles.
b. Thermal shock test
Automotive PCBs are more applied in the environment with high temperature, which is especially true for Thick Copper PCBs that have to deal with external heat and self-producing heat. As a result, automotive PCBs have a higher requirement on heat resistance.