The automotive electronics market is the third largest APPLICATION area of PCBS after computers and communications. With cars from the traditional mechanical products, evolution, gradually developed into intelligent, informatization, mechanical and electrical integration of high-tech products, electronic technology was widely applied in the car, whether the engine system, or the chassis system, security system, information system, the interior environment system are invariably adopted electronic products. Obviously, the automobile market has become another bright spot in the electronic consumer market. The development of automotive electronics has naturally driven the development of automotive PCB.
In today’s PCB key application object, automobile PCB occupies an important position. However, due to the special working environment, safety, high current and other requirements of automobiles, they have high requirements on PCB reliability and environmental adaptability, and involve a wide range of PCB technology types, which is a challenge for PCB enterprises. For the manufacturers who want to develop the automotive PCB market, they need to do more understanding and analysis of this new market.
Automotive PCBS have a special emphasis on high reliability and low DPPM. Then, does our company have the technology and experience in high reliability manufacturing? Is it consistent with the future product development direction? In the process control, can you do according to THE requirements of TS16949? Have low DPPM been achieved? These all need to be carefully evaluated, just see this tempting cake and blindly enter, will bring harm to the enterprise itself.
The following provides some representative special practices of automobile PCB manufacturers in the testing process for the general PCB colleagues for reference:
Second test method of automotive PCB
Some PCB manufacturers adopt the “second test method” to improve the rate of finding the defect after the first high voltage breakdown.
Bad board anti-stay test system
More and more PCB manufacturers have installed “good board marking system” and “bad board error proof box” in the optical board testing machine to effectively avoid artificial leakage. The good plate marking system marks the tested PASS plate for the test machine, which can effectively prevent the tested plate or bad plate from flowing to the customer. The error proof box of bad board is the signal of opening box output by the test system when PASS board is tested in the test process. Instead, when a bad board is tested, the box closes, allowing the operator to properly place the tested board.
Establish PPm quality system
At present PPm(defect rate permillion) quality system is widely used in PCB manufacturers. Among many customers of our company, HitachiChemICal in Singapore is the most worthy of reference for its application and the results obtained. There are more than 20 people in the factory who are responsible for the statistical analysis of online PCB quality abnormals and PCB quality abnormals returned. The SPC production process statistical analysis method was used to classify each bad board and each returned defective board for statistical analysis, and combined with micro-slice and other auxiliary tools to analyze which production process produced bad and defective board. According to the statistical data results, purposefully solve the problems in the process.
Comparative testing (automotive PCB)
Some customers used two different brands of PCB models in different batches for comparative testing, and tracked the PPm of the corresponding batches, so as to understand the performance of the two test machines, so as to choose a test machine with better performance to test automotive PCB.
Improve test parameters
Select higher test parameters to strictly detect this type of PCB, because if you choose higher voltage and threshold, increase the number of high voltage read leakage, can improve the detection rate of PCB defect board. For example, a large Taiwan-funded PCB company in Suzhou uses 300V, 30M and 20 Euro to test automotive PCB.
Check test machine parameters regularly
After long-term operation of the test machine, internal resistance and other related test parameters will be deviated. Therefore, it is necessary to adjust machine parameters regularly to ensure the accuracy of test parameters. The test equipment is maintained and internal performance parameters are adjusted in half a year or one year in a large number of PCB enterprises. The pursuit of “zero defect” automobile PCB has always been the direction of PCB people’s efforts, but due to the limitations of processing equipment, raw materials and other aspects, so far the world’s top 100 PCB enterprises are still exploring ways to reduce PPm.