Automotive electronics market is the third largest application area of PCB after computer and communication. As the car from the mechanical products in the traditional sense, gradually evolved and developed into intelligent, information-based, mechanical and electrical integration of high-tech products, the application of electronic technology in the car has a very wide, regardless of engine system or chassis system, security system, information system, car environment system all adopt electronic product. Automotive market has clearly become a bright spot in the consumer electronics market, the development of automotive electronics, naturally moving the development of automotive PCB.
The following provides a representative part of the professional production of automotive PCB enterprises in the test process of some special practices to give reference:
1, the two test method
Part of the PCB manufacturing enterprises to adopt the "two test method" to improve the detection of the first high voltage breakdown plate defects.
2, the bad board stay test system
The manufacturer of PCB more and more in the board testing machine installed "plate marking system" and "bad mistake proofing board box" in order to avoid man-made leakage. Good marking system for the test machine to test the PASS board to identify, can effectively prevent the test board or bad plate flow to the hands of customers. Bad board proofing box is in the testing process, test PASS test board, signal output of the system box; on the other hand, a bad test board, the box closed, allowing the operator to correct placement through the circuit board test.
3, the establishment of PPm quality system
At present, PPm (defect Partspermillion, PPM rate) quality system widely used in PCB manufacturers. In many of our customers, to Singapore's HitachiChemICal and its application to achieve the most worthy of reference. In this factory, more than and 20 people are in charge of the statistical analysis of abnormal quality of PCB and abnormal return of PCB quality. By using the statistical analysis method of SPC production process, each piece of bad plate and plate defects each returned classification statistical analysis, and the analysis of the defects and bad board in which the production process combined with micro slicing tool. According to the statistical result of the data, to solve the problems in the process.
4, comparative test method
Some customers of different quantities of PCB with two different brand models comparison test, PPm and track corresponding quantity, so as to understand the performance of the two kinds of test machine, in order to test automotive PCB selection testing machine with better performance.
5, improve test parameters
Select higher test parameters to strictly investigate such PCB. Because, if you choose a high voltage and high voltage threshold, increase the number of read leakage, can improve the detection rate of PCB defective plate. For example, a large Taiwan funded enterprises in Suzhou using 300V, 30M, 20 European test car PCB PCB.
6, regularly check the machine parameters
The test machine in the long run, testing and other related parameters of resistance will be deviation. Therefore, it is necessary to adjust the machine parameters regularly to ensure the accuracy of the test parameters. Test equipment in a large part of the large PCB companies are half a year or one year to complete the maintenance, adjustment of internal performance parameters. The pursuit of zero defect car PCB has been the direction of efforts for the majority of PCB people, but subject to restrictions on equipment, raw materials and other aspects, so far the world's top PCB companies are still exploring ways to reduce PPm.