PCB Tech - Method of optimizing the defect rate of PCB for automotive

Method of optimizing the defect rate of PCB for automotive

In today's key PCB applications, automotive PCB boards occupies an important position. PCB copy board, but due to the special working environment, safety and high current requirements of the car, it has higher requirements on the reliability and environmental adaptability of the PCB, and the types of PCB technology involved are also wide, which is for PCB companies, Is a challenge; and for circuit board manufacturers who want to develop the automotive PCB market, it is necessary to do more understanding and analysis of this new market.

Automotive PCBs particularly emphasize high reliability and low DPPM. So, does our company have the accumulation of technology and experience in high-reliability manufacturing? Is it consistent with the future product development direction? In terms of process control, is it able to do well in accordance with the requirements of TS16949? Has a low DPPM been achieved? All these need to be carefully evaluated. Just seeing this attractive piece of cake and entering blindly will bring harm to the enterprise itself.

The following provides a representative part of some special practices in the testing process of professional PCB manufacturers for automobiles, which are provided to the majority of PCB colleagues.

For reference:

1. The second test method

Some PCB manufacturers adopt the "second test method" to increase the rate of finding defective boards after the first high-voltage electrical breakdown.

2. Bad board foolproof test system
More and more PCB manufacturers have installed "good board marking system" and "bad board error prevention box" in the light board testing machine to effectively avoid human leakage. The good board marking system marks the tested PASS boards for the testing machine, which can effectively prevent the tested boards or bad boards from flowing into the hands of customers. The bad board error-proof box means that during the test, when the PASS board is tested, the test system outputs the signal that the box is opened; on the contrary, when the bad board is tested, the box is closed to allow the operator to correctly place the tested circuit board.

3. Establish the PPm quality system

Use SPC production process statistical analysis method to classify and analyze each defective board and each defective board returned, and combine with auxiliary tools such as microsectioning to analyze in which production process the defective and defective boards are produced. According to the statistical data results, we can solve the problems in the process purposefully.

4. Comparative test method
Some customers use two different brands of PCBs for comparative testing in different batches, and track the PPm of the corresponding batches, so as to understand the performance of the two testers, and then choose a better performance tester to test automotive PCBs.

5. Improve test parameters
Choose higher test parameters to strictly detect such PCBs. PCBA OEM foundry substitutes because if you choose a higher voltage and threshold, increase the number of high-voltage read leakage, which can increase the detection rate of PCB defective boards. ipcb is a high-precision, high-quality PCB manufacturer, such as: isola 370hr PCB, high-frequency PCB, high-speed PCB, ic substrate, ic test board, impedance PCB, HDI PCB, Rigid-Flex PCB, buried blind PCB, advanced PCB, microwave PCB, telfon PCB and other ipcb are good at PCB manufacturing.