Optimizing vehicle PCB defect rate method
Among the key applications of PCBs today, automotive PCBs occupy 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 PCB reliability and environmental adaptability, and the types of PCB technology involved are also wide, which is for PCB companies. It is a challenge; for manufacturers who want to develop the automotive PCB market, more understanding and analysis of the new market is needed.
1, the second test method
Some PCB manufacturers adopted the “secondary test method” to improve the rate of defect detection through 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 error. The good board marking system identifies the tested PASS board for the test machine, which can effectively prevent the tested board or bad board from flowing to the customer. The bad board error prevention box is the signal that the test system outputs the box opening when the PASS board is tested during the test; otherwise, when the bad board is tested, the box is closed, allowing the operator to correctly place the tested circuit board.
3. Establish a PPm quality system
At present, PPm (Partspermillion, defect rate of parts per million) quality system has been widely used in PCB manufacturers. Among the many customers of our company, the application and achievements of HitachiChemICal in Singapore are the most worthy of reference. More than 20 people in the factory are responsible for the statistical analysis of online PCB quality abnormalities and abnormal PCB quality returns. Using the statistical analysis method of SPC production process, each bad board and each defective board returned are classified and statistically analyzed, and combined with auxiliary tools such as micro-slices to analyze which manufacturing process produces bad and defective boards. Based on the statistical data results, purposefully solve the problems in the process.
4, comparative test method
Some customers use different brands of different types of PCBs (pcb board Printed company China)for comparative testing, and track the PPm of the corresponding batches to understand the performance of the two test machines, so that a better performance test machine can be selected to test the automotive PCB.
5, improve test parameters
Choose higher test parameters to strictly detect such PCB.PCBA OEM foundry materials, if you choose higher voltage and threshold, increase the number of high-voltage read leakage, can improve the detection rate of PCB defective board.