How to improve the rate of defect of automotive PCB
Today, in the key applications of PCB, PCB for vehicles plays a very important role. PCB copying has very high demands for the reliability and environmental adaptability because automotive requires special working environment, high degree of security and high current. Besides, it involves many types of technology. Therefore, it is a challenge for PCB enterprises. If manufacturers intend to expand the market of automotive PCB, they should have more understanding and thorough analysis of this new market.
Automotive PCB lays heavy stress on reliability and low DPPM. Have our enterprises had enough technologies and experiences in manufacturing in terms of reliability? Is it in line with the future development of the products? In terms of process control, will enterprises conform to the standard of TC16949? Have enterprises made low DPPM possible? These all need careful evaluation. By seeing only this piece of cake and jumping into these field blindly, it will bring much harm to itself.
1. Secondary testing:
The following are some typical techniques adopted by some professional automotive PCB enterprises in the process of testing for your reference:
Some PCB manufacturers adopt “secondary testing” to increase the finding rate of defective boards after the first high-voltage shock.
2. Fool-proof testing system in the malfunctional board
More and more PCB manufacturers have installed “marking system for functional board” and “error prevention box for malfunctional boards” on the light panel testing machines to avoid artificial omission. The “marking system for functional board” will mark the PASS board if it passes the test of the testing machines, which can effectively prevent those fail in the test or malfunctional boards flow to the hands of customers. In the testing process of “error prevention box for malfunctional boards”, when a PASS board is tested, the testing system will send the signal of opening boxes; on the contrary, when a malfunctional board is tested, the box will close to ensure workers put the PASS board in a right manner.
3. To create PPm quality system
The PPm (Parts per million) quality system has began to be widely applied among PCB manufacturers. Of all our clients, Hitachi ChemICal from Singapore has made remarkable achievements in its applications, which is worth learning. There are 20 professionals who are specially in charge of quality abnormities of PCB products online and responsible for statistic analysis of goods return because of PCB quality abnormities. Adoption of SPC to make statistic analysis of the production process will give them an opportunity to make statistic analysis after they categorize the malfunctional boards and returned defective boards in order to figure out which process has produces malfunctional or defective boards with the aid of micro cutting.
4. To compare testing method
Some clients even purchase two different models of machines with different brands in different batches to make comparison and track the PPm conditions of different machines to get more thorough understanding of the performance of the two machines so that they can choose the best testing machine to conduct test for automotive PCB.
5. To improve the testing parameter
Testing parameter of high levels is selected to conduct strict testing for the PCB. PCBAOEM chooses the OEM processing or materials because high voltage and threshold value can improve the chances of electric leakage by high voltage so as to increase the detection rate of PCB Prototype defective boards. For instance, one Taiwan funded large-scale PCB enterprise in Suzhou adopts 300V, 30M and 20 Opel of voltage to conduct testing for automotive PCB.
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