Quality Inspection for Outgoing PCBs

After 100% of electric test and appearance check, the PCB manufacturer will conduct “Outgoing Quality Check” to ensure the quality of completed boards meet client’s requirements. Besides compliance with client’s requests, the process of OQC could optimize the production process and improve the quality by detecting the potential quality issue.

The PCB manufacturer either follows client’s regulations or control plan to conduct quality inspection. If above not available, then the quality inspection will follow the PCB manufacturer’s standard. The strictness of quality inspection usually could be divided into two categories, automotive products or non-automotive products. Take ExPlus for instance, ExPlus follows MIL-STD-105E Level 2 for both categories. What is “MIL-STD-105E”? MIL-STD-105E stands for military standard 105E which has established for the acceptance or rejection of lots based on the assessment of items attributes. Based on the quantity of taken samples from the lot containing N units, the WHOLE lot is either accepted or rejected. For PCB used in automotive products, ExPlus follows “0 accepted 1 rejected” under MIL-STD-105E Level 2. Which means no matter how many units are inspected, the whole lot will be rejected if there’s one unit not meet the standard. On the other hand, ExPlus follows “MIL-STD-105E Level 2 0.65%” for non-automotive PCB boards. Take 1,000 units for example. Based on the below chart, if there’s only 1 unit not meet the standard within 80 units taken samples, then the whole lot is accepted. Again, sampling inspection is used for outgoing goods inspection after 100% of open circuit/broken circuit and appearance check are performed.