The reason is Supplier material or process problems, poor design and copper surface distribution, long storage time, exceeding the shelf life, PCB board damp, improper packaging or storage, moisture response Measures: Choose the package and store it with constant temperature and humidity equipment. Do a good job of PCB factory reliability test, for example: thermal stress test in PCB reliability test, Example: ALLPCB is based on more than 5 times of non-layering, and will be confirmed in each stage of the sample stage and mass production. Vendors may only request 2 times and will only confirm once in a few months.
