When the product loses the specified function, it is defined to be invalid. The process of failure analysis is to analysis and verify the failure according to the failure mode and phenomenon, simulate the failure situation and excavate its failure mechanism. It’s the process that looking for the physical or chemical processes that lead to the failure of parts, components and materials. The final goal is to analyze the failure mechanism by confirming the failure mode, clarify the failure causes, and give preventive countermeasures to reduce or avoid the recurrence of failure.

Principle of failure analysis: non destructive analysis shall be carried out first, followed by destructive analysis; First carry out external analysis, then internal (anatomical) analysis; First investigate and understand the conditions related to failure (application conditions, failure phenomena, etc.), and then analyze the failed devices.