Briefly describe the concepts of failure, failure mode and failure mechanism

Date：2022-05-27 14:43:04Views：1777

Failure means that the electrical performance parameters or physical and chemical performance indexes of electronic components in normal operation no longer meet the specified requirements after a certain stress test or field use.

Failure mode refers to the failure form and phenomenon of electronic components, such as open circuit, short circuit, no function, parameter drift or degradation, poor contact, etc. (it can also be subdivided according to the type of electronic components that are not connected to the network). The failure mode only indicates how the electronic components fail, and does not involve why the electronic components fail. With a certain number of failed electronic components, the percentage of various failure modes can be calculated, that is, the distribution of failure modes. The data of failure modes can be obtained from the known modes of similar processes, the test data of product sampling and evaluation, and the field data after use, but the failure information after use is the most reliable.

Failure mechanism is the essential reason for the failure of electronic components. It refers to the physical and chemical processes that cause the failure of electronic components. It describes how the electronic components fail, such as fatigue, corrosion and overstress, can cause the failure of electronic components. Failure causes can be broadly classified into three categories:

① Failure caused by design defect.

② Failure caused by process defects (they are related to process technology, process control and process equipment).

③ Overstress failure (they are related to service conditions, service environment and human factors).

The common failure mechanisms of electronic components can be roughly divided into deterioration caused by design defects, internal deterioration, surface deterioration, metallization system deterioration, and failure caused by oxide layer defects; Failure caused by bonding defects; Package deterioration; Corrosion failure; Service failure, etc. According to different categories of electronic components, the above failure mechanisms can be further subdivided, and the failure causes at the last level should be subdivided until they can no longer be subdivided.

In order to truly and accurately grasp the failure mode and failure mechanism of products, it is necessary to apply advanced failure analysis instruments and failure analysis technology to carry out in-depth and detailed failure analysis.