How to screen electronic components？
1. High temperature storage
Most of the failures of electronic components are caused by various physical and chemical changes in the body and on the surface, and they are closely related to temperature. After the temperature rises, the chemical reaction speed is greatly accelerated, and the failure process is also accelerated. So that the defective components can be exposed in time and removed.
High-temperature screening is widely used in semiconductor devices. It can effectively eliminate devices with failure mechanisms such as surface contamination, poor bonding, and defective oxide layers. Usually stored at the highest junction temperature for 24 to 168 hours.
2. Power electric aging
When screening, under the combined action of thermoelectric stress, it can well expose a variety of potential defects in the body and surface of components, which is an important item of reliability screening.
Various electronic components are usually aged for several hours to 168 hours under rated power conditions. Some products, such as integrated circuits, cannot be changed arbitrarily. However, high-temperature working methods can be used to increase the working junction temperature and reach a high stress state. The electrical stress of the components should be selected appropriately, which can be equal to or slightly higher than the rated conditions, but no new failure mechanism can be introduced.
Power aging requires special test equipment, and its cost is high, so the screening time should not be too long. Civil products usually take several hours, military high-reliability products can choose 100, 168 hours, and aerospace-grade components can choose 240 hours or even longer periods.
3. Temperature cycle
Electronic products will encounter different environmental temperature conditions during use. Under the stress of thermal expansion and contraction, components with poor thermal matching performance are prone to failure. The temperature cycle screening utilizes the thermal expansion and contraction stress between extreme high temperature and extreme low temperature, which can effectively eliminate products with thermal performance defects. Commonly used screening conditions for components are -55～+125℃, cycle 5-10 times.