As a well-known manufacturer of reliability testing equipment, we have many customers from the electronic component industry. We have very mature production experience. Today, follow us to learn more about the reliability test of the high and low temperature test chambers that can be used in the component industry.
Components are the foundation of the whole machine. During the manufacturing process, it may cause failures related to time or stress during use due to inherent defects or improper control of the manufacturing process.
In order to ensure the reliability of the whole batch of components and meet the requirements of the whole machine, the components that may have initial failure under the conditions of use must be eliminated. The process of the failure rate of components changing with time can be described by a failure rate curve similar to the "bathtub curve". The early failure rate decreases rapidly with the increase of time. The failure rate is basically unchanged during the service life (or accidental failure period).
Most of the failures of electronic components are caused by various physical and chemical changes in the body and surface, which are closely related to temperature. After the temperature rises, the chemical reaction speed is greatly accelerated, and the failure process is also accelerated. The defective components can be exposed in time and eliminated.
High-temperature screening is widely used in semiconductor devices, and it can effectively reject devices with failure mechanisms such as surface contamination, poor bonding, and oxide layer defects. Typically stored at maximum junction temperature for 24 to 168 hours.
High-temperature screening is simple, inexpensive, and can be implemented on many components. After high temperature storage, the parameter performance of the components can be stabilized, and the parameter drift in use can be reduced. The thermal stress and screening time of various components should be properly selected to avoid new failure mechanisms.
During screening, under the combined action of thermoelectric stress, a variety of potential defects in the body and surface of components can be well exposed, which is an important item in 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 change the conditions casually, but high temperature working methods can be used to increase the working junction temperature and achieve a high stress state. The electrical stress of the components should be properly selected and can be equal to or slightly higher than the rated conditions, but no new failure mechanisms can be introduced.
Power aging requires special test equipment, and its cost is high, so the screening time should not be too long. Civilian products are usually a few hours, military high-reliability products can choose 100, 168 hours, aerospace-grade components can choose 240 hours or even longer cycles.
Electronic products will encounter different ambient 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. The commonly used screening conditions for components are -55°C ~ +125°C, cycle 5 to 10 times.