Blue Room - Session 10

9:15 to 10:15 a.m. Thursday April 23, 2015

The Benefits and Disadvantages of Multi-Stress Accelerated Life Test Methods

The reliability of electronics products can be studied using various accelerated life test (ALT) methods. Typically, only one or two environmental stress conditions are used as accelerating factors during testing, since this simplifies both testing and analysis of the results. However, in real storage and operating conditions products may be subjected to several sequential and simultaneous environmental stresses, which may have critical effects on the reliability of a product. If such combined stress loadings are also used in ALTs, the tests will imitate the actual use conditions more faithfully, and thereby may achieve greater accuracy of failure mechanisms. Additionally, higher acceleration levels may be achieved using such multi-stress ALTs without increasing the stress levels.

Although the multi-stress ALTs have several advantages, they also have several disadvantages which restrict their use. These include, for example, the need for complex test equipment, difficult analysis of the test results, and the lack of test standards and earlier test data. In this presentation, both benefits and disadvantages of multi-stress ALTs are discussed by using several examples in which multi-stress ALTs have been used.

Key Words: Accelerated Life Testing (ALT), Multi-Stress Accelerated Life Testing, Humidity Testing, High Temperature Testing, Corrosion Testing, Electrical Stress Testing, Failure Analysis

Laura Frisk, Janne Kiilunen, Juha Pippola, Milad Mostofizadeh and Sanna Lahokallio

Tampere University of Technology