In HALT (Highly Accelerated Life Test) is a test that is performed in the development of a product after the first prototypes are available. During the HALT test the systems are stressed beyond the specification limits for temperature and vibration out to provoke failure and thus expose vulnerabilities. This can also be varied nor operating parameters such as the supply voltage. As part of the HALT function and destruction of the specimen boundaries are identified. The aim is to address the weaknesses of those limits as far as possible extend, in order to achieve higher reliability of the product. HALT is fundamentally different from traditional environmental assessments and has a different purpose. For HALT is not intended to qualify the candidate with respect specified environmental parameters, but stimulate the device under test until it comes to failures, to pick up weaknesses. Even if the stress at HALT are not comparable with the actual requirements in the field have shown the procedure that the weaknesses that we identified in stop after a few hours or days, usually the same are flying in the field often only after several years of losses.
The procedure for HALT is not strictly defined, but is also dependent on the particular DUT. A typical approach that has proven itself, is described briefly below. Here the product is successively subjected to four different stresses. 1st Temperature step test (cold and heat) 2 Rapid temperature cycling test third Vibration test in 4th Combined vibration test with rapid temperature change at all the tests carried out a gradual increase of the traffic, until it comes to malfunction or destruction of individual elements of the test piece, or until the limit of technology (for example, melting point of plastic). At the same time can still operating parameters such as voltage can be varied to create additional stress conditions.
With all the tests, the monitoring function of the specimen is of enormous significance, is to be able to accurately document the failures. As soon as there is a failure, the test is stopped, searched the place of the error and analyzed the cause. Next, the error should, if possible, at least temporarily resolved, and the tests will be continued. Because a goal of HALT is to function or destruction of the product as possible boundaries extend far. To be closer to about HALT, it offers itself as a HALT-Seminar to visit, which are offered regularly. There, on the one closer to the theoretical foundation and practical application.