HALT Test

A highly accelerated life test (HALT), is a stress testing methodology for accelerating product reliability. HALT testing is currently in use by most major manufacturing organizations to improve product reliability in a variety of industries, including electronics, computer, medical and military.

HALT can be effectively used multiple times over a product’s life time. During product development, it can find design weakness when changes are much less costly to make. By finding weaknesses and making changes early, HALT can lower product development costs and compress time to market. When HALT is used at the time a product is being introduced into the market, it can expose problems caused by new manufacturing processes. When used after a product has been introduced into the market, HALT can be used to audit product reliability caused by changes in components, manufacturing processes or suppliers etc.

Highly accelerated life testing (HALT) techniques are important in uncovering many of the weak links of a new product. These discovery tests rapidly find weaknesses using accelerated stress conditions. The goal of HALT is to proactively find weaknesses and fix them thereby increasing product reliability. Because of its accelerated nature, HALT is typically faster and less expensive than traditional testing techniques.

Environmental stresses are applied in a HALT procedure, eventually reaching a level significantly beyond that expected during use. The stresses used in HALT are typically hot and cold temperatures, temperature cycles, random vibration, power margining and power cycling. The product under test is in operation during HALT and is continuously monitored for failures. As stress-induced failures occur, the cause should be determined, and if possible, the problem should be repaired so that the test can continue to find other weaknesses.

In HALT, every stimulus of potential value (temperature, all-axis vibration, humidity, UV, radiation, etc.) can be used under accelerated test conditions during the development phase of a product to find the weak links in the design and fabrication processes. Accelerated stresses in combination (e.g. high-temperature ramp rates and all-axis vibration levels together) are necessary to compress or minimize the time to failure.