What Is HALT (Highly Accelerated Life Testing) And Why Perform HALT?

Highly Accelerated Life Testing (HALT) is a rigorous reliability test method that is used to expose product weaknesses. 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.

HALT of circuit boards in one of DES’s HALT chambers

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 or suppliers etc. The bottom line is that HALT can reduce product development time and cost, reduce warranty costs, improve customer satisfaction, gain market share, and increase profits.

HALT is not a qualification test, thus there are no predetermined pass/fail criteria. The goal of HALT is to quickly precipitate failures and then to determine their root causes. Once the causes of failure are determined, the failed components are repaired and the stress limits of the testing program are expanded.

Important HALT Definitions

6 Degrees Of Freedom (DOF): Refers to vibration with energy along three orthogonal translations and three rotations simultaneously

Grms: Grms is used to define the overall acceleration level of random vibration. Grms (root-mean-square) is the square root of the area under the PSD curve. More information about random vibration can be found in our blog article Sinusoidal and Random Vibration Testing Primer.

HALT Operational Limit: The stress level prior to where a product does not operate properly, but will return to correct operation if the stress level is reduced. Improper operation can be an out of specification condition. HALT is performed to determine the Operational Limits for low temperature, high temperature, vibration, and combined temperature and vibration.

HALT Destruct Limit: The stress level at which the unit becomes inoperable and will not return to correct operation if the stress level is reduced. HALT Destruct Limits are determined for low temperature, high temperature, vibration, and combined temperature and vibration.

Some Facts and Misconceptions about Highly Accelerated Life Testing