Highly Accelerated Life Testing, or HALT, is a technique used in the industry to speed up the design and test phases of product development, as well as limit the number of field failures and thus reduce warranty costs incurred by the manufacturer.
HALT Testing can be a competitive advantage for companies when performed correctly and at the right time.
The best time to begin HALT testing during the product development process is when prototypes first become available. HALT is designed to expose product flaws and weaknesses, therefore, a successful test will produce areas for product improvement. A lot of designers and manufacturers tend to wait until the product design is mature. At that time, further process improvements or design changes become too costly or timely. Ideally, HALT should be performed while the product is still fluid and moderate changes don’t become setbacks. This allows product design to move much more rapidly and efficiently, saving the company time and money. HALT testing can also eliminate the need for further verification if the product has proven reliable at the much more extreme conditions exposed to in HALT.
Delserro Engineering Solutions,
Inc. (DES) has the knowledge and experience to provide HALT testing services for
your product. We offer both standard and
customized test solutions depending on your testing needs. For more information on HASS, HALT
or other testing
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This article is a general outline on how to implement a HASS program after a successful HALT has been performed and corrective actions have been completed for any weaknesses found during HALT. For more information about HASS, please read our blog, What is HASS Testing? For more information about HALT, please read our blogs
HASS is an acronym for Highly Accelerated Stress Screening. HASS is performed during manufacturing on production products or components. It is a screening method used to expose manufacturing defects that would cause a failure in normal field environments including shipping, storage and use.
The HAST acronym stands for Highly Accelerated Temperature/Humidity Stress Test and is sometimes shortened to Highly Accelerated Stress Testing. HAST makes use of accelerated temperature and humidity conditions to precipitate failures which could be caused by long term exposure to humid environments.
HAST has been developed to replace Temperature-Humidity-Bias (THB) testing which has typical conditions of 85 ⁰C and 85 % RH along with a bias voltage applied to the sample. A typical THB test time would be 1000 hours. HAST uses increased test temperatures of 110 to 130 ⁰C which decreases the test time to as low as 96 hours compared to a THB test. Thus, by choosing HAST over THB for an accelerated reliability test, testing can be completed in days, not weeks.
Continue reading A Primer for HAST: Highly Accelerated Stress Testing →
Rapid Highly Accelerated Life Testing or Rapid HALT is a reliability test method that is used to expose product weaknesses. A Rapid HALT procedure is a modification of a Classical HALT procedure. For more information about Classical HALT procedures, refer to the following blog articles:
A Rapid HALT is an abbreviated HALT, typically one day of tests, making it a great cost-effective solution for those seeking faster qualitative results. Exposing a product to a Rapid HALT early in the design process can help reduce product development time and cost by enabling manufacturers to identify flaws or areas of improvement before it’s too late.
Rapid HALT’s are a good tool for assessing the reliability of different suppliers of components but can also be used to assess the reliability of less complicated products. For example, DES has performed Rapid HALT’s to evaluate the reliability of different suppliers of power supplies, cooling fans, and LED’s. DES has also performed a Rapid HALT to study different fastening methods in order to determine which was more robust.
Continue reading Rapid HALT – A Cost Effective Alternative to HALT →
A customer approached DES looking to find an accelerated test solution for an AC powered cooling fan used in one of their products. The product had been established in the marketplace and the company was now looking for ways to reduce cost by looking at different cooling fan suppliers. Most fans, however, have a mean life rated for over 20,000 hours, so a typical accelerated life test would require a significant amount of time and money.
Continue reading Cooling Fan Reliability Testing Case Study →
Product failures in HALT testing are defined as either the cessation of any functions or an out-of-specification condition for any performance characteristic. When a failure occurs, it is documented in DES’s HALT log. The exact time and test condition when each failure occurred is noted.
If the product fails to operate, the temperature or vibration will be changed toward ambient room conditions followed by a short dwell period to see if the product recovers. If the product is non-operational after dwelling at ambient conditions, trouble shooting will take place to find the failed component. The failed component will then be removed, repaired or replaced with a new component (as is practical) in an effort to expand the test stresses.
Continue reading What Kind Of Failures Occur During HALT? →
HALT procedures vary from lab to lab but are typically performed similar to DES’s procedure which is summarized below. DES’s HALT procedure is divided into 5 Stages: Stage 1 – Temperature Step Stresses, Stage 2 – Temperature Ramps, Stage 3 – Vibration Step Stresses, Stage 4 – Combined Temperature &Vibration Stresses, and Stage 5 – Temperature Destruct Limits.
Stage 1 is used to determine the HALT Operational Limits for temperature. The goal is not to cause destruction in Stage 1, but sometimes the operational and destruct limits occur simultaneously. The HALT Destruct Limits for temperature and vibration are typically found in Stages 3 to 5.
Temperature Step Stresses – Stage 1 (Figure 1)
Continue reading What Is A Typical HALT Procedure? →