Improving Reliability Through HALT and HASS Testing

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Summary

HALT & HASS technology uses a combination of accelerated stresses to expose product flaws early in the design and manufacturing stages (often at board level), improving product reliability and customer confidence. HALT & HASS will be defined and compared to traditional compliance testing to a pre-written test standard. We will discuss why companies are using HALT & HASS and finding success. The basic steps of HALT & HASS testing will be covered along with some examples of types of defects that can be precipitated and detected during HALT testing.

HALT & HASS is used to uncover many of the weak links inherent to the design and fabrication process of a new product as well as during the production phase to find manufacturing defects that could cause product failures in the field. The types of HALT & HASS chambers available in the market along with the equipment capabilities will be reviewed along with how they used for detection of flaws in design, making the product more rugged and reliable. These capabilities are key to precipitation and detection of product defects.

Conclusions

Every weakness found in HALT offers an opportunity for improvement. Large margins translate into high reliability and that can result in improved profit margins. Today, HALT is required on an ever-increasing number of commercial and military programs. Many of the leading companies are using HALT and HASS techniques successfully; however, most of the leaders are being quiet about it because of the phenomenal improvements in reliability and vast cost savings attained. The basic philosophy is, "find the weak spots however we can and then make them more robust."

Correct application of the techniques is essential to success and there are many incorrect sources of information on the techniques today. Consistently, completely and correctly used HALT and HASS always works to the benefit of the manufacturer and to the benefit of the end user. A typical return on investment for the techniques was 1,000:1 some 20 years ago and, with the improved techniques and much better equipment available today, we can do much better. This is why the real leaders do not publish.