The Halt/hass Application In Photoelectric Communication Products Research And Development Validation

This thesis’s objective is to study the feasibility of application of HALT (high accelerate life testing) test on reliability qualification of optical communication product. Target of the feasibility result is to reduce new product reliability qualification time and save qualification sample, finally reduce qualification cost and capture marketing share. It is the corporation management common expectation.In this thesis, author analyzed global HALT development status; introduced the basic theory of HALT and described the HALT test condition and the hardware requirements. According to the reliability requirements and status quo of the company,6 questions need to be addressed:1. Whether the HALT can completely or partially take place of the traditional reliability qualification.2. How to convert traditional reliability testing to HALT.3. How to apply the HALT on pre-qualification to detect the new product design bug, reduce the failure during qualification.4. How to use HASS to replace the traditional burn in to improve the infant mortality segregation.5. How to define a reasonable company spec and HALT procedure to proliferate to future new product introduction projects.6. How to perform fast failure analysis and define solid corrective action plan to fix the excursions.The result of multiple experiments demonstrated that:1. HALT is feasible to apply on optical commutation products, and 96hours HALT can be set as the qualification criteria for product in mature platform or technology.2. HALT is able to be used in the pre-qualification and design validation to check the design margin, verify the extreme user condition, and quickly expose the design bug.3. HALT has more advantages than the traditional reliability test item as shorter test time, smaller sample size, lower human and hardware cost, etc.4. The failure in HALT required for detail failure analysis to dig out the root cause and define corrective action to improve the product reliability and quality.5. HASS can replace the traditional burn in to screen out the infant mortality effectively, thus to avoid potential un-reliable product escaping to customer.6. HALT/HASS cannot calculate the MTBF or FIT. If data is required, the HTOL (high temperature operation life test) needs to be performed to calculate MTBF/FIT data.With the study result, Corporate has revised new product introduce reliability qualification procedure, which included HALT/HASS in limitation verification, design pre-qualification, reliability qualification and infant mortality segregation, and base on that new flow chart was made and will apply to new products. As long as the HALT pass/fail criteria is base on existing mature productsAnd known failure mechanism, this criterion cannot be applied on brand new platform or technology. HALT is suitable for design improvement of existing product, new product from mature platform, ongoing reliability monitoring. For the brand new design, HALT can help to find the design margin, and quickly expose the design bug. After design is improved, traditional reliability qualification can be applied to qualify the product. The HALT criteria for new product can only be determined after collecting enough mass production data which shows the product is stable and know the HALT duration for the new platform in order to satisfy the application requirement with the most optimized solution.HALT test has more advantages than traditional reliability test. For those customers who don’t need the MTBF/FIT data, and accept to use HALT as major qualification test item, the HALT will greatly enhance the efficiency of new product qualification process. However, in the optical communication industry, there are some additional tests required as fiber/cable integrity, electric optical interface durability, MSA, and FICOS compliance, etc., but if they can be combined with HALT, it will reduce test time obviously. For those products cannot use HALT as qualification gating item, HALT test still could be able to verify the design reliability during prototype phase, verify the condition limit, improve the reliability design margin, and finally improve the product quality to help designer avoid design bug so as to pass the qualification with less failure.Although the HALT has many advantages than others reliability test, there are still some issues need to be fixed, for example HALT will induce some un-expected failure mode which is hard to dig out the root cause, HALT cannot calculated MTBF FIT, and there is no any industry standard and difficult to define it. Author will take these issues into the study in future work and try best to come up with the answer.