FAQ 10: Should I burn-in GaAs ICs?


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The answer to this question depends on what is being sought in performing the burn-in. There are two primary reasons to perform burn-in. The most common reason is because it is a requirement to meet certain military ratings. In this case, the decision is simple, you either meet the requirement, or you don't. The second reason for performing a burn-in is to screen the devices. In this case, it's usually an economic decision. If it costs more to experience a failure than it does to perform the burn-in, then it makes sense to implement a screen. The problem comes in measuring the costs. Everyone knows that failures are expensive, not only in labor and material costs, but in damage to a company's reputation. But there are a lot of hidden costs with burn-in too. The ones typically left out are the costs of damaging and removing good devices incorrectly, and in measuring the effectiveness of the screen for removing all the devices that are actually bad.

Often, perfectly good devices are erroneously mistaken as "caught" defective devices, and the truly anomalous devices escape the screen. In the TriQuint experience of screening over 5,000 devices in an engineering mode and even more devices in a production mode, it has been proven that burn-in is not economical for GaAs devices from a supplier standpoint. The instance of screening anomalous devices in a 150°C 168 hour burn-in is at a practically undetectable level below 0.1%. The resulting damage to the devices is roughly an order of magnitude higher than that. This "double whammy" of extremely high costs and degradation of device quality indicates burn-in is an unwise screen to consider. Additionally, while performing these burn-ins, electrical testing screens or "guardbands" were found to be much more effective than burn-in screens.