New Methodologies for Evaluating Microelectronics Subject to Board-level Vibrations

Abstract

In this paper, a methodology is developed to test the durability of microelectronics subjected to vibrations at the board level. This type of analysis plays a critical role in assessing the overall reliability of the printed circuit assemblies used in harsh environmental conditions such as automotive applications which include vibration and temperature cycling. Such requirements can arise due to the general trend of mounting power electronics out of the relatively benign and protected traditional passenger compartment to the much harsher under the hood environment of engines and transmissions. Harsh environmental conditions can cause not only mechanical failures in device housings such as electronic control units used in the automotive applications but also create electrical failures in the printed circuit assemblies mounted inside the housing due to bending and printed circuit board deformation. These electrical failures may result from various failure modes such as circuit board cracking, board trace cracking, solder interconnection cracking, pad cratering, via failures, and component cracks. As a result, an initiative is being undertaken in updating the EIA/JEDEC JESD22-B103B standard which currently defines some vibration test parameters on the component level without specifying an appropriate test vehicle. In order to provide more meaningful test results data, the overall goal will be to place the emphasis on the board level by developing corresponding test methods which may include various levels of sinusoidal and random vibrations along with possible temperature cycling tests for automotive as well as other applications. Some preliminary testing has been carried out by different laboratories of the JESD22 working group participants. However due to varying capabilities of each testing laboratory the main challenge is to provide consistent results interpretation and comparison through simulation analysis which will be presented in this study.