Here is the abstract you requested from the HiTEC_2012 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Thermal Stress Reliability Study on Substrates for High Temperature, Silicon Carbide Power Electronic Modules|
|Keywords: Extreme Environment, Power Electronics Substrates, Reliability|
|The goal of this study is to investigate packaging techniques for extreme environment (i.e., -50 degC to 250 degC) power electronics. Areas of interest include substrate materials and baseplate/heat spreader materials. Multiple substrate technologies are evaluated, including direct bond copper (DBC), direct bond aluminum (DBA), and active metal braze (AMB) substrates. When possible, varying thicknesses of ceramic and metal layers are included to determine if that parameter affects reliability. Within each material and thickness sample lot, different layout geometries and overall sizes are tested, again to determine if that specific parameter has an impact on reliability. In a power electronics application, these substrates are required to be attached to a baseplate/heat spreader for mechanical support and to improve thermal performance. Therefore, a smaller sample size of substrate materials was also tested for reliability when soldered to a metal matrix composite (MMC) baseplate. To evaluate the reliability of said materials, several inspection methods are utilized, comprising of scanning acoustic microscopy (SAM), optical microscopy, florescent penetrant inspection, cross section analysis, and optical profilometery. This paper will present the results of thermal stress studies on each of the materials under varying conditions. The conditions include: thermal dwell conditions of 250 degC in excess of 1000 hours, thermal cycling from -25 degC to 225 degC up to 1000 cycles, and thermal cycling from -50 degC to 250 degC up to 1000 cycles. Current results will be presented and discussed, followed by plans for future reliability studies on an integrated module scale.|
|Robert Shaw, Project Engineer