Dynex's Power Module Test Engineer, Harley Neal will be presenting his paper, 'Experimental Investigation of Advanced Cu-Mo-Cu Clips for Enhanced Power Cycling Reliability of Die-top Interconnections' during one of the poster session at PCIM Europe in Nuremberg, 9 - 11 May 2023. In addition Dynex will be exhibiting again this year and hope to welcome you to our stand 9 - 311.
Introduction
The interconnection reliability of power semiconductor modules is a crucial factor in applications such as traction inverters where devices can experience harsh cycling conditions. It is believed that the traditional die-top aluminium wire bonds are one of the weak points.
Abstract
We report on the experimental test results of the power cycling lifetime comparison between traditional copper-based clips and the new Cu-Mo-Cu (CMC) clips. By using an in-house power cycling tester, the performance of both types of clips are evaluated comparatively. It is shown that the CMC clips can extend the power cycling lifetime by more than 3 times, due to the thermal expansion coefficient of the material being closer to that of the semiconductor dies. The sample preparation, test algorithm, electrical performance and failure analysis were presented.
A power cycling lifetime comparison between the new CMC clip and the traditional copper clip has been carried out over this study. It is shown that by using the new CMC clip, the power cycling lifetime can be extended by close to 3 times at a minimum with one sample exceeding the best standard copper sample by nearly 6 times. By the X-ray and SAM image comparison before and after the power cycling test, it can be seen that the CMC clips induce lower stress not only to the die top, but also to the die bottom solder layer showing the benefits of reducing thermal expansion coefficients differences. The Cu-Mo-Cu clips do have more variance when compared to the copper clips however even the worst preforming Cu-Mo-Cu clip still preformed slightly better than the best copper clip. Further work could be done on the design of the Cu-Mo-Cu clips in order to improve the performance consistency but current test show promising results.
The Power Point Presentation of the research paper will be available after the presentation at PCIM.
To receive a copy of Harley Neal's research paper and for an opportunity to discuss in detail the 'Experimental Investigation of Advanced Cu-Mo-Cu Clips for Enhanced Power Cycling Reliability of Die-top Interconnections', sign up to attend the PCIM conference or contact us to arrange a meeting with our team at powersolutions@dynexsemi.com