Seth Homer: As we've discussed, there are three attach levels of peak concern in the IGBT stack up. At Indium Corporation, we're redefining how we use solder at the die-attach, substrate, and baseplate to heat-sink levels, so we can achieve a more reliable IGBT that can perform increasingly higher standards. If you missed the first two videos in this series, be sure to check them out at indiumstg.wpenginepowered.com/IGBT.
今天，我们重点讨论堆叠的基底层。基板上可能连接有多个芯片，因此焊接极为重要。为了保持性能和可靠性，这一层需要克服自身的特殊挑战。与底部终端元件面临的挑战类似，基板也容易出现空洞。为确保达到最佳效果，许多装配商选择使用无助焊剂真空回流焊解决方案和还原气氛，以实现最低的空洞率；然而，即使在这种情况下，焊接质量也会对空洞率产生不利影响。
合金纯度和百分比也非常重要。在无法使用无助熔剂真空回流焊的情况下，可能需要使用助熔剂。这很棘手，因为挥发物也会导致空洞。正因为如此，高度工程化的助焊剂涂层才是最好的方法。除了空泡外，键合线共面性也很关键。由于元件较大，液态焊料可能无法在回流过程中均匀地支撑元件的重量。这会导致键合线不均匀，从而增加循环过程中的应力区域。
So, how can you achieve superior performance at the DBC substrate to baseplate level? The answer is to add a reinforcement matrix to the solder to act as a stand off. This creates constancy in the bondline thickness and adds strength laterally, resulting in enhanced thermal cycling survivability. Indium Corporation’s InFORMS® are reinforced solder preforms that are specifically designed to preserve the bondline co-planarity and add strength to the joint, increasing reliability to the process.
For more information on this subject, download our recent technical article, Novel technique to reduce Substrate Tilt and Improve Bondline Control or visit indiumstg.wpenginepowered.com/informs. And, as always, feel free to contact me directly [email protected]. Thank you.
节省保存
