This prevents stress concentration caused by wedging at thinner sections, which degrades fatigue resistance. Inform eliminates the need for time-consuming steps such as using cut wire bonds around the perimeter of the solder joint to control the collapse during reflow, as well as the high maintenance costs involved. The material addresses the challenge of controlling a solder joint bond-line between the DBC and baseplate by embedding a high-melting metal mesh into a traditional solder preform. During reflow, the solder melts and bonds to both the DBC and baseplate, while the high melting point metal mesh does not. Consequently, the solder joint collapse is limited to the thickness of the mesh, creating a uniform bond-line thickness across the solder joint. Inform can also generate twice the thermal cycling reliability. In a study by Indium and TT Electronics, Inform exhibited superior thermal cycling performance between -55°C and 150°C, surviving 3500 cycles with no delamination in the actual IGBT assemblies. The mesh can be tailored to the desired thickness of any device and spans the entire XY dimensions of the preform.
productronica innovation award 2015: hall A4, booth 214