Reliability testing of Ag sinter joints

Ag sintering is a joining technology which is used to enable higher application temperatures and to achieve a longer lifetime and higher reliability. Today this technology is almost solely used for the die attach of power semiconductor dies. In order to determine the lifetime of corresponding assemblies and to display the dependency of the results according to the variation of parameters such as the chip size or the Ag layer thickness, Si dies were mounted on Cu substrates and subjected to passive temperature cycles. The results of these tests confirm that Ag layers in general have a significantly longer lifetime than solder joints. In addition, an insight into the failure mechanisms is given.