Thermal stress analysis of conductive adhesive joints

The effect of die geometry and the bond layer thickness on the stress distribution in a conductive die attach assembly was analysed using finite element models. Models used for the analysis were those of a freely deforming assembly i.e. not restrained by packaging. It was found that the thinner the bondline, the greater the stress in the joint. The level of stress in the joint remains approximately constant for die sizes greater than (4x4)" and a sawn through die was found to be much better for stress management.