Influence of die adhesion properties on delamination of stacked chip interconnection encapsulated in plastic package

The chip-on-chip (COC) package in which a controller IC chip is adhered to a power MOSFET chip with a polyimide film is described. In the heat cycle test, the polyimide film showed a good performance but the mold resin used was delaminated from the IC chip surface. From the experimental and the thermal stress simulation, we demonstrate that the resin delamination is prevented by the polyimide film with a small thermal expansion coefficient. Thus we have successfully developed the high reliable COC package promising for automotive application.