Optimization of Epoxy Dispense for Rectangular Die

An epoxy bond is formed by attaching the die to the leadframe with the use of epoxy glue. A drop of epoxy is dispensed on the package and the die placed on top of it. The package needs to be heated at an elevated temperature to cure the epoxy properly. This process uses adhesives such as polyimide, epoxy and silver-filled glass as die attach material to mount the die on the die pad. The mass of epoxy on the die peripheral of the die is known as the Epoxy Coverage area after die bonded, this provide mechanical strength along die edge as shown in Figure 1. Common criteria or requirement for epoxy coverage is 100%. The problems in achieving and controlling the Epoxy Coverage and Inadequate corner coverage can lead to delamination at the corners.