Excimer laser applications in integrated circuit packaging

Abstract

Excimer laser ablation is applied in the deflashing and demarking of IC packages. It is found that mold flash filled in the interface holes of IC leadframe can be removed completely by the laser deflashing in a short period of time. With appropriate selection of laser parameters, deflashing quality and efficiency can be greatly improved. The laser deflashing is more efficient for higher pin count packages. It is a superior alternative in future applications. In laser demarking, ink marks on package surfaces can also be removed completely in a short time. The surface after the processing has good conditions for remarking. The package remarking shows good permanency. The lifetime for good marking is much longer for IC packages after the laser demarking than those after hydrogen flame-off. Laser processing can be used to replace hydrogen flame-off in the ink printing of IC packages for high efficiency and safety.