Laser DAF Cut Augmentation for Thin Wafers

Abstract

The semiconductor industry is becoming more inclined to thinner integrated circuit (IC) packages. Thinner packages with thin wafer or die prefer the die attach film (DAF) technology as the die adhesive material solution. As the wafer goes thinner, it becomes more of a challenge in process development, especially during its assembly preparatory stages. As the dies become smaller and thinner, wafer sawing process should have minimum effect on the mechanical integrity of the silicon so as not to alter its quality. New technologies were developed and introduced in the industry and one of this is the laser die attach film (DAF) cutting. The method was developed together with dies before grinding (DBG) as a cutting medium to address potential processability problems that may occur on the conventional mechanical blade saw. This paper discusses the laser DAF cut development covering the design of experiments (DOE) to understand the different characteristics of laser DAF solution. Validations are made through actual simulation and wafer processing. The paper also covers the interaction of different DAF thicknesses and parameters in order to define the critical characteristics in achieving optimal DAF cutting process responses.