반도체디스플레이기술학회지 (Journal of the Semiconductor & Display Technology)
- 제5권3호
- /
- Pages.5-10
- /
- 2006
- /
- 1738-2270(pISSN)
레이저를 이용한 웨이퍼 다이싱 특성
Characteristics of Laser Wafer Dicing
- Lee, Young-Hyun (Department of Electronic Engineering, Kangnam University) ;
- Choi, Kyung-Jin (Department of Electronic Engineering, Kangnam University) ;
- Yoo, Seung-Ryeol (School of Mechanical Engineering, Korea University of Technology and Education)
- 발행 : 2006.09.30
초록
This paper investigates cutting qualities after laser dicing and predicts the problems that can be generated by laser dicing. And through 3 point bending test, die strength is measured and the die strength after laser dicing is compared with the die strength after mechanical sawing. Laser dicing is chiefly considered as an alternative to overcome the defects of mechanical sawing such as chipping on the surface and crack on the back side. Laser micromachining is based on the thermal ablation and evaporation mechanism. As a result of laser dicing experiments, debris on the surface of wafer is observed. To eliminate the debris and protect the surface, an experiment is done using a water soluble coating material and ultrasonic. The consequence is that most of debris is removed. But there are some residues around the cutting line. Unlike mechanical sawing, chipping on the surface and crack on the back side is not observed. The cross section of cutting line by laser dicing is rough as compared with that by mechanical sawing. But micro crack can not be seen. Micro crack reduces die strength. To measure this, 3 point bending test is done. The die strength after laser dicing decreases to a half of the die strength after mechanical sawing. This means that die cracking during package assembly can occur.