펄스 Nd:YAG 레이저를 이용한 μ-BGA 기판의 개별칩 분리 연구

초록

In this paper, we have studied minimization of the burr which occurred after μ-BGA(ball grid array) singulation process, singulation of the multilayer with a pulsed Nd:YAG laser and observation of μ-BGA singulation characteristics. The thermal energy of a pulsed Nd:YAG(266, 532 nm) laser is used to cut the metal layer which doesn't well absorb laser beam. Especially, the photoresist and N2 blowing is effective to minimize of the surface demage and burr. In this experiment, the N2 blowing reduces a laser energy loss by debris and suppress a surface oxidation. The SEM(scanning electron microscopes) and non-contact 3D inspector are used to measure cutting line-width and surface demage. The μ-BGA singulation threshold energy is 75.0 J/cm2 at 30 ㎛/s scan speed.