Laser drilling and Plasma Cleaning Process for Blind Via Through Mold Interconnect

Abstract

Through Mold Interconnects (TMI) process is currently mainly used in advanced packaging processes. In this research, laser drilling technology is used to fabricate TMI on epoxy mold compound materials with different filling sizes and plasma is used to clean the epoxy residues after laser drilling. The micro-second ultraviolet (UV) laser is used for laser drilling. A punch mode is used to drill blind vias, and different laser beam sizes, fluence and number of pulses were adjusted to achieve blind vias with an aspect ratio of 1:1. The plasma cleaning using CF4/O2 gas chemistry after laser drilling is to use to clean the residual material on the surface of the blind vias.