IR Laser Debonding for Silicon Based Temporary Carrier Systems Enabling 2.5D and 3D Chiplet Integration Processes

Abstract

The development of temporary bonding solutions for advanced packaging industry allowing mechanical support during backside processing, is driven by the demand for more robust and reliable solutions in this field. Notwithstanding the growing acceptance of UV laser debonding technology, siliconbased carrier systems persist in their status as the preferred option. This paper details the findings of a study on the application of an infrared (IR) laser debonding technique combined with a temporary bonding adhesive on silicon carrier wafers. The aims of this study were twofold: firstly, to evaluate the potential of IR laser debonding, a technique that permits higher processing temperatures, thereby facilitating advancements in adhesives and other polymer-based processes, such as Redistribution Layer (RDL)-first applications; and secondly, to assess the cleanability of residues remaining after IR laser exposure on both the product and silicon carrier wafer debond interfaces. It has been demonstrated that the well-controlled debond mechanism and interface enable the application of various bonding methods, such as fusion or temporary bonding adhesives, by employing similar inorganic IR laser release layers. It is also shown that after IR laser debonding, the inorganic release layer residuals and the applied polymer layer can be removed using standardized cleaning methods, ensuring the technology's suitability for high- volume utilization and easy integration.