Shearing strength of temporary bonding adhesive applied to different substrates

Abstract

with the development of semiconductor industry, temporary bonding materials become more and more widely used in various process applications, such as wafer thinning, ultra-thin device preparation, thin wafers handing and so on. Different process applications may need different requirements for the application performance of materials. For example, the temporary bonding adhesive may be bonded with different surface of device wafer like gold layer, silicon and glass, which may also show different adhesive property. What needs to be emphasized is that the bonding wafers are easily peeling off with lower bonding strength, which may lead to low yield. And the bonding wafers with higher bonding strength may difficult to be released and cleaned. Therefore, the bonding strength of temporary bonding adhesive applied to different substrates should be considered as a crucial factor for application. There are several methods to release the wafers when de-bonding such as thermal sliding, mechanical peeling, solvent release and laser irradiation. In this paper, UV laser release systems with release layer and adhesive layer was focused. We studied several adhesive materials (both Adhesive B and Adhesive C were modified by Adhesive A) which showed different shearing strength with different substrates such as gold, silicon and glass. The shearing strength was studied by thrust force shearing force tester (DAGE 4000, USA). The chip with the size of 1mm ×1 mm was bonded on the substrates by the same pressure. The study showed that Adhesive C has higher shearing strength on different substrate. In addition, thermal stability was investigated by thermal gravimetric analyzer (TGA/DSC 2, Germany).