Heat-peelable pressure-sensitive adhesive sheet and method of recovering adherend

Abstract

The invention provides a heat-peelable pressure-sensitive adhesive sheet which, even when applied to a flexible adherend or extremely small adherend, enables the adherend to be efficiently peeled and recovered therefrom without breakage. The heat-peelable pressure-sensitive adhesive sheet includes a substrate, and arranged on one side thereof in the following order, an intermediate layer having a thickness 'A', and a heat-peelable pressure-sensitive adhesive layer having a thickness 'B' and containing heat-expandable microspheres with a largest particle diameter 'C'. The parameters A, B, and C satisfy the following conditions: C (A+B) 60 ([mu]m) and 0.25C B 0.8C, and the heat-peelable pressure-sensitive adhesive layer, when subjected to a heating treatment, shows an adhesive strength of less than 0.1 N / 20 mm after the heating treatment. The heat-peelable pressure-sensitive adhesive layer after the heating treatment preferably has an arithmetic mean surface roughness Ra of 5 [mu]m or smaller and a maximum height of the profile Rmax of 25 [mu]m or smaller. The substrate preferably has a glass transition temperature (Tg) of 60 DEG C or higher and a thickness of 50 [mu]m or smaller.

Description

technical field [0001] The present invention relates to a heat-peelable adhesive sheet and a method of recovering an adherend using the adhesive sheet, and more specifically, to a method for quickly and easily peeling and recovering an adherend by heat treatment. It also relates to a method for efficiently stripping and recovering semiconductor components and electronic components using the stripping recovery method. Background technique [0002] In recent years, with the miniaturization and thinning of semiconductor parts and electronic parts, not only has the handling of these parts become difficult, but also the improvement of productivity has become a big problem. In particular, a method of peeling and recovering small and fragile parts temporarily fixed to an adhesive sheet efficiently and without damage is a big problem. For the handling of small and thin parts, it is very effective to use a thermally peelable adhesive sheet that can be peeled naturally. [0003] Con...

AI Technical Summary

Problems solved by technology

However, when a highly flexible semiconductor chip or a very small part, which is called an ultra-thin chip in recent years and has a thickness of 40 μm or less, is an adherend, there is a problem that due to the adhesion The attached body tends to follow the surface irregularities of the heat-peelable adhesive sheet after heat treatment, so the contact area between the adhesive layer and the adhered body is not sufficiently reduced, and it takes time to peel off or cannot be peeled off, resulting in a significant decrease in productivity

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