| abstract |
When a heat-peelable adhesive sheet is used, there has been the case in which the heat-peelable adhesive sheet is wrongly used that is scheduled to be used differently according to a difference among workpieces, a difference among the steps, and the like. For this reason, it has been necessary to clearly check a usable heat-peelable adhesive sheet according to the differences among the workpieces or among the steps, so as not to cause such an error. In addition, when the heat-peelable adhesive sheet is transparent and colorless, it has been difficult to check whether the adhesive sheet has been accurately stuck on the workpiece. A heat-peelable adhesive sheet of which the tackiness agent layer is merely colored has had a possibility of polluting electronic components and giving damage to the electronic components, by the deposition of metal ions originating in the coloring agent onto a surface of the workpiece such as the electronic components. In order to solve these problems, a heat-peelable adhesive sheet is provided which includes a thermally expansive pressure-sensitive adhesive layer that contains thermally expansive microspheres and the coloring agent and that is provided on one side or both sides of the substrate, or a thermally expansive pressure-sensitive adhesive layer that contains thermally expansive microspheres and is provided on one side or both sides of the substrate through a colored intermediate layer, and which has a total light transmittance of 50% or more. |