ADHESIVE SHEET AND RELEASE SHEET

Abstract

There is provided an adhesive sheet comprising an adhesive base sheet, an adhesive layer, and a release sheet laminated in sequence from the adhesive base sheet. The release sheet comprises a release agent layer and a release base material laminated in sequence from the adhesive layer. A release force between the release sheet and the adhesive layer is decreased by an external stimulus.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and advantages of the present invention will be better understood from the following description, with reference to the accompanying drawings in which:

FIG. 1 is a sectional view of an adhesive sheet in a first embodiment of the present invention;

FIG. 2 is a sectional view of a release sheet in the first embodiment;

FIG. 3 is a view of a laminating apparatus for explaining one embodiment of use of the adhesive sheet; and

FIG. 4 is a sectional view of a release sheet in the second embodiment.

Claims

1. An adhesive sheet comprising: an adhesive base sheet, an adhesive layer, and a release sheet laminated in sequence from said adhesive base sheet,said release sheet comprising a release agent layer and a release base material laminated in sequence from said adhesive layer, said release agent layer decreasing a release force between said release sheet and said adhesive layer in response to an external stimulus.

2. A sheet according to claim 1, wherein said release agent layer comprises a release agent and at least one of an expandable fine particle that expands in response to said external stimulus and a gas generating fine particle that releases gas in response to said external stimulus, said release force being decreased by at least one of expansion of said expandable fine particle and the release of releasing gas by said gas generating fine particle.

3. A sheet according to claim 2, wherein said expandable fine particle comprises a shell and an expandable material encapsulated therein, said expandable material being vaporized or decomposed into gas by heating at or above a predetermined temperature so as to expand said shell outward.

4. A sheet according to claim 2, wherein an average diameter of at least one of said expandable fine particles and gas generating fine particles is not more than three times an average thickness of said release agent layer.

5. A sheet according to claim 2, wherein said release agent layer comprises 5 to 50 parts by weight of at least one of said expandable fine particles and gas generating fine particles with respect to 100 parts by weight of said release agent.

6. A sheet according to claim 2, further comprising a primer layer laminated between said release agent layer and said release base material so as to form a multilayer of said release agent layer and said primer layer, said multilayer comprises at least one of said expandable fine particles or gas generating fine particles.

7. A sheet according to claim 1, wherein an average thickness of said release agent layer is 0.1 to 20 μm.

8. A sheet according to claim 1, wherein said external stimulus is at least one of a heat and an activation energy beam.

9. A release sheet comprising: a release base material and a release agent layer for adhering to an adhesive material, said release agent laminated to said release base material, said release agent layer decreasing a release force between said release sheet and said adhesive material in response to an external stimulus.

10. An adhesive sheet for use with electronic materials, comprising: an adhesive base sheet, an adhesive layer, and a release sheet laminated in sequence from said adhesive base sheet,said release sheet comprising a release agent layer and a release base material laminated in sequence from said adhesive layer, said release agent layer decreasing a release force between said release sheet and said adhesive layer in response to an external stimulus, both said adhesive layer and said release agent layer consisting of a non-silicone compound.

11. A release sheet for use with electronic materials, comprising: a release base material, and a release agent layer for adhering to an adhesive material, said release agent layer laminated to said release base material, said release agent layer decreasing a release force between said release sheet and said adhesive material in response to an external stimulus, said release agent layer consisting of non-silicone compound.

12. A method for bonding an adhesive sheet to an adherend, comprising steps of: preparing said adhesive sheet that has been wound into a roll-like shape, said adhesive sheet comprising a adhesive base sheet, an adhesive layer, and a release sheet laminated in sequence from said adhesive base sheet, said release sheet comprising a release agent layer and a release base material laminated in sequence from said adhesive layer, said release agent layer decreasing a release force between said release sheet and said adhesive layer in response to an external stimulus;feeding the wound adhesive sheet into a form of a sheet;exposing said adhesive sheet fed out into a form of a sheet, to said external stimulus so that said release force is decreased;peeling said release sheet away from said adhesive sheet following decreasing said release force so as to expose said adhesive layer; andbonding the exposed adhesive layer to said adherend.

13. A method according to claim 12, wherein said adhesive sheet fed out into a form of a sheet is delivered to a releasing roll, and said release sheet is peeled away from said adhesive sheet in said releasing roll.