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

• US 20100028588A1
• Filed: 10/18/2007
• Published: 02/04/2010
• Est. Priority Date: 11/04/2006
• Status: Abandoned Application

• Current Assignee: Nitto Denko Corporation
• Original Assignee: Nitto Denko Corporation
• Inventors: Kiuchi, Kazuyuki
• Application Number:
  US12/311,974
• Publication Number:
  US 20100028588A1
• Time in Patent Office: Days
• US Class Current: 428/42.300
• CPC Class Codes: C08K 9/10 Encapsulated ingredients
• CPC Class Codes: C09J 2301/408 additives as essential feature of the adhesive layer
• CPC Class Codes: C09J 2301/412 presence of microspheres
• CPC Class Codes: C09J 2301/502 process for debonding adherents
• CPC Class Codes: C09J 5/06 involving heating of the applied adhesive
• CPC Class Codes: C09J 7/29 Laminated material metallised plastics C09J7/22
• CPC Class Codes: H01L 21/6836 Wafer tapes, e.g. grinding or dicing support tapes adhesive tapes in general C09J7/20
• CPC Class Codes: H01L 2221/68327 used during dicing or grinding
• CPC Class Codes: H01L 2221/68331 of passive members, e.g. die mounting substrate
• CPC Class Codes: H01L 2924/19041 being a capacitor
• CPC Class Codes: Y10T 428/1495 Adhesive is on removable layer
• CPC Class Codes: Y10T 428/24372 Particulate matter
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]

Abstract

To provide 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 (μm) 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 μm or smaller and a maximum height of the profile Rmax of 25 μm or smaller. The substrate preferably has a glass transition temperature (Tg) of 60° C. or higher and a thickness of 50 μm or smaller.

Claims

1. A heat-peelable pressure-sensitive adhesive sheet comprising 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”

, wherein the parameters. A, B, and C satisfy the following conditions;

C≦

(A+B)≦

60 (μ

m) and 0.25C≦

B≦

0.8C, and wherein 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.

2. The heat-peelable pressure-sensitive adhesive sheet of claim 1, wherein the heat-peelable pressure-sensitive adhesive layer after the heating treatment has an arithmetic mean surface roughness Ra of 5 μ

m or smaller.

3. The heat-peelable pressure-sensitive adhesive sheet of claim 1, wherein the heat-peelable pressure-sensitive adhesive layer after the heating treatment has a maximum height of the profile Rmax of 25 μ

m or smaller.

4. The heat-peelable pressure-sensitive adhesive sheet of claim 1, wherein the substrate has a glass transition temperature (Tg) of 60°

C. or higher and a thickness of 50 μ

m or smaller.

5. The heat-peelable pressure-sensitive adhesive sheet of claim 1, further comprising a continuous separator and being wound as a roll, wherein the substrate, the intermediate layer, and the heat-peelable pressure-sensitive adhesive layer are cut into pieces of a given shape, and the pieces are arrayed on the separator so that the heat-peelable pressure-sensitive adhesive layer is in contact with the separator.

6. A method of recovering an adherend, the adherend being placed on the heat-peelable pressure-sensitive adhesive layer of the heat-peelable pressure-sensitive adhesive sheet of claim 1, the method comprising the steps of applying heat to the heat-peelable pressure-sensitive adhesive layer via the substrate of the sheet or via the adherend to allow the heat-expandable microspheres in the heat-peelable pressure-sensitive adhesive layer to expand;

and subsequently peeling and recovering the adherend from the sheet.

7. The method of recovering an adherend, according to claim 6, wherein the adherend is a semiconductor component or an electronic component.

8. The heat-peelable pressure-sensitive adhesive sheet of claim 2, further comprising a continuous separator and being wound as a roll, wherein the substrate, the intermediate layer, and the heat-peelable pressure-sensitive adhesive layer are cut into pieces of a given shape, and the pieces are arrayed on the separator so that the heat-peelable pressure-sensitive adhesive layer is in contact with the separator.

9. The heat-peelable pressure-sensitive adhesive sheet of claim 3, further comprising a continuous separator and being wound as a roll, wherein the substrate, the intermediate layer, and the heat-peelable pressure-sensitive adhesive layer are cut into pieces of a given shape, and the pieces are arrayed on the separator so that the heat-peelable pressure-sensitive adhesive layer is in contact with the separator.

10. The heat-peelable pressure-sensitive adhesive sheet of claim 4, further comprising a continuous separator and being wound as a roll, wherein the substrate, the intermediate layer, and the heat-peelable pressure-sensitive adhesive layer are cut into pieces of a given shape, and the pieces are arrayed on the separator so that the heat-peelable pressure-sensitive adhesive layer is in contact with the separator.

11. A method of recovering an adherend, the adherend being placed on the heat-peelable pressure-sensitive adhesive layer of the heat-peelable pressure-sensitive adhesive sheet of claim 2, the method comprising the steps of applying heat to the heat-peelable pressure-sensitive adhesive layer via the substrate of the sheet or via the adherend to allow the heat-expandable microspheres in the heat-peelable pressure-sensitive adhesive layer to expand;

and subsequently peeling and recovering the adherend from the sheet.

12. A method of recovering an adherend, the adherend being placed on the heat-peelable pressure-sensitive adhesive layer of the heat-peelable pressure-sensitive adhesive sheet of claim 3, the method comprising the steps of applying heat to the heat-peelable pressure-sensitive adhesive layer via the substrate of the sheet or via the adherend to allow the heat-expandable microspheres in the heat-peelable pressure-sensitive adhesive layer to expand;

and subsequently peeling and recovering the adherend from the sheet.

13. A method of recovering an adherend, the adherend being placed on the heat-peelable pressure-sensitive adhesive layer of the heat-peelable pressure-sensitive adhesive sheet of claim 4, the method comprising the steps of applying heat to the heat-peelable pressure-sensitive adhesive layer via the substrate of the sheet or via the adherend to allow the heat-expandable microspheres in the heat-peelable pressure-sensitive adhesive layer to expand;

and subsequently peeling and recovering the adherend from the sheet.

14. The method of recovering an adherend, according to claim 11, wherein the adherend is a semiconductor component or an electronic component.

15. The method of recovering an adherend, according to claim 12, wherein the adherend is a semiconductor component or an electronic component.

16. The method of recovering an adherend, according to claim 13, wherein the adherend is a semiconductor component or an electronic component.