Adsorptive temporary fixing sheet and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-11565238-B2
Application number	US-201816603388-A
Country	US
Kind code	B2
Filing date	Jan 22, 2018
Priority date	Apr 5, 2017
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

Provided is an adsorption temporary fixing sheet having a sufficient shear adhesive strength in a direction parallel to its surface, and having a weak adhesive strength in a direction vertical to the surface. Also provided is a method of producing such adsorption temporary fixing sheet. The adsorption temporary fixing sheet includes a foam layer including an open-cell structure, wherein, when a silicon chip vertical adhesive strength of a surface of the foam layer after 20 hours at each of such different temperatures as −40° C., 23° C., or 125° C. is represented by V1 (N/1 cm□), V2 (N/1 cm□), or V3 (N/1 cm□) and when a silicon chip shearing adhesive strength of the surface of the foam layer after 20 hours at each of the different temperatures (−40° C., 23° C., or 125° C.) is represented by H1 (N/1 cm□), H2 (N/1 cm□), or H3 (N/1 cm□), relationships of V1<H1, V2<H2, and V3<H3 are satisfied.

First claim

The invention claimed is:

1. An adsorption temporary fixing sheet, comprising:
a silicone foam layer including an open-cell structure,
wherein the silicone foam layer has an arithmetic average surface roughness Ra of from 1 μm to 10 μm,
wherein, when a silicon chip vertical adhesive strength of a surface of the foam layer after 20 hours at −40° C. is represented by V1 (N/1 cm□), a silicon chip vertical adhesive strength thereof after 20 hours at 23° C. is represented by V2 (N/1 cm□), and a silicon chip vertical adhesive strength thereof after 20 hours at 125° C. is represented by V3 (N/1 cm□), and
a silicon chip shearing adhesive strength of the surface of the foam layer after 20 hours at −40° C. is represented by H1 (N/1 cm□), a silicon chip shearing adhesive strength thereof after 20 hours at 23° C. is represented by H2 (N/1 cm□), and a silicon chip shearing adhesive strength thereof after 20 hours at 125° C. is represented by H3 (N/1 cm□),
relationships of V1<H1, V2<H2, and V3<H3 are satisfied
where the silicon chip vertical adhesive strength is defined as follows: a surface opposite to an evaluation surface of the adsorption temporary fixing sheet is fixed onto a smooth stainless-steel plate with a silicone pressure-sensitive adhesive tape; a 2-kilogram roller is reciprocated once to bond a ground surface of a silicon chip having a thickness of 300 μm, which is obtained by grinding a silicon wafer with a grinder and singulating the silicon wafer into a 1 cm□ with a dicing saw, to the adsorption temporary fixing sheet, and the resultant is aged at each of −40° C., 23° C., and 125° C. for 20 hours, and is left at rest at 23° C. for 2 hours; a mirror surface opposite to the ground surface of the silicon chip is compressed under a state in which a double-sided tape is bonded to a tip of an adapter of 20 mmΦ at a compression rate of 0.01 N/sec in a vertical direction until a load of 0.05 N is applied thereto, followed by peeling of the silicon chip at 10 mm/sec; and a maximum load at a time of the peeling is defined as the silicon chip vertical adhesive strength, and
the silicon chip shearing adhesive strength is a shear adhesive strength measured as follows: the surface opposite to the evaluation surface of the adsorption temporary fixing sheet is fixed onto a smooth stainless-steel plate with a silicone pressure-sensitive adhesive tape; a 2-kilogram roller is reciprocated once to bond a ground surface of a silicon chip having a thickness of 300 μm, which is obtained by grinding a silicon wafer with a grinder and singulating the silicon wafer into a 1 cm□ with a dicing saw, to the adsorption temporary fixing sheet, and the resultant is aged at each of −40° C., 23° C., and 125° C. for 20 hours, and is left at rest at 23° C. for 2 hours; and a side surface of the silicon chip is pressed with a force gauge at a rate of 1 mm/sec, followed by the measurement of the shear adhesive strength.

2. The adsorption temporary fixing sheet according to claim 1 , wherein the V1 is 5 N/1 cm□ or less.

3. The adsorption temporary fixing sheet according to claim 1 , wherein the H1 is 0.5 N/1 cm□ or more.

4. The adsorption temporary fixing sheet according to claim 1 , wherein the V2 is 6.5 N/1 cm□ or less.

5. The adsorption temporary fixing sheet according to claim 1 , wherein the H2 is 0.6 N/1 cm□ or more.

6. The adsorption temporary fixing sheet according to claim 1 , wherein the V3 is 10 N/1 cm□ or less.

7. The adsorption temporary fixing sheet according to claim 1 , wherein the H3 is 0.7 N/1 cm□ or more.

8. The adsorption temporary fixing sheet according to claim 1 , wherein the silicone foam layer has an apparent density of from 0.15 g/cm 3 to 0.90 g/cm 3 .

Assignees

• Nitto Denko Corp

Inventors

• Iseki Toru
• Doi Kohei
• Kanada Mitsuhiro
• Kato Kazumichi
• Tokuyama Hideyuki

Classifications

• H10P72/7402

  Wafer tapes, e.g. grinding or dicing support tapes · CPC title

• H01L21/6836

  Electricity · mapped topic

• B01J20/3007

  Moulding, shaping or extruding · CPC title

• B01J20/28033

  Membrane, sheet, cloth, pad, lamellar or mat · CPC title

• C09J2483/00

  Presence of polysiloxane · CPC title