US-12617981-B2 - Pressure-sensitive adhesive sheet for semiconductor processing

Abstract

Provided is a pressure-sensitive adhesive sheet for semiconductor processing having excellent solvent resistance. The pressure-sensitive adhesive sheet for semiconductor processing includes a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition containing a base polymer, and a base material. The pressure-sensitive adhesive composition has a swelling degree S A of 2.1 times or less when immersed in an N,N-dimethylpropionamide solution at 23° C. for 1 hour.

Inventors

• Jun Akiyama
• Yuji Kato
• Taiki UENO

Assignees

• NITTO DENKO CORPORATION

Dates

Publication Date

20260505

Application Date

20230725

Priority Date

20220726

Claims (7)

1. 1 . A pressure-sensitive adhesive sheet for semiconductor processing, comprising: a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition containing a base polymer; and a base material, wherein the pressure-sensitive adhesive composition has a swelling degree S A of 2.1 times or less when immersed in an N,N-dimethylpropionamide solution at 23° C. for 1 hour, wherein the pressure-sensitive adhesive composition is a UV-curable pressure-sensitive adhesive, and wherein a content ratio of a cross-linking agent is in a range from 0.01 part by weight to 0.75 part by weight with respect to 100 parts by weight of the base polymer.
2. 2 . The pressure-sensitive adhesive sheet for semiconductor processing according to claim 1 , wherein a content ratio of an ester of one of acrylic acid or methacrylic acid having an alkyl group having 8 or more carbon atoms in all monomer components for forming the base polymer is 50 wt % or more.
3. 3 . The pressure-sensitive adhesive sheet for semiconductor processing according to claim 1 , wherein the base polymer is a polymer having a carbon-carbon double bond introduced thereinto.
4. 4 . The pressure-sensitive adhesive sheet for semiconductor processing according to claim 1 , wherein the base material contains one of a polyester-based resin or a polyolefin-based resin.
5. 5 . The pressure-sensitive adhesive sheet for semiconductor processing according to claim 1 , wherein the pressure-sensitive adhesive composition further contains a phosphoric acid ester-based surfactant.
6. 6 . The pressure-sensitive adhesive sheet for semiconductor processing according to claim 5 , wherein a content of the phosphoric acid ester-based surfactant is 0.03 part by weight or more with respect to 100 parts by weight of the base polymer.
7. 7 . The pressure-sensitive adhesive sheet for semiconductor processing according to claim 1 , wherein the pressure-sensitive adhesive sheet for semiconductor processing is used in a semiconductor processing process including a solvent washing step.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 U.S.C. Section 119 to Japanese Patent Application No. 2022-119112 filed on Jul. 26, 2022, which is herein incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present disclosure relates to a pressure-sensitive adhesive sheet for semiconductor processing. 2. Description of the Related Art A semiconductor wafer is used for various usages, such as a personal computer, a smartphone, and an automobile. In a processing process for the semiconductor wafer, a pressure-sensitive adhesive tape is used for protecting a surface thereof at the time of processing. In recent years, miniaturization and high functionalization of a large-scale integration (LSI) have been proceeding, and integration of integrated circuits (IC) has been performed not only in a two-dimensional manner but also in a three-dimensional manner. In any of those technologies, a wafer is thinly ground. The thinly ground wafer is brittle, and hence temporary bonding of the wafer is performed using an adhesive for protection of the wafer at the time of conveyance. The adhesive to be used for the temporary bonding is no longer needed after the conveyance to the next step, and hence is removed by, for example, solvent washing. However, performance of the pressure-sensitive adhesive tape used for protection of a semiconductor is reduced owing to the removal step with a solvent, and hence the wafer may not be sufficiently protected. In each of WO2018/083987A1 and Japanese Patent No. 5607847, there is a disclosure of a pressure-sensitive adhesive tape for semiconductor processing having excellent solvent resistance. However, a wafer ground to a thinner shape (e.g., about 50 μm) may not be sufficiently protected with such pressure-sensitive adhesive tape. SUMMARY OF THE INVENTION The present disclosure has been made to solve the above-mentioned problems of the related art, and an object of the present disclosure is to provide a pressure-sensitive adhesive sheet for semiconductor processing having excellent solvent resistance. 1. In a first aspect according to at least one embodiment of the present disclosure, there is provided a pressure-sensitive adhesive sheet for semiconductor processing, including a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition containing a base polymer, and a base material. The pressure-sensitive adhesive composition has a swelling degree SA of 2.1 times or less when immersed in an N,N-dimethylpropionamide solution at 23° C. for 1 hour.2. In the pressure-sensitive adhesive sheet for semiconductor processing according to the above-mentioned first aspect, a content ratio of an ester of one of acrylic acid or methacrylic acid having an alkyl group having 8 or more carbon atoms in all monomer components for forming the base polymer may be 50 wt % or more.3. In the pressure-sensitive adhesive sheet for semiconductor processing according to the above-mentioned first or second aspect, the base polymer may be a polymer having a carbon-carbon double bond introduced thereinto.4. In the pressure-sensitive adhesive sheet for semiconductor processing according to any one of the above-mentioned first to third aspects, the base material may contain one of a polyester-based resin or a polyolefin-based resin.5. In the pressure-sensitive adhesive sheet for semiconductor processing according to any one of the above-mentioned first to fourth aspects, the pressure-sensitive adhesive composition may further contain a phosphoric acid ester-based surfactant.6. In the pressure-sensitive adhesive sheet for semiconductor processing according to the above-mentioned fifth aspect, a content of the phosphoric acid ester-based surfactant may be 0.03 part by weight or more with respect to 100 parts by weight of the base polymer.7. The pressure-sensitive adhesive sheet for semiconductor processing according to any one of the above-mentioned first to sixth aspects may be used in a semiconductor processing process including a solvent washing step. BRIEF DESCRIPTION OF THE DRAWING The FIGURE is a schematic sectional view of a pressure-sensitive adhesive sheet for semiconductor processing according to at least one embodiment of the present disclosure. DESCRIPTION OF THE EMBODIMENTS A. Overall Configuration of Pressure-Sensitive Adhesive Sheet for Semiconductor Processing The FIGURE is a schematic sectional view of a pressure-sensitive adhesive sheet for semiconductor processing according to at least one embodiment of the present disclosure. In the illustrated example, a pressure-sensitive adhesive sheet 100 for semiconductor processing includes a base material 10 and a pressure-sensitive adhesive layer 20 arranged on one surface of the base material. The pressure-sensitive adhesive sheet for semiconductor processing may include any appropriate other layer (not shown). For example, any appropriate layer (e.g., an intermediate