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EP-4736733-A1 - CLEANING PUTTY AND METHOD FOR CLEANING MOUNTED SEMICONDUCTOR PARTS USING SAME

EP4736733A1EP 4736733 A1EP4736733 A1EP 4736733A1EP-4736733-A1

Abstract

Cleaning putty for cleaning a semiconductor package component is provided. The cleaning putty contains a millable silicone rubber composition as a main component, and has a degree of plasticity of 20 or more and less than 80 when determined in accordance with JIS K 6300-3:2019 / ISO 2007:1991, and adhesive strength with aluminum of 0.3 N or more and 4 N or less. A cleaning method using the cleaning putty includes cleaning a semiconductor package component by pressing the cleaning putty against a printed circuit board to which a silicone-based heat-dissipating material has been applied or attached, and then peeling off the cleaning putty therefrom. Thus, provided are cleaning putty provided with putty properties with which the cleaning putty selectively adheres to a silicone material without adhering to a substrate and a lead to prevent breakage of the component and can enter a minute gap, and a method for cleaning a semiconductor package component using the cleaning putty.

Inventors

  • SUZUMURA, KATSUYUKI

Assignees

  • Fuji Polymer Industries Co., Ltd.

Dates

Publication Date
20260506
Application Date
20241009

Claims (10)

  1. Cleaning putty for cleaning a semiconductor package component, comprising a millable silicone rubber composition as a main component, and having a degree of plasticity of 20 or more and less than 80 when determined in accordance with JIS K 6300-3:2019 / ISO 2007:1991, and adhesive strength with aluminum of 0.3 N or more and 4 N or less.
  2. The cleaning putty according to claim 1, wherein when the cleaning putty is pressed against an aluminum block and is then peeled off therefrom, a trace of interfacial fracture does not remain on an aluminum block side.
  3. The cleaning putty according to claim 1 or 2, wherein the cleaning putty is pressed against a printed circuit board or silicone rubber and is then removed therefrom, and a trace of interfacial fracture does not remain on a printed circuit board side but remains on a silicone rubber side.
  4. The cleaning putty according to any one of claims 1 to 3, wherein a content of the millable silicone rubber is 40 mass% or more and 100 mass% or less with respect to 100 mass% of the cleaning putty.
  5. The cleaning putty according to any one of claims 1 to 4, wherein the cleaning putty further contains organopolysiloxane containing a boric acid compound.
  6. The cleaning putty according to any one of claims 1 to 5, wherein the cleaning putty further contains organopolysiloxane other than the millable silicone rubber.
  7. The cleaning putty according to any one of claims 1 to 6, wherein the millable silicone rubber composition includes uncrosslinked millable silicone rubber.
  8. The cleaning putty according to any one of claims 1 to 7, wherein when a heat-dissipating material composed of a liquid thermally conductive silicone composition is applied to a printed circuit board to give a length of 10 mm, a width of 20 mm, and a thickness of 0.3 mm, followed by the measurement of the mass, and the cleaning putty is pressed against the printed circuit board and is then peeled off therefrom, a removal ratio in a first round is 60 mass%, and a removal ratio in a second round is 85 mass% or more.
  9. The cleaning putty according to any one of claims 1 to 8, wherein the cleaning putty is molded into a tape shape, a sheet shape, a rod shape, or a block shape.
  10. A method for cleaning a semiconductor package component using the cleaning putty according to any one of claims 1 to 9, the method comprising cleaning a semiconductor package component by pressing the cleaning putty against a printed circuit board to which a silicone-based heat-dissipating material has been applied or attached, and then peeling off the cleaning putty therefrom.

Description

Technical Field The present invention relates to cleaning putty, and a method for cleaning a semiconductor package component using the cleaning putty. Background Art In a process of producing a printed circuit board such as a CPU (central processing unit) or a GPU (graphics processing unit) on which semiconductor elements are mounted, minute dust particles are often generated. Also, when thermally conductive grease or thermally conductive putty serving as a heat-dissipating material for an electronic component is mounted on an electronic component, minute dust particles may be generated. If these minute dust particles are not removed, products will be rejected, which leads to a problem of a decrease in the product yield. Also, when being repaired or recoated, the heat-dissipating material needs to be removed, and insufficient removal poses problems of a deterioration of heat dissipation properties and contamination caused by detachment of the heat-dissipating material. Patent Document 1 proposes a silicone-based adhesive having a specific gel fraction and a specific degree of swelling in toluene. Patent Document 2 proposes a silicone-based adhesive with pores or cracks. Patent Document 3 proposes an addition reaction curable type silicone-based adhesive. Prior Art Documents Patent Documents Patent Document 1: Japanese Patent No. 6626125Patent Document 2: JP 2004-123760APatent Document 3: JP 2004-091703A Disclosure of Invention Problem to be Solved by the Invention However, a conventional adhesive even adheres to a substrate and leads arranged thereon, which may lead to breakage of the component. In addition, a minute gap between leads cannot be sufficiently cleaned through wiping using cloth or the like, and needle scraping needs to be conducted, which takes a long time. To solve the aforementioned conventional problems, the present invention provides cleaning putty provided with putty properties with which the cleaning putty selectively adheres to a silicone material without adhering to a substrate and a lead to prevent breakage of the component and can enter a minute gap, and a method for cleaning a semiconductor package component using the cleaning putty. Means for Solving Problem An embodiment of the present invention relates to cleaning putty for cleaning a semiconductor package component, the cleaning putty containing a millable silicone rubber composition as a main component, and having a degree of plasticity of 20 or more and less than 80 when determined in accordance with JIS K 6300-3:2019 / ISO 2007:1991, and adhesive strength with aluminum of 0.3 N or more and 4 N or less. In addition, an embodiment of the present invention relates to a method for cleaning a semiconductor package component using the cleaning putty, the method including cleaning a semiconductor package component by pressing the cleaning putty against a printed circuit board to which a silicone-based heat-dissipating material has been applied or attached, and then peeling off the cleaning putty therefrom. Effects of the Invention With the present invention, a cleaning putty that contains a millable silicone rubber composition as a main component and that has a degree of plasticity of 20 or more and less than 80 when determined in accordance with JIS K 6300-3:2019 / ISO 2007:1991 and adhesive strength with aluminum of 0.3 N or more and 4 N or less is obtained, thus making it possible to provide cleaning putty capable of significantly reducing time and a man-hour required for cleaning by being provided with putty properties with which the cleaning putty selectively adheres to a silicone material without adhering to a substrate and a lead to prevent breakage of the component and can enter a minute gap, and a method for cleaning a semiconductor package component using the cleaning putty. Brief Description of Drawings [FIG. 1] FIG. 1 is a schematic cross-sectional view of a semiconductor package component according to an embodiment of the present invention.[FIG. 2] FIG. 2 is a schematic perspective view of cleaning putty according to an embodiment of the present invention.[FIG. 3] FIG. 3 is a schematic perspective view of cleaning putty according to another embodiment of the present invention. Description of the Invention The present invention is directed to cleaning putty for cleaning a semiconductor package component. The semiconductor package component includes a printed circuit board such as a CPU (central processing unit) or a GPU (graphics processing unit) on which semiconductor elements are mounted. The cleaning putty of the present invention contains millable silicone rubber as a main component. The millable silicone rubber is solid silicone rubber, and is, for example, clayish silicone rubber that contains a linear polymer having a degree of polymerization of 3000 to 10000 as a main component, is formulated with various additives such as silica-based reinforcing filler, a lubricant, and a colorant, and is cured through heating