Putty for cleaning and method for cleaning semiconductor mounting component using same

Abstract

The present invention relates to a cleaning putty for cleaning a semiconductor mounting component, the cleaning putty comprising a millable silicone rubber composition as a main component, having a plasticity of 20 or more and less than 80 according to JIS K 6300-3: 2019, ISO 2007: 1991, and having an adhesive force with aluminum of 0.3 N or more and 4 N or less. The cleaning method using the cleaning putty includes pressing the cleaning putty on a printed substrate coated or adhered with a silicone-based heat dissipation material and peeling and cleaning the semiconductor mounting component. As a result, provided are: a cleaning putty which is imparted with putty characteristics such that the cleaning putty can be selectively adhered to a silicone material without adhering to a substrate or a lead wire, thereby preventing damage to a component, and can be submerged into a fine gap; and a method for cleaning a semiconductor mounting component using the cleaning putty. The cleaning putty is also imparted with a putty characteristic that can be selectively adhered to the silicone material without adhering to the substrate or the lead wire.

Description

TECHNICAL FIELD

[0001] The present application relates to a putty for cleaning and a cleaning method for a semiconductor mounting component using the same. BACKGROUND

[0002] In a manufacturing process of a printed board on which a semiconductor element such as a CPU (central processing unit) or a GPU (graphics processing unit) is mounted, fine dust is often generated. In addition, in a case where a thermally conductive lubricant or a thermally conductive putty, which is a heat dissipation material for an electronic component, is mounted in the electronic component, fine dust is sometimes generated. If the fine dust is not removed, it becomes a defective product, and there is a problem that the product yield is reduced. In addition, the fine dust needs to be removed when the heat dissipation material is repaired or recoated, and if the removal is insufficient, there are problems such as a reduction in heat dissipation or contamination caused by peeling. Patent Document 1 proposes a silicone-based adhesive having a specific gel fraction and a specific degree of swelling with respect to toluene. Patent Document 2 proposes a silicone-based adhesive having a void or a crack. Patent Document 3 proposes an addition reaction-curable silicone-based adhesive. PRIOR ART DOCUMENTS PATENT DOCUMENTS

[0003] Patent Document 1: Japanese Patent No. 6626125 Patent Document 2: Japanese Patent Application Laid-Open No. 2004-123760 Patent Document 3: Japanese Patent Application Laid-Open No. 2004-091703 SUMMARY PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] However, if the conventional adhesive is used, the adhesive adheres to the substrate or a lead wire disposed thereon, and thus the component can be damaged. In addition, fine gaps between the lead wires cannot be sufficiently cleaned by wiping with a cloth or the like, and need to be scraped with a needle, and thus a large amount of time is required.

[0005] The present application has been made to solve the above-described conventional problems, and provides a putty for cleaning and a cleaning method for a semiconductor mounting component using the same, the putty for cleaning being endowed with the following putty characteristics: damage to the component is prevented by selectively adhering to a silicone material without adhering to a substrate or a lead wire, and further can penetrate into fine gaps. MEANS FOR SOLVING THE PROBLEMS

[0006] One embodiment of the present invention relates to a cleaning putty for cleaning semiconductor mounting components, which is mainly composed of a compounded silicone rubber composition, and has a plasticity of 20 or more and less than 80 according to JIS K 6300-3:2019 and ISO 2007:1991, and an adhesion strength to aluminum of 0.3N or more and less than 4N.

[0007] In addition, one embodiment of the present invention relates to a cleaning method for semiconductor mounting components, which uses the above-mentioned cleaning putty to clean semiconductor mounting components. The cleaning putty is pressed onto a printed circuit board coated or attached with an organosilicon heat dissipation material and then peeled off to clean the semiconductor mounting components. Invention Effects

[0008] This invention provides a cleaning putty and a cleaning method for semiconductor mounting components using the cleaning putty. The cleaning putty is mainly composed of a compounded silicone rubber composition, and has a plasticity of 20 or more and less than 80 according to JIS K 6300-3:2019, ISO2007:1991, and an adhesion strength to aluminum of 0.3N or more and less than 4N. Thus, by imparting putty characteristics that allow it to selectively adhere to silicone materials without bonding to the substrate or leads to prevent component damage, and thus penetrate into fine gaps, the time and labor required for cleaning can be significantly reduced. Attached Figure Description

[0009] [ Figure 1 ] Figure 1 This is a schematic cross-sectional view of a semiconductor mounting component according to one embodiment of the present invention. [ Figure 2 ] Figure 2 This is a schematic perspective view of a cleaning putty according to one embodiment of the present invention. [ Figure 3 ] Figure 3 This is a schematic perspective view of a cleaning putty according to another embodiment of the present invention. Detailed Implementation

[0010] This invention relates to a cleaning putty for cleaning semiconductor mounting components. These semiconductor mounting components include printed circuit boards housing semiconductor elements such as CPUs (central processing units) and GPUs (graphics processing units). The cleaning putty of this invention uses a compounded silicone rubber as its main component. Compounded silicone rubber refers to a solid silicone rubber, such as a type of silicone rubber whose main component is a linear polymer with a degree of polymerization of 3000 to 10000, combined with various additives such as silica-based reinforcing fillers, lubricants, and colorants, and cured by heating with a vulcanizing agent in a clay-like state. Using this compounded silicone rubber, excellent workability, plasticity, and adhesion are achieved. In the above, the "main component" preferably contains 40% by mass or more of the above-mentioned compounded silicone rubber relative to 100% by mass of the cleaning putty. The upper limit is 100% by mass. As long as it falls within the above range, it may also include organopolysiloxanes other than the above-mentioned compounded silicone rubber. Furthermore, the compounded silicone rubber may also be an uncrosslinked compounded silicone rubber.

[0011] The putty for cleaning according to JIS K 6300-3:2019, ISO 2007:1991 has a plasticity of 20 or more and less than 80, preferably 20 or more and less than 75, and more preferably 20 or more and less than 70. If the plasticity is within the above range, it is soft, has good conformability, and easily penetrates fine gaps. If the plasticity is less than 20, it is too soft, easily tears, and easily remains between leads; if the plasticity is 80 or more, it hardens and is difficult to penetrate between leads, which is not preferred.

[0012] The adhesive strength (adhesive force) between the cleaning putty of the present invention and aluminum is 0.3N to 4N, preferably 0.4N to 3.8N, and more preferably 0.5N to 3.6N. When the adhesive strength (adhesive force) is within the above range, it selectively adheres to the silicone material without bonding to the substrate or leads, thereby preventing damage to the component. Furthermore, it is less likely to damage the leads or the like.

[0013] Preferably, when the cleaning putty is pressed onto the aluminum block and then peeled off, no interface damage marks remain on the aluminum block side. Furthermore, it is preferable that when the cleaning putty is pressed onto the printed circuit board or silicone rubber and then peeled off, interface damage marks remain on the silicone rubber side, not the printed circuit board side. This allows for efficient cleaning.

[0014] The putty for cleaning preferably further includes an organopolysiloxane containing a boric acid compound. This allows it to selectively bond with silicone materials without adhering to the substrate or leads, resulting in a putty that can prevent component damage and penetrate fine gaps.

[0015] A liquid thermally conductive silicone composition heat dissipation material is applied to a printed circuit board in a manner that is 10 mm long, 20 mm wide, and 0.3 mm thick. The mass is measured, and when the above-mentioned removal putty is pressed and peeled off, the removal rate is preferably 60% by mass for the first time and 85% by mass or more for the second time. Thus, by selectively bonding to the silicone material without adhering to the substrate or leads, a putty that can prevent component damage and penetrate into fine gaps is produced.

[0016] The cleaning putty of the present invention is preferably shaped into strips, sheets, rods, or blocks. This allows for the cleaning of various types of semiconductor mounting components.

[0017] In the cleaning method for semiconductor mounting components of the present invention, the aforementioned cleaning putty is pressed onto a printed circuit board coated or attached with an organosilicon-based heat dissipation material and then peeled off to clean the semiconductor mounting components. This provides the following advantages. (1) By making it difficult to adhere to the hands, preventing damage to components on the substrate, and improving workability to handle large areas, the process becomes easier, and materials that have entered narrow parts can be removed quickly and easily. (2) Due to its good affinity with organosilicon, liquid TIM can be adsorbed simply by pressing. (3) Because it is a soft putty, it can easily remove even gaps smaller than 1mm, such as the gaps between leads. (4) Because it can press a large area, it can remove a large area of ​​electronic components with many bumps and depressions in one go. (5) It can remove the silicone material without bonding it to the substrate material.

[0018] The following description uses accompanying drawings. Figure 1 This is a schematic cross-sectional view of a semiconductor mounting component 1 according to one embodiment of the present invention. The semiconductor mounting component 1 mounts an IC chip 3 on a printed circuit board 2. The printed circuit board 2 and the IC chip 3 are electrically connected by leads 4 and gold wires 5. The IC chip 3 is sealed with a sealing resin 6. Gaps 7a and 7b exist between the printed circuit board 2, the leads 4, and the sealing resin 6, and are cleaned as an example.

[0019] Figure 2 This is a schematic perspective view of a cleaning putty 8 according to one embodiment of the present invention. The cleaning putty 8 is generally strip-shaped, with a thickness of 2 mm at the front end. Figure 3 This is a schematic perspective view of a cleaning putty 9 according to another embodiment of the present invention. The cleaning putty 9 has three grooves 10a, 10b, and 10c formed at its front end to increase the contact area with dust. Because the cleaning putty of the present invention is soft, it can also be shaped into any form, such as a strip, sheet, rod, or block. Example

[0020] The following uses examples for illustration. The present invention is not limited to the examples.

[0021] Regarding various parameters, they are measured by the following methods. <Hardness (plasticity)> The hardness (plasticity) is measured in accordance with JIS K 6300-3 and ISO 2007:1991. Using a Wallace Rapid plastometer, at a measurement temperature of 23°C, between two metal plates, with a constant load (300 N) and a constant time (15 seconds), the specimen is compressed to a constant thickness (1 mm). Then, with a constant load (100 N) and a constant time (15 seconds), the thickness (t) of the compressed specimen is represented as a value multiplied by 100. The smaller this value, the softer it indicates. <Adhesive force of aluminum plate (adhesion)> It is measured using Takines checker HTC-1 (manufactured by Toyo Seiki Seisaku-sho, Ltd.). Press the contact head against the object with the following pressure and time, and detect the stress during peeling in a force sensor manner. In the following examples, the pressure of Takines checker (manufactured by Toyo Seiki Seisaku-sho, Ltd.) is 10 N, the time is 6 seconds, and the contact head is an aluminum F ring. <Interface failure between printed circuit board and silicone rubber> The printed circuit board material uses a general printed circuit board processed with solder mask. The silicone rubber uses a silicone rubber sheet with a thickness of 1 mm. Measurement method (1) Press the specimen against each material. (2) Peel the specimen and make a judgment according to the following evaluation criteria. None: No specimen remains on each material. Yes (small): A part of the specimen remains. Yes (large): Most of the specimen remains covered. <SPG-30B cleaning test> (SPG-30B is the name of a thermally conductive silicone product manufactured by Fuji Polymer Industries Co., Ltd.) Measurement method (1) Coat SPG-30B on a general substrate processed with solder mask to make it 10 mm long, 20 mm wide, and 0.3 mm thick, and measure the weight. (2) Press the specimen in a way that covers SPG. (3) Directly peel the specimen and measure the remaining weight of SPG. (First time) (4) Press the new surface of the specimen again, peel it, and measure the remaining weight of SPG. (Second time) (5) Calculate the rate of change from the initial weight as the removal rate.

[0022] (Example 1) • Manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "KE-1614H-U": 100g of an uncrosslinked compounded silicone rubber composition containing two organopolysiloxanes and boric acid compounds. • Manufactured by Toray Dow Corning Silicon Co., Ltd., trade name "CF3110": Polyorganosiloxane base polymer 8g Mix the above substances evenly to make a cleaning putty.

[0023] (Example 2) • Manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "KE-1614H-U": 100g of an uncrosslinked compounded silicone rubber composition containing two organopolysiloxanes and boric acid compounds. • Manufactured by Toray Dow Corning Silicon Co., Ltd., trade name "CF3110": Polyorganosiloxane basic polymer 20g Mix the above substances evenly to make a cleaning putty.

[0024] (Example 3) • Manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "KE-1614H-U": 100g of an uncrosslinked compounded silicone rubber composition containing two organopolysiloxanes and boric acid compounds. • Manufactured by Toray Dow Corning Silicon Co., Ltd., trade name "CF3110": Polyorganosiloxane basic polymer 37g Mix the above substances evenly to make a cleaning putty.

[0025] (Example 4) • Manufactured by Toray Dow Corning Silicones Co., Ltd., trade name "DAWSIL CF 9306": 100g of a compound silicone rubber composition containing organopolysiloxane, silica, quartz, diatomaceous earth. • Manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "X-93-1169": 5g of organopolysiloxane additive containing boric acid compounds. • Manufactured by Toray Dow Corning Silicon Co., Ltd., trade name "CF3110": Polyorganosiloxane basic polymer 20g Mix the above substances evenly to make a cleaning putty.

[0026] (Example 5) 100g of a compound silicone rubber composition manufactured by Toray D. Corning Silicon Co., Ltd., under the trade name "XIAMETER SE 1185 U", was used as a cleaning putty.

[0027] (Example 6) • Toray Dow Corning Silicones Co., Ltd., trade name "XIAMETER SE 1185 U": 100g of compounded silicone rubber composition. • Manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "X-93-1169": 5g of organopolysiloxane additive containing boric acid compounds. Mix the above substances evenly to make a cleaning putty.

[0028] (Comparative Example 1) 100g of a non-crosslinked compounded silicone rubber composition containing two organopolysiloxanes and boric acid compounds, manufactured by Shin-Etsu Chemical Industry Co., Ltd. and marketed under the trade name "KE-1614H-U", was used as a cleaning putty.

[0029] (Comparative Example 2) • Manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "KE-1614H-U": 100g of an uncrosslinked compounded silicone rubber composition containing two organopolysiloxanes and boric acid compounds. • Manufactured by Toray Dow Corning Silicon Co., Ltd., trade name "CF3110": Polyorganosiloxane basic polymer 74g Mix the above substances evenly to make a cleaning putty.

[0030] (Comparative Example 3) • Manufactured by Toray Dow Corning Silicones Co., Ltd., trade name "DAWSIL CF 9306": 100g of a compound silicone rubber composition containing organopolysiloxane, silica, quartz, diatomaceous earth. • Manufactured by Toray Dow Corning Silicon Co., Ltd., trade name "CF3110": Polyorganosiloxane basic polymer 20g Mix the above substances evenly to make a cleaning putty.

[0031] (Comparative Example 4) A cleaning putty is made using a silicone-based adhesive with "DOWSIL SH 4280" (peroxide-curing adhesive) manufactured by Toray Dow Corning Silicones Co., Ltd. as its main component.

[0032] (Comparative Example 5) We use a putty-like substance made by mixing acrylic resin gel sheets, manufactured by Fuji Polymer Industries under the trade name "SARCON NR-c", as a cleaning putty.

[0033] The above conditions and results are summarized in Tables 1-2.

[0034]

[0035]

[0036] The following information can be found in Tables 1 and 2. (1) The range of hardness (plasticity) of Examples 1-3 and Comparative Examples 1-2 was compared. Examples 1-3 were preferred, but Comparative Example 1 was too hard and did not penetrate between the leads, while Comparative Example 2 was too soft and easily broke, and was easily left between the leads. (2) In Examples 4 and 6, the performance of the SPG30B sweep test was improved by adding boric acid compounds compared with Comparative Example 3 and Example 5, respectively. (3) Comparative Example 4 is an organosilicon adhesive with peroxide-curing adhesive as the main component, but the interface damage from the substrate and silicone rubber is high, so it is not preferred. (4) Comparative Example 5 is an example of making putty by mixing gel sheets with acrylic resin, but the adhesion to aluminum is too high, making it easy to break, and the performance of SPG30B sweep test is low. Furthermore, the cleaning putty of Embodiments 1 to 6 of the present invention also demonstrates the following effects. (1) The cleaning of the flat part of the cleaning putty in Examples 1 to 6 can be done simply by pressing the cleaning putty to peel it off, which is highly operable and efficient. (2) The gap of the lead wire portion is about 0.3~0.5mm. In existing methods (such as commercially available paper towels, manufactured by Kinbury-Clark Company, trade name "Kimwipe") and the cleaning putty of Comparative Examples 1~5, the dust in the embedded lead wire portion and other places is difficult to remove and can be removed with a needle. However, the cleaning putty of Examples 1~6 can be peeled off by pressing even in narrow parts, which is highly operable and efficient. (3) The materials that need to be repaired are those that were incorrectly coated or recycled at around 70°C. However, they can also be removed by pressing and sweeping with putty and peeling off, which is easy to operate and efficient. Industrial applicability

[0037] The cleaning putty of the present invention is suitable for cleaning semiconductor mounting components. Explanation of reference numerals in the attached figures

[0038] 1 Semiconductor mounting components 2 Printed substrate 2 3 IC chips 4 Lead wires 5 gold threads 6. Sealing resin 7a, 7b gap 8,9 Clean with putty 10a, 10b, 10c slots

Claims

1. A cleaning putty for cleaning semiconductor mounting components, characterized in that, The main component is a compounded silicone rubber composition, which has a plasticity of 20 or more and less than 80 according to JIS K 6300-3:2019 and ISO 2007:1991, and an adhesion strength to aluminum of 0.3N or more and less than 4N.

2. The putty for cleaning according to claim 1, wherein, When the putty is pressed onto the aluminum block and then peeled off, no interface damage marks remain on the side of the aluminum block.

3. The cleaning putty according to claim 1 or 2, wherein, The cleaning putty is peeled off after being pressed onto the printed circuit board or silicone rubber, leaving no interface damage marks on the printed circuit board side, but on the silicone rubber side.

4. The cleaning putty according to any one of claims 1 to 3, wherein, The compounded silicone rubber is 40% to 100% by mass relative to 100% by mass of the cleaning putty.

5. The cleaning putty according to any one of claims 1 to 4, wherein, The cleaning putty further contains organopolysiloxanes containing boric acid compounds.

6. The cleaning putty according to any one of claims 1 to 5, wherein, The cleaning putty also contains organopolysiloxanes other than the compounded silicone rubber.

7. The cleaning putty according to any one of claims 1 to 6, wherein, The compounded silicone rubber composition comprises uncrosslinked compounded silicone rubber.

8. The cleaning putty according to any one of claims 1 to 7, wherein, A heat dissipation material consisting of a liquid thermally conductive silicone composition was coated on a printed circuit board in a manner with a longitudinal dimension of 10 mm, a transverse dimension of 20 mm, and a thickness of 0.3 mm. The mass was measured, and when the putty was pressed and peeled off, the removal rate was 60% by mass for the first time and 85% by mass or more for the second time.

9. The cleaning putty according to any one of claims 1 to 8, wherein, The cleaning putty is shaped into strips, sheets, rods, or blocks.

10. A method for cleaning semiconductor mounting components, comprising a method for cleaning semiconductor mounting components using the cleaning putty according to any one of claims 1 to 9, characterized in that, The cleaning putty is pressed onto the printed circuit board coated or attached with silicone-based heat dissipation material and then peeled off to clean the semiconductor mounting components.

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