JP3838994B2

JP3838994B2 - Heat dissipation member

Info

Publication number: JP3838994B2
Application number: JP2003158923A
Authority: JP
Inventors: 敏勝光永; 満椎葉; 博昭澤; 正人川野
Original assignee: Denki Kagaku Kogyo KK
Current assignee: Denka Co Ltd
Priority date: 2003-06-04
Filing date: 2003-06-04
Publication date: 2006-10-25
Anticipated expiration: 2023-06-04
Also published as: JP2004363272A

Description

【０００１】
【発明の属する技術分野】
本発明は、高柔軟性且つ高復元性の放熱部材に関する。詳しくは、コンピューター、ワードプロセッサーなどの情報処理機器におけるＩＣ、ＬＳＩ、ＣＰＵ、ＭＰＵ等の発熱性電子部品から発生した熱を効率よく放出するのに用いられる放熱部材の改良に関する。
【０００２】
【従来の技術】
従来、発熱性電子部品から発生した熱の除去は、発熱性電子部品を、放熱部材を介して放熱フィンや金属板に取り付けることによって行われている。放熱部材としては、シリコーンゴムなどの柔軟なマトリックスに熱伝導性フィラーの充填された放熱スペーサーが賞用されている。
【０００３】
放熱スペーサーの熱伝導性は、熱伝導性フィラーの充填量に依存しており、それを高めるほど熱伝導性は向上するが、その反面、柔軟性と復元性が低下する。このため、放熱スペーサーを凹凸のある面に押しつけ密着させて装着することが困難となるので、放熱が不十分となる。しかも、復元性が十分でないと、発熱性電子部品と放熱フィンを解体し、その間に挟まれている放熱部材を再使用する場合、それができなくなる。
【０００４】
放熱スペーサーの柔軟性と復元性を両立させることは難題であるが、本出願人は長年からその技術開発に携わり多くの特許を取得した（たとえば特許文献１〜３）。今日では、その技術・製品がさまざまな分野で受け入れられているが、依然として、高熱伝導性を維持したまま、更なる柔軟性と復元性の向上要求がある。
【０００５】
【特許文献１】
特許第３１７８８０５号公報
【特許文献２】
特許第３１８３５０２号公報
【特許文献３】
特許第３２８３４５４号公報
【０００６】
【発明が解決しようとする課題】
本発明の目的は、上記に鑑み、高熱伝導性を維持したまま、更なる高柔軟性且つ高復元性の放熱部材を提供することである。
【０００７】
【課題を解決するための手段】
すなわち、本発明は、熱伝導性フィラーを含有するシリコーン樹脂硬化物の粉砕物と、熱伝導性フィラーを含有する未硬化シリコーン樹脂との混合物を、成形・硬化させてなることを特徴とする放熱部材である。この場合において、粉砕物の熱伝導性フィラーの割合が５０体積％以上（１００％は含まない）で、未硬化シリコーン樹脂の熱伝導性フィラーの割合が４０体積％未満（０％は含まない）であることが好ましい。また、粉砕物の熱伝導性フィラーの割合が５０体積％未満（０％は含まない）で、未硬化シリコーン樹脂の熱伝導性フィラーの割合が４０体積％以上（１００％は含まない）であることが好ましい。更には、ＪＩＳＫ２２０７による針入度が９０（１／１０ｍｍ）以上、ＪＩＳＫ６２６２による圧縮永久歪みが４０％以下、熱伝導率が１Ｗ／ｍＫ以上であることが好ましい。
【０００８】
また、本発明は、熱伝導性フィラーを含有しないシリコーン樹脂硬化物の粉砕物と、熱伝導性フィラーを含有する未硬化シリコーン樹脂との混合物を、成形・硬化させてなることを特徴とする放熱部材である。この場合において、未硬化シリコーン樹脂の熱伝導性フィラーの割合が４０体積％以上（１００％は含まない）であることが好ましい。また、ＪＩＳＫ２２０７による針入度が９０（１／１０ｍｍ）以上、ＪＩＳＫ６２６２による圧縮永久歪みが４０％以下、熱伝導率が１Ｗ／ｍＫ以上であることが好ましい。
【０００９】
【発明の実施の形態】
以下、更に詳しく本発明について説明する。
【００１０】
本発明の放熱部材のマトリックスを構成するシリコー樹脂の硬化物は、高柔軟性を有するものであり、その具体例は付加反応型シリコーンの硬化物である。この付加反応型シリコーンとしては、一分子中にビニル基とＨ−Ｓｉ基の両方を有する一液型のシリコーン、又は末端あるいは側鎖にビニル基を有するオルガノポリシロキサンと末端あるいは側鎖に２個以上のＨ−Ｓｉ基を有するオルガノポリシロキサンとの二液性のシリコーンなどが用いられる。これの市販品としては、例えば東レダウコーニングシリコーン社製、商品名「ＳＥ１８８６Ａ／Ｂ」、ＧＥ東芝シリコーン社製、商品名「ＸＥ−１４−Ｂ８５３０」などがある。放熱部材の柔軟性は、付加反応によって形成される架橋密度や熱伝導性フィラーの充填量によって制御される。
【００１１】
本発明で使用される熱伝導性フィラーを例示すれば、アルミナ、炭化ケイ素、窒化アルミニウム、窒化ホウ素、窒化ケイ素、銀、銅、アルミニウムなどであり、中でもアルミナ、窒化アルミニウム、銀、銅、アルミニウムが特に好ましい。形状は球形に近いものが好ましく、また粒径は１００μm以下であることが好ましい。
【００１２】
柔軟性と復元性の両方を一段と高度なものとするためには、熱伝導性フィラーの割合の異なる部分を積極的に混在させることが必要となる。すなわち、本発明の放熱部材は、熱伝導性フィラーを含有するシリコーン樹脂硬化物の粉砕物と、熱伝導性フィラーを含有するか又は含有しない未硬化シリコーン樹脂との混合物を、成形・硬化させてなることが必要である。中でも、粉砕物の熱伝導性フィラーの割合が５０体積％以上（１００％は含まない）、特に６０〜８０体積％で、未硬化シリコーン樹脂の熱伝導性フィラーの割合が４０体積％未満（０％は含まない）、特に１５〜３５体積％であることが好ましい。粉砕物の熱伝導性フィラーの割合があまりにも多くなると、粉砕物を製造することが困難となり、また未硬化シリコーン樹脂の熱伝導性フィラーの割合があまりにも少ないと、放熱部材の高熱伝導性を確保することが困難となる。
【００１３】
上記態様は、粉砕物の熱伝導性フィラーの割合が５０体積％以上としたものであるが、これを５０体積％未満（０％は含まない）、特に２０〜４０とし、未硬化シリコーン樹脂の熱伝導性フィラーの割合を４０体積％以上（１０0％は含まない）、特に６０〜８０体積％とすることもできる。粉砕物の熱伝導性フィラーの割合があまりにも少ないと、放熱部材の高熱伝導性を確保することが困難となり、また未硬化シリコーン樹脂の熱伝導性フィラーの割合があまりにも多くなると、放熱部材の柔軟性、復元性が損なわれてくる。
【００１４】
本発明の放熱部材のように、所定量の熱伝導性フィラーを含有するか又は含有しないシリコーン樹脂硬化物の粉砕物の部分と、所定量の熱伝導性フィラーを含むか又は含まないシリコーン樹脂硬化物の部分とを積極的に混在させるには、所定量の熱伝導性フィラーを含有するか又は含有しないシリコーン樹脂硬化物を一旦製造し、その粉砕物を、熱伝導性フィラーを含有するか又は含有しない未硬化のシリコーン樹脂に配合し、硬化させることによって行うことができる。いずれの場合においても、粉砕物の平均粒度は２０〜４００μｍであることが好ましい。これ以外の粒度であっては、単なる均一混合物に近似した放熱性、柔軟性、復元性となり、柔軟性と復元性の両方を一段と高度にした放熱部材を得ることが困難となる。
【００１５】
本発明の放熱部材の柔軟性は、ＪＩＳＫ２２０７で測定された針入度が、９０（１／１０ｍｍ）以上であることが好ましい。針入度が９０（１／１０ｍｍ）未満であると、凹凸部に対する密着性が劣る、発熱性電子部品と放熱フィンとの距離が長くなる、電子部品に強い荷重がかかる、などして電子部品の損傷につながる。また、放熱部材の復元性は、ＪＩＳＫ６２６２による圧縮永久歪みが４０％以下であることが好ましい。圧縮永久歪みが４０％よりも大きいと、凹凸部への追従性が劣り、また解体後の放熱部材には使用時の跡が大幅に残るので、再使用が困難となる。更には、熱伝導率が１Ｗ／ｍＫ以上であることが好ましい。
【００１６】
本発明の放熱部材は、上記粉砕物の製造、粉砕物と未硬化シリコーン樹脂との混合、成形の各工程を経て製造される。粉砕物の製造は、未硬化シリコーン樹脂に所定量の熱伝導性フィラーを混合してから硬化させ、それを再混練することによって行われる。再混練の時間・混練力によって粉砕物の粒度を調整することができる。得られた粉砕物は、コンパウンド状である。原料の混合は万能混合機等を用いて行われ、また成形はドクターブレードによるシート化法によることが望ましい。シート化に際しては離型処理の施されたフィルム、例えばシリコーン塗布又はフッ素処理されたポリエチレンテレフタレートフィルムを用いることが好ましい。また、カレンダーロールによる成形でも問題はない。
【００１７】
【実施例】
以下、実施例を、比較例をあげて更に具体的に本発明を説明する。
【００１８】
実施例１〜６比較例１〜３
二液性の付加反応型シリコーン（東レダウコーニングシリコーン社製、商品名「ＳＥ１８８５Ａ／Ｂ」）のＡ液、Ｂ液を１対１の体積比で混合した混合物と、熱伝導性フィラーとしてアルミナ粉末（電気化学工業社製、商品名「ＤＡＷ−４５」）とを表１に示す割合で混合してスラリーを調製し、室温で真空脱泡した後、１２０℃、６時間処理して硬化させ、再混練して表１に示されるコンパウンド状の粉砕物を得た。顕微鏡で観察した粉砕物１００個の平均粒度は、９０μｍであった。
【００１９】
つぎに、付加型シリコーン（ＧＥ東芝シリコーン社製、商品名「ＸＥ１４−Ｂ８５３０」）のＡ剤：Ｂ剤を１：１体積比で混合した混合物と、上記アルミナ粉末と、上記粉砕物とを、表２、表３に示す割合で混合した後、室温で真空脱泡し、ドクターブレード塗工機でシート化し、１２０℃、６時間加熱して硬化させて放熱部材（寸法：幅５００ｍｍ、長さ５００ｍｍｍ、厚み１ｍｍ）を製造し、以下に従って、熱伝導率、針入度、圧縮率及び圧縮永久歪を測定した。それらの結果を表２、表３に示す。
【００２０】
（１）熱導率
放熱部材をＴＯ−３型銅製ヒーターケースと銅板との間に挟み、トルクレンチにより締め付けトルク２００ｇ−ｃｍを掛けてセットした後、銅製ヒーターケースに電力５Ｗをかけて４分間保持し、銅製ヒーターケースと銅板の温度差（℃）を測定し、熱抵抗（℃／Ｗ）＝温度差（℃）／電力（Ｗ）、により熱抵抗を算出し、熱伝導率（Ｗ／ｍ・Ｋ）＝厚み（ｍ）／｛熱抵抗（Ｋ／Ｗ）×測定面積（ｍ^２）｝、を算出した。
【００２１】
（２）圧縮率
縦１０mm、横１０mmに切り出した放熱部材に万能試験機で９．８Ｎの力を加え、レーザー変位計で変形量を測定し、圧縮率（％）＝変形量（mm）／元厚み（mm）×１００、により算出した。
【００２２】
（３）針入度
ＪＩＳＫ２２０７によって測定した。
【００２３】
（４）圧縮永久歪み
ＪＩＳＫ６３０１に準拠して測定した。すなわち、上記実施例・比較例の途中で得られた真空脱泡法スラリーを型枠に鋳込み、１２０℃、６時間処理して硬化させ、直径２９ｍｍ、厚み１２．７ｍｍの試験片を製造した。これを２５％圧縮した後（試験片の厚みが９．５２ｍｍになるまで圧縮した後）、１５０℃の大気中で２２時間放置した。その後、室温で圧縮を解除し、木版の上に３０分放置してから厚みを測定し、永久圧縮歪（％）＝［試験前の厚み（ｍｍ）−試験後の厚み（ｍｍ）］×１００／［試験前の厚み（mm）−圧縮時の厚み］、により算出した。
【００２４】
【表１】

【００２５】
【表２】

【００２６】
【表３】

【００２７】
表から、実施例の放熱部材は比較例に比べて、熱伝導率と針入度がいずれも大きく、発熱性電子部品への追従性と密着性に優れたものである。また、圧縮永久歪みも４０％以下であり、復元性に優れるため、凹凸部のある面への追従性に優れ、解体後の再使用も容易なものである。
【００２８】
【発明の効果】
本発明によれば、高熱伝導性を維持したまま、更なる柔軟性と復元性を向上させた放熱部材が提供される。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a highly flexible and highly recoverable heat radiating member. More specifically, the present invention relates to an improvement in a heat radiating member used for efficiently releasing heat generated from heat-generating electronic components such as ICs, LSIs, CPUs, and MPUs in information processing devices such as computers and word processors.
[0002]
[Prior art]
Conventionally, heat generated from the heat-generating electronic component is removed by attaching the heat-generating electronic component to a heat radiation fin or a metal plate via a heat radiation member. As the heat radiating member, a heat radiating spacer in which a flexible matrix such as silicone rubber is filled with a heat conductive filler is used.
[0003]
The thermal conductivity of the heat dissipating spacer depends on the filling amount of the thermal conductive filler, and the higher it is, the better the thermal conductivity is, but on the other hand, the flexibility and restorability are reduced. For this reason, since it becomes difficult to attach the heat dissipation spacer by pressing it against the uneven surface, the heat dissipation becomes insufficient. In addition, if the recoverability is not sufficient, it becomes impossible to disassemble the heat-generating electronic component and the heat dissipating fin and reuse the heat dissipating member sandwiched between them.
[0004]
Although it is difficult to achieve both flexibility and resiliency of the heat dissipation spacer, the applicant has been involved in the technological development for many years and obtained many patents (for example, Patent Documents 1 to 3). Today, the technology and products are accepted in various fields, but there is still a demand for further improvement in flexibility and resilience while maintaining high thermal conductivity.
[0005]
[Patent Document 1]
Japanese Patent No. 3178805 [Patent Document 2]
Japanese Patent No. 3183502 [Patent Document 3]
Japanese Patent No. 3283454 [0006]
[Problems to be solved by the invention]
In view of the above, an object of the present invention is to provide a heat radiating member having higher flexibility and higher resilience while maintaining high thermal conductivity.
[0007]
[Means for Solving the Problems]
That is, the present invention is a ground product of the silicone resin cured product containing a thermally conductive filler, a mixture of uncured silicone resin you containing a heat conductive filler, characterized by comprising by molding and curing It is a heat dissipation member. In this case, the proportion of the thermally conductive filler of the pulverized product is 50% by volume or more (not including 100%), and the proportion of the thermally conductive filler of the uncured silicone resin is less than 40% by volume (not including 0%). It is preferable that Further, the proportion of the thermally conductive filler in the pulverized product is less than 50% by volume (not including 0%), and the proportion of the thermally conductive filler in the uncured silicone resin is 40% by volume or more (not including 100%). It is preferable. Furthermore, it is preferable that the penetration according to JIS K2207 is 90 (1/10 mm) or more, the compression set according to JIS K6262 is 40% or less, and the thermal conductivity is 1 W / mK or more.
[0008]
In addition, the present invention provides a heat radiation characterized by molding and curing a mixture of a pulverized product of a cured silicone resin containing no thermally conductive filler and an uncured silicone resin containing a thermally conductive filler. It is a member. In this case, the proportion of the thermally conductive filler of the uncured silicone resin is preferably 40% by volume or more (not including 100%). Moreover, it is preferable that the penetration according to JIS K2207 is 90 (1/10 mm) or more, the compression set according to JIS K6262 is 40% or less, and the thermal conductivity is 1 W / mK or more.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
[0010]
The cured product of the silicone resin constituting the matrix of the heat dissipation member of the present invention has high flexibility, and a specific example thereof is a cured product of addition reaction type silicone. As this addition reaction type silicone, one-pack type silicone having both vinyl group and H-Si group in one molecule, or organopolysiloxane having vinyl group at the terminal or side chain and two at the terminal or side chain. Two-part silicone with organopolysiloxane having the above H-Si group is used. Examples of commercially available products include Toray Dow Corning Silicone, trade name “SE1886A / B”, GE Toshiba Silicone, trade name “XE-14-B8530”, and the like. The flexibility of the heat radiating member is controlled by the crosslink density formed by the addition reaction and the filling amount of the heat conductive filler.
[0011]
Examples of the thermally conductive filler used in the present invention are alumina, silicon carbide, aluminum nitride, boron nitride, silicon nitride, silver, copper, aluminum and the like, among which alumina, aluminum nitride, silver, copper and aluminum are included. Particularly preferred. The shape is preferably close to a sphere, and the particle size is preferably 100 μm or less.
[0012]
In order to make both flexibility and restorability even higher, it is necessary to actively mix portions having different proportions of the heat conductive filler. That is, the heat radiating member of the present invention is obtained by molding and curing a mixture of a pulverized product of a cured silicone resin containing a thermally conductive filler and an uncured silicone resin containing or not containing a thermally conductive filler. It is necessary to become. Among them, the proportion of the thermally conductive filler in the pulverized product is 50% by volume or more (not including 100%), particularly 60 to 80% by volume, and the proportion of the thermally conductive filler of the uncured silicone resin is less than 40% by volume (0 % Is not included), and it is particularly preferably 15 to 35% by volume. If the proportion of the thermally conductive filler in the pulverized product is too large, it will be difficult to produce the pulverized product, and if the proportion of the thermally conductive filler in the uncured silicone resin is too small, the high thermal conductivity of the heat dissipation member will be reduced. It becomes difficult to ensure.
[0013]
In the above embodiment, the proportion of the thermally conductive filler in the pulverized product is 50% by volume or more, but this is less than 50% by volume (not including 0%), particularly 20 to 40, and the uncured silicone resin The proportion of the thermally conductive filler may be 40% by volume or more (excluding 100%), particularly 60 to 80% by volume. If the proportion of the thermally conductive filler in the pulverized product is too small, it will be difficult to ensure the high thermal conductivity of the heat radiating member, and if the proportion of the thermally conductive filler in the uncured silicone resin is too large, Flexibility and resilience are impaired.
[0014]
As in the heat radiating member of the present invention, a portion of a pulverized product of a cured silicone resin containing or not containing a predetermined amount of a thermally conductive filler, and a cured silicone resin containing or not containing a predetermined amount of a thermally conductive filler In order to actively mix the product part, a cured silicone resin containing or not containing a predetermined amount of thermally conductive filler is once produced, and the pulverized product contains thermally conductive filler or It can carry out by mix | blending with the uncured silicone resin which does not contain, and making it harden | cure. In any case, the average particle size of the pulverized product is preferably 20 to 400 μm. If the particle size is other than this, the heat dissipation, flexibility and resilience approximate to that of a mere uniform mixture are obtained, and it becomes difficult to obtain a heat dissipating member with both flexibility and resilience being further enhanced.
[0015]
Regarding the flexibility of the heat dissipating member of the present invention, the penetration measured by JIS K2207 is preferably 90 (1/10 mm) or more. If the penetration is less than 90 (1/10 mm), the adhesiveness to the concave and convex portions is inferior, the distance between the heat generating electronic component and the heat radiating fin is increased, a strong load is applied to the electronic component, etc. Leading to damage. Moreover, it is preferable that the restoring property of a heat radiating member is 40% or less of the compression set by JISK6262. When the compression set is larger than 40%, the followability to the concavo-convex portion is inferior, and since the traces at the time of use remain in the heat dissipation member after dismantling, it becomes difficult to reuse. Furthermore, the thermal conductivity is preferably 1 W / mK or more.
[0016]
The heat radiating member of this invention is manufactured through each process of manufacture of the said ground material, mixing of a ground material, and an unhardened silicone resin, and shaping | molding. The pulverized product is produced by mixing a predetermined amount of a heat conductive filler with an uncured silicone resin, curing it, and re-kneading it. The particle size of the pulverized product can be adjusted by the re-kneading time and kneading force. The obtained pulverized product is in the form of a compound. The mixing of the raw materials is performed using a universal mixer or the like, and the molding is preferably performed by a sheeting method using a doctor blade. In forming the sheet, it is preferable to use a film subjected to a release treatment, for example, a polyethylene terephthalate film coated with silicone or treated with fluorine. Also, there is no problem with molding by a calendar roll.
[0017]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.
[0018]
Examples 1-6 Comparative Examples 1-3
A mixture of two-component addition reaction type silicone (trade name “SE1885A / B” manufactured by Toray Dow Corning Silicone Co., Ltd.) in a 1: 1 volume ratio, and alumina powder as a thermally conductive filler (Electrochemical Industry Co., Ltd., trade name “DAW-45”) was mixed at a ratio shown in Table 1 to prepare a slurry, vacuum defoamed at room temperature, then treated at 120 ° C. for 6 hours to be cured, The compound-like pulverized product shown in Table 1 was obtained by re-kneading. The average particle size of 100 pulverized products observed with a microscope was 90 μm.
[0019]
Next, a mixture obtained by mixing A type agent: B agent of addition type silicone (GE Toshiba Silicone, trade name “XE14-B8530”) in a 1: 1 volume ratio, the alumina powder, and the pulverized product, After mixing at the ratios shown in Table 2 and Table 3, vacuum deaeration at room temperature, sheeting with a doctor blade coating machine, heating and curing at 120 ° C. for 6 hours to heat radiation member (dimensions: width 500 mm, length 500 mm, thickness 1 mm), and thermal conductivity, penetration, compressibility and compression set were measured according to the following. The results are shown in Tables 2 and 3.
[0020]
(1) A thermal conductivity heat radiating member is sandwiched between a TO-3 type copper heater case and a copper plate, set with a torque wrench and tightened with a torque of 200 g-cm, and then applied with a power of 5 W to the copper heater case for 4 minutes. Hold, measure the temperature difference (° C.) between the copper heater case and the copper plate, calculate the thermal resistance by thermal resistance (° C./W)=temperature difference (° C.) / Power (W), and obtain thermal conductivity (W / m · K) = thickness (m) / {thermal resistance (K / W) × measured area (m ² )}.
[0021]
(2) 9.8 N force was applied to the heat dissipation member cut out to a compression rate of 10 mm in length and 10 mm in width with a universal testing machine, and the amount of deformation was measured with a laser displacement meter. Compression rate (%) = amount of deformation (mm) / The original thickness (mm) × 100 was calculated.
[0022]
(3) Needle penetration Measured according to JIS K2207.
[0023]
(4) Compression set Measured according to JIS K 6301. That is, the vacuum defoaming slurry obtained in the middle of the above-mentioned examples and comparative examples was cast into a mold and cured by treatment at 120 ° C. for 6 hours to produce a test piece having a diameter of 29 mm and a thickness of 12.7 mm. This was compressed by 25% (after compression until the thickness of the test piece was 9.52 mm) and then left in the atmosphere at 150 ° C. for 22 hours. Thereafter, the compression is released at room temperature, and the thickness is measured after being left on the wood block for 30 minutes. Permanent compression strain (%) = [thickness before test (mm) −thickness after test (mm)] × 100 / [Thickness before test (mm) −Thickness during compression]
[0024]
[Table 1]

[0025]
[Table 2]

[0026]
[Table 3]

[0027]
From the table, the heat dissipating member of the example has a larger thermal conductivity and penetration than the comparative example, and is excellent in followability and adhesion to the heat-generating electronic component. In addition, the compression set is 40% or less, and it is excellent in recoverability. Therefore, it is excellent in followability to a surface with uneven portions, and can be easily reused after dismantling.
[0028]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the heat radiating member which improved the further softness | flexibility and resilience is provided, maintaining high thermal conductivity.

Claims

And pulverized product of the silicone resin cured product containing a thermally conductive filler, a mixture of uncured silicone resin you containing a heat conductive filler, the heat radiation member, characterized by comprising by molding and curing.

The proportion of the thermally conductive filler in the pulverized product is 50% by volume or more (not including 100%), and the proportion of the thermally conductive filler in the uncured silicone resin is less than 40% by volume (not including 0%). The heat dissipating member according to claim 1.

The proportion of the thermally conductive filler in the pulverized product is less than 50% by volume (not including 0%), and the proportion of the thermally conductive filler in the uncured silicone resin is 40% by volume or more (not including 100%). The heat dissipating member according to claim 1.

A heat radiating member obtained by molding and curing a mixture of a pulverized product of a cured silicone resin containing no thermally conductive filler and an uncured silicone resin containing a thermally conductive filler.

The heat-radiating member according to claim 4, wherein the proportion of the thermally conductive filler of the uncured silicone resin is 40% by volume or more (not including 100%).

The penetration according to JIS K2207 is 90 (1/10 mm) or more, the compression set according to JIS K6262 is 40% or less, and the thermal conductivity is 1 W / mK or more. The heat radiating member of description.