JP4162955B2 - Adhesive silicone composition for heat dissipation member - Google Patents

Description

【００２０】
（式中、Ｒ⁵は独立に炭素原子数１〜６の１価アルキル基であり、ｍおよびｎは１以上の整数であり、ｍ+ｎの和は３〜300の範囲にあり、更にｍ／(ｍ+ｎ)の比の値は0.3よりも大である）
で表わされるオルガノハイドロジェンポリシロキサン： 上記(b)成分中のアルケニル基１モルに対する、該(c)成分中のＳｉＨ基のモル数が0.5〜20モルとなる量、
(d)白金系触媒： 有効量、および
(e)付加反応制御剤： 0.01〜１重量部
としたものが好適に用いられる。
【００２１】
上記(b)成分のアルケニル基含有オルガノポリシロキサンは、その分子構造は限定されず、例えば、直鎖状、分岐鎖状、一部分岐を有する直鎖状が挙げられ、好ましくは直鎖状、一部分岐を有する直鎖状である。また、このオルガノポリシロキサンは、これらの分子構造を有する単一の重合体、これらの分子構造からなる共重合体、またはこれらの重合体の混合物である。
【００２２】
また、(b)成分中のケイ素原子に結合しているアルケニル基としては、例えば、ビニル基、アリル基、1-ブテニル基、1-ヘキセニル基等が挙げられる。これらのなかでも、合成上の容易性、コスト等の点から、特にビニル基が好ましい。
【００２３】
アルケニル基以外のケイ素原子に結合している基としては、例えば、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ノニル基、デシル基、ドデシル基等のアルキル基；シクロペンチル基、シクロヘキシル基等のシクロアルキル基；フェニル基、トリル基、キシリル基、ナフチル基等のアリール基；ベンジル基、フェネチル基、2-フェニルプロピル基等のアラルキル基；クロロメチル基、3,3,3-トリフルオロプロピル基、3-クロロプロピル基等のハロゲン化アルキル基等が挙げられる。これらのうち、合成上の容易性、コスト等の点から、90モル％以上がメチル基とすることが好ましい。
【００２４】
また、ケイ素原子に結合したアルケニル基の結合部位は、分子鎖の末端、途中のいずれでもよいが、（Ａ）成分の粘着性の点から分子鎖両末端のみとすることが好ましい。
【００２５】
(b)成分のオルガノポリシロキサンの性状は、オイル状、生ゴム状であればよく、25℃における粘度は10,000mPa・s以上であり、取り扱い作業性の点から20,000mPa・s以下であることが好ましい。前記粘度が10,000mPa・s未満であると、得られる放熱部材の形状安定性が低下する傾向がある。
【００２６】
このような(b)成分のオルガノポリシロキサンの具体例としては、例えば、分子鎖両末端ジメチルビニルシロキシ基封鎖ポリジメチルシロキサン、分子鎖両末端メチルジビニルシロキシ基封鎖ポリジメチルシロキサン、分子鎖両末端ジメチルビニルシロキシ封鎖ジメチルシロキサン・メチルフェニルシロキサン共重合体等が挙げられる。これらは１種単独でも２種以上組み合わせて使用することができる。
【００２７】
また、（Ａ）成分の硬化性シリコーン粘着剤中の(a)および(b)成分の配合量は、(a)成分80〜20重量部、好ましくは70〜30重量部、また、(b)成分20〜80重量部、好ましくは30〜70重量部（但し、(a)+(b)=100重量部）とするのがよく、(a)成分の量が少なすぎても、また逆に多すぎても、粘着力（タック）が低下することがあるという問題がある。
【００２８】
上記(c)成分の下記一般式（２）：
【００２９】
【化５】

（式中、Ｒ⁵、ｍおよびｎは前記のとおりである）
で表わされるオルガノハイドロジェンポリシロキサンは架橋剤として作用するものである。
【００３０】
上記式中のＲ⁵としては、(b)成分のアルケニル基以外のケイ素原子に結合する基として挙げたものが例示される。中でも好ましくはメチル基である。
上記ｍおよびｎに関し、ｍ／(ｍ+ｎ)の比の値は0.3を越え、好ましくは0.5以上である。前記値が0.3以下であると、（Ａ）成分に十分な粘着性を付与できない。
また、(c)成分の25℃における粘度は、１〜5,000mPa・s、特に５〜500mPa・sであることが取り扱い性の点から好ましい。
【００３１】
(c)成分の使用量は、(b)成分中のアルケニル基１モルに対して、(c)成分中のＳｉＨ基のモル数が0.5〜20モル、特に好ましくは0.8〜15モルの範囲となる量である。前記モル数が0.5未満では架橋密度が低くなり、熱伝導性充填剤の保持力が低下することがあり、逆に20モルを越えると粘着力が低下する場合がある。
【００３２】
このような(c)成分のオルガノハイドロジェンポリシロキサンの具体例としては、例えば、分子鎖両末端トリメチルシロキシ基封鎖ジメチルシロキサン・メチルハイドロジェンシロキサン共重合体、分子鎖両末端トリメチルシロキシ基封鎖ジメチルシロキサン・メチルハイドロジェンシロキサン・メチルフェニルシロキサン共重合体等がが挙げられる。これらは１種単独でも２種以上組み合わせても使用することができる。
【００３３】
上記(d)成分の白金系触媒は、(b)成分中のアルケニル基と(c)成分中のＳｉＨ基とのヒドロシリル化付加反応を促進する成分である。
(d)成分としては、例えば、白金黒、塩化白金酸（アルコール溶液）、白金のオレフィン錯体、白金のアルコール錯体、白金のアルケニルシロキサン錯体、白金のカルボニル錯体等が挙げられる。本組成物において、白金系触媒の含有量は、特に限定されず、触媒としての有効量でよいが、通常、(b)成分に対して本成分中の白金金属原子が重量単位で１〜500ppmとなる量であり、好ましくは、10〜200ppmとなる量である。本成分の含有量が少なすぎると触媒効果がなく、多量に使用しても特に架橋・硬化速度は向上せず、経済的に不利となることがある。
【００３４】
上記(e)成分の付加反応制御剤は、室温における付加反応による硬化を防止し、付加反応硬化型の本発明組成物のシェルフライフ、ポットライフを確保するため、触媒活性を抑制する成分であって、例えば、1-エチニル-1-シクロヘキサノール等のアセチレン化合物、各種窒素化合物、有機リン化合物、オキシム系化合物、有機クロロ化合物等の公知の制御剤が用いられる。その配合量は、0.01〜１重量部、好ましくは0.03〜0.30重量部の範囲である。
【００３５】
この(e)成分は、シリコーン成分への分散性を高めるため、トルエン、キシレン、イソプロピルアルコール等の有機溶剤で希釈して使用することができる。（但し、前記有機溶剤の使用量は、後記（Ｂ）成分等に対応する、（Ａ）成分の硬化性シリコーン粘着剤の使用量には、算入しない。）
【００３６】
＜有機過酸化物硬化型シリコーン成分＞
また、（Ａ）成分の硬化性シリコーン粘着剤は、有機過酸化物硬化型のものとすることができる。
この場合の（Ａ）成分の組成としては、
前記(a)成分： 80〜20重量部、
(f)25℃における粘度が、10,000mPa・s以上であるオルガノポリシロキサン： 20〜80重量部（但し、(a)+(f)の合計量は、100重量部である）、および
(g)有機過酸化物： 0.2〜10重量部
としたものが好適に用いられる。
【００３７】
上記(f)成分のオルガノポリシロキサンのケイ素原子に結合する基としては、例えば、水酸基；メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ノニル基、デシル基、ドデシル基等のアルキル基；シクロペンチル基、シクロヘキシル基等のシクロアルキル基；フェニル基、トリル基、キシリル基、ナフチル基等のアリール基；ビニル基、アリル基、1-ブテニル基、1-ヘキセニル基等のアルケニル基；ベンジル基、フェネチル基、2-フェニルプロピル基等のアラルキル基；クロロメチル基、3,3,3-トリフルオロプロピル基、3-クロロプロピル基等のハロゲン化アルキル基等が挙げられる。これらの中でも、特にメチル基が好ましい。
【００３８】
また、この(f)成分のオルガノポリシロキサンとしては、下記式：
Ｒ₃ＳｉＯ-(Ｒ₂ＳｉＯ)_c-ＳｉＲ₃
(ＨＯ)Ｒ₂-(Ｒ₂ＳｉＯ)_d-ＳｉＲ₂(ＯＨ)
（式中、Ｒは前記例示と同じ、ｃおよびｄは各々500〜20,000の整数である）
で表わされるジオルガノポリシロキサンを好適に例示することができる。
【００３９】
(f)成分のオルガノポリシロキサンの性状は、オイル状、生ゴム状であればよく、25℃における粘度は10,000mPa・s以上であり、取り扱い作業性の点から20,000mPa・s以下であることが好ましい。前記粘度が10,000mPa・s未満であると、得られる放熱部材の形状安定性が低下する傾向がある。
【００４０】
このような(f)成分のオルガノポリシロキサンの具体例としては、例えば、分子鎖両末端ジメチルビニルシロキシ基封鎖ポリジメチルシロキサン、分子鎖両末端メチルフェニルビニルシロキシ基封鎖ポリジメチルシロキサン、分子鎖両末端ジメチルビニルシロキシ基封鎖ジメチルシロキサン・メチルフェニルシロキサン共重合体、分子鎖両末端ジメチルビニルシロキシ基封鎖ジメチルシロキサン・メチルビニルシロキサン共重合体、分子鎖両末端トリメチルシロキシ基封鎖ジメチルシロキサン・メチルビニルシロキサン共重合体、分子鎖両末端ジメチルビニルシロキシ基封鎖ポリメチル(3,3,3-トリフルオロプロピル)シロキサン、分子鎖両末端シラノール基封鎖ジメチルシロキサン・メチルビニルシロキサン共重合体、分子鎖両末端シラノール基封鎖ジメチルシロキサン・メチルビニルシロキサン・メチルフェニルシロキサン共重合体等が挙げられる。これらは１種単独でも２種以上組み合わせて使用することができる。
【００４１】
また、（Ａ）成分の硬化性シリコーン粘着剤中の(a)および(f)成分の配合量は、(a)成分80〜20重量部、好ましくは70〜30重量部、また、(f)成分20〜80重量部、好ましくは30〜70重量部（但し、(a)+(f)=100重量部）とするのがよく、(a)成分の量が少なすぎても、また逆に多すぎても、粘着力（タック）が低下することがあるという問題がある。
【００４２】
上記(g)成分の有機過酸化物としては、例えば、ベンゾイルパーオキサイド、4,4'-ジメチルベンゾイルパーオキサイド、3,3'-ジメチルベンゾイルパーオキサイド、2,2'-ジメチルベンゾイルパーオキサイド、2,2',4,4'-テトラクロロベンゾイルパーオキサイド、ジクミルパーオキサイド、2,5-ジメチル-2,5-ビス(t-ブチルパーオキシ)ヘキサン、ジ-t-ブチルパーオキサイド、t-ブチルパーベンゾエート等が挙げられる。これらは１種単独でも２種以上組み合わせても使用することができる。この有機過酸化物の添加量は、上記(a)成分と(f)成分の合計100重量部に対して0.5〜20重量部、特に0.7〜５重量部であることが好ましい。
【００４３】
なお、(a)成分と(f)成分とは単に混合して用いてもよいし、また、(f)成分が分子鎖の両末端にシラノール基（ＳｉＯＨ）を有するものである場合は、(a)成分と(f)成分とを縮合反応させて得られる縮合反応生成物として用いても差し支えない。後者の縮合反応を行うには、トルエンなどの溶剤に溶解した前記両成分の混合物を、アルカリ性触媒を用い、室温乃至還流下で反応させればよい。
【００４４】
［（Ｂ）成分］
本発明の（Ｂ）成分の熱伝導性充填剤は、高割合で配合され、本発明組成物から得られる粘着性放熱部材に良好な熱伝導性を付与し、発熱性電子部品の放熱特性を向上させる成分である。
【００４５】
この（Ｂ）成分としては、例えば、非磁性の銅、アルミニウム等の金属；酸化亜鉛、アルミナ、シリカ、マグネシア、チタニア、ジルコニア等の金属酸化物；窒化アルミニウム、窒化ケイ素、窒化硼素等の金属窒化物；人工ダイヤモンド；炭化珪素等の他、一般に公知の熱伝導充填剤とされる物質を全て用いることができる。また、これらは１種単独でも２種以上組合わせても使用することができる。
【００４６】
（Ｂ）成分は、形状としては球状が望ましく、平均粒径が0.1〜100μｍ、特に0.1〜25μｍのものを用いることが好ましい。平均粒径が0.1μｍ未満であると、混合充填時の粘度が高くなり作業性に乏しくなる。また、実際に放熱部材として形成して用いた場合にも加熱圧着時の粘性が高く電子部品と放熱部品の間隙が大きくなり熱抵抗として高くなり十分な放熱性能を発現することが難しくなる。一方、100μｍを越えると、作業上の粘度は低下するものの、やはり実際に放熱部材として用いた場合に、加熱圧着時の電子部品と放熱部品の間隙が100μｍ以下には圧着され得ないこととなり、熱抵抗として高くなり十分な放熱性能を発現することが難しくなる。流動性と熱伝導性の双方を良好なものとするためには、25μｍ以下のものが望ましい。また、熱伝導向上のためには平均粒径の異なる粒子を２種以上用いて最密充填に近づくような配合が推奨される。
【００４７】
上記（Ａ）成分100重量部に対して、この（Ｂ）成分の配合量は、500〜3000重量部の範囲とされ、好ましくは850〜2000重量部である。前記配合量が500重量部未満であると得られる放熱部材の熱伝導率が乏しいものとなるし、3000重量部を越えると加工性の乏しいものとなる。
【００４８】
［（Ｃ）成分］
本発明の粘着性放熱部材を構成する（Ｃ）成分は、下記一般式（１）：
Ｒ² _aＲ³ _bＳｉ(ＯＲ⁴)_4-a-b （１）
（式中、Ｒ²は炭素原子数６〜15の１価アルキル基、Ｒ³は非置換または置換の炭素原子数１〜８の１価炭化水素基、Ｒ⁴は炭素原子数１〜６の１価アルキル基であり、ａは１〜３の整数、ｂは０〜２の整数、ａ＋ｂの和は１〜３の整数である）
で表わされるオルガノシランである。
【００４９】
この（Ｃ）成分は、（Ａ）成分の硬化性シリコーン粘着剤と（Ｂ）成分の熱伝導性充填剤との「濡れ性」を向上させ、本発明組成物において、（Ａ）成分がマトリックスとなって、均一に（Ｂ）成分が高充填割合で分散させることを可能とする重要な役割りを有するものである。
【００５０】
上記Ｒ²としては、例えば、ヘキシル基、オクチル基、ノニル基、デシル基、ドデシル基、テトラデシル基等が挙げられる。このＲ¹基に代えて、炭素原子数が６未満のアルキル基としたオルガノシランを用いた場合には、充填剤との「濡れ性」が充分でなく、また、同じく炭素原子数が１５より大きなアルキル基としたオルガノシランを用いた場合には、オルガノシランが常温で固化するので、取り扱いが不便な上、得られる放熱部材の低温特性が低下する。
【００５１】
上記Ｒ³としては、例えば、メチル基、エチル基、プロピル基、ヘキシル基、オクチル基等のアルキル基；シクロペンチル基、シクロヘキシル基等のシクロアルキル基；ビニル基、アリル基等のアルケニル基；フェニル基、トリル基等のアリール基、2-フェニルエチル基、2-メチル-２-フェニルエチル基等のアラルキル基；3,3,3,-トリフロロプロピル基、2-(ナノフルオロブチル)エチル基、2-(ヘプタデカフルオロオクチル)エチル基、p-クロロフェニル基等のハロゲン化炭化水素基が挙げられるが、これらの中でも特にメチル基、エチル基が好ましい。
【００５２】
上記Ｒ⁴としては、例えば、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基等の１種または２種以上のアルキル基であり、特にメチル基、エチル基が好ましい。
また、ａは、１、２または３であるが、特に１であることが好ましい。
【００５３】
上記一般式（１）で表されるオルガノシランの具体例としては、下記のものを挙げることができる。
Ｃ₆Ｈ₁₂Ｓｉ(ＯＣＨ₃)₃、Ｃ₁₀Ｈ₂₁Ｓｉ(ＯＣＨ₃)₃、
Ｃ₁₂Ｈ₂₅Ｓｉ(ＯＣＨ₃)₃、Ｃ₁₂Ｈ₂₅Ｓｉ(ＯＣ₂Ｈ₅)₃、
Ｃ₁₀Ｈ₂₁Ｓｉ(ＣＨ₃)(ＯＣＨ₃)₂、Ｃ₁₀Ｈ₂₁Ｓｉ(Ｃ₆Ｈ₅)(ＯＣＨ₃)₂、
Ｃ₁₀Ｈ₂₁Ｓｉ(ＣＨ₃)(ＯＣ₂Ｈ₅)₂、Ｃ₁₀Ｈ₂₁Ｓｉ(ＣＨ=ＣＨ₂)(ＯＣＨ₃)₂、
Ｃ₁₀Ｈ₂₁Ｓｉ(ＣＨ₂ＣＨ₂ＣＦ₃)(ＯＣＨ₃)₂
これらは、１種単独でも２種以上を組合わせても使用することができる。
【００５４】
上記（Ａ）成分100重量部に対して、この（Ｃ）成分の配合量は、0.1〜50重量部の範囲とされ、好ましくは0.5〜20重量部である。前記配合量が0.1重量部未満であると「濡れ性」の乏しいものとなり、（Ａ）成分のマトリックス中に（Ｂ）成分が均一に分散した状態とすることができず、また、50重量部より多くしても特に効果が増大することがなく、不経済である。
【００５５】
［付加的成分−１］
本発明組成物を構成する上記（Ａ）〜（Ｃ）成分に加えて、得られる放熱部材の強度を向上させることを目的として、更に、下記成分を付加的に配合することができる。
【００５６】
＜（Ｄ）成分＞
（Ｄ）成分として、１分子中にケイ素原子に結合している２個以上のアルケニル基を有し、25℃における粘度が10ｍPa・s以上、10,000ｍPa・s未満、好ましくは100〜5,000ｍPa・sのオルガノポリシロキサンを、10〜500重量部配合することができる。
本（Ｄ）成分のケイ素原子に結合しているアルケニル基およびその他の基、並び本（Ｄ）成分の基本的構造については、上記(b)成分に関しての例示と同じものが例示される。また、この（Ｄ）成分の25℃における粘度が10ｍPa・s未満であると組成物の保存安定性が悪くなり、10,000ｍPa・s以上であると組成物の伸展性が損なわれる。
【００５７】
＜（Ｅ）成分＞
（Ｅ）成分として、下記(E1)成分および／または(E2)成分を配合することができる。
(E1)下記一般式（３）：
【００５８】
【化６】

（式中、Ｒ⁶は独立に炭素原子数１〜６の１価アルキル基であり、ｐおよびｑは１以上の整数であり、ｐ+ｑの和は５〜100の範囲にあり、更に、0.01≦ｐ／(ｐ+ｑ)≦0.3、好ましくは0.05≦ｐ／(ｐ+ｑ)≦0.2の範囲である）
で表わされるオルガノハイドロジェンポリシロキサン
【００５９】
本（E1）成分の上記Ｒ⁶および基本的構造については、上記(c)成分に関しての例示と同じものが例示される。また、上記ｐ／(ｐ+ｑ)の比の値が0.01未満であると架橋構造の形成による網状化が不十分となり、0.3より大きいと初期硬化後の未反応のＳｉＨ基の残存量が多くなり、水分等による経時的な余剰の架橋反応が進行し、得られる放熱部材の柔軟性が損なわれることとなる。
【００６０】
（E2）下記一般式（４）：
【００６１】
【化７】

（式中、Ｒ⁷は独立に炭素原子数１〜６の１価アルキル基であり、ｒは５〜1,000、好ましくは10〜100の整数である）
で表わされるオルガノハイドロジェンポリシロキサン
【００６２】
本（E2）成分のＲ⁷については、上記(c)成分に関しての例示と同じものが例示される。また、上記ｒが５未満であると揮発性成分となりやすいため電子部品に適用するうえで好ましくないし、1,000より大きいと組成物の粘度が高くなり取り扱いが困難となる。
【００６３】
本（Ｅ）成分の配合量は、上記（Ｄ）成分中のアルケニル基１モルに対する、該（Ｅ）成分中のＳｉＨ基のモル数が0.6〜5.0モル、好ましくは0.7〜3.5モルとなる量である。前記配合量が0.6未満であると十分な架橋構造を形成できず、必要な硬度が得られないことから好ましくない。また、5.0よりも大きいと未反応のＳｉＨ基が残存して水分等により余剰の架橋反応を生じ、得られる放熱部材の硬度が高くなり柔軟性が損なわれるため好ましくない。
【００６４】
上記(E1)および(E2)成分を併用する場合、その配合割合は、［(E1)中のＳｉＨ基の個数／(E2)中のＳｉＨ基の個数］の比の値が1.0〜10.0、好ましくは1.5〜5.0となる範囲である。前記値が1.0未満であると得られる放熱部材の柔軟性が損なわれ、また、10.0より大きいと硬化が不十分となることがある。
【００６５】
＜場合により配合する成分＞
上記（Ａ）成分の硬化性シリコーン粘着剤が、有機過酸化物硬化型のものである場合、更に、上記(d)成分の白金系触媒および(e)成分の付加反応制御剤を配合することが必要となる。その種類等については上記と同じである。白金系触媒の配合量は、特に限定されず、触媒としての有効量でよいが、通常、(Ｄ)成分に対して本成分中の白金金属原子が重量単位で１〜500ppmとなる量とするのがよい。付加反応制御剤の配合量は0.01〜１重量部の範囲とするのがよい。
【００６６】
［付加的成分−２］
＜（Ｆ）成分＞
本発明組成物を構成する上記（Ａ）〜（Ｃ）成分等に加えて、得られる放熱部材が、発熱性電子部品と放熱部品との間に配置された際に、強固に密着してしまいリワーク性を損ねることを抑制すること、および、シート等の形状に成形した際に、表面粗さを低減させることを目的として、更に、
（Ｆ）ケイ素原子に結合しているアルケニル基および水素原子を含まない、25℃における粘度が3,000mPa・s以下の直鎖状オルガノポリシロキサン： １〜200重量部
を付加的に配合することが有効である。
【００６７】
この（Ｆ）成分としては、例えば、ジメチルポリシロキサン、エチルメチルポリシロキサン、プロピルメチルポリシロキサン等のアルキルメチルシポリシロキサン；フェニルメチルポリシロキサン、トリルメチルポリシロキサン等のアリールメチルポリシロキサン；3,3,3-トリフロロプロピルメチルポリシロキサン、2-ノナフルオロブチルメチルポリシロキサン等のハロゲン化炭化水素基を有するポリシロキサンが挙げられる。これらは１種単独でも２種以上組み合わせて用いることができる。これらの中でも特にコストの点から、ジメチルポリシロキサン、フェニルメチルポリシロキサンが好ましい。
【００６８】
この（Ｆ）成分の25℃における粘度は、取り扱い性の点から3,000mPa・s以下とすることが好ましい。
（Ａ）成分に対する該（Ｆ）成分の配合量が１重量部未満であると上記効果が得られず、また、200重量部より多いと得られる放熱部材の熱伝導率が乏しいものとなる。
【００６９】
［その他の添加剤］
本発明組成物には、任意成分として、作業性および加工性向上のため、トルエン、キシレン、ヘキサン、ヘプタン、アセトン、メチルエチルケトン等の溶剤を配合することができる。
【００７０】
［粘着性放熱部材の製造方法］
(1)本発明組成物は、上記の各成分を２本ロール、バンバリーミキサー、ドウミキサー（ニーダー）、ゲートミキサー、プラネタリーミキサー等のゴム練機を用い、場合によっては加熱することによって均一に混合した後、場合により含有される溶剤を揮発・蒸散させることにより得ることができる。
【００７１】
(2)次いで、上記混練り後の組成物を溶剤に溶解させた後、発熱性電子部品または放熱部品面にシート状、フィルム上に塗工成形して、溶剤を揮発・蒸散させ、次いで80〜180℃程度の温度で加熱処理を施して（Ａ）成分の架橋・硬化反応を行うすることにより粘着性放熱部材を形成することができる。
【００７２】
(3)また、離型処理したポリマーフィルム、例えば、フッ素系離型剤を塗布したポリエチレンテレフタレートフィルム、フッ素系離型剤を塗布したポリプロピレンフィルム、シリコーン系離型剤を塗布したポリエチレンテレフタレートフィルム、シリコーン系離型剤を塗布したポリプロピレンフィルム等の上に、上記混練り後の組成物を溶剤に溶解させた後、塗工成形して、溶剤を揮発・蒸散させ、更に前記離型処理したポリマーフィルムで表面を被覆して、シート、フィルム等の形状を有する（未硬化状態の）粘着性放熱部材を得ることができる。なお、この放熱部材の使用・実装に際して、前記ポリマーフィルムは剥離・除去される。次いで、発熱性電子部品と放熱部品との間に密着させて介装し、80〜180℃程度の温度で加熱処理を施して（Ａ）成分の架橋・硬化反応を行う。
【００７３】
(4)更に、本発明組成物から得られる粘着性放熱部材の適用形態により、上記(3)のポリマーフィルム被覆された（未硬化段階の）粘着性放熱部材を、80〜180℃程度の温度で加熱処理を施して（Ａ）成分の架橋・硬化反応を行って、シート、フィルム等の形状を有する粘着性放熱部材としてもよい。この場合も、使用・実装に際して、前記ポリマーフィルムは剥離・除去される。
【００７４】
【実施例】
以下に、調製例、実施例および比較例を示し、本発明を具体的に説明するが、本発明は下記の実施例に限定されるものではない制限されるものではない。なお、下記例中の「部」は重量部を示す。「Ｍｅ」はメチル基を、「Ｖｉ」はビニル基を表す。
【００７５】
［調製例１］（（Ａ）成分：硬化性シリコーン粘着剤の調製）
５Ｌゲートミキサー（商品名：５リットルプラネタリーミキサー、井上製作所(株)製）を用いて、室温で下記成分を下記の混合比の割合でで30分間混合し、硬化性シリコーン粘着剤（Ａ−１〜Ａ−５）を得た。
【００７６】
(a)Ｍｅ₃ＳｉＯ_1/2単位／ＳｉＯ₂単位のモル比が0.85であるオルガノポリシロキサンの60重量％トルエン溶液
(b)下記構造式で表わされるメチルビニルポリシロキサン
【００７７】
【化８】

(c)下記構造式で表わされるメチルハイドロジェンポリシロキサン
【００７８】
【化９】

(d)白金-ジビルテトラメチルジシロキサン錯体を１重量％含有するトルエン溶液（白金金属原子として重量単位で5,000ppm含有）
【００７９】
(e)1-エチニル-1-シクロヘキサノールの50重量％トルエン溶液
(f)下記構造式で表わされるジメチルポリシロキサン
【００８０】
【化１０】

(g)ジベンゾイルパーオキサイド
【００８１】
・付加反応硬化型シリコーン粘着剤Ａ−１の組成
(a)：83部（固形分=50部）、(b)：50部、(c)：0.37部、(d)：0.8部（固形分=0.008部）、(e)0.2部（固形分=0.1部）、トルエン：34部
・付加反応硬化型シリコーン粘着剤Ａ−２の組成
(a)：100部（固形分=60部）、(b)：40部、(c)：0.74部、(d)：0.8部（固形分=0.008部）、(e)0.2部（固形分=0.1部）、トルエン：27部
・付加反応硬化型シリコーン粘着剤Ａ−３の組成
(a)：108部（固形分=65部）、(b)：35部、(c)：0.74部、(d)：0.8部（固形分=0.008部）、(e)0.2部（固形分=0.1部）、トルエン：34部
【００８２】
・有機過酸化物硬化型シリコーン粘着剤Ａ−４の組成
(a)：100部（固形分=60部）、(f)：40部、(c)：0.74部、(g)：２8部、トルエン：27部
・Ａ−５（(b)成分を配合しない比較用）の組成
(a)：167部（固形分=100部）、(c)：0.37部、(d)：0.8部（固形分=0.008部）、(e)0.2部（固形分=0.1部）
【００８３】
［実施例１〜１１、比較例１〜５］
５Ｌゲートミキサー（商品名：５リットルプラネタリーミキサー、井上製作所(株)製）を用いて、上記［調製例１］で得たＡ−１〜Ａ−５の組成を有する組成物（但し、固形分含有量を100重量部としたもの）に、更に、室温で下記成分を表１〜表３に記載の配合量（重量部）を加えて１時間混合して、粘着性放熱部材用の組成物を得た。
【００８４】
（Ｂ）熱伝導性充填剤
Ｂ−１：平均粒径7.4μｍのアルミニウム粉末
Ｂ−２：平均粒径5.3μｍのアルミナ粉末
Ｂ−３：平均粒径1.0μｍの酸化亜鉛粉末
【００８５】
（Ｃ）下記構造のオルガノシラン
Ｃ−１：Ｃ₁₀Ｈ₂₁Ｓｉ(ＯＣＨ₃)₃
Ｃ−２：Ｃ₆Ｈ₁₃Ｓｉ(ＯＣＨ₃)₃
（Ｄ）両末端がジメチルビニルシリル基で封鎖され、25℃における粘度が600mPa・sのジメチルポリシロキサン
（E1）下記構造式で表わされるメチルハイドロジェンポリシロキサン
【００８６】
【化１１】

（E2）下記構造式で表わされるメチルハイドロジェンポリシロキサン
【００８７】
【化１２】

（Ｆ）直鎖型オルガノポリシロキサン：ＫＦ−５４（商品名、信越化学工業(株)製）
【００８８】
［粘着性放熱部材の調製］
上記実施例１〜１１、比較例１〜５で得られた組成物をフッ素系離型剤を塗布したポリエチレンテレフタレート製フィルムの上にマルチコーター（商品名：マルチコーターMODEL200、(株)ヒラノテクシード製）を用いて、塗工成形して溶剤を揮発・蒸散させ、フッ素系離型剤を塗布したポリエチレンテレフタレート製フィルムで表面を被覆して（未硬化段階の）粘着性放熱部材を得た。次いで、これを、120℃の温度で30分間加熱処理し、架橋・硬化反応を行って、シート状の粘着性放熱部材を得た。
【００８９】
［諸特性値の測定・評価方法］
上記で得られた各粘着性放熱部材の特性値を、下記の試験方法による測定した。その結果を表１〜表３に示した。
【００９０】
厚み、熱抵抗
二枚の標準アルミニウムプレートの間に（フッ素系離型剤を塗布したポリエチレンテレフタレート製フィルムを剥離・除去した）放熱部材シートを挟んで、熱抵抗測定用サンプルを調製した。このサンプルの厚みを測定し、予め厚みが分かっている標準アルミプレートの厚み分を差し引くことによって、実質的なシートの厚みを求めた。
なお、上記測定に際しては、マイクロメーター（(株)ミツトヨ製、型式；Ｍ８２０−２５ＶＡ）を用いた。
また、前記サンプルについて熱抵抗（単位：℃-ｃｍ²/ｗ）を熱抵抗測定器（ホロメトリックス社製、マイクロフラッシュ）を用いて測定した。
【００９１】
粘着性
シートに成形した放熱部材（フッ素系離型剤を塗布したポリエチレンテレフタレート製フィルムを剥離・除去したもの）をステンレス板に貼りつけ、ゴム層で被覆された重さ２kgのローラーを１往復させることにより圧着し、室温で約１時間放置した後、接着面が垂直となるよう設置し、１分間放置して脱落の有無を確認し、次のとおり評価した。
評価Ａ：脱落無し
評価Ｂ：脱落あり
【００９２】
ヒートサイクル試験
25mm角にカットした（フッ素系離型剤を塗布したポリエチレンテレフタレート製フィルムを剥離・除去した）放熱部材シートを２枚の透明なガラス板(厚さ１mm，50mm×75mm)に挟み、次いでダブルクリップで左右両側を挟んで（圧力：196kPa（2kgf/cm²））サンプルとした。このサンプルを−30℃〜100℃のサイクル試験機に投入し、500サイクル後（１サイクル：30分間）のサンプルに発生したクラックの数を目視により観察し、次のとおり、評価した。
評価Ａ：クラック数 ０〜５
評価Ｂ：クラック数 ６以上
【００９３】
放熱部材シートの表面粗さ
（フッ素系離型剤を塗布したポリエチレンテレフタレート製フィルムを剥離・除去した）放熱部材シートの表面粗さを、表面粗さ測定器（(株)ミツトヨ製、型式；Ｓｕｆｅｃｔ−５０１）を用いて、算術平均粗さ（カットオフ値：λc＝８mm）により評価した。
【００９４】
【表１】

【００９５】
【表２】

【００９６】
【表３】

【００９７】
［評価］
比較例１は、硬化性ではないシリコーン粘着剤（Ａ−５）を用いた例であり、また、比較例２は、付加硬化型シリコーン組成のものであるが、上記(a)成分のオルガノポリシロキサンを欠如しており、ともに、粘着性の点で劣るものであることが分る。また、比較例３は、（Ｃ）成分のオルガノシランを欠如し、また、比較例４は、（Ｂ）成分の熱伝導性充填剤の配合量が多すぎるため、ともに、均一な組成物が得られていない。比較例５は、比較例４とは逆に（Ｂ）成分の熱伝導性充填剤の配合量が少なすぎるものであり、このため熱抵抗が高いものしか得られないことが分る。
【００９８】
【発明の効果】
本発明組成物からは、表面が粘着性を有する放熱部材を得ることができ、その粘着性の故に、ＩＣパッケージ等の発熱性電子部品とフィン等の放熱部品との間に介装した場合に、前記放熱部材が前記両者間で圧接固定されると、発熱性電子部品または放熱部品の表面に凹凸が存在する場合でも、その凹凸に放熱部材が追従して空隙を生じさせることがなく、界面熱抵抗の上昇を効果的に抑制することができることから、放熱効果を確実に発揮することができ、電子部品全体の信頼性を向上させることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressure-sensitive adhesive silicone composition for a heat radiation member containing a curable silicone pressure-sensitive adhesive, a heat conductive filler, and an organosilane (containing a monovalent alkyl group having 6 to 15 carbon atoms). A heat-dissipating member having excellent heat conductivity and sandwiched between a heat-generating electronic component that is higher than room temperature during operation and a heat-dissipating component that dissipates heat generated from the heat-generating electronic component. The present invention relates to an adhesive silicone composition suitable for forming.
[0002]
[Prior art]
The circuit design of recent electronic devices such as televisions, radios, computers, medical equipment, office machines, communication devices, etc. is becoming more complex. For example, as integrated circuits containing hundreds of thousands of transistors for these and other devices have been manufactured, design complexity has increased while smaller electronic components have been manufactured. As more and more components can be incorporated in increasingly smaller areas, device dimensions continue to shrink.
[0003]
These electronic components, especially IC packages such as CPUs mounted on a printed circuit board, have problems that the performance deteriorates due to temperature rise due to heat generation during use, or that a failure or malfunction occurs. In order to improve the above, conventionally, a heat-dissipating sheet or heat-dissipating grease having good thermal conductivity is interposed between the IC package and heat-dissipating components such as heat-dissipating fins. However, since the calorific value increases year by year as electronic components become smaller and higher in performance, development of a heat radiating member with better heat radiating performance is required. Although the conventional heat dissipation sheet has the merit that it can be mounted easily, the content of the heat conductive filler is limited from the viewpoint of processability in the manufacturing process, and the interfacial thermal resistance during mounting is further reduced. Since it is large, the actual heat dissipation performance is not fully exhibited. In addition, heat radiation grease has the advantage of following and closely adhering to the adherend surface without being affected by unevenness of the surface of the CPU, heat radiation fins, etc. There are drawbacks such as oil spilling when used for a long time.
[0004]
In contrast, JP 2000-509209 A and JP 2000-327917 A describe a phase change heat radiation sheet. However, in these cases, since there is a limit to the content of the heat conductive filler from the viewpoint of workability and workability, the contact surface after the phase transition follows and adheres mainly with the resin component, Although the increase in interfacial thermal resistance due to void formation can be prevented, there is a drawback that the resin itself causes interfacial thermal resistance.
[0005]
Japanese Patent Application Laid-Open No. 1-215855 discloses a tetrafunctional siloxane unit (ie, SiO 2) in the molecule of the heat dissipation sheet composition.₂Units) and monofunctional siloxane units (ie R)_ThreeSiO_1/2Although it is described that organopolysiloxane consisting of (unit) is added, this heat-dissipating sheet is insufficient in adhesiveness and has a large interfacial thermal resistance at the time of mounting, so that the actual heat dissipating performance is not sufficiently exhibited. There were drawbacks.
[0006]
[Problems to be solved by the invention]
In view of the above-mentioned problems of the prior art, the object of the present invention is that the surface of a sheet or the like placed between a heat-generating electronic component and a heat-dissipating component such as a heat-dissipating fin is particularly sticky. Adhesive heat radiating member with high heat conductive filler that can form adhesive heat radiating member with excellent heat radiating performance by reducing interface contact thermal resistance without causing voids at the interface It is to provide an adhesive silicone composition.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have found that a heat radiating member having the above performance is obtained from a composition in which a curable silicone adhesive is combined with a thermally conductive filler and a long-chain alkyl group-containing organosilane. The inventors have found that the present invention can be obtained and have reached the present invention.
[0008]
That is, the present invention
(A) (a) R¹ _ThreeSiO_1/2Unit (in the formula, R¹Independently represents a monovalent hydrocarbon group having 1 to 6 carbon atoms other than an alkenyl group) and SiO₂Including units, R¹ _ThreeSiO_1/2Unit / SiO₂Organopolysiloxane having a unit molar ratio of 0.6 to 1.7
Curable silicone adhesive containing: 100 parts by weight,
(B) Thermally conductive filler: 500 to 3,000 parts by weight, and
(C) The following general formula (1):
R² _aR^Three _bSi (OR^Four)_4-ab      (1)
(Wherein R²Is a monovalent alkyl group having 6 to 15 carbon atoms, R^ThreeIs an unsubstituted or substituted monovalent hydrocarbon group having 1 to 8 carbon atoms, R^FourIs independently a monovalent alkyl group having 1 to 6 carbon atoms, a is an integer of 1 to 3, b is an integer of 0 to 2, and the sum of a + b is an integer of 1 to 3)
Organosilane represented by: 0.1-50 parts by weight
The adhesive silicone composition for heat radiating members characterized by including this is provided.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
[0010]
[(A) component]
The component (A) curable silicone pressure-sensitive adhesive imparts adhesiveness to the heat dissipating member obtained from the composition of the present invention, and the heat dissipating member is composed of exothermic electronic components and heat dissipating components by blending the components. It has excellent properties that it adheres well to both sides and can avoid an increase in interfacial thermal resistance due to the formation of voids at the interface.
[0011]
This component (A) is, as described above, (a) R¹ _ThreeSiO_1/2Unit (in the formula, R¹Independently represents a monovalent hydrocarbon group having 1 to 6 carbon atoms other than an alkenyl group) and SiO₂Including units, R¹ _ThreeSiO_1/2Unit / SiO₂A polyorganosiloxane having a unit molar ratio of 0.6 to 1.7 is included.
[0012]
R in component (a) above¹As, for example, alkyl group such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group; cycloalkyl group such as cyclopentyl group, cyclohexyl group; phenyl group, etc., among these, A methyl group is preferred.
[0013]
R¹ _ThreeSiO_1/2Unit / SiO₂The molar ratio of units is 0.6 to 1.7, preferably 0.6 to 1.0. If the molar ratio is less than 0.6, the adhesive strength may decrease, and if it exceeds 1.7, the adhesive strength may decrease or the force for holding the heat conductive filler may decrease. .
[0014]
The component (a) may further contain a silanol group (≡SiOH), and its content is 4.0 mol% or less. When the silanol group is contained, the property that the tackiness is improved by the condensation reaction can be added.
[0015]
In addition, the component (a) can be easily obtained by hydrolyzing and condensing a silane compound mixture having a specific composition ratio, for example, consisting of trialkoxyalkylsilane and tetraalkoxysilane, in accordance with a conventionally known method. Obtainable.
[0016]
This component (a) can be used after being diluted with an organic solvent such as toluene, xylene, isopropyl alcohol or the like in order to enhance dispersibility when blended with other components. (However, the amount of the organic solvent used does not include the amount of the curable silicone pressure-sensitive adhesive of the component (A) corresponding to the component (B) described later.)
[0017]
<Addition reaction curable silicone component>
The component (a) alone is highly filled with the heat conductive filler of the component (B) to be described later, and even as a heat radiating member, it cannot maintain its stable shape and has sufficient adhesiveness. A heat radiating member cannot be obtained. Therefore, in order for the composition of the present invention to obtain a heat radiating member having a crosslinked structure, it is an important feature that the component (A) is a curable silicone pressure-sensitive adhesive containing a curable silicone component.
[0018]
The curable silicone pressure-sensitive adhesive as the component (A) can be an addition reaction curable type.
In this case, as the composition of the component (A),
Component (a): 80 to 20 parts by weight,
(b) Organopolysiloxane having two or more alkenyl groups bonded to silicon atoms in one molecule and a viscosity at 25 ° C. of 10,000 mPa · s or more: 20 to 80 parts by weight (provided that (a) The total amount of + (b) is 100 parts by weight)
(c) The following general formula (2):
[0019]
[Formula 4]

[0020]
(Wherein R^FiveIs independently a monovalent alkyl group having 1 to 6 carbon atoms, m and n are integers of 1 or more, the sum of m + n is in the range of 3 to 300, and m / (m + n) The ratio value of is greater than 0.3)
The amount of the SiH group in the component (c) is 0.5 to 20 mol relative to 1 mol of the alkenyl group in the component (b),
(d) platinum-based catalyst: effective amount, and
(e) Addition reaction control agent: 0.01 to 1 part by weight
Are preferably used.
[0021]
The molecular structure of the alkenyl group-containing organopolysiloxane of the component (b) is not limited, and examples thereof include linear, branched, and partially branched linear, preferably linear or partially It is a straight chain with a branch. The organopolysiloxane is a single polymer having these molecular structures, a copolymer comprising these molecular structures, or a mixture of these polymers.
[0022]
In addition, examples of the alkenyl group bonded to the silicon atom in the component (b) include a vinyl group, an allyl group, a 1-butenyl group, and a 1-hexenyl group. Among these, a vinyl group is particularly preferable from the viewpoint of ease of synthesis, cost, and the like.
[0023]
Examples of the group bonded to the silicon atom other than the alkenyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, and a dodecyl group. An cycloalkyl group such as a cyclopentyl group and a cyclohexyl group; an aryl group such as a phenyl group, a tolyl group, a xylyl group and a naphthyl group; an aralkyl group such as a benzyl group, a phenethyl group and a 2-phenylpropyl group; a chloromethyl group , Halogenated alkyl groups such as 3,3,3-trifluoropropyl group and 3-chloropropyl group. Of these, 90 mol% or more is preferably a methyl group from the viewpoint of ease of synthesis, cost, and the like.
[0024]
Further, the bonding site of the alkenyl group bonded to the silicon atom may be either at the end of the molecular chain or in the middle of the molecular chain, but is preferably only at both ends of the molecular chain from the point of tackiness of the component (A).
[0025]
The property of the organopolysiloxane of component (b) may be oily or raw rubber, and the viscosity at 25 ° C. should be 10,000 mPa · s or more, and it should be 20,000 mPa · s or less from the viewpoint of handling workability. preferable. When the viscosity is less than 10,000 mPa · s, the shape stability of the obtained heat radiating member tends to be lowered.
[0026]
Specific examples of the organopolysiloxane of component (b) include, for example, molecular chain both ends dimethylvinylsiloxy group-blocked polydimethylsiloxane, molecular chain both ends methyldivinylsiloxy group-blocked polydimethylsiloxane, and molecular chain both ends dimethylsiloxane. And vinylsiloxy-blocked dimethylsiloxane / methylphenylsiloxane copolymer. These can be used alone or in combination of two or more.
[0027]
The blending amount of the component (a) and the component (b) in the curable silicone pressure-sensitive adhesive of the component (A) is 80 to 20 parts by weight, preferably 70 to 30 parts by weight of the component (a). 20 to 80 parts by weight of component, preferably 30 to 70 parts by weight (provided that (a) + (b) = 100 parts by weight), and if the amount of component (a) is too small, Even if it is too much, there is a problem that the adhesive strength (tack) may be lowered.
[0028]
The following general formula (2) of the component (c):
[0029]
[Chemical formula 5]

(Wherein R^Five, M and n are as described above)
The organohydrogenpolysiloxane represented by the above formula acts as a crosslinking agent.
[0030]
R in the above formula^FiveExamples thereof include those exemplified as the group bonded to the silicon atom other than the alkenyl group of the component (b). Of these, a methyl group is preferred.
Regarding m and n, the value of the ratio m / (m + n) exceeds 0.3, preferably 0.5 or more. When the value is 0.3 or less, sufficient tackiness cannot be imparted to the component (A).
The viscosity at 25 ° C. of the component (c) is preferably 1 to 5,000 mPa · s, particularly preferably 5 to 500 mPa · s from the viewpoint of handleability.
[0031]
The amount of component (c) used is such that the number of moles of SiH groups in component (c) is 0.5 to 20 moles, particularly preferably 0.8 to 15 moles per mole of alkenyl groups in component (b). Is the amount. If the number of moles is less than 0.5, the crosslink density is low, and the holding power of the thermally conductive filler may be reduced. Conversely, if it exceeds 20 moles, the adhesive strength may be reduced.
[0032]
Specific examples of the organohydrogenpolysiloxane of component (c) include, for example, a trimethylsiloxy group-capped dimethylsiloxane / methylhydrogensiloxane copolymer having both molecular chains and a trimethylsiloxy group-capped dimethylsiloxane having both molecular chains. -A methyl hydrogen siloxane-methyl phenyl siloxane copolymer etc. are mentioned. These can be used singly or in combination of two or more.
[0033]
The platinum catalyst of component (d) is a component that promotes the hydrosilylation addition reaction between the alkenyl group in component (b) and the SiH group in component (c).
Examples of the component (d) include platinum black, chloroplatinic acid (alcohol solution), platinum olefin complexes, platinum alcohol complexes, platinum alkenylsiloxane complexes, platinum carbonyl complexes, and the like. In the present composition, the content of the platinum-based catalyst is not particularly limited, and may be an effective amount as a catalyst. Usually, the platinum metal atom in the component is 1 to 500 ppm by weight with respect to the component (b). The amount is preferably 10 to 200 ppm. When the content of this component is too small, there is no catalytic effect, and even when used in a large amount, the crosslinking / curing speed is not particularly improved, which may be economically disadvantageous.
[0034]
The addition reaction control agent of the component (e) is a component that suppresses the catalytic activity in order to prevent curing due to the addition reaction at room temperature and to secure the shelf life and pot life of the addition reaction curable type composition of the present invention. For example, known control agents such as acetylene compounds such as 1-ethynyl-1-cyclohexanol, various nitrogen compounds, organic phosphorus compounds, oxime compounds, and organic chloro compounds are used. The amount is 0.01 to 1 part by weight, preferably 0.03 to 0.30 part by weight.
[0035]
This component (e) can be used after being diluted with an organic solvent such as toluene, xylene, isopropyl alcohol, etc., in order to improve the dispersibility in the silicone component. (However, the amount of the organic solvent used does not include the amount of the curable silicone pressure-sensitive adhesive of the component (A) corresponding to the component (B) described later.)
[0036]
<Organic peroxide curable silicone component>
Further, the curable silicone pressure-sensitive adhesive as the component (A) can be an organic peroxide curable type.
In this case, as the composition of the component (A),
Component (a): 80 to 20 parts by weight,
(f) Organopolysiloxane having a viscosity at 25 ° C. of 10,000 mPa · s or more: 20 to 80 parts by weight (provided that the total amount of (a) + (f) is 100 parts by weight), and
(g) Organic peroxide: 0.2 to 10 parts by weight
Are preferably used.
[0037]
Examples of the group bonded to the silicon atom of the organopolysiloxane of the component (f) include a hydroxyl group; a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, Alkyl groups such as decyl group and dodecyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; aryl groups such as phenyl group, tolyl group, xylyl group and naphthyl group; vinyl group, allyl group, 1-butenyl group, 1- Alkenyl groups such as hexenyl group; Aralkyl groups such as benzyl group, phenethyl group, 2-phenylpropyl group; Halogenated alkyl groups such as chloromethyl group, 3,3,3-trifluoropropyl group, 3-chloropropyl group, etc. Is mentioned. Among these, a methyl group is particularly preferable.
[0038]
In addition, as the organopolysiloxane of the component (f), the following formula:
R_ThreeSiO- (R₂SiO)_c-SiR_Three
(HO) R₂-(R₂SiO)_d-SiR₂(OH)
(In the formula, R is the same as the above example, and c and d are each an integer of 500 to 20,000)
The diorganopolysiloxane represented by these can be illustrated suitably.
[0039]
The property of the organopolysiloxane of component (f) may be oily or raw rubber, and the viscosity at 25 ° C. should be 10,000 mPa · s or more, and should be 20,000 mPa · s or less from the viewpoint of handling workability. preferable. When the viscosity is less than 10,000 mPa · s, the shape stability of the obtained heat radiating member tends to be lowered.
[0040]
Specific examples of the organopolysiloxane of component (f) include, for example, molecular chain both ends dimethylvinylsiloxy group-blocked polydimethylsiloxane, molecular chain both ends methylphenylvinylsiloxy group-blocked polydimethylsiloxane, molecular chain both ends. Dimethylvinylsiloxy group-blocked dimethylsiloxane / methylphenylsiloxane copolymer, molecular chain both ends dimethylvinylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane copolymer, molecular chain both ends trimethylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane copolymer Dimethylvinylsiloxy group-blocked polymethyl (3,3,3-trifluoropropyl) siloxane, molecular chain-end silanol group-blocked dimethylsiloxane / methylvinylsiloxane copolymer, molecular chain-end silanol group Chain dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymers. These can be used alone or in combination of two or more.
[0041]
The blending amount of the component (a) and the component (f) in the curable silicone pressure-sensitive adhesive of the component (A) is 80 to 20 parts by weight, preferably 70 to 30 parts by weight of the component (a). 20 to 80 parts by weight of component, preferably 30 to 70 parts by weight (provided that (a) + (f) = 100 parts by weight), and if the amount of component (a) is too small, Even if it is too much, there is a problem that the adhesive strength (tack) may be lowered.
[0042]
Examples of the organic peroxide of the component (g) include benzoyl peroxide, 4,4′-dimethylbenzoyl peroxide, 3,3′-dimethylbenzoyl peroxide, 2,2′-dimethylbenzoyl peroxide, 2 , 2 ', 4,4'-Tetrachlorobenzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, di-t-butyl peroxide, t- Examples include butyl perbenzoate. These can be used singly or in combination of two or more. The amount of the organic peroxide added is preferably 0.5 to 20 parts by weight, particularly 0.7 to 5 parts by weight, based on 100 parts by weight of the total of the components (a) and (f).
[0043]
The component (a) and the component (f) may be used simply as a mixture, or when the component (f) has silanol groups (SiOH) at both ends of the molecular chain, It may be used as a condensation reaction product obtained by subjecting the component a) and the component (f) to a condensation reaction. In order to perform the latter condensation reaction, a mixture of the two components dissolved in a solvent such as toluene may be reacted at room temperature to reflux using an alkaline catalyst.
[0044]
[Component (B)]
The heat conductive filler of the component (B) of the present invention is blended at a high ratio, imparts good heat conductivity to the adhesive heat radiating member obtained from the composition of the present invention, and provides heat dissipation characteristics of the heat-generating electronic component. It is a component to improve.
[0045]
Examples of the component (B) include non-magnetic metals such as copper and aluminum; metal oxides such as zinc oxide, alumina, silica, magnesia, titania and zirconia; and metal nitrides such as aluminum nitride, silicon nitride and boron nitride. In addition to materials, artificial diamond, silicon carbide, etc., all materials that are generally known as heat conductive fillers can be used. These can be used alone or in combination of two or more.
[0046]
The component (B) preferably has a spherical shape and preferably has an average particle size of 0.1 to 100 μm, particularly 0.1 to 25 μm. When the average particle size is less than 0.1 μm, the viscosity at the time of mixing and filling becomes high and workability becomes poor. Also, when formed and used as a heat radiating member, the viscosity at the time of thermocompression bonding is high, the gap between the electronic component and the heat radiating component is increased, the heat resistance is increased, and it is difficult to exhibit sufficient heat radiating performance. On the other hand, if it exceeds 100 μm, the viscosity at work decreases, but when actually used as a heat radiating member, the gap between the electronic component and the heat radiating component during thermocompression bonding cannot be crimped to 100 μm or less. It becomes high as thermal resistance and it becomes difficult to express sufficient heat dissipation performance. In order to improve both fluidity and thermal conductivity, it is desirable that the thickness is 25 μm or less. In order to improve heat conduction, it is recommended to use two or more kinds of particles having different average particle sizes so as to approach close-packing.
[0047]
With respect to 100 parts by weight of component (A), the amount of component (B) is in the range of 500 to 3000 parts by weight, preferably 850 to 2000 parts by weight. If the blending amount is less than 500 parts by weight, the heat dissipation member obtained will have poor thermal conductivity, and if it exceeds 3000 parts by weight, the workability will be poor.
[0048]
[Component (C)]
(C) component which comprises the adhesive heat radiating member of this invention is following General formula (1):
R² _aR^Three _bSi (OR^Four)_4-ab      (1)
(Wherein R²Is a monovalent alkyl group having 6 to 15 carbon atoms, R^ThreeIs an unsubstituted or substituted monovalent hydrocarbon group having 1 to 8 carbon atoms, R^FourIs a monovalent alkyl group having 1 to 6 carbon atoms, a is an integer of 1 to 3, b is an integer of 0 to 2, and the sum of a + b is an integer of 1 to 3)
It is an organosilane represented by.
[0049]
This component (C) improves the “wetting property” between the curable silicone pressure-sensitive adhesive as the component (A) and the thermally conductive filler as the component (B). In the composition of the present invention, the component (A) is a matrix. Thus, the component (B) has an important role of allowing the component (B) to be uniformly dispersed at a high filling rate.
[0050]
R above²Examples thereof include hexyl group, octyl group, nonyl group, decyl group, dodecyl group, tetradecyl group and the like. This R¹When an organosilane having an alkyl group having less than 6 carbon atoms is used instead of the group, the “wetting property” with the filler is not sufficient, and the alkyl group having more than 15 carbon atoms is also used. When the organosilane used is used, the organosilane is solidified at room temperature, which is inconvenient to handle and lowers the low temperature characteristics of the resulting heat dissipation member.
[0051]
R above^ThreeAs, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group, a hexyl group or an octyl group; a cycloalkyl group such as a cyclopentyl group or a cyclohexyl group; an alkenyl group such as a vinyl group or an allyl group; a phenyl group or a tolyl group Aryl groups such as 2-phenylethyl group, 2-methyl-2-phenylethyl group, and the like; 3,3,3, -trifluoropropyl group, 2- (nanofluorobutyl) ethyl group, 2- ( Examples thereof include halogenated hydrocarbon groups such as heptadecafluorooctyl) ethyl group and p-chlorophenyl group. Among these, methyl group and ethyl group are particularly preferable.
[0052]
R above^FourExamples thereof include one or more alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group, and a methyl group and an ethyl group are particularly preferable.
Further, a is 1, 2 or 3, and 1 is particularly preferable.
[0053]
Specific examples of the organosilane represented by the general formula (1) include the following.
C₆H₁₂Si (OCH_Three)_Three, C_TenH_{twenty one}Si (OCH_Three)_Three,
C₁₂H_{twenty five}Si (OCH_Three)_Three, C₁₂H_{twenty five}Si (OC₂H_Five)_Three,
C_TenH_{twenty one}Si (CH_Three) (OCH_Three)₂, C_TenH_{twenty one}Si (C₆H_Five) (OCH_Three)₂,
C_TenH_{twenty one}Si (CH_Three) (OC₂H_Five)₂, C_TenH_{twenty one}Si (CH = CH₂) (OCH_Three)₂,
C_TenH_{twenty one}Si (CH₂CH₂CF_Three) (OCH_Three)₂
These can be used singly or in combination of two or more.
[0054]
With respect to 100 parts by weight of the component (A), the amount of the component (C) is in the range of 0.1 to 50 parts by weight, preferably 0.5 to 20 parts by weight. When the blending amount is less than 0.1 part by weight, the “wetting property” is poor, and the component (B) cannot be uniformly dispersed in the matrix of the component (A), and 50 parts by weight Even if it increases more, an effect does not increase in particular and it is uneconomical.
[0055]
[Additional component-1]
In addition to the above-mentioned components (A) to (C) constituting the composition of the present invention, the following components can be further added for the purpose of improving the strength of the obtained heat radiating member.
[0056]
<(D) component>
Component (D) has two or more alkenyl groups bonded to a silicon atom in one molecule, and has a viscosity at 25 ° C. of 10 mPa · s or more and less than 10,000 mPa · s, preferably 100 to 5,000 mPa · s. 10 to 500 parts by weight of the organopolysiloxane of s can be blended.
The alkenyl group and other groups bonded to the silicon atom of the component (D) and the basic structure of the component (D) are the same as those exemplified for the component (b). Further, when the viscosity of the component (D) at 25 ° C. is less than 10 mPa · s, the storage stability of the composition is deteriorated, and when it is 10,000 mPa · s or more, the extensibility of the composition is impaired.
[0057]
<(E) component>
As the component (E), the following component (E1) and / or component (E2) can be blended.
(E1) The following general formula (3):
[0058]
[Chemical 6]

(Wherein R⁶Is independently a monovalent alkyl group having 1 to 6 carbon atoms, p and q are integers of 1 or more, the sum of p + q is in the range of 5 to 100, and 0.01 ≦ p / (p + q) ≦ 0.3, preferably 0.05 ≦ p / (p + q) ≦ 0.2)
Organohydrogenpolysiloxane represented by
[0059]
R of this (E1) component⁶As for the basic structure, the same examples as those for the component (c) are exemplified. Further, when the value of the ratio p / (p + q) is less than 0.01, reticulation due to the formation of a crosslinked structure is insufficient, and when it is greater than 0.3, the residual amount of unreacted SiH groups after the initial curing is large. Thus, excessive cross-linking reaction over time due to moisture or the like proceeds, and the flexibility of the obtained heat radiating member is impaired.
[0060]
(E2) The following general formula (4):
[0061]
[Chemical 7]

(Wherein R⁷Is independently a monovalent alkyl group having 1 to 6 carbon atoms, and r is an integer of 5 to 1,000, preferably 10 to 100)
Organohydrogenpolysiloxane represented by
[0062]
R of this (E2) component⁷As for, the same examples as for the component (c) are exemplified. Further, when r is less than 5, it tends to be a volatile component, which is not preferable for application to electronic components. When it is more than 1,000, the viscosity of the composition becomes high and handling becomes difficult.
[0063]
The amount of component (E) is such that the number of moles of SiH groups in component (E) is 0.6 to 5.0 moles, preferably 0.7 to 3.5 moles per mole of alkenyl groups in component (D). It is. If the blending amount is less than 0.6, it is not preferable because a sufficient crosslinked structure cannot be formed and the required hardness cannot be obtained. On the other hand, when the ratio is larger than 5.0, unreacted SiH groups remain and an excessive crosslinking reaction occurs due to moisture or the like, so that the resulting heat dissipation member becomes harder and the flexibility is impaired.
[0064]
When the above components (E1) and (E2) are used in combination, the ratio of the ratio of [number of SiH groups in (E1) / number of SiH groups in (E2)] is 1.0 to 10.0, preferably Is a range of 1.5 to 5.0. When the value is less than 1.0, the flexibility of the obtained heat radiating member is impaired, and when it is more than 10.0, curing may be insufficient.
[0065]
<Components optionally blended>
When the curable silicone pressure-sensitive adhesive of component (A) is of an organic peroxide curable type, a platinum catalyst of component (d) and an addition reaction control agent of component (e) are further blended. Is required. About the kind etc., it is the same as the above. The compounding amount of the platinum-based catalyst is not particularly limited and may be an effective amount as a catalyst, but is usually an amount such that the platinum metal atom in the component is 1 to 500 ppm by weight with respect to the component (D). It is good. The addition amount of the addition reaction control agent is preferably in the range of 0.01 to 1 part by weight.
[0066]
[Additional component-2]
<(F) component>
In addition to the above-mentioned components (A) to (C) constituting the composition of the present invention, when the obtained heat dissipation member is disposed between the heat-generating electronic component and the heat-dissipating component, it adheres firmly. For the purpose of reducing the surface roughness when it is formed into a shape such as a sheet, etc.
(F) Linear organopolysiloxane containing no alkenyl groups and hydrogen atoms bonded to silicon atoms and having a viscosity at 25 ° C. of 3,000 mPa · s or less: 1 to 200 parts by weight
It is effective to add additionally.
[0067]
Examples of the component (F) include alkylmethylpolysiloxanes such as dimethylpolysiloxane, ethylmethylpolysiloxane, and propylmethylpolysiloxane; arylmethylpolysiloxanes such as phenylmethylpolysiloxane and tolylmethylpolysiloxane; 3,3 , 3-trifluoropropylmethylpolysiloxane, 2-nonafluorobutylmethylpolysiloxane, and other polysiloxanes having a halogenated hydrocarbon group. These can be used alone or in combination of two or more. Among these, dimethylpolysiloxane and phenylmethylpolysiloxane are particularly preferable from the viewpoint of cost.
[0068]
The viscosity of this component (F) at 25 ° C. is preferably 3,000 mPa · s or less from the viewpoint of handleability.
When the blending amount of the component (F) with respect to the component (A) is less than 1 part by weight, the above effect cannot be obtained, and when it is more than 200 parts by weight, the heat dissipation member obtained has poor thermal conductivity.
[0069]
[Other additives]
In the composition of the present invention, as an optional component, a solvent such as toluene, xylene, hexane, heptane, acetone, methyl ethyl ketone and the like can be blended for improving workability and workability.
[0070]
[Method for producing adhesive heat-dissipating member]
(1) The composition of the present invention is made uniform by heating each of the above components using a rubber kneader such as a two-roll, Banbury mixer, dough mixer (kneader), gate mixer, planetary mixer, etc. After mixing, it can be obtained by volatilizing and evaporating the solvent contained in some cases.
[0071]
(2) Next, after the composition after kneading is dissolved in a solvent, the sheet is formed on the surface of the heat-generating electronic component or the heat-dissipating component, and formed on a film to volatilize and evaporate the solvent. An adhesive heat-dissipating member can be formed by performing a heat treatment at a temperature of about ~ 180 ° C to carry out a crosslinking / curing reaction of the component (A).
[0072]
(3) Also, a release-treated polymer film, for example, a polyethylene terephthalate film coated with a fluorine-based mold release agent, a polypropylene film coated with a fluorine-based mold release agent, a polyethylene terephthalate film coated with a silicone mold release agent, silicone A polymer film obtained by dissolving the kneaded composition in a solvent on a polypropylene film or the like coated with a release agent, coating and molding, volatilizing and evaporating the solvent, and further releasing the polymer. The surface can be covered with an adhesive heat-dissipating member having a shape such as a sheet or a film (in an uncured state). The polymer film is peeled off and removed when the heat radiating member is used / mounted. Next, the heat-generating electronic component and the heat-dissipating component are placed in close contact with each other and subjected to a heat treatment at a temperature of about 80 to 180 ° C. to carry out a crosslinking / curing reaction of the component (A).
[0073]
(4) Further, according to the application form of the adhesive heat radiating member obtained from the composition of the present invention, the adhesive heat radiating member coated with the polymer film of (3) (in the uncured stage) is heated to a temperature of about 80 to 180 ° C. It is good also as an adhesive heat radiating member which has the shape of a sheet | seat, a film, etc. by performing heat processing in (A) and performing crosslinking | crosslinking and hardening reaction of (A) component. Also in this case, the polymer film is peeled and removed during use and mounting.
[0074]
【Example】
Hereinafter, the present invention will be described in detail with reference to Preparation Examples, Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following examples, “parts” represents parts by weight. “Me” represents a methyl group, and “Vi” represents a vinyl group.
[0075]
[Preparation Example 1] (Component (A): Preparation of curable silicone pressure-sensitive adhesive)
Using a 5 L gate mixer (trade name: 5 liter planetary mixer, manufactured by Inoue Seisakusho Co., Ltd.), the following components were mixed at room temperature for 30 minutes at the following mixing ratio, and a curable silicone pressure-sensitive adhesive (A- 1-A-5) was obtained.
[0076]
(a) Me_ThreeSiO_1/2Unit / SiO₂60 wt% toluene solution of organopolysiloxane with a unit molar ratio of 0.85
(b) Methyl vinyl polysiloxane represented by the following structural formula
[0077]
[Chemical 8]

(c) Methyl hydrogen polysiloxane represented by the following structural formula
[0078]
[Chemical 9]

(d) A toluene solution containing 1% by weight of a platinum-divirtetramethyldisiloxane complex (containing 5,000 ppm by weight as platinum metal atoms)
[0079]
(e) 50 wt% toluene solution of 1-ethynyl-1-cyclohexanol
(f) Dimethylpolysiloxane represented by the following structural formula
[0080]
[Chemical Formula 10]

(g) Dibenzoyl peroxide
[0081]
-Composition of addition reaction curable silicone adhesive A-1
(a): 83 parts (solid content = 50 parts), (b): 50 parts, (c): 0.37 parts, (d): 0.8 parts (solid content = 0.008 parts), (e) 0.2 parts (solid content) = 0.1 part), toluene: 34 parts
・ Composition of addition reaction curable silicone adhesive A-2
(a): 100 parts (solid content = 60 parts), (b): 40 parts, (c): 0.74 parts, (d): 0.8 parts (solid content = 0.008 parts), (e) 0.2 parts (solid content) = 0.1 part), toluene: 27 parts
-Composition of addition reaction curable type silicone adhesive A-3
(a): 108 parts (solid content = 65 parts), (b): 35 parts, (c): 0.74 parts, (d): 0.8 parts (solid content = 0.008 parts), (e) 0.2 parts (solid content) = 0.1 part), toluene: 34 parts
[0082]
-Composition of organic peroxide curable silicone adhesive A-4
(a): 100 parts (solid content = 60 parts), (f): 40 parts, (c): 0.74 parts, (g): 28 parts, toluene: 27 parts
・ Composition of A-5 (for comparison without blending component (b))
(a): 167 parts (solid content = 100 parts), (c): 0.37 parts, (d): 0.8 parts (solid content = 0.008 parts), (e) 0.2 parts (solid content = 0.1 parts)
[0083]
[Examples 1-11, Comparative Examples 1-5]
Using a 5 L gate mixer (trade name: 5 liter planetary mixer, manufactured by Inoue Seisakusho Co., Ltd.), a composition having a composition of A-1 to A-5 obtained in the above [Preparation Example 1] (however, solid In addition, the following components were added at room temperature to the blending amounts (parts by weight) shown in Tables 1 to 3 and mixed for 1 hour to obtain a composition for an adhesive heat radiating member: I got a thing.
[0084]
(B) Thermally conductive filler
B-1: Aluminum powder having an average particle size of 7.4 μm
B-2: Alumina powder having an average particle size of 5.3 μm
B-3: Zinc oxide powder having an average particle size of 1.0 μm
[0085]
(C) Organosilane having the following structure
C-1: C_TenH_{twenty one}Si (OCH_Three)_Three
C-2: C₆H₁₃Si (OCH_Three)_Three
(D) Dimethylpolysiloxane having both ends blocked with dimethylvinylsilyl groups and a viscosity at 25 ° C. of 600 mPa · s
(E1) Methyl hydrogen polysiloxane represented by the following structural formula
[0086]
Embedded image

(E2) Methyl hydrogen polysiloxane represented by the following structural formula
[0087]
Embedded image

(F) Linear organopolysiloxane: KF-54 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.)
[0088]
[Preparation of adhesive heat dissipation member]
Multi-coater (trade name: Multi-coater MODEL200, manufactured by Hirano Tech Seed Co., Ltd.) on the polyethylene terephthalate film coated with the fluorine-based mold release agent for the compositions obtained in Examples 1 to 11 and Comparative Examples 1 to 5 The film was coated and molded to volatilize and evaporate the solvent, and the surface was covered with a polyethylene terephthalate film coated with a fluorine-based release agent to obtain an adhesive (heat-cured) heat-dissipating member. Next, this was heat-treated at a temperature of 120 ° C. for 30 minutes, and subjected to crosslinking / curing reaction to obtain a sheet-like adhesive heat radiating member.
[0089]
[Methods for measuring and evaluating various characteristic values]
The characteristic value of each adhesive heat radiating member obtained above was measured by the following test method. The results are shown in Tables 1 to 3.
[0090]
Thickness, thermal resistance
A heat resistance measurement sample was prepared by sandwiching a heat radiating member sheet (with a polyethylene terephthalate film coated with a fluorine-based mold release agent removed) between two standard aluminum plates. The thickness of this sample was measured, and the substantial thickness of the sheet was determined by subtracting the thickness of a standard aluminum plate whose thickness was previously known.
In the measurement, a micrometer (manufactured by Mitutoyo Corporation, model: M820-25VA) was used.
In addition, thermal resistance (unit: ° C.-cm) for the sample²/ w) was measured using a thermal resistance measuring instrument (Holometrics, Micro Flash).
[0091]
Sticky
By attaching a heat dissipation member molded on a sheet (peeling and removing a polyethylene terephthalate film coated with a fluorine release agent) to a stainless steel plate and reciprocating a 2 kg roller covered with a rubber layer once After crimping and allowing to stand at room temperature for about 1 hour, it was placed so that the adhesive surface would be vertical, and left for 1 minute to confirm the presence or absence of dropping, and evaluated as follows.
Evaluation A: No dropout
Evaluation B: Omission
[0092]
Heat cycle test
A 25 mm square cut (peeling film made of polyethylene terephthalate coated with a fluorine release agent) was sandwiched between two transparent glass plates (thickness 1 mm, 50 mm x 75 mm), then double clip With both sides (pressure: 196kPa (2kgf / cm²)) Sample. This sample was put into a cycle tester at −30 ° C. to 100 ° C., and the number of cracks generated in the sample after 500 cycles (1 cycle: 30 minutes) was visually observed and evaluated as follows.
Evaluation A: Number of cracks 0-5
Evaluation B: Number of cracks 6 or more
[0093]
Surface roughness of heat dissipation material sheet
The surface roughness of the heat radiating member sheet (from which the polyethylene terephthalate film coated with a fluorine-based release agent was peeled and removed) was measured using a surface roughness measuring instrument (manufactured by Mitutoyo Corporation, model; Suffect-501). The arithmetic average roughness (cut-off value: λc = 8 mm) was evaluated.
[0094]
[Table 1]

[0095]
[Table 2]

[0096]
[Table 3]

[0097]
[Evaluation]
Comparative Example 1 is an example using a non-curable silicone adhesive (A-5), and Comparative Example 2 is an addition-curable silicone composition. It can be seen that siloxane is absent and both are poor in stickiness. Further, Comparative Example 3 lacks the organosilane as the component (C), and Comparative Example 4 has an excessive amount of the thermally conductive filler as the component (B). Not obtained. In contrast to Comparative Example 4, it can be seen that Comparative Example 5 has too little blending amount of the thermal conductive filler of component (B), and therefore only a high thermal resistance can be obtained.
[0098]
【The invention's effect】
From the composition of the present invention, a heat radiating member having a sticky surface can be obtained, and because of its stickiness, when it is interposed between a heat generating electronic component such as an IC package and a heat radiating component such as a fin. When the heat dissipating member is pressed and fixed between the two, even if there are irregularities on the surface of the heat-generating electronic component or the heat dissipating component, the heat dissipating member does not follow the irregularities to create a gap, and the interface Since the increase in thermal resistance can be effectively suppressed, the heat dissipation effect can be reliably exhibited, and the reliability of the entire electronic component can be improved.

Claims (6)

(A) (a) R ¹ ₃ SiO _1/2 unit (wherein R ¹ independently represents a monovalent hydrocarbon group having 1 to 6 carbon atoms other than alkenyl group) and SiO ₂ unit, and R Curable silicone adhesive containing organopolysiloxane having a molar ratio of ¹ ₃ SiO _1/2 units / SiO ₂ units of 0.6 to 1.7: 100 parts by weight
(B) Thermally conductive filler: 500 to 3,000 parts by weight, and (C) the following general formula (1):
R ² _a R ³ _b Si (OR ⁴ ) _4-ab (1)
Wherein R ² is a monovalent alkyl group having 6 to 15 carbon atoms, R ³ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and R ⁴ is independently 1 to 1 carbon atom. 6 is a monovalent alkyl group, a is an integer of 1 to 3, b is an integer of 0 to 2, and the sum of a + b is an integer of 1 to 3)
The adhesive silicone composition for heat radiating members characterized by including 0.1-50 weight part. The curable silicone adhesive of the component (A) is
Component (a): 80 to 20 parts by weight,
(b) Organopolysiloxane having two or more alkenyl groups bonded to silicon atoms in one molecule and a viscosity at 25 ° C. of 10,000 mPa · s or more: 20 to 80 parts by weight (provided that (a) The total amount of + (b) is 100 parts by weight)
(c) The following general formula (2):

Wherein R ⁵ is independently a monovalent alkyl group having 1 to 6 carbon atoms, m and n are integers of 1 or more, the sum of m + n is in the range of 3 to 300, and m / (M + n) ratio value is greater than 0.3)
The amount of the SiH group in the component (c) is 0.5 to 20 mol relative to 1 mol of the alkenyl group in the component (b),
(d) platinum-based catalyst: effective amount, and
(e) Addition reaction control agent: The composition according to claim 1, which is an addition reaction curing type silicone pressure-sensitive adhesive containing 0.01 to 1 part by weight. The curable silicone adhesive of the component (A) is
Component (a): 80 to 20 parts by weight,
(f) Organopolysiloxane having a viscosity at 25 ° C. of 10,000 mPa · s or more: 20 to 80 parts by weight (provided that the total amount of (a) + (f) is 100 parts by weight), and
(g) Organic peroxide: The composition according to claim 1, which is an organic peroxide-curable silicone pressure-sensitive adhesive containing 0.2 to 10 parts by weight. Furthermore, (D) organopolysiloxane having two or more alkenyl groups bonded to a silicon atom in one molecule and having a viscosity at 25 ° C. of 10 mPa · s or more and less than 10,000 mPa · s:
10 to 500 parts by weight, and (E) (E1) the following general formula (3):

Wherein R ⁶ is independently a monovalent alkyl group having 1 to 6 carbon atoms, p and q are integers of 1 or more, and the sum of p + q is in the range of 5 to 100, 0.01 ≦ p / (p + q) ≦ 0.3)
An organohydrogenpolysiloxane represented by: and / or
(E2) The following general formula (4):

(In the formula, R ⁷ is independently a monovalent alkyl group having 1 to 6 carbon atoms, and r is an integer of 5 to 1,000).
The amount of the SiH group in the component (E) is 0.6 to 5.0 moles with respect to 1 mole of the alkenyl group in the component (D). Item 4. The composition according to any one of Items 1 to 3. Furthermore,
(F) A linear organopolysiloxane containing no alkenyl group and hydrogen atom bonded to a silicon atom and having a viscosity at 25 ° C. of 3,000 mPa · s or less: 1 to 200 parts by weight Item 5. The composition according to any one of Items 1 to 4. The adhesive heat radiating member obtained by shape | molding the composition of any one of Claims 1-5 in the shape of a sheet | seat or a film, and giving heat processing.