JP5015366B2 - Thermally conductive molded body and method for producing the same - Google Patents
Thermally conductive molded body and method for producing the same Download PDFInfo
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- JP5015366B2 JP5015366B2 JP2000276242A JP2000276242A JP5015366B2 JP 5015366 B2 JP5015366 B2 JP 5015366B2 JP 2000276242 A JP2000276242 A JP 2000276242A JP 2000276242 A JP2000276242 A JP 2000276242A JP 5015366 B2 JP5015366 B2 JP 5015366B2
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- thermally conductive
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/73—Means for bonding being of different types provided for in two or more of groups H01L2224/10, H01L2224/18, H01L2224/26, H01L2224/34, H01L2224/42, H01L2224/50, H01L2224/63, H01L2224/71
- H01L2224/732—Location after the connecting process
- H01L2224/73251—Location after the connecting process on different surfaces
- H01L2224/73253—Bump and layer connectors
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- Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)
- Manufacture Of Macromolecular Shaped Articles (AREA)
- Casting Or Compression Moulding Of Plastics Or The Like (AREA)
- Carbon And Carbon Compounds (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Description
【0001】
【発明の属する技術分野】
本発明は、良好な熱伝導性と電気絶縁性を兼ね備えた熱伝導性成形体及びその製造方法に関するものである。さらに詳しくは、電子機器等において半導体素子や電源、光源、部品等が発生する熱を効率よく外部へ放散させるための放熱部材及び伝熱部材として好適な熱伝導性成形体及びその製造方法に関するものである。
【0002】
【従来の技術】
近年、電子機器の高性能化、小型化、軽量化に伴う半導体パッケージの高密度実装化、LSIの高集積化及び高速化等によって、電子機器から発生する熱対策が非常に重要な課題になっている。そうした中、プリント配線基板、半導体パッケージ、放熱板、筐体等を熱伝導性に優れる材料で形成する方法や、放熱板等の放熱部材と発熱源との間に熱伝導性を有する成形体(熱伝導性成形体)を介在させる方法等が従来放熱手段として採られている。
【0003】
従来の熱伝導性成形体としては、熱伝導性を向上させることを目的に、酸化アルミニウムや窒化ホウ素、窒化アルミニウム、酸化マグネシウム、酸化亜鉛、炭化ケイ素、黒鉛化炭素繊維等の熱伝導性充填材を高分子材料に配合してなる熱伝導性高分子組成物からなるものが知られている。例えば特開平9−283955号公報には、特定の平均アスペクト比の黒鉛質炭素繊維をシリコーンゴム等のマトリックス樹脂中に分散した熱伝導性シートが開示されている。
【0004】
【発明が解決しようとする課題】
ところが、特開平9−283955号公報に開示される熱伝導性シートは、炭素繊維が導電性であるために、プリント配線やリードピンに近接した位置で用いられる場合など、電気絶縁性を要求される用途には使用できないという問題があった。
【0005】
尚、特許第2695563号公報には、電気絶縁性を有する被膜で被覆された炭素繊維を、その被膜に対して相溶性を有する合成樹脂に均一分散した伝熱材料が提唱されている。ところが、この方法で炭素繊維を電気絶縁性被膜で被覆させることは必ずしも容易でなく、またその組成や製造方法、電気的性質に関しての詳細な記載がなく問題になっていた。
【0006】
また、特開平5−266880号公報、特開平8−31422号公報、特開平8−306359号公報によれば、リチウム二次電池の負極材料として、ホウ素化合物を含有する特定の炭素粉末が記載されている。また、特開平2−200819号公報には、ホウ素化合物を含有する特定の炭素素材が、高強度、高弾性の黒鉛繊維として開示されている。しかし、これらはいずれも熱伝導性を要求される用途とは異なる分野で検討されていた。
【0007】
本発明は、上記のような従来技術に存在する問題点に着目してなされたものである。その目的とするところは、良好な熱伝導性と電気絶縁性とを兼ね備え、電子機器等における放熱部材又は伝熱部材として好適な熱伝導性成形体及びその製造方法を提供することにある。
【0008】
【課題を解決するための手段】
上記の目的を達成するために、請求項1に記載の発明は、高分子材料に強磁性体を含まない繊維状の黒鉛化炭素粉末を配合した熱伝導性高分子組成物を所定の形状に成形してなる熱伝導性成形体であって、前記黒鉛化炭素粉末は、その製造過程における炭素化処理又は黒鉛化処理をホウ素化合物の存在下にて行うことで形成されたものであり、前記ホウ素化合物が窒化ホウ素を含むことで前記黒鉛化炭素粉末は窒化ホウ素を含むホウ素化合物(但し、強磁性体を除く)の被膜を表面に備えてなり、その黒鉛化炭素粉末が、一定方向に配向していることを要旨とする。
【0010】
請求項2に記載の発明は、請求項1に記載の熱伝導性成形体において、前記ホウ素化合物が、炭化ホウ素と窒化ホウ素の混合物、又は窒化ホウ素であることを要旨とする。
請求項3に記載の発明は、高分子材料にホウ素化合物を含有し、かつ強磁性体を含まない黒鉛化炭素粉末を配合した熱伝導性高分子組成物に対して磁場を印加し、前記黒鉛化炭素粉末を一定方向に配向させた状態で前記熱伝導性高分子組成物を固化させる熱伝導性成形体の製造方法であって、前記黒鉛化炭素粉末は、その製造過程における炭素化処理又は黒鉛化処理をホウ素化合物の存在下にて行うことで形成されたものであり、前記ホウ素化合物が窒化ホウ素を含むことで前記黒鉛化炭素粉末は窒化ホウ素を含むホウ素化合物(但し、強磁性体を除く)の被膜を表面に備えてなることを要旨とする。
請求項4に記載の発明は、請求項3に記載の熱伝導性成形体の製造方法において、前記熱伝導性高分子組成物に対して6〜10テスラの磁場を印加することを要旨とする。
【0011】
【発明の実施の形態】
以下、本発明を具体化した実施形態を詳細に説明する。
本実施形態における熱伝導性成形体は、高分子材料に熱伝導性充填材として特定の黒鉛化炭素粉末が配合されてなる熱伝導性高分子組成物を所定の形状に成形したものであり、その熱伝導性成形体中における黒鉛化炭素粉末は一定方向に配向している。
【0012】
まず、熱伝導性充填材として用いられる黒鉛化炭素粉末について説明する。
ここで用いられる黒鉛化炭素粉末にはホウ素化合物が含有されており、本実施形態の場合には、ホウ素化合物よりなる被膜が黒鉛化炭素粉末の表面に形成されている。具体的なホウ素化合物としては、窒化ホウ素、炭化ホウ素、炭窒化ホウ素、酸化ホウ素、塩化ホウ素、ホウ酸ナトリウム、ホウ酸カリウム、ホウ酸ニッケル、三フッ化ホウ素−メタノール錯体、ボラン−ジメチルアミン錯体等の有機ホウ素化合物、金属ホウ素等が挙げられる。その中でも、熱伝導性及び電気絶縁性に優れる窒化ホウ素、炭化ホウ素、炭窒化ホウ素が好ましく、特に窒化ホウ素が好適である。これらのホウ素化合物は、単独で含有させても、二種以上を組み合わせて含有させてもよい。
【0013】
黒鉛化炭素粉末に含有されるホウ素化合物の量は、ホウ素換算で黒鉛化炭素粉末の0.1〜20重量%の範囲が好ましく、より好ましくは0.3〜15重量%、特に好ましくは0.5〜10重量%である。0.1重量%よりも少ないと電気絶縁性が不足し、逆に20重量%を超えると、熱伝導性が低下するため好ましくない。
【0014】
黒鉛化炭素粉末の原料としては、例えば、ナフタレンやフェナントレン等の縮合多環炭化水素化合物、石油系ピッチや石炭系ピッチ等の縮合複素環化合物等が挙げられる。その中でも石油系ピッチ又は石炭系ピッチが好ましく、特に光学的異方性ピッチ、すなわちメソフェーズピッチが好ましい。
【0015】
黒鉛化炭素粉末の形態としては、繊維状、球状、鱗片状、ウィスカー状、マイクロコイル状、ナノチューブ状等が挙げられるが、特に限定されない。黒鉛化炭素粉末の大きさも特には限定されないが、繊維状のものの場合、繊維直径は5〜20μm、平均粒径は20〜800μmが好ましい。繊維直径及び平均粒径を上記の範囲とすることにより、高分子材料への配合を容易化できるとともに、得られる熱伝導性高分子組成物及び熱伝導性成形体の熱伝導性を向上させることができる。繊維直径が5μmよりも小さい場合や平均粒径が800μmよりも大きい場合は、高分子材料中に高濃度で黒鉛化炭素粉末を充填することが困難になる。一方、繊維直径が20μmを超える場合は生産性が悪くなり、また平均粒径が20μmよりも小さいと、かさ比重が小さくなって製造工程中の取扱い性や作業性に問題が生じることがあるので好ましくない。尚、黒鉛化炭素粉末の平均粒径の値は、レーザー回折方式による粒度分布から算出することができる。
【0016】
前記被膜を有する黒鉛化炭素粉末の熱伝導率は特に限定されないが、繊維状のものの場合、繊維の長さ方向における熱伝導率で200W/m・K以上が好ましく、より好ましくは400W/m・K以上、特に好ましくは1000W/m・K以上である。
【0017】
また、高分子材料に熱伝導性充填材として配合される黒鉛化炭素粉末は、カップリング剤やサイジング剤で処理することによって表面を改質させて用いてもよい。この場合、高分子材料との濡れ性や充填性を向上させたり、界面の剥離強度を改良したりすることができる。
【0018】
次に、高分子材料について説明する。
高分子材料としては、例えば、熱可塑性樹脂、熱可塑性エラストマー、熱硬化性樹脂、架橋ゴム等が挙げられる。
【0019】
熱可塑性樹脂としては、ポリエチレン、ポリプロピレン、エチレン−プロピレン共重合体等のエチレン−α−オレフィン共重合体、ポリメチルペンテン、ポリ塩化ビニル、ポリ塩化ビニリデン、ポリ酢酸ビニル、エチレン−酢酸ビニル共重合体、ポリビニルアルコール、ポリビニルアセタール、フッ素樹脂(ポリフッ化ビニリデン、ポリテトラフルオロエチレン等)、ポリエチレンテレフタレート、ポリブチレンテレフタレート、ポリエチレンナフタレート、ポリスチレン、ポリアクリロニトリル、スチレン−アクリロニトリル共重合体、ABS樹脂、ポリフェニレンエーテル(PPE)樹脂、変性PPE樹脂、脂肪族ポリアミド類、芳香族ポリアミド類、ポリイミド、ポリアミドイミド、ポリメタクリル酸類(ポリメタクリル酸メチル等のポリメタクリル酸エステル)、ポリアクリル酸類、ポリカーボネート、ポリフェニレンスルフィド、ポリサルホン、ポリエーテルサルホン、ポリエーテルニトリル、ポリエーテルケトン、ポリケトン、液晶ポリマー、アイオノマー等が挙げられる。
【0020】
熱可塑性エラストマーとしては、スチレン−ブタジエン共重合体及びスチレン−イソプレンブロック共重合体とそれらの水添物、スチレン系熱可塑性エラストマー、オレフィン系熱可塑性エラストマー、塩化ビニル系熱可塑性エラストマー、ポリエステル系熱可塑性エラストマー、ポリウレタン系熱可塑性エラストマー、ポリアミド系熱可塑性エラストマー等が挙げられる。
【0021】
熱硬化性樹脂としては、エポキシ樹脂、ポリイミド樹脂、ビスマレイミド樹脂、ベンゾシクロブテン樹脂、フェノール樹脂、不飽和ポリエステル樹脂、ジアリルフタレート樹脂、シリコーン樹脂、ウレタン樹脂、熱硬化型PPE樹脂、熱硬化型変性PPE樹脂等が挙げられる。
【0022】
架橋ゴムとしては、天然ゴム、ブタジエンゴム、イソプレンゴム、スチレン−ブタジエン共重合ゴム、ニトリルゴム、水添ニトリルゴム、クロロプレンゴム、エチレンプロピレンゴム、塩素化ポリエチレン、クロロスルホン化ポリエチレン、ブチルゴム、ハロゲン化ブチルゴム、フッ素ゴム、ウレタンゴム、シリコーンゴム等が挙げられる。
【0023】
これらの高分子材料の中でも電気的及び熱的信頼性の点から、シリコーンゴム、エポキシ樹脂、ポリイミド樹脂、ビスマレイミド樹脂、ベンゾシクロブテン樹脂、フッ素樹脂、PPE樹脂及びポリアセタール樹脂が好ましい。また、誘電率、誘電正接が小さく、かつ高周波領域での周波数特性を要求される配線基板用途には、フッ素樹脂や熱硬化型PPE樹脂、熱硬化型変性PPE樹脂及びポリオレフィン系樹脂が好ましい。これらの高分子材料は、一種を単独で用いても、二種以上を適宜組み合わせて用いてもよく、二種以上の高分子材料からなるポリマーアロイを使用してもよい。また、高分子材料の架橋方法については特に限定されず、熱硬化、光硬化、湿気硬化等、公知の架橋方法を採用することができる。
【0024】
続いて、上記の黒鉛化炭素粉末を高分子材料に配合して得られる熱伝導性高分子組成物、及びその熱伝導性高分子組成物を所定の形状に成形した熱伝導性成形体について説明する。
【0025】
高分子材料に配合される黒鉛化炭素粉末の量は、目的とする最終製品の要求性能によって適宜決定されるが、100重量部の高分子材料に対して5〜500重量部が好ましく、10〜300重量部がより好ましく、20〜200重量部が特に好ましい。この配合量が5重量部よりも少ないと、得られる熱伝導性高分子組成物及び熱伝導性成形体の熱伝導率が小さくなって放熱特性が低下する。逆に500重量部を超えると配合組成物の粘度が増大して黒鉛化炭素粉末を均一に分散させることが困難になり、また気泡の混入が避けられず好ましくない。
【0026】
熱伝導性高分子組成物には、上述の黒鉛化炭素粉末の他に、その他の熱伝導性充填材、難燃材、軟化剤、着色材、安定剤等を必要に応じて配合してもよい。その他の熱伝導性充填材としては、酸化アルミニウム、窒化ホウ素、窒化アルミニウム、酸化亜鉛、炭化ケイ素、水酸化アルミニウム等の金属酸化物、金属窒化物、金属炭化物、金属水酸化物等が挙げられる。また、その形態としては、球状、粉状、繊維状、針状、鱗片状、ウィスカー状、マイクロコイル状、単層ナノチューブ、多層ナノチューブ状等が挙げられる。尚、併用する充填材が導電性である場合には、得られる熱伝導性高分子組成物及び熱伝導性成形体の電気絶縁性を損ねるおそれがあるので、その配合量をなるべく少なくする方が好ましい。また、粘度を低下させるために揮発性の有機溶剤や反応性可塑剤を添加してもよい。
【0027】
熱伝導性成形体をシート状に成形する場合、その厚みは特に限定されないが、実用性の点から0.05〜10mmの範囲が好ましい。
熱伝導性成形体の熱伝導率及び電気絶縁性については特に限定されないが、熱伝導率は1W/m・K以上が好ましく、より好ましくは2W/m・K以上、特に好ましくは5W/m・K以上である。電気絶縁性は、表面抵抗値で106Ω/□以上が好ましく、より好ましくは108Ω/□以上、特に好ましくは109Ω/□以上である。
【0028】
次に上記の熱伝導性成形体の使用方法を説明する。
熱伝導性成形体は、電子機器等において半導体素子や電源、光源、部品等が発生する熱を効率よく外部へ放散させるための放熱部材及び伝熱部材等として用いられる。具体的には、シート状に加工して半導体素子等の発熱部材と放熱器等の放熱部材との間に介在させて用いたり、放熱板、半導体パッケージ用部品、ヒートシンク、ヒートスプレッダー、ダイパッド、プリント配線基板、冷却ファン用部品、ヒートパイプ、筐体等に成形加工して用いられたりする。
【0029】
図1は、シート状の熱伝導性成形体を伝熱部材として用いた例を示す図である。図1(a)に示す例では、半導体素子11(ボールグリッドアレイ型半導体パッケージ)と放熱板12との間に熱伝導性成形体13が介在されている。図1(b)に示す例では、半導体素子11(チップサイズ型半導体パッケージ)とプリント配線基板14との間に熱伝導性成形体13が介在されている。図1(c)に示す例では、半導体素子11(ピングリッドアレイ型半導体パッケージ)とヒートシンク15との間に熱伝導性成形体13が介在されている。図1(d)に示す例では、複数の半導体素子11と筐体16との間に熱伝導性成形体13が介在されている。また、図2は、熱伝導性成形体をプリント配線基板として用いた例を示す図である。同図に示すプリント配線基板17は、熱伝導性高分子組成物を板状に成形してなる基板18を備え、その基板18上には銅箔などからなる導電層19が形成されている。
【0030】
次に、熱伝導性成形体の製造方法を説明する。
黒鉛化炭素粉末の原料としてピッチを用いる場合は、紡糸、不融化、炭素化及び黒鉛化の各工程を経て黒鉛化炭素繊維を製造し、その黒鉛化炭素繊維を粉砕又は切断することにより黒鉛化炭素粉末とする。尚、粉砕又は切断は、黒鉛化処理の後に限定されるものでなく、不融化処理の後に行っても、炭素化処理の後に行ってもよいが、繊維の縦割れが比較的防げることから炭素化処理の後に行うことが好ましい。また、炭素化処理の後に粉砕又は切断した場合には、黒鉛化処理の際に、粉砕又は切断して新たに露出した面において縮重合反応、環化反応が進みやすい傾向にあることから、熱伝導性に優れた黒鉛化炭素粉末を得やすいという利点もある。
【0031】
紡糸工程における紡糸方法としては、メルトスピニング法、メルトブロー法、遠心紡糸法、渦流紡糸法等が挙げられるが、紡糸時の生産性や得られる黒鉛化炭素粉末の品質の観点からメルトブロー法が好ましい。メルトブロー法の場合、数十ポイズ以下の低粘度で紡糸し、かつ高速冷却することによって、黒鉛層面が繊維軸に平行に配列しやすくなるという利点もある。
【0032】
メルトブロー法の場合、紡糸孔の直径は0.1〜0.5mmが好ましく、0.15〜0.3mmがより好ましい。紡糸孔の直径が0.1mmよりも小さいと目詰まりが生じやすく、また紡糸ノズルの製作が困難になるため好ましくない。逆に0.5mmを超えると、繊維直径が25μm以上と大きくなりやすく、また繊維直径がばらつきやすくなり品質管理上も好ましくない。紡糸速度は、生産性の面から毎分500m以上が好ましく、毎分1500mm以上がより好ましく、毎分2000m以上が特に好ましい。紡糸温度は、原料ピッチの軟化点以上でピッチが変質しない温度以下であればよいが、通常は300〜400℃、好ましくは300〜380℃である。前記紡糸温度との関係から、原料ピッチの軟化点は好ましくは230〜350℃、より好ましくは250〜310℃である。
【0033】
不融化工程における不融化処理の方法としては、二酸化窒素や酸素等の酸化性ガス雰囲気中で加熱処理する方法、硝酸やクロム酸等の酸化性水溶液中で処理する方法、光やγ線等により重合処理する方法等が挙げられるが、空気中で加熱処理する方法が簡便なことから好ましい。空気中で加熱処理する方法を採る場合、好ましくは平均昇温速度3℃/分以上で、より好ましくは5℃/分以上で、350℃程度まで昇温させながら加熱処理することが望ましい。
【0034】
続く炭素化工程における炭素化処理及びは黒鉛化工程における黒鉛化処理は、不活性ガス雰囲気中で加熱処理することによって行われる。炭素化処理の際の処理温度は好ましくは250℃以上、より好ましくは500℃以上である。また黒鉛化処理の際の処理温度は好ましくは2500℃以上、より好ましくは3000℃以上である。
【0035】
本実施形態における黒鉛化炭素粉末は、炭素化処理又は黒鉛化処理の少なくとも一方をホウ素化合物の存在下にて行うことにより得られる。その方法としては、炭素化処理又は黒鉛化処理の際にホウ素化合物を混合する方法、予め原料ピッチにホウ素化合物を混合させておき、その混合物を紡糸する方法等が挙げられる。
【0036】
粉砕又は切断処理には、ビクトリーミル、ジェットミル、高速回転ミル等の粉砕機、又はチョップド繊維で用いられる切断機等が用いられる。粉砕又は切断を効率よく行うためには、ブレードを取付けたロータを高速に回転させることにより、繊維軸に対して直角方向に繊維を寸断する方法が適切である。この粉砕又は切断処理によって生じる黒鉛化炭素粉末の平均粒径は、ロータの回転数、ブレードの角度等を調整することにより制御される。繊維の粉砕方法としてはボールミル等の磨砕機による方法もあるが、この方法の場合、繊維の直角方向への加圧力が働いて繊維軸方向への縦割れの発生が多くなるので不適当である。
【0037】
上記のようにして得られた黒鉛化炭素粉末を高分子材料に配合し、攪拌、脱泡、混練等の操作を施すことにより、熱伝導性高分子組成物が得られる。そして、その熱伝導性高分子組成物を所定の形状に成形することで熱伝導性成形体が得られる。
【0038】
熱伝導性高分子組成物中における黒鉛化炭素粉末を一定方向に配向させる方法としては、流動場又はせん断場を利用する方法、磁場を利用する方法、電場を利用する方法等が挙げられる。その中でも、熱伝導性高分子組成物に磁場を印加して黒鉛化炭素粉末を磁力線と平行に配向させる方法が、効率的で、なおかつ配向方向を任意に設定できることから好ましい。前記黒鉛化炭素粉末が磁場により効果的に配向する理由としては、六方晶グラファイト構造の窒化ホウ素の結晶構造が黒鉛の結晶構造と同形状であるために両方の反磁性体が類似した磁気異方性を示すためと考えられる。
【0039】
磁場配向を利用して熱伝導性成形体を製造する場合には、金型のキャビティ内に注入された前記熱伝導性高分子組成物に対して磁場を印加し、その熱伝導性高分子組成物中に含まれる黒鉛化炭素粉末を一定方向に配向させた状態で熱伝導性高分子組成物を固化させる。
【0040】
例えば図3に示すような板状の熱伝導性成形体21において黒鉛化炭素粉末を厚み方向(図3におけるZ軸方向)に配向させる場合には、図4(a)に示すように、磁力線Mの向きが熱伝導性成形体21(図3参照)の厚み方向に一致するように磁場発生手段22を配置して、金型23のキャビティ23a内に注入された熱伝導性高分子組成物24に対して磁場を印加する。また、熱伝導性成形体21の面内方向(図3におけるX軸方向、Y軸方向等)に黒鉛化炭素粉末を配向させる場合には、図4(a)に示すように、磁力線Mの向きが熱伝導性成形体21(図3参照)の面内方向に一致するように磁場発生手段22を配置して、金型23のキャビティ23a内に注入された熱伝導性高分子組成物24に対して磁場を印加する。
【0041】
尚、図4(a),(b)に示す例では、一対の磁場発生手段22を金型23を間に挟んで配置させるようにしたが、各例において一方の磁場発生手段22を省略してもよい。また、図4(a),(b)に示す例では、互いのS極とN極とが対向するように一対の磁場発生手段22を配置したが、S極同士又はN極同士が対向するように一対の磁場発生手段22を配置してもよい。さらに、磁力線Mは必ずしも直線状でなくてもよく、曲線状や矩形状でもよい。また、磁力線Mが一方向だけでなく2方向以上に延びるように磁場発生手段22を配置してもよい。
【0042】
前記磁場発生手段22としては、永久磁石、電磁石等が挙げられる。磁場発生手段によって形成される磁場の磁束密度は、0.05〜30テスラの範囲が好ましく、より好ましくは0.5テスラ以上、特に好ましくは2テスラ以上である。
【0043】
以上詳述した本実施形態によれば次のような効果が発揮される。
・ 本実施形態における黒鉛化炭素粉末は、熱伝導性及び電気絶縁性を有するホウ素化合物よりなる被膜を表面に有することで、良好な熱伝導性と電気絶縁性の双方を兼ね備えている。このため、この黒鉛化炭素粉末が配合された熱伝導性成形体を電気絶縁性が要求される用途において放熱部材又は伝熱部材として使用した場合でも、電気的な障害を発生させることなくその機能を発揮することができる。
【0044】
・ 例えば繊維状の黒鉛化炭素粉末の場合、繊維の長さ方向における熱伝導性が非常に優れている。従って、この繊維状の黒鉛化炭素粉末が配合された熱伝導性成形体では、黒鉛化炭素粉末を一定方向に配向させることによってその配向方向における熱伝導性を著しく向上させることができ、熱伝導性に異方性を有する熱伝導性成形体を得ることができる。
【0045】
・ ホウ素化合物よりなる被膜は、黒鉛化炭素粉末の製造過程における炭素化処理又は黒鉛化処理をホウ素化合物の存在下にて行うことにより形成されるので、その被膜の形成を容易かつ確実とすることができる。
【0046】
・ 熱伝導性と電気絶縁性に特に優れる窒化ホウ素によって被膜を形成することで、熱伝導性と電気絶縁性を一層向上させることができる。
【0047】
【実施例】
次に、実施例及び比較例を挙げて前記実施形態をさらに具体的に説明する。
尚、各例において、熱伝導率はレーザーフラッシュ法、表面抵抗値はJIS−K6911に準拠して測定した。
【0048】
(黒鉛化炭素粉末の試作例1)
メソフェーズピッチ100%を原料に紡糸、不融化、炭素化の各工程を経て得られる炭素繊維を粉砕して炭素粉末を得た。この炭素粉末に対し、炭化ホウ素と窒化ホウ素の混合物(重量比で1:1)を混合した後、窒素雰囲気下で3000℃まで加熱して黒鉛化処理を行い、黒鉛化炭素粉末を得た。
【0049】
この黒鉛化炭素粉末の表面を電子顕微鏡及びESCA(X線光電子分光法)にて分析したところ、表面に炭化ホウ素及び窒化ホウ素よりなる被膜が観察された。黒鉛化炭素粉末の繊維直径、平均粒径、繊維の長さ方向における熱伝導率及びホウ素化合物の含有量(ホウ素換算)を測定した結果を表1に示す。
【0050】
(黒鉛化炭素粉末の試作例2)
メソフェーズピッチ80重量%と窒化ホウ素20重量%の混合物を紡糸して不融化した後、窒素雰囲気下で2000℃まで段階的に加熱して炭素化し、さらに3200℃まで加熱して黒鉛化処理を行い、黒鉛化炭素粉末を得た。
【0051】
この黒鉛化炭素繊維の表面を電子顕微鏡及びESCAにて分析したところ、表面に窒化ホウ素よりなる被膜が観察された。黒鉛化炭素粉末の繊維直径、平均粒径、繊維の長さ方向における熱伝導率及びホウ素化合物の含有量(ホウ素換算)を測定した結果を表1に示す。
【0052】
(黒鉛化炭素粉末の試作例3)
メソフェーズピッチ100%を原料に紡糸、不融化、炭素化の各工程を経て得られる炭素繊維を粉砕して炭素粉末を得た。この炭素粉末を窒素雰囲気下で3000℃まで加熱して黒鉛化処理を行い、黒鉛化炭素粉末を得た。
【0053】
この黒鉛化炭素繊維の表面には、ホウ素化合物よりなる被膜は観察されなかった。黒鉛化炭素粉末の繊維直径、平均粒径、繊維の長さ方向における熱伝導率及びホウ素化合物の含有量(ホウ素換算)を測定した結果を表1に示す。
【0054】
(黒鉛化炭素粉末の試作例4)
メソフェーズピッチ100%を原料に紡糸、不融化した後、窒素雰囲気下で2000℃まで段階的に加熱して炭素化し、さらに3200℃まで加熱して黒鉛化処理を行い、黒鉛化炭素粉末を得た。
【0055】
この黒鉛化炭素繊維の表面には、ホウ素化合物よりなる被膜は観察されなかった。黒鉛化炭素粉末の繊維直径、平均粒径、繊維の長さ方向における熱伝導率及びホウ素化合物の含有量(ホウ素換算)を測定した結果を表1に示す。
【0056】
【表1】
(実施例1)
試作例1の黒鉛化炭素粉末をシランカップリング剤で表面処理し、その処理後の黒鉛化炭素粉末120重量部を不飽和ポリエステル樹脂(株式会社日本触媒製エポラック)100重量部に混合して熱伝導性高分子組成物を調製した。続いて、その熱伝導性高分子組成物を所定の金型のキャビティ内に注入し、磁力線の向きが熱伝導性成形体の厚み方向に一致する磁場(磁束密度6テスラ)を印加して熱伝導性高分子組成物中の黒鉛化炭素粉末を十分に配向させた後に加熱硬化させて、厚み1.5mm×縦20mm×横20mmの板状の熱伝導性成形体を得た。
【0057】
この熱伝導性成形体中の黒鉛化炭素粉末は厚み方向に揃って配向していた。熱伝導性成形体の厚み方向(Z軸方向)における熱伝導率、面内方向(X軸方向)における熱伝導率及び表面抵抗値を測定した結果を表2に示す。
【0058】
(実施例2)
実施例1において、磁力線の向きが熱伝導性成形体の面内方向(Y軸方向)に一致する磁場をキャビティ内の熱伝導性高分子組成物に印加するように変更した。それ以外は実施例1と同様にして板状の熱伝導性成形体を作製した。
【0059】
この熱伝導性成形体中の黒鉛化炭素粉末は面内方向(Y軸方向)に揃って配向していた。熱伝導性成形体の厚み方向(Z軸方向)における熱伝導率、面内方向(X軸方向及びY軸方向)における熱伝導率及び表面抵抗値を測定した結果を表2に示す。
【0060】
(実施例3)
試作例1の黒鉛化炭素粉末をシランカップリング剤で表面処理し、その処理後の黒鉛化炭素粉末80重量部を液状エポキシ樹脂(スリーボンド株式会社製 TB2280C)100重量部に混合して熱伝導性高分子組成物を調製した。続いて、その熱伝導性高分子組成物を所定の金型のキャビティ内に注入し、磁力線の向きが熱伝導性成形体の厚み方向に一致する磁場(磁束密度10テスラ)を印加して熱伝導性高分子組成物中の黒鉛化炭素粉末を十分に配向させた後に加熱硬化させて、厚み3mm×縦20mm×横20mmの板状の熱伝導性成形体を得た。
【0061】
この熱伝導性成形体中の黒鉛化炭素粉末は厚み方向に揃って配向していた。熱伝導性成形体の厚み方向(Z軸方向)における熱伝導率、面内方向(X軸方向)における熱伝導率及び表面抵抗値を測定した結果を表2に示す。
【0062】
(実施例4)
実施例3において、磁力線の向きが熱伝導性成形体の面内方向(Y軸方向)に一致する磁場をキャビティ内の熱伝導性高分子組成物に印加するように変更した。それ以外は実施例3と同様にして板状の熱伝導性成形体を作製した。
【0063】
この熱伝導性成形体中の黒鉛化炭素粉末は面内方向(Y軸方向)に揃って配向していた。熱伝導性成形体の厚み方向(Z軸方向)における熱伝導率、面内方向(X軸方向及びY軸方向)における熱伝導率及び表面抵抗値を測定した結果を表2に示す。
【0064】
(実施例5)
試作例2の黒鉛化炭素粉末をシランカップリング剤で表面処理し、その処理後の黒鉛化炭素粉末110重量部と酸化アルミニウム粉末(昭和電工株式会社製 AS−20)60重量部とを、液状シリコーンゴム(GE東芝シリコーン株式会社製 TSE3070)100重量部に混合して熱伝導性高分子組成物を調製した。続いて、その熱伝導性高分子組成物を所定の金型のキャビティ内に注入し、磁力線の向きが熱伝導性成形体の厚み方向に一致する磁場(磁束密度10テスラ)を印加して熱伝導性高分子組成物中の黒鉛化炭素粉末を十分に配向させた後に加熱硬化させて、厚み0.5mm×縦20mm×横20mmの板状の熱伝導性成形体(アスカーC硬度17)を得た。
【0065】
この熱伝導性成形体中の黒鉛化炭素粉末は厚み方向に揃って配向していた。熱伝導性成形体の厚み方向(Z軸方向)における熱伝導率、面内方向(X軸方向)における熱伝導率及び表面抵抗値を測定した結果を表2に示す。
【0066】
(実施例6)
実施例5において、磁力線の向きが熱伝導性成形体の面内方向(Y軸方向)に一致する磁場をキャビティ内の熱伝導性高分子組成物に印加するように変更した。それ以外は実施例5と同様にして板状の熱伝導性成形体(アスカーC硬度17)を作製した。
【0067】
この熱伝導性成形体中の黒鉛化炭素粉末は面内方向(Y軸方向)に揃って配向していた。熱伝導性成形体の厚み方向(Z軸方向)における熱伝導率、面内方向(X軸方向及びY軸方向)における熱伝導率及び表面抵抗値を測定した結果を表2に示す。
【0068】
(実施例7)
スチレン系熱可塑性エラストマー(旭化成工業株式会社製 タフテックH1053)100重量部に溶剤としてトルエン2000重量部を加えて溶解し、そこに試作例2の黒鉛化炭素粉末40重量部を混合して熱伝導性高分子組成物を調製した。続いて、その熱伝導性高分子組成物を所定の金型のキャビティ内に注入し、磁力線の向きが熱伝導性成形体の高さ方向に一致する磁場(磁束密度8テスラ)を印加して熱伝導性高分子組成物中の黒鉛化炭素粉末を十分に配向させた後に加熱硬化させて、高さ40mm×縦20mm×横20mmの熱伝導性成形体を得た。
【0069】
この熱伝導性成形体中の黒鉛化炭素粉末は高さ方向に揃って配向していた。熱伝導性成形体の高さ方向(Z軸方向)における熱伝導率、面内方向(X軸方向)における熱伝導率及び表面抵抗値を測定した結果を表2に示す。
【0070】
【表2】
(比較例1)
実施例1において、試作例1の黒鉛化炭素粉末に代えて試作例3の黒鉛化炭素粉末を使用するように変更するとともに、熱伝導性高分子組成物を硬化させる際の磁場の印加を省略した。それ以外は実施例1と同様にして熱伝導性成形体を作製した。
【0071】
この熱伝導性成形体中の黒鉛化炭素粉末は一定方向に配向せずランダムに分散していた。熱伝導性成形体の厚み方向(Z軸方向)における熱伝導率、面内方向(X軸方向及びY軸方向)における熱伝導率及び表面抵抗値を測定した結果を表3に示す。
【0072】
(比較例2)
比較例1において、磁力線の向きが熱伝導性成形体の厚み方向に一致する磁場(磁束密度6テスラ)を印加して熱伝導性高分子組成物中の黒鉛化炭素粉末を十分に配向させた後に加熱硬化させるように変更した。それ以外は比較例1と同様にして熱伝導性成形体を作製した。
【0073】
この熱伝導性成形体中の黒鉛化炭素粉末は厚み方向に揃って配向していた。熱伝導性成形体の厚み方向(Z軸方向)における熱伝導率、面内方向(X軸方向)における熱伝導率及び表面抵抗値を測定した結果を表3に示す。
【0074】
(比較例3)
実施例5において、試作例2の黒鉛化炭素粉末に代えて試作例4の黒鉛化炭素粉末を使用するように変更するとともに、熱伝導性高分子組成物を硬化させる際の磁場の印加を省略した。それ以外は実施例1と同様にして熱伝導性成形体を作製した。
【0075】
この熱伝導性成形体中の黒鉛化炭素粉末は一定方向に配向せずランダムに分散していた。熱伝導性成形体の厚み方向(Z軸方向)における熱伝導率、面内方向(X軸方向及びY軸方向)における熱伝導率及び表面抵抗値を測定した結果を表3に示す。
【0076】
(比較例4)
比較例3において、磁力線の向きが熱伝導性成形体の厚み方向に一致する磁場(磁束密度10テスラ)を印加して熱伝導性高分子組成物中の黒鉛化炭素粉末を十分に配向させた後に加熱硬化させるように変更した。それ以外は比較例3と同様にして熱伝導性成形体(アスカーC硬度17)を作製した。
【0077】
この熱伝導性成形体中の黒鉛化炭素粉末は厚み方向に揃って配向していた。熱伝導性成形体の厚み方向(Z軸方向)における熱伝導率、面内方向(X軸方向)における熱伝導率及び表面抵抗値を測定した結果を表3に示す。
【0078】
【表3】
表2に示すように、ホウ素を含有する黒鉛化炭素粉末を使用した実施例1〜7の熱伝導性成形体は、熱伝導率の値と表面抵抗値の値がともに大きく、このことから熱伝導性と電気絶縁性がともに優れていることが示された。それに対して、表3に示すように、ホウ素を含有しない黒鉛化炭素粉末を使用した比較例1〜4の熱伝導性成形体は、熱伝導率の値は大きいが表面抵抗値の値は小さく、このことから熱伝導性には優れるが電気絶縁性に劣ることが示された。
【0079】
また、実施例1〜7において、黒鉛化炭素粉末の配向方向における熱伝導率の値が、その他の方向における熱伝導率の値に比べて著しく大きく、実施例1〜7の熱伝導性成形体は熱伝導性に異方性があることが示された。
【0080】
(実施例8)
実施例1の板状の熱伝導性成形体を使って配線基板を作製した。熱伝導性成形体を基板とし、その基板上にエポキシ系接着剤を塗布し、厚さ35μmの銅箔をプレスで加圧接着した後、銅箔をエッチングすることにより、基板上に導体回路を形成した。その配線基板上にトランジスタ(株式会社東芝製 TO−220)を半田付けし、反対面を冷却ファンで冷却しながら通電し、トランジスタと配線基板の温度差より熱抵抗を求めたところ、0.23℃/Wであった。
【0081】
(比較例5)
比較例2の板状の熱伝導性成形体を使って実施例8と同様にして配線基板を作製した。そして、その配線基板上にトランジスタ(株式会社東芝製 TO−220)を半田付けし、反対面を冷却ファンで冷却しながら通電したが、回路がショートして作動しなかった。
【0086】
【発明の効果】
本発明は、以上のように構成されているため、次のような効果を奏する。
請求項1及び2に記載の発明によれば、良好な熱伝導性と電気絶縁性とを兼ね備えることができる。
【0087】
また、被膜の形成を容易かつ確実とすることができる。
【0088】
請求項3及び4に記載の発明によれば、良好な熱伝導性と電気絶縁性とを兼ね備えた熱伝導性成形体を効率的に製造することができる。
【図面の簡単な説明】
【図1】 (a)〜(d)は熱伝導性成形体の使用例を示す側面図。
【図2】 同じく熱伝導性成形体の使用例を示す断面図。
【図3】 四角板状の熱伝導性成形体を示す斜視図。
【図4】 (a),(b)は熱伝導性成形体の製造方法を示す概念図。
【符号の説明】
13,21…熱伝導性成形体、18…熱伝導性成形体としての基板。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermally conductive molded body having good thermal conductivity and electrical insulation and a method for producing the same. More specifically, the present invention relates to a heat conductive molded body suitable as a heat radiating member and a heat transfer member for efficiently dissipating heat generated by a semiconductor element, a power source, a light source, a component, etc. in an electronic device and the like, and a method for manufacturing the same. It is.
[0002]
[Prior art]
In recent years, countermeasures against heat generated from electronic devices have become very important issues due to high-density mounting of semiconductor packages, high integration and high speed of LSIs, etc., accompanying the performance, miniaturization, and weight reduction of electronic devices. ing. Under such circumstances, a method of forming a printed wiring board, a semiconductor package, a heat sink, a housing, etc. with a material having excellent heat conductivity, or a molded body having heat conductivity between a heat radiation member such as a heat sink and a heat source ( Conventionally, a method of interposing a thermally conductive molded body) is adopted as a heat radiating means.
[0003]
Conventional heat conductive molded bodies have heat conductive fillers such as aluminum oxide, boron nitride, aluminum nitride, magnesium oxide, zinc oxide, silicon carbide, and graphitized carbon fiber for the purpose of improving heat conductivity. A composition comprising a thermally conductive polymer composition obtained by blending a polymer material with a polymer is known. For example, JP-A-9-283955 discloses a heat conductive sheet in which graphitic carbon fibers having a specific average aspect ratio are dispersed in a matrix resin such as silicone rubber.
[0004]
[Problems to be solved by the invention]
However, the heat conductive sheet disclosed in Japanese Patent Application Laid-Open No. 9-283955 is required to have an electrical insulation property when the carbon fiber is conductive and used in a position close to a printed wiring or a lead pin. There was a problem that it could not be used for purposes.
[0005]
Japanese Patent No. 2695563 proposes a heat transfer material in which carbon fibers coated with a coating having electrical insulation properties are uniformly dispersed in a synthetic resin having compatibility with the coating. However, it is not always easy to coat carbon fibers with an electrically insulating film by this method, and there has been a problem because there is no detailed description of the composition, manufacturing method, and electrical properties.
[0006]
In addition, according to JP-A-5-266880, JP-A-8-31422, and JP-A-8-306359, a specific carbon powder containing a boron compound is described as a negative electrode material for a lithium secondary battery. ing. JP-A-2-200819 discloses a specific carbon material containing a boron compound as a high-strength, high-elasticity graphite fiber. However, all of these have been studied in fields different from applications that require thermal conductivity.
[0007]
The present invention has been made paying attention to the problems existing in the prior art as described above. An object of the present invention is to provide a thermally conductive molded article that has both good thermal conductivity and electrical insulation and is suitable as a heat radiating member or a heat transfer member in electronic equipment and the like, and a method for manufacturing the same.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 provides a polymer material.Does not contain ferromagnetsA thermally conductive molded body formed by molding a thermally conductive polymer composition containing fibrous graphitized carbon powder into a predetermined shape, wherein the graphitized carbon powder is carbonized in the production process or It is formed by performing graphitization treatment in the presence of a boron compound, and the boron compound contains boron nitride, so that the graphitized carbon powder contains boron nitride containing boron nitride (however, a ferromagnetic substance is added). Except that the graphitized carbon powder is oriented in a certain direction.
[0010]
The invention according to claim 2 is summarized in that, in the thermally conductive molded article according to claim 1, the boron compound is a mixture of boron carbide and boron nitride, or boron nitride.
The invention according to claim 3For polymer materialsContains boron compoundsAnd does not contain ferromagnetsGraphitized carbon powderArrangeA method for producing a thermally conductive molded body, wherein a magnetic field is applied to the combined thermally conductive polymer composition, and the thermally conductive polymer composition is solidified in a state where the graphitized carbon powder is oriented in a certain direction. The graphitized carbon powder is formed by performing carbonization treatment or graphitization treatment in the production process in the presence of a boron compound, and the boron compound contains boron nitride. The gist of the graphitized carbon powder is that it is provided with a coating of a boron compound containing boron nitride (excluding a ferromagnetic material) on the surface.
Invention of Claim 4 makes it a summary to apply the magnetic field of 6-10 Tesla with respect to the said heat conductive polymer composition in the manufacturing method of the heat conductive molded object of Claim 3. .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments embodying the present invention will be described in detail.
The thermally conductive molded body in the present embodiment is obtained by molding a thermally conductive polymer composition in which a specific graphitized carbon powder is blended as a thermally conductive filler into a polymer material into a predetermined shape, The graphitized carbon powder in the thermally conductive compact is oriented in a certain direction.
[0012]
First, the graphitized carbon powder used as the heat conductive filler will be described.
The graphitized carbon powder used here contains a boron compound, and in the case of this embodiment, a film made of a boron compound is formed on the surface of the graphitized carbon powder. Specific boron compounds include boron nitride, boron carbide, boron carbonitride, boron oxide, boron chloride, sodium borate, potassium borate, nickel borate, boron trifluoride-methanol complex, borane-dimethylamine complex, etc. Organic boron compounds, metal boron, and the like. Among these, boron nitride, boron carbide, and boron carbonitride having excellent thermal conductivity and electrical insulation are preferable, and boron nitride is particularly preferable. These boron compounds may be contained alone or in combination of two or more.
[0013]
The amount of the boron compound contained in the graphitized carbon powder is preferably in the range of 0.1 to 20% by weight of the graphitized carbon powder in terms of boron, more preferably 0.3 to 15% by weight, particularly preferably 0.8. 5 to 10% by weight. If the amount is less than 0.1% by weight, the electrical insulation is insufficient. On the other hand, if it exceeds 20% by weight, the thermal conductivity is lowered, which is not preferable.
[0014]
Examples of the raw material for the graphitized carbon powder include condensed polycyclic hydrocarbon compounds such as naphthalene and phenanthrene, condensed heterocyclic compounds such as petroleum pitch and coal pitch, and the like. Among them, petroleum pitch or coal pitch is preferable, and optically anisotropic pitch, that is, mesophase pitch is particularly preferable.
[0015]
Examples of the form of the graphitized carbon powder include, but are not limited to, fibrous, spherical, scale-like, whisker-like, microcoiled, and nanotube-like. The size of the graphitized carbon powder is not particularly limited, but in the case of a fibrous one, the fiber diameter is preferably 5 to 20 μm and the average particle diameter is preferably 20 to 800 μm. By making the fiber diameter and the average particle diameter within the above ranges, the blending into the polymer material can be facilitated, and the thermal conductivity of the resulting thermally conductive polymer composition and thermally conductive molded body can be improved. Can do. When the fiber diameter is smaller than 5 μm or the average particle diameter is larger than 800 μm, it becomes difficult to fill the polymer material with the graphitized carbon powder at a high concentration. On the other hand, when the fiber diameter exceeds 20 μm, the productivity is deteriorated, and when the average particle size is smaller than 20 μm, the bulk specific gravity becomes small, which may cause problems in handling and workability during the manufacturing process. It is not preferable. In addition, the value of the average particle diameter of graphitized carbon powder can be calculated from the particle size distribution by the laser diffraction method.
[0016]
The thermal conductivity of the graphitized carbon powder having the coating is not particularly limited, but in the case of a fibrous material, the thermal conductivity in the length direction of the fiber is preferably 200 W / m · K or more, more preferably 400 W / m ·. K or more, particularly preferably 1000 W / m · K or more.
[0017]
Further, the graphitized carbon powder blended in the polymer material as a heat conductive filler may be used by modifying the surface by treating with a coupling agent or a sizing agent. In this case, the wettability and filling property with the polymer material can be improved, and the peel strength at the interface can be improved.
[0018]
Next, the polymer material will be described.
Examples of the polymer material include a thermoplastic resin, a thermoplastic elastomer, a thermosetting resin, and a crosslinked rubber.
[0019]
Examples of the thermoplastic resin include ethylene-α-olefin copolymers such as polyethylene, polypropylene, and ethylene-propylene copolymers, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, and ethylene-vinyl acetate copolymers. , Polyvinyl alcohol, polyvinyl acetal, fluororesin (polyvinylidene fluoride, polytetrafluoroethylene, etc.), polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polystyrene, polyacrylonitrile, styrene-acrylonitrile copolymer, ABS resin, polyphenylene ether ( PPE) resin, modified PPE resin, aliphatic polyamide, aromatic polyamide, polyimide, polyamideimide, polymethacrylic acid (polymethyl methacrylate, etc.) Li methacrylate), polyacrylic acids, polycarbonate, polyphenylene sulfide, polysulfone, polyether sulfone, polyether nitrile, polyether ketone, polyketone, liquid crystal polymer, ionomer and the like.
[0020]
As thermoplastic elastomers, styrene-butadiene copolymers and styrene-isoprene block copolymers and their hydrogenated products, styrene thermoplastic elastomers, olefin thermoplastic elastomers, vinyl chloride thermoplastic elastomers, polyester thermoplastics Examples thereof include elastomers, polyurethane-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and the like.
[0021]
Thermosetting resins include epoxy resin, polyimide resin, bismaleimide resin, benzocyclobutene resin, phenol resin, unsaturated polyester resin, diallyl phthalate resin, silicone resin, urethane resin, thermosetting PPE resin, thermosetting modification PPE resin etc. are mentioned.
[0022]
Cross-linked rubbers include natural rubber, butadiene rubber, isoprene rubber, styrene-butadiene copolymer rubber, nitrile rubber, hydrogenated nitrile rubber, chloroprene rubber, ethylene propylene rubber, chlorinated polyethylene, chlorosulfonated polyethylene, butyl rubber, and halogenated butyl rubber. , Fluorine rubber, urethane rubber, silicone rubber and the like.
[0023]
Among these polymer materials, silicone rubber, epoxy resin, polyimide resin, bismaleimide resin, benzocyclobutene resin, fluorine resin, PPE resin, and polyacetal resin are preferable from the viewpoint of electrical and thermal reliability. For wiring board applications that have a low dielectric constant and dielectric loss tangent and require frequency characteristics in a high frequency region, fluororesins, thermosetting PPE resins, thermosetting modified PPE resins, and polyolefin resins are preferable. These polymer materials may be used singly or in appropriate combination of two or more, or a polymer alloy composed of two or more polymer materials may be used. Moreover, it does not specifically limit about the crosslinking method of a polymeric material, Well-known crosslinking methods, such as thermosetting, photocuring, and moisture curing, are employable.
[0024]
Subsequently, a thermally conductive polymer composition obtained by blending the above graphitized carbon powder into a polymer material, and a thermally conductive molded body obtained by molding the thermally conductive polymer composition into a predetermined shape will be described. To do.
[0025]
The amount of graphitized carbon powder to be blended in the polymer material is appropriately determined depending on the required performance of the target final product, but is preferably 5 to 500 parts by weight with respect to 100 parts by weight of the polymer material. 300 parts by weight are more preferable, and 20 to 200 parts by weight are particularly preferable. When this compounding quantity is less than 5 weight part, the heat conductivity of the heat conductive polymer composition and heat conductive molding which are obtained will become small, and a thermal radiation characteristic will fall. On the other hand, when the amount exceeds 500 parts by weight, the viscosity of the blended composition increases, making it difficult to uniformly disperse the graphitized carbon powder, and mixing of bubbles is unavoidable, which is not preferable.
[0026]
In addition to the above graphitized carbon powder, other thermally conductive fillers, flame retardants, softeners, colorants, stabilizers and the like may be added to the thermally conductive polymer composition as necessary. Good. Examples of other thermally conductive fillers include metal oxides such as aluminum oxide, boron nitride, aluminum nitride, zinc oxide, silicon carbide, and aluminum hydroxide, metal nitrides, metal carbides, and metal hydroxides. Examples of the form include a spherical shape, a powder shape, a fiber shape, a needle shape, a scale shape, a whisker shape, a microcoil shape, a single-wall nanotube, and a multi-wall nanotube shape. In addition, when the filler used in combination is conductive, there is a risk of impairing the electrical insulation properties of the obtained heat conductive polymer composition and the heat conductive molded article. Therefore, it is better to reduce the blending amount as much as possible. preferable. In order to reduce the viscosity, a volatile organic solvent or a reactive plasticizer may be added.
[0027]
When the heat conductive molded body is formed into a sheet shape, the thickness is not particularly limited, but is preferably in the range of 0.05 to 10 mm from the viewpoint of practicality.
The thermal conductivity and electrical insulation of the thermally conductive molded body are not particularly limited, but the thermal conductivity is preferably 1 W / m · K or more, more preferably 2 W / m · K or more, particularly preferably 5 W / m ·. K or more. Electrical insulation has a surface resistance value of 106Ω / □ or more is preferable, more preferably 108Ω / □ or more, particularly preferably 109Ω / □ or more.
[0028]
Next, the usage method of said heat conductive molded object is demonstrated.
A heat conductive molded object is used as a heat radiating member, a heat transfer member, etc. for efficiently radiating the heat which a semiconductor element, a power supply, a light source, components, etc. generate in an electronic device etc. outside. Specifically, it is processed into a sheet shape and used between a heat-generating member such as a semiconductor element and a heat-dissipating member such as a radiator, or a heat sink, semiconductor package component, heat sink, heat spreader, die pad, print It is used after being molded into wiring boards, cooling fan parts, heat pipes, casings, and the like.
[0029]
FIG. 1 is a diagram showing an example in which a sheet-like thermally conductive molded body is used as a heat transfer member. In the example shown in FIG. 1A, a thermally conductive molded
[0030]
Next, the manufacturing method of a heat conductive molded object is demonstrated.
When pitch is used as a raw material for graphitized carbon powder, graphitized carbon fiber is produced through steps of spinning, infusibilization, carbonization and graphitization, and then graphitized by grinding or cutting the graphitized carbon fiber. Use carbon powder. The pulverization or cutting is not limited to after the graphitization treatment, and may be performed after the infusibilization treatment or after the carbonization treatment. It is preferable to carry out after the conversion treatment. In addition, when pulverized or cut after the carbonization treatment, the condensation polymerization reaction or cyclization reaction tends to proceed on the newly exposed surface after pulverization or cutting during the graphitization treatment. There is also an advantage that it is easy to obtain graphitized carbon powder having excellent conductivity.
[0031]
Examples of the spinning method in the spinning step include a melt spinning method, a melt blowing method, a centrifugal spinning method, a vortex spinning method, and the like. The melt blowing method is preferable from the viewpoint of productivity at the time of spinning and the quality of the graphitized carbon powder obtained. In the case of the melt blow method, there is an advantage that the graphite layer surface can be easily arranged in parallel to the fiber axis by spinning at a low viscosity of several tens of poises and cooling at a high speed.
[0032]
In the case of the melt blow method, the diameter of the spinning hole is preferably 0.1 to 0.5 mm, and more preferably 0.15 to 0.3 mm. If the diameter of the spinning hole is smaller than 0.1 mm, clogging is likely to occur, and it becomes difficult to manufacture the spinning nozzle, which is not preferable. On the other hand, if it exceeds 0.5 mm, the fiber diameter tends to be as large as 25 μm or more, and the fiber diameter tends to vary, which is not preferable for quality control. The spinning speed is preferably 500 m / min or more from the viewpoint of productivity, more preferably 1500 mm / min or more, and particularly preferably 2000 m / min or more. The spinning temperature may be not lower than the temperature at which the pitch is not lower than the softening point of the raw material pitch, but is usually 300 to 400 ° C, preferably 300 to 380 ° C. From the relationship with the spinning temperature, the softening point of the raw material pitch is preferably 230 to 350 ° C, more preferably 250 to 310 ° C.
[0033]
As an infusibilization method in the infusibilization process, a heat treatment method in an oxidizing gas atmosphere such as nitrogen dioxide or oxygen, a treatment method in an oxidizing aqueous solution such as nitric acid or chromic acid, light, γ-ray, etc. Although the method of superposing | polymerizing is mentioned, The method of heat-processing in the air is preferable from the simplicity. In the case of adopting a heat treatment method in the air, it is desirable to perform the heat treatment while raising the temperature to about 350 ° C., preferably at an average temperature rising rate of 3 ° C./min or more, more preferably at 5 ° C./min or more.
[0034]
The carbonization treatment in the subsequent carbonization step and the graphitization treatment in the graphitization step are performed by heat treatment in an inert gas atmosphere. The treatment temperature during the carbonization treatment is preferably 250 ° C. or higher, more preferably 500 ° C. or higher. The treatment temperature during graphitization is preferably 2500 ° C or higher, more preferably 3000 ° C or higher.
[0035]
The graphitized carbon powder in the present embodiment can be obtained by performing at least one of carbonization treatment or graphitization treatment in the presence of a boron compound. Examples of the method include a method of mixing a boron compound at the time of carbonization treatment or graphitization treatment, a method of mixing a boron compound in a raw material pitch in advance, and spinning the mixture.
[0036]
For the pulverization or cutting treatment, a pulverizer such as a Victory mill, a jet mill, a high-speed rotary mill, or a cutting machine used for chopped fibers is used. In order to efficiently perform pulverization or cutting, a method of cutting fibers in a direction perpendicular to the fiber axis by rotating a rotor to which blades are attached at high speed is appropriate. The average particle diameter of the graphitized carbon powder generated by this pulverization or cutting treatment is controlled by adjusting the rotational speed of the rotor, the angle of the blade, and the like. Although there is a method using a grinding machine such as a ball mill as a method for pulverizing the fiber, this method is not appropriate because the pressurization force in the perpendicular direction of the fiber acts to increase the occurrence of vertical cracks in the fiber axis direction. .
[0037]
The heat conductive polymer composition is obtained by blending the graphitized carbon powder obtained as described above into a polymer material and performing operations such as stirring, defoaming and kneading. And the heat conductive molded object is obtained by shape | molding the heat conductive polymer composition in a defined shape.
[0038]
Examples of the method for orienting the graphitized carbon powder in the thermally conductive polymer composition in a certain direction include a method using a flow field or a shear field, a method using a magnetic field, and a method using an electric field. Among them, the method of applying a magnetic field to the thermally conductive polymer composition and orienting the graphitized carbon powder in parallel to the magnetic field lines is preferable because the orientation direction can be arbitrarily set. The reason why the graphitized carbon powder is effectively aligned by a magnetic field is that the hexagonal graphite structure of boron nitride has the same shape as that of graphite because the crystal structure of boron nitride is the same as that of graphite. It is thought to show sex.
[0039]
When producing a thermally conductive molded body using magnetic field orientation, a magnetic field is applied to the thermally conductive polymer composition injected into the mold cavity, and the thermally conductive polymer composition is applied. The thermally conductive polymer composition is solidified in a state where the graphitized carbon powder contained in the product is oriented in a certain direction.
[0040]
For example, when the graphitized carbon powder is oriented in the thickness direction (Z-axis direction in FIG. 3) in the plate-like thermally conductive compact 21 as shown in FIG. 3, the lines of magnetic force are shown in FIG. 4 (a). Thermally conductive polymer composition injected into the
[0041]
In the example shown in FIGS. 4A and 4B, the pair of magnetic field generating means 22 is arranged with the
[0042]
Examples of the magnetic field generating means 22 include permanent magnets and electromagnets. The magnetic flux density of the magnetic field generated by the magnetic field generating means is preferably in the range of 0.05 to 30 Tesla, more preferably 0.5 Tesla or more, and particularly preferably 2 Tesla or more.
[0043]
According to the embodiment described above in detail, the following effects are exhibited.
The graphitized carbon powder in the present embodiment has both a good thermal conductivity and an electrical insulation property by having a coating film made of a boron compound having a thermal conductivity and an electrical insulation property on the surface. For this reason, even when this heat conductive molded body containing the graphitized carbon powder is used as a heat radiating member or heat transfer member in an application where electrical insulation is required, its function can be performed without causing an electrical failure. Can be demonstrated.
[0044]
For example, in the case of fibrous graphitized carbon powder, the thermal conductivity in the fiber length direction is very excellent. Therefore, in the heat conductive molded body in which the fibrous graphitized carbon powder is blended, the heat conductivity in the orientation direction can be remarkably improved by orienting the graphitized carbon powder in a certain direction, and the heat conduction The heat conductive molded object which has anisotropy in property can be obtained.
[0045]
-A coating made of a boron compound is formed by performing carbonization treatment or graphitization treatment in the process of producing graphitized carbon powder in the presence of a boron compound, so that the formation of the coating is easy and reliable. Can do.
[0046]
-The thermal conductivity and electrical insulation can be further improved by forming a film with boron nitride which is particularly excellent in thermal conductivity and electrical insulation.
[0047]
【Example】
Next, the embodiment will be described more specifically with reference to examples and comparative examples.
In each example, the thermal conductivity was measured according to the laser flash method, and the surface resistance value was measured according to JIS-K6911.
[0048]
(Prototype example 1 of graphitized carbon powder)
Carbon fiber obtained by spinning, infusibilizing, and carbonization using 100% mesophase pitch as raw material was pulverized to obtain carbon powder. This carbon powder was mixed with a mixture of boron carbide and boron nitride (1: 1 by weight), and then heated to 3000 ° C. in a nitrogen atmosphere to perform graphitization to obtain graphitized carbon powder.
[0049]
When the surface of the graphitized carbon powder was analyzed with an electron microscope and ESCA (X-ray photoelectron spectroscopy), a film made of boron carbide and boron nitride was observed on the surface. Table 1 shows the results of measuring the fiber diameter, average particle diameter, thermal conductivity in the fiber length direction, and boron compound content (in terms of boron) of the graphitized carbon powder.
[0050]
(Prototype example 2 of graphitized carbon powder)
A mixture of 80% by weight of mesophase pitch and 20% by weight of boron nitride is spun and infusible, and then gradually heated to 2000 ° C. in a nitrogen atmosphere for carbonization, and further heated to 3200 ° C. for graphitization. A graphitized carbon powder was obtained.
[0051]
When the surface of the graphitized carbon fiber was analyzed with an electron microscope and ESCA, a film made of boron nitride was observed on the surface. Table 1 shows the results of measuring the fiber diameter, average particle diameter, thermal conductivity in the fiber length direction, and boron compound content (in terms of boron) of the graphitized carbon powder.
[0052]
(Prototype example 3 of graphitized carbon powder)
Carbon fiber obtained by spinning, infusibilizing, and carbonization using 100% mesophase pitch as raw material was pulverized to obtain carbon powder. The carbon powder was heated to 3000 ° C. in a nitrogen atmosphere to perform graphitization to obtain graphitized carbon powder.
[0053]
A film made of a boron compound was not observed on the surface of the graphitized carbon fiber. Table 1 shows the results of measuring the fiber diameter, average particle diameter, thermal conductivity in the fiber length direction, and boron compound content (in terms of boron) of the graphitized carbon powder.
[0054]
(Prototype example 4 of graphitized carbon powder)
After spinning and infusibilizing 100% mesophase pitch, carbonization was performed by stepwise heating to 2000 ° C. in a nitrogen atmosphere, and further graphitizing treatment was performed by heating to 3200 ° C. to obtain graphitized carbon powder. .
[0055]
A film made of a boron compound was not observed on the surface of the graphitized carbon fiber. Table 1 shows the results of measuring the fiber diameter, average particle diameter, thermal conductivity in the fiber length direction, and boron compound content (in terms of boron) of the graphitized carbon powder.
[0056]
[Table 1]
Example 1
The graphitized carbon powder of Prototype Example 1 is surface-treated with a silane coupling agent, and 120 parts by weight of the graphitized carbon powder after the treatment is mixed with 100 parts by weight of an unsaturated polyester resin (Epolac manufactured by Nippon Shokubai Co., Ltd.) and heated. A conductive polymer composition was prepared. Subsequently, the thermally conductive polymer composition is injected into a cavity of a predetermined mold, and a magnetic field (magnetic flux density of 6 Tesla) in which the direction of the magnetic field lines matches the thickness direction of the thermally conductive molded body is applied. The graphitized carbon powder in the conductive polymer composition was sufficiently oriented and then cured by heating to obtain a plate-like thermally conductive molded body having a thickness of 1.5 mm × length 20 mm × width 20 mm.
[0057]
The graphitized carbon powder in the thermally conductive molded body was aligned in the thickness direction. Table 2 shows the results of measuring the thermal conductivity in the thickness direction (Z-axis direction), the thermal conductivity in the in-plane direction (X-axis direction), and the surface resistance value of the thermally conductive molded body.
[0058]
(Example 2)
In Example 1, the magnetic field in which the direction of the magnetic field lines coincided with the in-plane direction (Y-axis direction) of the thermally conductive molded body was changed to be applied to the thermally conductive polymer composition in the cavity. Other than that was carried out similarly to Example 1, and produced the plate-shaped heat conductive molded object.
[0059]
The graphitized carbon powder in the thermally conductive molded body was aligned in the in-plane direction (Y-axis direction). Table 2 shows the results of measuring the thermal conductivity in the thickness direction (Z-axis direction), the thermal conductivity in the in-plane direction (X-axis direction and Y-axis direction), and the surface resistance value of the thermally conductive molded body.
[0060]
(Example 3)
The graphitized carbon powder of Prototype Example 1 is surface-treated with a silane coupling agent, and 80 parts by weight of the graphitized carbon powder after the treatment is mixed with 100 parts by weight of a liquid epoxy resin (TB2280C, manufactured by ThreeBond Co., Ltd.) to conduct heat. A polymer composition was prepared. Subsequently, the thermally conductive polymer composition is injected into a cavity of a predetermined mold, and a magnetic field (magnetic flux density of 10 Tesla) in which the direction of the magnetic field lines matches the thickness direction of the thermally conductive molded body is applied. The graphitized carbon powder in the conductive polymer composition was sufficiently oriented and then cured by heating to obtain a plate-like thermally conductive molded body having a thickness of 3 mm × length 20 mm × width 20 mm.
[0061]
The graphitized carbon powder in the thermally conductive molded body was aligned in the thickness direction. Table 2 shows the results of measuring the thermal conductivity in the thickness direction (Z-axis direction), the thermal conductivity in the in-plane direction (X-axis direction), and the surface resistance value of the thermally conductive molded body.
[0062]
Example 4
In Example 3, a magnetic field in which the direction of magnetic field lines coincided with the in-plane direction (Y-axis direction) of the thermally conductive molded body was changed to be applied to the thermally conductive polymer composition in the cavity. Other than that was carried out similarly to Example 3, and produced the plate-shaped heat conductive molded object.
[0063]
The graphitized carbon powder in the thermally conductive molded body was aligned in the in-plane direction (Y-axis direction). Table 2 shows the results of measuring the thermal conductivity in the thickness direction (Z-axis direction), the thermal conductivity in the in-plane direction (X-axis direction and Y-axis direction), and the surface resistance value of the thermally conductive molded body.
[0064]
(Example 5)
The graphitized carbon powder of Prototype Example 2 is surface-treated with a silane coupling agent, and 110 parts by weight of the graphitized carbon powder after the treatment and 60 parts by weight of aluminum oxide powder (AS-20, Showa Denko KK) are liquid. A thermally conductive polymer composition was prepared by mixing with 100 parts by weight of silicone rubber (GESE Silicone Co., Ltd. TSE3070). Subsequently, the thermally conductive polymer composition is injected into a cavity of a predetermined mold, and a magnetic field (magnetic flux density of 10 Tesla) in which the direction of the magnetic field lines matches the thickness direction of the thermally conductive molded body is applied. After fully orienting the graphitized carbon powder in the conductive polymer composition, it is cured by heating to obtain a plate-like thermally conductive molded body (Asker C hardness 17) having a thickness of 0.5 mm × length 20 mm × width 20 mm. Obtained.
[0065]
The graphitized carbon powder in the thermally conductive molded body was aligned in the thickness direction. Table 2 shows the results of measuring the thermal conductivity in the thickness direction (Z-axis direction), the thermal conductivity in the in-plane direction (X-axis direction), and the surface resistance value of the thermally conductive molded body.
[0066]
(Example 6)
In Example 5, a magnetic field in which the direction of the magnetic field lines coincided with the in-plane direction (Y-axis direction) of the thermally conductive molded body was changed to be applied to the thermally conductive polymer composition in the cavity. Other than that was carried out similarly to Example 5, and produced the plate-shaped heat conductive molded object (Asker C hardness 17).
[0067]
The graphitized carbon powder in the thermally conductive molded body was aligned in the in-plane direction (Y-axis direction). Table 2 shows the results of measuring the thermal conductivity in the thickness direction (Z-axis direction), the thermal conductivity in the in-plane direction (X-axis direction and Y-axis direction), and the surface resistance value of the thermally conductive molded body.
[0068]
(Example 7)
Styrene-based thermoplastic elastomer (Tuftec H1053, manufactured by Asahi Kasei Kogyo Co., Ltd.) is dissolved by adding 2000 parts by weight of toluene as a solvent, and 40 parts by weight of graphitized carbon powder of Prototype Example 2 is mixed therewith for thermal conductivity. A polymer composition was prepared. Subsequently, the thermally conductive polymer composition is injected into a cavity of a predetermined mold, and a magnetic field (magnetic flux density of 8 Tesla) in which the direction of the magnetic field line coincides with the height direction of the thermally conductive molded body is applied. The graphitized carbon powder in the thermally conductive polymer composition was sufficiently oriented and then cured by heating to obtain a thermally conductive molded body having a height of 40 mm × length 20 mm × width 20 mm.
[0069]
The graphitized carbon powder in the thermally conductive molded body was aligned in the height direction. Table 2 shows the results of measuring the thermal conductivity in the height direction (Z-axis direction), the thermal conductivity in the in-plane direction (X-axis direction), and the surface resistance value of the thermally conductive molded body.
[0070]
[Table 2]
(Comparative Example 1)
In Example 1, in place of the graphitized carbon powder of Prototype Example 1, the graphitized carbon powder of Prototype Example 3 was changed to be used, and the application of a magnetic field when curing the thermally conductive polymer composition was omitted. did. Other than that was carried out similarly to Example 1, and produced the heat conductive molded object.
[0071]
The graphitized carbon powder in the thermally conductive molded body was randomly distributed without being oriented in a certain direction. Table 3 shows the results of measuring the thermal conductivity in the thickness direction (Z-axis direction), the thermal conductivity in the in-plane direction (X-axis direction and Y-axis direction), and the surface resistance value of the thermally conductive molded body.
[0072]
(Comparative Example 2)
In Comparative Example 1, the graphitized carbon powder in the thermally conductive polymer composition was sufficiently oriented by applying a magnetic field (magnetic flux density of 6 Tesla) in which the direction of the magnetic field lines coincided with the thickness direction of the thermally conductive molded body. It changed so that it might be heat-cured later. Other than that was carried out similarly to the comparative example 1, and produced the heat conductive molded object.
[0073]
The graphitized carbon powder in the thermally conductive molded body was aligned in the thickness direction. Table 3 shows the results of measuring the thermal conductivity in the thickness direction (Z-axis direction), the thermal conductivity in the in-plane direction (X-axis direction), and the surface resistance value of the thermally conductive molded body.
[0074]
(Comparative Example 3)
In Example 5, in place of the graphitized carbon powder of Prototype Example 2, the graphitized carbon powder of Prototype Example 4 was changed to be used, and application of a magnetic field when curing the thermally conductive polymer composition was omitted. did. Other than that was carried out similarly to Example 1, and produced the heat conductive molded object.
[0075]
The graphitized carbon powder in the thermally conductive molded body was randomly distributed without being oriented in a certain direction. Table 3 shows the results of measuring the thermal conductivity in the thickness direction (Z-axis direction), the thermal conductivity in the in-plane direction (X-axis direction and Y-axis direction), and the surface resistance value of the thermally conductive molded body.
[0076]
(Comparative Example 4)
In Comparative Example 3, the graphitized carbon powder in the thermally conductive polymer composition was sufficiently oriented by applying a magnetic field (magnetic flux density of 10 Tesla) in which the direction of the magnetic field lines coincided with the thickness direction of the thermally conductive molded body. It changed so that it might be heat-cured later. Other than that was carried out similarly to the comparative example 3, and produced the heat conductive molded object (Asker C hardness 17).
[0077]
The graphitized carbon powder in the thermally conductive molded body was aligned in the thickness direction. Table 3 shows the results of measuring the thermal conductivity in the thickness direction (Z-axis direction), the thermal conductivity in the in-plane direction (X-axis direction), and the surface resistance value of the thermally conductive molded body.
[0078]
[Table 3]
As shown in Table 2, the thermal conductive molded bodies of Examples 1 to 7 using boron-containing graphitized carbon powder have a large thermal conductivity value and a large surface resistance value. Both conductivity and electrical insulation were shown to be excellent. On the other hand, as shown in Table 3, the heat conductive molded bodies of Comparative Examples 1 to 4 using a graphitized carbon powder containing no boron have a large thermal conductivity value but a small surface resistance value. From this, it was shown that the thermal conductivity was excellent but the electrical insulation was poor.
[0079]
Moreover, in Examples 1-7, the value of the thermal conductivity in the orientation direction of the graphitized carbon powder is remarkably larger than the values of the thermal conductivity in the other directions, and the thermally conductive molded articles of Examples 1-7. Was shown to be anisotropic in thermal conductivity.
[0080]
(Example 8)
A wiring board was produced using the plate-like thermally conductive molded body of Example 1. A thermally conductive molded body is used as a substrate, an epoxy adhesive is applied on the substrate, a copper foil having a thickness of 35 μm is pressure-bonded with a press, and then the copper foil is etched to form a conductor circuit on the substrate. Formed. The transistor (TOSHIBA Corporation TO-220) was soldered on the wiring board, and the opposite surface was energized while being cooled with a cooling fan. The thermal resistance was determined from the temperature difference between the transistor and the wiring board. It was ° C / W.
[0081]
(Comparative Example 5)
A wiring board was produced in the same manner as in Example 8 using the plate-like thermally conductive molded body of Comparative Example 2. Then, a transistor (TO-220 manufactured by Toshiba Corporation) was soldered on the wiring board and energized while cooling the opposite surface with a cooling fan, but the circuit was short-circuited and did not operate.
[0086]
【The invention's effect】
Since this invention is comprised as mentioned above, there exist the following effects.
Claim 1And 2According to the invention described in (1), it is possible to combine good thermal conductivity and electrical insulation.
[0087]
Also,Easy and reliable film formation.
[0088]
Claim3 andAccording to the invention described in item 4, it is possible to efficiently produce a thermally conductive molded body having both good thermal conductivity and electrical insulation.
[Brief description of the drawings]
FIGS. 1A to 1D are side views showing an example of using a thermally conductive molded body.
FIG. 2 is a cross-sectional view showing a usage example of a thermally conductive molded body.
FIG. 3 is a perspective view showing a square plate-like thermally conductive molded body.
4A and 4B are conceptual diagrams showing a method for manufacturing a thermally conductive molded body.
[Explanation of symbols]
13, 21 ... Thermally conductive molded body, 18 ... Substrate as the thermally conductive molded body.
Claims (4)
前記黒鉛化炭素粉末は、その製造過程における炭素化処理又は黒鉛化処理をホウ素化合物の存在下にて行うことで形成されたものであり、前記ホウ素化合物が窒化ホウ素を含むことで前記黒鉛化炭素粉末は窒化ホウ素を含むホウ素化合物(但し、強磁性体を除く)の被膜を表面に備えてなり、その黒鉛化炭素粉末が、一定方向に配向していることを特徴とする熱伝導性成形体。A thermally conductive molded body formed by molding a thermally conductive polymer composition containing a fibrous graphitized carbon powder not containing a ferromagnetic material into a polymer material into a predetermined shape,
The graphitized carbon powder is formed by performing carbonization treatment or graphitization treatment in the production process in the presence of a boron compound, and the boron compound contains boron nitride so that the graphitized carbon powder is contained. The powder is provided with a coating of a boron compound containing boron nitride (except for a ferromagnetic material) on the surface, and the graphitized carbon powder is oriented in a certain direction, and the thermally conductive molded product .
前記黒鉛化炭素粉末は、その製造過程における炭素化処理又は黒鉛化処理をホウ素化合物の存在下にて行うことで形成されたものであり、前記ホウ素化合物が窒化ホウ素を含むことで前記黒鉛化炭素粉末は窒化ホウ素を含むホウ素化合物(但し、強磁性体を除く)の被膜を表面に備えてなることを特徴とする熱伝導性成形体の製造方法。 Containing a boron compound in a polymer material, and a magnetic field was applied to the thermally conductive polymer composition was combined distribution graphitized carbon powder containing no ferromagnetic, orienting the graphitized carbon powder in a predetermined direction A method for producing a thermally conductive molded body in which the thermally conductive polymer composition is solidified in a state in which
The graphitized carbon powder is formed by performing carbonization treatment or graphitization treatment in the production process in the presence of a boron compound, and the boron compound contains boron nitride so that the graphitized carbon powder is contained. A method for producing a thermally conductive molded product, characterized in that the powder is provided with a coating of a boron compound containing boron nitride (excluding a ferromagnetic material) on the surface.
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JP2004149722A (en) | 2002-10-31 | 2004-05-27 | Polymatech Co Ltd | Thermally conductive polymer molded product |
JP4768302B2 (en) * | 2004-04-06 | 2011-09-07 | 三菱エンジニアリングプラスチックス株式会社 | Molded body made of highly heat conductive insulating polycarbonate resin composition |
JP4817785B2 (en) * | 2005-09-30 | 2011-11-16 | 三菱エンジニアリングプラスチックス株式会社 | Highly heat conductive insulating polycarbonate resin composition and molded body |
JP5054313B2 (en) * | 2006-01-26 | 2012-10-24 | 帝人株式会社 | Heat resistant resin composition and method for producing the same |
JP5054314B2 (en) * | 2006-01-27 | 2012-10-24 | 帝人株式会社 | Polyethersulfone resin composition having excellent thermal stability and method for producing the same |
JPWO2010021408A1 (en) * | 2008-08-21 | 2012-01-26 | 株式会社豊田自動織機 | Method for producing thermally conductive resin molding |
TW201139641A (en) * | 2010-01-29 | 2011-11-16 | Nitto Denko Corp | Heat dissipation structure |
KR101322328B1 (en) * | 2011-05-20 | 2013-10-28 | 전자부품연구원 | Manufacturing Apparatus And Method Of Thermally Conductive Sheet Having Orientation |
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WO2016176024A1 (en) * | 2015-04-27 | 2016-11-03 | Dow Global Technologies Llc | Process for making a fabricated article from polyolefin |
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US20200051793A1 (en) * | 2018-08-13 | 2020-02-13 | Skc Solmics Co., Ltd. | Ring-shaped element for etcher and method for etching substrate using the same |
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