JP2011054610A - Thermal conductive sheet and method of manufacturing the same - Google Patents
Thermal conductive sheet and method of manufacturing the same Download PDFInfo
- Publication number
- JP2011054610A JP2011054610A JP2009199637A JP2009199637A JP2011054610A JP 2011054610 A JP2011054610 A JP 2011054610A JP 2009199637 A JP2009199637 A JP 2009199637A JP 2009199637 A JP2009199637 A JP 2009199637A JP 2011054610 A JP2011054610 A JP 2011054610A
- Authority
- JP
- Japan
- Prior art keywords
- conductive
- heat
- resin layer
- heat conductive
- insulating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
Landscapes
- Laminated Bodies (AREA)
- Cooling Or The Like Of Electrical Apparatus (AREA)
- Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)
Abstract
Description
本発明は、熱伝導性シートに関し、さらに詳しくは、電気電子機器の各種半導体素子や電源、光源、ヒーター、部品などの熱源にて発生する熱を外部に放散又は拡散させる熱伝導性、電気絶縁性、耐熱性及び低コスト性を兼ね備えた熱伝導性シートに関するものである。 The present invention relates to a heat conductive sheet, and more specifically, heat conductivity and electric insulation for radiating or diffusing heat generated in various semiconductor elements and power sources such as power supplies, light sources, heaters, and components of electric and electronic equipment to the outside. The present invention relates to a heat conductive sheet having both heat resistance, heat resistance and low cost.
本明細書において、配合を示す「比」、「部」、「％」などは特に断わらない限り質量基準であり、「／」印は一体的に積層されていることを示す。また、「ＥＢ」は「電子線」、「ＬＬ」は「直鎖状低密度ポリエチレン」、及び「ＳＢＲ」は「スチレン−ブタジエンラバー」の略語、機能的表現、通称、又は業界用語である。また、「表面抵抗値の単位Ωは当業界では通常Ω／□とも表示される。 In the present specification, “ratio”, “part”, “%” and the like indicating the composition are based on mass unless otherwise specified, and the “/” mark indicates that they are integrally laminated. “EB” is an abbreviation, functional expression, common name, or industry term for “electron beam”, “LL” for “linear low density polyethylene”, and “SBR” for “styrene-butadiene rubber”. In addition, “unit of surface resistance value Ω is usually expressed as Ω / □ in the industry.
（背景技術）近年、電気電子機器の高性能化、小型化及び軽量化に伴い、電気電子機器及び部品の集積度が高まっている。電子機器や部品の集積度が高まると、より小さい区域により多くの部品や集積回路が組み込まれるので、熱が逃げきれずに高温になってしまい、電子機器の故障や誤動作を生じることがある。従って、これらの電子機器や電子部品等から発生する熱を効果的に拡散させ、外部へ放散させる放熱対策が課題になっている。電気電子機器や部品の放熱対策としては、機器や個々の集積回路にもホットスポットの形成を防ぐために放熱体を設ける。発熱源となる発熱性電子部品等の被装着部位の凹凸に柔軟に追従させて、発熱性電子部品等に密着した状態で取り付けられる。例えば、トランジスタやサイリスタ等の発熱性電子部品等にはヒートシンク等の放熱部材を、熱伝導性の良好な熱伝導性シート（放熱シートともいう）を介して取り付ける。しかしながら、発熱性電子部品から発生する熱を効率良く放熱部材へ伝導させて放熱させる熱伝導性シートには、高い熱伝導率が求められ、かつ、高い耐熱性も求められている。また、電気を使用する電気電子機器及び部品用なので、高い電気絶縁性も求められ、さらに、効率よく大量に製造することができる低コスト性も求められている。
即ち、熱伝導性シートは、高い熱伝導率、高い耐熱性、高い電気絶縁性、低コストが求められている。
(Background Art) In recent years, with the improvement in performance, size, and weight of electrical and electronic equipment, the degree of integration of electrical and electronic equipment and components has increased. As the degree of integration of electronic devices and components increases, many components and integrated circuits are incorporated in a smaller area, so that heat cannot escape and become high temperature, which may cause failure or malfunction of the electronic devices. Therefore, a heat dissipation measure for effectively diffusing heat generated from these electronic devices and electronic components and dissipating the heat to the outside is an issue. As a heat dissipation measure for electrical and electronic equipment and components, a heat radiator is provided in the equipment and individual integrated circuits in order to prevent formation of hot spots. It is attached in a state of being in close contact with the heat-generating electronic component or the like by flexibly following the unevenness of the mounting site of the heat-generating electronic component or the like serving as a heat generation source. For example, a heat radiating member such as a heat sink is attached to a heat-generating electronic component such as a transistor or a thyristor via a heat conductive sheet (also referred to as a heat radiating sheet) having good heat conductivity. However, a heat conductive sheet that efficiently conducts heat generated from a heat-generating electronic component to a heat radiating member to dissipate heat is required to have high heat conductivity and high heat resistance. In addition, since it is used for electrical and electronic equipment and parts that use electricity, high electrical insulation is also required, and low cost that enables efficient mass production is also required.
That is, the thermal conductive sheet is required to have high thermal conductivity, high heat resistance, high electrical insulation, and low cost.
（従来技術）従来、熱伝導性シートの構成材料としては、マトリックス成分としてシリコーンが多く用いられている（例えば、特許文献１参照。）。しかしながら、マトリックス成分としてシリコーンを用いると、熱伝導性、柔軟性、耐熱性に優れた熱伝導性シートを得ることができる。しかし、シリコーンは他の高分子材料と比べて高価であり、さらには、シロキサンによる電子機器の接点不良などの不具合が生じ得るという問題点があり、また、価格及びシロキサン対策から、シリコーンの代わりにポリオレフィン系樹脂等を用い場合には、熱伝導性シートとして必要な耐熱性が不足するという欠点がある。
また、熱伝導性充填剤としては、熱伝導率の高いカーボンや金属粉のような導電性の熱伝導性充填剤が従来から多く用いられている（例えば、特許文献２〜４参照。）。しかしながら、熱伝導性シートは各種電子部品に使われるために絶縁性に優れるものがよく、電気の良導電性の熱伝導性充填剤では、短絡などの危険性がある。
そこで、絶縁性を保ちつつ高熱伝導率を実現するため、窒化ホウ素といった絶縁性の熱伝導性充填剤が用いられている（例えば、特許文献５参照。）。しかしながら、絶縁性の熱伝導性充填剤は、導電性の熱伝導性充填剤に比べ、熱伝導率が低く、更に価格も高いという欠点がある。
そこで、さらに、導電性の熱伝導性充填剤を含有した熱伝導性シートの表面に、ＰＥＴフィルムを積層し、絶縁層とすることが知られている（例えば、特許文献６参照。）。しかしながら、上記の方法では、熱伝導性シートの製造に加え、ＰＥＴフィルムを積層する工程が加わるためコストアップに繋がり、また更には、伸びの少ないＰＥＴフィルムを積層するために、柔軟な熱伝導性シートの変形を阻害し、表面形状追従性を著しく低下させるという欠点もある。
(Prior Art) Conventionally, as a constituent material of a heat conductive sheet, silicone is often used as a matrix component (see, for example, Patent Document 1). However, when silicone is used as the matrix component, a thermally conductive sheet excellent in thermal conductivity, flexibility, and heat resistance can be obtained. However, silicone is expensive compared to other polymer materials, and there are also problems such as poor contact of electronic devices due to siloxane, and in place of silicone due to price and siloxane countermeasures In the case of using a polyolefin-based resin or the like, there is a drawback that the heat resistance necessary for the heat conductive sheet is insufficient.
Moreover, as a heat conductive filler, many conductive heat conductive fillers, such as carbon and metal powder with high heat conductivity, are conventionally used (for example, refer patent documents 2-4). However, since the heat conductive sheet is used for various electronic components, it is preferable that the heat conductive sheet has an excellent insulating property, and there is a risk of a short circuit or the like in the case of a heat conductive filler with good electrical conductivity.
Therefore, in order to achieve high thermal conductivity while maintaining insulation, an insulating thermal conductive filler such as boron nitride is used (for example, see Patent Document 5). However, insulating heat conductive fillers have the disadvantages of low thermal conductivity and high price compared to conductive heat conductive fillers.
Therefore, it is further known that a PET film is laminated on the surface of a heat conductive sheet containing a conductive heat conductive filler to form an insulating layer (see, for example, Patent Document 6). However, in the above method, in addition to the production of the heat conductive sheet, a step of laminating the PET film is added, which leads to an increase in cost. There is also a drawback that the deformation of the sheet is hindered and the surface shape followability is remarkably lowered.
そこで、本発明は上記のような問題点を解消するために、本発明者らは鋭意研究を進め、本発明の完成に至ったものである。その目的は、高い熱伝導率、高い耐熱性、高い電気絶縁性、低コストな熱伝導性シートを提供することである。 In order to solve the above-described problems, the present inventors have made extensive studies and have completed the present invention. The object is to provide a thermal conductive sheet having high thermal conductivity, high heat resistance, high electrical insulation and low cost.
上記の課題を解決するために、本発明の請求項１の発明に係わる熱伝導性シートは、導電性かつ熱伝導性のフィラーと熱可塑性樹脂との体積基準での配合割合が導電性かつ熱伝導性のフィラー：熱可塑性樹脂＝１０〜９０：９０〜１０からなる導電性熱伝導性樹脂層の片面又は両面に、絶縁性かつ熱伝導性のフィラーと熱可塑性樹脂との体積基準での配合割合が絶縁性かつ熱伝導性のフィラー：熱可塑性樹脂＝１０〜９０：９０〜１０からなる絶縁性熱伝導性樹脂層を設けてなり、前記導電性熱伝導性樹脂層及び前記絶縁性熱伝導性樹脂層が電子線の照射で架橋させてなるように、したものである。
請求項２の発明に係わる熱伝導性シートは、上記導電性熱伝導性樹脂層及び上記絶縁性熱伝導性樹脂層の熱可塑性樹脂が、１００ｅＶの吸収エネルギーにより結合される分子の数Ｇ（ｘ）が１．０以上であるように、したものである。
請求項３の発明に係わる熱伝導性シートは、上記熱可塑性樹脂が直鎖状低密度ポリエチレン又はスチレン−ブタジエンラバーであるように、したものである。
請求項４の発明に係わる熱伝導性シートは、２５０℃下に３分間静置後の加熱収縮率が５％以下であるように、したものである。
請求項５の発明に係わる熱伝導性シートの製造方法は、請求項１〜４のいずれかに記載の熱伝導性シートの製造方法であって、（１）上記導電性熱伝導性樹脂層及び上記絶縁性熱伝導性樹脂層を共押出法で成膜する工程と、（２）電子線を照射して前記導電性熱伝導性樹脂層及び前記絶縁性熱伝導性樹脂層とを架橋する架橋工程と、からなるように、したものである。
In order to solve the above problems, the heat conductive sheet according to the invention of claim 1 of the present invention is such that the mixing ratio of the conductive and heat conductive filler and the thermoplastic resin on a volume basis is conductive and heat. Conductive filler: Thermoplastic resin = 10 to 90: Blending of insulating and thermally conductive filler and thermoplastic resin on one side or both sides of a conductive thermal conductive resin layer composed of 10 to 90:90 on a volume basis Insulating and thermally conductive filler: thermoplastic resin = 10 to 90: An insulating thermally conductive resin layer composed of 90 to 10 is provided, and the conductive thermally conductive resin layer and the insulating thermally conductive material are provided. The conductive resin layer is cross-linked by electron beam irradiation.
The thermally conductive sheet according to the invention of claim 2 is characterized in that the number of molecules G (x that the thermoplastic resin of the conductive thermally conductive resin layer and the insulating thermally conductive resin layer are bonded by absorbed energy of 100 eV. ) Is 1.0 or more.
The heat conductive sheet according to the invention of claim 3 is such that the thermoplastic resin is linear low density polyethylene or styrene-butadiene rubber.
The heat conductive sheet according to the invention of claim 4 is such that the heat shrinkage after standing at 250 ° C. for 3 minutes is 5% or less.
The manufacturing method of the heat conductive sheet concerning invention of Claim 5 is a manufacturing method of the heat conductive sheet in any one of Claims 1-4, Comprising: (1) The said electroconductive heat conductive resin layer and A step of forming the insulating heat conductive resin layer by a co-extrusion method; and (2) cross-linking that irradiates an electron beam to cross-link the conductive heat conductive resin layer and the insulating heat conductive resin layer. And a process.
請求項１の本発明によれば、高い熱伝導率、高い耐熱性、高い電気絶縁性の効果を奏する。
請求項２の本発明によれば、電子線の照射で架橋しより高い耐熱性の効果を奏する。
請求項３の本発明によれば、より安定して架橋し、高くかつ安定した耐熱性の効果を奏する。
請求項４の本発明によれば、加熱収縮率が少ないので、微細で高精度な電子機器や部品にも使用できる効果を奏する。
請求項５の本発明によれば、公知で安定した加工工程である積層化・共押出成形、及び電子線架橋技術を用いれるので、低コストで製造できる効果を奏する。
According to the first aspect of the present invention, the effects of high thermal conductivity, high heat resistance, and high electrical insulation are achieved.
According to the second aspect of the present invention, crosslinking is effected by irradiation with an electron beam, and a higher heat resistance effect is exhibited.
According to this invention of Claim 3, it bridge | crosslinks more stably and there exists an effect of the high and stable heat resistance.
According to the present invention of claim 4, since the heat shrinkage rate is small, there is an effect that it can be used for fine and highly accurate electronic devices and parts.
According to the present invention of claim 5, since the lamination / coextrusion molding and the electron beam cross-linking techniques, which are known and stable processing steps, are used, an effect of being manufactured at low cost is obtained.
以下、本発明の実施形態について、図面を参照しながら、詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
（熱伝導性シート）本願発明の熱伝導性シート１は図１に示すように、導電性熱伝導性フィラー１３と熱可塑性樹脂１１とからなる導電性熱伝導性樹脂層１０の両面に、絶縁性熱伝導性フィラー２３と熱可塑性樹脂２１とからなる絶縁性熱伝導性樹脂層２０が設けられている。また、図２に示すように、導電性熱伝導性フィラー１３と熱可塑性樹脂１１とからなる導電性熱伝導性樹脂層１０の片面に、絶縁性熱伝導性フィラー２３と熱可塑性樹脂２１とからなる絶縁性熱伝導性樹脂層２０を設けてもよい。そして、導電性熱伝導性樹脂層１０及び絶縁性熱伝導性樹脂層２０が電子線の照射で架橋されている。 (Thermal Conductive Sheet) As shown in FIG. 1, the thermally conductive sheet 1 of the present invention is insulated on both surfaces of a conductive thermally conductive resin layer 10 comprising a conductive thermally conductive filler 13 and a thermoplastic resin 11. An insulating heat conductive resin layer 20 made of a conductive heat conductive filler 23 and a thermoplastic resin 21 is provided. In addition, as shown in FIG. 2, the insulating thermal conductive filler 23 and the thermoplastic resin 21 are formed on one side of the conductive thermal conductive resin layer 10 including the conductive thermal conductive filler 13 and the thermoplastic resin 11. An insulating heat conductive resin layer 20 may be provided. The conductive heat conductive resin layer 10 and the insulating heat conductive resin layer 20 are cross-linked by electron beam irradiation.
（熱可塑性樹脂）熱可塑性樹脂１１、２１は熱可塑性を有するということで、通常耐熱性が低いという欠点がある。そこで電子線（ＥＢ）を照射することで、架橋構造を構成させて、耐熱寸法安定性、耐溶融性などの耐熱物性の向上を発現させる。１００ｅＶの吸収エネルギーにより架橋結合される分子の数として数値化されたＧ（ｘ）値があり、Ｇ（ｘ）値が高いほど架橋性が高く、逆に分解性の指標としてはＧ（ｓ）値などがある。そこで、本願発明に用いる熱可塑性樹脂１１、２１はポリマー材料固有のＧ（ｘ）値が１．０以上のものを用い、電子線（ＥＢ）を照射して架橋構造とすることで、上記の耐熱物性を満足させられるので、即ち、熱可塑性かつ架橋性を有する樹脂で熱可塑性架橋樹脂ともいえる。 (Thermoplastic Resin) The thermoplastic resins 11 and 21 have thermoplasticity, and thus have a drawback of usually low heat resistance. Therefore, by irradiating with an electron beam (EB), a cross-linked structure is formed to improve the heat-resistant physical properties such as heat-resistant dimensional stability and melt resistance. There is a G (x) value that is quantified as the number of molecules that are cross-linked by an absorption energy of 100 eV. The higher the G (x) value, the higher the crosslinkability, and conversely, G (s) There are values. Therefore, the thermoplastic resins 11 and 21 used in the present invention have a G (x) value unique to the polymer material of 1.0 or more, and are irradiated with an electron beam (EB) to form a crosslinked structure. Since the heat-resistant physical properties can be satisfied, that is, it is a thermoplastic and crosslinkable resin and can be said to be a thermoplastic crosslinked resin.
（熱可塑性架橋樹脂）Ｇ（ｘ）＝１．０以上の樹脂としては、例えば、低密度ポリエチレン、直鎖状低密度ポリエチレン、イソプレンラバー、スチレン−ブタジエンラバー、クロロプレンラバーなどがあげられる。なかでも、熱伝導性フィラーをコンパウンド化などの混練化しやすさや、樹脂自身が柔軟性な材料であることから、直鎖状低密度ポリエチレン、スチレン−ブタジエンラバーなどが好ましい。また、熱可塑性樹脂１１と熱可塑性樹脂２１とは、同一でも異なる樹脂でもよい。 (Thermoplastic cross-linked resin) Examples of the resin having G (x) = 1.0 or more include low density polyethylene, linear low density polyethylene, isoprene rubber, styrene-butadiene rubber, and chloroprene rubber. Among these, linear low density polyethylene, styrene-butadiene rubber, and the like are preferable because the heat conductive filler is easily kneaded such as compounding and the resin itself is a flexible material. Further, the thermoplastic resin 11 and the thermoplastic resin 21 may be the same or different resins.
（添加剤）導電性熱伝導性樹脂層１０及び絶縁性熱伝導性樹脂層２０の熱伝導性樹脂組成物には、必要に応じて物性調整剤、可塑剤等が加えられても良い。上記物性調整剤としては、例えば、ビニルトリエトキシシラン、３−アミノプロピルトリエトキシシラン等の各種シランカップリング剤が挙げられる。上記可塑剤としては、例えば、リン酸トリブチル、リン酸トリクレジル等のリン酸エステル類；フタル酸ジオクチル等のフタル酸エステル類；グリセリンモノオレイル酸エステル等の脂肪酸一塩基酸エステル類；アジピン酸ジオクチル等の脂肪酸二塩基酸エステル類；ポリプロピレングリコール類やポリエチレングリコール類等のポリエーテル類；ポリα−オレフィン等の液状炭化水素類；クロロフルオロカーボン類；シリコンオイル等の従来公知の可塑剤が挙げられ、これらは単独、又は２種以上を併用してもよい。さらに、難燃剤、タレ防止剤、酸化防止剤、老化防止剤、紫外線吸収剤、着色剤、溶剤、香料、顔料、染料等が添加されても良い。 (Additive) A physical property adjuster, a plasticizer, etc. may be added to the heat conductive resin composition of the conductive heat conductive resin layer 10 and the insulating heat conductive resin layer 20 as necessary. Examples of the physical property modifier include various silane coupling agents such as vinyltriethoxysilane and 3-aminopropyltriethoxysilane. Examples of the plasticizer include phosphoric esters such as tributyl phosphate and tricresyl phosphate; phthalic esters such as dioctyl phthalate; fatty acid monobasic esters such as glycerol monooleate; dioctyl adipate; Fatty acid dibasic acid esters; polyethers such as polypropylene glycols and polyethylene glycols; liquid hydrocarbons such as poly α-olefins; chlorofluorocarbons; and conventionally known plasticizers such as silicone oil. May be used alone or in combination of two or more. Furthermore, flame retardants, sagging inhibitors, antioxidants, anti-aging agents, ultraviolet absorbers, colorants, solvents, fragrances, pigments, dyes, and the like may be added.
（導電性熱伝導性フィラー）導電性熱伝導性フィラー１３としては、特に限定されず、通常、熱伝導性樹脂組成物中に配合される導電性のものを用いることが出来る。例えば、銅、銀、鉄、アルミニウム、ニッケル等の金属充填材；チタン等の金属合金充填材；カーボン等の炭素系充填材等が挙げられる。また無機充填材粒子に銀や銅等の金属材料を表面被覆したもの；金属充填材粒子に無機材料や炭素材料を表面被覆したもの等も挙げられる。 (Conductive Thermally Conductive Filler) The conductive thermally conductive filler 13 is not particularly limited, and a conductive one usually incorporated in the thermally conductive resin composition can be used. Examples thereof include metal fillers such as copper, silver, iron, aluminum, and nickel; metal alloy fillers such as titanium; carbon-based fillers such as carbon. In addition, examples include inorganic filler particles having a surface coated with a metal material such as silver or copper; metal filler particles having a surface coated with an inorganic material or a carbon material, and the like.
導電性熱伝導性フィラー１３は単独、又は２種類以上を併用しても良く、導電性かつ熱伝導性のフィラーに加え、絶縁性かつ熱伝導性のフィラーを添加しても良い。例えば、アルミナ、酸化マグネシウム、酸化ベリリウム、酸化チタン等の酸化物類；窒化ホウ素、窒化ケイ素、窒化アルミニウム等の窒化物類；炭化ケイ素等の炭化物類；ダイヤモンド等の絶縁性炭素系充填材；石英、石英ガラス等のシリカ粉類が挙げられる。上記熱伝導性フィラーは、ポリオレフィン樹脂との親和性を向上させるためにシラン処理等の各種表面処理を行っても良い。 The conductive heat conductive filler 13 may be used alone or in combination of two or more kinds, and an insulating and heat conductive filler may be added in addition to the conductive and heat conductive filler. For example, oxides such as alumina, magnesium oxide, beryllium oxide, and titanium oxide; nitrides such as boron nitride, silicon nitride, and aluminum nitride; carbides such as silicon carbide; insulating carbon-based filler such as diamond; quartz And silica powders such as quartz glass. The heat conductive filler may be subjected to various surface treatments such as silane treatment in order to improve the affinity with the polyolefin resin.
導電性熱伝導性フィラー１３の配合量は、導電性かつ熱伝導性のフィラーと熱可塑性樹脂との体積基準での配合割合が導電性かつ熱伝導性のフィラー：熱可塑性樹脂＝１０〜９０：９０〜１０とする。導電性熱伝導性フィラー１３の含有量が１０体積％未満であると効率的な熱伝導性を得にくくなり、９０体積％を超えると樹脂組成物の柔軟性が低下し、発熱体や放熱体の表面の凹凸への密着追従性が悪く接触熱抵抗が増大し効率的な熱伝導性が得られなくなる。より好ましくは１５〜６０体積％である。 The blending amount of the conductive heat conductive filler 13 is such that the blend ratio of the conductive and heat conductive filler and the thermoplastic resin on a volume basis is conductive and heat conductive filler: thermoplastic resin = 10 to 90: 90-10. When the content of the conductive heat conductive filler 13 is less than 10% by volume, it becomes difficult to obtain efficient thermal conductivity, and when it exceeds 90% by volume, the flexibility of the resin composition is lowered, and a heating element or a heat radiator. The adhesion followability to the unevenness of the surface is poor and the contact thermal resistance increases, so that efficient thermal conductivity cannot be obtained. More preferably, it is 15-60 volume%.
（絶縁性熱伝導性フィラー）絶縁性熱伝導性フィラー２３としては、アルミナ、酸化マグネシウム、酸化ベリリウム、酸化チタン等の酸化物類；窒化ホウ素、窒化ケイ素、窒化アルミニウム等の窒化物類；炭化ケイ素等の炭化物類；ダイヤモンド等の絶縁性炭素系充填材；石英、石英ガラス等のシリカ粉類が挙げられる。これらの熱伝導性フィラーは、樹脂との親和性を向上させるためにシラン処理等の各種表面処理を行っても良い。 (Insulating thermal conductive filler) As the insulating thermal conductive filler 23, oxides such as alumina, magnesium oxide, beryllium oxide and titanium oxide; nitrides such as boron nitride, silicon nitride and aluminum nitride; silicon carbide Carbides such as diamond; insulating carbon-based fillers such as diamond; silica powders such as quartz and quartz glass. These thermally conductive fillers may be subjected to various surface treatments such as silane treatment in order to improve the affinity with the resin.
絶縁性熱伝導性フィラー２３の配合量は、絶縁性かつ熱伝導性のフィラーと熱可塑性樹脂との体積基準での配合割合が絶縁性かつ熱伝導性のフィラー：熱可塑性樹脂＝１０〜９０：９０〜１０とする。絶縁性熱伝導性フィラー２３の含有量が１０体積％未満であると効率的な熱伝導性を得にくくなり、９０体積％を超えると樹脂組成物の柔軟性が低下し、発熱体や放熱体の表面の凹凸への密着追従性が悪く接触熱抵抗が増大し効率的な熱伝導性が得られなくなる。より好ましくは１５〜６０体積％である。 The blending amount of the insulating heat conductive filler 23 is such that the blending ratio of the insulating and heat conductive filler and the thermoplastic resin on a volume basis is the insulating and heat conductive filler: thermoplastic resin = 10 to 90: 90-10. When the content of the insulating heat conductive filler 23 is less than 10% by volume, it becomes difficult to obtain efficient heat conductivity, and when it exceeds 90% by volume, the flexibility of the resin composition is lowered, and a heating element or a heat radiator. The adhesion followability to the unevenness of the surface is poor and the contact thermal resistance increases, so that efficient thermal conductivity cannot be obtained. More preferably, it is 15-60 volume%.
（製造方法）本願発明の熱伝導性シート１の製造方法は、（１）上記導電性熱伝導性樹脂層及び上記絶縁性熱伝導性樹脂層を共押出法で成膜する工程と、（２）電子線を照射して前記導電性熱伝導性樹脂層及び前記絶縁性熱伝導性樹脂層とを架橋する架橋工程と、からなる。共押出成形は成膜と同時に積層化でき、また、電子線照射工程は公知で安定した加工工程であり、高品質な熱伝導性シート１を低コストで製造することができる。 (Manufacturing method) The manufacturing method of the heat conductive sheet 1 of this invention consists of (1) the process of forming the said conductive heat conductive resin layer and the said insulating heat conductive resin layer into a film by a coextrusion method, (2 And a cross-linking step of cross-linking the conductive heat conductive resin layer and the insulating heat conductive resin layer by irradiating an electron beam. Co-extrusion molding can be laminated simultaneously with film formation, and the electron beam irradiation process is a known and stable processing process, and a high-quality heat conductive sheet 1 can be manufactured at low cost.
（共押出法）導電性熱伝導性樹脂層１０／絶縁性熱伝導性樹脂層２０の２層、又は、絶縁性熱伝導性樹脂層２０／導電性熱伝導性樹脂層１０／絶縁性熱伝導性樹脂層２０の３層構成の層を共押出法で成膜する。共押出法による熱伝導性シート１（架橋前）の製造には、Ｔダイ共押出機、カレンダー成形機＋貼り合せ、インフレ−ション共押出機等を使用して押出成形することができる。好ましくはＴダイ共押出機である。 (Co-extrusion method) Two layers of conductive thermal conductive resin layer 10 / insulating thermal conductive resin layer 20, or insulating thermal conductive resin layer 20 / conductive thermal conductive resin layer 10 / insulating thermal conductivity A three-layered layer of the conductive resin layer 20 is formed by coextrusion. In the production of the heat conductive sheet 1 (before crosslinking) by the coextrusion method, it can be extruded using a T-die coextrusion machine, a calendering machine + bonding, an inflation coextrusion machine or the like. A T-die co-extruder is preferred.
熱伝導性シート１の製造にあたっては、事前に熱可塑性樹脂１１と導電性熱伝導性フィラー１３とを混合・混練した導電性熱伝導性樹脂層１０組成物とする。同様に、熱可塑性樹脂２１と絶縁性熱伝導性フィラー２３とを混合・混練した絶縁性熱伝導性樹脂層２０組成物としてから、上記の共押出法で成膜するのが好ましい。導電性熱伝導性樹脂層１０組成物、又は絶縁性熱伝導性樹脂層２０組成物を製造するために、必要に応じてその他成分を混練・混合させてもよい。を混練・混合させる方法としては、特に限定されるものではなく、例えば、混練機、押出機、ミキサー、ロール、ニーダー、攪拌機等の一般的な装置を用いることが出来る。また、必要に応じて混練・混合時に装置内を減圧、脱気しても良い。 In manufacturing the heat conductive sheet 1, a conductive heat conductive resin layer 10 composition obtained by mixing and kneading the thermoplastic resin 11 and the conductive heat conductive filler 13 in advance is used. Similarly, the insulating heat conductive resin layer 20 composition obtained by mixing and kneading the thermoplastic resin 21 and the insulating heat conductive filler 23 is preferably formed by the coextrusion method. In order to produce the conductive heat conductive resin layer 10 composition or the insulating heat conductive resin layer 20 composition, other components may be kneaded and mixed as necessary. The method for kneading and mixing is not particularly limited, and for example, general apparatuses such as a kneader, an extruder, a mixer, a roll, a kneader, and a stirrer can be used. If necessary, the inside of the apparatus may be depressurized and deaerated during kneading and mixing.
（厚さ）熱伝導性シート１の総厚みは、２０〜８００μｍが好ましい。より好ましくは、５０〜６００μｍが好ましい。２０μｍ未満では、成形安定性が低くなり、厚み精度が低下する。８００μｍを超えると、押出成形による製造が難しくなる。導電性熱伝導性樹脂層１０の厚みは、１０〜７８０μｍが好ましい。より好ましくは、４０〜６００μｍが好ましい。１０μｍ未満では、成形安定性が低くなり、厚み精度が低下する。７８０μｍを超えると、押出成形による製造が難しくなるためである。絶縁性熱伝導性樹脂層２０の厚みは５〜２００μｍが好ましい。より好ましくは、１０〜１００μｍが好ましい。５μｍ未満では、成形安定性が低くなり、厚み精度が低下し、更に絶縁効果が低下するためである。２００μｍを超えると、熱伝導率が低下するとともに価格が高いものとなっしまう。 (Thickness) The total thickness of the heat conductive sheet 1 is preferably 20 to 800 μm. More preferably, 50-600 micrometers is preferable. If it is less than 20 μm, the molding stability is lowered and the thickness accuracy is lowered. When it exceeds 800 μm, it becomes difficult to produce by extrusion. The thickness of the conductive heat conductive resin layer 10 is preferably 10 to 780 μm. More preferably, 40-600 micrometers is preferable. If it is less than 10 μm, the molding stability is lowered and the thickness accuracy is lowered. If it exceeds 780 μm, it is difficult to produce by extrusion. The thickness of the insulating heat conductive resin layer 20 is preferably 5 to 200 μm. More preferably, 10-100 micrometers is preferable. If it is less than 5 μm, the molding stability is lowered, the thickness accuracy is lowered, and the insulating effect is further lowered. When it exceeds 200 μm, the thermal conductivity is lowered and the price is increased.
（電子線照射）共押出法で成膜した熱伝導性シート１（架橋前）は、電子線を照射して架橋処理を行い熱可塑性樹脂１１、２１を架橋させる。架橋処理を行うことで、熱伝導シートの耐熱性を高めることができる。電子線源としては、コックロフトワルトン型、パンデグラフ型、共振変圧器型、絶縁コア変圧器型、直線型、ダイナミトロン型、高周波型等の各種電子線加速器を用いることができる。 (Electron beam irradiation) The heat conductive sheet 1 (before crosslinking) formed by co-extrusion is irradiated with an electron beam to perform a crosslinking treatment to crosslink the thermoplastic resins 11 and 21. By performing the crosslinking treatment, the heat resistance of the heat conductive sheet can be increased. As the electron beam source, various electron beam accelerators such as a Cockloft Walton type, a pandegraph type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type can be used.
架橋効率を高めるために、導電性熱伝導性樹脂層１０及び／又は絶縁性熱伝導性樹脂層２０に架橋助剤等を添加しても良い。架橋助剤の種類は特に限定されるものではないが、例えば、トリアリルイソシアヌレート、トリアリルシアヌレート、トリメタアリルイソシアヌレート、ジアリルモノグリシジルイソシアヌレート、トリメチロールプロパントリメタクリレート、エチレングリコールジメタクリレート、ジアリルフタレート、ジビニルベンゼン、ジイソプロペニルベンゼン、Ｎ，Ｎ’−ｍ−フェニレンビスマレイミド、ポリブタジエン等があげられる。これらの架橋助剤は単独で使用してもよいし、２種以上を併用してもよい。 In order to increase the crosslinking efficiency, a crosslinking aid or the like may be added to the conductive thermal conductive resin layer 10 and / or the insulating thermal conductive resin layer 20. The type of the crosslinking aid is not particularly limited. For example, triallyl isocyanurate, triallyl cyanurate, trimethallyl isocyanurate, diallyl monoglycidyl isocyanurate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, Examples include diallyl phthalate, divinyl benzene, diisopropenyl benzene, N, N′-m-phenylene bismaleimide, and polybutadiene. These crosslinking aids may be used alone or in combination of two or more.
熱伝導性シート１には、片側あるいは両面に粘着層を付与してもよい。粘着層としては、特に限定されるものではなく、例えばアクリル樹脂系、シリコーン樹脂系などの公知の粘着剤が例示できる The heat conductive sheet 1 may be provided with an adhesive layer on one side or both sides. The adhesive layer is not particularly limited, and examples thereof include known adhesives such as acrylic resin and silicone resin.
以下、実施例及び比較例により、本発明を更に詳細に説明するが、これに限定されるものではない。 EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, it is not limited to this.
（実施例１）（１）導電性熱伝導性樹脂層１０として、直鎖状低密度ポリエチレン（ダウ・ケミカル社ＩＮＦＵＳＥ Ｄ９５０７．１０、Ｇ（ｘ）値＝２．５、メルトインデックス＝５ｇ／１０分、密度＝０．８６６ｇ／ｃｍ3、ＤＳＣ融点＝１１９℃）５０質量部（５７．７体積部）、黒鉛（新越化成株式会社 ＷＦ−０２５ 平均粒径＝２５μｍ、密度＝２．２ｇ／ｃｍ3）５０質量部（２２．７体積部）からなる樹脂組成物を調整した。
また、絶縁性熱伝導性樹脂層２０として、直鎖状低密度ポリエチレン（ダウ・ケミカル社ＩＮＦＵＳＥ Ｄ９５０７．１０、Ｇ（ｘ）値＝２．５、メルトインデックス＝５ｇ／１０分、密度＝０．８６６ｇ／ｃｍ3、ＤＳＣ融点＝１１９℃）３３質量部（３８．１体積部）、酸化亜鉛（堺化学工業株式会社 ＬＰＺＩＮＣ−１１ 平均粒径＝１１μｍ）６７質量部（１２．０体積部）からなる樹脂組成物を調整した。（２）次に、上記で調整した各樹脂組成物を用いて、Ｔダイ共押出製膜機により、絶縁性熱伝導性樹脂層２０／導電性熱伝導性樹脂層１０／絶縁性熱伝導性樹脂層２０の３層構成の層を、導電性熱伝導性樹脂層１０が１４０μｍ、両絶縁性熱伝導性樹脂層２０がそれぞれ７０μｍとなるように、共押出成形により総厚２８０μｍの熱伝導性シート１に（架橋前）を製造し、加速電圧１６５ｋＶ、照射線量２００ｋＧｙの電子線を２回照射し、実施例１の熱伝導性シート１を得た。
Example 1 (1) As the conductive thermal conductive resin layer 10, linear low density polyethylene (Dow Chemical Company INFUSE D9507.10, G (x) value = 2.5, melt index = 5 g / 10) Minute, density = 0.866 g / cm 3 , DSC melting point = 119 ° C.) 50 parts by mass (57.7 parts by volume), graphite (WF-025, average particle size = 25 μm, density = 2.2 g / cm 3 ) A resin composition consisting of 50 parts by mass (22.7 parts by volume) was prepared.
Moreover, as the insulating heat conductive resin layer 20, linear low density polyethylene (Dow Chemical Company INFUSE D9507.10, G (x) value = 2.5, melt index = 5 g / 10 min, density = 0.0.0). From 866 g / cm 3 , DSC melting point = 119 ° C.) 33 parts by mass (38.1 parts by volume), zinc oxide (LPZINC-11, average particle size = 11 μm) 67 parts by mass (12.0 parts by volume) A resin composition was prepared. (2) Next, using each resin composition prepared as described above, T-die coextrusion film-forming machine is used for insulating heat conductive resin layer 20 / conductive heat conductive resin layer 10 / insulating heat conductive. The resin layer 20 is composed of three layers, and the heat conductive resin layer 10 has a total thickness of 280 μm by coextrusion molding so that the conductive heat conductive resin layer 10 has a thickness of 140 μm and both insulating heat conductive resin layers 20 have a thickness of 70 μm. A sheet 1 (before crosslinking) was produced, and an electron beam with an acceleration voltage of 165 kV and an irradiation dose of 200 kGy was irradiated twice to obtain a thermally conductive sheet 1 of Example 1.
（実施例２）導電性熱伝導性樹脂層１０及び絶縁性熱伝導性樹脂層２０として各樹脂組成物を調整する際に、トリアリルイソシアヌレート（ＴＡＩＣ）（日本化成株式会社）を１質量部（０．８６体積部）添加した以外は、実施例１と同様にして、実施例２の熱伝導性シート１を得た。 (Example 2) When adjusting each resin composition as the conductive thermal conductive resin layer 10 and the insulating thermal conductive resin layer 20, 1 part by mass of triallyl isocyanurate (TAIC) (Nippon Kasei Co., Ltd.) A heat conductive sheet 1 of Example 2 was obtained in the same manner as Example 1 except that (0.86 parts by volume) was added.
（実施例３）導電性熱伝導性樹脂層１０として、スチレン−ブタジエンラバー（旭化成ケミカルズ社タフプレン３１５、Ｇ（ｘ）値＝２．９、メルトインデックス＝３．５ｇ／１０分（１９０℃）、密度＝０．９３０ｇ／ｃｍ3、Ｓｔ含有／Ｂｄ含有＝２０／８０）５０質量部（５３．８体積部）、黒鉛（新越化成株式会社 ＷＦ−０２５ 平均粒径＝２５μｍ、密度＝２．２ｇ／ｃｍ3）５０質量部（２２．７体積部）からなる樹脂組成物を調整した。また、絶縁性熱伝導性樹脂層２０としても、導電性熱伝導性樹脂層１０と同様の樹脂を６７質量部（７２．０体積部）、窒化ホウ素（ＢＮ）（Ｍｏｍｅｎｔｉｖｅ社 ＰＴＸ６０ 平均粒径＝６０μｍ）３３質量部（１４．３体積部）からなる樹脂組成物を調整した。実施例１と同様にして、実施例３の熱伝導性シート１を得た。 (Example 3) As the conductive heat conductive resin layer 10, styrene-butadiene rubber (Tahprene 315, Asahi Kasei Chemicals Corporation, G (x) value = 2.9, melt index = 3.5 g / 10 min (190 ° C.), Density = 0.930 g / cm 3 , St content / Bd content = 20/80) 50 parts by mass (53.8 parts by volume), Graphite (Shinetsu Chemical Co., Ltd. WF-025, average particle size = 25 μm, density = 2. 2 g / cm 3 ) A resin composition consisting of 50 parts by mass (22.7 parts by volume) was prepared. Further, as the insulating thermal conductive resin layer 20, 67 parts by mass (72.0 parts by volume) of the same resin as the conductive thermal conductive resin layer 10 and boron nitride (BN) (Momentive PTX60 average particle size = 60 μm) A resin composition consisting of 33 parts by mass (14.3 parts by volume) was prepared. The heat conductive sheet 1 of Example 3 was obtained in the same manner as Example 1.
（実施例４）導電熱伝導性樹脂層及び絶縁熱伝導性樹脂層として各樹脂組成物を調整する際に、トリアリルイソシアヌレート（ＴＡＩＣ）（日本化成株式会社）を３質量部（２．５８体積部）添加した以外は、実施例３と同様にして、実施例４の熱伝導性シート１を得た。 (Example 4) When adjusting each resin composition as a conductive heat conductive resin layer and an insulating heat conductive resin layer, 3 parts by mass (2.58) of triallyl isocyanurate (TAIC) (Nippon Kasei Co., Ltd.) A heat conductive sheet 1 of Example 4 was obtained in the same manner as in Example 3 except that (volume part) was added.
（評価方法）加熱収縮率、熱伝導率、表面抵抗値で評価した。 (Evaluation method) The heat shrinkage rate, thermal conductivity, and surface resistance were evaluated.
（測定方法）加熱収縮率は２５０℃のタルクバスに３分間放置した後、長さの変化から加熱収縮率を測定した。熱伝導率は、Ｎｅｔｚｓｃｈ Ｎａｎｏｆｌａｓｈ ＬＦＡ４４７を用いた。表面抵抗値は、抵抗率計（株式会社ダイアインスツルメンツ「ハイレスタＵＰ ＭＣＰ−ＨＴ４５０型」）を用いて、２３℃−５０％ＲＨ雰囲気下で測定した。加熱収縮率、熱伝導率、抵抗率を表１に示す。 (Measuring method) The heat shrinkage rate was measured by measuring the heat shrinkage rate from the change in length after being left in a talc bath at 250 ° C. for 3 minutes. The thermal conductivity was Netzsch Nanoflash LFA447. The surface resistance value was measured in a 23 ° C.-50% RH atmosphere using a resistivity meter (Dia Instruments Inc. “Hiresta UP MCP-HT450 type”). Table 1 shows the heat shrinkage, thermal conductivity, and resistivity.
（評価結果）本発明の熱伝導性シートである実施例１〜４では、１０14以上の表面抵抗値であり、高い絶縁性が示された。また、加熱収縮率は５％以下であり、電子線照射により耐熱性が向上していた。電子線照射の有無で熱伝導率に大きな差異は現れず、熱伝導性シートとして充分な熱伝導率を有していることが確認された。 (Evaluation results) In Examples 1 to 4 which are the heat conductive sheets of the present invention, the surface resistance value was 10 14 or more, and high insulation was shown. Moreover, the heat shrinkage rate was 5% or less, and the heat resistance was improved by electron beam irradiation. It was confirmed that there was no significant difference in thermal conductivity depending on the presence or absence of electron beam irradiation, and that the thermal conductivity was sufficient as a thermal conductive sheet.
（産業上の利用可能性）本発明は、熱が発生する電子機器、部品や集積回路に利用することができる。しかしながら、高い熱伝導率を必要とする用途であれば、特に限定されるものではない。 (Industrial Applicability) The present invention can be used for electronic devices, components, and integrated circuits that generate heat. However, the application is not particularly limited as long as the application requires high thermal conductivity.
１：熱伝導性シート
１０：導電性熱伝導性樹脂層
１１：熱可塑性樹脂
１３：導電性熱伝導性フィラー
２０：絶縁性熱伝導性樹脂層
２１：熱可塑性樹脂
２３：絶縁性熱伝導性フィラー
1: Thermal conductive sheet 10: Conductive thermal conductive resin layer 11: Thermoplastic resin 13: Conductive thermal conductive filler 20: Insulating thermal conductive resin layer 21: Thermoplastic resin 23: Insulating thermal conductive filler
Claims (5)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009199637A JP2011054610A (en) | 2009-08-31 | 2009-08-31 | Thermal conductive sheet and method of manufacturing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009199637A JP2011054610A (en) | 2009-08-31 | 2009-08-31 | Thermal conductive sheet and method of manufacturing the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2011054610A true JP2011054610A (en) | 2011-03-17 |
Family
ID=43943360
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2009199637A Withdrawn JP2011054610A (en) | 2009-08-31 | 2009-08-31 | Thermal conductive sheet and method of manufacturing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2011054610A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014021046A1 (en) * | 2012-07-30 | 2014-02-06 | 株式会社村田製作所 | Electronic apparatus and heat conductive sheet |
| WO2014064806A1 (en) * | 2012-10-25 | 2014-05-01 | 三菱電機株式会社 | Semiconductor device |
| JP2015193753A (en) * | 2014-03-31 | 2015-11-05 | 住友化学株式会社 | adhesive tape |
| US9353245B2 (en) | 2014-08-18 | 2016-05-31 | 3M Innovative Properties Company | Thermally conductive clay |
| JP2020136607A (en) * | 2019-02-25 | 2020-08-31 | 信越ポリマー株式会社 | Heat radiation structure, and device including the same |
-
2009
- 2009-08-31 JP JP2009199637A patent/JP2011054610A/en not_active Withdrawn
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014021046A1 (en) * | 2012-07-30 | 2014-02-06 | 株式会社村田製作所 | Electronic apparatus and heat conductive sheet |
| JP5850160B2 (en) * | 2012-07-30 | 2016-02-03 | 株式会社村田製作所 | Electronics |
| WO2014064806A1 (en) * | 2012-10-25 | 2014-05-01 | 三菱電機株式会社 | Semiconductor device |
| CN104756248A (en) * | 2012-10-25 | 2015-07-01 | 三菱电机株式会社 | Semiconductor device |
| JP5949935B2 (en) * | 2012-10-25 | 2016-07-13 | 三菱電機株式会社 | Semiconductor device |
| JPWO2014064806A1 (en) * | 2012-10-25 | 2016-09-05 | 三菱電機株式会社 | Semiconductor device |
| US9601408B2 (en) | 2012-10-25 | 2017-03-21 | Mitsubishi Electric Corporation | Semiconductor device |
| JP2015193753A (en) * | 2014-03-31 | 2015-11-05 | 住友化学株式会社 | adhesive tape |
| US9353245B2 (en) | 2014-08-18 | 2016-05-31 | 3M Innovative Properties Company | Thermally conductive clay |
| JP2020136607A (en) * | 2019-02-25 | 2020-08-31 | 信越ポリマー株式会社 | Heat radiation structure, and device including the same |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI661040B (en) | Thermally conductive sheet | |
| JP6662458B2 (en) | Thermal conductive silicone rubber composite sheet | |
| JP5471868B2 (en) | Thermally conductive silicone rubber composite sheet | |
| JP6136952B2 (en) | Thermally conductive composite silicone rubber sheet | |
| JP2011052094A (en) | Thermally conductive sheet and method for producing the same | |
| JP2011054610A (en) | Thermal conductive sheet and method of manufacturing the same | |
| KR20160085253A (en) | Heat sink | |
| WO2014083890A1 (en) | Heat-conducting foam sheet for electronic instruments and heat-conducting laminate for electronic instruments | |
| JPWO2018101445A1 (en) | Heat conduction sheet | |
| JP2009066817A (en) | Thermally-conductive sheet | |
| JP5516034B2 (en) | Highly insulating heat conductive sheet and heat dissipation device using the same | |
| JP2011054609A (en) | Thermally conductive sheet and method of manufacturing the same | |
| JP2015189884A (en) | Thermosetting resin composition, resin sheet, prepreg and laminate sheet | |
| JP6669258B2 (en) | Thermal conductive sheet | |
| JP2010031107A (en) | Sheet with antistatic function | |
| JP2012012425A (en) | Heat-conductive sheet | |
| JP2011054611A (en) | Thermally conductive sheet and method of manufacturing the same | |
| JP7235633B2 (en) | Thermally conductive resin sheet | |
| JP2018134779A (en) | Multilayer resin sheet, method for producing multilayer resin sheet, multilayer resin sheet cured product, multilayer resin sheet laminate, and multilayer resin sheet laminate cured product | |
| JP6448736B2 (en) | Thermally conductive sheet | |
| TWI761435B (en) | Thermally conductive sheet | |
| JP2011054705A (en) | Thermal conductive sheet and method of manufacturing the same | |
| JP2011054706A (en) | Thermal conductive sheet and method of manufacturing the same | |
| JP2012054314A (en) | Heat dissipation sheet and method of producing the same | |
| JP2006278445A (en) | Thermally conductive sheet |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20121106 |