JP2001345406A - Heat conducting material - Google Patents
Heat conducting materialInfo
- Publication number
- JP2001345406A JP2001345406A JP2000166175A JP2000166175A JP2001345406A JP 2001345406 A JP2001345406 A JP 2001345406A JP 2000166175 A JP2000166175 A JP 2000166175A JP 2000166175 A JP2000166175 A JP 2000166175A JP 2001345406 A JP2001345406 A JP 2001345406A
- Authority
- JP
- Japan
- Prior art keywords
- heat conductive
- heat
- electronic component
- conductive base
- base material
- 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.)
- Granted
Links
Landscapes
- Laminated Bodies (AREA)
- Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、熱伝導材の技術分
野に属する。The present invention belongs to the technical field of heat conductive materials.
【０００２】[0002]
【従来の技術】コンピュータのＣＰＵには発生する熱を
効率よく放出するためにヒートシンクが取り付けられて
いる。このヒートシンクとＣＰＵの外面との接触が良好
でないと（ギャップがあると）放熱効率が低下するの
で、熱伝導性の良好なインターフェース材をヒートシン
クとＣＰＵの間に充填してギャップを防いでいた。2. Description of the Related Art A heat sink is attached to a CPU of a computer in order to efficiently release generated heat. If the contact between the heat sink and the outer surface of the CPU is not good (if there is a gap), the heat radiation efficiency is reduced. Therefore, an interface material having good thermal conductivity is filled between the heat sink and the CPU to prevent the gap.
【０００３】このインターフェース材としての熱伝導材
には、樹脂等の母材中にセラミックス等からなる充填材
を分散させたもの、例えば加硫ＥＰＤＭ樹脂とセラミッ
クス粉体を混練してなる熱伝導材あるいはパラフィンと
セラミックス粉体を混練してなる熱伝導材がある。[0003] The heat conductive material as the interface material is a material obtained by dispersing a filler made of ceramic or the like in a base material such as resin, for example, a heat conductive material obtained by kneading a vulcanized EPDM resin and ceramic powder. Alternatively, there is a heat conductive material obtained by kneading paraffin and ceramic powder.
【０００４】[0004]
【発明が解決しようとする課題】ところで、板状の熱伝
導基材による伝熱量（Ｑ）については、下記の数式１に
示す関係が成り立つことが知られている。By the way, it is known that the relationship shown in the following equation 1 holds for the amount of heat transfer (Q) by the plate-shaped heat conductive substrate.
【０００５】[0005]
【数１】 Ｑ：伝熱量 λ：熱伝導率［Ｋｃａｌ／ｍｈ℃］ Ｑ1−Ｑ2：表裏の温度差 ｘ：板厚 Ｆ：表面積 Ｔ：時間 したがって、熱伝導効率を上げるには（伝熱量Ｑを大き
くするには）、熱伝導率λのよいものを使うか板厚ｘを
薄くすればよい。(Equation 1) Q: heat transfer amount λ: thermal conductivity [Kcal / mh ° C.] Q 1 -Q 2 : temperature difference between front and back x: plate thickness F: surface area T: time Therefore, to increase heat transfer efficiency, increase heat transfer amount Q To do so, a material having a good thermal conductivity λ may be used or the thickness x may be reduced.
【０００６】ところで熱伝導率λの向上（すなわち熱伝
導材の改良）には多大な研究を要するのが普通であり、
人的また経済的負担が大きい。また、先人により研究し
尽くされた感もある。これに比べて板厚ｘを薄くする手
法はどちらかと言えば安易である。しかし、熱伝導基材
の板厚ｘを薄くすると、例えば剛性が小さくなって取り
扱い難くなるという問題がある。[0006] By the way, improvement of the thermal conductivity λ (that is, improvement of the heat conductive material) usually requires a great deal of research.
High human and financial burden. There is also a feeling that they have been thoroughly studied by their predecessors. On the other hand, the method of reducing the plate thickness x is rather easy. However, when the thickness x of the heat conductive base material is reduced, for example, there is a problem that the rigidity is reduced and the handling becomes difficult.
【０００７】なお、従来の熱伝導材（例えば加硫ＥＰＤ
Ｍ樹脂とセラミックス粉体を混練してなる熱伝導材）
は、その使用時の温度条件では固形であったので、ＣＰ
Ｕあるいはヒートシンクの形状に追随して変形すること
がなく、例えばＣＰＵの表面との間あるいはヒートシン
クの表面との間に微細な空隙が生じてしまい、十分な熱
伝導効果が得られないという問題もあった。なお、こう
した問題はＣＰＵに限定されるものではなく使用時に発
熱する電子部品に共通の問題である。[0007] A conventional heat conductive material (for example, vulcanized EPD)
Thermal conductive material obtained by kneading M resin and ceramic powder)
Is a solid under the temperature conditions at the time of its use.
There is also a problem that a small gap is generated between the surface of the CPU or the surface of the heat sink without being deformed following the shape of the U or the heat sink, for example, and a sufficient heat conduction effect cannot be obtained. there were. These problems are not limited to the CPU, but are common to electronic components that generate heat during use.
【０００８】本発明は熱伝導基材の板厚ｘを薄くした際
の取り扱いの問題を解決することを目的としている。An object of the present invention is to solve the problem of handling when the thickness x of the heat conductive base material is reduced.
【０００９】[0009]
【課題を解決するための手段、発明の実施の形態及び発
明の効果】上記課題を解決するための請求項１記載の熱
伝導材は、被装着体の表面に向けて押圧されると該表面
の形状に追随して変形する性質を持つ厚さが１ｍｍ以下
の板状の熱伝導基材と、該熱伝導基材の２面または１面
に貼着された保護シートとからなることを特徴とする。Means for Solving the Problems, Embodiments of the Invention and Effects of the Invention The heat conductive material according to the first aspect of the present invention for solving the above-mentioned problems, when pressed against the surface of the mounted body, A heat conductive base material having a thickness of 1 mm or less having a property of being deformed following the shape of the heat conductive base material, and a protective sheet attached to two or one surface of the heat conductive base material. And
【００１０】熱伝導基材は、被装着体（例えばＣＰＵ）
の表面に向けて押圧されるとその表面の形状に追随して
変形する性質を持ち、しかも厚さが１ｍｍ以下の板状で
ある。要するに熱伝導基材だけでは例えば平板状に姿勢
を保つのが難しいのであるが、２面または１面に保護シ
ートが貼着されているから、その保護シートが支持体と
なって熱伝導基材の過剰な変形を阻止する。したがっ
て、熱伝導材を例えばＣＰＵの表面に取り付ける際に取
り扱いが簡単となり、作業性が向上する。[0010] The heat conductive base material is an object to be mounted (eg, CPU).
It has the property of deforming following the shape of the surface when pressed toward the surface, and has a thickness of 1 mm or less. In short, it is difficult to maintain the posture of a flat plate, for example, by using only the heat conductive base material. To prevent excessive deformation of Therefore, when the heat conductive material is attached to, for example, the surface of the CPU, handling is simplified, and workability is improved.
【００１１】熱伝導材を電子部品（例えばＣＰＵ）とヒ
ートシンクとの間に介装する作業は、例えば次のように
行われる。まず、熱伝導材の１面を露出させた状態とす
る（２面に保護シートが貼着されているなら、１枚を剥
がす。）。この熱伝導基材の１面に保護シートが貼着さ
れた状態で、その熱伝導基材の露出面を電子部品（例え
ばＣＰＵ）の目的の面に当接させる。そして、例えば保
護シート側から押圧したり加熱する（熱転写）ことで熱
伝導基材を電子部品の表面に密着させてから保護シート
を剥がす。その保護シートを剥がした面にヒートシンク
を当ててビスなどで電子部品に固定する。The operation of interposing a heat conductive material between an electronic component (for example, CPU) and a heat sink is performed, for example, as follows. First, one surface of the heat conductive material is exposed (if a protective sheet is stuck on two surfaces, one is peeled off). With the protective sheet adhered to one surface of the heat conductive substrate, the exposed surface of the heat conductive substrate is brought into contact with the target surface of the electronic component (eg, CPU). Then, the protective sheet is peeled off, for example, by pressing or heating (thermal transfer) from the protective sheet side to bring the heat conductive base material into close contact with the surface of the electronic component. A heat sink is applied to the surface from which the protective sheet has been peeled off, and fixed to the electronic component with screws or the like.
【００１２】この際にビス等による力（例えば締め付け
力）が、ヒートシンクと電子部品とで熱伝導基材を挟み
付ける力（挟持力）として作用する。熱伝導基材は厚さ
が１ｍｍ以下の板状で、被装着体（例えばＣＰＵ）の表
面に向けて押圧されるとその表面の形状に追随して変形
する性質を持つので、電子部品とヒートシンクとで熱伝
導基材を挟持すれば、その挟持力＝押圧力により電子部
品及びヒートシンクの双方の表面形状に追随して変形す
る。これにより熱源となる電子部品と放熱のためのヒー
トシンクとの双方に熱伝導基材が密着する。熱伝導基材
と電子部品及びヒートシンクの表面との間に微細な空隙
が生じることがないから、十分な熱伝導効果が得られ
る。At this time, the force of the screw or the like (for example, a tightening force) acts as a force (a holding force) for holding the heat conductive base material between the heat sink and the electronic component. The heat conductive substrate is a plate having a thickness of 1 mm or less, and has a property of being deformed following the shape of the surface when pressed against the surface of the mounted body (for example, CPU). When the heat conductive base material is sandwiched between the electronic component and the heat sink, the heat conductive base material is deformed following the surface shape of both the electronic component and the heat sink by the holding force = the pressing force. As a result, the heat conductive base material adheres to both the electronic component serving as the heat source and the heat sink for heat dissipation. Since there is no minute gap between the heat conductive substrate and the surfaces of the electronic component and the heat sink, a sufficient heat conductive effect can be obtained.
【００１３】熱伝導基材の厚さは１ｍｍ以下であれば良
好な熱伝導効率とできるが、これが薄ければ薄いほどよ
いことは言うまでもない。よって、好ましくは０．５ｍ
ｍ以下である。ただし、薄くしすぎると、保護シートが
あっても、また請求項３記載のサポート材があっても、
取付作業時の破断などの可能性が高まる。また、取付作
業時の屈曲などでサポート材が熱伝導基材の表面に露出
するおそれもある。したがって、熱伝導基材の板厚は
０．１ｍｍ以上とするのが好ましい。つまり、熱伝導基
材の厚さは０．５ｍｍ以下、０．１ｍｍ以上とするのが
好ましい。If the thickness of the heat conductive base material is 1 mm or less, good heat transfer efficiency can be obtained, but it goes without saying that the thinner the heat conductive base material, the better. Therefore, preferably 0.5m
m or less. However, if the thickness is too small, even if there is a protective sheet, and even if there is a support material according to claim 3,
The possibility of breakage during mounting work increases. In addition, the support material may be exposed on the surface of the heat conductive base material due to bending or the like during the mounting operation. Therefore, it is preferable that the plate thickness of the heat conductive substrate is 0.1 mm or more. That is, the thickness of the heat conductive substrate is preferably 0.5 mm or less, and 0.1 mm or more.
【００１４】なお、被装着体の表面に向けて押圧される
と該表面の形状に追随して変形する例としては、塑性変
形や弾性変形がある。つまり、そのように変形する性質
としては可塑性や弾性が例示される。また、保護シート
の剛性が高すぎると上述の作業性が悪くなるおそれがあ
るので、ある程度の柔軟性を持つ材料例えば紙やプラス
チックフィルムなどを使用するのが望ましい。Examples of deformations following the shape of the surface when pressed against the surface of the mounted body include plastic deformation and elastic deformation. That is, plasticity and elasticity are exemplified as the property of such deformation. In addition, if the rigidity of the protective sheet is too high, the above-described workability may be deteriorated. Therefore, it is desirable to use a material having a certain degree of flexibility, such as paper or a plastic film.
【００１５】請求項２記載の熱伝導材は、請求項１記載
の熱伝導材において、前記保護シートは、前記熱伝導基
材の表面を損なわずに剥離可能であることを特徴とす
る。上述の通り、熱伝導材を電子部品等に装着する際に
は保護シートを取り除く必要があるので、保護シートを
剥がすときに熱伝導基材の表面の一部が保護シート側に
はぎ取られるようなことは好ましくない。したがって、
請求項２記載のように熱伝導基材の表面を損なわずに剥
離可能であることが好ましい。According to a second aspect of the present invention, in the heat conductive material according to the first aspect, the protective sheet can be peeled off without damaging the surface of the heat conductive substrate. As described above, it is necessary to remove the protective sheet when attaching the heat conductive material to an electronic component or the like, so that when the protective sheet is peeled off, a part of the surface of the heat conductive substrate is peeled off to the protective sheet side. It is not preferable. Therefore,
As described in claim 2, it is preferable that the heat conductive substrate can be peeled without damaging the surface.
【００１６】そのためには、保護シートとしていわゆる
剥離紙を用いたり、保護シートと熱伝導基材との間に剥
離層を設けておくとよい。請求項３記載の熱伝導材は、
請求項１または２記載の熱伝導材において、全部または
一部が前記熱伝導基材の内部に配されて該熱伝導基材を
支持するサポート材を備えたことを特徴とする。For this purpose, a so-called release paper may be used as the protective sheet, or a release layer may be provided between the protective sheet and the heat conductive substrate. The heat conductive material according to claim 3 is
The heat conductive material according to claim 1 or 2, further comprising a support member that is disposed in whole or in part in the heat conductive base material and supports the heat conductive base material.
【００１７】このサポート材は、全部または一部が熱伝
導基材の内部に配されているので、熱伝導基材を内部か
ら支持することができる。このため、保護シートをより
薄くあるいはより柔軟にすることが可能となる。また、
保護シートを剥がした後もサポート材が熱伝導基材を支
持しているので、作業性がより良好になる。Since the support material is entirely or partially disposed inside the heat conductive substrate, the heat conductive substrate can be supported from the inside. For this reason, it becomes possible to make a protective sheet thinner or more flexible. Also,
The workability is further improved because the support material supports the heat conductive substrate even after the protective sheet is peeled off.
【００１８】ただし、熱伝導材の使用時にもサポート材
が熱伝導基材と一体化したままとなるので、サポート材
の熱伝導性が良好でなければならない。そのようなサポ
ート材は、例えば請求項４記載の金属箔にて実現でき
る。特に、金、銀、銅、アルミ等の熱伝導率が高い金属
の箔が好ましい。また、金属箔を使用すれば電磁シール
ド効果も期待できる。なお、サポート材は熱伝導性が良
好であればよいので、金属箔に限定されるわけではな
い。However, since the support material remains integrated with the heat conductive substrate even when the heat conductive material is used, the heat conductivity of the support material must be good. Such a support material can be realized, for example, by the metal foil according to the fourth aspect. Particularly, a metal foil having a high thermal conductivity such as gold, silver, copper, or aluminum is preferable. If a metal foil is used, an electromagnetic shielding effect can be expected. The support material is not limited to metal foil, as long as it has good thermal conductivity.
【００１９】金属箔を用いる場合、単なる箔であると、
箔を境にしてその両側の熱伝導基材が分離されるおそれ
があるので、請求項５記載のように金属箔に穴（多数の
穴）を設けておき、金属箔の両側の熱伝導材を穴を介し
て連続させるとよい。穴は物理的な加工（例えばドリル
やレーザ）で設けても化学的な加工によって設けても、
どちらでもよい。また、穴の方向も金属箔の表面に垂直
方向でも表面に対して傾斜する方向でも構わないし、途
中で曲がっていてもよい。ただし、穴の配置に偏りが無
いのが好ましい。When using a metal foil, if it is a simple foil,
Since there is a possibility that the heat conductive base material on both sides of the foil may be separated from the foil, holes (a large number of holes) are provided in the metal foil as described in claim 5, and the heat conductive material on both sides of the metal foil is provided. Is preferably continuous through the holes. Whether the holes are made by physical processing (for example, drill or laser) or by chemical processing,
either will do. Also, the direction of the hole may be a direction perpendicular to the surface of the metal foil, a direction inclined with respect to the surface, or may be bent in the middle. However, it is preferable that the arrangement of the holes is not biased.
【００２０】請求項６記載の熱伝導材は、請求項１ない
し５のいずれか記載の熱伝導材において、前記熱伝導基
材は、融点が３０〜７０℃かつ１００℃における粘度が
７００００ｃＰ以上の有機材料中に該熱伝導基材の３０
〜９０重量％の充填剤を分散してなることを特徴とす
る。The heat conductive material according to claim 6 is the heat conductive material according to any one of claims 1 to 5, wherein the heat conductive base material has a melting point of 30 to 70 ° C. and a viscosity at 100 ° C. of 70,000 cP or more. 30 of the heat conductive substrate in an organic material
It is characterized in that the filler is dispersed in an amount of up to 90% by weight.
【００２１】この熱伝導基材の母材となる有機材料とし
ては、オレフィン系樹脂、具体的には酢酸ビニル−エチ
レン共重合体、ポリエチレン、ポリイソブチレン、エチ
レン−エチルアルコール等のオレフィン系樹脂であっ
て、上記の条件（融点が３０〜７０℃、１００℃におけ
る粘度が７００００ｃＰ以上）を満たすもの、分子量７
０００〜５００００の未加硫ＥＰＤＭ（未加硫エチレン
−プロピレンゴム）等が例示されるが、上記の融点及び
粘度条件を満たすものなら特に限定なく使用できる。The organic material serving as the base material of the heat conductive base material is an olefin resin, specifically, an olefin resin such as vinyl acetate-ethylene copolymer, polyethylene, polyisobutylene, ethylene-ethyl alcohol and the like. Satisfying the above conditions (melting point is 30 to 70 ° C., viscosity at 100 ° C. is 70,000 cP or more), molecular weight 7
Examples include 000 to 50,000 unvulcanized EPDM (unvulcanized ethylene-propylene rubber), but any material that satisfies the above melting point and viscosity conditions can be used without any particular limitation.
【００２２】充填材としては、セラミックス、その一種
であるソフトフェライト、金属粉、金属磁性体、炭素繊
維等を使用できる。セラミックスは熱伝導率が高いた
め、熱伝導基材の熱伝導性能を高めることができる。セ
ラミックスの例としては炭化珪素、窒化硼素、アルミ
ナ、水酸化アルミニウム、酸化亜鉛、マグネシア、水酸
化マグネシウム、窒化珪素、窒化アルミニウム等をあげ
ることができる。As the filler, ceramics, one of which is soft ferrite, metal powder, metal magnetic material, carbon fiber, etc. can be used. Since ceramics have high thermal conductivity, the thermal conductivity of the thermally conductive substrate can be enhanced. Examples of ceramics include silicon carbide, boron nitride, alumina, aluminum hydroxide, zinc oxide, magnesia, magnesium hydroxide, silicon nitride, aluminum nitride, and the like.
【００２３】ソフトフェライトとしてはＮｉ−Ｚｎ系フ
ェライト、Ｍｎ−Ｚｎフェライト等が例示される。ソフ
トフェライトは磁性シールド効果が高いため、これを充
填剤とすることによって、磁性シールド効果の高い熱伝
導基材を実現できる。金属粉の場合、金、銀、銅、アル
ミ等を使用できる。これらの金属粉は、熱伝導率が高い
と同時に電界シールド効果に優れるため、これらを充填
剤とすることによって、熱伝導効果と電界シールド効果
の双方に優れた熱伝導基材を実現できる。Examples of the soft ferrite include Ni-Zn ferrite and Mn-Zn ferrite. Since soft ferrite has a high magnetic shielding effect, a heat conductive base material having a high magnetic shielding effect can be realized by using this as a filler. In the case of metal powder, gold, silver, copper, aluminum and the like can be used. Since these metal powders have a high thermal conductivity and an excellent electric field shielding effect, by using them as a filler, it is possible to realize a heat conductive base material having both an excellent heat conduction effect and an electric field shielding effect.
【００２４】金属磁性体としては、ケイ素鋼（Ｆｅ−Ｓ
ｉ）、パーマロイ（Ｆｅ−Ｎｉ）、センダスト（Ｆｅ−
Ａｌ−Ｓｉ）、パーメンジュール（Ｆｅ−Ｃｏ）、Ｓｕ
Ｓ（Ｆｅ−Ｃｒ）がある。こうした金属磁性体は磁性シ
ールド効果が高いため、これらを充填剤とすることによ
って磁性シールド効果に優れる熱伝導基材を実現でき
る。As the metal magnetic material, silicon steel (Fe--S
i), permalloy (Fe-Ni), sendust (Fe-
Al-Si), permendur (Fe-Co), Su
There is S (Fe-Cr). Since such a metal magnetic material has a high magnetic shielding effect, a heat conductive base material having an excellent magnetic shielding effect can be realized by using these as a filler.
【００２５】炭素繊維は、ＰＡＮ系、ピッチ系、ＶＧＣ
Ｆ、グラファイト、カール状等を使用できる。炭素繊維
は熱伝導率が高いと同時に電界シールド効果が高いた
め、これらを熱伝導基材とすることによって、熱伝導効
果と電界シールド効果の双方に優れた熱伝導基材が実現
できる。The carbon fibers are PAN type, pitch type, VGC
F, graphite, curl, and the like can be used. Since carbon fibers have a high thermal conductivity and a high electric field shielding effect at the same time, by using them as a heat conducting substrate, a heat conducting substrate excellent in both the heat conducting effect and the electric field shielding effect can be realized.
【００２６】なお、充填材は上に例示したものに限定さ
れるわけではない。また、１種類の充填材を単独で使用
してもよいし、複数種類を混用してもよい。充填剤の構
成単位の形状としては、粒状のもの、フレーク状のも
の、あるいは繊維状のもの等が使用可能である。The filler is not limited to those described above. In addition, one type of filler may be used alone, or a plurality of types may be mixed. As the shape of the constituent unit of the filler, a granular one, a flake-like one, a fibrous one or the like can be used.
【００２７】熱伝導基材を構成する有機材料の融点が３
０〜７０℃の温度範囲にあるので、この融点以上に加熱
されると有機材料が液化する。ただし、有機材料の１０
０℃における粘度が７００００ｃＰ以上であるから、融
点付近ではそれよりも高粘度である。このため融点以上
となって液化してもきわめて流動しにくい状態である。
また、有機材料中に分散している充填剤が有機材料の過
度の流動化を防止する。したがって、熱伝導基材として
は例えば粘土のような可塑性を呈する。この有機材料が
液化した状態での熱伝導基材の可塑性（流動性）は充填
剤の配合割合によって調整できる。この場合、有機材料
及び充填剤の種類（組合せ）にもよるが、充填材の配合
割合は熱伝導基材の３０〜９０重量％の範囲にするとよ
い。The melting point of the organic material constituting the heat conductive substrate is 3
Since the temperature is in the range of 0 to 70 ° C., the organic material is liquefied when heated above this melting point. However, 10 of organic materials
Since the viscosity at 0 ° C. is 70,000 cP or more, the viscosity is higher near the melting point. For this reason, even if it liquefies because it has a melting point or higher, it is in a state where it is extremely difficult to flow.
In addition, the filler dispersed in the organic material prevents excessive fluidization of the organic material. Therefore, the heat conductive base material exhibits plasticity such as clay. The plasticity (fluidity) of the heat conductive substrate in a state where the organic material is liquefied can be adjusted by the mixing ratio of the filler. In this case, depending on the type (combination) of the organic material and the filler, the compounding ratio of the filler is preferably in the range of 30 to 90% by weight of the heat conductive substrate.
【００２８】このように比較的低温（有機材料の融点以
上）で可塑性を持つので、これを電子部品の表面に接触
させた状態で有機材料の融点以上に加熱し、電子部品の
表面形状に追随して塑性変形させることができ、それに
より電子部品の表面に密着させることができる。その際
に、電子部品とヒートシンクとで熱伝導基材を挟んでお
けば電子部品とヒートシンクとの双方に熱伝導基材を密
着させることができる。Since the material has plasticity at a relatively low temperature (above the melting point of the organic material), it is heated to a temperature above the melting point of the organic material while being in contact with the surface of the electronic component, and follows the surface shape of the electronic component. Plastic deformation, thereby making it possible to adhere to the surface of the electronic component. At that time, if the heat conductive base material is sandwiched between the electronic component and the heat sink, the heat conductive base material can be brought into close contact with both the electronic component and the heat sink.
【００２９】有機材料の融点を高め（７０℃に近い温
度）に設定しておけば、熱伝導基材が電子部品の通常の
使用状態で可塑性を持つ可能性は低い。この場合、上記
のようにして電子部品とヒートシンクの間に熱伝導基材
を挟んで可塑化させることで密着させてから電子部品を
使用すればよい。If the melting point of the organic material is set high (a temperature close to 70 ° C.), it is unlikely that the heat conductive base material has plasticity in a normal use state of the electronic component. In this case, the electronic component may be used after the heat conductive base material is sandwiched between the electronic component and the heat sink to be plasticized so that they are in close contact with each other.
【００３０】また有機材料の融点を低め（３０℃に近い
温度）に設定しておけば、熱伝導基材が接触する電子部
品からの熱により昇温して可塑性を持つ。そして、電子
部品及びヒートシンクの表面形状に追随して変形し、電
子部品及びヒートシンクに良好に密着する。なお、上述
したとおり粘性が高いから、電子部品の発熱によって流
出する（液だれする）ことはない。If the melting point of the organic material is set to a low value (a temperature close to 30 ° C.), the temperature rises due to the heat from the electronic component in contact with the heat conductive substrate, and the organic material has plasticity. And it deforms following the surface shape of an electronic component and a heat sink, and adheres well to an electronic component and a heat sink. As described above, since the viscosity is high, the component does not flow out (drip) due to heat generation of the electronic component.
【００３１】電子部品の発熱の程度と有機材料の融点の
設定とにより上記のような２通りの使用ができるが、ど
ちらにしても熱伝導基材を電子部品及びヒートシンクに
良好に密着させることができる。その結果、熱伝導基材
を介しての熱伝導効率が良好となり、電子部品の熱を良
好に放熱できる。Depending on the degree of heat generation of the electronic component and the setting of the melting point of the organic material, the above two types of applications can be used. In either case, the heat conductive base material can be brought into good contact with the electronic component and the heat sink. it can. As a result, the heat conduction efficiency through the heat conductive base material is improved, and the heat of the electronic component can be radiated well.
【００３２】また、電子部品及びヒートシンクの表面形
状に忠実に追随して変形するから、ヒートシンクから電
子部品にかかる荷重が均等に分散され、電子部品の一部
に偏った荷重がかることがない。さらに、常温で可塑性
を有する有機材料を用いれば、熱伝導基材を例えば電子
部品の表面にあてがう際に電子部品の表面形状に追随さ
せて塑性変形させることができるから、その後の加熱あ
るいは昇温によって有機材料が液化したときの密着性が
より良好になる。In addition, since the shape is deformed so as to closely follow the surface shapes of the electronic component and the heat sink, the load applied from the heat sink to the electronic component is evenly distributed, and a partial load is not applied to a part of the electronic component. Furthermore, if an organic material having plasticity at room temperature is used, for example, when a heat conductive base material is applied to the surface of an electronic component, it can be plastically deformed by following the surface shape of the electronic component. Thereby, the adhesion when the organic material is liquefied becomes better.
【００３３】[0033]
【実施例】（熱伝導基材）以下に示す有機材料と充填材
を２本ロールの混練機を用いて混練した後、成形し、シ
ート状の熱伝導基材（実施例１、２、比較例１、２）を
得た。なお、比較例１は有機材料としての未加硫ＥＰＤ
Ｍを単独で成形してシート状としたものである。実施例
１、２及び比較例２の熱伝導基材は、図１に例示するよ
うに有機材料中に充填剤が分散した構造となっている。 〈実施例１〉 未加硫ＥＰＤＭ（有機材料） ：１００重量部 ＳｉＣ（充填剤） ：２３０重量部 〈実施例２〉 未加硫ＥＰＤＭ（有機材料） ：１００重量部 ＢＮ（充填剤） ：１２０重量部 〈比較例１〉 未加硫ＥＰＤＭのみ 〈比較例２〉 パラフィン（分子量１０００）（有機材料） ：１００重量部 Ａｌ2Ｏ3（充填剤） ：１５０重量部 これら実施例１、２及び比較例１、２の熱伝導基材の特
性は表１に示す通りである。なお、粘度はＢ型粘度計を
用いて測定し、熱伝導率は京都電子工業が販売する熱伝
導計ＱＴＭ−５００を用いて測定した。EXAMPLES (Thermal Conductive Substrate) The following organic materials and fillers were kneaded using a two-roll kneader, then molded and formed into a sheet-like thermal conductive substrate (Examples 1 and 2; Examples 1 and 2) were obtained. Comparative Example 1 is an unvulcanized EPD as an organic material.
M is formed alone to form a sheet. The heat conductive base materials of Examples 1 and 2 and Comparative Example 2 have a structure in which a filler is dispersed in an organic material as illustrated in FIG. <Example 1> Unvulcanized EPDM (organic material): 100 parts by weight SiC (filler): 230 parts by weight <Example 2> Unvulcanized EPDM (organic material): 100 parts by weight BN (filler): 120 Parts by weight <Comparative Example 1> Unvulcanized EPDM only <Comparative Example 2> Paraffin (molecular weight 1000) (organic material): 100 parts by weight Al 2 O 3 (filler): 150 parts by weight These Examples 1 and 2 and Comparative Examples The properties of the heat conductive substrates of Examples 1 and 2 are as shown in Table 1. The viscosity was measured using a B-type viscometer, and the thermal conductivity was measured using a thermal conductivity meter QTM-500 sold by Kyoto Electronics Industry.
【００３４】[0034]
【表１】 ここで、液だれとは、熱伝導基材を電子部品とヒートシ
ンクの間に挟んで使用した際に熱伝導基材が流動化し流
れ出す現象をいう。[Table 1] Here, the dripping means a phenomenon in which the heat conductive base material flows and flows out when the heat conductive base material is used between the electronic component and the heat sink.
【００３５】表１から明らかなとおり、実施例１、２の
熱伝導基材は、熱伝導率が高く、有機材料の融点を大幅
に上回る１００℃でも液だれを生じていない。一方、比
較例１の場合は１００℃で液だれを起こしている。この
ことから充填剤の使用が液だれ防止に有効なことが判
る。また、比較例２の熱伝導基材は、熱伝導率が低く、
１００℃で液だれを起こしている。 （熱伝導材）上記実施例１、２の熱伝導基材を使用し
て、図２（ａ）に示す構造の熱伝導材を製造した。この
熱伝導材１０は、実施例１（または実施例２）の熱伝導
基材１１、メッシュ銅箔１２及び剥離紙１３から構成さ
れている。メッシュ銅箔１２は、図２（ｂ）に示すよう
に多数の穴（網目）を有するメッシュ状であり、上下の
熱伝導基材１１は網目を通して連続している。熱伝導材
１０の厚さ（剥離紙１３を含む）は１ｍｍ以下（本実施
例の場合、上下の熱伝導基材１１の合計厚さは約０．５
ｍｍ）であり、メッシュ銅箔１２の厚さは約３０μｍで
ある。なお、図２は熱伝導材１０の断面構造を模式的に
示すものであり、実際の寸法を反映してはいない。As is clear from Table 1, the heat conductive substrates of Examples 1 and 2 have high thermal conductivity and do not drip even at 100 ° C., which is much higher than the melting point of the organic material. On the other hand, in the case of Comparative Example 1, dripping occurred at 100 ° C. This indicates that the use of the filler is effective for preventing dripping. Further, the heat conductive base material of Comparative Example 2 has a low heat conductivity,
It is dripping at 100 ° C. (Thermal Conductive Material) A thermal conductive material having a structure shown in FIG. 2A was manufactured using the thermal conductive base materials of Examples 1 and 2 described above. The heat conductive material 10 is composed of the heat conductive substrate 11, the mesh copper foil 12, and the release paper 13 of the first embodiment (or the second embodiment). The mesh copper foil 12 has a mesh shape having a large number of holes (mesh) as shown in FIG. 2B, and the upper and lower heat conductive base materials 11 are continuous through the mesh. The thickness of the heat conductive material 10 (including the release paper 13) is 1 mm or less (in this embodiment, the total thickness of the upper and lower heat conductive base materials 11 is about 0.5
mm), and the thickness of the mesh copper foil 12 is about 30 μm. FIG. 2 schematically shows a cross-sectional structure of the heat conductive material 10 and does not reflect actual dimensions.
【００３６】この熱伝導材１０は、メッシュ銅箔１２が
電子部品（例えばＣＰＵ）の表面に沿う姿勢で電子部品
とヒートシンクとの間に挿入されて使用される。その装
着手順は次のようなものである。まず、熱伝導材１０の
図２（ａ）における上の面（剥離紙１３で覆われていな
い面）をＣＰＵの放熱面に当接し、剥離紙１３側から押
圧しながら例えば１００℃程度に加熱する。すると、熱
伝導基材１１が可塑化してＣＰＵの放熱面に密着する
（つまり熱転写する。）。The heat conductive material 10 is used by inserting the mesh copper foil 12 between the electronic component and the heat sink in a posture along the surface of the electronic component (eg, CPU). The mounting procedure is as follows. First, the upper surface (the surface not covered with the release paper 13) of the heat conductive material 10 in FIG. 2A is brought into contact with the heat radiation surface of the CPU, and is heated to, for example, about 100 ° C. while being pressed from the release paper 13 side. I do. Then, the heat conductive base material 11 is plasticized and adheres to the heat radiation surface of the CPU (that is, heat is transferred).
【００３７】その後、剥離紙１３を剥がし、その剥離紙
１３を剥がした面にヒートシンクを当ててビスなどで電
子部品に固定する。このビス等による力（例えば締め付
け力）が、ヒートシンクと電子部品とで熱伝導基材１１
を挟み付ける力（挟持力）として作用する。Thereafter, the release paper 13 is peeled off, and a heat sink is applied to the surface from which the release paper 13 has been peeled off, and is fixed to an electronic component with screws or the like. The force (for example, the tightening force) of the screw or the like is applied to the heat conductive base material 11 by the heat sink and the electronic component.
Acts as a pinching force (pinching force).
【００３８】熱伝導基材１１は厚さが１ｍｍ以下（実施
例では約０．５ｍｍ）の板状で、ＣＰＵまたはヒートシ
ンクの表面に向けて押圧されるとその表面の形状に追随
して変形する性質を持つので、ＣＰＵとヒートシンクと
で熱伝導基材１１を挟持すれば、その挟持力＝押圧力に
よりＣＰＵ及びヒートシンクの双方の表面形状に追随し
て変形する。これにより熱源となるＣＰＵと放熱のため
のヒートシンクとの双方に熱伝導基材１１が密着する。
熱伝導基材１１とＣＰＵ及びヒートシンクの表面との間
に微細な空隙が生じることがないから、十分な熱伝導効
果が得られる。The heat conductive substrate 11 is a plate having a thickness of 1 mm or less (approximately 0.5 mm in the embodiment). When pressed against the surface of the CPU or the heat sink, the heat conductive substrate 11 is deformed to follow the shape of the surface. When the heat conductive base material 11 is sandwiched between the CPU and the heat sink, the heat conductive base material 11 is deformed by following the surface shape of both the CPU and the heat sink by the holding force = the pressing force. As a result, the heat conductive substrate 11 comes into close contact with both the CPU serving as a heat source and the heat sink for heat radiation.
Since there is no minute gap between the heat conductive substrate 11 and the surfaces of the CPU and the heat sink, a sufficient heat conductive effect can be obtained.
【００３９】また、ヒートシンクを取り付けた後に再度
加熱して熱伝導基材１１を可塑化させて、今度はヒート
シンクの表面に密着させてもよい。または、ＣＰＵの使
用に伴う発熱で熱伝導基材１１が加熱されれば、それに
よって可塑化してＣＰＵ及びヒートシンクの表面に密着
する。どちらにしても熱伝導基材１１をＣＰＵ及びヒー
トシンクに良好に密着させることができる。その結果、
熱伝導基材１１を介しての熱伝導効率が良好となり、Ｃ
ＰＵの熱を良好に放熱できる。Further, after the heat sink is attached, the heat conductive substrate 11 may be heated again to plasticize the heat conductive base material 11 and then adhere to the surface of the heat sink. Alternatively, if the heat conductive base material 11 is heated by the heat generated by the use of the CPU, the heat conductive base material 11 is plasticized and adheres to the surfaces of the CPU and the heat sink. In any case, the heat conductive substrate 11 can be brought into close contact with the CPU and the heat sink. as a result,
The heat conduction efficiency through the heat conduction base material 11 becomes good, and C
The heat of PU can be radiated well.
【００４０】また、ＣＰＵ及びヒートシンクの表面形状
に忠実に追随して変形するから、ヒートシンクからＣＰ
Ｕにかかる荷重が均等に分散され、ＣＰＵの一部に偏っ
た荷重がかることがない。熱伝導材１０の取付作業に当
たっては、保護シートに該当する剥離紙１３及びサポー
ト材に該当するメッシュ銅箔１２が支持材となって熱伝
導基材１１を支持するので、取り扱いやすく、作業性も
良好になる。Further, since the deformation follows the surface shapes of the CPU and the heat sink faithfully, the heat sink can be used to remove the CP.
The load applied to U is evenly distributed, so that an uneven load is not applied to a part of the CPU. At the time of attaching the heat conductive material 10, the release paper 13 corresponding to the protective sheet and the mesh copper foil 12 corresponding to the support material serve as a support material to support the heat conductive base material 11, so that it is easy to handle and workability is improved. Become good.
【００４１】メッシュ銅箔１２は熱伝導性が良いから、
ＣＰＵからヒートシンクへの伝導を阻害しない。また、
銅箔１２による電磁シールド効果も期待できる。銅箔１
２が熱伝導基材１１の内部に配されているので、ＣＰＵ
またはヒートシンクとの密着性は熱伝導基材１１によっ
て確保される。Since the mesh copper foil 12 has good thermal conductivity,
Does not hinder conduction from the CPU to the heat sink. Also,
An electromagnetic shielding effect by the copper foil 12 can also be expected. Copper foil 1
2 is arranged inside the heat conductive base material 11, so that the CPU
Alternatively, adhesion to the heat sink is ensured by the heat conductive base material 11.
【００４２】しかも、メッシュの網目にて銅箔１２の両
側の熱伝導基材１１を連続させているので、熱伝導基材
１１が銅箔１２から分離するおそれもない。なお、図３
（ａ）に例示するように、熱伝導基材１１の両面に剥離
紙１３（または他の保護シート）を張り付けた構造とし
たり、図３（ｂ）、（ｃ）に例示するようにサポート材
を用いない構造とすることもできる。その場合、図３
（ｂ）のように熱伝導基材１１の一方の面に剥離紙１３
（保護シート）を張り付けた構造としても、図３（ｃ）
のように熱伝導基材１１の両方の面に剥離紙１３（保護
シート）を張り付けた構造としても、どちらでもよい。In addition, since the heat conductive base material 11 on both sides of the copper foil 12 is continuous with the mesh of the mesh, there is no possibility that the heat conductive base material 11 is separated from the copper foil 12. Note that FIG.
As shown in FIG. 3A, a release paper 13 (or another protective sheet) is attached to both sides of the heat conductive base material 11 or a support material as shown in FIGS. 3B and 3C. May be used. In that case, FIG.
As shown in (b), a release paper 13 is provided on one surface of the heat conductive base material 11.
Fig. 3 (c)
The structure in which the release paper 13 (protective sheet) is attached to both surfaces of the heat conductive substrate 11 as described above may be used.
【００４３】以上、本発明について説明したが、本発明
は上述の各例に限定されるものではなく、本発明の要旨
を逸脱しない範囲でさまざまに実施できることは言うま
でもない。例えば熱伝導基材の厚さを約０．５ｍｍとし
ているが、これを更に薄くする（例えば０．１ｍｍ程度
とする）ことも可能である。この厚さが小さければ小さ
いほど熱伝導効率すなわちＣＰＵなどの電子部品からヒ
ートシンクへの放熱効率が向上する。Although the present invention has been described above, it is needless to say that the present invention is not limited to the above-described embodiments, and can be variously implemented without departing from the gist of the present invention. For example, the thickness of the heat conductive substrate is set to about 0.5 mm, but it can be further reduced (for example, to about 0.1 mm). The smaller the thickness, the higher the heat conduction efficiency, that is, the efficiency of heat radiation from the electronic component such as the CPU to the heat sink.
【図１】 実施例の熱伝導基材の内部構造の模式図であ
る。FIG. 1 is a schematic diagram of the internal structure of a heat conductive substrate of an example.
【図２】 実施例の熱伝導基材を用いた熱伝導材の説明
図である。FIG. 2 is an explanatory diagram of a heat conductive material using the heat conductive base material of the example.
【図３】 実施例の熱伝導基材を用いた他の熱伝導材の
説明図である。FIG. 3 is an explanatory diagram of another heat conductive material using the heat conductive base material of the example.
１０ 熱伝導材 １１ 熱伝導基材 １２ メッシュ銅箔（サポート材） １３ 剥離紙（保護シート） Reference Signs List 10 heat conductive material 11 heat conductive base material 12 mesh copper foil (support material) 13 release paper (protective sheet)
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 4F100 AA14A AA14C AA16A AA16C AB01B AB17B AB33B AK75A AK75C AR00A AR00C AR00D BA04 BA07 BA10A BA10D CA23A CA23C DC11B DC16B DG10D GB41 JA04A JA04C JA06A JA06C JJ01 JJ01A JJ01C JL14D YY00A YY00C 5F036 AA01 BA04 BA23 BB21 BD01 BD21 ──────────────────────────────────────────────────の Continued on the front page F-term (reference) 4F100 AA14A AA14C AA16A AA16C AB01B AB17B AB33B AK75A AK75C AR00A AR00C AR00D BA04 BA07 BA10A BA10D CA23A CA23C DC11B DC16B DG10D GB41 JA04A JA04J01A01J06A01J06A01J06A01 BD01 BD21
Claims (6)
表面の形状に追随して変形する性質を持つ厚さが１ｍｍ
以下の板状の熱伝導基材と、 該熱伝導基材の２面または１面に貼着された保護シート
とからなることを特徴とする熱伝導材。1. A thickness of 1 mm having a property of being deformed following the shape of the surface when pressed against the surface of the mounted body.
A heat conductive material comprising: the following plate-shaped heat conductive base; and a protective sheet adhered to two or one surface of the heat conductive base.
剥離可能であることを特徴とする熱伝導材。2. The heat conductive material according to claim 1, wherein the protective sheet is peelable without damaging the surface of the heat conductive base material.
て、 全部または一部が前記熱伝導基材の内部に配されて該熱
伝導基材を支持するサポート材を備えたことを特徴とす
る熱伝導材。3. The heat conductive material according to claim 1, further comprising a support member that is disposed in whole or in part inside the heat conductive base material and supports the heat conductive base material. Heat conductive material.
材。4. The heat conductive material according to claim 3, wherein said support material is a metal foil.
伝導材。5. The heat conductive material according to claim 4, wherein a hole is provided in the metal foil.
導材において、 前記熱伝導基材は、融点が３０〜７０℃かつ１００℃に
おける粘度が７００００ｃＰ以上の有機材料中に該熱伝
導基材の３０〜９０重量％の充填剤を分散してなること
を特徴とする熱伝導材。6. The heat conductive material according to claim 1, wherein the heat conductive base material is contained in an organic material having a melting point of 30 to 70 ° C. and a viscosity at 100 ° C. of 70,000 cP or more. A heat conductive material, characterized in that 30 to 90% by weight of a filler is dispersed in the material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000166175A JP3431576B2 (en) | 2000-06-02 | 2000-06-02 | Thermal conductive material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000166175A JP3431576B2 (en) | 2000-06-02 | 2000-06-02 | Thermal conductive material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001345406A true JP2001345406A (en) | 2001-12-14 |
| JP3431576B2 JP3431576B2 (en) | 2003-07-28 |
Family
ID=18669534
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000166175A Expired - Fee Related JP3431576B2 (en) | 2000-06-02 | 2000-06-02 | Thermal conductive material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3431576B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003264261A (en) * | 2002-03-07 | 2003-09-19 | Hitachi Industrial Equipment Systems Co Ltd | Power device and sheet for heat connection |
| JP2006291123A (en) * | 2005-04-14 | 2006-10-26 | Idemitsu Kosan Co Ltd | Thermal conductive resin composition |
| JP2008294413A (en) * | 2007-04-25 | 2008-12-04 | Hitachi Chem Co Ltd | Thermally conductive film |
| JP2010212613A (en) * | 2009-03-12 | 2010-09-24 | Kyocera Corp | Heat dissipation structure of base station apparatus |
| JP2011177929A (en) * | 2010-02-26 | 2011-09-15 | Nippon Steel Chem Co Ltd | Metal-insulating resin substrate and method of manufacturing the same |
-
2000
- 2000-06-02 JP JP2000166175A patent/JP3431576B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003264261A (en) * | 2002-03-07 | 2003-09-19 | Hitachi Industrial Equipment Systems Co Ltd | Power device and sheet for heat connection |
| JP2006291123A (en) * | 2005-04-14 | 2006-10-26 | Idemitsu Kosan Co Ltd | Thermal conductive resin composition |
| JP2008294413A (en) * | 2007-04-25 | 2008-12-04 | Hitachi Chem Co Ltd | Thermally conductive film |
| JP2010212613A (en) * | 2009-03-12 | 2010-09-24 | Kyocera Corp | Heat dissipation structure of base station apparatus |
| JP2011177929A (en) * | 2010-02-26 | 2011-09-15 | Nippon Steel Chem Co Ltd | Metal-insulating resin substrate and method of manufacturing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3431576B2 (en) | 2003-07-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TW549011B (en) | Dissipation of heat from a circuit board having bare silicon chips mounted thereon | |
| JP5752299B2 (en) | Method for manufacturing heat conductive sheet, heat conductive sheet, and heat dissipation member | |
| JP4459470B2 (en) | Electronic component heat dissipation structure and heat dissipation sheet used therefor | |
| US6886625B1 (en) | Elastomeric heat sink with a pressure sensitive adhesive backing | |
| EP3255969A1 (en) | Heat-conducting sheet and electronic device | |
| CN107871721A (en) | Heat conductive sheet and preparation method thereof and semiconductor device | |
| JP2020116873A (en) | Manufacturing method of heat-conductive sheet | |
| JP7384560B2 (en) | Thermal conductive sheets, mounting methods for thermal conductive sheets, manufacturing methods for electronic devices | |
| KR102155811B1 (en) | The manufacturing method for heat radiation adhesive and heat radiation tape with excellent in-plane thermal conductivity comprising the same | |
| US5978221A (en) | Radiating spacer, its use and silicone composition | |
| JP3340112B2 (en) | Thermal conductive material and manufacturing method thereof | |
| JP2002164481A (en) | Heat conductive sheet | |
| JPH11317480A (en) | Radiating part and manufacture thereof | |
| JP3431576B2 (en) | Thermal conductive material | |
| JP2006121051A (en) | Thermal conductive sheet and manufacturing method of same | |
| CN209912866U (en) | Composite heat conduction gasket, heat dissipation assembly and heat dissipation device | |
| JP3178805B2 (en) | Heat radiation spacer | |
| JP4749631B2 (en) | Heat dissipation member | |
| JP3283454B2 (en) | Heat radiation spacer | |
| TWM540741U (en) | Multi-layer composite heat conduction structure | |
| JP3466135B2 (en) | Thermal conductive material | |
| JP2002167560A (en) | Thermally conductive resin sheet | |
| JP4101391B2 (en) | Heat dissipation member for electronic parts | |
| JP2001156227A (en) | Anisotropic thermal-conductive sheet | |
| JP3372487B2 (en) | Silicone rubber molding |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080523 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090523 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090523 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100523 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100523 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110523 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120523 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120523 Year of fee payment: 9 |
|
| LAPS | Cancellation because of no payment of annual fees |