JP2022139002A

JP2022139002A - Interfacial heat conduction material and interfacial heat conduction method

Info

Publication number: JP2022139002A
Application number: JP2021039198A
Authority: JP
Inventors: 教文小宅; Norifumi Koyake; 健二福井; Kenji Fukui; 昌孝出口; Masataka Deguchi
Original assignee: Denso Corp; Toyota Central R&D Labs Inc
Current assignee: Denso Corp; Toyota Central R&D Labs Inc
Priority date: 2021-03-11
Filing date: 2021-03-11
Publication date: 2022-09-26

Abstract

To provide an interfacial heat-conductive material that can accommodate both of great undulations between objects and interfacial small asperities.SOLUTION: An interfacial heat-conductive material 100 fills voids between objects and promotes heat movement between the objects. The interfacial heat-conductive material contains a liquid heat-conductive material 12 in liquid state in combination with a solid heat-conductive material 10 in solid state.SELECTED DRAWING: Figure 1

Description

本発明は、界面熱伝導材及び界面熱伝導方法に関する。 The present invention relates to an interfacial heat conduction material and an interfacial heat conduction method.

異なる物体の間の隙間を埋めて、当該物体間の熱の移動を促進するための熱伝導材料が用いられている。例えば、窒化ホウ素をマトリックス中に分散させた熱伝導性複合材料が開示されている（特許文献１）。また、例えば、ビニル基を含有するシリコーン等を含む熱伝導性フィラーが開示されている（特許文献２）。 Thermally conductive materials are used to fill gaps between different objects to facilitate heat transfer between the objects. For example, a thermally conductive composite material in which boron nitride is dispersed in a matrix is disclosed (Patent Document 1). Further, for example, a thermally conductive filler containing silicone containing a vinyl group is disclosed (Patent Document 2).

特開２０２０－４５４５６号公報JP 2020-45456 A 特開２０１６－２１６５２３号公報JP 2016-216523 A

ところで、従来の熱伝導性材に関する技術は、熱伝導フィルムや熱伝導グリスのように、各材料自体の熱伝導率を向上させる技術である。 By the way, conventional techniques related to thermally conductive materials are techniques for improving the thermal conductivity of each material itself, such as thermally conductive films and thermally conductive greases.

しかしながら、熱伝導グリスを用いた場合、物体間の界面形状に大きなうねりがあった場合、その界面形状に対してグリスが十分に埋められず、熱伝導が十分でなくなることがある。また、物体の熱膨張等による変形で熱伝導グリスが界面から押し出されるポンプアウト現象が起こるおそれがある。 However, when thermally conductive grease is used, if there is a large undulation in the shape of the interface between objects, the grease may not sufficiently fill the shape of the interface, resulting in insufficient heat conduction. In addition, deformation due to thermal expansion or the like of an object may cause a pump-out phenomenon in which the heat-conducting grease is pushed out from the interface.

また、熱伝導シートを用いた場合、物体間の界面の小さな凹凸に対応できず、熱伝導が十分でなくなることがある。 Moreover, when a heat-conducting sheet is used, it may not be able to cope with small irregularities on the interface between objects, resulting in insufficient heat conduction.

本発明の１つの態様は、物体間の空隙を埋めて、前記物体間の熱移動を促進する界面熱伝導材であって、液体状の液体熱伝導材と、固体状の固体熱伝導材とを組み合わせて構成されることを特徴とする界面熱伝導材である。 One aspect of the present invention is an interfacial heat conductive material that fills gaps between objects and promotes heat transfer between the objects, comprising a liquid heat conductive material and a solid heat conductive material. It is an interfacial heat conductive material characterized by being configured by combining

ここで、前記液体熱伝導材の粘性は、５０Ｐａ・ｓ以下であることが好適である。 Here, the viscosity of the liquid thermally conductive material is preferably 50 Pa·s or less.

また、前記物体の少なくとも一方の表面の粗さは、算術平均粗さ０．８μｍ以上であることが好適である。 Further, it is preferable that at least one surface of the object has an arithmetic mean roughness of 0.8 μm or more.

また、前記液体熱伝導材は、シリコーンを基材としていることが好適である。また、前記固体熱伝導材は、カーボン系材料を基材していることが好適である。 Moreover, it is preferable that the liquid thermally conductive material is based on silicone. Moreover, it is preferable that the solid heat conductive material is based on a carbon-based material.

また、前記固体熱伝導材の厚さは、１００μｍ以上５００μｍ以下であることが好適である。 Moreover, it is preferable that the thickness of the solid thermal conductive material is 100 μm or more and 500 μm or less.

また、前記固体熱伝導材の表裏面に前記液体熱伝導材が設けられていることが好適である。 Moreover, it is preferable that the liquid heat conductive material is provided on the front and back surfaces of the solid heat conductive material.

本発明の別の態様は、物体間の空隙を埋めて、前記物体間の熱移動を促進する界面熱伝導方法であって、液体状の液体熱伝導材と、固体状の固体熱伝導材とを組み合わせて用いることを特徴とする界面熱伝導方法である。 Another aspect of the present invention is an interfacial heat conduction method for filling gaps between objects to promote heat transfer between the objects, comprising a liquid heat conducting material and a solid heat conducting material. It is an interfacial heat conduction method characterized by using a combination of

本発明によれば、物体間のおおきなうねりと、界面の小さな凹凸の両方に適応した界面熱伝導材及び界面熱伝導方法を提供することができる。 According to the present invention, it is possible to provide an interfacial heat-conducting material and an interfacial heat-conducting method that are suitable for both large undulations between objects and small irregularities on the interface.

本発明の実施の形態における界面熱伝導材の構成を示す図である。It is a figure which shows the structure of the interfacial heat-conducting material in embodiment of this invention. 界面熱伝導材について説明するための図である。It is a figure for demonstrating an interfacial thermally-conductive material. 界面熱伝導材について説明するための図である。It is a figure for demonstrating an interfacial thermally-conductive material. 界面熱伝導材について説明するための図である。It is a figure for demonstrating an interfacial thermally-conductive material. 界面熱伝導材について説明するための図である。It is a figure for demonstrating an interfacial thermally-conductive material. 界面熱伝導材について説明するための図である。It is a figure for demonstrating an interfacial thermally-conductive material. 本発明の実施の形態における界面熱伝導方法を示す図である。It is a figure which shows the interfacial heat conduction method in embodiment of this invention. 本発明の実施の形態における界面熱伝導方法を示す図である。It is a figure which shows the interfacial heat conduction method in embodiment of this invention. 定常法熱伝導率測定装置を説明するための図である。It is a figure for demonstrating a stationary method thermal conductivity measuring apparatus. 液体熱伝導材のみを用いた場合の定常法熱伝導率の測定結果例を示す図である。It is a figure which shows the example of a measurement result of steady method thermal conductivity at the time of using only a liquid thermally-conductive material. 本発明の実施の形態における界面熱伝導材を用いた場合の定常法熱伝導率の測定結果例を示す図である。It is a figure which shows the example of a measurement result of steady-state method thermal conductivity at the time of using the interfacial thermally-conductive material in embodiment of this invention. 界面熱抵抗の押し付け圧力依存性を示す図である。It is a figure which shows the pressing pressure dependence of interfacial thermal resistance. 界面熱抵抗の表面粗さ依存性を示す図である。It is a figure which shows the surface roughness dependence of interfacial thermal resistance. 界面熱抵抗の液体熱伝導材の粘性依存性を示す図である。It is a figure which shows the viscosity dependence of the liquid thermally-conductive material of interfacial thermal resistance. 界面熱抵抗の液体熱伝導材の初期厚さ依存性を示す図である。FIG. 4 is a diagram showing the dependence of interfacial thermal resistance on the initial thickness of a liquid thermally conductive material.

本発明の実施の形態における界面熱伝導材１００は、図１の断面図に示すように、シート状の固体熱伝導材１０とペースト状の液体熱伝導材１２とを組み合わせて構成される。界面熱伝導材１００では、シート状の固体熱伝導材１０の表裏面にペースト状の液体熱伝導材１２を塗布した構成を有する。 An interfacial heat conductive material 100 according to an embodiment of the present invention is configured by combining a sheet-like solid heat conductive material 10 and a paste-like liquid heat conductive material 12, as shown in the cross-sectional view of FIG. The interfacial heat conductive material 100 has a configuration in which a paste-like liquid heat conductive material 12 is applied to the front and back surfaces of a sheet-like solid heat conductive material 10 .

固体熱伝導材１０は、カーボン系材料やエラストマー等をシート状に形成したものとすることができる。固体熱伝導材１０の厚さは、１００μｍ以上５００μｍ以下とすることが好適である。固体熱伝導材１０は、厚み方向に対して２０Ｗ／ｍＫ以上の熱伝導率を有することが好適である。 The solid thermally conductive material 10 can be made of a carbon-based material, an elastomer, or the like formed into a sheet. The thickness of the solid heat conductive material 10 is preferably 100 μm or more and 500 μm or less. The solid thermal conductive material 10 preferably has a thermal conductivity of 20 W/mK or more in the thickness direction.

液体熱伝導材１２は、金属等の熱伝導材料フィラーを基材となるシリコーン等の粘性のあるペーストに混ぜたものや液体金属とすることができる。 The liquid thermally conductive material 12 can be a liquid metal or a mixture of a thermally conductive material filler such as metal mixed with a viscous paste such as silicone as a base material.

固体熱伝導材１０及び液体熱伝導材１２は、特に限定されるものでなく、以下に示す特徴を備えるものであればよい。 The solid thermally conductive material 10 and the liquid thermally conductive material 12 are not particularly limited as long as they have the following characteristics.

図２は、界面熱伝導材１００が適用される物体１及び物体２の界面の状態を示す図である。物体１と物体２が固体同士の場合、接合部の界面には一般的に表面粗さや表面のうねりが原因となって空隙Ｓが存在する。この空隙Ｓには熱伝導率が非常に低い空気が存在するため、物体１と物体２の界面を介した熱の移動が阻害される。これを接触熱抵抗と呼ぶ。この熱抵抗が原因となり、例えば、ＣＰＵ等の電子素子とヒートシンクの接合面の放熱が阻害されて性能の低下や故障が発生する原因となり得る。 FIG. 2 is a diagram showing the state of the interface between objects 1 and 2 to which the interfacial heat conductor 100 is applied. When the object 1 and the object 2 are solid bodies, a gap S generally exists at the interface between the joints due to surface roughness and surface undulation. Since air having a very low thermal conductivity exists in the air gap S, heat transfer through the interface between the objects 1 and 2 is impeded. This is called contact thermal resistance. Due to this thermal resistance, for example, heat radiation from the joint surface between an electronic device such as a CPU and a heat sink is hindered, which may cause deterioration in performance or failure.

当該問題を解決するために、図３に示すように、物体１と物体２の接合界面には界面熱伝導材と呼ばれる材料が挿入される。この材料を挿入することで、空気に代わって、物体間の空隙Ｓが空気よりも熱伝導率が高い別の材料で充填される。これによって、放熱性が向上する。 In order to solve this problem, as shown in FIG. 3, a material called interfacial heat conductive material is inserted in the joint interface between the objects 1 and 2. FIG. By inserting this material, instead of air, the gap S between the objects is filled with another material having a higher thermal conductivity than air. This improves heat dissipation.

例えば、界面熱伝導材として液体状の材料からなる液体熱伝導材１２が用いられる。液体熱伝導材１２は、物体間の空隙Ｓを効率よく充填するので放熱性向上に効果がある。しかしながら、液体熱伝導材１２の問題点の一つは薄くなることである。例えば、物体１と物体２が温度変化して熱膨張した場合に物体間の空隙Ｓが大きくなる領域が生ずるおそれがあるが、図４に示すように、液体熱伝導材１２はそのような変形に追従し難く、物体間の空隙Ｓが拡がってしまうという問題を抱えている。また、変形が小さい場合でも、加熱と冷却との熱サイクルが繰り返されることによって、液体熱伝導材１２が徐々に界面外へ流出し、界面に空隙Ｓが発生するポンプアウト現象が生ずるおそれがある。この場合も熱抵抗が大きくなる問題の原因となる。 For example, a liquid thermally conductive material 12 made of a liquid material is used as the interfacial thermally conductive material. The liquid heat-conducting material 12 efficiently fills the space S between the objects, so it is effective in improving heat dissipation. However, one problem with liquid thermally conductive material 12 is that it is thin. For example, when the objects 1 and 2 thermally expand due to temperature changes, there is a possibility that a region in which the gap S between the objects becomes large will occur. is difficult to follow, and there is a problem that the gap S between objects widens. Moreover, even if the deformation is small, the liquid thermal conductive material 12 may gradually flow out of the interface due to repeated thermal cycles of heating and cooling, and a pump-out phenomenon may occur in which a gap S is generated at the interface. . This also causes the problem of increased thermal resistance.

一方、図５に示すように、物体１と物体２の接合界面に弾力性のある固体熱伝導材１０を適用する方法がある。固体熱伝導材１０は熱伝導率が高いため、厚みを厚くすることができることに加えて、圧縮性があるため熱膨張等による大きな変形に追従できる。 On the other hand, as shown in FIG. 5, there is a method of applying an elastic solid heat-conducting material 10 to the joint interface between the objects 1 and 2 . Since the solid thermal conductive material 10 has a high thermal conductivity, it can be made thicker and can follow large deformation due to thermal expansion or the like due to its compressibility.

しかしながら、シート状の固体熱伝導材１０は物体の表面粗さに沿わせることが難しく、物体と固体熱伝導材１０との間に空隙Ｓが生じてしまうおそれがある。そのため、液体熱伝導材１２と比べて熱抵抗が大きくなることがある。また、固体熱伝導材１０は圧縮して使うため、物体間の圧力が弱くなった場合や熱変形・経年劣化等によって熱抵抗が高くなってしまう問題を抱えている。 However, it is difficult for the sheet-like solid thermally conductive material 10 to conform to the surface roughness of the object, and there is a possibility that a gap S may be generated between the object and the solid thermally conductive material 10 . Therefore, the thermal resistance may be greater than that of the liquid thermally conductive material 12 . In addition, since the solid thermal conductive material 10 is used in a compressed state, there is a problem that the thermal resistance increases due to a decrease in pressure between objects, thermal deformation, deterioration over time, and the like.

本実施の形態における界面熱伝導材１００はシート状の固体熱伝導材１０とペースト状の液体熱伝導材１２とを組み合わせて構成し、図６に示すように、物体１と物体２と間の接合界面にペースト状の液体熱伝導材１２を充填すると共に、シート状の固体熱伝導材１０も挿入する。 The interfacial thermal conductive material 100 in the present embodiment is configured by combining a sheet-like solid thermal conductive material 10 and a paste-like liquid thermal conductive material 12, and as shown in FIG. A paste-like liquid heat-conducting material 12 is filled in the joining interface, and a sheet-like solid heat-conducting material 10 is also inserted.

このように固体熱伝導材１０と液体熱伝導材１２とを組み合わせた場合、熱抵抗は２つの材料の和にならず、物体１と物体２との間の熱抵抗は減少する。さらに、ペースト状の液体熱伝導材１２が物体表面の細かな凹凸を充填し、ある程度厚みがあるシート状の固体熱伝導材１０が物体表面のおおきなうねりを吸収することができる。 When the solid thermally conductive material 10 and the liquid thermally conductive material 12 are combined in this way, the thermal resistance is not the sum of the two materials, and the thermal resistance between the objects 1 and 2 is reduced. Furthermore, the paste-like liquid heat-conducting material 12 fills fine irregularities on the surface of the object, and the sheet-like solid heat-conducting material 10 having a certain thickness can absorb large undulations on the surface of the object.

なお、本実施の形態では、シート状の固体熱伝導材１０の表裏面にペースト状の液体熱伝導材１２を予め塗布した界面熱伝導材１００とし、界面熱伝導材１００に物体１と物体２を押し付けて使用する態様としたが、本発明の界面熱伝導方法はこれに限定されるものではない。 In the present embodiment, the interfacial heat conductive material 100 is formed by applying the pasty liquid heat conductive material 12 to the front and back surfaces of the sheet-like solid heat conductive material 10 in advance. However, the interfacial heat conduction method of the present invention is not limited to this.

図７に示すように、物体１と物体２の対向する面にペースト状の液体熱伝導材１２を塗布した状態で、シート状の固体熱伝導材１０に押し付けて接合するようにしてもよい。 As shown in FIG. 7, a paste-like liquid thermally conductive material 12 may be applied to the facing surfaces of the object 1 and the object 2, and then pressed against a sheet-like solid thermally conductive material 10 for bonding.

また、図８に示すように、固体熱伝導材１０の片面だけに液体熱伝導材１２を塗布して、物体１と物体２とを接合させるようにしてもよい。 Alternatively, as shown in FIG. 8, the object 1 and the object 2 may be joined by applying the liquid thermally conductive material 12 only on one side of the solid thermally conductive material 10 .

図９は、界面熱伝導材１００の効果を測定するための定常法熱伝導率測定装置の構成を示す。定常法熱伝導率測定装置では、熱伝導率が既知である上部及び下部の銅ブロックの間に測定対象物を挟み込んで適切な力で押し付けた状態で測定対象物の熱伝導率を測定する。測定時には、上部の銅ブロックの上端部及び下部の銅ブロックの下端部に温度差をつける。上部の銅ブロック及び下部の銅ブロックには１０ｍｍ間隔で熱電対を設け、それぞれの熱電対によって温度Ｔ１～Ｔ８を測定する。低温部から高温部までの熱勾配から熱流束が解析でき、上部の銅ブロックと下部の銅ブロックとの接触面に温度差（図中、温度ジャンプと示す）から測定対象物の接触熱抵抗を知ることができる。このとき、接触面に温度差（温度ジャンプ）が小さいほど、測定対象物の熱抵抗は小さい。 FIG. 9 shows the configuration of a steady-state thermal conductivity measuring device for measuring the effect of the interfacial thermal conductive material 100. As shown in FIG. In the steady-state thermal conductivity measuring device, the thermal conductivity of the object to be measured is measured while the object to be measured is sandwiched between upper and lower copper blocks whose thermal conductivity is known and pressed with an appropriate force. During measurement, a temperature difference is applied between the upper end of the upper copper block and the lower end of the lower copper block. Thermocouples are provided on the upper copper block and the lower copper block at intervals of 10 mm, and temperatures T1 to T8 are measured by each thermocouple. The heat flux can be analyzed from the thermal gradient from the low temperature part to the high temperature part, and the contact thermal resistance of the object to be measured can be calculated from the temperature difference (indicated as temperature jump in the figure) on the contact surface between the upper copper block and the lower copper block. can know At this time, the smaller the temperature difference (temperature jump) on the contact surface, the smaller the thermal resistance of the object to be measured.

図１０は、測定対象物として物体１と物体２とを液体熱伝導材１２のみで接合したときの定常法熱伝導率の測定結果を示す。上部及び下部の銅ブロックで測定対象物を挟み込んだ圧力は１ＭＰａとした。その結果、液体熱伝導材１２の熱抵抗は１２．７ｍｍ^２Ｋ／Ｗであった。なお、固体熱伝導材１０のみを用いた場合の熱抵抗は２０ｍｍ^２Ｋ／Ｗであった。 FIG. 10 shows the measurement results of the steady-state thermal conductivity when the objects 1 and 2 as objects to be measured are joined only with the liquid thermal conductive material 12 . The pressure at which the object to be measured was sandwiched between the upper and lower copper blocks was 1 MPa. As a result, the thermal resistance of the liquid thermally conductive material 12 was 12.7 mm ² K/W. The thermal resistance when only the solid thermal conductive material 10 was used was 20 mm ² K/W.

図１１は、測定対象物として物体１と物体２とを固体熱伝導材１０の表裏面に液体熱伝導材１２を塗布した界面熱伝導材１００で接合したときの定常法熱伝導率の測定結果を示す。上部及び下部の銅ブロックで測定対象物を挟み込んだ圧力は１ＭＰａとした。その結果、固体熱伝導材１０及び液体熱伝導材１２で構成される界面熱伝導材１００の熱抵抗は１３．６ｍｍ^２Ｋ／Ｗであった。 FIG. 11 shows measurement results of steady-state thermal conductivity when object 1 and object 2, which are objects to be measured, are joined by interfacial thermal conductive material 100 in which liquid thermal conductive material 12 is applied to the front and back surfaces of solid thermal conductive material 10. indicate. The pressure at which the object to be measured was sandwiched between the upper and lower copper blocks was 1 MPa. As a result, the thermal resistance of the interfacial heat conductive material 100 composed of the solid heat conductive material 10 and the liquid heat conductive material 12 was 13.6 mm ² K/W.

このように、固体熱伝導材１０の表裏面に液体熱伝導材１２を塗布した界面熱伝導材１００を用いた場合、液体熱伝導材１２のみを用いた場合に比べてわずかに熱抵抗は大きくなったが、物体表面の細かい凹凸と大きなうねりに追従できるようになった。 As described above, when the interfacial heat conductive material 100 in which the liquid heat conductive material 12 is applied to the front and back surfaces of the solid heat conductive material 10 is used, the thermal resistance is slightly larger than when only the liquid heat conductive material 12 is used. However, it has become possible to follow fine irregularities and large undulations on the surface of the object.

図１２は、定常法熱伝導率測定装置において測定対象物に印加する圧力を変化させたときの界面熱抵抗率を測定した結果を示す。図１２において、ラインＡは固体熱伝導材１０のみを用いた場合、ラインＢは液体熱伝導材１２のみを用いた場合、ラインＣは固体熱伝導材１０の表裏面に液体熱伝導材１２を塗布した界面熱伝導材１００を用いた場合を示す。なお、測定対象物の接合表面の表面粗さは算術平均粗さＲａ＝０．８～１．０μｍであった。 FIG. 12 shows the result of measuring the interfacial thermal resistivity when changing the pressure applied to the object to be measured in the steady-state thermal conductivity measuring apparatus. In FIG. 12, line A uses only the solid heat conductive material 10, line B uses only the liquid heat conductive material 12, and line C uses the liquid heat conductive material 12 on the front and back surfaces of the solid heat conductive material 10. The case where the applied interfacial heat conductive material 100 is used is shown. The surface roughness of the joint surface of the object to be measured was an arithmetic mean roughness Ra of 0.8 to 1.0 μm.

界面熱伝導材１００を用いた場合、固体熱伝導材１０及び液体熱伝導材１２を組み合わせたのにも関わらず、固体熱伝導材１０のみを用いた場合に比べて界面熱抵抗は十分に小さく、液体熱伝導材１２のみを用いた場合に比べても界面熱抵抗の大きな増加はみられなかった。 When the interfacial thermal conductor 100 is used, despite the combination of the solid thermal conductor 10 and the liquid thermal conductor 12, the interfacial thermal resistance is sufficiently smaller than when only the solid thermal conductor 10 is used. , no significant increase in the interfacial thermal resistance was observed even when compared with the case where only the liquid thermal conductive material 12 was used.

このように、界面熱伝導材１００を用いることによって、界面熱抵抗を低く抑えつつ、ペースト状の液体熱伝導材１２によって物体表面の細かな凹凸を充填し、ある程度厚みがあるシート状の固体熱伝導材１０によって物体表面のおおきなうねりを吸収することができる。また、熱膨張等による物体界面の状態の変化にも追従させることができる。 In this way, by using the interfacial thermal conductive material 100, while keeping the interfacial thermal resistance low, the paste-like liquid thermal conductive material 12 fills fine irregularities on the surface of the object, and forms a sheet-like solid heat with a certain thickness. The conductive material 10 can absorb large undulations on the object surface. In addition, changes in the state of the object interface due to thermal expansion or the like can also be followed.

図１３は、固体熱伝導材１０の表裏面に液体熱伝導材１２を塗布した界面熱伝導材１００を用いた場合の物体の表面粗さの影響を測定した結果を示す。測定時において上部及び下部の銅ブロックで測定対象物を挟み込んだ圧力は１ＭＰａとした。 FIG. 13 shows the results of measuring the effect of surface roughness of an object when interfacial thermal conductive material 100 in which liquid thermal conductive material 12 is applied to the front and back surfaces of solid thermal conductive material 10 is used. The pressure at which the object to be measured was sandwiched between the upper and lower copper blocks during measurement was 1 MPa.

物体の表面粗さが算術平均粗さＲａ＝０．３μｍの条件下では、固体熱伝導材１０のみを用いた方が界面熱抵抗は小さかった。一方、物体の表面粗さが算術平均粗さＲａ＝０．８μｍの条件下では、固体熱伝導材１０のみを用いるより界面熱伝導材１００の方が界面熱抵抗は小さかった。すなわち、界面熱伝導材１００は、表面粗さがＲａ＝０．８ｕｍより粗い界面でより効果的だといえる。 Under the condition that the surface roughness of the object had an arithmetic mean roughness Ra of 0.3 μm, the interfacial thermal resistance was smaller when only the solid thermal conductive material 10 was used. On the other hand, under the condition that the surface roughness of the object had an arithmetic average roughness Ra of 0.8 μm, the interfacial thermal resistance was lower with the interfacial heat conductive material 100 than with the solid heat conductive material 10 alone. That is, it can be said that the interfacial heat conductive material 100 is more effective at an interface with a surface roughness greater than Ra=0.8 um.

図１４は、固体熱伝導材１０の表裏面に液体熱伝導材１２を塗布した界面熱伝導材１００における液体熱伝導材１２の粘性の影響を測定した結果を示す。界面熱伝導材１００の液体熱伝導材１２の粘性が５００Ｐａ・ｓの場合、固体熱伝導材１０のみを用いた場合よりも界面熱抵抗が高くなった。これに対して、界面熱伝導材１００の液体熱伝導材１２の粘性が５０Ｐａ・ｓの場合、固体熱伝導材１０のみを用いた場合よりも界面熱抵抗は低く抑えられた。 FIG. 14 shows the results of measuring the influence of the viscosity of the liquid heat conductive material 12 on the interfacial heat conductive material 100 in which the liquid heat conductive material 12 is applied to the front and back surfaces of the solid heat conductive material 10 . When the viscosity of the liquid heat conductive material 12 of the interfacial heat conductive material 100 was 500 Pa·s, the interfacial thermal resistance was higher than when only the solid heat conductive material 10 was used. On the other hand, when the viscosity of the liquid heat conductor 12 of the interfacial heat conductor 100 was 50 Pa·s, the interfacial thermal resistance was kept lower than when only the solid heat conductor 10 was used.

このように、固体熱伝導材１０と液体熱伝導材１２とを組み合わせた界面熱伝導材１００を構成する場合、粘性が比較的低い液体熱伝導材１２を用いることが好適である。特に、液体熱伝導材１２の粘性が５０Ｐａ・ｓ以下であることが好適である。 Thus, when forming the interfacial heat conductive material 100 by combining the solid heat conductive material 10 and the liquid heat conductive material 12, it is preferable to use the liquid heat conductive material 12 with relatively low viscosity. In particular, it is preferable that the viscosity of the liquid thermally conductive material 12 is 50 Pa·s or less.

図１５は、固体熱伝導材１０の表裏面に液体熱伝導材１２を塗布した界面熱伝導材１００における液体熱伝導材１２の初期厚さの影響を測定した結果を示す。具体的には、物体の表面に液体熱伝導材１２を塗布してそのまま固体熱伝導材１０を挟んでから定常法熱伝導率測定装置にて押し付けた場合と、物体の表面に液体熱伝導材１２を塗布して定常法熱伝導率測定装置にて一旦液体熱伝導材１２を延ばした後に固体熱伝導材１０を挟んでから再度押し付けた場合とについて界面熱抵抗を測定した。 FIG. 15 shows the results of measuring the effect of the initial thickness of the liquid heat conductive material 12 on the interfacial heat conductive material 100 in which the liquid heat conductive material 12 is applied to the front and back surfaces of the solid heat conductive material 10 . Specifically, the case where the liquid thermal conductive material 12 is applied to the surface of the object, the solid thermal conductive material 10 is sandwiched as it is, and it is pressed by the steady method thermal conductivity measurement device, and the liquid thermal conductive material is applied to the surface of the object 12 was applied, the liquid thermal conductive material 12 was temporarily stretched by a steady-state thermal conductivity measuring device, and then the solid thermal conductive material 10 was sandwiched and then pressed again to measure the interfacial thermal resistance.

液体熱伝導材１２を延ばす前に固体熱伝導材１０を挟み込んで押し付けた場合、固体熱伝導材１０のみを用いた場合よりも界面熱抵抗が高くなった。これに対して、液体熱伝導材１２を一旦延ばした後に固体熱伝導材１０を挟み込んで押し付けた場合、固体熱伝導材１０のみを用いた場合よりも界面熱抵抗は低く抑えられた。 When the solid thermal conductive material 10 was sandwiched and pressed before the liquid thermal conductive material 12 was extended, the interfacial thermal resistance was higher than when only the solid thermal conductive material 10 was used. On the other hand, when the solid thermal conductive material 10 was sandwiched and pressed after the liquid thermal conductive material 12 was once extended, the interfacial thermal resistance was kept lower than when only the solid thermal conductive material 10 was used.

このように、固体熱伝導材１０と液体熱伝導材１２とを組み合わせた界面熱伝導材１００を構成する場合、液体熱伝導材１２を延ばして初期厚さを薄くした後に固体熱伝導材１０を挟み込んで押し付けることが好適である。 In this way, when the interfacial heat conductive material 100 is formed by combining the solid heat conductive material 10 and the liquid heat conductive material 12, the liquid heat conductive material 12 is extended to reduce the initial thickness, and then the solid heat conductive material 10 is formed. It is preferable to pinch and press.

１物体、２物体、１０固体熱伝導材、１２液体熱伝導材、１００界面熱伝導材。
1 body, 2 body, 10 solid thermal conductor, 12 liquid thermal conductor, 100 interfacial thermal conductor.

Claims

An interfacial heat conductive material that fills voids between objects and promotes heat transfer between the objects,
1. An interfacial thermal conductive material comprising a combination of a liquid thermal conductive material and a solid thermal conductive material.

The interfacial heat conductive material according to claim 1,
The interfacial heat conductive material, wherein the liquid heat conductive material has a viscosity of 50 Pa·s or less.

The interfacial heat conductive material according to claim 1 or 2,
An interfacial heat conductive material, wherein at least one surface of the object has an arithmetic mean roughness of 0.8 μm or more.

The interfacial heat conductive material according to any one of claims 1 to 3,
The interfacial heat conductive material, wherein the liquid heat conductive material is based on silicone.

The interfacial heat conductive material according to any one of claims 1 to 4,
An interfacial heat conductive material, wherein the solid heat conductive material uses a carbon-based material as a base material.

The interfacial heat conductive material according to any one of claims 1 to 5,
An interfacial thermal conductive material, wherein the solid thermal conductive material has a thickness of 100 μm or more and 500 μm or less.

The interfacial heat conductive material according to any one of claims 1 to 6,
An interfacial heat conductive material, wherein the liquid heat conductive material is provided on front and back surfaces of the solid heat conductive material.

An interfacial heat transfer method for filling voids between objects to facilitate heat transfer between said objects, comprising:
An interfacial heat conduction method, characterized by using a combination of a liquid heat conductive material and a solid heat conductive material.