JP2010062310A - Heat spreader and method of manufacturing the same - Google Patents

Heat spreader and method of manufacturing the same Download PDF

Info

Publication number
JP2010062310A
JP2010062310A JP2008226202A JP2008226202A JP2010062310A JP 2010062310 A JP2010062310 A JP 2010062310A JP 2008226202 A JP2008226202 A JP 2008226202A JP 2008226202 A JP2008226202 A JP 2008226202A JP 2010062310 A JP2010062310 A JP 2010062310A
Authority
JP
Japan
Prior art keywords
copper
heat spreader
heat transfer
base material
heat
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
Application number
JP2008226202A
Other languages
Japanese (ja)
Other versions
JP5198982B2 (en
Inventor
Akira Fukui
彰 福井
Masahiro Omachi
正弘 大町
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Allied Material Corp
Original Assignee
Allied Material Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Allied Material Corp filed Critical Allied Material Corp
Priority to JP2008226202A priority Critical patent/JP5198982B2/en
Publication of JP2010062310A publication Critical patent/JP2010062310A/en
Application granted granted Critical
Publication of JP5198982B2 publication Critical patent/JP5198982B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/0001—Technical content checked by a classifier
    • H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Landscapes

  • Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat spreader that is formed in a nearly flat plate shape, has its surface-directional coefficient of thermal expansion close to those of an element, a ceramic substrate, etc., and also has higher thickness-directional thermal conductivity than the conventional one, and a method of manufacturing the same. <P>SOLUTION: The heat spreader 1 is ≤20 ppm. in amount of oxygen that copper constituting a plurality of heat conductive members 5 contains, the plurality of heat conductive members 5 being provided penetrating a base 2 made of a low-thermal-expansion material in a nearly flat plate shape from a top surface 3 to a reverse surface 4 along the thickness and exposed on both the surfaces. The method of manufacturing the heat spreader 1 includes compressing and molding powder of the low-thermal-expansion material 14 and a rod material 10 made of copper into a column shape both at temperature less than the fusion point of the copper and baking them, and then cutting them in a direction crossing the length direction of the column to manufacture the heat spreader 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、特にパワー半導体素子等の、動作時に大きな発熱を伴う素子からの熱除去用として好適に使用されるヒートスプレッダと、その製造方法に関するものである。   The present invention relates to a heat spreader that is preferably used for removing heat from an element that generates a large amount of heat during operation, such as a power semiconductor element, and a manufacturing method thereof.

電気自動車やハイブリッド自動車、鉄道車両等において誘導モータを駆動させる際に、直流から交流への電力変換を行うためのインバータ回路に用いる絶縁ゲート型バイポーラトランジスタ等のパワー半導体素子や、あるいはプラズマディスプレイパネル等の画像表示素子、コンピュータ用のマイクロプロセッサユニット、レーザーダイオード等の、動作時に大きな発熱を伴う素子においては、前記熱をできるだけ速やかに除去することが求められる。発生した熱を速やかに除去しないと素子自体が過熱して誤動作（熱暴走）したり、破損したりするおそれがあるためである。   Power semiconductor elements such as insulated gate bipolar transistors used in inverter circuits for converting power from direct current to alternating current when driving induction motors in electric vehicles, hybrid vehicles, railway vehicles, etc., or plasma display panels, etc. In an element that generates a large amount of heat during operation, such as an image display element, a microprocessor unit for a computer, or a laser diode, it is required to remove the heat as quickly as possible. This is because if the generated heat is not removed promptly, the element itself may overheat, causing malfunction (thermal runaway) or damage.

近年、前記各種装置類のより一層の高性能化および高出力化の進展に伴って、半導体素子を、現在一般的に用いられているケイ素（Ｓｉ）系、ガリウム−砒素（ＧａＡｓ）系、インジウム−燐（ＩｎＰ）系の素子から、炭化ケイ素（ＳｉＣ）系、窒化ガリウム（ＧａＮ）系の素子へと移行することが検討されている。その場合、素子の動作可能温度を、例えばケイ素系の素子等の１２０℃前後から、炭化ケイ素系の素子等の２００℃前後まで引き上げることが可能となり、過熱による誤動作や破損等をこれまでよりも起こりにくくできるものと考えられているが、素子からの熱をできるだけ速やかに除去する必要があることには変わりはない。   In recent years, along with the progress of higher performance and higher output of the various devices, semiconductor elements are now generally used in silicon (Si) -based, gallium-arsenic (GaAs) -based, indium. -Transition from a phosphorus (InP) element to a silicon carbide (SiC) element or a gallium nitride (GaN) element has been studied. In that case, it becomes possible to raise the operable temperature of the element from, for example, about 120 ° C. of a silicon-based element or the like to about 200 ° C. of a silicon carbide-based element or the like. Although it is thought that it can be made difficult to occur, it is still necessary to remove heat from the element as quickly as possible.

素子からの熱を速やかに除去して誤動作や破損を防止するためには、前記素子を、例えば平板状に形成したヒートスプレッダの、前記表面または裏面に直接に、あるいはセラミック基板等を介してはんだ接合等して搭載した状態で、前記ヒートスプレッダを冷却器等にネジ止め等して固定するのが一般的である。前記ヒートスプレッダとしては従来、銅（Ｃｕ）やアルミニウム（Ａｌ）等の金属、もしくは合金によって全体を一体に形成したものが用いられてきた。   In order to quickly remove the heat from the element and prevent malfunction and damage, the element is soldered directly to the front or back surface of the heat spreader formed in a flat plate shape, for example, or via a ceramic substrate. In general, the heat spreader is fixed to a cooler or the like by screwing or the like in a mounted state. As the heat spreader, a heat spreader that has been integrally formed of a metal such as copper (Cu) or aluminum (Al) or an alloy has been used.

しかし近時、先に説明したＳｉ系、ＧａＡｓ系、ＩｎＰ系、ＳｉＣ系、ＧａＮ系等の素子や、あるいは窒化アルミニウム（ＡｌＮ）、酸化アルミニウム（Ａｌ2Ｏ3）、窒化ケイ素（Ｓｉ3Ｎ4）等のセラミック基板等と熱膨張係数が近い、タングステン（Ｗ）、モリブデン（Ｍｏ）またはこれらを含む合金等を主要成分とする低熱膨張材料からなるものをヒートスプレッダとして用いることが検討されている。これは、素子やセラミック基板の熱膨張係数と、ヒートスプレッダの熱膨張係数とをできるだけ近づけることによって、素子の動作による発熱と停止後の冷却とを繰り返した際に、熱膨張係数の違いに基づいて素子に過剰な応力が加わって前記素子自体が破損したり、はんだ接合が破壊されたりするのを抑制できると考えられるためである。 However recently, Si system described above, GaAs-based, InP-based, SiC-based, elements and, or aluminum nitride GaN-based, etc. (AlN), aluminum oxide (Al 2 O 3), silicon nitride (Si 3 N 4 It has been studied to use as a heat spreader a material made of a low thermal expansion material whose main component is tungsten (W), molybdenum (Mo), or an alloy containing these, which has a thermal expansion coefficient close to that of a ceramic substrate or the like. This is based on the difference in thermal expansion coefficient when heat generation due to operation of the element and cooling after stopping are repeated by making the thermal expansion coefficient of the element or ceramic substrate and the thermal expansion coefficient of the heat spreader as close as possible. This is because it can be considered that excessive stress is applied to the element to damage the element itself or break the solder joint.

かかる低熱膨張材料からなるヒートスプレッダとしては、例えば
(i) 前記タングステン等の粉末と、銅等の粉末とを混合した混合物を、前記銅等の融点以上に加熱して溶融させると共にタングステン等からなる粉末間に浸透させたのち、冷却して一体化させたものや、
(ii) タングステン等の粉末からなる多孔質体（スケルトン）を作製し、前記焼結体の細孔中に、溶融させた銅等を含浸させたのち冷却して一体化させたもの、
等が挙げられる。 As a heat spreader made of such a low thermal expansion material, for example,
(i) A mixture obtained by mixing a powder of tungsten or the like and a powder of copper or the like is heated to a melting point or higher of the copper or the like and is infiltrated between powders of tungsten or the like, and then cooled and integrated. Or
(ii) a porous body (skeleton) made of powder of tungsten or the like, and impregnated with molten copper or the like in the pores of the sintered body and then cooled and integrated;
Etc.

これらのヒートスプレッダにおいて形成材料として銅等を併用しているのは、タングステン等だけでは不足する熱伝導率を補って高い熱伝導率を付与することを意図しているためである。しかし、前記従来構造では熱膨張係数と熱伝導率の関係が複合則に従い熱伝導率が制約されるため、ヒートスプレッダに、素子やセラミック基板と同等程度の熱膨張係数を維持しながら、高い熱伝導率を付与することはできなかった。   The reason why copper or the like is used as a forming material in these heat spreaders is that it is intended to provide high thermal conductivity by compensating for the thermal conductivity that is insufficient with tungsten alone. However, in the conventional structure, the relationship between the thermal expansion coefficient and the thermal conductivity is restricted in accordance with the composite rule, so that the heat spreader maintains a thermal expansion coefficient comparable to that of the element or the ceramic substrate while maintaining a high thermal conductivity. The rate could not be granted.

そこで改善策として、前記タングステン等からなる平板状の基材に、その表面から裏面へ厚み方向に貫通させて複数の貫通孔を形成し、前記貫通孔中に、溶融させた銅等を流し込んだのち冷却させて一体化させたヒートスプレッダが提案されている（特許文献１参照）。また前記(ii)のヒートスプレッダを形成するにあたり、タングステン等の粉末中に、平均短径が５０μｍ以上の銅等の塊を混合した状態で焼結体を形成し、形成した焼結体の細孔中に、さらに溶融させた銅等を含浸させたのち冷却して一体化させたヒートスプレッダも提案されている（特許文献２参照）。   Therefore, as a measure for improvement, a plurality of through holes were formed in the flat base material made of tungsten or the like in the thickness direction from the front surface to the back surface, and molten copper or the like was poured into the through holes. A heat spreader that has been cooled and integrated has been proposed (see Patent Document 1). In forming the heat spreader of (ii) above, a sintered body is formed in a state where a mass of copper or the like having an average minor axis of 50 μm or more is mixed in a powder of tungsten or the like, and the pores of the formed sintered body There has also been proposed a heat spreader that is impregnated with molten copper or the like and then cooled and integrated (see Patent Document 2).

前者のヒートスプレッダによれば、タングステン等からなる基材によって、特にその面方向の熱膨張係数を素子やセラミック基板等の熱膨張係数に近づけながら、厚み方向に貫通させた貫通孔に充填した銅によって、前記厚み方向の熱伝導率を向上できると考えられている。
また後者のヒートスプレッダにおいては、その内部に、前記銅等の塊に起因する比較的大きな銅プール相が形成される。そのため、タングステン等の粉末からなる焼結体によって、前記面方向の熱膨張係数を素子やセラミック基板等の熱膨張係数に近づけながら、焼結体の細孔中の銅相を経由する熱伝導の熱伝導率を、前記銅相と連続させて前記銅プール相を設けることで、従来に比べて向上できると考えられている。 According to the former heat spreader, with a base material made of tungsten or the like, particularly with copper filled in a through-hole penetrating in the thickness direction while bringing the thermal expansion coefficient in the surface direction close to the thermal expansion coefficient of an element or a ceramic substrate. It is considered that the thermal conductivity in the thickness direction can be improved.
Further, in the latter heat spreader, a relatively large copper pool phase resulting from the lump of copper or the like is formed therein. Therefore, the sintered body made of powder of tungsten or the like allows the thermal conductivity of the surface direction to be close to the thermal expansion coefficient of the element, ceramic substrate, etc., while conducting heat conduction via the copper phase in the pores of the sintered body. It is considered that the thermal conductivity can be improved as compared with the prior art by providing the copper pool phase in a continuous manner with the copper phase.

また特許文献３には、タングステン等と同様に熱膨張係数の小さい黒鉛からなる基材に貫通孔を形成し、前記貫通孔中に、溶融させた銅等を流し込んだのち冷却させて一体化させたヒートスプレッダが記載されている。かかるヒートスプレッダによれば、先の特許文献１に記載のものと同様に、黒鉛からなる基材によって面方向の熱膨張係数を素子やセラミック基板等の熱膨張係数に近づけながら、厚み方向に貫通させた貫通孔に充填した銅によって、前記厚み方向の熱伝導率を向上できると考えられている。   In Patent Document 3, a through-hole is formed in a base material made of graphite having a small thermal expansion coefficient like tungsten and the like, and molten copper is poured into the through-hole and then cooled and integrated. A heat spreader is described. According to such a heat spreader, similar to the one described in Patent Document 1, the thermal expansion coefficient in the plane direction is made to penetrate in the thickness direction by using a base material made of graphite while approaching the thermal expansion coefficient of an element or a ceramic substrate. It is considered that the thermal conductivity in the thickness direction can be improved by the copper filled in the through holes.

ところが発明者の検討によると、前記いずれの構成を採用しても、それらの構造から期待される程度の高い熱伝導性をヒートスプレッダに付与することはできなかった。
特開２００３−１７６３７号公報 再公表特許ＷＯ２００４／０３８０４９号 特開２００７−１２３５１６号公報 However, according to the inventor's study, even if any of the above-described configurations is adopted, it has not been possible to impart high heat conductivity to the heat spreader as expected from those structures.
JP 2003-17637 A Republished patent WO2004 / 038049 JP 2007-123516 A

本発明の目的は、略平板状に形成され、その面方向の熱膨張係数が素子やセラミック基板等の熱膨張係数と近い上、厚み方向の熱伝導率が現状よりもさらに高いヒートスプレッダと、その製造方法とを提供することにある。   An object of the present invention is a heat spreader that is formed in a substantially flat plate shape, whose thermal expansion coefficient in the surface direction is close to the thermal expansion coefficient of an element, a ceramic substrate, etc., and whose thermal conductivity in the thickness direction is even higher than the present state, and its It is to provide a manufacturing method.

銅は、不純物が少なく純銅に近いほど熱伝導率が高いことが知られている。しかし、特許文献１、３に記載のヒートスプレッダにおいては、いずれも銅等をその融点以上に加熱して溶融させた状態で、基材に設けた貫通孔に流し込んでいる。また特許文献２に記載のヒートスプレッダにおいては、タングステン等の粉末と共に焼成して多孔質の焼結体を形成する際の加熱によって銅等の塊を溶融させて銅プール相を形成している。また、先に説明したように銅等を溶融させた状態で、前記焼結体の細孔中に含浸させて銅相を形成している。   It is known that copper has a higher thermal conductivity as it has fewer impurities and is closer to pure copper. However, in each of the heat spreaders described in Patent Documents 1 and 3, the copper or the like is poured into a through-hole provided in the base material in a state in which copper or the like is heated to a melting point or higher. In the heat spreader described in Patent Literature 2, a copper pool phase is formed by melting a lump of copper or the like by heating when forming a porous sintered body by firing with a powder of tungsten or the like. Further, as described above, in a state where copper or the like is melted, the pores of the sintered body are impregnated to form a copper phase.

そのため、前記溶融時に銅の一部が酸化されて酸化銅を生成し、前記酸化銅が銅との共晶によって熱伝導率を低下させたり、溶融した銅中に、基材に含まれる低融点不純物が溶け込み、溶け込んだ低融点不純物が結晶粒界に析出することで熱伝導率を低下させたりするおそれがあり、前記いずれの構成でも、ヒートスプレッダの厚み方向に高い熱伝導率を付与できないことが判明した。そこで発明者は、低熱膨張材料からなる略平板状の基材の表面から裏面へ貫通させて、銅からなる複数の伝熱部材を設けた構造のヒートスプレッダにおいて、前記伝熱部材の熱伝導率を向上することを検討した。   Therefore, a part of copper is oxidized at the time of melting to produce copper oxide, and the copper oxide has a low melting point contained in the base material in the copper that is reduced in thermal conductivity by eutectic with copper or in the molten copper Impurities may be melted, and the melted low-melting point impurities may be precipitated at the grain boundaries, leading to a decrease in thermal conductivity. found. In view of this, in the heat spreader having a structure in which a plurality of heat transfer members made of copper are provided by penetrating from the front surface to the back surface of a substantially flat base material made of a low thermal expansion material, the inventor determines the heat conductivity of the heat transfer member. We examined improvement.

その結果、伝熱部材を構成する銅の含有酸素量を２０ｐｐｍ以下とすれば、前記酸素と、それ以外の不純物とを含む全ての不純物の含有不純物量を前記特許文献１ないし３等の従来の技術に比べて著しく少なくして熱伝導率が大きい状態を維持することができ、ヒートスプレッダの厚み方向に、前記伝熱部材を経由することで、従来の同様な構造からなるものよりも高く、かつ全体が銅等からなるものにより近い、高い熱伝導率を付与できることを見出した。したがって本発明は、低熱膨張材料からなり略平板状の基材と、前記基材の表面から裏面へ厚み方向に貫通させて設けられていると共に前記両面において露出された、銅からなる複数の伝熱部材とを含み、前記伝熱部材を構成する銅の含有酸素量が２０ｐｐｍ以下であることを特徴とするヒートスプレッダである。   As a result, if the amount of oxygen contained in the copper constituting the heat transfer member is 20 ppm or less, the amount of impurities contained in all impurities including the oxygen and other impurities can be reduced from the conventional ones such as Patent Documents 1 to 3. It can be remarkably reduced compared to the technology to maintain a high thermal conductivity state, by passing through the heat transfer member in the thickness direction of the heat spreader, higher than that of a conventional similar structure, and It has been found that high thermal conductivity can be imparted, which is closer to the whole made of copper or the like. Therefore, the present invention provides a substantially flat base material made of a low thermal expansion material, and a plurality of copper conductors that are provided through the front surface to the back surface of the base material in the thickness direction and exposed on both surfaces. A heat spreader comprising: a heat member, wherein the oxygen content of copper constituting the heat transfer member is 20 ppm or less.

なお本発明のヒートスプレッダにおいて、面方向の熱膨張係数を素子やセラミック基板等の熱膨張係数に近づけて、素子の動作による発熱と停止後の冷却とを繰り返した際に、熱膨張係数の違いに基づいて素子に過剰な応力が加わって前記素子自体が破損したり、はんだ接合が破壊されたりするのを防止する効果をできるだけ高めることを考慮すると、前記面方向の熱膨張係数は１６×１０-6／Ｋ以下であるのが好ましい。 In the heat spreader of the present invention, when the thermal expansion coefficient in the surface direction is brought close to the thermal expansion coefficient of the element or the ceramic substrate, and the heat generation due to the operation of the element and the cooling after the stop are repeated, the difference in the thermal expansion coefficient is caused. In consideration of increasing the effect of preventing the element itself from being damaged due to excessive stress being applied to the element or from destroying the solder joint, the thermal expansion coefficient in the plane direction is 16 × 10 −. It is preferably 6 / K or less.

また本発明のヒートスプレッダにおいて、面方向の熱膨張係数を素子やセラミック基板等の熱膨張係数に近づけながら、前記のように伝熱部材の良好な熱伝導率を活かして、素子からの熱をできるだけ速やかに、かつ効率よく、ヒートスプレッダを介して冷却器等に伝えて除去することを考慮すると、各伝熱部材は、基材の厚み方向と交差する面方向の断面積が、前記基材の表面から裏面まで同一とされていると共に、前記面方向における、複数の伝熱部材の断面積の合計の、ヒートスプレッダの全体での断面積中に占める割合が１％以上、５０％以下であるのが好ましい。   Further, in the heat spreader of the present invention, the thermal expansion coefficient in the plane direction is brought close to the thermal expansion coefficient of the element, the ceramic substrate, etc. Considering that the heat transfer member is quickly and efficiently transmitted to a cooler or the like via a heat spreader and removed, each heat transfer member has a cross-sectional area in the plane direction that intersects the thickness direction of the base material. The ratio of the total cross-sectional area of the plurality of heat transfer members in the surface direction to the entire cross-sectional area of the heat spreader is 1% or more and 50% or less. preferable.

本発明は、前記本発明のヒートスプレッダを製造する製造方法であって、
(a) 圧縮成形により柱状の圧縮成形体を得るための型内に、銅からなり伝熱部材のもとになる複数本の棒材を、それぞれの軸方向を柱の長さ方向と略平行に向けて配設すると共に、前記型内の各棒材間の隙間に、基材のもとになるタングステン、モリブデン、セラミック、およびダイヤモンドからなる群より選ばれた少なくとも一種の粉末、および銅と接合可能な金属または合金の粉末を含む低熱膨張材料を充填した後、銅の融点未満の温度で圧縮成形して、柱状で、かつ前記複数の棒材がそれぞれの軸方向を柱の長さ方向と略平行に向けて埋設された圧縮成形体を形成する工程と、
(b) 前記圧縮成形体を、銅の融点未満の温度で焼成して焼結体を形成する工程と、
(c) 前記焼結体を柱の長さ方向と交差方向に切断して略平板状のヒートスプレッダを製造する工程と
を含むことを特徴とするものである。 The present invention is a manufacturing method for manufacturing the heat spreader of the present invention,
(a) In a mold for obtaining a columnar compression molded body by compression molding, a plurality of rods made of copper and serving as a heat transfer member are arranged with their axial directions substantially parallel to the column length direction. And at least one powder selected from the group consisting of tungsten, molybdenum, ceramics, and diamond as a base material, and copper in the gaps between the bars in the mold After filling with a low thermal expansion material containing a metal or alloy powder that can be joined, it is compression-molded at a temperature below the melting point of copper, is columnar, and the plurality of rods have their respective axial directions in the length direction of the column. Forming a compression molded body embedded substantially parallel to the
(b) firing the compression molded body at a temperature lower than the melting point of copper to form a sintered body;
(c) cutting the sintered body in a direction intersecting with the length direction of the column to produce a substantially flat plate-shaped heat spreader.

本発明によれば、酸化や不純物の混入により熱伝導率が小さくなる原因となる、伝熱部材のもとになる銅を溶融させる工程を経ることなしに、略平板状の基材の表面から裏面へ貫通させて、銅からなる複数の伝熱部材を設けた構造のヒートスプレッダを製造することができる。そのため、前記伝熱部材のもとになる棒材として、例えば無酸素銅等からなるものを使用することで、伝熱部材を構成する銅の含有酸素量を２０ｐｐｍ以下として熱伝導率が大きい状態を維持することができ、伝熱部材を経由するヒートスプレッダの厚み方向の熱伝導率を向上することができる。   According to the present invention, from the surface of the substantially flat base material without passing through the step of melting copper that becomes the basis of the heat transfer member, which causes the thermal conductivity to be reduced due to oxidation or contamination of impurities. A heat spreader having a structure in which a plurality of heat transfer members made of copper are provided through the back surface can be manufactured. Therefore, as a bar material that becomes the basis of the heat transfer member, for example, by using a material made of oxygen-free copper or the like, a state in which the thermal conductivity is large with the oxygen content of copper constituting the heat transfer member being 20 ppm or less The heat conductivity in the thickness direction of the heat spreader that passes through the heat transfer member can be improved.

前記本発明の製造方法においては、前記焼結体を、切断に先立って銅の融点未満の温度で、塑性加工により柱の長さ方向と交差方向に圧縮変形させて塑性加工体を形成した後、前記塑性加工体を前記交差方向に切断して略平板状のヒートスプレッダを製造するのが好ましい。これにより、製造されるヒートスプレッダのうち基材の緻密性を向上させて、前記基材自体の熱伝導率を高めることができ、ヒートスプレッダの全体での厚み方向の熱伝導率をさらに向上することができる。   In the manufacturing method of the present invention, the sintered body is compressed and deformed in a direction crossing the length direction of the column by plastic working at a temperature lower than the melting point of copper prior to cutting to form a plastic processed body. It is preferable to manufacture the substantially flat plate-shaped heat spreader by cutting the plastic processed body in the intersecting direction. Thereby, it is possible to improve the denseness of the base material in the manufactured heat spreader, to increase the thermal conductivity of the base material itself, and to further improve the thermal conductivity in the thickness direction of the entire heat spreader. it can.

また、棒材からなる伝熱部材の、面方向の断面積および形成ピッチを小さくして、ヒートスプレッダの面方向に、前記伝熱部材による熱伝導が良好な領域をきめ細かく配置して、素子等から冷却器等への熱伝導の性能を向上することもできる。   Also, by reducing the cross-sectional area and the formation pitch in the surface direction of the heat transfer member made of a bar, finely arrange the region where the heat transfer by the heat transfer member is good in the surface direction of the heat spreader, The performance of heat conduction to the cooler or the like can also be improved.

本発明によれば、略平板状に形成され、その面方向の熱膨張係数が素子やセラミック基板等の熱膨張係数と近い上、厚み方向の熱伝導率が現状よりもさらに高いヒートスプレッダと、その製造方法とを提供することができる。   According to the present invention, a heat spreader that is formed in a substantially flat plate shape and has a thermal expansion coefficient close to that of an element, a ceramic substrate, etc., and has a higher thermal conductivity in the thickness direction than the present state, and A manufacturing method.

図１は、本発明のヒートスプレッダの、実施の形態の一例を示す斜視図である。図２は、前記例のヒートスプレッダの内部構造を示す拡大断面図である。両図を参照して、この例のヒートスプレッダ１は、矩形平板状の基材２と、前記基材２の表面３から裏面４へ厚み方向に貫通させて設けられていると共に前記両面３、４において露出された、銅からなる複数の伝熱部材５とを含んでいる。   FIG. 1 is a perspective view showing an example of an embodiment of a heat spreader of the present invention. FIG. 2 is an enlarged cross-sectional view showing the internal structure of the heat spreader of the above example. With reference to both drawings, the heat spreader 1 of this example is provided with a rectangular flat plate-like base material 2 and a surface 3 through a back surface 4 of the base material 2 that penetrates in the thickness direction and the both surfaces 3, 4 And a plurality of heat transfer members 5 made of copper and exposed at.

前記伝熱部材５を構成する銅の含有酸素量は２０ｐｐｍ以下である必要がある。これにより、先に説明したように伝熱部材５を構成する銅における酸素と、それ以外の不純物とを含む全ての不純物の含有不純物量を著しく少なくして熱伝導率が大きい状態を維持することができ、ヒートスプレッダ１の厚み方向に、前記伝熱部材５を経由することで、従来の同様な構造からなるものよりも高く、かつ全体が銅等からなるものにより近い、高い熱伝導率を付与することができる。   The amount of oxygen contained in the copper constituting the heat transfer member 5 needs to be 20 ppm or less. As a result, as described above, the amount of impurities contained in all impurities including oxygen and other impurities in the copper constituting the heat transfer member 5 is significantly reduced, and the state of high thermal conductivity is maintained. By passing through the heat transfer member 5 in the thickness direction of the heat spreader 1, a higher thermal conductivity is provided, which is higher than that of the conventional structure and closer to that of the whole made of copper or the like. can do.

なお伝熱部材５を構成する銅の含有酸素量を、本発明では、例えば金属用の酸素・窒素同時分析装置（ＬＥＣＯ社製のＴＣ−４３６ＡＲ）等を用いた赤外線吸収法によって求めた値でもって規定することとする。この方法では、例えばヘリウムガス等の雰囲気中で試料を溶融したときに発生するガス中の酸素量を、赤外線吸収法によって測定することができる。   In the present invention, the oxygen content of copper constituting the heat transfer member 5 is a value determined by an infrared absorption method using, for example, a metal oxygen / nitrogen simultaneous analyzer (TC-436AR manufactured by LECO). It shall be specified. In this method, for example, the amount of oxygen in a gas generated when a sample is melted in an atmosphere such as helium gas can be measured by an infrared absorption method.

先に説明したように伝熱部材５を構成する銅は、不純物が少なく純銅に近いほど熱伝導率が高くなる傾向を示すため、その含有酸素量は前記範囲内でも小さいほど好ましい。しかし、前記伝熱部材５のもとになる銅材の工業的な生産工程や生産性等を考慮すると、含有酸素量は３ｐｐｍ以上であるのが好ましい。
また、これらの事情を併せ考慮すると、伝熱部材５を構成する銅の含有酸素量は、前記範囲内でも１０ｐｐｍ以下、特に４ｐｐｍ以上、９ｐｐｍ以下であるのが好ましい。また、前記のように熱伝導率が大きい状態を維持することを考慮すると、前記酸素と、それ以外の不純物とを含む全ての不純物の含有不純物量も小さいほど好ましく、４００ｐｐｍ以下、特に２００ｐｐｍ以下であるのが好ましい。含有不純物量は、例えばグロー放電質量分析装置（ＧＤ−ＭＳ）等を用いて測定することができる。 As described above, the copper constituting the heat transfer member 5 tends to have a higher thermal conductivity as it has less impurities and is closer to pure copper. Therefore, the oxygen content is preferably as small as possible within the above range. However, considering the industrial production process and productivity of the copper material that is the basis of the heat transfer member 5, the oxygen content is preferably 3 ppm or more.
Considering these circumstances together, it is preferable that the oxygen content of copper constituting the heat transfer member 5 is 10 ppm or less, particularly 4 ppm or more and 9 ppm or less even within the above range. In consideration of maintaining a state of high thermal conductivity as described above, the amount of impurities contained in all impurities including oxygen and other impurities is preferably as small as possible, and is preferably 400 ppm or less, particularly 200 ppm or less. Preferably there is. The amount of impurities contained can be measured using, for example, a glow discharge mass spectrometer (GD-MS).

伝熱部材５を構成する銅の含有酸素量および含有不純物量は、例えば後述する本発明の製造方法のように、酸化や不純物の混入が発生する主な原因となる銅を溶融させる工程を経ることなしにヒートスプレッダ１を製造することと、その際に、伝熱部材５のもとになる材料として、例えば無酸素銅等からなるものを使用することにより、前記範囲内に調整できる。詳細は後述する。   The amount of oxygen contained and the amount of impurities contained in the copper constituting the heat transfer member 5 are subjected to a step of melting copper, which is the main cause of oxidation and contamination of impurities, as in the production method of the present invention described later, for example. By manufacturing the heat spreader 1 without any problems and using a material made of oxygen-free copper or the like as a material for the heat transfer member 5 at that time, the heat spreader 1 can be adjusted within the above range. Details will be described later.

図の例では、個々の伝熱部材５は、基材２の厚み方向と交差する面方向の断面形状が、前記基材２の表面３から裏面４まで同一直径の円形である円柱状に形成されている。伝熱部材５を円柱状とした場合には、前記伝熱部材５と基材２との界面に角部が形成されないため、素子の動作による発熱と停止後の冷却とを繰り返した際に、前記基材２が、膨張収縮による前記角部への応力集中によって破損するのを防止できる。   In the example of the figure, each heat transfer member 5 is formed in a columnar shape in which the cross-sectional shape in the plane direction intersecting the thickness direction of the base material 2 is a circle having the same diameter from the front surface 3 to the back surface 4 of the base material 2. Has been. When the heat transfer member 5 has a cylindrical shape, corners are not formed at the interface between the heat transfer member 5 and the base material 2, so when repeating heat generation due to the operation of the element and cooling after stopping, It can prevent that the said base material 2 is damaged by the stress concentration to the said corner | angular part by expansion / contraction.

また前記円柱状のように、伝熱部材５の断面積を、基材２の表面３から裏面４まで同一とした場合には、例えば途中に断面積の小さい部分を有する伝熱部材５に比べて、素子からの熱をできるだけ速やかに、かつ効率よく、ヒートスプレッダ１を介して冷却器等に伝えて除去することができる。また、途中に断面積の大きい部分を有する伝熱部材５では、隣り合う伝熱部材５間に局部的に基材２の薄い部分が生じて、前記発熱と冷却とを繰り返した際に、基材２が、前記部分への応力集中によって破損するおそれがあるのに対し、伝熱部材５の断面積を同一とした場合には、かかる破損の発生を抑制することもできる。   Moreover, when the cross-sectional area of the heat transfer member 5 is the same from the front surface 3 to the back surface 4 of the base material 2 as in the columnar shape, for example, compared to the heat transfer member 5 having a small cross-sectional area in the middle. Thus, the heat from the element can be transferred to the cooler or the like via the heat spreader 1 and removed as quickly and efficiently as possible. Further, in the heat transfer member 5 having a portion with a large cross-sectional area in the middle, a thin portion of the base material 2 is locally generated between the adjacent heat transfer members 5, and when the heat generation and cooling are repeated, While the material 2 may be damaged due to stress concentration on the portion, when the heat transfer member 5 has the same cross-sectional area, the occurrence of such damage can be suppressed.

伝熱部材５の、基材２の厚み方向と交差する面方向の断面積を、前記基材２の表面３から裏面４まで同一とした場合に、前記面方向における、複数の伝熱部材５の断面積の合計の、ヒートスプレッダ１の全体での断面積中に占める割合ＲSは１％以上、５０％以下であるのが好ましい。前記割合ＲSが１％未満では、たとえ伝熱部材５を構成する銅の含有酸素量が小さく熱伝導率が大きくても、素子からの熱をできるだけ速やかに、かつ効率よく、ヒートスプレッダを介して冷却器等に伝えて除去できないおそれがある。 When the cross-sectional area of the heat transfer member 5 in the plane direction intersecting the thickness direction of the base material 2 is the same from the front surface 3 to the back surface 4 of the base material 2, the plurality of heat transfer members 5 in the surface direction. The ratio R S of the total cross-sectional area in the total cross-sectional area of the heat spreader 1 is preferably 1% or more and 50% or less. When the ratio R S is less than 1%, even if the amount of oxygen contained in the copper constituting the heat transfer member 5 is small and the thermal conductivity is large, the heat from the element is transmitted as quickly and efficiently as possible through the heat spreader. There is a risk that it cannot be removed by transmitting to a cooler.

また前記割合ＲSが５０％を超える場合には、相対的に基材２の割合が小さくなるため、前記基材２による、ヒートスプレッダ１の面方向の熱膨張係数を素子やセラミック基板等の熱膨張係数に近づける効果が得られず、素子の動作による発熱と停止後の冷却とを繰り返した際に、熱膨張係数の違いに基づいて素子に過剰な応力が加わって前記素子自体が破損したり、はんだ接合が破壊されたりするおそれがある。また前記発熱と冷却とを繰り返した際に、熱膨張係数の小さい基材２が割れたりするおそれもある。 Further, when the ratio R S exceeds 50%, the ratio of the base material 2 becomes relatively small. Therefore, the thermal expansion coefficient of the heat spreader 1 in the surface direction by the base material 2 is determined by the heat of an element or a ceramic substrate. The effect of approaching the expansion coefficient cannot be obtained, and when the heat generation due to the operation of the element and the cooling after the stop are repeated, the element itself is damaged due to excessive stress applied to the element based on the difference in the thermal expansion coefficient. The solder joint may be destroyed. Further, when the heat generation and the cooling are repeated, the base material 2 having a small thermal expansion coefficient may be broken.

なお、これらの事情を併せ考慮すると、前記割合ＲSは、前記範囲内でも２０％以上、３０％以下であるのがさらに好ましい。前記割合ＲSは、伝熱部材５の数および個々の伝熱部材５の断面積を適宜変更することにより、前記範囲内に調整できる。
また図の例では、複数の伝熱部材５が、基材２の矩形の一辺に平行な複数の列（図では７列）に配列されていると共に、各列内で、それぞれの伝熱部材５が等ピッチに配列されている。また各列は、それぞれ列内の伝熱部材５のピッチの半ピッチ分の間隔で等間隔に配列されていると共に、隣り合う列の伝熱部材５は互いに半ピッチ分ずつずらして配列されている。 In consideration of these circumstances, the ratio R S is more preferably 20% or more and 30% or less even within the above range. The ratio R S can be adjusted within the above range by appropriately changing the number of heat transfer members 5 and the cross-sectional area of each heat transfer member 5.
Further, in the example of the figure, the plurality of heat transfer members 5 are arranged in a plurality of rows (seven rows in the figure) parallel to one side of the rectangle of the base material 2, and each heat transfer member is in each row. 5 are arranged at an equal pitch. In addition, each row is arranged at equal intervals by a half pitch of the pitch of the heat transfer members 5 in the row, and the heat transfer members 5 in adjacent rows are arranged shifted by a half pitch from each other. Yes.

複数の伝熱部材５を上記のように配列すれば、前記伝熱部材５を基材２の表面３および裏面４において等間隔で、かつ均一に露出させて、素子等から冷却器等への熱伝導に、面方向において偏りが生じるのを防止できる。また、素子の動作による発熱と停止後の冷却とを繰り返した際に、前記面方向での膨張収縮に偏りが生じるのを防止して、基材２が、前記膨張収縮による応力集中によって破損するのを防止することもできる。   If the plurality of heat transfer members 5 are arranged as described above, the heat transfer members 5 are exposed at equal intervals and uniformly on the front surface 3 and the back surface 4 of the base member 2, so that the elements and the like are transferred to the cooler and the like. It is possible to prevent the heat conduction from being biased in the surface direction. Further, when the heat generation due to the operation of the element and the cooling after the stop are repeated, the expansion and contraction in the surface direction is prevented from being biased, and the base material 2 is damaged by the stress concentration due to the expansion and contraction. Can also be prevented.

前記伝熱部材５を含むヒートスプレッダ１の、面方向の熱膨張係数は１６×１０-6／Ｋ以下であるのが好ましい。これにより、先に説明したようにヒートスプレッダ１の、面方向の熱膨張係数を素子やセラミック基板等の熱膨張係数に近づけて、素子の動作による発熱と停止後の冷却とを繰り返した際に、熱膨張係数の違いに基づいて素子に過剰な応力が加わって前記素子自体が破損したり、はんだ接合が破壊されたりするのを防止する効果を高めることができる。 The heat spreader 1 including the heat transfer member 5 preferably has a thermal expansion coefficient in the surface direction of 16 × 10 −6 / K or less. Thereby, as described above, when the thermal expansion coefficient in the surface direction of the heat spreader 1 is brought close to the thermal expansion coefficient of the element, the ceramic substrate, etc., when the heat generated by the operation of the element and the cooling after the stop are repeated, Based on the difference in thermal expansion coefficient, it is possible to enhance the effect of preventing the element itself from being damaged or the solder joint from being destroyed due to excessive stress applied to the element.

なお熱膨張係数は、前記効果をさらに向上することを考慮すると、前記範囲内でも１４×１０-6／Ｋ以下、特に１２×１０-6／Ｋ以下であるのが好ましい。また熱膨張係数の下限は特に限定されないが、例えば先に説明したタングステン等の粉末と、銅等の粉末とを含む低熱膨張材料の焼成によって基材２を形成する場合は、その材料上の制約および製法上の制約等から、熱膨張係数は８．０×１０-6／Ｋ以上であるのが好ましい。 The thermal expansion coefficient is preferably 14 × 10 −6 / K or less, more preferably 12 × 10 −6 / K or less even within the above range, in consideration of further improving the effect. Further, the lower limit of the thermal expansion coefficient is not particularly limited. For example, when the base material 2 is formed by firing the low thermal expansion material including the powder such as tungsten described above and the powder such as copper, restrictions on the material are included. In view of restrictions on the production method and the like, the thermal expansion coefficient is preferably 8.0 × 10 −6 / K or more.

基材２がその他の低熱膨張材料からなる場合は、それぞれの材料に応じた熱膨張係数の好ましい下限値が設定される。前記熱膨張係数は、ヒートスプレッダ１のうち基材２を構成する低熱膨張材料の種類や組成、あるいは基材２を形成する際の焼成条件等を調整したり、ヒートスプレッダ１における、前記基材２と伝熱部材５との体積比率を調整したりすることにより、前記範囲内に調整できる。   When the base material 2 consists of another low thermal expansion material, the preferable lower limit of the thermal expansion coefficient according to each material is set. The thermal expansion coefficient can be adjusted by adjusting the type and composition of the low thermal expansion material constituting the base material 2 of the heat spreader 1, the firing conditions when forming the base material 2, and the base material 2 in the heat spreader 1. By adjusting the volume ratio with the heat transfer member 5, it can be adjusted within the above range.

ヒートスプレッダ１の、厚み方向の熱伝導率を、本発明では、先に説明したように伝熱部材５を構成する銅の含有酸素量を調整することにより、従来に比べて高くすることができる。しかし熱伝導率は、面方向の熱膨張係数と二律背反の関係にあり、その好適な範囲を一律に規定することはできない。熱膨張係数との兼ね合いで、前記好適な範囲を規定するのがよい。   In the present invention, the heat conductivity of the heat spreader 1 in the thickness direction can be increased as compared with the prior art by adjusting the amount of oxygen contained in the copper constituting the heat transfer member 5 as described above. However, the thermal conductivity has a trade-off relationship with the thermal expansion coefficient in the plane direction, and the preferred range cannot be defined uniformly. The preferable range should be defined in consideration of the thermal expansion coefficient.

例えばヒートスプレッダ１の、面方向の熱膨張係数が１０×１０-6／Ｋ以上、１１×１０-6／Ｋ以下である場合に、厚み方向の熱伝導率は２４０Ｗ／ｍ・Ｋ以上であるのが好ましい。また前記熱膨張係数が８×１０-6／Ｋ以上、９×１０-6／Ｋ以下である場合には、前記熱伝導率は１８０Ｗ／ｍ・Ｋ以上であるのが好ましい。また熱伝導率の上限は特に限定されないものの、その材料上の制約等から３５０Ｗ／ｍ・Ｋ以下であるのが好ましい。 For example, when the thermal expansion coefficient in the surface direction of the heat spreader 1 is 10 × 10 −6 / K or more and 11 × 10 −6 / K or less, the thermal conductivity in the thickness direction is 240 W / m · K or more. Is preferred. When the thermal expansion coefficient is 8 × 10 −6 / K or more and 9 × 10 −6 / K or less, the thermal conductivity is preferably 180 W / m · K or more. The upper limit of the thermal conductivity is not particularly limited, but is preferably 350 W / m · K or less because of restrictions on the material.

基材２としては、例えば
(1) タングステン、モリブデン、セラミック、およびダイヤモンドからなる群より選ばれた少なくとも一種の粉末と、銅と接合可能な金属または合金の粉末とを含む低熱膨張材料を圧縮成形したのち、例えば非酸化性雰囲気中で、前記金属または合金の融点未満の温度で焼成したもの、または前記焼結体を、さらに金属または合金の融点未満の温度に加熱しながら圧縮成形して複合構造の緻密化を図ったもの、
(2) あらかじめ形成された、タングステン、モリブデン、およびセラミックからなる群より選ばれた少なくとも一種からなる多孔質体（スケルトン）の細孔中に、例えば真空炉中で、溶融させた金属または合金を含浸させたもの、および
(3) タングステンまたはモリブデンの板材
からなる群より選ばれた少なくとも１種が挙げられる。 As the substrate 2, for example,
(1) After compression molding a low thermal expansion material containing at least one powder selected from the group consisting of tungsten, molybdenum, ceramic, and diamond, and a metal or alloy powder that can be bonded to copper, for example, non-oxidizing property The composite structure was densified by compression molding while heating at a temperature lower than the melting point of the metal or alloy in the atmosphere, or by heating the sintered body to a temperature lower than the melting point of the metal or alloy. thing,
(2) A molten metal or alloy is formed in the pores of a porous body (skeleton) made of at least one selected from the group consisting of tungsten, molybdenum, and ceramic, for example, in a vacuum furnace. Impregnated, and
(3) At least one selected from the group consisting of tungsten or molybdenum plates.

このうち(1)(2)において用いる金属または合金としては、伝熱部材５のもとになる銅と接合可能な種々の金属や合金がいずれも使用可能であるが、特に銅の融点〔＝１３５７．６Ｋ（１０８４．４℃）〕未満の温度で良好に接合させることを考慮すると銅または銅合金が好ましい。また(1)において使用する銅または銅合金の粉末としては、例えばアトマイズ法等によって作製された純銅粉末や、日本工業規格ＪＩＳ Ｈ３１００：２００６「銅及び銅合金の板並びに条」において規定されたＣ１０２０「無酸素銅」、Ｃ１１００「タフピッチ銅」等の粉末等が挙げられる。前記銅または銅合金の粉末は、前記工程を経て形成される基材２中に、タングステン等の粉末をできるだけ細かくかつ均等に分布させて、その分布に偏りがない基材２を得ることを考慮すると、平均粒径が３０μｍないし６０μｍであるのが好ましい。   Among these, as the metal or alloy used in (1) and (2), any of various metals and alloys that can be bonded to copper as the heat transfer member 5 can be used. In view of good bonding at a temperature of less than 1357.6K (1084.4 ° C.)], copper or a copper alloy is preferable. In addition, as the powder of copper or copper alloy used in (1), for example, pure copper powder produced by an atomizing method or the like, or C1020 defined in Japanese Industrial Standard JIS H3100: 2006 “Plate and Strip of Copper and Copper Alloy” Examples thereof include powders such as “oxygen-free copper” and C1100 “tough pitch copper”. Considering that the copper or copper alloy powder distributes the powder of tungsten or the like as finely and uniformly as possible in the base material 2 formed through the above-mentioned process, and obtains the base material 2 without uneven distribution. Then, it is preferable that an average particle diameter is 30 micrometers-60 micrometers.

タングステンの粉末としては、前記タングステンまたはその合金からなる粉末が挙げられる。タングステンの粉末は、前記平均粒径を有する銅または銅合金の粉末と混合し、前記工程を経て形成される基材２中に、できるだけ細かくかつ均等に分布させて、その分布に偏りがない基材２を得ることを考慮すると、平均粒径が４μｍないし１０μｍであるのが好ましい。   Examples of the tungsten powder include the powder made of tungsten or an alloy thereof. The tungsten powder is mixed with the copper or copper alloy powder having the average particle diameter, and is distributed as finely and evenly as possible in the base material 2 formed through the above-described process, so that the distribution is not biased. In consideration of obtaining the material 2, the average particle diameter is preferably 4 μm to 10 μm.

またモリブデンの粉末としては、前記モリブデンまたはその合金からなる粉末が挙げられる。モリブデンの粉末は、前記平均粒径を有する銅または銅合金の粉末と混合し、前記工程を経て形成される基材２中に、できるだけ細かくかつ均等に分布させて、その分布に偏りがない基材２を得ることを考慮すると、平均粒径が２μｍないし６μｍであるのが好ましい。   Examples of the molybdenum powder include powder made of the molybdenum or an alloy thereof. Molybdenum powder is mixed with copper or copper alloy powder having the above average particle diameter, and is distributed as finely and uniformly as possible in the base material 2 formed through the above-mentioned process. In consideration of obtaining the material 2, the average particle diameter is preferably 2 μm to 6 μm.

セラミックの粉末としては、例えば炭化ケイ素（ＳｉＣ）、窒化ケイ素（Ｓｉ3Ｎ4）、酸化アルミニウム（Ａｌ2Ｏ3）等からなる粉末が挙げられる。セラミックの粉末は、前記平均粒径を有する銅または銅合金の粉末と混合し、前記工程を経て形成される基材２中に、できるだけ細かくかつ均等に分布させて、その分布に偏りがない基材２を得ることを考慮すると、平均粒径が３０μｍないし６０μｍであるのが好ましい。 Examples of the ceramic powder include powder made of silicon carbide (SiC), silicon nitride (Si 3 N 4 ), aluminum oxide (Al 2 O 3 ), and the like. The ceramic powder is mixed with the copper or copper alloy powder having the above average particle diameter, and is distributed as finely and uniformly as possible in the base material 2 formed through the above-mentioned process, so that the distribution is not biased. In consideration of obtaining the material 2, the average particle size is preferably 30 μm to 60 μm.

ダイヤモンドの粉末としては、例えば工業用ダイヤモンドの粉末が挙げられる。ダイヤモンドの粉末は、前記平均粒径を有する銅または銅合金の粉末と混合し、前記工程を経て形成される基材２中に、できるだけ細かくかつ均等に分布させて、その分布に偏りがない基材２を得ることを考慮すると、平均粒径が１０μｍないし５０μｍであるのが好ましい。粉末材料がダイヤモンドである場合の基材２の形成方法は、例えば特開２００４−１７５６２６号公報に詳しい。   Examples of the diamond powder include industrial diamond powder. The diamond powder is mixed with the copper or copper alloy powder having the above average particle diameter, and is distributed as finely and uniformly as possible in the base material 2 formed through the above-mentioned process, and the distribution is not biased. In consideration of obtaining the material 2, the average particle size is preferably 10 μm to 50 μm. A method of forming the base material 2 when the powder material is diamond is detailed in, for example, Japanese Patent Application Laid-Open No. 2004-175626.

前記タングステン等の粉末と、銅または銅合金の粉末との配合割合は特に限定されない。ただし、前記低熱膨張材料からなる基材２の熱膨張係数は、タングステン等の割合を増減させることで調整可能であるため、ヒートスプレッダ１の、面方向の熱膨張係数が、先に説明した範囲内の任意の値となるように、あるいは後述する本発明の製造方法では、そのうち特に塑性加工の工程での加工性を向上するために、両者の配合割合を調整すればよい。   The blending ratio of the powder of tungsten or the like and the copper or copper alloy powder is not particularly limited. However, since the thermal expansion coefficient of the base material 2 made of the low thermal expansion material can be adjusted by increasing or decreasing the ratio of tungsten or the like, the thermal expansion coefficient in the surface direction of the heat spreader 1 is within the range described above. In the production method of the present invention to be described later, in order to improve the workability particularly in the plastic working process, the blending ratio of both may be adjusted.

例えばタングステンの粉末と、銅または銅合金の粉末との配合割合は、銅または銅合金の質量％で表して２５質量％ないし６０質量％であるのが好ましい。またモリブデンの粉末と、銅または銅合金の粉末との配合割合も、同様に銅または銅合金の質量％で表して２５質量％ないし６０質量％であるのが好ましい。このいずれの組み合わせにおいても、銅または銅合金が２５質量％未満では塑性加工時の加工性が低下するおそれがあり、６０質量％を超える場合には、ヒートスプレッダ１の、面方向の熱膨張係数が前記好適な範囲を超えるおそれがある。   For example, the blending ratio of tungsten powder and copper or copper alloy powder is preferably 25% by mass to 60% by mass in terms of mass% of copper or copper alloy. Similarly, the blending ratio of the molybdenum powder and the copper or copper alloy powder is preferably 25% by mass to 60% by mass in terms of the mass% of the copper or copper alloy. In any of these combinations, if the copper or copper alloy is less than 25% by mass, the workability at the time of plastic working may be reduced, and if it exceeds 60% by mass, the thermal expansion coefficient in the surface direction of the heat spreader 1 is low. There is a risk of exceeding the preferred range.

また(2)において使用する多孔質体は、例えばタングステン等の粉末を樹脂等のバインダと混合した混合物を所定の形状に成形したのち、焼成してバインダを除去すると共にタングステン等の粉末を焼結させる等して形成される。粉末材料がタングステンまたはモリブデンである多孔質体、ならびに前記多孔質体を用いた基材の形成方法は、例えば特開昭５９−２１０３２号公報に詳しい。また(3)のタングステンまたはモリブデンの板材としては、それぞれ基材２の形状に形成した板材が用いられる。   The porous body used in (2) is, for example, formed into a predetermined shape by mixing a mixture of a powder such as tungsten with a binder such as a resin, and then fired to remove the binder and sinter the powder such as tungsten. Formed. A porous body in which the powder material is tungsten or molybdenum, and a method for forming a base material using the porous body are detailed in, for example, Japanese Patent Application Laid-Open No. 59-21032. Further, as the tungsten or molybdenum plate material of (3), a plate material formed in the shape of the substrate 2 is used.

伝熱部材５は、例えば銅の棒材によって形成される。前記銅の棒材としては、伝熱部材５を構成する銅の含有酸素量、および含有不純物量を前記範囲内とするために、例えば日本工業規格ＪＩＳ Ｈ３１００：２００６「銅及び銅合金の板並びに条」において規定されたＣ１０２０「無酸素銅」（銅純度９９．９６質量％、含有酸素量１０ｐｐｍ以下）等の棒材が挙げられる。前記棒材のサイズは、製造するヒートスプレッダ１に求められる、先に説明した、複数の伝熱部材５の断面積の合計の割合ＲS、面方向の熱膨張係数、厚み方向の熱伝導率、あるいはヒートスプレッダ１の製造方法（圧縮変形の工程が入る場合は圧縮率を考慮する必要がある）等に応じて任意に設定できる。 The heat transfer member 5 is formed of, for example, a copper bar. As the copper bar, in order to keep the amount of oxygen contained in the heat transfer member 5 and the amount of impurities contained within the above range, for example, Japanese Industrial Standard JIS H3100: 2006 “copper and copper alloy plate and Bars such as C1020 “oxygen-free copper” (copper purity 99.96% by mass, oxygen content of 10 ppm or less) defined in “Article”. The size of the bar is determined by the heat spreader 1 to be manufactured, the ratio R S of the cross-sectional areas of the plurality of heat transfer members 5 described above, the thermal expansion coefficient in the plane direction, the thermal conductivity in the thickness direction, Or it can set arbitrarily according to the manufacturing method (it is necessary to consider a compression rate when the process of compression deformation enters) etc. of the heat spreader 1, etc.

本発明のヒートスプレッダ１のうち、基材２が(1)の焼結体からなるものは、先に説明した本発明の製造方法によって製造することができる。図３ないし図７は、前記本発明の製造方法によってヒートスプレッダ１を製造する工程を説明する図である。
図３を参照して、この例の製造方法では、まず圧縮成形により柱状の圧縮成形体を得るための型を用意する。すなわち圧縮成形用の型窩６を構成する上型（上杵）７、下型（下杵）８、およびダイ（臼）９と、これらで構成される型窩６内の柱の両端に対応する位置に設置されて、銅からなり伝熱部材５のもとになる複数本の棒材１０を、それぞれの軸方向を柱の長さ方向と略平行に向けて保持するための一対の治具１１と、前記型窩６内に治具１１によって保持した棒材１０の周囲を囲むように設置されて、前記治具１１と共に、柱状の圧縮成形体に対応する成形空間１２を構成する治具１３とを用意する。前記治具１１、１３は、それぞれウレタン等で形成される。 Among the heat spreaders 1 of the present invention, the substrate 2 made of the sintered body (1) can be manufactured by the manufacturing method of the present invention described above. 3 to 7 are views for explaining a process of manufacturing the heat spreader 1 by the manufacturing method of the present invention.
With reference to FIG. 3, in the manufacturing method of this example, first, a mold for obtaining a columnar compression-molded body by compression molding is prepared. That is, it corresponds to the upper mold (upper collar) 7, the lower mold (lower collar) 8, and the die (mortar) 9 constituting the mold cavity 6 for compression molding and both ends of the pillar in the mold cavity 6 composed of these. A pair of jigs for holding a plurality of rods 10 made of copper and serving as the base of the heat transfer member 5 with their respective axial directions substantially parallel to the length direction of the columns. A jig 11 is installed in the mold cavity 6 so as to surround the periphery of the bar 10 held by the jig 11, and together with the jig 11, a jig forming a molding space 12 corresponding to a columnar compression molded body. A tool 13 is prepared. The jigs 11 and 13 are each formed of urethane or the like.

前記一対の治具１１間に複数本の棒材１０を保持すると共に、前記成形空間１２内の、各棒材１０間の隙間に、基材２のもとになるタングステン、モリブデン、セラミック、およびダイヤモンドからなる群より選ばれた少なくとも一種の粉末、および銅と接合可能な金属または合金の粉末を含む低熱膨張材料１４を充填する。
次いで上型７を、図中に実線の矢印で示すように型窩６に挿入して下型８の方向に押し込むと、その際の圧力によって治具１１、１３が変形して、成形空間１２内の棒材１０と、低熱膨張材料１４とを、図の上下方向だけでなく左右方向、前後方向からも加圧するいわゆる等方圧成形が行なわれ、それによって図４に示すように柱状で、かつ前記複数の棒材１０がそれぞれの軸方向を柱の長さ方向と略平行に向けて埋設された圧縮成形体１５が形成される。 A plurality of rods 10 are held between the pair of jigs 11, and tungsten, molybdenum, ceramic, and the base material 2 are formed in the gaps between the rods 10 in the molding space 12. A low thermal expansion material 14 containing at least one powder selected from the group consisting of diamond and metal or alloy powder that can be bonded to copper is filled.
Next, when the upper mold 7 is inserted into the mold cavity 6 and pushed in the direction of the lower mold 8 as shown by solid arrows in the drawing, the jigs 11 and 13 are deformed by the pressure at that time, and the molding space 12 is deformed. So-called isotropic pressure molding is performed in which the inner rod 10 and the low thermal expansion material 14 are pressurized not only in the vertical direction but also in the horizontal direction and the front-rear direction, thereby forming a columnar shape as shown in FIG. In addition, a compression molded body 15 is formed in which the plurality of rods 10 are embedded with their respective axial directions substantially parallel to the column length direction.

圧縮成形は、伝熱部材５のもとになる棒材１０が溶融して酸化されたり不純物が混入したりするのを防止するために、前記棒材１０を形成する銅の融点未満の温度で行なう。ここでいう銅の融点未満の温度で圧縮成形するとは、前記圧縮成形のための型を積極的に銅の融点以上に加熱せずに、室温（５℃ないし３５℃）付近で圧縮成形することを指す。圧縮成形時には、型の内部圧力の上昇に伴って内部温度が局部的に上昇することがあるが、前記室温付近で圧縮成形をする場合には、型内において、特に棒材１０を形成する銅が溶融するような高温への温度上昇が広範囲にわたって発生するおそれはない。   The compression molding is performed at a temperature lower than the melting point of the copper forming the bar 10 in order to prevent the bar 10 serving as the heat transfer member 5 from being melted and oxidized or mixed with impurities. Do. Here, compression molding at a temperature lower than the melting point of copper means compression molding near room temperature (5 ° C. to 35 ° C.) without actively heating the mold for compression molding above the melting point of copper. Point to. During compression molding, the internal temperature may rise locally as the internal pressure of the mold rises. However, when compression molding is performed near the room temperature, the copper that forms the bar 10 in the mold is particularly good. There is no fear that the temperature rise to a high temperature that melts will occur over a wide range.

圧縮成形時の圧力は２９４ＭＰａ以上、５８８ＭＰａ以下に設定するのが好ましい。圧縮成形時の圧力が２９４ＭＰａ未満では、圧縮成形体１５の強度が不足して、特に焼成のために型から取り出す際や取り出した後の焼成工程等において型崩れしやすくなるおそれがある。また、圧縮成形時の圧力が５８８ＭＰａを超えても、圧縮成形体１５の強度をそれ以上に高める効果は得られない上、前記高圧の圧縮成形を行うための装置が大掛かりになりすぎるという問題もある。   The pressure at the time of compression molding is preferably set to 294 MPa or more and 588 MPa or less. If the pressure at the time of compression molding is less than 294 MPa, the strength of the compression molded body 15 is insufficient, and there is a risk that the mold will be easily lost particularly when it is taken out of the mold for firing or in the firing step after removal. In addition, even if the pressure at the time of compression molding exceeds 588 MPa, the effect of further increasing the strength of the compression molded body 15 cannot be obtained, and there is a problem that the apparatus for performing the high pressure compression molding becomes too large. is there.

次に、前記圧縮成形体１５を、例えば非酸化性雰囲気中で、銅の融点未満の温度で焼成すると、低熱膨張材料１４を構成する金属または合金の粉末とタングステン等の粉末とが焼結されると共に、銅からなる棒材１０が、溶融することなく前記金属または合金と接合されて、焼結体１６が形成される。焼成は、図示していないが圧縮成形体１５を型から取り出した状態で、あるいは取り出した圧縮成形体１５を、型崩れを防止するための簡単な（熱容量の小さい）型枠に嵌め込む等した状態で行なうようにするのが好ましい。これにより、焼成に要するエネルギーと時間とを削減して生産性を向上できる。   Next, when the compression molded body 15 is fired, for example, in a non-oxidizing atmosphere at a temperature lower than the melting point of copper, the metal or alloy powder constituting the low thermal expansion material 14 and the powder such as tungsten are sintered. At the same time, the bar 10 made of copper is joined to the metal or alloy without melting to form the sintered body 16. Although firing is not illustrated, the compression molded body 15 is taken out from the mold, or the removed compression molded body 15 is fitted into a simple (small heat capacity) mold frame to prevent the collapse of the mold. It is preferable to carry out in the state. Thereby, the energy and time required for firing can be reduced and the productivity can be improved.

焼成の温度は、先に説明したように銅の融点未満であればよいが、特に９００℃以上、１０８０℃以下であるのが好ましい。また焼成の時間は０．５時間以上、２時間以下であるのが好ましい。
焼成の温度が１０８０℃を超えるか、または焼成の時間が２時間を超える場合には、たとえ棒材１０を形成する銅が溶融しなくても、酸素やその他の不純物が銅中に過剰に熱拡散して、前記銅の含有酸素量、含有不純物量が先に説明した範囲を超えてしまい、目的とする、前記銅からなる伝熱部材５による、ヒートスプレッダ１の厚み方向の熱伝導率を向上する効果が得られないおそれがある。また、焼成の温度が９００℃未満であるか、または焼成の時間が０．５時間未満である場合には十分な強度を有する焼結体１６が得られず、次工程で前記焼結体１６を塑性加工する際に、割れ等が生じやすくなるおそれがある。 As described above, the firing temperature may be lower than the melting point of copper, but is preferably 900 ° C. or higher and 1080 ° C. or lower. The firing time is preferably 0.5 hours or more and 2 hours or less.
When the firing temperature exceeds 1080 ° C. or the firing time exceeds 2 hours, oxygen and other impurities are excessively heated in the copper even if the copper forming the bar 10 does not melt. Diffusion causes the copper-containing oxygen content and impurity content to exceed the ranges described above, and improves the intended heat conductivity in the thickness direction of the heat spreader 1 by the heat transfer member 5 made of copper. May not be effective. Further, when the firing temperature is less than 900 ° C. or the firing time is less than 0.5 hours, the sintered body 16 having sufficient strength cannot be obtained, and the sintered body 16 is not used in the next step. When plastic working, there is a possibility that cracks and the like are likely to occur.

次に、前記焼結体１６を、必要に応じて、銅の融点未満の温度で、塑性加工により柱の長さ方向と交差方向に圧縮変形させる。詳しくは、図５に示すように焼結体１６の柱の長さ方向と交差方向の断面積よりも開口面積が小さい開口部１７を有するダイ１８を用意し、前記焼結体１６をダイ１８の開口部１７を通過させることで前記交差方向に圧縮変形させながら、図中に白矢印で示す方向に引き抜く引抜加工をすることにより塑性加工体１９を形成する。   Next, the sintered body 16 is compressed and deformed in a direction intersecting with the length direction of the column by plastic working at a temperature lower than the melting point of copper, if necessary. Specifically, as shown in FIG. 5, a die 18 having an opening 17 having an opening area smaller than the cross-sectional area in the direction crossing the length direction of the pillar of the sintered body 16 is prepared. The plastic working body 19 is formed by drawing in the direction indicated by the white arrow in the drawing while being compressed and deformed in the intersecting direction by passing through the opening 17.

あるいは、図６に示すように焼結体１６を、前記焼結体１６の外周と接する通孔２０を有するガイド部材２１によってガイドしながら図中に黒矢印で示す方向に押し出して、ダイ１８の開口部１７を通過させることで前記交差方向に圧縮変形させる押出加工をすることにより塑性加工体１９を形成する。前記引抜加工、押出加工は、それぞれ開口部１７の開口面積が異なる複数のダイ１８を交換して使用しながら、塑性加工体１９が所定の断面積になるまで複数回に分けて段階的に行なってもよい。   Alternatively, as shown in FIG. 6, the sintered body 16 is extruded in the direction indicated by the black arrow in the drawing while being guided by a guide member 21 having a through hole 20 in contact with the outer periphery of the sintered body 16. The plastic working body 19 is formed by performing an extrusion process of compressing and deforming in the intersecting direction by passing through the opening 17. The drawing process and the extrusion process are performed in stages in a plurality of steps until the plastic workpiece 19 has a predetermined cross-sectional area while exchanging and using a plurality of dies 18 each having a different opening area of the opening 17. May be.

前記引抜加工、押出加工等の塑性加工の温度は、先に説明したように銅の融点未満であればよいが、特に２００℃以上、５００℃以下であるのが好ましい。塑性加工の温度が２００℃未満では、塑性加工時に、焼結体１６に割れ等が発生するおそれがあり、５００℃を超える場合には、塑性加工をするための装置の熱対策が難しくなりすぎるという問題を生じるおそれがある。   The temperature of plastic working such as drawing or extrusion may be less than the melting point of copper as described above, but is preferably 200 ° C. or higher and 500 ° C. or lower. If the temperature of the plastic working is less than 200 ° C., there is a possibility that the sintered body 16 will be cracked during the plastic working. If it exceeds 500 ° C., it is too difficult to take measures against heat of the apparatus for performing the plastic working. May cause problems.

前記塑性加工を行うことにより、製造されるヒートスプレッダ１のうち基材２の緻密性を向上させて、前記基材２自体の熱伝導率を高めることができ、ヒートスプレッダ１の全体での厚み方向の熱伝導率をさらに向上することができる。また、棒材１０からなる伝熱部材５の、面方向の断面積および形成ピッチを小さくして、ヒートスプレッダ１の面方向に、前記伝熱部材５による熱伝導が良好な領域をきめ細かく配置して、素子等から冷却器等への熱伝導の性能を向上することもできる。なお塑性加工は、ヒートスプレッダ１に要求される性能や仕様等によっては省略しても良い。   By performing the plastic working, it is possible to improve the denseness of the base material 2 in the heat spreader 1 to be manufactured, to increase the thermal conductivity of the base material 2 itself, and in the thickness direction of the heat spreader 1 as a whole. The thermal conductivity can be further improved. Further, the cross-sectional area in the surface direction and the formation pitch of the heat transfer member 5 made of the bar 10 are reduced, and a region where the heat transfer by the heat transfer member 5 is excellent is finely arranged in the surface direction of the heat spreader 1. The performance of heat conduction from the element or the like to the cooler or the like can be improved. The plastic working may be omitted depending on the performance and specifications required for the heat spreader 1.

次に、図７に一点鎖線で示すように塑性加工体１９、または塑性加工しない場合は焼結体１６を柱の長さ方向と交差方向に切断し、さらに必要に応じて切断面を研磨等することにより、低熱膨張材料からなり略平板状の基材２と、前記基材２の表面３から裏面４へ厚み方向に貫通させて設けられていると共に前記両面３、４において露出された、銅からなる複数の伝熱部材５とを含む平板状のヒートスプレッダ１が製造される。   Next, as shown by a one-dot chain line in FIG. 7, the plastic working body 19 or, if not plastic working, the sintered body 16 is cut in the direction intersecting with the length direction of the column, and the cut surface is polished if necessary. By doing so, the substantially flat base material 2 made of a low thermal expansion material, and provided through the surface 3 to the back surface 4 of the base material 2 in the thickness direction and exposed on the both surfaces 3 and 4, A flat plate-shaped heat spreader 1 including a plurality of heat transfer members 5 made of copper is manufactured.

なお、基材２が(1)の焼結体からなるヒートスプレッダ１は、以上で説明した製造方法の他に、例えばあらかじめ平板状に形成した基材２を用いて、下記の製造方法によって製造することもできる。すなわち、基材２の厚み方向に貫通させて複数の貫通孔を形成したものを用意し、前記基材２の貫通孔の内周面を、必要に応じて銅めっきした後、前記貫通穴に、伝熱部材５のもとになる銅の棒材を基材２の厚みとほぼ一致する長さに切断したものを挿入して組立体を構成する。   In addition, the heat spreader 1 which the base material 2 consists of a sintered compact of (1) manufactures with the following manufacturing method using the base material 2 previously formed, for example in flat form other than the manufacturing method demonstrated above. You can also. That is, after preparing what formed several through-holes penetrated in the thickness direction of the base material 2, and copper-plating the inner peripheral surface of the through-hole of the said base material 2 as needed, it is in the said through-hole. Then, an assembly is configured by inserting a copper bar material that is the basis of the heat transfer member 5 into a length that substantially matches the thickness of the substrate 2.

そして、前記組立体をそのままの状態で、あるいは型枠に嵌め込む等した状態で、銅の融点未満、好ましくは９００℃以上、１０８０℃以下の温度で、０．５時間以上、２時間以下程度に亘って焼成すると、前記基材２と棒材とが、基材２中の金属または合金の拡散接合、または銅めっき層による銅拡散接合によって一体化されて、ヒートスプレッダ１が製造される。基材２が(2)の焼結体や(3)の板材からなるヒートスプレッダ１も、上記と同様にして製造することができる。   Then, the assembly is left as it is or fitted into a mold, and the temperature is lower than the melting point of copper, preferably 900 ° C. or higher and 1080 ° C. or lower. The base material 2 and the bar are integrated by diffusion bonding of a metal or alloy in the base material 2 or copper diffusion bonding by a copper plating layer, and the heat spreader 1 is manufactured. The heat spreader 1 in which the substrate 2 is made of the sintered body (2) or the plate material (3) can also be manufactured in the same manner as described above.

これらのヒートスプレッダ１においても、伝熱部材５のもとになる棒材として無酸素銅等からなるものを使用することで、前記のように焼成の工程を銅の融点未満の温度で行うことと相まって、伝熱部材５の含有酸素量、および含有不純物量を先に説明した範囲内として、厚み方向の熱伝導率を向上することができる。
本発明の構成は、以上で説明した図の例のものには限定されず、本発明の要旨を逸脱しない範囲で、種々の設計変更を施すことができる。 In these heat spreaders 1 as well, by using a material made of oxygen-free copper or the like as a bar material that becomes the basis of the heat transfer member 5, the firing step is performed at a temperature lower than the melting point of copper as described above. In combination, the thermal conductivity in the thickness direction can be improved by setting the oxygen content and the impurity content of the heat transfer member 5 within the range described above.
The configuration of the present invention is not limited to the example of the drawings described above, and various design changes can be made without departing from the gist of the present invention.

〈実施例１ないし１９、比較例１〉
図１に示す矩形平板状（５０ｍｍ×５０ｍｍ×２．８ｍｍ）の基材２を備え、前記基材２の面方向の中央の、４８ｍｍ×４８ｍｍの領域内に、前記基材２の表面３から裏面４へ厚み方向に貫通させて、直径０．３１ｍｍの円柱状の伝熱部材５が、図１に示す配列で、かつ表１に示すピッチで設けられたヒートスプレッダ１を、図３ないし図７の工程を経て製造することとして、下記の各種材料および型を用意した。 <Examples 1 to 19 and Comparative Example 1>
A rectangular flat plate-like (50 mm × 50 mm × 2.8 mm) base material 2 shown in FIG. 1 is provided, and from the surface 3 of the base material 2 within a 48 mm × 48 mm region in the center in the surface direction of the base material 2. A heat spreader 1 in which cylindrical heat transfer members 5 having a diameter of 0.31 mm are provided in the arrangement shown in FIG. 1 and at the pitch shown in Table 1 through the back surface 4 in the thickness direction is shown in FIGS. The following various materials and molds were prepared for manufacturing through the above steps.

（基材２のもとになる低熱膨張材料１４）
平均粒径が４０μｍ、見かけ密度が２．０ｇ／ｃｍ3の銅粉末と、平均粒径が６μｍのタングステン粉末、または平均粒径が５μｍのモリブデン粉末とを、表１に示す重量比で配合して調製した。
（伝熱部材５のもとになる棒材１０）
先に説明したＪＩＳ Ｈ３１００：２００６において規定されたＣ１０２０「無酸素銅」（銅純度９９．９６質量％、含有酸素量１０ｐｐｍ以下）からなる直径１ｍｍの丸棒材を用意した。 (Low thermal expansion material 14 as the base material 2)
A copper powder having an average particle diameter of 40 μm and an apparent density of 2.0 g / cm 3 and a tungsten powder having an average particle diameter of 6 μm or a molybdenum powder having an average particle diameter of 5 μm are blended in a weight ratio shown in Table 1. Prepared.
(Bar 10 which becomes the base of the heat transfer member 5)
A round bar material having a diameter of 1 mm made of C1020 “oxygen-free copper” (copper purity 99.96 mass%, oxygen content 10 ppm or less) defined in JIS H3100: 2006 described above was prepared.

（型）
その内部に、前記伝熱部材５に対応する棒材が、柱の長さ方向と略平行に、前記伝熱部材５の配列に合わせて埋設された１６０ｍｍ×１６０ｍｍ×６００ｍｍの四角柱状の圧縮成形体１５を製造するために、図３に示すステンレス鋼製の上型７、下型８、およびダイ９と、ウレタン製の治具１１、１３とを用意した。前記上型７、下型８、およびダイ９によって形成される型窩６内に治具１１、１３をセットすることで構成される成形空間１２の寸法は、上型７と下型８とに挟まれて圧縮される縦方向を２００ｍｍ、幅方向を１６０ｍｍ、長さ方向を６００ｍｍとした。また、治具１１によって保持される複数の棒材１０のピッチは表１に示す値とした。 (Type)
A 160 mm × 160 mm × 600 mm square columnar compression molding in which a bar corresponding to the heat transfer member 5 is embedded in parallel with the arrangement of the heat transfer members 5 substantially parallel to the length direction of the columns. In order to manufacture the body 15, an upper mold 7, a lower mold 8, and a die 9 made of stainless steel and urethane jigs 11 and 13 shown in FIG. 3 were prepared. The dimensions of the molding space 12 configured by setting jigs 11 and 13 in the mold cavity 6 formed by the upper mold 7, the lower mold 8, and the die 9 are the same as the upper mold 7 and the lower mold 8. The longitudinal direction to be sandwiched and compressed was 200 mm, the width direction was 160 mm, and the length direction was 600 mm. Further, the pitch of the plurality of bars 10 held by the jig 11 was set to the values shown in Table 1.

（圧縮成形体１５の作製）
前記下型８とダイ９とで形成した型窩６内にセットした一対の治具１１間に、前記棒材１０を、それぞれの軸方向を柱の長さ方向と略平行に向けて保持させると共に、前記治具１１と、型窩６内に、棒材１０の周囲を囲むように設置した治具１３とで形成した成形空間１２内に、基材２のもとになる低熱膨張材料１４を充填した。 (Preparation of compression molded body 15)
Between the pair of jigs 11 set in the mold cavity 6 formed by the lower mold 8 and the die 9, the bar 10 is held with the respective axial directions substantially parallel to the length direction of the pillars. At the same time, the low thermal expansion material 14 that becomes the base of the base material 2 is formed in the molding space 12 formed by the jig 11 and the jig 13 that is installed in the mold cavity 6 so as to surround the periphery of the bar 10. Filled.

次いで室温（５℃ないし３５℃）下、上型７を、図３中に実線の矢印で示すように型窩６に挿入し、前記縦方向の寸法が１６０ｍｍになるまで２０ＭＰａの圧力で下型８の方向に押し込んで、先に説明した等方圧縮成形により１６０ｍｍ×１６０ｍｍ×６００ｍｍの四角柱状の圧縮成形体１５を作製した。
（焼結体１６の作製）
前記圧縮成形体１５を型から取り出し、非酸化性雰囲気中で、表１に示す温度および時間で焼成して焼結体１６を作製した。 Next, at room temperature (5 ° C. to 35 ° C.), the upper die 7 is inserted into the die cavity 6 as shown by the solid line arrow in FIG. 3, and the lower die is pressed at a pressure of 20 MPa until the longitudinal dimension becomes 160 mm. The rectangular columnar compression-molded body 15 of 160 mm × 160 mm × 600 mm was produced by pressing in the direction 8 and by the isotropic compression molding described above.
(Preparation of sintered body 16)
The compression molded body 15 was taken out from the mold and fired at a temperature and time shown in Table 1 in a non-oxidizing atmosphere to produce a sintered body 16.

（塑性加工体１９の作製）
前記焼結体１６を、図５に示すようにダイ１８の開口部１７を通過させることで長さ方向と交差方向に圧縮変形させながら、図中に白矢印で示す方向に引き抜く引抜加工をすることにより、５０ｍｍ×５０ｍｍ×６０００ｍｍの塑性加工体１９を作製した。引抜加工は、開口部１７の開口面積が異なる複数のダイ１８を交換して使用しながら、塑性加工体１９の、断面の寸法が前記５０ｍｍ×５０ｍｍになるまで複数回に分けて段階的に行なった。 (Preparation of plastic working body 19)
As shown in FIG. 5, the sintered body 16 is pulled in the direction indicated by the white arrow in the drawing while being compressed and deformed in the direction intersecting with the length direction by passing through the opening 17 of the die 18. Thus, a plastic processed body 19 of 50 mm × 50 mm × 6000 mm was produced. The drawing process is performed in stages while exchanging and using a plurality of dies 18 having different opening areas of the opening 17 until the cross-sectional dimension of the plastic processed body 19 reaches 50 mm × 50 mm. It was.

（ヒートスプレッダ１の製造）
図７に一点鎖線で示すように前記塑性加工体１９を柱の長さ方向と交差方向に厚み３ｍｍとなるように切断した後、両面の切断面を研磨して、低熱膨張材料からなり略平板状の基材２と、前記基材２の表面３から裏面４へ厚み方向に貫通させて設けられていると共に前記両面３、４において露出された、銅からなる複数の伝熱部材５とを含む矩形平板状（５０ｍｍ×５０ｍｍ×２．８ｍｍ）のヒートスプレッダ１を製造した。 (Manufacture of heat spreader 1)
As shown by the one-dot chain line in FIG. 7, the plastic working body 19 is cut so as to have a thickness of 3 mm in the direction intersecting the length of the column, and then the cut surfaces on both sides are polished to form a substantially flat plate made of a low thermal expansion material. And a plurality of heat transfer members 5 made of copper, which are provided in a thickness direction from the front surface 3 to the back surface 4 of the base material 2 and are exposed on the both surfaces 3 and 4. The heat spreader 1 having a rectangular flat plate shape (50 mm × 50 mm × 2.8 mm) was manufactured.

（割合ＲSの計測）
前記ヒートスプレッダ１の表面３に露出した複数の伝熱部材５の数と直径、および前記表面の表面積を計測した結果から、前記複数の伝熱部材５の断面積の合計の、ヒートスプレッダ１の全体での断面積中に占める割合ＲSを求めた。
（含有酸素量の測定）
前記ヒートスプレッダ１から取り出し、基材２と接合していた円柱の外周面の近傍の領域を除去した伝熱部材５の含有酸素量を、酸素・窒素同時分析装置（前出のＬＥＣＯ社製のＴＣ−４３６ＡＲ）を用いた赤外線吸収法によって測定した。 (Measurement of ratio R S )
From the results of measuring the number and diameter of the plurality of heat transfer members 5 exposed on the surface 3 of the heat spreader 1 and the surface area of the surface, the total of the cross-sectional areas of the plurality of heat transfer members 5 is the total of the heat spreader 1. The ratio R S occupying in the cross-sectional area was determined.
(Measurement of oxygen content)
The oxygen content in the heat transfer member 5 that was removed from the heat spreader 1 and removed the region in the vicinity of the outer peripheral surface of the cylinder that had been joined to the base material 2 was measured using an oxygen / nitrogen simultaneous analyzer (the above-mentioned TC manufactured by LECO). -436AR) was measured by an infrared absorption method.

（熱伝導率の測定）
前記ヒートスプレッダ１の、厚み方向の熱伝導率（Ｗ／ｍ・Ｋ）を、レーザーフラッシュ法によって測定した。
（熱膨張係数の測定）
前記ヒートスプレッダ１の、面方向の熱膨張係数（×１０-6／Ｋ）を、示差熱膨張計を用いて測定した。 (Measurement of thermal conductivity)
The heat conductivity (W / m · K) in the thickness direction of the heat spreader 1 was measured by a laser flash method.
(Measurement of thermal expansion coefficient)
The thermal expansion coefficient (× 10 −6 / K) in the surface direction of the heat spreader 1 was measured using a differential thermal dilatometer.

以上の結果を表１に示す。   The results are shown in Table 1.

Figure 2010062310
Figure 2010062310

表１の実施例１〜８、比較例１の結果より、焼成の温度と時間とを調製することで、伝熱部材５を構成する銅の含有酸素量を調整できること、前記含有酸素量が２０ｐｐｍを超える比較例１に比べて、２０ｐｐｍ以下とした実施例１〜８は、面方向の熱膨張係数を銅レベルに維持しながら、厚み方向の熱伝導率を向上できることが判った。
また実施例４、実施例９〜１５の結果より、伝熱部材５のもとになる棒材１０のピッチを変化させることで、前記伝熱部材５のピッチを変化させて割合ＲSを調整できること、前記割合ＲSを調整することで、面方向の熱膨張係数と厚み方向の熱伝導率を調整できることが判った。 From the results of Examples 1 to 8 and Comparative Example 1 in Table 1, the amount of oxygen contained in copper constituting the heat transfer member 5 can be adjusted by adjusting the firing temperature and time, and the amount of oxygen contained is 20 ppm. In comparison with Comparative Example 1 exceeding 20 ppm, it was found that Examples 1 to 8 having 20 ppm or less can improve the thermal conductivity in the thickness direction while maintaining the thermal expansion coefficient in the plane direction at the copper level.
Further, from the results of Example 4 and Examples 9 to 15, the ratio R S is adjusted by changing the pitch of the heat transfer member 5 by changing the pitch of the bar 10 that is the basis of the heat transfer member 5. It was found that the thermal expansion coefficient in the plane direction and the thermal conductivity in the thickness direction can be adjusted by adjusting the ratio R S.

また実施例４、実施例１６〜１９の結果より、低熱膨張材料の組成を変化させることで、面方向の熱膨張係数と厚み方向の熱伝導率を調整できることが判った。   Moreover, from the results of Example 4 and Examples 16 to 19, it was found that the thermal expansion coefficient in the plane direction and the thermal conductivity in the thickness direction can be adjusted by changing the composition of the low thermal expansion material.

本発明のヒートスプレッダの、実施の形態の一例を示す斜視図である。It is a perspective view which shows an example of embodiment of the heat spreader of this invention. 前記例のヒートスプレッダの内部構造を示す拡大断面図である。It is an expanded sectional view which shows the internal structure of the heat spreader of the said example. 本発明のヒートスプレッダの製造方法の一例のうち、圧縮成形によって圧縮成形体を形成する工程を説明する断面図である。It is sectional drawing explaining the process of forming a compression molding body by compression molding among an example of the manufacturing method of the heat spreader of this invention. 図３の工程で形成される圧縮成形体、およびそれを次工程で焼成して形成される焼結体の、端部付近の外観を示す拡大斜視図である。It is an expansion perspective view which shows the external appearance of an edge part vicinity of the compression molding body formed at the process of FIG. 3, and the sintered compact formed by baking it at the next process. 前記製造方法の一例のうち、引抜加工によって塑性加工体を形成する工程を説明する断面図である。It is sectional drawing explaining the process of forming a plastic-working body by drawing out among examples of the said manufacturing method. 前記製造方法の一例のうち、押出加工によって塑性加工体を形成する工程を説明する断面図である。It is sectional drawing explaining the process of forming a plastic processing body by an extrusion process among examples of the said manufacturing method. 前記製造方法の一例のうち、組成加工体を切断してヒートスプレッダを製造する工程を説明する斜視図である。It is a perspective view explaining the process of cut | disconnecting a composition processed body and manufacturing a heat spreader among examples of the said manufacturing method.

符号の説明Explanation of symbols

１ ヒートスプレッダ
２ 基材
３ 表面
４ 裏面
５ 伝熱部材
６ 型窩
７ 上型
８ 下型
９ ダイ
１０ 棒材
１１ 治具
１２ 成形空間
１３ 治具
１４ 低熱膨張材料
１５ 圧縮成形体
１６ 焼結体
１７ 開口部
１８ ダイ
１９ 塑性加工体
２０ 通孔
２１ ガイド部材 DESCRIPTION OF SYMBOLS 1 Heat spreader 2 Base material 3 Front surface 4 Back surface 5 Heat transfer member 6 Mold cavity 7 Upper mold 8 Lower mold 9 Die 10 Bar 11 Jig 12 Molding space 13 Jig 14 Low thermal expansion material 15 Compression molded body 16 Sintered body 17 Opening Part 18 Die 19 Plastic workpiece 20 Through hole 21 Guide member

Claims (5)

低熱膨張材料からなり略平板状の基材と、前記基材の表面から裏面へ厚み方向に貫通させて設けられていると共に前記両面において露出された、銅からなる複数の伝熱部材とを含み、前記伝熱部材を構成する銅の含有酸素量が２０ｐｐｍ以下であることを特徴とするヒートスプレッダ。   A substantially flat base material made of a low thermal expansion material, and a plurality of heat transfer members made of copper that are provided to penetrate from the front surface to the back surface of the base material in the thickness direction and exposed on the both surfaces. The heat spreader is characterized in that the oxygen content of copper constituting the heat transfer member is 20 ppm or less. 面方向の熱膨張係数が１６×１０-6／Ｋ以下である請求項１に記載のヒートスプレッダ。 The heat spreader according to claim 1, wherein a thermal expansion coefficient in a plane direction is 16 × 10 -6 / K or less. 各伝熱部材は、基材の厚み方向と交差する面方向の断面積が、前記基材の表面から裏面まで同一とされていると共に、前記面方向における、複数の伝熱部材の断面積の合計の、ヒートスプレッダの全体での断面積中に占める割合が１％以上、５０％以下である請求項１または２に記載のヒートスプレッダ。   Each heat transfer member has the same cross-sectional area in the surface direction intersecting the thickness direction of the base material from the front surface to the back surface of the base material, and the cross-sectional area of the plurality of heat transfer members in the surface direction. The heat spreader according to claim 1 or 2, wherein a total ratio of the total heat spreader in the cross-sectional area of the heat spreader is 1% or more and 50% or less. 請求項１ないし３のいずれかに記載のヒートスプレッダを製造する製造方法であって、
(a) 圧縮成形により柱状の圧縮成形体を得るための型内に、銅からなり伝熱部材のもとになる複数本の棒材を、それぞれの軸方向を柱の長さ方向と略平行に向けて配設すると共に、前記型内の各棒材間の隙間に、基材のもとになるタングステン、モリブデン、セラミック、およびダイヤモンドからなる群より選ばれた少なくとも一種の粉末、および銅と接合可能な金属または合金の粉末を含む低熱膨張材料を充填した後、銅の融点未満の温度で圧縮成形して、柱状で、かつ前記複数の棒材がそれぞれの軸方向を柱の長さ方向と略平行に向けて埋設された圧縮成形体を形成する工程と、
(b) 前記圧縮成形体を、銅の融点未満の温度で焼成して焼結体を形成する工程と、
(c) 前記焼結体を柱の長さ方向と交差方向に切断して略平板状のヒートスプレッダを製造する工程と
を含むことを特徴とするヒートスプレッダの製造方法。 A manufacturing method for manufacturing the heat spreader according to any one of claims 1 to 3,
(a) In a mold for obtaining a columnar compression molded body by compression molding, a plurality of rods made of copper and serving as a heat transfer member are arranged with their axial directions substantially parallel to the column length direction. And at least one powder selected from the group consisting of tungsten, molybdenum, ceramics, and diamond as a base material, and copper in the gaps between the bars in the mold After filling with a low thermal expansion material containing a metal or alloy powder that can be joined, it is compression-molded at a temperature below the melting point of copper, is columnar, and the plurality of rods have their respective axial directions in the length direction of the column. Forming a compression molded body embedded substantially parallel to the
(b) firing the compression molded body at a temperature lower than the melting point of copper to form a sintered body;
(c) cutting the sintered body in a direction intersecting with the length direction of the column to manufacture a substantially flat plate-shaped heat spreader. 前記焼結体を、切断に先立って銅の融点未満の温度で、塑性加工により柱の長さ方向と交差方向に圧縮変形させて塑性加工体を形成した後、前記塑性加工体を前記交差方向に切断して略平板状のヒートスプレッダを製造する請求項４に記載のヒートスプレッダの製造方法。   Prior to cutting, the sintered body is compressed and deformed in a direction intersecting with the length direction of the column by plastic working at a temperature lower than the melting point of copper, and then the plastic processed body is formed in the intersecting direction. The method for producing a heat spreader according to claim 4, wherein the heat spreader is produced by cutting into a substantially flat plate shape.
JP2008226202A 2008-09-03 2008-09-03 Heat spreader and manufacturing method thereof Expired - Fee Related JP5198982B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2008226202A JP5198982B2 (en) 2008-09-03 2008-09-03 Heat spreader and manufacturing method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2008226202A JP5198982B2 (en) 2008-09-03 2008-09-03 Heat spreader and manufacturing method thereof

Publications (2)

Publication Number Publication Date
JP2010062310A true JP2010062310A (en) 2010-03-18
JP5198982B2 JP5198982B2 (en) 2013-05-15

Family

ID=42188804

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2008226202A Expired - Fee Related JP5198982B2 (en) 2008-09-03 2008-09-03 Heat spreader and manufacturing method thereof

Country Status (1)

Country Link
JP (1) JP5198982B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015182385A1 (en) * 2014-05-29 2015-12-03 株式会社アライドマテリアル Heat spreader and process for producing same

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6042742U (en) * 1983-08-31 1985-03-26 日本電気株式会社 semiconductor equipment
JPH07321258A (en) * 1994-05-24 1995-12-08 Fujitsu Ltd Semiconductor device
JP2002124611A (en) * 2000-10-16 2002-04-26 Yamaha Corp Heat sink for electronic device, method for manufacturing the same and semiconductor laser module employing the heat sink
JP2003017637A (en) * 2001-06-29 2003-01-17 Toho Kinzoku Co Ltd Composite material
JP2003213362A (en) * 2002-01-21 2003-07-30 Taiheiyo Cement Corp Copper matrix composite material
JP2005002470A (en) * 2003-05-16 2005-01-06 Hitachi Metals Ltd High thermal conduction and low thermal expansion composite material, heat radiation substrate, and their production method

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6042742U (en) * 1983-08-31 1985-03-26 日本電気株式会社 semiconductor equipment
JPH07321258A (en) * 1994-05-24 1995-12-08 Fujitsu Ltd Semiconductor device
JP2002124611A (en) * 2000-10-16 2002-04-26 Yamaha Corp Heat sink for electronic device, method for manufacturing the same and semiconductor laser module employing the heat sink
JP2003017637A (en) * 2001-06-29 2003-01-17 Toho Kinzoku Co Ltd Composite material
JP2003213362A (en) * 2002-01-21 2003-07-30 Taiheiyo Cement Corp Copper matrix composite material
JP2005002470A (en) * 2003-05-16 2005-01-06 Hitachi Metals Ltd High thermal conduction and low thermal expansion composite material, heat radiation substrate, and their production method

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015182385A1 (en) * 2014-05-29 2015-12-03 株式会社アライドマテリアル Heat spreader and process for producing same
CN106460191A (en) * 2014-05-29 2017-02-22 联合材料公司 Heat spreader and process for producing same
JPWO2015182385A1 (en) * 2014-05-29 2017-04-20 株式会社アライドマテリアル Heat spreader
US10215512B2 (en) 2014-05-29 2019-02-26 A.L.M.T. Corp. Heat spreader and method for manufacturing the same

Also Published As

Publication number Publication date
JP5198982B2 (en) 2013-05-15

Similar Documents

Publication Publication Date Title
US8858865B2 (en) Silicon nitride substrate manufacturing method, silicon nitride substrate, silicon nitride circuit substrate, and semiconductor module
CN108495831B (en) Silicon nitride sintered substrate, silicon nitride sintered substrate sheet, circuit substrate, and method for producing silicon nitride sintered substrate
CN109789486B (en) Optical or optoelectronic component and method for the production thereof
JP6129738B2 (en) Ceramic circuit board
JP5698947B2 (en) Heat sink for electronic device and method for manufacturing the same
JP6182889B2 (en) Thermoelectric conversion module and method for manufacturing thermoelectric conversion module
JP6115900B2 (en) Heat spreader
US9096471B2 (en) Method for producing a layered material
RU2639615C2 (en) Improved method of producing thermoelectric elements by powder metallurgy
EP2735391A1 (en) Composite material for heat dissipating substrate, and method for manufacturing composite material for heat dissipating substrate
JPH1084059A (en) Silicon nitride circuit board
JP4382154B2 (en) Heat spreader and manufacturing method thereof
JP5198982B2 (en) Heat spreader and manufacturing method thereof
JP4138844B2 (en) Cr-Cu alloy, manufacturing method thereof, heat sink for semiconductor, and heat dissipation component for semiconductor
JP5866075B2 (en) Bonding material manufacturing method, bonding method, and power semiconductor device
JP2001335859A (en) Aluminum-silicon carbide composite material and its production method
WO2004038049A1 (en) Composite material, method for producing same and member using same
JP2002176119A (en) Silicon nitride substrate, silicon nitride circuit substrate using the same, and method of manufacturing the same
JP2002076451A (en) Thermoelectric transducing element and its manufacture
JP4200770B2 (en) Thermoelectric material ingot, method for producing the same, and method for producing the thermoelectric module
JPH0878578A (en) Material for heat dissipating substrate and manufacturing method thereof
JP2009149966A (en) METHOD FOR PRODUCING Cr-Cu ALLOY SHEET
JP2023055311A (en) Method of manufacturing heat dissipation member
JP2003300788A (en) Method for producing aluminum alloy-silicon carbide- based composite and structure for producing the same
JP2021158355A (en) Manufacturing method of thermoelectric conversion element and manufacturing method of thermoelectric conversion module using the same

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20110309

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20120213

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20130124

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20130207

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20160215

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Ref document number: 5198982

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

Free format text: JAPANESE INTERMEDIATE CODE: R150

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

LAPS Cancellation because of no payment of annual fees