JP4876097B2 - HEAT SPREADER, MANUFACTURING METHOD THEREOF, AND SEMICONDUCTOR DEVICE - Google Patents

HEAT SPREADER, MANUFACTURING METHOD THEREOF, AND SEMICONDUCTOR DEVICE Download PDF

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JP4876097B2
JP4876097B2 JP2008121265A JP2008121265A JP4876097B2 JP 4876097 B2 JP4876097 B2 JP 4876097B2 JP 2008121265 A JP2008121265 A JP 2008121265A JP 2008121265 A JP2008121265 A JP 2008121265A JP 4876097 B2 JP4876097 B2 JP 4876097B2
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plating layer
mass
heat spreader
substrate
thickness
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JP2009010340A (en
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浩一 高島
伸一 山形
治 諏訪多
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ALMT Corp
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/10—Bump connectors; Manufacturing methods related thereto
    • H01L2224/15—Structure, shape, material or disposition of the bump connectors after the connecting process
    • H01L2224/16—Structure, shape, material or disposition of the bump connectors after the connecting process of an individual bump connector
    • H01L2224/161—Disposition
    • H01L2224/16151—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/16221—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/16225—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/73—Means for bonding being of different types provided for in two or more of groups H01L2224/10, H01L2224/18, H01L2224/26, H01L2224/34, H01L2224/42, H01L2224/50, H01L2224/63, H01L2224/71
    • H01L2224/732—Location after the connecting process
    • H01L2224/73251—Location after the connecting process on different surfaces
    • H01L2224/73253—Bump and layer connectors

Description

本発明は、半導体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、前記ヒートスプレッダの製造方法と、前記ヒートスプレッダを用いた半導体装置とに関する。   The present invention relates to a heat spreader suitably used for removing heat from a semiconductor element, a method for manufacturing the heat spreader, and a semiconductor device using the heat spreader.

半導体素子の動作時に発生する熱を、前記素子外に直接に、あるいはヒートシンク、ステム、パッケージ等を介して間接的に除去するために、サブマウントやリッド、ベース基板等と呼ばれる半導体素子搭載部材としてヒートスプレッダが用いられる。ヒートスプレッダにフィン等を一体に形成したヒートシンク等も使用される。
従来のヒートスプレッダは、Ｓｉ（ケイ素）やセラミック等によって形成されるのが一般的であった。しかし近時、Ｗ（タングステン）からなる多孔質体の細孔内にＣｕ（銅）を溶浸させて形成されたＣｕ−Ｗ複合材料や、Ｍｏ（モリブデン）からなる多孔質体の細孔内にＣｕを溶浸させて形成されたＣｕ−Ｍｏ複合材料等からなるヒートスプレッダが提案されている（特許文献１参照）。 As a semiconductor element mounting member called a submount, lid, base substrate or the like for removing heat generated during operation of a semiconductor element directly to the outside of the element or indirectly through a heat sink, stem, package, etc. A heat spreader is used. A heat sink or the like in which fins or the like are integrally formed on the heat spreader is also used.
Conventional heat spreaders are generally formed of Si (silicon) or ceramics. However, recently, a Cu-W composite material formed by infiltrating Cu (copper) into the pores of a porous body made of W (tungsten), or the pores of a porous body made of Mo (molybdenum) A heat spreader made of a Cu—Mo composite material formed by infiltrating Cu into a metal has been proposed (see Patent Document 1).

ヒートスプレッダは、例えば半導体素子、ヒートシンク、ステム、パッケージ等（以下、これらを「他部材」と総称する場合がある。また、半導体素子を除く他の部材を「熱除去部材」と総称する場合がある。）が接続される複数の接続面を備えた任意の立体形状に形成される。そして、前記複数の接続面のうち少なくとも１つの接続面に半導体素子、他の接続面にヒートシンク、ステム、パッケージ等の熱除去部材を接続して半導体装置が構成される。   The heat spreader is, for example, a semiconductor element, a heat sink, a stem, a package, or the like (hereinafter, these may be collectively referred to as “other members”. Other members other than the semiconductor elements may be collectively referred to as “heat removal members”. .) Is formed in an arbitrary three-dimensional shape having a plurality of connection surfaces to which the connection surfaces are connected. A semiconductor device is configured by connecting a semiconductor element to at least one of the plurality of connection surfaces and connecting a heat removal member such as a heat sink, a stem, and a package to the other connection surfaces.

前記半導体装置には、例えば温度＋８５℃、相対湿度８５％の高温高湿環境下で１０００時間、静置する高温高湿試験や、あるいは温度＋１５０℃で３０分間静置する工程と、温度−６５℃で３０分間静置する工程とを１サイクルとして、前記サイクルを１０００サイクルに亘って繰り返すヒートサイクル試験等に合格しうる高い信頼性を有していることが求められる。   In the semiconductor device, for example, a high-temperature and high-humidity test for 1000 hours in a high-temperature and high-humidity environment at a temperature of + 85 ° C. and a relative humidity of 85%, or a step of leaving at a temperature of + 150 ° C. for 30 minutes, It is required to have high reliability that can pass a heat cycle test or the like in which the step of standing at 30 ° C. for 30 minutes is one cycle and the cycle is repeated over 1000 cycles.

しかし、先に説明した複合材料からなるヒートスプレッダは、その表面に露出したＣｕが、前記高温高湿環境下等の様々な環境下で酸化したり腐食したりしやすいため、半導体装置に、前記の試験をクリアする高い信頼性を付与することは困難である。そこで特許文献１では、前記複合材料によって所定の立体形状に形成した、ヒートスプレッダのもとになる基体の少なくとも接続面にＮｉ（ニッケル）めっきを施して、厚み約１μｍ程度のＮｉめっき層を形成した後、水素ガス等の還元性雰囲気中で８００℃程度に加熱してヒートスプレッダを製造することが提案されている。   However, in the heat spreader made of the composite material described above, the Cu exposed on the surface is likely to be oxidized or corroded under various environments such as the high temperature and high humidity environment. It is difficult to give high reliability to clear the test. Therefore, in Patent Document 1, Ni (nickel) plating is applied to at least the connection surface of the base that is the base of the heat spreader, which is formed into a predetermined three-dimensional shape using the composite material, to form a Ni plating layer having a thickness of about 1 μm. Thereafter, it has been proposed to produce a heat spreader by heating to about 800 ° C. in a reducing atmosphere such as hydrogen gas.

Ｎｉめっき層を加熱するのは、ＣｕとＮｉが全率固溶することを利用して、基体中のＣｕをＮｉめっき層中に拡散させるためである。これによりＮｉめっき層が基体と強固に一体化されて、前記Ｎｉめっき層が、半導体装置の使用時の熱履歴（半導体素子の動作時の発熱等）によって脹れを生じたり基体から剥離したりするのを抑制できる。
しかし高温で熱処理した場合には、基体中のＣｕがＮｉめっき層の最表面まで拡散して、前記最表面に露出した状態で蓄積される傾向がある。そして露出したＣｕは酸化したり腐食したりしやすいため、その露出量が多いほど、Ｎｉめっき層の、前記高温高湿環境等に対する耐性が低下して、半導体装置に高い信頼性を付与できないおそれがある。 The reason for heating the Ni plating layer is to diffuse Cu into the Ni plating layer by utilizing the fact that Cu and Ni are completely dissolved. As a result, the Ni plating layer is firmly integrated with the base body, and the Ni plating layer is swelled or peeled off from the base body due to a thermal history during use of the semiconductor device (eg, heat generation during operation of the semiconductor element). Can be suppressed.
However, when heat treatment is performed at a high temperature, Cu in the substrate tends to diffuse to the outermost surface of the Ni plating layer and accumulate in a state exposed on the outermost surface. And since exposed Cu is easy to oxidize or corrode, the greater the amount of exposure, the lower the resistance of the Ni plating layer to the high-temperature and high-humidity environment and the like, and there is a risk that high reliability cannot be imparted to the semiconductor device. There is.

特に、近年に至って増加する傾向にある、ヒートスプレッダの接続面に、他部材を、樹脂接着剤を用いて接着して組み立てられる半導体装置において、Ｎｉめっき層の最表面に露出したＣｕが酸化したり腐食したりすると、前記他部材の、ヒートスプレッダに対する接続の強度が低下したり、他部材がヒートスプレッダから剥離したりするという重大な欠陥を生じるおそれがある。   In particular, in semiconductor devices assembled by bonding other members to the heat spreader connection surface using a resin adhesive, which tends to increase in recent years, Cu exposed on the outermost surface of the Ni plating layer may be oxidized. Corrosion may cause a serious defect that the strength of the connection of the other member to the heat spreader is reduced or the other member is peeled off from the heat spreader.

かかる問題を解消するため、熱処理の温度を下げたり、Ｎｉめっき層の上にさらにＡｕめっき層を積層したりすることも検討されている。しかし前者の場合には、当然ながら、基体からＮｉめっき層中に拡散するＣｕの全体量が少なくなって、前記Ｎｉめっき層の、基体に対する密着性が低下するため、他部材の、ヒートスプレッダに対する接続の強度が却って低下したり、前記他部材がＮｉめっき層ごとヒートスプレッダから剥離したりするおそれがある。また後者の場合には、ヒートスプレッダの製造コストが著しく増加するという問題がある。   In order to solve this problem, it has been studied to lower the temperature of the heat treatment or to further stack an Au plating layer on the Ni plating layer. However, in the former case, of course, the total amount of Cu diffusing from the substrate into the Ni plating layer is reduced, and the adhesion of the Ni plating layer to the substrate is lowered. Therefore, the connection of other members to the heat spreader There is a risk that the strength of the other member may decrease or the other member may be peeled off from the heat spreader together with the Ni plating layer. In the latter case, there is a problem that the manufacturing cost of the heat spreader is remarkably increased.

そこで、基体の少なくとも接続面に、Ｎｉめっき層に代えて、その最表面がＡｌ（アルミニウム）の自然酸化による酸化膜で被覆されたＡｌ被覆層を形成したり（特許文献２参照）、ダイヤモンドライクカーボン膜を形成したり（特許文献３参照）することが提案されている。しかし前者のＡｌ被覆層は、特に塩素を含む雰囲気中で劣化して、基体に対する密着性が低下しやすいという問題がある。先に説明した樹脂接着剤には、その熱伝導性を高めるためにＡｇ（銀）フィラーが配合されることがあるが、前記Ａｇフィラーが配合される樹脂接着剤には、そのもとになる樹脂とＡｇフィラーとの親和性を高めるために塩素が配合されるのが一般的である。   Therefore, instead of the Ni plating layer, an Al coating layer whose outermost surface is coated with an oxide film formed by natural oxidation of Al (aluminum) is formed on at least the connection surface of the substrate (see Patent Document 2), or diamond-like It has been proposed to form a carbon film (see Patent Document 3). However, the former Al coating layer is deteriorated particularly in an atmosphere containing chlorine, and there is a problem that the adhesion to the substrate tends to be lowered. The resin adhesive described above may contain an Ag (silver) filler in order to increase its thermal conductivity, but the resin adhesive containing the Ag filler is the basis. In general, chlorine is blended in order to increase the affinity between the resin and the Ag filler.

そのためヒートスプレッダの接続面に、他部材を、樹脂接着剤を用いて接続して組み立てられる半導体装置に、前者のＡｌ被覆層を有するヒートスプレッダを用いた場合には、前記Ａｌ被覆層が樹脂接着剤中の塩素によって劣化しやすいため、他部材の、ヒートスプレッダに対する接続の強度が却って低下したり、前記他部材がＡｌ被覆層ごとヒートスプレッダから剥離したりしやすくなるおそれがある。また後者の場合には、ヒートスプレッダの製造コストが著しく増加するという問題がある。
特開平０６−０１３４９４号公報 特開平１０−２８４６４３号公報 特開２００４−１０４０７４号公報 Therefore, when the former heat spreader having an Al coating layer is used for a semiconductor device assembled by connecting other members to the connection surface of the heat spreader using a resin adhesive, the Al coating layer is not contained in the resin adhesive. Therefore, the strength of the connection of the other member to the heat spreader may be lowered, or the other member may be easily peeled off from the heat spreader together with the Al coating layer. In the latter case, there is a problem that the manufacturing cost of the heat spreader is remarkably increased.
Japanese Patent Laid-Open No. 06-013494 Japanese Patent Laid-Open No. 10-284463 JP 2004-104074 A

本発明の目的は、他部材の接続の強度が低下したり、前記他部材が剥離したりしにくいため、半導体装置に高い信頼性を付与できるヒートスプレッダと、前記ヒートスプレッダを用いた半導体装置とを提供することにある。本発明の他の目的は、前記本発明のヒートスプレッダを効率的に、しかも再現性よく製造するための製造方法を提供することにある。   An object of the present invention is to provide a heat spreader capable of imparting high reliability to a semiconductor device and a semiconductor device using the heat spreader because the strength of connection of the other member is reduced or the other member is hardly peeled off. There is to do. Another object of the present invention is to provide a production method for producing the heat spreader of the present invention efficiently and with good reproducibility.

前記課題を解決するため、発明者は、先に説明したＣｕ−Ｗ複合材料等のＣｕを含む複合材料からなる基体と、前記基体の少なくとも接続面に形成されたＮｉめっき層とを備えたヒートスプレッダにおいて、前記基体から拡散されてＮｉめっき層中に含まれるＣｕの含有量に、前記Ｎｉめっき層の厚み方向において濃度差をつけることを検討した。
その結果、接続面にＮｉめっきを施して、厚み０．２μｍ以上、１．２μｍ以下の第１めっき層を形成し、式(I)：
６２０℃≦Ｔ１≦８５０℃ (I)
を満足する温度Ｔ１（℃）で熱処理して前記基体中から前記第１めっき層中にＣｕを拡散させたのち、前記第１めっき層の表面にＮｉめっきを施して、厚み０．６μｍ以上、２．５μｍ以下の第２めっき層を形成し、式(II)：
３００℃≦Ｔ２≦５８０℃ (II)
を満足する温度Ｔ２（℃）で熱処理して前記第２めっき層と前記第１めっき層とを一体化させてＮｉめっき層を形成することで、
Ｎｉめっき層の基体との界面側の、前記界面から厚み方向に０．２μｍ以上、１．９μｍ以下の範囲でのＣｕの含有量ＲＨ（質量％）を式(III)：
２．５質量％≦ＲＨ (III)
を満足する高濃度とし、かつ
前記Ｎｉめっき層の最表面にＣｕを含有させないか、または前記最表面におけるＣｕの含有量ＲＳ（質量％）を式(IV)：
０質量％＜ＲＳ≦０．３質量％ (IV)
を満足する低濃度として、Ｎｉめっき層の最表面にＣｕを露出させないか、あるいは露出されるＣｕの量を少なくすると、
Ｎｉめっき層の、基体に対する良好な密着性を確保しながら、前記Ｎｉめっき層の、高温高湿環境等に対する耐性を向上して、前記Ｃｕが酸化したり腐食したりすることによる、他部材の、ヒートスプレッダに対する接続の強度が低下したり、前記他部材がヒートスプレッダから剥離したりする不具合が発生するのを、これまでよりも抑制できることを見出した。 In order to solve the above problems, the inventor has provided a heat spreader including a base body made of a composite material containing Cu, such as the Cu-W composite material described above, and a Ni plating layer formed on at least a connection surface of the base body. Then, a study was made to make a concentration difference in the thickness direction of the Ni plating layer to the Cu content diffused from the substrate and contained in the Ni plating layer.
As a result, Ni plating is applied to the connection surface to form a first plating layer having a thickness of 0.2 μm or more and 1.2 μm or less . Formula (I):
620 ° C. ≦ T 1 ≦ 850 ° C. (I)
After heat-treating at a temperature T 1 (° C.) satisfying the above conditions, Cu is diffused from the substrate into the first plating layer, and then Ni plating is applied to the surface of the first plating layer to obtain a thickness of 0.6 μm or more. Forming a second plating layer of 2.5 μm or less , and formula (II):
300 ° C ≦ T 2 ≦ 580 ° C (II)
By forming a Ni plating layer by integrating the second plating layer and the first plating layer by heat treatment at a temperature T 2 (° C.) that satisfies the following conditions:
The content R H (% by mass) of Cu in the range of 0.2 μm or more and 1.9 μm or less in the thickness direction from the interface on the interface side with the substrate of the Ni plating layer is expressed by the formula (III):
2.5 mass% ≤ R H (III)
And Cu is not contained in the outermost surface of the Ni plating layer, or the content R S (% by mass) of Cu in the outermost surface is represented by the formula (IV):
0% by mass <R S ≦ 0.3% by mass (IV)
If the Cu concentration is not exposed on the outermost surface of the Ni plating layer or the amount of exposed Cu is reduced,
While ensuring good adhesion of the Ni plating layer to the substrate, the resistance of the Ni plating layer to the high temperature and high humidity environment is improved, and the Cu is oxidized or corroded. It has been found that it is possible to suppress the occurrence of problems that the strength of the connection to the heat spreader is reduced or the other member is peeled off from the heat spreader.

また、前記Ｎｉめっき層を形成するＮｉや、Ｎｉめっき層に含まれるＣｕは、Ａｌのように樹脂接着剤中の塩素によっては劣化しにくいため、前記劣化によって、他部材の、ヒートスプレッダに対する接続の強度が低下したり、前記他部材がＮｉめっき層ごとヒートスプレッダから剥離したりするおそれがないこと、Ａｕめっきを施したりダイヤモンドライクカーボン膜を形成したりする場合のように、ヒートスプレッダの製造コストを増加させるおそれがないことも判明した。   Further, Ni that forms the Ni plating layer and Cu contained in the Ni plating layer are unlikely to deteriorate due to chlorine in the resin adhesive, such as Al. Therefore, due to the deterioration, connection of other members to the heat spreader is caused. Increased heat spreader manufacturing costs, such as when there is no risk that the strength will be reduced or the other members may be peeled off from the heat spreader together with the Ni plating layer, and when Au plating is applied or a diamond-like carbon film is formed. It has also been found that there is no fear of doing so.

したがって本発明は、Ｗ、Ｍｏ、またはダイヤモンドと、Ｃｕとの複合材料からなり、他部材との接続のための接続面を有する基体を備え、前記基体の少なくとも前記接続面にＮｉめっき層が形成されたヒートスプレッダであって、前記Ｎｉめっき層が、前記接続面にＮｉめっきを施して、厚み０．２μｍ以上、１．２μｍ以下の第１めっき層を形成し、式(I)：
６２０℃≦Ｔ１≦８５０℃ (I)
を満足する温度Ｔ１（℃）で熱処理して前記基体中から前記第１めっき層中にＣｕを拡散させたのち、前記第１めっき層の表面にＮｉめっきを施して、厚み０．６μｍ以上、２．５μｍ以下の第２めっき層を形成し、式(II)：
３００℃≦Ｔ２≦５８０℃ (II)
を満足する温度Ｔ２（℃）で熱処理して前記第２めっき層と前記第１めっき層とを一体化させて形成され、
前記Ｎｉめっき層は、前記基体との界面から厚み方向に０．２μｍ以上、１．９μｍ以下の範囲にＣｕの含有量ＲＨ（質量％）が式(III)：
２．５質量％≦ＲＨ (III)
を満足する高Ｃｕ領域を有すると共に、前記Ｎｉめっき層の最表面がＣｕを含まないか、または前記最表面におけるＣｕの含有量ＲＳ（質量％）が式(IV)：
０質量％＜ＲＳ≦０．３質量％ (IV)
を満足し、かつ前記Ｎｉめっき層の、前記基体に対する密着強度ＳＡ（Ｎ／ｍｍ２）が９０Ｎ／ｍｍ２以上であることを特徴とする。 Therefore, the present invention includes a base body made of a composite material of W, Mo, or diamond and Cu, and having a connection surface for connection to other members, and a Ni plating layer is formed on at least the connection surface of the base body. In the heat spreader, the Ni plating layer performs Ni plating on the connection surface to form a first plating layer having a thickness of 0.2 μm or more and 1.2 μm or less . Formula (I):
620 ° C. ≦ T 1 ≦ 850 ° C. (I)
After heat-treating at a temperature T 1 (° C.) satisfying the above conditions, Cu is diffused from the substrate into the first plating layer, and then Ni plating is applied to the surface of the first plating layer to obtain a thickness of 0.6 μm or more. Forming a second plating layer of 2.5 μm or less , and formula (II):
300 ° C ≦ T 2 ≦ 580 ° C (II)
Formed by integrating the second plating layer and the first plating layer by heat treatment at a temperature T 2 (° C.) satisfying
The Ni plating layer has a Cu content R H (mass%) in the range of 0.2 μm or more and 1.9 μm or less in the thickness direction from the interface with the substrate, with the formula (III):
2.5 mass% ≤ R H (III)
And the outermost surface of the Ni plating layer does not contain Cu, or the Cu content R S (% by mass) on the outermost surface is represented by the formula (IV):
0% by mass <R S ≦ 0.3% by mass (IV)
And the adhesion strength S A (N / mm 2 ) of the Ni plating layer to the substrate is 90 N / mm 2 or more.

基体は、特にＣｕ−Ｗ複合材料からなり、前記Ｃｕ−Ｗ複合材料におけるＷの含有量が７５質量％以上、９５質量％以下であるのが好ましい。前記Ｃｕ−Ｗ複合材料からなる基体は、接続面に接続される他部材、すなわち種々の半導体材料からなる半導体素子や、Ｓｉ、セラミック等からなるヒートシンク、ステム、パッケージ等との熱膨張係数の整合性に優れると共に高い熱伝導率を有する上、コスト安価に製造できる。 Group body, especially made of Cu-W composite material, the Cu-W W content in the composite material is 75 wt% or more, preferably not more than 95 wt%. The substrate made of the Cu-W composite material matches the thermal expansion coefficient with other members connected to the connection surface, that is, semiconductor elements made of various semiconductor materials, heat sinks, stems, packages, etc. made of Si, ceramics, etc. In addition to being excellent in properties, it has high thermal conductivity and can be manufactured at low cost.

本発明の半導体装置は、半導体素子と、前記半導体素子の動作時に発生する熱を除去するための、前記本発明のヒートスプレッダとを備えることを特徴とする。前記本発明によれば、前記ヒートスプレッダの機能によって、例えば高温高湿環境下等の様々な環境下で他部材の接続の強度が低下したり、前記他部材が剥離したりするのを防止して、半導体装置に高い信頼性を付与できる。   The semiconductor device of the present invention includes a semiconductor element and the heat spreader of the present invention for removing heat generated during operation of the semiconductor element. According to the present invention, the function of the heat spreader prevents the connection strength of other members from being reduced or the other members from being peeled off under various environments such as a high temperature and high humidity environment. High reliability can be imparted to the semiconductor device.

半導体装置の具体的な構成としては、ヒートスプレッダが複数の接続面を備え、前記複数の接続面のうち少なくとも１つの接続面に前記半導体素子、他の接続面に熱除去部材が、それぞれＡｇフィラーを配合した樹脂接着剤を介して接続されている半導体装置が挙げられる。また前記半導体装置においては、半導体素子や熱除去部材の、ヒートスプレッダの接続面に対する接続の強度を示す接着強度が、それぞれ１５．７Ｎ／ｍｍ ２ 以上であるのが好ましい。 As a specific configuration of the semiconductor device, a heat spreader includes a plurality of connection surfaces, and the semiconductor element is provided on at least one connection surface of the plurality of connection surfaces, and a heat removal member is provided on each of the other connection surfaces. The semiconductor device connected through the mix | blended resin adhesive is mentioned. In the semiconductor device, it is preferable that the bonding strength of the semiconductor element or the heat removal member, which indicates the strength of connection to the connection surface of the heat spreader, is 15.7 N / mm 2 or more.

また本発明は、前記本発明のヒートスプレッダを製造するための製造方法であって、Ｗ、Ｍｏ、またはダイヤモンドと、Ｃｕとの複合材料からなる前記基体の少なくとも前記接続面にＮｉめっきを施して厚みが０．２μｍ以上、１．２μｍ以下の第１めっき層を形成し、式(I)：
６２０℃≦Ｔ１≦８５０℃ (I)
を満足する温度Ｔ１（℃）で熱処理して前記基体中から前記第１めっき層中にＣｕを拡散させる工程と、前記第１めっき層の表面にＮｉめっきを施して厚みが０．６μｍ以上、２．５μｍ以下の第２めっき層を形成し、式(II)：
３００℃≦Ｔ２≦５８０℃ (II)
を満足する温度Ｔ２（℃）で熱処理して前記第２めっき層と前記第１めっき層とを一体化させて前記Ｎｉめっき層を形成する工程とを含むことを特徴とする。 Further, the present invention is a manufacturing method for manufacturing the heat spreader of the present invention, wherein at least the connection surface of the substrate made of a composite material of W, Mo, or diamond and Cu is subjected to Ni plating to obtain a thickness. A first plating layer having a thickness of 0.2 μm or more and 1.2 μm or less is formed, and the formula (I):
620 ° C. ≦ T 1 ≦ 850 ° C. (I)
And a step of diffusing Cu from the substrate into the first plating layer by performing a heat treatment at a temperature T 1 (° C.) that satisfies the following conditions: Ni plating is applied to the surface of the first plating layer, and the thickness is 0.6 μm or more. Forming a second plating layer of 2.5 μm or less, and formula (II):
300 ° C ≦ T 2 ≦ 580 ° C (II)
And a step of forming the Ni plating layer by integrating the second plating layer and the first plating layer by heat treatment at a temperature T 2 (° C.) satisfying the above.

前記本発明の製造方法によれば、本発明のヒートスプレッダを、Ｎｉめっきと熱処理とを繰り返すだけで、再現性よく、かつ効率的に製造できる。すなわち、前記工程を経てＮｉめっき層を形成する場合には、高Ｃｕ領域の厚みとＣｕの含有量とを第１めっき層の厚みおよびＣｕの含有量とほぼ一致できると共に、低Ｃｕ領域の厚みとＣｕの含有量とを第２めっき層の厚みおよびＣｕの含有量とほぼ一致できる。   According to the manufacturing method of the present invention, the heat spreader of the present invention can be manufactured with good reproducibility and efficiency simply by repeating Ni plating and heat treatment. That is, when the Ni plating layer is formed through the above steps, the thickness of the high Cu region and the Cu content can be substantially matched with the thickness of the first plating layer and the Cu content, and the thickness of the low Cu region. And the Cu content can be substantially matched with the thickness of the second plating layer and the Cu content.

また、第１および第２めっき層におけるＣｕの含有量は、それぞれのめっき層に対する熱処理の条件、特に温度を変更することで任意に調整できる。そのため、それぞれのめっき層の厚みと熱処理の条件とを変更することで、高Ｃｕ領域の厚みとＣｕの含有量、Ｎｉめっき層の最表面におけるＣｕの含有量、ならびに前記最表面を含む低Ｃｕ領域の厚みとＣｕの含有量を任意に調整でき、本発明のヒートスプレッダを、再現性よく、かつ効率的に製造できる。   In addition, the Cu content in the first and second plating layers can be arbitrarily adjusted by changing the conditions of the heat treatment for each plating layer, particularly the temperature. Therefore, by changing the thickness of each plating layer and the heat treatment conditions, the thickness of the high Cu region and the Cu content, the Cu content in the outermost surface of the Ni plating layer, and the low Cu containing the outermost surface The thickness of the region and the Cu content can be arbitrarily adjusted, and the heat spreader of the present invention can be manufactured with good reproducibility and efficiency.

本発明によれば、他部材の接続の強度が低下したり、前記他部材が剥離したりしにくいため、半導体装置に高い信頼性を付与できるヒートスプレッダと、前記ヒートスプレッダを用いた半導体装置とを提供することができる。また本発明によれば、前記本発明のヒートスプレッダを効率的に、しかも再現性よく製造するための製造方法を提供することができる。   According to the present invention, there is provided a heat spreader capable of imparting high reliability to a semiconductor device and a semiconductor device using the heat spreader because the connection strength of the other member is reduced or the other member is hardly peeled off. can do. Moreover, according to this invention, the manufacturing method for manufacturing the heat spreader of the said this invention efficiently and with sufficient reproducibility can be provided.

図１は、本発明のヒートスプレッダの、実施の形態の一例の要部であるＮｉめっき層の一部を拡大した断面図である。
本発明は、Ｗ、Ｍｏ、またはダイヤモンドと、Ｃｕとの複合材料からなり、他部材との接続のための接続面を有する基体を備え、前記基体の少なくとも前記接続面にＮｉめっき層が形成されたヒートスプレッダであって、前記Ｎｉめっき層が、前記接続面にＮｉめっきを施して、厚み０．２μｍ以上、１．２μｍ以下の第１めっき層を形成し、式(I)：
６２０℃≦Ｔ１≦８５０℃ (I)
を満足する温度Ｔ１（℃）で熱処理して前記基体中から前記第１めっき層中にＣｕを拡散させたのち、前記第１めっき層の表面にＮｉめっきを施して、厚み０．６μｍ以上、２．５μｍ以下の第２めっき層を形成し、式(II)：
３００℃≦Ｔ２≦５８０℃ (II)
を満足する温度Ｔ２（℃）で熱処理して前記第２めっき層と前記第１めっき層とを一体化させて形成され、
前記Ｎｉめっき層は、前記基体との界面から厚み方向に０．２μｍ以上、１．９μｍ以下の範囲にＣｕの含有量ＲＨ（質量％）が式(III)：
２．５質量％≦ＲＨ (III)
を満足する高Ｃｕ領域を有すると共に、前記Ｎｉめっき層の最表面がＣｕを含まないか、または前記最表面におけるＣｕの含有量ＲＳ（質量％）が式(IV)：
０質量％＜ＲＳ≦０．３質量％ (IV)
を満足し、かつ前記Ｎｉめっき層の、前記基体に対する密着強度ＳＡ（Ｎ／ｍｍ２）が９０Ｎ／ｍｍ２以上であることを特徴とする。 FIG. 1 is an enlarged cross-sectional view of a part of a Ni plating layer that is a main part of an example of an embodiment of a heat spreader of the present invention.
The present invention comprises a substrate made of a composite material of W, Mo, or diamond and Cu, and having a connection surface for connection to other members, and a Ni plating layer is formed on at least the connection surface of the substrate. In the heat spreader, the Ni plating layer performs Ni plating on the connection surface to form a first plating layer having a thickness of 0.2 μm or more and 1.2 μm or less . Formula (I):
620 ° C. ≦ T 1 ≦ 850 ° C. (I)
After heat-treating at a temperature T 1 (° C.) satisfying the above conditions, Cu is diffused from the substrate into the first plating layer, and then Ni plating is applied to the surface of the first plating layer to obtain a thickness of 0.6 μm or more. Forming a second plating layer of 2.5 μm or less , and formula (II):
300 ° C ≦ T 2 ≦ 580 ° C (II)
Formed by integrating the second plating layer and the first plating layer by heat treatment at a temperature T 2 (° C.) satisfying
The Ni plating layer has a Cu content R H (mass%) in the range of 0.2 μm or more and 1.9 μm or less in the thickness direction from the interface with the substrate, with the formula (III):
2.5 mass% ≤ R H (III)
And the outermost surface of the Ni plating layer does not contain Cu, or the Cu content R S (% by mass) on the outermost surface is represented by the formula (IV):
0% by mass <R S ≦ 0.3% by mass (IV)
And the adhesion strength S A (N / mm 2 ) of the Ni plating layer to the substrate is 90 N / mm 2 or more.

基体１を形成する複合材料としては、
(a) 先に説明したように、ＷやＭｏからなる多孔質体の細孔内にＣｕを溶浸させて形成されたＣｕ−Ｗ複合材料やＣｕ−Ｍｏ複合材料が挙げられる他、
(b) 多数の微小なダイヤモンド粒子を結合材としてのＣｕで結合した複合構造を有するＣｕ−ダイヤモンド複合材料、
等も挙げられる。 As a composite material forming the substrate 1,
(a) As described above, Cu-W composite material and Cu-Mo composite material formed by infiltrating Cu into the pores of a porous body made of W or Mo can be mentioned,
(b) a Cu-diamond composite material having a composite structure in which a large number of minute diamond particles are bonded with Cu as a binder;
And so on.

基体１は、半導体素子の動作時の発熱をできるだけスムースに除去することを考慮すると、熱伝導率が１７０Ｗ／ｍ・Ｋ以上、６５０Ｗ／ｍ・Ｋ以下、特に２００Ｗ／ｍ・Ｋ以上、６５０Ｗ／ｍ・Ｋ以下であるのが好ましい。The substrate 1 has a thermal conductivity of 170 W / m · K or more and 650 W / m · K or less, particularly 200 W / m · K or more and 650 W / It is preferably m · K or less.

熱伝導率が前記範囲未満では、半導体素子の動作時の発熱を効率的に逃がせないため、前記半導体素子の動作効率が低下したり、寿命が短くなったり、或いは寿命前に半導体素子が破損したりするおそれがある。一方、熱伝導率が前記範囲を超えるものは、Ｃｕを含む材料としては作製することが困難である。 If the thermal conductivity is less than the above range, heat generated during the operation of the semiconductor element cannot be efficiently escaped, so that the operation efficiency of the semiconductor element is reduced, the life is shortened, or the semiconductor element is damaged before the life. There is a risk of On the other hand, a material having a thermal conductivity exceeding the above range is difficult to produce as a material containing Cu.

また基体１は、種々の半導体材料からなる半導体素子や、Ｓｉ、セラミック等からなるヒートシンク、ステム、パッケージ等との熱膨張係数の整合性を向上することを考慮すると、その熱膨張係数が２．０×１０-6／Ｋ以上、１０×１０-6／Ｋ以下であるのが好ましい。熱膨張係数が前記範囲未満であるか、あるいは前記範囲を超える場合には、このいずれにおいても熱膨張係数の整合性が低下する。そのため、ヒートスプレッダ４の接続面２に前記他部材を接続する際や半導体装置の使用時の熱履歴等によって半導体素子に過剰な応力が生じて、前記半導体素子の特性が劣化したり、半導体素子が破損したりするおそれがある。 In consideration of improving the consistency of the thermal expansion coefficient of the base 1 with semiconductor elements made of various semiconductor materials, heat sinks, stems, packages, etc. made of Si, ceramics, etc., the thermal expansion coefficient is 2. It is preferably 0 × 10 −6 / K or more and 10 × 10 −6 / K or less. When the thermal expansion coefficient is less than the above range or exceeds the above range, the consistency of the thermal expansion coefficient is lowered in either case. For this reason, when connecting the other member to the connection surface 2 of the heat spreader 4 or when the semiconductor device is used, excessive stress is generated in the semiconductor element, and the characteristics of the semiconductor element deteriorates. There is a risk of damage.

また、半導体素子等の他部材の、ヒートスプレッダ４に対する接続の強度が低下したり、前記他部材がヒートスプレッダ４から剥離したりするおそれもある。なお、例えば半導体素子としてＳｉ系、ＧａＡｓ（ガリウム−砒素）系、ＧａＮ（窒化ガリウム）系等の半導体材料からなるものを用いる場合、前記半導体素子に対する熱膨張係数の整合性をさらに向上することを考慮すると、基体１の熱膨張係数は、前記範囲内でも４．０×１０-6／Ｋ以上、８．０×１０-6／Ｋ以下であるのがさらに好ましい。 Further, the strength of the connection of other members such as semiconductor elements to the heat spreader 4 may be reduced, or the other members may be peeled off from the heat spreader 4. For example, when a semiconductor device made of a semiconductor material such as Si, GaAs (gallium-arsenide), or GaN (gallium nitride) is used, the matching of the thermal expansion coefficient with the semiconductor device is further improved. Considering the above, it is more preferable that the thermal expansion coefficient of the substrate 1 is 4.0 × 10 −6 / K or more and 8.0 × 10 −6 / K or less even within the above range.

また近時、ヒートスプレッダ４それ自体を半導体素子への電気的接続のための電極としても機能させることが試みられており、そのためには基体１の比抵抗が１．６×１０-8Ωｍ以上、１．０×１０-3Ωｍ以下であるのが好ましい。比抵抗が前記範囲を超える場合には、それ自体を素子の電極として機能させる効果が十分に得られないだけでなく、電極として機能させた際に基体１自体が発熱するおそれもある。また、比抵抗が前記範囲未満である材料（複合材料を含む）は特別なものに限られており、高価で、しかも製造が容易でない。そのため基体１の、ひいてはヒートスプレッダ４や半導体装置の生産性を低下させ、製造コストを高騰させる要因となる。 Recently, it has been attempted to make the heat spreader 4 itself function as an electrode for electrical connection to a semiconductor element. For that purpose, the specific resistance of the substrate 1 is 1.6 × 10 −8 Ωm or more, It is preferable that it is 1.0 × 10 −3 Ωm or less. When the specific resistance exceeds the above range, not only the effect of functioning itself as an electrode of the element cannot be sufficiently obtained, but also the base 1 itself may generate heat when functioning as an electrode. Moreover, materials (including composite materials) whose specific resistance is less than the above range are limited to special ones, are expensive, and are not easy to manufacture. For this reason, the productivity of the base body 1, and thus the heat spreader 4 and the semiconductor device, is lowered, and this increases the manufacturing cost.

前記各特性を、いずれも好適な範囲内に調整するためには、基体１の複合構造や組成を調整すればよい。かかる調整によって、各特性がいずれも前記範囲を満足する基体１を形成できる。熱伝導率と熱膨張係数の観点から好適な基体１の材料としては、(a)のＣｕ−Ｗ複合材料やＣｕ−Ｍｏ複合材料、(b)のＣｕ−ダイヤモンド複合材料が挙げられ、特に製造コストの観点からは(a)のうちＣｕ−Ｗ複合材料が好ましい。なお、(b)のＣｕ−ダイヤモンド複合材料におけるダイヤモンドの割合は４０質量％以上、６０質量％以下であるのが好ましい。 In order to adjust each of the above characteristics within a suitable range, the composite structure and composition of the substrate 1 may be adjusted . Depending mow adjustment, both the respective characteristics can forming the substrate 1 that satisfies the above range. Suitable materials for the substrate 1 from the viewpoint of thermal conductivity and thermal expansion coefficient include (a) Cu—W composite material and Cu—Mo composite material, and (b) Cu—diamond composite material. From the viewpoint of cost, a Cu—W composite material is preferable among (a). In addition, it is preferable that the ratio of the diamond in the Cu-diamond composite material of (b) is 40 mass% or more and 60 mass% or less.

また(a)のＣｕ−Ｗ複合材料におけるＷの割合は７５質量％以上、９５質量％以下、特に８０質量％以上、９０質量％以下であるのが好ましい。Ｗの割合が前記範囲未満では、Ｃｕ−Ｗ複合材料からなる基体１の熱膨張係数が前記範囲を超えるため、接続面２に接続される他部材、すなわち、種々の半導体材料からなる半導体素子や、Ｓｉ、セラミック等からなるヒートシンク、ステム、パッケージ等との、熱膨張係数の整合性が取れなくなるおそれがある。   The proportion of W in the Cu-W composite material (a) is preferably 75% by mass or more and 95% by mass or less, particularly preferably 80% by mass or more and 90% by mass or less. When the ratio of W is less than the above range, the thermal expansion coefficient of the base 1 made of the Cu—W composite material exceeds the above range, so that other members connected to the connection surface 2, that is, semiconductor elements made of various semiconductor materials, There is a risk that the thermal expansion coefficient will not be consistent with heat sinks, stems, packages, etc. made of Si, ceramics or the like.

またＷの割合が前記範囲を超える場合には、Ｃｕ−Ｗ複合材料からなる基体１の熱伝導率が先に説明した範囲未満となって、半導体素子の動作時の発熱を効率的に逃がすことができないため、半導体素子の動作効率が低下したり、寿命が短くなったり、寿命前に半導体素子が破損したりするおそれがある。前記Ｃｕ−Ｗ複合材料からなる基体１は、先に説明した特許文献１に記載の製造方法によって製造できる。   When the W ratio exceeds the above range, the thermal conductivity of the substrate 1 made of the Cu—W composite material becomes less than the above-described range, and the heat generated during the operation of the semiconductor element is efficiently released. Therefore, there is a possibility that the operating efficiency of the semiconductor element is lowered, the life is shortened, or the semiconductor element is damaged before the life. The base body 1 made of the Cu—W composite material can be manufactured by the manufacturing method described in Patent Document 1 described above.

すなわちＷの粉末を、必要に応じて、結合材として機能する少量のＮｉを添加したＷ合金の粉末や樹脂バインダ等と混合して所定の立体形状にプレス成形した後、還元性雰囲気中で焼結させてＷからなる多孔質体を作製し、前記多孔質体の細孔内に、還元性雰囲気中で、加熱して溶融させたＣｕを溶浸させてＣｕ−Ｗ複合材料からなる基体１の前駆体を得る。そして前記前駆体を、必要に応じてワイヤ放電加工等によって所定の基体１の立体形状に切り出すと共に、その接続面２を所定の表面粗さとなるように仕上げ加工して基体１が製造される。   That is, if necessary, W powder is mixed with a W alloy powder or a resin binder to which a small amount of Ni that functions as a binder is added, press-molded into a predetermined three-dimensional shape, and then fired in a reducing atmosphere. Then, a porous body made of W is prepared, and Cu that has been heated and melted in a reducing atmosphere is infiltrated into the pores of the porous body to form a substrate 1 made of a Cu—W composite material. To obtain a precursor. Then, the precursor 1 is cut into a predetermined three-dimensional shape of the base 1 by wire electric discharge machining or the like as required, and the base 1 is manufactured by finishing the connection surface 2 to have a predetermined surface roughness.

接続面２の表面粗さは、日本工業規格ＪＩＳ Ｂ０６０１：２００１「製品の幾何特性仕様（ＧＰＳ）−表面性状：輪郭曲線方式−用語，定義及び表面性状パラメータ」において規定された粗さ曲線の算術平均粗さＲａで表して１．６μｍ以下であるのが好ましい。算術平均粗さＲａが前記範囲を超える場合には、接続面２に接続される他部材との間で良好な熱伝導が得られないおそれがある。   The surface roughness of the connecting surface 2 is an arithmetic operation of a roughness curve defined in Japanese Industrial Standard JIS B0601: 2001 “Product Geometrical Specification (GPS) —Surface Properties: Contour Curve Method—Terminology, Definition, and Surface Property Parameters”. The average roughness Ra is preferably 1.6 μm or less. When arithmetic average roughness Ra exceeds the said range, there exists a possibility that favorable heat conduction may not be obtained between the other members connected to the connection surface 2. FIG.

基体１の形状等は、接続面２に接続する半導体素子の形状や寸法、あるいは前記接続面２に半導体素子やヒートシンク、ステム、パッケージ等の他部材を接続して構成される半導体装置の全体の形状等に合わせて任意に設定できるが、例えば平板状の基体１の場合はその厚みが０．１５ｍｍ以上、１０ｍｍ以下、特に１ｍｍ以上、３ｍｍ以下であるのが好ましい。厚みが前記範囲を超える場合には半導体装置の薄型化、小型化が難しい上、材料費が嵩んで、ヒートスプレッダ４の、ひいては半導体装置の製造コストを増加させる原因にもなる。   The shape or the like of the base 1 is the shape or size of a semiconductor element connected to the connection surface 2 or the entire semiconductor device configured by connecting other members such as a semiconductor element, a heat sink, a stem, and a package to the connection surface 2. For example, in the case of the flat substrate 1, the thickness is preferably 0.15 mm or more and 10 mm or less, particularly preferably 1 mm or more and 3 mm or less. If the thickness exceeds the above range, it is difficult to reduce the thickness and size of the semiconductor device, and the material cost increases, leading to an increase in the manufacturing cost of the heat spreader 4 and thus the semiconductor device.

一方、厚みが前記範囲未満では、基体１が反りを生じやすくなって、接続面２に、半導体素子等の他部材を良好に密着できないおそれがある。また、ヒートスプレッダ４の熱容量が不足して熱を十分に除去できないおそれもある。平板状の基体１の反り量は、例えば平面形状が矩形状の基体１の場合、その対角線方向の長さ１ｍｍあたり１μｍ以下、特に０．５μｍ以下であるのが好ましい。反り量が前記範囲を超える場合には、前記のように接続面２に、半導体素子等の他部材を良好に密着できないおそれがある。   On the other hand, if the thickness is less than the above range, the base body 1 tends to be warped, and there is a possibility that other members such as a semiconductor element cannot be satisfactorily adhered to the connection surface 2. Moreover, there is a possibility that the heat capacity of the heat spreader 4 is insufficient and heat cannot be removed sufficiently. The amount of warpage of the flat substrate 1 is, for example, preferably 1 μm or less, particularly 0.5 μm or less per 1 mm length in the diagonal direction when the substrate 1 has a rectangular planar shape. When the amount of warpage exceeds the above range, there is a possibility that other members such as a semiconductor element cannot be satisfactorily adhered to the connection surface 2 as described above.

そのため、半導体素子の動作時の発熱を効率的に逃がせなくなって、半導体素子の動作効率が低下したり、寿命が短くなったり、寿命前に半導体素子が破損したりするおそれがある。なお反り量の最小値は、対角線方向の長さ１ｍｍあたり０μｍであって反りがないのが最も好ましい。基体１は前記平板状の他、例えば特許文献３に記載された、平板の片面に半導体素子を収容する凹部を有する凹形状等の任意の立体形状に形成できる。   Therefore, heat generated during the operation of the semiconductor element cannot be efficiently released, and the operation efficiency of the semiconductor element may be reduced, the lifetime may be shortened, or the semiconductor element may be damaged before the lifetime. The minimum value of the warp amount is most preferably 0 μm per 1 mm length in the diagonal direction and no warp. In addition to the flat plate shape, the base body 1 can be formed in an arbitrary three-dimensional shape such as a concave shape having a concave portion for accommodating a semiconductor element on one surface of a flat plate described in Patent Document 3, for example.

前記基体１の、少なくとも接続面２に形成されるＮｉめっき層３は、先に説明したように、基体１との界面から厚み方向に０．２μｍ以上、１．９μｍ以下の範囲にＣｕの含有量ＲＨ（質量％）が式(III)：
２．５質量％≦ＲＨ (III)
を満足する高Ｃｕ領域５を有すると共に、その最表面６がＣｕを含まないか、または前記最表面６におけるＣｕの含有量ＲＳ（質量％）が式(IV)：
０質量％＜ＲＳ≦０．３質量％ (IV)
を満足し、かつ前記Ｎｉめっき層３の、基体１に対する密着強度ＳＡ（Ｎ／ｍｍ２）が９０Ｎ／ｍｍ２以上である必要がある。これにより、Ｎｉめっき層３の、基体１に対する良好な密着性を確保しながら、前記Ｎｉめっき層３の最表面に露出されるＣｕの量を少なくして、Ｎｉめっき層３の、高温高湿環境等に対する耐性を向上できる。そのため、前記Ｃｕが酸化したり腐食したりすることによる、他部材の、ヒートスプレッダ４に対する接続の強度が低下したり、前記他部材がヒートスプレッダ４から剥離したりする不具合が発生するのを抑制できる。 As described above, the Ni plating layer 3 formed on at least the connection surface 2 of the base body 1 contains Cu in the range of 0.2 μm or more and 1.9 μm or less in the thickness direction from the interface with the base body 1. The amount R H (mass%) is the formula (III):
2.5 mass% ≤ R H (III)
And the outermost surface 6 does not contain Cu, or the Cu content R S (% by mass) in the outermost surface 6 is represented by the formula (IV):
0% by mass <R S ≦ 0.3% by mass (IV)
And the adhesion strength S A (N / mm 2 ) of the Ni plating layer 3 to the substrate 1 needs to be 90 N / mm 2 or more. Thereby, the amount of Cu exposed on the outermost surface of the Ni plating layer 3 is reduced while ensuring good adhesion of the Ni plating layer 3 to the substrate 1, so that the high temperature and high humidity of the Ni plating layer 3 can be reduced. Resistance to the environment can be improved. Therefore, it is possible to suppress the occurrence of problems that the strength of the connection of other members to the heat spreader 4 due to the oxidation or corrosion of the Cu or the other members peeling off from the heat spreader 4 is generated.

高Ｃｕ領域５の厚みが１．９μｍ以下に限定されるのは、厚みが１．９μｍを超える場合には、Ｎｉめっき層３の全体の厚みにもよるが、前記高Ｃｕ領域５からのＣｕの拡散を抑制して、その最表面６を、Ｃｕを含まないか、またはその含有量ＲＳが式(IV)を満足する状態にできないためである。つまり高Ｃｕ領域５の厚みが１．９μｍを超えると、Ｎｉめっき層３の、高温高湿環境等に対する耐性を向上する効果が得られない。 The reason why the thickness of the high Cu region 5 is limited to 1.9 μm or less is that when the thickness exceeds 1.9 μm , the Cu from the high Cu region 5 depends on the total thickness of the Ni plating layer 3. This is because the outermost surface 6 does not contain Cu or the content R S of the outermost surface 6 does not satisfy the formula (IV). That is, when the thickness of the high Cu region 5 exceeds 1.9 μm , the effect of improving the resistance of the Ni plating layer 3 to a high temperature and high humidity environment cannot be obtained.

また高Ｃｕ領域５の厚みは、前記範囲内でも０．２μｍ以上である必要がある。高Ｃｕ領域の厚みを前記範囲内とすることによって、前記高Ｃｕ領域５を設けたことによる、Ｎｉめっき層３の、基体１に対する良好な密着性を維持する効果をさらに向上できる。
また高Ｃｕ領域５におけるＣｕの含有量ＲＨが式(III)を満足する範囲に限定されるのは、含有量ＲＨが２．５質量％未満では、基体１から高Ｃｕ領域５へのＣｕの拡散が十分でないことになり、Ｎｉめっき層３の、基体１に対する良好な密着性を確保する効果、つまりＮｉめっき層３の、基体１に対する密着強度ＳＡ（Ｎ／ｍｍ２）を９０Ｎ／ｍｍ２以上とする効果が得られないためである。 The thickness of the high Cu region 5 is required to be on 0.2μm or more in the above range. By setting the thickness of the high Cu region within the above range, the effect of maintaining good adhesion of the Ni plating layer 3 to the substrate 1 by providing the high Cu region 5 can be further improved.
Further, the Cu content RH in the high Cu region 5 is limited to the range satisfying the formula (III) when the content RH is less than 2.5% by mass from the substrate 1 to the high Cu region 5. The diffusion of Cu is not sufficient, and the effect of ensuring good adhesion of the Ni plating layer 3 to the substrate 1, that is, the adhesion strength S A (N / mm 2 ) of the Ni plating layer 3 to the substrate 1 is 90N. This is because the effect of at least / mm 2 cannot be obtained.

含有量ＲＨは、２０質量％以下であるのが好ましい。含有量ＲＨが２０質量％を超える場合には、Ｎｉめっき層３の全体の厚みにもよるが、前記高Ｃｕ領域５からのＣｕの拡散を抑制して、Ｎｉめっき層３の最表面６を、Ｃｕを含まないか、またはその含有量ＲＳが式(IV)を満足する状態にできないおそれがある。つまり高Ｃｕ領域５におけるＣｕの含有量ＲＨが２０質量％を超える場合にも、Ｎｉめっき層３の、高温高湿環境等に対する耐性を向上する効果が得られないおそれがある。なお含有量ＲＨは、前記範囲内でも７質量％以下であるのがさらに好ましい。 The content RH is preferably 20% by mass or less. When the content RH exceeds 20% by mass, the outermost surface 6 of the Ni plating layer 3 is suppressed by suppressing the diffusion of Cu from the high Cu region 5, although it depends on the total thickness of the Ni plating layer 3. May not contain Cu, or the content RS thereof may not satisfy the formula (IV) . That is, even when the Cu content RH in the high Cu region 5 exceeds 20 mass%, the effect of improving the resistance of the Ni plating layer 3 to a high-temperature and high-humidity environment or the like may not be obtained. The content RH is more preferably 7% by mass or less even within the above range.

Ｎｉめっき層３の最表面６におけるＣｕの含有量ＲＳが式(IV)を満足する範囲に限定されるのは、含有量ＲＳが０．３質量％を超える場合には、Ｎｉめっき層３の、高温高湿環境等に対する耐性を向上する効果が得られないためである。なお、Ｎｉめっき層３の耐性を向上する効果を考慮すると、前記最表面６はＣｕを含有していない、言い換えれば含有量ＲＳが０質量％であるのが最も好ましく、本発明は、含有量ＲＳが０．３質量％以下で、０質量％までの範囲を包含している。 The reason why the content R S of Cu on the outermost surface 6 of the Ni plating layer 3 is limited to the range satisfying the formula (IV) is that when the content R S exceeds 0.3 mass% , the Ni plating layer This is because the effect of improving the resistance to the high temperature and high humidity environment of 3 cannot be obtained. In consideration of the effect of improving the resistance of the Ni plating layer 3, the outermost surface 6 does not contain Cu, in other words, the content RS is most preferably 0% by mass. The amount R S is 0.3 mass% or less and includes the range up to 0 mass%.

ただしＮｉめっき層３の、基体１に対する良好な密着性を確保する効果との兼ね合いを考慮すると、Ｎｉめっき層３の最表面６は、前記式(IV)の範囲でＣｕを含有していても差し支えない。
Ｎｉめっき層３の、基体１に対する密着強度ＳＡ（Ｎ／ｍｍ２）が９０Ｎ／ｍｍ２以上に限定されるのは、密着強度ＳＡが９０Ｎ／ｍｍ２未満では、前記Ｎｉめっき層３の、基体１に対する良好な密着性を確保できないためである。つまり密着強度ＳＡが９０Ｎ／ｍｍ２未満では、ヒートスプレッダ４の接続面２に他部材を接続する際や、半導体装置の使用時の熱履歴等によってＮｉめっき層３が脹れを生じたり基体１から剥離したりしやすくなる。 However, considering the balance between the Ni plating layer 3 and the effect of ensuring good adhesion to the substrate 1, the outermost surface 6 of the Ni plating layer 3 may contain Cu in the range of the formula (IV). There is no problem.
The reason why the adhesion strength S A (N / mm 2 ) of the Ni plating layer 3 to the substrate 1 is limited to 90 N / mm 2 or more is that when the adhesion strength S A is less than 90 N / mm 2 , This is because good adhesion to the substrate 1 cannot be ensured. That adhesion The strength S A is less than 90 N / mm 2, and when connecting the other member connection surface 2 of the heat spreader 4, the substrate or cause swelling of Ni plating layer 3 by thermal history or the like during use of the semiconductor device 1 It becomes easy to peel from.

前記密着強度ＳＡは高いほど好ましく、その上限は特に限定されないが、実用的な密着強度を有するＮｉめっき層３を備えたヒートスプレッダ４を、生産性良く製造すること等を考慮すると、密着強度ＳＡ（Ｎ／ｍｍ２）は９００Ｎ／ｍｍ２以下であるのが好ましい。
Ｎｉめっき層３は、これも先に説明したように、その最表面６から厚み方向に０．３μｍ以上の範囲にＣｕを含まないか、またはその含有量ＲＬ（質量％）が式(V)：
０質量％＜ＲＬ＜０．５質量％ (V)
を満足する低Ｃｕ領域７を有しているのが好ましい。Ｎｉめっき層３の最表面６側に低Ｃｕ領域７を設けることによって、前記最表面６に蓄積されるＣｕの量をさらに少なくして、前記Ｃｕの酸化や腐食による、他部材の、ヒートスプレッダ４に対する接続の強度が低下したり、前記他部材がヒートスプレッダ４から剥離したりする不具合の発生をより一層有効に防止できる。 The adhesion strength S A is preferably as high as, but its upper limit is not particularly limited, the heat spreader 4 having a Ni plating layer 3 with a practical adhesion strength, considering the high productivity can be produced and the like, adhesion strength S A (N / mm 2 ) is preferably 900 N / mm 2 or less.
As described above, the Ni plating layer 3 does not contain Cu in the range of 0.3 μm or more from the outermost surface 6 in the thickness direction, or the content R L (mass%) is expressed by the formula (V ) :
0% by mass <R L <0.5% by mass (V)
It is preferable to have a low Cu region 7 that satisfies the above. By providing the low Cu region 7 on the outermost surface 6 side of the Ni plating layer 3, the amount of Cu accumulated on the outermost surface 6 is further reduced, and the heat spreader 4 of other members due to oxidation or corrosion of the Cu. It is possible to more effectively prevent the occurrence of a problem that the strength of the connection with respect to the lowering or the other member peels from the heat spreader 4.

低Ｃｕ領域７の厚みが０．３μｍ以上であるのが好ましいのは、厚みが０．３μｍ未満では、高Ｃｕ領域５の厚みやＣｕの含有量ＲH等にもよるが、かかる低Ｃｕ領域７を設けることによる前記効果が十分に得られないおそれがあるためである。低Ｃｕ領域７の厚みの上限は、特に限定されないが４．５μｍであるのが好ましい。厚みが４．５μｍを超えても、それ以上の効果は得られない。のみならず、Ｎｉめっき層３の全体の厚みが大きくなり、残留応力が高くなって、前記Ｎｉめっき層３が、ヒートスプレッダ４の接続面２に他部材を接続する際や、半導体装置の使用時の熱履歴等によって脹れを生じたり基体１から剥離したりしやすくなるおそれがある。 The thickness of the low Cu region 7 is preferably 0.3 μm or more. If the thickness is less than 0.3 μm, the low Cu region 7 depends on the thickness of the high Cu region 5 and the Cu content RH. This is because the above-described effect due to the provision of 7 may not be sufficiently obtained. The upper limit of the thickness of the low Cu region 7 is not particularly limited, but is preferably 4.5 μm. Even if the thickness exceeds 4.5 μm, no further effect can be obtained. Not only that, the overall thickness of the Ni plating layer 3 is increased and the residual stress is increased, so that the Ni plating layer 3 connects another member to the connection surface 2 of the heat spreader 4 or when a semiconductor device is used. There is a risk that the thermal history or the like may cause swelling or peeling from the substrate 1.

低Ｃｕ領域７におけるＣｕの含有量ＲＬが式(V)を満足する範囲であるのが好ましいのは、含有量ＲＬが０．５質量％以上では、高Ｃｕ領域５の厚みやＣｕの含有量ＲＨ等にもよるが、かかる低Ｃｕ領域７を設けることによる前記効果が十分に得られないおそれがあるためである。なお、Ｎｉめっき層３の耐性を向上する効果を考慮すると、前記低Ｃｕ領域７はＣｕを含有していない、言い換えれば含有量ＲＬが０質量％であるのが最も好ましく、本発明は、含有量ＲＬが０．５質量％未満で、０質量％までの範囲を包含している。 It is preferable that the Cu content RL in the low Cu region 7 satisfies the formula (V) . If the content RL is 0.5 mass% or more, the thickness of the high Cu region 5 and the Cu content Although depending on the content RH and the like, the effect of providing the low Cu region 7 may not be sufficiently obtained. In consideration of the effect of improving the resistance of the Ni plating layer 3, the low Cu region 7 does not contain Cu, in other words, the content RL is most preferably 0% by mass. The content RL is less than 0.5% by mass and includes a range up to 0% by mass.

ただしＮｉめっき層３の、基体１に対する良好な密着性を確保する効果との兼ね合いを考慮すると、低Ｃｕ領域７は、前記式(V)の範囲でＣｕを含有していても差し支えない。
図１では、高Ｃｕ領域５と低Ｃｕ領域７とが直接に接触するように記載されているが、前記両領域５、７間には、いずれの領域に課された条件も満足しない中間層が介在してもよい。 However, considering the balance between the Ni plating layer 3 and the effect of ensuring good adhesion to the substrate 1, the low Cu region 7 may contain Cu in the range of the formula (V) .
In FIG. 1, it is described that the high Cu region 5 and the low Cu region 7 are in direct contact with each other, but an intermediate layer that does not satisfy the conditions imposed on any region between the regions 5 and 7. May be interposed.

Ｎｉめっき層３中に含まれるＣｕの含有量の、厚み方向の分布を、本発明では、マーカス型高周波グロー放電発光表面分析装置〔ホリバ・ジョバンイボン社（HORIBA JOBIN YVON S. A. S.）製のＪＹ５０００ＲＦ−ＰＳＳ〕を用いて測定した値でもって表すこととする。
前記分析装置は、測定試料を、その最表面からアルゴンプラズマによって厚み方向に削りながら、所定の厚みごとに元素分析を繰り返す装置であって、前記分析装置によれば、測定試料を最表面から深さ数１０μｍに及ぶ範囲まで、分解能よく元素分析できると共に、分析面積が４ｍｍφと広いので、偏析等の影響を少なくして、測定試料のより平均的な情報を得ることが可能である。 In the present invention, the distribution of the Cu content in the Ni plating layer 3 in the thickness direction is determined according to the present invention by the Marcus type high-frequency glow discharge luminescent surface analyzer (JY5000RF-PSS manufactured by HORIBA JOBIN YVON SAS). ] And the value measured using
The analyzer is an apparatus that repeats elemental analysis for each predetermined thickness while scraping a measurement sample from the outermost surface with argon plasma in the thickness direction. According to the analyzer, the measurement sample is deepened from the outermost surface. Elemental analysis can be performed with high resolution up to a range of several tens of μm, and the analysis area is as wide as 4 mmφ, so that the influence of segregation and the like can be reduced and more average information of the measurement sample can be obtained.

本発明では、前記分析装置を用いて、測定試料を、その最表面からアルゴンプラズマによって厚み方向に削りながら、厚み約０．００３μｍごとに元素分析した結果を、例えば図４、図５に示すようにプロットして、試料中に含まれるＣｕ等の各元素の、厚み方向の含有量の分布曲線を求める。図５は、図４の分布曲線のうちＣｕの分布曲線を拡大して示したグラフである。   In the present invention, the results of elemental analysis for each thickness of about 0.003 μm while the measurement sample was shaved from the outermost surface with argon plasma in the thickness direction using the analyzer as shown in FIGS. 4 and 5, for example. To obtain a distribution curve of the content in the thickness direction of each element such as Cu contained in the sample. FIG. 5 is an enlarged graph showing the Cu distribution curve in the distribution curve of FIG.

次に前記分布曲線から、測定試料の最表面、つまりＮｉめっき層３の最表面６におけるＣｕの含有量ＲＳ（質量％）を求めると共に、Ｎｉめっき層３の主成分であるＮｉの含有量と、基体１としての、図の例の場合はＣｕ−Ｗ複合材料の主成分であるＷの含有量とが一致する点を、基体１とＮｉめっき層３との界面とする。
そして前記界面からＮｉめっき層３の最表面６へ向けて、前記Ｎｉめっき層３の厚み方向の、Ｃｕの含有量ＲＨ（質量％）が２．５質量％以上、２０質量％以下である領域の厚みを求めて高Ｃｕ領域５の厚みとすると共に、前記最表面６から基体１へ向けて、前記Ｎｉめっき層３の厚み方向の、Ｃｕの含有量ＲＬ（質量％）が０．５質量％未満である領域の厚みを求めて低Ｃｕ領域７の厚みとする。 Next, the Cu content R S (% by mass) at the outermost surface of the measurement sample, that is, the outermost surface 6 of the Ni plating layer 3 is obtained from the distribution curve, and the Ni content as the main component of the Ni plating layer 3 is obtained. In the case of the example shown in the figure as the substrate 1, the point where the content of W, which is the main component of the Cu—W composite material, is the interface between the substrate 1 and the Ni plating layer 3.
Then, from the interface toward the outermost surface 6 of the Ni plating layer 3, the Cu content R H (% by mass) in the thickness direction of the Ni plating layer 3 is 2.5% by mass or more and 20% by mass or less. The thickness of the region is determined to be the thickness of the high Cu region 5, and the Cu content R L (% by mass) in the thickness direction of the Ni plating layer 3 from the outermost surface 6 toward the substrate 1 is 0.00. The thickness of the region that is less than 5% by mass is determined as the thickness of the low Cu region 7.

基体１に対するＮｉめっき層３の密着強度ＳA（Ｎ／ｍｍ2）は、本発明では日本工業規格ＪＩＳ Ｋ６８５０：１９９９「接着剤−剛性被着材の引張せん断接着強さ試験方法」に規定された試験方法を応用した、下記の測定方法によって測定した値でもって表すこととする。
すなわち矩形平板状のヒートスプレッダを２枚用意し、前記２枚のヒートスプレッダの、それぞれ矩形の短辺側の一端から長さ方向の１２．５ｍｍの範囲を半田接合部として、Ｐｂ−Ｓｎ共晶半田（Ｐｂ：６０質量％、Ｓｎ：４０質量％）を用いて、２２０℃×３分間の条件で半田接合したものを試験片として用意する。次に前記試験片の、互いに反対方向に突出した２つの非接着部を、それぞれ精密万能試験機（オートグラフ）のつかみ具で保持して、試験片の幅方向の中心線と、つかみ具の中心線とが一致するように注意しながら５０ｍｍ／分の速度で、それぞれ反対方向に引っ張った際の破断応力（Ｎ/ｍｍ2）を、Ｎｉめっき層３の基体１に対する密着強度ＳA（Ｎ／ｍｍ2）とする。 The adhesion strength S A (N / mm 2 ) of the Ni plating layer 3 to the substrate 1 is defined in the present invention in Japanese Industrial Standard JIS K6850: 1999 “Adhesive-Tensile Adhesive Tensile Shear Bond Strength Test Method”. It shall be expressed with the value measured by the following measurement method applying the above test method.
That is, two rectangular plate-shaped heat spreaders are prepared, and a Pb-Sn eutectic solder (1b) in the length direction from one end of the rectangular short side of each of the two heat spreaders is used as a solder joint. Pb: 60% by mass and Sn: 40% by mass) are prepared as test pieces by solder bonding under the conditions of 220 ° C. × 3 minutes. Next, the two non-adhesive portions of the test piece protruding in opposite directions are held by the grips of a precision universal tester (autograph), respectively, and the center line in the width direction of the test piece and the grip While taking care to match the center line, the breaking stress (N / mm 2 ) when pulled in the opposite direction at a speed of 50 mm / min is used as the adhesion strength S A (N / Mm 2 ).

例えばＮｉめっき層３が、高Ｃｕ領域のもとになる第１めっき層と、低Ｃｕ領域のもとになる第２めっき層とを積層して形成されており、しかも両めっき層が、第２めっき層形成後の熱処理が不十分であった等の理由で十分に一体化されていない場合に、前記測定を実施すると、Ｎｉめっき層３は、基体１との界面ではなく前記両めっき層の界面で剥離することがある。その際に測定される密着強度は、厳密には、Ｎｉめっき層３の全体としての、基体１に対する密着強度ではなく、前記界面での両めっき層間の密着強度であることになる。   For example, the Ni plating layer 3 is formed by laminating a first plating layer that is a source of a high Cu region and a second plating layer that is a source of a low Cu region. When the measurement is carried out when the heat treatment after the formation of the two plating layers is not sufficiently integrated or the like, the Ni plating layer 3 is not the interface with the substrate 1 but the both plating layers. May peel off at the interface. Strictly speaking, the adhesion strength measured at this time is not the adhesion strength to the substrate 1 as a whole of the Ni plating layer 3 but the adhesion strength between the two plating layers at the interface.

しかし前記両密着強度は同じ測定によって求められ、区別することが困難である上、両めっき層間の界面での剥離は、Ｎｉめっき層３の全体が基体１から剥離する場合と同じ結果を引き起こすことになる。そのため２層構造のＮｉめっき層３は、基体１に対する密着強度に優れるだけでなく、第１めっき層と第２めっき層との界面での密着性にも優れている必要があると考えられる。したがって本願発明でいうところの、Ｎｉめっき層３の、基体１に対する密着強度ＳA（Ｎ／ｍｍ2）には、前記界面での剥離によって測定される密着強度をも含むこととする。 However, both adhesion strengths are determined by the same measurement and are difficult to distinguish, and peeling at the interface between both plating layers causes the same result as when the entire Ni plating layer 3 peels from the substrate 1. become. Therefore, it is considered that the Ni plating layer 3 having a two-layer structure not only has excellent adhesion strength to the substrate 1, but also needs to have excellent adhesion at the interface between the first plating layer and the second plating layer. Accordingly, the adhesion strength S A (N / mm 2 ) of the Ni plating layer 3 to the substrate 1 as referred to in the present invention includes the adhesion strength measured by peeling at the interface.

Ｎｉめっき層３の全体の厚みは５μｍ以下、特に０．６μｍ以上、５μｍ以下であるのが好ましい。厚みが５μｍを超える場合には残留応力が高くなって、Ｎｉめっき層３が、ヒートスプレッダ４の接続面２に他部材を接続する際や、半導体装置の使用時の熱履歴等によって脹れを生じたり基体１から剥離したりしやすくなるおそれがある。一方、厚みが０．６μｍ未満では、高Ｃｕ領域５を備えると共に、その最表面６におけるＣｕの含有量ＲＳが０．３質量％以下であるＮｉめっき層３を形成するのが実質的に困難である。 The total thickness of the Ni plating layer 3 is preferably 5 μm or less, particularly 0.6 μm or more and 5 μm or less. When the thickness exceeds 5 μm, the residual stress increases, and the Ni plating layer 3 is swollen by connecting other members to the connection surface 2 of the heat spreader 4 or by thermal history during use of the semiconductor device. Or the substrate 1 may be easily peeled off. On the other hand, when the thickness is less than 0.6 μm, it is substantially formed of the Ni plating layer 3 having the high Cu region 5 and having the Cu content R S on the outermost surface 6 of 0.3% by mass or less. Have difficulty.

前記Ｎｉめっき層３を有する本発明のヒートスプレッダ４は、
(i) Ｗ、Ｍｏ、またはダイヤモンドと、Ｃｕとの複合材料からなる前記基体の少なくとも前記接続面にＮｉめっきを施して厚みが０．２μｍ以上、１．２μｍ以下の第１めっき層を形成し、式(I)：
６２０℃≦Ｔ１≦８５０℃ (I)
を満足する温度Ｔ１（℃）で熱処理して前記基体中から前記第１めっき層中にＣｕを拡散させる工程と、
(ii) 前記第１めっき層の表面にＮｉめっきを施して厚みが０．６μｍ以上、２．５μｍ以下の第２めっき層を形成し、式(II)：
３００℃≦Ｔ２≦５８０℃ (II)
を満足する温度Ｔ２（℃）で熱処理して前記第２めっき層と前記第１めっき層とを一体化させて前記Ｎｉめっき層を形成する工程と、
を含む本発明の製造方法によって製造できる。 The heat spreader 4 of the present invention having the Ni plating layer 3 is:
(i) Ni plating is performed on at least the connection surface of the substrate made of a composite material of W, Mo, or diamond and Cu to form a first plating layer having a thickness of 0.2 μm or more and 1.2 μm or less. Formula (I):
620 ° C. ≦ T 1 ≦ 850 ° C. (I)
Diffusing Cu from the substrate to the first plating layer by heat treatment at a temperature T 1 (° C.) satisfying
(ii) Ni plating is applied to the surface of the first plating layer to form a second plating layer having a thickness of 0.6 μm or more and 2.5 μm or less, and the formula (II):
300 ° C ≦ T 2 ≦ 580 ° C (II)
A step of forming the Ni plating layer by integrating the second plating layer and the first plating layer by heat treatment at a temperature T 2 (° C.) that satisfies the following conditions:
It can manufacture by the manufacturing method of this invention containing this.

すなわち前記(i)の工程において、基体１の、少なくとも接続面２に直接に接するように形成した第１めっき層を温度Ｔ1（℃）で熱処理して基体１中からＣｕを第１めっき層中に拡散させた後、(ii)の工程において第１めっき層上に積層した第２めっき層を温度Ｔ2（℃）で熱処理して前記第１めっき層と一体化させる。
そうすると、基体１との界面から第１めっき層の厚みにほぼ対応した範囲が高Ｃｕ領域５とされると共に、最表面６を含む、第２めっき層の厚みにほぼ対応した範囲が低Ｃｕ領域７とされたＮｉめっき層３が形成される。 That is, in the step (i), the first plating layer formed so as to be in direct contact with at least the connection surface 2 of the substrate 1 is heat-treated at a temperature T 1 (° C.), and Cu is formed from the substrate 1 into the first plating layer. After the diffusion, the second plating layer laminated on the first plating layer in the step (ii) is heat-treated at a temperature T 2 (° C.) to be integrated with the first plating layer.
Then, the range substantially corresponding to the thickness of the first plating layer from the interface with the base body 1 is the high Cu region 5 and the range substantially including the outermost surface 6 and corresponding to the thickness of the second plating layer is the low Cu region. 7 is formed.

また、第１および第２めっき層に対する熱処理の温度Ｔ1、Ｔ2を、それぞれ前記範囲内で変更することで、それぞれのめっき層におけるＣｕの含有量を任意に調整できる。そのため前記製造方法によれば、前記第１および第２めっき層の厚みと熱処理の条件とを変更することで、高Ｃｕ領域５の厚みとＣｕの含有量ＲH（質量％）、Ｎｉめっき層３の最表面６におけるＣｕの含有量ＲS（質量％）、ならびに前記最表面６を含む低Ｃｕ領域７の厚みとＣｕの含有量ＲL（質量％）を任意に、しかも再現性よく調整でき、本発明のヒートスプレッダ４を、Ｎｉめっきと熱処理とを繰り返すだけで、再現性よく、かつ効率的に製造できる。 Further, by changing the temperatures T 1 and T 2 of the heat treatment for the first and second plating layers within the above ranges, the Cu content in each plating layer can be arbitrarily adjusted. Therefore, according to the manufacturing method, the thickness of the high Cu region 5 and the Cu content R H (mass%), the Ni plating layer are changed by changing the thicknesses of the first and second plating layers and the heat treatment conditions. The content R S (mass%) of Cu in the outermost surface 6 of 3 and the thickness of the low Cu region 7 including the outermost surface 6 and the content R L (mass%) of Cu are arbitrarily adjusted with good reproducibility. The heat spreader 4 of the present invention can be manufactured with good reproducibility and efficiency simply by repeating Ni plating and heat treatment.

前記製造方法において、工程(i)の第１めっき層の形成と熱処理、並びに工程(ii)の第２めっき層の形成と熱処理はそれぞれ１回ずつ行うのが、工程数を減らして製造コストを低減する上で好ましい。しかし、それぞれの工程を厚み方向に２回以上に分けて繰り返し行うようにしてもよい。その場合には、各層の厚みと熱処理の条件とを個別に変更することで、Ｎｉめっき層の厚み方向におけるＣｕの含有量の分布をより細かく制御できる。   In the manufacturing method, the formation and heat treatment of the first plating layer in step (i) and the formation and heat treatment of the second plating layer in step (ii) are each performed once, which reduces the number of steps and reduces the manufacturing cost. It is preferable in terms of reduction. However, each process may be repeated in two or more times in the thickness direction. In that case, the distribution of the Cu content in the thickness direction of the Ni plating layer can be more finely controlled by individually changing the thickness of each layer and the heat treatment conditions.

第１および第２めっき層を形成するためのＮｉめっき処理としては電気Ｎｉめっき、無電解Ｎｉめっき、および気相めっき（ＰＶＤ法、ＣＶＤ法を含む）のいずれを採用してもよい。このうち無電解Ｎｉめっきとしては、
(a) 還元剤として次亜リン酸ソーダ〔ＮａＨ2ＰＯ2等〕を用いた無電解Ｎｉ−Ｐめっき、
(b) 還元剤として水素化ホウ素化合物〔ＮａＢＨ4、(ＣＨ3)2ＨＮ・ＢＨ3、(Ｃ2Ｈ5)2ＨＮ・ＢＨ3等〕を用いた無電解Ｎｉ−Ｂめっき、および
(c) 還元剤としてヒドラジン化合物〔Ｎ2Ｈ4、Ｎ2Ｈ4・Ｈ2ＳＯ4、Ｎ2Ｈ4・ＨＣｌ、Ｎ2Ｈ4・２ＨＣｌ等〕を用いた狭義の無電解Ｎｉめっき、
のいずれを採用してもよい。 As the Ni plating treatment for forming the first and second plating layers, any of electric Ni plating, electroless Ni plating, and vapor phase plating (including PVD method and CVD method) may be employed. Among these, as electroless Ni plating,
(a) electroless Ni-P plating using sodium hypophosphite [NaH 2 PO 2 or the like] as a reducing agent,
(b) electroless Ni-B plating using a borohydride compound [NaBH 4 , (CH 3 ) 2 HN · BH 3 , (C 2 H 5 ) 2 HN · BH 3, etc.] as a reducing agent, and
(c) narrowly electroless Ni plating using a hydrazine compound [N 2 H 4 , N 2 H 4 .H 2 SO 4 , N 2 H 4 .HCl, N 2 H 4 .2HCl, etc.] as a reducing agent,
Any of these may be adopted.

なお(a)の無電解Ｎｉ−Ｐめっきによって形成されるＮｉめっき層中に含まれるＰの含有量は６質量％以上、１５質量％以下、特に９質量％以上、１２質量％以下であるのが好ましい。また(b)の無電解Ｎｉ−Ｂめっきによって形成されるＮｉめっき層中に含まれるＢの含有量は０．１質量％以上、５質量％以下、特に０．３質量％以上、３質量％以下であるのが好ましい。   In addition, the content of P contained in the Ni plating layer formed by electroless Ni—P plating in (a) is 6% by mass or more and 15% by mass or less, particularly 9% by mass or more and 12% by mass or less. Is preferred. The content of B contained in the Ni plating layer formed by electroless Ni-B plating in (b) is 0.1% by mass or more and 5% by mass or less, particularly 0.3% by mass or more and 3% by mass. It is preferable that:

第１めっき層は、電気Ｎｉめっき、または(b)の無電解Ｎｉ−Ｂめっきによって形成するのが好ましい。電気Ｎｉめっきによって形成されるめっき層は、ほぼ純Ｎｉからなるため、基体１からのＣｕの拡散によって、前記基体１に対してより強固に一体化できる。また無電解Ｎｉ−Ｂめっきによって形成されるめっき層は、電気めっきによるものに比べて均一性や緻密性に優れている。   The first plating layer is preferably formed by electric Ni plating or electroless Ni-B plating of (b). Since the plating layer formed by electric Ni plating is substantially made of pure Ni, it can be more firmly integrated with the base body 1 by diffusion of Cu from the base body 1. Moreover, the plating layer formed by electroless Ni-B plating is excellent in uniformity and denseness compared to those formed by electroplating.

第１めっき層の厚みは０．２μｍ以上、１．２μｍ以下である必要がある。厚みが０．２μｍ未満では、Ｎｉめっき層３中に、十分な厚みを有する高Ｃｕ領域を形成できないため、前記Ｎｉめっき層３の、基体１に対する密着強度が大幅に低下する。そして、ヒートスプレッダ４の接続面２に他部材を接続する際や、半導体装置の使用時の熱履歴等によって、前記Ｎｉめっき層３が脹れを生じたり基体１から剥離したりしやすくなる。 The thickness of the first plating layer needs to be 0.2 μm or more and 1.2 μm or less . In the thickness is less than 0.2 [mu] m, in the Ni plating layer 3, can not form a high-Cu region having a sufficient thickness, the Ni plating layer 3, adhesive strength to the substrate 1 is you significantly reduced. Then, and when connecting the other member connection surface 2 of the heat spreader 4, by heat history or the like during use of the semiconductor device, the Ni plating layer 3 may turn easily peeled off from the resulting or substrate 1 to swelling.

また、厚みが１．２μｍを超える場合には残留応力が高くなったり、基体１と第１めっき層との熱膨張係数の差に起因する熱応力が高くなったりしやすいため、前記(i)の工程の温度Ｔ１での熱処理中に、前記第１めっき層が脹れを生じたり基体１から剥離したりしやすくなる。
第２めっき層は、Ｎｉめっき層３の最表面６を形成する層であるため、前記最表面６上に接続される他部材や、前記他部材を最表面６に接続するために用いられる樹脂接着剤等との相性や要求される特性等に応じて最適なＮｉめっき方法を選択して形成すればよい。例えば前記最表面６に、先に説明したＡｇフィラーと塩素とを含む樹脂接着剤を用いて他部材を接続する場合は、無電解Ｎｉ−Ｐめっきによって第２めっき層を形成するのが好ましい。Ｎｉ−Ｐめっき層は、熱処理をすることでＮｉ3Ｐを生じ、前記Ｎｉ3Ｐが、樹脂接着剤中のＡｇフィラーや塩素イオンと良好な結合性を有するため、接続の信頼性を向上できる。 Further, when the thickness exceeds 1.2 μm , the residual stress tends to be high, or the thermal stress due to the difference in thermal expansion coefficient between the substrate 1 and the first plating layer tends to be high. of during the heat treatment at a temperature T 1 of the process, that of easily peeled off from or substrate 1 results in the first plating layer is swollen.
Since the second plating layer is a layer that forms the outermost surface 6 of the Ni plating layer 3, another member connected to the outermost surface 6 or a resin used to connect the other member to the outermost surface 6. What is necessary is just to select and form the optimal Ni plating method according to compatibility with an adhesive agent, a required characteristic, etc. For example, when the other member is connected to the outermost surface 6 using the above-described resin adhesive containing Ag filler and chlorine, it is preferable to form the second plating layer by electroless Ni—P plating. The Ni—P plating layer generates Ni 3 P by heat treatment, and the Ni 3 P has good bonding properties with Ag filler and chlorine ions in the resin adhesive, and therefore the connection reliability can be improved.

第２めっき層の厚みは０．６μｍ以上、２．５μｍ以下である必要がある。厚みが０．６μｍ未満では、前記(ii)の工程の温度Ｔ２での熱処理時に、第１めっき層中から第２めっき層中に拡散するＣｕの量が多くなりすぎる。そのため、Ｎｉめっき層３の最表面６におけるＣｕの含有量ＲＳ（質量％）を、式(IV)を満足する含有量に抑制できなかったり、前記Ｎｉめっき層３中に、所定の厚みを有する低Ｃｕ領域を形成できなかったりする。 The thickness of the second plating layer needs to be 0.6 μm or more and 2.5 μm or less . In the thickness is less than 0.6 .mu.m, the during heat treatment at a temperature T 2 of the process of (ii), the amount of Cu diffused from the first plating layer on the second plated layer is too large. Therefore, the content R S (% by mass) of Cu on the outermost surface 6 of the Ni plating layer 3 cannot be suppressed to a content satisfying the formula (IV), or a predetermined thickness is set in the Ni plating layer 3. It may not be formed a low-Cu region having.

一方、厚みが２．５μｍを超えても、それ以上の効果は得られない。のみならず、Ｎｉめっき層３の全体の厚みが大きくなり、残留応力が高くなるため、前記Ｎｉめっき層３が、ヒートスプレッダ４の接続面２に他部材を接続する際や、半導体装置の使用時の熱履歴等によって脹れを生じたり基体１から剥離したりしやすくなる。 On the other hand, even if the thickness exceeds 2.5 μm , no further effect can be obtained. Not only that, the overall thickness of the Ni plating layer 3 is increased and the residual stress is increased. Therefore, when the Ni plating layer 3 connects another member to the connection surface 2 of the heat spreader 4 or when a semiconductor device is used. of that easily peeled off from the resulting or substrate 1 to swelling by such thermal history.

先に説明したように、第１めっき層の熱処理の温度Ｔ１（℃）が式(I)を満足する温度とされるのは、６２０℃未満では、基体１中から第１めっき層中に十分な量のＣｕを拡散させて、Ｎｉめっき層３の、基体１に対する良好な密着性を確保できないためである。一方、８５０℃を超える場合には、第１めっき層中に拡散するＣｕの量が多くなりすぎて、却って、Ｎｉめっき層３の、基体１に対する良好な密着性を確保できないためである。のみならず、基体１と第１めっき層との熱膨張係数の差に起因する熱応力が高くなって、温度Ｔ１での熱処理中に、前記第１めっき層が脹れを生じたり基体１から剥離したりしやすくなるおそれもある。 As described above, the heat treatment temperature T 1 (° C.) of the first plating layer satisfies the formula (I) when the temperature is less than 620 ° C. , from the substrate 1 to the first plating layer. This is because a sufficient amount of Cu is diffused to ensure good adhesion of the Ni plating layer 3 to the substrate 1. On the other hand, when the temperature exceeds 850 ° C., the amount of Cu diffusing into the first plating layer is too large, and on the contrary, good adhesion of the Ni plating layer 3 to the substrate 1 cannot be ensured. Not only the thermal stress is high due to the difference in thermal expansion coefficients of the substrate 1 and the first plating layer, during heat treatment at a temperature T 1, the substrate or cause the first plating layer is swollen 1 There is also a possibility that it will be easily peeled off.

第２めっき層の熱処理の温度Ｔ２（℃）が式(II)を満足する温度とされるのは、３００℃未満では、第１および第２めっき層を良好に一体化できないためである。一方、５８０℃を超える場合には、第１めっき層中から第２めっき層中に拡散するＣｕの量が多くなりすぎて、Ｎｉめっき層３の最表面６におけるＣｕの含有量ＲＳ（質量％）を、式(IV)を満足する含有量に抑制できないためである。 The reason why the temperature T 2 (° C.) of the heat treatment of the second plated layer satisfies the formula (II) is that if the temperature is less than 300 ° C., the first and second plated layers cannot be integrated well. On the other hand, when the temperature exceeds 580 ° C. , the amount of Cu diffusing from the first plating layer into the second plating layer becomes too large, and the Cu content R S (mass on the outermost surface 6 of the Ni plating layer 3). %) Cannot be suppressed to a content satisfying the formula (IV).

本発明の半導体装置は、半導体素子と、前記半導体素子の動作時に発生する熱を除去するための、前記本発明のヒートスプレッダとを備えることを特徴とするものである。半導体装置の具体的な構成としては、ヒートスプレッダが複数の接続面を備え、前記複数の接続面のうち少なくとも１つの接続面に前記半導体素子、他の接続面に熱除去部材が、それぞれＡｇフィラーを配合した樹脂接着剤を介して接続されたものが挙げられる。 The semiconductor device of the present invention comprises a semiconductor element and the heat spreader of the present invention for removing heat generated during operation of the semiconductor element. As a specific configuration of a semiconductor device, the heat spreader comprises a plurality of connecting surfaces, at least one of said semiconductor element connection surface of the plurality of connecting surfaces, the heat removing member to the other connection surface is, the Ag filler, respectively The thing connected through the mix | blended resin adhesive is mentioned.

前記半導体装置においては、ヒートスプレッダの接続面に他部材を接続する際や、半導体装置の使用時の熱履歴等によって、前記他部材の、ヒートスプレッダに対する接続の強度が低下したり剥離したりするのをさらに確実に防止して、半導体装置に高い信頼性を付与することを考慮すると、前記他部材の、ヒートスプレッダの接続面に対する接続の強度を示す初期の接着強度ＳＢ（Ｎ／ｍｍ２）が１５．７Ｎ／ｍｍ ２ 以上であるのが好ましい。また、温度＋８５℃、相対湿度８５％の高温高湿環境下で１０００時間、静置する高温高湿試験を行った後の前記接着強度ＳＢ（Ｎ／ｍｍ２）が５Ｎ／ｍｍ２以上であるのが好ましい。 In the semiconductor device, when other members are connected to the connection surface of the heat spreader, or due to thermal history during use of the semiconductor device, the strength of the connection of the other members to the heat spreader is reduced or peeled off. In consideration of further preventing and giving high reliability to the semiconductor device, the initial adhesive strength S B (N / mm 2 ) indicating the strength of connection of the other member to the connection surface of the heat spreader is 15 It is preferably 7 N / mm 2 or more . In addition, the adhesive strength S B (N / mm 2 ) after performing a high temperature and high humidity test for 1000 hours in a high temperature and high humidity environment with a temperature of + 85 ° C. and a relative humidity of 85% is 5 N / mm 2 or more. Preferably there is.

接着強度ＳB（Ｎ／ｍｍ2）は、日本工業規格ＪＩＳ Ｋ ６８５０：１９９９「接着剤−剛性被着材の引張せん断接着強さ試験方法」に規定された試験方法で測定される接着強度でもって表すこととする。また測定の際には、ヒートスプレッダの接続面に、実際に他部材を接続するために用いる樹脂接着剤を使用することとする。前記接着強度ＳB（Ｎ／ｍｍ2）は、初期および高温高湿試験後のいずれにおいても高ければ高いほど好ましく、その上限は、それぞれ前記測定方法における測定限界、つまり測定に使用した樹脂接着剤の接着強度や、あるいは半導体素子等の他部材自体の破壊強度等に達しても構わない。 The adhesive strength S B (N / mm 2 ) is an adhesive strength measured by a test method defined in Japanese Industrial Standard JIS K 6850: 1999 “Testing method for tensile shear adhesive strength of adhesive-rigid substrate”. I will express it. In the measurement, a resin adhesive used for actually connecting another member to the connection surface of the heat spreader is used. The adhesive strength S B (N / mm 2 ) is preferably as high as possible both in the initial stage and after the high-temperature and high-humidity test, and the upper limit thereof is the measurement limit in the measurement method, that is, the resin adhesive used in the measurement. It may be possible to reach the adhesive strength of, or the breaking strength of other members such as semiconductor elements.

図２は、本発明の半導体装置の、実施の形態の一例を示す断面図である。図の例の半導体装置８は、平板状のパッケージ９と、前記パッケージ９の図において上側の面１０の中央部に、半田バンプ１１を介して接続された平板状の半導体素子１２と、前記本発明のヒートスプレッダ４とを備えている。
ヒートスプレッダ４は、図の例では、先に説明したように全体が平板状で、かつ前記平板の、図において下側の面１３の中央部に、前記半導体素子１２を収容するための凹部１４が設けられた凹形状に形成された基体１を備えている。そして前記基体１の、凹部１４の底面１５が半導体素子１２との接続のための接続面２とされ、前記凹部１４の周囲の面１３がパッケージ９との接続のための接続面２とされていると共に、図の例の場合は外周面の全面に、先に説明したようにＣｕの含有量を厚み方向に分布させたＮｉめっき層３が形成されてヒートスプレッダ４が構成されている。 FIG. 2 is a cross-sectional view showing an example of an embodiment of the semiconductor device of the present invention. The semiconductor device 8 in the illustrated example includes a flat package 9, a flat semiconductor element 12 connected to a central portion of the upper surface 10 in the figure of the package 9 via a solder bump 11, and the book The heat spreader 4 of the invention is provided.
In the example shown in the figure, the heat spreader 4 has a flat plate shape as described above, and a recess 14 for accommodating the semiconductor element 12 is formed in the center of the flat surface of the lower surface 13 of the flat plate. The base 1 formed in the concave shape provided is provided. The bottom surface 15 of the recess 14 of the base body 1 is a connection surface 2 for connection to the semiconductor element 12, and the surface 13 around the recess 14 is a connection surface 2 for connection to the package 9. In addition, in the case of the example shown in the figure, the heat spreader 4 is configured by forming the Ni plating layer 3 in which the Cu content is distributed in the thickness direction as described above on the entire outer peripheral surface.

前記ヒートスプレッダ４を、前記接続面１５上のＮｉめっき層３と、半導体素子１２の、図において上側の面１６との間に樹脂接着剤の層１７、接続面１３上のＮｉめっき層３と、パッケージ９の上側の面１０との間に樹脂接着剤の層１８を挟んで接着して互いに固定することで半導体装置８が構成されている。前記半導体装置８においては、半導体素子１２の動作時の熱を、ヒートスプレッダ４を介して直接に、また前記ヒートスプレッダ４とパッケージ９とを介して間接的に除去できる。   The heat spreader 4 includes a Ni plating layer 3 on the connection surface 15 and a layer 17 of a resin adhesive between the upper surface 16 of the semiconductor element 12 in the figure, a Ni plating layer 3 on the connection surface 13, and A semiconductor device 8 is configured by adhering a resin adhesive layer 18 between the upper surface 10 of the package 9 and fixing them together. In the semiconductor device 8, heat during operation of the semiconductor element 12 can be directly removed via the heat spreader 4 and indirectly via the heat spreader 4 and the package 9.

のみならず、前記半導体素子１２をパッケージ９とヒートスプレッダ４とで外部から保護しているため、ヒートスプレッダ４が先に説明した本発明の構成を有するものであことと相まって、半導体素子１２の動作の安定性や、半導体装置８の信頼性等を向上できる。なお、半導体装置の構成は、図の例のものには限定されず、例えば平板状のヒートスプレッダの片面に半導体素子、反対面にヒートシンク、ステム、パッケージ等を接続する等、様々な構成を採用できる。   In addition, since the semiconductor element 12 is protected from the outside by the package 9 and the heat spreader 4, the operation of the semiconductor element 12 is coupled with the heat spreader 4 having the configuration of the present invention described above. Stability and reliability of the semiconductor device 8 can be improved. The configuration of the semiconductor device is not limited to the example shown in the figure, and various configurations can be adopted, for example, a semiconductor element is connected to one surface of a flat plate-shaped heat spreader, and a heat sink, stem, package, etc. are connected to the opposite surface. .

〈実施例１〉
（基体の作製）
平均粒径３μｍのＷ粉末に１質量％のアクリルバインダを加えて平均粒径５０μｍに造粒し、前記造粒物を、幅３０ｍｍ×長さ１１０ｍｍの平面形状が矩形状の凹部を有する金型の、前記凹部内に充填して面圧１．５ｔｏｎ／ｃｍ2の圧力をかけて矩形平板状にプレス成形し、次いで水素ガス雰囲気中で８００℃で１時間の加熱をしてバインダを除去させた後、引き続き水素ガス雰囲気中で１２５０℃に加熱して焼結させてＷからなる多孔質体を作製した。 <Example 1>
(Preparation of substrate)
A 1% by weight acrylic binder is added to W powder having an average particle size of 3 μm and granulated to an average particle size of 50 μm, and the granulated product is a mold having a concave portion having a rectangular shape of 30 mm width × 110 mm length The concave portion is filled and pressed into a rectangular flat plate with a surface pressure of 1.5 ton / cm 2 , and then heated at 800 ° C. for 1 hour in a hydrogen gas atmosphere to remove the binder. Then, the porous body made of W was produced by heating and sintering at 1250 ° C. in a hydrogen gas atmosphere.

次に前記多孔質体を、その空隙量の１．３倍の体積のＣｕ板と重ねた状態で、水素ガス雰囲気中で１２５０℃に加熱してＣｕを溶解させることで、前記Ｃｕを、Ｗからなる多孔質体の細孔内に溶浸させてＣｕ−Ｗ複合材料（Ｃｕ：１０質量％、Ｗ：９０質量％）からなる基体の前駆体を得、前記前駆体の板の、互いに平行な２面（接続面）と、前記２面と交差する４側面とをそれぞれ研削加工して幅２５ｍｍ×長さ１００ｍｍ×厚み２ｍｍの矩形平板状の基体を作製した。   Next, the porous body is heated to 1250 ° C. in a hydrogen gas atmosphere in a state where the porous body is overlapped with a Cu plate having a volume 1.3 times as large as the void volume. A substrate precursor made of a Cu-W composite material (Cu: 10% by mass, W: 90% by mass) is obtained by infiltration into the pores of the porous body made of, and the precursor plates are parallel to each other. The two flat surfaces (connection surfaces) and four side surfaces intersecting with the two surfaces were each ground to produce a rectangular flat substrate having a width of 25 mm, a length of 100 mm, and a thickness of 2 mm.

（ヒートスプレッダの製造）
前記基体の表面の全面に、電気Ｎｉめっきによって厚み１．２μｍの第１めっき層を形成し、水素ガス雰囲気中で８００℃に加熱して熱処理した後、前記第１めっき層上に、無電解Ｎｉ−Ｐめっきによって厚み１μｍの第２めっき層を形成し、水素ガス雰囲気中で５００℃に加熱して熱処理してＮｉめっき層を形成すると共に、ヒートスプレッダを製造した。 (Manufacture of heat spreader)
A first plating layer having a thickness of 1.2 μm is formed on the entire surface of the substrate by electric Ni plating, heated at 800 ° C. in a hydrogen gas atmosphere and heat-treated, and then electrolessly formed on the first plating layer. A second plating layer having a thickness of 1 μm was formed by Ni-P plating, heated to 500 ° C. in a hydrogen gas atmosphere and heat-treated to form a Ni plating layer, and a heat spreader was manufactured.

（Ｃｕ等の含有量分布の測定）
前記ヒートスプレッダのＮｉめっき層について、前出のマーカス型高周波グロー放電発光表面分析装置〔ホリバ・ジョバンイボン社（HORIBA JOBIN YVON S. A. S.）製のＪＹ５０００ＲＦ−ＰＳＳ〕を用いて、Ｃｕ等の元素の、厚み方向の含有量の分布を測定した。測定は、先に説明したように測定試料を、その最表面からアルゴンプラズマによって厚み方向に削りながら、厚み約０．００３μｍごとに元素分析した結果をプロットすることで行った。結果を図４に示す。また、図４のうちＣｕの分布曲線を拡大して図５に示す。 (Measurement of content distribution of Cu, etc.)
About the Ni plating layer of the heat spreader, using the above-mentioned Marcus type high-frequency glow discharge luminescence surface analyzer (JY5000RF-PSS manufactured by HORIBA JOBIN YVON SAS), the thickness direction of elements such as Cu The distribution of the content of was measured. The measurement was performed by plotting the results of elemental analysis for each thickness of about 0.003 μm while cutting the measurement sample from the outermost surface with argon plasma in the thickness direction as described above. The results are shown in FIG. 4 is an enlarged view of the Cu distribution curve shown in FIG.

両図よりＮｉめっき層は、基体との界面（Ｎｉの含有量とＷの含有量とが一致する点）から最表面（表面からの深さ０μｍの点）に向かって厚み方向に１μｍの範囲が、Ｃｕの含有量ＲＨ（質量％）が式(III)の範囲内で、かつ最大含有量が４．８質量％である高Ｃｕ領域、Ｎｉめっき層の最表面のＣｕの含有量ＲＳ（質量％）が０．０１質量％（測定限界）未満で、かつ、前記最表面から基体に向かって厚み方向に１．１μｍの範囲が、Ｃｕの含有量ＲＬ（質量％）が式(V)の範囲内である低Ｃｕ領域となっていることが確認された。 From both figures, the Ni plating layer is in the range of 1 μm in the thickness direction from the interface with the substrate (the point where the Ni content coincides with the W content) from the outermost surface (the point having a depth of 0 μm from the surface). However, the Cu content R H (% by mass) is within the range of the formula (III) and the maximum content is 4.8% by mass, the Cu content R on the outermost surface of the Ni plating layer. S (mass%) is less than 0.01 mass% (measurement limit), and the range of 1.1 μm in the thickness direction from the outermost surface toward the substrate is such that the Cu content R L (mass%) is expressed by the formula It was confirmed that the low Cu region was within the range of (V) .

（接着強度の測定）
日本工業規格ＪＩＳ Ｋ ６８５０：１９９９「接着剤−剛性被着材の引張せん断接着強さ試験方法」に規定された試験方法に則って、他部材の、ヒートスプレッダの接続面に対する接続の強度を示す接着強度を測定した。すなわち図３に示すように、前記ヒートスプレッダ４を２枚用意し、前記２枚のヒートスプレッダ４の、それぞれ短辺側の一端から長さ方向の１２．５ｍｍの範囲を接着部１９として、７０質量％のＡｇフィラーを含む液状のエポキシ樹脂接着剤の層２０を介して、前記接着部１９から、各々のヒートスプレッダ４の非接着部２１がそれぞれ反対方向に突出するように重ね合わせた状態で、１８０℃で１時間の加熱をして接着剤を硬化させた後、さらに１５０℃で２４時間、乾燥させて密着強度測定用の試験片２２を作製した。 (Measurement of adhesive strength)
Adhesion indicating the strength of connection of other members to the connection surface of the heat spreader in accordance with the test method defined in Japanese Industrial Standard JIS K 6850: 1999 “Testing Method for Tensile Shear Adhesive Strength of Adhesive-Rigid Adherent” The strength was measured. That is, as shown in FIG. 3, two heat spreaders 4 are prepared, and the range of 12.5 mm in the length direction from one end on the short side of each of the two heat spreaders 4 is 70 mass%. 180 ° C. in a state where the non-adhesive portions 21 of the respective heat spreaders 4 protrude in opposite directions from the adhesive portions 19 through the liquid epoxy resin adhesive layer 20 containing the Ag filler. After heating for 1 hour to cure the adhesive, it was further dried at 150 ° C. for 24 hours to produce a test piece 22 for measuring adhesion strength.

そして前記試験片２２の、互いに反対方向に突出した２つの非接着部２１を、それぞれ図示しない精密万能試験機（オートグラフ）のつかみ具で保持して、試験片２２の幅方向の中心線と、つかみ具の中心線とが一致するように注意しながら、５０ｍｍ／分の速度で、図中に白抜きの矢印で示すようにそれぞれ反対方向に引っ張った際の破断応力（Ｎ/ｍｍ2）を、初期の接着強度として求めたところ１７．６Ｎ／ｍｍ2であって、実施例１のヒートスプレッダは、他部材の接続の強度に優れていることが確認された。 Then, the two non-adhesive portions 21 of the test piece 22 protruding in opposite directions are respectively held by grippers of a precision universal testing machine (autograph) not shown, and the center line in the width direction of the test piece 22 is The breaking stress (N / mm 2 ) when pulled in the opposite direction as indicated by the white arrow in the figure at a speed of 50 mm / min, taking care to match the center line of the gripper The initial adhesive strength was 17.6 N / mm 2 , and it was confirmed that the heat spreader of Example 1 was excellent in the connection strength of other members.

また、同様にして作製した試験片２２を、温度＋８５℃、相対湿度８５％の高温高湿環境下で１０００時間、静置した後、同様にして接着強度を求めたところ１１．８Ｎ／ｍｍ2であって、実施例１のヒートスプレッダは、前記高温高湿環境に対する耐性にも優れていることが判った。
（密着強度の測定）
Ｎｉめっき層の、基体に対する密着強度を、前記接着強度の測定方法を応用した下記の方法で測定した。すなわち２枚のヒートスプレッダを、エポキシ樹脂接着剤に代えてＰｂ−Ｓｎ共晶半田（Ｐｂ：６０質量％、Ｓｎ：４０質量％）を用いて、２２０℃×３分間の条件で半田接合したものを試験片として、前記と同様にして破断応力を測定したところ、オートグラフの測定限界である１００Ｎ／ｍｍ2を超えており、Ｎｉめっき層は基体に対して強固に密着していることが確認された。 Further, a test piece 22 was produced in the same manner, temperature + 85 ° C., 85% relative humidity high temperature and high humidity for 1000 hours in an environment, allowed to stand, was determined the adhesion strength in the same manner 11.8 N / mm 2 The heat spreader of Example 1 was found to be excellent in resistance to the high temperature and high humidity environment.
(Measurement of adhesion strength)
The adhesion strength of the Ni plating layer to the substrate was measured by the following method using the method for measuring the adhesive strength. In other words, two heat spreaders were joined by soldering at 220 ° C. for 3 minutes using Pb—Sn eutectic solder (Pb: 60 mass%, Sn: 40 mass%) instead of the epoxy resin adhesive. As a test piece, when the breaking stress was measured in the same manner as described above, it exceeded the autograph measurement limit of 100 N / mm 2 , and it was confirmed that the Ni plating layer was firmly adhered to the substrate. It was.

〈比較例１〉
第２めっき層の熱処理温度を８００℃としたこと以外は実施例１と同様にして、ヒートスプレッダを製造した。前記ヒートスプレッダのＮｉめっき層について、実施例１と同様にして、Ｃｕ等の元素の厚み方向の含有量の分布を測定した。結果を図６に示す。また図６のうち、Ｃｕの分布曲線を拡大して図７に示す。両図よりＮｉめっき層は、基体との界面から最表面に向かって厚み方向に１．８μｍの範囲が、Ｃｕの含有量ＲＨ（質量％）が式(III)の範囲内で、かつ最大含有量が６．３質量％である高Ｃｕ領域になっていることが確認されたが、多量のＣｕがＮｉめっき層の最表面まで拡散しており、前記Ｎｉめっき層の最表面のＣｕの含有量ＲＳ（質量％）が０．８質量％と高い上、低Ｃｕ領域が形成されていないことが判った。 <Comparative example 1>
A heat spreader was manufactured in the same manner as in Example 1 except that the heat treatment temperature of the second plating layer was 800 ° C. About the Ni plating layer of the said heat spreader, it carried out similarly to Example 1, and measured distribution of content of elements, such as Cu, in the thickness direction. The results are shown in FIG. Further, in FIG. 6, the Cu distribution curve is enlarged and shown in FIG. From both figures, the Ni plating layer has a maximum thickness in the range of 1.8 μm from the interface with the substrate toward the outermost surface, a Cu content R H (% by mass) within the range of formula (III) , and the maximum. Although it was confirmed that the content was a high Cu region having a content of 6.3% by mass, a large amount of Cu diffused to the outermost surface of the Ni plating layer, and the Cu of the outermost surface of the Ni plating layer was It was found that the content R S (% by mass) was as high as 0.8% by mass and no low Cu region was formed.

また前記ヒートスプレッダについて、実施例１と同様にして、Ｎｉめっき層の密着強度を求めたところ、オートグラフの測定限界である１００Ｎ／ｍｍ2を超えており、Ｎｉめっき層は、基体に対して強固に密着していることが確認された。また実施例１と同様にして接着強度を求めたところ、初期の接着強度は１６．７Ｎ／ｍｍ2であって、比較例１のヒートスプレッダは他部材の接続の強度に優れていることが確認されたが、高温高湿環境下で静置した後の接着強度は２．９Ｎ／ｍｍ2と大きく低下しており、前記高温高湿環境に対する耐性が不十分であることが判った。 Further, when the adhesion strength of the Ni plating layer was determined for the heat spreader in the same manner as in Example 1, it exceeded the autograph measurement limit of 100 N / mm 2 , and the Ni plating layer was strong against the substrate. It was confirmed that it was closely attached to. Further, when the adhesive strength was determined in the same manner as in Example 1, the initial adhesive strength was 16.7 N / mm 2 , and it was confirmed that the heat spreader of Comparative Example 1 was excellent in the connection strength of other members. However, the adhesive strength after standing in a high-temperature and high-humidity environment was greatly reduced to 2.9 N / mm 2 , indicating that the resistance to the high-temperature and high-humidity environment was insufficient.

〈実施例２、比較例２、３〉
第１めっき層の厚みを０．０５μｍ（比較例２）、０．２μｍ（実施例２）、２．１μｍ（比較例３）としたこと以外は実施例１と同様にして、ヒートスプレッダを製造した。
〈実施例３、４、比較例４〉
第２めっき層の厚みを０．３μｍ（比較例４）、０．６μｍ（実施例３）、２．５μｍ（実施例４）としたこと以外は実施例１と同様にして、ヒートスプレッダを製造した。 <Example 2, Comparative Examples 2 and 3>
A heat spreader was manufactured in the same manner as in Example 1 except that the thickness of the first plating layer was 0.05 μm (Comparative Example 2), 0.2 μm (Example 2), and 2.1 μm (Comparative Example 3). .
<Examples 3 and 4 and Comparative Example 4>
A heat spreader was manufactured in the same manner as in Example 1 except that the thickness of the second plating layer was 0.3 μm (Comparative Example 4), 0.6 μm (Example 3), and 2.5 μm (Example 4). .

〈実施例５、６、比較例５〉
第１めっき層の熱処理温度Ｔ1（℃）を５００℃（比較例５）、６２０℃（実施例５）、９００℃（比較例６）としたこと以外は実施例１と同様にして、ヒートスプレッダを製造した。
〈実施例６〉
第１めっき層の熱処理温度Ｔ1（℃）を８５０℃とし、かつ第２めっき層の厚みを２．５μｍ、熱処理温度Ｔ2（℃）を５８０℃としたこと以外は実施例１と同様にしてヒートスプレッダを製造した。 <Examples 5 and 6, Comparative Example 5>
The heat spreader was performed in the same manner as in Example 1 except that the heat treatment temperature T 1 (° C.) of the first plating layer was 500 ° C. (Comparative Example 5), 620 ° C. (Example 5), and 900 ° C. (Comparative Example 6). Manufactured.
<Example 6>
Example 1 except that the heat treatment temperature T 1 (° C.) of the first plating layer was 850 ° C., the thickness of the second plating layer was 2.5 μm, and the heat treatment temperature T 2 (° C.) was 580 ° C. To produce a heat spreader.

〈実施例７〜９、比較例７〜１０〉
第２めっき層の熱処理温度Ｔ2（℃）を２５０℃（比較例７）、２８０℃（比較例８）、３００℃（実施例７）、３５０℃（実施例８）、５５０℃（実施例９）、６２０℃（比較例９）、７００℃（比較例１０）としたこと以外は実施例１と同様にして、ヒートスプレッダを製造した。 <Examples 7-9, Comparative Examples 7-10>
The heat treatment temperature T 2 (° C.) of the second plating layer is 250 ° C. (Comparative Example 7), 280 ° C. (Comparative Example 8), 300 ° C. (Example 7), 350 ° C. (Example 8), 550 ° C. (Example) 9), 620 ° C. (Comparative Example 9), 700 ° C. (Comparative Example 10)

〈実施例１０〉
第２めっき層を電気Ｎｉめっきによって形成したこと以外は実施例１と同様にして、ヒートスプレッダを製造した。
〈実施例１１〉
第１および第２めっき層を、いずれも無電解Ｎｉ−Ｂめっきによって形成したこと以外は実施例１と同様にして、ヒートスプレッダを製造した。 <Example 10>
A heat spreader was manufactured in the same manner as in Example 1 except that the second plating layer was formed by electric Ni plating.
<Example 11>
A heat spreader was manufactured in the same manner as in Example 1 except that both the first and second plating layers were formed by electroless Ni-B plating.

〈実施例１２〉
下記の工程を経て作製したＣｕ−Ｍｏ複合材料からなる基体を使用したこと以外は実施例１と同様にして、ヒートスプレッダを製造した。
（基体の作製）
平均粒径３μｍのＭｏ粉末に１質量％のアクリルバインダを加えて平均粒径５０μｍに造粒し、前記造粒物を、幅３０ｍｍ×長さ１１０ｍｍの平面形状が矩形状の凹部を有する金型の、前記凹部内に充填して面圧１．５ｔｏｎ／ｃｍ2の圧力をかけて矩形平板状にプレス成形し、次いで水素ガス雰囲気中で８００℃で１時間の加熱をしてバインダを除去させた後、引き続き水素ガス雰囲気中で１２５０℃に加熱して焼結させてＭｏからなる多孔質体を作製した。 <Example 12>
A heat spreader was manufactured in the same manner as in Example 1 except that a substrate made of a Cu-Mo composite material manufactured through the following steps was used.
(Preparation of substrate)
A 1% by weight acrylic binder is added to Mo powder with an average particle size of 3 μm and granulated to an average particle size of 50 μm, and the granulated product is a mold having a concave portion with a rectangular shape of 30 mm width × 110 mm length The concave portion is filled and pressed into a rectangular flat plate with a surface pressure of 1.5 ton / cm 2 , and then heated at 800 ° C. for 1 hour in a hydrogen gas atmosphere to remove the binder. After that, the porous body made of Mo was manufactured by heating and sintering at 1250 ° C. in a hydrogen gas atmosphere.

次に前記多孔質体を、その空隙量の１．３倍の体積のＣｕ板と重ねた状態で、水素ガス雰囲気中で１２５０℃に加熱してＣｕを溶解させることで、前記Ｃｕを、Ｍｏからなる多孔質体の細孔内に溶浸させてＣｕ−Ｍｏ複合材料（Ｃｕ：１５質量％、Ｍｏ：８５質量％）からなる基体の前駆体を得、前記前駆体の板の、互いに平行な２面（接続面）と、前記２面と交差する４側面とをそれぞれ研削加工して幅２５ｍｍ×長さ１００ｍｍ×厚み２ｍｍの矩形平板状の基体を作製した。   Next, the porous body is heated to 1250 ° C. in a hydrogen gas atmosphere in a state where the porous body is overlapped with a Cu plate having a volume 1.3 times larger than the void volume, thereby dissolving the Cu. A base body precursor made of a Cu—Mo composite material (Cu: 15% by mass, Mo: 85% by mass) is obtained by infiltrating into the pores of the porous body made of, and the precursor plates are parallel to each other. The two flat surfaces (connection surfaces) and four side surfaces intersecting with the two surfaces were each ground to produce a rectangular flat substrate having a width of 25 mm, a length of 100 mm, and a thickness of 2 mm.

〈実施例１３〉
下記の工程を経て作製したＣｕ−ダイヤモンド複合材料からなる基体を使用したこと以外は実施例１と同様にして、ヒートスプレッダを製造した。
（基体の作製）
平均粒径１５μｍのダイヤモンド粒子とＣｕ粉末とを、ダイヤモンド複合材料の総体積に占めるダイヤモンド粒子の割合が６０体積％となるように配合した混合物を、プレス圧２ｔｏｎ／ｃｍ2の条件で予備成形後、真空中でモリブデンからなるカプセル中に封止した。次いで前記カプセルを加圧圧力５ＧＰａ、加熱温度１１００℃の条件で５分間、加圧しながら加熱し、次いで圧力を保持した状態で温度を５００℃以下に下げて３０分間、保持したのち常温、常圧に戻してカプセルを回収した。 <Example 13>
A heat spreader was produced in the same manner as in Example 1 except that a substrate made of a Cu-diamond composite material produced through the following steps was used.
(Preparation of substrate)
After preforming a mixture in which diamond particles having an average particle size of 15 μm and Cu powder are blended so that the proportion of diamond particles in the total volume of the diamond composite material is 60% by volume under the condition of a press pressure of 2 ton / cm 2 And sealed in a capsule made of molybdenum in a vacuum. Next, the capsule was heated while being pressurized for 5 minutes under the conditions of a pressure of 5 GPa and a heating temperature of 1100 ° C., and then the temperature was lowered to 500 ° C. or lower and maintained for 30 minutes while maintaining the pressure. The capsule was recovered.

次に前記カプセルの表面を研削することでモリブデンを除去して焼結体を取り出し、放電加工して幅２５ｍｍ×長さ５０ｍｍに切り出した後、平面研磨して幅２５ｍｍ×長さ５０ｍｍ×厚み２ｍｍの矩形平板状の基体を作製した。
〈比較例１１〉
熱処理した第１めっき層の上に第２めっき層を形成しなかったこと以外は実施例１と同様にして、ヒートスプレッダを製造した。 Next, the surface of the capsule is ground to remove the molybdenum, and the sintered body is taken out. After electric discharge machining and cut into a width of 25 mm × a length of 50 mm, the surface is polished to a width of 25 mm × a length of 50 mm × a thickness of 2 mm. A rectangular flat substrate was prepared.
<Comparative Example 11>
A heat spreader was manufactured in the same manner as in Example 1 except that the second plating layer was not formed on the heat-treated first plating layer.

前記各実施例、比較例のヒートスプレッダについて、実施例１と同様にして、Ｎｉめっき層におけるＣｕ等の元素の、厚み方向の含有量の分布を求めると共に、前記Ｎｉめっき層の基体に対する密着強度、並びに初期および高温高湿環境下で静置した後の接着強度を求めた。結果を実施例１、比較例１の結果と併せて表１、表２に示す。   About the heat spreaders of the respective examples and comparative examples, the distribution of the content in the thickness direction of elements such as Cu in the Ni plating layer was determined in the same manner as in Example 1, and the adhesion strength of the Ni plating layer to the substrate, In addition, the adhesive strength after standing in an initial and high-temperature and high-humidity environment was determined. The results are shown in Tables 1 and 2 together with the results of Example 1 and Comparative Example 1.

Figure 0004876097
Figure 0004876097

Figure 0004876097
Figure 0004876097

表の実施例１および比較例１、１１の結果より、Ｎｉめっき層のＣｕの分布に差をつける必要があること、実施例１、２および比較例２、３の結果より、第１めっき層の厚みによって規定される高Ｃｕ領域の厚みは２μｍ以下、特に０．１μｍ以上、２μｍ以下であるのが好ましいこと、実施例１、３、４および比較例４の結果より、第２めっき層の厚みによって規定される低Ｃｕ領域の厚みは０．３μｍ以上であるのが好ましいことが判った。   From the results of Example 1 and Comparative Examples 1 and 11 in the table, it is necessary to make a difference in the Cu distribution of the Ni plating layer, and from the results of Examples 1 and 2 and Comparative Examples 2 and 3, the first plating layer From the results of Examples 1, 3, 4 and Comparative Example 4, the thickness of the high Cu region defined by the thickness of the second plating layer is preferably 2 μm or less, particularly 0.1 μm or more and 2 μm or less. It was found that the thickness of the low Cu region defined by the thickness is preferably 0.3 μm or more.

また実施例１、５、６および比較例５、６の結果より、第１めっき層の熱処理温度は６００℃を超え、８５０℃以下である必要があること、実施例１、７〜９および比較例７〜１０の結果より、第２めっき層の熱処理温度は３００℃以上、６００℃以下である必要があることが判った。また実施例１〜９および比較例１、４、９、１０の結果より、Ｎｉめっき層の最表面におけるＣｕの含有量は０．５質量％未満である必要があることが判った。   Moreover, from the results of Examples 1, 5, 6 and Comparative Examples 5 and 6, the heat treatment temperature of the first plating layer needs to be over 600 ° C. and 850 ° C. or less, Examples 1, 7 to 9 and Comparative From the results of Examples 7 to 10, it was found that the heat treatment temperature of the second plating layer needs to be 300 ° C. or more and 600 ° C. or less. Moreover, it turned out that content of Cu in the outermost surface of Ni plating layer needs to be less than 0.5 mass% from the result of Examples 1-9 and Comparative Examples 1, 4, 9, and 10.

さらに実施例１、１０、１１の結果より、第１のめっき層は電気Ｎｉめっきで形成するのが好ましく、第２のめっき層は無電解Ｎｉ−Ｐめっきで形成するのが好ましいこと、実施例１、１２、１３の結果より、基体はＣｕ−Ｗ複合材料で形成するのが好ましいことが判った。
〈実施例１４〉
（基体の作製）
平均粒径３μｍのＷ粉末に１質量％のアクリルバインダを加えて平均粒径５０μｍに造粒し、前記造粒物を、縦３５ｍｍ×横３５ｍｍの平面形状が矩形状の凹部を有する金型の、前記凹部内に充填して面圧１．５ｔｏｎ／ｃｍ2の圧力をかけて矩形平板状にプレス成形し、次いで水素ガス雰囲気中で８００℃で１時間の加熱をしてバインダを除去させた後、引き続き水素ガス雰囲気中で１２５０℃に加熱して焼結させてＷからなる多孔質体を作製した。 Further, from the results of Examples 1, 10, and 11, it is preferable that the first plating layer is formed by electric Ni plating, and the second plating layer is preferably formed by electroless Ni—P plating. From the results of 1, 12, and 13, it was found that the substrate is preferably formed of a Cu—W composite material.
<Example 14>
(Preparation of substrate)
A 1% by weight acrylic binder is added to W powder having an average particle size of 3 μm and granulated to an average particle size of 50 μm. The granulated product is a mold having a concave portion having a rectangular shape of 35 mm in length and 35 mm in width. The inside of the recess was filled and pressed into a rectangular flat plate with a surface pressure of 1.5 ton / cm 2 and then heated at 800 ° C. for 1 hour in a hydrogen gas atmosphere to remove the binder. Subsequently, the porous body made of W was produced by heating and sintering at 1250 ° C. in a hydrogen gas atmosphere.

次に前記多孔質体を、その空隙量の１．３倍の体積のＣｕ板と重ねた状態で、水素ガス雰囲気中で１２５０℃に加熱してＣｕを溶解させることで、前記Ｃｕを、Ｗからなる多孔質体の細孔内に溶浸させてＣｕ−Ｗ複合材料（Ｃｕ：１０質量％、Ｗ：９０質量％）からなる基体の前駆体を得、前記前駆体の板の、互いに平行な２面（接続面）と、前記２面と交差する４側面とをそれぞれ研削加工して縦３０ｍｍ×横３０ｍｍ×厚み１ｍｍの矩形平板状とした。そして前記平板の片面に、機械加工によって縦１９ｍｍ×横１９ｍｍ×深さ０．２５ｍｍの、平面形状が矩形状の凹部を座ぐり加工して、図２に示すように平板状で、かつ前記平板の、図において下側の面１３の中央部に凹部１４が設けられた基体１を作製した。   Next, the porous body is heated to 1250 ° C. in a hydrogen gas atmosphere in a state where the porous body is overlapped with a Cu plate having a volume 1.3 times as large as the void volume. A substrate precursor made of a Cu-W composite material (Cu: 10% by mass, W: 90% by mass) is obtained by infiltration into the pores of the porous body made of, and the precursor plates are parallel to each other. The two surfaces (connection surfaces) and the four side surfaces intersecting with the two surfaces were each ground to form a rectangular flat plate of 30 mm length × 30 mm width × 1 mm thickness. Then, a concave portion having a rectangular shape of 19 mm in length, 19 mm in width, and 0.25 mm in depth is machined on one side of the flat plate to form a flat plate shape as shown in FIG. In the figure, the base body 1 in which the concave portion 14 was provided in the central portion of the lower surface 13 was produced.

（ヒートスプレッダの製造）
前記基体１の表面の全面に、電気Ｎｉめっきによって、厚み１．２μｍの第１めっき層を形成し、水素ガス雰囲気中で８００℃に加熱して熱処理した後、前記第１めっき層上に、無電解Ｎｉ−Ｐめっきによって、厚み１μｍの第２めっき層を形成し、水素ガス雰囲気中で５００℃に加熱して熱処理してＮｉめっき層３を形成して、Ｃｕの含有量の分布が実施例１と同じヒートスプレッダ４を製造した。 (Manufacture of heat spreader)
A first plating layer having a thickness of 1.2 μm is formed on the entire surface of the substrate 1 by electric Ni plating, heated to 800 ° C. in a hydrogen gas atmosphere, and then heat-treated, and then on the first plating layer, A second plating layer having a thickness of 1 μm is formed by electroless Ni—P plating, heated to 500 ° C. in a hydrogen gas atmosphere and heat-treated to form a Ni plating layer 3, and the distribution of Cu content is carried out. The same heat spreader 4 as in Example 1 was produced.

（半導体装置の製造）
縦３０ｍｍ×横３０ｍｍ×厚み１ｍｍのアルミナ製のパッケージ９の、図２において上側の面１０の中央部に、半田バンプ１１を介して、縦１５ｍｍ×横１５ｍｍ×厚み０．２ｍｍのシリコン系の半導体素子１２を接続した後、前記半導体素子１２の図において上側の面と、ヒートスプレッダ４の凹部１４の底面１５である接続面２上のＮｉめっき層３との間、およびパッケージ９の上側の面１０と、ヒートスプレッダ４の凹部１４の周囲の面１３である接続面２上のＮｉめっき層３との間に、それぞれ１５質量％のＡｇフィラーを含む液状のエポキシ樹脂接着剤の層を挟んだ状態で、１５０℃で１時間の加熱をして接着剤を硬化させて図２に示す半導体装置８を製造した。 (Manufacture of semiconductor devices)
A silicon-based semiconductor having a length of 15 mm, a width of 15 mm, and a thickness of 0.2 mm through a solder bump 11 in the center of the upper surface 10 in FIG. 2 of an alumina package 9 having a length of 30 mm × width of 30 mm × thickness of 1 mm. After the element 12 is connected, the upper surface 10 between the upper surface in the figure of the semiconductor element 12 and the Ni plating layer 3 on the connection surface 2 which is the bottom surface 15 of the recess 14 of the heat spreader 4 and the upper surface 10 of the package 9. And a layer of a liquid epoxy resin adhesive containing 15% by mass of an Ag filler between the Ni plating layer 3 on the connection surface 2 which is the surface 13 around the recess 14 of the heat spreader 4. The semiconductor device 8 shown in FIG. 2 was manufactured by heating the adhesive at 150 ° C. for 1 hour to cure the adhesive.

（接着強度の測定）
接着強度の測定のために、接着面が直径１０ｍｍの円形である治具を用意した。そして前記半導体装置８を、温度＋８５℃、相対湿度８５％の高温高湿環境下で１０００時間、静置した後、パッケージ９の、図２において下側の面２３の中央部と、基体１の、図において上側の面２４の中央部のＮｉめっき層３上とに、それぞれ前記治具の接着面を、半導体装置の製造で使用したのと同じエポキシ樹脂接着剤の層を挟んで重ねた状態で、１５０℃で１時間の加熱をして接着剤を硬化させて、それぞれの面に治具を接着した。 (Measurement of adhesive strength)
In order to measure the adhesive strength, a jig having a circular bonded surface with a diameter of 10 mm was prepared. The semiconductor device 8 is allowed to stand for 1000 hours in a high-temperature and high-humidity environment with a temperature of + 85 ° C. and a relative humidity of 85%, and then the center portion of the lower surface 23 in FIG. In the figure, the bonding surface of the jig is overlapped on the Ni plating layer 3 in the center of the upper surface 24 with the same epoxy resin adhesive layer used in the manufacture of the semiconductor device interposed therebetween. Then, the adhesive was cured by heating at 150 ° C. for 1 hour, and a jig was bonded to each surface.

そして一対の治具を、図２の上下方向に引っ張って引張強度の推移を測定したところ、引張強度が４．９Ｎ／ｍｍ2の時点で引張強度の推移に変化が見られたが、外観上は、パッケージ９とヒートスプレッダ４との間で剥離等は見られなかった。そのため測定を中止し、半導体装置８を分解して内部を確認したところ、半導体素子１２とヒートスプレッダ４との間や、半導体素子１２とパッケージ９との間では剥離等は見られず、半導体素子１２自体が破損しているのが確認された。 Then, when the transition of the tensile strength was measured by pulling the pair of jigs up and down in FIG. 2, the transition of the tensile strength was observed when the tensile strength was 4.9 N / mm 2. No peeling or the like was observed between the package 9 and the heat spreader 4. Therefore, measurement was stopped and the semiconductor device 8 was disassembled and the inside was confirmed. As a result, no peeling or the like was observed between the semiconductor element 12 and the heat spreader 4 or between the semiconductor element 12 and the package 9. It was confirmed that it was damaged.

〈比較例１２〉
第２めっき層の熱処理温度を８００℃としたこと以外は実施例１４と同様にして、Ｃｕの含有量の分布が比較例１と同じヒートスプレッダ４を製造し、前記ヒートスプレッダ４を使用したこと以外は実施例１４と同様にして、図２に示す半導体装置８を製造した。そして前記半導体装置８を温度＋８５℃、相対湿度８５％の高温高湿環境下で１０００時間、静置した後、実施例１４と同様にして引っ張り強度の推移を測定したところ、引張強度が０．９８Ｎ／ｍｍ2の時点で、ほぼ同時にパッケージ９とヒートスプレッダ４との間、および半導体素子１２とヒートスプレッダ４との間で剥離した。そこで剥離面を観察したところ、いずれの剥離面においても、Ｎｉめっき層３中のＣｕの腐食によって、エポキシ樹脂接着剤が前記Ｎｉめっき層３から剥離したことが確認された。 <Comparative example 12>
Except that the heat treatment temperature of the second plating layer was set to 800 ° C., the heat spreader 4 having the same Cu content distribution as that of Comparative Example 1 was manufactured in the same manner as in Example 14 except that the heat spreader 4 was used. In the same manner as in Example 14, the semiconductor device 8 shown in FIG. The semiconductor device 8 was allowed to stand for 1000 hours in a high-temperature and high-humidity environment at a temperature of + 85 ° C. and a relative humidity of 85%, and the transition of the tensile strength was measured in the same manner as in Example 14. At the time of 98 N / mm 2 , peeling was performed between the package 9 and the heat spreader 4 and between the semiconductor element 12 and the heat spreader 4 almost simultaneously. Then, when the peeling surface was observed, it was confirmed that the epoxy resin adhesive peeled from the Ni plating layer 3 due to corrosion of Cu in the Ni plating layer 3 in any peeling surface.

本発明のヒートスプレッダの、実施の形態の一例の要部であるＮｉめっき層の一部を拡大した断面図である。It is sectional drawing which expanded a part of Ni plating layer which is the principal part of an example of embodiment of the heat spreader of this invention. 本発明の半導体装置の、実施の形態の一例を示す断面図である。It is sectional drawing which shows an example of embodiment of the semiconductor device of this invention. 本発明の、実施例、比較例において、接着強度を測定するために作製した試験片の概略を示す断面図である。It is sectional drawing which shows the outline of the test piece produced in order to measure adhesive strength in the Example of this invention and a comparative example. 本発明の、実施例１のヒートスプレッダにおける、Ｎｉめっき層の厚み方向の、元素の分布曲線を示すグラフである。It is a graph which shows the element distribution curve of the thickness direction of Ni plating layer in the heat spreader of Example 1 of this invention. 図４の分布曲線のうち、Ｃｕの分布曲線を拡大して示したグラフである。It is the graph which expanded and showed the distribution curve of Cu among the distribution curves of FIG. 比較例１のヒートスプレッダにおける、Ｎｉめっき層の厚み方向の、元素の分布曲線を示すグラフである。6 is a graph showing an element distribution curve in a thickness direction of a Ni plating layer in the heat spreader of Comparative Example 1; 図６の分布曲線のうち、Ｃｕの分布曲線を拡大して示したグラフである。It is the graph which expanded and showed the distribution curve of Cu among the distribution curves of FIG.

符号の説明Explanation of symbols

１ 基体
２、１３、１５ 接続面
３ Ｎｉめっき層
４ ヒートスプレッダ
５ 高Ｃｕ領域
６ 最表面
７ 低Ｃｕ領域
８ 半導体装置
９ パッケージ（他部材）
１２ 半導体素子（他部材）
１７、１８ 樹脂接着剤の層 DESCRIPTION OF SYMBOLS 1 Base | substrate 2, 13, 15 Connection surface 3 Ni plating layer 4 Heat spreader 5 High Cu area | region 6 Outer surface 7 Low Cu area | region 8 Semiconductor device 9 Package (other members)
12 Semiconductor elements (other members)
17, 18 Layer of resin adhesive

Claims (6)

Ｗ、Ｍｏ、またはダイヤモンドと、Ｃｕとの複合材料からなり、他部材との接続のための接続面を有する基体を備え、前記基体の少なくとも前記接続面にＮｉめっき層が形成されたヒートスプレッダであって、前記Ｎｉめっき層が、前記接続面にＮｉめっきを施して、厚み０．２μｍ以上、１．２μｍ以下の第１めっき層を形成し、式(I)：
６２０℃≦Ｔ１≦８５０℃ (I)
を満足する温度Ｔ１（℃）で熱処理して前記基体中から前記第１めっき層中にＣｕを拡散させたのち、前記第１めっき層の表面にＮｉめっきを施して、厚み０．６μｍ以上、２．５μｍ以下の第２めっき層を形成し、式(II)：
３００℃≦Ｔ２≦５８０℃ (II)
を満足する温度Ｔ２（℃）で熱処理して前記第２めっき層と前記第１めっき層とを一体化させて形成され、
前記Ｎｉめっき層は、前記基体との界面から厚み方向に０．２μｍ以上、１．９μｍ以下の範囲にＣｕの含有量ＲＨ（質量％）が式(III)：
２．５質量％≦ＲＨ (III)
を満足する高Ｃｕ領域を有すると共に、前記Ｎｉめっき層の最表面がＣｕを含まないか、または前記最表面におけるＣｕの含有量ＲＳ（質量％）が式(IV)：
０質量％＜ＲＳ≦０．３質量％ (IV)
を満足し、かつ前記Ｎｉめっき層の、前記基体に対する密着強度ＳＡ（Ｎ／ｍｍ２）が９０Ｎ／ｍｍ２以上であることを特徴とするヒートスプレッダ。 A heat spreader comprising a base material made of a composite material of W, Mo, or diamond and Cu and having a connection surface for connection to another member, and a Ni plating layer formed on at least the connection surface of the base material. Then, the Ni plating layer performs Ni plating on the connection surface to form a first plating layer having a thickness of 0.2 μm or more and 1.2 μm or less, and the formula (I):
620 ° C. ≦ T 1 ≦ 850 ° C. (I)
After heat-treating at a temperature T 1 (° C.) satisfying the above conditions, Cu is diffused from the substrate into the first plating layer, and then Ni plating is applied to the surface of the first plating layer to obtain a thickness of 0.6 μm or more. Forming a second plating layer of 2.5 μm or less , and formula (II):
300 ° C ≦ T 2 ≦ 580 ° C (II)
Formed by integrating the second plating layer and the first plating layer by heat treatment at a temperature T 2 (° C.) satisfying
The Ni plating layer has a Cu content R H (mass%) in the range of 0.2 μm or more and 1.9 μm or less in the thickness direction from the interface with the substrate, with the formula (III):
2.5 mass% ≤ R H (III)
And the outermost surface of the Ni plating layer does not contain Cu, or the Cu content R S (% by mass) on the outermost surface is represented by the formula (IV):
0% by mass <R S ≦ 0.3% by mass (IV)
And the adhesion strength S A (N / mm 2 ) of the Ni plating layer to the substrate is 90 N / mm 2 or more. 前記基体がＣｕ−Ｗ複合材料からなり、前記Ｃｕ−Ｗ複合材料におけるＷの含有量が７５質量％以上、９５質量％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 the substrate is made of a Cu-W composite material, and the content of W in the Cu-W composite material is 75 mass% or more and 95 mass% or less. 半導体素子と、前記半導体素子の動作時に発生する熱を除去するための、請求項１または２に記載のヒートスプレッダとを備えることを特徴とする半導体装置。 And the semiconductor element, the operation for removing the heat generated during the semiconductor device, a semiconductor device characterized by comprising a heat spreader according to claim 1 or 2. 前記ヒートスプレッダが複数の接続面を備え、前記複数の接続面のうち少なくとも１つの接続面に前記半導体素子、他の接続面に熱除去部材が、それぞれＡｇフィラーを配合した樹脂接着剤を介して接続されている請求項３に記載の半導体装置。 The heat spreader includes a plurality of connection surfaces, and the semiconductor element is connected to at least one connection surface of the plurality of connection surfaces, and the heat removal member is connected to the other connection surface via a resin adhesive containing an Ag filler. The semiconductor device according to claim 3 . 前記接続面に対する前記半導体素子、および前記熱除去部材の接着強度ＳＢ（Ｎ／ｍｍ２）が、それぞれ１５．７Ｎ／ｍｍ２以上である請求項４に記載の半導体装置。 5. The semiconductor device according to claim 4 , wherein an adhesive strength S B (N / mm 2 ) of the semiconductor element and the heat removal member with respect to the connection surface is 15.7 N / mm 2 or more, respectively. 請求項１または２に記載のヒートスプレッダを製造するための製造方法であって、Ｗ、Ｍｏ、またはダイヤモンドと、Ｃｕとの複合材料からなる前記基体の少なくとも前記接続面にＮｉめっきを施して厚みが０．２μｍ以上、１．２μｍ以下の第１めっき層を形成し、式(I)：
６２０℃≦Ｔ１≦８５０℃ (I)
を満足する温度Ｔ１（℃）で熱処理して前記基体中から前記第１めっき層中にＣｕを拡散させる工程と、前記第１めっき層の表面にＮｉめっきを施して厚みが０．６μｍ以上、２．５μｍ以下の第２めっき層を形成し、式(II)：
３００℃≦Ｔ２≦５８０℃ (II)
を満足する温度Ｔ２（℃）で熱処理して前記第２めっき層と前記第１めっき層とを一体化させて前記Ｎｉめっき層を形成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。 It is a manufacturing method for manufacturing the heat spreader according to claim 1 or 2 , wherein Ni plating is applied to at least the connection surface of the base made of a composite material of W, Mo, or diamond and Cu, and the thickness is increased. A first plating layer of 0.2 μm or more and 1.2 μm or less is formed, and the formula (I):
620 ° C. ≦ T 1 ≦ 850 ° C. (I)
And a step of diffusing Cu from the substrate into the first plating layer by performing a heat treatment at a temperature T 1 (° C.) that satisfies the following conditions: Ni plating is applied to the surface of the first plating layer, and the thickness is 0.6 μm or more. Forming a second plating layer of 2.5 μm or less, and formula (II):
300 ° C ≦ T 2 ≦ 580 ° C (II)
And a step of forming the Ni plating layer by integrating the second plating layer and the first plating layer by heat treatment at a temperature T 2 (° C.) satisfying .
JP2008121265A 2007-05-31 2008-05-07 HEAT SPREADER, MANUFACTURING METHOD THEREOF, AND SEMICONDUCTOR DEVICE Expired - Fee Related JP4876097B2 (en)

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