JP2009224715A - Heat dissipation plate, and module equipped with the same - Google Patents

Heat dissipation plate, and module equipped with the same Download PDF

Info

Publication number
JP2009224715A
JP2009224715A JP2008070112A JP2008070112A JP2009224715A JP 2009224715 A JP2009224715 A JP 2009224715A JP 2008070112 A JP2008070112 A JP 2008070112A JP 2008070112 A JP2008070112 A JP 2008070112A JP 2009224715 A JP2009224715 A JP 2009224715A
Authority
JP
Japan
Prior art keywords
semiconductor element
region
thermal expansion
heat
heat sink
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2008070112A
Other languages
Japanese (ja)
Inventor
Masanori Usui
正則 臼井
Koji Hotta
幸司 堀田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Motor Corp
Toyota Central R&D Labs Inc
Original Assignee
Toyota Motor Corp
Toyota Central R&D Labs Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toyota Motor Corp, Toyota Central R&D Labs Inc filed Critical Toyota Motor Corp
Priority to JP2008070112A priority Critical patent/JP2009224715A/en
Publication of JP2009224715A publication Critical patent/JP2009224715A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • 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
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/31—Structure, shape, material or disposition of the layer connectors after the connecting process
    • H01L2224/32—Structure, shape, material or disposition of the layer connectors after the connecting process of an individual layer connector
    • H01L2224/321—Disposition
    • H01L2224/32151—Disposition the layer 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
    • H01L2224/32221—Disposition the layer 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
    • H01L2224/32225—Disposition the layer 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
    • H01L2224/01—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
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/4805—Shape
    • H01L2224/4809—Loop shape
    • H01L2224/48091—Arched
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/10—Details of semiconductor or other solid state devices to be connected
    • H01L2924/11—Device type
    • H01L2924/13—Discrete devices, e.g. 3 terminal devices
    • H01L2924/1301—Thyristor
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/10—Details of semiconductor or other solid state devices to be connected
    • H01L2924/11—Device type
    • H01L2924/13—Discrete devices, e.g. 3 terminal devices
    • H01L2924/1304—Transistor
    • H01L2924/1305—Bipolar Junction Transistor [BJT]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/10—Details of semiconductor or other solid state devices to be connected
    • H01L2924/11—Device type
    • H01L2924/13—Discrete devices, e.g. 3 terminal devices
    • H01L2924/1304—Transistor
    • H01L2924/1305—Bipolar Junction Transistor [BJT]
    • H01L2924/13055—Insulated gate bipolar transistor [IGBT]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/10—Details of semiconductor or other solid state devices to be connected
    • H01L2924/11—Device type
    • H01L2924/13—Discrete devices, e.g. 3 terminal devices
    • H01L2924/1304—Transistor
    • H01L2924/1306—Field-effect transistor [FET]
    • H01L2924/13091—Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]

Landscapes

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

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for reducing damage due to a difference in thermal expansion of an adhesion portion between a heat dissipation plate and a semiconductor element portion while suppressing a decrease in heat dissipation performance of the heat dissipation plate. <P>SOLUTION: A module 10 includes a semiconductor element 22, a cooler 32, and the heat dissipation plate 12 provided between the semiconductor element 22 and cooler 32 and bonded to a reverse surface of the semiconductor element 22, and the heat dissipation plate 12 has a first region and a second region within an adhesion range where the semiconductor element 22 is bonded. The first region is provided at a peripheral edge of the adhesion range, and the second region is provided at a center part of the adhesion range, the difference in coefficient of thermal expansion between the reverse surface of the semiconductor element 22 and the first region being smaller than that between the reverse surface of the semiconductor element 22 and the second region and the coefficient of thermal expansion of the second region being higher than that of the first region. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、少なくとも半導体素子を含む半導体素子部と冷却器の間に設けられている放熱板に関する。本発明はさらに、その放熱板を備えたモジュールにも関する。   The present invention relates to a heat sink provided between a semiconductor element portion including at least a semiconductor element and a cooler. The invention further relates to a module comprising the heat sink.

半導体素子を利用して電流や電圧を制御する技術は、様々な分野で用いられている。半導体素子は、自らの電力損失によって作動時に発熱する。半導体素子の温度が上昇すると、半導体素子の特性が変化してしまう。このような温度に応じた特性変化を抑制するために、半導体素子を冷却する技術が求められている。   Techniques for controlling current and voltage using semiconductor elements are used in various fields. The semiconductor element generates heat during operation due to its own power loss. When the temperature of the semiconductor element rises, the characteristics of the semiconductor element change. In order to suppress such a characteristic change according to temperature, a technique for cooling a semiconductor element is required.

なかでも、サイリスタ、MOSFET(Metal Oxide Semiconductor Field Effect Transistor)、IGBT(Insulated Gate Bipolar Transistor)、ダイオードに代表される半導体素子は、大電流を制御するために用いられることが多い。例えば車載用のインバータ回路に用いられるこの種の半導体素子は、作動時の発熱量が極めて大きい。このため、この種の半導体素子を冷却する技術が特に求められている。   In particular, thyristors, MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), IGBTs (Insulated Gate Bipolar Transistors), and semiconductor elements represented by diodes are often used to control a large current. For example, this type of semiconductor element used in an in-vehicle inverter circuit generates a very large amount of heat during operation. For this reason, a technique for cooling this type of semiconductor element is particularly required.

従来技術では、半導体素子を含む半導体素子部で発生した熱を放熱するために冷却器が用いられている。従来技術ではさらに、半導体素子部と冷却器の間に放熱板が設けられている。放熱板は、半導体素子部と冷却器の間で熱を横方向に拡散して半導体素子部から冷却器に熱を放熱する。このため、半導体素子部の熱は、冷却器の表面の広い範囲に放熱されるので、半導体素子部を効率良く冷却することができる。   In the prior art, a cooler is used to dissipate heat generated in a semiconductor element portion including a semiconductor element. In the prior art, a heat radiating plate is further provided between the semiconductor element portion and the cooler. The heat radiating plate diffuses heat laterally between the semiconductor element portion and the cooler to radiate heat from the semiconductor element portion to the cooler. For this reason, since the heat | fever of a semiconductor element part is thermally radiated to the wide range of the surface of a cooler, a semiconductor element part can be cooled efficiently.

従来の放熱板には、放熱の効率を高めるために、銅やアルミニウム等の熱伝導率の高い金属材料が用いられている。これらの金属材料は、熱膨張率が高い。一方において、半導体素子部の熱膨張率は低い。この関係から、半導体素子が作動して高温に達すると、放熱板と半導体素子部との間の熱膨張率の差に比例して放熱板と半導体素子部との間に界面応力が加わる。この界面応力は、放熱板と半導体素子部との接着部にひずみを生じさせる。半導体素子が作動と非作動を繰り返し切り替わることによって、放熱板と半導体素子部との接着部が繰り返しひずみによってダメージを受ける。その結果、接着部にクラック等が発生する虞がある。前記したように、放熱板と半導体素子部との間に加わる界面応力は、放熱板と半導体素子部との間の熱膨張率の差に比例している。   Conventional heat sinks use metal materials having high thermal conductivity such as copper and aluminum in order to increase the heat dissipation efficiency. These metal materials have a high coefficient of thermal expansion. On the other hand, the coefficient of thermal expansion of the semiconductor element portion is low. From this relationship, when the semiconductor element operates and reaches a high temperature, an interfacial stress is applied between the heat sink and the semiconductor element portion in proportion to the difference in coefficient of thermal expansion between the heat sink and the semiconductor element portion. This interfacial stress causes distortion in the bonded portion between the heat sink and the semiconductor element portion. When the semiconductor element is repeatedly switched between operation and non-operation, the bonded portion between the heat sink and the semiconductor element portion is damaged by repeated strain. As a result, there is a risk that cracks or the like may occur in the bonded portion. As described above, the interfacial stress applied between the heat radiating plate and the semiconductor element portion is proportional to the difference in coefficient of thermal expansion between the heat radiating plate and the semiconductor element portion.

そこで、熱膨張率の差を低減するために、特許文献１は、熱膨張率の低いモリブデンを含む放熱板を提案している。特許文献１の放熱板は、３０〜７０％の銅と残部が実質的にモリブデンからなる複合金属の芯板と、その芯板の表面と裏面のそれぞれに銅板を被覆した銅／銅−モリブデン複合金属／銅からなるクラッド材である。特許文献１の技術は、銅とモリブテンの複合金属で放熱板を構成することによって、低い熱膨張率と高い熱伝導率の両立を図ろうとするものである。   Therefore, in order to reduce the difference in coefficient of thermal expansion, Patent Document 1 proposes a heat radiating plate containing molybdenum having a low coefficient of thermal expansion. The heat dissipation plate of Patent Document 1 is a composite metal core plate made of 30 to 70% copper and the balance substantially made of molybdenum, and a copper / copper-molybdenum composite in which the front and back surfaces of the core plate are coated with a copper plate. It is a clad material made of metal / copper. The technology of Patent Document 1 intends to achieve both a low thermal expansion coefficient and a high thermal conductivity by forming a heat sink with a composite metal of copper and molybdenum.

特開２００７−１４２１２６号公報JP 2007-142126 A

特許文献１の技術は、銅とモリブテンの組成比や複合金属の形態を工夫することによって、放熱板全体の熱膨張率と熱伝導率を所望の値に調整しようとするものである。しかしながら、特許文献１の技術では、銅とモリブテンの組成比や複合金属の形態をいくら工夫したとしても、依然として放熱板の熱膨張率と熱伝導率の間にトレードオフの関係が存在している。即ち、放熱板の熱膨張率を優先して熱膨張率を所望の値に調整すれば、熱伝導率を犠牲にしなければならない。逆に、放熱板の熱伝導率を優先して熱伝導率を所望の値に調整すれば熱膨張率を犠牲にしなければならない。特許文献１のように、放熱板全体の熱膨張率と熱伝導率を同時に調整する技術の範疇では、熱膨張率と熱伝導率の間のトレードオフの関係を打破することができない。   The technique of patent document 1 tries to adjust the thermal expansion coefficient and thermal conductivity of the whole heat sink to desired values by devising the composition ratio of copper and molybdenum and the form of the composite metal. However, in the technology of Patent Document 1, no matter how much the composition ratio of copper and molybdenum and the form of the composite metal are devised, there is still a trade-off relationship between the thermal expansion coefficient and the thermal conductivity of the heat sink. . That is, if the thermal expansion coefficient is adjusted to a desired value by giving priority to the thermal expansion coefficient of the heat sink, the thermal conductivity must be sacrificed. Conversely, if the thermal conductivity is adjusted to a desired value by giving priority to the thermal conductivity of the heat sink, the thermal expansion coefficient must be sacrificed. As in Patent Document 1, in the category of the technique of simultaneously adjusting the thermal expansion coefficient and the thermal conductivity of the entire heat sink, the trade-off relationship between the thermal expansion coefficient and the thermal conductivity cannot be overcome.

本発明は、従来の技術思想とは全く異なり、新規で斬新な形態を採用することにより、放熱板の熱膨張率と熱伝導率の間に存在しているトレードオフの関係を打破する技術を提供する。   The present invention is completely different from the conventional technical idea, and a technology that breaks the trade-off relationship existing between the thermal expansion coefficient and the thermal conductivity of the heat sink by adopting a new and novel form. provide.

本発明者らは、放熱板と半導体素子部の接着範囲に着目した。本発明者らは、半導体素子部と放熱板との間の熱膨張率の差による繰り返しひずみが、接着範囲の周縁で最大であり、接着範囲の周縁がダメージを受けてクラック等が発生し易いことを見出した。一方、接着範囲の中央部は、半導体素子部から流入してくる熱量が接着範囲の周縁よりも大きいことを見出した。即ち、本発明者らは、接着範囲の面内において、熱膨張率を優先して考慮すべき領域と熱伝導率を優先して考慮すべき領域が存在することを見出した。本明細書で開示される技術は、上記の新たな知見を利用するものであり、放熱板の熱膨張率と熱伝導率が接着範囲において変化していることを特徴としている。これにより、熱膨張率を優先して考慮すべき領域では、放熱板の熱膨張率が適宜に調整されており、クラック等の発生を劇的に抑制することができる。一方、熱伝導率を優先して考慮すべき領域では、放熱板の熱伝導率が適宜に調整されており、半導体素子部で発生した熱を効率的に放熱することができる。したがって、本明細書で開示される技術は、接着範囲の場所に応じて熱膨張率と熱伝導率が適宜に調整されているので、放熱板の熱膨張率と熱伝導率の間に存在しているトレードオフの関係を打破することができる。   The inventors paid attention to the bonding range between the heat sink and the semiconductor element portion. The inventors of the present invention have the largest repeated strain due to the difference in the coefficient of thermal expansion between the semiconductor element portion and the heat sink, and the periphery of the adhesion range is damaged, and cracks and the like are likely to occur. I found out. On the other hand, the center part of the adhesion range has found that the amount of heat flowing in from the semiconductor element part is larger than the peripheral edge of the adhesion range. That is, the present inventors have found that there are a region in which the thermal expansion coefficient should be preferentially considered and a region in which the thermal conductivity should be preferentially considered in the bonding range. The technology disclosed in the present specification utilizes the above-described new knowledge, and is characterized in that the thermal expansion coefficient and thermal conductivity of the heat radiating plate are changed in the bonding range. Thereby, in a region where the thermal expansion coefficient should be considered with priority, the thermal expansion coefficient of the heat radiating plate is appropriately adjusted, and the occurrence of cracks and the like can be dramatically suppressed. On the other hand, in a region where heat conductivity should be considered with priority, the heat conductivity of the heat radiating plate is appropriately adjusted, and heat generated in the semiconductor element portion can be efficiently radiated. Therefore, the technique disclosed in this specification exists between the thermal expansion coefficient and the thermal conductivity of the heat sink because the thermal expansion coefficient and the thermal conductivity are appropriately adjusted according to the location of the bonding range. You can break the trade-off relationship.

本明細書で開示される放熱板は、少なくとも半導体素子を含む半導体素子部と冷却器の間に設けられている。半導体素子部は、半導体素子のみで構成されていてもよいし、半導体素子以外のもの、例えば、半導体素子の裏面に接着されている絶縁部材や、その絶縁部材の表面に貼り付けられた導電箔等を含んでいてもよい。放熱板は、半導体素子部と冷却器の間に設けられている部材のことであり、半導体素子部の熱を冷却器にまで放熱する。放熱板は、複数の板が積層したものでもよい。冷却器は、典型的には水冷式や空冷式のヒートシンクであり、冷却能力を向上させるために表面積が広くなるような形態を備えていることが多い。半導体素子部と放熱板は、例えば、はんだ、ろう、接着剤によって接着されている。放熱板と冷却器は、例えば、グリース、はんだ、ろう、接着剤によって接着されている。ただし、これらの接着方法に限定されるものではない。本明細書で開示される放熱板の熱膨張率と熱伝導率は、半導体素子部に接着する接着範囲で変化していることを特徴としている。放熱板の接着範囲の熱膨張率は、中央部よりも周縁で低い。さらに、放熱板の接着範囲の熱伝導率は、周縁よりも中央部で高い。ここで、接着範囲の中央部とは、接着範囲の周縁を除く少なくとも一部の領域を示している。
この放熱板によると、放熱板と半導体素子部との間の熱膨張率の差が、接着範囲の周縁で小さく調整されている。クラック等の発生が生じ易い接着範囲の周縁で熱膨張率の差が小さく調整されているので、クラック等の発生を劇的に抑制することができる。一方、接着範囲の中央部で放熱板の熱伝導率が高く調整されているので、半導体素子部で発生した熱を効率的に冷却器にまで放熱することができる。 The heat sink disclosed in the present specification is provided between a semiconductor element portion including at least a semiconductor element and a cooler. The semiconductor element portion may be composed of only the semiconductor element, or other than the semiconductor element, for example, an insulating member bonded to the back surface of the semiconductor element, or a conductive foil attached to the surface of the insulating member Etc. may be included. A heat sink is a member provided between the semiconductor element part and the cooler, and dissipates heat of the semiconductor element part to the cooler. The heat radiating plate may be a laminate of a plurality of plates. The cooler is typically a water-cooled or air-cooled heat sink, and is often provided with a configuration that increases the surface area in order to improve the cooling capacity. The semiconductor element part and the heat sink are bonded by, for example, solder, brazing, or adhesive. The heat sink and the cooler are bonded by, for example, grease, solder, brazing, or adhesive. However, it is not limited to these adhesion methods. The thermal expansion coefficient and thermal conductivity of the heat radiating plate disclosed in the present specification are characterized in that they change within the bonding range where the heat radiating plate is bonded to the semiconductor element portion. The thermal expansion coefficient in the bonding range of the heat sink is lower at the periphery than at the center. Furthermore, the thermal conductivity of the bonding range of the heat sink is higher at the center than at the periphery. Here, the center part of the adhesion range indicates at least a part of the region excluding the peripheral edge of the adhesion range.
According to this heat radiating plate, the difference in coefficient of thermal expansion between the heat radiating plate and the semiconductor element portion is adjusted to be small at the periphery of the bonding range. Since the difference in coefficient of thermal expansion is adjusted to be small at the periphery of the adhesion range where cracks and the like are likely to occur, the occurrence of cracks and the like can be dramatically suppressed. On the other hand, since the heat conductivity of the heat radiating plate is adjusted to be high at the central portion of the bonding range, the heat generated in the semiconductor element portion can be efficiently radiated to the cooler.

放熱板は、半導体素子部に接着する接着範囲に第１領域と第２領域を有しているのが好ましい。第１領域は接着範囲の周縁に設けられており、第２領域は接着範囲の中央部に設けられている。そして、放熱板の第１領域の熱膨張率は、放熱板の第２領域の熱膨張率よりも低い。さらに、放熱板の第２領域の熱伝導率は、第１領域の熱伝導率よりも高い。   It is preferable that the heat sink has a first region and a second region in a bonding range for bonding to the semiconductor element portion. The first region is provided at the periphery of the adhesion range, and the second region is provided at the center of the adhesion range. And the thermal expansion coefficient of the 1st area | region of a heat sink is lower than the thermal expansion coefficient of the 2nd area | region of a heat sink. Furthermore, the thermal conductivity of the second region of the heat sink is higher than the thermal conductivity of the first region.

この放熱板では、半導体素子部との接着範囲の周縁に、半導体素子部との熱膨張率の差が小さい第１領域が設けられている。これにより、半導体素子の発熱による繰り返しひずみによって放熱板と半導体素子部との接着部の周縁が受けるダメージを低減することができる。また、この放熱板では、半導体素子部との接着範囲の中央部に、熱伝導率の高い第２領域が設けられている。そのため、放熱板の第２領域によって、半導体素子の熱を効率的に冷却器にまで放熱することができる。   In this heat radiating plate, a first region having a small difference in thermal expansion coefficient from the semiconductor element portion is provided at the periphery of the bonding range with the semiconductor element portion. Thereby, the damage which the periphery of the adhesion part of a heat sink and a semiconductor element part receives by the repeated distortion by the heat_generation | fever of a semiconductor element can be reduced. Moreover, in this heat sink, the 2nd area | region with high heat conductivity is provided in the center part of the adhesion | attachment range with a semiconductor element part. Therefore, the heat of the semiconductor element can be efficiently radiated to the cooler by the second region of the heat radiating plate.

この放熱板の第１領域は第１材料で構成され、第２領域は第２材料で構成されていてもよい。この場合、第１材料の熱膨張率が第２材料の熱膨張率よりも低く、第２材料の熱伝導率が第１材料の熱伝導率よりも高いことが好ましい。
上記の放熱板は、材料を変えるだけで特性の異なる２つの領域を形成することができる。この構成によれば、異なる特性を有する放熱板を容易に作製することができる。 The 1st field of this heat sink may be constituted by the 1st material, and the 2nd field may be constituted by the 2nd material. In this case, it is preferable that the thermal expansion coefficient of the first material is lower than that of the second material, and the thermal conductivity of the second material is higher than that of the first material.
The above-mentioned heat sink can form two regions having different characteristics only by changing the material. According to this structure, the heat sink which has a different characteristic can be produced easily.

また、第１領域と第２領域は、第３材料と第４材料の複合材料で構成されていてもよい。第３材料の熱膨張率が第４材料の熱膨張率よりも小さく、第４材料の熱伝導率が第３材料の熱伝導率よりも高い。この場合、第１領域の第４材料に対する第３材料の割合が、第２領域の第４材料に対する第３材料の割合よりも高いことが好ましい。
この構成によると、第３材料と第４材料の割合を調整することによって、熱膨張率と熱伝導率を細かく調整することができる。このため、第１領域において所望の熱膨張率を実現するとともに、第２領域において所望の熱伝導率を実現することができる。
なお、この複合材料は、第４材料が第３材料に分散した形態を備えていることが好ましい。 The first region and the second region may be composed of a composite material of the third material and the fourth material. The thermal expansion coefficient of the third material is smaller than the thermal expansion coefficient of the fourth material, and the thermal conductivity of the fourth material is higher than the thermal conductivity of the third material. In this case, it is preferable that the ratio of the third material to the fourth material in the first region is higher than the ratio of the third material to the fourth material in the second region.
According to this configuration, the coefficient of thermal expansion and the thermal conductivity can be finely adjusted by adjusting the ratio of the third material and the fourth material. For this reason, while achieving a desired coefficient of thermal expansion in the first region, it is possible to achieve a desired thermal conductivity in the second region.
The composite material preferably has a form in which the fourth material is dispersed in the third material.

この放熱板では、第１領域が接着範囲の周縁を一巡しているのが好ましい。接着範囲の周縁の全体に亘ってクラック等の発生を抑制することができる。なお、必要に応じて、第１領域は、接着範囲の周縁に断続的に設けられていてもよい。   In this heat radiating plate, it is preferable that the first region goes around the periphery of the bonding range. Generation | occurrence | production of a crack etc. can be suppressed over the whole periphery of the adhesion | attachment range. In addition, the 1st area | region may be intermittently provided in the periphery of the adhesion | attachment range as needed.

本明細書で開示される技術は、新規で有用なモジュールを提供することもできる。このモジュールは、少なくとも半導体素子を含む半導体素子部と、冷却器と、半導体素子部と冷却器の間に設けられている放熱板とを備えている。放熱板の熱膨張率は、半導体素子部に接着する接着範囲の中央部よりも周縁で低い。さらに、放熱板の熱伝導率が、接着範囲の周縁よりも中央部で高い。   The technology disclosed herein can also provide a new and useful module. The module includes a semiconductor element portion including at least a semiconductor element, a cooler, and a heat sink provided between the semiconductor element portion and the cooler. The thermal expansion coefficient of the heat radiating plate is lower at the periphery than the central portion of the bonding range where the heat radiating plate is bonded to the semiconductor element portion. Furthermore, the heat conductivity of the heat sink is higher at the center than at the periphery of the bonding range.

本明細書で開示される技術では、半導体素子が、半導体基板の中央部に設けられている活性領域と、その活性領域の周囲を一巡している終端領域を備えているのが好ましい。活性領域はトランジスタ又はダイオードのメイン構造を有しており、終端領域は耐圧保持構造を有しているのが好ましい。
半導体素子の終端領域は、実質的には電流が流れない領域であり、この領域での発熱は無視できることが多い。このため、放熱板の熱伝導率が接着範囲の周縁で小さくなっていても、半導体素子部の熱を冷却器にまで放熱する事象に深刻な影響を与えるものではない。したがって、放熱板の接着範囲の周縁は、熱伝導率よりも熱膨張率を優先すべき領域である。本明細書で開示される放熱板は、放熱板の接着範囲の周縁で熱膨張率が選択的に小さくなっている。本明細書で開示される放熱板は、終端領域を有する半導体素子との組合せて用いられるときに特に有用である。 In the technology disclosed in this specification, it is preferable that the semiconductor element includes an active region provided in the central portion of the semiconductor substrate and a termination region that goes around the active region. The active region preferably has a main structure of a transistor or a diode, and the termination region preferably has a withstand voltage holding structure.
The termination region of the semiconductor element is a region where no current flows substantially, and heat generation in this region is often negligible. For this reason, even if the thermal conductivity of the heat radiating plate decreases at the periphery of the bonding range, it does not seriously affect the event of radiating the heat of the semiconductor element part to the cooler. Therefore, the periphery of the bonding range of the heat sink is a region where the thermal expansion coefficient should be prioritized over the thermal conductivity. The heat dissipation plate disclosed in this specification has a small thermal expansion coefficient at the periphery of the bonding range of the heat dissipation plate. The heat sink disclosed in this specification is particularly useful when used in combination with a semiconductor element having a termination region.

本明細書で開示される放熱板は、半導体素子部に接着する接着範囲内の場所に応じて熱膨張率と熱伝導率が適宜に調整されているので、放熱板の熱膨張率と熱伝導率の間に存在しているトレードオフの関係を打破することができる。この結果、本明細書で開示される放熱板は、半導体素子部で発生した熱を冷却器に効率的に放熱するとともに、接着範囲の周縁のダメージを低減することができる。   Since the thermal expansion coefficient and thermal conductivity of the radiator plate disclosed in this specification are appropriately adjusted according to the location within the bonding range to be bonded to the semiconductor element portion, the thermal expansion coefficient and thermal conductivity of the radiator plate are adjusted. The trade-off relationship that exists between rates can be broken down. As a result, the heat dissipating plate disclosed in the present specification can efficiently dissipate heat generated in the semiconductor element portion to the cooler, and can reduce damage on the periphery of the bonding range.

本実施例の技術の特徴を列記する。
（第１特徴） 半導体素子部は、半導体素子のみを有していてもよく、半導体素子の他に両面に導電箔が施された絶縁板を含んでいてもよい。
（第２特徴） 発熱部が絶縁基板を含んでいる場合、絶縁基板の一方の面に導電箔には半導体素子が接着されており、他方の面の導電箔には放熱板が接着されている。
（第３特徴） 放熱板の熱膨張係数は、半導体素子の半導体材料の熱膨張係数よりも大きい。
（第４特徴） 半導体素子は、パワーデバイスである。
（第５特徴） 半導体素子は、半導体基板の中心部に形成されている活性領域と、その活性領域の周囲を一巡している終端領域を有する。活性領域は、トランジスタ又はダイオードのメイン構造が設けられた領域のことをいう。終端領域は、耐圧保持を目的とした構造が設けられた領域をいう。終端領域には、典型的にはガードリング構造、フィールドプレート構造が設けられている。
（第６特徴） 第５特徴において、放熱板の第２領域は、平面視したときに、半導体素子の活性領域の下方に位置している。
（第７特徴） 第６特徴において、放熱板の第２領域は、平面視したときに、半導体素子の活性領域よりも広くなっている。 The technical features of this embodiment will be listed.
(First Feature) The semiconductor element portion may include only a semiconductor element, or may include an insulating plate having conductive foils on both sides in addition to the semiconductor element.
(Second feature) When the heat generating portion includes an insulating substrate, a semiconductor element is bonded to the conductive foil on one surface of the insulating substrate, and a heat sink is bonded to the conductive foil on the other surface. .
(3rd characteristic) The thermal expansion coefficient of a heat sink is larger than the thermal expansion coefficient of the semiconductor material of a semiconductor element.
(Fourth feature) The semiconductor element is a power device.
(Fifth Feature) The semiconductor element has an active region formed in the central portion of the semiconductor substrate and a termination region that goes around the active region. The active region refers to a region where a main structure of a transistor or a diode is provided. The term “termination region” refers to a region provided with a structure for maintaining a withstand voltage. In the termination region, a guard ring structure and a field plate structure are typically provided.
(Sixth Feature) In the fifth feature, the second region of the heat sink is located below the active region of the semiconductor element when viewed in plan.
(Seventh feature) In the sixth feature, the second region of the heat sink is wider than the active region of the semiconductor element when viewed in plan.

以下、図面を参照して実施例を説明する。図１は、パワーモジュール１０の概略側面図である。図２は、パワーモジュール１０の一部を抜粋した縦断面図である。図３は、放熱板１２の上面図である。図４は、半導体素子２２の要部断面図である。パワーモジュール１０は、半導体素子２２と外部端子１４と放熱板１２を備えている。図４に示すように、半導体素子２２は、半導体素子２２の中央部に設けられている活性領域２２Ａと、その活性領域２２Ａの周囲を一巡している終端領域２２Ｂを備えている。活性領域２２Ａはトランジスタ又はダイオードのメイン構造２７を有している。終端領域２２Ｂは耐圧保持構造であるガードリング構造２５を有している。
半導体素子２２には、例えば、サイリスタ、IGBT、MOSFET、ダイオードを使用することができる。半導体素子２２は、外部端子１４ａを介して外部から電力が供給され、外部端子１４ｂを介して外部に電力を供給する。半導体素子２２は、外部から電力が供給されると、自らの電力損失によって作動時に発熱する。半導体素子２２の熱膨張率は、３×１０−６／Ｋである。外部端子１４ａ，１４ｂと半導体素子２２は、それぞれボンディングワイヤ１６ａ，１６ｂで接続されている。外部端子１４ａ，１４ｂは、図示省略した絶縁層を介して放熱板１２に接着されている。
半導体素子２２は、それぞれはんだの接着層２４によって放熱板１２と接着されている。半導体素子２２と放熱板１２との接着には、はんだ付以外の方法も利用することができ、例えば、ろうや接着剤を用いることができる。 Embodiments will be described below with reference to the drawings. FIG. 1 is a schematic side view of the power module 10. FIG. 2 is a longitudinal sectional view of a part of the power module 10 extracted. FIG. 3 is a top view of the heat sink 12. FIG. 4 is a cross-sectional view of the main part of the semiconductor element 22. The power module 10 includes a semiconductor element 22, an external terminal 14, and a heat sink 12. As shown in FIG. 4, the semiconductor element 22 includes an active region 22A provided at the center of the semiconductor element 22 and a termination region 22B that goes around the active region 22A. The active region 22A has a main structure 27 of a transistor or a diode. The termination region 22B has a guard ring structure 25 that is a pressure resistant holding structure.
For the semiconductor element 22, for example, a thyristor, IGBT, MOSFET, or diode can be used. The semiconductor element 22 is supplied with electric power from the outside through the external terminal 14a and supplies electric power to the outside through the external terminal 14b. When power is supplied from the outside, the semiconductor element 22 generates heat during operation due to its own power loss. The thermal expansion coefficient of the semiconductor element 22 is 3 × 10 −6 / K. The external terminals 14a and 14b and the semiconductor element 22 are connected by bonding wires 16a and 16b, respectively. The external terminals 14a and 14b are bonded to the heat sink 12 via an insulating layer (not shown).
Each of the semiconductor elements 22 is bonded to the heat sink 12 by an adhesive layer 24 of solder. For bonding the semiconductor element 22 and the heat radiating plate 12, a method other than soldering can be used. For example, brazing or an adhesive can be used.

放熱板１２は、平面視したときに、矩形状の平板である。図２，３に示すように、放熱板１２は、複数の孔４２を有する基材４０と孔４２に充填されている充填部材４４で構成されている。基材４０は、例えば、モリブデンやタングステン等の熱膨張率が低い材料（例えば、熱膨張率がモリブデンの場合５．１×１０−６／Ｋ、タングステンの場合４．５×１０−６／Ｋ）で作製されている。図２，３に示すように、基材４０では、半導体素子２２と接着層２４を介して接着している接着範囲１２Ａの中央部における孔４２の密度が、接着範囲１２Ａの周縁における孔４２の密度よりも高い。充填部材４４は、例えば、銅やアルミニウム等の熱伝導率の高い材料（例えば、熱伝導率が銅の場合３９３Ｗ／ｍＫ、アルミニウムの場合２３８Ｗ／ｍＫ）で作製されている。即ち、放熱板１２は、接着範囲１２Ａの中央部では熱伝導率の高い充填部材４４が多く分布しており、接着範囲１２Ａの周縁では熱膨張率の低い基材４０が多く分布している。放熱板１２の接着範囲１２Ａの中央部の熱膨張率は、１５〜２２×１０−６／Ｋであり、放熱板１２の接着範囲１２Ａの周縁の熱膨張率は、４．５〜１０×１０−６／Ｋである。放熱板１２は、例えば、含浸処理によって作製される。
放熱板１２は、グリース３０を介して冷却器３２に固定されている。冷却器３２の熱膨張率は、銅の場合１７×１０−６／Ｋであり、アルミニウムの場合２２×１０−６／Ｋである。 The heat radiating plate 12 is a rectangular flat plate when viewed in plan. As shown in FIGS. 2 and 3, the heat radiating plate 12 includes a base member 40 having a plurality of holes 42 and a filling member 44 filled in the holes 42. The base material 40 is made of, for example, a material having a low thermal expansion coefficient such as molybdenum or tungsten (for example, 5.1 × 10 −6 / K when the thermal expansion coefficient is molybdenum, 4.5 × 10 −6 / K when tungsten is used). ). As shown in FIGS. 2 and 3, in the base material 40, the density of the holes 42 in the central portion of the bonding range 12 </ b> A bonded to the semiconductor element 22 via the bonding layer 24 is equal to the density of the holes 42 in the periphery of the bonding range 12 </ b> A. Higher than density. The filling member 44 is made of a material having high thermal conductivity such as copper or aluminum (for example, 393 W / mK when the thermal conductivity is copper and 238 W / mK when aluminum). That is, in the heat radiating plate 12, many filling members 44 having high thermal conductivity are distributed in the central portion of the bonding range 12 </ b> A, and many base materials 40 having low thermal expansion coefficients are distributed in the periphery of the bonding range 12 </ b> A. The thermal expansion coefficient at the center of the bonding range 12A of the heat sink 12 is 15 to 22 × 10 −6 / K, and the thermal expansion coefficient at the periphery of the bonding range 12A of the heat sink 12 is 4.5 to 10 × 10. -6 / K. The heat sink 12 is produced by, for example, an impregnation process.
The heat sink 12 is fixed to the cooler 32 via the grease 30. The coefficient of thermal expansion of the cooler 32 is 17 × 10 −6 / K in the case of copper, and 22 × 10 −6 / K in the case of aluminum.

この放熱板１２では、半導体素子２２との接着範囲１２Ａの中央部、即ち、半導体素子２２の活性領域２２Ａの下方に熱伝導率の高い充填部材４４が多く分布しているため、半導体素子２２の活性領域２２Ａの熱を効率よく冷却器３２に伝えることができる。一方において、放熱板１２では、半導体素子２２との接着範囲１２Ａの周縁に熱膨張率の低い基材４０が多く分布している。半導体素子２２の終端領域２２Ｂは、実質的には電流が流れない領域であり、この領域での発熱は無視できる。このため、放熱板１２の熱伝導率が接着範囲１２Ａの周縁で小さくなっていても、半導体素子２２の熱を冷却器３２にまで放熱する事象に深刻な影響を与えるものではない。したがって、放熱板１２の接着範囲１２Ａの周縁は、熱伝導率よりも熱膨張率を優先すべき領域である。放熱板１２は、接着範囲１２Ａの周縁で熱膨張率が選択的に小さくなっている。そのため、放熱板１２と半導体素子２２の熱膨張率の差によってダメージを受けやすい接着範囲１２Ａの周縁の接着層２４のダメージを低減させることができる。また、放熱板１２の接着範囲１２Ａでは、中心から周縁に向かうに従って、徐々に熱膨張率が低い基材４０の分布が多くなっている。接着層２４に与えられる歪みΔεは、Δε＝（ＴＣＥｓｕｂ−ＴＣＥＳｉ）×Ｔｍａｘ−Ｔｍｉｎ）×Ｌ０となる。ここで、Ｌ０は初期の中心からの距離であり、ＴＣＥｓｕｂは放熱板１２の線膨張係数であり、ＴＣＥＳｉは半導体素子２２の線膨張係数であり、Ｔｍａｘは最高温度であり、Ｔｍｉｎは最低温度である。この式でも明らかなように、放熱板１２の線膨張係数が一定の場合、歪みは、半導体素子２２の周縁に向かうに従って増加する。しかしながら、この放熱板１２によれば、放熱板１２の線膨張係数が接着範囲１２Ａの中心から周縁に向かって小さくなっていることから、接着層２４の周縁に与えられるダメージを小さくすることができる。 In the heat radiating plate 12, since many filling members 44 having high thermal conductivity are distributed in the central portion of the adhesion range 12 </ b> A with the semiconductor element 22, that is, below the active region 22 </ b> A of the semiconductor element 22, The heat of the active region 22A can be efficiently transferred to the cooler 32. On the other hand, in the heat sink 12, many base materials 40 having a low coefficient of thermal expansion are distributed around the periphery of the adhesion range 12 </ b> A with the semiconductor element 22. The termination region 22B of the semiconductor element 22 is a region where no current flows substantially, and heat generation in this region can be ignored. For this reason, even if the thermal conductivity of the heat radiating plate 12 decreases at the periphery of the bonding range 12A, it does not seriously affect the event of radiating the heat of the semiconductor element 22 to the cooler 32. Therefore, the periphery of the adhesion range 12A of the heat sink 12 is a region where the thermal expansion coefficient should be given priority over the thermal conductivity. The thermal expansion coefficient of the heat radiating plate 12 is selectively reduced at the periphery of the bonding range 12A. Therefore, it is possible to reduce damage to the adhesive layer 24 at the periphery of the adhesion range 12 </ b> A that is easily damaged by the difference in thermal expansion coefficient between the heat dissipation plate 12 and the semiconductor element 22. Further, in the bonding range 12A of the heat radiating plate 12, the distribution of the base material 40 having a low coefficient of thermal expansion gradually increases from the center toward the periphery. The strain Δε applied to the adhesive layer 24 is Δε = (TCE sub −TCE Si ) × T max −T min ) × L 0 . Here, L 0 is the distance from the initial center, TCE sub is the linear expansion coefficient of the heat sink 12, TCE Si is the linear expansion coefficient of the semiconductor element 22, T max is the maximum temperature, and T min is the minimum temperature. As is apparent from this equation, when the linear expansion coefficient of the heat sink 12 is constant, the strain increases toward the periphery of the semiconductor element 22. However, according to the heat radiating plate 12, the linear expansion coefficient of the heat radiating plate 12 decreases from the center of the bonding range 12A toward the peripheral edge, so that damage given to the peripheral edge of the adhesive layer 24 can be reduced. .

放熱板は、上記した放熱板１２以外の形状であってもよい。図５，６，７には、他の放熱板の例を示す。図５，６に示すように、放熱板５０は、半導体素子２２との接着範囲１２Ａの周縁に沿って一巡するＵ字状の溝５４を有する基材５２と、溝５４を埋めている環状部材５６を有している。基材５２は、例えば、銅やアルミニウム等の熱伝導率の高い材料で作製されている。環状部材５６は、例えば、モリブデンやタングステン等の熱膨張率が低い材料で作製されている。放熱板５０は、基材５２をプレス加工して溝５４を形成し、溝５４の形状に合うように作製された環状部材５６を貼り合わせて作製される。   The heat sink may have a shape other than the heat sink 12 described above. 5, 6 and 7 show examples of other heat radiating plates. As shown in FIGS. 5 and 6, the heat radiating plate 50 includes a base member 52 having a U-shaped groove 54 that makes a round along the periphery of the bonding range 12 </ b> A with the semiconductor element 22, and an annular member that fills the groove 54. 56. The base material 52 is made of a material having high thermal conductivity such as copper or aluminum. The annular member 56 is made of a material having a low coefficient of thermal expansion, such as molybdenum or tungsten. The heat radiating plate 50 is manufactured by pressing the base material 52 to form the groove 54 and bonding the annular member 56 manufactured so as to match the shape of the groove 54.

図７に示すように、放熱板６０は、半導体素子２２の接着範囲１２Ａの周縁に沿って一巡する階段状の溝６４を有する基材６２と、溝６４を埋めている環状部材６６を有している。基材６２は、例えば、銅やアルミニウム等の熱伝導率の高い材料で作製されている。環状部材６６は、例えば、モリブデンやタングステン等の熱膨張率が低い材料で作製されている。放熱板６０は、放熱板５０と同様の作製方法で作製されてもよいし、あるいは、予め溝６４と対応する部分が切り抜かれた平板に、その切り抜かれた部分に環状部材６６と同一の材料を貼り付けたものを複数貼り合わせて作製されてもよい。   As shown in FIG. 7, the heat radiating plate 60 includes a base member 62 having a step-like groove 64 that makes a circuit along the periphery of the bonding range 12 </ b> A of the semiconductor element 22, and an annular member 66 that fills the groove 64. ing. The base material 62 is made of a material having high thermal conductivity such as copper or aluminum. The annular member 66 is made of a material having a low coefficient of thermal expansion, such as molybdenum or tungsten. The heat radiating plate 60 may be manufactured by the same manufacturing method as the heat radiating plate 50, or a flat plate in which a portion corresponding to the groove 64 has been cut out in advance, and the same material as that of the annular member 66 in the cut out portion. It may be produced by pasting a plurality of pasted materials.

放熱板５０，６０では、半導体素子２２との接着範囲１２Ａの周縁が環状部材５６，６６とされている。また、接着範囲１２Ａの中央部は基材５２，６２とされている。即ち、放熱板５０，６０と半導体素子２２の接着範囲１２Ａの周縁は熱膨張率が低い材料で作製され、放熱板５０，６０の接着範囲１２Ａの中央部は、熱伝導率の高い材料で作製されている。これにより、放熱板５０，６０の放熱性能の低下を抑制し、放熱板５０，６０と半導体素子２２の接着層２４のダメージを低減することができる。
また、放熱板５０，６０の接着範囲１２Ａの中央部の基材５２，６２は、半導体素子２２の活性領域２２Ａの下方に位置しているとともに、上方から見たときに活性領域２２Ａよりも広くなっている。これにより、放熱板５０，６０は、活性領域２２Ａの熱を横方向に広げつつ冷却器３２にまで放熱することができる。 In the heat radiating plates 50 and 60, the peripheral edges of the bonding range 12 </ b> A with the semiconductor element 22 are annular members 56 and 66. Further, the central part of the adhesion range 12 </ b> A is the base materials 52 and 62. That is, the periphery of the bonding range 12A between the heat sinks 50 and 60 and the semiconductor element 22 is made of a material having a low coefficient of thermal expansion, and the central portion of the bonding range 12A of the heat sinks 50 and 60 is made of a material having a high heat conductivity. Has been. Thereby, the fall of the thermal radiation performance of the heat sinks 50 and 60 can be suppressed, and the damage of the heat sink 50, 60 and the contact bonding layer 24 of the semiconductor element 22 can be reduced.
Further, the base materials 52 and 62 at the center of the adhesion range 12A of the heat sinks 50 and 60 are located below the active region 22A of the semiconductor element 22 and wider than the active region 22A when viewed from above. It has become. Thereby, the heat sinks 50 and 60 can radiate the heat to the cooler 32 while spreading the heat of the active region 22A in the lateral direction.

（変形例）
上記した実施例では、放熱板の表面に半導体素子のみがはんだによって接着されていた。しかしながら、本明細書で開示される技術は、放熱板の表面に半導体素子を含む半導体素子部が接着されている場合にも有効である。ここでは、上記した実施例と異なる点について説明する。
図８に示すように、半導体素子部７０は、半導体素子２２と絶縁板７４と金属配線７２を有している。半導体素子部７０には、半導体素子２２の他に、半導体素子２２と放熱板１２との間に配置されているものも含まれる。半導体素子２２は、絶縁板７４の表面に形成されている金属配線７２にはんだ等の接着層２４によって接着されている。絶縁板７４は、裏面に形成されている金属配線７２を介して放熱板１２の表面にはんだ等の接着層７６によって接着されている。絶縁板７４は、絶縁性のセラミックス（例えば、ＡｌＮ、Ｓｉ３Ｎ４、Ａｌ２Ｏ３）で作製されている。 (Modification)
In the above-described embodiments, only the semiconductor element is bonded to the surface of the heat sink with solder. However, the technique disclosed in this specification is also effective when a semiconductor element portion including a semiconductor element is bonded to the surface of the heat sink. Here, differences from the above-described embodiment will be described.
As shown in FIG. 8, the semiconductor element unit 70 includes a semiconductor element 22, an insulating plate 74, and a metal wiring 72. The semiconductor element unit 70 includes, in addition to the semiconductor element 22, one disposed between the semiconductor element 22 and the heat sink 12. The semiconductor element 22 is bonded to a metal wiring 72 formed on the surface of the insulating plate 74 by an adhesive layer 24 such as solder. The insulating plate 74 is bonded to the surface of the heat radiating plate 12 by a bonding layer 76 such as solder via metal wiring 72 formed on the back surface. The insulating plate 74 is made of insulating ceramics (for example, AlN, Si 3 N 4 , Al 2 O 3 ).

放熱板１２の基材４０では、半導体素子部７０の裏面（絶縁板７４の裏面に形成されている金属配線７２）との接着範囲７０Ａの中央部の領域における孔４２の密度が、接着範囲７０Ａの周縁に対向する領域での孔４２の密度よりも高い。即ち、放熱板１２は、接着範囲７０Ａの中央部では熱伝導率の高い充填部材４４が多く分布しており、接着範囲７０Ａの周縁では熱膨張率の低い基材４０が多く分布している。   In the base material 40 of the heat sink 12, the density of the holes 42 in the central region of the adhesion range 70A with the back surface of the semiconductor element portion 70 (the metal wiring 72 formed on the back surface of the insulating plate 74) is the adhesion range 70A. It is higher than the density of the holes 42 in the region facing the peripheral edge. That is, in the heat radiating plate 12, a large number of filling members 44 having a high thermal conductivity are distributed at the center of the bonding range 70A, and a large number of base materials 40 having a low coefficient of thermal expansion are distributed at the periphery of the bonding range 70A.

半導体素子部７０では、半導体素子部７０の裏面の熱膨張率は、絶縁板７４の熱膨張率（ＡｌＮの場合４．８×１０−６／Ｋ、Ｓｉ３Ｎ４の場合３．２×１０−６／Ｋ、Ａｌ２Ｏ３の場合７．１×１０−６／Ｋ）に大きく依存する。絶縁板７４に用いられるセラミックスの熱膨張率は、銅やアルミニウム等に比べて非常に小さい。この放熱板１２では、半導体素子部７０との接着範囲７０Ａの周縁に熱膨張率の低い基材４０が多く分布している。これにより、放熱板１２と半導体素子部７０の裏面の熱膨張率の差によってダメージを受けやすい接着範囲７０Ａの周縁の接着層７６のダメージを低減させることができる。また、放熱板１２では、接着範囲７０Ａの中央部の領域に熱伝導率の高い充填部材４４が多く分布しているため、絶縁板７４を介して伝わってきた半導体素子２２の熱を効率よく冷却器３２に伝えることができる。
また、半導体素子部７０では、半導体素子２２の活性領域２２Ａで発生した熱が、絶縁板７４を通過する際に横方向に広がる。変形例の放熱板１２では、上方から見たときに、充填部材４４が多く分布している領域が半導体素子２２の活性領域２２Ａよりも広くなっている。その結果、変形例の放熱板１２は、絶縁板７４を通過して横方向に広がった熱を効率的に冷却器３２に放熱することができる。 In the semiconductor element portion 70, the thermal expansion coefficient of the back surface of the semiconductor element section 70 is the thermal expansion coefficient of the insulating plate 74 (4.8 × 10 −6 / K for AlN, 3.2 × 10 for Si 3 N 4. -6 / K, and in the case of Al 2 O 3 , it largely depends on 7.1 × 10 −6 / K) The thermal expansion coefficient of the ceramic used for the insulating plate 74 is very small compared to copper, aluminum, or the like. In the heat radiating plate 12, many base materials 40 having a low coefficient of thermal expansion are distributed around the periphery of the adhesion range 70 </ b> A with the semiconductor element portion 70. Thereby, it is possible to reduce damage to the adhesive layer 76 at the periphery of the adhesion range 70 </ b> A that is easily damaged by the difference in thermal expansion coefficient between the heat dissipation plate 12 and the back surface of the semiconductor element portion 70. Moreover, in the heat sink 12, since many filling members 44 with high thermal conductivity are distributed in the central region of the bonding range 70A, the heat of the semiconductor element 22 transmitted through the insulating plate 74 is efficiently cooled. Can be communicated to vessel 32.
In the semiconductor element unit 70, heat generated in the active region 22 </ b> A of the semiconductor element 22 spreads in the lateral direction when passing through the insulating plate 74. In the heat radiating plate 12 of the modified example, when viewed from above, a region where a large amount of the filling member 44 is distributed is wider than the active region 22A of the semiconductor element 22. As a result, the heat radiating plate 12 of the modified example can efficiently radiate the heat spread through the insulating plate 74 in the lateral direction to the cooler 32.

変形例においても、上記した放熱板５０，６０を用いることができる。図９は、変形例において放熱板５０を用いた場合の縦断面図と示す。図１０は、変形例において放熱板６０を用いた場合の縦断面図と示す。
基材５２の溝５４と基材６２の溝６４は、放熱板５０，６０の半導体素子部７０との接着範囲７０Ａの周縁に沿って一巡している。これらの構成によっても、放熱板５０，６０の放熱性能の低下を抑制し、放熱板５０，６０と半導体素子部７０の接着層７６のダメージを低減することができる。
また、放熱板５０，６０の接着範囲７０Ａの中央部の基材５２，６２は、半導体素子２２の活性領域２２Ａの下方に位置しているとともに、上方から見たときに活性領域２２Ａよりも広くなっている。これにより、放熱板５０，６０は、絶縁板７４を通過して横方向に広げがった熱を効率的に冷却器３２にまで放熱することができる。 Also in the modified example, the heat sinks 50 and 60 described above can be used. FIG. 9 shows a longitudinal sectional view in the case where the heat sink 50 is used in the modification. FIG. 10 shows a longitudinal cross-sectional view when the heat sink 60 is used in the modification.
The groove 54 of the base material 52 and the groove 64 of the base material 62 make a round along the periphery of the adhesion range 70 </ b> A with the semiconductor element part 70 of the heat sinks 50 and 60. Also with these configurations, it is possible to suppress a decrease in the heat dissipation performance of the heat sinks 50 and 60, and to reduce damage to the heat sinks 50 and 60 and the adhesive layer 76 between the semiconductor element portions 70.
Further, the base materials 52 and 62 in the central portion of the bonding range 70A of the heat sinks 50 and 60 are located below the active region 22A of the semiconductor element 22 and wider than the active region 22A when viewed from above. It has become. Thereby, the heat radiating plates 50 and 60 can efficiently radiate the heat that has spread through the insulating plate 74 in the lateral direction to the cooler 32.

以上、本発明の具体例を詳細に説明したが、これらは例示に過ぎず、特許請求の範囲を限定するものではない。特許請求の範囲に記載の技術には、以上に例示した具体例を様々に変形、変更したものが含まれる。
例えば、放熱板５０，６０の環状部材５６，６６は、半導体素子部との接着範囲の周縁に断続的に配置されていてもよい。
また、本明細書または図面に説明した技術要素は、単独であるいは各種の組合せによって技術的有用性を発揮するものであり、出願時請求項記載の組合せに限定されるものではない。また、本明細書または図面に例示した技術は複数目的を同時に達成し得るものであり、そのうちの一つの目的を達成すること自体で技術的有用性を持つものである。 Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
For example, the annular members 56 and 66 of the heat radiating plates 50 and 60 may be intermittently disposed at the periphery of the bonding range with the semiconductor element portion.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

本実施例のパワーモジュールを示す側面図。The side view which shows the power module of a present Example. 図１の一部を抜粋した縦断面図。The longitudinal cross-sectional view which extracted a part of FIG. 図２の放熱板の上面図。The top view of the heat sink of FIG. 本実施例の半導体素子の要部縦断面図。The principal part longitudinal cross-sectional view of the semiconductor element of a present Example. 本実施例のその他の放熱板を示す縦断面図。The longitudinal cross-sectional view which shows the other heat sink of a present Example. 図５の放熱板の上面図。The top view of the heat sink of FIG. 本実施例のその他の放熱板を示す縦断面図。The longitudinal cross-sectional view which shows the other heat sink of a present Example. 本実施例の変形例を示す縦断面図。The longitudinal cross-sectional view which shows the modification of a present Example. 変形例のその他の放熱板を示す縦断面図。The longitudinal cross-sectional view which shows the other heat sink of a modification. 変形例のその他の放熱板を示す縦断面図。The longitudinal cross-sectional view which shows the other heat sink of a modification.

符号の説明Explanation of symbols

１０：パワーモジュール
１２，５０，６０：放熱板
２２：半導体素子
２４：接着層
３２：冷却器
４０，５２，６２：基材
４２：孔
４４：充填部材
５４，６４：溝
５６，６６：環状部材
７０：半導体素子部
７４：絶縁板 10: power module 12, 50, 60: heat sink 22: semiconductor element 24: adhesive layer 32: cooler 40, 52, 62: base material 42: hole 44: filling member 54, 64: groove 56, 66: annular member 70: Semiconductor element 74: Insulating plate

Claims (8)

少なくとも半導体素子を含む半導体素子部と冷却器の間に設けられている放熱板であって、
半導体素子部に接着する接着範囲の熱膨張率が、中央部よりも周縁で低く、
前記接着範囲の熱伝導率が、周縁よりも中央部で高い放熱板。 A heat sink provided between a semiconductor element part including at least a semiconductor element and a cooler,
The coefficient of thermal expansion of the bonding range to be bonded to the semiconductor element part is lower at the periphery than the center part,
A heat radiating plate in which the thermal conductivity of the bonding range is higher at the center than at the periphery. 前記接着範囲に第１領域と第２領域を有しており、
第１領域は、前記接着範囲の周縁に設けられており、
第２領域は、前記接着範囲の中央部に設けられており、
第１領域の熱膨張率は、第２領域の熱膨張率よりも低く、
第２領域の熱伝導率は、第１領域の熱伝導率よりも高いことを特徴とする請求項１に記載の放熱板。 A first region and a second region in the adhesion range;
The first region is provided at the periphery of the adhesion range,
The second region is provided at the center of the adhesion range,
The thermal expansion coefficient of the first region is lower than the thermal expansion coefficient of the second region,
The heat dissipation plate according to claim 1, wherein the thermal conductivity of the second region is higher than the thermal conductivity of the first region. 第１領域は第１材料で構成されており、第２領域は第２材料で構成されており、
第１材料の熱膨張率は、第２材料の熱膨張率よりも低く、
第２材料の熱伝導率は、第１材料の熱伝導率よりも高いことを特徴とする請求項２に記載の放熱板。 The first region is composed of a first material, the second region is composed of a second material,
The coefficient of thermal expansion of the first material is lower than the coefficient of thermal expansion of the second material,
The heat dissipation plate according to claim 2, wherein the thermal conductivity of the second material is higher than the thermal conductivity of the first material. 第１領域と第２領域は、第３材料と第４材料の複合材料で構成されており、
第３材料の熱膨張率は、第４材料の熱膨張率よりも低く、
第４材料の熱伝導率が、第３材料の熱伝導率よりも高く、
第１領域の第４材料に対する第３材料の割合が、第２領域の第４材料に対する第３材料の割合よりも高いことを特徴とする請求項３に記載の放熱板。 The first region and the second region are composed of a composite material of a third material and a fourth material,
The thermal expansion coefficient of the third material is lower than the thermal expansion coefficient of the fourth material,
The thermal conductivity of the fourth material is higher than the thermal conductivity of the third material,
The heat dissipation plate according to claim 3, wherein a ratio of the third material to the fourth material in the first region is higher than a ratio of the third material to the fourth material in the second region. 前記複合材料は、前記第４材料が前記第３材料に分散した形態を備えていることを特徴とする請求項４に記載の放熱板。   The heat sink according to claim 4, wherein the composite material has a form in which the fourth material is dispersed in the third material. 前記第１領域は、前記接着範囲の周縁を一巡していることを特徴とする請求項２〜５のいずれか一項に記載の放熱板。   The heat radiating plate according to any one of claims 2 to 5, wherein the first region makes a round of a periphery of the adhesion range. 少なくとも半導体素子を含む半導体素子部と、冷却器と、半導体素子部と冷却器の間に設けられている放熱板とを備えるモジュールであって、
半導体素子部に接着する接着範囲の放熱板の熱膨張率が、中央部よりも周縁で低く、
前記接着範囲の放熱板の熱伝導率が、周縁よりも中央部で高いモジュール。 A module comprising at least a semiconductor element part including a semiconductor element, a cooler, and a heat sink provided between the semiconductor element part and the cooler,
The thermal expansion coefficient of the heat sink in the bonding range to be bonded to the semiconductor element part is lower at the periphery than the center part,
The module whose heat conductivity of the heat sink of the said adhesion | attachment range is higher in a center part than a periphery. 前記半導体素子は、半導体基板の中央部に設けられている活性領域と、その活性領域の周囲を一巡している終端領域を備えており、
前記活性領域は、トランジスタ又はダイオードのメイン構造を有しており、
前記終端領域は、耐圧保持構造を有していることを特徴とする請求項７に記載のモジュール。 The semiconductor element includes an active region provided in a central portion of a semiconductor substrate, and a termination region that goes around the active region,
The active region has a main structure of a transistor or a diode,
The module according to claim 7, wherein the termination region has a pressure resistance holding structure.
JP2008070112A 2008-03-18 2008-03-18 Heat dissipation plate, and module equipped with the same Pending JP2009224715A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2008070112A JP2009224715A (en) 2008-03-18 2008-03-18 Heat dissipation plate, and module equipped with the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2008070112A JP2009224715A (en) 2008-03-18 2008-03-18 Heat dissipation plate, and module equipped with the same

Publications (1)

Publication Number Publication Date
JP2009224715A true JP2009224715A (en) 2009-10-01

Family

ID=41241162

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2008070112A Pending JP2009224715A (en) 2008-03-18 2008-03-18 Heat dissipation plate, and module equipped with the same

Country Status (1)

Country Link
JP (1) JP2009224715A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014030659A1 (en) * 2012-08-23 2014-02-27 日産自動車株式会社 Insulating substrate、multilayer ceramic insulating substrate, joined structure of power semiconductor device and insulating substrate, and power semiconductor module

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10150124A (en) * 1996-03-21 1998-06-02 Furukawa Electric Co Ltd:The Heat generating semiconductor device mounting composite substrate and semiconductor device using the substrate
JPH10270613A (en) * 1997-03-21 1998-10-09 Honda Motor Co Ltd Semiconductor circuit board using gradient functional material
JP2001105124A (en) * 1999-10-04 2001-04-17 Kubota Corp Heat radiation substrate for semi conductor device
JP2002043480A (en) * 2000-07-26 2002-02-08 Hitachi Ltd Semiconductor device
JP2002524862A (en) * 1998-09-04 2002-08-06 ブラッシュ ウェルマン セラミック プロダクツ Functionally classified metal substrate and process for making it
JP2007142126A (en) * 2005-11-18 2007-06-07 Allied Material Corp Composite material, semiconductor-mounted heat dissipating board, and ceramic package using the same
JP2007227615A (en) * 2006-02-23 2007-09-06 Toyota Central Res & Dev Lab Inc Semiconductor device
JP2009059821A (en) * 2007-08-30 2009-03-19 Toyota Motor Corp Semiconductor device

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10150124A (en) * 1996-03-21 1998-06-02 Furukawa Electric Co Ltd:The Heat generating semiconductor device mounting composite substrate and semiconductor device using the substrate
JPH10270613A (en) * 1997-03-21 1998-10-09 Honda Motor Co Ltd Semiconductor circuit board using gradient functional material
JP2002524862A (en) * 1998-09-04 2002-08-06 ブラッシュ ウェルマン セラミック プロダクツ Functionally classified metal substrate and process for making it
JP2001105124A (en) * 1999-10-04 2001-04-17 Kubota Corp Heat radiation substrate for semi conductor device
JP2002043480A (en) * 2000-07-26 2002-02-08 Hitachi Ltd Semiconductor device
JP2007142126A (en) * 2005-11-18 2007-06-07 Allied Material Corp Composite material, semiconductor-mounted heat dissipating board, and ceramic package using the same
JP2007227615A (en) * 2006-02-23 2007-09-06 Toyota Central Res & Dev Lab Inc Semiconductor device
JP2009059821A (en) * 2007-08-30 2009-03-19 Toyota Motor Corp Semiconductor device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014030659A1 (en) * 2012-08-23 2014-02-27 日産自動車株式会社 Insulating substrate、multilayer ceramic insulating substrate, joined structure of power semiconductor device and insulating substrate, and power semiconductor module

Similar Documents

Publication Publication Date Title
JP6520437B2 (en) Semiconductor device
JP2007019203A (en) Heat radiator
US10090222B2 (en) Semiconductor device with heat dissipation and method of making same
US20130328200A1 (en) Direct bonded copper substrate and power semiconductor module
JP2010171279A (en) Heat radiator
JP2006303290A (en) Semiconductor device
JP2006190798A (en) Semiconductor device
JP7136355B2 (en) Circuit structure of semiconductor module
JP5349572B2 (en) Radiator and method of manufacturing radiator
JP5301497B2 (en) Semiconductor device
JP4180980B2 (en) Semiconductor device
JP2008277442A (en) Heat dissipation board
JP7170614B2 (en) semiconductor equipment
JP2008294281A (en) Semiconductor device and manufacturing method therefor
JP5060453B2 (en) Semiconductor device
JP2008294282A (en) Semiconductor device and method of manufacturing semiconductor device
JP4375299B2 (en) Power semiconductor device
JP5092274B2 (en) Semiconductor device
JP2009224715A (en) Heat dissipation plate, and module equipped with the same
JP5061740B2 (en) Power module substrate
JP6118583B2 (en) Insulating substrate
JP2012009736A (en) Semiconductor element, method of manufacturing the same and semiconductor device
JP3960192B2 (en) Radiator
JP2020141023A (en) Semiconductor device
JP7455058B2 (en) semiconductor module

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20101207

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20120213

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20121002

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20121129

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20130521