JP6423731B2 - Semiconductor module - Google Patents

Description

  The technology disclosed in this specification relates to a semiconductor module.

  Patent Document 1 discloses a semiconductor module including a heat transfer member that transfers heat of a semiconductor chip to a cooler. The heat transfer member has a set of sheet members joined via an intermediate layer. Each of the sheet members is configured by laminating a plurality of sheets having thermal conductivity anisotropy. The sheet | seat which comprises a sheet | seat member has high heat conductivity in the surface direction of the sheet | seat surface. In the sheet member, the stacking direction of the plurality of sheets is arranged so as to be orthogonal to the direction connecting the semiconductor chip and the cooler. Thereby, since the sheet surface of the sheet constituting the sheet member is parallel to the direction connecting the semiconductor chip and the cooler, the heat transfer member can efficiently transfer the heat of the semiconductor chip to the cooler. it can.

  In the heat transfer member of Patent Document 1, in a set of sheet members joined via an intermediate layer, a stacking direction of a plurality of sheets constituting one sheet member and a plurality of sheets constituting the other sheet member It arrange | positions so that a lamination direction may orthogonally cross. Thereby, when the heat transfer member is observed as a whole, the heat transferred to the heat transfer member can be spread in a plane perpendicular to the direction connecting the semiconductor chip and the cooler. Heat is efficiently transferred to the cooler.

JP2011-258755A (particularly FIG. 4)

  A sheet having thermal conductivity anisotropy also has anisotropy in linear expansion coefficient. For example, when the sheet is graphite, the linear expansion coefficient in the in-plane direction of the sheet surface is smaller than the linear expansion coefficient in the thickness direction (direction perpendicular to the sheet surface). For this reason, in the heat transfer member of Patent Document 1, in one set of sheet members joined via an intermediate layer, the direction in which one sheet member has a large linear thermal expansion coefficient and the linear thermal expansion coefficient of the other sheet member The direction with large is non-parallel. In other words, the direction in which the linear thermal expansion coefficient of one sheet member is large and the direction in which the linear thermal expansion coefficient of the other sheet member is small are parallel. For this reason, in the heat transfer member of patent document 1, one heat transfer member mechanically restrains the other heat transfer member, and a high thermal stress is added. Accordingly, the heat transfer member is thermally deformed so as to be curved. When such a curvature occurs, a space is formed on the joint surface where the heat transfer member is in contact with the other member, and the heat transfer efficiency is greatly reduced. The technique disclosed in the present specification provides a technique for suppressing heat deformation of a heat transfer member so as to be bent.

  One embodiment of a semiconductor module disclosed in the present specification includes a heating element, a cooler, and a heat transfer member provided between the heating element and the cooler. The heat transfer member includes an intermediate layer, a first sheet layer, and a second sheet layer. The intermediate layer is thermally conductive isotropic. The first sheet layer is in contact with the surface of the intermediate layer on the heating element side, and is configured by laminating a plurality of first sheets having thermal conductivity anisotropy. In the first sheet layer, the stacking direction of the plurality of first sheets is arranged so as to be orthogonal to the direction connecting the heating element and the cooler. The second sheet layer is in contact with the cooler side surface of the intermediate layer, and is configured by laminating a plurality of second sheets having thermal conductivity anisotropy. In the second sheet layer, the stacking direction of the plurality of second sheets is arranged so as to be orthogonal to the direction connecting the heating element and the cooler. The stacking direction of the plurality of first sheets and the stacking direction of the plurality of second sheets are arranged in parallel.

  In the heat transfer member of the semiconductor module disclosed in this specification, in the first sheet layer and the second sheet layer that are adjacent to each other via the intermediate layer, the stacking direction of the plurality of first sheets constituting the first sheet layer and the second sheet layer It arrange | positions so that the lamination direction of the some 2nd sheet | seat which comprises a sheet | seat layer may become parallel. For this reason, the direction in which the linear expansion coefficient of the first sheet layer is large and the direction in which the linear expansion coefficient of the second sheet layer is large are parallel. Thereby, it is suppressed that the first sheet layer and the second sheet layer are mechanically constrained to each other, the thermal stress is relaxed, and the heat transfer member is suppressed from being deformed so as to be bent.

The principal part sectional drawing of the semiconductor module of an Example is shown typically. The perspective view of the heat-transfer member of an Example is typically shown. An exploded perspective view of a heat transfer member of an example is typically shown. The principal part sectional drawing of the semiconductor module of a modification is typically shown.

  The technical features disclosed in this specification will be summarized below. The items described below have technical usefulness independently.

  One embodiment of the semiconductor module disclosed in the present specification may include a heating element, a cooler, and a heat transfer member provided between the heating element and the cooler. The type of the heating element is not particularly limited as long as it generates heat. For example, the heating element may be an electronic element. Typically, the heating element is a power semiconductor element, and an IGBT, a MOSFET, and a diode are exemplified as an example. The type of the cooler is not particularly limited as long as it is configured to be able to exchange heat with the refrigerant. The heat transfer member may have an intermediate layer, a first sheet layer, and a second sheet layer. The material for the intermediate layer is not particularly limited as long as it has thermal conductivity isotropic characteristics. For example, the material of the intermediate layer may be ceramic or metal. Examples of the ceramic include silicon nitride, aluminum nitride, and aluminum oxide. Examples of the metal include copper and aluminum. Note that the material of the intermediate layer is preferably ceramic. In this case, the heat transfer member can function as an insulating substrate. The first sheet layer is in contact with the surface of the intermediate layer on the heating element side, and is configured by laminating a plurality of first sheets having thermal conductivity anisotropy. The first sheet is a material whose thermal conductivity in the in-plane direction of the sheet surface is higher than the thermal conductivity in the thickness direction (direction orthogonal to the sheet surface). For example, examples of the material of the first sheet include graphite, graphene, a composite material in which carbon fiber is impregnated with metal, and a metal-impregnated graphite composite material. In the first sheet layer, the stacking direction of the plurality of first sheets is arranged so as to be orthogonal to the direction connecting the heating element and the cooler. The second sheet layer is in contact with the cooler side surface of the intermediate layer, and is configured by laminating a plurality of second sheets having thermal conductivity anisotropy. The second sheet is also a material having a higher thermal conductivity in the in-plane direction of the sheet surface than in the thickness direction (a direction orthogonal to the sheet surface). For example, examples of the material for the second sheet include graphite, graphene, a composite material in which carbon fiber is impregnated with metal, and a metal-impregnated graphite composite material. The first sheet and the second sheet are preferably made of the same material. In the second sheet layer, the stacking direction of the plurality of second sheets is arranged so as to be orthogonal to the direction connecting the heating element and the cooler. The stacking direction of the plurality of first sheets and the stacking direction of the plurality of second sheets are arranged in parallel.

  The heat transfer member disclosed in the present specification may further include a third sheet layer and a fourth sheet layer. The third sheet layer is provided so as to face the intermediate layer with the first sheet layer interposed therebetween, and is configured by laminating a plurality of third sheets having thermal conductivity anisotropy. The third sheet is a material whose thermal conductivity in the in-plane direction of the sheet surface is higher than the thermal conductivity in the thickness direction (direction orthogonal to the sheet surface). For example, examples of the material of the third sheet include graphite, graphene, a composite material in which carbon fiber is impregnated with metal, and a metal-impregnated graphite composite material. In the third sheet layer, the stacking direction of the plurality of third sheets is arranged so as to be orthogonal to the direction connecting the heating element and the cooler. The fourth sheet layer is provided so as to face the intermediate layer with the second sheet layer interposed therebetween, and is configured by laminating a plurality of fourth sheets having thermal conductivity anisotropy. The fourth sheet is also a material having a thermal conductivity in the in-plane direction of the sheet surface that is higher than the thermal conductivity in the thickness direction (direction perpendicular to the sheet surface). For example, examples of the material for the fourth sheet include graphite, graphene, a composite material in which carbon fiber is impregnated with metal, and a metal-impregnated graphite composite material. The third sheet and the fourth sheet are desirably made of the same material. In the fourth sheet layer, the stacking direction of the plurality of fourth sheets is arranged so as to be orthogonal to the direction connecting the heating element and the cooler. The stacking direction of the plurality of third sheets and the stacking direction of the plurality of fourth sheets are arranged in parallel. The stacking direction of the plurality of first sheets and the stacking direction of the plurality of third sheets are arranged to intersect each other. Note that it is desirable that the stacking direction of the plurality of first sheets and the stacking direction of the plurality of third sheets are orthogonal to each other. The stacking direction of the plurality of second sheets and the stacking direction of the plurality of fourth sheets are arranged so as to intersect each other. In addition, it is desirable that the stacking direction of the plurality of second sheets and the stacking direction of the plurality of fourth sheets are arranged to be orthogonal to each other. According to the semiconductor module of this embodiment, when the heat transfer member is observed as a whole, the heat transferred to the heat transfer member can also spread in a plane orthogonal to the direction connecting the heating element and the cooler. Therefore, the heat of the heating element is efficiently transferred to the cooler.

  The heat transfer member disclosed in the present specification may further include a first bonding layer and a second bonding layer. The first bonding layer is provided between the first sheet layer and the third sheet layer and is in contact with both. The second bonding layer is provided between the second sheet layer and the fourth sheet layer and is in contact with both. The materials of the first bonding layer and the second bonding layer are not particularly limited as long as they have thermal conductivity isotropic characteristics. For example, the first bonding layer and the second bonding layer may be ceramic or metal. Examples of the ceramic include silicon nitride, aluminum nitride, and aluminum oxide. Examples of the metal include copper and aluminum. The first bonding layer and the second bonding layer are preferably made of the same material.

  As shown in FIG. 1, the semiconductor module 10 is a double-sided cooling type semiconductor module, and includes a pair of semiconductor chips 20 and 30, a pair of metal blocks 24 and 34, and a plurality of heat transfer members 22, 26, 32 and 36. And a plurality of electrode plates 28, 42, 44, a pair of insulating layers 52, 54, and a pair of coolers 62, 64. The pair of coolers 62 and 64 press the pair of semiconductor chips 20 and 30, the pair of metal blocks 24 and 34, the plurality of heat transfer members 22, 26, 32 and 36, and the pair of insulating layers 52 and 54, and adhere to each other. Is configured to do. The semiconductor module 10 is used as one of the three semiconductor elements constituting the lower arm of the three-phase inverter.

  The semiconductor chip 20 is an IGBT. The collector electrode on the lower surface of the semiconductor chip 20 is joined to the upper surface of the heat transfer member 22 via solder. The lower surface of the heat transfer member 22 is in close contact with the cooler 62 through the insulating layer 52. Grease is applied to the upper and lower surfaces of the insulating layer 52. The heat transfer member 22 is provided between the semiconductor chip 20 and the cooler 62 and transfers the heat of the semiconductor chip 20 to the cooler 62. The emitter electrode on the upper surface of the semiconductor chip 20 is joined to the lower surface of the metal block 24 by solder. Copper is used as the material of the metal block 24. The upper surface of the metal block 24 is joined to the lower surface of the heat transfer member 26 via solder. The upper surface of the heat transfer member 26 is in close contact with the cooler 64 through the insulating layer 54. Grease is applied to the upper and lower surfaces of the insulating layer 54. The heat transfer member 26 is provided between the semiconductor chip 20 and the cooler 64, and transfers the heat of the semiconductor chip 20 to the cooler 64. The gate electrode on the upper surface of the semiconductor chip 20 is electrically connected to the control electrode plate 28 through a wire.

  The semiconductor chip 30 is a diode. The cathode electrode on the lower surface of the semiconductor chip 30 is joined to the upper surface of the heat transfer member 32 via solder. The lower surface of the heat transfer member 32 is in close contact with the cooler 62 through the insulating layer 52. The heat transfer member 32 is provided between the semiconductor chip 30 and the cooler 62, and transfers the heat of the semiconductor chip 30 to the cooler 62. The anode electrode on the upper surface of the semiconductor chip 30 is joined to the lower surface of the metal block 34 via solder. Copper is used as the material of the metal block 34. The upper surface of the metal block 34 is joined to the lower surface of the heat transfer member 36 via solder. The upper surface of the heat transfer member 36 is in close contact with the cooler 64 through the insulating layer 54. The heat transfer member 36 is provided between the semiconductor chip 30 and the cooler 64, and transfers the heat of the semiconductor chip 30 to the cooler 64.

  The heat transfer member 22 and the heat transfer member 32 are actually configured integrally as one heat transfer member. As will be described later, a metal layer is exposed on the upper surfaces of the heat transfer member 22 and the heat transfer member 32, and the metal layer is electrically connected to the output electrode plate 42. That is, the collector electrode on the lower surface of the semiconductor chip 20 and the cathode electrode on the lower surface of the semiconductor chip 30 are electrically connected to the output electrode plate 42 via the heat transfer members 22 and 32.

  Actually, the heat transfer member 26 and the heat transfer member 36 are also integrally formed as one heat transfer member. A metal layer is exposed on the lower surfaces of the heat transfer member 26 and the heat transfer member 36, and the metal layer is electrically connected to the input electrode plate 44. That is, the emitter electrode on the upper surface of the semiconductor chip 20 and the anode electrode on the upper surface of the semiconductor chip 30 are electrically connected to the input electrode plate 44 through the metal blocks 24 and 34 and the heat transfer members 26 and 36.

  The pair of semiconductor chips 20, 30, the pair of metal blocks 24, 34 and the plurality of heat transfer members 22, 26, 32, 36 are covered with an insulating resin 56. A part of the electrode plates 28, 42, 44 is exposed from the insulating resin 56.

  The heat transfer members 22, 26, 32, and 36 have the same configuration. Below, with reference to FIG.2 and FIG.3, the heat-transfer member 22 is demonstrated in detail, and the description about the other heat-transfer members 26,32,36 is abbreviate | omitted.

  As shown in FIGS. 2 and 3, the heat transfer member 22 includes an intermediate layer 70, a plurality of graphite layers 71, 72, 73, 74 and a plurality of metal layers 81, 82, 83, 84. The plurality of graphite layers 71, 72, 73, 74 include a first graphite layer 71, a second graphite layer 72, a third graphite layer 73, and a fourth graphite layer 74. The graphite layers 71, 72, 73, 74 are examples of the sheet layer described in the claims. The plurality of metal layers 81, 82, 83, 84 include a first metal layer 81, a second metal layer 82, a third metal layer 83, and a fourth metal layer 84. The first metal layer 81 and the second metal layer 82 are examples of the bonding layer described in the claims.

  The intermediate layer 70 is disposed at the center in the stacking direction (z-axis direction) of the heat transfer member 22. The material of the intermediate layer 70 is a heat conductive isotropic metal, and in this example, copper is used.

  The first graphite layer 71 is bonded to the surface of the intermediate layer 70 on the semiconductor chip 20 side. The first graphite layer 71 is configured as a laminate in which a plurality of oriented graphite sheets are laminated in the x-axis direction. In the oriented graphite sheet constituting the first graphite layer 71, the thermal conductivity in the in-plane direction of the sheet surface parallel to the yz plane is the thermal conductivity in the thickness direction (the direction perpendicular to the sheet surface and the x-axis direction). Higher and has thermal conductivity anisotropy. The stacking direction (x-axis direction) of the plurality of oriented graphite sheets constituting the first graphite layer 71 is arranged so as to be orthogonal to the direction (z-axis direction) connecting the semiconductor chip 20 and the cooler 62. . In other words, the sheet surface (yz plane) of the oriented graphite sheet constituting the first graphite layer 71 is arranged so as to be parallel to the direction (z-axis direction) connecting the semiconductor chip 20 and the cooler 62. Yes.

  The second graphite layer 72 is bonded to the surface of the intermediate layer 70 on the cooler 62 side. The second graphite layer 72 is configured as a laminate in which a plurality of oriented graphite sheets are laminated in the x-axis direction. In the oriented graphite sheet constituting the second graphite layer 72, the thermal conductivity in the in-plane direction of the sheet surface parallel to the yz plane is the thermal conductivity in the thickness direction (the direction perpendicular to the sheet surface and the x-axis direction). Higher and has thermal conductivity anisotropy. The stacking direction (x-axis direction) of the plurality of oriented graphite sheets constituting the second graphite layer 72 is arranged to be orthogonal to the direction (z-axis direction) connecting the semiconductor chip 20 and the cooler 62. . In other words, the sheet surface (yz plane) of the oriented graphite sheet constituting the second graphite layer 72 is arranged so as to be parallel to the direction (z-axis direction) connecting the semiconductor chip 20 and the cooler 62. Yes.

  The third graphite layer 73 is disposed so as to face the intermediate layer 70 with the first metal layer 81 and the first graphite layer 71 interposed therebetween. The third graphite layer 73 is configured as a laminate in which a plurality of oriented graphite sheets are laminated in the y-axis direction. In the oriented graphite sheet constituting the third graphite layer 73, the thermal conductivity in the in-plane direction of the sheet surface parallel to the xz plane is the thermal conductivity in the thickness direction (the direction perpendicular to the sheet surface and the y-axis direction). Higher and has thermal conductivity anisotropy. The stacking direction (y-axis direction) of the plurality of oriented graphite sheets constituting the third graphite layer 73 is arranged to be orthogonal to the direction (z-axis direction) connecting the semiconductor chip 20 and the cooler 62. . In other words, the sheet surface (xz plane) of the oriented graphite sheet constituting the third graphite layer 73 is arranged so as to be parallel to the direction (z-axis direction) connecting the semiconductor chip 20 and the cooler 62. Yes. Further, the stacking direction (y-axis direction) of the plurality of oriented graphite sheets constituting the third graphite layer 73 is in relation to the stacking direction (x-axis direction) of the plurality of oriented graphite sheets constituting the first graphite layer 71. Are arranged so as to be orthogonal to each other.

  The fourth graphite layer 74 is disposed so as to face the intermediate layer 70 with the second metal layer 82 and the second graphite layer 72 interposed therebetween. The fourth graphite layer 74 is configured as a laminate in which a plurality of oriented graphite sheets are laminated in the y-axis direction. In the oriented graphite sheet constituting the fourth graphite layer 74, the thermal conductivity in the in-plane direction of the sheet plane parallel to the xz plane is the thermal conductivity in the thickness direction (the direction perpendicular to the sheet plane and the y-axis direction). Higher and has thermal conductivity anisotropy. The stacking direction (y-axis direction) of the plurality of oriented graphite sheets constituting the fourth graphite layer 74 is arranged so as to be orthogonal to the direction (z-axis direction) connecting the semiconductor chip 20 and the cooler 62. . In other words, the sheet surface (xz plane) of the oriented graphite sheet constituting the fourth graphite layer 74 is arranged so as to be parallel to the direction (z-axis direction) connecting the semiconductor chip 20 and the cooler 62. Yes. Further, the stacking direction (y-axis direction) of the plurality of oriented graphite sheets constituting the fourth graphite layer 74 is in the stacking direction (x-axis direction) of the plurality of oriented graphite sheets constituting the second graphite layer 72. Are arranged so as to be orthogonal to each other.

  The material of the plurality of metal layers 81, 82, 83, 84 is a heat conductive isotropic metal, and copper is used in this example. The first metal layer 81 is disposed between the first graphite layer 71 and the third graphite layer 73, and joins the first graphite layer 71 and the third graphite layer 73. The second metal layer 82 is disposed between the second graphite layer 72 and the fourth graphite layer 74, and joins the second graphite layer 72 and the fourth graphite layer 74. The third metal layer 83 is bonded to the third graphite layer 73 and is bonded to the semiconductor chip 20 via solder. The fourth metal layer 84 is bonded to the fourth graphite layer 74 and is in close contact with the cooler 62 through the insulating layer 52. These metal layers 81, 82, 83, and 84 are used as bonding layers. In particular, the first metal layer 81 and the second metal layer 82 firmly join the graphite layers and improve the heat transfer efficiency between the graphite layers.

  The heat transfer member 22 has a vertically symmetrical form with respect to the intermediate layer 70. That is, the first graphite layer 71 and the second graphite layer 72 are configured to have a symmetrical form with respect to the intermediate layer 70, and the first metal layer 81 and the second metal layer 82 are configured with respect to the intermediate layer 70. The third graphite layer 73 and the fourth graphite layer 74 are configured to have a symmetrical configuration with respect to the intermediate layer 70, and the third metal layer 83 and the fourth graphite layer 74 are configured to have a symmetrical configuration. The metal layer 84 is configured to have a symmetric form with respect to the intermediate layer 70. For this reason, the stacking direction (x-axis direction) of the plurality of oriented graphite sheets constituting the first graphite layer 71 and the stacking direction (x-axis direction) of the plurality of oriented graphite sheets constituting the second graphite layer 72 are parallel. The stacking direction (y-axis direction) of the plurality of oriented graphite sheets constituting the third graphite layer 73 and the stacking direction (y-axis direction) of the plurality of oriented graphite sheets constituting the fourth graphite layer 74 are parallel. It is.

  The oriented graphite sheet has a linear expansion coefficient in the in-plane direction of the sheet surface of about 1 ppm / K, and a linear expansion coefficient in the thickness direction (direction perpendicular to the sheet surface) of about 25 ppm / K. For this reason, the first graphite layer 71 and the second graphite layer 72 have a large linear expansion coefficient in the x-axis direction. However, since the first graphite layer 71 and the second graphite layer 72 are configured to have a symmetrical form with respect to the intermediate layer 70, their linear expansion coefficients in the x-axis direction are the same. For this reason, since it restrains that the 1st graphite layer 71 and the 2nd graphite layer 72 mutually restrain mechanically, a thermal stress is relieved. The third graphite layer 73 and the fourth graphite layer 74 have a large linear expansion coefficient in the y-axis direction. However, since the third graphite layer 73 and the fourth graphite layer 74 are configured to have a symmetrical form with respect to the intermediate layer 70, their linear expansion coefficients in the y-axis direction are the same. For this reason, since the 3rd graphite layer 73 and the 4th graphite layer 74 are suppressed from mutually restraining mechanically, thermal stress is relieved. As a result, the heat transfer member 22 is suppressed from being thermally deformed so as to be bent.

  As described above, in the heat transfer member 22, the sheet surfaces of the plurality of graphite layers 71, 72, 73, 74 are arranged so as to be parallel to the direction connecting the semiconductor chip 20 and the cooler 62. Further, the intermediate layer 70 and the plurality of metal layers 81, 82, 83, 84 are thermally conductive isotropic. For this reason, the heat transfer member 22 can efficiently transfer the heat of the semiconductor chip 20 to the cooler 62.

  Further, in the heat transfer member 22, the stacking direction (x-axis direction) of the plurality of oriented graphite sheets constituting the first graphite layer 71 and the stacking direction (y of the plurality of oriented graphite sheets constituting the third graphite layer 73 are described. The axial directions are orthogonal to each other, and the stacking direction (x-axis direction) of the plurality of oriented graphite sheets constituting the second graphite layer 72 and the plurality of oriented graphite sheets constituting the fourth graphite layer 74 are arranged. The stacking direction (y-axis direction) is orthogonal to each other. Thereby, when the heat transfer member 22 is observed as a whole, the heat transferred to the heat transfer member 22 can spread also in the xy plane, so that the heat of the semiconductor chip 20 is efficiently transferred to the cooler 62. Heat is transferred.

  In the heat transfer member 22, the intermediate layer 70 may be formed of an insulating ceramic. When the material of the intermediate layer 70 is an insulator, the heat transfer member 22 can also function as an insulating substrate. When such a heat transfer member 22 (the same applies to the other heat transfer members 26, 32, 36) is used, as shown in FIG. 4, the heat transfer members 22, 26, 32, 36 and the coolers 62, 64 are used. Insulating layers 52 and 54 (see FIG. 1) between them become unnecessary. As described above, since the insulating layers 52 and 54 are unnecessary, the grease applied to the upper and lower surfaces of the insulating layers 52 and 54 is also unnecessary. For this reason, the grease-less semiconductor module 10 can be constructed by using the heat transfer members 22, 26, 32, 36 in which the intermediate layer 70 is formed of an insulating ceramic. As a result, the semiconductor module 10 can have an extremely high cooling capacity.

  The embodiments 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. In addition, the technology exemplified in this specification or the drawings achieves a plurality of objects at the same time, and has technical usefulness by achieving one of them.

10: Semiconductor module 20, 30: Semiconductor chips 22, 26, 32, 36: Heat transfer members 24, 34: Metal blocks 28, 42, 44: Electrode plate 56: Insulating resin 62, 64: Cooler 70: Intermediate layer 71 : First graphite layer 72: Second graphite layer 73: Third graphite layer 74: Fourth graphite layer 81, 82, 83, 84: Metal layer

Claims (6)

A heating element;
A cooler,
A heat transfer member provided between the heating element and the cooler,
The heat transfer member is
A thermally conductive isotropic intermediate layer;
The intermediate layer is in contact with the surface on the heating element side and is configured by laminating a plurality of first sheets having thermal conductivity anisotropy, and the laminating direction of the plurality of first sheets is the heating element and the cooling. A first sheet layer disposed so as to be orthogonal to the direction of connecting the containers;
The intermediate layer is in contact with the surface on the cooler side, and is configured by laminating a plurality of second sheets having thermal conductivity anisotropy, and the laminating direction of the plurality of second sheets is the heating element and the A second sheet layer disposed so as to be orthogonal to the direction connecting the coolers,
The stacking direction of the plurality of first sheets and the stacking direction of the plurality of second sheets are arranged in parallel ,
A semiconductor module , wherein the first sheet and the second sheet are graphite . The semiconductor module according to claim 1 , wherein the material of the intermediate layer is ceramic. The heat transfer member is
It is provided so as to face the intermediate layer via the first sheet layer, and is formed by laminating a plurality of third sheets having thermal conductivity anisotropy, and the stacking direction of the plurality of third sheets A third sheet layer disposed so as to be orthogonal to the direction connecting the heating element and the cooler;
It is provided so as to face the intermediate layer via the second sheet layer, and is configured by laminating a plurality of fourth sheets having thermal conductivity anisotropy, and the stacking direction of the plurality of fourth sheets A fourth sheet layer disposed so as to be orthogonal to the direction connecting the heating element and the cooler,
The stacking direction of the plurality of third sheets and the stacking direction of the plurality of fourth sheets are arranged in parallel,
The stacking direction of the plurality of first sheets and the stacking direction of the plurality of third sheets are arranged to intersect,
The semiconductor module according to claim 1 , wherein the stacking direction of the plurality of second sheets and the stacking direction of the plurality of fourth sheets are arranged to intersect each other. The semiconductor module according to claim 3 , wherein the third sheet and the fourth sheet are graphite. The heat transfer member is
Provided between the first sheet layer and the third sheet layer, in contact with both, a thermally conductive isotropic first bonding layer;
5. The semiconductor according to claim 3 , further comprising: a second bonding layer that is provided between the second sheet layer and the fourth sheet layer, is in contact with both, and is thermally conductive and isotropic. 5. module. The semiconductor module according to claim 5 , wherein a material of the first bonding layer and the second bonding layer is a metal.

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