JP2006278558A - Insulated heat transmission structure and substrate for use of power module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulated heat transmission structure and a substrate for use of a power module, capable of efficiently conducting heat on a heat generator to a heat radiator for heat radiation, and also being able to exhibit stable performance over a long time, even with thermal deformation applied by an action of a temperature cycle or the like. <P>SOLUTION: The insulated heat transmission structure 1 includes an insulation layer on at least part of the surface of a plate-like heat transfer member 4, made of pure Al or an Al alloy. The insulation layer 2 includes a ceramic layer 6 on which a film of ceramic, consisting of one or two or more of compositions including Al<SB>2</SB>O<SB>3</SB>, Si<SB>3</SB>N<SB>4</SB>and AlN, is formed directly on the heat transfer member. In addition, the coefficients of the thermal expansion of ceramic layers 6, 7 and 8 that are laminated to constitute the insulating layer 2 are structured so as to sequentially decrease, starting from the heat transfer member 4 going toward the surface of the insulating layer 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an insulated heat transfer structure and a manufacturing method thereof, and more particularly to an electronic component such as a semiconductor chip, a circuit board on which the electronic component is mounted, an insulated heat transfer structure, and a power module substrate including the same. .

  Conventionally, as shown in FIG. 15, an electronic component 103 such as a semiconductor chip is provided on one surface of an insulating substrate 101 made of DBA (Al / AlN / Al), DBC (Cu / AlN / Cu), etc. via a solder layer 102. A heat sink 104 made of AlSiC, Cu / Mo / Cu, or the like is bonded to the other surface of the insulating substrate 101 via a solder layer 102, and Al, Cu is bonded to the heat sink 104 via a thermal conductive grease layer 105. There is known a power module substrate 100 to which a heat sink 106 made of the above is joined (for example, see Patent Document 1).

  In the power module substrate 100 having such a configuration, the heat generated from the electronic component 103 such as a semiconductor chip is transmitted to the heat sink 106 through the heat radiating plate 104 and dissipated to dissipate the electronic component such as the semiconductor chip. The thermal load acting on 103 can be reduced.

  By the way, in the power module substrate 100a configured as described above, the thermal conductivity is enhanced by interposing the thermal conductive grease layer 105 between the heat sink 104 and the heat sink 106. The layer 105 cannot sufficiently reduce the thermal resistance, and cannot efficiently conduct and dissipate heat of the electronic component 103 such as a semiconductor chip.

  On the other hand, in order to cope with the above problems, as shown in FIGS. 16 and 17, a brazing layer 107 is interposed between the insulating substrate 101 and the heat sink 104 and between the heat sink 104 and the heat sink 106. Power module substrates 100b and 100c configured to reduce thermal resistance by bonding together are known.

However, the thermal expansion coefficient of the insulating substrate 101 (7 × 10 ⁻⁶ / K), the thermal expansion coefficient of the heat sink 104 (10 to 15 × 10 ⁻⁶ / K), and the thermal expansion coefficient of the heat sink 106 (Al: 23 × 10 ⁻⁶ / K, Cu: 15 to 16 × 10 ⁻⁶ / K) are different from each other, so that the insulating substrate 101 and the heat sink are affected by thermal deformation due to a cooling process after brazing operation, a temperature cycle during actual use, and the like. Peeling, cracking, etc. will occur between the heat sink 104 and between the radiator and the heat sink.
JP-A-1-286348

  The present invention has been made in view of the above-described conventional problems, and can efficiently conduct heat from the heat generating body side to the heat dissipating body side to dissipate heat, and can be subjected to thermal deformation by an action such as a temperature cycle. It is an object of the present invention to provide an insulated heat transfer structure and a power module substrate that can exhibit stable performance over a long period of time.

The present invention employs the following configuration in order to solve the above problems.
The invention according to claim 1 is an insulating heat transfer structure in which an insulating layer is provided on at least a part of the surface of a plate-like heat transfer member made of pure Al or an Al alloy, and the insulating layer includes Al ₂ O ₃ , Si ₃ N ₄ , AlN is provided with a ceramic layer in which ceramics having one or more compositions are directly formed on the heat transfer member.

According to this invention, the insulating layer has a surface of a heat transfer member made of pure Al (4N-Al having a purity of 99.99% or more) or an Al alloy, and Al ₂ O ₃ , Si ₃ N ₄ , AlN Since it has a ceramic layer on which a ceramic of a type or a mixture of two or more types of ceramics is directly formed, there is no thermal interface when heat is transferred from the insulating layer to the heat transfer member. Conduction is performed efficiently. Moreover, the pure Al or Al alloy constituting the heat transfer member and the ceramic layer made of one or more kinds of ceramics of Al ₂ O ₃ , Si ₃ N ₄ and AlN both have high thermal conductivity and high cooling ability. Insulating heat transfer structure is obtained. Moreover, since the ceramic is directly formed on the surface of pure Al or Al alloy, the bonding strength is high, and the ceramic layer can be formed as thin as 10 μm to 100 μm. Even when subjected to thermal deformation, peeling and cracking are suppressed, and stable quality and performance can be exhibited over a long period of time.

The invention according to claim 2 is the insulating heat transfer structure according to claim 1, wherein the ceramic layer is made of Al ₂ O ₃ , Si ₃ N _4. It is characterized by being made of ceramics having a composition of at least two of AlN.
According to this invention, the coefficient of thermal expansion is 2.8 by forming as a ceramic layer of a composite ceramic having a composition composed of a mixture of two or more of Al ₂ O ₃ , Si ₃ N ₄ , and AlN. Ceramics with x10 ⁻⁶ / K to 7.7 × 10 ⁻⁶ / K, thermal conductivity between 24 W / m · K to 200 W / m · K, and desired thermal expansion coefficient and thermal conductivity Strain due to temperature distribution in the layer and thermal expansion difference in the temperature distribution can be suppressed, and the ceramic layer and thus the insulating layer can be prevented from peeling and cracking.

The invention according to claim 3 is the insulated heat transfer structure according to claim 1 or 2, wherein the insulating layer is formed on the surface side of the directly formed ceramic layer with Al ₂ O ₃ , Si. ₃ N ₄ and AlN, ceramics having one or more compositions, wherein one or more ceramic layers having different compositions from the ceramic layers are laminated.
According to this invention, the insulating layer is formed by directly forming a ceramic layer composed of one or more of Al ₂ O ₃ , Si ₃ N ₄ , and AlN on the heat transfer member, and Al on the surface side. _A ceramic layer composed of one or more of ₂ O ₃ , Si ₃ N ₄ , and AlN and having a composition different from that of the ceramic layer is formed by laminating, so that each ceramic layer has a desired value of heat conduction. The temperature distribution and strain in each ceramic layer and between each ceramic layer are controlled by adjusting the heat flow and thermal expansion that move in the insulating layer by adjusting the heat flow rate and the thermal expansion coefficient, and these ceramic layers and thus the insulation. Layer peeling and cracking can be suppressed.
be able to.

The invention according to claim 4 is the insulating heat transfer structure according to claim 3, wherein the thermal expansion coefficient of the laminated ceramic layers is gradually decreased from the heat transfer member toward the surface side of the insulating layer. It is comprised so that it may become.
According to the present invention, the thermal expansion coefficient of the laminated ceramic layers is configured to gradually decrease from the heat transfer member toward the surface side of the insulating layer, so that the heating element is provided on the surface side of the insulating layer. When the surface side of the insulating layer is at a high temperature and the heat transfer member side is at a lower temperature than the surface side, the difference in thermal expansion that occurs between the ceramic layers is determined by the thermal expansion coefficient of each ceramic layer x temperature. The strain on the surface side of the insulating layer and the heat transfer member side can be suppressed, and peeling and cracking of the ceramic layer, and consequently the insulating layer, can be suppressed.

The invention according to claim 5 is the insulated heat transfer structure according to any one of claims 1 to 4, wherein the heat transfer member has a heat dissipation fin or a refrigerant flow path in the heat transfer member main body. It is formed.
According to this invention, the fin for heat dissipation is formed in the heat transfer member main body, or the refrigerant flow path is formed inside the heat transfer member main body. With this configuration, heat entering from the ceramic layer reaches the heat radiation fins or the refrigerant flow path without passing through the thermal interface with different thermal conductivity such as the joint surface, and the heat is taken away by the refrigerant. Can be cooled efficiently.

The invention according to claim 6 is the insulated heat transfer structure according to any one of claims 1 to 5, wherein the heat transfer member is connected to a heat sink having a fin for heat dissipation or a refrigerant flow path. It is characterized by being.
According to the present invention, since the heat transfer member is connected to the heat sink having the heat radiation fins or the refrigerant flow path, the heat entered from the ceramic layer is taken away from the heat sink and can be efficiently cooled.
Further, since the heat sink is separate from the heat transfer member, it is easy to manufacture.

The invention according to claim 7 is the insulated heat transfer structure according to any one of claims 1 to 6, wherein a high thermal conductor layer is formed on an upper surface of the ceramic layer. To do.
According to this invention, since the high thermal conductor layer is formed on the upper surface of the ceramic layer (the surface on the side opposite to the heat transfer member, hereinafter the same), the thermal conductivity is high, and the heat generation The bodies can be easily joined with solder or the like.

The invention according to claim 8 is the insulated heat transfer structure according to claim 7, wherein the high thermal conductor layer is made of Al, Cu, Ag, or Au.
According to the present invention, since the thermal conductivity of Al, Cu, Ag, or Au is high, the heat of the heating element is transferred well. In addition, Al has a small deformation stress with respect to the strain amount and is less hardened by a thermal cycle, so that reliability is improved.

The invention according to claim 9 is the insulated heat transfer structure according to claim 7 or claim 8, wherein a circuit for mounting a semiconductor chip is formed in the high thermal conductor layer. And
According to this invention, a semiconductor chip is mounted on a circuit, and heat generated in the semiconductor chip can be conducted from one high thermal conductor layer on which the semiconductor chip is mounted to the other high thermal conductor layer. .

The invention according to claim 10 is the insulated heat transfer structure according to any one of claims 7 to 9, characterized in that the high thermal conductor layer is divided and formed.
According to the present invention, a semiconductor chip is mounted on one of the high thermal conductor layers, and the other high thermal conductor layer and the electrode of the semiconductor chip are connected by the wire or the like, and can be used as an electronic circuit.

The invention according to claim 11 is the insulated heat transfer structure according to claim 10, wherein one of the high heat conductor layers formed by division is thicker than that of the other high heat conductor layers. It differs from at least one of these thicknesses.
According to this invention, transient heat can be suppressed by appropriately changing the thickness of the separately formed high thermal conductor layer.

The invention according to claim 12 is the insulated heat transfer structure according to any one of claims 7 to 11, wherein a surface of the high thermal conductor layer is covered with a nickel plating layer. And
According to the present invention, since the nickel plating layer provides good bondability with solder, high heat dissipation can be maintained. Therefore, the product life is improved.

The invention according to claim 13 is the insulated heat transfer structure according to any one of claims 7 to 12, wherein a terminal structure is formed on at least a part of the high thermal conductor layer. Features.
According to this invention, it connects with another electronic circuit etc. via a terminal structure.

The invention according to claim 14 is a power module substrate, wherein a semiconductor chip is provided on the upper surface of the high thermal conductor layer of the insulated heat transfer structure according to any one of claims 7 to 13. It is characterized by.
According to this invention, as described above, no peeling or cracking occurs between the high thermal conductor layer and the insulating heat transfer layer. Further, when heat generated by the semiconductor chip is conducted, heat can be radiated more efficiently.

According to the insulated heat transfer structure and the power module substrate according to the present invention, since the heat transfer member and the insulating layer including the ceramic layer are directly joined and there is no interface, heat conduction is efficiently performed, and the ceramic layer and Since the heat transfer member is joined with a sufficient strength, peeling of the insulating layer and generation of cracks are suppressed, and high reliability and performance can be obtained.
In addition, the influence of thermal strain in the insulating layer can be reduced, and the occurrence of peeling or cracking of the ceramic layer can be suppressed.
Moreover, since the number of parts can be reduced, the manufacturing process can be simplified and the manufacturing cost can be reduced.

Hereinafter, a first embodiment of an insulated heat transfer structure according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the insulating heat transfer structure 1 according to the present embodiment has an insulating layer 2 on at least a part of the surface of a plate-like heat transfer member 4 made of an Al alloy such as 1000 series (JIS 1050). It has.
As shown in FIG. 2, the insulating layer 2 includes a first ceramic layer (ceramic layer) 6, a second ceramic layer (ceramic layer) 7, and a third ceramic layer (ceramic layer) 8. The first ceramic layer 6 is directly formed on the surface of the heat transfer member 4 by a normal temperature impact solidification phenomenon using ceramic particles made of, for example, Al ₂ O ₃ as a raw material.

The first ceramic layer 6 is further formed on the surface side of the Al ₂ O ₃ bonding layer formed directly by bonding Al alloy crystal particles and Al ₂ O ₃ particles on the surface of the heat transfer member 4 between the particles. Al ₂ O ₃ is formed to a thickness of, for example, 30 μm by interparticle bonding.
The second ceramic layer 7 has a composition formed by mixing, for example, Al ₂ O ₃ and Si ₃ N _4, and is formed on the surface side of the first ceramic layer 6 with a thickness of, for example, 30 μm. Yes.
The third ceramic layer 8 is formed on the surface side of the second ceramic layer 7 by using ceramic particles having a composition formed by mixing Al ₂ O ₃ and AlN on the surface side of the second ceramic layer 7. For example, it is formed to a thickness of 40 μm.
Thus, ceramic layers 7 and 8 having a composition different from that of the first ceramic layer 6 made of ceramics having a composition of one or more of Al ₂ O ₃ , Si ₃ N ₄ , and AlN are 2 The layers are continuously laminated by interparticle bonding, and are configured as an insulating layer 2 having a thickness of 100 μm, for example.

  The thickness of the insulating layer 2 is preferably 10 μm to 100 μm, and since the thickness of the insulating layer 2 is 10 μm or more, the insulating property and the mechanical strength of the insulating layer 2 against external force are sufficient. Since the insulating layer 2 has a thickness of 100 μm or less, good heat conduction in the insulating layer 2 and a temperature difference between the front and back of the insulating layer 2 are reduced, and the occurrence of cracks is suppressed.

Next, a method for manufacturing the insulated heat transfer structure 1 having the above-described configuration will be described with reference to FIG. FIG. 3A shows the configuration of an aerosol deposition (hereinafter referred to as AD) apparatus used for forming the insulating layer 2, and FIG. 3B shows the structure of ceramics applied to the heat transfer member 4. It is a figure which shows the formation state of the insulating layer 2 which becomes.
The configuration of the AD device 70 includes a high-pressure gas supply source 71, an aerosol generator 72, a film forming chamber 73, a pipe 74 that connects the high-pressure gas supply source 71 and the aerosol generator 72 in a communicable manner, and an aerosol generator. 72 and a film forming chamber 73 are connected to each other so as to be able to communicate with each other, and the inside of the film forming chamber 73 can be depressurized from about 50 Pa to about 1 kPa by a vacuum pump 76. In the film forming chamber 73, an XYZθ stage for placing a film formation object and a film forming mask and making it movable relative to the nozzle 78 is provided.

Next, the operation of the AD device 70 will be described.
First, gas is supplied from the high-pressure gas supply source 71 to the aerosol generator 72, and the fine particles and the gas are stirred and mixed in the aerosol generator 72 to form an aerosol.
A pressure difference is generated between the aerosol generator 72 and the film forming chamber 73 depressurized by the vacuum pump 76, and the aerosolized fine particles are accelerated in the transport tube 75 by the gas flow generated by the pressure difference, and the nozzle. The ceramic fine particles are ejected from the nozzle 78 to the film formation object in the film formation chamber 73.
The ejected ceramic fine particles 81 collide at high speed with the heat transfer member 4 which is a film formation object, and are bonded to each other by an active effect by forming a new surface.

  As shown in FIG. 3B, the outline of the portion where the ceramic particles 81 sprayed from the nozzles 78 are deposited on the heat transfer member 4 which is the film formation object is as follows. The heat transfer member 4 is used to move the mask 79 and the heat transfer member 4 to a predetermined position with respect to the nozzle 78 by an XYZθ stage, and ceramic particles 81 are formed on the surface of the heat transfer member 4 through the opening of the mask 79. Are collided at high speed to form the ceramic layers 6, 7, 8.

When the insulating layer 2 in the above embodiment, for example, _Al 2 after the _{O 3} first ceramic layer 6 made of formed, _Al 2 _{O 3} particles and _Si 3 _{N 4} ceramic having a composition particles composed by mixing the particle as a raw material, _Al 2 is sprayed on the surface side of the ceramic layer composed of _{O 3} to form a second ceramic layer 7 made of _Al 2 _{O 3} and _Si 3 _{N 4,} further the surface side, for example, Al ₂ The third second ceramic layer 8 is formed by injecting ceramic particles having a composition formed by mixing O ₃ particles and AlN particles as raw materials.

In this way, a ceramic layer composed of _Al 2 _{O 3,,} the ceramic layer 7 having the composition of _Al 2 _{O 3} and _Si 3 _{N 4,} and a ceramic layer 8 having the composition of _Al 2 _{O 3} and AlN, Insulating layers 2 that are sequentially laminated are formed.
The ceramic layers 6, 7, and 8 are formed by exchanging ceramic raw materials in the aerosol generator 72 of the AD device 70.

The outline of the manufacturing conditions in film formation is as follows.
Deposition object temperature Normal temperature Deposition chamber vacuum degree 100-200 Pa
Raw material particle size 0.08-2 μm
The injection speed of the raw material particles is about 300 to 1000 m / sec. Thus, the ceramic layer 6 directly formed on the surface of the heat transfer member 4, the ceramic layer 7 and the ceramic layer 8 have a relative density of 95% or more and an adhesion strength of about It has excellent characteristics of 20 MPa or more.
In addition, the film formation rate is as high as about 5 to 50 μm / min, and the film-forming thickness is as wide as about 0.5 μm to about 1 mm. Can be reduced.

According to the insulating heat transfer structure 1 configured in this way, the heat transfer member 4 is composed of Al alloy, and Al ₂ O ₃ , Si ₃ N ₄ , and AlN that form the insulating layer. Since the ceramic of composition has high heat conductivity, the insulated heat transfer structure 1 with high cooling ability is obtained.
Moreover, since the ceramic layer 6 made of Al ₂ O ₃ is directly formed on the surface of the heat transfer member 4 made of the Al alloy, the insulating layer 2 made of the ceramic layers 6, 7, and 8, the insulating layer 2 There is no thermal interface between the heat transferred from the heat transfer member 4 to the heat transfer member 4, and heat conduction is performed efficiently.

  In addition, since the first ceramic layer 6 is directly formed on the surface of the Al alloy and the insulating layer 2 is formed, the bonding strength is high, and the thickness is about 0.5 μm to about 1 mm. Even when subjected to thermal deformation due to the action of a temperature cycle or the like, the temperature difference between the front and back surfaces of the first ceramic layer 6 is small, and the occurrence of peeling and cracking of the first ceramic layer 6 is suppressed, providing stable quality and performance for a long time. Can be exerted over.

Further, since the first ceramic 6 and the second ceramic 7 and the second ceramic 7 and the third ceramic 8 are directly bonded, the bonding strength between them is high. Peeling and cracking are suppressed.
Further, since there is no thermal interface between the ceramic layers, the thermal conductivity between these ceramic layers is high, and an insulating layer having good thermal conductivity can be obtained.
Further, by adopting the above-described configuration, components such as an insulating substrate and a heat radiating plate are unnecessary, and it is possible to reduce the number of components, simplify the manufacturing process and handling of components, and reduce manufacturing costs.

Next, a second embodiment will be described with reference to FIG.
The embodiment described here has the same basic configuration as the first embodiment described above, and is obtained by adding another element to the first embodiment described above. Therefore, in FIG. 4, the same components as those in FIG.
In the power module substrate 5 according to the second embodiment, the insulating layer 2 is formed on the surface of the heat transfer member 4, and the upper surface side of the insulating layer 2 is made of pure Al (4N-Al having a purity of 99.99% or more). A high thermal conductor layer is formed, and the high thermal conductor layer is divided and arranged as circuit layers 3a and 3b.
According to the power module substrate 5 configured as described above, the heat conduction from the high heat conductor layers 3a and 3b to the heat transfer member 4 is efficiently performed and the electric power is obtained, as in the first embodiment. A static circuit can be formed.

Next, a third embodiment will be described with reference to FIG. The embodiment described here is similar in basic configuration to the above-described second embodiment, and is obtained by adding another element to the above-described second embodiment. Therefore, in FIG. 5, the same components as those in FIG.
In the power module substrate 10 according to the third embodiment, the surfaces of the high thermal conductor layers 3 a and 3 b are covered with a nickel plating layer (hereinafter abbreviated as Ni plating layer) 16.

  The power module substrate 10 thus configured also has the same operations and effects as those of the second embodiment described above, but by covering the surfaces of the high thermal conductor layers 3a and 3b with the Ni plating layer 16. When bonding with other members using solder, good bonding with the solder can be obtained, so that high heat dissipation and reliability can be ensured. Therefore, the product life is improved.

Next, a fourth embodiment will be described with reference to FIG. The embodiment described here is similar in basic configuration to the above-described second embodiment, and is obtained by adding another element to the above-described second embodiment. Therefore, in FIG. 6, the same components as those in FIG.
In the power module substrate 15 according to the fourth embodiment, Cu high thermal conductor layers 3a and 3b having different thicknesses are arranged on the upper surface side of the insulating layer 2 as a heat block.

  According to the power module substrate 15 configured as described above, the same effects and advantages as those of the second embodiment described above are obtained, but the thicknesses of the high thermal conductor layers 3a and 3b formed separately are appropriately changed. Thus, transient heat can be efficiently suppressed.

Next, a fifth embodiment will be described with reference to FIG.
The embodiment described here is similar in basic configuration to the above-described fourth embodiment, and is obtained by adding another element to the above-described fourth embodiment. Therefore, in FIG. 7, the same components as those in FIG.
In the power module substrate 20 in the fifth embodiment, the surfaces of the high thermal conductor layers 3 a and 3 b of the power module substrate 15 in the fourth embodiment described above are covered with the Ni plating layer 16.

  The power module substrate 20 configured in this manner is coated with the Ni plating layer 16 on the surfaces of the high thermal conductor layers 3a and 3b in addition to the functions and effects of the fourth embodiment described above. Since good bondability is obtained, high heat dissipation and reliability can be ensured as in the third embodiment described above. Therefore, the product life is improved.

Next, a sixth embodiment will be described with reference to FIG.
The embodiment described here is similar in basic configuration to the above-described second embodiment, and is obtained by adding another element to the above-described second embodiment. Therefore, in FIG. 8, the same components as those in FIG.
In the power module substrate 25 according to the sixth embodiment, the insulating layer 2 is formed on the surface of the heat transfer member 4 made of Al alloy, and a Cu circuit layer is disposed as the high thermal conductor layer 3 on the insulating layer 2. ing. A semiconductor chip 32 is mounted on the surface of the circuit layer that is the high thermal conductor layer 3 via the solder layer 31.

  According to the power module substrate 25 configured in this way, the semiconductor chip 32 has a good effect on the high thermal conductor layer 3 through the solder layer 31, although the same operation and effect as the second embodiment described above are obtained. Since they are connected, the heat generated in the semiconductor chip 32 can be efficiently radiated to the heat transfer member 4 through the high thermal conductor layer 3.

Next, a seventh embodiment will be described with reference to FIG.
The embodiment described here is similar in basic configuration to the above-described sixth embodiment, and is obtained by adding another element to the above-described sixth embodiment. Therefore, in FIG. 9, the same components as those in FIG.
In the power module substrate 30 according to the seventh embodiment, heat radiation fins 4a are formed on one surface of a heat transfer member 4 made of an Al alloy.

  According to the power module substrate 30 configured in this manner, there are the same operations and effects as the above-described sixth embodiment, and there is no thermal interface between the heat transfer member 4 and the heat radiation fin 4a. The heat transferred to the heat transfer member 4 is efficiently dissipated from the heat dissipation fin 4a without hindering heat transfer.

Next, an eighth embodiment will be described with reference to FIG. The basic configuration of the embodiment described here is the same as that of the above-described third embodiment, and another element is added to the above-described third embodiment. Therefore, in FIG. 10, the same components as those in FIG.
In the power module substrate 35 in the eighth embodiment, the insulating layer 2 is formed on one surface of the heat transfer member 4 made of Al or the like, and the surfaces of the high thermal conductor layers 3 a and 3 b are formed on the upper surface side of the insulating layer 2. A circuit layer made of Cu covered with the Ni plating layer 16 is disposed. Further, the power module substrate 35 has heat radiation fins 4a formed on one surface of the heat transfer member 4 made of an Al alloy.

  According to the power module substrate 35 configured as described above, there are the same operations and effects as the third embodiment described above, and there is no thermal interface between the heat transfer member 4 and the heat radiation fins 4a. The heat transferred to the heat transfer member 4 is efficiently dissipated from the heat dissipation fin 4a without hindering heat transfer.

Next, a ninth embodiment will be described with reference to FIG. The basic configuration of the embodiment described here is the same as that of the above-described third embodiment, and another element is added to the above-described third embodiment. Therefore, in FIG. 11, the same components as those in FIG.
In the power module substrate 40 according to the ninth embodiment, the insulating layer 2 is formed on one surface of the heat transfer member 4 made of Al or the like, the high heat conductor layer is formed on the upper surface side of the insulating layer 2, and high heat conduction is achieved. A circuit layer 3a made of Cu and a terminal member 3b made of Cu in which the surface of the body layer is covered with the Ni plating layer 16 are arranged.

  The power module substrate 40 thus configured also has the same operations and effects as those of the third embodiment described above. However, the high thermal conductor layer 3b has a terminal structure. Easy connection with other electronic circuits.

Next, a tenth embodiment will be described with reference to FIG.
The embodiment described here is similar in basic configuration to the above-described sixth embodiment, and is obtained by adding another element to the above-described sixth embodiment. Therefore, in FIG. 12, the same components as those in FIG.
In the power module substrate 45 according to the tenth embodiment, the insulating layer 2 is formed on one surface of the heat transfer member 4 made of Al or the like, and the upper surface side of the insulating layer 2 is coated with the Ni plating layer 16 on the surface. Cu heat blocks 3a and 3b are disposed as conductor layers.
A semiconductor chip 32 is mounted on the surface of the high thermal conductor layer 3 a via a solder layer 31.

  The power module substrate 45 thus configured also has the same operations and effects as the sixth embodiment described above, and the heat generated in the semiconductor chip 32 is as in the eleventh embodiment described later. By doing so, heat can be efficiently transferred to the heat transfer member 4 via the high thermal conductor layer 3b.

Next, an eleventh embodiment will be described with reference to FIG.
The basic configuration of the embodiment described here is the same as that of the tenth embodiment described above, and another element is added to the above-described tenth embodiment. Therefore, in FIG. 13, the same components as those in FIG.
In the power module substrate 50 according to the eleventh embodiment, a heat sink 57 is attached using screws 56 in a state where a heat conductive grease layer (not shown) is interposed on the lower surface of the heat transfer member 4.
A semiconductor chip 32 is mounted on the surface of the high thermal conductor layer 3a via a solder layer 31, and the surface of the semiconductor chip 32 and the surface of the high thermal conductor layer 3b are connected by an Al wire 51. .

The power module substrate 50 thus configured also has the same operations and effects as those of the tenth embodiment described above, but the heat generated in the semiconductor chip 32 is dissipated by the heat sink 57.
Moreover, since the semiconductor chip 32 and the high thermal conductor layer 3b are connected by the Al wire 51, the heat generated in the semiconductor chip 32 is efficiently transferred to the heat transfer member 4 through the high thermal conductor layer 3b. Further, since the heat transfer member 4 and the heat sink 57 are individually manufactured, the manufacture is easy.

Next, a twelfth embodiment will be described with reference to FIG.
The basic configuration of the embodiment described here is the same as that of the tenth embodiment described above, and another element is added to the above-described tenth embodiment. Therefore, in FIG. 14, the same components as those in FIG.
The power module substrate 55 in the twelfth embodiment is formed with a refrigerant flow path 4b for allowing the refrigerant to pass through the main body of the heat transfer member 4, and the surface of the high thermal conductor layer 3a is interposed with a solder layer 31. A semiconductor chip 32 is mounted, and the surface of the semiconductor chip 32 and the surface of the high thermal conductor layer 3 b are connected by an Al wire 51.

  The power module substrate 55 configured in this way also has the same operation and effect as the above-described eleventh embodiment, and the refrigerant flow path 4b for passing the refrigerant through the main body of the heat transfer member 4 is formed. In addition, since there is no thermal interface related to heat conduction between the heat transfer member 4 and the refrigerant passing through the refrigerant flow path 4b, the heat conduction is not hindered and is efficiently cooled.

In addition, this invention is not limited to the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.
For example, in the above embodiment, the case where an Al alloy is used as the heat transfer member 4 has been described, but pure Al may be used instead of the Al alloy.
Further, as the ceramic constituting the insulating layer 2, a ceramic obtained by mixing Al ₂ O ₃ as the first ceramic layer 6 and a mixture of Al ₂ O ₃ and Si ₃ N ₄ as the second ceramic layer 7 is used. As the ceramic layer 8, ceramics in which Al ₂ O ₃ and AlN are mixed are used to explain the case of a total of 3 layers, but the ceramic composition and the number of layers constituting the ceramic layers 6, 7, 8 are described. Can be appropriately selected as necessary.

Moreover, in the said embodiment, the thickness of the insulating layer 2 shall be 100 micrometers, and the thickness of the 1st ceramic layer 6, the 2nd ceramic layer 7, and the 3rd ceramic layer 8 which comprise the insulating layer 2 is each set. Although the thickness is 30 μm, 30 μm, and 40 μm, the thickness of the insulating layer 2 and the thickness of each ceramic layer constituting the insulating layer 2 can be set to arbitrary thicknesses.
In addition, the configuration in which the thermal expansion coefficient of the insulating layer 2 is sequentially reduced in the order of the first ceramic layer 6, the second ceramic layer 7, and the third ceramic layer 8 has been described. It is not necessary to sequentially reduce the arrangement.
Further, the arrangement order of the first ceramic layer 6, the second ceramic layer 7, and the third ceramic layer 8 may be controlled by the thermal conductivity, both the thermal expansion coefficient and the thermal conductivity.

  In addition, as a method of directly forming the ceramic layer 6 by film formation, a method of directly bonding the first ceramic layer 6 and the second ceramic layer 7, and the second ceramic layer 7 and the third ceramic layer 8, AD Although the case where the method is used has been described, the film may be directly formed or directly bonded using plasma spraying or laser spraying, and the AD method, plasma spraying, or laser spraying may be arbitrarily changed for each ceramic layer to be laminated. The ceramic layers 6, 7, 8 may be formed by applying a plurality of film forming methods.

  Further, the heat radiation fin formed on the heat transfer member 4 in the above embodiment, the presence or absence of the refrigerant flow path, the high heat transfer layer 3, the terminal member 3b, the nickel plating layer 16, the solder layer 31, the semiconductor chip 32, the heat sink 57, the combination of the mounting screw 56 and the like can be freely selected.

  In addition to Cu and pure Al, the material used for the high thermal conductor layer 3 may have a thermal conductivity of 50 W / mK or higher, preferably 150 W / mK or higher, and a pure metal having a Vickers hardness of Hv 50 to 100. (Cu, Ag, Au, etc.) and alloys thereof can be used. Moreover, you may use the pure metal, alloy, etc. which have the same characteristic, without limiting to these.

  According to the power module substrate of the present invention, the heat on the heat generating body side is efficiently conducted to the heat radiating body side to dissipate heat, and stable performance is exhibited over a long period of time even if it is subjected to thermal deformation due to an action such as a temperature cycle. And industrial applicability is recognized.

It is a schematic sectional drawing which shows the insulated heat-transfer structure based on the 1st Embodiment of this invention. It is a schematic sectional drawing which shows the structure of the insulating layer which concerns on the 1st Embodiment of this invention. (A) It is a figure which shows the outline of the manufacturing process of the insulated heat-transfer structure based on the 1st Embodiment of this invention. (B) It is a figure which shows the outline of the film-forming process of the insulating layer which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the insulated heat-transfer structure based on the 2nd Embodiment of this invention, Comprising: It is a schematic sectional drawing which shows the example applied to the board | substrate for power modules. It is explanatory drawing which shows the insulated heat-transfer structure based on the 3rd Embodiment of this invention, Comprising: It is a schematic sectional drawing which shows the example applied to the board | substrate for power modules. It is explanatory drawing which shows the insulated heat-transfer structure which concerns on the 4th Embodiment of this invention, Comprising: It is a schematic sectional drawing which shows the example applied to the board | substrate for power modules. It is explanatory drawing which shows the insulated heat-transfer structure which concerns on the 5th Embodiment of this invention, Comprising: It is a schematic sectional drawing which shows the example applied to the board | substrate for power modules. It is explanatory drawing which shows the insulated heat-transfer structure based on the 6th Embodiment of this invention, Comprising: It is a schematic sectional drawing which shows the example applied to the board | substrate for power modules. It is explanatory drawing which shows the insulated heat-transfer structure based on the 7th Embodiment of this invention, Comprising: It is a schematic sectional drawing which shows the example applied to the board | substrate for power modules. It is explanatory drawing which shows the insulated heat-transfer structure based on the 8th Embodiment of this invention, Comprising: It is a schematic sectional drawing which shows the example applied to the board | substrate for power modules. It is explanatory drawing which shows the insulated heat-transfer structure based on the 9th Embodiment of this invention, Comprising: It is a schematic sectional drawing which shows the example applied to the board | substrate for power modules. It is explanatory drawing which shows the insulated heat-transfer structure based on the 10th Embodiment of this invention, Comprising: It is a schematic sectional drawing which shows the example applied to the board | substrate for power modules. It is explanatory drawing which shows the insulated heat-transfer structure based on the 11th Embodiment of this invention, Comprising: It is a schematic sectional drawing which shows the example applied to the board | substrate for power modules. It is explanatory drawing which shows the insulated heat-transfer structure based on the 11th Embodiment of this invention, Comprising: It is a schematic sectional drawing which shows the example applied to the board | substrate for power modules. It is the schematic sectional drawing which showed an example of the board | substrate for conventional power modules. It is the schematic sectional drawing which showed the other example of the board | substrate for conventional power modules. It is the schematic sectional drawing which showed the other example of the board | substrate for conventional power modules.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulation heat transfer structure 2 Insulation layer 3, 3a, 3b High heat conductor layer 4 Heat transfer member 4a Heat radiation fin 4b Refrigerant flow path 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 Power Module Substrate 6, 7, 8 Ceramic Layer 16 Ni Plating Layer (Nickel Plating Layer)
32 Semiconductor chip 57 Heat sink

Claims (14)

An insulating heat transfer structure including an insulating layer on at least a part of the surface of a plate-like heat transfer member made of pure Al or an Al alloy,
The insulating layer includes a ceramic layer in which ceramics having a composition of one or more of Al ₂ O ₃ , Si ₃ N ₄ , and AlN are directly formed on a heat transfer member. Heat transfer structure. An insulated heat transfer structure according to claim 1,
The ceramic layer is made of ceramics having a composition of at least two of Al ₂ O ₃ , Si ₃ N ₄ , and AlN. An insulated heat transfer structure according to claim 1 or claim 2,
The insulating layer is a ceramic having a composition of one or more of Al ₂ O ₃ , Si ₃ N ₄ , and AlN on the surface side of the directly formed ceramic layer. An insulating heat transfer structure, wherein one or more ceramic layers having different compositions are laminated. An insulated heat transfer structure according to claim 3,
The insulating heat transfer structure is configured such that the thermal expansion coefficient of the laminated ceramic layers is gradually decreased from the heat transfer member toward the surface side of the insulating layer. An insulated heat transfer structure according to any one of claims 1 to 4,
The heat transfer member is an insulated heat transfer structure in which a heat dissipation fin or a refrigerant flow path is formed in a heat transfer member body.   The insulated heat transfer structure according to any one of claims 1 to 5, wherein the heat transfer member is connected to a heat sink having a heat radiation fin or a refrigerant flow path. Thermal structure.     The insulated heat transfer structure according to any one of claims 1 to 6, wherein a high thermal conductor layer is formed on an upper surface of the ceramic layer.     8. The insulated heat transfer structure according to claim 7, wherein the high thermal conductor layer is made of Al, Cu, Ag, or Au.   9. The insulated heat transfer structure according to claim 7, wherein a circuit for mounting a semiconductor chip is formed on the high thermal conductor layer.   The insulated heat transfer structure according to any one of claims 7 to 9, wherein the high heat conductor layer is divided and formed.   11. The insulated heat transfer structure according to claim 10, wherein a thickness of one of the divided high-heat conductor layers is different from a thickness of at least one of the other high-heat conductor layers. An insulated heat transfer structure characterized by that.   The insulated heat transfer structure according to any one of claims 7 to 11, wherein a surface of the high thermal conductor layer is covered with a nickel plating layer. An insulated heat transfer structure according to any one of claims 7 to 12,
An insulating heat transfer structure, wherein a terminal structure is formed on at least a part of the high thermal conductor layer. A power module substrate, wherein a semiconductor chip is provided on an upper surface of the high thermal conductor layer of the insulated heat transfer structure according to any one of claims 7 to 13.

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