TW202348119A - Heat dissipation member - Google Patents

Abstract

Provided is a novel heat dissipation member that is not available in the prior art. The heat dissipation member 11 is for use in a semiconductor module 1 and consists of a SiSiC member comprising: a heat dissipation plate 12 having a semiconductor element 2 and an insulating substrate 3 arranged on one surface side; and a heat sink 13 formed integrally with the heat dissipation plate 12. The heat sink 13 preferably comprises a protrusion 14 protruding from the heat dissipation plate 12.

Description

Heat dissipation component

The invention relates to a heat dissipation component.

A semiconductor module generally includes a semiconductor element, an insulating substrate, a heat sink, and a heat sink in this order (Patent Documents 1 to 3). The heat generated by the semiconductor element is transferred to the heat sink through the insulating substrate and heat sink plate, and is released from the fins of the heat sink to the outside of the semiconductor module. As the material of the heat sink, select a material with an expansion coefficient close to that of the insulating substrate and a high thermal conductivity. On the other hand, for heat sinks, basically only good heat dissipation is required. As the material, metals with high thermal conductivity and easy processing are selected. Prior technical literature patent documents

Patent Document 1: Japanese Patent Application Publication No. 2010-219215 Patent Document 2: International Publication No. 00/076940 Patent document 3: Japanese Patent Application Publication No. 2001-185665

[Problem to be solved by the invention]

In semiconductor modules (power modules) that handle high power (for example, 8 to 12 MW), silicon carbide (SiC) is sometimes used as the semiconductor element and silicon nitride (Si ₃ N ₄ ) is used as the insulating substrate. In this case, it is desirable to select a material having an expansion coefficient close to that of silicon nitride as a material for the heat sink plate. Thereby, the adhesion between the insulating substrate and the heat dissipation plate is improved, so the heat generated by the semiconductor element is less likely to move from the insulating substrate to the heat dissipation plate.

However, the heat sink plate and the heat sink fin are joined via the heat sink fin. The heat sink is a different component from the heat sink and the heat sink, and has relatively low thermal conductivity. Therefore, when the heat generated by the semiconductor element further moves to the heat sink through the insulating substrate and the heat sink plate, the heat movement may be hindered by the heat sink. At this time, heat dissipation may not be sufficient.

The present invention was completed in view of the above circumstances, and aims to provide an unprecedented novel heat dissipation member. [Technical means to solve problems]

As a result of intensive research, the present inventors found that the above object can be achieved by adopting the following configuration, and completed the present invention.

That is, the present invention provides the following [1] to [10]. [1] A heat dissipation member for a semiconductor module, which is a SiSiC member and includes: a heat dissipation plate on which a semiconductor element and an insulating substrate are arranged on one side; and a heat dissipation fin formed integrally with the heat dissipation plate. [2] The heat dissipation member according to the above [1], wherein the heat dissipation fin is provided with a plurality of protrusions protruding from the heat dissipation plate. [3] The heat dissipation member according to the above [2], wherein the number of the protrusions per unit area of the front surface of the heat dissipation plate is 1/cm ² or more. [4] The heat dissipation member according to the above [2] or [3], wherein the cross-sectional area C _P of one of the protrusions when cut along the front surface of the heat dissipation plate is 1 to 100 mm ² . [5] The heat dissipation member according to any one of [2] to [4] above, wherein the surface area increase rate is 1.3 or more, wherein the surface area increase rate is obtained by dividing the surface area S of the heat dissipation member having the protrusion. A value obtained by dividing ₁ by the surface area S ₂ of the heat dissipation member assuming that the protrusion is not provided. [6] The heat dissipation member according to any one of the above [1] to [5], wherein the average linear expansion coefficient at 30 to 300°C is 2 to 5 ppm/K. [7] The heat dissipation member according to any one of the above [1] to [6], wherein the thermal conductivity is 150 W/(m･K) or more. [8] The heat dissipation member according to any one of the above [1] to [7], wherein the SiC content is 90 volume % or less. [9] The heat dissipation member according to any one of the above [1] to [8], wherein the average particle size of SiC is in the range of 2 to 100 μm. [10] A semiconductor module having the heat dissipation member according to any one of the above [1] to [9]. [Effects of the invention]

According to the present invention, an unprecedented novel heat dissipation member can be provided.

[Semiconductor Module] FIG. 1 schematically shows a cross-sectional view of the semiconductor module 1 . The semiconductor module 1 schematically includes a semiconductor element 2, an insulating substrate 3, and a heat dissipation member 11 in this order. A plurality of conductor circuits 4 are formed on one side of the insulating substrate 3 . The semiconductor element 2 is fixed to one conductor circuit 4 via a solder layer 5 and is connected to other conductor circuits 4 via wires 6 . A metal layer 7 is formed on substantially the entire other surface of the insulating substrate 3 , and the heat dissipation member 11 is bonded to the metal layer 7 via a solder layer 8 .

The semiconductor element 2 is not particularly limited, and conventionally known semiconductor elements can be used. When the semiconductor module 1 is a semiconductor module that handles high power, the material of the semiconductor element may be, for example, silicon carbide (SiC).

Examples of the material of the insulating substrate 3 include insulating materials such as aluminum oxide (Al ₂ O ₃ ), aluminum nitride (AlN), and silicon nitride (Si ₃ N ₄ ). When the material of the semiconductor element 2 is SiC, for example, Si ₃ N ₄ can be used as the material of the insulating substrate 3 .

Examples of materials for the metal layer 7, the conductor circuit 4, and the wire 6 include conductive materials such as copper and aluminum.

〈Heat dissipation member (SiSiC member)〉 The heat dissipation member 11 is a SiSiC member. SiSiC components are composite materials containing silicon (Si) and silicon carbide (SiC). The heat dissipation member 11 (also referred to as "SiSiC member 11") includes a heat dissipation plate 12 on which the semiconductor element 2 and the insulating substrate 3 are arranged on one side, and a heat dissipation fin 13 formed integrally with the heat dissipation plate 12 . That is, in the heat dissipation member 11, the heat dissipation plate 12 and the heat dissipation fin 13 are formed integrally without any joints.

"Heat Dissipation Plate" The heat dissipation plate 12 is a member that supports the insulating substrate 3, and is, for example, a plate-shaped member. As described above, the semiconductor element 2 and the insulating substrate 3 are arranged on one side of the heat sink 12 . The heat sink 12 has a front surface 17 , a back surface 18 and a side surface 19 . The front surface 17 is the surface of the heat dissipation plate 12 on which a plurality of protrusions 14 are provided. The back side 18 is the side opposite to the front side 17 of the heat sink 12 . The side 19 is the side connecting the front 17 and the back 18 .

"Heat sink" The heat sink 13 is cooled by being in contact with the refrigerant. As a cooling method, it can be air-cooled or water-cooled. By cooling the heat sink 13 , the heat generated by the semiconductor element 2 is transferred to the heat sink 13 through the insulating substrate 3 and the heat sink 12 , and is released to the outside of the semiconductor module 1 . At this time, the heat sink 12 and the heat sink 13 are not joined through a heat sink (not shown), but are formed integrally. Therefore, when the heat generated by the semiconductor element 2 moves from the heat sink 12 to the heat sink 13, the movement of the heat is not easily hindered. That is, it has excellent heat dissipation properties.

FIG. 2 is a perspective view of the heat dissipation member 11 provided with a plurality of protrusions 14 . The heat sink 13 preferably has a protrusion 14 protruding from the heat sink 12 as a portion that contacts the refrigerant. The heat dissipation plate 12 and the protruding portion 14 are seamlessly formed integrally.

As shown in FIGS. 1 and 2 , the heat sink 13 is preferably provided with a plurality of protrusions 14 . Thereby, the area in contact with the refrigerant is increased, so the cooling efficiency is improved. From the viewpoint of improving heat dissipation through high density, the number of protrusions 14 per unit area of the front surface of the heat sink 12 (the side where the protrusions 14 are provided) is preferably 1/cm ² or more, more preferably 5/cm ² or more, further preferably 10/cm ² or more. From a rational viewpoint of the heat dissipation member 11, the number of protrusions 14 per unit area of the surface of the heat dissipation plate 12 is preferably 500 pieces/cm ² or less, and more preferably 300 pieces/cm ² or less. The protrusion 14 may be provided to form a flow path for the refrigerant, and may be a plate-shaped protrusion 14, for example.

(shape of protrusion) The shape of the protruding portion 14 is not particularly limited, and can be appropriately set from the viewpoint of improving the fluidity of the fluid and preventing or reducing interference with other components. Examples include: cylindrical shape; polygonal cylindrical shape (including plate shape); cylindrical shape and polygonal columnar shapes; shapes after a part of these shapes are deformed (hereinafter also referred to as "deformed shapes"); and other shapes. A cylindrical protrusion 14 is illustrated in FIG. 2 . As a specific example of the deformed shape, there may be mentioned a shape in which arbitrary concave and convex portions or through-holes are formed on the bottom surface 15 and/or the side surface 16 of the protruding portion 14 (the exposed surface of the protruding portion 14 except the bottom surface 15 ); 14 A shape that tapers (the cross-sectional area decreases) from the front 17 of the heat sink 12 toward the bottom 15; etc. Among them, the shape of the protrusion 14 is preferably cylindrical in order not to hinder the flow of the refrigerant (either gas or liquid) and to ensure a sufficient surface area.

(Height of protrusion H) The height H of the protrusion 14 (the shortest distance from the bottom surface 15 to the front surface 17 of the heat sink 12) is preferably 1 mm or more, more preferably 3 mm or more, and further preferably 5 mm or more. On the other hand, the height H is preferably 50 mm or less, more preferably 40 mm or less, further preferably 30 mm or less, particularly preferably 20 mm or less.

(Cross-sectional area C _P of the protruding portion) The cross-sectional area C _P of the protruding portion 14 when cut along the front surface 17 of the heat sink 12 is preferably 1 mm ² or more, and more preferably 3 mm ^{2 or} more. On the other hand, since the protrusions 14 can be arranged at a high density, the cross-sectional area C _P is preferably 100 mm ² or less, more preferably 70 mm ² or less, further preferably 50 mm ² or less, and particularly preferably 30 mm 2 or less. mm ² or less, preferably 15 mm ² or less. The cross-sectional area C _P is the cross-sectional area of one protrusion 14 .

(Cross-sectional area C _V of the protruding portion) The cross-sectional area C _V of the protruding portion 14 when cut along the direction perpendicular to the front surface 17 of the heat sink 12 so as to maximize the cross-sectional area of the protruding portion is preferably 1 mm ² or more. , preferably 10 mm ² or more. On the other hand, the cross-sectional area C _V is preferably 500 mm ² or less, more preferably 250 mm ² or less, further preferably 100 mm ² or less, particularly preferably 80 mm ² or less, and most preferably 60 mm ² or less. The cross-sectional area C _V is the cross-sectional area of one protrusion 14 .

(Surface area increase rate due to protrusions) A value obtained by dividing the surface area S 1 of the heat dissipation member 11 having the protrusions 14 by the surface area S ₂ of the heat dissipation member ₁₁ assuming that the protrusions 14 are not provided. (S ₁ /S ₂ ) is called "surface area increase rate". The surface area S ₁ and the surface area S ₂ respectively do not include the areas of the back 18 (the side where the protruding portion 14 is not provided) and the side 19 of the heat dissipation plate 12 . In order to obtain sufficient cooling efficiency, the surface area increase rate is preferably 1.3 or more, more preferably 1.5 or more, and further preferably 2 or more. In addition, the greater the surface roughness of the protruding portion, the easier it is for the surface area to increase, so it is better to have a larger surface roughness of the protruding portion. The surface roughness (Sa) of the protrusion is preferably 1 μm or more, more preferably 5 μm or more. On the other hand, the upper limit is not particularly limited, but is preferably 500 μm or less. The surface roughness (Sa) of the protruding portion can be determined by observing any area of the protruding portion 14 using a laser microscope (VK-X1000 manufactured by Keyence Corporation) and using image analysis software (VK-X1000 manufactured by Keyence Corporation). H2X) and find it.

Furthermore, the above-mentioned height H, cross-sectional area C _P , cross-sectional area C _V and surface area increase rate can be observed by using an X-ray CT scanner (model: SHIMADZU SM4-225CT FPD) to observe the heat dissipation member 11 and use the obtained data The image analysis software determines the value without damaging the heat dissipation member 11.

"Average Linear Expansion Coefficient" The average linear expansion coefficient of the heat dissipation member 11 at 30 to 300°C (hereinafter also referred to as "expansion coefficient") is preferably 2 ppm/K or more, more preferably 2.5 ppm/K or more, and still more preferably 3 ppm/K above. On the other hand, the expansion coefficient of the heat dissipation member 11 is preferably 5 ppm/K or less, more preferably 4.5 ppm/K or less, and further preferably 4 ppm/K or less. An example of a method for making the expansion coefficient of the heat dissipation member 11 fall within the above range is a method of making the SiC content of the heat dissipation member 11 fall within the following range. The average linear expansion coefficient is measured according to the method described in JIS R 1618 using a thermal dilatometer (LIX-1 manufactured by Advance Riko Co., Ltd.), for example.

However, as described above, when the material of the semiconductor element 2 is SiC, for example, Si ₃ N ₄ can be used as the material of the insulating substrate 3 . The expansion coefficient of Si ₃ N ₄ also depends on the content of impurities, for example, 2 to 3 ppm/K. At this time, if the expansion coefficient of the heat dissipation member 11 is within the above range, the expansion coefficients of the insulating substrate 3 and the heat dissipation member 11 are close to each other, so warpage caused by the difference in expansion coefficient is less likely to occur. That is, peeling due to warping is less likely to occur.

"Thermal Conductivity" The thermal conductivity of the heat dissipation member 11 is preferably 150 W/(m･K) or more, more preferably 160 W/(m･K) or more, and further preferably 165 W/(m･K) or more. An example of a method for making the thermal conductivity of the heat dissipation member 11 fall within the above range is a method of making the SiC content of the heat dissipation member 11 fall within the following range. Thermal conductivity was determined at room temperature (23°C) by the flash method using LFA 467 (Nanoflash) xenon lamp manufactured by NETZSCH.

"SiC content" The heat dissipation member 11 needs to appropriately contain Si elemental substance. Therefore, the SiC content of the heat dissipation member 11 is preferably 90 volume % or less, more preferably 75 volume % or less, further preferably 60 volume % or less, particularly preferably 50 volume % or less. Furthermore, as described below, SiC has a higher density than Si element. Therefore, when the SiC content is small, the heat dissipation member 11 is relatively lightweight compared to the case where the SiC content is large.

On the other hand, if the content of Si element is too high, the strength (four-point bending strength, etc.) of the heat dissipation member 11 may be insufficient. Therefore, in order to obtain sufficient strength, the SiC content of the heat dissipation member 11 is preferably 10 volume % or more, more preferably 20 volume % or more, and further preferably 30 volume % or more.

The SiC content (unit: volume %) is determined from the optical microscope photograph as follows. In the micrograph of the cross-section of the heat dissipation member 11, the gray part is SiC, and the lighter white part is Si elemental substance. Based on the micrograph of any cross-section of the heat dissipation member 11, use image analysis software (WinROOF2015) to find the area ratio of SiC and Si elements, and use the calculated area ratio directly as the respective volume ratio. The SiC content is the average value obtained from any five visual fields.

<Average particle diameter of SiC> Consider the case where the heat dissipation member 11 has a cylindrical or polygonal columnar protrusion 14 with a small cross-sectional area C _P (for example, 5 mm ² or less). In this case, if the average particle diameter of the SiC constituting the protruding portion 14 is too large, the bonding amount of the SiCs becomes relatively small, and the shape of the protruding portion 14 is easily deformed. Therefore, the average particle size of SiC in the heat dissipation member 11 including the protruding portion 14 is preferably 100 μm or less, more preferably 80 μm or less, further preferably 60 μm or less, still more preferably 40 μm or less, and particularly preferably 20 μm or less, preferably 15 μm or less.

On the other hand, the average particle diameter of SiC in the heat dissipation member 11 is preferably 2 μm or more, more preferably 5 μm or more, and further preferably 8 μm or more.

The average particle diameter of SiC was determined from an optical microscope photograph in the same manner as the SiC content. Based on the microscope photograph of any cross-section of the heat dissipation member 11, the particle size (circular equivalent diameter) of each SiC particle is measured using image analysis software (WinROOF2015). The average value of the particle diameters of SiC found in any five visual fields was used as the average particle diameter of SiC.

"4-point bending strength" The 4-point bending strength of the heat dissipation member 11 is preferably 130 MPa or more, more preferably 160 MPa or more, and further preferably 200 MPa or more. The 4-point bending strength is measured at 20°C based on the bending strength test method (4-point bending strength) described in JIS R 1601:2008.

<Density> The density of the heat dissipation member 11 is preferably 2.3 g/cm ³ or more, more preferably 2.5 g/cm ³ or more, and further preferably 2.6 g/cm ³ or more. On the other hand, the density of the heat dissipation member 11 is preferably 3.2 g/cm ³ or less, more preferably 3.1 g/cm ³ or less, further preferably 3.0 g/cm ³ or less. Density is measured according to the method described in JIS Z 8807-2012.

[Manufacturing method of heat dissipation member (SiSiC member)] Next, a method of manufacturing the heat dissipation member 11 will be described.

〈Preparation of SiC molded body〉 First, a SiC molded body (not shown) containing SiC particles is formed. The SiC molded body is also a porous body having a plurality of pores. Therefore, as described below, the molten Si element is impregnated into the SiC molded body. The void ratio of the SiC formed body is preferably 30 volume % or more, more preferably 40 volume % or more. On the other hand, the porosity of the SiC molded body is preferably 70 volume % or less, more preferably 65 volume % or less, and still more preferably 60 volume % or less. The void ratio is determined using a mercury porometer.

The size and shape of the SiC molded body can be appropriately set according to the size and shape of the heat dissipation member 11 (SiSiC member 11) finally obtained. For example, when the heat dissipation member 11 finally obtained has the protrusion 14 , a SiC molded body having a protrusion having the same shape as the protrusion 14 is produced.

As a method for producing a SiC molded body, the 3D printing method described below is preferred.

"3D Printing Method" SiC molded bodies are produced using, for example, 3D (three-dimensional) printing methods such as laser irradiation molding method and adhesive injection molding method. In the 3D printing method, layers are formed layer by layer and stacked sequentially to obtain a laminated body of a desired shape, that is, a SiC molded body. The thickness of each layer laminated sequentially is, for example, 0.01 to 0.3 mm.

In the laser irradiation modeling method, a layer containing SiC particles and adhesive is irradiated with laser. The heat of the laser melts and solidifies the adhesive present in the irradiated area, thereby bonding the SiC particles to each other. By performing this operation on each layer laminated sequentially, a SiC molded body is produced.

In the adhesive jet molding method, an adhesive is jetted from an inkjet nozzle to a layer containing SiC particles. In the area where the adhesive was sprayed, the SiC particles bonded to each other. By performing this operation on each layer laminated sequentially, a SiC molded body is produced. In the adhesive injection molding method, the layer containing SiC particles can also be pre-contained with a hardener (such as an aqueous solution of acidic substances containing xylene sulfonic acid, sulfuric acid, etc.), and only in the area where the sprayed adhesive contacts the hardener. to react (harden) the adhesive. The content of the hardener is, for example, 0.1 to 1% by mass relative to the SiC particles. It is also possible to harden the adhesive by spraying the adhesive onto the layer containing SiC particles without using a hardener, and then performing heat treatment. The heat treatment temperature is, for example, 150 to 250°C.

The SiC particles are preferably α-SiC. The average particle diameter of the SiC particles to be used is appropriately selected so that the average particle diameter of SiC in the finally obtained SiSiC member 11 is a desired value. The average particle diameter of the SiC particles was measured using a laser diffraction and scattering particle size distribution measuring device (MT3300EXII, manufactured by MicrotracBEL Corporation).

Examples of the binder include thermosetting resins such as phenol resins; self-curing resins such as furan resins; and the like.

However, Patent Documents 1 to 3 specifically describe a method different from the 3D printing method as a method of producing a SiC molded body. For example, refer to Example 1 of Patent Document 1 ([0068] to [0069]), Example 1 of Patent Document 2 (pages 13 to 18), and Example 1 of Patent Document 3 ([0054] to [0060 ]). Specifically, in Patent Document 1 ([0068]), as "Example 1", it is described that "SiC powder with an average particle diameter of 50 μm and SiC powder with an average particle diameter of 10 μm were prepared at a weight ratio of 7:3. An organic binder and water are added to the mixture at a certain ratio to prepare a slurry (slurry), and the above slurry is used to form a molded body by the slurry casting method."

However, when the methods described in Patent Documents 1 to 3 are used to produce a SiC molded body having a cylindrical or polygonal columnar protrusion with a small cross-sectional area C _P (for example, 5 mm ² or less), it is easy to cause Deformed protrusions (or protrusions formed in a shape that is easily deformed). In contrast, by using the above-described 3D printing method to produce a SiC molded body, protrusions that are deformed are less likely to be formed (the shape of the formed protrusions is less likely to be deformed).

〈Impregnated with Si〉 Next, the SiC molded body is impregnated with silicon (Si). Hereinafter, this is also referred to as "Si impregnation". Specifically, for example, the SiC formed body and the Si elemental substance are heated in a state where they are in contact with each other (the SiC formed body and the Si elemental substance) so that the Si elemental substance is melted. Thereby, the molten Si elemental substance is impregnated into the porous body, that is, the SiC molded body, by the capillary phenomenon. In this manner, the SiSiC member 11 is obtained as a composite material in which the Si element is impregnated into the SiC molded body. At this time, by melting the Si element in a state of being disposed on the upper surface of the SiC formed body, it is easier to impregnate the molten Si element into the SiC formed body by utilizing gravity. The environment in which Si element is melted is preferably a reduced pressure environment.

The heating temperature may be equal to or higher than the melting point of Si. The melting point of Si varies slightly depending on the measurement method, but is approximately 1410 to 1414°C. The heating temperature is preferably 1420°C or above.

The amount of Si introduced into the SiC formed body can be appropriately set based on the SiC content of the SiSiC member 11 finally obtained, and the like.

The obtained SiSiC member 11 is sintered by heating when the Si element is melted. That is, SiC is combined with each other and SiC is combined with Si, thereby obtaining a dense sintered body. Therefore, the obtained SiSiC member 11 is a composite material containing Si and SiC, and is also a sintered body. [Example]

Hereinafter, an Example is given and this invention is demonstrated concretely. However, the present invention is not limited to the examples described below. In the following, Example 1 is an example, and Examples 2 to 4 are reference examples.

<Example 1> A SiC molded body was produced using 3D printing. That is, a powder lamination type 3D printer is used to produce SiC molding by the binder injection molding method. Specifically, first, a layer (thickness: 0.03 mm) is formed using SiC particles, and an adhesive is sprayed onto the formed layer from an inkjet nozzle. Repeat this step to produce a heat sink with 292 cylindrical protrusions (cross-sectional area C _P : 3.14 mm ² , height H: 6 mm) integrated into the area equivalent to the heat sink (140 mm × 45 mm × 3 mm). SiC molded body. As the SiC particles, α-SiC powder (average particle diameter: 10 μm, manufactured by Shinano Electric Refining Co., Ltd.) was used. As the adhesive, "BA005" manufactured by ExOne Co., Ltd. is used.

Next, Si impregnation was performed. More specifically, first, Si elemental substance is arranged on the SiC molded body in the reaction furnace. The amount of the Si element to be arranged was adjusted so that the SiC content (unit: volume %) of the SiSiC member obtained would be the value shown in Table 1 below (the same applies below). Thereafter, the inside of the reaction furnace was heated to 1470°C while being in a reduced pressure environment. Thereby, the Si element is melted and impregnated into the SiC formed body.

In this way, a SiSiC member, which is a sintered body containing Si element and SiC, is obtained as a heat dissipation member. 〈Example 2〉 A SiC formed body was produced in the same manner as in Example 1, except that α-SiC powder with an average particle diameter of 30 μm was used as the SiC particles. Thereafter, in the same manner as in Example 1, the SiC molded body was impregnated with Si to produce a SiSiC member. 〈Example 3〉 A SiC formed body was produced in the same manner as in Example 1, except that α-SiC powder with an average particle diameter of 50 μm was used as the SiC particles. Thereafter, in the same manner as in Example 1, the SiC molded body was impregnated with Si to produce a SiSiC member.

〈Example 4〉 According to the method described in Example 1 ([0068] to [0069]) of Patent Document 1, a SiC molded body was produced. Thereafter, in the same manner as in Example 1, the SiC molded body was impregnated with Si to produce a SiSiC member.

〈Example 5〉 According to the method described in Example 1 of Patent Document 2 (pages 13 to 18), a SiC molded body was produced. Thereafter, in the same manner as in Example 1, the SiC molded body was impregnated with Si to produce a SiSiC member.

〈Example 6〉 According to the method described in Example 1 ([0054] to [0060]) of Patent Document 3, a SiC molded body was produced. Thereafter, in the same manner as in Example 1, the SiC molded body was impregnated with Si to produce a SiSiC member.

In the above manner, the SiSiC members (heat dissipation members) of Examples 1 to 6 were obtained.

<Various physical properties> For the SiSiC members of Examples 1 to 6, the expansion coefficient, thermal conductivity, SiC content, average particle size of SiC, four-point bending strength, density and surface area increase rate (S ₁ / _S2 ). Furthermore, the cross-sectional area C _P (average value) of the protruding portion and the maintenance rate of the height H of the protruding portion were measured according to the following method. Furthermore, regarding the SiSiC members of Examples 1 to 4, the heat dissipation amount of each member was evaluated through heat dissipation simulation. The physical property measurement and simulation results are shown in Table 1 below. Regarding Example 1, the surface roughness (Sa) of the protruding portion was measured using a laser microscope (VK-X1000 manufactured by Keyence Corporation). The result was 9.4 μm. In addition, when the physical property values are not measured, "-" is recorded in Table 1 below. "Unmeasurable" in the table means that the shape deformation of the protrusion can be visually confirmed.

The average value of the cross-sectional area C _P of the protrusions is determined by randomly selecting 25 protrusions among the plurality of protrusions formed on the SiSiC member, measuring the cross-sectional area C _P of each, and calculating the average value. average value. The maintenance rate of the height H of the protrusion is determined by the following method. First, 25 protrusions were randomly selected from a plurality of protrusions formed on the SiSiC member. Then, for each of the 25 protrusions, the ratio of the height of the actually produced protrusion to the height set by the 3D printer (6 mm) (actual height/set height) was found, and 25 The maintenance rate of the height H of the protrusion is determined by the ratio of the protrusions in which the above-mentioned height ratio of the root protrusion is within the specified range (0.95 to 1.05). In the measurement of the surface area increase rate (S ₁ /S ₂ ), the surface area increase rate in Example 4 using the slurry casting method to produce a SiC molded body was 1.22. The surface area increase rates of Example 5 using the slurry casting method and Example 6 using the slurry extrusion method were judged to be significantly less than 1.3 based on the shapes of the protrusions that could be visually confirmed. The simulation of heat dissipation is obtained as follows: using simulation software (Simcenter STAR-CCM+ 2020.1 (Build 15.02.007-R8)), setting the temperature of the semiconductor device side of the SiSiC component to 150°C, and setting the protruding portion The heat transfer coefficient is set to 10000 W/(m ² ･K), and the calculation is performed assuming water cooling.

[Table 1] Table 1 example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Manufacturing method of SiC molded body 3D printing method Method described in Patent Document 1 (Example 1) Method described in Patent Document 2 (Example 1) Method described in Patent Document 3 (Example 1) thermal expansion coefficient [ppm/K] 3.39 3.39 3.39 3 6 4.2 thermal conductivity [W/(m･K)] 169 178 184 - 150 100 SiC content [Volume%] 40 40 40 - 50 77 Average particle size of SiC [μm] 10 30 50 38 30 20 4 point bending strength [MPa] 300 190 170 - - - density [g/cm ³ ] 2.66 2.64 2.67 - - - The average value of the cross-sectional area C _P of the protrusion [mm ² ] 3.14 3.14 3.14 Unable to measure Unable to measure Unable to measure Surface area increase rate S ₁ /S ₂ - 3.18 3.15 2.81 1.22 Obviously less than 1.3 Obviously less than 1.3 The maintenance ratio of the height H of the protrusion (actual height/set height) is a ratio of the protrusion of 0.95 to 1.05 [%] 100% 84% 64% 0～10% 0～10% 0～10% Heat dissipation simulation results [W] 183 188 179 89 - -

〈Summary of evaluation results〉 As shown in Table 1 above, compared with the SiSiC members of Examples 4 to 6, the SiSiC members of Examples 1 to 3 have good heat dissipation properties, as indicated by the height H maintenance rate, and have high heat dissipation properties. It is shown that the heat dissipation fins of the heat dissipation member according to the embodiment of the present invention have excellent performance. Furthermore, the entire contents of the specification, patent scope, drawings and abstract of Japanese Patent Application No. 2022-80009 filed on May 16, 2022 are quoted here and adopted as the disclosure content of the specification of the present invention.

1:Semiconductor module 2: Semiconductor components 3: Insulating substrate 4: Conductor circuit 5: Solder layer 6: Wire 7:Metal layer 8: Solder layer 11: Heat dissipation component (SiSiC component) 12:Heating plate 13:Heat sink 14:Protrusion 15: Bottom surface of the protrusion 16: Side of the protrusion 17: Front of heat sink 18:The back of the heat sink 19: Side of heat sink

FIG. 1 is a schematic cross-sectional view of a semiconductor module. FIG. 2 is a perspective view of a heat dissipation member equipped with a protruding portion.

1:Semiconductor module

2: Semiconductor components

3: Insulating substrate

4: Conductor circuit

5: Solder layer

6: Wire

7:Metal layer

8: Solder layer

11: Heat dissipation component (SiSiC component)

12:Heating plate

13:Heat sink

14:Protrusion

17: Front of heat sink

18:The back of the heat sink

19: Side of heat sink

Claims (10)

A heat dissipation component for semiconductor modules, which is a SiSiC component and has: A heat dissipation plate, which is provided with semiconductor components and insulating substrates on one side; and The heat sink is integrally formed with the above heat sink plate. The heat dissipation component of claim 1, wherein the heat dissipation fins are provided with a plurality of protrusions protruding from the heat dissipation plate. The heat dissipation member of claim 2, wherein the number of the protrusions per unit area of the front surface of the heat dissipation plate is 1/cm ² or more. The heat dissipation member of claim 2, wherein the cross-sectional area C _P of one of the protrusions when cut along the front of the heat dissipation plate is 1 to 100 mm ² . The heat dissipation member of claim 2, wherein the surface area increase rate is 1.3 or more, wherein the surface area increase rate is obtained by dividing the surface area S ₁ of the heat dissipation member with the protrusion by the case where the protrusion is not provided. The value obtained from the surface area S ₂ of the above-mentioned heat dissipation member. For example, the heat dissipation component of any one of claims 1 to 5, wherein the average linear expansion coefficient at 30 to 300°C is 2 to 5 ppm/K. For example, the heat dissipation component of any one of claims 1 to 5, with a thermal conductivity of 150 W/(m･K) or more. The heat dissipation component of any one of claims 1 to 5, wherein the SiC content is less than 90% by volume. The heat dissipation member according to any one of claims 1 to 5, wherein the average particle size of SiC is in the range of 2 to 100 μm. A semiconductor module having a heat dissipation member according to any one of claims 1 to 5.