JP6710083B2 - Heat radiating member, power semiconductor module, and LED package - Google Patents

Description

The present invention relates to a heat radiation member, and a power semiconductor module and an LED package including the heat radiation member.

2. Description of the Related Art In recent years, with higher performance and smaller size of electric devices and electronic devices, electronic components such as semiconductor elements tend to be highly integrated and highly densified. When electronic components are highly integrated and highly densified, power consumption generally increases and heat generation also increases. The heat generated inside the electronic component may cause problems such as deterioration and malfunction of the electronic component. Therefore, a heat countermeasure member such as a heat sink is used for the electronic component as a heat countermeasure.

For example, the applicant of the present application discloses in Patent Document 1 that the alumina content is 95.0% by weight or more and the thermal emissivity is 0.93 to 0.98 and the thermal conductivity is 30 to 60 W/m·K. We have proposed a ceramic radiant solid material. Further, the present applicant proposes, in Patent Document 2, a ceramic for a heat radiating member, which is a sintered body of alumina having a feature that the content of alumina is 99.5 mass% or more.

JP 2006-298703 A International Publication No. 2011/152363

Among semiconductor elements, light emitting diode (LED) elements and power semiconductor elements can be said to generate a relatively large amount of heat. Therefore, a heat countermeasure member having excellent heat dissipation is required for substrates and devices on which they are mounted. is necessary.

A power semiconductor used for controlling and supplying electric power to lighting equipment including an LED element, a solar power generation device, an automobile (hybrid vehicle/electric vehicle), an electric train, a power transmission system, a production facility, a household electric appliance, and the like. Industrial equipment equipped with an element is required to have a higher-performance heat radiation member because of an increase in heat generation amount.

Therefore, the present invention is intended to provide a heat radiating member having further excellent heat radiation performance.

The present invention provides a plate-shaped portion made of alumina ceramics having an alumina content of 99.0% by mass or more and at least a flat surface having curved polishing marks on the surface arranged on the heat source side. A heat radiation member is provided.

According to the present invention, it is possible to provide a heat radiating member having further excellent heat dissipation performance.

It is a figure for demonstrating the structure of the heat radiation member which concerns on one Embodiment of this invention, and is a schematic diagram showing the side surface of the heat radiation member. It is a figure for demonstrating the structure of the heat radiation member which concerns on one Embodiment of this invention, and is a schematic diagram showing the cross section of the heat radiation member provided with the fixing member of an example. It is a figure for demonstrating the structure of the heat radiation member which concerns on one Embodiment of this invention, and is a schematic diagram showing the side surface of the heat radiation member provided with the fixing member of another example. It is a top view showing a schematic structure of a case-shaped heat radiation member concerning one embodiment of the present invention. It is the sectional view on the AA line of FIG. It is sectional drawing corresponding to FIG. 5 showing the schematic structure of the case-shaped heat radiation member which concerns on another embodiment of this invention. It is a schematic diagram showing the side surface of one structural example of the power semiconductor module which concerns on one Embodiment of this invention. It is a schematic diagram showing the side surface of another one structural example of the power semiconductor module which concerns on one Embodiment of this invention. It is a schematic diagram showing the side surface of another example of a structure of the power semiconductor module which concerns on one Embodiment of this invention. It is sectional drawing corresponding to FIG. 5 showing the example of 1 structure of the LED package which concerns on one Embodiment of this invention. It is a conceptual diagram showing the measuring method of the heater surface temperature used for evaluation of heat dissipation in an Example. It is a schematic diagram for explaining a warp measuring method, and is a diagram showing a state in which 0 is set. It is a schematic diagram for explaining the method of measuring the warp, and is a diagram showing a state in which the distance (height) from the surface of the surface plate to the surface of the warped portion of the measured object at the highest position is measured. It is a schematic diagram for explaining the measuring method of the warp, and is a diagram showing a state in which the distance (height) from the surface of the surface plate to the surface of the portion of the object to be measured that is in contact with the surface of the surface plate is measured. ..

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

In the heat radiating member of one embodiment of the present invention, the content of alumina is 99.0 mass% or more, and at least the surface arranged on the heat source side is formed with a flat surface having curved polishing marks. A plate-shaped portion made of alumina ceramics is provided. The plate-shaped portion constitutes a plate-shaped portion in the heat radiation member. The plate-shaped portion can be formed of, for example, an alumina ceramic plate, and also has a shape having a bent portion or a wall portion rising from the plate-shaped portion, and an alumina ceramic material formed in a three-dimensional shape such as a case. It is also possible to configure it with a plate-shaped portion that is a part of the. Hereinafter, the heat radiation member of the present embodiment will be described by taking as an example a heat radiation member including an alumina ceramics plate forming a plate-shaped portion.

<Heat radiation member>
[Alumina ceramic plate]
The inventors of the present invention have made earnest studies on an alumina ceramics plate having further excellent heat dissipation performance. As a result, between the surface of the alumina ceramics plate disposed on the heat source side and the member (contacted member) with which the surface contacts We paid attention to the fact that it becomes difficult for heat to transfer when there are voids. Then, the inventors of the present invention considered that it is important not to generate a void as much as possible between the surface of the alumina ceramic plate arranged on the heat source side and the contacted member. Therefore, the present inventors have made the surface of the alumina ceramic plate, which is arranged at least on the heat source side, a flat surface having curved polishing marks so as to be in contact with the surface of the alumina ceramic plate which is arranged on the heat source side. It has been found that a gap is less likely to be formed between the member and the heat radiating member having a further excellent heat radiation performance. Further, as a result of the study by the present inventors, in the case where a flat surface having a curved polishing mark is formed on the surface of the alumina ceramic plate which is arranged on the heat source side, a linear polishing mark is formed on the surface. It has been found that the above-mentioned voids are much less likely to occur as compared with the case where the flat surface is formed.

That is, in the heat radiating member according to one embodiment of the present invention, the content of alumina is 99.0 mass% or more, and a flat surface having a curved polishing mark is formed on at least the surface arranged on the heat source side. The alumina ceramic plate (a plate portion made of alumina ceramics) is provided.

In the heat radiating member of the present embodiment, the alumina ceramic plate may be used alone as the heat radiating member or may be used as the heat radiating member combined with other members. Examples of suitable other members include, for example, a plate-shaped member having a thermal conductivity higher than that of the alumina ceramics plate (hereinafter, may be referred to as “high thermal conductivity plate-shaped member”). You can Examples of the plate member having high thermal conductivity include a copper plate, an aluminum plate, and an aluminum nitride ceramics plate. Further, as another suitable member, a member (frame member made of alumina ceramics) formed of alumina ceramics in a frame shape can be cited.

When the heat radiating member of the present embodiment is used, the flat surface of the alumina ceramic plate may directly contact the heat source (heating element). Further, the flat surface of the alumina ceramic plate has a higher thermal conductivity than that of an alumina ceramic plate such as an aluminum nitride ceramic plate (hereinafter, also referred to as “AlN ceramic plate”) described later. The heat source may be provided in contact with the highly heat-conductive plate-shaped member that is provided and via the high heat-conductive plate-shaped member. Further, the flat surface of the alumina ceramics plate may directly contact the frame member made of alumina ceramics at the outer peripheral side portion thereof, and the heat source (heating element) or the high thermal conductive plate-shaped member at the inner peripheral side of the frame member. May be in direct contact with. Therefore, as the above-mentioned contacted member, in addition to the heat source, for example, the above-mentioned highly heat-conductive plate-shaped member and the frame member made of alumina ceramics can be cited.

The alumina ceramic plate that constitutes the plate-shaped portion included in the heat radiating member of the present embodiment has a content of alumina of 99.0 mass% or more, and therefore has a relatively high thermal conductivity and thermal emissivity among the alumina ceramics. Can have. A flat surface having curved polishing marks is formed on at least the heat source side of the alumina ceramics plate, so that the alumina ceramics plate causes the alumina ceramics plate to contact the contacted member on the heat source side ( Good adhesion to a heat source or an AlN ceramics plate). Thereby, the heat from the heat source side is efficiently transmitted to the alumina ceramic plate, and due to the high heat radiation performance of the alumina ceramic plate, the heat can be converted into infrared rays and emitted from the surface. Therefore, the heat radiating member according to the present embodiment has further excellent heat dissipation performance.

The flat surface having curved polishing marks formed on at least the heat source side of the alumina ceramics plate can be obtained by polishing the surface of the alumina ceramics plate by a rotary polishing method. From this point of view, the flat surface having the curved polishing marks can be said to be the flat surface having the rotary polishing marks. By adjusting the degree of polishing by this rotary polishing method, it is possible to adjust the arithmetic mean roughness Ra and the warp described later on the surface of the alumina ceramics plate. In addition, the flat surface having the curved polishing marks may be provided on at least a portion of the surface of the alumina ceramics plate that is disposed on the heat source side, which is in contact with the contacted member, and is provided on a part of the surface. Although it may be provided, it is preferably provided on the entire surface.

In the heat radiating member of the present embodiment, a flat surface having curved polishing marks may be formed on the surface of the alumina ceramic plate opposite to the surface arranged on the heat source side. The alumina ceramic plate may have a flat plate shape having the above-mentioned flat surfaces on both sides, or a shape having unevenness or a curved surface on the surface opposite to the surface arranged on the heat source side. It is preferable to have a flat plate shape. The plan-view shape of the alumina ceramics plate is not particularly limited, and may be a shape suitable for the heat source, and examples thereof include a circular shape and a rectangular shape.

The present inventors have made an alumina ceramic plate having a specific warp described later so that a large gap is not generated between the surface of the alumina ceramic plate arranged on the heat source side and the contacted member, and the alumina ceramic plate It was found that the heat radiation member more effective as a heat countermeasure member for the heat source can be obtained by making the flat surface having the curved polishing mark in 1) a flat surface having a specific surface roughness described later.

That is, the alumina ceramic plate (plate-shaped portion) has a warp of 200 μm or less, and the arithmetic mean of the flat surface (hereinafter, simply referred to as “alumina ceramic plate flat surface”) arranged on the heat source side. The roughness Ra is preferably 1.0 μm or less. As a result, it is possible to further enhance the effect of heat radiation described above, and it becomes more effective as a heat countermeasure member for the heat source. If the warp of the alumina ceramic plate exceeds 200 μm or Ra of the flat surface of the alumina ceramic plate exceeds 1.0 μm, the flat surface of the alumina ceramic plate and the contacted member (heat source, AlN ceramic plate, etc.) Voids are likely to occur, which may cause a loss of heat conduction, which may result in a lower emissivity.

In the present specification, the “warp” can be measured using a micrometer by placing an object to be measured (alumina ceramic plate or the like) on a surface plate. Specifically, the distance (height) from the surface plate to the surface of the highest part of the DUT and the distance (height) from the surface plate to the surface of the part in contact with the surface are It can be measured with a micrometer and can be determined from the difference between them. In the present specification, the “arithmetic mean roughness Ra” of the flat surface is the arithmetic mean roughness Ra measured according to the regulation of JIS B 0601:2013. The arithmetic average roughness Ra can be measured by, for example, a surface roughness measuring device or an image measuring device. In the present specification, the lower the warpage and the arithmetic average roughness Ra, the higher the flatness of the flat surface. Therefore, the lower limit of the warpage and Ra is not particularly limited, but the warpage is 1 μm or more in manufacturing. Ra may be 0.01 μm or more.

The warp of the alumina ceramic plate (plate-shaped portion) is more preferably 150 μm or less, and further preferably 100 μm or less. When the warp of the alumina ceramics plate is 150 μm or less, the alumina ceramics plate is easily adhered to the contacted member, and it is difficult to form a gap between the flat surface of the alumina ceramics plate and the contacted member. Therefore, the effect of heat radiation can be further enhanced, and the heat radiation member can be made more effective as a heat countermeasure member for the heat source.

The arithmetic mean roughness Ra of the flat surface of the alumina ceramics plate (plate-shaped portion) is more preferably 0.6 μm or less, and further preferably 0.4 μm or less. Even if the arithmetic mean roughness Ra of the flat surface of the alumina ceramic plate is 0.6 μm or less, the alumina ceramic plate easily adheres to the non-contact member, and a gap is formed between the flat surface of the alumina ceramic plate and the contacted member. Is unlikely to occur. Therefore, the effect of heat radiation can be further enhanced, and the heat radiation member can be made more effective as a heat countermeasure member for the heat source.

From the viewpoint that the flat surface of the alumina ceramic plate and the contacted member are more closely contacted with each other and voids are less likely to be formed between them, the alumina ceramic plate has a warp of 100 μm or less and an arithmetic mean roughness Ra of the flat surface. It is more preferably 0.5 μm or less.

The thickness of the alumina ceramics plate is preferably 0.5 to 10 mm, more preferably 0.5 to 8 mm, from the viewpoint of converting heat generated from a heat source into infrared rays to be emitted from the surface and from the viewpoint of strength. , And more preferably 1 to 6 mm. The thickness of the alumina ceramic plate is preferably 0.5 mm or more, more preferably 1 mm or more, further preferably 2 mm or more. The thickness of the alumina ceramic plate is preferably 10 mm or less, more preferably 8 mm or less, and further preferably 6 mm or less.

A commercially available alumina ceramic plate can also be used for the heat radiation member of the present embodiment. The characteristics and manufacturing method of the alumina ceramics plate that can be preferably used for the heat radiation member will be described in more detail.

The alumina ceramic plate is a high-purity alumina sintered body in which the content of alumina (Al ₂ O ₃ ) is 99.0 mass% or more. The content of alumina in the alumina ceramic plate is preferably 99.5% by mass or more, and more preferably 99.7% by mass or more, from the viewpoint of having high thermal conductivity and thermal emissivity. In the composition of the alumina ceramic plate, the balance other than alumina is a substance derived from a sintering aid or unavoidable impurities. The alumina ceramics plate may contain, as the balance other than alumina, one or more elements derived from the sintering aid. Examples of the sintering aid include Mg(OH) ₂ , MgO, SiO ₂ , Na ₂ O, Fe ₂ O ₃ , CaO and the like. The total of the balance is preferably 1.0% by mass or less, more preferably 0.5% by mass or less, still more preferably 0.3% by mass or less.

From the viewpoint of having high thermal conductivity and thermal emissivity, and from the viewpoint of having high mechanical strength, the alumina ceramics plate preferably has crystal grains with a grain size of 1 to 10 μm, and the average value of the crystal grain size is It is preferably 2 to 7 μm. Further, an alumina ceramics plate containing such crystal grains in an area of 30×20 μm in a range of 30 to 55 is preferable. In the present specification, the crystal grain size and the number of crystal grains can be confirmed by observation with a scanning electron microscope (SEM).

The crystalline alumina ceramic plate as described above is suitable because it has a dense structure. The density of the alumina ceramic plate is preferably 3.8 g / cm ³ or more, more preferably 3.93 g / cm ³ or more, further preferably 3.96 g / cm ³ or more. In this specification, the density value is a value calculated by the Archimedes method.

By using the alumina ceramic plate having the above-mentioned suitable alumina content, crystal grains, and density, the thermal conductivity at 25°C is 33 W/m·K or more, and the thermal emissivity at 100°C is 0.90 or more. The alumina ceramic plate can be used. The alumina ceramics plate having such high thermal conductivity and thermal emissivity can be obtained by adjusting the alumina powder raw material used for producing the alumina ceramics plate, the sintering aid added, the firing temperature, and the like. .. The thermal conductivity of the alumina ceramic plate at 25° C. is more preferably 36 W/m·K or more, and the thermal emissivity at 100° C. is more preferably 0.95 or more. In this specification, the value of the thermal conductivity is a value determined from the measurement of the thermal conductivity by the laser flash method, which is defined by JIS R 1611:2010. Further, in the present specification, the value of the thermal emissivity is a value obtained by measuring the temperature rise on the surface of the heating element by the heating plate method.

By having the above-mentioned preferable alumina content, crystal grains, and density, an alumina ceramic plate having excellent mechanical strength can be obtained. As such an alumina ceramic plate having excellent mechanical strength, specifically, an alumina ceramic plate having a bending strength at a temperature of 25° C. in the range of 300 to 500 MPa is preferable. In this specification, the value of bending strength is a value obtained by a three-point bending test specified in JIS R 1601:2008.

The alumina ceramic plate preferably has excellent insulating properties. Specifically, the volume resistivity of the alumina ceramic plate at a temperature of 25° C. is preferably larger than 1.0×10 ¹⁴ Ω·cm. In the present specification, the volume specific resistance value is a value measured by using an insulation resistance meter.

(Method of manufacturing alumina ceramic plate)
The above-mentioned suitable alumina ceramics plate includes a firing step of heating a plate-shaped compact containing alumina and firing at a predetermined firing temperature to obtain a sintered body, and an alumina sintered body obtained by the firing step (alumina It can be manufactured by a manufacturing method including a polishing step of polishing the surface of a sintered plate). In this manufacturing method, it is preferable to include a molding step of pressure-forming a raw material containing alumina to obtain a plate-shaped molded body before the firing step. Before the molding step, a raw material powder containing alumina powder is added. It is more preferable to include a granulation step of forming a granule. Further, in the molding step, it is preferable to pressure-mold a raw material containing alumina granules, and the raw material containing alumina granules obtained in the granulating step can be used.

In the granulation step and molding step, it is preferable to use alumina powder or alumina granules having an alumina content of 99.0% by mass or more, preferably 99.5% by mass or more, more preferably 99.7% by mass or more. You can Further, in the granulating step, alumina powder having an average particle diameter of 0.2 to 1 μm can be preferably used as a raw material powder. The average particle diameter is a value measured by a laser diffraction/scattering type particle size distribution measuring device. As the alumina powder, publicly available known ones can be used, and for example, α-alumina powder obtained by the Bayer method, alumina powder obtained by the sol-gel method, and the like can be used. Further, it is preferable to add the above-mentioned sintering aid to the raw material.

In the granulating step, it is preferable to make the above-mentioned alumina powder used as the raw material powder into granules of 50 to 100 μm. The method of granulation is not particularly limited, but for example, by adding an organic binder as described below to alumina powder to form a slurry, and then spraying and drying the granules for molding having a particle size of 50 to 100 μm. Can be easily obtained. The granules thus obtained will be spherical. Further, by granulating, the handling property of the alumina powder raw material composed of fine particles can be improved, which is advantageous in production.

As a suitable method of pressure molding in the molding step, a method of applying a predetermined molding pressure using a mold to produce a molded body (dry mold molding) can be mentioned. The molding pressure is preferably 1,000 kg/cm ² or more so that a dense molded body having a density of 2.40 g/cm ³ or more can be obtained, and cracking or damage occurs in the molded body. In order not to occur, it is preferably 2,500 kg/cm ² or less. The density of the molded product is calculated from the mass of the molded product and the volume obtained from the measured dimensions of the molded product. Further, the method for producing the molded body is not limited to the dry mold molding, and examples thereof include cold isostatic pressing (CIP), hot pressing (HP), hot isostatic pressing (HIP), injection molding, and casting molding. , Extrusion molding, doctor blade method (tape molding) and the like may be used.

As the organic binder that can be used in the above-mentioned granulation step and molding step, any of those conventionally used in the production of ceramics can be used. Specifically, in the firing step, it is possible to use an organic compound which has a characteristic that it melts at the time of heating the molded body and exhibits appropriate viscosity, and does not remain after firing to give a sintered body. Examples of such organic compounds include polyvinyl alcohol, polyesters, acrylic resins, cellulose derivatives, and polyethers. When the organic binder is used in the production of the alumina ceramic plate, it is preferable to include a degreasing step of removing the organic binder from the molded body.

In the firing step, the molded body obtained in the molding step can be heated in an air atmosphere (in an oxidizing atmosphere) and fired at a predetermined firing temperature. The firing temperature is preferably 1,480 to 1,600° C., and more preferably 1,500 to 1,600° C. in order to obtain an alumina ceramics plate having excellent heat radiation properties. The firing time at the firing temperature is preferably about 0.5 to 4 hours, more preferably about 1 to 2 hours. Further, it is preferable that the firing in the firing step is performed in a batch type furnace in which air is circulated. Further, after the firing step, it is preferable to have a cooling step in which the fired product is rapidly cooled at a rate 1.3 to 2.0 times the heating rate up to the firing temperature to obtain a sintered body.

Further, in the method for producing an alumina ceramic plate, it is preferable that after the firing step, a polishing step of polishing the surface of the alumina sintered body (alumina ceramic plate) obtained in the firing step is included. In this polishing step, at least one surface of the alumina sintered body, which is the bonding surface, may be polished, or both surfaces may be polished. As the polishing method, rotary polishing is more preferable. By rotationally polishing the surface of the alumina sintered body, it is possible to obtain an alumina ceramics plate having a flat surface having the above-mentioned curved polishing marks.

[Heat radiation member provided with aluminum nitride ceramics plate]
It is preferable that the heat radiation member of one embodiment of the present invention further includes an aluminum nitride ceramics plate provided on the surface of the plate-shaped portion that is arranged on the heat source side. This aluminum nitride ceramics plate has flat surfaces having curved polishing marks on both sides, and is bonded to the alumina ceramics plate in a state where the flat surface of the aluminum nitride ceramics plate and the flat surface of the alumina ceramics plate are in direct contact with each other. There is.

As an example of one aspect of the heat radiating member including the AlN ceramic plate, the heat radiating member 10 including the alumina ceramic plate 20 as the flat plate-shaped portion and the flat AlN ceramic plate 30 as shown in FIG. The structure of the heat radiation member will be further described. In the drawings, components common to the drawings are given the same reference numerals and the description thereof may be omitted.

The heat radiating member 10 shown in FIG. 1 includes the above-mentioned alumina ceramic plate 20 in which a flat surface 20a having curved polishing marks is formed on the surface 20a arranged on the heat source 50 side, and the flat surface of the alumina ceramic plate 20. And an AlN ceramic plate 30 provided on 20a. Flat surfaces having curved polishing marks are formed on both sides 30a, 30b of the AlN ceramics plate 30, and the alumina ceramics plate 20 and the AlN ceramics plate 30 are in a state where the flat surfaces 20a, 30a are in direct contact with each other. Are joined together. A surface 20b opposite to the surface 20a arranged on the heat source 50 side of the alumina ceramic plate 20 is also a flat surface 20b on the whole surface, and the flat surface 20b may be a flat surface having a curved polishing mark. ..

The AlN ceramics plate 30 has a flat plate shape, and includes flat surfaces (hereinafter, simply referred to as “a flat surface of the AlN ceramics plate”) 30a and 30b having curved polishing marks on both surfaces. Since the AlN ceramics plate 30 has the flat surfaces 30a and 30b having curved polishing marks on both sides, the flat surface 20a of the alumina ceramics plate 20 and the flat surface 30a of the AlN ceramics plate 30 interfere with each other, and the joining surfaces thereof are joined together. It is possible to further improve the adhesiveness of the above, and it is also possible to adhere well to the heat source (heat generating body) 50. The flat surfaces 30a and 30b having curved polishing marks formed on both surfaces of the AlN ceramics plate 30 are also obtained by polishing both surfaces of the AlN ceramics plate by rotary polishing, similarly to the flat surface 20a of the alumina ceramics plate 20. be able to.

The plan view shape of the AlN ceramics plate 30 is not particularly limited, and may be a shape corresponding to the heat source, and examples thereof include a circular shape and a rectangular shape. The external dimensions of the AlN ceramics plate 30 may be the same as or different from the external dimensions of the alumina ceramics plate 20.

In the heat radiation member 10 including the alumina ceramic plate 20 and the AlN ceramic plate 30, the flat surface 30a of the AlN ceramic plate 30 and the flat surface 20a of the alumina ceramic plate 20 are in direct contact with each other without an adhesive or the like. .. Therefore, when the heat radiating member 10 is provided by bringing the heat source (heat generating body) 50 into contact with the AlN ceramic plate 30 side, the heat generated from the heat source 50 is quickly generated by the high thermal conductivity of the AlN ceramic plate 20. It can be transmitted to the ceramic plate 20. Then, the alumina ceramics plate 20 can absorb the heat transmitted by the AlN ceramics plate 30, and due to the high heat radiation performance of the alumina ceramics plate 20, the heat can be converted into infrared rays and emitted from the surface. As described above, by combining two types of heat transfer methods, that is, heat conduction by the AlN ceramics plate 30 arranged on the heat source 50 side and radiation by the alumina ceramics plate 20 arranged on the AlN ceramics plate 30, The heat from the heat source 50 can be effectively released. With this heat radiating member 10, it is possible to continuously perform the operation of radiating heat due to heat transfer as described above, without interruption. From such an action and effect, in the heat radiation member 10, it is preferable to dispose the AlN ceramic plate 30 on the heat source 50 side.

(Fixing member)
As shown in FIGS. 2 and 3, the heat radiation member 10 (10A, 10B) may include a fixing member 40 (41, 42) that joins the alumina ceramic plate 20 and the AlN ceramic plate 30. Since the alumina ceramics plate 20 and the AlN ceramics plate 30 are joined by the fixing member 40 in a state where the flat surface 20a of the alumina ceramics plate 20 and the flat surface 30a of the AlN ceramics plate 30 are in direct contact with each other, both ceramics plates It is possible to make the flat surfaces 20a and 30a more closely contact the flat surfaces 20 and 30.

The type of the fixing member 40 is not particularly limited, and is not limited to the form shown in FIGS. 2 and 3. Suitable fixing members 40 may include, for example, screws, bolts, nuts, screws, pins, washers, aluminum foil tapes, adhesive tapes, springs and the like. As the fixing member 40, one kind or two or more kinds may be used. The fixing member 40 joins the alumina ceramic plate 20 and the AlN ceramic plate 30 by applying pressure from the viewpoint of further adhering the flat surface 20a of the alumina ceramic plate 20 and the flat surface 30a of the AlN ceramic plate 30 to each other. Is preferred. In this case, the surface pressure of one fixing member 40 is preferably 0.8 N/mm ² or more, and more preferably 1.0 to 1.2 N/mm ² .

As shown in FIG. 2, when a screw, a bolt, a nut, a screw, a pin, or the like is used as the fixing member 41, the alumina ceramic plate 20 and the AlN ceramic plate 30 each have a through hole 20c into which the fixing member 41 can be inserted. , 30c are preferable. Although not shown, the fixing member 41 for joining the alumina ceramics plate 20 and the AlN ceramics plate 30 may be fixed to the target member to which the heat radiation member 10A is attached. Further, the heat radiation member 10A may be attached to the target member by using a fixing member different from the fixing member 41 that joins the alumina ceramics plate 20 and the AlN ceramics plate 30. As for the fixing member other than the fixing member 41, the one exemplified above can be used similarly to the fixing member 40.

As shown in FIG. 3, when a tape-shaped fixing member 42 such as an aluminum foil tape or an adhesive tape is used as the fixing member 42, the tape-shaped fixing member 42 is a surface of the alumina ceramic plate 20 opposite to the heat source side. It is preferable that the heat radiating member 10 is provided so as to extend from 20b to the heat source side surface 30b of the AlN ceramic plate 30.

From the viewpoint of ensuring a contact surface between the heat source to which the heat radiating member 10 is applied and the heat radiating member 10 (AlN ceramics plate 30), the fixing member 40 is provided at the end side of the alumina ceramics plate 20 and the AlN ceramics plate 30 ( The outer peripheral side) is preferable. The number of fixing members 40 used for joining the alumina ceramics plate 20 and the AlN ceramics plate 30 is not particularly limited. Depending on the shapes of the alumina ceramic plate 20 and the AlN ceramic plate 30, the number of fixing members 40 that can stably bond them can be used. For example, when the alumina ceramics plate 20 and the AlN ceramics plate 30 are rectangular flat plates, the four fixing members 40 can be provided at the portions corresponding to the four corners of the rectangular shape in plan view.

In order to make it difficult for the above-mentioned voids to occur between the flat surface 20a of the alumina ceramic plate 20 and the flat surface 30a of the AlN ceramic plate 30, and between the flat surface 30b of the AlN ceramic plate 30 and the heat source (heating element) 50. In addition, it is preferable that the flat surfaces 30a and 30b of the AlN ceramics plate 30 also have specific warpage and surface roughness.

It is preferable that the AlN ceramics plate 30 has a warp of 200 μm or less and an arithmetic mean roughness Ra of the flat surfaces 30a and 30b of 1.0 μm or less. Thereby, the flat surface 30a of the AlN ceramics plate 30 and the flat surface 20a of the alumina ceramics plate 20, and the flat surface 30b of the AlN ceramics plate 30 and the heat source 50 can be more closely adhered. Then, the heat generated from the heat source 50 can be efficiently transmitted to the alumina ceramic plate 20.

The warp of the AlN ceramics plate 30 is more preferably 150 μm or less, and further preferably 100 μm or less. Since the warp of the AlN ceramics plate 30 is 150 μm or less, the AlN ceramics plate 30 is more likely to be in close contact with both the alumina ceramics plate 20 and the heat source 50, and a void is unlikely to form between them. Therefore, the heat dissipation performance of the heat radiating member 10 can be further enhanced, and the heat radiating member 10 can be made more effective as a heat countermeasure member for the heat source 50.

The arithmetic mean roughness Ra of the flat surfaces 30a and 30b of the AlN ceramics plate 30 is more preferably 0.6 μm or less, and further preferably 0.4 μm or less. The fact that the arithmetic mean roughness Ra of the flat surfaces 30a, 30b of the AlN ceramics plate 30 is 0.6 μm or less also makes it easier to adhere to both the alumina ceramics plate 20 and the heat source 50, and a void is generated between them. hard. Therefore, the heat dissipation performance of the heat radiating member 10 can be further enhanced, and the heat radiating member 10 can be made more effective as a heat countermeasure member for the heat source 50.

From the viewpoint that the flat surface 30a of the AlN ceramic plate 30 and the flat surface 20a of the alumina ceramic plate 20 are more closely adhered to each other and voids are less likely to occur between the flat surfaces, the AlN ceramic plate 30 has a warp of 100 μm or less. It is more preferable that the flat surface 30a has an arithmetic average roughness Ra of 0.5 μm or less.

The AlN ceramics plate 30 preferably has a thickness of 10 mm or less, more preferably 8 mm or less, and further preferably 6 mm or less in order to efficiently transfer the heat generated from the heat source 50 to the alumina ceramics plate 20. .. On the other hand, the thickness of the AlN ceramics plate 30 is preferably 0.5 mm or more, and more preferably 1 mm or more, from the viewpoint of strength. The total thickness of the AlN ceramics plate 30 and the alumina ceramics plate 20 is preferably 15 mm or less, and more preferably 12 mm or less.

A commercially available AlN ceramic plate 30 may be used for the heat radiation member 10 of the present embodiment. The characteristics and manufacturing method of the AlN ceramics plate 30 that can be preferably used for the heat radiation member 10 will be described in more detail.

The AlN ceramics plate 30 is a sintered body of aluminum nitride. The content of aluminum nitride (hereinafter sometimes referred to as “AlN”) in the AlN ceramic plate 30 is preferably 90% by mass or more, and more preferably 95% by mass or more. In the composition of the AlN ceramics plate 30, the balance other than AlN is an element derived from sintering aids (oxides of rare earth elements and oxides of alkaline earth metals) or unavoidable impurities, mainly O and Y. And so on. The total of the balance is preferably 10% by mass or less, more preferably 5% by mass or less.

Since it is preferable that the AlN ceramics plate 30 has a dense structure, the density of the AlN ceramics plate 30 is preferably 3.2 g/cm ³ or more, more preferably 3.3 g/cm ³ or more. ..

As the AlN ceramics plate 30, an AlN ceramics plate 30 having a thermal conductivity of 80 W/m·K or more at a temperature of 25° C. is preferable so that heat generated from the heat source 50 can be rapidly dispersed and transferred to the alumina ceramics plate 20. .. The thermal conductivity of the AlN ceramics plate 30 at a temperature of 25° C. is more preferably 150 W/m·K or more, still more preferably 170 W/m·K or more.

The AlN ceramics plate 30 preferably has a bending strength in the range of 300 to 600 MPa at a temperature of 25° C. from the viewpoint of mechanical strength. Since the AlN ceramics plate 30 preferably has excellent insulating properties in the applications described below, the volume resistivity of the AlN ceramics plate 30 at a temperature of 25° C. is larger than 1.0×10 ¹³ Ω·cm. Preferably.

(Method of manufacturing AlN ceramics plate)
The manufacturing method of the AlN ceramics plate 30 is not particularly limited. For example, a plate-shaped compact containing AlN is heated and fired at a predetermined firing temperature to obtain a sintered body, and the surface of the AlN sintered body (AlN sintered plate) obtained in the firing step is The AlN ceramics plate can be manufactured by a manufacturing method including a polishing step of polishing. In this manufacturing method, it is preferable to include a molding step of pressure-molding a raw material containing AlN to obtain a plate-shaped molded body before the firing step.

In the molding step, AlN powder or AlN granules having an AlN content of preferably 90 mass% or more, more preferably 95 mass% or more can be suitably used as the AlN-containing raw material. Further, it is preferable to add a sintering aid and an organic binder described later to the raw material containing AlN. As the sintering aid that can be used in the production of the AlN plate, rare earth element oxides such as Y ₂ O ₃ are mainly used, and in addition to these, alkaline earth metal oxides, fluorides, borides, and the like are listed. it can.

As a preferred method of pressure molding in the molding step, a method of producing a molded body by applying a predetermined molding pressure using a mold (dry mold molding), cold isostatic pressing (CIP), hot pressing (HP) ), hot isostatic pressing (HIP), and injection molding can be used. When the organic binder is used, it is preferable to perform a degreasing step of removing the organic binder from the plate-shaped molded body containing AlN after the molding step. In the degreasing step, for example, it is preferable to heat the plate-shaped compact in a degreasing furnace in the range of 300 to 700° C. to remove the organic binder.

In the firing step, the firing temperature for firing the plate-shaped compact containing AlN is preferably 1,500 to 2,100° C., the firing time is preferably about 1 to 50 hours, and the firing is performed in a nitrogen atmosphere or the like. It is preferable that the firing is performed in a firing furnace in a non-oxidizing atmosphere.

After the firing step, it is preferable to include a polishing step of polishing both surfaces of the AlN sintered plate obtained in the firing step by a rotary polishing method. By rotating and polishing both surfaces of the AlN sintered plate, it is possible to obtain an AlN ceramics plate having flat surfaces having the above-mentioned curved polishing marks on both surfaces.

[Case-shaped heat radiation member]
In the heat radiating member of one embodiment of the present invention, a frame portion made of alumina ceramics capable of surrounding the heat source can be provided on the surface side of the above-mentioned plate-shaped portion that is arranged on the heat source side. This heat radiation member is formed in a case shape by including a frame portion provided on the surface of the plate portion that is arranged on the heat source side. In this case-shaped heat radiating member, the plate-shaped portion and the frame portion can be formed as separate members (that is, an alumina ceramics plate and a frame member, respectively). As an example of one aspect of the configuration, the heat radiation member 15 including the alumina ceramic plate 20 and the frame member 70 made of alumina ceramics as shown in FIGS. 4 and 5 is cited, and the case-shaped heat radiation member of the present embodiment is described. The configuration will be described. FIG. 4 is a plan view showing a schematic configuration of the case-shaped heat radiation member 15 according to the embodiment of the present invention. FIG. 5 is a cross-sectional view taken along the line AA of FIG.

The heat radiating member 15 shown in FIGS. 4 and 5 includes an alumina ceramic plate 20 as a plate-shaped portion in which a flat surface 20a having curved polishing marks is formed on the surface 20a arranged on the heat source 50 side. The heat radiating member 15 also includes a frame member 70 made of alumina ceramics, which is provided on the outer peripheral side of the flat surface 20a of the alumina ceramics plate 20. By providing the frame member 70, the heat radiation member 15 is formed in a case shape. In the case-shaped heat radiation member 15, the heat source 50 such as a semiconductor element can be arranged on the inner peripheral side of the opening 70a of the frame member 70, that is, inside the case.

The frame member 70 is directly provided on the surface (flat surface) 20a of the alumina ceramic plate 20 arranged on the heat source 50 side as long as it is provided on the surface 20a side of the alumina ceramic plate 20 arranged on the heat source 50 side. You don't have to. For example, although not shown, the case-shaped heat radiating member 15 is provided with the above-mentioned high thermal conductive plate-shaped member such as an AlN ceramic plate on the surface (flat surface) 20a of the alumina ceramic plate 20 that is arranged on the heat source 50 side. You can In this case, the frame member 70 may be provided via a highly heat conductive plate member. Further, for example, the above-described highly heat-conductive plate-shaped member may be provided on the inner peripheral side of the opening 70a of the frame member 70 provided on the outer peripheral side portion of the flat surface 20a of the alumina ceramic plate 20. In this case, the thickness (height) of the frame member 70 is larger than the thickness (height) of the highly heat conductive plate member, so that the heat radiation member 15 is formed in a case shape.

Alumina ceramics as a material of the frame member 70 is preferably the same as that described in the description of the alumina ceramics plate 20, and for example, the content of alumina (Al ₂ O ₃ ) is 99.0 mass% or more. Preferably. The thickness (height) of the frame member 70 is not particularly limited as long as the frame member 70 can form the case-shaped heat radiating member 15 together with the alumina ceramic plate 20 and the like, but can be, for example, about 2 to 15 mm. ..

Further, the frame member 70 can be manufactured by a manufacturing method including the molding step and the firing step described in the description of the method for manufacturing the alumina ceramic plate 20. For example, a frame-shaped molded body is obtained by press molding using a raw material powder containing alumina powder (preferably a granulated powder) and a mold that can be molded into a frame shape, and then the molded body is fired. Thus, the frame member 70 can be manufactured. A polishing step may be performed in the manufacturing process of the frame member 70. Similar to the alumina ceramic plate 20, the frame member 70 preferably has a flat surface having the above-mentioned curved polishing marks on at least the surface 70b arranged on the alumina ceramic plate 20 side.

Here, for example, a semiconductor package such as an LED package has conventionally been configured such that a semiconductor element such as an LED element (LED chip) and a sealant such as a transparent resin are housed in a case. .. In such a semiconductor package, since the case is filled with the sealant, heat from the semiconductor element (heat source) is likely to accumulate in the case. If the heat radiation member 15 is used as a case used in a semiconductor package, not only can the alumina ceramic plate 20 be expected to radiate heat downward in the semiconductor element (heat source 50), but the frame member 70 can also dissipate heat inside the case. It can also be expected to release in the direction. Therefore, the case-shaped heat radiation member of the present embodiment is more suitable for a semiconductor package and further suitable for an LED package.

In the case-shaped heat radiating member of the present embodiment, it is preferable that the frame portion is in direct contact with and joined to the flat surface of the plate-shaped portion. With this configuration, the heat transferred to the frame part is easily transferred from the frame part to the plate-shaped part, and the heat can be radiated more efficiently. In the case-shaped heat radiation member 15 shown in FIG. 5, the frame is fixed by a fixing member 41 such as a screw (more preferably an insert nut) inserted through holes 20c and 70c provided in the alumina ceramic plate 20 and the frame member 70, respectively. The member 70 and the flat surface 20a of the alumina ceramics plate 20 are joined in a state of being in direct contact with each other. The frame member 70 and the flat surface 20a of the alumina ceramics plate 20 may be joined in a state of being in direct contact with each other by the above-mentioned tape-shaped fixing member.

Furthermore, it is preferable that the case-shaped heat radiation member of the present embodiment includes a mounting portion for mounting on a device (for example, a board and a case) including a heat source such as a semiconductor element. In the heat radiating member 15 shown in FIGS. 4 and 5, the alumina ceramics plate 20 is formed to be larger than the outer shape of the frame member 70 in plan view, and the alumina ceramics plate 20 has a position on the outer peripheral side of the frame member 70. A mounting hole 20d is provided as a mounting portion. The alumina ceramic plate 20 and the frame member 70 may have substantially the same outer shape in plan view.

The case-shaped heat radiation member 15 includes an alumina ceramics plate 20 and a frame member 70 made of alumina ceramics, which are separately formed. Therefore, in manufacturing the case-shaped heat radiation member, there is also an advantage that the flat surface 20a having the above-mentioned curved polishing marks can be easily formed on the surface of the plate-shaped portion which is the inner bottom surface of the case.

On the other hand, in the case-shaped heat radiation member of this embodiment, the plate-shaped portion and the frame portion may be integrally molded. As an example of one aspect of the configuration, a case-shaped heat radiation member 16 as shown in FIG. 6 can be exemplified. The case-shaped heat radiation member 16 is formed by integrally forming a plate-shaped portion 25 that forms the bottom surface of the case and a frame portion 26 that forms the side surface of the case. In the case-shaped heat radiating member in which the plate-shaped portion and the frame portion are integrally molded, since the plate-shaped portion and the frame portion are integrally molded, it is not necessary to use the above-mentioned fixing member. It is possible to reduce the number of parts, and there is an advantage that there is no additional step of joining the plate portion and the frame portion in the production of the heat radiation member. Even in the case-shaped heat radiation member 16 in which the plate-shaped portion 25 and the frame portion 26 are integrally formed, a flat surface having a curved polishing mark on the surface 25a of the plate-shaped portion 25 arranged on the heat source 50 side. 25a is formed. Further, this case-shaped heat radiating member 16 is also manufactured in the same manner as the above-described manufacturing method of the alumina ceramics plate, except that a mold which has a plate-shaped portion 25 and a frame portion 26 and can be molded into a case shape is used. You can

(Heat radiation member kit)
The heat radiating member 10 including the alumina ceramic plate 20 and the AlN ceramic plate 30 and the heat radiating member 15 including the alumina ceramic plate 20 and the frame member 70 are included in a kit for assembling the heat radiating members 10 and 15 during use. It can also be distributed as a form. The heat radiation member kit using the AlN ceramics plate includes the above-mentioned alumina ceramics plate and the aluminum nitride ceramics plate provided on the surface of the alumina ceramics plate which is arranged on the heat source side. The aluminum nitride ceramics plate in this heat radiating member kit has flat surfaces having curved polishing marks on both sides, and the alumina nitride ceramics plate and the alumina ceramics plate are in direct contact with each other, and the alumina It is joined to a ceramic plate. The heat radiating member kit in which the frame member is used includes the above-mentioned alumina ceramic plate and the frame member made of alumina ceramic provided on the surface of the alumina ceramic plate which is arranged on the heat source side. These heat radiation member kits may further include the above-mentioned fixing member.

In the heat radiating member according to the embodiment of the present invention described in detail above, the content of alumina is 99.0 mass% or more, and at least the flat surface having the curved polishing mark on the surface arranged on the heat source side is Since the formed alumina ceramics plate is provided, the heat source side can satisfactorily adhere to the contacted member (heat source, AlN ceramics plate, etc.). Thereby, the heat from the heat source side is efficiently transmitted to the alumina ceramic plate, and due to the high heat radiation performance of the alumina ceramic plate, the heat can be converted into infrared rays and emitted from the surface. Therefore, the heat radiation member according to the embodiment of the present invention has excellent heat dissipation performance.

Further, the heat radiating member 10 in which the AlN ceramics plate 30 is provided on the surface 20a of the alumina ceramics plate 20 arranged on the heat source 50 side, the flat surface 30a of the AlN ceramics plate 30 arranged on the heat source 50 side and the alumina ceramics plate. The flat surface 20a of 20 is directly contacted and joined without using an adhesive or the like. Therefore, when the heat radiation member 10 is arranged by bringing the AlN ceramics plate 30 into contact with the heat source 50, the heat generated from the heat source 50 can be effectively radiated. More specifically, the heat generated from the heat source 50 is rapidly conducted to the AlN ceramics plate 30 and the alumina ceramics plate 20 due to the high thermal conductivity of the AlN ceramics plate 30, and the alumina ceramics plate 20 has a high heat radiation performance. Due to, heat can be converted to infrared radiation and radiated from the surface.

Furthermore, in the case-shaped heat radiation members 15 and 16 described above, the heat generated from the heat source 50 such as a semiconductor element (more preferably an LED element) arranged on the inner peripheral side of the frame member 70 (frame portion 26) is a case. Easy to release to the outside. Specifically, when the heat source (a component such as a semiconductor element) 50 generates heat during operation, the heat generated from the heat source 50 is absorbed by the alumina ceramic plate 20 (plate portion 25) due to its thermal conductivity, and It becomes possible to radiate heat by utilizing the high emissivity of the alumina ceramic plate 20 (plate-shaped portion 25) (using the principle of heat radiation by infrared radiation). Further, the heat inside the case can be absorbed by the alumina ceramics plate 20 (plate-shaped portion 25) and the frame member 70 (frame portion 26) due to their thermal conductivity, and can be released to the outside of the case at a high emissivity. it can. Therefore, while ensuring stable operation of parts such as semiconductor elements arranged on the inner peripheral side of the frame member 70 (frame portion 26) in the case-shaped heat radiation members 15 and 16, it also contributes to improvement of product life. You can

As described above, since the heat radiation member can quickly release the heat from the heat source, as a heat source, a member (heating element) that may generate heat, for example, a power semiconductor element, an LED element, and those are installed. It is useful as a heat-resistant member such as a circuit board and a power generation cell of a solar cell module. When the heat radiation member is used as a heat countermeasure member for the power generation cell of the solar cell module, the heat radiation member can be provided on the back surface of the power generation cell. When the heat radiation member is used as a heat countermeasure member for a module including a power semiconductor element or a module including an LED element, an AlN ceramics plate or an alumina ceramics plate is used as a heat source (heating element) of the power semiconductor element or the LED element. They may be arranged so as to come into contact with each other (see FIGS. 7 and 10 to be described later), and an AlN ceramic plate or an alumina ceramic plate comes into contact with a circuit board having a heating element such as a power semiconductor element or an LED element from the circuit board side. May be arranged (see FIG. 8 described later).

The heat radiation member may be configured as a heat radiation circuit board (see FIG. 9 described later). As the heat radiating circuit board, for example, a heat radiating member in which a circuit is provided on the surface of the aluminum nitride ceramic plate opposite to the flat surface joined to the alumina ceramic plate is preferable. In this case, the module provided with various semiconductor elements such as a power semiconductor element and an LED element in the circuit provided on the AlN ceramics plate can be obtained.

The circuit is formed by forming a thin film of a conductive metal such as silver, nickel, or copper on the surface of an AlN ceramic plate by PVD (physical vapor deposition) or CVD (chemical vapor deposition), or by conducting the above-mentioned conduction. It can be formed by printing an ink containing a conductive metal as particles. If the surface of the AlN ceramics plate forming the circuit is a flat surface like the bonding surface with the alumina ceramics plate, the circuit can be easily formed by thin film formation or printing. Furthermore, if the surface of the AlN ceramics plate forming the circuit is a flat surface having the above-mentioned specific arithmetic mean roughness Ra and warpage as in the case of the above-mentioned suitable bonding surface (flat surface), the circuit is more easily manufactured. Can be formed, and a circuit having a complicated pattern can be formed.

As described above, the heat radiation member according to the embodiment of the present invention can have the following configurations.
[1] A plate-shaped portion made of alumina ceramics having an alumina content of 99.0 mass% or more and at least a flat surface having a curved polishing mark is formed on a surface arranged on the heat source side. Heat radiation member.
[2] The heat radiation member according to [1], wherein the plate-shaped portion has a warp of 200 μm or less and an arithmetic mean roughness Ra of the flat surface of 1.0 μm or less.
[3] The heat radiation member according to [2], wherein the warp of the plate-shaped portion is 150 μm or less.
[4] The heat radiation member according to the above [2] or [3], wherein the arithmetic average roughness Ra of the flat surface of the plate-shaped portion is 0.6 μm or less.
[5] An aluminum nitride ceramics plate provided on a surface of the plate-shaped portion arranged on the heat source side is provided, and the aluminum nitride ceramics plate is provided with flat surfaces having curved polishing marks on both surfaces, and The heat according to any one of [1] to [4], which is joined to the plate-shaped portion in a state where the flat surface of the aluminum nitride ceramics plate and the flat surface of the plate-shaped portion are in direct contact with each other. Radiant member.
[6] The heat radiating member according to [5], wherein the aluminum nitride ceramics plate has a warp of 200 μm or less and an arithmetic mean roughness Ra of the flat surface of 1.0 μm or less.
[7] The heat radiation member according to [6], wherein the warpage of the aluminum nitride ceramics plate is 150 μm or less.
[8] The heat radiation member according to [6] or [7], wherein the arithmetic average roughness Ra of the flat surface of the aluminum nitride ceramics plate is 0.6 μm or less.
[9] The heat radiation member according to any one of [5] to [8], including a fixing member that joins the plate-shaped portion and the aluminum nitride ceramics plate.
[10] The heat radiation member according to any one of [5] to [9], wherein each of the plate-shaped portion and the aluminum nitride ceramics plate is a flat plate having a thickness of 10 mm or less.
[11] The heat according to any one of [5] to [10], wherein a circuit is provided on a flat surface of the aluminum nitride ceramics plate opposite to the flat surface that is joined to the plate-shaped portion. Radiant member.
[12] The heat radiation member according to any one of [1] to [11], which includes an alumina ceramics plate that constitutes the plate-shaped portion.
[13] The case-shaped [1] provided with a frame portion made of alumina ceramics, which is provided on a surface side of the plate-shaped portion arranged on the heat source side and can surround the heat source. ~ The heat radiation member according to any one of [11].
[14] The plate-shaped portion and the frame portion are members formed separately, and the frame portion is directly contacted and joined to the flat surface of the plate-shaped portion [13]. The heat radiating member according to.
[15] The heat radiation member according to the above [13], wherein the plate-shaped portion and the frame portion are integrally molded.

<Power semiconductor module>
Next, a power semiconductor module according to an embodiment of the present invention will be described. The power semiconductor module of the present embodiment includes the heat radiation member described above and a power semiconductor element arranged on the flat surface side of the alumina ceramic plate in the heat radiation member. 7 to 9 show configuration examples of the power semiconductor module 100 using the heat radiation member 10 including the alumina ceramic plate 20 and the AlN ceramic plate 30 described above. The heat radiation member 10 used in the power semiconductor module 100 does not need to have the AlN ceramics plate 30 provided on the surface 20a of the alumina ceramics plate 20 located on the heat source (power semiconductor element) 51 side. In this case, the heat source (power semiconductor element, circuit board, etc.) may be directly arranged on the surface 20a of the alumina ceramic plate 20 arranged on the heat source 51 side, or a circuit may be formed.

As shown in FIG. 7, the power semiconductor module 100A includes a circuit board 60, a power semiconductor element 51 provided on the circuit board 60, and a heat provided by disposing the AlN ceramics plate 30 side on the power semiconductor element 51. A configuration including the radiating member 10 can be adopted. In this power semiconductor module 100A, the heat generated from the power semiconductor element (heat source) 51 is quickly transmitted to the AlN ceramics plate 30 and the alumina ceramics plate 20 by the high thermal conductivity of the AlN ceramics plate 30, and the heat generated by the alumina ceramics plate 20 is increased. It can be converted into infrared rays and emitted from the surface due to its high heat radiation performance.

As shown in FIG. 8, the power semiconductor module 100B has a circuit board 60, a power semiconductor element 51 provided on the circuit board 60, and a surface of the circuit board 60 on which the power semiconductor element 51 is provided. It is possible to adopt a configuration in which the heat radiation member 10 provided with the AlN ceramics plate 30 side disposed is provided on the surface side of. Further, as shown in FIG. 9, in the power semiconductor module 100C, the heat radiating member provided with the circuit 61 on the surface 30b of the AlN ceramic plate 30 opposite to the flat surface 30a joined to the alumina ceramic plate 20 ( A heat radiating circuit board 11 can be used. In this case, the power semiconductor module 100C can be configured to include the thermal radiation circuit board 11 and the power semiconductor element 51 provided on the circuit 61 of the thermal radiation circuit board 11. In these power semiconductor modules 100B and 100C, the heat generated from the power semiconductor element (heat source) 51 can be released from the circuit board 60 or the circuit 61 side.

In the power semiconductor module 100 shown in FIGS. 7 to 9, the alumina ceramic plate 20 and the AlN ceramic plate 30 may be joined by the above-mentioned fixing member.

<LED package>
Next, an LED package according to an embodiment of the present invention will be described. The LED package of the present embodiment includes the case-shaped heat radiation member described above and the LED element mounted on the inner peripheral side of the frame portion of the case-shaped heat radiation member. As one mode example of the LED package of the present embodiment, a schematic configuration of an LED package 150 using the case-shaped heat radiating member 15 provided with the alumina ceramic plate 20 and the frame member 70 made of alumina ceramics is shown in FIG. .. As shown in FIG. 10, the LED package 150 is mounted on the inner peripheral side of the case-shaped heat radiating member 15 and the opening 70a of the frame member (frame portion) 70 made of alumina ceramics in the heat radiating member 15. And the LED element 55.

A flat surface 20a having a curved polishing mark is formed on the surface 20a of the alumina ceramic plate (plate-shaped portion) 20 of the heat radiating member 15 arranged on the LED element (heat source) 55 side. It is preferable that the flat surface 20a of the alumina ceramics plate 20 is bonded to the LED element 55 in a direct contact state, and the frame member 70 is bonded to the flat surface 20a in a direct contact state so as to surround the LED element 55. .. An LED element 55 is mounted inside a case formed by the alumina ceramic plate 20 and the frame member 70.

A sealant 56 can be filled in the case, as is commonly found in conventional surface mount LED packages. As the sealant 56, for example, a transparent resin such as an epoxy resin and a silicone resin can be used. For example, in the case of a white LED package, a blue LED element can be used as the LED element 55 and the encapsulant 56 can contain a phosphor. An electrode (not shown) electrically conductively connected to the LED element 55 by a wire 57 or the like can be provided on the alumina ceramics plate 20 forming the bottom of the case-shaped heat radiation member 15.

Since the LED package 150 of the present embodiment includes the case-shaped heat radiation member 15 described above, heat generated from the LED element 55 arranged on the inner peripheral side of the frame member 70 in the heat radiation member 15 is generated outside the case (frame member). It is easy to release it to the outside of 70). Specifically, the alumina ceramic plate 20 can absorb the heat generated when the LED element 55, which is a heat source, generates heat during operation due to its thermal conductivity, and can radiate heat due to its high emissivity. Further, the heat inside the case can be absorbed by the alumina ceramic plate 20 and the frame member 70 due to their thermal conductivity, and can be released to the outside of the case at a high emissivity thereof, so that the accumulation of heat inside the case is suppressed. can do. Therefore, it is possible to contribute to the improvement of the product life while ensuring the stable operation of the LED element.

In the LED package of the present embodiment, a case-shaped heat radiation member (see, for example, FIG. 6) in which the plate-shaped portion and the frame portion are integrally molded can be used. Also in the case of an LED package that uses a case-shaped heat radiation member that is an integrally molded product of a plate-shaped portion and a frame portion, an LED that uses the case-shaped heat radiation member 15 that includes the alumina ceramic plate 20 and the frame member 70. The same effect as that of the package 150 can be obtained.

Next, the heat radiating member according to the above-described embodiment will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[Materials used]
As the alumina ceramics plate, an alumina ceramics plate having a content of alumina of 99.5% by mass or more (trade name “N-9H” manufactured by Nishimura Ceramics Co., Ltd.) was used. The density of this alumina ceramic plate was 3.93 g/cm ³ , the bending strength was 340 MPa, the thermal conductivity was 39 W/m·K, the thermal emissivity was 0.97, and the volume resistivity was 1.0×10 ¹⁶ Ω.・It was more than cm.
As the AlN ceramic plate, an aluminum nitride ceramic plate (manufactured by Nishimura Ceramics Co., Ltd.) having an aluminum nitride content of 99.5 mass% or more was used. This AlN ceramic plate has a density of 3.3 g/cm ³ , a bending strength of 350 MPa, a thermal conductivity of 170 W/mK, a thermal emissivity of 0.93, and a volume resistivity value of 1.0×10 ¹³ Ω.・It was more than cm.
The density, bending strength, thermal conductivity, thermal emissivity, and volume resistivity of each of the used alumina ceramic plate and AlN ceramic plate were measured according to the methods described below.

(density)
The density was determined by the Archimedes method. Specifically, the size of the sample was set to a disk shape with a diameter of 30 mm and a thickness of 5 mm, and the dry mass (W1) after drying at 100° C. for 2 hours and the mass (W2) in water were measured to obtain the density= It was determined by (W1)/(W1-W2).

(Bending strength)
Using a sample having a length of 4 mm, a width of 40 mm, and a thickness of 3 mm, a bending strength tester was used to measure the bending strength at a temperature of 25° C. in accordance with the regulations of JIS R 1601:2008.

(Thermal conductivity)
According to JIS R 1611:2010, the thermal conductivity was measured using a thermal conductivity measuring device by the laser flash method. A mirror-finished sample having a diameter of 10 mm and a thickness of 3 mm was used as the measurement sample. Then, after measuring the density of the sample by the Archimedes method, the specific heat and the thermal diffusivity were measured by using a measuring device, and the thermal conductivity (W/m·K) at a temperature of 25° C. was calculated by the following formula.
Thermal conductivity = (density), (specific heat), (thermal diffusivity)

(Thermal emissivity)
The heat emissivity at 100° C. was measured by measuring the temperature rise on the surface of the heating element using the heating plate method (measuring machine; thermometer HFT-40-Anritsu Keiki Co., Ltd.). That is, a mica heater is used as a heating element, the applied voltage is adjusted to maintain its surface (upper surface) temperature constant, and then a plate to be measured (AlN ceramics plate or alumina ceramics plate) is brought into close contact with the surface of the heating element for measurement. The measurement was performed by measuring the surface temperature of the heating element in the part where the target plate was not in close contact.

(Volume resistivity)
The volume resistivity at a temperature of 25° C. was measured using an insulation resistance meter. A cubic sample having a length, width, and height of 10 mm was used as a measurement sample, and silver electrodes were provided on two opposing surfaces of the sample, and measurement was performed with an insulation resistance meter.

[Example 1]
As the alumina ceramics plate of the above product, an alumina ceramics plate manufactured to have dimensions of 100 mm in width, 50 mm in length and 6 mm in thickness was used. Using a rotary polishing machine (diamond abrasive grains 2 to 4 μm, rotation speed 50 to 150 rpm; the same applies to the following rotary polishing machines) on both sides of this alumina ceramics plate, the warp is 100 μm or less, and the arithmetic average is used. The polishing was performed while adjusting the polishing time and the number of revolutions so that the roughness Ra was in the range of 0.5 to 1.0 μm, and a flat surface was formed. Observation of both sides of the alumina ceramics plate subjected to the above-mentioned polishing treatment with an optical microscope confirmed that there were curved polishing marks. Further, the warp of the alumina ceramic plate subjected to the above-mentioned polishing treatment and Ra of the flat surface arranged on the heat source side were measured by the measuring method described later. The alumina ceramic plate processed as described above was used as a heat radiation member.

[Example 2]
As the alumina ceramics plate of the above product, an alumina ceramics plate manufactured to have dimensions of 100 mm in width, 50 mm in length and 6 mm in thickness was used. A rotary polishing machine was used on both sides of this alumina ceramics plate to adjust the polishing time and the number of rotations so that the warp was in the range of 100 to 200 μm and the arithmetic average roughness Ra was 0.5 μm or less. Treatment was performed to form a flat surface. Observation of both sides of the alumina ceramics plate subjected to the above-mentioned polishing treatment with an optical microscope confirmed that there were curved polishing marks. Further, the warp of the alumina ceramic plate subjected to the above-mentioned polishing and Ra of the flat surface arranged on the heat source side were measured by the measuring method described later. The alumina ceramic plate processed as described above was used as a heat radiation member.

[Example 3]
As the alumina ceramics plate of the above product, an alumina ceramics plate manufactured to have dimensions of 100 mm in width, 50 mm in length and 6 mm in thickness was used. Both sides of this alumina ceramics plate were subjected to rotary polishing using a rotary polishing machine while adjusting the polishing time and the number of revolutions so that the warp was 100 μm or less and the arithmetic average roughness Ra was 0.5 μm or less. A flat surface was formed.
As the AlN ceramic plate of the above-mentioned product, an AlN ceramic plate manufactured to have dimensions of 100 mm in width, 50 mm in length and 5 mm in thickness was used. Both surfaces of this AlN ceramic plate were subjected to rotary polishing using a rotary polishing machine while adjusting the polishing time and the number of revolutions so that the warp was 100 μm or less and the arithmetic average roughness Ra was 0.5 μm or less. A flat surface was formed.
Observation of both surfaces of the alumina ceramic plate and the AlN ceramic plate, which had been subjected to the above-mentioned polishing treatment, with an optical microscope confirmed that they had curved polishing marks. Further, the warp and Ra of each of the alumina ceramic plate and the AlN ceramic plate that had been subjected to the above-described polishing treatment were measured by the measuring method described later.
Through holes for inserting screws were provided at the same positions of the four corners of the alumina ceramic plate and the AlN ceramic plate processed as described above in a plan view using a drilling machine. As shown in FIG. 11, the flat surface 21a of the alumina ceramics plate 21 and the flat surface 31a of the AlN ceramics plate 31 are overlapped with each other, and M3 screws 43 are inserted into the through holes 21c and 31c at 0.8 N/mm ² . The heat radiating member 12 in which the alumina ceramics plate 21 and the AlN ceramics plate 31 were bonded and fixed was manufactured.

[Example 4]
A heat radiating member was produced in the same manner as in Example 3 except that the conditions for the polishing treatment on both sides of the alumina ceramic plate and both sides of the AlN ceramic plate were changed. In Example 4, the polishing time and the rotational speed were adjusted on both sides of the alumina ceramics plate and both sides of the AlN ceramics plate so that the warp was in the range of 100 to 200 μm and the arithmetic average roughness Ra was 0.5 μm or less. It was subjected to rotary polishing. Observation of both surfaces of the alumina ceramic plate and the AlN ceramic plate, which had been subjected to the above-mentioned polishing treatment, with an optical microscope confirmed that they had curved polishing marks. Further, the warp and Ra of each of the alumina ceramic plate and the AlN ceramic plate that had been subjected to the above-described polishing treatment were measured by the measuring method described later.

[Example 5]
A heat radiating member was produced in the same manner as in Example 3 except that the conditions for rotary polishing on both sides of the alumina ceramics plate and both sides of the AlN ceramics plate were changed. In Example 5, the polishing time and the rotation speed were adjusted so that the warp was 100 μm or less and the arithmetic mean roughness Ra was in the range of 0.5 to 1.0 μm on both surfaces of the alumina ceramic plate and both surfaces of the AlN ceramic plate. Meanwhile, a rotary polishing process was performed. Observation of both surfaces of the alumina ceramic plate and the AlN ceramic plate, which had been subjected to the above-mentioned polishing treatment, with an optical microscope confirmed that they had curved polishing marks. Further, the warp and Ra of each of the alumina ceramic plate and the AlN ceramic plate that had been subjected to the above-described polishing treatment were measured by the measuring method described later.

[Comparative Example 1]
As the alumina ceramic plate of the above-mentioned product, an alumina ceramic plate having a surface of 100 mm, a length of 50 mm, and a thickness of 6 mm, the surface of which was not polished, was used alone as a heat radiation member.

[Comparative example 2]
As the alumina ceramics plate of the above product, an alumina ceramics plate manufactured to have dimensions of 100 mm in width, 50 mm in length and 6 mm in thickness was used. Both surfaces of this alumina ceramics plate were subjected to a linear polishing treatment using a surface grinder (manufactured by Taisei Co., Ltd.) under the conditions of a polishing speed of 0.3 to 25 m/min and a polishing time of 30 minutes to form flat surfaces. did. When both surfaces of the alumina ceramics plate subjected to the above-mentioned polishing treatment were observed with an optical microscope, it was confirmed that there were linear polishing marks. Further, the warp of the alumina ceramic plate subjected to the above-mentioned polishing and Ra of the flat surface arranged on the heat source side were measured by the measuring method described later. The alumina ceramic plate processed as described above was used as a heat radiation member.

[Comparative Example 3]
As the AlN ceramics plate of the above-mentioned product, an AlN ceramics plate having a surface of 100 mm, a length of 50 mm, and a thickness of 5 mm, the surface of which was not polished, was used alone as a heat radiation member.

[Example 6]
As the alumina ceramics plate of the above product, an alumina ceramics plate manufactured to have dimensions of 100 mm in width, 100 mm in width and 6 mm in thickness was used. Both sides of this alumina ceramics plate were subjected to rotary polishing using a rotary polishing machine while adjusting the polishing time and the number of revolutions so that the warp was 100 μm or less and the arithmetic average roughness Ra was 0.5 μm or less. , A flat surface was formed. Observation of both sides of the alumina ceramics plate subjected to the above-mentioned polishing treatment with an optical microscope confirmed that there were curved polishing marks. Further, the warp of the alumina ceramic plate subjected to the above-mentioned polishing and Ra of the flat surface arranged on the heat source side were measured by the measuring method described later. The alumina ceramic plate processed as described above was used as a heat radiation member.

[Example 7]
As the alumina ceramic plate of the above product, an alumina ceramic plate manufactured to have dimensions of 100 mm in width, 100 mm in length and 6 mm in thickness was used. Using a rotary polishing machine, the polishing time and the number of rotations were adjusted on both sides of this alumina ceramic plate so that the warp was in the range of 100 to 200 μm and the arithmetic average roughness Ra was 0.5 to 1.0 μm or less. On the other hand, a rotary polishing process was performed to form a flat surface. Observation of both sides of the alumina ceramics plate subjected to the above-mentioned polishing treatment with an optical microscope confirmed that there were curved polishing marks. Further, the warp of the alumina ceramic plate subjected to the above-mentioned polishing and Ra of the flat surface arranged on the heat source side were measured by the measuring method described later. The alumina ceramic plate processed as described above was used as a heat radiation member.

[Example 8]
As the alumina ceramic plate of the above product, an alumina ceramic plate manufactured to have dimensions of 100 mm in width, 100 mm in length and 6 mm in thickness was used. Rotate both sides of this alumina ceramics plate by using a rotary polishing machine while adjusting the polishing time and the number of rotations so that the warp is 100 μm or less and the arithmetic average roughness Ra is in the range of 0.5 to 1.0 μm. A polishing process was performed to form a flat surface. Observation of both sides of the alumina ceramics plate subjected to the above-mentioned polishing treatment with an optical microscope confirmed that there were curved polishing marks. Further, the warp of the alumina ceramic plate subjected to the above-mentioned polishing and Ra of the flat surface arranged on the heat source side were measured by the measuring method described later. The alumina ceramic plate processed as described above was used as a heat radiation member.

[Example 9]
As the alumina ceramic plate of the above product, an alumina ceramic plate manufactured to have dimensions of 100 mm in width, 100 mm in length and 6 mm in thickness was used. Both sides of this alumina ceramics plate were subjected to rotary polishing under the same conditions as the polishing treatment applied to the alumina ceramics plate used in Example 3 to form flat surfaces.
Further, as the AlN ceramic plate of the above product, an AlN ceramic plate manufactured to have dimensions of 100 mm in width, 100 mm in length, and 6 mm in thickness was used, and both surfaces thereof were subjected to polishing treatment applied to the AlN ceramic plate used in Example 3. A rotary polishing process was performed under the same conditions to form a flat surface.
Observation of both surfaces of the alumina ceramic plate and the AlN ceramic plate, which had been subjected to the above-mentioned polishing treatment, with an optical microscope confirmed that they had curved polishing marks. Further, the warp and Ra of each of the alumina ceramic plate and the AlN ceramic plate that had been subjected to the above-described polishing treatment were measured by the measuring method described later.
Through holes for inserting screws were provided at the same positions of the four corners of the alumina ceramic plate and the AlN ceramic plate processed as described above in a plan view using a drilling machine. As shown in FIG. 11, the flat surface 21a of the alumina ceramics plate 21 and the flat surface 31a of the AlN ceramics plate 31 are overlapped with each other, and M3 screws 43 are inserted into the through holes 21c and 31c at 0.8 N/mm ² . The heat radiating member 12 in which the alumina ceramics plate 21 and the AlN ceramics plate 31 were bonded and fixed was manufactured.

[Example 10]
A heat radiating member was produced in the same manner as in Example 9 except that the conditions for the polishing treatment on both sides of the alumina ceramics plate and both sides of the AlN ceramics plate were changed. In Example 10, the conditions for the polishing treatment on both sides of the alumina ceramics plate were the same as those for the alumina ceramics plate used in Example 4, and the conditions for the polishing treatment on both sides of the AlN ceramics plate were performed. The conditions were the same as the polishing treatment applied to the AlN ceramic plate used in Example 4.
Observation of both surfaces of the alumina ceramic plate and the AlN ceramic plate, which had been subjected to the above-mentioned polishing treatment, with an optical microscope confirmed that they had curved polishing marks. Further, the warp and Ra of each of the alumina ceramic plate and the AlN ceramic plate that had been subjected to the above-described polishing treatment were measured by the measuring method described later.

[Example 11]
A heat radiating member was produced in the same manner as in Example 9 except that the conditions for the polishing treatment on both sides of the alumina ceramics plate and both sides of the AlN ceramics plate were changed. In Example 11, the conditions for the polishing treatment on both sides of the alumina ceramics plate were the same as those for the alumina ceramics plate used in Example 5, and the conditions for the polishing treatment on both sides of the AlN ceramics plate were performed. The conditions were the same as the polishing treatment applied to the AlN ceramic plate used in Example 5.
Observation of both surfaces of the alumina ceramic plate and the AlN ceramic plate, which had been subjected to the above-mentioned polishing treatment, with an optical microscope confirmed that they had curved polishing marks. Further, the warp and Ra of each of the alumina ceramic plate and the AlN ceramic plate that had been subjected to the above-described polishing treatment were measured by the measuring method described later.

(Measurement of arithmetic average roughness Ra and warpage)
The arithmetic mean roughness Ra and the warp of the surfaces to be the bonding surfaces of the alumina ceramic plate and the AlN ceramic plate used in each example were measured as follows. The results are shown in Tables 1 to 3.
(Arithmetic mean roughness Ra)
The arithmetic average roughness Ra was measured using a surface roughness meter (manufactured by Tokyo Seimitsu Co., Ltd.) according to JIS B 0601:2013.
(warp)
The warpage was measured using a surface plate and a micrometer (manufactured by Nikon Corporation, trade name "Digimicro MFC-501"). First, as shown in FIG. 12A, the measuring portion (tip) 5a of the micrometer 5 was applied to the surface of the surface plate 4 and 0 was set. Next, as shown in FIG. 12B, the object to be measured (each alumina ceramics plate, each AlN ceramics plate) 6 is placed on the surface plate 4 with the warped surface facing down (the bulging surface facing up). The distance (height) h ₁ from the surface of the surface plate 4 to the surface of the portion of the DUT 6 at the highest position was measured. Further, as shown in FIG. 12C, the distance (height) h ₂ from the surface of the surface plate 4 to the surface of the portion of the DUT 6 in contact with the surface of the surface plate 4 (the end of the DUT) is It was measured. Then, the warpage was calculated from the warpage=h ₁ −h ₂ .

(Evaluation of heat dissipation)
With respect to the heat radiating member of each of the above examples, the heater surface temperature during heating was measured according to the following method, and the heat radiating characteristics (heat radiating property) of each were evaluated.
As the heater (heat source), a flat plate having a width of 50 mm and a length of 4 mm and a thickness of 4 mm, a surface made of SUS, and a mica heater incorporated therein was used. As shown in FIG. 11, regarding the heat radiation member 12 of Examples 3 to 5 and 9 to 11, the surface 31b of the upper side of the AlN ceramics plate 31 (the side opposite to the surface 31a on which the alumina ceramics plate 21 is provided) is formed. The heater 52 was placed at the central position, and the surface 31b of the AlN ceramic plate 31 and the heater 52 were brought into close contact with each other.
Further, in Examples 1, 2 and 6 to 8 and Comparative Examples 1 and 2, a heater was placed on the center position of the surface of the alumina ceramics plate to bring them into close contact, and in Comparative Example 3, the heater was placed at the center position of the surface of the AlN ceramics plate. A heater was put on and brought into close contact.
A temperature sensor 2 (K type thermocouple, model HFT-40 manufactured by Anritsu Keiki Co., Ltd.) is attached to the surface (side surface) of the heater 52, and a predetermined input power (1W, 4W, 8W, 14W, 19.5W) is applied. The heater 52 was energized and the heater surface temperature was measured 30 minutes after the energization. Tables 1 to 3 show the heater surface temperatures when the input power is 1 W, 4 W, 8 W, 14 W and 19.5 W, respectively. As shown in FIG. 11, the temperature measurement is performed by using the support 3 in the box 1 (310 mm in width, 310 mm in length, 310 mm in height) made of acrylic resin for measurement conforming to the JEDEC standard and using the heat radiating member. The lower surface (the surface 21b of the alumina ceramic plate opposite to the heat source side) was set at a height of 50 mm away from the bottom surface of the box 1, and the lid was sealed with the same acrylic resin. The temperature was measured every 1 minute after the heater was energized. Although there were some differences depending on the applied power, in any case, the temperature did not change after 20 minutes and the temperature became constant, so the temperature after 30 minutes was taken as the measurement temperature. For comparison, in the case of using the heater alone without using the heat radiating member, the heater surface temperature after 30 minutes of energization was measured in the same manner as above. The measurement results are shown in Tables 1 to 3 as "heat source only".

As a result, in the heat radiation members of Examples 1, 2, and 6 to 8, when the alumina ceramic plate whose surface was not polished was used alone (Comparative Example 1), the surface was linearly polished. It was confirmed that the heat dissipation performance was superior to the case where the alumina ceramic plate was used alone (Comparative Example 2) and the case where the AlN ceramic plate was used alone (Comparative Example 3). Further, in comparison with the heat radiating members of Examples 1 and 2 in which the heat radiating members of Examples 3 to 5 use the same size of alumina ceramic plate, Examples 9 to 11 use the same size of alumina ceramic plate. It was confirmed that the heat radiation member had better heat dissipation performance than the heat radiation members of Examples 6 to 8. Therefore, it was confirmed that an alumina ceramics plate having a flat surface having curved polishing marks on at least the surface arranged on the heat source side is extremely effective as a heat radiation member.

The heat radiating member (Examples 3 to 5 and 9 to 11) in which the alumina ceramics plate and the AlN ceramics plate are joined in a state where the flat surface of the alumina ceramics plate and the flat surface of the AlN ceramics plate are in direct contact with each other is a heat source. It was confirmed that the temperature rise in the can be further suppressed, and that it has excellent heat dissipation performance. In particular, when the warp of each of the alumina ceramic plate and the AlN ceramic plate was 100 μm or less (Examples 3, 5, 9, and 11), it was confirmed that the heat dissipation performance was more excellent, and each flat surface It was confirmed that, when Ra of 0.1 μm or less (Examples 3 and 9), the heat dissipation performance was further excellent.

The heat radiation member according to the present technology is, for example, a lighting device including an LED element, a solar power generation device, an automobile (hybrid vehicle/electric vehicle), a train, a power transmission system, solar power generation, a production facility, and a household appliance. Can be used as a heat countermeasure member in an industrial device or the like including a power semiconductor element used for controlling and supplying electric power.

10, 11, 12: Heat radiating member 15, 16: Case-shaped heat radiating member 20, 21: Alumina ceramic plate 25: Alumina ceramic plate portion 26: Alumina ceramic frame portion 30, 31: Aluminum nitride ceramics Plate 40: Fixing member 50: Heat source 51: Power semiconductor element 55: LED element 60: Circuit board 61: Circuit 70: Frame member 100: Power semiconductor module

Claims (17)

A plate-shaped portion made of alumina ceramics, in which the content of alumina is 99.0 mass% or more, and a flat surface having a curved polishing mark is formed on at least the surface arranged on the heat source side ,
An aluminum nitride ceramics plate provided on a surface arranged on the heat source side of the plate-shaped portion ,
The aluminum nitride ceramics plate is provided with flat surfaces having curved polishing marks on both the surface arranged on the heat source side and the surface opposite to the heat source side, and is provided on the opposite surface of the aluminum nitride ceramics plate. The heat radiating member joined to the plate-shaped portion in a state where the flat surface and the flat surface of the plate-shaped portion are in direct contact with each other . The heat radiating member according to claim 1, wherein the plate-shaped portion has a warp of 200 μm or less, and an arithmetic mean roughness Ra of the flat surface of the plate-shaped portion is 1.0 μm or less. The heat radiation member according to claim 2, wherein the warp of the plate-shaped portion is 150 μm or less. The heat radiation member according to claim 2, wherein the arithmetic average roughness Ra of the flat surface of the plate-shaped portion is 0.6 μm or less. The aluminum nitride ceramic plate, warpage is at 200μm or less, and in any one of claims 1 to 4 arithmetic average roughness Ra of the flat surface of the aluminum nitride ceramic plate is of 1.0μm or less The heat radiating member described. The heat radiation member according to claim 5 , wherein the warpage of the aluminum nitride ceramics plate is 150 μm or less. The heat radiation member according to claim 5 or 6 , wherein the arithmetic average roughness Ra of the flat surface of the aluminum nitride ceramics plate is 0.6 µm or less. Heat radiating member according to claim 1 comprising a fixing member for bonding the aluminum nitride ceramic plate and the plate-like portion. The heat radiating member according to any one of claims 1 to 8 , wherein each of the plate-shaped portion and the aluminum nitride ceramics plate is a flat plate having a thickness of 10 mm or less. Wherein the flat surface opposite to the flat surface joined to the plate-like portion of the aluminum nitride ceramic plate, the heat radiating member according to any one of claims 1 to 9, the circuit is provided. Heat radiating member according to any one of claims 1 to 10 comprising alumina ceramic plate constituting the plate-like portion. Any of claims 1 to 10 , which is formed in a case shape by including a frame portion made of alumina ceramics, which is provided on a surface side of the plate-shaped portion arranged on the heat source side and which can surround the heat source. The heat radiation member according to item 1. The plate-shaped portion and the frame portion are members formed separately,
The heat radiation member according to claim 12 , wherein the frame portion is in direct contact with and bonded to the flat surface of the plate-shaped portion. The heat radiation member according to claim 12 , wherein the plate-shaped portion and the frame portion are integrally molded. A plate-shaped portion made of alumina ceramics, in which the content of alumina is 99.0 mass% or more, and a flat surface having a curved polishing mark is formed on at least the surface arranged on the heat source side,
A frame part made of alumina ceramics capable of surrounding the heat source, which is provided on the surface side of the plate-shaped part arranged on the heat source side, is formed in a case shape,
A heat radiation member in which the plate-shaped portion and the frame portion are integrally molded. A heat radiating member according to any one of claims 1-14,
A power semiconductor element arranged on the flat surface side of the plate-shaped portion in the heat radiation member,
Power semiconductor module comprising. A case-shaped heat radiation member according to any one of claims 12 to 15,
An LED package comprising: an LED element mounted on an inner peripheral side of the frame portion in the case-shaped heat radiation member.

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