WO2023095228A1 - Heat dissipation member, electronic device, and production method for heat dissipation member - Google Patents

Abstract

This heat dissipation member (10) comprises a heat radiation layer (12A) that is provided on a surface of a substrate (11A) and contains ceramic particles (21) and a binder (22). Surfaces of the ceramic particles (21) protrude from the surface (22a) of the binder (22).

Description

Heat dissipation member, electronic device, and method for manufacturing heat dissipation member

The present disclosure relates to a heat dissipation member, an electronic device, and a method for manufacturing a heat dissipation member.

Conventionally, heat dissipation sheets with high thermal conductivity are sometimes used as heat countermeasures for electronic devices. Such a conventional heat dissipation sheet is disclosed in Patent Document 1, for example.

JP 2017-87673 A

The heat dissipation sheet disclosed in Patent Document 1 includes a heat transfer layer and a heat radiation layer. The heat transfer layer has a role of transferring heat generated from the heat source to the heat radiation layer. The heat radiation layer has a role of radiating the heat transferred from the heat transfer layer as infrared rays. Moreover, the thermal radiation layer contains a binder and a thermally conductive inorganic filler.

Here, in the heat radiation layer of the heat radiation sheet disclosed in Patent Document 1, the inorganic filler is provided in the binder. Thus, when the inorganic filler is buried in the binder, heat radiation from the inorganic filler is blocked by the binder. As a result, in the heat dissipation sheet disclosed in Patent Literature 1, there is a possibility that heat dissipation may be deteriorated.

The present disclosure has been made to solve the above problems, and provides a heat dissipation member, an electronic device, and a method for manufacturing the heat dissipation member in which heat dissipation from sources other than the binder is not blocked by the binder. It is an object.

A heat dissipating member according to the present disclosure is provided on the surface of a base material and includes a heat emitting layer containing ceramic particles and a binder, the surface of the ceramic particles protruding from the surface of the binder.

According to the present disclosure, heat radiation from sources other than the binder is not blocked by the binder.

2 is a vertical cross-sectional view of a heat radiating member according to Embodiment 1; FIG. FIG. 2 is an enlarged view of a main portion of FIG. 1; 2 is a plan view of the heat radiating member according to Embodiment 1; FIG. FIG. 4 is a vertical cross-sectional view of a heat dissipation member provided with a heat source; 4 is a flow chart showing a method for manufacturing a heat radiating member according to Embodiment 1; 4A and 4B are diagrams showing configurations of examples when the heat radiating member according to the first embodiment is implemented; FIG. 1 is a vertical cross-sectional view of an electronic device to which the heat dissipation member according to Embodiment 1 is applied; FIG. FIG. 8 is a longitudinal sectional view of a heat radiating member according to Embodiment 2; FIG. 11 is a vertical cross-sectional view of a heat radiating member according to Embodiment 3;

Hereinafter, in order to describe the present disclosure in more detail, embodiments for carrying out the present disclosure will be described according to the attached drawings.

Embodiment 1.
A heat radiating member 10 according to Embodiment 1 will be described with reference to FIGS. 1 to 6. FIG.

First, the configuration of the heat radiating member 10 according to Embodiment 1 will be described with reference to FIGS. 1 to 4. FIG. FIG. 1 is a vertical cross-sectional view of a heat radiating member 10 according to Embodiment 1. FIG. 2 is an enlarged view of a main part of FIG. 1. FIG. FIG. 3 is a plan view of the heat dissipation member 10 according to Embodiment 1. FIG. FIG. 4 is a vertical cross-sectional view of the heat dissipation member 10 including the heat source 40. As shown in FIG.

The heat dissipation member 10 according to Embodiment 1 includes a base material 11A and a heat emission layer 12A. The base material 11A has a role of absorbing heat emitted from a heat source such as a semiconductor element and transmitting the absorbed heat to the thermal radiation layer 12A. The thermal radiation layer 12A has a role of radiating the heat transferred from the substrate 11A as infrared rays from its surface.

The thermal radiation layer 12A has a plurality of ceramic particles 21 and a binder 22. A plurality of ceramic particles 21 are provided inside the binder 22 . The binder 22 is provided on the surface of the substrate 11A. Both the ceramic particles 21 and the binder 22 radiate the heat transferred from the substrate 11A as infrared rays.

At this time, the ceramic particles 21 provided inside the binder 22 are the ceramic particles 21 that are in contact with the surface of the base material 11A, the ceramic particles 21 that have a part of the surface (spherical surface) protruding from the surface 22a of the binder 22, and , ceramic particles 21, etc. whose surfaces are in contact with each other.

Here, the surface of the thermal emission layer 12A includes the surface 22a of the binder 22 and the surfaces of the portions of the ceramic particles 21 protruding from the surface 22a. In addition, as shown in FIG. 3, the ceramic particles 21 having a part of the surface protruding from the surface 22a of the binder 22 are projected on the surface 22a of the binder 22 in the direction perpendicular to the surface 22a of the binder 22. A ceramic particle 21 having a portion protruding from the surface 22a is meant.

Therefore, infrared radiation from the surfaces of the portions of the ceramic particles 21 protruding from the surface 22 a of the binder 22 is directed to the outside of the heat dissipation member 10 without being blocked by the binder 22 . Also, the ceramic particles 21 are made of a material having an infrared emissivity higher than that of the binder 22 .

Therefore, the radiation member 10 as a whole has a higher infrared emissivity than a radiation member in which the ceramic particles 21 do not protrude from the surface 22 a of the binder 22 . As a result, the heat radiation performance of the heat radiation member 10 is improved.

The ceramic particles 21 are formed by appropriately selecting a material having an infrared emissivity higher than that of the binder 22 . The ceramic particles 21 are, for example, aluminum nitride, silicon nitride, boron nitride, zinc oxide, aluminum oxide, crystalline silica, titanium oxide, manganese ferrite ((FeMn)2O3), and ferric oxide (Fe2O3). It is made of at least one of these materials.

The particle size of the ceramic particles 21 is preferably 10 μm or more and 100 μm or less, for example. Here, the particle size of the ceramic particles 21 is the cumulative mass 50% particle size. If the particle size of the ceramic particles 21 is less than 10 μm, the ceramic particles 21 tend to settle inside the binder 22 and may not protrude from the surface 22 a of the binder 22 . In addition, when the particle size of the ceramic particles 21 exceeds 100 μm, the thickness of the heat emitting layer 12A increases to bind the ceramic particles 21, and the heat conduction from the substrate 11A to the heat emitting layer 12A decreases. There is a risk of

The binder 22 may be any material as long as it can bind the ceramic particles 21 to the surface of the substrate 11A. This binder 22 is formed by appropriately selecting either one of an organic binder and an inorganic binder.

In addition, the binder 22 may contain an inorganic filler. In this case, the inorganic filler should be made of a material having a thermal conductivity higher than that of the binder 22 . Inorganic fillers include, for example, metal powder, aluminum nitride powder, aluminum oxide powder, zinc oxide powder, magnesium oxide powder, silicon oxide powder, silicate powder, silicon nitride powder, silicon carbide powder, tungsten carbide powder, boron nitride powder, Any one or more of aluminum hydroxide powder, magnesium hydroxide powder, aluminum oxynitride powder, cordierite powder, mullite powder, graphite powder, carbon nanotube, diamond powder, carbon fiber, fullerene, etc. formed.

When the binder 22 is an organic binder, the organic binder is formed of at least one of epoxy resin, unsaturated polyester resin, phenol resin, melamine resin, silicone resin, polyimide resin, and the like. It is

In addition, among the organic binders described above, epoxy resins are most preferable because of their excellent adhesiveness. Examples of epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, orthocresol novolac type epoxy resins, phenol novolac type epoxy resins, alicyclic aliphatic epoxy resins, and glycidyl-aminophenol type epoxy resins. be done. Epoxy resin is made of one or more of these resins.

Furthermore, when an epoxy resin is used as the thermosetting resin, the curing agent applied to the epoxy resin is, for example, an alicyclic acid such as methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, and hymic anhydride. Anhydrides; aliphatic acid anhydrides such as dodecenyl succinic anhydride; aromatic acid anhydrides such as phthalic anhydride and trimellitic anhydride; organic dihydrazides such as dicyandiamide and adipic acid dihydrazide; ) phenol; dimethylbenzylamine; 1,8-diazabicyclo(5,4,0)undecene and its derivatives; imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole etc. Curing agents for epoxy resins are formed from one or more of these curing agents.

The blending amount of the curing agent must be appropriately set according to the type of thermosetting resin and curing agent used. In general, it is preferable to use 0.1 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the thermosetting resin.

On the other hand, when the binder 22 is an inorganic binder, the inorganic binder includes, for example, sol-gel glass, organic-inorganic hybrid glass, water glass, one-liquid inorganic adhesive, and two-liquid inorganic adhesive. It is made of one or more materials.

The material of the base material 11A is not particularly limited as long as it does not interfere with the formation of the thermal emission layer 12A. 11 A of base materials are formed with any one material, for example among metals, such as aluminum and iron, resin, and ceramics. In particular, when a material with high thermal conductivity such as metal is used for the base material 11A, as shown in FIG. The base material 11A can laterally spread the heat transferred from the heat source 40 . Therefore, the heat radiating member 10 can improve the heat radiating performance with respect to the heat source 40 and cool the heat source 40 .

The shape of the substrate 11A is not particularly limited as long as it does not interfere with the formation of the thermal radiation layer 12A. This point will be described in detail in the second and third embodiments.

Here, as the proportion of the surface of the heat radiation layer 12A where the surface of the ceramic particles 21 protrudes from the surface 22a of the binder 22 increases, the radiation member 10 can improve the infrared emissivity. However, if the content of the binder 22 contained in the thermal emission layer 12A is insufficient, the ceramic particles 21 are likely to fall off the binder 22, and the strength of the thermal emission layer 12A may also decrease. Therefore, the occupation ratio of the surfaces of the ceramic particles 21 on the surface of the heat emitting layer 12A is preferably 20 to 70%.

However, the occupancy rate of the surface of the ceramic particles 21 on the surface of the heat radiation layer 12A is, as shown in FIG. It shows the ratio of the projected area occupied by the surfaces of the ceramic particles 21 protruding from 22a. This occupancy can be obtained, for example, using the following formula (1).

Occupancy = (Projected area of surface of protruding ceramic particles)/(Projected area of surface of thermal emission layer) x 100 (1)

In addition, in the heat dissipation member 10, it is sufficient that at least the heat emission layer 12A is provided on the surface opposite to the surface with which the heat source 40 contacts. Moreover, the heat radiation layer 12A does not need to cover the entire surface opposite to the surface in contact with the heat source 40, and may be appropriately provided within a range in which the heat radiation property can be exhibited.

Next, a method for manufacturing the heat radiating member 10 according to Embodiment 1 will be described with reference to FIG. FIG. 5 is a flow chart showing a method for manufacturing the heat radiating member 10 according to the first embodiment.

At step ST11, the binder 22 is diluted with a solvent.

In step ST12, a thermally conductive filler different from the ceramic particles 21 is dispersed and mixed with the diluted binder 22. Methods for mixing and dispersing the thermally conductive filler in the binder 22 include, for example, methods using a kneader, ball mill, planetary ball mill, kneading mixer, bead mill, and the like. Note that step ST12 may be omitted in the manufacturing method of the heat dissipation member 10 .

At step ST13, the binder 22 is applied to the surface of the base material 11A. Examples of the method of applying the binder 22 to the base material 11A include methods using a spray method, a dipping method, a brush coating method, a screen printing method, a transfer method, and the like. The thickness when the binder 22 is applied is calculated backward from the drying shrinkage rate and cure shrinkage rate of the binder 22, and is appropriately adjusted so that the thickness of the binder 22 after drying and curing becomes a desired thickness.

In step ST14, the ceramic particles 21 are sprinkled on the applied binder 22. Examples of the method of sprinkling the ceramic particles 21 on the binder 22 include a method of putting the ceramic particles 21 in a mesh sieve and sprinkling from above, and a method of powder coating using a spray nozzle. The amount of the ceramic particles 21 to be sprinkled is appropriately adjusted according to the thickness of the applied binder 22 and the particle size of the ceramic particles 21 so that the surface occupancy of the protruding ceramic particles 21 becomes a desired occupancy. be done.

At step ST15, the ceramic particles 21 not bound to the binder 22 are removed. Methods for removing the unbound ceramic particles 21 from the binder 22 include, for example, a method of blowing off the ceramic particles 21 with an air blow, a method of sucking the ceramic particles 21 with a vacuum, and the like. Here, this step ST15 (the step of removing the ceramic particles 21 not bound to the binder 22) is performed immediately after the ceramic particles 21 are sprinkled, after the solvent is dried, or after the binder 22 is cured. It should be implemented at one time.

In step ST16, the solvent contained in the applied binder 22 is dried at a desired temperature. Examples of the heat treatment method for removing the solvent from the binder 22 include methods using a drying oven, a hot plate, a hot air blower, an electric furnace, a high-frequency heating furnace, and the like. Further, the heat treatment temperature for solvent removal from the binder 22 is appropriately adjusted with reference to the boiling point of the solvent used. At this time, the heat treatment is preferably performed at a temperature several tens of degrees lower than the boiling point of the solvent. When the heat treatment is performed at a temperature higher than the boiling point of the solvent, the solvent rapidly evaporates, crater-like holes are generated on the surface 22a of the binder 22, and the thickness of the binder 22 tends to become uneven.

At step ST17, the binder 22 is heated at a desired temperature and hardened. As a result, the thermal emission layer 12A is formed. Examples of the heat treatment method for curing the binder 22 include methods using a drying oven, a hot plate, a hot air blower, an electric furnace, a high-frequency heating furnace, and the like. Further, the heat treatment temperature for curing the binder 22 is appropriately adjusted with reference to the curing temperature of the binder 22 used. Then, the manufacturing method of the heat radiating member 10 ends.

It should be noted that the method for manufacturing the heat dissipating member 10 described above can also be applied to the method for manufacturing the heat dissipating members 20 and 30, which will be described later.

Next, the effects of the heat radiating member 10 according to Embodiment 1 will be described with reference to FIG. FIG. 6 is a diagram showing the configuration of each example when the heat radiating member 10 according to Embodiment 1 is implemented.

FIG. 6 shows the specific configuration of the samples of Examples 1-5 to which the configuration of the heat dissipation member 10 is applied, and the specific configurations of the samples of Comparative Examples 1 and 2 to which the configuration of the heat dissipation member 10 is not applied. is shown.

[Example 1]
In Example 1, a mixture of an epoxy resin and a solvent was applied to the surface of a 5 cm×5 cm aluminum substrate 11A so as to have a thickness of 100 μm. Next, in Example 1, 0.751 g of alumina particles were sprinkled on the surface of the epoxy resin using a sieve so that the occupancy of the alumina particles was 15%. Next, in Example 1, after drying the solvent in a drying oven, the epoxy resin was cured. Thus, the heat dissipation member 10 of Example 1 is a sample in which the heat emission layer 12A is formed on the surface of the substrate 11A.

[Example 2]
Example 2 is a sample obtained in the same manner as in Example 1, except that the amount of alumina particles added was changed to 0.766 g and the occupancy rate was 20%.

[Example 3]
Example 3 is a sample obtained in the same manner as in Example 1, except that the amount of alumina particles added was changed to 0.798 g so that the occupancy rate was 30%.

[Example 4]
Example 4 is a sample obtained in the same manner as in Example 1, except that the amount of alumina particles added was changed to 0.925 g so that the occupancy was 70%.

[Example 5]
Example 5 is a sample obtained in the same manner as in Example 1, except that the amount of alumina particles added was changed to 0.956 g so that the occupancy rate was 80%.

[Comparative Example 1]
Comparative Example 1 is a sample in which the thermal emitting layer 12A is not formed on the surface of the aluminum substrate 11A measuring 5 cm×5 cm.

[Comparative Example 2]
Comparative Example 2 is a sample obtained in the same manner as in Example 1, except that the surface of the epoxy resin was not sprinkled with alumina particles so that the occupancy rate was 0%.

The cooling performance (heat dissipation performance) was evaluated as follows for the samples of Examples 1-5 and Comparative Examples 1 and 2 described above.

In this evaluation method, a ceramic heater (heat source 40) is attached to the surface of the substrate 11A opposite to the surface on which the heat radiation layer 12A is provided. Each sample is left for several hours with power applied to the ceramic heater until the temperature of each sample and the temperature of the ceramic heater reach the saturation temperature. After that, the surface temperature of the ceramic heater is measured using a thermocouple or the like.

The evaluation results of the cooling performance are based on the saturation temperature obtained in the sample of Example 1, and the saturation temperature obtained in each sample of Examples 2-5 and Comparative Examples 1 and 2 is the saturation temperature of Example 1. ◎ is lower than , 〇 is equal, and x is higher.

In the sample of Example 2, the occupancy of the alumina particles was 20%, which improved the cooling performance and lowered the saturation temperature. In the sample of Example 3, the occupancy of the alumina particles was 30%, so that the cooling performance was improved and the saturation temperature was lowered. In the sample of Example 4, the occupancy of the alumina particles was 70%, so that the cooling performance was improved and the saturation temperature was lowered. In the sample of Example 5, the binding of the alumina particles was insufficient, and it was judged that the sample was not suitable for the evaluation of the occupancy rate of the alumina particles.

In the sample of Comparative Example 1, since the thermal radiation layer 12A was not provided, the cooling performance decreased and the saturation temperature increased. In the sample of Comparative Example 2, since the alumina particles did not protrude from the surface of the epoxy resin serving as the binder 22, the cooling performance decreased and the saturation temperature increased.

Next, electronic device 100 to which heat dissipation member 10 according to Embodiment 1 is applied will be described with reference to FIG. FIG. 7 is a longitudinal sectional view of electronic device 100 to which heat dissipation member 10 according to Embodiment 1 is applied.

As shown in FIG. 7, the electronic device 100 is, for example, a high frequency module. This electronic device 100 includes a heat dissipation member 10 , a ceramic substrate 51 , a circuit pattern 52 , a high frequency circuit 53 , a circuit 54 , bonding wires 55 and a case 60 .

The ceramic substrate 51 is, for example, a multilayer dielectric substrate. The ceramic substrate 51 is attached to the surface of the substrate 11A opposite to the surface provided with the thermal emission layer 12A. As a method for attaching the ceramic substrate 51 to the base material 11A, for example, bonding by soldering, bonding by sintered metal, or the like can be used. At this time, when bonding the ceramic substrate 51 to the base material 11A, the electronic device 100 may form a metal layer such as a metallized layer in advance on the surface of the base material 11A to improve bonding.

The circuit pattern 52 is provided on the surface of the ceramic substrate 51 . The surface of the ceramic substrate 51 is the surface located opposite to the surface of the ceramic substrate 51 in contact with the substrate 11A.

The high frequency circuit 53 is provided on the surface of the circuit pattern 52 . A semiconductor bare chip that serves as a heat source, for example, is mounted on the high-frequency circuit 53 . Also, the circuit 54 is provided on the surface of the circuit pattern 52 . This circuit 54 is mounted with, for example, a semiconductor bare chip that serves as a heat source. The high frequency circuit 53 and the circuit 54 are electrically connected to the circuit pattern 52 via bonding wires 55 .

The case 60 is provided on the ceramic substrate 51 so as to cover the ceramic substrate 51 , the circuit pattern 52 , the high frequency circuit 53 , the circuit 54 and the bonding wires 55 . This case 60 has a case body 61 and a cover 62 . The case 60 is made of, for example, a metal material or a resin material.

The case body 61 constitutes a vertical wall of the case 60 surrounding the ceramic substrate 51 . One end of the case body 61 is attached to the surface of the ceramic substrate 51 or the surface of the circuit pattern 52 . The cover 62 is provided at the other end of the case body 61 so as to cover the circuit pattern 52 , the high frequency circuit 53 , the circuit 54 and the bonding wires 55 .

Therefore, in the electronic device 100, the base material 11A absorbs heat emitted from the semiconductor bare chips of the high-frequency circuit 53 and the semiconductor bare chips of the circuit 54, and the absorbed heat can be transferred to the thermal radiation layer 12A. Then, the electronic device 100 can radiate the heat transferred to the heat radiation layer 12A from the surfaces of the ceramic particles 21 and the surface 22a of the binder 22 as infrared rays. As a result, the electronic device 100 can cool the semiconductor bare chip.

It should be noted that the electronic device 100 can employ heat dissipating members 20 and 30 described later instead of the heat dissipating member 10 described above.

As described above, the heat dissipation member 10 according to Embodiment 1 is provided on the surface of the substrate 11A and includes the heat emission layer 12A containing the ceramic particles 21 and the binder 22. The surface of the ceramic particles 21 extends from the surface 22a of the binder 22. protrude. Therefore, in the heat dissipation member 10 , heat dissipation from the ceramic particles 21 is not blocked by the binder 22 .

In the heat dissipation member 10 , the infrared emissivity of the ceramic particles 21 is higher than the infrared emissivity of the binder 22 . For this reason, heat dissipation member 10 can aim at improvement in heat dissipation.

In the heat radiating member 10, the occupancy rate of the surfaces of the ceramic particles 21 protruding from the surface 22a of the binder 22 on the surface of the heat radiation layer 12A is 20 to 70%. Therefore, the heat dissipation member 10 can prevent the bonding of the ceramic particles 21 to the binder 22 from becoming insufficient.

In the heat dissipation member 10, the grain size of the ceramic particles 21 is 10-100 μm. Therefore, the heat dissipation member 10 can suppress the sedimentation of the ceramic particles 21 inside the binder 22 and the increase in the thickness of the heat radiation layer 12A.

The ceramic particles 21 are any one of aluminum nitride, silicon nitride, boron nitride, zinc oxide, aluminum oxide, crystalline silica, titanium oxide, manganese ferrite ((FeMn)2O3), and ferric oxide (Fe2O3). It is made of one or more materials. Therefore, the heat radiating member 10 can easily obtain the ceramic particles 22 having a higher infrared emissivity than the binder 22 .

In the heat dissipation member 10, the base material 11A is made of any one of metal, resin, and ceramic. Therefore, the heat dissipation member 10 can sufficiently absorb the heat generated from the heat source by the base material 11A. As a result, the heat dissipation member 10 can cool the heat source.

Further, the electronic device 100 according to Embodiment 1 includes the heat dissipation member 10 . Therefore, in the electronic device 100 , the heat emitted from the heat source is transferred to the ceramic particles 21 , so that the heat radiation from the ceramic particles 21 is not blocked by the binder 22 .

The electronic device 100 includes a ceramic substrate 51 in contact with the base material 11A of the heat dissipation member 10, a circuit pattern 52 provided on the ceramic substrate 51, and a high frequency circuit 53 and a circuit 54 provided on the circuit pattern 52 and having semiconductors mounted thereon. Prepare. Therefore, in the electronic device 100 , the heat emitted from the semiconductor is transmitted to the ceramic particles 21 , so that the heat radiation from the ceramic particles 21 is not blocked by the binder 22 . As a result, the electronic device 100 can cool the semiconductors mounted in the high- frequency circuits 53 and 54 .

The electronic device 100 includes a ceramic substrate 51 , a circuit pattern 52 , a high frequency circuit 53 , and a case 60 that covers the circuit 54 . Therefore, the electronic device 100 can protect the ceramic substrate 51 , the circuit pattern 52 , the high-frequency circuit 53 , and the circuit 54 with the case 60 .

Furthermore, in the method for manufacturing the heat radiating member 10 according to Embodiment 1, the binder 22 is diluted with a solvent, the diluted binder 22 is applied to the surface of the base material 11A, and the binder 22 applied to the surface of the base material 11A is coated with , the ceramic particles 21 are sprinkled, the ceramic particles 21 not bound to the binder 22 are removed, the solvent is dried, and the binder 22 is heated and hardened. Therefore, in the heat dissipation member 10 , heat dissipation from the ceramic particles 21 is not blocked by the binder 22 .

Embodiment 2.
A heat radiating member 20 according to Embodiment 2 will be described with reference to FIG. FIG. 8 is a vertical cross-sectional view of a heat radiating member 20 according to Embodiment 2. FIG. It should be noted that configurations having functions similar to those of the configuration described in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 8, the heat dissipation member 20 includes a base material 11B and a heat emission layer 12B. The base material 11B has a role of absorbing heat emitted from a heat source such as a semiconductor element and transmitting the absorbed heat to the thermal emission layer 12B. The thermal radiation layer 12B has a role of radiating the heat transferred from the base material 11B as infrared rays from its surface.

The base material 11B is formed in a semi-cylindrical shape. Therefore, the surface of the substrate 11B on which the heat emitting layer 12B is provided is a curved surface. On the other hand, the thermal radiation layer 12B is provided along the curved surface of the base material 11B. This heat emitting layer 12B has a plurality of ceramic particles 21 and a binder 22. As shown in FIG. A surface 22a of the binder 22 is curved. The surface of the ceramic particle 21 protrudes from the curved surface 22a.

As described above, the heat radiation member 20 according to Embodiment 2 is provided on the surface of the base material 11B and includes the heat radiation layer 12B containing the ceramic particles 21 and the binder 22. The surface of the ceramic particles 21 extends from the surface 22a of the binder 22. protrude. Therefore, the binder 22 does not block heat radiation from the ceramic particles 21 in the heat radiation member 20 .

Embodiment 3.
A heat radiating member 30 according to Embodiment 3 will be described with reference to FIG. FIG. 9 is a vertical cross-sectional view of a heat radiating member 30 according to Embodiment 3. FIG. It should be noted that configurations having functions similar to those of the configuration described in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 9, the heat dissipation member 30 includes a base material 11C and a heat emission layer 12C. The base material 11C has a role of absorbing heat emitted from a heat source such as a semiconductor element and transmitting the absorbed heat to the thermal emission layer 12C. The thermal radiation layer 12C has a role of radiating the heat transferred from the substrate 11C as infrared rays from its surface.

The base material 11C is formed in a flat plate shape. In addition, the surface of the substrate 11C on which the thermal emission layer 12C is provided is an uneven surface. On the other hand, the thermal radiation layer 12B is provided on the uneven surface of the base material 11C. This heat emitting layer 12C has a plurality of ceramic particles 21 and a binder 22. As shown in FIG. A surface 22a of the binder 22 is flat. The surfaces of the ceramic particles 21 protrude from the planar surface 22a.

As described above, the heat radiation member 30 according to Embodiment 3 is provided on the surface of the substrate 11C and includes the heat radiation layer 12C containing the ceramic particles 21 and the binder 22. The surface of the ceramic particles 21 extends from the surface 22a of the binder 22. protrude. Therefore, the binder 22 does not block the heat radiation from the ceramic particles 21 in the heat radiation member 30 .

In addition, within the scope of the disclosure, the present disclosure can freely combine each embodiment, modify any component of each embodiment, or omit any component in each embodiment. .

The heat dissipating member according to the present disclosure is suitable for use as a heat dissipating member, etc., because the heat dissipation from the ceramic particles is not blocked by the binder by projecting the surface of the ceramic particles from the surface of the binder.

10, 20, 30 heat dissipation member, 11A to 11C base material, 12A to 12C heat radiation layer, 21 ceramic particles, 22 binder, 22a surface, 40 heat source, 51 ceramic substrate, 52 circuit pattern, 53 high frequency circuit, 54 circuit, 55 Bonding wire, 60 case, 61 case body, 62 cover, 100 electronic device.

Claims (10)

1. provided on the surface of the base material and comprising a heat emitting layer containing ceramic particles and a binder;
   The heat dissipating member, wherein the surface of the ceramic particles protrudes from the surface of the binder.
2. 2. The heat dissipating member according to claim 1, wherein the infrared emissivity of the ceramic particles is higher than the infrared emissivity of the binder.
3. 2. The heat dissipating member according to claim 1, wherein the surface of the heat emitting layer is occupied by the surface of the ceramic particles protruding from the surface of the binder in a range of 20 to 70%.
4. 2. The heat dissipating member according to claim 1, wherein the ceramic particles have a particle size of 10 to 100 μm.
5. The ceramic particles are aluminum nitride, silicon nitride, boron nitride, zinc oxide, aluminum oxide, crystalline silica, titanium oxide, manganese ferrite ((FeMn)2O3), and ferric oxide (Fe2O3). The heat dissipating member of claim 1, wherein the heat dissipating member is made of one or more materials.
6. 2. The heat dissipating member according to claim 1, wherein the base material is made of any one of metal, resin, and ceramic.
7. An electronic device comprising the heat dissipation member according to any one of claims 1 to 6.
8. a substrate in contact with the base material of the heat dissipation member;
   a circuit pattern provided on the substrate;
   8. The electronic device according to claim 7, further comprising a circuit provided on the circuit pattern and having a semiconductor mounted thereon.
9. 9. The electronic device according to claim 8, further comprising a case provided so as to cover the substrate, the circuit pattern, and the circuit.
10. diluting the binder with a solvent,
    Applying the diluted binder to the surface of the base material,
    Sprinkling ceramic particles on the binder applied to the surface of the base material,
    removing ceramic particles not bound to the binder;
    drying the solvent;
    A method for manufacturing a heat dissipating member, comprising heating and curing the binder.

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