JPH10182235A - Aluminum nitride member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an AlN member less liable to the reduction of heat conductivity at the joined part, having high bonding strength and suitable for use as a heat radiating member for a semiconductor device. SOLUTION: This AlN member consists of AlN sintered compacts joined to each other and the heat conductivity measured through the joined part 3 is >=95% of that of the sintered compacts. This member has an internal cavity for circulating a refrigerant and the cavity communicates with the outside through two or more openings 2 acting as refrigerant feeding and discharging holes. This member has a recess 4 for mounting a semiconductor device in the surface and may have a metallic layer on the bottom of the recess 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum nitride member which has almost no decrease in thermal conductivity at a bonding portion and has a high bonding strength and is suitable as a heat radiating member for a semiconductor device.

[0002]

2. Description of the Related Art Sintered aluminum nitride has high thermal conductivity and electrical insulation, and is therefore used as a heat dissipating member for various devices and equipment. However, the shape of the aluminum nitride sintered body used as the heat dissipating member is not limited to a simple shape such as a plate or a column, but also requires a complicated shape such as a hollow body or a three-dimensional body having a complicated surface. There are cases.

In particular, it is difficult to manufacture a hollow heat radiating member having a cavity therein as an integrally molded product. what if,
When manufacturing by integral molding, first, a method of manufacturing a block of aluminum nitride sintered body and shaving the inside of the block can be considered, but such a method is inferior in production efficiency and yield. However, there is a problem that the manufacturing cost is high.

Therefore, as a method of manufacturing a structure made of an aluminum nitride sintered body having a complicated shape, parts each having a shape capable of forming a cavity therein by joining are separately manufactured, and these are joined together. The above-mentioned structure can be considered.

As the above-mentioned joining method, the following method has been conventionally proposed.

[0006] 1. A method of joining an aluminum nitride sintered body using a glass material such as lead glass (JP-A-2-8847)
No. 1) 2. 2. A method of joining an aluminum nitride sintered body using a brazing material such as silver brazing containing titanium and a resin such as a silicone resin or an epoxy resin. A method in which the bonding surfaces of aluminum nitride sintered bodies are brought into close contact with each other and heated, and bonded by diffusion bonding in which aluminum nitride grain boundary phase components are bonded by diffusion (Japanese Patent Laid-Open No. 2-1247).
No. 78) 4. A paste containing a powder and a binder having the same composition as the ceramic green body is applied to the joining surface of the ceramic green body to be joined, and the green body is brought into close contact with the joining surface and dried, and then subjected to cold isostatic pressing. A method of subjecting to a pressure press treatment and then to a baking treatment (JP-A-5-254)
No. 947)

[0007]

SUMMARY OF THE INVENTION However, the above 1)
The bonding structure obtained by the method of using a glass material as a bonding material between the aluminum nitride sintered bodies described in the above, since the thermal conductivity of such a glass material is lower than that of the aluminum nitride sintered body, An important property of the body has the problem that the thermal conductivity is impaired at the joint. Such a decrease in the thermal conductivity at the joint is fatal when used for the heat dissipation member. That is, in the heat radiating member made of the hollow body, transfer of heat between the refrigerant inside the hollow body and a solid substance such as a semiconductor element in contact with the outer plane of the hollow body is performed through the wall of the hollow body. In this case, when the temperature of the solid substance coming into contact with the outside of the hollow body rises, heat is diffused through the wall of the hollow body and heat exchange is performed with the internal refrigerant. At this time, if there is a joint having low thermal conductivity in the middle of the wall constituting the hollow body, diffusion of heat at the joint is hindered, so that there is a problem that the performance of the heat radiating member is reduced.

[0008] In addition, the joining structure obtained by the method of using a brazing material as a joining material for the aluminum nitride sintered bodies described in the above item 2 is an aluminum nitride sintered body at a joining portion due to the conductivity of the brazing material. In addition to the impaired electrical insulation, the thermal shock resistance is poor due to the difference in the coefficient of thermal expansion between aluminum nitride and the brazing material. On the other hand, in a bonded structure obtained by a method using a resin as a bonding material between aluminum nitride sintered bodies, the thermal conductivity is impaired at a bonded portion. In addition, there is also a problem that the strength and heat resistance of the joint are inferior to those of the aluminum nitride sintered body other than the joint (hereinafter, “base material portion”).

[0009] Further, the bonding method by diffusion described in the above 3 is that the bonding surface is processed with high precision in order to ensure the adhesion between the bonding surfaces of the aluminum nitride sintered body before bonding, or the bonding method is used for bonding. Heat treatment and the like, and it is difficult to perform the above-mentioned treatment until a satisfactory thermal conductivity and adhesive strength are secured at the joint.

[0010] Furthermore, after pressing between the ceramic green bodies to be bonded to the bonding surface described above in 4 through a paste containing a powder and a binder having the same composition as the green bodies, pressurization is performed, followed by firing. Although the joint structure obtained by the above method can sufficiently satisfy the strength of the joint, the thermal conductivity at the joint is not sufficient, and there is still room for improvement.

[0011]

Means for Solving the Problems The present inventors have intensively studied to solve the above problems. As a result, a paste having the same composition as the green body is applied to at least one bonding surface of the green body of two or more aluminum nitrides, and after performing defoaming treatment, the green body is brought into close contact with the bonding surface and dried. By performing degreasing and firing, an aluminum nitride member having an extremely high thermal conductivity at the joint was successfully obtained, and the present invention was proposed.

That is, according to the present invention, the joint between the base materials made of the aluminum nitride sintered body is made of the aluminum nitride sintered body, and the thermal conductivity measured through the joint is the thermal conductivity of the base material. 95% or more of the aluminum nitride member, having a cavity inside, the cavity being connected to the outside by two or more openings, and having a concave portion on the surface.

In the present invention, the thermal conductivity is determined according to JIS.
R 1611 (one-dimensional laser flash method).

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the shape of an aluminum nitride member is not particularly limited. For example, it may be a rectangular parallelepiped as shown in FIG. 1, or may be an arbitrary shape such as a cube, a polygonal column, or a column. The aluminum nitride member 1 shown in FIG. 1 is configured by joining two parts 1-A and 1-B as shown in FIG. And, as shown in FIG.
The cavity 6 is connected to the outside by openings 2 and 2 '. The opening serves as a supply port and a discharge port for supplying or discharging a refrigerant for heat exchange to a cavity inside the aluminum nitride member when the aluminum nitride member of the present invention is used as a heat dissipation member. .

In the present invention, it is sufficient that the cavity 6 is formed so that the refrigerant flows evenly inside the aluminum nitride member. Therefore, as shown in FIG. 2, one large cavity 6 extending inside the aluminum nitride member may be formed, and a cavity having a relatively small cross-sectional area may be formed inside the aluminum nitride member as shown in FIG. It can also be formed by folding and meandering. The number of the cavities 6 is not limited to one, and a plurality of independent cavities may be provided inside the aluminum nitride member.

The openings 2 and 2 'connecting the cavity 6 inside the aluminum nitride member to the outside are provided with at least two coolant supply ports and discharge ports per cavity.
When a plurality of cavities are independent of each other, two or more openings are provided for each of the cavities.

The aluminum nitride member of the present invention has a recess 4 on the surface. An object to be radiated such as a semiconductor element is mounted in the recess 4. When it is necessary to bury the heat radiating object in the concave portion 4,
Is covered with a substrate or the like, the depth of the concave portion may be greater than the height of the object to be mounted. The recesses are usually
Is provided on the upper surface of the aluminum nitride member as shown in FIG. Also, it can be provided on both upper and lower surfaces. The number of the concave portions is not particularly limited, and may be appropriately determined according to the number, size, type, and necessity of electrical insulation of the heat radiation target to be mounted.

Further, in the concave portion 4 of the aluminum nitride member of the present invention, a metal layer is provided on the bottom surface of the concave portion or the outer peripheral projection 5 which comes into contact with the heat radiation target as necessary. This metal layer
In order to mount the object to be radiated by a method such as soldering,
Further, it is used for bonding with the substrate when the concave portion 4 on which the heat radiation target is mounted is covered with a substrate or the like.

As the kind of metal forming the metal layer, a known metal used for metallizing aluminum nitride can be used. For example, a laminate of a metal thin film using titanium or zirconium as a bonding layer with aluminum nitride, specifically, titanium / platinum / gold, titanium / nickel / gold, zirconium / platinum / gold, zirconium / nickel / gold, etc. A laminate of a combination of metal thin films can be used. In addition, gold and tin, lead and tin,
Those formed with alloy films of various solder compositions such as gold and germanium can also be used.

The aluminum nitride member of the present invention has an extremely high thermal conductivity of 95% or more of the thermal conductivity of the base material made of the aluminum nitride sintered body measured through the above-mentioned joint. There has been no report of a case where the thermal conductivity measured through the joint shows such a high value in the aluminum nitride joined structure obtained by the conventionally proposed joining method, and this was first achieved by the manufacturing method described later. It was done.

Further, the aluminum nitride member of the present invention, which exhibits such high thermal conductivity at the joint, is also excellent in joint strength, and is measured with the joint as the center.
It has a point bending strength of 20 kg / mm ² or more.

However, the bending strength and the thermal conductivity which is a feature of the present invention are not necessarily correlated. For example, as shown in a comparative example described later, a known method not depending on the production method of the present invention is used. The joining structure of the obtained aluminum nitride sintered body has a low thermal conductivity of the joining portion even when the bending strength of the joining portion reaches the same strength as the base material, thereby achieving the object of the present invention. Can not.

The interface of the joint of the aluminum nitride member of the present invention is observed by a scanning microscope, and as a result, the joint interface is completely disappeared and homogenized to the extent that it cannot be determined.

The aluminum nitride member of the present invention can be manufactured by the following method. That is, two or more aluminum nitride green bodies in which cavities are formed inside by joining, and a surface of the green body located on the upper surface and / or the lower surface opposite to a bonding surface with another green body. A paste containing the aluminum nitride powder as a main component is applied to at least one bonding surface of the green body in which an opening connecting the internal cavity and the outside is formed. After foaming, the green body is brought into close contact with the joint surface, and dried, degreased and fired.

The aluminum nitride green body used in the above method is formed for each part for constituting the target aluminum nitride member. For example, when obtaining the aluminum nitride member of FIG. 1, 1-A, as shown in FIG.
1-B, respectively.
In order to obtain the aluminum nitride member of the above, the aluminum nitride member is formed into parts having shapes of 1-A, 1-B and 1-C as shown in FIG.

The composition of the green body is composed of aluminum nitride powder and an organic binder, and a composition in which a sintering aid, a plasticizer, and the like are blended as necessary is generally employed. As the organic binder, polyvinyl butyral, polymethyl methacrylate, carboxymethyl cellulose, polyvinyl pyrrolidone, polyethylene glycol,
Known materials such as polyethylene oxide, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polystyrene, acrylic resin, ethylcellulose, waxes and the like can be mentioned.

Examples of the sintering aid include alkaline earth metal compounds such as magnesium oxide, calcium oxide and strontium oxide, yttrium oxide, lanthanum oxide, erbium oxide, ytterbium oxide, holmium oxide, and the like.
One or two or more rare earth element compounds such as dysprosium oxide and gadolinium oxide and complex oxides such as calcium aluminate are generally used. Further, examples of the plasticizer include phthalic acid-based and glycol-based plasticizers.

The mixing ratio of the organic binder in the green body may be an amount sufficient to maintain the strength of the green body, but aluminum nitride applied to the bonding surface of the green body at the time of subsequent bonding In order to suppress drying due to absorption of the vehicle in the paste containing powder as a main component into the green body and to secure time for the defoaming treatment, the paste is contained at least 1% by weight or more, preferably 4% by weight or more. It is preferable that the mixing ratio be appropriately selected within such a range according to the molding method. However,
In order to avoid the influence of residual carbon at the time of degreasing, the ratio of the organic binder is desirably 20% by weight or less, particularly preferably 6% by weight or less.

The mixing ratio of the sintering aid in the green body is preferably 0 to 10% by weight, particularly preferably 2 to 7% by weight. The plasticizer is used in an amount of 0 to 80 with respect to the organic binder.
% By weight, especially 10 to 50% by weight, is suitable.

The method for molding the green body is not particularly limited, and a known molding method is employed. For example, as a molding method, a known molding method such as hydraulic press molding, cold isostatic pressing, extrusion molding, injection molding, and casting is employed.

The form of the molding material used in such a molding method is prepared into a powder form wetted by adding a vehicle to the above-mentioned composition, or a paste-like or clay-like form obtained by adding a vehicle to the above-mentioned composition. Examples include a form and a form as a mere powder mixture without using a vehicle. A suitable form may be selected and used according to the molding method. As the above-mentioned vehicle, an organic solvent which does not react with aluminum nitride and is easily evaporated is preferably used. Generally, those having a boiling point of less than 150 ° C, preferably 120 ° C or less, particularly preferably 40 to 120 ° C, are suitable. Specific examples of the vehicle include toluene, ethyl alcohol,
Isopropyl alcohol and the like.

In the method for manufacturing an aluminum nitride member of the present invention, the composition of the paste applied to the bonding surface of the green body of aluminum nitride contains aluminum nitride powder as a main component, and a vehicle is added thereto to form a paste. Is used without any particular limitation, but with respect to the solid content excluding organic compound components such as an organic binder, a composition containing the same solid content as the green body, for example, a sintering aid for aluminum nitride It is preferable that the compositions have the same ratio.

As a vehicle constituting the paste, an organic solvent which does not react with aluminum nitride is generally used. Particularly preferably, in the defoaming treatment described below,
Those which have a low vapor pressure at room temperature and are difficult to dry so that the vehicle does not dry within the standing time for defoaming, generally have a boiling point of 150 ° C. or higher, preferably 180 ° C. or higher, especially 1 ° C.
Those having a temperature of 80 to 300 ° C are preferred. Specific examples of the vehicle include terpineol, n-butyl carbitol acetate, and the like.

The solid content concentration of the paste cannot be specified unconditionally depending on the method of applying the paste to the green body.
About 40 to 85% by weight is preferable. Further, at the above solid content concentration, a suitable viscosity of the paste is 10,000 to 1
50,000 centipoise, especially 20000-5000
It is 0 centipoise. That is, when the viscosity is less than 10,000 centipoise, it tends to be difficult to secure a sufficient coating thickness on the joint surface by one coating. Also,
If the viscosity of the paste exceeds 150,000 centipoise, a long time is required for defoaming in the defoaming treatment described later, and in some cases, the defoaming tends to be incomplete.

In the present invention, the paste applied to the joint surface is subjected to the defoaming process described later efficiently, and the defoaming process is performed before the application in order to reduce defects in the joint portion of the obtained aluminum nitride member. It is preferred to do so.

In the method for manufacturing an aluminum nitride member according to the present invention, an operation of applying the paste to the bonding surface of the green body is performed. In a mode in which the paste is applied to such a joint surface, the paste may be applied to at least one of the joint surfaces, but it is more preferable to apply the paste to both surfaces to be joined.

The paste can be applied to the green body by a known method such as brush coating, roller coating, dipping, spraying, printing, and spin coating.
Desirably, a roller coating method and a dipping method that can obtain a uniform coating thickness are preferable. More preferably, it is more preferable to adopt a coating method by a printing method in order to make the thickness of the paste uniform.

The thickness of the paste applied to the surface of the green body is not particularly limited. However, in the defoaming treatment described below, it is preferable that the thickness is such that the wet state can be maintained for 1 minute or more, preferably 3 minutes or more after application. It is possible to remove air bubbles in the paste and to smooth the surface, and it is possible to reproduce an aluminum nitride member having a thermal conductivity measured through a joint portion of 95% or more of the thermal conductivity of the base material portion with good reproducibility. Preferred to obtain.

Although the thickness cannot be unconditionally limited by the boiling point of the vehicle constituting the paste, it is generally 20 to 500 μm, preferably 50 to 300 μm.
It is. That is, the drying of the applied paste is more predominant in drying by absorption of the vehicle into the green body than in drying by evaporation of the vehicle. Therefore, in order to suppress drying of the surface of the applied paste, it is preferable to increase the thickness of the paste to some extent.

In the production method of the present invention, the defoaming treatment
A method for removing air bubbles contained in the paste applied to the surface of the green sheet is employed without particular limitation. Generally, in the case of normal pressure, it is preferable that the paste is allowed to stand for at least 2 minutes, preferably at least 3 minutes, more preferably at least 5 minutes after application of the paste. In the case where the apparatus is allowed to stand under reduced pressure, the above time can be reduced. When the defoaming is performed under reduced pressure, it is preferable to perform the depressurization at a reduced pressure of 5 × 10 ⁴ to 10 ⁵ Pa. As the temperature in the defoaming treatment, a temperature around room temperature is generally adopted, but 0 to 50 ° C., preferably,
A range of 10 to 25C is appropriate.

After the defoaming process is performed, before the paste applied to the green body is dried, that is, in a state where the surface of the green body is wet by the paste, the bonding surfaces of the green bodies are brought into close contact with each other. As the pressure for such close contact, a range in which the green body is not damaged is employed. Generally, 10
1000 g / cm ^2, in particular, 15~200g / cm ² are suitable.

Next, the operations of drying, degreasing, and firing the green body having the bonding surfaces adhered thereto are sequentially performed. Known conditions for the drying, degreasing, and baking are employed without particular limitation. For example, drying is preferably performed in a temperature range from room temperature to a temperature lower than the boiling point of the vehicle used. Generally, it is desirable to perform degreasing in an inert atmosphere such as nitrogen or in air, and the degreasing temperature at that time may be selected from the range of 300 to 1000 ° C. according to the above atmosphere. Further, sintering is performed in a non-oxidizing atmosphere
It is common to carry out at an arbitrary temperature selected from the range of 00 to 1950 ° C.

The aluminum nitride member produced in this way has a joint having substantially the same thermal conductivity and strength as the base material.

The interface at the joint of the aluminum nitride member of the present invention produced by the above method is observed by a scanning microscope, and as a result, the joint interface is completely disappeared and homogenized to the extent that it cannot be discriminated.

The above results show that when a paste containing the composition powder and the organic binder having the same composition as the constituent powder of the green body was applied to the surface of the green body, the paste filled the fine irregularities on the surface of the green body. Presumes that the bonding interface between the paste and the green body disappears by infiltrating from the surface of the green body to the inside, and it is as if the molded body was integrally formed. In addition, by performing a defoaming treatment on the paste forming the joint, defects in the joint can be eliminated, and an aluminum nitride member having a joint having high thermal conductivity and high strength can be obtained.

[0046]

As will be understood from the above description, the aluminum nitride member of the present invention has a very small decrease in the thermal conductivity at the joint with respect to the aluminum nitride sintered body as the base material, and has a high thermal conductivity. It has bonding strength.
Furthermore, the aluminum nitride member of the present invention efficiently transfers heat generated during operation of the high-power semiconductor element to the refrigerant flowing through the cavity through the aluminum nitride sintered body when the high-power semiconductor element is mounted in the recess. Can conduct. Therefore, the aluminum nitride member of the present invention can be suitably used as a heat dissipation member of a semiconductor element.

[0047]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but it should be understood that the present invention is by no means restricted to such specific Examples.

In the examples, the thermal conductivity of the aluminum nitride sintered body was measured by LF / TCM FA8510B (Rigaku Denki Co., Ltd.) using a one-dimensional laser flash method. Also, the measurement of the three-point bending strength
The measurement was performed according to JIS R1601.

Example 1 An aluminum nitride member having the structure shown in FIG. 1 was manufactured by the following method. A mold comprising 100 parts by weight of aluminum nitride powder (H grade, manufactured by Tokuyama Corporation), 5 parts by weight of yttrium oxide fine powder as a sintering aid and 4 parts by weight of methyl acrylate as an organic binder was filled in a mold. By pressing at a pressure of 1000 kg / cm ² , a green body having a cavity 4 for forming the cavity 6 as shown in FIG. 2 and the concave portion 4 on the upper surface, and a green body having only the cavity were formed. Next, openings 2 and 2 'for pipe attachment are provided on the side surfaces of the latter green body.
Was provided.

On the other hand, the paste is made of aluminum nitride 10
It was prepared by mixing 0 parts by weight, 5 parts by weight of yttrium oxide fine powder as a sintering aid, 3 parts by weight of ethyl cellulose (grade 4 centipoise) as an organic binder, and 50 parts by weight of terpineol as a vehicle. The viscosity of the obtained paste was 20,000 centipoise. The paste obtained by the above method was applied to each bonding surface of the green body by using a screen of 80 mesh for about 7 minutes.
Printing was performed at a thickness of 0 μm. 9.33x after paste printing
By removing the bubbles from the printed paste and smoothing the surface of the paste by performing a defoaming treatment by allowing the paste to stand for 2 minutes under a reduced pressure of 10 ⁴ Pa. After that, 30 g / cm ²
The bonding surfaces of the green bodies were brought into close contact with each other at the pressure described below. The adhered green body was dried at room temperature for 24 hours, degreased in air at 600 ° C., baked in nitrogen atmosphere at 1830 ° C., and 60 mm × 60 mm × 40 mm and 50 mm ×
An aluminum nitride member having a recess of 50 mm × 15 mm (depth) was obtained.

The thermal conductivity of the obtained aluminum nitride member was measured by a one-dimensional method. The size of the sample for measurement was φ10 × t4 mm, and this sample was cut out from the aluminum nitride member obtained by the above method so as to include a joint and the joint became the center of the thickness of the sample. . A sample of the same size consisting of a base material portion not including the joint was also prepared, and the thermal conductivity was measured.

The bending strength of the joint was measured by a three-point bending method by preparing a sample so that the joint was at the center. The results are shown in Table 1. The thermal conductivity of the joint was 100% of that of the base material, and the flexural strength was 99% of that of the base material.

Further, titanium (0.2 μm), nickel (2 μm) and gold (0.3 μm) are sequentially formed on the entire upper surface of the aluminum nitride member where the concave portion is formed by sputtering, and then the bottom portion of the concave portion is formed. Etching was performed by a wet etching method so that only the metal layer remained. Next, a 120 W heater was soldered on the metal layer. Resin pipes were adhered to the two openings of the aluminum nitride member with an epoxy resin to provide cooling water supply and discharge ports.

Water at 20 ° C. was supplied to the cooling water supply port at a flow rate of 150 cc / min, and electricity was supplied to the heater. After the steady state, the heater temperature was 70 ° C., and the temperature of the water exiting the outlet was 29 ° C.

Comparative Example In Example 1, after the paste was printed on the bonding surface of the green body, the respective bonding surfaces of the two green bodies were immediately adhered to each other with a pressure of 30 g / cm ² without degassing. I let it. Thereafter, drying, degreasing, and firing were performed in the same manner as in Example 1 to obtain an aluminum nitride member. About the obtained aluminum nitride member, the thermal conductivity and the bending strength were measured in the same manner as in Example 1. The results are shown in Table 1. The thermal conductivity of the joint was 90% of that of the base material, and the bending strength was 46% of that of the base material.

Example 2 Example 1 was repeated in the same manner as in Example 1 except that the time of the defoaming treatment was changed to 3 minutes after the paste was applied to the bonding surface of the green body, and the pressure was reduced to normal pressure. An aluminum nitride member was obtained. About the obtained aluminum nitride member,
The thermal conductivity and bending strength of the joint were measured in the same manner as in Example 1. The results are shown in Table 1. The thermal conductivity of the joint was equal to that of the base material portion, and the bending strength was 87% of that of the base material portion.

Example 3 Example 1 was repeated in the same manner as in Example 1 except that the time of the defoaming treatment was changed to 7 minutes after the paste was applied to the bonding surface of the green body, and the pressure was reduced to normal pressure. An aluminum nitride member was obtained. About the obtained aluminum nitride member,
The thermal conductivity and bending strength of the joint were measured in the same manner as in Example 1. The results are shown in Table 1. The thermal conductivity of the joint was equal to that of the base material, and the bending strength was 94% of that of the base material.

[0058]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a perspective view showing a typical embodiment of an aluminum nitride member of the present invention.

FIG. 2 is a perspective view showing a state before joining the aluminum nitride member of FIG. 1;

FIG. 3 is a perspective view showing another typical embodiment of the aluminum nitride member of the present invention.

FIG. 4 is a perspective view showing a state before joining of the aluminum nitride member of FIG. 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Aluminum nitride member 1-A, 1-B, 1-C Parts of aluminum nitride member 2, 2 'Opening part 3 Joining part 4 Concave part 5 Outer peripheral protrusion of concave part 6 Cavity

Claims (2)

[Claims] A joint between base materials made of an aluminum nitride sintered body is made of an aluminum nitride sintered body, and the thermal conductivity measured through the joint is 95% or more of the thermal conductivity of the base material. An aluminum nitride member having a cavity inside, the cavity being connected to the outside by two or more openings, and having a concave portion on the surface. 2. The aluminum nitride member according to claim 1, wherein a metal layer is provided at the bottom of the concave portion.