JP2003342073A - Aluminum nitride sintered compact having metallized layer and its manufacturing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aluminum nitride sintered compact having a metallized layer free from cracks, which shows a high bond strength between aluminum nitride and the metallized layer. <P>SOLUTION: In the aluminum nitride sintered compact having the metallized layer at its surface and/or inside, the metallized layer comprises W which is a conductive, high-melting point metal and an adhesion-enhancing inorganic material comprising at least two selected from Al<SB>2</SB>O<SB>3</SB>, SiO<SB>2</SB>and MgO, wherein the inorganic material has a coefficient of thermal expansion of 3×10<SP>-6</SP>-6×10<SP>-6</SP>/K. Preferably, mullite (3Al<SB>2</SB>O<SB>3</SB>2SiO<SB>2</SB>) or an inorganic powder obtained by pulverizing the oxide mixture vitrified at a temperature not lower than its melting point, is used as the inorganic material. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate for semiconductors and ICs, an aluminum nitride sintered body having a metallized layer, which is useful as a packaging material, and a method for producing the same.

[0002]

2. Description of the Related Art Aluminum nitride sintered bodies are excellent in heat dissipation due to their high thermal conductivity, and are also excellent in electrical insulation and mechanical strength. Often used as a material.

When the aluminum nitride sintered body is used as a substrate or a package, it is necessary to form a metallized layer on the surface and / or inside of the aluminum nitride sintered body. However, aluminum nitride is poor in wettability with a metal, so that metallization is difficult. Therefore, in order to improve the wettability and secure the adhesive strength with aluminum nitride when metallized, various components for enhancing the adhesion have been conventionally studied.

A conventional example in which the bonding strength between the aluminum nitride sintered body base material and the metallized layer is increased by using the metallized layer forming material containing such an adhesion-enhancing component is as follows. Is the street.

(JP-A-8-109084) Mo,
One or more metals selected from W and Ta, one or more metals selected from Al and rare earth elements, and Ti, Zr, H
The bonding strength is increased by using a material to which the adhesion-enhancing component of at least one selected from f is added as a material for forming the metallized layer.

(Japanese Patent Application Laid-Open No. 63-115393) W and / or Mo metal containing SiO ₂ , Al ₂ O ₃ and CaO as main components, and MgO, BaO and B ₂ if necessary.
The bonding strength is increased by using, as a material for forming the metallized layer, a material to which an adhesion-enhancing component mixed with at least one of O ₃ is added.

(JP-A-63-195183) WO and / or Mo metal containing CaO, BaO, SrO, Y ₂
One or more of O ₃ , CeO ₂ , and Gd ₂ O ₃ , and Al ₂ O ₃ and Al
The bonding strength is increased by using a material to which the adhesion-enhancing component consisting of one or more of N is added as a material for forming the metallized layer.

(JP-A-6-116068) Mo,
Adhesion in which a second metallization layer is laminated on a first metallization layer containing at least one selected from W and Ta, and the second metallization layer contains at least SiO ₂ or Al ₂ O _3. The bonding strength is increased by including the reinforcing component.

On the other hand, in recent years, the metallization layer may be required to have a low resistance, and it has become necessary to increase the thickness of the metallization layer. Usually, the metallization layer thickness is about 0.02 mm, but in some cases it may be about 0.1 mm. Further, in recent years, aluminum nitride has been often used as a package, but in this case, there is a high demand for a multilayer wiring board structure, and a through hole (via hole) is a conductive portion which is metallized in order to secure conduction between layers. Vias need to be formed. Conventionally, the via diameter was 0.2 to 0.25 mm before firing. After sintering, it is generally 0.15 to 0.2 mm.
However, there is a strong demand for the vias to have a low resistance, which is 0.3 to 0.45 mm in recent years, and 0.25 to 0.4 m after sintering.
A via diameter of m is often required.

However, according to the conventional measures, although the bonding strength between the metallized layer and aluminum nitride is improved, if the metallized layer becomes thicker or the through holes are filled with the metallized layer, It was found that cracks may occur inside the metal. That is, when the thickness of the metallization is about 0.02 mm, which is a normal metallization, there is no problem in the bonding strength and no defects such as cracks are generated in the metallization layer, but the thickness of the metallization is less than 0. When the thickness is increased to about 1 mm, cracks are generated in the metallized layer, the strength of the metallized layer itself is reduced, and in severe cases, the metallized layer is broken. Similar problems also occurred when attempting to fill the through-hole with a metallization layer. Although there was no problem in the conventional metallization of a through hole having a through hole diameter, a problem occurred when the through hole diameter was increased to 0.3 mm before sintering, and therefore the metallization layer was thickened. It was thought that it was due to the same cause as in the above case.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and prevents cracks from occurring in the metallized layer even when the metallized layer becomes thick, and at the same time, aluminum nitride is used. High bond strength with metallized layer,
An object is to provide an aluminum nitride sintered body having a metallized layer and a method for manufacturing the same.

[0012]

To achieve the above object, the present invention has the following constitution. (1) In the aluminum nitride sintered body having a metallized layer on the surface and / or inside, the metallized layer is composed of a conductor refractory metal and an adhesion-enhancing inorganic substance, the conductor refractory metal is W, and the adhesion is The thermal expansion coefficient of the reinforcing inorganic material is 3 × 10.
^-6 / ^K~6 × 10 ^-6 / K aluminum nitride sintered body having a metallized layer, which is a. (2) Nitriding having a metallized layer as described in (1) above, wherein the adhesion-enhancing inorganic substance is an oxide mixture consisting of at least two kinds selected from Al ₂ O ₃ , SiO ₂ and MgO. Aluminum sintered body. (3) Mullite (3Al
₂ O ₃ .2SiO ₂ ) is used, and an aluminum nitride sintered body having a metallized layer according to the above (2) is used.

(4) A ceramic green sheet containing aluminum nitride as a main component is coated with a paste containing a conductor refractory metal and an adhesion-enhancing inorganic substance, and the whole is sintered at the same time to form a nitride having a metallized layer. In the method for producing an aluminum sintered body, the conductor refractory metal contained in the paste is W, and the adhesion enhancing inorganic substance is an oxide composed of at least two kinds selected from Al ₂ O ₃ , SiO ₂ and MgO. A method for producing an aluminum nitride sintered body having a metallized layer, which is a mixture. (5) Mullite (3Al
₂ O ₃ .2SiO ₂ ) is used, The method for producing an aluminum nitride sintered body having a metallized layer according to the above (4). (6) The metallized layer according to the above (4) or (5), characterized in that, as the inorganic substance for enhancing adhesion, an inorganic substance powder obtained by vitrifying at a temperature equal to or higher than the melting point of the oxide mixture and then pulverizing is used. Manufacturing method of aluminum nitride sintered body.

(7) A through hole is punched in a ceramic green sheet containing aluminum nitride as a main component, and a paste containing a conductor refractory metal and an adhesion enhancing inorganic substance is filled in the through hole, and then the whole is baked at the same time. In the method for producing an aluminum nitride sintered body having a metallized layer by binding, the conductor refractory metal contained in the paste is W, and the adhesion enhancing inorganic substance is Al ₂
A method for producing an aluminum nitride sintered body having a metallized layer, which is an oxide mixture composed of at least two kinds selected from O ₃ , SiO ₂ , and MgO. (8) Mullite (3Al
₂ O ₃ .2SiO ₂ ) is used, and the method for producing an aluminum nitride sintered body having a metallized layer according to the above (7). (9) The metallized layer according to the above (7) or (8), characterized in that, as the inorganic substance for enhancing adhesion, an inorganic substance powder that is vitrified at a temperature equal to or higher than the melting point of the oxide mixture and then pulverized is used. Manufacturing method of aluminum nitride sintered body.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An aluminum nitride sintered body base material constituting an aluminum nitride sintered body having a metallized layer of the present invention contains aluminum nitride powder as a main component and is widely known as a sintering aid. 0.1 to 10 wt% of powder of compound such as yttrium, rare earth metal, alkali metal, etc.
%, And is obtained by molding and sintering the powder for sintering added.

As a molding method, aluminum nitride powder and sintering aid powder are mixed with a resin binder such as polyvinyl butyral (PVB) and a plasticizer such as dibutyl phthalate (DBP), and the mixture is granulated and then pressed. Or the like, or after mixing, a green sheet may be produced by a doctor blade method. Further, the extrusion method or the like can also be applied.

However, in order to obtain a multilayer structure, it is necessary to laminate the aluminum nitride and the metallized layer before sintering and co-fire them. In this case, green sheets are often used because press molding is difficult. In addition, since it is difficult to form through holes and vias by press molding, it is common to use a green sheet for simultaneous firing. Below, the manufacturing method by co-firing mainly using a green sheet will be described.

If necessary, through holes are formed in the green sheet by using punches or the like. This through hole is filled with a paste having a composition described later. As a filling method, a known method such as screen printing can be applied. Further, if necessary, circuit wiring and the like are similarly formed by applying a paste having a composition described later. As a coating method, a well-known method such as screen printing, brush coating, and spin roller coating can be applied.

In the present invention, the paste used for forming the via and the circuit wiring comprises a conductor powder, an adhesion enhancing inorganic substance powder, a resin binder and a solvent, and the conductor powder is W powder. This is because this green sheet needs to simultaneously sinter aluminum nitride and the conductor-forming composition, but the sintering temperature of aluminum nitride powder and W powder can be close, and the coefficient of thermal expansion is also close. Therefore, it is preferable to use W powder as the conductor powder.

However, in order to bring the sintering temperatures of the aluminum nitride powder and the W powder close to each other, the average particle diameter of the W powder should be 1 μm.
It is preferable that the thickness is not less than m and not more than 5 μm. In many cases, W powders having different average particle diameters are mixed and used, but in this case, W having an average particle diameter of 1 μm or more and 5 μm or less is used.
Is preferably 50 wt% or more. If the average particle size of the W powder is smaller than 1 μm, the sintering start temperature of W becomes too low as compared with the sintering temperature of aluminum nitride, so that cracks easily occur at W or at the interface between aluminum nitride and W. On the other hand, if the average particle size of the W powder is larger than 5 μm, the sinterability of W is significantly deteriorated, and W is not sufficiently sintered at the sintering temperature of aluminum nitride, which is not preferable.

The adhesion-enhancing inorganic powder has a coefficient of thermal expansion of 3 × 10 ⁻⁶ / K to 6 × 10 ⁻⁶ after sintering.
It is preferably / K. Conventionally, there is no concept of controlling the coefficient of thermal expansion of the adhesion enhancing inorganic substance alone, and as described above, only matching of the coefficient of thermal expansion between the aluminum nitride and the conductor material has been considered. As in the past, no problem occurred when the printed film thickness was thin. However, as the printed film thickness increases and the need for vias and vias increases with the multilayering of aluminum nitride, unless the coefficient of thermal expansion of the adhesion-enhancing inorganic substance is controlled, cracks may occur in the metallized layer after sintering. Occurs,
It has been found that there is a problem that the strength of the metallized layer itself is also reduced. In order to avoid these, the coefficient of thermal expansion of the inorganic substance for adhesion enhancement should be 3 × 10 ⁻⁶ / K to 6 × 10 ⁻⁶ / K.
It turns out that it is necessary to do.

Furthermore, in order for the above-mentioned adhesion-enhancing inorganic powder to have the desired characteristics, it must be softened or melted near the sintering temperature of aluminum nitride, which will be described later. In the sintering process of aluminum nitride and W, the inorganic powder inhibits the sintering of W while the sintering temperature is lower than the softening and melting temperatures of the adhesion enhancing inorganic powder. On the other hand, the sintering temperature softens,
Once the inorganic powder softens and starts melting above the melting temperature, it has the function of accelerating the sintering of W. When aluminum nitride and W are co-sintered, the softening and melting temperatures of the adhesion-enhancing inorganic must also be close to the sintering temperature of aluminum nitride in order to match the timing of W sintering with aluminum nitride.

The adhesion-enhancing inorganic material softens or melts at the W portion to bond W grains to each other, bond aluminum nitride to W, and the like. If the softening and melting temperatures are too low, the adhesion-enhancing inorganic substance diffuses not only in the W portion but also in the aluminum nitride portion due to the capillary phenomenon. On the other hand, if the softening and melting temperatures are too high, the adhesion-enhancing inorganic substance remains a powder, and desired properties cannot be obtained.

An oxide mixture can be used as the adhesion-enhancing inorganic component. In particular, considering the softening and melting temperatures, the oxide mixture of at least two kinds selected from Al ₂ O ₃ , SiO ₂ and MgO can be softened and the melting temperature can be brought close to the sintering temperature of aluminum nitride. ,preferable.

The inorganic substance for enhancing adhesion in the paste is Al
The powders of ₂ O ₃ , SiO ₂ and MgO may be mixed in the required amounts, or powders of composites such as mullite (3Al ₂ O ₃ · 2SiO ₂ ) and spinel (Al ₂ O ₃ · MgO) may be used. May be.

For example, since MgO easily segregates, MgO
It is better to use spinel powder than to use powder. Further, in order to ensure a uniform mixed state, it is preferable to reduce the types of powder used. For example, it is preferable to use mullite (3Al ₂ O ₃ .2SiO ₂ ) which does not contain MgO which tends to segregate and which can be composed of only a single powder, as the adhesion-enhancing inorganic substance from the viewpoint of obtaining a mixture having a uniform composition. Therefore, it is possible to effectively prevent the occurrence of cracks in the metallized layer. From the same viewpoint, it is easy to ensure a uniform mixed state by using an inorganic material powder which is vitrified at a temperature equal to or higher than the melting point of the adhesion enhancing inorganic material and then ground.

The content of the adhesion-enhancing inorganic material contained in the paste, that is, the content of the adhesion-enhancing inorganic material in the metallized layer is preferably 1 to 20 wt%. If the content is less than 1 wt%, the effect of the adhesion-enhancing inorganic substance does not appear. On the other hand, if the content exceeds 20 wt%, the increase in the resistance value of the metallized layer cannot be ignored,
Not preferable.

A paste is obtained by dispersing these powders in a resin binder such as ethyl cellulose or nitrocellulose and a solvent such as butyl carbitol or terpineol. Usually, the resin binder is mixed in an amount of 1 to 3 parts by weight, when W powder and the inorganic substance for enhancing adhesion are 100 parts by weight,
The solvent is mixed in an amount of 3 to 15 parts by weight.

After filling the through holes of the aluminum nitride green sheet with the paste as described above or printing the circuit, the green sheets are laminated as needed. Lamination is performed by setting the sheets in a mold and then thermocompressing them under a pressure of about 5 to 10 MPa for about 10 to 20 minutes while heating them to about 50 to 80 ° C. with a pressing machine. If necessary, a solvent or an adhesive may be applied between the sheets.

The laminated sheets are cut into arbitrary shapes and then sintered. Prior to sintering, a degreasing treatment may be performed at a temperature of, for example, 300 ° C. to 800 ° C. in order to remove the resin binder, the plasticizer, and the paste medium of the aluminum nitride green sheet.

Sintering is carried out in a non-oxidizing atmosphere, but it is preferably carried out in a nitrogen atmosphere. The sintering temperature and the sintering time are set so that the characteristics such as the thermal conductivity of the aluminum nitride sintered body after sintering have desired values. Generally the sintering temperature is 1
The temperature is 600 ° C. to 2000 ° C., and the sintering time is set to about 1 hour to 5 hours.

As described above, in the aluminum nitride sintered body having the metallized layer of the present invention, even if the metallized layer becomes thicker, cracks do not occur in the metallized layer, and the metallized layer and aluminum nitride sinter are formed. The joint strength with the body is high. Further, even if the simultaneous sintering method using a green sheet, which has been mainly described so far, is not used, for example, after the aluminum nitride sintered body is simply sintered, a paste that realizes the metallized layer of the present invention is applied. In a non-oxidizing atmosphere, 1600 ° C to 20
Even when the metallization layer is thickened by sintering at 00 ° C., the metallization layer has a metallization layer with a high bonding strength without causing cracks in the metallization layer. An aluminum nitride sintered body can be obtained.

[0033]

Example 1 97 parts by weight of aluminum nitride powder and 3 parts by weight of Y ₂ O ₃ powder were mixed, and polyvinyl butyral was used as a resin binder and dibutyl phthalate was used as a plasticizer. 10 parts by weight and 5 parts by weight were mixed and a green sheet having a thickness of 0.5 mm was formed by a doctor blade method. Use the mold to make this 10
After punching out to 0 mm x 100 mm, φ with a puncher
A 0.3 mm through hole was formed.

On the other hand, a paste sample having a composition as shown in Table 1 was prepared. In each of the paste samples shown in Table 1, 85 parts by weight of W powder and 15 parts by weight of inorganic powder for enhancing adhesion were mixed with a resin binder so that the ratio of the inorganic material in the metallized layer of the through hole was 15 wt%. And 5 parts by weight of ethyl cellulose as a solvent and 5 parts by weight of butyl carbitol as a solvent. The W powder used had an average particle size of 2 μm. Al ₂ O ₃ and Si in the inorganic powder for adhesion enhancement shown in Table 1
The composition ratio of O ₂ and MgO is 1 for the inorganic powder for adhesion enhancement.
This is the value when 00 is set. Further, in Sample 7, mullite was used as the adhesion-enhancing inorganic powder. The value of the coefficient of thermal expansion of the inorganic substance shown in Table 1 is a value measured by making an evaluation pellet with only the inorganic substance powder for adhesion enhancement.

[0035]

[Table 1]

This paste sample was filled in the through hole using a screen printer. Further, 5 parts by weight of butyl carbitol was mixed with the same paste to reduce the viscosity, and circuit printing was performed using a screen having a screen printing machine of 325 mesh and an emulsion thickness of 20 μm.

Next, two sheets after printing were laminated and laminated. Lamination was performed by stacking two sheets on a mold and heat-pressing for 2 minutes at a pressure of 10 MPa while heating at 50 ° C. with a press. After that, degreasing is performed at 600 ° C. in a nitrogen atmosphere, and 1800 in a nitrogen atmosphere.
Sintering was performed under the condition of 3 ° C. for 3 hours.

After sintering, a metallization layer having a thickness of 10 μm was formed on the circuit printed portion on the aluminum nitride sintered body, and the metallization layer was formed in the through hole of φ0.25 mm in the via portion. Had been formed. In this state, the presence or absence of cracks in the printed circuit part and the via part is checked for 40
It was confirmed with a double microscope.

Next, a Ni plating layer having a thickness of 3 to 5 μm was formed on the metallization layer of the aluminum nitride substrate on which this metallization layer was formed by electroless plating. Next 800 ° C
Anneal the plating layer in the homing gas of
Fe-Ni- with 0.5 mm and tensile strength of 500 MPa
Co alloy pins were brazed with silver braze. The brazing temperature was 800 ° C., and the atmosphere was a mixed gas atmosphere of hydrogen and nitrogen. Next, the aluminum nitride substrate is fixed, and Fe
The -Ni-Co alloy pin was pulled to measure the strength, and the fracture mode was observed. Further, in order to confirm the presence or absence of cracks in the circuit printed portion and the via portion, the cross section was polished and observed with an electron microscope (1000 times).

The results of these evaluations are shown in Table 1. According to the paste composition of the present invention, no crack was generated on the circuit printed surface and the via portion. On the other hand, regarding the samples other than the present invention, cracks were found not only in the vias but also in the surrounding aluminum nitride in Sample 3 having a small coefficient of thermal expansion of the inorganic material. Further, regarding Samples 1 and 2 having a large coefficient of thermal expansion, cracks were observed in the vias.

Regarding tensile strength and fracture mode,
In the paste formulation of the present invention, the brazed portion between the metallized layer and the Fe-Ni-Co wire fractured at a tensile strength of 20 MPa. From this, it can be seen that the bonding strength between the aluminum nitride and the metallized layer is 20 MPa or more. On the other hand, some metallized layers formed with a paste formulation outside the scope of the present invention had a bond strength lower than 20 MPa, and fracture occurred in the metallized layer directly above the via.

[Example 2] With respect to the sample 7 of Example 1,
The influence was investigated by changing the proportion of the inorganic substance in the metallized layer of the through hole. Table 2 shows the changed ratios. The experimental method is such that the through hole diameter is 0.1 m after sintering.
except that I changed the puncher to be m
Same as Example 1.

The sample surface was polished after sintering,
The presence or absence of cracks was confirmed by an electron microscope at 1000 times. In addition, the conductivity of the upper and lower surfaces of the sample was measured with a tester, and the non-defective rate of the conductive via was measured. The results are shown in Table 2. When the proportion of the inorganic through holes in the metallized layer was 1 to 20 wt%, no cracks were generated and the conduction was good. When this ratio was smaller than 1 wt%, cracks were found in the via. On the contrary, when the content was more than 20 wt%, a via having no conduction was recognized.

[0044]

[Table 2]

[Embodiment 3] Regarding the sample 7 of the embodiment 1,
The effect was investigated by changing the particle size of the W powder used.
The experimental method and the like were the same as in Example 1. Each sample was evaluated in the same manner as in Example 1 based on the tensile strength of the pin and the presence or absence of cracks in the via and aluminum nitride. W
When the average particle size of the powder was 1 μm to 5 μm, no particular change was observed in the characteristics.

[0046]

[Table 3]

[0047]

According to the present invention, in a metallized layer formed on a sintered aluminum nitride body and comprising a conductor refractory metal and an adhesion-enhancing inorganic substance, the conductor refractory metal has a coefficient of thermal expansion close to that of aluminum nitride. In the case of selecting, the coefficient of thermal expansion of the adhesion-enhancing inorganic material is also 3 × 10 ⁻⁶ / K to 6
By setting it to be 10 ⁻⁶ / K, even when the metallization layer is thickened to about 0.1 mm or the metallization layer is formed in the through hole, cracks can be prevented and the adhesion strength with AlN can be increased. I can. Therefore, aluminum nitride is used as an IC
It can be suitably used as a substrate or a package for the.

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Claims (9)

[Claims] 1. An aluminum nitride sintered body having a metallized layer on the surface and / or inside, wherein the metallized layer is composed of a conductor refractory metal and an adhesion enhancing inorganic material, and the conductor refractory metal is W, The inorganic material for adhesion enhancement has a coefficient of thermal expansion of 3 × 10 ⁻⁶ / K to 6 × 10 ⁻⁶ / K, the aluminum nitride sintered body having a metallized layer. 2. The adhesion enhancing inorganic material is Al ₂ O ₃ or Si.
The aluminum nitride sintered body having a metallized layer according to claim 1, which is an oxide mixture of at least two kinds selected from O ₂ and MgO. 3. The aluminum nitride sintered body having a metallized layer according to claim ₂ , wherein mullite (3Al ₂ O ₃ .2SiO ₂ ) is used as the adhesion enhancing inorganic substance. 4. An aluminum nitride having a metallized layer by applying a paste containing a conductor refractory metal and an adhesion-enhancing inorganic substance to a ceramic green sheet containing aluminum nitride as a main component, and then simultaneously sintering the whole paste. In the method for producing a sintered body, the conductor refractory metal contained in the paste is W, and the adhesion enhancing inorganic substance is A.
at least 2 selected from l ₂ O ₃ , SiO ₂ and MgO
A method for producing an aluminum nitride sintered body having a metallized layer, which is an oxide mixture composed of at least one kind. 5. The method for manufacturing an aluminum nitride sintered body having a metallized layer according to claim 4, wherein mullite (3Al ₂ O ₃ .2SiO ₂ ) is used as the adhesion enhancing inorganic substance. 6. The inorganic powder for adhering, which is obtained by vitrifying at a temperature equal to or higher than the melting point of the oxide mixture and then pulverizing the inorganic powder.
A method for producing an aluminum nitride sintered body having the metallized layer according to claim 1. 7. A ceramic containing aluminum nitride as a main component.
A through hole in the green sheet
Conductor refractory metal and adhesion enhancing inorganic substance inside the hole
Sintering the whole at the same time after filling the containing paste
To produce an aluminum nitride sintered body with a metallized layer
In the manufacturing method, the high melting point of the conductor contained in the paste
The point metal is W, and the adhesion enhancing inorganic material is Al.₂O₃,
SiO ₂And at least two kinds selected from MgO
A metallization layer characterized by being an oxide mixture consisting of
And a method for manufacturing an aluminum nitride sintered body having. 8. The method for manufacturing an aluminum nitride sintered body having a metallized layer according to claim 7, wherein mullite (3Al ₂ O ₃ .2SiO ₂ ) is used as the adhesion enhancing inorganic substance. 9. The inorganic powder for adhering, which is obtained by vitrifying at a temperature equal to or higher than the melting point of the oxide mixture and then pulverizing the powder.
A method for producing an aluminum nitride sintered body having the metallized layer according to claim 1.