JP2003342088A - Aluminum nitride sintered compact having metallized layer and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aluminum nitride sintered compact having a metallized layer, wherein the bonding force between the aluminum nitride and the metallized layer is high, and the metallized layer has no cracks. <P>SOLUTION: The aluminum nitride sintered compact has a metallized layer either on its surface or in its inside, wherein the metallized layer is composed of W which is a conductive high-melting metal and at least one matching inorganic substance selected from among Al<SB>2</SB>O<SB>3</SB>, SiO<SB>3</SB>, and MgO. It is possible to heighten the bonding strength between the metallized layer and the aluminum nitride by reducing the average particle diameter of the matching inorganic substance to 5 μm or smaller and by using an inorganic substance powder prepared by vitrifying spinel or a mixture of the oxides at the melting point or higher and grinding the product. <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, a metallized layer is formed on the surface and / or inside of the aluminum nitride sintered body.
Need to be formed. 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,
The bonding strength is increased by using a material to which the adhesion-enhancing component consisting of one or more kinds selected from Hf is added as a material for forming the metallized layer.

[0006] metal (JP 63-115393 JP) W and / or _{Mo, SiO 2, Al 2 O} 3, C
aO as a main component, and if necessary, MgO, Ba
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 and B ₂ O ₃ is added.

(JP-A-63-195183) W
And / or Mo metal to CaO, BaO, SrO,
Y_TwoO_Three, CeO _Two, Gd_TwoO_ThreeOne or more of, and Al_Two
O_Three, An adhesion-enhancing component consisting of one or more of AlN
Joined by using the added material as the material for forming the metallized layer
It has increased strength.

(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 through-holes having a diameter of through-holes, there was a problem when the diameter of through-holes increased to 0.3 mm before sintering, resulting in a thick metalized layer. It was considered the same cause.

[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 made of a conductor refractory metal and a matching inorganic substance, and the conductor refractory metal is W, and the matching metal is used. An aluminum nitride sintered body having a metallized layer, characterized in that the average particle size of the inorganic material is 0.3 μm or more and 5 μm or less. (2) Average particle size of the matching inorganic material is 0.5 μm
The aluminum nitride sintered body having the metallized layer as described in (1) above, having a thickness of 3 μm or less. (3) The matching inorganic material is A1 ₂ O ₃ , SiO ₂
And an oxide mixture of at least one selected from MgO, and an aluminum nitride sintered body having a metallized layer according to the above (1) or (2). (4) As the matching inorganic material, spinel (A1
₂ O ₃ · MgO) is used, and the aluminum nitride sintered body having the metallized layer according to the above (3) is used.

(5) Aluminum nitride having a metallized layer is obtained by applying a paste containing a conductor refractory metal and a matching inorganic substance to a ceramic green sheet containing aluminum nitride as a main component, and then simultaneously sintering the entire paste. In the method for producing a sintered body, the conductor refractory metal contained in the paste is W, and a powder having an average particle size of 0.3 μm or more and 2 μm or less is used as the matching inorganic substance. Of manufacturing an aluminum nitride sintered body having an oxide layer. (6) The matching inorganic material has an average particle size of 0.5 μm
The method for producing an aluminum nitride sintered body having a metallized layer as described in (5) above, which is a powder having a particle size of 1 μm or less. (7) The matching inorganic material is A1 ₂ O ₃ , SiO ₂
And an oxide mixture of at least one selected from MgO, and the method for producing an aluminum nitride sintered body having a metallized layer according to the above (5) or (6). (8) The matching inorganic material is spinel (A1 ₂ O ₃
(MgO), the method for producing an aluminum nitride sintered body having a metallized layer according to the above (7). (9) The aluminum nitride having a metallized layer according to the above (5) or (6), wherein the matching inorganic substance is an inorganic substance powder vitrified at a temperature equal to or higher than the melting point of the oxide mixture and then pulverized. Manufacturing method of sintered body.

(10) A through hole is formed in a ceramic green sheet containing aluminum nitride as a main component,
In a method for producing an aluminum nitride sintered body having a metallized layer by filling a paste containing a conductor refractory metal and a matching inorganic substance inside the through hole, and sintering the whole simultaneously, in the paste, A method for producing an aluminum nitride sintered body having a metallized layer, characterized in that the conductor refractory metal contained therein is W, and powder having an average particle diameter of 0.3 μm or more and 2 μm or less is used as the matching inorganic substance. . (11) The matching inorganic material has an average particle size of 0.5 μ.
The method for producing an aluminum nitride sintered body having a metallized layer according to the above (10), characterized in that the powder is m or more and 1 μm or less. (12) The matching inorganic material is A1 ₂ O ₃ , SiO
_{2. A} method for producing an aluminum nitride sintered body having a metallized layer according to the above (10) or (11), which is an oxide mixture comprising at least one selected from ₂ and MgO. (13) The matching inorganic material is spinel (A1 ₂ O
₃ · MgO), the method for producing an aluminum nitride sintered body having a metallized layer according to the above (12). (14) The aluminum nitride calcination having a metallized layer according to the above (10) or (11), wherein the matching inorganic material is an inorganic material powder which is vitrified at a temperature equal to or higher than the melting point of the oxide mixture and then ground. A method for producing a bound 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 vias and circuit wiring is conductor powder, matching inorganic powder,
It is composed of a resin binder and a solvent, and W powder is used as the conductor 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.
It is preferable to use 50 wt% or more of powder.

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.
Cracks are likely to occur at the interface. 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 matching inorganic material preferably has an average particle size after sintering of 0.3 μm or more and 5 μm or less. The reason for this is due to the bonding mechanism between aluminum nitride and metal. Analyzing the joining mechanism between aluminum nitride and metal, aluminum nitride particles,
It has been found that the contribution of the joining due to the interlock in which the W particles and the matching inorganic particles mechanically mesh with each other is large. In particular, W does not completely densify at the sintering temperature of aluminum nitride and has a structure with a large number of pores. The matching inorganic substance effectively fills these pores, and the bonding strength of W and It has a function of improving the bonding strength between aluminum nitride and W.

Generally, the particle size of aluminum nitride after sintering is 1 to 2 μm, and the particle size of W is also about 1 to 3 μm. These and the matching inorganic substance are joined by interlocking, but in order for the interlocking to function sufficiently, it is necessary that the respective particle sizes be the same.
If even one of the three particles has a large difference in particle size, not only will interlocking between particles be less likely to occur, but the remaining 2
It may even hinder the mating process. As a result of examining the optimum particle size of the matching inorganic material, the average particle size is 0.3 μm or more,
It has been found that the thickness is preferably 5 μm or less.

After sintering, in order to make the matching inorganic particles have an average particle size of 0.3 μm or more and 5 μm or less, the matching inorganic particles in the paste must have an average particle size of 0.3 μm or more and 2 μm or less. There is. If the matching inorganic particles having an average particle size larger than this are used, the matching particles grow excessively during sintering, so that the particle size after sintering exceeds 5 μm. On the other hand, the average particle size is 0.3μ
When the matching inorganic particles smaller than m are used, the particles are too small to be uniformly mixed in the paste, and the paste is formed in an agglomerated state. Therefore, abnormal grain growth or unsintering is likely to occur, so that it cannot be used as a matching inorganic substance particle.

Further, recently, there is a tendency that the demand for the adhesion strength between aluminum nitride and a metallized layer becomes higher,
For example, it is required to maintain sufficient strength even after a reliability test such as a heat cycle test in which the atmosphere is alternately exposed to -40 ° C and 85 ° C for 1000 times or more. In addition, the demand level is increasing year by year.

In order to meet these levels, it is necessary to control the average particle size of the above-mentioned inorganic matching material after sintering more precisely, and it is preferable that the average particle size is 0.5 μm or more and 3 μm or less. This is because it is necessary to further approach the grain sizes of aluminum nitride and W.

Thus, in order to make the average particle diameter of the matching inorganic material after sintering 0.5 μm or more and 3 μm or less, the average particle diameter of the matching inorganic particles in the paste is 0.5 μm or more. It must be 1 μm or less.
If the matching inorganic particles having a larger average particle diameter than this are used, the particles may become agglomerated in the paste due to the small size of the particles. In the case of an agglomerated state, abnormal grain growth and unsintering are likely to occur, so that the required adhesion strength cannot be obtained.

The content of the matching inorganic material contained in the paste, that is, the content of the matching inorganic material in the metallized layer is preferably 1 to 20 wt%. If the content is less than 1 wt%, the effect of the matching inorganic substance does not appear.

That is, the matching inorganic substance functions to increase the adhesion strength between the aluminum nitride and the metallized layer by the interlocking effect of meshing with the aluminum nitride particles and the W particles, but the content thereof is less than 1 wt%. Since a sufficient interlock effect cannot be obtained, the adhesion strength decreases. On the other hand, the content is 20w
When it exceeds t%, an increase in the resistance value of the metallized layer cannot be ignored, which is not preferable.

As the matching inorganic component,
Oxide mixtures can be used. In particular, considering the melting point, an oxide mixture of at least one selected from A1 ₂ O ₃ , SiO ₂ and MgO is preferable because the melting point can be set to the sintering temperature of aluminum nitride or higher.

For example, A1_TwoO_ThreeSuitable for use alone
be able to. However, A1 _TwoO_ThreeUse a simple substance
And mixed to improve the sinterability of aluminum nitride
Abnormal growth due to reaction with the sintering aid of aluminum nitride
This may produce particles. This abnormally grown particle
Deteriorates the adhesion strength between aluminum nitride and the metallized layer
It is not preferable because it causes the problem. Avoids abnormally grown particles
To kick, A1_TwoO_Three, SiO_Two, MgO 2 types
It is preferable to use an oxide mixture composed of the above.

The matching inorganic substance in the paste is A1.
Powders of ₂ O ₃ , SiO ₂ , and MgO may be mixed in required amounts, or powder of a composite such as spinel (A1 ₂ O ₃ .MgO) may be used. For example, since MgO easily segregates, it is better to use spinel powder than to use MgO powder. Further, in order to ensure a uniform mixed state, it is preferable to reduce the types of powder used.

For example, spinel (A1 ₂ O ₃₎ which does not contain MgO powder which tends to segregate and which can be constituted by only a single powder
It is preferable to use (MgO) as a matching inorganic substance from the viewpoint of obtaining a mixture having a uniform composition. In particular, by using spinel (A1 ₂ O ₃ .MgO), cracks generated in the metallized layer can be prevented. Can be effectively prevented. From the same viewpoint, it is easy to ensure the mixed state by using the inorganic powder that is pulverized after being vitrified at the melting point of the matching inorganic material or more.

On the other hand, depending on the selection ratio of A1 ₂ O ₃ , SiO ₂ and MgO, the particle growth rate of the particles with respect to the sintering temperature is high, and it may be difficult to control the particle size of the matching inorganic material. It is preferable to avoid such a ratio.
In general, when all three types of A1 ₂ O ₃ , SiO ₂ , and MgO are used, the growth rate of particles with respect to the sintering temperature can be slowed down.

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, and the solvent is mixed in an amount of about 3 to 15 parts by weight, when the W powder and the matching inorganic substance are 100 parts by weight.

After filling the through holes of the green sheet of aluminum nitride with the paste as described above or printing the circuit, the green sheets are laminated if necessary. 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.

The 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 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.

By the above, even if the metallized layer becomes thicker, no cracks are generated in the metallized layer and the aluminum nitride having the metallized layer of the present invention has a high bonding strength with aluminum nitride. A sintered body can be obtained.

Even if the simultaneous sintering method using a green sheet, which has been mainly described so far, is not used, for example, after a single body of an aluminum nitride sintered body is once obtained by sintering, the metallized layer of the present invention is obtained. Even if the metallization layer becomes thicker, cracks do not occur in the metallization layer by applying a paste that realizes the above to the substrate and sintering at 1600 ° C. to 2000 ° C. in a non-oxidizing atmosphere. It is possible to obtain an aluminum nitride sintered body having the metallized layer of the present invention which has a high bonding strength with aluminum.

[0041]

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. 100 by using this mold
After punching out to mm x 100 mm, use a puncher to
A 0.3 mm through hole was formed.

On the other hand, a paste sample having the composition shown in Table 1 was prepared. Table 1 shows Al ₂ O ₃ , SiO ₂ , and Mg when the matching inorganic material is 100.
The compounding ratio of O is also shown. Each of the paste samples shown in Table 1 contained 85 parts by weight of W powder and 15 parts by weight of inorganic powder as a resin binder so that the ratio of the inorganic powder in the metallized layer of the through hole was 15 wt%. It was prepared by dispersing 5 parts by weight of ethyl cellulose and 5 parts by weight of butyl carbitol as a solvent. The W powder used had an average particle size of 2 μm. In Sample 8, spinel was used as the inorganic powder.

[0043]

[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 printed circuit portion on the aluminum nitride sintered body, and a metallization layer was formed on 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 F
The e-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).

Further, the tensile strength of the metallized layer to aluminum nitride was measured after conducting a heat cycle test of 5000 times of alternately exposing to an atmosphere of -40 ° C and 85 ° C.
The sample was exposed to each atmosphere for 30 minutes or more.

Table 1 shows the results of these evaluations. The evaluation result of the presence / absence of cracks indicates the result of the test which was not subjected to the heat cycle test. With respect to the powder particle size within the range of the present invention and the average particle size of the matching inorganic substance in the sintered body within the range of the present invention, no crack was generated on the circuit printed surface or the via portion. However, when the matching inorganic particles had a particle size of 0.5 μm or more and 3 μm or less, a slight decrease in strength was observed after the thermal cycle test, which is a reliability test. On the other hand, regarding those outside the scope of the present invention, cracks were found in the vias.

Regarding the tensile strength and the fracture mode, when the particle size of the matching inorganic material in the sintered body is out of the range of the present invention, the tensile strength is 20 MPa and the metallized layer and Fe are
-The brazed portion with the Ni-Co wire was broken. From this, the bonding strength between the aluminum nitride and the metallized layer is 20
It turns out that it is above MPa. On the other hand, some metallized layers formed with a paste formulation outside the scope of the present invention had a bond strength of less than 20 MPa and were destroyed in the metallized layer directly above the via.

[Example 2] Regarding the sample 8 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.
Same as Example 1 except that the puncher was changed to m.

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%, cracks did not occur and 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.

[0054]

[Table 2]

[Example 3] With respect to the sample 8 of Example 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. The sample is the sample of Example 1.
The tensile strength of the pin and the presence or absence of cracks in the via and aluminum nitride were evaluated in the same manner as in, and the evaluation results are shown in Table 3. No change was observed in the characteristics when the average particle size of the W powder was 1 μm to 5 μm.

[0056]

[Table 3]

[Example 4] Regarding the sample 8 of Example 1,
The influence was investigated by changing the particle size of the inorganic powder (spinel powder) used. The experimental method was the same as in Example 1. The 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, and the evaluation results are shown in Table 4 together with the paste composition.

[0058]

[Table 4]

As shown in Table 4, with the powder particle size within the range of the present invention and the average particle size of the matching inorganic particles in the sintered body within the range of the present invention, cracks are generated on both the circuit printed surface and the via part. Didn't. However, the particle diameter of the matching inorganic material in the sintered body is 0.5 μm or more and 3 μm
For those not listed below, a slight decrease in strength was observed after the heat cycle test, which is a reliability test. On the other hand, for those outside the scope of this patent, cracks were found in the vias.

Regarding the tensile strength and the fracture mode, when the particle diameter of the matching inorganic material in the sintered body is outside the scope of the present invention, the tensile strength is 20 MPa and the metallization layer and Fe are
-The brazed portion with the Ni-Co wire was broken. From this, the bonding strength between the aluminum nitride and the metallized layer is 20M.
It is understood that it is Pa 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 of less than 20 MPa and were destroyed in the metallized layer directly above the via.

[0061]

According to the present invention, in a metallized layer formed of aluminum nitride and composed of a conductor refractory metal and a matching inorganic material, when W having a thermal expansion coefficient close to that of aluminum nitride is selected as the conductor refractory metal. By controlling the average particle size of the matching inorganic material to be 0.3 μm or more and 5 μm or less, more preferably 0.5 μm or more and 3 μm or less, the metallization layer can be thickened to about 0.1 mm or the metal in the through hole can be formed. Even when a layer is formed, it is possible to prevent the occurrence of cracks and increase the adhesion strength with aluminum nitride. Therefore, aluminum nitride can be preferably used as a substrate or a package for IC.

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Claims (14)

[Claims] 1. An aluminum nitride sintered body having a metallized layer on the surface and / or inside thereof, wherein the metallized layer comprises a conductor refractory metal and a matching inorganic substance, and the conductor refractory metal is W, An aluminum nitride sintered body having a metallized layer, wherein the matching inorganic material has an average particle size of 0.3 μm or more and 5 μm or less. 2. The aluminum nitride sintered body having a metallized layer according to claim 1, wherein the matching inorganic material has an average particle size of 0.5 μm or more and 3 μm or less. 3. The matching inorganic material is A1 ₂ O ₃ ,
_{2. An} oxide mixture composed of at least one selected from SiO ₂ and MgO.
Or an aluminum nitride sintered body having the metallized layer according to 2. 4. The aluminum nitride sintered body having a metallized layer according to claim 3, wherein spinel (A1 ₂ O ₃ .MgO) is used as the matching inorganic substance. 5. A ceramic green sheet containing aluminum nitride as a main component is coated with a paste containing a conductor refractory metal and a matching inorganic material, and then the whole is sintered at the same time to form an aluminum nitride sintered body having a metallized layer. In the method for producing a bonded body, the conductor refractory metal contained in the paste is W, and a powder having an average particle diameter of 0.3 μm or more and 2 μm or less is used as the matching inorganic material, which is characterized by being metallized. A method for manufacturing an aluminum nitride sintered body having a layer. 6. The method for producing an aluminum nitride sintered body having a metallized layer according to claim 5, wherein the matching inorganic material is a powder having an average particle size of 0.5 μm or more and 1 μm or less. 7. The matching inorganic material is A1 ₂ O ₃ ,
6. An oxide mixture composed of at least one selected from SiO ₂ and MgO.
Or a method for producing an aluminum nitride sintered body having the metallized layer according to 6. 8. The matching inorganic material is spinel (A).
12. The method for manufacturing an aluminum nitride sintered body having a metallized layer according to claim 7, wherein the sintered body is ₁₂ O ₃ .MgO). 9. The aluminum nitride calcination having a metallized layer according to claim 5, wherein the matching inorganic substance is an inorganic substance powder which is vitrified at a melting point of the oxide mixture or higher and then pulverized. A method for producing a bound body. 10. A ceramic green sheet containing aluminum nitride as a main component is provided with through holes, and a paste containing a conductor refractory metal and a matching inorganic substance is filled in the through holes, and then the whole is sintered at the same time. Thus, in the method for producing an aluminum nitride sintered body having a metallized layer, the conductor refractory metal contained in the paste is W, and the matching inorganic material has an average particle size of 0.3 μm or more and 2 μm or less. A method for producing an aluminum nitride sintered body having a metallized layer, which comprises using a powder. 11. The method for producing an aluminum nitride sintered body having a metallized layer according to claim 10, wherein the matching inorganic substance is a powder having an average particle size of 0.5 μm or more and 1 μm or less. 12. The matching inorganic material is A1.
_At least 1 selected from ₂ O ₃ , SiO ₂ and MgO
The method for producing an aluminum nitride sintered body having a metallized layer according to claim 10 or 11, which is an oxide mixture of at least one kind. 13. The method for producing an aluminum nitride sintered body having a metallized layer according to claim 12, wherein the matching inorganic substance is spinel (A1 ₂ O ₃ .MgO). 14. The aluminum nitride sinter having a metallized layer according to claim 10, wherein the matching inorganic material is an inorganic material powder which is vitrified at a temperature equal to or higher than the melting point of the oxide mixture and then ground. Body manufacturing method.