JPH0977561A - Aluminum nitride sintered body - Google Patents

Abstract

(57) [Abstract] [Problem] In the conventional AlN sintered body, mechanical strength,
It has been a subject to satisfy all of thermal conductivity, low-temperature sinterability, adhesiveness with a conductor, and glass sealing property. SOLUTION: The main component is aluminum nitride particles having an average particle size of 2 μm or less, and at least one selected from rare earth elements is 1 to 8% by weight in terms of oxide, and at least one selected from alkaline earth metal elements. 0.3 in terms of oxide
It is an aluminum nitride sintered body containing ˜7% by weight and 5 to 25% by weight in terms of oxide of at least one element selected from Bi, Pb, Sb, In and Sn. The aluminum nitride sintered body of the present invention can be sintered at a low sintering temperature of 1973K or lower.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to aluminum nitride.
(AlN) Sintered body, more specifically, aluminum nitride sintered body that can be sintered at low temperature, is dense and has good thermal conductivity, and has good adhesion to a conductor layer and glass sealing property. .

[0002]

2. Description of the Related Art In recent years, as semiconductor elements such as ICs and LSIs have become faster and more highly integrated, the required characteristics of circuit boards and semiconductor packages have become more severe. For example, in order to efficiently dissipate the heat generated from the semiconductor element, high thermal conductivity is required, and in order to minimize the risk of breakage due to thermal stress of the semiconductor element, the coefficient of thermal expansion of the semiconductor element is It is required to be close to that.

By the way, as a ceramic material as an insulating material for a circuit board or a package, alumina (Al ₂
O ₃ ) ceramics have been commonly used until now. However, although alumina ceramics have higher thermal conductivity than conventional plastic materials and glass materials, their thermal conductivity is still insufficient at around 20 W / m K, and their thermal expansion coefficient is 7 × 10 ^-6 / K. Expansion coefficient of silicon and silicon
Since it is about twice as large as (4.5 × 10 ^-6 / K), it cannot be said that it has sufficient characteristics for high integration and high speed of semiconductor elements.

From the above, attention has been paid to aluminum nitride (AlN) sintered bodies instead of alumina ceramics,
The application of multi-layer circuit boards to insulating materials has been studied in various fields. The AlN sintered body has a coefficient of thermal expansion of 4.0 × 10 ⁻⁶ / K, which is almost equal to the coefficient of thermal expansion of silicon, and is characterized in that the thermal stress of the semiconductor element can be sufficiently reduced. Furthermore, since a material having a thermal conductivity of more than 100 W / m K has been obtained, it is possible to sufficiently cope with an increase in the amount of heat generated due to higher integration and higher speed of semiconductor elements.

By the way, in order to obtain a dense and highly heat-conductive AlN sintered body, a sintering aid for trapping oxygen of AlN crystal grains, for example, an alkaline earth metal compound or a rare earth compound is added, and usually 1973K Sintered at the above high temperature. However, such an AlN sintered body sintered at a high temperature has problems such as a decrease in mechanical strength as the crystal grains grow. Such a decrease in the mechanical strength of the AlN sintered body is fatal when applied to a semiconductor chip mounting substrate or package. Therefore, it is necessary to lower the sintering temperature.

On the other hand, cost reduction is an urgent task for expanding the applications of AlN sintered compacts in the future, and in order to realize the use of the existing continuous furnace, the reduction of the sintering temperature has been studied as an attempt. There is. As a result of recent research and development, improvements in AlN sintering aids have made it possible to use ultra-fine AlN powder, etc.
It is becoming possible to reduce the sintering temperature to a temperature around 1873K.

Examples of the sintering aid effective for lowering the sintering temperature include rare earth elements and alkalis disclosed in JP-A-61-209959, JP-B-5-17190 and JP-A-62-153173. Halides of earth metal elements are described. Similarly, as a method of lowering the sintering temperature of the AlN sintered body, for example, JP-A-1-183469 discloses a method of simultaneously adding a rare earth oxide and an alkaline earth metal oxide as a sintering aid. Has been done.

[0008]

However, in the conventional low-temperature sintering method for AlN sintered bodies described in the above-mentioned publications, AlN that is sufficiently dense and has a high thermal conductivity at a temperature lower than 1973K is used. No sintered body is obtained. For example, in the methods described in JP-A-61-209959 and JP-A-62-153173, it is not possible to achieve a high thermal conductivity exceeding 100 W / mK at 1873K. In addition,
In the method described in Japanese Patent Publication No. -17190, a thermal conductivity of 120 W / m K is achieved, but all are obtained by firing at a temperature of 1973 K or higher. Furthermore, if a large amount of a halide of a rare earth element or an alkaline earth metal element is added, AlN
A lot of precipitates appear on the surface of the sintered body, which not only causes uneven burning and uneven color, but also reduces the smoothness of the surface, which requires a polishing step when forming a conductor circuit in a later step. It has many problems.

Further, in the method described in Japanese Patent Laid-Open No. 1-183469, Y ₂ O ₃ and CaO are added at the same time to obtain a density of 3.27 g / cm ^{3 by} sintering at 1873 K for 8 hours.
Although a thermal conductivity of 139 W / m K has been achieved, it is considered that a pore-free and dense sintered body is not obtained in view of the described grain boundary phase component.

On the other hand, when used as a circuit board or the like,
It is also necessary to consider the adhesion between the AlN insulating layer and the metal conductor layer. That is, when co-firing an AlN compact with a metal conductor layer formed on the surface or inside at high temperature,
If the adhesion between the metal conductor layer and the AlN insulating layer is not good, problems such as peeling of the conductor layer from the insulating layer may occur after firing. When the multilayer circuit board obtained by firing is used as a packaging material, a semiconductor element may be mounted and then glass sealing using a cap may be performed to protect the element. Therefore, the glass sealing property also needs to be good. However, it is the current situation that AlN materials up to now have not sufficiently obtained all of the above mechanical strength, thermal conductivity, low-temperature sinterability, adhesion to conductors, and glass sealing property. .

As described above, the AlN sintered body has been required to satisfy all of mechanical strength, thermal conductivity, low temperature sinterability, adhesion to a conductor, and glass sealing property.

The present invention has been made in order to solve such a problem and is capable of sintering at a low temperature, has high mechanical strength and thermal conductivity, and has excellent adhesion to a conductor and glass sealing property. It is intended to provide an excellent aluminum nitride sintered body.

[0013]

The aluminum nitride sintered body of the present invention comprises aluminum nitride particles having an average particle size of 2 μm or less as a main component, and at least 1 selected from rare earth elements.
1 to 8% by weight in terms of oxide, 0.3 to 7% by weight in terms of oxide of at least one selected from alkaline earth metal elements, and at least one selected from Bi, Pb, Sb, In and Sn. The element is characterized by containing 5 to 25% by weight in terms of oxide.

The aluminum nitride sintered body of the present invention comprises (1)
At least one element selected from rare earth elements, (2)
At least one element selected from alkaline earth metal elements and (3) at least one element selected from Bi, Pb, Sb, In and Sn are contained at the same time. Each compound contained is added as a sintering aid. And, by simultaneously adding the compounds of (1) and (2), low temperature sintering at 1973K or lower becomes possible. Furthermore, by adding the compound of (3), sintering and densification at low temperature are promoted, and the adhesion to the conductor layer and the glass sealing property are improved.

Examples of the rare earth element (1) include Sc, Y and lanthanum series elements, and the addition amount thereof is in the range of 1 to 8% by weight in terms of oxide. If the amount of the rare earth element compound added is less than 1% by weight in terms of oxide, the sinterability is insufficient,
Even if it is sufficiently sintered, the effect of trapping oxygen is reduced, and the thermal conductivity is reduced. -If more than 8% by weight,
The grain boundary phase generated inside the AlN sintered body becomes excessive, which causes a decrease in thermal conductivity. A more preferable addition amount is 1.5 to 7% by weight in terms of oxide.

The alkaline earth metal element of (2) is C
a, Ba, Sr, etc., and the addition amount thereof is 0 in terms of oxide.
The range is 3 to 7% by weight. If the amount of the alkaline earth metal element compound added is less than 0.3% by weight in terms of oxide, the sinterability will be insufficient, and even if it is sufficiently sintered, the oxygen trapping effect will be low and high thermal conductivity cannot be achieved. On the other hand, if it exceeds 7% by weight, the grain boundary phase generated inside the AlN sintered body becomes excessive, which causes a decrease in thermal conductivity. In addition, the water resistance is deteriorated in the AlN sintered body in which a large amount of the alkaline earth metal compound is generated. More preferable addition amount is 0.5 to 5
% By weight.

The element selected from Bi, Pb, Sb, In and Sn in (3) has a low melting point of its oxide and generates a liquid phase at a low temperature. It has an effect of facilitating the arrangement and promoting the sintering. Further, it has the effect of reacting with the oxide layer (Al ₂ O ₃ ) on the surface of the AlN grains to generate a eutectic liquid phase at a lower temperature and promote sintering.

Furthermore, the presence of the compound containing the element (3) improves the adhesion between the conductor layer and the AlN insulating layer when the conductor layer is formed by simultaneous firing or in a later step. That is, as described above, the compound containing the element of (3) forms a liquid phase at a low temperature, and this liquid phase has low viscosity and very good wettability, so that part of this liquid phase is a conductive layer. By penetrating into the inside and solidifying after cooling, the conductor layer and the AlN insulating layer are firmly bonded. This improves the adhesion between the conductor layer and the AlN insulating layer.

Further, the element (3) is an element which can be contained in the glass, and when these elements, Al and oxygen are simultaneously present on the surface of the sintered body, the glass sealed by the element (3) is It diffuses into the AlN sintered body and firmly seals the sealing glass with the AlN sintered body, and at the same time, the wetting angle of the glass with respect to the AlN sintered body becomes small, and good glass sealing becomes possible.

The addition amount of the compound containing the element (3) is in the range of 5 to 25% by weight in terms of oxide. If the amount added is less than 5% by weight, the effect of promoting sintering will be insufficient. Furthermore, since the compound containing the element (3) generally has a high vapor pressure at high temperatures, it easily volatilizes during the sintering process, and if it is less than 5% by weight, it is a conductor layer co-fired or a conductor produced after sintering. The effect of improving the adhesion strength of the layer decreases,
Furthermore, the amount of the element (3) remaining in the AlN sintered body during glass sealing becomes small, and as a result, the effect of improving the glass sealing property also decreases. On the other hand, if it exceeds 25% by weight, the amount of the grain boundary phase generated at the grain boundaries increases, which causes a decrease in thermal conductivity. In particular, if the element (3) is added in a large amount, the wettability of the grain boundary phase with respect to the AlN grains is improved, the AlN grains are separated from each other, and as a result, heat transfer is hindered, which is not preferable. A more preferable addition amount is in the range of 7 to 20% by weight.

The AlN sintered body to which the compound of each element of (1), (2) and (3) described above is added can be densified even by low temperature sintering at 1973 K or less, and high thermal conductivity can be obtained. In addition, the average particle size of AlN particles can be set to 2 μm or less. That is, it becomes possible to suppress coarsening of AlN grains, and due to the average grain size being 2 μm or less, higher strength can be obtained as compared with the conventional AlN sintered body. AlN after sintering
If the average grain size of the crystal grains exceeds 2 μm, the mechanical strength deteriorates. Furthermore, by adding the compound of the element (3), it is possible to improve the adhesion between the conductor layer and the AlN insulating layer and also improve the glass sealing property.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Modes for carrying out the present invention will be described below.

First, a manufacturing method for realizing the AlN sintered body of the present invention will be described. The AlN sintered body of the present invention is preferably manufactured by applying the manufacturing method described below.

The AlN powder used for producing the AlN sintered body of the present invention has an average primary particle size in the range of 0.03 to 1.4 μm in consideration of the particle size after sintering, among all the powders that are practically available. It is desirable that the amount of impurity oxygen is in the range of 0.2 to 3.5% by weight.

If the average primary particle size of the AlN powder is 0.03 μm or less, it may be difficult to handle the powder and it may be difficult to mold the powder. − On the other hand, if the average primary particle size of AlN powder exceeds 1.4 μm, it is 1973K or less,
Low-temperature sintering at 3 K or less may be difficult, and the average particle size of AlN particles after sintering may exceed 2 μm, resulting in deterioration of mechanical strength. The more preferable average primary particle size of the AlN powder is in the range of 0.05 to 1.2 μm.

The amount of impurity oxygen in the AlN powder means the amount of oxygen that effectively participates in sintering immediately before sintering. If the impurity oxygen content is less than 0.2% by weight, 1
Low-temperature sintering below 973K, especially below 1873K may become difficult, or the AlN material may deteriorate in the handling stage of mixing and molding before sintering. -, The amount of impurity oxygen is 3.5% by weight
If it exceeds, it may not be possible to obtain a highly heat-conductive AlN sintered body. More preferable amount of impurity oxygen is
It is in the range of 0.5 to 2.0% by weight.

Next, each compound containing the above-mentioned elements (1), (2) and (3) is added to the above-mentioned AlN powder as a sintering aid. The sintering aid present as a compound of the rare earth element (1) or a compound of the alkaline earth metal element (2) inside the AlN sintered body after firing is added as powder or liquid to the AlN powder. Specifically, oxides, carbonates, oxalates, nitrates, alkoxides, halides and the like, a solution in which a nitrate is further dissolved in alcohol, or a combination thereof is used. The compound containing the element (3) added as a sintering aid is preferably an oxide or a compound which becomes an oxide during firing, and examples thereof include carbonates, nitrates, oxalates, alkoxides and aqueous solutions thereof. , Alcohol solutions, and the like. (1),
The amount of addition of each compound containing the elements (2) and (3) and the reason for the addition are as described above.

In the raw material powder consisting of the AlN powder and the sintering aid, Ti, Ti and
0.05 to 1 weight of oxides, carbides, fluorides, carbonates, oxalates, nitrates, etc. of transition metals such as W, Mo, Ta, Nb, Mn
You may mix | blend in the range of%. Further, aluminum compounds such as alumina (Al ₂ O ₃ ) effective for lowering the sintering temperature, phosphorus compounds, boron compounds, and silicon oxide (SiO ₂ ) and silicon nitride (Si ₃ ) for increasing mechanical strength. N ₄ )
1 weight of silicon compound such as
You may add in the range below%.

The mixed raw material powder consisting of the AlN powder and the sintering aid described above is preferably molded after kneading and granulating by adding a binder. As a molding method used at this time, for example, a die press, a hydrostatic press, a sheet molding method such as a doctor blade, or the like, or a combination thereof can be used. As a binder,
For example, acrylic type, methacrylic type, PVB type and the like are used. As a solvent for dispersing these binders, for example, alcohols such as n-butanol, methyl isobutyl, toluene, xylene and the like are used. The amount of the binder added varies depending on the particle size of the AlN powder used, but it is preferably 2 to 12 parts by weight, more preferably 3 to 10 parts by weight, based on 100 parts by weight of the mixed raw material powder. .

Next, the molded body is heated to a maximum temperature of 1273K or less in a non-oxidizing atmosphere such as a nitrogen gas stream to remove the vanida, and then in a non-oxidizing atmosphere at a temperature of 1973K or less, more preferably 1673K. Sinter at temperatures ranging from ~ 1973K. In the step of removing the binder, it is possible to use an atmosphere containing oxygen such as air or an atmosphere containing water vapor by appropriately selecting the maximum temperature for heating while paying attention to the oxidation of AlN.

If sintering is performed at a temperature higher than 1973K in the above-mentioned sintering process, the compound containing the element (3) is highly evaporated and AlN grain growth occurs, so that an average grain size of 2 μm or less can be achieved. Difficult and resulting AlN
There is a problem that the strength of the sintered body decreases. Also, 167
At 3K Sueman, the firing time required to completely densify becomes long, which is not preferable. The atmosphere pressure during the sintering process is preferably 0.9 atm or higher. If it is less than 0.9 atm, in particular, the volatilization of the compound containing the element (3) becomes severe, the effect of promoting sintering is reduced, and the adhesion with the conductor, the glass sealing property, etc. may not be sufficiently improved. is there.

The non-oxidizing atmosphere during sintering is nitrogen,
It is possible to use a single gas or a mixed gas of argon, or a mixed gas in which a part of these is hydrogen, CO _2, or the like. Further, it is desirable to perform firing in a sintering furnace equipped with carbon, tungsten, molybdenum and the like in a firing container selected from AlN, BN, carbon and the like. By applying the manufacturing method as described above, the average particle size of 2μ
Mainly composed of AlN particles of m or less, (1) at least one selected from rare earth elements is 1 to 8 wt% in terms of oxide, (2)
0.3 to 7 wt% of at least one selected from alkaline earth metal elements in terms of oxide, and (3) Bi, Pb, Sb, In
It is possible to reproducibly obtain the AlN sintered body of the present invention containing 5 to 25% by weight in terms of oxide of at least one element selected from and Sn.

The AlN sintered body of the present invention can be used as a high-temperature high-strength material, a heat sink, or the like, but it is subjected to metallization to form a conductor circuit, or a conductor layer is provided on the molded body. It is preferably used as various circuit boards, package bases, etc. by forming a conductor circuit by co-firing. By using the AlN sintered body of the present invention as an insulating portion, a circuit board or a package base having excellent heat dissipation, mechanical strength, and good circuit characteristics free from defects such as separation from a conductor layer is produced. can do. Furthermore, when mounting a semiconductor element and performing glass sealing,
It is possible to manufacture a package or the like having a good glass sealing property.

[0034]

Embodiments of the present invention will be described below.

Example 1 The average primary particle size was 0.6 μm, and the amount of impurity oxygen was 0.9% by weight.
AlN powder with a mean particle size of 0.1 μm and a purity of 99.9% Y ² O
3.0% by weight of ₃ powders, and an average particle size of 0.2 μm, purity 9
Add 1.0% by weight of 9.9% CaCo ₃ in terms of CaO and 8.0% by weight of Bi ² O ₃ with an average particle size of 0.5 μm and a purity of 99.9%.
And WO ₃ having an average particle size of 0.3 μm and a purity of 99.9% is 0 in terms of W.
3% by weight was added, and n-butanol was added thereto, and the mixture was crushed and mixed by a wet ball mill, and then n-butanol was removed to obtain a raw material powder.

Subsequently, 5 parts by weight of an acrylic binder was added to 100 parts by weight of the raw material powder together with an organic solvent for granulation, and the mixture was uniaxially pressed at a pressure of 50 MPa to produce a compact. The compact was set in a container made of an AlN sintered body, and fired at 1873K for 6 hours in a nitrogen gas atmosphere of 2 atm in a graphite heater furnace to obtain an AlN sintered body. When the density of the obtained AlN sintered body was measured by the Archimedes method, it was 3.31 g / cm ³ and was sufficiently densified. Also,
When the fractured surface of the AlN sintered body was observed by SEM and the microstructure was confirmed, the pores disappeared almost completely. From this result, it was confirmed that the AlN sintered body was completely densified. .

No unevenness of color or baking due to seepage of the grain boundary phase was observed on the surface of the AlN sintered body. The fracture surface of the AlN sintered body was observed by SEM, and the average grain size of AlN grains was 1.8 μm as determined by the intercept method. Furthermore, the obtained AlN sintered body has a diameter of 10 mm and a thickness of 3
A mm disk was cut out and its thermal conductivity was measured by the laser flash method according to JIS-R1611 at room temperature. 142 W / m
It was K. Further, when the 4-point bending strength was measured according to JIS-R1601, it was 320 MPa, and the strength was high despite the low sintering temperature.

On the other hand, 97% by weight of tungsten having an average particle size of 1.1 μm and 3% by weight of AlN mixed powder (raw material powder) to which the above-mentioned additive as a filler is added are provided on the surface of the molded body produced by the above-mentioned method. A paste prepared by mixing with an organic solvent was applied by a screen printing method and sintered up to the same conditions as described above. Next, after plating the 2 mm square conductor part on the surface of the obtained AlN sintered body with Ni,
Solder the wire and perform a tensile strength test.
The adhesion strength between the sintered body and the conductor layer was measured. As a result, the tensile strength showed a high value of 7.4 kgf / 2 mm square.

Further, two concave AlN sintered bodies were manufactured according to the method described above. After stacking the obtained two concave AlN sintered bodies so that their opening surfaces face each other,
Glass sealing was performed using a glass having the composition shown in Table 1 below in a nitrogen atmosphere.

[0040]

[Table 1] After leaving the sealed AlN sintered body in a chamber filled with helium gas at 5 atm for 40 minutes, 0.1 Pa inside the chamber.
A vacuum was drawn on the order and air was reintroduced to 1 atm. After performing this helium cleaning step three times, the sample was taken out of the chamber and left in the air for 30 minutes. After the treatment as described above, a helium leak test (fine leak detection) was performed, and the leak amount was detected by a mass spectrometer. As a result, the leak amount was 1.0 × 10 ^-10 atm ・ cc ・ sec ^-1 or less, which was a good value.

Example 2 The average primary particle size was 0.8 μm, and the amount of impurity oxygen was 0.7% by weight.
AlN powder of Dy ₂ O with an average particle size of 0.1 μm and a purity of 99.9%
₃ powder 5% by weight, average particle size 0.2 μm, purity 99.9
% BaCO ₃ in an amount of 1% by weight calculated as BaO, and 10% by weight of Sb ₂ O ₃ having an average particle size of 0.5 μm and a purity of 99.9% and 0.3% by weight of TiO ₂ having a purity of 99.9% in terms of Ti. Then, n-butanol was added to these, and the mixture was crushed and mixed by a wet ball mill, and then n-butanol was removed to obtain a raw material powder.

Subsequently, 5 parts by weight of an acrylic binder was added to 100 parts by weight of the raw material powder together with an organic solvent for granulation, and the mixture was uniaxially pressed at a pressure of 70 MPa to prepare a compact. This molded body was set in a container made of an AlN sintered body, and fired at 1923 K in a nitrogen gas atmosphere of 1 atm in a graphite furnace for 4 hours to obtain a desired AlN sintered body.

The density and thermal conductivity of the obtained AlN sintered body, 4
Point bending strength, adhesion with conductor and glass sealing
When measured under the same conditions and methods as in Example 1, 3.33 g / cm ³ , 153 W / m K, 311 MPa, 6.9 kgf / 2 mm square,
Good values of 1.0 × 10 ^-10 atm ・ cc ・ sec ^-1 or less were shown.

Comparative Example 1 The same AlN powder as in Example 1 was mixed with Bi ₂ O ₃ as an additive.
Was added in the same proportion as in Example 1 except that
Molding, degreasing and sintering were performed in the same manner as in Example 1. The obtained AlN sintered body had a density of 3.28 g / cm ³ and an average particle size of 1.4 μm. The thermal conductivity was 135 W / m K and the four-point bending strength was 325 MPa, but the microstructure of the fracture surface of the AlN sintered body was observed by SEM. As a result, a small number of small pores were found inside the sintered body. And was not a completely dense AlN sintered body.

When the adhesion with the conductor was evaluated in the same manner as in Example 1, only a low value of 3.5 kgf / 2 mm square was obtained. Furthermore, when the glass sealing property was evaluated by the helium leak characteristic in the same manner as in Example 1, it was 5.0 × 10 5.
^It showed a large value of ^-7 atm / cc / sec ^-1, and confirmed that the glass sealing property was low.

Comparative Example 2 An AlN raw material powder having the same sintering aids, additives, etc. as in Example 1 was prepared, molded and degreased, and then, under conditions of 2073K × 2 hours in a carbon furnace. Sintered. The density of the obtained AlN sintered body was densified to 3.30 g / cm ^3, and the thermal conductivity was 178 W / m.
Although it was as high as K, the average grain size of AlN grains was 8.7 μm and the four-point bending strength was 190 MPa, which is lower than that of Example 1. Furthermore, when the adhesion to the conductor and the glass sealing property were evaluated by the same method as in Example 1, 2.7 kgf / 2 mm square,
The value was 6.8 × 10 ^-7 atm ・ cc ・ sec ^-1 which was insufficient.

Examples 3 to 12 Example 1 was repeated except that the AlN powder, the sintering aid and the additives shown in Table 2 below were used, and the sintering conditions were the pressure, temperature and time shown in Table 2. By the same method, 10 types of AlN sintered bodies were prepared. In Example 6, Y ₂ O ₃
Was added as a solution of Y (NO ₃ ) ₃ .6H ₂ O dissolved in n-butanol.

Regarding the obtained AlN sintered bodies of Examples 3 to 12, the density, the thermal conductivity, the average particle size, the 4-point bending strength, the adhesion with the conductor, and the glass sealing property were compared with those of Example 1. It evaluated by the same method. The results are shown in Table 3 below.

[0049]

[Table 2]

[Table 3]

[0050]

As described above, the AlN sintered body of the present invention has fine AlN crystal grains and is sufficiently dense despite being sintered at a low sintering temperature of 1973K or lower. Has high thermal conductivity. In addition, the mechanical strength is high due to the small particle size, and the adhesion with the conductor is strong based on the type of sintering additive, and AlN has good sealing properties when glass sealing is performed. A sintered body can be provided. Therefore, the AlN sintered body of the present invention is effectively used not only as a structural material based on its high strength and high thermal conductivity but also as a constituent material for a metallized substrate, a multilayer co-firing circuit substrate, and a package substrate. It can be applied.

[0051]

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Fumio Ueno 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Incorporated Toshiba Research and Development Center

Claims (1)

[Claims] 1. An aluminum nitride particle having an average particle diameter of 2 μm or less as a main component and at least selected from rare earth elements.
1 to 8% by weight in terms of oxide, 0.3 to 7 in terms of oxide of at least one selected from alkaline earth metal elements
%, And at least one element selected from Bi, Pb, Sb, In, and Sn in an amount of 5 to 25% by weight in terms of oxide.