JPH0564697B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to an aluminum nitride sintered body suitable as a material for integrated circuit wiring boards or IC packages, and a method for manufacturing the same.
The present invention relates to an aluminum nitride sintered body that has excellent thermal conductivity and is non-transparent, and a method for manufacturing the same. (Prior Art) In recent years, advances in electronic technology have led to higher density and faster calculation functions for electronic devices. As a result, this type of wiring board is required to have high integration and high reliability, and among others, has characteristics such as low thermal expansion, high thermal conductivity, excellent dimensional stability, and long-term stability. something is required. As a wiring board with such characteristics,
Various ceramic materials are known, such as sintered bodies of alumina, beryllia, silicon carbide, or aluminum nitride, but among these, aluminum nitride sintered bodies have one of the characteristics required as a wiring board material: electrical insulation. It is a material that has particularly excellent properties in terms of thermal conductivity, coefficient of thermal expansion, mechanical strength, etc., and is attracting attention. (Problems to be Solved by the Invention) By the way, aluminum nitride sintered bodies as a wiring board material have extremely excellent thermal conductivity due to recent advances in raw material powder purification technology and sintering technology. We are getting what we want. However, although the aluminum nitride sintered body has such excellent thermal conductivity, it has a light transmittance that is inappropriate for use as a wiring board material. In other words, such a translucent aluminum nitride sintered body not only makes it difficult to recognize the set position of the wiring board in the automated wiring board manufacturing process using optical sensors, but also causes malfunctions. Therefore, it has some disadvantages. Therefore, the inventors of the present invention conducted various studies to develop an aluminum nitride sintered body that can solve the above-mentioned drawbacks, and found that V, Nb, Ta, Ni
Alternatively, the present invention has been completed based on the new finding that by incorporating elements such as Pd into the aluminum nitride sintered body, the translucency can be removed without deteriorating the thermal conductivity of the aluminum nitride sintered body. be. That is, an object of the present invention is to obtain an aluminum nitride sintered body that has high thermal conductivity, is non-transparent, and is suitable as a material for wiring boards, and a method for manufacturing the same. be. (Means for Solving the Problems) To explain the means taken by the present invention to solve the above problems, first, the aluminum nitride sintered body according to the present invention is as follows. That is, "85 parts by weight or more of aluminum nitride, 0.1 to 10 parts by weight of at least one of group A elements or group A elements, and V, Nb,
An aluminum nitride sintered body containing 0.01 to 5 parts by weight of at least one selected from Ta, Ni, or Pd, and having a density of 3.0 g/cm ³ or more. . In other words, the aluminum nitride sintered body according to the present invention contains 85 parts by weight or more of aluminum nitride, and the remainder is a group a element or a
At least one selected from group elements and at least one selected from V, Nb, Ta, Ni, or Pd, and the density thereof is 3.0 g/cm ³ or more. be. The reason why the aluminum nitride sintered body of the present invention contains 0.1 to 10 parts by weight of a group a element or at least one selected from group a elements based on 85 parts by weight or more of aluminum nitride is that these elements Since these metals are used as sintering aids, if the amount is less than 0.1 part by weight, sufficient densification of the sintered body will not be achieved, while if the amount of these metals is more than 10 parts by weight, the thermal conductivity of the sintered body, This is because various properties such as volume resistivity deteriorate. Furthermore, the aluminum nitride sintered body of the present invention contains V, Nb, and more than 85 parts by weight of aluminum nitride.
The reason for containing 0.01 to 5 parts by weight of at least one selected from Ta, Ni, or Pd is that if the content of these metals is less than 0.01 part by weight, the sintered body will not become non-transparent. On the other hand, if the amount of these metals exceeds 5 parts by weight, these metals will form a solid solution in the aluminum nitride particles and reduce the thermal conductivity of the sintered body. Note that the sintered body to which Pd is added has the advantage that due to the catalytic effect of Pb, if the sintered body is used as a material for a wiring board, electroless copper plating can be performed by a full additive method. Next, a method of manufacturing the above-described aluminum nitride sintered body according to the present invention will be explained. The production method of the present invention is based on "aluminum nitride powder with a purity of 98% by weight or more".
0.1 to 10 parts by weight of at least one selected from group a elements, group a elements, or compounds thereof per 100 parts by weight in terms of elements;
After adding 0.01 to 5 parts by weight of at least one selected from V, Nb, Ta, Ni, Pd, or a compound thereof in terms of element and forming the mixture into a desired shape, A method for producing an aluminum nitride sintered body, which comprises heating and sintering at 1700 to 2100°C in a non-oxidizing atmosphere. According to the production method according to the present invention, the purity is 98
At least one selected from Group A elements, Group A elements, or compounds thereof may be added in an amount of 0.1 to 10 parts by weight in terms of metal elements to 100 parts by weight of aluminum nitride powder of 100 parts by weight or more. is necessary. The reason is that the aluminum nitride sintered body obtained by adding these metals or compounds as sintering aids and sintering is a wiring board for electronic circuits that has electrical insulation, low coefficient of thermal expansion, and high thermal conductivity. This is because it has extremely excellent properties required as a material. In addition, the reason why such substances are limited to 0.1 to 10 parts by weight in terms of metal elements is
This is because if the amount of these substances added is less than 0.1 part by weight, the effect as a sintering aid cannot be fully exhibited, making it difficult to obtain a high-density sintered body. This is because if the aluminum nitride concentration is more than 30%, the strength of the sintered body will be lowered due to a decrease in the concentration of aluminum nitride. Further, according to the production method according to the present invention, at least one of V, Nb, Ta, Ni, Pd, or a compound thereof is added to 100 parts by weight of aluminum nitride powder having a purity of 98% by weight or more. It is necessary to add 0.01 to 5 parts by weight of the seeds in terms of elements. The reason for this is that the aluminum nitride sintered body obtained by adding these metals can be made black, that is, non-transparent. The reason for limiting the addition amount to 0.01 to 5 parts by weight calculated as 0.01 to 5 parts by weight is because if the amount added is less than 0.01 part by weight, the coloring will be insufficient; This is because if the amount is larger than this, the problem of deterioration of insulation will occur. When the aluminum nitride sintered body according to the present invention made non-transparent as described above is used as a material for a wiring board, an automatic machine equipped with a light sensor on the wiring board is used. When electronic components are mounted on a machine, the automated mounting work using the optical sensor of the automatic machine can be performed without malfunction. Furthermore, in the firing of the aluminum nitride sintered body according to the present invention, at least one selected from group a elements, group a elements, or compounds thereof is added to 100 parts by weight of aluminum nitride powder.
0.1 to 10 parts by weight in terms of elements, V, Nb, Ta,
At least one selected from Ni, Pd, or their compounds, calculated as an element, from 0.01 to
After adding 5 parts by weight and mixing the mixture, the mixture is molded into a desired shape and then fired. It is necessary to perform this firing by heating at 1700 to 2100°C in a non-oxidizing atmosphere. The reason is that the firing temperature is 1700℃.
This is because if the firing temperature is lower, it is difficult to produce a dense sintered body, while if the firing temperature is higher than 2100°C, the crystal grains once sintered tend to become coarse.
Further, as the non-oxidizing atmosphere, for example, at least one of argon, helium, hydrogen, nitrogen, etc. may be used, or a vacuum may be used. Note that for firing in the present invention, either a pressureless sintering method or a pressure sintering method can be applied. Next, the aluminum nitride sintered body and the manufacturing method thereof according to the present invention will be explained in more detail using Examples and Comparative Examples. (Example) Example 1 Average particle size is approximately 1.5 μm and oxygen content is 1.0% by weight
94g of aluminum nitride powder with an average particle size of 2~
5 g of 3 μm yttrium oxide powder, 1 g of palladium powder, and 600 ml of benzene were placed in a ball mill, mixed for 6 hours, and then freeze-dried. An appropriate amount of this dried product was taken, molded using a uniaxial mold press at a pressure of 5 kg/cm ² , and then fired to obtain a sintered body. The temperature increase process during firing ranges from room temperature to
The temperature increases at a rate of 8℃/min up to 700℃, and above 700℃, the temperature increases at a rate of 13℃/min.
Holds time. The firing atmosphere was a nitrogen stream at atmospheric pressure. The obtained sintered body is black in color and its density is 3.35
Kg/cm ³ , volume resistivity at room temperature is 6×
10 ¹³ Ω・cm, thermal conductivity at room temperature is 169W/
It was m.k. After forming a pattern on the surface of this sample using photoresist, it was immersed in an electroless copper plating tank.
As a result, copper was deposited in areas other than the resist, and a circuit could be formed using the deposited copper. In addition, this aluminum nitride sintered body has a thickness of 0.5 mm.
As shown in Figure 1, when the sample is
The transmittance for light with a wavelength of 0.18 μm to 25 μm is 0.1
% or less. Example 2 Sintered bodies were obtained in the same manner as in Example 1, except that the type of metal was changed as shown in Table 1. The properties of the sintered body thus obtained are shown in Table 1. From Table 1, it can be seen that by adding Pd, Nb or Ta, it is possible to obtain a black sintered body without reducing the thermal conductivity. Comparative Example 1 As a comparative example, a sintered body was prepared in the same manner as in Example 1 except for the addition of metal, but without any metal added, and its various properties were investigated. The results are shown in Table 1. In addition, this sample was prepared in the same manner as in Example 1, and the thickness was
A 0.5 mm sample was used, and its transmittance to light having a wavelength of 0.18 μm to 25 μm was measured. The results are shown in Figure 2.

【table】

[Table] Example 3 Average particle size is approximately 1.5 μm and oxygen content is 1.0% by weight
94g of aluminum nitride powder with an average particle size of 2~
5 g of 3 μm yttrium oxide powder, 1 g of palladium powder, and 600 ml of benzene were placed in a ball mill, mixed for 6 hours, and then freeze-dried. An appropriate amount of this dried product was collected and molded using a uniaxial mold press at a pressure of 5 kg/cm ² to obtain a green body.
This formed body was placed in an airtight aluminum nitride container, heated to 1900° C. in a nitrogen gas atmosphere under normal pressure, and fired for 3 hours to obtain a sintered body. Then,
This sintered body was placed in an open aluminum nitride container, heated to 1900° C. in a nitrogen gas stream under normal pressure, and fired for 1 hour. The obtained sintered body is black in color and its density is 3.31
g/cm ³ , volume resistivity at room temperature is 2×
10 ¹³ Ω・cm, thermal conductivity at room temperature is 189W/
It was m.k. Example 4 Sintered bodies were obtained in the same manner as in Example 3, except that the type of metal was changed as shown in Table 2. The physical properties of the obtained sintered body are shown in Table 2. (Effects of the Invention) As detailed above, the aluminum nitride sintered body according to the present invention contains 85 parts by weight or more of aluminum nitride, 0.1 to 0.1 to at least one selected from group A elements or group A elements. 10 parts by weight, and V, Nb,
It contains 0.01 to 5 parts by weight of at least one selected from Ta, Ni, or Pd, and has a density of 3.0 g/cm ³ or more. This makes it possible to produce a non-transparent aluminum nitride sintered body suitable as a material for circuit wiring boards or IC packages. In addition, "aluminum nitride powder with a purity of 98% by weight or more"
0.1 to 10 parts by weight of at least one selected from group a elements, group a elements, or compounds thereof per 100 parts by weight in terms of elements;
After adding 0.01 to 5 parts by weight of at least one selected from V, Nb, Ta, Ni, Pd, or a compound thereof in terms of element and forming the mixture into a desired shape, By heating and sintering at 1700 to 2100°C in a non-oxidizing atmosphere, an aluminum nitride sintered body having the above effects can be produced.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the transmittance of the aluminum nitride sintered body according to Example 1 of the present invention to light of each wavelength, and FIG. 2 is a graph showing the transmittance of the aluminum nitride sintered body according to Comparative Example 1 to light of each wavelength. It is a graph showing the rate.

Claims (1)

[Claims] 1 85 parts by weight or more of aluminum nitride, 0.1 to 10 parts by weight of a group a element or at least one selected from group a elements, and V, Nb,
An aluminum nitride sintered body containing 0.01 to 5 parts by weight of at least one selected from Ta, Ni, or Pd, and having a density of 3.0 g/cm ³ or more. 2 The aluminum nitride sintered body has a thermal conductivity of
100W/m・K or more, volume resistivity 10 ¹² Ω・cm
The aluminum nitride sintered body according to claim 1, which is above and exhibits a black color. 3 Aluminum nitride powder with a purity of 98% by weight or more
0.1 to 10 parts by weight of at least one selected from group a elements, group a elements, or compounds thereof, in terms of elements per 100 parts by weight;
After adding 0.01 to 5 parts by weight of at least one selected from V, Nb, Ta, Ni, Pd, or a compound thereof in terms of element and forming the mixture into a desired shape, A method for producing an aluminum nitride sintered body, which comprises heating and sintering at 1700 to 2100°C in a non-oxidizing atmosphere.