JPH01119557A - Colored alumina sintered body - Google Patents

Abstract

PURPOSE:To obtain the colored alumina-based sintered compact having high heat conductivity and strength without deteriorating its electrical characteristics by consisting the title compact of alumina having a specified composition, a colorant consisting of Cr2O3 and metallic Mo or W in a specified ratio, and a sintering aid. CONSTITUTION:In the colored alumina-based sintered compact consisting of alumina, a colorant, and a sintering aid, the amts. of alumina and colorants are denoted respectively by X (wt.%) and Y (wt.%) in the figure, and the amts. are confined within the area enclosed with points A(96.0, 0.5), B(92.0, 0.5), C(87.8, 4.7), and D(91.8, 4.7). The colorant is formed from Cr2O3 and metallic Mo and/or W, and the ratio of the Mo and W to Cr2O3 is controlled to 1.5-5.0. By this method, a clored alumina-based sintered compact having high heat conductivity of >=20W/mk, high strength, and sufficient and homogeneous color tone and having an excellent heat radiating property is obtained without deteriorating its electrical characteristics.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a coloring method for use in insulating substrates such as semiconductor element housing packages that house semiconductor integrated circuit elements and multilayer wiring boards on which semiconductor S integrated circuit elements are mounted. This invention relates to an alumina sintered body.

[Conventional technology]

Conventionally, packages that house semiconductor integrated circuit elements and multilayer wiring boards on which semiconductor integrated circuit elements are mounted use alumina (mu/!os), which has excellent electrical insulation, as a base material, and tungsten (W) is coated on the surface. , molybdenum (MO)
It is manufactured by applying electrical wiring made of metal such as , manganese (Mn), etc.

However, when connecting a semiconductor integrated circuit element to the external lead terminals of a package, etc. using an automatic wire bonder, the target mark for positioning on the package, etc. is detected and aligned by the sensor of the automatic machine, but the golden target The poor color contrast between the mark and the white alumina substrate sometimes led to incorrect alignment.

Therefore, in order to eliminate the above conventional drawbacks, we added titanium (Ti), copper (Cu), nickel (Niχ cobalt (Co), iron (Fe), vanadium (V), phosphorus, molybdenum, manganese, etc. to alumina). A method has been used in which a coloring agent mainly consisting of an oxide is added and fired at a temperature of 1500 to 1600° C. in a humidified hydrogen-nitrogen mixed gas atmosphere to obtain a colored aluminum-based sintered body.

However, the colored alumina sintered body obtained by adding the above-mentioned coloring agent and firing in a humidified hydrogen-nitrogen mixed gas atmosphere may have uneven color and various electrical properties such as electrical insulation and dielectric loss. There was a problem that it caused deterioration.

Therefore, in order to eliminate the above-mentioned drawbacks, it is special to obtain colored ceramics by incorporating chromium oxide and metal molybdenum and/or tungsten in an amount equal to or less than the chromium oxide into an alumina porcelain composition consisting of alumina and a mineralizer. Kosho 6
This method is proposed in Japanese Patent No. 1-12868.

[Problems to be solved by the invention] However, with the recent improvement in the performance of information processing devices,
Semiconductor elements constituting these devices have rapidly become denser and more highly integrated, and as a result, the semiconductor elements require large amounts of power to operate, resulting in a significant increase in the amount of heat generated by the semiconductor elements. For this reason, when the alumina-based colored ceramics are used as an insulating substrate for semiconductor element storage packages, multilayer wiring boards, etc., the alumina-based colored ceramics has a low thermal conductivity of about 17 W/mK, which dissipates heat. There is a risk that the insulating substrate may have insufficient thermal conductivity, making it difficult to operate the semiconductor element normally and stably.

On the other hand, automatic machines such as the automatic wire bonder are used to manufacture the semiconductor element storage package and mount the semiconductor element, and the alumina ceramic has a low bending strength of about 80klAx" and is resistant to chipping. It is desired to have high strength because it has poor hardness and abrasion resistance.

[Purpose of the invention]

The present invention has been devised to address the above-mentioned drawbacks, and its purpose is to color the powder to a sufficient density for use as an insulating substrate for puff cages for housing semiconductor devices and multilayer wiring boards, and to heat it without deteriorating its electrical characteristics. The object of the present invention is to provide a colored alumina sintered body with high strength and improved conductivity.

[Means for solving problems]

The present invention provides a colored alumina sintered body consisting of a coloring agent and a sintering aid, in which the capacity of the alumina and the coloring agent is within the range surrounded by each point of the following MBOD in the m1 diagram. , the coloring agent is made of chromium oxide and metal molybdenum and/or tungsten, the ratio of the amount of metal molybdenum and/or tungsten to the amount of chromium oxide is more than 1.5 and less than 5.0, and the thermal conductivity is 20 W/ mK or more, and each point of Mu BOD is: Mu: alumina 95.0% by weight, colorant o, s weight% B
: Full isu 92.0ifi%, colorant 0.5?1ttX
C: 87.8% by weight of alumina, 4.7wtl of colorant and D
: The amount of alumina is 91.811 parts, and the colorant is 4.7 parts by weight and 11 parts.

That is, the present invention sets the volumes of alumina and colorant to specific amounts, and. First, the amount of metal molybdenum and/or tungsten in the colorant is 1.5% relative to the above amount of chromium oxide.
By containing more than 5.0 and less than 5.0, surprisingly 20
High thermal conductivity of W/mK or more and bending strength of 50.0 k
A colored alumina sintered body with high strength of #/am or more has been realized. This is because there is less chromium oxide dissolved in alumina, which eliminates the cause of phonon scattering within the grains, improving thermal conductivity and suppressing grain growth in the alumina sintered body, resulting in increased strength. considered to be a thing.

In addition, in the present invention, if the ratio of the amount of metal molybdenum and/or tungsten to the amount of chromium oxide in the colorant is 1.5 or less, the thermal conductivity will not improve and the same (5,
If it exceeds 0, the electrical characteristics will deteriorate, making it inappropriate.

In addition, in the present invention, the colorant Y in the colored alumina sintered body is outside the line B shown in FIG. If the amount is less than 0.5% by weight, the aluminum-based sintered body will appear gray, making it difficult to achieve accurate positioning using the automatic wire bonder or the like.

Similarly, outside the CD line shown in FIG. 1, that is, when the coloring agent amount Y exceeds 4.7% by weight, the electrical properties, especially the dielectric constant, become high to 11 or more, and are used in semiconductor element storage packages and multilayer wiring boards. This makes it unsuitable for use as an insulating substrate.

On the other hand, outside the Be line shown in Fig. 1, that is, alumina ff1
If X and colorant ff1Y are each in a range below the BO line, the thermal conductivity and strength will be low, making it impossible to achieve the object of the present invention.

Similarly, the amount of alumina X and the colorant fiY are
In the range beyond the AD line shown in the figure, the tungsten,
It is difficult to uniformly deposit a metallized metal layer for electrical wiring made of a metal such as molybdenum or manganese, which is impractical.

In addition, in the present invention, the above-mentioned alumina amount X and colorant mY
is within the range surrounded by the points of BOEF below in Table 1, preferably within the range surrounded by the points of BGHF below.

x (1! to amount) Y (weight%) B 92.0 0.5 0 87.8 47E
90.8 4.7F
94.5 0.5G
89.5 8.0H92,88,0 [Example] Next, the present invention will be explained based on an example.

First, alumina (AI! gOa) powder with a purity of 99.8 and an average particle size of 1.8 μm and 810! , Oak, MgO, etc. as main components and chromium oxide (Or20g) and after sintering, metal molybdenum (MO) or tungsten (
A coloring agent consisting of at least one molybdenum or tungsten oxide or salt W) was weighed so that the content after sintering would be as shown in Table 1, and the coloring agent was rotated together with an organic solvent and an alumina ball. The mixture was mixed and pulverized in a mill, and then a binder such as butyral resin was added and mixed to the mixed pulverized product to prepare a raw material slurry.

The slurry thus obtained was formed into a sheet shape by the doctor blade method, and a plurality of the formed bodies were heated and bonded together, and then
1500-16 in a humidified hydrogen-nitrogen mixed gas atmosphere
It was fired for 2 hours at a firing temperature within the range of 00'C to obtain a colored alumina sintered body.

After that, the colored alumina sintered body was made into a diameter of 1°! It was polished into a disc shape with a thickness of 2 ays, and its thermal conductivity was adjusted using the laser flash method.
0IIM, using a 8m x 4gsg square prism, JI8
The 8-point bending strength was measured based on the regulations of R1601.

Similarly, it was polished into a plate shape with a length and width of 50B and a thickness of 2 am, and the volume resistivity (100°C, relative humidity 50X) and dielectric constant (
The dielectric loss was derived by measuring the dielectric loss (room temperature, IMHz).

Further, a metallized tungsten metal layer is deposited on the surface of the colored alumina sintered body, and the surface of the metallized metal layer is plated with nickel, and a low thermal expansion metal piece is brazed to this with a low-temperature brazing material. 8 kl//y
The metal piece was pulled with a tensile stress of zm2 to confirm the presence or absence of peeling, and the strength of the metallization was evaluated.

The amounts of alumina and each coloring agent in the sintered body were measured by ICP emission spectrometry.

The results are shown in Table 1.

Moreover, sample number 69.70.71 shows a conventional example.

/ / As is clear from Table 1, conventional sample numbers 69 and 70
．． Sample No. 71 has a low thermal conductivity of 17 W/mK, a low bending strength of 80 kIIAll" J:, and a low bending strength of 80 klI/B2.

2.4.10 and 51.62 are cases outside of AB 4m shown in Figure 1 or when the ratio of the amount of metal molybdenum and/or tungsten to the amount of chromium oxide in the colorant is 1.5 or less, and in both cases the color tone is becomes gray and is not practical. In addition, sample number 14.82 is outside the Be cotton line shown in Figure 1, sample number 5o is outside the CD line shown in Figure 1, and sample numbers 8, 21.8
6 is the case outside the MuD line shown in FIG. 1, and the thermal conductivity and dielectric constant are 1.6 and 1.6, respectively. Dielectric loss and metallization strength are not satisfactory. Monda sample number 4, 10, 25, 29゜3
7.45,62 and 7,1B, 27,81°41.49
, 55.68, the ratio of the amount of metal molybdenum and/or tungsten to the amount of chromium oxide is 1.5 or less or 5
In cases where the thermal conductivity exceeds ゜0, respectively, the thermal conductivity is 19 W/m
[It does not satisfy electrical characteristics such as 3 tonne ratio or dielectric loss.]

In contrast, the colored alumina sintered body of the present invention has a thermal conductivity of 20 W/mK or more and a bending strength of 50 k, 9/mK or more.
It had an extremely high sn2 or higher, and both color tone and electrical properties were satisfactory as an insulating substrate for semiconductor element storage packages, multilayer wiring boards on which semiconductor integrated circuit elements are mounted, and the like.

〔Effect of the invention〕

According to the present invention, it is possible to obtain a colored alumina sintered body having surprisingly high thermal conductivity, high strength, and sufficient and homogeneous color tone without deteriorating electrical characteristics. A package for storing semiconductor elements with good heat dissipation? It is possible to reduce the number of multi-delivery wiring boards by 1υ.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the content ranges of the amount of alumina X and the amount of colorant Y in the colored alumina sintered body of the present invention. Patent applicant Kyocera Corporation

Claims (1)

[Claims] In a colored alumina sintered body consisting of alumina, a colorant, and a sintering aid, each amount of the alumina and colorant is within the range surrounded by each point ABCD below in FIG. 5. The coloring agent is composed of chromium oxide and molybdenum metal and/or tungsten, and the ratio of the amount of molybdenum metal and/or tungsten to the amount of chromium oxide exceeds 1.5.
0 or less and a thermal conductivity of 20 w/mK or more. A: 96.0% by weight of alumina, 0.5% by weight of colorant B: 92.0% by weight of alumina, 0.5% by weight of colorant C: 87.8% by weight of alumina, 4.7% by weight of colorant D: Alumina 91.8% by weight, colorant 4.7% by weight