JPH0745335B2 - Colored alumina sintered body - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a colored alumina used for an insulating substrate such as a semiconductor element housing package for housing a semiconductor integrated circuit element or a multilayer wiring board on which the semiconductor integrated circuit element is mounted. Quality sintered body.

[Conventional technology]

Conventionally, a package for housing a semiconductor integrated circuit device, a multilayer wiring board on which the semiconductor integrated circuit device is mounted, and the like use alumina (Al ₂ O ₃ ) having excellent electrical insulation as a substrate, and tungsten (W) is formed on the surface thereof. , Molybdenum (Mo), manganese (Mn), and other electrical wiring made of metal.

However, when connecting a semiconductor integrated circuit device to an external lead terminal of a package or the like with an automatic wire bonder, the alignment target mark of the package or the like is detected by the sensor of the automatic machine and aligned, but a gold target Due to the weak color tone contrast between the mark and the white alumina substrate, misalignment may occur.

Therefore, in order to solve the above-mentioned conventional defects, titanium (Ti), copper (Cu), nickel (Ni), cobalt (Co), iron (Fe), vanadium (V), tungsten,
Add a colorant consisting mainly of oxides such as molybdenum and manganese, and add 1500 in a humidified hydrogen-nitrogen mixed gas atmosphere.
A method of obtaining a colored alumina-based sintered body by firing at a temperature of ~ 1600 ° C has been used.

However, the colored alumina-based sintered body obtained by firing in a hydrogen-nitrogen mixed gas atmosphere which is humidified by adding the above-mentioned coloring agent causes color unevenness, and has various electrical characteristics such as electric insulation and dielectric loss. There was a problem of causing deterioration of.

Therefore, in order to eliminate the above-mentioned drawbacks, it is preferable to obtain a colored ceramics by adding an alumina porcelain composition comprising alumina and a mineralizer to chromium oxide and molybdenum and / or tungsten in an amount equal to or less than the chromium oxide. Kosho 61
-12868.

[Problems to be solved by the invention]

However, in recent years, as the performance of information processing devices has increased,
The density and integration of the semiconductor elements that compose the semiconductor elements have rapidly increased, and the semiconductor elements require a large amount of power when operating, resulting in a significant increase in the amount of heat generated by the semiconductor elements. Therefore, when using the above-mentioned alumina coloring ceramics as an insulating substrate such as a package for housing a semiconductor element or a multilayer wiring board, the alumina coloring ceramic has a thermal conductivity of about 17 W / mK and is insufficient for heat dissipation. However, it may be difficult to operate the semiconductor element normally and stably, and a high thermal conductivity is desired for the insulating substrate.

On the other hand, the semiconductor element storage package, etc., is used in the manufacturing or mounting of the semiconductor element, and an automatic machine such as the automatic wire bonder is used, and the bending strength of the alumina ceramics is as low as about 30 kg / mm ^2. In addition, chipping resistance and wear resistance are poor, so higher strength is desired.

[Object of the Invention]

The present invention has been devised in view of the above-mentioned drawbacks, and its object is to conduct heat conduction without deteriorating various electrical characteristics while coloring to a sufficient density as an insulating substrate of a package for accommodating semiconductor elements or a multilayer wiring board. The object is to provide a high-strength colored alumina-based sintered body that achieves an improved rate.

[Means for solving problems]

The present invention relates to a colored alumina sintered body comprising alumina, a colorant and a sintering aid, wherein the respective amounts of the alumina and the colorant are within the range surrounded by the following ABCD points in FIG. The colorant is composed of chromium oxide and metallic molybdenum and / or tungsten, the ratio of the amount of metallic molybdenum and / or tungsten to the amount of chromium oxide is more than 1.5 and 5.0 or less, the thermal conductivity is 20 W / mk or more, and the bending strength is A colored alumina-based sintered body characterized by being 50 kg / mm ² or more.

A: Alumina 96.0 wt%, colorant 0.5 wt% B: Alumina 92.0 wt%, colorant 0.5 wt% C: Alumina 87.8 wt%, colorant 4.7 wt% D: Alumina 91.8 wt%, colorant 4.7 wt% .

That is, the present invention is to set each amount of alumina and colorant to a specific amount, and by containing the amount of metallic molybdenum and / or tungsten in the colorant in an amount of more than 1.5 and 5.0 or less with respect to the amount of chromium oxide. Surprisingly, this is a high-strength colored alumina sintered body having a high thermal conductivity of 20 W / mK or more and a bending strength of 50.0 kg / mm ² or more. This is because the amount of chromium oxide that forms a solid solution in alumina is small, the cause of phonon scattering within the grains is eliminated, thermal conductivity is improved, and grain growth of the alumina sintered body is suppressed, resulting in increased strength. It is considered to be a thing.

In the present invention, if the ratio of the amount of metallic molybdenum and / or tungsten to the amount of chromium oxide in the colorant is 1.5 or less, the thermal conductivity does not improve, and if it exceeds 5.0, the electrical characteristics are deteriorated. Will be appropriate.

In the present invention, the amount X of alumina in the colored alumina sintered body and the amount Y of the coloring agent composed of chromium oxide, molybdenum and / or tungsten are outside the line AB shown in FIG. 1, that is, the coloring agent Y is 0.5. If the content is less than 10% by weight, the alumina-based sintered body is gray and it is difficult to accurately align the automatic wire bonder.

Similarly, outside the CD line shown in FIG. 1, that is, the colorant amount Y
If the content exceeds 4.7% by weight, the electrical characteristics, especially the dielectric constant will be 1
It becomes high as 1 or more, which makes it unsuitable for use as an insulating substrate for a semiconductor element housing package, a multilayer wiring board, or the like.

On the other hand, outside the BC line shown in FIG. 1, that is, when the alumina amount X and the colorant amount Y are less than the BC line, the thermal conductivity and the strength are low, and the object of the present invention cannot be achieved.

Similarly, in the range where the alumina amount X and the colorant amount Y each exceed the AD line shown in FIG. 1, the metallized metal layer for electric wiring, which is made of the metal such as tungsten, molybdenum or manganese, is uniformly deposited. Is difficult and impractical.

In the present invention, the amount of alumina X and the amount of colorant Y described above are used.
Is within the range surrounded by the following BCEF points in FIG. 1, preferably within the range surrounded by the following BGHF points.

 X (wt%) Y (wt%) B 92.0 0.5 C 87.8 4.7 E 90.3 4.7 E 94.5 0.5 G 89.5 3.0 H 92.0 3.0 [Examples] Next, the present invention will be described based on Examples.

First, alumina (purity 99.8%, average particle size 1.8 μm) (Al
₂ O ₃ ) powder and a sintering aid mainly composed of SiO ₂ , CaO, MgO, etc. and chromium oxide (Cr ₂ O ₃ ) and after sintering, metal molybdenum (M 2
o) or tungsten (W), which is at least one of molybdenum or tungsten oxide or a coloring agent made of hydrochloric acid, is weighed so that the content after sintering is the weight shown in Table 1, and an organic solvent and A raw material slurry was prepared by mixing and grinding with an alumina ball in a rotary mill, and then adding and mixing a binder such as butyral resin to the mixed and ground product.

The slurry thus obtained is formed into a sheet by the doctor blade method, and a plurality of the formed bodies are heated and adhered to each other,
Firing was performed for 2 hours at a firing temperature in the range of 1500 to 1600 ° C. in a humidified hydrogen-nitrogen mixed gas atmosphere to obtain a colored alumina sintered body.

Then, the colored alumina sintered body is 10 mm in diameter and 2 m in thickness.
Polished in the shape of a disk of m, and the thermal conductivity was similarly polished by the laser flash method. Length 40 mm, 3 mm x 4
Three-point bending strength was measured based on the JIS R 1601 rule using a square prism of mm square.

In the same way, the plate shape of 50 mm in length and width and 2 mm in thickness is polished, and the volume resistivity (100 mm) is measured according to JIS C 2141.
℃, relative humidity 50%) and dielectric constant (room temperature, 1MHz) were measured and the dielectric loss was derived.

Further, while depositing a metallized metal layer of tungsten on the surface of the colored alumina crystalline body, nickel plating is performed on the metallized metal layer surface, and a metal piece with low thermal expansion is brazed with a low melting point brazing material, The metal piece was pulled with a tensile stress of 3 kg / mm ² , the presence or absence of peeling was confirmed, and the strength of metallization was evaluated.

The amounts of alumina and each colorant in the sintered body were measured by ICP emission spectroscopy.

The results are shown in Table 1.

Further, sample numbers 69, 70 and 71 are conventional examples.

As is clear from Table 1, the sample numbers 69, 70 and 71 of the conventional example all have low thermal conductivity of 17 W / mK and bending strength of 30 kg / mm ²
And low. The sample numbers 1, 2, 4, 10, 51, 62 are shown in Fig. 1.
This is the case where the ratio of the amount of molybdenum metal and / or tungsten to the amount of chromium oxide outside the AB line or in the colorant is 1.5 or less, and the color tone is gray and not practical.
Sample numbers 14 and 32 are outside the BC line shown in Fig. 1, sample number 5
0 is outside the CD line shown in FIG. 1, and sample numbers 3, 21, and 36 are outside the AD line shown in FIG. 1, and the thermal conductivity, dielectric constant, dielectric loss, and metallization strength are not satisfactory. . Sample numbers 4,10,25,29,37,45,62 and 7,13,27,31,41,19,5
5,68 is when the ratio of the amount of molybdenum metal and / or tungsten to the amount of chromium oxide is 1.5 or less or exceeds 5.0, and the thermal conductivity is 19 W / mK or less, or the electrical characteristics such as dielectric constant and dielectric loss are satisfied. Not something to do.

On the other hand, the colored alumina-based sintered body of the present invention has a thermal conductivity of 20 W / mK or more, and a bending strength of 50 kg / mm ² or more, which is extremely high, and has a color tone and various electrical characteristics in a package for storing semiconductor elements and It has been satisfactory as an insulating substrate such as a multilayer wiring board on which a semiconductor integrated circuit element is mounted.

〔The invention's effect〕

According to the present invention, it is possible to obtain a colored alumina-based sintered body having a high thermal conductivity and a sufficient and uniform color tone of high strength, which is surprisingly high without deteriorating various electrical characteristics. It is possible to obtain a package for housing a semiconductor element and a multilayer wiring board that have good heat dissipation.

[Brief description of drawings]

FIG. 1 is a diagram showing the content range of the amount of alumina X and the amount of colorant Y in the colored alumina sintered body of the present invention.

Claims (1)

[Claims] 1. In a colored alumina sintered body comprising alumina, a coloring agent and a sintering aid, the respective amounts of the alumina and the coloring agent are within a range surrounded by respective points of ABCD shown in FIG. The coloring agent is composed of chromium oxide and molybdenum and / or tungsten, and the ratio of molybdenum and / or tungsten to chromium oxide exceeds 1.5.
5.0 or less, thermal conductivity of 20W / mk or more, bending strength of 50k
A colored alumina-based sintered body characterized by having g / mm ² or more. A: Alumina 96.0% by weight, colorant 0.5% by weight B: Alumina 92.0% by weight, colorant 0.5% by weight C: Alumina 87.8% by weight, colorant 4.7% by weight D: Alumina 91.8% by weight, colorant 4.7% by weight