JPS62252340A - Sintered glass and sintered glass ceramic - Google Patents

Abstract

PURPOSE:To obtain sintered glass or sintered glass ceramic suitable as a material for multilayer printed circuit board, by forming a powdery glass composition composed mainly of SiO2, Al2O3 and MgO or a mixture of the composition and specific aggregate and calcining the formed product. CONSTITUTION:A powdery glass composition consisting of 45-60(wt)% SiO2, 10-25% Al2O3 and 25-40% MgO is mixed with <=5% nucleation agent composed of one or more substances selected from TiO2, ZrO2, SnO2, P2O5, ZnO, As2O3, MoO3, etc. The obtained powdery mixture is optionally mixed with 5-30pts.wt. (based on 100pts. of the mixture) of at least one kind of aggregate selected from silica, cordierite, forsterite, steatite, anorthite and celsian. The produced mixture is formed and calcined at <=1,000 deg.C to obtain sintered glass or sintered glass ceramic having dense texture and low dielectric constant and suitable as a material for multilayer printed circuit board.

Description

[Detailed Description of the Invention] [Technical Field] This invention is used as an insulating material for multilayer wiring boards on which a large number of highly integrated LSIs are mounted.
The present invention relates to a glass sintered body and a glass ceramic sintered body that can be co-fired with low resistance conductive metals such as silver-palladium and gold.

[Background technology]

Conventionally, there have been the following types of substrates on which LSIs are mounted. That is, a green sheet is formed using alumina as the main material, and a high melting point metal (Mo
, W, etc.) is printed by thick film technology. Thereafter, a multilayer green sheet made by laminating these green sheets together is fired in a high-temperature non-oxidizing atmosphere at about 1500°C. The thus obtained product is a so-called alumina sheet multilayer fabric.

However, in the multilayer wiring board mainly made of alumina as described above, the transfer time of the multilayer wiring board is shortened due to the high dielectric constant of alumina and the high resistance of the fine wiring conductor (high melting point metal such as Mo or W). It became long, and it was difficult to meet the demand for faster speeds.

To solve this problem, low resistance metal materials (Au, Ag, AgP
It is also conceivable to form miniaturized wiring using d, Cu, etc.). However, each of the above-mentioned low-resistance metal materials has a melting point of around 1000° C., which is much lower than the sintering temperature of alumina. Therefore, even if it were used, there was a problem that the wiring pattern would melt before sintering and shrink due to surface tension, resulting in disconnection or connection with other wiring.

To solve this problem, the melting point (
There is a need for a material that can be fired at temperatures below 1000°C (about 1000°C) and has a low dielectric constant.

To meet this requirement, multilayer wiring boards made of glass or glass powder sintered bodies (glass-ceramic bodies) have been proposed.

A specific example of such a glass powder sintered body is the
No. 22399, Japanese Patent Application Laid-open No. 178752/1983,
It is described in Japanese Patent Publication No. 57-6257. However, since both of them contain elements with relatively high ionic conductivity, such as Na, Li, and Pb, a migration phenomenon occurs. Therefore, there is a problem in that insulation, which is the most important characteristic of a wiring board, tends to deteriorate.

[Purpose of the invention]

In view of these circumstances, this invention is sufficiently densified by firing at a temperature lower than the melting point of low-resistance metals, and there is no fear of insulation deterioration due to migration phenomena even when used as a multilayer wiring board material. The object of the present invention is to provide a glass sintered body and a glass ceramic sintered body that also have a low dielectric constant.

[Disclosure of the invention]

In order to achieve the above object, the first invention provides 5iOz
A glass sintered body is obtained by firing a molded body of powder of a glass composition containing , AlzOz, and MgO as main components, and the composition of the glass composition is 45 to 60% by weight of 5iOz and 10% by weight of Al2O. ~25 wt%, MgO 25-40 wt%, Ti0z, Zr0z, 5nOz, P20S, Z
The gist of the present invention is a glass sintered body characterized in that the proportion of at least one nucleating agent selected from the group consisting of nO, AszO, and MoO3 is 5% by weight or less, and the second invention , 5i02, a glass ceramic sintered body obtained by firing a powder compact in which aggregate and powder of a glass composition containing AlzOz and MgO as main components are mixed, the composition of the glass composition being: Sin, 45-60% by weight, Al2O3, 10-25% by weight, MgO, 25-40% by weight, Tilt, Zr0z, Snug, P2O5, Z
nO1As20. and M o 03 in a proportion of 5% by weight or less, and the aggregate is present in a proportion of 5 to 30 parts by weight based on 100 parts by weight of the glass composition. The subject matter is a glass-ceramic sintered body characterized by the following.

Below, the first and second inventions will be explained in detail.

Powder of a glass composition within the above composition range and a powder in which the powder of this glass composition and aggregate are mixed (glass-ceramic powder) can be sufficiently densified at a firing temperature of 900 to 1000'C. Since the main crystal phase of the sintered body is cordierite, the dielectric constant is low and the mechanical strength is high.

Further, since the raw materials can be melted at a temperature of about 1400° C. or lower during glass production, a normal melting furnace or clay crucible can be used, which is convenient for production. In addition, the above glass composition is free from Na- to -L, which may cause migration.
It does not contain elements with relatively high ionic conductivity such as i-Pb. Therefore, the glass sintered body obtained by firing the molded body of the powder of this glass composition has no fear of insulation deterioration due to migration.

The reason why the composition ratio of the glass composition used in the first and second inventions is limited as described above is as follows.

When the composition ratio of S i Oz exceeds 60% by weight, the sintering temperature becomes high and densification does not occur below 1000°C. 4
If it is less than 5% by weight, 1500 to 160
Even at 0°C, sufficient vitrification cannot be achieved, and even if glass is obtained, sufficient crystallization does not occur at temperatures below 1000°C.

When the composition ratio of A+2off exceeds 25% by weight, the temperature at which sintering can be performed increases, and sufficient sintering cannot be performed at a firing temperature of 1000° C. or lower. If it is less than 10% by weight, the amount of cordierite crystals as the main crystal phase decreases, resulting in a sintered body with a large amount of glass, which not only increases the dielectric constant but also makes it difficult to densify.

When the composition ratio of MgO exceeds 40% by weight, 1400~
It becomes difficult to obtain transparent glass at 1500°C. At the same time, the sintering temperature also increases. If it is less than 25% by weight, it will be difficult to form a dense sintered body.

The nucleating agent is used at a composition ratio of 5% by weight or less in order to more reliably form the crystals of the sintered body into α-cordierite. As the nucleating agent, 7i02, Z I"Oz, S
nOZ, PtO5, ZnOlMoO:l
% Adz 03 and the like, each of which can be used singly or in combination.

When the nucleating agent exceeds 5% by weight, the crystallization rate becomes extremely rapid, resulting in insufficient densification and a single sintered body.

The aggregate (crystal or glass) used in the second invention is not particularly limited, but includes silica (quartz, quartz glass, cristobalite, etc.), cordierite, forsterite, wollastonite, alumina, steatite. , anorthite, and celsian, each of which may be used singly or in combination.

The aggregate functions not only to increase the mechanical strength of the sintered body but also to decrease the dielectric constant. If the addition ratio of aggregate exceeds 30 parts by weight based on 100 parts by weight of the glass composition, a large number of bores will be included in the bulk of the sintered body. If it is less than 5 parts by weight, the above-mentioned function will not be observed.

If aggregates that do not contain the above-mentioned elements with relatively high ion conductivity, such as the above-mentioned silica and cordierite, are used, there is no risk of deterioration of the insulation properties due to the migration phenomenon.

The powder of the above-mentioned glass composition was obtained by, for example, blending each component so that the weight percent composition was within the above-mentioned range, melting the powder, and then rapidly cooling the melt so as not to precipitate crystals to obtain a transparent glass. It is then obtained by finely pulverizing it, but it may also be obtained by other methods. The particle size of the powder of the glass composition is not particularly limited, but the average particle size is preferably 1 to 10 μm. When the average particle size exceeds 10 μm, the surface unevenness of the glass sintered body and glass ceramic sintered body becomes severe, and when used as a wiring board, the conductor accuracy of the circuit may deteriorate. Furthermore, since the crystallization temperature may become high, sufficient crystal precipitation will not occur if the temperature is 1000° C. or lower, resulting in a sintered body with a low amount of crystals, so there is a possibility that a reduction in dielectric constant cannot be expected. At the same time, the mechanical strength may become low, which may lead to a lack of practicality.

On the other hand, if it is less than 1 μm, the crystallization rate of the glass composition may accelerate, and the crystallization may end before sufficient sintering occurs, making it difficult to increase the sintered density. There is.

The particle size of the aggregate is also not particularly limited, but it is preferably set to be approximately the same as or slightly smaller than the particle size of the glass composition.

The method of mixing the glass composition and aggregate is not particularly limited, and may be wet or dry. Preferably, the mixing is uniform.

Examples of the powder of the above-mentioned glass composition and the molded body of the powder in which the powder and the aggregate are mixed include, but are not limited to, green sheets or a stack of a plurality of green sheets. When an organic substance such as a resin or a solvent is used to obtain a molded body, it is preferable to perform pre-firing in advance to remove the organic substance, and then carry out firing for sintering. Note that the organic substance is not particularly limited, and various types can be used. Moreover, materials other than organic substances may be used, or a molded article may be obtained without using anything.

The conditions for firing the molded body are not particularly limited, but since sintering can be performed at a temperature lower than the melting point (I Q Q around 0°C) of the above-mentioned low-resistance metal material, the molded body is fired at that temperature. By doing so, it is possible to print and simultaneously fire a low-resistance metal material.

Note that when the sintered bodies according to the first and second inventions are used for wiring boards, a method other than the method of co-firing with a metal material may be used. Further, the application is not limited to wiring boards such as multilayer wiring boards and boards.

Next, the first and second inventions will be explained in detail based on examples.

Glass raw materials were prepared to have compositions shown in Examples 1 to 25 and Comparative Examples 1 to 5 in Table 1, and after mixing, the glass materials were placed in an alumina crucible and melted at a heating temperature of about 1400°C. The melt thus obtained was dropped into water to obtain a transparent glass composition (frit). This composition was wet or dry milled in a ball mill to obtain a glass powder with an average particle size of 1 to 10 μm.

This glass powder and the aggregate shown in Table 1 were wet mixed to obtain glass ceramic powder.

Polybutyl methacrylate resin, dibutyl phthalate, toluene, etc. were added to the glass powder and glass ceramic powder, respectively, and kneaded, followed by defoaming treatment under reduced pressure to obtain a slurry. Thereafter, using this slurry, a continuous sheet of 0.2 am thick was produced on a film sheet by a doctor blade method. After this was dried, it was peeled off from the film sheet and punched out to obtain a green sheet of an appropriate size. Next, through-holes were formed in each green sheet, and a wiring pattern was printed using a low-resistance metal conductor paste. A plurality of green sheets with through holes and wiring patterns formed thereon were laminated and press-molded to form a molded body.

2. This laminated green sheet is heated from room temperature to 500°C.
Raise the temperature at a rate of 5°C/min and keep at 500'C for 2 hours.
The mixture was held for 5 minutes to ensure sufficient degreasing. After that, 3.3℃
/mtn to the predetermined sintering temperature shown in Table 1, and held at this sintering temperature for 3 hours to sinter the laminated green sheet. After this, at a rate of 1.8°C/min,
The temperature was lowered to 00° C., and then naturally cooled to obtain a sintered body.

Examples 1 to 25 and Comparative Examples 1 to 5 thus obtained
The dielectric constant and water absorption rate of the sintered body were measured, and the results are shown in Table 1. The relative dielectric constant was measured at a frequency of IMHz. Measurement of water absorption rate is based on JIS C-214
I followed 1.

As is clear from Table 1, the sintered bodies of the examples were all fired at a temperature of 1000° C. or lower, but they had lower water absorption and were denser than those of the comparative examples. In the sintered body of Comparative Example 4, since the addition ratio of aggregate exceeds the above range, it can be seen that there are many pores. Comparative example 5
Since the sintered body is fired from powder that does not contain a nucleating agent or aggregate, the firing temperature is high and the dielectric constant is high. Furthermore, the water absorption rate was high, indicating that sintering was insufficient. The sintered body of the example has a low dielectric constant and excellent electrical properties,
Among these, sintered bodies using aggregate have lower dielectric constants and better electrical properties. Further, all of the sintered bodies of the examples were fired at a temperature of 1000° C. or lower, which indicates that the sintered bodies can be fired at a temperature lower than the melting point of the above-mentioned low-resistance metal material.

〔Effect of the invention〕

As described above, the glass sintered body of the first invention is formed by firing a molded body of powder of the glass composition having the above composition, so it is dense and has a small dielectric constant.

Moreover, since it can be sintered at a low temperature of 1000℃ or less,
Suitable for multilayer wiring board materials that are printed with low-resistance metal materials and subjected to simultaneous firing.

As described above, the glass-ceramic sintered body of the second invention is made by firing a powder compact made of the powder of the glass composition having the above composition and aggregate, and is therefore dense. The mechanical strength is increased and the dielectric constant is further reduced than the glass sintered body of the invention.

Claims (3)

[Claims] (1) A glass sintered body obtained by firing a powder compact of a glass composition containing SiO_2, Al_2O_3 and MgO as main components, the composition of the glass composition being: 45 to 60% by weight of SiO_2; Al_2O_3 is 10-25% by weight, MgO is 25-40% by weight, TiO_2, ZrO_2, SnO_2, P_2O_5,
A glass sintered body characterized in that at least one nucleating agent selected from the group consisting of ZnO, As_2O_3 and MoO_3 is contained in a proportion of 5% by weight or less. (2) A glass-ceramic sintered body obtained by firing a molded body of powder in which aggregate is mixed with powder of a glass composition containing SiO_2, Al_2O_3, and MgO as main components, the composition of the glass composition being is, SiO_2 is 45~
60% by weight, Al_2O_3 10-25% by weight, MgO 25-40% by weight, TiO_2, ZrO_2, SnO_2, P_2O_5,
At least one nucleating agent selected from the group consisting of ZnO, As_2O_3 and MoO_3 is present in a proportion of 5% by weight or less, and the aggregate is present in a proportion of 5 to 30 parts by weight based on 100 parts by weight of the glass composition. A glass ceramic sintered body characterized by the following. (3) The glass ceramic sintered body according to claim 2, wherein the aggregate is at least one selected from the group consisting of silica, cordierite, forsterite, steatite, anorthite, and celsian.