JPH0676227B2 - Glass ceramic sintered body - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an insulating material such as a multilayer wiring board for mounting a large number of highly integrated LSIs that can be co-fired with a low resistance metal such as silver, silver-palladium, or gold. The present invention relates to a glass ceramic sintered body used for manufacturing.

[Background technology]

2. Description of the Related Art In recent years, in multi-layer wiring boards on which a large number of highly integrated LSIs and various elements are mounted, the use of multi-layer wiring boards made of ceramic material has been expanding as the demand for miniaturization and high reliability has increased.

In the ceramic multilayer wiring board, a green sheet is formed by using alumina as a main material, and a conductor wiring of a refractory metal (Mo, W, etc.) is printed and formed on the green sheet by a thick film technique. Then, a multilayer green sheet obtained by laminating and stacking the green sheets is obtained by firing in a high temperature non-oxidizing atmosphere of about 1500 to 1600 ° C.

However, in the above-mentioned multilayer wiring board using alumina as the main material, due to the high relative permittivity of alumina and the high resistance of the fine wiring conductor (high melting point metal such as Mo and W), the wiring in the multilayer structure is The transmission time of the propagating signal was long, and it was difficult to meet the demand for higher speed.

In order to solve this problem, it is conceivable to form a fine wiring using a low resistance metal material (Au, Ag, Ag-Pd, Cu, etc.) instead of the high resistance refractory metal material. However, the melting point of each of the low resistance metal materials described above is around 1000 ° C., which is much lower than the sintering temperature of alumina. Therefore, even if it is used, there is a problem that the wiring pattern melts before the sintering and contracts due to the surface tension, resulting in disconnection.

In order to solve this problem, a multilayer wiring board of glass or a glass powder sintered body (glass-ceramic body) has been proposed.

Such glass powder sintered body, especially SiO ₂ --Al ₂ O ₃ --M
Specific examples of gO type (hereinafter referred to as "cordierite type") are disclosed in JP-B-59-22399, JP-A-59-178752, JP-B-57-6257, and JP-B-59-59. -46900 publication. However, all of the glass powder sintered bodies described in JP-B-59-22399, JP-B-57-6257 and JP-A-59-178752,
Since the composition contains elements having relatively high ionic conductivity such as Na, K, Li and Pb, a migration phenomenon occurs. Therefore, there is a problem that deterioration of the insulating property, which is the most important characteristic of the substrate, is likely to occur. On the other hand, the glass powder fired body described in Japanese Examined Patent Publication No. 59-46900 does not contain the above-mentioned elements having high ionic conductivity, and there is no deterioration of the insulating property due to the migration. Moreover, the glass powder sintered body described in JP-B-59-46900 becomes a dense sintered body at a firing temperature around 950 ° C. However, when the temperature exceeds 1000 ° C, the uncrystallized glass phase in the bulk is melted and the upper wiring is broken. Further, at a firing temperature near 900 ° C., the amount of μ-cordierite is larger than that of α-cordierite, and the desired electrical characteristics and thermal expansion coefficient cannot be obtained. Not only that, α
There was a problem that only a crystal body having poor reproducibility in which the crystal type and the μ type were mixed was obtained. In addition, in the conventional glass-ceramic powder, since the firing shrinkage ratio of the conductor wiring and the molded body does not match well, the low resistance metal wiring is printed and formed on the molded body (green sheet) and co-fired. In some cases, there was a defect that the substrate after firing was warped or the dimensional accuracy was deteriorated. Moreover, the temperature at which the raw material mixture is melted is high (1500 ° C. or higher), and there is a problem in the case of manufacturing by a normal manufacturing method.

[Object of the Invention]

In view of such circumstances, the present invention is sufficiently densified even by firing at a low temperature of 1000 ° C. or lower, has a low dielectric constant, and even when used as a multilayer wiring board material, insulation deterioration due to a migration phenomenon is caused. Does not happen,
An object of the present invention is to provide a glass-ceramic sintered body suitable for wiring formation using a low-resistance metal material.

[Disclosure of Invention]

In order to achieve the above-mentioned object, the inventors have conducted extensive studies to improve the performance of a sintered body by combining a new type of glass (crystallizing glass) and a filler. As a result, the present invention has been completed.

That is, the present invention is a glass ceramic sintered body obtained by firing a mixture of a glass composition powder and a filler, wherein the glass composition powder is SiO ₂ 48 to 63 wt%, Al ₂ O ₃ 10 25 wt%, B ₂ O ₃ 4 to 10 wt%, MgO 10 to 25 wt%, 3 to 20 wt% of the MgO of the mother glass consisting are BaO, S
For the main component formed by substituting at least one selected from the group consisting of rO and CaO, TiO ₂ , ZrO ₂ , SnO ₂ , P ₂ O ₅ , Zn
A composition comprising at least 3% by weight of at least one nucleating agent selected from the group consisting of O, MoO ₃ , Ta ₂ O ₅ , Nb ₂ O ₅ , As ₂ O ₃ and Li ₂ O. And a glass ceramic sintered body characterized in that the glass composition powder and the filler are mixed in a proportion of 70 to 95% by weight of the glass composition powder and 5 to 30% by weight of the filler. To do.

The glass ceramic sintered body according to the present invention will be described in detail below.

The mother glass has a composition of 48 to 63% by weight of SiO _{2 and} 10 to ₂ of Al ₂ O _3.
5% by weight, 4 to 10% by weight of B ₂ O _{3 and} 10 to 25% by weight of MgO. In such a mother glass, 3 to 20% by weight of MgO is replaced with at least one selected from the group consisting of BaO, SrO and CaO (hereinafter referred to as "RO").
By doing so, a relatively low level dielectric constant is obtained as compared with the relatively high dielectric constant of alumina (about 10 for 96% alumina). As described above, SiO ₂ -Al ₂ O ₃ -M
gO-B ₂ O ₃ system the MgO of the glass composition, BaO, SrO, be substituted 3 to 20 wt% alkaline earth metal oxides such as CaO, SiO ₂ of the above composition range which are not substituted −Al ₂ O ₃ −MgO
Similar to the -B ₂ O ₃ -based glass composition, at around 850 ° C and at most 950
Non-porous sintering can be performed at firing temperatures up to ° C. Further, as described above, the main crystal phase of the sintered body is cordierite, so that the dielectric constant is low and the mechanical strength is high. Moreover, since the melting temperature of the glass raw material can be sufficiently 1400 ° C., the melting can be completed in a usual clay crucible or a melting furnace for a sufficient time, which is convenient from the viewpoint of production. If 3% by weight or less, preferably 0.5 to 2% by weight, of a nucleating agent is further added to this glass composition, the crystals of the sintered body can be more surely converted into α-cordierite. . The nucleation _{agent, TiO 2, ZrO 2, SnO} 2, P 2 O 5, ZnO, Mo
O ₃ , Ta ₂ O ₅ , Nb ₂ O ₅ , As ₂ O ₃ and Li ₂ O are included.

When the composition ratio of SiO ₂ exceeds 63% by weight, it is difficult to form a dense sintered body. If it is less than 48% by weight, the crystallization temperature of the glass powder rises, so that it cannot be sufficiently crystallized at a firing temperature of 950 ° C. or less, or densification becomes difficult.

When the composition ratio of Al ₂ O ₃ exceeds 25% by weight, the temperature at which sintering can be performed increases, and sufficient sintering cannot be performed at a firing temperature of 950 ° C or lower. When it is less than 10% by weight, cordierite crystals are reduced and a large amount of SiO ₂ -MgO type crystals are precipitated,
The relative permittivity increases.

When the composition ratio of MgO exceeds 25% by weight, it is considered that magnesium silicate is likely to precipitate, but the deformation becomes large and the practicality is poor. If it is less than 10% by weight, it is difficult to form a dense sintered body.

If B ₂ O ₃ is added to the cordierite-based glass composition, it can be further fired at a low temperature, and the phase change from μ-cordierite to α-cordierite is 10%.
Although it can be carried out at a temperature of 00 ° C. or less, when the composition ratio of B ₂ O ₃ exceeds 10% by weight, a large amount of glass phase tends to cause foaming, and the temperature range in which firing is possible becomes narrow. In addition, the mechanical strength is weak and the practicability becomes poor. If it is less than 4% by weight, crystallization of the surface layer of the glass powder will proceed too rapidly, and it will be difficult to form a dense sintered body.

When the substitution rate of RO replacing MgO exceeds 20% by weight, MgO
Since the amount of the component is reduced, the precipitation of α-cordierite crystals is deteriorated, and the electrical characteristics are deteriorated. If it is less than 3% by weight, the effect is not exhibited.

If the amount of the nucleating agent exceeds 3% by weight, crystallization will proceed so rapidly that a dense sintered body will not be obtained.

The filler used in the present invention is not particularly limited, but at least selected from α-quartz, fused silica, cristobalite, cordierite, steatite, forsterite, wollastonite, anorthite, sergian, and alumina. One kind is mentioned.

The filler not only increases the mechanical strength of the sintered body, but also reduces the relative dielectric constant. Addition ratio is 5% to 30% by weight, preferably 5% by weight
~ 20% by weight. If the addition ratio of the filler exceeds 30% by weight, it becomes difficult to sinter, and it becomes impossible to sinter below 1000 ° C. Also, a large amount of pores will be contained inside the sintered body bulk. When the amount of the filler is less than 5% by weight, it is difficult to recognize the effects of adding the filler, such as lowering the dielectric constant, adjusting the thermal expansion coefficient, and improving the thermal conductivity.

Among the above-mentioned fillers, if a filler such as α-quartz, fused silica, cristobalite, and cordierite is used, the coefficient of thermal expansion becomes particularly close to that of silicon, so that high density is achieved. It is useful as a multi-layered substrate, and if a group other than the above is used, the thermal conductivity is particularly improved, so that it tends to be useful as a multi-layered substrate.

If a filler that does not contain the above-mentioned elements having relatively high ionic conductivity is used as the filler, even if the sintered body is used as the material for the multilayer wiring board, there is no risk of deterioration of the insulation due to the migration phenomenon.

The powder of the above glass composition is prepared, for example, by mixing the respective components so that the composition in% by weight falls within the above range, melting the mixture, and rapidly cooling the melt so as not to precipitate crystals, to obtain transparent glass. Although it can be obtained by pulverizing, it may 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. If the average particle size exceeds 10 μm, the surface irregularities of the glass-ceramic sintered body become severe, and when the wiring board is used, the conductor accuracy of the circuit may deteriorate. Further, since the crystallization temperature may increase, sufficient crystal precipitation does not occur by firing at 1000 ° C. or less, and a sintered body with a low crystal amount is obtained, so that a decrease in the dielectric constant may not be expected. At the same time, the mechanical strength may decrease, which may impair practicality. On the other hand, if it is less than 1 μm, the crystallization rate of the glass composition may be increased, crystallization may be completed before sufficient sintering occurs, and the sintered density may be difficult to increase. is there.

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

The method of mixing the glass composition and the filler is not particularly limited, and either a wet method or a dry method may be used. 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 to remove the organic substance and then perform firing for sintering. The organic substance is not particularly limited, and various types can be used. Further, a material other than an organic material may be used, or the molded body may be obtained without using anything.

Examples of a powder compact formed by mixing the powder of the glass composition and the filler include, but are not limited to, a green sheet or a laminate of a plurality of sheets.

The conditions for firing the shaped body are not particularly limited, but since firing can be performed even if firing is performed at a temperature lower than the melting point (around 1000 ° C.) of the low resistance metal material, it is recommended that firing be performed at that temperature. For example, a low resistance metal material can be printed and co-fired. Of course, it is not necessary to perform simultaneous firing.

Applications of the glass ceramic sintered body according to the present invention are not limited to wiring boards such as multilayer wiring boards.

Next, a glass ceramic sintered body according to the present invention will be described in detail based on examples.

Glass compositions G-1 to G-18 (of which G-1 to G-14 are those of the examples, and G-15 to G- are shown in Table 1).
18 is a comparative example) was mixed, put in an alumina crucible and melted at a heating temperature of about 1400-1500 ° C. The molten liquid thus obtained is dropped into water,
A transparent glass composition (frit) was obtained. This composition was wet or dry pulverized in an alumina ball mill to give a glass powder having an average particle size of 1 to 10 μm.

Each glass powder thus obtained and each filler were mixed in the proportions shown in Table 2, and further, polybutyl methacrylate resin as an organic binder, dibutyl phthalate as a plasticizer, toluene as a solvent, and the like were kneaded. , Defoamed under reduced pressure. Then, a 0.2 mm-thick continuous sheet was produced on the film sheet by the doctor blade method using this kneaded material. After this was dried, it was peeled from the film sheet and punched to form a green sheet having 5 mm square.

Next, a wiring pattern made of a through hole and a low resistance metal material was formed by printing on each green sheet. A plurality of green sheets having the wiring pattern and the like formed thereon were laminated and press-molded to obtain a molded body.

First of all, the laminated green sheet is heated at a rate of 150 ° C. for 5 hours.
The temperature was raised to 00 ° C. and the temperature was maintained for 2 hours and 45 minutes to remove the organic substances in the green sheet. 200 ℃ / hour after that
The temperature was raised to the predetermined firing temperature shown in Table 2 at a rate of time, and this state was maintained for 3 hours, then lowered to 400 ° C at a rate of 110 ° C / hour, and then allowed to cool naturally. I got a union.

The permittivity (relative permittivity) and water absorption rate of the thus obtained sintered bodies of Examples 1 to 20 and Comparative Examples 1 to 8 were measured, and the results are also shown in Table 2. The coefficient of thermal expansion and the coefficient of thermal conductivity are also shown. Measurement of relative permittivity is 1MHz
At the frequency of. The water absorption was measured according to JIS C-2141.

As shown in Table 2, in the sintered bodies of Examples 1 to 20, as compared with the sintered bodies of Comparative Examples 1 to 8, the sintered body temperature was 950 ° C. or less and the sintered body was extremely dense. The tied state is achieved. The relative permittivity is also a small value that is sufficiently practical. The coefficient of thermal expansion and thermal conductivity are also good.

The sintered bodies of Comparative Examples 1 to 8 did not become a dense sintered body unless they were fired at a temperature of 1100 ° C. or higher. Further, since the sintered bodies of Comparative Examples 1 to 8 are not in a densely sintered state, their relative permittivity values are apparent values (measured values appear small), and the true values of the materials themselves. is not. Therefore, in the comparative example, the relative permittivity, thermal expansion coefficient, and thermal conductivity are not shown.

〔The invention's effect〕

As described above, the glass-ceramic sintered body of the present invention is formed by firing a powder compact formed by mixing the powder of the glass composition having the specially selected composition and the filler powder, Moreover, the relative dielectric constant is small. Moreover, it can be achieved at sintering temperatures below 100 ° C. Since it is dense and has a low relative dielectric constant, this sintered body is suitable for a multilayer wiring board material.Because the firing temperature is 1000 ° C or less, it is possible to perform firing at the same time by printing a low resistance metal material. The wiring can also be formed.

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Claims (2)

[Claims] 1. A glass ceramic sintered body obtained by firing a mixture of a glass composition powder and a filler, wherein the glass composition powder is SiO ₂ 48 to 63 wt%, Al ₂ O ₃ 10 to 25% by weight, B ₂ O ₃ 4 to 10% by weight, MgO 10 to 25% by weight, and 3 to 20% by weight of the above MgO of the mother glass is BaO, S.
For the main component formed by substituting at least one selected from the group consisting of rO and CaO, TiO ₂ , ZrO ₂ , SnO ₂ , P ₂ O ₅ , Zn
A composition comprising at least 3% by weight of at least one nucleating agent selected from the group consisting of O, MoO ₃ , Ta ₂ O ₅ , Nb ₂ O ₅ , As ₂ O ₃ and Li ₂ O. A glass-ceramic sintered body characterized in that the glass composition powder and the filler are mixed in a proportion of 70 to 95% by weight of the glass composition powder and 5 to 30% by weight of the filler. 2. A patent in which the filler is at least one selected from the group consisting of α-quartz, fused silica, cristobalite, cordierite, steatite, forsterite, wollastonite, anorthite, sergian and alumina. The glass ceramic sintered body according to claim 1.