JPH04286181A - Composition for ceramic board - Google Patents

Abstract

PURPOSE:To provide a composition for a ceramic board, which can be baked at an extremely low temperature, in which the paste of Au, Ag, etc., can be used as an internal electrode, which satisfies various required characteristics such as volume specific resistivity, a dielectric constant, a dielectric loss tangent, breakdown strength, etc., and in which the rate of change of electrostatic capaci tance to a temperature change can be adjusted as + or -0 to + or -100ppm/ deg.C, in the composition for the ceramic board used for manufacturing various multilayer interconnection boards. CONSTITUTION:The title composition is composed of 60-95wt.% glass frit and 40-5wt.% titanate, said titanate consists of SrTiO3, CaTiO3, etc., or the solid solution, etc., of these titanate, and said glass frit is made up of 30-40wt.% SiO2, 10-20wt.% Al2O3, 5-20wt.% CaO+MgO, 5-15wt.% ZnO, 10-20wt.% TiO2, 0.5-2wt.% B2O3 and 0.2-1wt.% ZrO2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic substrate composition suitable for multilayer wiring boards on which electronic circuits such as conductors and resistors are formed in multiple layers.

0002

[Prior Art] Currently, electronic components with multilayer circuits are manufactured by printing circuits and insulating layers alternately on a sintered alumina substrate and firing them; A second method is to print a circuit on a ceramic substrate, laminate the circuits so that they do not touch each other, press them, and then bake them. In the first method, unevenness occurs in the insulating layer formed thereon due to the influence of the circuit, and the unevenness becomes larger as the upper layer increases. When the unevenness becomes large, it becomes difficult to print the next circuit on top of the unevenness, and the limit is usually around 10 layers. In contrast, with the second method, circuits are always printed on a substrate that is nearly flat, so it is possible to manufacture products with a large number of laminated layers, making it possible to form high-density integrated circuits. . The ceramic composition used for the substrate in this second method is Al2
There are products in which O3 powder and 15 wt% or less glass powder are fixed with an organic binder, and products in which Pb and B are mixed into the Al2O3-SiO2 system and fired at low temperatures. vol. 35, No. 1
6, P51-58, 1987, Nobuyuki Sugishita "Japanese Science Information" HIC paste materials and printing and firing technology, P13-21,
1989, etc.

0003

[Problems to be Solved by the Invention] However, in the second conventional method described above, the one in which Al2O3 powder and 15 wt% or less glass powder are fixed with an organic binder has an extremely high firing temperature of 1450° to 1600°C. In addition, expensive materials such as Mo and W, which do not deteriorate at this firing temperature, must be used to construct the circuit, and the firing must be performed in a reducing atmosphere, resulting in poor productivity and workability. there were. The Al2O3-SiO2 system mixed with Pb and B has the advantage of being able to be fired at low temperatures, but the rate of change in capacitance (hereinafter referred to as TCC) with respect to temperature changes is too large and the quality is said to be unstable. There was a problem.

[0004] The present invention solves the above-mentioned conventional problems, and can be fired at an extremely low temperature, that is, 750° to 950°C, and pastes such as Au, Ag, Ag-Pd, and Cu can be used as internal electrodes. Moreover, it satisfies the characteristics required for a multilayer wiring board that forms electronic circuits in multiple layers, such as volume resistivity, dielectric constant, dielectric loss tangent, and dielectric breakdown strength. Furthermore, TCC is ±0 ppm/℃ to ± 100ppm/
The object of the present invention is to provide a composition for a ceramic substrate that can be adjusted within a temperature range of .degree.

[0005]

[Means for Solving the Problems] The composition for ceramic substrates of the present invention to solve this object has a weight of 60 to 95 wt.
% glass frit and 40-5 wt% titanate, specifically, the titanate is SrTiO3
, CaTiO3, MgTiO3, BaTiO3, or
These are solid solution compositions of titanates. Further, the glass frit essentially contains SiO2 in a range of 30 to 30% by weight.
40, Al2O3 is 10-20, CaO+MgO is 5-
20, ZnO 5-15, TiO2 10-20, B2
It has a structure in which O3 is 0.5 to 2 and ZrO2 is 0.2 to 1.

[0006] If the glass frit is less than 60 wt%, the firing temperature will be high, making it difficult to perform the firing at a low temperature, which is the object of the present invention. On the other hand, the glass frit is 9
If it exceeds 5 wt%, the flexural strength and moisture resistance of the fired product will decrease, which is not preferable. Furthermore, it becomes difficult to adjust the TCC. Glass frit is 65wt% to 94wt% in the above range
is more desirable.

[0007] If SiO2 is less than 30 wt%, the softening temperature will be low and large deformation will occur during firing, and if it exceeds 40 wt%, the firing temperature will become too high, both of which are undesirable.

[0008] If Al2O3 is less than 10 wt%, the flexural strength of the fired product will be poor, and if it exceeds 20 wt%, the softening temperature of the glass will be high and a high firing temperature will be required, so both are not preferred.

[0009] CaO and MgO are added for the purpose of improving the meltability during glass frit production and adjusting the thermal expansion coefficient of the glass. If the total amount is less than 5 wt%, the above-mentioned meltability will not be sufficiently improved and devitrification will easily occur during frit production, and if it exceeds 20 wt%, the coefficient of thermal expansion will become too large, so both are not preferred.

[0010] ZnO is desirably added in an amount of 5 wt % or more in order to improve the meltability of the glass. If it exceeds 15 wt%, the softening temperature of the glass becomes too low and large deformation tends to occur during firing, which is not preferable.

[0011] TiO2 is preferably added in an amount of 10 wt% or more in order to improve the meltability and chemical stability of the glass. If it exceeds 20 wt%, the softening temperature of the glass will become high and a high firing temperature will be required, which is not preferable.

[0012] B2O3 is a flux, 0.5w
If it is less than t%, the firing temperature becomes too high, and if it exceeds 2wt%, the chemical stability of the glass decreases, both of which are unfavorable.

[0013] ZrO2 is preferably added in an amount of 0.2 wt% or more in order to improve the chemical stability of the glass.
If it exceeds 1 wt%, it is not preferable because it impairs the melting properties during glass frit production.

[0014]

[Operation] With this configuration, it is possible to bake at an extremely low temperature compared to conventional ones, that is, 750° to 950°C, and pastes such as Au, Ag, Ag-Pd, and Cu, which are widely used in thick film technology, can be used as internal electrodes. In addition, the fired body has high bending strength, excellent thermal conductivity, low dielectric constant, high insulation resistance, and excellent moisture resistance, and is particularly compatible with glass frits that have positive TCC characteristics. The titanate-based calcination reaction with negative TCC characteristics can facilitate the adjustment of TCC.

[0015]

[Embodiment] An embodiment of the present invention will be described below.

[0016] The glass frit has SiO2 of 38, Al2O3 of 19, CaO+MgO of 18, and Zn in weight percent.
O is 13, TiO2 is 10, B2O3 is 1.5, ZrO
Mix each raw material so that 2 is 0.5, and 14
The mixture was melted with stirring at a temperature of 00° to 1500°C, and after melting, it was pulverized into water or flakes to produce a glass frit.

Next, using SrTiO3 as the glass frit and titanate, 85 wt% and 15 wt%, respectively.
The mixture was weighed so as to yield t%, ground in a ball mill, and mixed to obtain a composition of the present invention.

To this pulverized and mixed composition, 10% of a binder was added, and after granulation and molding, it was baked at 850° C. for 15 minutes. After processing this fired body into a diameter of 30 mm and a thickness of 0.35 mm, an Ag electrode was baked and the TCC was measured, and it was found to be ±0 ppm/°C from -25°C to 85°C.

Next, various binders, plasticizers, and solvents are added and kneaded to this pulverized and mixed composition to obtain a viscosity of 10p.
A paste of s to 30 ps was prepared. This paste was made into a green sheet with a thickness of about 0.1 mm by a conventional doctor blade method. Fifty of these green sheets were stacked, and then thermocompression bonded at 35° C. under a pressure of about 50 tons, and baked at 850° C. for 30 minutes. When various properties of the fired sheet were measured, the specific volume resistivity was 1014 to 10.
16Ωcm, dielectric constant 12-14, dielectric loss tangent ≦5×10-
4. Dielectric breakdown strength 750-900KV/cm, bending strength 2000-2500kg/cm, TCC (-25℃~
85°C) ±0 ppm/°C. That is, results were obtained that satisfied the required characteristics of a good ceramic substrate as a multilayer wiring board on which electronic circuits such as conductors and resistors are formed in multiple layers.

Next, using SrTiO3 as the glass frit and titanate, 94 wt% and 6 wt%, respectively.
The materials were weighed so as to be t%, ground and mixed in a ball mill, and a fired green sheet was obtained by the above method. The firing temperature in this case was 780°C. When various properties of the fired sheet were measured, values such as volume resistivity, dielectric constant, dielectric loss tangent, dielectric breakdown strength, and bending strength were found to be equivalent to those described above. TCC was +50 ppm/°C.

CaT as glass frit and titanate
In the case of compositions using iO3 and mixed with 70 wt% and 30 wt%, respectively, the volume resistivity, dielectric constant, dielectric loss tangent, dielectric breakdown strength, bending strength, etc. have the same values as above at a firing temperature of 870°C. I got it. TCC was -15 ppm/°C.

[0022] When SrCaTi2O6 solid solution is used as the titanate, the amount of SrCaTi2O6 mixed is 60%.
When a green sheet fired body was obtained using the above method at a firing temperature of 890°C when Obtained. TCC was -30 ppm/°C.

Other titanates include MgTiO3,
Similar results were obtained using BaTiO3 and solid solutions of these titanates.

Furthermore, similar results were obtained with laminated fired bodies using pastes of Au, Ag, Ag-Pd, Cu, etc. as internal electrodes. The above results are shown in (Table 1).

[0025]

[Table 1]

Next, fired bodies were made outside the composition range of the present invention shown in Table 2, and their properties were investigated. The results are shown in (Table 2).

[0027]

[Table 2]

As is clear from Tables 1 and 2, the composition of the present invention can be fired at an extremely low temperature, which was previously impossible, and the TCC can be easily adjusted. I understand.

[0029]

As described above, the present invention comprises a composition of a predetermined amount of glass frit and a titanate, and the titanate includes SrTiO3, CaTiO3, MgTiO3.
, BaTiO3, or a solid solution of these titanates, and the glass frit includes a predetermined amount of SiO2,
Al2O3, CaO+MgO, ZnO, TiO2, B2
By creating a composition for ceramic substrates consisting of a mixture of O3 and ZrO2, it is now possible to perform firing at an extremely low temperature, that is, 750 to 950°C, which was previously impossible. It has also become possible to use pastes such as , Cu, etc. as internal electrodes. Furthermore, various required properties of the fired body, namely volume resistivity,
It satisfies the good characteristics of a ceramic substrate as a multilayer wiring board for forming electronic circuits in multiple layers, such as dielectric constant, dielectric loss tangent, dielectric breakdown strength, and bending strength, and also has a TCC of ±0 ppm/
It is possible to realize a ceramic substrate composition that can be easily adjusted in the range of .degree. C. to ±100 ppm/.degree. C. and that can be mass-produced at low cost.

Claims (3)

[Claims] Claim 1: 60-95% by weight glass frit and 40% by weight
A composition for a ceramic substrate, characterized in that it consists of ~5% by weight of a titanate. 2. The titanate is SrTiO3, CaTi
2. The composition for a ceramic substrate according to claim 1, comprising one or more of O3, MgTiO3, BaTiO3, or a solid solution of these titanates. 3. The glass frit comprises SiO2 in weight percent.
is 30-40, Al2O3 is 10-20, CaO+Mg
O is 5-20, ZnO is 5-15, TiO2 is 10-2
2. The composition for a ceramic substrate according to claim 1, characterized in that the content of ZrO2 is 0.0, B2O3 is 0.5 to 2, and ZrO2 is 0.2 to 1.