JPS6350305B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a ceramic composition that is an insulating material for circuit boards, and particularly to a ceramic composition that is optimal as an insulating material for multilayer circuit boards. In today's world where electronic circuits are required to be highly integrated, circuit boards tend to become more multi-layered, smaller, thinner, and more dense. In order to obtain high reliability under these circumstances, multilayer circuit boards are desired to have high insulation properties, high bending strength, and a coefficient of thermal expansion as small as possible. Until now, alumina porcelain with good insulation has been mainly used as an insulating porcelain material for multilayer circuit boards, but this alumina porcelain has a low sintering temperature.
The temperature is 1500-1600℃. For this reason, in the production of multilayer circuit boards, in which a conductive material for wiring is printed on the surface of a porcelain sheet in advance and then fired at the same time as the porcelain is sintered, W, Mo, etc. are used as the conductive material. , Pt, or other high melting point materials, which is a factor that increases the cost of the above-mentioned substrate. In other words, in order to reduce the cost of the multilayer circuit board from the viewpoint of the conductive material, it is necessary to use a metal material such as Ni as the conductive material.
This requires an insulating porcelain material that can be sintered at relatively low temperatures below 1300°C in a non-oxidizing atmosphere. The present invention was made to solve the above-mentioned problems with conventional porcelain materials, and can be sintered at temperatures below 1300°C in a non-oxidizing atmosphere, and is required as a material for multilayer circuit boards. The object is to provide an insulating porcelain composition with various properties. The porcelain composition according to the present invention contains MgO from 1 to
61.5 mol%, ZrO ₂ 1-45.5 mol%, BaO, SrO,
5 oxides consisting of at least one of CaO and ZnO
~45 mol% and a mixture containing SiO ₂ at a ratio of 31.3 to 66.6 mol% was sintered. Hereinafter, as an example of the present invention, samples were prepared from a plurality of ceramic compositions having different formulations, and the results of tests conducted on each sample will be described. Sample 1 in the attached table is as described in the same table,
55.1 mol% SiO ₂ , 11.4 mol% CaO ₂ , MgO
This sample was made from a ceramic composition containing 25.2 mol% and 8.3 mol% of _ZrO2 . First, to explain this manufacturing method, first, 50.9g of SiO ₂ powder,
17.6 g of CaCO ₃ powder, 15.7 g of MgO powder, and 15.8 g of ZrO powder were weighed, and these were wet mixed by ball milling together with alumina balls for about 15 hours. Next, this mixture was dehydrated and dried, and then pre-calcined in air at a temperature of about 850° C. for about 2 hours.
Thereafter, the mixture was wet-stirred with alumina balls and pulverized to produce a calcined material. Next, 20 wt % polyvinyl alcohol was added to the same material as a binder, mixed and granulated, and this was pressure-molded into a plate shape at a pressure of 1000 kg/cm ² . Next, this was placed in a furnace and heated at a rate of 100°C per hour to 600°C in air.
Burned polyvinyl alcohol. Thereafter, the inside of the furnace was changed to a reducing atmosphere containing 97.0 vol% N ₂ and 3.0 vol% H ₂ , and the temperature was maintained at 1200° C. for 3 hours to obtain Sample 1. The sintering temperature FT at this time is shown in the attached table. In addition, according to the purpose of the test, the sample
A disc-shaped one with a diameter of 1.6 cm and a thickness of 0.1 cm, and a length of 2
A rectangular plate with a width of 1 cm, a width of 1 cm, and a thickness of 0.2 cm was manufactured. This sample 1 was tested by the following method. First, regarding the electrical characteristics, we used the disk-shaped sample mentioned above, applied indium-gallium alloy to both main surfaces, provided electrodes with a diameter of 1.4 cm, and measured the dielectric constant ε, Q (quality factor) and resistance. Rate ρ(Ω
cm) was measured. Of these, only the resistivity ρ is shown in the separate table. Note that the dielectric constant ε was calculated from the capacitance measured at a frequency of 1 MHz, and Q was measured at the same time as the capacitance described above. Further, the resistivity ρ was calculated from the results of measuring the insulation resistance 30 seconds after the start of applying a DC voltage of 100V. Regarding the physical and mechanical properties, the thermal expansion coefficient α (/°C) and the bending strength τ (Kg/cm ² ) were measured using the above-mentioned rectangular plate-shaped sample. Thermal expansion coefficient α is 20~
The coefficient of linear expansion at a temperature of 500°C was measured, and the bending strength τ was determined by measuring the breaking strength P (Kg) under the condition that the distance between the supporting points l = 0.7cm, and τ = 3Pl/2wt ² (Kg/cm ² )
It was calculated using the formula. However, w is the width of the sample (cm), t
is the thickness of the sample (cm). Hereinafter, for Samples 2 to 30, the powders were mixed so that each of the above porcelain materials had the content ratio shown in each column of the attached table, and the same method and conditions as Sample 1 were used (however, the firing temperature was different for each). Created. The firing temperature FT of each sample at this time is shown in each column of the attached table. The above-mentioned characteristics of each of the samples thus prepared were measured using the same method and conditions as Sample 1, and only the resistivity ρ of each sample is shown in the separate table. As is clear from the table, all of these samples have a sintering temperature FT of 1300℃ or less and a resistivity ρ.
was 1×10 ¹³ Ωcm or more. On the other hand, eight samples No. 31 to No. 38 were prepared using porcelain materials that did not meet the above-mentioned content ratio requirements using the same method and conditions as the above-mentioned samples (however, the firing temperatures were different for each sample). Firing temperature FT at this time
are shown in the attached table. Various properties of these samples were also measured using the same methods and conditions as those for the above samples, and only the resistivity ρ of each sample is shown in the separate table. As is clear from the table, these samples have a sintering temperature FT of 1300
℃ or less, and the resistivity ρ is 1×10 ¹³ or more, which either do not satisfy any of the above conditions, or the material cannot be sintered. These results were obtained because the effects of each porcelain material were exhibited synergistically, especially in the former group of samples, but the general effects of each of these porcelain materials and the corresponding test results, etc. The details are as follows. (1) If the content of SiO ₂ is too low, the sintering temperature will be high; if the content is too high, the sintering temperature will be high, and the insulation properties will be lowered. Among samples 1 to 30, sample 17 has the lowest content of 31.3 mol%, but while the same sample could be sintered at 1300°C, it was possible to sinter at a lower content of 20.0 mol%. Sample 31, which had the same temperature, required a temperature of 1400°C for sintering. On the other hand, among samples 1 to 30, this content is 60.8~
The relatively large amount of 66.6mol% is 2, 4, 7, 10
and 11, but both of these are
While it was possible to sinter at a temperature below 1200°C, sample 32 with a higher content of 75.0 mol% required a temperature of 1450°C for sintering. Moreover, the resistivity ρ of the former was 5×10 ¹³ Ωcm or more, whereas the resistivity ρ of the latter was as low as 10 ¹¹ Ωcm. (2) If the content of oxides consisting of CaO, SrO, BaO, and ZrO is small, the sintering temperature will be high, and if it is too large, the range of temperatures that can be sintered will be narrowed.
Sintering becomes difficult. 5.0mol in samples 1 to 30
Samples 16 to 16 have the lowest percentage of these oxides.
18, but while all of these could be sintered at temperatures below 1300℃,
In sample 33 with a content of 3.0 mol%, sintering
A temperature of 1450℃ was required. Also, among samples 1 to 30, samples 19 to 21 contain relatively large amounts of these oxides at 41.8 to 45.0 mol%;
While it was possible to sinter at a temperature below °C, sample 34, which had an even higher content of 45.0 mol%, had a narrow range of sinterable temperatures and was not suitable for industrialization. (3) If the MgO content is too low, the range of temperatures that can be sintered will be narrowed, and if it is too high, the firing temperature will become high and the insulation properties will decrease. Among samples 1 to 30, sample has the least MgO at 1.0 mol%.
18, 21 and 25, but none of these samples
While it was possible to sinter at temperatures below 1300°C, sample 35, which had an even lower content of 0.1 mol%, was not suitable for industrialization because the range of temperatures at which it could be sintered was narrow. On the other hand, samples 1 to 30
Sample 17 contains the highest amount of MgO at 61.5 mol%, but when comparing the same sample with sample 36, which contains more MgO at 62.7 mol%, the former is
It was possible to sinter at 1300°C, whereas the latter required a temperature of 1350°C for sintering. Furthermore, while the resistivity ρ of the former was 10 ¹³ Ωcm, the resistivity ρ of the latter was as low as 10 ¹¹ Ωcm. (4) When the content of ZrO ₂ is low, the insulation property decreases,
On the other hand, if this amount is too large, the sintering temperature will become high. Among samples 1 to 30, samples 16 and 19 have the lowest content of 1.0 mol%, but while the resistivity ρ of these samples was more than 10 ¹³ Ωcm,
The resistivity ρ of sample 37, which had an even lower content of 0.1 mol%, was as low as 10 ¹¹ Ωcm. Also, this content in samples 1 to 30
Comparing sample 18, which has the highest content at 45.5 mol%, and sample 38, which has an even higher content of 47.0 mol%, the former can be sintered at 1300°C, while the latter requires a temperature of 1350°C. It cost. In addition, samples 1 to 30 all have a relative dielectric constant ε of 9 or less, a Q of 500 or more, and a thermal expansion coefficient α of 8.0×10 ^-6 /
℃ or less, the bending strength was 1000 Kg/cm ² or more, and we were able to obtain practical values for properties other than insulation as a multilayer circuit board. The publication of these detailed figures will be omitted. As described above, the ceramic composition according to the present invention can be sintered at a temperature of 1300° C. or lower in a non-oxidizing atmosphere. Therefore, it becomes possible to manufacture a multilayer circuit board using a metal such as NI as a conductive material for circuit wiring, and it is possible to reduce costs in terms of conductive material for wiring. Moreover, even by firing under these conditions, the properties required as a multilayer circuit board material can be obtained, and in particular, high insulation properties can be obtained, making it possible to cope with higher wiring densities.

【table】

[Table] * Sintering is not possible because the sintering temperature range is too narrow.

Claims (1)

[Claims] 1 MgO 1-61.5 mol%, ZrO ₂ 1-45.5 mol
%, 5 to 45 mol% of an oxide consisting of at least one of BaO, SrO, CaO, and ZnO, and 31.3 to 45 mol% of SiO ₂
An insulating porcelain composition characterized by being made by sintering a mixture containing 66.6 mol%.