JPS6233682B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a powdery inorganic composition for an insulating layer firing paste used for forming multilayer thick film circuits and the like.

Conventionally, the most common method for manufacturing multilayer thick film circuits, etc. is to deposit gold (Au), silver (Ag), platinum (Pt), palladium (Pd), tungsten (W), molybdenum (Mo) on a ceramic substrate such as alumina. )
Then, a conductor circuit is printed using a conductor layer firing paste made of these alloys, and this is placed in a furnace and fired to form a conductor circuit, or a conductor circuit is formed by a plating method, and then these conductor circuits are printed. In order to form an insulating layer that insulates the conductor circuit and the second layer conductor circuit, a method is used in which an insulating layer firing paste is applied, placed in a furnace, and fired to laminate the insulating layer. In this case, when applying the insulating layer firing paste, it is necessary to leave a connection hole connecting the first layer conductor circuit and the second layer conductor circuit. The applied layer of insulating layer firing paste is then placed in the oven again to be fired and fixed to form an insulating layer having the expected shape upon application. Next, a second layer conductor circuit is formed so that the connection hole in the insulating layer is filled with the conductor layer firing paste, and is fired and fixed. In this way, the third phase and fourth layer conductor circuits are formed using the same method as necessary, and a desired multilayer electronic circuit is mounted by connecting an IC or LSI to the top layer depending on the application. was.

The insulating layers necessary for forming these multilayer circuits can be sintered densely at relatively low temperatures, have few pinholes, are acid resistant (especially required when forming conductor circuits by the plating method), and have high withstand voltage. , low thermal resistance, low dielectric constant, and other requirements are strongly desired. The insulating layer firing paste that has been conventionally used for this purpose generally uses crystallized glass as an inorganic substance, and combines glass powder obtained by pulverizing this crystallized glass with a binder such as ethyl cellulose or polyvinyl butyral and a solvent such as butyl carbyl. It was dispersed and kneaded in a vehicle in which tall acetate and terpineol were dissolved. However, although conventional insulating layer firing pastes using only crystallized glass are supposed to crystallize and form an insulating layer by reheating, sufficient crystallization is often not achieved, and when this occurs, acid-resistant It lacks properties and densification is insufficient. It also had drawbacks such as a higher thermal resistance value compared to alumina (Al ₂ O ₃ ), spinel (MgO.Al ₂ O ₃ ), etc.

The purpose of the present invention is to provide a powdered inorganic composition for an insulating layer firing paste that eliminates these drawbacks, that is, has excellent densification, few pinholes, low thermal resistance, and excellent voltage resistance and acid resistance. It is about providing.

According to the present invention, 30 to 70 parts by weight of powdered glass having a specific surface area of 1 to 8 m ² /g (hereinafter referred to as glass powder for simplicity) and 0.8 to 9.5 parts by weight of the remaining part to make 100 parts by weight. It is a mixture of powdered ceramics (hereinafter referred to as ceramic powder for simplicity) with a specific surface area of m ² /g, and it is dispersed in a vehicle to form a paste, which is then applied and fired to form an insulating layer. is a powdered inorganic composition in which the glass powder contains 10 to 80% by weight of SiO 2 and 55 to 55% by weight of SiO ₂ when the raw material composition is expressed in terms of oxides.
Weight%, _{B2O3 3-35} % by weight, CaO0.2-12% by weight,
MgO0.2 _~ 12wt%, BaO0.1~10wt%, _Al2O30
~20% by weight, _Li2O0.1 ~5% by weight, NaO0.1~5% by weight, K2O0.1 _~ 5% by weight, TiO2 _0.1 ~5% by weight,
Its raw material composition is an inorganic oxide in the range of 0.1 to 5% by weight of ZrO ₂ and 0.1 to 5% by weight of ZnO, and at least four types of SiO ₂ B ₂ O ₃ , PbO, and Na ₂ O in the inorganic oxide are It is included as an essential constituent composition, and when the raw material composition of the ceramic powder is expressed in terms of oxides, it contains Al ₂ O ₃ , MgO・Al ₂ O ₃ , Al ₂ O ₃・SiO ₂ ,
_3The raw material composition contains at least one inorganic oxide group selected from each composition group represented by Al 2 O 3 ・SiO _{2 ,} MgO ・SiO ₂ , ZnO ・Al ₂ O ₃ A powdered inorganic composition for insulating layer firing paste is obtained.

Such a powdered inorganic composition for insulating layer firing paste of the present invention can be manufactured using, for example, the following materials and methods. That is, glass powder is obtained by blending various raw material powders to a desired composition, melting the mixture into a glassy state, and then wet-pulverizing the powder in an alumina ball mill using alcohol as a dispersion medium to obtain a desired particle size. things are appropriate.

In addition, ceramic powder is a powder obtained by homogeneously blending various raw material powders to a desired composition, pre-firing, and solid-phase reaction to form a ceramic, or when the specific surface area of the ceramic powder obtained in this way is too large. It is appropriate to grind this and adjust it to a desired specific surface area. Then, these glass powder and ceramic powder are weighed to have a desired blending ratio, and wet-mixed using alcohol as a dispersion medium, for example, to form a homogeneous mixed powder of glass powder and ceramic powder, that is, the insulating layer firing of the present invention. A powdered inorganic composition for paste is obtained. Note that the raw material powder used in this case is expressed in terms of oxide for clarity, but it goes without saying that it can be used in the form of minerals, oxides, carbonates, hydroxides, etc. in the usual manner.

A vehicle is added to the thus obtained powdered inorganic composition of the present invention, and the mixture is thoroughly kneaded using, for example, a three-roll or agate crusher, and is uniformly dispersed to obtain the desired insulating layer baking paste. . In the present invention, there are no restrictions on the components of the vehicle. As the binder, commonly used binders such as ethyl cellulose and polyvinyl butyral are sufficient, and it is convenient to form a 5 to 15% by weight solution using a solvent. As a solvent, β
Alternatively, α-terpineol, n-butyl carbitol, butyl carbitol acetate, ethyl carbitol acetate, etc. may be used alone or in combination of two or more.

Next, in the present invention, we will discuss the blending ratio of glass powder and ceramic powder in the powdered inorganic composition for insulating layer firing paste, the specific surface area (particle size) of glass powder and ceramic powder, and the raw material composition of glass powder and ceramic powder. The reason for limiting the scope as stated in the claims will be explained below.

First, the composition of the glass powder, which is one of the main components of the powdered inorganic composition for insulating layer firing paste according to the present invention, is as follows: (1) SiO ₂ 10-80% by weight, B ₂ O ₃ 3-35% weight%,
PbO2 - 55% by weight and Na ₂ O 0.1 - 5% by weight are essential main components, and their composition ratio greatly influences the properties of the glass. However, by selecting the composition ratio within a limited range, it is possible to achieve a satisfactory balance of various properties such as glass softening temperature, coefficient of thermal expansion, dielectric constant, and acid resistance, resulting in insulation. An excellent layered paste can be obtained. When selecting a composition outside the limited range, for example, if the composition of PbO and B ₂ O ₃ is increased too much, the softening temperature will be significantly lowered and the acid resistance will also be lowered, which is not preferable.

(2) The effect of adding 0 to 20% by weight of Al ₂ O ₃ is that acid resistance and water resistance are improved, and shape retention properties during coating and firing processes are improved. However, if it exceeds the limited range, the viscosity will increase too much and vitrification will become difficult.

(3) Li ₂ O 0.1-5% by weight, Na ₂ O 0.1-5% by weight,
If the alkali metal oxide, such as 0.1 to 5% by weight of K ₂ O, is within a limited range, it will appropriately control the softening point of the glass, but if it exceeds the limited range, the acid resistance will deteriorate, which is undesirable.

(4) MgO0.2-12% by weight, CaO0.2-12% by weight,
Alkali metal oxide of BaO 0.1-10% by weight, and the rest TiO ₂ 0.1-5% by weight, ZrO ₂ 0.1-5
% by weight, ZnO of 0.1 to 5% by weight contributes to crystallizing a part of the glass by reheating during the formation of the insulating layer, and is also effective in densification. However, outside the limited range, the viscosity may become too high or densification may be inhibited.

Regarding ceramic 2 powder, which is another main component of the powdered inorganic composition for insulating layer firing paste, (5) As for the composition of ceramics, when the raw material composition is expressed in terms of oxides, it is Al ₂ O ₃ , MgO・
Al ₂ O ₃ , Al ₂ O ₃・SiO ₂ , 3Al ₂ O ₃・SiO ₂ , MgO・
The raw material composition should include at least one inorganic oxide group selected from the composition groups represented by SiO ₂ and ZnO.Al ₂ O ₃ . If you choose a composition other than these, the thermal resistance may become larger, the dielectric loss may become larger,
A dense insulating layer may not be obtained, or the balance between desired characteristics may be lost.

Furthermore, regarding the blending of glass powder and ceramic powder, (6) Add 30 to 70 parts by weight of glass powder.
By appropriately selecting 100 parts by weight and the remainder being ceramic powder within the limited range of the present invention, it is possible to achieve denseness, lower thermal resistance, withstand voltage,
An insulating layer with excellent acid resistance, dielectric constant, etc. can be obtained. However, if the ceramic powder exceeds the specified range, a dense insulating layer will not be obtained at relatively low temperatures of 800 to 1000°C, and pinholes will increase and acid resistance will deteriorate. Further, if it is less than the limited range, although the insulating layer is dense, the surface tends to foam, the adhesion with the conductor decreases, and the thermal resistance increases, which is not preferable.

Furthermore, regarding the particle size of glass powder and ceramic powder, (7) the specific surface area of ceramic powder is 0.8 to 9.5 m ² /
The range of gr, and the specific surface area of glass powder is 1.0~
A range of 8.0 m ² /gr is suitable for each, and by appropriately selecting and combining powder particles in this range, a suitable insulating layer with fewer dense pinholes and high adhesion strength to the conductor can be obtained. can get. However, outside the limited range, pinholes in the insulating layer increase, surface roughness increases, and sintering at 800 to 1000°C becomes insufficient, which is not preferable.

Although various reasons for limiting the present invention have been explained above, the effects brought about by the limiting range do not change dramatically at the boundaries thereof. Naturally, it is a relative matter, and it is inevitable that there will be some fluctuations as circumstances change when implementing the present invention, such as the ease of production technology, the balance between purity and price of raw materials, etc. be. For example, when looking at raw materials distributed under the expression Al ₂ O ₃ , there are various purity and forms. The inventor has developed various Al ₂ O ₃
The present invention was carried out using the following methods, but the reality is that some of them yielded truly good results, while others were less than impressive. Among these Al ₂ O ₃ , we conducted a precise analysis of those that obtained sufficiently satisfactory results when used as raw materials for ceramics.
It contained some impurities. For example, SiO ₂ 0.03-1.0% by weight, MgO 0.03-1.0% by weight, CaO 0.03-0.5% by weight, Fe ₂ O ₃ 0.01-0.1% by weight, Na ₂ O 0.01-0.5% by weight. It was %. These trace amounts of impurities seem to be effective in sintering well at low temperatures. Among the raw materials constituting the present invention, for those used in considerably large amounts, it is necessary to determine the blending ratio of the raw materials in consideration of such impurities. However, when the constituent elements containing these impurities themselves need to be added in only trace amounts to the whole, the absolute amount becomes extremely small, on the order of the square of a trace amount, and this poses a serious problem. It won't be. In order to cope with this situation, in the present invention, these trace amounts of impurities are included in the expression Al ₂ O ₃ etc. as fluctuations. The same applies to other raw materials. Therefore, when calculating the raw materials that are particularly required to be added in small amounts in the present invention,
I would like to know how much of the impurities are contained in other raw materials before calculating the amount.

Since the embodiments of the present invention are wide-ranging and it is difficult to fully explain them all, one typical embodiment will be specifically mentioned below, and one part of the present invention will be explained in detail based on the example.

Example 1 _SiO2 64.9% by weight, _{B2O3 6.8} % by weight, PbO16.6% by weight, _Na2O2.7 % by weight, _K2O2.17 % by weight,
A glass powder having a composition of 0.41% by weight of MgO, 5.38% by weight of CaO, 0.1% by weight of BaO, 0.21% by weight of TiO ₂ and 0.93% by weight of ZrO ₂ was prepared by a conventional method, and then alcohol was added using an alumina ball mill. as a dispersion medium
Wet milling was carried out for 16 hours.

This was sized with a sieve and then dried with alcohol to obtain a glass powder having a particle size with a specific surface area of 2.68 m ² /gr. Ceramics powder contains SiO ₂ 0.28% by weight,
Purity 99.69% including impurities of 0.05% by weight NaO, 0.3% by weight MgO, 0.03% by weight CaO, 0.05% by weight Fe ₂ O ₃
A powder with a particle size of Al ₂ O ₃ and a specific surface area of 2.58 m ² /gr was used. The blending ratio of glass powder and ceramic powder was 54 parts by weight of glass powder and 46 parts by weight of ceramic powder. Weigh a predetermined amount of each powder, and use alcohol as a dispersion medium in an alumina ball mill.
After mixing for a period of time, the alcohol was dried to obtain a homogeneous glass-ceramic mixed powder. The vehicle was a 15% by weight solution of ethyl cellulose, and butyl carbitol acetate was used as the solvent. 30 parts by weight of vehicle and 70 parts by weight of glass-ceramic mixed powder were kneaded using three rolls, and the powder was uniformly dispersed in the vehicle to form a paste. The obtained insulating paste was evaluated by metallizing Au on a 96% Al ₂ O ₃ substrate to form a lower electrode, applying the insulating layer firing paste prepared according to the present invention on top of this using a screen, drying it, and then applying a 930° C.
The material was sintered in an electric furnace at ℃ for 10 minutes. The atmosphere during sintering was air, and the sintering cycle (heating peak temperature, temperature cooling, removal from the furnace) was 60 minutes.
Application, drying, and sintering of the insulating layer firing paste were repeated twice to obtain an insulating layer with a thickness of 40 μm.

Au paste was applied to the surface of the obtained insulating layer, dried, and baked at 930° C. for 8 minutes to obtain an upper electrode. This was measured at 1MHz. The dielectric constant is 7.8, and the dielectric loss is
0.0025, insulation resistance is 2.3×10 ¹² Ωcm (at100VDC)
It was hot. The measurement of pinholes takes advantage of the fact that when measuring the weak leakage current flowing in an insulating layer, the leakage current increases when there are many pinholes, and conversely, the leakage current decreases when there are few pinholes.
The method was first carried out under the same conditions as in this example described above.
Conductor (Au, Ag/Pb, Ag/Pt, etc.) on Al ₂ O ₃ substrate
A 40-μm-thick insulating layer is formed on it, and a part of the metallization is used as an electrode. this
It was also immersed in a 15% by weight NaC aqueous solution (electrolyte), and the other electrode was a copper plate, immersed in the same aqueous solution, and DC10V was applied to measure leakage current. The leakage current is
It was 240μA.

Vehicle-free glass ceramic powder
Pressure molded at 800Kg/cm ² and then heated at 930℃-10 in an electric furnace.
Sintering was performed for a minute to obtain a sintered body with a diameter of 20 mm and a thickness of 1 mm.
This was measured and a value of thermal conductivity of 0.02 cal/cm·°C·sec was obtained. Although the surface roughness of the insulating layer thus formed on the conductor was as small as 5 μm, the adhesion strength to the conductor was sufficient.

Example 2 SiO ₂ 59.3% by weight, B ₂ O ₃ 6.2% by weight, PbO 15.3% by weight, Al ₂ O ₃ 8.4% by weight, Na ₂ O2.2% by weight, K ₂ O2.0
Weight%, MgO0.34weight%, CaO4.7weight%,
Glass with a composition ratio of 0.17% by weight of BaO, 0.29% by weight of Fe ₂ O ₃ , 0.17% by weight of TiO ₂ , 0.84% by weight of ZrO ₂ and 0.09% by weight of ZnO was prepared with a specific surface area of 2.54 m ² /gr. 50 parts by weight, SiO ₂ 0.1% by weight, Na ₂ O 0.05% by weight, MgO 0.25% by weight, CaO 0.01% by weight,
Fe ₂ O ₃ 99.51% pure with 0.08% impurities by weight
Example 50 parts by weight of ceramic powder prepared by pulverizing Al ₂ O ₃ to have a specific surface area of 1.95 m ² /g
The mixture was mixed, dried, and made into a paste using the same method and conditions as 1. An insulating layer was formed and various properties were measured. As a result, dielectric constant 8.0, dielectric loss 0.0015, insulation resistance 1.5×
10 ¹³ Ωcm (at 100 VDC), leakage current 150 μA, and thermal conductivity 0.018 cal/cm・℃・sec. Furthermore, the surface roughness of the insulating layer was 4.5 μm at maximum, and the adhesion strength to the conductor was also good.

Example 3 SiO ₂ 54.7% by weight, B ₂ O ₃ 5.8% by weight, PbO 14.0% by weight, Al ₂ O ₃ 15.6% by weight, Na ₂ O 2.0% by weight,
K ₂ O 1.9% by weight, MgO 0.31% by weight, CaO 4.4% by weight, BaO 0.16% by weight, ZnO 0.08% by weight, TiO ₂ 0.16
A glass with a composition ratio of 0.26% by weight of Fe ₂ O ₃ and 0.78% by weight of ZrO ₂ was prepared by a normal method, and then alcohol was used as a dispersion medium using an alumina ball mill.
Wet milled for 24 hours. This was sized with a sieve and then dried with alcohol to prepare a glass powder with a specific surface area of 3.4 m ² /gr. Ceramics powder contains 1.25% by weight of SiO ₂ , 0.02% by weight of Na ₂ O, 1.18% by weight of MgO, 0.68% by weight of CaO
% by weight, purity with impurities of Fe ₂ O ₃ 0.03% by weight
A 96.84% Al ₂ O ₃ powder was prepared in the same manner as the glass powder to obtain a ceramic powder with a specific surface area of 2.56 m ² /g. 55 parts by weight of this glass powder and 45 parts by weight of ceramic powder were blended, and this was used in the example -
The mixture was mixed, dried, and made into a paste using the same method and conditions as 1. An insulating layer was formed, and various properties were measured. As a result, dielectric constant 8.3, dielectric loss 0.0017, insulation resistance 3.5
×10 ¹⁵ Ωcm (at100VDC), leakage current 210μA,
Thermal conductivity was 0.0096 cal/cm・℃・sec. Furthermore, the surface roughness of the insulating layer was small and the adhesion to the conductor was good.

Example 4 Glass powder and ceramic powder were prepared under the same conditions as Example 1, such as the composition, composition ratio, and specific surface area. The blending ratio of glass powder and ceramic powder is 35% of the amount of ceramic powder.
It was prepared according to the method and conditions of Example 1, with the remaining glass powder being 100 parts by weight.
Bibicle uses ethylcellulose as a binder
A solution of 15% by weight in the solvent β-terpineol was used. Then, 70 parts by weight of the mixed powder was dispersed in 30 parts by weight of vehicle and thoroughly kneaded with three rolls to form a paste.

The resulting paste was already Au metalized.
Screen printed on _{Al2O3 substrate} and dried at 930℃
Sintered in air for 10 minutes at a peak temperature of 45μ
An insulating layer of m was obtained. Furthermore, Au is added to the surface of this insulating layer.
The paste was applied, fired, and metallized. Various properties of the four samples thus obtained were measured in the same manner as in Example-1. The result is the dielectric constant
As the blending ratio of ceramic powder increased between 7.5 and 8.9, the dielectric constant also tended to increase. Dielectric loss is 0.0012 to 0.0025, insulation resistance is 1.4×10 ¹¹ to 3.2×
There was no big difference at 10 ¹¹ Ωcm. Samples for measuring leakage current and thermal conductivity were prepared using the method and conditions of Example-1. As a result of measurement, the leakage current is 130~890μ
A showed a tendency to increase in proportion to the blending ratio of ceramic powder. Thermal conductivity is 0.0056~
It is 0.028 cal/cm・℃・sec and increases as the blending ratio of ceramic powder increases. Furthermore, the surface roughness of the insulating layer was small and the adhesion strength to the conductor was sufficient.

Example 5 _SiO2 64.9% by weight, _{B2O3 6.8} % by weight, PbO16.6% by weight, _Na2O2.7 % by weight, _K2O2.17 % by weight,
Glass having a composition ratio of 0.41% by weight of MgO, 5.38% by weight of CaO, 0.1% by weight of BaO, 0.21% by weight of TiO ₂ and 0.93% by weight of ZrO ₂ was ground for 46 hours in an alumina ball mill using alcohol as a dispersion medium. After sifting this with a sieve, alcohol was dried to obtain a glass powder with a specific surface area of 6.4 m ² /g. As ceramic powder, MgO・
Al ₂ O ₃ powder was used and the specific surface area was adjusted to 3.5 m ² /gr. The blending ratio of glass powder and ceramic powder is 40 parts by weight, 45 parts by weight, and 50 parts by weight of ceramic powder.
Change it to parts by weight, and add up the rest as glass powder.
100 parts by weight of glass-ceramics mixed powder was obtained.

Powder mixing, vehicle used, pasting, coating, drying, sintering, formation of an insulating layer, measurement of various properties, etc. were carried out in the same manner and under the same conditions as in Example-1. The results are dielectric constant 7.6~8.5, dielectric loss 0.0021~
0.0032, insulation resistance 1.6×10 ¹² ~ 4.5×10 ¹¹ Ωcm, leakage current 350 ~ 580 μA, thermal conductivity 0.0067 ~
It was 0.012 cal/cm・℃・sec. Furthermore, the adhesion to the conductor was also good.

Example 6 Glass powder contains 55% by weight of SiO ₂ , 6.8% by weight of B ₂ O _{3 ,} 6.5% by weight of PbO2, 2.7% by weight of NaO, 17% by weight of K ₂ O2, 0.41% by weight of MgO, 5.38% by weight of CaO weight%,
A glass with a composition ratio of 0.1% by weight of BaO, 0.21% by weight of TiO ₂ , and 0.93% by weight of ZrO ₂ was prepared, ground for 32 hours using alcohol as a dispersion medium using an alumina ball mill, sized with a sieve, and then dried to determine the specific surface area. 4.7m ² /g
was prepared. As ceramic powder
Al ₂ O ₃・SiO ₂ , 3Al ₂ O ₃・SiO ₂ , MgO, SiO ₂ ,
There are four types of ZnO and Al ₂ O ₃ , and each has a specific surface area.
The particles were adjusted to a particle size of 3.1 to 3.6 m ² /g. The blending ratio of glass powder and ceramic powder was 45 parts by weight of ceramic powder and the remainder glass powder. Powder mixing, vehicle used, pasting, coating, drying, sintering, formation of an insulating layer, measurement of various properties, etc. were carried out in the same manner and under the same conditions as in Example-1. As a result, the dielectric constant was around 7.8 for the one using Al ₂ O ₃ · SiO ₂ , around 8.5 for the one using 3Al ₂ O ₃ · SiO ₂ , around 6.7 for the one using MgO · SiO ₂ , and around 6.7 for the one using ZnO. In the case of using Al ₂ O ₃ , it was around 7.5. Dielectric loss is 0.0051, 0.0034, respectively.
0.0048, 0.0073, insulation resistance is also 2×10 ¹¹ Ω
cm, 2.6×10 ¹² Ωcm, 1.4×10 ¹⁰ Ωcm, 3.7×10 ¹¹ Ω
cm, leakage current is 230μA, 370μA, 190
μA, 250 μA. The surface condition of the insulating layer and the adhesion strength with the conductor were good.

Example 7 _SiO2 64.9% by weight, _B2O3 6.8% by weight, PbO16.6% by weight, _{Na2O2.7 %} by weight, _K2O2.17 % by weight,
Glass powder with a composition ratio of 0.41% by weight of MgO, 5.38% by weight of CaO, 0.1% by weight of BaO, 0.21% by weight of TiO ₂ , 0.93% by weight of ZrO ₂ and a powder specific surface area of 1.96 m ² /gr, and 0.3% of SiO ₂
wt%, Na ₂ O0.04 wt%%, MgO0.34 wt%,
It is made of Al ₂ O ₃ with a purity of 99.29% including impurities of 0.02% by weight of CaO and 0.03% by weight of Fe ₂ O _3.The specific surface area is (1) 1.72.
Ceramic powders having particle sizes of m ² /g, (2 ^{) 2.58 m 2} /g, and (3) 6.6 ^{m 2} /g were used. The blending ratio of the glass powder and the ceramic powder was 46 parts by weight of the ceramic powder and the remainder was a glass/ceramics mixed powder of the glass powder. Mixing these powders,
The vehicle, pasting, coating, drying, formation of a sintered insulating layer, measurement of various properties, etc. were carried out in the same manner and under the same conditions as in Example-1. As a result, for each combination, the dielectric constant was 7.6 to 8.5, and the dielectric loss was 0.0011.
0.0043, insulation resistance 1.6×10 ¹¹ to 2.4×10 ¹¹ Ωcm, and leakage current 160 to 580 μA. The maximum surface roughness of the insulating layer is 5.5 to 9.3 μm, and the larger the specific surface area of the ceramic powder, the smaller the surface roughness.
The adhesion strength with the conductor was sufficient without much difference.

Example 8 The composition and composition ratio of the glass powder were the same as in Example 7, and the specific surface area of the powder was 3.47 m ² /gr.
The ceramic powder was Al ₂ O ₃ and the powder specific surface area, amount of impurities, and purity were the same as in Example-7. The blending ratio of glass powder and ceramic powder was 85% glass powder and 15% ceramic powder, which was mixed into a paste, applied to an alumina substrate, dried, and sintered to form an insulating layer, and various properties were measured. It was conducted using the same method and conditions as Example 1. The result is that the dielectric constant is
4.6, dielectric loss 0.0012, insulation resistance 5.8×10 ¹¹ Ωcm,
Leakage current 210-490μA, thermal conductivity 0.009cal/
It was cm・℃・sec. The surface roughness of the insulating layer and its adhesion to the conductor were also good.

Example 9 SiO ₂ 59.3% by weight, B ₂ O ₃ 6.2% by weight, PbO 15.3% by weight, Al ₂ O ₃ 8.4% by weight, Na ₂ O2.2% by weight, K ₂ O2.0
Weight%, MgO0.34weight%, CaO4.7weight%,
Glass having a composition ratio of 0.17% by weight BaO, 0.29% by weight Fe ₂ O ₃ , 0.17% by weight TiO _{2 ,} 0.84% by weight ZrO 2 , and 0.09% by weight ZnO was prepared so that the specific surface area was 2.54 m ² /g. As glass powder 15 parts by weight and ceramic powder
_A powder specific surface area ^of _{2.6 m 2 /}
A glass-ceramics mixed powder consisting of 85 parts by weight of gr ceramic powder was prepared using the same method and conditions as in Example 1, made into an insulating paste, applied onto an alumina substrate on which a conductive circuit was formed, dried, and sintered. An insulating layer was formed and various properties were measured. the result,
Dielectric constant is 9.2, dielectric loss is 0.0009, insulation resistance is 6.2×
10 ¹² Ωcm, and the leakage current was 210 μA. Surface roughness of insulating layer An insulating layer with good adhesion to the conductor and substrate and with few pinholes was obtained.

Example 10 SiO ₂ , 10.5% by weight B ₂ O ₃ 24.0% by weight, ZnO 58% by weight, Al ₂ O ₃ 2.0% by weight, BaO 2.0% by weight, BaO 2.0% by weight, PbO 2.4% by weight, ZrO ₂ 0.6 Weight%, TiO ₂ 0.2
9 parts by weight of glass powder having a specific surface area of 3.1 m ² /g and having a composition of 0.1% by weight Na ₂ O, 0.2% by weight K ₂ O, and 41 parts by weight of the same glass powder used in Example-1. parts by weight and 50 parts by weight of fused alumina as ceramic powder were mixed in a ball mill, and then made into a paste in the same manner as in Example-1 to obtain an insulating paste. This was applied to an alumina substrate on which a conductor circuit had been formed, dried, and sintered to form an insulating layer. Various properties were measured in the same manner as in Example-1. As a result, the dielectric constant was 7.5, the dielectric loss was 0.0020, the insulation resistance was 1.1×10 ¹² Ωcm, the leakage current was 305 μA, and the thermal conductivity was
It was 0.025 cal/cm・℃・sec. The surface roughness of the insulating layer was 3 μm on average, and the adhesion to the conductor and ceramic substrate was also good.

Comparative Example A Conventionally, in insulating pastes for thick film lamination, crystallized glass has been used as an inorganic material. For example, using only glass powder with a composition ratio of 53% by weight of SiO ₂ , 3% by weight of Al ₂ O ₃ , 11.7% by weight of Li ₂ O, 12% by weight of MgO, 8.4% by weight of ZrO ₂ , and 11.9% by weight of P ₂ O ₅ , It was made into a paste using the method and conditions of Example 1, coated and sintered to form an insulating layer, and various properties were measured. As a result, insulation resistance 3×
It had a value of 10 ⁹ Ωcm, a thermal conductivity of 0.0048 cal/cm·°C·sec, a leakage current of 1680 μA, etc., and was clearly inferior to the above-mentioned product obtained by implementing the present invention.

Comparative example B One of the composition ratios of 30% by weight of SiO ₂ , 10% by weight of Al ₂ O ₃ , 6% by weight of BaO, 10% by weight of ZnO, 6% by weight of CaO, 8% by weight of B ₂ O ₃ , 8% by weight of TiO ₂ , and 2% by weight of MaO Using only partially crystallized glass powder, an insulating layer was formed using the method and conditions of Example 1, and various properties were measured.
As a result, the insulation resistance was 1.6×10 ¹⁰ Ωcm, and the thermal conductivity was
The leakage current was 0.0046cal/cm・℃・sec and 1300μA.

As explained above, the results of using the powdered inorganic composition for insulating layer firing paste of the present invention are that the dense thermal conductivity of the insulating layer is superior to that of conventional crystallized glass-based insulating pastes, and This makes it possible to provide an insulating paste with high adhesion strength, contributing to higher density packaging and improved reliability of thick-film multilayer electronic circuits.

In addition to those described in the examples, ceramic powders used in the present invention include, for example, basic refractory materials such as CaO.Al ₂ O _{3.2SiO 2} or CaO.
It goes without saying that SiO ₂ , double silicates, etc. are also effective, and a composite combination thereof is also effective.

Claims (1)

[Claims] 1. 30 to 70 parts by weight of powdered glass having a specific surface area of 1 to 8 m ² /g, and the remainder having a specific surface area of 0.8 to 9.5 m ² /g. It is a powdered inorganic composition for forming an insulating layer by dispersing it in a vehicle, applying it to a paste form, and firing it, which has the composition of the powdered glass. When the raw material composition is expressed in terms of oxide, SiO ₂ 10~80
Weight%, PbO ₂ - 55% by weight, B ₂ O ₃ 3 - 35% by weight, CaO 0.2 - 12% by weight, MgO 0.2 - 12% by weight, BaO 0.1 - 10% by weight, Al ₂ O ₃ 0 - 20% by weight, Li ₂ O 0.1-5% by weight, Na ₂ O 0.1-5% by weight, K ₂ O 0.1-5% by weight, TiO ₂ 0.1-5% by weight, ZrO ₂ 0.1-5% by weight, The raw material composition is an inorganic oxide in the range of 0.1 to 5% by weight of ZnO, and at least four of the inorganic oxides, SiO ₂ , B ₂ O ₃ , PbO, and Na ₂ O, are included as essential constituents. The composition of the powdered ceramics is Al ₂ O ₃ , MgO・Al ₂ O ₃ , when the raw material composition is expressed in terms of oxides.
Al ₂ O ₃・SiO ₂ , 3Al ₂ O ₃・SiO ₂ , MgO・SiO ₂ ,
A powdery inorganic composition for an insulating layer firing paste, characterized in that it contains as a raw material composition at least one inorganic oxide group selected from each composition group represented by ZnO・Al ₂ O ₃ .