JPH0369529A - Insulator glass composition - Google Patents

Abstract

PURPOSE:To obtain an insulator glass compsn. ensuring improved heat resistance, surface smoothness and withstand voltage characteristic by mixing a glass compsn. contg. SiO2, Al2O3, ZnO, TiO2 and MgO with wollastonite. CONSTITUTION:A glass compsn. consisting of, by weight, 20-50% SiO2, 10-20% Al2O3, 10-20% CaO, 10-15.49% ZnO, 10-20% TiO2, 0-3% B2O3, 0.5-10% MgO, 0-3% ZrO2, 0-3% P2O5 and 0-2% F2 is mixed with 0.1-5wt.% wollastonite (CaO.SiO2) to obtain an insulator glass compsn. Since this compsn. contains fine wollastonite powder as an external crystal nucleating agent, Zn2SiO4, CaO.Al2O3.2SiO2 and CaO.TiO2.SiO2 are deposited as crystal phases by heat treatment at about <=850 deg.C. When a small amt. of fine ceramic powder is further added, heat resistance and surface smoothness are considerably improved and withstand voltage characteristic is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates primarily to a crystallized glass composition for forming electrically insulating droplets for crossover of thick film integrated circuits.

(b) Prior Art Conventionally, a crystallized glass composition containing a refractory filler for forming an electrical insulating layer of this type of thick film integrated circuit has been developed.
2-10940Q, a crystallized glass composition characterized by forming anorsite crystals (CaO''A I203 2Si02> as the main crystals), and a sintered glass composition as disclosed in Japanese Patent Publication No. 62-21739. There are glass compositions that partially precipitate BaA2F02 crystals during the process.Other examples include Japanese Patent Publication No. 46-42917,
Glass compositions for forming electrically insulating layers are also disclosed in Japanese Patent Publication No. Sho F-6168@, Japanese Patent Publication No. Sho F-10844, Japanese Patent Publication No. 34645/1987, and the like.

(c) Problems to be solved by the invention However, the crystallized crow disclosed in Japanese Patent Publication No. 62-10940 mentioned above has two crystallization temperatures;
In order to stably crystallize B with good reproducibility by heat treatment at One peak had to appear on the low temperature side. Of the two peaks, the one on the high temperature side is compared to the low temperature side (850'
In order to shift to C), it was necessary to lower the transition point and softening point of the glass, and it was inevitably necessary to contain a large amount of a fluxing agent such as B2O3 or ZnO.

However, when a large amount of this flux is contained, the temperature at which the glass softens decreases, and the glass phase flows and reacts with the conductor until it crystallizes. This refers to the breakdown strength of an insulating layer when a high voltage (250 kV/Cm or more) is applied to it. Generally, fillers are added to prevent this deterioration, but this results in a problem of lowering the surface roughness.

Furthermore, this reduction in surface roughness results in non-uniformity in coating thickness, requiring printing and firing at least twice to compensate for thinner areas. In addition, in order to suppress the peak on the high temperature side to 850'C or less, reduce the reaction with the conductor, and improve the heat resistance of the glass phase other than the crystal phase, it is necessary to add a considerable amount of refractory filler. In this case, there was a problem in that as the amount of filler increased, adhesive strength and surface smoothness deteriorated.

(d) Means for Solving the Problems The present invention was developed in order to solve the drawbacks of the above-mentioned prior art, and in terms of weight %: 102 1203 CaO ZnO T + 02 120~50% 110~ 20% 110-20% 110-15.49%: 10-20% B2O3: 0-3% MgO: 0.5-10% ZrO: 0-3% P2O5: 0-3% F2: 0-2% Wollastonite (CaO
4S i 02 ) 0.1 to 5%).

That is, wollastonite ~ (CaO-3
By using a small amount of iO2), glass that has been crystallized in two temperature ranges can be simultaneously crystallized in one temperature range, and the flux component that should be included as a constituent of crystallized glass can be greatly reduced. It is possible to form a highly reliable insulating layer with low reactivity with conductors and resistors.

Furthermore, ordinary ceramic fine powder (α-A1203, η
-A1203. γ-AI203°θ-AI203. Zirconia, zircon, titanium oxide, cordierite, β-
Eucryptite.

Spodumene, 5i02. By adding a small amount of Mgo, etc., not only can further heat resistance be imparted, but also the addition amount is only a small amount compared to the conventional method, so surface smoothness is greatly improved, and the most important dielectric strength property is improved. can be greatly improved.

The reasons for limiting the composition of the present invention are as follows.

s r 02 is a glass-forming oxide, and if SiO2 is less than 20%, the glass softening point will be too low, and the precipitated crystal phase ZnS104, CaO'' A I
203 ・23! Since it is a constituent component of 02, if it is too small, these crystal phases will be difficult to precipitate.

Conversely, if 8102 is 50% or more, the expansion coefficient becomes too low. This S i 02 is more preferably 30 to 40%.

Al2O3 is a glass intermediate oxide, and if A203 is less than 10%, the transition point will be too low, and it will be difficult to precipitate CaO-A203.2SiQ2, which is one of the crystal phases, and the chemical durability will be poor. Become. , Al2O3 or 2
If it is 0% or more, the liquidus temperature becomes too high and devitrification occurs during melting.

CaO is a glass-modified oxide and a crystal constituent component. If CaO is less than 10%, the expansion coefficient becomes too small and the CaO-A I203, which is one of the crystal phases, becomes too small.
-23 Precipitation of F02 becomes difficult. If the CaO content is 20% or more, the expansion coefficient becomes too large and the chemical durability deteriorates.

This CaO is more preferably 15 to 20%.

MgO is a glass-modified oxide, and chemical durability deteriorates when MgO is less than 0.5%. If MgO is 10% or more, phase separation becomes easy. This MgO is more preferably 0.5 to 5%.

ZnO is used as a fluxing agent, crystal constituent and engraving coefficient modifier, and when ZnO is less than 10%, the main crystal phase is Zn2S! 04 becomes difficult to precipitate, and when ZnO exceeds 15.5%, the transition point of the glass decreases, and
The expansion coefficient also becomes too small, and the heat resistance of the remaining glass phase deteriorates.

T! 02 is a glass-forming oxide that provides chemical durability and also contains one of the crystalline phases, Cao-Ti
02-3 i It is a constituent of 02.

When TiO2 is less than 10%, precipitation of crystal phase becomes difficult,
If the content of 102 is 20% or more, the liquidus temperature becomes too high and devitrification occurs during melting.

B203 is used as a fluxing agent, and when B2O3 is 3% or more, heat resistance deteriorates. This B2O3 is more preferably 0.5 to 2%.

ZrO2 is used as a crystal nucleating agent and to improve chemical durability, and if ZrO2 is 3% or more, it tends to remain undissolved in the glass as java. This ZrO2
is more preferably 0.2 to 1%.

P2O5 is used as a crystal nucleating agent and a fluxing agent for ZrO2, and if P2O5 exceeds 3%, chemical durability deteriorates.

This P2O5 is more preferably 0.1 to 1%.

F2 is used as a crystal nucleating agent and a fluxing agent.
Above this, the chemical durability deteriorates and it becomes more likely to react with the conductor. This "2" is more preferably 0.1 to 1%.

(Hereinafter, blank space) In order to make the glass made of the above composition into a glass that crystallizes in a temperature range of 850'C or less, wollastonite (CaO 5i02>) is added at 0.1% as a crystal nucleating agent.
~5% by weight is used. If wollastonite is less than 0.1%, it will not be effective as an external crystal nucleating agent and the crystal peaks will be in two places, and if it is more than 5%, it will react with the conductor and deteriorate the electrical properties.

By using a small amount within the above range and heat-treating at 850'C, Zn2F04 can be formed as a crystalline phase.
, Ca0-AI2o3628102, CaO"T:
02''S: By precipitating 02, the fluxing agent component can be greatly reduced, and a highly reliable glass can be obtained as an insulating glass for thick film circuits.

Furthermore, in order to impart heat resistance to the above glass, ordinary ceramic fine powders such as α-alumina, Y)-alumina, γ-alumina, θ-alumina, zirconia, zircon, titanium oxide, cordierite, β - Eucryptite, subodumene, F02, MgO, etc. can be added in an amount of 0.1 to 5% by weight. This ceramic fine powder is 0
．． If it is less than 1% by weight, the effect disappears, and if it is less than 5% by weight.
If it exceeds, the planar smoothness will deteriorate and the withstand voltage characteristics will also deteriorate.

(E) Function The present invention is capable of forming Z n2 S l 04, Ca0- as a crystalline phase by heat treatment at about 850'C or less by adding fine wollastonite powder as an external crystal nucleating agent.
A I2O3・23 io2, cao-TO2・S
By using a glass composition that precipitates +02 and further adding a small amount of fine ceramic powder, the heat resistance and surface smoothness are greatly improved, and the withstand voltage characteristics are improved.

(F) Example According to the usual method, each component raw material was appropriately weighed and mixed to achieve the target composition shown in the table, and the patch was prepared.
Melt at 00°C for 1 to 3 hours to obtain molten glass. This molten glass is crushed into glass pieces, and the glass pieces and wollastonite, and if necessary, ceramic fine powder are finely pulverized and classified using a ball mill, etc., to obtain particles with an average particle size of 2 to 3 μm. Maximum particle size 10)tl
m of glass ceramic fine powder. This glass ceramic fine powder was kneaded with a well-known vehicle agent, for example, a solution of 5% ethyl cellulose, alpha terpineol and butyl carpitol acetate mixed in a ratio of 2:1 to form a paste. Next, a conductive paste and an insulating paste were screen printed on the board, dried, and baked at 850'C for 10 minutes to form a conductive film and an insulating film alternately, and the properties shown in the table were measured. The results are shown in the same table.

As shown in the table, Examples 1 to 5 of the present application have higher dielectric breakdown strength and better acid resistance and surface smoothness than Comparative Examples 1 to 6.

(G) Effect 2 of the present invention The glass composition of the present invention has various properties listed below, and is therefore suitable as a glass composition for forming an electrically insulating layer for crossover of thick film integrated circuits. It is.

In addition, the explanation of the shelf life in the table is as follows.

・DTA characteristics 250 m3 of each glass powder was placed in a holder of a differential thermal analyzer, and the temperature was raised from room temperature at a rate of 20'Q/min.
The transition point, softening point, and first and second crystal peaks (°C) were measured and shown in the table.

・Thermal expansion coefficient After compression molding each powder test into a rod shape, the coefficient of thermal expansion was 10 at 850°C.
The thermal expansion coefficient (50-350°C average, unit: X10-7°C-1) of the sample heated for 1 minute was measured and shown in the table.

・Dielectric constant, reading loss of each sample fired product (850°C 110 minutes) at 25°C16
The dielectric constant (ε>) and dielectric loss (tan δ) at 0% Rth and 1 MHz were measured and shown in the table.

It is desirable that ε is 11 or less, and tan δ is 20×10 −4 or less.

・Volume resistivity Calculated products of each sample (850'C, 10 minutes) at 25°C16
0%Rl-(, Volume resistivity at 50V (1014
0 hm-cm> was measured and shown in the table. This value is 10
It is required that the thickness be 14 ohm-cm or more.

- Dielectric breakdown strength The dielectric breakdown strength (K V / cm ) of each sample fired product (850'C, 10 minutes) was measured and shown in the table. It is desirable that this value is 250 KV/cm or more.

- Acid resistance: Place the baked product of each sample (850°C, 110 minutes) in a 20% oxalic acid aqueous solution, heat it to 90°C for 10 minutes, measure the weight loss rate (%) of the sample, and display the value. It was shown to. This value is preferably 0.1% or less.

・Surface roughness The surface roughness (μ
Rabbit) was measured and shown in the table. This value is desirably 0°6 μm or less.

Claims (2)

[Claims] (1) In weight% display: SiO_2: 20-50% A_2O_3: 10-20% CaO: 10-20% ZnO: 10-15.49% TiO_2: 10-20% B_2O_3: 0-3% MgO: 0. Wollastonite (CaO
-SiO_2) 0.1 to 5% of an insulating glass composition. (2) In weight%: SiO_2: 30-40% Al_2O_3: 10-20% CaO: 15-20% ZnO: 10-15.49% TiO_2: 10-20% B_2O_3: 0.5-2%' MgO : 0.5-5% ZrO_2: 0.2-1% P_2O_5: 0.1-1% F_2: 0.1-1% Wollastonite (CaO
-SiO_2) 0.1-5% and ceramic fine powder 0.1
An insulating glass composition formed by mixing ~5%.