JPS6231903A - Material for insulation layer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in an insulating layer material suitable for use in an insulating layer of a thick film multilayer substrate, particularly using a copper-based conductor paste.

[Technical background of the invention]

As is well known, in recent years, hybrid integrated circuits have come into widespread use in order to reduce the size and weight of electronic devices and the like. This hybrid integrated circuit is made of a thick film substrate made of an insulating substrate made of a ceramic material such as alumina, and a wiring layer formed by printing and firing a conductive material, a resistive material, etc.
It is constructed by combining passive elements and active elements of type H and F. Recently, in order to make electronic devices smaller and lighter, there has been a demand for even higher densities.
As for thick film substrates, the wiring layers are formed in multiple layers with insulating layers interposed therebetween.

In addition, recently, copper-based conductor paste has been used as the conductor material, instead of the silver-palladium-based conductor paste that was commonly used in the past, to improve electrical characteristics and reliability. At the same time, consideration has been given to making it economically advantageous.

A thick film multilayer board using such a copper-based conductive paste is manufactured as follows. First, a ruthenium oxide-based resistance paste was printed on an insulating substrate made of a 90% aluminum material using a screen printing method, and
A resistor layer is formed by firing at a temperature of 50°C. after that,
It is manufactured by printing and firing a copper-based conductive paste and a glass-based insulating paste in such a way that they are alternately laminated.

In this case, the above-mentioned copper-based conductive paste and glass-based insulating paste are fired in order to prevent oxidation of the copper.
It must be carried out in an inert gas such as a raw gas, and furthermore, it needs to be carried out at a low temperature of about 600° C. in order to suppress fluctuations in the resistance value of the resistor layer that has already been formed.

For this reason, lead oxide (p
A product containing a large amount of bo) has been developed, but when this is fired in an elementary gas, lead precipitates and the insulation performance deteriorates significantly, making it unsuitable for practical use. .

Therefore, there has been a demand for a lead-free glass composition for an insulating layer that can be fired at a low temperature of about 600°C. A method has been developed in which a composition for low-temperature firing having a crystallization temperature of 550 to 650°C is fired near the crystallization temperature.

[Problems with background technology]

However, completely crystallized glass as described above has problems such as relatively easy pinhole formation, poor insulation between the upper and lower wiring layers, and difficulty in adhesion between the upper wiring layers. There is. Furthermore, a glass composition having such a composition has the disadvantage that the wettability of alumina to an insulating substrate is not good and the adhesion is insufficient.

[Purpose of the invention]

This invention was made in consideration of the above circumstances, and provides an extremely good insulating layer material that has excellent insulating performance and adhesion, can be fired at low temperatures, and does not significantly change the resistance value of the already formed resistor layer. The purpose is to provide i-fees.

[Summary of the invention]

That is, the insulating layer material according to the present invention has, in weight%,
5to2 5-20, ZnO 45-60, B2O3 1B-30, R20 (20 for Li20+Na2O+)
0, 1-3, Aj205 0.5-5, B120st
-0.5~5, F 0.5~2.8 no 2 0.5
~2, CoOt0~2, ZrO2, P2O5 0~2,
ZrO2 is blended in a ratio of 0 to 5, cdo'fr: 0 to 5, and pbo is blended in a ratio of 0 to 3, so as to have a crystallization temperature of 650 to 750°C.

Here, the reason for limiting each component to the above-mentioned mixing ratio is as follows.

8102: If it is less than 5 excellent, the viscosity during melting will be low;
Hard to vitrify. Furthermore, if the temperature is more than 20 degrees, the softening temperature will rise, making it impossible to fire at a low temperature (600C).

If Zn01 is less than 45%, crystallization will not be possible, D.
If it exceeds 60%, the crystallization temperature is too low.

If n2o3$ is less than 15%, the softening temperature will be high; if it is more than 30%, sufficient crystallization will not occur.

R20! To promote glass melting, Li2O, Na
One or more of 2O and R20 can be added, but if the total amount exceeds 3, the insulation resistance value will be lowered.

A no. o3to, 5* If it is too low, the crystallization temperature will be too low, and if it is more than 5%, the softening temperature of the glass will be too high.

B12O3! If it is less than 0.5%, the wettability of the glass to the alumina substrate will be poor, and if it is more than 5%, the expansion coefficient will be too large.

It is added to promote the melting of Pg glass, but if it exceeds 2 inches, the expansion coefficient increases.

Added to improve the water resistance of 5nOz-rich glass. If the amount is less than 0.5 ts, there will be no effect, and if it is more than 2 ts, the effect will not improve.

CoOe P2()5 * Zr02s CdO * p
As for bo, although it is not an essential component, if one or more of them are contained at 01%, the insulation resistance will not deteriorate and it will contribute to maintaining the stability of the glass. If it exceeds .3%, the glass may become unevenly cuffed, the insulation resistance may deteriorate, or no increase in effectiveness can be expected.

Note that RO (M
(gO, CaO, BaO, 5rO) components are often added, but in this invention, the addition of the RO acid component reduces the adhesion of the conductor on the glass insulating layer, so it is not added.

[Embodiments of the invention]

An embodiment of the present invention will be described below.

That is, the raw materials are mixed to have the composition shown in Table 1. In addition, in Table 1, sample numbers (1) to (3)
Sample numbers (4), I, and (5) indicate conventional materials for insulating layers, respectively.

Then, the mixture prepared as shown in Table 1 was prepared at 1300~
The platinum melts at a temperature of 1400°C and becomes vitrified. Next, this glass is crushed and sieved, and then crushed by a wet method to obtain a powder having an average particle size of 5 μm. and,
This powder is kneaded with an appropriate amount of vehicle (eg, ethyl cellulose, terpineol, etc.) to form a glass paste.

The first layer, copper-based conductor and ruthenium oxide (
The above glass paste was printed so as to form a wiring layer similar to that of the Ru02)-based resistor, and then heated at 600° C. in a nitrogen gas atmosphere.
By baking at .degree. C. for 10 minutes, an insulating layer with a thickness of about 40 .mu.m is formed. Then, a copper-based conductor that will become a second wiring layer is similarly formed on this insulating layer.

In this way, the above-mentioned glass composition for the insulating layer is 600
Since it is fired at a low temperature of .degree. C., the insulating layer can be formed without being completely crystallized, and the insulating properties can be improved without creating pinholes as in the conventional method. The physical properties of the glass composition produced as described above, the insulation resistance value of the insulating layer formed, the adhesion of the insulating layer to the alumina substrate surface, the solder wettability of the copper-based conductor on the insulating layer, etc. Shown in 2.

In this case, the insulation resistance was determined by applying 50 V DC between each conductor of the first wiring layer and the second wiring layer after leaving it in a constant temperature and humidity chamber at 60°C for 1000 hours. This is the resistance value at room temperature.

Adhesion can also be determined by soldering a lead wire to the second layer conductor and pulling it vertically. When the peel strength was measured, a value of 1 Y/- or more was considered good.

Furthermore, the solder wettability was
Using eutectic solder, the sample was immersed at 230° C. for 3 seconds and then pulled out, and the sample was evaluated as good if 90 inches or more of the second layer conductor area was wet with the solder.

Here, in the above embodiment, it was explained that the copper-based conductor is fired in an inert gas atmosphere, but the insulating layer material according to the present invention has a thickness that is similar to that for firing a silver-palladium-based conductor in air. It goes without saying that the present invention can also be applied to a single-layer substrate with multiple layers.

Table 1 Note that the present invention is not limited to the above embodiments, and can be implemented with various modifications without departing from the gist thereof.

〔Effect of the invention〕

Therefore, as detailed above, according to the present invention, an extremely good insulating layer which has excellent insulating performance and adhesion, can be fired at a low temperature, and does not significantly fluctuate the resistance value of the already formed resistor layer. materials can be provided.

Applicant’s agent: Patent attorney Takehiko Suzue”

Claims (1)

[Claims] In weight%, SiO_2 is 5-20, ZnO is 45-6
0, B_2O_3 from 15 to 30, R_2O(Li_2O
+Na_2O+K_2O) from 0.1 to 3, Al_2O_
3 from 0.5 to 5, Bi_2O_3 from 0.5 to 5, F from 0
．． 5-2, SnO_2 0.5-2, CoO 0-2,
A material for an insulating layer, characterized in that P_2O_5 is blended in a ratio of 0 to 2, ZrO_2 is 0 to 5, CdO is 0 to 5, and PbO is 0 to 3.