JPS62137897A - Insulating layer compound - 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] [Industrial application field] The present invention relates to a composition for an insulating layer.

[Prior Art] Electronic components are known in which a conductor is formed on a substrate by a thick film method, an insulating layer is formed on the conductor, and a conductor is further formed on the insulating layer. Such conductors are copper paste), Ag-Pd
It is formed by printing and firing a paste. Copper conductors have advantages over Ag--Pd conductors, such as lower resistance and electrical migration, and less resistance to corrosion by soldering. However, copper is easily oxidized, and in order to prevent this, firing to form a conductor requires an oxygen concentration of 1
The process is carried out in a nitrogen atmosphere of 0 ppm or less. For the same purpose, an insulating layer formed on a copper conductor is fired in an atmosphere similar to that of copper.

However, when a conventional composition for an insulating layer is fired in such an atmosphere, the organic binder in the composition is not sufficiently removed, resulting in foaming or blackening, and the dielectric breakdown voltage is low.

Problems to be Solved by the Invention] An object of the present invention is to provide a composition for an insulating layer that can be fired in an atmosphere with a low oxygen concentration without causing the above-mentioned problems.

[Means for solving the problems] The present invention comprises SiO2-Al2O3-B2O2 glass powder in an amount of 60 to 95% by weight and a refractory filler such as alumina in an amount of 5 to 95% by weight.
In a composition formed by adding an organic binder to a glass-ceramic composition consisting of 40% by weight, an insulating layer is formed by firing in a non-oxidizing atmosphere in which a softening agent that oxidizes the organic binder is added to the composition. Provided is a composition for an insulating layer.

The oxidizing agent added in the present invention has an oxygen concentration of about 10 ppm.
There is no particular limitation as long as it has the effect of simmering and removing the organic rubber in the composition when it is fired in the following non-oxidizing atmosphere to form the insulating layer. Among them, MI+02 and TiO;+ are easy to handle and obtain.

CeO2, V2O5, CrzOa, CO2O3, MO
O3 and WO:+ are particularly desirable. Such oxidizing agents may be used alone or in combination.

The amount of the oxidizing agent added is 0.05 to 5 by weight to the glass composition which is a total stitch of glass powder and refractory filler.
It is preferable to add %. Addition amount of softening agent is 0.05%
If it is less than 5%, the effect of the addition will be small, and if it exceeds 5%, the insulating layer will not become dense and the withstand voltage characteristics will decrease, which is undesirable.
is more desirable.

The glass powder according to the present invention is SiO, +-A1, which has the property of partially crystallizing to suppress the reaction with copper conductors.
2fh-BzCL+ type is preferred.

If the content of this type of glass powder is less than 60%, a sufficiently dense sintered layer will not be formed and the electrical properties will deteriorate, which is undesirable.
On the other hand, if the content is more than 95%, the reactivity with the copper conductor becomes large and the solder wettability of the copper conductor is impaired, which is not preferable.

On the other hand, as a refractory filler, alumina (Al2O3
), Zir Dy (ZrSi04), -1-gelite (
28g0, 2AI203, 5Si02) can be used alone or in combination, but all of these fillers have low reactivity with copper conductors and are compatible with glass, resulting in a dense sintered layer. It has the characteristic of being easy.

The glass powder in the present invention is substantially 5iOz 30 to 50A1203 in weight%.
12.5~20MgO+GaO+S
rO+BaO 5 ~40PbO◆ZnOl
~25 8203 1 ~
7Ti02+ Zr(b I
~ 7shiizO+Na2O+K2O
A composition consisting of 0 to 3 is preferable. The reason is as follows.

SiO2 is a glass network homer and is a component of the main crystal (/helium aluminum silicate) that is precipitated by firing. If SiO2 is less than 30%, the glass softening temperature will be too low and the reactivity with the copper conductor will be large, which is undesirable. On the other hand, if it is more than 50%, the glass will become too hard and a dense sintered layer cannot be obtained, which is not preferable. do not have. The preferred range is 33-47% by weight.

Al2O3 is a crystal component that precipitates. If it is less than 12.5%, it becomes crystallized, which is undesirable.
If it exceeds 0%, devitrification will occur during glass melting, which is undesirable, and it is preferably 14 to 18%.

MgO+CaO+SrO+BaCl is a component for crystallization adjustment, expansion coefficient adjustment, and solubility adjustment, and if the content is less than 5%, it becomes a crystallized inorganic component, which is not preferable. on the other hand,
If it exceeds 40%, the coefficient of thermal expansion becomes too steep, which is not preferable. It is preferably 8 to 38%.

The content of PbO + ZnO used as a flux component is 1
If it is less than 2%, there is no effect and it is not preferable.
If it is more than 5%, the glass softening temperature becomes too low, which is not preferable. It is preferably 2 to 23%.

B203 is used as a flux component, but if it is less than 1%, it is ineffective, and if it is more than 7%, it reacts with the organic binder, partially reducing the glass, and lowering the electrical properties, so it is not preferable, preferably 2 to 5%. It is.

Ti02+ZrO2 is used as a crystallization modifier.

Less than 1% is ineffective. On the other hand, if it exceeds 7%, the softening temperature of the glass becomes too high, which is undesirable.The total amount is preferably 2 to 5%.

Li2O + Na2O + K2O is a discoloration of glass melting [1
However, from the electrical migration aspect, 3
less than %.

As refractory fillers, alumina (A1203), Zirco 7 (ZrSiO4), cordierite (28g
O・2AI203・5S i02) alone or J
It is mixed with the glass powder and used. 409 in content
If it exceeds 6, a dense sintered layer cannot be obtained, which is not preferable.

On the other hand, if it is less than 5%, the reaction between the glass and the copper conductor becomes large, which impairs the wetting of the copper conductor, which is not preferable. It is preferably 7 to 35% by weight.

The organic binder 1 used in the present invention is not particularly limited, and for example, ethyl cellulose, nitrocellulose, or acrylic resin dissolved in α-terpineol can be used.

[Example] Each raw material was mixed to have a target composition, put into a platinum crucible, heated and stirred at 1400 to 1500°C for 3 to 4 hours, and dissolved.Next, this was pulverized, and further processed into refractories using a pulverizer. The average particle size of the powder after pulverizing and mixing filler and glass powder at a predetermined ratio is used for screen printing.

The thickness was adjusted to 1.5 to 2.5 μm.

Next, these powders and a vehicle were mixed to form a paste; here, a commonly used vehicle of ethyl cellulose and α-terpineol was used. Further, an oxidizing agent was added thereto and the mixture was kneaded using an Lraikai machine and three rollers to obtain a paste. Table 1 shows the compositions of the refractory filler, oxidizing agent, and glass powder and their mixing ratios.

Next, using these pastes, the total thickness of 200 meshes was 1
The electrical insulation properties and the solder wettability of the copper conductor were evaluated using a capacitor pattern printed using a 0.05 μm screen. The materials used for the top and bottom conductors were DuPont code numbers 9922 and 9.
823, and the firing was performed at 900°C at a concentration of 02 of 5 ppm.
M was performed for 10 minutes. The thickness of the insulating layer was 40±2 μm. As is clear from Table 1, one composition according to the present invention is:
It has excellent electrical properties and good solder wetting. As a comparative example, similar tests were conducted on compositions other than the composition according to the present invention, which are also shown in Table 1. Note that the evaluation method for each characteristic may be as follows.

Characteristic Evaluation Method Insulation Resistance Insulation resistance was measured when 100 ν was applied using a vibrating capacitance type scattering current electrometer manufactured by Takeda Riken. Temperature 25±
1°C, humidity 45±1%, insulation layer thickness: 40±2μm.

℃, temperature and humidity 5±1%.

5 step up L with dielectric breakdown voltage of 100V, hold each voltage for 1 minute, temperature 25 ± 1°C, humidity 45 ± 1% to show breakdown voltage value.

After applying solder wettability Tamura Kaken XA-100 flux, 23
5 sec in Pb-3n solder bath at 0±5℃
I pulled down the display L. It is expressed as the area covered by solder relative to the Cu band area.

[Effects of the Invention] According to the present invention, an insulating layer having excellent dielectric breakdown voltage and solder IX fragility can be formed by firing in an atmosphere with a low oxygen concentration that does not cause oxidation of copper.

Claims (4)

[Claims] (1) In a composition obtained by adding an organic binder to a glass-ceramic composition consisting of 60 to 95% by weight of SiO_2-Al_2O_3-B_2O_3-based glass powder and 5 to 40% by weight of a refractory filler such as alumina, A composition for an insulating layer, which is formed by firing in a non-oxidizing atmosphere in which an oxidizing agent that oxidizes the organic binder is added to the composition. (2) The oxidizing agent is applied to the glass-ceramic composition,
Claim 1 in which 0.05 to 5% by weight is added
The composition for an insulating layer as described in . (3) The oxidizing agent is MnO_2, TiO_2, CeO_
2, V_2O_5, Cr_2O_3, Co_2O_3,
The composition for an insulating layer according to claim 1 or 2, which is at least one selected from MoO_3 and WO_3. (4) The glass powder is substantially SiO in weight percent.
_2 30~50 Al_2O_3 12.5~20 MgO+CaO+SrO+BaO 5~40PbO+Z
The composition for an insulating layer according to claim 1, comprising: nO 1-25 B_2O_3 1-7 TiO_2+ZrO_2 1-7 Li_2O+Na_2O+K_2O 0-3.