JPS62128964A - Ceramic composition for low temperature burning - 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 porcelain composition for low-temperature firing, and particularly to an electric circuit board, for example, a composition for laminating a plurality of sheet-shaped porcelains to form a circuit between the porcelains. The present invention relates to a ceramic composition for low-temperature firing that is passed through a multilayer electric circuit board.

(Prior Art) The inventors of the present invention separately proposed the following, although it is not yet publicly known, as an electric circuit board that can be fired at a low temperature, has high resistivity, low dielectric constant, and low dielectric loss. We proposed a composition with the following composition.

That is, this porcelain composition contains 5i0225-80% by weight, Ba015-70% by weight, and BZO:I 1.
5 to 5% by weight, and one in which the above composition further contains 30% by weight or less of Al2O3 and/or 15% by weight or less of TiO2.

In addition, this porcelain composition can be easily pulverized after calcination in the manufacturing process, and even when fired in either an oxidizing atmosphere or a non-oxidizing atmosphere, the electrical properties such as specific resistance, etc. It has excellent effects such as no change in mechanical properties such as bending strength and no change in thermal properties.

(Problems to be Solved by the Invention) However, when forming a conductor pattern, such as an electrode, on the surface of a ceramic substrate made of these ceramic compositions, sintering of the porcelain and baking of the electrode paste are necessary. However, when the porcelain is sintered, the glass component in the porcelain migrates to the conductor side, resulting in a phenomenon in which soldering to the conductor deteriorates.

Therefore, the main object of the present invention is to provide a porcelain composition for low-temperature firing that has excellent solderability.

(Means for solving the problem) This invention provides 5iOz 25 to 80% by weight, BaO, S
15 to 70% by weight of one or two of rO and B
2O2 1.5-5% by weight and optionally Al2O3
The main components consisting of 30% or less, Cr2O3, C
A composition in which any one of uO, NiO, CO2O3, and FezO is added, and the additive is Crz
In the case of O= or CuO, it is added in the range of 0.2 to 10% by weight, and when the additive is NiO, Co, O, and Fc4
In the case of No. 03, it is a porcelain composition for low-temperature firing characterized in that it is added in an amount of 1 to 10% by weight.

(Effects of the Invention) According to the present invention, it is possible to prevent deterioration in soldering properties of the conductor that occurs when forming a conductor pattern and sintering the porcelain at the same time. On top is a chip capacitor.

It becomes possible to mount chip elements such as IC chips and L chips. As a result, a substrate made of this low-firing ceramic composition can be used as a multilayer substrate for tuners, integrated circuits, etc., which enables high-density packaging and can be made smaller than conventional ones.

The above objects, other objects, features and advantages of the present invention will become more apparent from the detailed description of the following embodiments.

(Example) As the main component raw material, BaCO3 or BaO, SrC
O3 or SrO, Sin, AlzOi, 820:
1 or BN or B4C, and as an additive, C
r2O3, CuO1NiO, CO2O3 and FezO
3 were weighed and mixed to obtain porcelain having the composition ratio shown in the attached table. 850~
After calcining at 950°C and pulverizing, a mechanical binder was added and kneaded, and the mixture was formed into a sheet with a thickness of IH by a doctor blade method to obtain a green sheet.

This green sheet was cut into a rectangular plate with a length of 30 m and a width of 10 fi, and a copper paste prepared by mixing copper powder with a particle size of 5 μm or less and an organic vehicle at a weight ratio of 80:20 was printed on the surface of the green sheet. This is then heated to a temperature of 900 to 1100 in a reducing or non-oxidizing atmosphere of nitrogen-steam.
A test sample was prepared by firing at ℃ for 1 hour.

This test sample was preheated at 150°C for 20 seconds,
After applying chlorine-based flux to the surface of the copper electrode, 230±
Soldering was performed by immersing it in a lead-tin solder bath at 10° C. for 5 seconds. The specific resistance was also measured under the condition of 100 V in series, and the results are shown in the separate table along with the firing temperature.

In addition, when judging the soldering quality, when looking at the surface of the copper electrode visually, if the solder covers 90% or more of the copper electrode surface, it is marked as "○", and if 90% of the surface is not grooved, it is marked as "○". "×"
And so.

In addition, the samples marked with * in the attached table are outside the scope of this invention, and the others are within the scope of this invention.

The reasons for limiting the main components and additives in the porcelain composition for low-temperature firing of the present invention are as follows.

(1) The main component Sing was set at 25 to 80% by weight because
It is as follows.

If the main component 5i02 is less than 25% by weight, the dielectric constant will be higher than 10, leading to deterioration of the characteristics of electronic equipment when the operating frequency is high. Moreover, if it exceeds 80% by weight, the bending strength becomes lower than the practical value of 1500 kg/cut, and at the same time, the sintering temperature becomes 1000° C. or higher, making it impossible to use Cu as an internal electrode material, which is not preferable.

(2) The reason why the main component BaO is 15 to 70% by weight is that if the main component BaO is less than 15% by weight, the bending strength will be lower than the practical 1500 kg/ci, and if it exceeds 70% by weight, This is because the dielectric constant becomes larger than 10, which is not preferable.

(3) The main component B2O3 is 1.5 to 5% by weight.
When the main component B2O3 is less than 1.5% by weight, the sintering temperature is 1.
This is because if the temperature exceeds 000°C and the content exceeds 5% by weight, the bending strength becomes less than 1500 kg/cnl, which is not preferable.

(4) The main component Al2O3 added as necessary has the effect of lowering the sintering temperature and dielectric constant, but if it exceeds 30% by weight, the dielectric loss increases to 0.2 or more, which is not preferable.

(5) When the additives Cr2O3h and CuO are less than 0.2% by weight, soldering becomes poor (sample number 3 in the attached table).
and Sample No. 8), and if it exceeds 10% by weight, the specific resistance becomes low (see Sample No. 12 in the attached table), which is not preferable.

(6) Additives NiO, Co20i and FezO3 are 1
If it is less than 10% by weight, the soldering properties will be poor, and if it exceeds 10% by weight, the specific resistance will be small (sample number 11 in the attached table).
Reference) Unfavorable.

In addition, when manufacturing an electric circuit board using the ceramic composition for low-temperature firing of the present invention, it can be performed, for example, as follows. Ba and Sr, which are the raw materials for the main components
One or two of these, oxides of Si, B, and AI, or powders of compounds that decompose into oxides during firing, and additives such as Cr2O3, CuO, NiO, and C0ZO3.
and FezOx, the raw material mixture is calcined at 850 to 950°C, and then pulverized, the powder is kneaded with a binder, and then formed into a sheet. The obtained green sheet is heated to 85% in an oxidizing atmosphere, non-oxidizing atmosphere, or reducing atmosphere.
What is necessary is just to bake at 0 degreeC - 1000 degreeC. In addition, when manufacturing multilayer electric circuit boards, Ag+
A circuit may be printed using a conductive paste containing a conductive material such as Ag-Pd+Cu or Ni, a plurality of them may be laminated, and then fired in an atmosphere depending on the conductive material constituting the conductive paste. Cu or Ni as internal conductive material
When using base metals such as, it is preferable to sinter in a non-oxidizing or reducing atmosphere in order to prevent their oxidation. For example, nitrogen is passed through water vapor (70°C) as a carrier gas to create a nitrogen-steam atmosphere (usually Nz99
．． 7 to 99.8%) at 850 to 1000°C. In addition, the reason why a trace amount of oxygen is contained is as follows.

This is because even if the binder used to form the green sheet is calcined, it remains as carbon, and this is removed by completely burning it.

Patent applicant Murata Manufacturing Co., Ltd. Agent: Patent Attorney Oka 1) Zenhiro (1 other person)

Claims (1)

[Claims] 1 SiO_25-80% by weight, 15-70% by weight of one or two of BaO and SrO, and B_2O_3
The main component consists of 1.5 to 5% by weight, Cr_2O_3,
CuO, NiO, Co_2O_3 and Fe_2O_3
A porcelain composition in which any one of the following is added, and when the additive is Cr_2O_3 or CuO, 0.2
It is added in a range of ~10% by weight, and the additives are NiO, Co
In the case of _2O_3 and Fe_2O_3, 1 to 10
A porcelain composition for low-temperature firing, characterized in that it is added in a range of % by weight. 2. The porcelain composition for low-temperature firing according to claim 1, which contains 30% by weight or less of Al_2O_3 as a main component.