JPH051961B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention provides a resistor that can be formed into a thick film resistor or a similar resistor by firing in a non-oxidizing atmosphere and has high moisture resistance. The present invention relates to a paste-like resistance material that can be used. [Prior art] An unfired ceramic sheet (green sheet) coated with a conductor paste of a base metal such as nickel and a resistor paste containing molybdenum boride, fluoride, and glass is heated in a non-oxidizing atmosphere. A method of firing a multilayer ceramic circuit board having both thick film conductors and thick film resistors is disclosed in commonly assigned Japanese Patent Application No. 1976-197. In this method, no precious metals are used to form the thick film conductors and thick film resistors;
The cost of multilayer ceramic circuit boards can be reduced. [Problems to be Solved by the Invention] However, the thick film resistor formed from the resistive material according to the above application does not have sufficient moisture resistance. For example, when left in an environment with a temperature of 60°C and a relative humidity of 95% for 1000 hours, the rate of change in resistance will be about +5% to +10%. Therefore, an object of the present invention is to provide a resistor material that can be formed into a resistor by firing in a non-oxidizing atmosphere and that can have a resistance change rate within ±2% in a humidity test. There is a particular thing. [Means for Solving the Problems] The resistive material according to the present invention for achieving the above-mentioned object includes 15 to 80% by weight of tungsten boride, 10 to 75% by weight of glass, and calcium carbonate (CaCO ₃ ). , strontium carbonate (SrCO ₃ ), and barium carbonate (BaCO ₃ ) in an amount of 10 to 75% by weight, an organic binder, and a solvent. [Function] By printing a paste-like resistance material having the above composition on a green sheet and baking it in a non-oxidizing atmosphere, a thick film resistor having a resistance change rate within ±2% in a humidity test can be obtained. Therefore, a base metal thick film resistor can be formed simultaneously with the formation of a thick film conductor using a conductor paste of a base metal such as nickel. [Example 1] Next, a resistor material according to an example of the present invention and a method of forming a multilayer ceramic circuit board using the same will be described. First, 78.0 parts by weight of silicon dioxide (SiO ₂ ), 5.5 parts by weight of zinc oxide (ZnO), 12.0 parts by weight of zirconium oxide (ZrCO ₃ ), and calcium carbonate (CaCO _{3 )} .
3.0 parts by weight, and 1.5 parts by weight of aluminum oxide (Al ₂ O ₂ )
Mix parts by weight and heat in aluminum tube at 1400℃ for 30 minutes.
After melting for a minute, the melt was poured into water and rapidly cooled. This quenched product is taken out, placed in an alumina mortar, and ground to approximately 50 μm. This is then placed in a polyethylene pot mill with ethanol and ground for 150 hours using an alumina pole, resulting in a powder with a particle size of 10 μm or less. Got the glass. Next, the above glass and tungsten boride (one or more of WB, W ₂ B, and W ₂ B ₅ ) were weighed in the proportions shown in the table, and placed in a pole mill and stirred. Next, this was heat-treated at 1200°C for 1 hour in an argon gas atmosphere, and then placed in a polyethylene pot mill with ethanol and ground for 24 hours with an alumina pole to form a powder of a mixture of tungsten boride and glass with a size of 10 μm or less. I got it. That is, mixed powders of glass and tungsten boride in various proportions shown in Sample Nos. 1 to 30 in the table were obtained. Next, the proportions of glass, tungsten boride, and carbonate (one or more of CaCO ₃ , SrCO ₃ , and BaCO ₃ ) are as shown in the composition column of samples No. 1 to 30 in the table. Carbonate was added to the mixed powder of glass and tungsten boride, and the mixture was mixed to obtain a powder of the resistance material mixture according to the present invention. That is, in sample No. 1, the composition of the resistance material mixture was 10% by weight of glass, 80% by weight of WB,
The content of CaCO ₃ was 10% by weight, and the remaining samples Nos. 2 to 30 had the same weight proportions as shown in the composition column. Next, 100 parts by weight of the powder of the mixture of resistance materials of each sample was added with 10 parts of ethylcellulose as an organic binder.
An organic binder solution, ie, 25 parts by weight of a vehicle, consisting of 90 parts by weight of butyl carbitol as a solvent was added and kneaded in a three-roll mill to obtain a resistor paste with about 800 voids. On the other hand, a green sheet for printing the above resistor paste was produced by the following method. _{Al2O3 powder}
Ceramic raw material powder consisting of 50 parts by weight, 20 parts by weight of SiO ₂ powder, 25 parts by weight of SrO powder, 1 part by weight of Li ₂ O powder, and 4 parts by weight of MgO powder, a binder consisting of an aqueous solution of acrylic acid ester polymer, and glycerin. , a carboxylic acid salt, and water were placed in a pole mill and mixed to prepare a slip, and after degassing, a long green sheet with a thickness of 200 μm was prepared using a doctor blade method.
Then, two types of green sheet pieces, 9 mm x 9 mm and 6 mm x 9 mm, were cut out from this green sheet. Next, as shown in FIG. 1, nickel (Ni) powder and an organic binder solution (10 parts by weight of ethyl cellulose) were added to turpentine oil on top of the former green sheet piece 1.
A conductive paste prepared by kneading 90 parts by weight of Ni conductor paste in a ratio of 3:1 was printed using a 200 mesh screen and dried at 125°C for 10 minutes to form a Ni conductor as shown in Figure 1. Film 2 was formed. Next, the resistor paste according to the present invention was screen printed in the same manner as the conductor paste and dried to form a resistor film 3 as shown in FIG. Next, on top of the green sheet piece 1, another green sheet piece 4 of the size indicated by the chain line is laminated,
Thermocompression bonding is carried out at 100℃ and 150Kg/cm ² , and then heat treated at 500℃ in an oxidizing atmosphere to scatter and decompose the organic binder and solvent (organic vehicle), and N ₂ (98.5% by volume)
+H ₂ (1.5% by volume) at 1100℃, 2
As shown in FIG. 2, the porcelain layers 1a and 4
A multilayer ceramic circuit board for a hybrid integrated circuit having a thick film conductor 2a and a thick film resistor 3a was completed. The size of the portion of the resistor 3a that does not cover the conductor 2a is 3 mm x 3 mm, and the film thickness is 18 μm. Further, the composition of the resistor 3a substantially matches the inorganic composition of the resistor material before firing. Next, the sheet resistance R ₀ (Ω/□) of this resistor 3a at 25° C. was measured using a digital multimeter. Next, each sample (multilayer ceramic circuit board) was left in an environment with a temperature of 60°C and a relative humidity of 95% for 1000 hours, and then the sheet resistance R ₁ (Ω/□) was measured again using a digital multimeter. The resistance change rate △R of the thick film conductor 2a during the test is (R ₁
−R ₀ /R ₀ )×100%. The above R ₀ and ΔR are shown in the characteristics column of the table. Note that k in the R ₀ value column means ×10 ³ .

[Example 2]

In order to confirm that the same effects as in Example 1 can be obtained even if the composition of the glass is changed, glass powder was prepared as follows. Silicon dioxide (SiO ₂ )
75.0 parts by weight, 13.0 parts by weight of boron trioxide (B ₂ O ₃ ),
10.0 parts by weight of calcium carbonate (CaCO ₃ ) and 2.0 parts by weight of aluminum oxide (Al ₂ O ₃ ) were mixed and a powdered glass was obtained in the same manner as in Example 1. Next, use this glass, glass 30% by weight,
WB15% by weight, _W2B15 % by weight, _{W2B5 10} % by weight,
A paste containing a mixture of resistive materials with a composition of 10% by weight of CaCO ₃ , 10% by weight of SrCO ₃ and 10% by weight of BaCO ₃ was obtained in the same manner as in Example 1 and used in the same manner as in Example 1. When a multilayer ceramic circuit board with the same structure was formed and its electrical characteristics were measured in the same manner as in Example 1, the sheet resistance value R ₀ was 6.325 kΩ/
□, resistance change rate △R was +0.8%. As is clear from Example 2, there is no significant difference in resistance characteristics even if the composition of the glass is changed. That is, the glass used in the present invention is not necessarily limited to one specified composition. Note that SiO ₂ −ZnO− in Example 1
ZrO ₂ -CaO-Al ₂ O ₃ -based glass, SiO ₂ - of Example 2
All B ₂ O ₃ -CaO-Al ₂ O ₃ type glasses have a working point (temperature at which 1×10 ⁴ noise is obtained) of 900 to 1200°C. The glass according to the present invention is Example 1
900~
Metal oxides (PbO,
Any material may be used as long as it does not contain SnO ₂ , Bi ₂ O ₃ , etc.). [Modifications] The present invention is not limited to the above-described embodiments, and, for example, the following modifications are possible. (a) Even if the firing temperature of a green sheet coated with a resistor paste containing tungsten boride, glass, and carbonate is varied in the range of 1000℃ to 1200℃, the resistance value R ₀ and the resistance change rate △R remain unchanged. It has been confirmed that there is almost no change. For example, with the same composition as sample No. 28 of Example 1, only the firing temperature was changed.
The resistance value _R0 when changing to 1000℃, 1050℃, 1150℃, 1200℃ is 6.283kΩ/□, 6.252kΩ/□,
6.248kΩ/□, 6.272kΩ/□, and the resistance change rate △R is +1.1%, +1.0%, +1.2%, +0.9
It was %. Almost similar results were obtained with other compositions. (b) The atmosphere when firing the green sheet may be a neutral atmosphere (inert atmosphere). Also,
The heat treatment temperature in an oxidizing atmosphere for decomposing and scattering organic matter before firing the green sheet may be varied, for example, from 400°C to 600°C. (c) The firing temperature of the mixture of glass and tungsten boride in an argon atmosphere is, for example, 900-
It may be varied within a range of 1200°C. Further, this firing may be performed in an inert atmosphere other than argon gas, in vacuum, in a neutral atmosphere, or in a reducing atmosphere. (d) The organic binder solution (vehicle) for making the resistor paste may be one in which a resin such as nitrocellulose is dissolved in a high boiling point solvent such as turpentine oil or butylcarpitol acetate. Further, the amount of this organic binder solution is preferably about 15 to 35 parts by weight. [Effects of the Invention] As is clear from the above, the paste-like resistive material of the present invention and the conductive paste of a base metal such as nickel can be co-fired in a non-oxidizing atmosphere, and the resistive material of the present invention does not contain a noble metal. Not yet. Therefore, it is possible to contribute to miniaturization and cost reduction of multilayer ceramic circuit boards or similar electric circuit components. Furthermore, the resistive material of the present invention can provide a resistor with better moisture resistance than the resistive material of the patent application mentioned above.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing patterns of a green sheet, a conductor film, and a resistor film when manufacturing a multilayer ceramic circuit board according to an embodiment of the present invention, and FIG. 2 is a portion corresponding to the - line in FIG. 1. FIG. 3 is a cross-sectional view showing the multilayer ceramic circuit board after firing. 1... Green sheet piece, 2... Conductor film, 3...
...Resistor film, 4... Green sheet piece.

Claims (1)

[Scope of Claims] 1. 15 to 80% by weight of tungsten boride, 10 to 75% by weight of glass, and 10 to 75% of carbonate of at least one of calcium carbonate, strontium carbonate, and barium carbonate.
% by weight of a powder mixture, an organic binder, and a solvent. 2 The tungsten boride includes monotungsten boride (WB), ditungsten boride (W ₂ B),
The resistance material according to claim 1, which is at least one of ditungsten pentaboride (W ₂ B ₅ ). 3. The resistance material according to claim 1 or 2, wherein the glass has a working point in the range of 900 to 1200°C.