JPH0362284B2 - - 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, i.e., a green sheet, coated with a conductive paste of a base metal such as nickel, and coated with a resistor paste containing molybdenum boride and metal fluoride 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 resistance material according to the present invention for achieving the above object contains 20 to 70% by weight of molybdenum boride and glass.
10 to 70% by weight, 5 to 50% by weight of at least one fluoride selected from calcium fluoride ( _CaF2 ), strontium fluoride ( _SrF2 ), and barium fluoride ( _BaF2 ), and calcium carbonate ( A powder of a mixture consisting of 10 to 60% by weight of at least one carbonate of CaCO ₃ ), strontium carbonate (SrCO ₃ ), and barium carbonate (BaCO ₃ ), an organic binder, and a solvent (vehicle). Become. [Function] If a paste-like resistance material having the above composition is printed on a green sheet and fired in a non-oxidizing atmosphere, a thick film resistor having a resistance change rate within ±2% in a humidity test can be obtained. Therefore, it is possible to form a base metal thick film resistor simultaneously with the formation of a thick film conductor using a base metal conductor paste 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, silicon dioxide (SiO ₂ ) 78.0% by weight, zinc oxide (ZnO) 5.5% by weight, zirconium oxide (ZrO ₂ )
12.0% by weight, 3.0% by weight of calcium carbonate (CaCO ₃ ), and 1.5% by weight of aluminum oxide (Al ₂ O ₃ ) were mixed and melted at 1400°C for 30 minutes in an alumina crucible, and this melt was poured into water. , rapidly cooled. Take out this quenched material and put it in an alumina mortar, about
Grind it to about 50 μm, then put it in a polyethylene pot mill with ethanol and grind it with alumina balls for 150 hours until the particle size is reduced.
A powdered glass with a size of 10 μm or less was obtained. Next, the above glass, molybdenum boride (one or more of Mo ₂ B, Mo ₂ B ₆ , MoB, and MoB ₂ ) and fluoride (one or more of CaF ₂ , SrF ₂ , and BaF ₂ ) were placed in a table. It was weighed in the proportion shown, placed in a ball mill, and stirred. Next, this was heated to 1200℃ in an argon gas atmosphere.
The mixture was heat-treated for 1 hour, and then placed in a polyethylene pot mill with ethanol and ground for 24 hours with an alumina ball to obtain a powder of a mixture of molybdenum boride, glass, and fluoride with a particle size of 10 μm or less.
That is, mixed powders of glass, molybdenum boride, and fluoride in various proportions shown in Sample Nos. 1 to 32 in the table were obtained. Next, the weight ratio of glass, molybdenum boride, and carbonate of fluoride (one or more of CaCO ₃ , SrCO ₃ , BaCO ₃ ) is as shown in the composition column of samples No. 1 to 32 in the table. As shown, carbonate was added to the above-mentioned mixed powder of glass, molybdenum boride, and fluoride, and the powder of the resistance material according to the present invention was obtained by mixing. That is, in sample No. 1, the composition of the resistance material was 10% by weight of glass, 20% by weight of Mo ₂ B,
CaF ₂ was 10% by weight and CaCO ₃ was 60% by weight, and the remaining samples Nos. 2 to 32 had the compositions shown in the composition column. Next, add 100 parts by weight of the resistance material powder of each sample to
An organic binder solution or vehicle consisting of 10 parts by weight of ethyl cellulose as an organic binder dissolved in 90 parts by weight of butyl carbitol as a solvent.
Add 25 parts by weight and knead with a three-roll mill to give approx.
A resistor paste of 800 poise was obtained. On the other hand, a green sheet for printing the above resistor paste was produced by the following method. _{Al2O3 powder}
50% by weight, 20% by weight of _SiO2 powder, 25% by weight of SrO powder, 1% by weight of _Li2O powder, and 4% by weight of MgO powder.
A ceramic raw material powder consisting of a powder, a binder consisting of an aqueous solution of an acrylic acid ester polymer, glycerin, a carboxylic acid salt, and water are placed in a ball mill and mixed to prepare a slip,
After degassing, the thickness is measured using the doctor blade method.
A 200 μm long green sheet was produced. And from this green sheet, 9mm x 9mm and 6mm
Two types of green sheet pieces measuring 9 mm were cut out. Next, as shown in FIG.
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, 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 thickness of the film 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 .

【table】

[Modified example]

The present invention is not limited to the embodiments described above, and the following modifications are possible, for example. (a) Even if the firing temperature of a green sheet coated with a resistor paste containing molybdenum boride, glass, fluoride, and carbonate is varied in the range of 1000°C to 1200°C, the resistance value R ₀ and the rate of change in resistance will change. It has been confirmed that ΔR hardly changes. for example,
When the same composition as Sample No. 3 of Example 1 was used but only the firing temperature was changed to 1000°C, 1050°C, 1150°C, and 1200°C, the resistance value R ₀ was 140.0×10 ³ Ω/□, 141.2×
10 ³ Ω/□, 140.5×10 ³ Ω/□, 140.9×10 ³ Ω/
□, and the resistance change rate △R is +1.2%, +
They were 1.6%, +1.5%, and +1.3%. 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) Calcination temperature of a mixture of glass, molybdenum boride, and fluoride in an argon atmosphere, e.g.
It may be changed within the range of 900 to 1200°C. In addition, this firing is performed in an inert atmosphere other than argon gas.
Alternatively, it may be carried out 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 butyl carbitol 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 drawings]

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 Molybdenum boride 20-40% by weight, glass 10-60% by weight, at least one fluoride selected from calcium fluoride, strontium fluoride, and barium fluoride 5-
50% by weight, at least one carbonate selected from calcium carbonate, strontium carbonate, and barium carbonate 10~
A paste-like resistance material consisting of a powder mixture consisting of 60% by weight, an organic binder, and a solvent. 2 The molybdenum boride includes molybdenum boride di(Mo ₂ B), molybdenum pentaboride (Mo ₂ B ₅ ), molybdenum boride monoboride (MoB), and molybdenum diboride (MoB ₂ ). The resistance material according to claim 1, which is at least one of the following. 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.