JPH11288801A - Resistor paste, formation method for thick-film resistor, and manufacture of thick-film substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thick-film resistor of small temperature coefficient resistance(TRC), without using a material which adversely affects the environment such as lead. SOLUTION: On a ceramic substrate 1, where Cu group conductors 2 and 3 are arranged, this resistor paste for which conductive powder constituting of a mixed power (Cu/Ni=60/40 to 80/20) of copper powder and nickel powder, the glass powder of 3-20 pts.wt. to the 100 pts.wt. of the conductive powder and the copper oxide powder of 1-10 pts.wt. are disposed to a vehicle, composed of organic resin and a solvent with the ratio of conductive components of 75-90 wt.% is printed. Then, it is calcined in a nitrogen atmosphere, and a thick film substrate is manufactured. For the resistor paste, the main component of glass is composed of ZnO or BaO or both and a copper oxide consists of Cu2 O or CuO or the mixture of Cu2 O and CuO. The grain diameter of the copper powder is 0.1-2 μm, the grain diameter of the nickel powder is 0.1 μm-2 μm and the grain diameter of the copper oxide is 1 μm-10 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming a resistor paste, a thick film resistor, and a method for manufacturing a thick film substrate.

[0002]

2. Description of the Related Art A method of manufacturing a thick film substrate having a thick film resistor will be described with reference to FIG. First, a noble metal paste made of Ag, Pd, and glass frit is screen-printed on the ceramic substrate 11 and fired in air to form a conductor (electrode).
12 and 13 are formed. Then, a resistor paste made of RuO ₂ or Ag—Pd and lead oxide glass is printed thereon, and fired in air to form the thick film resistor 14.

Here, the noble metal paste is expensive, and when it is used in a circuit of a hybrid IC, there is a concern that the reliability of a part joint portion may be reduced due to solder erosion, and electromigration of Ag (silver) may occur. As a measure against this,
A Cu electrode is used instead of the Ag electrode.

[0004]

However, when a Cu electrode is used, firing is performed in a nitrogen atmosphere in order to prevent oxidation. When a conventional ruthenium oxide or Ag-Pd is used for a resistor, nitrogen is not used. It is difficult to obtain desired resistance value and temperature coefficient of resistance (TCR) due to reduction in an atmosphere.

[0005] In recent years, there has been a demand for environmental protection, and harmful substances such as Pb and Cd have been increasingly used. SUMMARY OF THE INVENTION It is an object of the present invention to provide a thick film resistor having a small temperature coefficient of resistance (TCR) without using a substance such as lead which has an adverse effect on the environment.

[0006]

According to a first aspect of the present invention, there is provided a resistor paste for firing in a nitrogen atmosphere, comprising a conductive powder comprising a mixed powder of copper powder and nickel powder or a Cu-Ni alloy powder; 3 to 20 parts by weight of glass powder and 1 to 10 parts by weight of copper oxide powder are added to a vehicle composed of an organic resin and a solvent in an amount of 75 to 100 parts by weight.
It is characterized by being dispersed at 90% by weight.

According to a fifth aspect of the present invention, as a method of forming a thick film resistor, a conductive powder composed of a mixed powder of a copper powder and a nickel powder or a Cu—Ni alloy powder and 100 parts by weight of the conductive powder are used. 3 to 20 parts by weight of a glass powder and 1 to 10 parts by weight of a copper oxide powder are dispersed in a vehicle composed of an organic resin and a solvent at a ratio of a conductive component of 75 to 90% by weight to form a resistor paste. This paste is fired in a nitrogen atmosphere to form a thick film resistor.

According to a ninth aspect of the present invention, as a method of manufacturing a thick film substrate, a mixed powder of copper powder and nickel powder or Cu-N
a conductive powder composed of an i-alloy powder, 3 to 20 parts by weight of glass powder and 1 to 10 parts by weight based on 100 parts by weight of the conductive powder.
A resistor paste in which a weight part of a copper oxide powder is dispersed in a vehicle made of an organic resin and a solvent with a conductive component ratio of 75 to 90% by weight is printed. Thereafter, firing is performed in a nitrogen atmosphere.

In this way, a thick film resistor having a small temperature coefficient of resistance can be formed as a Cu-Ni-based thick film resistor without using a substance such as lead which has an adverse effect on the environment.

Here, the mixing ratio of copper and nickel is set to Cu / Ni = 60 / 40-
When the ratio is 80/20, the temperature coefficient of resistance can be further reduced. Therefore, it is suitable for use in a vehicle where the temperature environment is severe.

Further, in the resistor paste, the main component of the glass of the resistor paste is ZnO or BaO, or ZnO and BaO, and the copper oxide is Cu ₂ O or CuO, or It is more preferable to use a mixture of Cu ₂ O and CuO.

Further, in the resistor paste, the particle size of the copper powder is 0.1 μm to 2 μm.
m, particle size of nickel powder is 0.1 μm to 2 μm, Cu-N
It is more preferable that the particle diameter of the i-alloy powder be 0.1 μm to 2 μm and the particle diameter of the copper oxide be 1 μm to 10 μm.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a thick film substrate according to the present embodiment. In this example, the thick-film resistor 4 is used in a vehicle and has a temperature coefficient of resistance (TCR) of 200 pp in a range of -55 ° C to 125 ° C.
m / ° C or less.

As shown in FIG. 1, a Cu-based conductor 2 serving as an electrode material is formed on a ceramic substrate 1 made of alumina, and a Cu-based conductor 2 serving as an electrode material is provided at a position separated from the Cu-based conductor 2. A system conductor 3 is formed. A Cu-Ni thick film resistor 4 is formed on the ceramic substrate 1, and a Cu-based conductor (electrode) 2 and a Cu-based conductor (electrode) 3
And a Cu-Ni-based thick-film resistor 4 is arranged between them.

Next, a method of manufacturing the thick film substrate will be described. First, a Cu-Ni-based thick film resistor paste for forming the Cu-Ni-based thick film resistor 4 is prepared. This resistor paste is composed of a mixed powder of copper powder and nickel powder, and the mixing ratio of copper and nickel is Cu / Ni = 60 /
A conductive powder of 40 to 80/20, and the conductive powder 1
3 to 20 parts by weight of glass powder and 1 part by weight
10 to 10 parts by weight of copper oxide powder was added to a vehicle comprising an organic resin and a solvent, and the proportion of the conductive component was 75 to 90% by weight.
It is what is dispersed.

The particle size of the copper powder is 0.1 μm to 2 μm,
The particle size of the nickel powder is 0.1 μm to 2 μm, which is a preferable range for performing screen printing. More preferably, the particle size of the nickel powder is 0.5 μm to 1 μm.
m. As the copper powder, those obtained by classifying reduced copper powder with a reducing agent of copper sulfate or copper chloride or atomized copper powder can be used. As the nickel powder, nickel sulfate, reduced nickel of nickel chloride, atomized nickel, nickel decomposed from carbo nickel, and metal powder obtained by melting and recrystallizing these can be used.

Here, by changing the mixing ratio of the Cu powder and the Ni powder, the resistance value and the temperature coefficient of resistance (TCR) can be changed.
This ratio is appropriately selected so that That is, C
By setting the u / Ni weight ratio to 60/40 to 80/20, the TCR becomes 200 pp in the range of −55 ° C. to 125 ° C.
m / ° C. or less.

Although the conductive powder is composed of a mixed powder of copper powder and nickel powder, the conductive powder may be composed of a Cu-Ni alloy powder. In this case, the particle size of the Cu—Ni alloy powder may be 0.1 μm to 2 μm.

The glass powder is necessary for bonding the thick film resistor 4 to the ceramic substrate 1 and for adjusting the resistance value, but does not contain Pb or Cd and contains ZnO or BaO or both as main components. And The softening point of glass is 5
Desirably, the thermal expansion coefficient is 50 to 650 ° C. and the thermal expansion coefficient is 85 to 97 × 10 ⁻⁷ / ° C. Here, the softening point of the glass can be adjusted by the ratio of zinc and barium.

More specifically, as the glass frit, zinc borate, barium borate, or borosilicate glass having a melting point of 500 ° C. to 800 ° C. is preferable. Further, the copper oxide (powder) is made of Cu ₂ O or CuO, or a mixture of Cu ₂ O and CuO. The particle size of the copper oxide is 1 μm to 10 μm, which is a preferable range for performing screen printing.

As described above, the conductive powder, the glass powder, and the copper oxide powder are kneaded with the vehicle to form a paste composition, which is printed by a 100-400 mesh printing screen. Therefore, those having an average particle diameter of about 1 μm, which has almost no particles of 20 μm or more, are particularly suitable.

As the solvent used for the vehicle, terpene solvents, ester alcohols, aromatic hydrocarbons, and ester solvents are used. Examples of the terpene-based solvent include limonene, paramenthane, pinane, terpineol, dihydroterpineol, and the like. Examples of the ester alcohol include 2.2.4 trimethyl1.3 pentanediol. As aromatic hydrocarbons, xylene,
Examples include isopropylbenzene, methylcyclohexane, and toluene. Examples of the ester solvent include ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, and diethylene glycol monobutyl ether acetate. Alternatively, a plurality of mixed solvents among these solvents may be used.

The organic resin used in the vehicle includes
Cellulose resin, acrylic resin, and alkyd resin are used. Examples of the cellulosic resin include ethyl cellulose and nitrocellulose. Examples of the acrylic resin include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate or a mixture of a plurality of these, and a copolymer of a plurality of monomers. . Examples of the alkyd resin include polyhydric alcohols such as dihydric ethylene glycol and propylene glycol, trihydric alcohols such as glycerin and trimethylolpropane, polyhydric alcohols such as diglycerin,
Triglycerin and the like can be used.

Further, examples of the added organic agent include polybasic acid phthalic anhydride, succinic acid, maleic acid and itaconic acid. As a modifying agent which is one of the added organic agents, fatty acids such as soybean oil, tung oil and dehydrated castor oil, oleic acid, stearic acid and the like can be mentioned. In addition, rosin, shellac, and the like are given as natural resins that are one of the added organic agents, and ester gums, phenol resins, and acrylic resins are given as synthetic resins.

When manufacturing a thick film substrate, first,
As shown in FIG. 1, a Cu-based conductor paste is applied on a ceramic substrate 1 by screen printing. Further, by sintering, Cu-based conductors 2 and 3 as electrode materials are obtained.

Subsequently, the above-mentioned Cu-Ni thick film resistor paste is applied on the ceramic substrate 1 by screen printing. Then, it is fired in a nitrogen atmosphere to
An i-system thick film resistor 4 is obtained.

As a result, the thick film substrate shown in FIG. 1 is manufactured. In the following, the resistance value, TCR and adhesive strength were measured and evaluated by changing the components and composition of the thick film resistor paste.
I will explain that.

Tables 1, 2 and 3 show the evaluation results. As samples, Examples 1 to 20 and Comparative Examples 1 to 3 were used as indicated by vertical items in Tables 1, 2, and 3. In Tables 1, 2 and 3, the horizontal items are the ratio of the conductive component of the resistor paste (Cu-Ni content) and C
The composition ratios of u and Ni, the glass main component, the glass component ratio, and the copper oxide ratio are shown. In addition, Tables 1, 2,
As indicated by the item next to 3, the measurement items include sheet resistance (unit: mΩ / □), TCR at 25 ° C. to 150 ° C., −
TCR and adhesive strength at 55 ° C to 25 ° C (unit: Kg /
□).

In Examples 1 to 20, the ratio of the conductive component (C
u-Ni content) is 75 to 90 wt%, and Cu and N
The ratio of i is Cu / Ni = 60/40 to 80/20, and the glass amount is 3 to 20 with respect to 100 parts by weight of the conductive powder.
Parts by weight, and the amount of the copper oxide is 1 to 10 parts by weight based on 100 parts by weight of the conductive powder.

On the other hand, in Comparative Example 1, the amount of glass was 1 part by weight with respect to 100 parts by weight of the conductive powder. In Comparative Example 2, the ratio of Cu and Ni was Cu / Ni = 90/10. In Example 3, the ratio of Cu and Ni is Cu / Ni = 5.
0/50.

In Comparative Example 1, the adhesive strength was as low as 0.3 kg / □, but in Examples 1 to 20, the adhesive strength was 1.5 kg / □ or more. In Comparative Example 2, 25
TCR at 150C to 150C and T at -55C to 25C
Although CR was as large as 500 ppm in both cases, Examples 1 to 20
TCR at 25 ° C. to 150 ° C. and −55 ° C. to 2
The TCR at 5 ° C. was both 200 ppm or less. Further, in Comparative Example 3, although the sheet resistance was as large as 60 mΩ / □,
In Examples 1 to 20, the sheet resistance was 47 mΩ / □ or less.

As described above, this embodiment has the following features. (A) As a resistor paste for firing in a nitrogen atmosphere, a conductive powder composed of a mixed powder of copper powder and nickel powder (or Cu-Ni alloy powder), and 3 to 100 parts by weight of the conductive powder.
A dispersion of 20 parts by weight of glass powder and 1 to 10 parts by weight of copper oxide powder in a vehicle composed of an organic resin and a solvent with a conductive component ratio of 75 to 90% by weight was used. (B) The resistor paste was fired in a nitrogen atmosphere to form a Cu-Ni thick film resistor 4. (C) In particular, the resistor paste of (a) was printed on the substrate 1 on which the Cu-based conductors 2 and 3 as electrode materials were arranged, and then fired in a nitrogen atmosphere to produce a thick film substrate. .

Thus, the thick-film resistor 4 having a small temperature coefficient of resistance (TCR) can be formed as the Cu-Ni-based thick-film resistor 4 without using a substance having an adverse effect on the environment such as lead. it can. (D) Since the mixing ratio of copper and nickel in the resistor paste is set to Cu / Ni = 60/40 to 80/20, the temperature coefficient of resistance (TCR) can be further reduced. Therefore, it is suitable for use in a vehicle where the temperature environment is severe as in the present embodiment. (E) The main component of the glass in the resistor paste is ZnO
Or BaO, or ZnO and BaO, and the copper oxide is Cu ₂ O or CuO, or Cu ₂ O and Cu
Since it is made of a mixture of O, it is more preferable. (F) The particle size of the copper powder in the resistor paste is 0.1 μm
２2 μm, the particle size of the nickel powder is 0.1 μm to 2 μm, and the particle size of the copper oxide is 1 μm to 10 μm, which is more preferable.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a thick film substrate according to an embodiment.

FIG. 2 is a cross-sectional view of a thick film substrate for explaining a conventional technique.

[Explanation of symbols]

1. Ceramic substrate, 2. Cu-based conductor, 3. Cu-based conductor, 4. Cu-Ni thick film resistor.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Kobayashi 3993 Narukawa, Niigata City Inside Namics Corporation

Claims (12)

[Claims] 1. A mixed powder of copper powder and nickel powder or Cu-
A conductive powder made of a Ni alloy powder;
3 to 20 parts by weight of glass powder and 1 to 1 part by weight
A resistor paste for firing in a nitrogen atmosphere, wherein 0 parts by weight of a copper oxide powder is dispersed in a vehicle comprising an organic resin and a solvent at a ratio of 75 to 90% by weight of a conductive component. 2. The mixing ratio of copper and nickel is Cu / Ni = 6.
The resistor paste according to claim 1, wherein the ratio is 0/40 to 80/20. 3. The main component of glass is ZnO or BaO,
Alternatively, it is composed of ZnO and BaO, and the copper oxide is Cu ₂ O
_2. The resistor paste according to claim 1, comprising CuO or a mixture of Cu2O and CuO. 4. A copper powder having a particle size of 0.1 μm to 2 μm, a nickel powder having a particle size of 0.1 μm to 2 μm, a Cu—Ni alloy powder having a particle size of 0.1 μm to 2 μm, and a copper oxide particle size. Is 1 μm
2. The resistor paste according to claim 1, which has a thickness of 10 to 10 [mu] m. 5. A mixed powder of copper powder and nickel powder or Cu-
A conductive powder made of a Ni alloy powder;
3 to 20 parts by weight of glass powder and 1 to 1 part by weight
0 parts by weight of a copper oxide powder is dispersed in a vehicle composed of an organic resin and a solvent at a conductive component ratio of 75 to 90% by weight to form a resistor paste, and the paste is fired in a nitrogen atmosphere to form a thick film. A method for forming a thick film resistor, comprising forming a resistor. 6. The mixing ratio of copper and nickel is Cu / Ni = 6.
6. The method for forming a thick film resistor according to claim 5, wherein the ratio is 0/40 to 80/20. 7. The main component of glass is ZnO or BaO,
Alternatively, it is composed of ZnO and BaO, and the copper oxide is Cu ₂ O
Or CuO or Cu ₂ O and forming method according to claim 5 thick film resistor according consisting of a mixture of CuO,. 8. The particle size of the copper powder is 0.1 μm to 2 μm, the particle size of the nickel powder is 0.1 μm to 2 μm, the particle size of the Cu—Ni alloy powder is 0.1 μm to 2 μm, and the particle size of the copper oxide. Is 1 μm
6. The method for forming a thick film resistor according to claim 5, wherein the thickness is from 10 to 10 [mu] m. 9. A conductive powder comprising a mixed powder of copper powder and nickel powder or a Cu—Ni alloy powder on a substrate on which a Cu-based conductor as an electrode material is disposed, and 100 parts by weight of the conductive powder. 3
-20 parts by weight of glass powder and 1-10 parts by weight of copper oxide powder in a vehicle comprising an organic resin and a solvent,
A method for manufacturing a thick film substrate, comprising: a step of printing a resistor paste in which a conductive component is dispersed at a ratio of 75 to 90% by weight; and a step of firing in a nitrogen atmosphere. 10. The mixing ratio of copper and nickel is Cu / Ni =
The method for producing a thick film substrate according to claim 9, wherein the thickness is 60/40 to 80/20. 11. The main component of glass is ZnO or Ba.
O, or ZnO and BaO, and the copper oxide is Cu
10. The method for producing a thick film substrate according to claim 9, comprising a mixture of ₂ O or CuO, or a mixture of Cu ₂ O and CuO. 12. The particle size of copper powder is 0.1 μm to 2 μm, the particle size of nickel powder is 0.1 μm to 2 μm, the particle size of Cu—Ni alloy powder is 0.1 μm to 2 μm, and the particle size of copper oxide Is 1μ
The method for producing a thick film substrate according to claim 9, wherein the thickness is from 10 to 10 m.