JP2020013913A - Composition for thick film resistor, paste for thick film resistor, and thick film resistor - Google Patents

Abstract

To provide a thick film resistor substantially free of lead while having good electrical characteristics of low current noise and having a desired resistance and TCR.SOLUTION: A conductive component includes at least one selected from ruthenium dioxide, calcium ruthenate, strontium ruthenate, and barium ruthenate. A glass component is substantially free of lead and contains bismuth oxide in an amount of 1% by mass or more and 5% by mass or less. Such a composition for a thick film resistor, a paste for the thick film resistor, and the thick film resistor are provided.SELECTED DRAWING: None

Description

  The present invention relates to a composition for a thick film resistor and a paste for a thick film resistor used for forming a thick film resistor in a resistor component such as a chip resistor and a hybrid IC, and a paste formed using the same. It relates to a thick film resistor.

  Conventionally, as a resistor film in a resistor component, there are a thick film resistor formed using a paste and a thin film resistor formed by sputtering a film forming material. Of these, thick film resistors are widely used in resistance components such as chip resistors and hybrid ICs, because their manufacturing facilities are inexpensive and their productivity is high.

The thick film resistor is formed by printing a paste for a thick film resistor on a ceramic substrate and firing the paste. This paste for a thick film resistor is substantially composed of a conductive powder, a glass frit, and an organic vehicle for making them into a paste suitable for printing. As the conductive powder, ruthenium dioxide (RuO ₂₎ and pyrochlore type ruthenium based oxide _{(Pb 2 Ru 2 O 7-} X, Bi 2 Ru 2 O 7) ruthenium (Ru) based oxides, such as is, as a glass frit the borosilicate lead glass _{(PbO-SiO 2 -B 2 O} 3) or aluminum borosilicate lead glass _{(PbO-SiO 2 -B 2 O} 3 -Al 2 O 3) lead borosilicate containing a large amount of lead, such as Glass is used in each case.

  The reason that the ruthenium-based oxide is used as the conductive powder is mainly because of its characteristic that the resistance value gradually changes with the change of the concentration. The reason why lead borosilicate glass is used for the glass frit is that it has good wettability with Ru-based oxides, its thermal expansion coefficient is close to the thermal expansion coefficient of the substrate, and it is suitable for viscosity during firing and the like. Because it is.

  However, since the use of a thick-film resistor paste containing harmful lead is not desirable from the viewpoint of environmental problems, the practical use of a lead-free thick-film resistor paste has been strongly demanded in recent years.

For this reason, research and development of lead-free thick film resistor pastes are currently underway, and lead-free glass frit has been proposed for thick film resistor compositions used in thick film resistor pastes. It has been done. For example, Japanese Patent Application Laid-Open No. 8-253342 discloses that 5-70 mol% of Bi ₂ O ₃ , 18-35 mol% of SiO ₂ , 0.1-40 mol% of CuO, 5-25 mol% of ZnO, 0.5 to 40 mol% of CoO, wherein the MnO of 0.5 to 40 mol% _Fe 2 _{O 3,} and 0.5 to 40 mol%, the glass frit is disclosed that does not contain lead and cadmium. Further, JP 2003-257242, in a weight ratio alkali metal of 1% or less, _Bi 2 _{O 3} is 10 to 30% SiO ₂ is 25 to 40% BaO 30 to 40%, and ZnO 5 to 7% _Al 2 _{O 3} 4 to _7%, the glass frit is disclosed B 2 _{O 3} does not contain lead composed of the composition of from 0.01 to 8%. As described above, glass frit containing bismuth oxide (Bi ₂ O ₃ ) is used in the composition for thick film resistor and the paste for thick film resistor in these documents. However, since bismuth oxide in the glass frit has an effect of lowering the resistance value, as the content of bismuth oxide increases, the proportion of the conductive powder in the resistance paste must be reduced, and accordingly, There is a problem that current noise increases in the obtained resistor.

JP-A-8-253342 JP 2003-257242 A

  An object of the present invention is to provide a lead-free thick film resistor composition, a thick film resistor paste, and a thick film resistor that can form a resistor having good electrical characteristics. It is in.

The composition for a thick film resistor of the present invention includes a conductive powder and a glass frit,
The conductive powder includes at least one selected from ruthenium dioxide, calcium ruthenate, strontium ruthenate, and barium ruthenate, and
The glass frit does not contain lead virtually, and contains less than 5 wt% or more 1 wt% of bismuth oxide _(Bi 2 _{O 3),}
It is characterized by the following.

In the glass frit, the composition excluding bismuth oxide has a content of 30% by mass or more and 50% by mass or less of silicon oxide (SiO ₂ ), 10% by mass or more and 25% by mass or less of boron oxide (B ₂ O ₃ ), and 5% by mass or more. 15% by mass or less of alkaline earth metal oxide (RO: R is at least one selected from Ca, Sr and Ba) 10% by mass or more and 30% by mass or less of zinc oxide (ZnO), 2% by mass or more It is preferable to be made of 6% by mass or less of alumina (Al ₂ O ₃ ) and 10% by mass or less of an alkali metal oxide (R ₂ O: R is at least one selected from Li, Na, and K).

  The glass frit preferably has a softening point of 550 ° C. or more and 750 ° C. or less.

The glass frit preferably has a coefficient of thermal expansion of 40 × 10 ⁻⁷ / K or more and 100 × 10 ⁻⁷ / K or less.

The composition for a thick film resistor of the present invention comprises titanium oxide (TiO ₂ ), niobium oxide (Nb ₂ O ₅ ), tin oxide (SnO ₂ ), tantalum oxide (Ta ₂ O ₅ ), and copper oxide (Cu ₂ It is preferable that at least one selected from O, CuO) is further contained in a range of 0.05% by mass or more and 10% by mass or less based on the total mass of the conductive powder and the glass frit.

  The paste for a thick-film resistor of the present invention includes a composition for a thick-film resistor and an organic vehicle, and the composition for a thick-film resistor of the present invention is used as the composition for a thick-film resistor. It is characterized by the following.

  The content of the organic vehicle is preferably 30% by mass or more and 50% by mass or less based on the mass of the thick film resistor paste.

  The thick film resistor of the present invention comprises a fired body containing a conductive component and a glass component, wherein the conductive component is at least one selected from ruthenium dioxide, calcium ruthenate, strontium ruthenate, and barium ruthenate. And the glass component is substantially free of lead and contains bismuth oxide in an amount of 1% by mass or more and 5% by mass or less.

In the glass component, the composition excluding bismuth oxide has a composition of 30% by mass or more and 50% by mass or less of silicon oxide (SiO ₂ ), 10% by mass or more and 25% by mass or less of boron oxide (B ₂ O ₃ ), and 5% by mass or more. 15% by mass or less of alkaline earth metal oxide (RO: R is at least one selected from Ca, Sr and Ba) 10% by mass or more and 30% by mass or less of zinc oxide (ZnO), 2% by mass or more It is preferable to be made of 6% by mass or less of alumina (Al ₂ O ₃ ) and 10% by mass or less of an alkali metal oxide (R ₂ O: R is at least one selected from Li, Na, and K).

  The glass of the glass component preferably has a softening point of 550 ° C. or more and 750 ° C. or less.

The glass of the glass component preferably has a coefficient of thermal expansion in the range of 40 × 10 ⁻⁷ / K or more and 100 × 10 ⁻⁷ / K or less.

The thick-film resistor of the present invention includes titanium oxide (TiO ₂ ), niobium oxide (Nb ₂ O ₅ ), tin oxide (SnO ₂ ), tantalum oxide (Ta ₂ O ₅ ), and copper oxide (Cu ₂ O, CuO). ) Is preferably further contained in the range of 0.05% by mass or more and 10% by mass or less based on the total mass of the conductive component and the glass component.

  The composition for a thick film resistor, the paste for a thick film resistor, and the thick film resistor of the present invention can exhibit good electrical characteristics without containing harmful lead. By replacing with a thick film resistor paste containing, a resistor component such as a chip resistor or a hybrid IC having no problem of environmental pollution can be provided, and its industrial value is extremely large.

  Hereinafter, the composition for a thick-film resistor, the thick-film resistor paste, and the thick-film resistor of the present invention will be described in detail.

(1) Composition for Thick Film Resistor The composition for a thick film resistor of the present invention comprises a conductive powder and a glass frit, wherein the conductive powder is composed of ruthenium dioxide (RuO ₂ ), calcium ruthenate ( CaRuO ₃ ), at least one selected from strontium ruthenate (SrRuO ₃ ), and barium ruthenate (BaRuO ₃ ), and the glass frit is substantially free of lead and contains bismuth oxide. It is characterized by containing from 1% by mass to 5% by mass.

[Conductive powder]
The conductive powder constituting the composition for a thick film resistor of the present invention contains at least one selected from ruthenium dioxide, calcium ruthenate, strontium ruthenate, and barium ruthenate. These conductive powders can be obtained by a known manufacturing method.

  Calcium ruthenate, strontium ruthenate, or barium ruthenate is obtained by a dry method in which ruthenium dioxide powder and calcium, strontium, or hydroxide or carbonate of barium are mechanically mixed, heat-treated, and then pulverized. be able to. In order to obtain these powders having a small particle size and uniformity, a solution containing ruthenium chloride, calcium chloride, strontium chloride, or barium chloride is added to an aqueous alkaline solution, and the mixture is precipitated. Is washed and dried, and then roasted at a temperature of about 600 ° C. or more and 900 ° C. or less.

  The average particle size of the conductive powder determined by the BET method is preferably 1.0 μm or less, and more preferably 0.2 μm or less. This makes it possible to appropriately suppress the variation in the resistance value and the magnitude of the current noise in the thick-film resistor obtained by firing.

  In the composition for a thick film resistor of the present invention, the content of the conductive powder is appropriately adjusted according to the desired resistance value in the obtained thick film resistor, the type and the particle size of the conductive powder and the glass frit. You. For example, when obtaining a high-resistance resistor having an area resistance value of 5 kΩ or more, the content of the conductive powder is usually 5% by mass or more and 30% by mass or less.

[Glass frit]
The glass frit constituting the composition for a thick film resistor of the present invention is characterized by being substantially free of lead and containing bismuth oxide in an amount of 1% by mass to 5% by mass.

  Here, "substantially does not contain lead" means that the lead content in the glass frit is equal to or less than the regulation value (0.1% by mass) of the RoHS directive or the lead content is measured in a normal measurement. It means below the detection limit in the instrument.

  Bismuth oxide in the glass frit plays a role in moving the temperature coefficient of resistance (TCR) to the plus (+) side when a thick film resistor is formed.

 The content of bismuth oxide in the glass frit is from 1% by mass to 5% by mass. When the content of bismuth oxide in the glass frit is 1% by mass or more, the effect of moving the TCR to the plus (+) side can be sufficiently exhibited. If the content of bismuth oxide in the glass frit exceeds 5% by mass, the resistance value of the obtained thick-film resistor becomes too low, which is not preferable.

The other glass components in the glass frit constituting the composition for a thick film resistor of the present invention are not particularly limited, but in particular, alkaline earth zinc aluminoborosilicate glass (SiO ₂ —B ₂ O _{3) -RO-ZnO-Al 2 O 3} : R is Ca, Sr, and if at least one) selected from Ba, bismuth oxide _(Bi 2 _{O 3)} 1 mass or more and 5 mass% or less of the other, 30 mass% or more and 50 mass% or less of silicon oxide (SiO ₂ ), 10 mass% or more and 25 mass% or less of boron oxide (B ₂ O ₃ ), and alkaline earth metal oxide (RO: R is Ca, Sr, and at least one) of a 15% by weight 5% or more by mass or less is selected from Ba, 30 wt% to 10 wt% of zinc oxide (ZnO) or less, alumina _(Al 2 _{O 3)} 2 mass% or more 6 wt% Lower, alkali metal oxides _(R 2 O: _R is Li, Na, and at least one selected from K) that is preferred to use a glass frit containing more than 10 wt%.

In the composition for a thick film resistor according to the present invention, borosilicate glass (SiO ₂ -B ₂ O ₃ ), aluminoborosilicate glass (SiO ₂ -B ₂ O ₃ -Al ₂ O ₃ ), or borosilicate glass alkaline earth glass _{(SiO 2 -B 2 O 3 -RO} : R is Ca, Sr, and at least one selected from Ba), to 1 mass or more of bismuth oxide _(Bi 2 _{O 3)} 5 wt% Hereinafter, the added glass frit can also be suitably used.

  The average particle size of the glass frit constituting the composition for a thick film resistor of the present invention is preferably 5 μm or less, and more preferably 1 μm or more and 3 μm or less in D50 (median diameter) measured by a laser diffraction type particle size distribution measurement. More preferably, there is. If the particle size of the glass frit is small, the conductive path in the thick film resistor can be made fine, so that the variation in the resistance value of the thick film resistor and the current noise can be suppressed. In order to obtain a glass frit having a desired average particle size, the melted and cooled glass frit may be ground using a known grinding method such as a ball mill or a jet mill.

  In the glass frit constituting the composition for a thick film resistor of the present invention, the softening point of the glass is preferably in a range of 550 ° C or more and 750 ° C or less, more preferably in a range of 600 ° C or more and 700 ° C or less. preferable. If the softening point of the glass is lower than 550 ° C., the glass frit will be excessively melted when the thick film resistor paste is fired to form the resistor, and the pattern of the resistor will be lost. On the other hand, when the softening point of the glass is higher than 750 ° C., the glass frit becomes difficult to melt and becomes less compatible (wet) with the conductive powder, so that the current noise of the obtained thick film resistor increases.

  Here, the softening point is determined by measuring the temperature of the glass in the air by differential thermal analysis at 5 ° C./min or more and 20 ° C./min or less, and the lowest differential heat curve of the obtained differential heat curve. Is the temperature of the peak at which the next differential thermal curve on the higher temperature side than the temperature at which the decrease occurs appears.

In the glass frit constituting the composition for a thick-film resistor of the present invention, the thermal expansion coefficient of the glass is preferably in a range of 40 × 10 ⁻⁷ / K or more and 100 × 10 ⁻⁷ / K or less, and 50 × 10 ⁻⁷ / K or less. More preferably, it is in the range of 10 ⁻⁷ / K or more and 90 × 10 ⁻⁷ / K or less. For example, when using an alumina substrate, by using a glass frit made of glass having a thermal expansion coefficient in this range, the thermal expansion coefficient of the obtained thick-film resistor becomes close to the thermal expansion coefficient of the alumina substrate. , Eliminating the problem of tensile stress. The coefficient of thermal expansion can be measured by molding a glass frit into a rod shape and using a thermomechanical analyzer (TMA).

  The softening point and the coefficient of thermal expansion of the glass frit can be controlled by examining the composition of the glass frit.

  The content of the glass frit in the composition for a thick film resistor is also appropriately adjusted according to the desired resistance value, the type and the particle size of the conductive powder and the glass frit in the obtained thick film resistor. For example, when obtaining a high-resistance resistor having an area resistance value of 5 kΩ or more, the content of the glass frit is usually 70% by mass or more and 95% by mass or less according to the content of the conductive powder.

[Optional components]
In the composition for a thick film resistor of the present invention, titanium oxide (TiO ₂ ) or niobium oxide (Nb ₂ O ₅ ) can be added in addition to the conductive powder and the glass frit. In particular, titanium oxide (TiO ₂ ) and niobium oxide (Nb ₂ O ₅ ) have an effect of reducing current noise, but have a problem of moving the TCR to the minus (−) side. In the composition for a thick film resistor according to the present invention, the amount of titanium oxide (TiO ₂ ) or niobium oxide (Nb ₂ O ₅ ) is reduced by adding bismuth oxide in an amount of 1% by mass to 5% by mass in a glass frit. It is possible to reduce the current noise while keeping the TCR close to zero.

In addition, for example, for the purpose of adjusting electrical properties such as sheet resistance and resistance temperature coefficient, adjusting expansion coefficient, improving withstand voltage, and other modifications, the composition for a thick film resistor of the present invention is used. In addition to the conductive powder and the glass frit, inorganic components such as tin oxide (SnO ₂ ), tantalum oxide (Ta ₂ O ₅ ), and copper oxide (Cu ₂ O, CuO) can be appropriately contained.

  The content of these inorganic components is generally in the range of 0.05% by mass to 10% by mass with respect to the total mass of the conductive powder and the glass frit.

(2) Paste for thick-film resistor The paste for thick-film resistor of the present invention comprises a composition for a thick-film resistor and an organic vehicle. It is characterized in that a composition for a film resistor is used. Specifically, the paste for a thick film resistor of the present invention is composed of a kneaded product of the composition for a thick film resistor of the present invention and an organic vehicle. Hereinafter, the details will be described.

[Organic vehicle]
The organic vehicle constituting the paste for a thick-film resistor is composed of at least a resin and a solvent.

  Examples of the resin that can be used as the organic vehicle include an ethyl cellulose resin, a butyral resin (polyvinyl butyral), and an acrylic resin. These resins are preferably resins that decompose at a temperature before the glass is softened. More preferably, a resin that decomposes at a temperature of 500 ° C. or less is preferable.

  As a solvent for dissolving the resin, terpineol, butyl carbitol, butyl carbitol acetate and the like can be used.

  The compounding ratio of the resin and the solvent of the organic vehicle prepared with the resin and the solvent can be appropriately adjusted depending on the desired viscosity and use.

  In addition, a plasticizer having a high boiling point can be further added from the viewpoint of controlling the drying speed of the paste in consideration of the continuous printability required for the thick film resistor paste. In this case, the mixing ratio of the plasticizer can also be appropriately adjusted according to the desired drying speed.

  The ratio of the organic vehicle to the thick film resistor paste is not particularly limited, but is generally 30% by mass or more and 50% by mass or less based on the mass of the thick film resistor paste.

[Other ingredients]
The paste for a thick film resistor of the present invention may contain additives in addition to the composition for a thick film resistor and an organic vehicle. For example, a dispersant can be included from the viewpoint of preventing aggregation of the conductive powder and other inorganic components. Further, from the viewpoint of application workability, a rheology control agent can be included.

[Method of preparing paste for thick film resistor]
The paste for the thick-film resistor may be prepared by a known technique, for example, a three-roll mill or a ball mill.

  In the paste for a thick film resistor, it is desirable to disperse the conductive powder, glass frit, and other inorganic components, and to disperse them in an organic vehicle.

(3) Thick film resistor The thick film resistor of the present invention comprises a fired body containing a conductive component and a glass component, wherein the conductive component is ruthenium dioxide, calcium ruthenate, strontium ruthenate, and barium ruthenate. And the glass component is substantially free of lead and contains bismuth oxide in an amount of 1% by mass to 5% by mass. That is, the thick-film resistor of the present invention is formed by using the thick-film resistor paste of the present invention, and is constituted by a fired body containing the thick-film resistor composition of the present invention.

  Therefore, the conductive component has the same composition as the conductive powder constituting the composition for a thick film resistor of the present invention, and the glass component has the same composition as the glass frit constituting the composition for a thick film resistor of the present invention. The composition becomes Therefore, description of the conductive component and the glass component is omitted here.

  Hereinafter, a method of manufacturing the thick film resistor will be described. The resistance value of the thick film resistor can be appropriately adjusted by the ratio of the conductive powder and the glass frit in the thick film resistor.

[Method of manufacturing thick film resistor]
The method of manufacturing the thick film resistor of the present invention is not limited to the following content, and the processing conditions and the like can be appropriately changed using known means and methods.

  First, an application step of applying the thick film resistor paste to the substrate is performed. That is, an electrode made of silver (Ag), palladium (Pd), or the like is formed on a ceramic substrate such as alumina, and the thick film resistor paste of the present invention is applied thereon by means such as screen printing.

  Next, a firing step of firing the substrate coated with the thick film resistor paste is performed to produce a thick film resistor. Specifically, in the coating step, the paste for a thick-film resistor applied to the substrate is dried using an oven or the like, and then fired using a belt furnace or the like, so that the conductive component and the glass component To obtain a fired body containing Basically, components other than the conductive powder and the glass frit included in the paste for the thick film resistor, that is, the resin and the solvent constituting the organic vehicle, and the addition of other organic substances The agent is completely decomposed through a firing step.

  Through the steps described above, the thick film resistor of the present invention is obtained.

  According to the thick film resistor of the present invention, ruthenium dioxide, calcium ruthenate, strontium ruthenate, and a conductive component containing at least one selected from barium ruthenate, and substantially free of lead, and At least 1% by mass to 5% by mass of bismuth oxide. Therefore, a thick-film resistor that does not contain lead, has a high resistance value, has low current noise, and has good electrical characteristics is provided.

The thick film resistor of the present invention can contain titanium oxide (TiO ₂ ) and niobium oxide (Nb ₂ O ₅ ) in addition to the conductive component and the glass component.

  In the above, the present invention has been described mainly using specific embodiments, and the best configuration and method for carrying out the present invention have been disclosed. However, the present invention is not limited to these. Without departing from the scope of the technical idea and the purpose of the present invention, those skilled in the art may omit, add, change, or modify the above-described embodiment in terms of shape, material, quantity, and other detailed configurations. Additions are possible, and these are also included in the scope of the present invention.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples of the present invention. However, the present invention is not limited by the following examples.

[Preparation of composition for thick film resistor]
(Conductive powder)
Ruthenium dioxide was produced by roasting ruthenium hydroxide in air at 800 ° C. for 2 hours. Its BET average particle size was 0.050 μm.

  Other conductive powders were prepared by mixing ruthenium dioxide with calcium hydroxide, strontium hydroxide, or barium carbonate, and baking the resulting mixture at 800 ° C. for 2 hours. Thereafter, the particle size was adjusted by crushing. Regarding each BET average particle size, calcium ruthenate was 0.054 μm, strontium ruthenate was 0.059 μm, and barium ruthenate was 0.058 μm.

(Glass frit)
Table 1 shows the compositions of seven types (a to g) of glass frit used in Examples and Comparative Examples of the present invention. The glass frit was made through the usual steps of mixing, melting, quenching, and grinding. In the pulverizing step, each glass frit was pulverized until the particle diameter became 2 μm or less (1.2 μm to 1.7 μm) in D50 (median diameter) by laser diffraction type particle size distribution measurement.

(Organic vehicle)
A solution obtained by dissolving ethyl cellulose in terpineol was used as the organic vehicle. The mixing ratio was 1: 9 for ethyl cellulose: terpineol.

[Preparation of paste for thick film resistor]
The target film thickness and area resistance value of the thick film resistor after firing were set to 7 μm to 9 μm and 10 kΩ (± 15%), respectively, and were described as Examples 1 to 13 and Comparative Examples 1 to 6. The composition for a thick film resistor containing the conductive powder, the glass frit, and the titanium oxide as an inorganic component in the proportions shown in Table 2 and an organic vehicle were mixed in the proportions shown in Table 2, and 3 The mixture was kneaded by this roll mill to prepare a thick film resistor resistor paste.

[Production of thick film resistor]
For each of Examples 1 to 13 and Comparative Examples 1 to 6, the paste for a thick film resistor produced as described above was formed on an alumina substrate on which electrodes were previously formed using an AgPd paste. The paste was applied by screen printing to a size of 1 mm and the distance between the electrodes was 1 mm (1 mm × 1 mm), and then the paste for a thick film resistor applied to the substrate was dried at 150 ° C. for 10 minutes using an oven. Thereafter, the thick film resistors shown in Table 2 were prepared by firing using a belt firing furnace under the conditions of a peak temperature of 850 ° C., a peak time of 9 minutes, and a total firing time of 30 minutes. did.

[Evaluation of thick film resistor]
In order to evaluate the electrical characteristics of the thick film resistors manufactured in the respective examples and comparative examples, the area resistance, the temperature coefficient of resistance (TCR), and the current noise of each thick film resistor were measured as follows. did.

(Area resistance value)
The sheet resistance of the thick film resistor was measured by a four-terminal method using a multimeter (manufactured by Keithley, Model 2001).

(Temperature coefficient of resistance)
The temperature coefficient of resistance was calculated as follows.

High temperature resistance temperature coefficient (HTCR) = [(R ₁₂₅ −R ₂₅ ) / R ₂₅ (125-25)] × 10 ⁶ (ppm / ° C.)

Temperature coefficient of low temperature resistance (CTCR) = [(R− ₅₅₋ R ₂₅ ) / R ₂₅ (−55−25)] × 10 ⁶ (ppm / ° C.)

Here, R ₂₅ is a resistance value at 25 ° C., R ₁₂₅ is a resistance value at 125 ° C., and R ₋₅₅ is a resistance value at −55 ° C.

(Current noise)
The current noise was measured using a noise meter (Model 315C, manufactured by Quant-Tech) at an application of 1/10 W.

  Table 3 shows the measurement results of the sheet resistance, the temperature coefficient of resistance, and the current noise for Examples 1 to 13 and Comparative Examples 1 to 6.

[Discussion]
More thick film resistor containing a glass component from the electrical characteristics of the fabricated thick film resistor in the examples and comparative examples including bismuth oxide (Bi 2 _{O 3)} of the present invention (Examples 1 to 13 In comparison with Comparative Examples 1 to 6 in which bismuth oxide was not contained in the glass component, the sheet resistance was 10 kΩ ± 15%, which is the desired value, and the TCR was about the same as ± 60 ppm / ° C. or less. However, it can be understood that the current noise is sufficiently small, that is, -10 dB or less, which is excellent as a thick-film resistor. As the content of the conductive powder decreased with an increase in the current noise, the current noise increased.

Claims (12)

Including a conductive powder and a glass frit,
The conductive powder includes at least one selected from ruthenium dioxide, calcium ruthenate, strontium ruthenate, and barium ruthenate, and
The glass frit does not contain lead virtually, and contains less than 5 wt% or more 1 wt% of bismuth oxide _(Bi 2 _{O 3),}
A composition for a thick film resistor.   The composition for a thick-film resistor according to claim 1, wherein the content of the conductive powder is 5% by mass or more and 30% by mass or less.   The composition for a thick film resistor according to claim 1, wherein a softening point of the glass of the glass frit is 550 ° C. or more and 750 ° C. or less. The composition for a thick film resistor according to any one of claims 1 to 3, wherein a coefficient of thermal expansion of the glass of the glass frit is in a range of 40 × 10 ⁻⁷ / K or more and 100 × 10 ⁻⁷ / K or less. .   At least one selected from titanium oxide, niobium oxide, tin oxide and copper oxide is further contained in a range of 0.05% by mass or more and 10% by mass or less based on the total mass of the conductive powder and the glass frit. The composition for a thick-film resistor according to any one of claims 1 to 4.   A thick film comprising a composition for a thick film resistor and an organic vehicle, wherein the composition for a thick film resistor according to any one of claims 1 to 5 is used as the composition for a thick film resistor. Paste for resistor.   The paste for a thick film resistor according to claim 6, wherein the content of the organic vehicle is 30% by mass or more and 50% by mass or less based on the mass of the paste for a thick film resistor. Consisting of a fired body containing a conductive component and a glass component,
The conductive component includes at least one selected from ruthenium dioxide, calcium ruthenate, strontium ruthenate, and barium ruthenate, and
The glass component is substantially free of lead and contains bismuth oxide in an amount of 1% by mass to 5% by mass,
Thick film resistor.   The thick film resistor according to claim 8, wherein the content of the conductive component is 5% by mass or more and 30% by mass or less.   The thick film resistor according to claim 8, wherein a softening point of the glass of the glass component is 550 ° C. or more and 750 ° C. or less. The thick-film resistor according to any one of claims 8 to 10, wherein the glass of the glass component has a coefficient of thermal expansion in a range of 40 x ^10-7 / K or more and 100 x ^10-7 / K or less.   At least one selected from titanium oxide, niobium oxide, tin oxide, and copper oxide is further added in a range of 0.05% by mass or more and 10% by mass or less based on the total mass of the conductive component and the glass component. The thick film resistor according to any one of claims 8 to 11, which contains.