Thick film resistive paste, thick film resistor and electronic component

Abstract

The present invention provides a thick film resistor paste for a resistor body having a small resistance change rate and excellent surge resistance for an electronic component that is becoming smaller, a thick film resistor body using the thick film resistor paste, and an electronic component having the thick film resistor body. The solution is a thick film resistor paste for a resistor body containing a glass powder and an organic vehicle, the glass powder containing a conductive substance composed of ruthenium oxide and lead ruthenate, the conductive substance-containing glass powder containing 10 mass% or more and 70 mass% or less of the conductive substance, and, in the glass composition, 3 mass% or more and 60 mass% or less of silicon oxide, 30 mass% or more and 90 mass% or less of lead oxide, and 5 mass% or more and 50 mass% or less of boron oxide, relative to 100 mass% of the glass component, and the total content of the silicon oxide, the lead oxide, and the boron oxide is 50 mass% or more, relative to 100 mass% of the glass component.

Description

Technical Field

[0001] This invention relates to thick film resistive paste, and more specifically, to thick film resistive paste containing glass powder with ruthenium oxide and lead ruthenate as conductive materials, which can be used to form thick film resistors with excellent surge resistance, thick film resistors using the thick film resistive paste, and electronic components having the thick film resistors. Background Technology

[0002] Thick-film resistor paste typically consists of conductive powder, glass powder, and an organic vehicle that forms the paste suitable for printing. This thick-film resistor paste is printed in any pattern, and the glass is sintered at a high temperature, typically 800–1000°C. This allows it to be used, for example, as a thick-film resistor in electronic components such as thick-film chip resistors. Since the resistance value can be gradually changed by adjusting the mixing ratio with the glass powder, ruthenium oxide powder and lead ruthenate powder are widely used as conductive powders.

[0003] For example, Patent Document 1 describes a technique for obtaining a resistive paste by adding a carrier using ethyl cellulose as a binder and toluene and ethanol as solvents to a mixture of mullite as inorganic particles, lead borosilicate glass as glass particles, and ruthenium dioxide as conductive particles, and then using the resistive paste to form a thick film resistor.

[0004] Furthermore, Patent Document 2 describes a technique for obtaining a resistive paste by adding a carrier using ethyl cellulose as a binder and terpineol and butyl carbitol acetate as solvents to a mixture of zircon as inorganic particles, lead borosilicate glass as glass particles, and ruthenium dioxide as conductive particles, and a thick film resistor formed using the resistive paste.

[0005] In recent years, with the miniaturization of electronic components such as thick-film chip resistors, there is a demand for improved electrical performance of thick-film resistors, especially those with excellent surge resistance and voltage withstand capabilities. When a sudden high voltage (surge voltage) is applied to a thick-film resistor, it typically exhibits a negative resistance change, but the smaller this change, the better. This negative resistance change is attributed to the heat generated during voltage application. In existing thick-film resistor pastes, glass powders bond together during sintering, but the softening of the glass powders is limited to the surface layer. Therefore, in the thick-film resistor after sintering the thick-film resistor paste, a dielectric layer corresponding to the glass particle size exists. Conductive powder is distributed around this dielectric layer, giving the thick-film resistor conductivity. When a surge voltage is applied to such a structure, it is assumed that current flows through the conductive portion, causing localized heating of the periphery and a change in resistance.

[0006] One method to improve the surge resistance of thick-film resistors is to increase the amount of lead ruthenate in the thick-film resistor paste. Increasing the amount of lead ruthenate in the thick-film resistor paste is believed to create a strong conductive portion with a thick conductive path in the thick-film resistor after sintering, thereby suppressing heat generation when surge voltage is applied and mitigating the impact of resistance changes.

[0007] However, increasing the amount of lead ruthenate leads to an increase in the temperature coefficient of resistance (TCR). TCR represents the rate of change of resistance per unit temperature and is one of the important characteristics of thick-film resistors. When increasing the amount of lead ruthenate to increase the TCR, even if the resistance change caused by heat generation when applying surge voltage is suppressed, the resistance of the conductive part itself will still change.

[0008] Therefore, when increasing the amount of lead ruthenate, it is necessary to bring the TCR close to 0. This TCR can be adjusted by adding additives mainly composed of metal oxides to the thick-film resistor; examples of metal oxides include manganese oxide, niobium oxide, and titanium oxide. However, since the adjustment range of additives is limited, the amount of lead ruthenate that can be increased is also limited.

[0009] Another way to improve the surge resistance of thick-film resistors is to make the distribution of conductors in the thick-film resistor more uniform. When the conductors are uniformly distributed, the current will flow evenly through the resistor when a surge voltage is applied, thereby reducing the impact of localized heat generation.

[0010] Existing technical documents

[0011] Patent documents

[0012] Patent Document 1: Japanese Patent Application Publication No. 4-320003

[0013] Patent Document 2: Japanese Patent Application Publication No. 6-163202 Summary of the Invention

[0014] The problem that the invention aims to solve

[0015] However, in recent years, the increasingly miniaturized electronic components have required thick-film resistors with higher surge resistance.

[0016] The purpose of this invention is to provide a thick-film resistor paste for a resistor with a small resistance change rate and excellent surge resistance, a thick-film resistor using the thick-film resistor paste, and an electronic component having the thick-film resistor for electronic components that are becoming increasingly miniaturized.

[0017] Methods for solving problems

[0018] Through various research results, the inventors discovered that when a thick-film resistor is formed by using a thick-film resistive paste containing conductive glass with ruthenium oxide and lead ruthenate, which is composed of a specific composition, it has superior surge resistance compared to the past, thus leading to and completing this invention.

[0019] That is, the thick film resistive paste of the present invention is characterized by containing glass powder and an organic carrier, wherein the glass powder contains a conductive material composed of ruthenium oxide and lead ruthenate, the aforementioned conductive glass powder contains 10% by mass or more and 70% by mass or less of the conductive material, and the glass composition contains, relative to 100% by mass, 3% by mass or more and 60% by mass of silicon oxide, 30% by mass or more and 90% by mass of lead oxide, and 5% by mass or more and 50% by mass of boron oxide, and the total content of silicon oxide, lead oxide and boron oxide is 50% by mass or more relative to 100% by mass of the glass composition.

[0020] Furthermore, in the thick film resistive paste of the present invention, the average particle size of the aforementioned conductive glass powder is preferably 5 μm or less.

[0021] Furthermore, the thick film resistor of the present invention is characterized in that it is formed from a sintered body of any of the thick film resistor pastes of the present invention described above.

[0022] Furthermore, the electronic component of the present invention is characterized by having the thick film resistor described above.

[0023] Invention Effects

[0024] According to the present invention, a thick-film resistor paste having superior surge protection performance compared to the past, a thick-film resistor using the thick-film resistor paste, and an electronic component having the thick-film resistor can be provided. Detailed Implementation

[0025] The embodiments of the present invention will be described below, but the present invention is not limited to the embodiments described below. Various modifications and substitutions can be added to the embodiments described below within the scope of the present invention.

[0026] The thick-film resistive paste of this embodiment contains glass powder and an organic carrier. The glass powder contains a conductive material formed from ruthenium oxide and lead ruthenate. The components are described in detail below.

[0027] (Conductive material)

[0028] The conductive material in the thick-film resistive paste of the present invention is a mixed conductive material composed of ruthenium oxide and lead ruthenate. Conventional thick-film resistive pastes contain the conductive material and glass separately in powder form. However, in the thick-film resistive paste of the present invention, the conductive material is not used alone; instead, a structure containing conductive glass powder is formed. This conductive glass powder is obtained by using a mixed conductive material composed of ruthenium oxide powder and lead ruthenate powder as a conductive material as part of the raw material to produce conductive glass, which is then pulverized.

[0029] There is no particular limitation on the particle size of lead ruthenate used in forming conductive glass powder, but a particle size of 5 μm is preferred. 2 Particle sizes with a specific surface area of ​​≥ 5 m² / g are preferred. 2 When the particle size of lead ruthenate is too large, the uniformity of the conductive area in the thick film resistor will be reduced, and the surge protection performance may be deteriorated.

[0030] There is no particular limitation on the particle size of ruthenium oxide used in forming conductive glass powder, but a particle size of 20 μm is preferred. 2 Particle sizes with a specific surface area of ​​≥ 20 m² / g are preferred. 2 When the ruthenium oxide particle size is too large, the uniformity within the thick film resistor will decrease, and the surge protection performance may deteriorate.

[0031] (Glass composition)

[0032] The conductive glass in the thick-film resistive paste of the present invention contains silicon oxide (SiO2), lead oxide (PbO), and boron oxide (B2O3). In addition, it may also contain magnesium oxide (MgO), calcium oxide (CaO), barium oxide (BaO), strontium oxide (SrO), cadmium oxide (CdO), tin oxide (SnO), zinc oxide (ZnO), bismuth oxide (Bi2O3), etc. Furthermore, it may also contain aluminum oxide (Al2O3).

[0033] (Silicon oxide: SiO2)

[0034] SiO2 is a component constituting the framework of the glass composition of the present invention, and its amount is 3% by mass or more and 60% by mass or less relative to 100% by mass of the glass composition contained in the conductive glass. When it is greater than 60% by mass, the softening point of the formed glass becomes too high. Furthermore, when it is less than 3% by mass, a chemically stable glass cannot be obtained.

[0035] (Lead oxide: PbO)

[0036] In addition to lowering the softening point and promoting wetting and dispersibility with ruthenium oxide, PbO also chemically stabilizes lead ruthenate and inhibits its decomposition. Its concentration should be between 30% and 90% by mass relative to 100% of the glass composition in the conductive glass. Below 30% by mass, the softening point of the resulting glass becomes excessively high. Furthermore, above 90% by mass, it is difficult to obtain a chemically stable glass state.

[0037] (Boron oxide: B2O3)

[0038] Both B2O3 and SiO2 are components that form the framework of the glass composition of this invention, and have the effect of lowering the softening point of the formed glass. Their proportions are 5% by mass or more and 50% by mass or less relative to 100% by mass of the glass composition contained in the conductive glass. When the proportion is less than 5% by mass, the toughness of the formed glass decreases, making it prone to cracking, and the laser trimming properties deteriorate. Furthermore, when the proportion is greater than 50% by mass, phase separation of the glass composition is more likely to occur, and the water resistance also decreases.

[0039] (Total content of essential glass components)

[0040] The total content of SiO2, PbO, and B2O3 is 50% by mass or more relative to 100% by mass of the glass composition in the conductive glass. If it is less than 50% by mass, it is difficult to form a stable glass, and it is difficult to meet the surge resistance performance of the thick film resistor in this invention.

[0041] (Other glass components)

[0042] In addition to the essential glass components mentioned above, to enhance various properties without degrading the properties of the conductive glass, oxides may be further included as glass components. Specifically, Al₂O₃, MgO, CaO, BaO, SrO, CdO, SnO, ZnO, Bi₂O₃, etc., may be included. The amount of these glass components is 20% by mass or less relative to 100% by mass of the glass components contained in the conductive glass.

[0043] (Conductive glass)

[0044] In the conductive glass used in the thick-film resistive paste of the present invention, the ratio of conductive material to glass component is such that, relative to 100% by mass of the conductive glass component, the conductive material is 10% by mass or more and 70% by mass or less, and the glass component is 30% by mass or more and 90% by mass or less. If the conductive material is less than 10% by mass, the resistivity of the manufactured conductive glass powder becomes too high, exhibiting almost no conductivity. Furthermore, if it is greater than 70% by mass, the glass component cannot completely cover the conductive powder, and the conductive glass becomes brittle. By adjusting the ratio of conductive material to glass component, the resistance value of the thick-film resistor can be adjusted to be close to the target resistance value. By changing the ratio of ruthenium oxide to lead ruthenate, the resistance value and TCR can be adjusted more precisely. Since there are limitations to the adjustment range of TCR, it is necessary to adjust the ratio of ruthenium oxide to lead ruthenate to obtain the desired TCR.

[0045] The conductive glass is pulverized to an average particle size of less than 5 μm. If the average particle size is greater than 5 μm, the uniformity of the thick-film resistor decreases, and the effect of improving surge resistance may not be achieved, thus the result is unsatisfactory. Ball mills, planetary mills, and bead mills can be used as pulverizing methods.

[0046] It should be noted that in this invention, the average particle size refers to the median particle size, which is the value measured by ultrasonically dispersing the powder to be tested in a sodium hexametaphosphate aqueous solution (2 g / L) using a particle size analyzer (HPA9320-100X, manufactured by Micro TrackBell) with pure water solvent.

[0047] (Other additives)

[0048] In the thick-film resistive paste of the present invention, for the purpose of adjusting and improving the resistivity, TCR, and other properties of the thick-film resistive body, borosilicate glass without conductive materials and commonly used additives may be further included. Furthermore, to improve dispersibility, a dispersant may be included as an additive. Examples of main additives include niobium oxide (Nb₂O₅), tantalum oxide (Ta₂O₅), titanium oxide (TiO₂), copper oxide (CuO), manganese oxide (MnO₂), zirconium oxide (ZrO₂), and aluminum oxide (Al₂O₃). The content of the additives can be adjusted according to the desired improved properties, and is preferably 10% by mass or less out of 100% by mass of the total inorganic matter.

[0049] (Organic carrier)

[0050] The organic carrier used in the thick-film resistive paste of the present invention is not particularly limited, and can be a substance commonly used in resistive pastes, which is made by dissolving resins such as ethyl cellulose and rosin in solvents such as terpineol. The amount of organic carrier can be adjusted appropriately according to the printing method, etc., and is usually 20% to 50% by mass relative to 100% of the total amount of resistive paste.

[0051] (Manufacturing method of thick film resistor paste)

[0052] There are no particular restrictions on the method of manufacturing thick film resistive paste by mixing conductive glass and organic carrier, and adding lead borosilicate glass powder and additives as needed. Common three-roll mills, bead mills, etc. can be used.

[0053] (Manufacturing method of thick film resistors)

[0054] The obtained thick film resistor paste is printed on a ceramic substrate, and after the organic solvent is removed by drying, a thick film resistor can be obtained by firing at a temperature of, for example, 800°C to 900°C.

[0055] Example

[0056] The present invention will be further described below based on detailed embodiments, but the present invention is not limited to these embodiments.

[0057] (Evaluation of a 1kΩ resistivity element in Example 1)

[0058] A conductive glass was produced by mixing and melting glass materials in a ratio of 48% by mass, ruthenium oxide in a ratio of 2% by mass, and lead ruthenate in a ratio of 50% by mass, followed by cooling. The composition of the conductive glass produced was as follows, relative to 100% by mass of the glass composition: SiO2 33% by mass, PbO 46% by mass, Al2O3 5% by mass, B2O3 7% by mass, ZnO 3% by mass, and CaO 6% by mass.

[0059] The obtained conductive glass was pulverized using a ball mill to an average particle size of approximately 1 μm. A thick-film resistor composition comprising 59% by mass of conductive glass powder, 1% by mass of Nb₂O₅ as an additive, and the remainder being an organic carrier was mixed using a three-roll mill to disperse the various inorganic materials within the organic carrier, thus preparing the thick-film resistor paste of Example 1. It should be noted that the organic carrier was a substance obtained by dissolving 20 parts by mass of ethyl cellulose in 100 parts by mass of terpineol. The composition of the thick-film resistor paste of Example 1 and the composition of the conductive glass used in the manufacture of the thick-film resistor paste are shown in Table 1.

[0060] <Evaluation Experiment>

[0061] (Preparation of evaluation samples)

[0062] Thick-film resistive paste was printed to a width of 1.0 mm between five pairs of electrodes spaced 1.0 mm apart on an alumina substrate and dried in a belt furnace at a peak temperature of 150°C for 5 minutes. Then, it was fired in a belt furnace at a peak temperature of 850°C for 9 minutes. Five samples with the same treatment were prepared per alumina substrate to obtain thick-film resistive bodies for evaluation (a total of 25).

[0063] (Film thickness measurement)

[0064] For film thickness, a stylus-type surface roughness meter was used to select any one of the evaluation samples, taking the alumina substrate as the unit, and the film thickness of 5 thick film resistors was measured. The average value of these 5 samples was taken as the actual measured film thickness.

[0065] (Converting area resistivity)

[0066] The resistance values ​​at 25°C of 5 evaluation samples (a total of 25 samples) formed on 5 alumina substrates were measured using a circuit meter (2001 MULTIMETER, manufactured by Keithley Corporation), and the average value was taken as the actual measured resistance value. The equivalent area resistivity value for a film thickness of 7 μm was calculated using the following formula (1). The calculated equivalent area resistivity values ​​are shown in Table 3.

[0067] Converted area resistivity (kΩ) = Actual measured resistance (kΩ) × (Actual measured film thickness (μm) / 7 (μm)) ···(1)

[0068] (Temperature resistance temperature coefficient: High-temperature TCR)

[0069] For five thick-film resistivity elements of an evaluation sample formed on a single alumina substrate, their resistance values ​​were measured after being held at 25°C and 125°C for 30 minutes in a constant temperature bath. The measured resistance values ​​were used as R0. 25 R 125 The high-temperature TCR was calculated using the following formula (2). The average high-temperature TCR of the five samples is shown in Table 3.

[0070] High-temperature TCR (ppm / ℃) = [(R 125 -R 25 ) / R 25 ] / (100)×10 6 …(2)

[0071] (Evaluation of resistance)

[0072] A glass paste was prepared by dispersing a glass material containing 30% by mass SiO2, 55% by mass PbO, 5% by mass Al2O3, and 10% by mass B2O3 in an organic carrier with the same composition as used in Example 1, and then mixing it using a three-roll mill. The glass paste was coated onto a thick-film resistor covering the evaluation sample and dried in a belt furnace at a peak temperature of 150°C for 5 minutes. After that, it was fired in a belt furnace at a peak temperature of 600°C for 5 minutes. The resistance value of the thick-film resistor covered with the glass paste was set as the initial resistance value Rs(t), and laser trimming was performed using a laser trimming device (SL432R, manufactured by OMRON Laserfront) so that the resistance value became 1.5 times Rs(t). The laser trimming conditions were linear cutting, cutting speed of 100 mm / sec, laser intensity of 2 W, and Q rate of 6 kHz. The resistance value after trimming was set as Re(t), and the ratio of the resistance value deviation before and after trimming was calculated using the following formula (3).

[0073] Resistance deviation (%) = (Re(t) - 1.5 × Rs(t)) / Rs(t) × 100…(3)

[0074] If any one of the five thick-film resistors has a resistance value deviation of more than 1%, the resistance adjustment performance is marked as "×". If all resistance value deviations are less than 1%, the performance is marked as "〇". The evaluation results are shown in Table 3.

[0075] (Evaluation of surge resistance performance: rate of change of resistance value)

[0076] When the resistance rating is "0", an electrostatic discharge test is performed on the thick-film resistor of the evaluation sample using a semiconductor electrostatic tester (ESS-6008, manufactured by Noise Research Institute) with a voltage applied under the conditions of a 200pF capacitance and a 0Ω internal resistance. A 5kV voltage is applied to the thick-film resistor of the evaluation sample five times at 1-second intervals. The resistance value Rs before voltage application and the resistance value Re after voltage application are measured, and the rate of change of resistance value is calculated using the following formula (4). The average value of the calculated resistance change rates of the five samples is shown in Table 3.

[0077] Resistance change rate (%) = (Re - Rs) / Rs × 100…(4)

[0078] (Examples 2-12)

[0079] Glass materials, ruthenium oxide, and lead ruthenate were mixed and melted in the proportions shown in Table 1, and then cooled to produce conductive glass. The contents of SiO2, PbO, Al2O3, B2O3, ZnO, and CaO, relative to 100% by mass of the glass composition, in the produced conductive glasses are shown in Table 1.

[0080] The conductive glass powders obtained by ball milling were made to achieve the average particle size values ​​shown in Table 1. A thick-film resistor composition containing conductive glass powder, additives, and an organic carrier in the proportions shown in Table 1 was mixed using a three-roll mill to disperse the various inorganic materials within the organic carrier, thus preparing the thick-film resistor pastes of Examples 2-12. The organic carrier had the same composition as that used in Example 1.

[0081] Furthermore, thick-film resistivity samples for evaluation were prepared using the same method as in Example 1, and the same evaluation was performed as in Example 1. The evaluation results are shown in Table 3.

[0082] (Comparative Example 1)

[0083] Thick-film resistive paste is prepared using existing manufacturing methods, in which conductive materials and glass are added in powder form, without using glass containing conductive materials. However, when ruthenium oxide powder, lead ruthenate powder, and glass powder are added instead of using conductive glass powder obtained by crushing glass containing conductive materials, differences in electrical resistance (TCR) and other properties occur if the resistivity is adjusted to suit the thick-film resistive paste. Therefore, in Comparative Example 1 prepared by existing manufacturing methods, the proportions of ruthenium oxide powder, lead ruthenate powder, and glass added as conductive materials were changed to adjust the TCR and other properties. That is, a thick-film resistive composition containing 6% by mass of ruthenium oxide powder, 17% by mass of lead ruthenate powder, 36% by mass of glass powder, 1% by mass of Nb2O5 as an additive, and the remainder being an organic carrier was prepared. The various inorganic materials were dispersed in the organic carrier by mixing using a three-roll mill to produce the thick-film resistive paste of Comparative Example 1. The glass composition within the prepared thick-film resistive paste is as follows, relative to 100% by mass: SiO2 33% by mass, PbO 47% by mass, Al2O3 5% by mass, B2O3 7% by mass, ZnO 3% by mass, and CaO 5% by mass. The organic carrier has the same composition as that used in Example 1. The composition of the thick-film resistive paste of Comparative Example 1 and the composition of the glass used in the manufacture of the thick-film resistive paste are shown in Table 2.

[0084] Furthermore, thick-film resistivity samples for evaluation were prepared using the same method as in Example 1, and the same evaluation was performed as in Example 1. The evaluation results are shown in Table 3.

[0085] (Comparative Example 2)

[0086] A conductive glass is produced by mixing and melting glass in a ratio of 70% by mass, ruthenium oxide in a ratio of 5% by mass, and lead ruthenate in a ratio of 25% by mass, followed by cooling. The composition of the conductive glass is as follows: relative to 100% by mass of the glass composition, SiO2 is 30% by mass, PbO is 65% by mass, Al2O3 is 2% by mass, and B2O3 is 3% by mass.

[0087] The obtained conductive glass was pulverized using a ball mill to an average particle size of approximately 1 μm. A thick-film resistor composition comprising 69% by mass of the conductive glass powder, 2% by mass of Mn₂O₃ as an additive, and the remainder being an organic carrier was mixed using a three-roll mill to disperse the various inorganic materials within the organic carrier, thus preparing the thick-film resistor paste of Comparative Example 2. The organic carrier had the same composition as that used in Example 1.

[0088] Furthermore, thick-film resistivity samples for evaluation were prepared using the same method as in Example 1, and the same evaluation was performed as in Example 1. The evaluation results are shown in Table 3.

[0089] (Comparative Examples 3-10)

[0090] Glass materials, ruthenium oxide, and lead ruthenate were mixed and melted in the proportions shown in Table 1, and then cooled to produce conductive glass. The contents of SiO2, PbO, Al2O3, B2O3, ZnO, and CaO, relative to 100% by mass of the glass composition, in the produced conductive glasses are shown in Table 1.

[0091] The conductive glass powders obtained by ball milling were made to achieve the average particle size values ​​shown in Table 1. A thick-film resistor composition containing conductive glass powder, additives, and an organic carrier in the proportions shown in Table 1 was mixed using a three-roll mill to disperse the various inorganic materials in the organic carrier, thus preparing the thick-film resistor pastes of Comparative Examples 3-10. The organic carrier had the same composition as that used in Example 1.

[0092] Furthermore, thick-film resistivity samples for evaluation were prepared using the same method as in Example 1, and the same evaluation was performed as in Example 1. The evaluation results are shown in Table 3.

[0093] [Table 1]

[0094]

[0095] [Table 2]

[0096]

[0097] [Table 3]

[0098] [Table 3]

[0099]

[0100] As shown in Table 3, it was confirmed that compared with the thick film resistor of Comparative Example 1 formed by using a conventional thick film resistor paste made without conductive glass powder, the resistance change rate of the thick film resistors of Examples 1 to 12 formed by using a thick film resistor paste made with conductive glass powder was very low before and after the electrostatic discharge test, and they had excellent surge resistance performance.

[0101] Furthermore, conductive glass was prepared using a glass composition with a boron oxide content less than that required by the present invention, and thick film resistive paste obtained by using the conductive glass was used to form thick film resistive bodies of Comparative Examples 2, 6, 8, and 10. It was confirmed that the resistivity of the thick film resistive bodies of Comparative Examples 2, 6, 8, and 10 was insufficient and not suitable for commercialization.

[0102] Furthermore, in the thick film resistive body of Comparative Example 3 formed by using a thick film resistive paste obtained by using a conductive glass with a conductive content less than the required range of the present invention, it was confirmed that the resistance value of the conductive glass powder became too high and showed almost no conductivity.

[0103] Furthermore, in the thick film resistive body of Comparative Example 4, which was formed by using a thick film resistive paste obtained by using a conductive glass with a conductive content exceeding the scope of the present invention, it was confirmed that the rate of change of resistance value before and after the electrostatic discharge test was very high, and the surge resistance performance was poor.

[0104] Furthermore, in the thick-film resistors of Comparative Examples 5 and 7 formed by using glass components with a content of silicon oxide or lead oxide, or a total content of these essential glass components exceeding the scope of the present invention, or in the thick-film resistors of Comparative Example 9 formed by using glass components with a boron oxide content exceeding the scope of the present invention, it was confirmed that compared with the thick-film resistors of Examples 1 to 12, the rate of change of resistance value before and after the electrostatic discharge test was high, and the surge resistance performance was poor.

[0105] The above test results confirm that the thick film resistor formed using the thick film resistor paste of the present invention has excellent resistance adjustment and surge protection performance, and can be appropriately used in electronic components that have been developing towards miniaturization in recent years.

Claims

1. A thick-film resistor paste, characterized in that, It contains conductive glass powder and an organic carrier, wherein the conductive glass powder comprises a conductive material composed of ruthenium oxide and lead ruthenate. Relative to 100% by mass of the conductive glass composition, the conductive glass powder contains 10% by mass and less than 70% by mass of conductive material. Furthermore, the glass composition contains, relative to 100% by mass, 33% to 60% by mass of silicon dioxide, 30% to 90% by mass of lead oxide, and 5% to 50% by mass of boron oxide. Furthermore, relative to 100% by mass of the glass composition, the combined content of silicon oxide, lead oxide, and boron oxide is 50% by mass or more.

2. The thick film resistive paste according to claim 1, characterized in that, The average particle size of the conductive glass powder is less than 5 μm.

3. A thick film resistor formed from a sintered body of the thick film resistor paste as described in claim 1 or 2.

4. An electronic component comprising the thick-film resistor as described in claim 3.

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