JP2018092730A - Composition for resistor and resistor paste containing the same furthermore thick film resistor therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resistor composition that does not contain a lead component and has excellent characteristics that a resistance temperature coefficient is close to 0 within ±100 ppm/°C, a resistor paste, furthermore, a thick film resistor therewith.SOLUTION: A composition for resistors characterized by containing ruthenium-based conductive particles that do not contain lead and glass powder as main constituents, in which the glass powder is a powder of Si-B-Al-Ba-Zn-O system glass containing SiO, BO, AlO, BaO, and ZnO, relative to 100% by mass of the glass powder, 20% by mass or larger and 45% by mass or smaller of SiO, 5% by mass or larger and 12% by mass or smaller of BO, 5% by mass or larger and 20% by mass or smaller of AlO, 4% by mass or larger and 35% by mass or smaller of BaO, and 5% by mass or larger and 35% by mass or smaller of ZnO are contained, a sum total of these SiO, BO, AlO, BaO, and ZnO is 39% by mass or larger relative to a total of the glass powder.SELECTED DRAWING: None

Description

  The present invention relates to a resistor paste for forming a resistor used for manufacturing an electronic component such as a chip resistor, a hybrid IC, or a resistor network, a resistor composition constituting the paste, and a resistor. The present invention relates to a thick film resistor formed using a body paste.

Generally, a thick film resistor used for manufacturing an electronic component such as a chip resistor, a hybrid IC, or a resistor network is formed by printing and baking a resistor paste on a ceramic substrate. As a composition used for forming this thick film resistor, a composition mainly composed of ruthenium-based conductive particles typified by ruthenium oxide and glass powder is widely used.
The reason why these ruthenium-based conductive particles and glass powder are widely used in the composition for thick film resistors is that they can be fired in air and the resistance temperature coefficient (TCR) can be brought close to zero. In other words, it is possible to form a resistor having a wide range of resistance values.

  The resistance composition of such a ruthenium-based conductive particle and glass powder can be changed in resistance value depending on its blending ratio. That is, when the mixing ratio of the ruthenium-based conductive particles is increased, the resistance value is decreased, and when the mixing ratio of the ruthenium-based conductive particles is decreased, the resistance value is increased. By utilizing this fact, in the thick film resistor, a desired resistance value appears by adjusting the mixing ratio of the ruthenium-based conductive particles and the glass powder.

Ruthenium-based conductive particles most frequently used in thick film resistors include ruthenium oxide (RuO ₂ ) having a rutile crystal structure and lead ruthenate (Pb ₂ Ru ₂ O ₇ ) having a pyrochlore crystal structure. Is mentioned. These are all oxides showing metallic conductivity.

  On the other hand, the glass powder used for the thick film resistor is generally a glass powder having a softening point lower than the firing temperature of the resistor paste, and a glass powder containing lead oxide (PbO) is often used. It was done. The reason for this is that PbO has the effect of lowering the softening point of the glass powder, so it can be easily changed to a softening point suitable for thick film resistors over a wide range by changing the content rate, and PbO is contained. As a result, it is possible to produce glass powder with relatively high chemical durability, and high insulation and excellent voltage resistance.

By the way, in a resistor composition composed of ruthenium-based conductive particles and glass powder, if a low resistance value is desired, a large amount of ruthenium-based conductive particles and a small amount of glass powder are blended, and if a high resistance value is desired, ruthenium. The resistance value is adjusted by blending a large amount of glass powder with few conductive particles. At this time, the resistance temperature coefficient tends to be a large positive value in the low resistance region where many ruthenium-based conductive particles are blended, and the resistance temperature coefficient becomes negative in the high resistance region where there are few ruthenium-based conductive particles blended. There are easy features.
The temperature coefficient of resistance represents the rate of change of the resistance value with respect to the temperature change, and is one of the important characteristics of the resistor.

In general, various electronic components generate heat during operation, but if the resistance value changes due to heat generation, the operation of the electronic component changes, so a resistance temperature coefficient close to 0 is often required.
This resistance temperature coefficient can be adjusted by adding an additive mainly made of a metal oxide called a modifier to the resistor composition. Of these adjustments, it is relatively easy to adjust the resistance temperature coefficient to the negative side, and examples of the adjusting agent include manganese oxide, niobium oxide, and titanium oxide.
However, there is almost no regulator that adjusts the resistance temperature coefficient to a positive value, and it has been practically impossible to adjust the resistance temperature coefficient of a resistor composition having a negative resistance temperature coefficient to near zero.

Therefore, in a high resistance value region where the temperature coefficient of resistance tends to be negative, it is necessary to use a combination of conductive particles and glass powder that has a positive temperature coefficient of resistance.
Lead ruthenate (Pb ₂ Ru ₂ O ₇ ) used as such a combination has a higher specific resistance than ruthenium oxide (RuO ₂ ), and has a high resistance temperature coefficient and a positive value when a thick film resistor is formed. There is a feature to become. For this reason, in the high resistance value region, lead ruthenate (Pb ₂ Ru ₂ O ₇ ) has been frequently used as conductive particles.

Thus, a material containing a lead component in both conductive particles and glass powder has been used in a conventional resistor composition having a particularly high resistance value region.
However, the lead component is undesirable from the viewpoint of influence on the human body and pollution, and is a regulated substance under the RoHS Directive, etc., and there is a strong demand for the development of a resistor composition that does not contain lead.

As such a composition, Patent Document 1 discloses a resistor paste using calcium ruthenate, strontium ruthenate, and barium ruthenate as ruthenium-based conductive particles, and has an average particle diameter of 5 μm or more as a feature. Conductive particles having a size of 50 μm or less are used.
However, usually, when conductive particles having a large particle size are used, the formed resistor has a large current noise, and it may not be possible to obtain good load characteristics. It has a problem that it is difficult to keep it low.

  Patent Document 2 discloses a composition of bismuth ruthenate and glass powder containing bismuth as ruthenium-based conductive particles, but the resistance temperature coefficient of the resistor formed by this combination has a large negative value. Therefore, the temperature coefficient of resistance cannot be a value close to 0 within ± 100 ppm / ° C.

Patent Document 3 discloses a thick film resistor including ruthenium oxide and SiO ₂ —B ₂ O ₃ —K ₂ O glass powder, and describes that the thick film resistor does not have a negative temperature coefficient of resistance. However, since 1 part by mass or more of the alkali metal oxide is contained in the glass composition, there is a possibility that the glass insulating property and the load characteristic of the resistor are deteriorated.

  Patent Document 4 proposes a method of suppressing decomposition of ruthenium-based conductive particles not containing lead by using glass powder in which ruthenium oxide is dissolved. However, since the amount of ruthenium oxide dissolved in the glass powder is greatly affected by variations in manufacturing conditions and greatly fluctuates, there is a problem that the resistance value is not stable.

Patent Document 5 discloses a method of suppressing the decomposition of ruthenium composite oxide into ruthenium oxide by bringing the basicity of glass powder close to the basicity of ruthenium composite oxide and further precipitating a crystal phase in the glass. Proposed. This method is characterized by the presence of MSi ₂ Al ₂ O ₈ crystals (M: Ba and / or Sr) in the thick film resistor, but it is difficult to uniformly disperse such crystals. The resistance value may not be stable.

As described above, a technique related to a resistor composition not containing lead has been proposed, but a device comparable to a resistor containing lead has not yet been invented. The biggest reason for this is that lead ruthenate (Pb ₂ Ru ₂ O ₇ ), which is a conductive material containing lead, cannot be used. As described above, this lead ruthenate (Pb ₂ Ru ₂ O ₇ ) has not only a higher specific resistance than ruthenium oxide (RuO ₂ ), but also has a feature that the temperature coefficient of resistance tends to be positive.

Therefore, a technique has been proposed in which the temperature coefficient of resistance is brought close to 0 even in a high resistance region by using lanthanum oxide, compared with a thick film resistor formed using ruthenium oxide (RuO ₂ ) and conventional lead-containing glass powder. . (Patent Documents 6 to 7).
Patent Documents 6 and 7 have found that lanthanum oxide and neodymium oxide greatly increase the resistance value of a thick film resistor formed using ruthenium oxide (RuO ₂ ) and glass powder, and ruthenium oxide (RuO ₂ ). A technique has been proposed in which the resistance value is increased while increasing the blending amount, and the temperature coefficient of resistance approaches 0 even in a high resistance region.
However, Patent Documents 6 and 7 specifically describe only examples using glass powder containing lead, and thick film resistors formed using glass powder containing no lead and ruthenium oxide (RuO ₂ ). However, since the resistance value is not significantly increased by lanthanum oxide, it is very difficult to bring the temperature coefficient of resistance close to 0 in the high resistance region.

JP-A-2005-129806 JP-A-8-253342 JP 2001-196201 A JP 2003-7517 A JP 2007-103594 A JP 58-117264 A Japanese Patent Laid-Open No. 62-124164

As described above, attempts have been made to use lead-free conductive particles and glass powder, and various resistor pastes have been disclosed, but the resistors still have satisfactory characteristics in terms of practical use. The paste has not been mass-produced.
Therefore, the present invention has been made in view of such a situation, and forms a thick film resistor having excellent characteristics close to 0 with a temperature coefficient of resistance within ± 100 ppm / ° C. without containing a lead component. It is an object of the present invention to provide a resistor composition and a resistor paste, and to provide a thick film resistor using them.

In order to achieve the object, the present inventor has conducted extensive research, and as a result, in the composition for a resistor mainly composed of conductive particles not containing lead and glass powder not containing lead, the component of the glass powder is SiO. ₂ , B ₂ O ₃ , Al ₂ O ₃ , BaO, ZnO are essential, and the composition of the components is 20% by mass to 45% by mass of SiO ₂ with respect to 100% by mass of the total amount of glass powder, B ₂ O ₃ is 5% by mass to 12% by mass, Al ₂ O ₃ is 5% by mass to 20% by mass, BaO is 4% by mass to 35% by mass, and ZnO is 5% by mass to 35% by mass. , A thick film resistor having an excellent temperature coefficient of resistance close to 0 within ± 100 ppm / ° C. without containing a lead component, and a resistor composition and a resistor paste for forming the resistor Can be obtained And the present invention has been achieved.

The first aspect of the present invention includes a ruthenium-based conductive particles containing no lead, a resistance-body composition comprising a glass powder containing no lead as a major constituent, a glass powder, SiO _2, B The powder of Si—B—Al—Ba—Zn—O-based glass containing ₂ O ₃ , Al ₂ O ₃ , BaO, and ZnO, with respect to the total amount of glass powder of 100% by mass, SiO ₂ is 20% by mass or more, 45 wt% or _less, B 2 _{O 3} is 5 mass% or more, 12 wt% or less, _Al 2 _{O 3} is 5 mass% or more, 20 wt% or less, BaO is 4 mass% or more, 35 wt% or less, ZnO 5 A resistor comprising not less than 35% by mass and not more than 35% by mass, wherein the total of SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , BaO, ZnO is 39% by mass or more of the total amount of the glass powder. Composition.

  According to a second invention of the present invention, the resistor composition in the first invention further contains a lanthanum compound, and the content of the lanthanum compound is ruthenium-based conductive particles not containing lead and glass powder not containing lead. When the total content is 100 parts by mass, the composition for resistors is 0.01 to 5 parts by mass.

  A third invention of the present invention is a resistor composition, wherein the lanthanum compound in the second invention is one or two of lanthanum oxide and lanthanum hydroxide.

  According to a fourth aspect of the present invention, the mass ratio of the lead-free ruthenium-based conductive particles to the lead-free glass powder in the first to third aspects is in the range of 50:50 to 10:90. This is a resistor composition.

According to a fifth aspect of the present invention, there is provided a resistor composition, wherein the ruthenium-based conductive particles not containing lead in the first to fourth aspects are ruthenium oxide (RuO ₂ ).

According to a sixth aspect of the present invention, there is provided a composition for a resistor, wherein the specific surface area of ruthenium oxide (RuO ₂ ) in the fifth aspect is 5 m ² / g or more and 150 m ² / g or less. .

  A seventh invention of the present invention includes the resistor composition according to any one of the first to sixth inventions and an organic vehicle, and the resistor composition is substantially dispersed in the organic vehicle. This is a resistor paste.

  According to an eighth aspect of the present invention, there is provided a thick film resistor including the fired body of the resistor paste according to the seventh aspect.

  According to a ninth aspect of the present invention, there is provided the thick film resistor according to the eighth aspect, wherein the thick film resistor includes a fired body on a ceramic substrate.

According to the present invention, it is possible to obtain a thick film resistor whose resistance temperature coefficient has a value close to 0 within ± 100 ppm / ° C. in a high resistance value region where the resistance temperature coefficient has a negative value. it can.
In producing the thick film resistor, a resistor paste using a resistor composition using ruthenium oxide can be used as in the conventional case.

Prior to the description of the embodiments, the configuration of the present invention will be described.
The resistor paste is generally fired at a temperature of about 800 to 900 ° C. Generally, the softening point of the glass powder used as the raw material of the resistor paste needs to be lower than the firing temperature. In the glass powder not containing lead, SiO ₂ is used as a skeleton, and the softening point is adjusted by the type and blending amount of other metal oxides. In the present invention, B ₂ O ₃ , Al ₂ O ₃ , BaO, ZnO or the like is used as a metal oxide other than SiO ₂ .

As a result of evaluating the characteristics of the resistor obtained by firing the resistor composition comprising the glass powder and the ruthenium-based conductive particles in which the compounding ratio of these components was variously changed, in the glass powder component within a certain range, When the content of B ₂ O ₃ in the glass powder component is high, the resistance temperature coefficient of the resistor tends to be negative, and when the content of B ₂ O ₃ is low, the resistance temperature coefficient of the resistor becomes positive. I found that it tends to be.

In the resistor composition not containing lead, it is not possible to use lead ruthenate (Pb ₂ Ru ₂ O ₇ ), which is a conductive particle that makes the resistance temperature coefficient of the resistor a large positive value. Since other ruthenium-based conductive particles cannot have a large positive temperature coefficient of resistance, the composition of the glass powder component is important. If the temperature coefficient of resistance becomes too negative, it is difficult to adjust to a value near 0 of ± 100 ppm / ° C. using an additive or the like, so the temperature coefficient of resistance is ± 100 ppm / ° C. with an additive or the like. It is important to set a positive value that can be adjusted to a value near 0. As a result of extensive studies by the present inventors, as a result of using a SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —BaO—ZnO-based glass powder as a component of the lead-free glass powder, a resistance temperature coefficient is obtained. It was found that it was possible to adjust to an appropriate softening point while having a positive value, and also had chemical stability.
Hereinafter, the constituent member of the present invention, its form, and the like will be described in detail.

<SiO ₂ >
SiO ₂ is a component serving as a skeleton of the glass structure of the present invention, and the amount of SiO ₂ blended is 20% by mass or more and 45% by mass or less with respect to 100% by mass of the total amount of glass powder.
If the blending amount is less than 20% by mass, the chemical stability becomes low and the characteristics vary. On the other hand, if it exceeds 45% by mass, the softening point will increase too much.

<B ₂ O ₃ >
B ₂ O _{3 is} also a component that becomes a skeleton of the glass structure of the present invention, has an effect of lowering the softening point of the glass, and is an important component for making the resistance temperature coefficient of the thick film resistor positive. . The amount of B ₂ O ₃ is 100 wt% glass powder total contrast, is 12 mass% or more and 5 mass% or less.
If the blending amount is less than 5% by mass, the toughness of the glass is lowered and cracks are likely to occur. On the other hand, when the amount is more than 12% by mass, phase separation is likely to occur, and the glass is easily dissolved in water. In addition, the temperature coefficient of resistance of the thick film resistor tends to be a negative value, and it becomes difficult to adjust to near 0 within ± 100 ppm / ° C. Furthermore, since there exists an effect which suppresses the effect which increases the resistance value at the time of adding a lanthanum compound, it is necessary to set it as 12 mass% or less.

<Al ₂ O ₃ >
Al ₂ O ₃ is a component that improves the durability of the glass structure of the present invention.
The amount of Al ₂ O ₃ is 100 wt% glass powder total amount to, 20 mass% or less than 5 wt%. If the blending amount is less than 5% by mass, phase separation of the glass tends to occur and the durability of the glass structure is lowered. When it is more than 20% by mass, the softening point is excessively increased.

<BaO>
BaO is a component that has the effect of lowering the softening point when contained in glass powder that does not contain lead as in the present invention, and is a component that has the effect of increasing the dielectric constant and increasing the insulation when a voltage is applied. is there.
The compounding quantity of BaO is 4 mass% or more and 35 mass% or less with respect to 100 mass% of glass powder total amount. If the blending amount is less than 4% by mass, the softening point of the glass cannot be lowered sufficiently. When it is more than 35% by mass, the durability of the glass structure is lowered.

<ZnO>
ZnO is also a component having an effect of lowering the softening point when it is contained in glass powder not containing lead as in the present invention.
The compounding quantity of ZnO is 5 mass% or more and 35 mass% or less with respect to 100 mass% of glass powder total amount. If the blending amount is less than 5% by mass, the softening point of the glass cannot be lowered sufficiently. When it is more than 35% by mass, the durability of the glass structure is lowered.

  The total amount of the glass component can be set to a resistance temperature coefficient near 0 within a target ± 100 ppm / ° C. by setting the blending amount to at least 39 mass% as the blending amount with respect to the total amount of the glass powder. A product satisfying the above characteristics can be obtained. In order to make the temperature coefficient of resistance closer to 0 and to obtain stable characteristics, the total amount of the glass components is desirably 50% by mass or more, more preferably 60% by mass or more based on the total amount of the glass powder.

<Other glass powder components>
The essential components of the glass powder in the present invention are the above-mentioned SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , BaO, and ZnO, but other components may be contained within a range not impairing the effects of the present invention. Examples include the following.
CaO can be used as a component that lowers the softening point, like BaO. Bi ₂ O ₃ can also be used as a component that lowers the softening point of the glass. However, if it is contained in a large amount, the glass tends to crystallize, and various properties may be deteriorated. ZrO ₂ is a component that can increase the chemical stability of the glass, but if it is contained in a large amount, the softening point of the glass cannot be lowered and the softening point may become too high. .
Alkali metal oxides such as K, Na, and Li have a great effect of lowering the softening point, but since the insulating properties of the glass are lowered, the addition of the resistor within a range where there is no problem in reducing the electrical characteristics of the resistor. desirable.

<Grain size of glass powder>
The particle size of the glass powder is not particularly defined and may be selected according to the purpose of use. However, if it is too large, the resistance value variation of the resistor increases or the load characteristics deteriorate, which is not preferable. In order to avoid these, it is desirable that the average particle size of the glass powder be 3 μm or less, and more preferably 1.5 μm or less.
Glass powders larger than 3 μm can be reduced in size by pulverization, and a ball mill, a planetary mill, a bead mill, or the like can be used for pulverization of the glass powder. In order to sharpen the particle size of the pulverized glass powder, it is preferable to use wet pulverization.

<Conductive particles>
In the present invention, it is essential to use ruthenium-based conductive particles as the conductive particles.
Ruthenium oxide is preferably used as the ruthenium-based conductive particles not containing lead. The resistance temperature coefficient of the glass powder that does not contain lead and the resistor formed using ruthenium oxide as the conductive particles tends to be negative and the resistance value is too low. By adopting the structure of the object, it is possible to solve the “defect that the temperature coefficient of resistance becomes a negative value and the resistance value becomes too low”.

The ruthenium oxide to be used preferably has a specific surface area of 5 m ² / g or more and 150 m ² / g or less. In general, when conductive particles having a large specific surface area are used, the resistance value of the resistor appears low, and the resistance temperature coefficient tends to be low when compared with the same resistance value. Therefore, it is preferable to use ruthenium oxide particles having a specific surface area of 5 m ² / g or more and 50 m ² / g or less in a composition that desires a high resistance value.

  As conductive particles other than ruthenium oxide, bismuth ruthenate, calcium ruthenate, strontium ruthenate, barium ruthenate, or the like may be used. If necessary, two or more kinds of conductive particles or non-ruthenium-based conductive particles may be mixed and used.

<Ratio of conductive particles to glass powder>
The ratio between the ruthenium-based conductive particles and the glass powder can be changed depending on the desired resistance value and the like. Usually, the mass of the ruthenium-based conductive particles: the mass of the glass powder = 50: 50 to 5:95.
If there are more ruthenium-based conductive particles, the film structure of the thick film resistor becomes fragile, and the resistance value is likely to change due to a temperature cycle or the like, and the change with time is likely to occur. Also, if the amount of ruthenium-based conductive particles is less than this, the resistance temperature coefficient tends to be a negative value, and it may be difficult to approach 0, which is not preferable.

<Lanthane compound>
The lanthanum compound is not limited as long as it forms an oxide in the air, but lanthanum oxide and lanthanum hydroxide are suitable. By including the lanthanum compound, the resistance value can be greatly increased, and the amount by which the resistance temperature coefficient changes in the negative direction can be reduced.
If the particle size of the lanthanum compound is too large, it causes an increase in the resistance value variation of the resistor. Therefore, the average particle size is preferably 3 μm or less, more preferably 1.5 μm or less.

  The content of the lanthanum compound is preferably 0.01 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass in total of the ruthenium-based conductive particles and the glass powder. If the amount is less than 0.01 parts by mass, the effect of increasing the resistance value can hardly be expected. If the amount exceeds 5 parts by mass, the variation in resistance value may become too large, which is not preferable.

<Additives>
To the resistance composition of the present invention, an additive generally used for the purpose of improving and adjusting the resistance value, resistance temperature coefficient, load characteristic, trimming property of the resistor may be added.
Typical additives include Nb ₂ O ₅ , Ta ₂ O ₅ , TiO ₂ , CuO, MnO ₂ , ZrO ₂ , Al ₂ O ₃ , SiO ₂ , ZrSiO _{4 and the} like. By adding these additives, a resistor having more excellent characteristics can be produced.
The amount to be added is adjusted depending on the purpose, but is usually 10 parts by mass or less with respect to 100 parts by mass in total of the ruthenium-based conductive particles and the glass powder.

<Organic vehicle>
The ruthenium-based conductive particles and glass powder are mixed and dispersed in an organic vehicle in order to obtain a paste for printing after adding an additive as necessary.
The organic vehicle to be used is not particularly limited, and a solution in which a resin such as ethyl cellulose, acrylic acid ester, methacrylic acid ester, rosin, maleic acid ester is dissolved in a solvent such as terpineol, butyl carbitol, or butyl carbitol acetate is usually used. Used. Moreover, a dispersing agent, a plasticizer, etc. can be added as needed.

The blending ratio of the organic vehicle is appropriately adjusted by printing or coating method, but is about 20 to 200 parts by mass with respect to 100 parts by mass in total of the ruthenium-based conductive particles and the glass powder.
The method for dispersing ruthenium-based conductive particles, glass powder, additives and the like in the organic vehicle is not particularly limited, and a three-roll mill, a bead mill, a planetary mill or the like generally used for dispersing fine particles is used. be able to.

The present invention will be specifically described, but the present invention is not limited to these examples.
[Test 1: Characteristic evaluation of glass powder]
First, glass powders having various compositions were prepared, and the occurrence of crystallization of the glass powder and the softening point of each glass powder were confirmed.
When glass powder that is vigorously crystallized is used for the resistor, the resistance value of the resistor varies widely and the electrical characteristics also deteriorate, so that it cannot be used as the resistor composition of the present invention. In this evaluation, “◯” indicates that almost no crystallization was confirmed, and “x” indicates that crystallization was remarkably confirmed.

In addition, when glass powder having a too high softening point, such as a softening point exceeding 800 ° C., is used for the resistor, the resistance value of the resistor greatly varies and the electrical characteristics also deteriorate. It cannot be used as a composition. Therefore, the softening point of each glass powder was measured.
The softening point was measured using TG-DTA (TG / DTA320 type, manufactured by Seiko Denshi), the DTA curve was measured, and the value obtained from the third inflection point of the obtained DTA curve was taken as the softening point.
Table 1 shows the composition, crystallization state, and softening point of the glass powder used in this test.

  As can be seen in Table 1, the glass powders M, T, and V were markedly crystallized, and it was confirmed that they were not suitable as the resistor composition of the present invention. Further, the glass powders N, O, S and U had a softening point exceeding 800 ° C., and it was confirmed that the glass powders N, O, S and U are not suitable as the resistor composition of the present invention.

[Test 2: Evaluation of resistor composition]
Ruthenium oxide particles having two kinds of specific surface areas as ruthenium-based conductive particles, and glass powders A to L, a to c, and P to have no problems in crystallization state and softening point (800 ° C. or less) in Test 1 as glass powders. Using R, d, and e, a resistance paste was prepared by adding 43 parts by mass of an organic vehicle to 100 parts by mass of the conductive particles and the glass powder, and sufficiently dispersing the mixture with a three roll mill. In addition, regarding Examples 15 and 16 in Table 2 below, in addition to the organic vehicle, TiO and Nb ₂ O ₅ were further added in an amount of 0.3 parts by mass with respect to a total of 100 parts by mass of the conductive particles and the glass powder. .

  Next, the produced resistance paste is printed between a pair of electrodes of 1 wt% Pd and 99 wt% Ag previously formed by firing on an alumina substrate, dried at 150 ° C. for 5 minutes, and then a peak temperature of 850 ° C. × The thick film resistor was formed by firing in 9 minutes for a total of 30 minutes. The size of the thick film resistor was such that the resistor width was 1.0 mm and the resistor length (between electrodes) was 1.0 mm.

With respect to the formed thick film resistor, the film thickness and the resistance value are measured, respectively, the converted area resistance value when the film thickness is 7 μm, the temperature coefficient of resistance from 25 ° C. to −55 ° C. (Cold-TCR: Hereinafter, C-TCR), a temperature coefficient of resistance from 25 ° C. to 125 ° C. (Hot-TCR: hereinafter, H-TCR) was calculated.
Hereinafter, each measurement method and calculation method will be described.

The film thickness was measured using a stylus-type surface roughness / contour shape measuring machine, and the average value of the film thickness measurement values of each of the five thick film resistors was defined as “measured film thickness”. It was used for calculation. In addition, the average value of the measured value was in the range of 6.5 to 8.0 μm.
The resistance value was measured by the four-terminal method, and the average value of the measured values of the 25 thick film resistors was set as the “measured resistance value” and used for the calculation of the converted area resistance value below.
Using the “measured film thickness” and “measured resistance value” calculated for each sample, the converted area resistance value when the film thickness was 7 μm was calculated by the following formula (1).

The temperature coefficient of resistance is obtained by measuring the resistance value after holding the thick film resistor at −55 ° C., 25 ° C., and 125 ° C. for 15 minutes, and setting the resistance values to R ₋₅₅ , R ₂₅ , and R _125. The values calculated by the following formulas (2) and (3) were calculated from five thick film resistors, and the average value of the values was used.

  Table 2 shows the converted area resistance value and resistance temperature coefficient (C-TCR, H-TCR) values of each sample obtained by the above calculation method, together with the blending conditions at the time of pasting each sample.

In each of Examples 1 to 18 within the scope of the present invention, the values of C-TCR and H-TCR could be within ± 100 ppm / ° C.
In Examples 1 to 12, ruthenium oxide particles having a specific surface area of 60 m ² / g and glass powders A to L were used, and all of them showed good values with a resistance temperature coefficient within ± 100 ppm / ° C. I understand.

Examples 13 to 16 use ruthenium oxide particles having a specific surface area of 20 m ² / g and glass powders A and K. The resistance temperature coefficient is shifted to the positive side as compared with the case of using ruthenium oxide particles having a specific surface area of 60 m ² / g. In Example 14, the resistance temperature coefficient is a high value. However, as shown in Examples 15 and 16, by adding TiO ₂ and Nb ₂ O ₅ respectively, the resistor paste of the present invention is used. It can be seen that the amount of change can be further reduced by adjusting the temperature coefficient of resistance.

On the other hand, Comparative Examples 1 to 3 use ruthenium oxide particles having a specific surface area of 60 m ² / g and glass powders P, Q, and R. In both cases, the temperature coefficient of resistance is large and shows a negative value, and it can be seen that adjustment is not possible within ± 100 ppm / ° C. In Comparative Examples 4 to 6, although ruthenium oxide particles having a specific surface area of 20 m ² / g are used, the temperature coefficient of resistance is also a large negative value and cannot be adjusted within ± 100 ppm / ° C.

[Resistor Composition Containing La Compound]
In the embodiment of the resistor compositions containing La compound, a ruthenium oxide (RuO ₂₎ and made of a glass powder a composition having a specific surface area of ^{15 m} 2 / g, in Example 19-21 was added lanthanum oxide, In all cases, the temperature coefficient of resistance is within ± 100 ppm / ° C. However, in Example 21, it was observed that the resistance value was greatly increased by adding 2 parts by mass of lanthanum oxide.
In Examples 22 and 23, by adding 0.7 parts by mass of lanthanum oxide to the glass powders b and c, the resistance temperature coefficient is within ± 100 ppm / ° C. Examples 24 and 25 are examples in which lanthanum oxide was added to a resistor composition composed of ruthenium oxide (RuO ₂ ) having a specific surface area of 90 m ² / g and glass powders a and b. It can be seen that since the particle diameter of ruthenium oxide (RuO ₂ ) is fine, the resistance temperature coefficient is slightly negative, but is within ± 100 ppm / ° C.

Comparative Example 7 is an example in which lanthanum oxide was not added to a composition composed of ruthenium oxide (RuO ₂ ) having a specific surface area of 15 m ² / g and glass powder a, and the resistance temperature coefficient was set within ± 100 ppm / ° C. I could not.
Comparative Examples 8 and 10 are resistance compositions composed of ruthenium oxide particles having a specific surface area of 15 m ² / g and glass powders d and e, and Comparative Examples 9 and 11 are obtained by adding lanthanum oxide to Comparative Examples 8 and 10, respectively. This is an example. When the glass powders b and c outside the composition range of the present invention are used, the increase in resistance value is reduced even when lanthanum oxide is added, and the anti-temperature coefficient is negative even though the resistance value is low compared to the examples. It was not possible to be within ± 100 ppm / ° C.

  As can be seen from the test results of the Examples and Comparative Examples shown in Tables 1 and 2, according to the present invention, the resistance temperature coefficient of the thick film resistor using ruthenium-based conductive particles and glass powder as raw materials was difficult according to the present invention. It can be seen that a positive value can be obtained, and that the temperature coefficient of resistance can be easily adjusted to a value close to 0 within ± 100 ppm / ° C.

Claims (9)

A composition for a resistor containing ruthenium-based conductive particles containing no lead and glass powder containing no lead as main components,
The glass powder is a powder of Si—B—Al—Ba—Zn—O-based glass containing SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , BaO, and ZnO,
For a total amount of 100% by mass of the glass powder,
The SiO ₂ is 20% by mass or more and 45% by mass or less,
The B ₂ O ₃ is 5% by mass or more and 12% by mass or less,
The Al ₂ O ₃ is 5% by mass or more and 20% by mass or less,
The BaO is 4 mass% or more and 35 mass% or less,
ZnO contains 5 mass% or more and 35 mass% or less,
The composition for a resistor, wherein the total of SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , BaO, and ZnO is 39% by mass or more of the total amount of the glass powder. The resistor composition includes a lanthanum compound,
The content of the lanthanum compound is 0.01 to 5 parts by mass when the total content of the ruthenium-based conductive particles not containing lead and the glass powder not containing lead is 100 parts by mass. The composition for resistors according to claim 1.   The composition for a resistor according to claim 2, wherein the lanthanum compound is one or two of lanthanum oxide and lanthanum hydroxide.   4. The mass ratio of the lead-free ruthenium-based conductive particles and the lead-free glass powder is in the range of 50:50 to 10:90, according to claim 1. Resistor composition. The composition for resistors according to any one of claims 1 to 4, wherein the ruthenium-based conductive particles not containing lead are ruthenium oxide (RuO ₂ ). The composition for a resistor according to claim 5, wherein the ruthenium oxide (RuO ₂ ) has a specific surface area of 5 m ² / g or more and 150 m ² / g or less. The resistor composition according to any one of claims 1 to 6 and an organic vehicle,
A resistor paste, wherein the resistor composition is contained in the organic vehicle in a substantially dispersed manner.   A thick film resistor comprising the fired body of the resistor paste according to claim 7.   The thick film resistor according to claim 8, wherein the thick film resistor includes the fired body on a ceramic substrate.