JPH0562802A - Thick-film resistive paste and thick film resistor - Google Patents

Abstract

(57) [Summary] [Object] The object of the present invention is to provide a thick film resistive coating film which can stably realize a high resistance region and has excellent performance, and a paste composition using the same. It is to provide a membrane resistor. [Structure] A thick film resistance paste containing 15 to 50% by weight of ruthenium oxide and / or pyrochlore-type ruthenate and 85 to 50% by weight of lead borosilicate glass in a paste solid content. It is characterized in that it contains 0.5 to 5% by weight of tin and / or titanium oxide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paste composition for forming a thick film resistance film which can stably realize a high resistance region and has excellent performance, and a thick film resistor using the same. It is a thing.

[0002]

2. Description of the Related Art A thick film resistance paste is basically a composition in which a conductive powder and a glass powder are dispersed and mixed in an organic vehicle, and when applied on a refractory substrate and baked at a predetermined temperature, A resistance film is formed on the substrate, and an electrode is connected to the resistance film to form a resistor.

As the conductive powder of this resistance paste, a wide resistance value can be realized and a resistance temperature coefficient is small, so that ruthenium oxide or Pb ₂ Ru ₂ can be obtained.
Pyrochlore-type ruthenate represented by O ₆ to ₇ is often used.

Further, in order to obtain a desired resistance value, the area resistance value is, for example, 1 kΩ / □, 10 kΩ / □, 100 kΩ / □.
It is common to prepare a resistance paste with a standard value adjusted every 10 times as described above, and use them by appropriately blending them. However, this blending makes the resistance value and the temperature coefficient of resistance approximately intermediate values. It is necessary to secure this with series resistance paste.

What is important in the series is to specify the glass to be used. Glass has a function of binding conductive powder to a substrate, and it is necessary to select a softening point and a thermal expansion coefficient that are appropriate, but since the characteristics such as resistance value, resistance temperature coefficient, noise, and withstand voltage also influence, The characteristics of the series are determined by the glass composition used.

As such glass, lead oxide 45 to 7
5, silicon oxide 25 to 50, boron oxide 0.1 to 5% by weight each
Generally, lead borosilicate glass containing as a main component is used,
Various components are further added to this if necessary.

The resistance value naturally changes depending on the mixing ratio of the conductive powder,
The conductive powder content in the paste solid content is usually 15 to 50% by weight, and the glass powder content is 85 to 50% by weight. The conductive powder content is set to 15% by weight or more because if it is less than this, it becomes difficult to adjust the resistance value and characteristics such as noise and withstand voltage deteriorate.

However, when the amount of the conductive powder is set to 15% by weight or more, titanium oxide, tantalum oxide, niobium oxide, titanate, tantalate, niobate which has an effect of increasing the resistance value for realizing high resistance is obtained. Although it is necessary to add salt or the like, the addition of these materials negatively increases the temperature coefficient of resistance. Since it is necessary to keep the temperature coefficient of resistance within a certain range, there is a restriction on the addition of the resistance increasing agent, and it is difficult to stably achieve 5 MΩ / □ or more.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a paste composition capable of stably realizing a high resistance region with an amount of conductive powder of 15% by weight or more, and capable of forming a thick film resistor having excellent performance. And to provide a thick film resistor using the same.

[0010]

To achieve the above object, the composition of the present invention comprises ruthenium oxide and / or pyrochlore type ruthenate in an amount of 15 to 50 in the paste solid content.
A thick film resistance paste containing 45% by weight of lead oxide, 45 to 75% of lead oxide, 25 to 50% of silicon oxide, and 0.1 to 5% by weight of boron oxide of 85 to 50% by weight of lead borosilicate glass. In the above, the glass is characterized by containing 0.5 to 5% by weight of tin oxide and / or titanium oxide.

The thick film resistor of the present invention is obtained by applying the above composition to a refractory substrate and forming a resistance coating on the substrate, and the ruthenium oxide and / or pyrochlore type ruthenate is added to the refractory substrate in an amount of 15 to 15. 50 wt% and lead oxide 45-75,
Silicon oxide 25 to 50, boron oxide 0.1 to 5% by weight as a main component, and tin oxide and / or titanium oxide 0.5 to 0.5
85 to 50% by weight of lead borosilicate glass containing 5% by weight
It is characterized in that the resistance coating containing and is formed on the refractory substrate.

[0012]

The main components and contents of the glass used in the present invention are the same as those of the conventional ones, and lead oxide 45 to 75, silicon oxide 25 to
50, and each of boron oxide 0.1 to 5% by weight. In the present invention, in addition to this main component, tin oxide and / or titanium oxide is contained in an amount of 0.5 to 5% by weight. If the content of tin oxide or titanium oxide in the glass component is too small, it is not effective, and if it is too large, the coefficient of thermal expansion of the resistance coating obtained by firing becomes large, and the adhesion strength with the substrate decreases, which is not preferable. .. Therefore, the content of tin oxide and / or titanium oxide needs to be 0.5 to 5% by weight.

Alkaline earth metal oxides such as calcium oxide, barium oxide and strontium oxide have the effect of positively increasing the temperature coefficient of resistance, and 0.1 to 5 in the glass.
It is better to contain it by weight%. If the content of the alkaline earth metal oxide exceeds 5% by weight, the coefficient of thermal expansion of the resistance coating becomes too large, so 5% by weight is the upper limit.

Further, zinc oxide has a function of suppressing the shape effect of the resistance coating, that is, the phenomenon that the area resistance value becomes smaller as the ratio of the length to the width of the coating becomes smaller. It can be contained in the range of%.

Other oxides known as vitrifying components may be contained in the range of 0.1 to 5% by weight in order to adjust the softening point and thermal expansion coefficient of glass.

Such a glass powder is contained in the paste solid content in an amount of 15 to 50% by weight of a conductive powder composed of ruthenium oxide and / or pyrochlore-type ruthenate.
The content is 85 to 50% by weight.

The conductive powder and the glass powder are kneaded with a suitable organic vehicle to form a paste having a property suitable for screen printing. During this kneading, an appropriate amount of titanium oxide, tantalum oxide, niobium oxide, titanate, tantalate, niobate, or the like can be added to increase the resistance value. The added amount of these resistance value increasing agents is appropriately 0.1 to 5% by weight in the paste solid content. If the amount of addition is too large, the temperature coefficient of resistance increases too negatively, so it is preferable to set the upper limit to 5% by weight.

[0018]

EXAMPLES In experiments, glasses A and B having the compositions shown in Table 1 were used.
And C were prepared. Glass A is a conventional composition and glasses B and C are compositions according to the invention.

[0019]

[Table 1]

85% by weight of this glass powder and Pb ₂ Ru ₂
15% by weight of O _6,5 powder was mixed, and 30 parts by weight of an organic vehicle was added and kneaded to 70 parts by weight of this solid content.
Experiment No. shown in. Pastes 1, 8 and 13 were obtained.

These pastes were sampled and Ta ₂ O ₅ or TiO ₂ was added as a resistance increasing agent in an amount of 0.
Experiment N shown in Table 2 was mixed by adding 5, 1 or 2% by weight.
o. 2 to 7, 9 to 12 and 14 to 19 pastes were obtained.

The obtained resistance paste is printed in a predetermined pattern on an alumina substrate on which electrodes have been formed in advance, dried and baked to form a resistance film, and the resistance film is formed at -55 ° C, 25 ° C, 1 ° C.
The sheet resistance and the temperature coefficient of resistance (TCR) were calculated from the measurement of the resistance at 25 ° C. Low temperature side TCR (CTCR)-
Temperature coefficient of resistance between 55 ° C and 25 ° C, TC on high temperature side
R (HTCR) is between 25 ° C and 125 ° C.
The results are summarized in Table 2.

[0023]

[Table 2]

It can be seen from Table 2 that when tin oxide or titanium oxide is contained in the glass, the resistance value can be increased without negatively increasing the temperature coefficient of resistance.

[0025]

According to the present invention, the amount of conductive powder is 15% by weight.
With the above, a high resistance region of 5 MΩ / □ or more can be stably realized. As a result, excellent resistors can be manufactured without impairing performance such as noise and withstand voltage.

Claims (8)

[Claims] 1. Ruthenium oxide and / or pyrochlore-type ruthenate in a paste solid content is 15 to 50% by weight, and lead oxide is 45 to 75, silicon oxide is 25 to 50, and boron oxide is 0.1 to 5% by weight. In a thick film resistance paste containing 85 to 50% by weight of lead borosilicate glass whose main component is tin oxide, tin oxide and / or titanium oxide is contained in the glass in an amount of 0.
A thick film resistance paste containing 5 to 5% by weight. 2. The paste solid content contains 0.1 to 5% by weight of at least one of titanium oxide, tantalum oxide, niobium oxide, titanate, tantalate and niobate. Thick film resistance paste. 3. 0.1% of at least one of calcium oxide, barium oxide and strontium oxide is added to the glass.
The thick film resistor paste according to claim 1 or 2, containing 5 to 5% by weight. 4. The thick film resistance paste according to claim 1, wherein the glass contains 0.1 to 5% by weight of zinc oxide. 5. A ruthenium oxide and / or a pyrochlore type ruthenate of 15 to 50% by weight and a lead oxide of 45 to 50% by weight.
75, silicon oxide 25 to 50, boron oxide 0.1 to 5% by weight as a main component, and tin oxide and / or titanium oxide 0.5 to 5% by weight lead borosilicate glass 85 to 85% 5
A thick film resistor having a resistance coating containing 0% by weight formed on a refractory substrate. 6. The resistance coating according to claim 5, which contains 0.1 to 5% by weight of at least one of titanium oxide, tantalum oxide, niobium oxide, titanate, tantalate and niobate. Thick film resistor. 7. 0.1% of at least one of calcium oxide, barium oxide and strontium oxide in the glass.
The thick film resistor according to claim 5 or 6, containing 5 to 5% by weight. 8. The thick film resistor according to claim 5, wherein the glass contains 0.1 to 5% by weight of zinc oxide.