JPS637585B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention improves the temperature coefficient of resistance (hereinafter referred to as "TCR") in the high resistance region of a ruthenium oxide thick film resistor made of ruthenium oxide and glass,
In addition, noise, voltage coefficient of resistance value (hereinafter referred to as “VCR”)
) with improved resistance characteristics. Thick film resistors made of ruthenium oxide and glass are
When the ratio of ruthenium oxide to glass was in the range of 60:40 to 5:95, the resistance value varied from several Ω/□ to 10 MΩ/□, and the desired resistance value was obtained. It is desirable that the resistance value of the resistor does not change depending on the ambient temperature during use, that is, that the TCR is zero. However, although the relationship between resistance value and TCR varies depending on the grain size of ruthenium oxide and the composition and grain size of glass, there is a region where TCR is 0 in the medium resistance region, but after this region the resistance value becomes low. As the resistance value increases, the TCR becomes more positive, and as the resistance value becomes higher, the TCR becomes more negative, and it has the disadvantage that it is susceptible to the influence of ambient temperature over most of the resistance value range. Incorporation of various additives is known as a method of improving TCR. For example, MnO ₂ ,
Al ₂ O ₃ , TiO ₂ , ZrO ₂ , etc. have the effect of shifting TCR in the negative direction, resulting in a positively large TCR.
It is effective for resistors in the low resistance range. However, in the case of resistors in the high resistance range, for example, U.S. Patent No.
No. 3324049 describes the addition of copper oxide or the use of glass containing copper oxide, but when copper oxide is added, the TCR approaches 0, but at the same time the resistance value decreases and the VCR also decreases. Getting worse. Also, British Patent No. 1470497 describes colloidal
Although it has been described that the TCR changes in the positive direction when AlOOH is added, the resistance value also decreases in this case. Therefore, as a result, TCR in the high resistance region
It was not possible to obtain a value close to 0. Another method is to coarsen the grain size of ruthenium oxide and glass, but this method increases noise and
The variation in resistance value is also large, making it unsuitable for practical use. As described above, the conventional method cannot be said to be a preferable method for improving TCR in a high resistance region. The present inventors conducted research to solve these problems and improved TCR by adding lanthanum oxide and/or neodymium oxide to a ruthenium oxide glass resistor that exhibits a high resistance value.
It is an improved version of VCR. That is, the present invention provides ruthenium oxide, glass,
This is a resistance paint consisting of lanthanum oxide and/or neodymium oxide and an organic vehicle. Lanthanum oxide and/or neodymium oxide are
When added to a ruthenium oxide-glass resistor with a negative TCR, it has the special effect of bringing the TCR closer to 0, but increasing the resistance value. This is an extremely unique performance considering that conventional additives have the disadvantage of reducing resistance. In this way, the present invention not only improves TCR, but also contains more conductive particles and less glass compared to conventional resistors with the same resistance value, so noise is reduced and VCR is also improved. It also has the effect of improving it. As described above, the addition of lanthanum oxide and/or neodymium oxide produces unexpected and excellent effects. The ruthenium oxide, glass, and organic vehicle used in the resistive paint of the present invention may be those commonly used in resistive paints. Ruthenium oxide may be used in the form of being previously treated and contained in glass. Lanthanum oxide and/or neodymium oxide are
There are no particular restrictions on particle size, but
It only needs to be 10μ or less, and preferably 0.1 to 2μ. These oxides are used in an amount of 0.05 to 7 parts by weight based on a total of 100 parts by weight of ruthenium oxide and glass. If it is less than 0.05 parts by weight, the effect of adding it will not be seen much, and if it is used in excess of 7 parts by weight,
TCR now shifts to the negative side, and TCR
It is not an improvement. Lanthanum oxide and neodymium oxide may be used alone or in combination, or may be incorporated in glass in advance. The present invention will be explained below with reference to Examples, but the present invention is not limited thereto. Table 1 shows Examples 1 to 10 and Comparative Examples 1 to 5. Examples and comparative examples with the same resistance value are shown together for ease of comparison. In each of the Examples except Examples 4 and 7, the respective components shown in Table 1 were mixed and then subjected to roll mixing to obtain a uniformly dispersed resistance paint. The glass used was PbO52.0% by weight.
The particles had a composition of 8.3% B ₂ O ₃ , 36.5% SiO ₂ , and 3.3% Al ₂ O ₃ and had an average particle size of 3 μm, and the ruthenium oxide had a specific surface area of 23 m ² /g. The organic vehicle is a homogeneous mixture of 7.5 parts ethylcellulose, 32.5 parts terpineol, and 5.0 parts dibutyl phthalate by weight. In Example 4, ruthenium oxide, glass, and lanthanum oxide were placed in a platinum crucible, heated to the melting temperature of glass, then rapidly cooled, and then finely ground, uniformly dispersed in an organic vehicle in the same manner as above, and used as a resistance paint. did. In Example 7, glass and lanthanum oxide were treated in the same manner as in Example 4, and then this and ruthenium oxide were uniformly dispersed in an organic vehicle.
It was made into a resistance paint. The resistance paint obtained in this way
After screen-printing a 1 mm x 1 mm pattern on an alumina substrate with terminals formed with Ag-Pd thick film conductors, it was dried and then heated to the peak temperature using a belt furnace.
It was baked at 850°C for 10 minutes. The resistance value, TCR, noise, and VCR of the obtained resistor were measured, and the results are also shown in Table 1. The resistance value was measured using a digital multimeter (TR-6855) manufactured by Takeda Riken Kogyo Co., Ltd., and was converted to a thickness of 12 μm. TCR was measured over a temperature range of -25°C to +125°C. The noise is made by Quan-Tech.
Measured by Resistor Noise Test (MODEL-2136). The smaller the noise value, the better.
The VCR is General Radio's Megohm Bridge.
(MODEL-1644A) measured at 10 to 100V. Similar to TCR, it is preferable for VCR to be as close to 0 as possible.

[Table] (All parts are parts by weight)
Comparing Example 1 and Comparative Example 1, Example 2 and Comparative Example 2, Example 3 and Comparative Example 3, Examples 4 to 6 and Comparative Example 4, and Examples 7 to 10 and Comparative Example 5, it is found that the present invention It can be seen that the resistor obtained by this method has an improved TCR compared to a conventional resistor having the same resistance value. Furthermore, it has been shown to be superior in terms of noise and VCR. Table 2 also shows that the resistance value increases when ruthenium oxide and glass are mixed in the same ratio and lanthanum oxide is added. Similar comparisons can be made between Examples 9 and 10 and Comparative Example 4 in Table 1. The experimental method and measurement method are the same as described above.

[Table] As described above, the present invention improves resistance in the high resistance range by adding lanthanum oxide and/or neodymium oxide to the ruthenium oxide-glass resistance film.
It improves TCR and brings it closer to 0, and also improves noise and VCR, making it extremely excellent in practical terms.

Claims (1)

[Scope of Claims] 1. A resistance paint comprising ruthenium oxide, glass, lanthanum oxide and/or neodymium oxide, and an organic vehicle. 2. The resistive paint according to claim 1, wherein lanthanum oxide and/or neodymium oxide are included in the glass in advance. 3. The resistance paint according to claim 1, wherein ruthenium oxide and lanthanum oxide and/or neodymium oxide are included in the glass in advance. 4 The weight ratio of ruthenium oxide and glass is 30:70 ~
5:95, the sum of ruthenium oxide and glass
The resistance paint according to any one of claims 1 to 3, wherein the lanthanum oxide and/or neodymium oxide is contained in an amount of 0.05 to 7 parts by weight per 100 parts by weight.