JP3245933B2 - Resistor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistor capable of preventing variations in characteristics, improving environmental resistance to humidity and the like, and increasing power capacity.

[0002]

2. Description of the Related Art Conventionally, a cermet resistor has been widely known as a resistance element having excellent accuracy. For such a resistor, for example, a resistor paste made of Ru oxide or a Ru compound is printed on the surface of an alumina substrate to form a thick resistive film, which is baked at 800 to 900 ° C. Then, a glass paste is applied to the surface of the resistive film of the alumina substrate and then baked to form a glass film, thereby improving environmental resistance to humidity and the like.

[0003]

However, in the above-mentioned conventional resistor, there is a problem that the resistance value is easily changed since the glass film is coated on the resistance film, and the characteristics are easily varied. In addition, a pinhole may be formed in the glass film, and as a result, there is a problem that moisture or the like invades in an atmosphere with high humidity to deteriorate the resistance characteristic. Further, in the above-mentioned conventional resistor, since the thermal expansion coefficients of the alumina substrate, the resistive film, and the glass film are different from each other, the adhesion of the resistive film to the substrate is low, and as a result, a large power capacity cannot be obtained, and about 100 mW. Was the limit.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and it is possible to prevent variations in characteristics by preventing a change in resistance value, to improve environmental resistance to humidity, and to obtain a large power capacity. It is intended to provide a resistor that can be used.

[0005]

Accordingly, the present invention provides a ceramic sintered body in which at least one resistive film is buried inside, and the sintered body is composed mainly of ZnO, One of Bi, Pb, B and Si as a component
It is characterized by containing one or more elements. The invention according to claim 2 is characterized in that at least one element of Bi, Pb, B, and Si is contained in a total amount of 0.5 to 20 mol%. It is characterized in that a plurality of ceramic sheets are laminated with the above-mentioned resistive film interposed therebetween, and the laminated body is integrally sintered together with the resistive film.

[0006] Here, the added amount of the subcomponent is 0.5 to 20 mol%.
It is desirable that If the addition amount is less than 0.5 mol%, sintering may not proceed and may not be used as a resistance element. If the addition amount exceeds 20 mol%, the ceramic sintered body and the resistance film are liable to react with each other. This is because variations in the values may increase or the power capacity may decrease. The sub-components include Sb, Co, Mn, Ti, Fe, Ni used in ordinary ZnO-based ceramics.
Etc. may be included.

[0007]

According to the resistor according to the present invention, the resistance film is buried inside the sintered body and the periphery of the resistance film is covered with ceramics, so that the conventional glass coating can be eliminated, and the resistance value can be reduced accordingly. Variations in characteristics due to changes can be avoided. In addition, since the problem of pinholes can be solved, environmental resistance to humidity and the like can be improved, and from this point, deterioration of resistance characteristics can be avoided. Furthermore, since a predetermined amount of Bi, Pb, B, and Si, which contains ZnO as a main component and lowers the sintering temperature, is added, the adhesion between the resistance film and the sintered body can be improved. Since the periphery is surrounded by the same sintered body, heat dissipation can be improved, distortion due to a difference in coefficient of thermal expansion can be reduced, and a large power capacity can be obtained.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and 2 are views for explaining a resistor according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a cermet resistor according to the present embodiment. The resistor 1 has a structure in which a substantially rectangular parallelepiped ceramic sintered body 3 has a resistance film 4 made of Ru oxide or a compound thereof embedded therein. The left and right end faces 4a, 4b of the resistance film 4 are exposed on the left and right side faces 3a, 3b of the sintered body 3, and the other end faces are sealed in the sintered body 3. The left and right side surfaces 3 of the sintered body 3
An external electrode 5 made of Ag-Pd is formed on each of the end surfaces 4a and 3b.
a, 4b.

The sintered body 3 contains ZnO as a main component and one of Bi, Pb, B and Si as a subcomponent.
A laminate is formed by laminating a plurality of ceramic sheets 2 each containing at least one element in an amount of 0.5 to 20 mol%, and integrally sintering the laminate. In this case, one ceramic sheet 2 located at the center in the thickness direction is used.
The resistive film 4 is pattern-formed on the upper surface of the
The remaining ceramics sheet 2 is superimposed on the ceramics sheet 2 on which is formed in a sandwich shape.

Next, the operation and effect of this embodiment will be described. According to the resistor 1 of the present embodiment, since the resistor film 4 is embedded in the sintered body 3, the periphery of the resistor film 4 is covered with ceramics, so that the conventional glass coating can be eliminated. As a result, variations in characteristics due to changes in resistance can be avoided. In addition, since the problem of pinholes can be solved, environmental resistance to humidity and the like can be improved, and deterioration of resistance characteristics can be avoided.

Further, since the sintered body 3 is made of a ceramic material containing ZnO as a main component and Bi, Pb, B, Si added in an amount of 0.5 to 20 mol%, the sintering temperature can be reduced. The resistance film 4 thus obtained has good adhesion to the sintered body 3, and since the periphery of the resistance film 4 is surrounded by the above-mentioned ceramic material, the heat dissipation can be improved and the coefficient of thermal expansion can be improved. The distortion due to the difference can be reduced, and the power capacity can be improved accordingly. Incidentally, while the resistance of the conventional resistance element was about 100 mW, the resistance of the present embodiment can achieve a power capacity of 10 times or more while reducing the size of the conventional element.

Further, in the present embodiment, the step of baking after applying the conventional glass paste can be omitted, so that the manufacturing cost can be reduced accordingly. Furthermore, since the resistance film can be laminated, the same pattern,
Various resistance films having different resistance values can be freely set in the same process.

Next, one method of manufacturing the resistor 1 of the present embodiment will be described. First, ZnO is used as a main component, and B
i, Pb, B and Si are replaced by Bi ₂ O ₃ and Pb, respectively.
₂ O ₃ , B ₂ O ₃ , and SiO ₂ oxides are added to form a ceramic powder by mixing them in an amount of 0.5 to 20 mol%. Pure water is added to the powder, and the mixture is pulverized and mixed by a ball mill to form a slurry.

Next, the slurry is evaporated to dryness to give 75
Pre-fire at 0 ° C for 2 hours. The calcined product is roughly pulverized, and pure water is added thereto, and finely pulverized by a ball mill to form a ceramic material. Next, a solvent in which ethyl alcohol and toluene are mixed at a ratio of 6: 4 is added to the raw materials, and mixed with a ball mill to form a slurry.

[0015] The above slurry is treated by a doctor blade method.
After forming a green sheet having a thickness of 70 μm and drying the green sheet, the green sheet is cut into a predetermined size to form a large number of rectangular ceramic sheets 2.

Next, RuO ₂ : Ru ₂ Pb ₂ O ₇ : Ru
Vehicle and glass are added to a composition prepared by mixing ₂ Bi ₂ O ₇ = 6: 2: 2 mol to form a resistance paste. The resistance paste is printed on the upper surface of the one ceramic sheet 2 to form the resistance film 4. Next, a plurality of ceramic sheets 2 are superimposed and laminated on the upper and lower surfaces of the ceramic sheet 2 on which the resistive film 4 is formed, and a pressure of ² t / cm ² is applied thereto and pressure-bonded, thereby forming a laminate. To form

Next, the laminate is cut into a predetermined size, heated to 400 ° C. to disperse the binder, heated to 930 ° C. and heated for 3 hours, and fired for 3 hours. To form After the obtained sintered body 3 is barrel-polished, Ag: Pd = 7: 3 on the left and right side surfaces 3a and 3b thereof.
Apply electrode paste consisting of wt.
The external electrodes 5 are formed by baking for minutes, and the external electrodes 5 are electrically connected to the left and right end faces 4a, 4b of the resistive film 4.
Thereby, the resistor 1 of the present embodiment is manufactured.

[0018]

[Table 1]

Next, a test performed to confirm the effect of the resistor 1 of this embodiment will be described. This test is shown in Table 1.
As shown in the figure, a large number of sample Nos. 1 to N were prepared by changing the amount of the additive added in the range of 0.1 to 40 mol%.
o. 55 was prepared, and the resistance value (Ω) of each sample, 3 CV
(3σ / average × 100% σ is the standard deviation), and the power capacity (mW) was measured (in the table, an asterisk indicates the outside of the claims of the present invention).

[0020]

[Table 2]

Table 2 shows the results. As is clear from the table, each sample No. in which the addition amount of the sub-component was less than 0.5 mol%.
In the case of 1, 9, 17, 25, the sintering of ceramics has not progressed and cannot be used as a resistor. In addition, each sample No. 7, 8, 15, 16,
In the case of 23, 24, 31, 32, 52 to 55, the resistance value varies, and the power capacity is as low as 96 to 410 mW. On the other hand, in each of Sample Nos. 2 to 6, 10 to 14, 18 to 22, 26 to 3 in which the addition amount was in the range of 0.5 to 20 mol%.
In the case of 0, 33 to 51, the variation of the resistance value is small,
In addition, it can be seen that the power capacity is greatly improved to 830 to 1830 mW.

[0022]

As described above, according to the resistor of the present invention, a resistance film is embedded in a sintered body, and Zn is added to the sintered body.
O as a main component, and Bi, Pb, B, and Si as 1 to 20
The use of a ceramic material with mol% added has the effect of avoiding variations in characteristics due to changes in resistance and improving environmental resistance to humidity, etc.
There is an effect that the power capacity can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a resistor according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a method for manufacturing the resistor of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resistor 2 Ceramics sheet 3 Sintered body 4 Resistance film

────────────────────────────────────────────────── ─── Continued from the front page (72) Inventor Hiroji Tani 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Murata Manufacturing Co., Ltd. (56) References JP-A-63-37601 (JP, A) JP-A 64-47001 (JP, A) JP-A 64-2402 (JP, A) JP-A-2-184552 (JP, A) JP-A 1-130502 (JP, A) JP-A 1-152704 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01C ^7/ 02-7/22

Claims (3)

(57) [Claims] 1. A ceramic sintered body having at least one
And the sintered body has ZnO as a main component, and Bi, Pb, B, and Si as subcomponents.
A resistor comprising one or more of the following elements. 2. The method according to claim 1, wherein said Bi, Pb,
0.5 to 20 mol in total of one or more elements of B and Si
%. 3. The ceramic sintered body according to claim 1, wherein the ceramics sintered body is formed by laminating a plurality of ceramics sheets with the resistive film interposed therebetween, and integrally sintering the laminated body together with the resistive film. A resistor, characterized in that: