JPS61119002A - Thermosensitive resistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a temperature-sensitive resistor whose resistance value changes greatly depending on the temperature, and which has a small hysteresis particularly in the region of sudden resistance changes and is suitable for forming film-like elements. The present invention relates to a temperature-sensitive resistor.

[Background of the invention]

On an insulating substrate such as an alumina substrate, a resistance paste made of VO2 powder, which has a temperature-sensitive resistance material whose resistance value changes greatly at about 68°C, is applied to a thickness of 11rA using printing technology, and this is processed in air to form a thick film. Formation of a temperature sensing element has been carried out (Japanese Patent Application Laid-Open No. 158696/1983).

VO2 is extremely easily oxidized at high temperatures of 600° C. or higher, so heat treatment is performed in carbon dioxide gas. Performing heat treatment, that is, firing, in a special atmosphere such as carbon dioxide gas instead of in air requires extremely strict management, both from the equipment issue of controlling the atmosphere and from the standpoint of suppressing variations in temperature-sensitive element characteristics. was necessary.

From this point of view, metal boron powder is added to V○2 powder and glass frit, and the mixture is fired in air (Japanese Patent Publication No. 57-25961).

However, as shown in Figure 1, VO2 has hysteresis in its temperature-resistance characteristics, and for example, the temperature difference for a given resistance value in a region of rapid change can be as much as 2°C. Alternatively, the temperature sensing element of the film-like fired body has been used only as a controller with low precision.

In order to eliminate this hysteresis, Ba, Sr, A Q t Nby Fe are added to VO2 with a particle size of 50 μm or less.
A temperature-sensitive material with rapid resistance change is known, which is made by mixing and sintering oxide powders of P and P (Japanese Patent Publication No. 46-8547).

However, in order to apply the hysteresis to a high-precision temperature sensor that utilizes extremely high temperature dependence in the region of sudden changes in high and low resistance values, or to a high-frequency oscillator that utilizes minute temperature changes in this region, the hysteresis described above must be applied. It has been desired to further reduce the resistance and keep the difference between the two resistance values at a predetermined temperature within 5%.

[Purpose of the invention]

The purpose of the present invention is to improve the above-mentioned drawbacks of the prior art and to
The object of the present invention is to provide a temperature-sensitive resistor having extremely small hysteresis in resistance characteristics and capable of being fired in air.

[Existing necessity of the invention]

The above purpose is to (a) VO, and dioxide-type metal oxides RuO2, RhO2. Powder of a reaction sintered body with Rho or MoO□, (b) metallic boron powder, and (C)
A mixture of glass frit, and the above (a)
, (b).

The composition of the mixture consisting of (C) is within the range surrounded by the line connecting points A to E in the triangular composition diagram of these three components in Figure 2, and the sintered body of (a) is Vo , 65-8
5% by weight, RuO2, RhO2. Rho□ or M
This is achieved with a temperature-sensitive resistor obtained by heat-treating a mixture of 35 to 15% o O in an oxidizing atmosphere.

However, the above points A to E represent the following composition.

Vo2, RuO2, RhO2. Rho, metallic boron glass reaction sintered body (weight%) (weight%) (weight%) A 60
30 10B 85
5 10C55540 D 50 10 4
0E 50 30
20 Note that when a mixture of Vo2 and RuO2, RhO, Rho, or MoO2 in the above ratio is reacted and sintered.

VO2, which exhibits sudden temperature-sensitive characteristics, has a pre-distorted crystal structure, so atoms gradually begin to move starting from the V○2 crystal part that is distorted due to temperature, and as a result, the resistance value also increases. It is expected that changes will follow gradually.

At this time, compared to the case where 'JO, is used alone, the temperature range corresponding to the sudden change region is expanded and the amount of change in resistance value is reduced, but the hysteresis is reduced and the resistance value is almost unique to temperature. It comes to be determined by

In addition, the particle size of each of the above powders is the same as that of ordinary thick film materials.
It is less than μm.

In addition, when the blending ratio of metallic boron is within the above range, an unfired temperature-sensitive resistance paste printed on an insulating substrate such as alumina can be heat-treated using a normal air-fired thick film belt, resulting in oxidation of Vo2. There is no decrease in the rate of change in resistance value due to temperature change, and there is no decrease in the strength of the sintered product.

Further, the glass is mainly used to bond the V○2-based reaction sintered body and the substrate. Outside the above range, film strength decreases, resistance increases, or temperature sensitivity decreases.

Alternatively, the composition consisting of the above (a), (b), and (c) may be kneaded with an organic vehicle and used in the form of a paste.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail by way of examples.

Example 1 VO,:s powder with an average particle size of 2 μm and RuO□lead powder were mixed in the proportions indicated by Nα1 to Nα28 in Table 1, and these were used to form the powder by press molding. 11 diameter 10
mm, M 5mm+ green compact, 30pp of 02
Heat treatment was performed at 1000° C. for 10 minutes in an N2 atmosphere containing m. The heat treatment of vQ2 basically needs to be carried out in a non-oxidizing atmosphere to prevent its oxidation, but in this example, which involves one reaction, a small amount of 02 was included. Next, this sintered body was crushed with a crusher to create powder with an average particle size of 1.5 μm.

The glass frit has an average particle size of 1, prepared by a general method.
．． 0 μm compositions A and B shown in Table 2 were used.

VO2 sintered powder, glass frit and average particle size 1
．． 0 μm metal boron powder is mixed in the proportions shown in Table 1 & 1 to Blood 28, and 40 g of organic vehicle (5% ethyl cellulose α-terpineol solution) is added to each 100 g of total powder and kneaded. It was made into a paste.

The paste was formed in advance on an alumina substrate 1 with a diameter of 2.5 mm and a thickness of 0.2 mm in an 850°C thick film belt furnace.
Printed between Pd-based electrodes, dried at 150°C to volatilize α-terpineol, and baked in air at 700°C for 10 minutes to form a thick film bottom resistor with a 1 mm opening and a thickness of 40 μm as shown in Figure 3. An n-type temperature-sensitive resistance element provided with a body 3 was formed.

Resistance value RL of the element at 50°C, resistance value R at 100°C, 5
The ratio RL/R11 of resistance values between 0° C. and 100° C. (indicating the maximum value of the ratio of two resistance values at a predetermined temperature in hysteresis) was measured.

In order to obtain a temperature change in resistance value greater than that of a conventional general thick film thermistor element, the value RL/R11 is desired to be 10 or more, and for use as a practical circuit, the resistance value at 50° C. is desired to be 500 kΩ or less. The maximum resistance value ratio in hysteresis is 1 because the difference between the two resistance values is 5% or less.
．． 05 or less is desirable.

As is clear from Notes 1 to N1128 in Table 1, the reaction sintered main powder of vQ and Ru G 2, metallic boron powder, and glass frit 1 to 1 are within the range of the triangular composition diagram shown in FIG.
And in the reaction sintered body with vQ2, RuO□ is 15 to 3
All desired properties were obtained in the composition at 5 wt%.

Example 2 A thick film temperature-sensitive resistance element in which a thick film resistor was provided on an alumina substrate was obtained in the same manner as in Example 1 except that RhO2 was used instead of RuO2 and RhO.

The properties are as shown in Table 3, and were also similar to Example 1.

Example 3 A thick film temperature-sensitive resistance element in which a thick film resistor was provided on an alumina substrate was obtained in the same manner as in Example 1 except that M2O3 was used instead of RuO2 and RhO.

The properties are shown in Table 4 and were also similar to Example 1.

Margins below [Effects of the Invention] As described above, according to the present invention, a temperature-sensitive resistor with extremely low hysteresis in temperature-resistance characteristics has been created, and can be used for highly accurate temperature measurement and control, or for utilizing minute temperature fluctuations. High frequency oscillator has become possible.

[Brief explanation of the drawing]

FIG. 1 is a temperature-resistance characteristic of a vO2 single crystal, FIG. 2 is a triangular composition diagram showing the composition range of a temperature-sensitive resistor of the present invention, and FIG. 3 is a sectional view of a thick-film temperature-sensitive resistor element. 1...Ceramic substrate, 2...Ag-Pd electric spoon, 3...
・Thick film temperature sensitive resistor.

Claims (1)

[Claims] 1. VO_2 and RuO_2, RhO_2 or Mo
A temperature-sensitive resistor obtained by heat-treating a mixture of reaction sintered body powder with O_2, metallic boron powder, and glass frit in an oxidizing atmosphere. 2. The composition of the mixture consisting of the reaction sintered powder of VO_2 and RuO_2, RhO_2 or MoO_2, metallic boron powder, and glass frit connects points A-E in the triangular composition diagram of these three components. The temperature-sensitive resistor according to claim 1, wherein the temperature-sensitive resistor is in the range surrounded by a dotted line. However, the above points A to E indicate the following compositions. VO_2 and RuO_2, RhO_2 or MoO_
Reaction sintered body with 2 (wt%) Metallic boron powder (wt%)
) Glass frit (wt%) A 60 30 10 B 85 5 10 C 55 5 40 D 50 10 40 E 50 30 20 3, the reaction sintered body of the VO_2 and RuO_2, RhO_2 or MoO_2 has a weight of VO_265 to 85 %, RuO_2, RhO_2 or MoO_2 is 35
2. The temperature-sensitive resistor according to claim 1, wherein the temperature-sensitive resistor is obtained by reaction-sintering a mixture consisting of 15% by weight.