JPS61131401A - 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 temperature, and which has a small ζ-steresis particularly in a region where the resistance suddenly changes, and is suitable for forming a film-like element. Regarding temperature-sensitive resistors. .

[Background of the Invention] 1. A temperature-sensitive resistance paste made of Vow lit powder, whose resistance value changes significantly at about 68°C, is coated on an alumina substrate using thick film printing technology, and the paste is fired to obtain a A membrane thermosensitive coefficient is known (Japanese Patent Application Laid-Open No. 158696/1983).

In this case, the temperature-sensitive resistor ■0. Because it is extremely easily oxidized at temperatures above 600'C, it is heat-treated in carbon dioxide gas. When heat treatment, that is, firing, is performed in a special atmosphere such as 11 carbon dioxide gas instead of in air, there are equipment problems such as atmosphere control, and extremely strict control is required to suppress variations in temperature-sensitive element characteristics. It was necessary. From this point of view, adding metallic boron powder to vO1O1 powder lath,
This was then fired in the air (Tokukō 5).
7-25961).

However, as shown in Figure 1, vOl has hysteresis in its temperature-resistance characteristics, and for example, the temperature difference for a given resistance value in a sudden change region is as much as 2°C.
Ceramic sintered bodies or film-like sintered bodies made of these materials have been used only as thermosensing elements and low-precision controllers.・In order to eliminate this hysteresis, Ba # Sj-+ AJ y Nb is added to VO8 with a particle size of 50μ or less.
* A temperature-sensitive material with rapid resistance changes was developed by mixing F6 and P(7) oxide powders and sintering them (Special Publication Publication No. 46-8
547).

However, the above-mentioned temperature-sensitive resistance materials can be applied to high-precision temperature detectors that take advantage of extremely high temperature dependence in the region of sudden changes in high and low resistance values, or to high-frequency oscillators that take advantage of minute temperature changes in this region. In order to achieve this, the hysteresis is further reduced so that the difference between the two resistance values at a given temperature is within 5%.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a temperature-sensitive resistor which improves the drawbacks of the prior art, has extremely small hysteresis in temperature-resistance characteristics, and can be obtained by firing in air.

[Summary of the invention]

The above purpose is vO! and Cr, which is a dioxide-type metal oxide.
Reaction with OW The composition of the mixture consisting of the sintered powder, metallic boron powder, and glass powder is in the range surrounded by the line connecting points A to E in the triangular composition diagram of FIG. 2, and VO1
The blending ratio of and Crow is 70-90% by weight, 30-1
This is achieved with a temperature-sensitive resistor obtained by heat-treating a zero-weight temperature-sensitive resistor composition in an oxidizing atmosphere.

A 60 30 10B 8
5 5 10C55540 D 50 10 40E 5
0 50 20 Note that VOt and C occupy in the temperature sensitive resistor obtained by heat treatment (firing) in an oxidizing atmosphere.
In the reaction sintered body with rQ, CrO is 10 to 50% by weight.

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 Crow is blended with VO8 in the above ratio, vOl, which exhibits rapid temperature change characteristics, has a crystal structure that is pre-distorted, so that the movement of atoms starting from the VOt crystal part that is distorted with respect to temperature is inhibited. It is expected that this will start gradually and that the resistance value will gradually follow this change.

At this time, ■0. Compared to the case of using only one of them, the temperature range corresponding to the rapid change region is expanded, and the amount of change in resistance value is reduced, but the hysteresis is reduced, and the resistance value is determined almost uniquely with respect to temperature.

This makes it possible to heat-process a temperature-sensitive material film printed on a substrate such as alumina using a conventional air-sintering thick-film belt furnace.

When the content of metallic boron is out of a predetermined range, this effect is lost, resulting in a decrease in the temperature change rate of the resistance value and a decrease in the strength of the sintered film, which are thought to be due to oxidation of VO.

Glass mainly acts only on the bonding of the vO3-based powder itself and the bonding with the substrate, and if it deviates from a predetermined range, the film strength will decrease, the resistance value will increase, or the temperature sensitivity will decrease.

When the above-mentioned temperature-sensitive resistor composition is applied by printing onto a substrate, an organic vehicle is added thereto and kneaded to form a paste.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example VO2 powder with an average particle size of 2 μm and Cr0t powder were mixed at the mixing ratio shown in /161-428 in Table 1, and a compact with a diameter of 10 txm and a thickness of 5 cm was prepared using a press mold. N containing 30FPIL, 1000°C in atmosphere
The sample was heat-treated for 10 minutes. ■The heat treatment for o must basically be carried out in a non-oxidizing atmosphere to prevent oxidation.
In this example involving a reaction, 0. Contains a small amount of.

Next, this sintered body was crushed with a crusher to create a powder with an average particle size of t5 μm.

The glass frit has an average particle diameter t prepared by a general method.
The compositions A and B shown in Table 2 of Oμ folding were used.

vO7-based sintered body powder, glass frit, and average particle size t
0 μm metallic boron powder in the proportions shown in /161 to 428 in Table 1, and 40 t of organic vehicle (5% ethyl cellulose α-terpineol solution) was added to each of the 100 t total amount of these mixed powders. It was kneaded to form a paste.

These pastes were printed between the M-Pd electrodes 2 formed in advance on an alumina substrate 1 with a length of 2.51 wI and a thickness of 0.2 cm in a thick film belt furnace at 850°C, and dried at 150°C. α-Terpineol was volatilized to % 700
After baking at ℃ for 10 minutes, 1gIm0, g
A thick-film element equipped with a thick-film temperature-sensitive resistor 3 having a thickness of 40 mm was obtained.

These resistance values RL at 50℃, resistance values at 100℃ &,
The ratio of resistance values at 50° C. and 100° C., Rt/& (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 that is greater than that of conventional general thick film thermistor elements, Rt/~ is required to be 10 or more, and for use as a practical circuit, the resistance value at 50°C must be 500Ω or less. is necessary. The maximum resistance value ratio in hysteresis must be tOS or less in order to keep the difference between the two resistance values to 5% or less.

Table 1/161-428 t)'UeA Rakanayo 5
The reaction sintered body powder, metallic boron powder, and glass powder are in the range shown in the triangular composition diagram shown in FIG.
% by weight of the compositions all obtained the desired properties.

Margins below [Effects of the Invention] As described above, according to the present invention, a temperature-sensitive material for thick film resistance sudden changes with extremely low hysteresis in temperature-resistance characteristics can be produced, and it can be used for highly accurate temperature measurement and control. It has become possible to create a high-frequency oscillator using small temperature fluctuations.

[Brief explanation of drawings]

FIG. 1 is a temperature-resistance characteristic diagram of the vO1 single crystal, and FIG. 2 is a triangular composition diagram showing the composition range of the temperature-sensitive resistor used in the present invention.
FIG. 3 is a cross-sectional view of the thick film temperature-sensitive element. 1... Ceramic substrate, 2.'' AJ-PrL system electrode... Thick film temperature sensitive resistor.

Claims (1)

[Claims] 1. A temperature-sensitive resistor obtained by heat-treating a mixture of reaction sintered powder of VO_2 and CrO_2, metallic boron powder, and glass powder in an oxidizing atmosphere. 2. The composition of the mixture consisting of the reaction sintered powder of VO_2 and CrO_2, metallic boron, and glass powder is within the range surrounded by the line connecting points A to E in the triangular composition diagram. A temperature-sensitive resistor according to claim 1. Reaction sintered body powder of VO_2 and CrO_2 Metallic boron powder Glass powder (wt%) (
Weight%) (Weight%) A 60
30 10 B 85
5 10 C 55
5 40 D 50
10 40 E 50
50 20 3, the reaction sintered powder of VO_2 and CrO_2 is VO_2
The temperature-sensitive resistor according to claim 1, having a composition of _270 to 90% by weight and CrO_230 to 10% by weight.