JPS60170901A - Thermistor - 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 Industrial Application The present invention relates to a thermistor that detects temperature by mechanically contacting an object whose riA degree is to be detected. This relates to a thermistor that detects the temperature of

Configuration of conventional example and its problems Conventional 4 Temperature detection in this building t1G1 As shown in the figure, thermocouple 2f is mechanically brought into contact with pot bottom 1, and the thermoelectromotive force of thermocouple 2 is detected. Mud - At this time, the thermocouple 2 was fixed to the support container 3 in order to bring it into strong mechanical contact with the pot bottom 1. However,
The drawback is that thermoelectromotive force usually only has a small value. For example, Alme/Lake Chromel thermoelectric has excellent heat resistance (500-1000°C in air) and is inexpensive, but it generates only an electromotive force of ~401 tVIC. The electromotive force of the copper-constantan thermocouple λ"+J1 platinum-platinum/rhodium thermocouple is (30 to 60) ILV/'C
Not only is it not possible to obtain t, but the thermal properties are small (copper-constantan thermal strength) and expensive (platinum-constantan).
There were disadvantages such as platinum rhodium thermoelectric power).

There are four other types of thermal power, but all of them have the drawbacks mentioned above. In order to electrically detect the small thermoelectromotive force mentioned above and control the amount of heat generated by the heat source, a large electrical amplification is required, which increases the price and requires a complex electrical circuit. There are also drawbacks such as becoming θ] (raw.

On the other hand, when a thermistor is used instead of the thermocouple described in item 1 to detect the temperature, the rate of change of the resistance value of 17i1' can be as large as (1 to 7%/°C). Therefore, it has the advantage of not requiring a complicated electrical circuit, but still being low cost. In this case, the thermistor element is selected to be as small as possible and to have a low heat capacity. This is because miniaturization allows faster thermal response. Such small thermistor elements include F, , Ni, co,
There are composite metal oxide thermistor elements such as Mn. However, even if the capacitance IIV of the thermistor element itself is small,
It is difficult to reduce the thermal resistance of the connection part with the support container 39
71 [However, there was a drawback that the thermal response was slow.

OBJECTS OF THE INVENTION The present invention solves these conventional drawbacks, and aims to provide a thermistor with good response by reducing the thermal resistance of the connection part with the support container. do.

Structure of the Invention The thermistor of the present invention is constructed by brazing a flat metal oxide thermistor element and a support container via T i 7i'i or Zr foil.

In this way, the thermistor element and the support container are connected by soldering, so that the thermal resistance of the connection becomes extremely small.

Description of examples An embodiment of the present invention is shown in FIG.

The flat metal oxide thermistor element 4 and the support container 3 are connected by soldering through the entire soldering period 6.7 with a Ti foil 5 interposed therebetween. The brazing connection between T12i'i5 and the support container 3 is made by metal bonding through the brazing period 6. Metal oxide thermistor element 4 F@, Co
, Ni, Mn, and the like are often used. This metal oxide thermistor element 4 and T
It is connected to the i-foil 5 throughout the row month 7. Usually, the metal oxide 4 and the row AJJ layer 7 do not mix with each other. In other words, since there is almost no chemical bonding force between the two, it is difficult to connect the metal oxide thermistor element 4 ([.
When the wax cap 7 is formed between the r foil 5) and the metal oxide thermistor element 4, the wax cap 7 and the metal oxide thermistor element 4 wet each other well, and the Ti foil 5 and the metal oxide thermistor element 4 and are connected to each other through Low Month 7. The details of this reason are unknown, but when the wax alloy is heated to the phase line temperature or higher, a large amount of Ti atoms (or Zr atoms) increase the melting alloy IQ.
7 and reaches the surface of the metal oxide thermistor element 4, and the surface of the metal oxide thermistor element 40 is metallized, so that the Tl foil 5 and the gold J thermistor element 4 are connected by a row (;I). 4.

As described above, in the MINUTA of the present invention, the metal oxide thermistor element 4 and the support container 3 are connected by soldering through the Ti foil 5 throughout the entire soldering period.

For this reason, when the 90% thermal response time (Fig. 1, which was initially maintained at T1°C), the temperature at the bottom of the pot suddenly changes to T2°C (>T+''C), the temperature of the thin film Zami 7 Tachisop changes to TI+0.9 (
T2-T+)"C (measured at room temperature, T2-approximately 100°C) also showed high-speed response with 3 to 5 degrees. The adhesive strength of is 10
It was 0 to 500 g/mrl, and showed sufficient strength to withstand next month.

・The thermal expansion coefficient of the metal oxide thermistor element 4 is (
50 to 90)
(7) It is desirable that the material is made of Ag HA selected from W, FeCr alloy, Fe-Ni alloy, etc. In fact, the metal oxide thermistor element 4 and the Fe-Cr alloy support container 3 were connected by the row shown in FIG.
C → Presentation l) Even after conducting 1000 cycles of underwater thermal shock tests, no mechanical deterioration (such as cracking) of the brazed joints was observed, and there was almost no change in thermal response. Ta.

Furthermore, the Ag-Cu eutectic root brazing is superior in terms of brazing yield.

This is because this silver solder is easy to process into a foil shape and is also used industrially in foil shape, so when forming the thermistor of the present invention, the support container 3 and the metal oxide thermistor element are This is because a Ti foil or Z r 7i5 is interposed between the soldering material layer 6.7 and the soldering material layer 6.7, and a foil-like soldering material is placed at the position of the soldering material layer 6.7 and heated, thereby making it possible to easily perform the soldering:1 connection.

Effect of the invention According to the present invention, the following effects can be obtained.

(1) Since the metal oxide thermistor element and the support container are connected by Lowie τ1, the thermal resistance between them is extremely small. Therefore, a thermistor with fast thermal response can be realized.

(2) Since the metal oxide thermistor element is firmly connected to the support container by Lowey N1, the mechanical strength of the support container is increased. Therefore, practical mechanical strength can be ensured when mechanical impact is applied to the support container by the bottom of the pot or the like.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional example showing temperature detection using a thermocouple.
FIG. 2 is a sectional view of a thermistor according to an embodiment of the present invention. 3.Support container, 4.-Metal oxide thermistor element, 5
Ti foil or Zr foil, 6.7. Low month.

Claims (1)

[Scope of Claims] (1) A thermistor in which a flat metal oxide thermistor element and a support container are soldered together via titanium foil or zirconium foil. 9) The support container is made of iron - Nisokeru-cobalt alloy, iron -
2. The thermistor according to claim 1, wherein the thermistor is made of a material selected from Ninoke/Si alloy, iron-chromium alloy, titanium, molybdenum, tungsten, and the like. (3) The thermistor according to claim 1, wherein the wax is a silver-copper eutectic silver wax.