JPS63316404A - Manufacture of glass-sealed thermistor - Google Patents

Abstract

PURPOSE:To simplify a manufacturing process and to reduce a cost by a method wherein nickel-plated Dumet wires are fixed to platinum electrode faces on both sides of a raw body for a thermistor by a parallel gap welding operation and this assembly is hermetically sealed in the air by using a glass material. CONSTITUTION:Two nickel-plated Dumet wires 7 are fixed to electrode faces on both sides of a raw body 6 for an Mn-Ni-Cr-Zr-related thermistor where platinum electrodes are formed on opposite faces by using a parallel gap welding operation; a whole part excluding one part of the Dumet wires is hermetically sealed in the air by using a glass material 9. Because the Dumet wires 7 are plated with nickel, the wires can be welded to the electrode faces of the raw body 6 for the thermistor without removing surface oxide films on the Dumet wires 7. Because the wires are plated with nickel, the assembly can be sealed in the air by using the glass material 9; in addition, a change rate of a resistance value before and after a sealing operation by using the glass material is low and its influence is little. Accordingly, it is possible to obtain a thermistor device whose characteristic is stable.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is used as a temperature sensor for household electrical appliances, housing equipment, automobile equipment, etc., and is particularly applicable to gas and
The present invention relates to a method for manufacturing glass-encapsulated thermistors, which are useful for oil-burning equipment and the like.

2. Prior Art Conventionally, this type of glass-encapsulated thermistor is shown in FIGS.
The configuration was as shown in the figure. Figure 2(a).

In (b), 1 is an Mn-Ni-0r-Zr thermistor body in the form of a flat plate or a disk with electrodes formed on opposite surfaces, and a Dumet wire 2 is coated with a conductive paint 3 or by welding 4. It was fixed to both electrode surfaces of the thermistor body 1, and the entire Dumet wire 2 except for a part was hermetically sealed in a neutral or inert atmosphere with a glass material 6.

Problems to be Solved by the Invention This conventional configuration has the following problems.

(1) As a method of fixing the Dumet wire to the electrode surface formed on the thermistor body, a method using conductive paint or a method of welding after removing the surface oxide film of the Dumet wire is used.

These methods require complicated manufacturing steps and cannot be manufactured at low cost.

(2) Due to the oxidation of the Dumet wire, glass sealing cannot be performed in the atmosphere, and glass sealing cannot be performed at a low cost because glass sealing is performed in a neutral or inert atmosphere.

(3) Mn-)ii-Cr-Zr with platinum electrode
When the thermistor element of the system is sealed with glass in a neutral or inert atmosphere, the resistance value increases by a factor of 10 to 20, making it impossible to produce a thermistor element with stable characteristics.

The present invention solves these problems by solving the complexity of the manufacturing process and reducing costs.

The object of the present invention is to provide a thermistor element that is inexpensive and highly reliable.

Means for solving the problem In order to solve this problem, the present invention provides Mn-Ni-0
Dumet wires with nickel plating applied to the platinum electrode surfaces on both sides of the r-Zr type thermistor body are fixed by parallel gap welding, and the structure is hermetically sealed in the atmosphere with a glass material.

Function According to this configuration, by applying nickel plating to the Dumet wire, it is possible to weld it to the electrode surface of the thermistor element without removing the surface oxide film of the Dumet wire. There is no need to secure it. Further, by applying nickel plating, it is possible to encapsulate glass in the atmosphere, and the rate of change in resistance value before and after glass encapsulation is low, and its variation is small. Therefore, the present invention uses a nickel-plated Dumet wire and encapsulates it in the atmosphere, thereby solving the problems of complexity and cost in the manufacturing process, and providing a thermistor element with stable characteristics. will be possible.

Embodiment FIG. 1 is a cross-sectional view of a glass-encapsulated thermistor according to an embodiment obtained by the method of the present invention. In FIG. A Dumet wire 7 with nickel plating applied to both electrode surfaces of an Mn-Ni-0r-Zr type thermistor body 6, such as a shape, is fixed by parallel gap welding 8, and the entire Dumet wire 7 except for a part is fixed. was hermetically sealed in the atmosphere with an alkali barium glass material 9.

As described above, according to this embodiment, by using the nickel-plated Dumet wire, it is possible to weld to the electrode surface of the thermistor element body without removing the surface oxide film of the Dumet wire, and If the glass sealing temperature is up to 700'C, the nickel plating will oxidize to gray color.
The sealing condition with the glass material was the best. Furthermore, the rate of change in resistance value before and after glass sealing was suppressed to a lower level than when sealing in a neutral or inert atmosphere, and the variation thereof was also small. 4 of the thermistor element obtained in this example.
In the high temperature storage test at 00°C, the rate of change in resistance value was within 1% even after 1000 hours, and no cracks occurred in the glass because an alkali barium glass material was used.

Moreover, it goes without saying that the glass material is not limited to an alkali barium glass material.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) By using a nickel-plated Dumet wire, there is no need to use conductive paint to fix the thermistor body electrode surface, or to remove the surface oxide film of the Dumet wire and weld it. The Dumet wire, which is nickel-plated directly on the electrode surface of the thermistor body, can be fixed using parallel gap welding, which solves the complexity of the process and reduces costs.

(2) By using nickel-plated Dumet wire, it is possible to seal the glass in the atmosphere.
It can be manufactured without using neutral or inert gas, making it possible to reduce costs.

By sealing with glass in the atmosphere, the rate of change in resistance before and after glass sealing can be kept low, and a thermistor with stable characteristics can be manufactured with small variations.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a glass-encapsulated thermistor according to an embodiment obtained by the method of the present invention, and FIG. FIG. 3 is a sectional view showing a glass-encapsulated thermistor. 6... Thermistor element, 7... Nickel plated Dumet wire, 8... Parallel gap welding, 9... Alkali barium glass material . Fig. 1 wE2 Fig. 6 - Na S star element body 9 - AlI/pazocum glass material Fig. 3

Claims (1)

[Claims] Mn-Ni-Cr- with platinum electrodes formed on both opposing sides
Two Dumet wires with nickel plating applied to the electrode surfaces on both sides of a Zr-based thermistor element are fixed using parallel gap welding, and the entire Dumet wire except for a part is exposed to the atmosphere using a glass material. A method for manufacturing a glass-encapsulated thermistor characterized by hermetically sealing it.