JPH03248503A - Thermistor - Google Patents

Abstract

PURPOSE:To obtain thermistors improve in humidity resistance with no factors of corrosion and excellent in adhesion of a lead terminal with a glass body by equipping a lead terminal with a copper suboxide layer at a joint with the glass body, and the part of exposure from the glass body with a metal plating layer made in advance. CONSTITUTION:Lead terminals 2a, 2b used is each equipped with a copper suboxide layer at a joint with a glass body 24, and the part of exposure from the glass body 24 with metal plating layers 3a, 3b made in advance. This structure therefore requires no process of metal plating prevents corrosion, and improves adhesion with the glass body 24 because of its joint with the copper suboxide layer 30. This attains simplification of manufacturing process and reduction of manufacturing cost and can provide a thermistor 1 which is excellent in adhesion with the glass body 24 and causes no corrosion.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a glass-sealed thermistor.

(Prior Art) Conventional examples of thermistors used as temperature sensors in various electronic devices that generate heat will be described with reference to FIGS. 4 to 6.

The axial type thermistor 20 shown in FIG. 4(b) is
Thermistor element body 21 and this thermistor element body 2
Picture electrodes 22a provided on both end surfaces of 1.

A pair of lead terminals 23a connected to 22b.

23b, a substantially cylindrical glass body 24 that seals the outer periphery of the end regions of the thermistor element body 21 and lead terminals 23a, 23b, and a coating on the outer periphery of the portions of the lead terminals 23a, 23b that are exposed from the glass body 24. Ni (
or Sn) plating layers 27a and 27b.

One end surface of the lead terminal 23a is connected to the electrode 22a.
The outer peripheral portion is joined to the inner surface of the glass body 24, and the other end face is provided with a cylindrical dumet portion 26a to which a lead wire 25a such as a copper wire is welded. The other lead terminal 23b also includes a lead wire 25b and a dumet portion 26b similar to the lead terminal 23a.

The dumet portion 26a is made of Ni, as shown in FIG.
The outer periphery of the -Fe alloy core 28 is covered with a Cu outer shell 29, and a Cu 20 (cuprous oxide) layer 30 is further provided on the outer periphery of the outer shell 29.

In order to manufacture the thermistor 20, first, the method shown in FIG.
), the dumet portion 26a.

Lead terminals 23a and 23b are prepared by welding lead wires 25a and 25b to 26b, respectively, and each dumet part 26a,
The end face of 26b is connected to both electrodes 22a of the thermistor element body 21.
, 22b, the outer circumferences of the thermistor element body 21 and both Dumet parts 26a and 26b are sealed with the glass body 24 in an inert gas atmosphere.

Next, as shown in FIG. 4(b), each lead wire 25a is exposed outward from both end surfaces of the glass body 24.

The outer periphery of 25b is plated with Ni (or Sn) to obtain the thermistor 20 shown in the figure.

However, in the case of the thermistor 20 having the above configuration, after the thermistor element body 21 and the Dumet parts 26a and 26b are sealed with the glass body 24, Ni (or Sn) plating is applied to the lead wire 25a.

25b, so the dumet part 26a,
There is a problem in that the plating solution adheres and remains in the boundary area between the lead wires 25a and 25b of the lead wire 26b, causing corrosion, and cleaning the plating solution is also difficult. Furthermore, since a plating process is essential, there is a problem in that the number of manufacturing steps increases and the product cost increases.

FIG. 6(b) shows a conventional radial type thermistor 40.

When manufacturing this thermistor 40, first of all, as shown in FIG.
), both electrodes 22a of the thermistor element body 21
, 22b, the ends of Dumet wires 32a and 32b as lead terminals having a CH2O layer 31 on the outer periphery are joined by paste (Ag, Au, etc.) 33 or welding, and then the thermistor element is heated in air or an inert gas. Main body 21. The paste 33 and the outer periphery of the end regions of the Dumet wires 32a and 32b are sealed in the glass body 34.

Next, as shown in FIG. 6(b), Ni is applied to the outer periphery of the Dumet wires 32a and 32b exposed outward from the glass body 34.
(or Sn) plating layer 35 is formed to produce a product.

However, in the case of this thermistor 40 as well, as in the case of the thermistor 20, corrosion is likely to occur, and a plating process is essential, resulting in a large number of manufacturing steps and high manufacturing costs.

Conventionally, in order to omit the plating process as described above, attempts have been made to manufacture a thermistor by connecting a Dumet wire with a Ni plating layer formed on the outer periphery to the thermistor element body and then sealing with glass ( Unexamined Japanese Patent Publication 1986-
No. 246802).

(Problems to be Solved by the Invention) The present invention has been made in view of the above circumstances, and can simplify the manufacturing process and reduce the manufacturing cost, and has good adhesion to the glass body, preventing corrosion. The purpose of this invention is to provide a thermistor with no problems.

[Structure of the Invention (Means for Solving the Problems)] The present invention connects the ends of lead terminals to electrodes provided on the thermistor element body, and the outer periphery of the end areas of the thermistor element body and the lead terminals is covered with glass. In the thermistor sealed by the glass body, the lead terminal is provided with a cuprous oxide layer at the joint part with the glass body, and a metal plating layer formed in advance on the part exposed from the glass body. be.

(for production) The operation of the thermistor having the above configuration will be explained below.

By using a lead terminal in this thermistor that has a cuprous oxide layer on the joint part with the glass body and a pre-formed metal plating layer on the part exposed from the glass body, a metal plating process is no longer necessary. In addition, corrosion is eliminated, and since the cuprous oxide layer is bonded to the glass body, the adhesion to the glass body is also improved.

(Example) Embodiments of the present invention will be described below with reference to FIG.

FIG. 1 shows an axial type thermistor 1, and elements having the same functions as the thermistor 20 shown in FIG. 4(b) are designated by the same reference numerals.

The difference between this thermistor 1 and the thermistor 20 is that the lead terminals 2a and 2b include dumet parts 26a,
The structure is such that only the Cu20 layer 30 on the outer periphery of the Dumet parts 26a, 26b is bonded to the inner surface of the glass body 24 by using lead wires 4a, 4b whose outer peripheries have been previously coated with Ni (or Sn) plating layers 3a, 3b. , the lead wire 4
a and 4b have a structure exposed from the glass body 24.

According to this thermistor 1, the lead terminal 2a.

Lead wire 4a is plated in advance as 2b.

By using the thermistor 4b, the thermistor 1
A plating process is not required in the manufacturing stage of the thermistor 1, the manufacturing process is simplified, and the manufacturing cost of the thermistor 1 can be reduced.

Furthermore, since plating is not performed at the manufacturing stage, there is no plating solution remaining attached to the dumet parts 26a, 26b, etc., and corrosion is also eliminated.

Further, on the inner surface of the glass body 24, there are dumet parts 23a, 2.
Since only the Cu2O layer 30 of 3b is to be bonded,
The adhesion between each dumet portion 26a, 26b and the glass body 24 is also improved.

Note that in the thermistor 1, although not shown in FIG.
It is also possible to use one having a Cu2O layer in the end face regions of 6a and 26b.

Next, referring to FIG. 2, the other side of the embodiment of the present invention will be described. In the thermistor IA shown in the same figure, those having the same functions as the thermistor 1 shown in FIG.

The thermistor IA shown in FIG. 2 is different from the thermistor 1 described above in that the sealed area of the glass body 24 is slightly reduced at both ends thereof, and the leads of the dumet parts 26a and 26b are preliminarily formed as lead terminals 2c and 2d. line 4a,
There is also a Ni (or Sn) plating layer 5 on the end face area on the 4h side.
The reason is that a material with a and 5b formed thereon was used.

This thermistor IA can also exhibit the same action and effect as the thermistor 1 described above.

Next, with reference to FIG. 3, still another example of the embodiment of the present invention will be described.

The figure shows a radial type thermistor 10. In this thermistor 10, those having the same functions as the thermistor 40 shown in FIG. 6 are denoted by the same reference numerals.

The thermistor 10 shown in FIG. 3 is different from the thermistor 40 described above in that lead terminals 11a and llb are preliminarily coated with a Cu2O layer on the entire outer periphery of the dumet wires 32a and 32b.
1, and further Ni (or Sn) plating layers 12a, 12b on the outer periphery of the Cu2O layer 31 excluding the end regions.
The reason is that a pre-formed one was used.

That is, Cu2 at the ends of lead terminals 11a and llb
The O layers 31, 31 are each directly bonded to the glass body 34, and are also bonded and fixed to the electrodes 22a, 22b by paste 33, respectively. And lead terminals 11a, ll
The area of the Ni plating layers 12a and 12b in b is the glass body 34.
It is designed to be exposed on the outside.

According to this thermistor 10, Cu2O
Since the structure is such that only the layer 31 is bonded to the glass body 34,
The plating process at the manufacturing stage is no longer necessary, which simplifies the manufacturing process and reduces manufacturing costs. It also eliminates corrosion due to residual plating solution, and also improves the close contact between the lead terminals 11a and llb and the glass body 34. The properties are also improved.

The present invention is not limited to the embodiments described above,
Various modifications are possible within the scope of the gist.

[Effects of the Invention] According to the present invention described in detail above, by improving the structure of the lead terminal as described above, it is possible to simplify the manufacturing process and reduce the manufacturing cost, and also to eliminate corrosion factors and improve moisture resistance. It is possible to provide a thermistor with improved adhesiveness between the lead terminal and the glass body.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the thermistor according to the present invention, FIG. 2 is a sectional view showing the other side of the embodiment of the present invention, and FIG. 3 is a sectional view showing yet another example of the embodiment of the present invention. Cross-sectional view, Figure 4 (
a) is a cross-sectional view showing the manufacturing process of a conventional axial-type thermistor, FIG. 4(b) is a cross-sectional view of a conventional axial-type thermistor, and FIG. 5 is a cross-sectional view taken along line I-I in FIG. 4(a). 6(a) is a sectional view showing the manufacturing process of a conventional radial type thermistor, and FIG. 6(b) is a sectional view of the conventional radial type thermistor. 1, IA, 10... Thermistor, 2a, 2b... Lead terminal, 3a, 3b-Ni plating layer, 4a, 4b... Lead wire, 26a, 26b... Dumet part, 24... Glass body. Figure IA Figure (0) L, I

Claims (1)

[Claims] In a thermistor in which an end of a lead terminal is connected to an electrode provided on a thermistor element body, and the outer periphery of the end region of the thermistor element body and the lead terminal is sealed with a glass body, the lead terminal is bonded to the glass body. 1. A thermistor comprising a cuprous oxide layer on a portion thereof and a metal plating layer formed in advance on a portion exposed from a glass body.