JPH07201524A - Glass-enclosed thermistor - Google Patents

Abstract

(57) [Summary] [Objective] Regarding a glass-enclosed thermistor used as a temperature sensor, a glass-enclosed thermistor that reduces open defects after airtight sealing in the manufacturing process and has improved reliability against thermal shock and external force The purpose is to supply. [Structure] Stat part 1 of slag lead wires 18 and 19
By processing the connection-side end surfaces 14a and 15b of the electrodes 4 and 15 into an uneven shape, the electrode surfaces 12 and 1 of the thermistor element body 11 are formed.
Since the connection with 3 is stable, the contact area becomes smaller, and the pressure contact pressure increases, the occurrence of open defects after hermetic sealing can be reduced even if lead wires are deformed, misaligned, or foreign matter is mixed. In addition, reliability against thermal shock and external force can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass-enclosed thermistor used as a temperature sensor for home appliances, household appliances, automobile equipment and the like.

[0002]

2. Description of the Related Art A conventional glass-enclosed thermistor will be described with reference to the sectional view of FIG. In FIG. 4, 1 is a thermistor element body in which electrodes 2 and 3 are formed on opposite surfaces, and slag lead wires 8 and 9 composed of stat portions 4 and 5 and lead portions 6 and 7 are connected to the stat portion connecting side. End face 4a,
5a (not shown because it overlaps the electrodes 2 and 3) and the electrode surfaces 2 and 3 of the thermistor element body are parallel to each other, and the pair of slug lead wires 8 and 9 are arranged on the same straight line by pressure welding. In the electrically connected state, the thermistor element body 1 and the slag lead wires 8 and 9 around the stat portions 4 and 5 were hermetically sealed with glass 10.

[0003]

However, in the above-mentioned conventional structure, both the connection-side end surface of the stat portion electrically connected by pressure contact and the electrode surface of the thermistor body are smooth, which causes the following problems. was there. (1) When the slag lead wire, thermistor element body, and glass are set in a carbon jig for airtight sealing in the manufacturing process, due to deformation of the slag lead wire, abrasion of the carbon jig, and the like, the end surface on the connection side of the stat part If the electrodes of the thermistor body are not connected in parallel, the unstable contact will occur at the outer periphery of the end face of the connecting side of the stat part and the edge of the electrode surface of the thermistor body, and Airtight sealing is often performed while the body is tilted, and open defects after airtight sealing and fluctuations in resistance value due to thermal shock and external force are applied. (2) If foreign matter is present between the connection-side end surface of the stat portion and the electrode surface of the thermistor body in the manufacturing process, even a very small foreign matter is likely to cause an open failure after hermetically sealing. (3) Since the contact area between the connection-side end surface of the stat portion and the electrode surface of the thermistor body is large, the pressure contact pressure is small, and fluctuations in the resistance value are likely to occur due to thermal shock and external force.

The present invention solves such a problem. Even if the slag lead wire is deformed, the carbon fitting is worn or foreign matter is mixed in during the manufacturing process, the stat portion can be stably maintained. An object of the present invention is to provide a glass-enclosed thermistor in which the connection-side end surface is connected to the electrode surface of the thermistor element body and the reliability against thermal shock and external force is improved.

[0005]

In order to solve this problem, the glass-enclosed thermistor of the present invention is characterized in that the connection-side end surface of the stat portion of the slag lead wire is processed into an uneven shape or a convex shape. Further, the present invention is characterized in that the electrode surface of the thermistor element body has an uneven shape.

[0006]

According to this structure, the connection-side end surface of the stat portion of the slag lead wire processed into the uneven shape or the convex shape and the electrode surface of the uneven thermistor body are stably connected, and the contact area is further increased. It becomes smaller and the pressure contact pressure per unit area increases. Therefore, even if the slag lead wire is deformed in the manufacturing process, the carbon jig is worn out, the carbon jig is misaligned during setting, or foreign matter is mixed into the contact area, the occurrence of open defects after hermetic sealing is reduced. It is possible to provide a glass-encapsulated thermistor which is capable of improving the reliability against thermal shock and external force.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the embodiments shown in FIGS.

In FIG. 1, reference numeral 11 is a thermistor element body in which electrode surfaces 12 and 13 are formed on opposite surfaces. Slag lead wires 18 and 19 composed of stat portions 14 and 15 and lead portions 16 and 17 having the same coefficient of thermal expansion as that of glass
Is provided with the tip portions 14a and 15a which are processed into an uneven shape. In a state where the connection side end surfaces 14a and 15a and the electrode surfaces 12 and 13 of the thermistor body are parallel to each other, and the slag lead wires 18 and 19 are pressure-contacted and electrically connected in the same straight line. , The thermistor body 11
And the stat portion 1 of the slag lead wires 18 and 19
The periphery of Nos. 4 and 15 is hermetically sealed with glass 20 to form a glass-enclosed thermistor.

According to the embodiment shown in FIG. 1, the connection-side end surface 14a of the stat portions 14 and 15 processed into the uneven shape,
15a allows the connection-side end surfaces 14a and 15a of the stat portions 14 and 15 and the electrode surfaces 12 and 1 of the thermistor element body.
Since 3 is connected in a stable state, and the connection area becomes smaller and the pressure contact pressure increases, the slag lead wire is deformed during the manufacturing process, the carbon jig is worn out, and the position shift or the contact part Even if foreign matter is mixed in, the occurrence of open defects after hermetically sealing can be reduced, and the reliability against thermal shock and external force can be improved.

The second embodiment, whose cross-sectional view is shown in FIG. 2, has substantially the same construction as that of the embodiment shown in FIG. 1, except that the connection-side end faces 14a, 15a of the stat portions 14, 15 have a convex shape. Since the processed connection side end faces 14b and 15b are used, the same effect as that of the embodiment shown in FIG. 1 can be obtained.

The third embodiment, whose cross-sectional view is shown in FIG. 3, has substantially the same structure as that of the embodiment shown in FIG. 1, except that the electrode surfaces 12 and 13 of the thermistor element body are roughened. By using the surfaces 12a and 13a, it is possible to obtain a higher effect than the embodiment shown in FIG.

[0012]

As described above, the glass-encapsulated thermistor according to the present invention is a thermistor element body in which the connection-side end surface of the stat portion of the slag lead wire is processed from uneven to convex, or at the same time, the electrode surface is uneven. Because I am using
It has the following effects.

The connecting side end surface of the stat portion of the slag lead wire and the electrode surface of the thermistor element body are connected in a stable state,
Also, since the contact area decreases and the pressure contact pressure increases, even if there is misalignment at the time of carbon jig setting due to deformation of the slag lead wire or abrasion of the carbon jig in the manufacturing process, or foreign matter entering the contact part, The occurrence of open defects after hermetically sealing can be reduced, and the reliability against thermal shock and external force can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a glass-enclosed thermistor that is a first embodiment of the present invention.

FIG. 2 is a sectional view of a glass-enclosed thermistor according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a glass-enclosed thermistor according to a third embodiment of the present invention.

FIG. 4 is a cross-sectional view of a conventional glass-enclosed thermistor.

[Explanation of symbols]

 11 Thermistor Element 12 Electrode of Thermistor Element 13 Electrode of Thermistor Element 14 Stud part of slag lead wire 14a Connection side end face of stat part of slag lead wire 15 Stud part 15b Connection end face 16 Lead part of slag lead wire 17 Lead Part 18 Slag lead wire 19 Slag lead wire 20 Glass

Claims (3)

[Claims] 1. A stat part for external connection, which has a thermistor element body having electrodes formed on opposite surfaces thereof and a coefficient of thermal expansion equal to that of glass, and the end face of the connection side of the thermistor element body is processed into an uneven shape. A pair of slag lead wires consisting of lead portions, and glass for encapsulation coating, wherein the connection side end surface of the stat portion and both electrode surfaces of the thermistor body are electrically connected by pressure contact, the thermistor A glass-enclosed thermistor in which the body and the periphery of the slag lead wire stat are hermetically sealed with glass. 2. The glass-enclosed thermistor according to claim 1, wherein the connection-side end surfaces of the stat portions of the pair of slag lead wires are processed into a convex shape instead of the uneven shape. 3. The glass-encapsulated thermistor according to claim 1, wherein both electrode surfaces of the thermistor element body are uneven.