JP2000164093A - Thermal fuse and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal fuse capable of sufficiently securing the sealing strength of its metal terminal, free of the risk of a fuse element being exposed, and securing sufficiently the insulating performance between the applicable electronic appliance and fuse element. SOLUTION: On the oversurface of a first insulating material 11, an insulating plate 13 is installed covering part of at least two metal terminals 12a and 12b installed on the oversurface of the first insulating material 11, and flux 15 is applied in such a way as covering a fuse element 14 connected between the metal terminals 12a and 12b positioned at an opening 13a in the insulating plate 13, and on the oversurface of this plate 13, a second insulating material 16 is installed in such a way as covering at least the connecting parts of the fuse element 14 with the metal terminals 12a and 12b and the flux 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to prevent thermal damage to electrical and electronic equipment due to overheating of the equipment.
In particular, the present invention relates to a thermal fuse frequently used for a secondary battery and a secondary circuit, and a method for manufacturing the same.

[0002]

2. Description of the Related Art A conventional thermal fuse is disclosed in Japanese Patent Publication No. 7-954.
The one described in Japanese Patent Publication No. 19 is known.

Hereinafter, a conventional thermal fuse will be described with reference to the drawings. FIG. 10 is a sectional view of a conventional thermal fuse.

In FIG. 10, reference numeral 1 denotes a thermoplastic insulating plate. Reference numerals 2a and 2b denote a pair of metal terminals. The pair of metal terminals 2a and 2b are provided at both ends of the lower surface of the insulating plate 1 so that one end protrudes outward from the insulating plate 1. It consists of. In addition, the bulge 2
c and 2 d are provided, and the bulging portions 2 c and 2 d are exposed on the upper surface of the insulating plate 1. Numeral 3 denotes a fuse element made of a low melting point fusible alloy.
It is connected by welding between c and 2d. Reference numeral 4 denotes a flux applied on the fuse element 3. Reference numeral 5 denotes a sheet-shaped insulating cover. The insulating cover 5 covers the fuse element 3 and the flux 4 and is thermally fused to the upper surface of the insulating plate 1.

A method of manufacturing the conventional thermal fuse configured as described above will be described below with reference to the drawings.

[0006] First, as shown in FIG.
A pair of metal terminals 2a and 2b are arranged on the upper surface of the insulating plate 1, and the insulating plate 1 is placed on the upper surface so that the bulging portions 2c and 2d of the pair of metal terminals 2a and 2b are exposed on the upper surface of the insulating plate 1. Then, while the receiving table 6 is being heated, the insulating plate 1 is pressurized by the pressurizing plate 7 so that the end surfaces of the bulging portions 2c and 2d of the pair of metal terminals 2a and 2b are thermally fused to the insulating plate 1.

Next, as shown in FIG. 11B, a pair of metal terminals 2a, 2b exposed on the upper surface of the insulating plate 1.
The fuse element 3 is connected between the bulging portions 2c and 2d by a welding machine 8, and a flux 4 (not shown) is applied on the fuse element 3.

Finally, as shown in FIG. 11C, the insulating cover 5 is placed on the upper surface of the insulating plate 1 so as to cover the fuse element 3 and the flux 4, and then the center of the upper surface of the insulating cover 5 is formed. The cooling plate 9 is brought into contact with the cooling element 9 to cool the fuse element 3 by the circulation of the cryogen 9a.
Are thermally fused to produce a conventional thermal fuse.

[0009]

The conventional thermal fuse having the above-described structure is constructed by heat-sealing the insulating plate 1 and the end surfaces of the bulging portions 2c and 2d of the pair of metal terminals 2a and 2b. Since the sealing strength between the pair of metal terminals 2a, 2b and the insulating plate 1 is ensured, if the pair of metal terminals 2a, 2b is to be made smaller in order to reduce the size of the thermal fuse, heat fusion is required. The area becomes small, and the sealing strength between the pair of metal terminals 2a and 2b and the insulating plate 1 cannot be secured. Further, since the lower surface of the fuse element 3 is exposed, when the lower surface side of the fuse element 3 is brought into contact with an electronic device or the like to attach a thermal fuse to the electronic device, the insulation between the electronic device and the lower surface of the fuse element 3 is provided. There was a problem that the property could not be maintained.

The present invention solves the above-mentioned conventional problems. Even if the size of the metal terminal is reduced in order to reduce the size of the thermal fuse, the sealing strength of the metal terminal can be sufficiently ensured and the fuse element is exposed. It is another object of the present invention to provide a thermal fuse capable of sufficiently maintaining insulation between an electronic device and a fuse element.

[0011]

In order to achieve the above object, a thermal fuse according to the present invention comprises a first insulating material and the first insulating material having one end protruding outward from the first insulating material. At least two metal terminals disposed on the upper surface of the insulating material, and disposed on the upper surface of the first insulating material so as to cover a part of the metal terminals located on the upper surface of the first insulating material; and An insulating plate having an opening, a fuse element located at the opening of the insulating plate, and connected between the metal terminals, a flux applied so as to cover at least the fuse element, and at least the fuse element A second insulating material disposed on an upper surface of the insulating plate so as to cover the connection portion with the metal terminal and the flux; Even if the metal terminal is made smaller to achieve its shape, the sealing strength of the metal terminal can be sufficiently ensured, and the fuse element is not exposed, and the temperature at which the insulation between the electronic device and the fuse element can be sufficiently maintained A fuse is obtained.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is characterized in that the first insulating material and the first insulating material have one end projecting outward from the first insulating material. At least two metal terminals disposed on the upper surface and an opening disposed on the upper surface of the first insulating material so as to cover a part of the metal terminals located on the upper surface of the first insulating material. An insulating plate, a fuse element located at an opening of the insulating plate, and connected between the metal terminals, a flux applied so as to cover at least the fuse element, and at least the fuse element and the metal terminal. And a second insulating material disposed on the upper surface of the insulating plate so as to cover the connection portion and the flux. According to this configuration, the metal terminal is formed by the first insulating material, the insulating plate, Since the metal element is disposed between the first and second insulating members, regardless of the size of the metal terminal, an excellent sealing strength of the metal terminal can be obtained. Since the second insulating material is provided between the metal terminals and covers the fuse element, the fuse element is not exposed,
This has an effect that the insulation between the electronic device and the fuse element can be sufficiently maintained.

According to a second aspect of the present invention, the width of the portion of the metal terminal sealed by the first insulating material and the insulating plate is made smaller than the width of the unsealed portion. For example, since the bonding area between the first insulating material and the insulating plate is increased, an anchor effect is obtained at the narrowed portion of the metal terminal, and the sealing strength of the metal terminal is further increased. .

According to a third aspect of the present invention, the surface of the metal terminal is plated with metal. According to this configuration, the metal terminal and the fuse element are connected by heat of the metal terminal by resistance welding or the like. At this time, since the wettability of the metal plating applied to the surface of the metal terminal is good, the metal terminal and the fuse element are easily connected.

According to a fourth aspect of the present invention, a slit or a hole is provided at one end of the metal terminal projecting outward from the first insulating material. By doing so, even when attaching the metal terminal to an electronic device or the like, since both sides of the portion provided with the slit or hole can be spot-welded, the first spot-welded portion is fixed by the slit or hole. To reduce the stress on the first spot-welded portion when performing the second spot welding, thereby increasing the welding strength between the metal terminal and the electronic device. It has the effect of being able to do.

According to a fifth aspect of the present invention, there is provided a step of disposing at least two metal terminals on the upper surface of the first insulating material such that one end protrudes outward from the first insulating material. Disposing an insulating plate having an opening on the upper surface of the first insulating material so as to cover a part of the metal terminal located on the upper surface of the first insulating material; A step of connecting a fuse element between the metal terminals so as to be positioned, a step of applying a flux so as to cover at least the fuse element, and a step of covering a connection between the fuse element and the metal terminal and the flux. Disposing a second insulating material on the upper surface of the insulating plate. According to this manufacturing method, the metal terminal is disposed between the first insulating material and the insulating plate. Regardless of the size of the metal terminal, in addition to obtaining a metal terminal having excellent sealing strength, the fuse element is connected between the metal terminals disposed on the upper surface of the first insulating material, and Since the second insulating material is provided so as to cover, the fuse element is not exposed, and has an effect that the insulation between the electronic device and the fuse element can be sufficiently maintained.

According to a sixth aspect of the present invention, the first insulating material, the metal terminal, and the insulating plate are joined by heat generation of the metal terminal. According to this manufacturing method, the metal terminal is heated. By doing so, the metal terminal and the first insulating material and the insulating plate that are in contact with the metal terminal can be simultaneously heat-sealed, so that the three terminals can be easily joined.

According to a seventh aspect of the present invention, two or more thermal fuses are transported at once by using a frame for connecting two or more pairs of metal terminals. Therefore, the transfer between manufacturing facilities is easy, mass production is easy, and the tape can be supplied as it is to an automatic mounting machine to be attached to an electronic device as a taping product.

The invention according to claim 8 is the first insulating material,
According to this manufacturing method, at least one of the second insulating material and the insulating plate is formed of a continuous strip and manufactured using the same. According to this manufacturing method, two or more thermal fuses are formed at a time. Since the transfer can be performed, the transfer between the manufacturing facilities is easy, the mass production is easy, and the tape can be supplied as it is to an automatic mounting machine for attaching to an electronic device as a taping product.

(Embodiment 1) Hereinafter, a thermal fuse according to Embodiment 1 of the present invention will be described with reference to the drawings.

FIG. 1A is a top view in which a part of the thermal fuse according to the first embodiment of the present invention is cut away, and FIG.
Is a sectional view of the same.

In FIGS. 1A and 1B, reference numeral 11 denotes a first insulating material made of a thermoplastic resin.
1 is ABS, SAN, polysanfone, polycarbonate, noryl, vinyl chloride resin, polyethylene, polyester, polypropylene, polyamide, polyacetal, polyester, PPS, fluororesin, or any one of these. It is composed of the main component. Reference numerals 12a and 12b denote a pair of metal terminals partially provided with a square notch 24a to be described later. The pair of metal terminals 12a and 12b are provided at both ends of the upper surface of the first insulating material 11, and one end is provided at the first end. Projecting outward from the first insulating material 11;
Further, the portion provided with the rectangular cutout portion 24a is arranged so as to be located on the upper surface of the first insulating material 11, and is made of a single metal such as copper, nickel, iron, or an alloy thereof.
Reference numeral 13 denotes an insulating plate having an opening 13a. The insulating plate 13 has at least a square cutout 2 of a pair of metal terminals 12a and 12b located on the upper surface of the first insulating material 11.
4a and a pair of metal terminals 12a, 12b
Other end (side not protruding outward from first insulating material 11)
Are arranged on the upper surface of the first insulating material 11 so as to be exposed in the opening 13a. Also, this insulating plate 1
For 3, it is preferable to use the same material as the first insulating material 11, but it is also possible to use a different material. Reference numeral 14 denotes a fuse element. The fuse element 14 is located at the opening 13a of the insulating plate 13 and is connected between the pair of metal terminals 12a and 12b exposed at the opening 13a of the insulating plate 13.
It is made of a low melting point fusible alloy which is an alloy of lead, cadmium, bismuth, indium and the like. A flux 15 is applied so as to cover at least the fuse element 14 and the connection between the fuse element 14 and the pair of metal terminals 12a and 12b, and is made of a rosin-based material. 1
Reference numeral 6 denotes a second insulating material. The second insulating material 16 includes at least a fuse element 14 and a pair of metal terminals 12a, 1a.
It is arranged on the upper surface of the insulating plate 13 so as to cover the connection with the 2b and the flux 15. The second insulating material 16 is preferably made of the same material as that of the first insulating material 11, but may be made of a different material.

The manufacturing method of the thermal fuse according to the first embodiment of the present invention configured as described above will be described below with reference to the drawings.

FIGS. 6A to 6E are process diagrams showing a method for manufacturing a thermal fuse according to the first embodiment of the present invention.

First, as shown in FIG. 6 (a), rectangular cutouts 24a are partially formed at both ends of the upper surface of the first insulating material 11.
A pair of metal terminals 12a and 12b provided with a pair of one ends project outward from the first insulating material 11 and a portion provided with a rectangular cutout 24a is located on the upper surface of the first insulating material 11. To be placed.

Next, as shown in FIG. 6B, a pair of metal terminals 12a, 12a located on the upper surface of the first insulating material 11 is formed.
b so as to cover at least the square notch 24a and to expose the other end of the pair of metal terminals 12a and 12b (the side not protruding outward from the first insulating material 11) to the opening 13a. The insulating plate 13 having the portion 13a is disposed on the upper surface of the first insulating material 11, and the first insulating material 11 is joined to the pair of metal terminals 12a and 12b and the insulating plate 13 by thermal fusion. . At this time,
A hot plate heated to 300 ° C. is brought into contact with the insulating plate 13 and pressurized from above to perform heat fusion. However, it is necessary to adjust the pressure to such a level that the insulating plate 13 is not deformed and is in close contact with the pair of metal terminals 12a and 12b.

Next, as shown in FIG. 6C, a fuse element 14 is formed between a pair of metal terminals 12a and 12b exposed at an opening 13a of the insulating plate 13 by, for example, resistance welding, spot welding, laser welding, or the like. Connected by welding or the like.

Next, as shown in FIG. 6D, at least the fuse element 14 and the pair of metal terminals 12 are formed.
The flux 15 is applied by a heating dispenser or the like so as to cover the connection between the fuse elements 14a and 12b. The flux 15 may be filled in the entire opening 13 a of the insulating plate 13.

Finally, as shown in FIG. 6E, at least the fuse element 14 and the pair of metal terminals 12a,
So as to cover the connection portion with 12b and the flux 15;
A second insulating material 16 is arranged on the upper surface of the insulating plate 13,
The second in which the fuse element 14 is not arranged on the lower surface
Pressing the upper surface of the portion of the insulating material 16 of the first insulating material 11
And the insulating plate 13 and the second insulating material 16 are fused at a time by ultrasonic welding. In this case, a heat fusion method can be used as a method other than the ultrasonic welding. However, if there is a possibility that the heat at the time of the heat fusion may reach the fuse element 14 and be blown, a cooling mechanism is provided. I just need.
By using such a method, the first insulating material 1
Since the first and second insulating members 16 and the insulating plate 13 can be firmly adhered to each other, a highly insulative thermal fuse that can reliably seal the fuse element 14 can be obtained.

As another method of joining the first insulating material 11, the pair of metal terminals 12a, 12b, and the insulating plate 13, a pair of metal terminals 12a, 12 shown in FIG.
A resistance heating method using the heat generation of b may be used. That is, the pair of metal terminals 12
a and 12b are arranged on the electrodes 20 and 21 and
0, 21 and a pair of metal terminals 12a, 1
Heat generation can be performed by pressing the insulation plate 13 while pressing the insulating plate 13 while generating heat between 200 and 200 ° C. to 300 ° C., and pressing the jig 22. Thus, the pair of metal terminals 1
By generating heat from the pair of metal terminals 12a and 12b, the pair of metal terminals 12a and 12b
b and the first insulating material 11 and the insulating plate 1
3 can be thermally fused at the same time, so that these three can be easily joined.

In the above description, the method of manufacturing the thermal fuse individually has been described.
It is also possible to manufacture continuously.

FIG. 8 is a top view showing a state before the thermal fuse manufactured using the frame is divided into individual parts. One end of the pair of metal terminals 12a and 12b (the first insulating material 1) is shown in FIG.
2) a metal frame 2 at the tip of
By connecting two or more pairs of the metal terminals 12a and 12b to the frame 23, a plurality of thermal fuses can be continuously assembled. Also,
The frame 23 has holes 23a at regular intervals for transportation and positioning. Therefore, since two or more thermal fuses can be transported at one time, transport between manufacturing facilities is easy, and mass production is facilitated. Also,
By using a resin or paper-based material other than metal, the frame 23 can be supplied as it is to an automatic mounting machine for attaching to an electronic device as a taping product.

FIG. 9 is a top view showing a state in which the first insulating material 11 is formed of a continuous strip and the thermal fuse manufactured using the same is not divided individually. A plurality of thermal fuses can be continuously assembled by using the insulating material 11 formed of a continuous strip. The first insulating material 11 has a hole 11a for transport and positioning. Therefore, since two or more thermal fuses can be transported at one time, transport between manufacturing facilities is easy, and mass production is facilitated. Further, since it can be used continuously, it can be supplied as it is to an automatic mounting machine for attaching to an electronic device as a taping product. The first
The same effect can be obtained by using an insulating plate 13 or a second insulating material 16 which is continuous in a strip shape instead of the insulating material 11 described above.

With this configuration, the pair of metal terminals 12a and 12b are disposed between the first insulating member 11 and the insulating plate 13, so that the pair of metal terminals
Regardless of the size of the pair of metal terminals 12a, 12b,
a and 12b having excellent sealing strength are obtained, and the fuse element 14 is connected between the pair of metal terminals 12a and 12b disposed on the upper surface of the first insulating material 11; Is provided, the fuse element 14 is not exposed, and the insulation between the electronic device and the fuse element 14 can be sufficiently maintained.

Further, as shown in FIG.
Since square cutouts 24a are provided in portions of 2a and 12b which are sealed by the first insulating material 11 and the insulating plate 13, they are sealed by the first insulating material 11 and the insulating plate 13. The width of the metal terminals 12a, 12b can be made narrower than the width of the unsealed metal terminals 12a, 12b, so that the bonding area between the first insulating material 11 and the insulating plate 13 can be increased in the narrowed portion. Therefore, an anchor effect can be obtained, and the sealing strength of the metal terminals 12a and 12b can be further increased. Also, the metal terminal 12
The tensile strength and bending strength of a and 12b can also be improved. In the metal terminals 12a and 12b, the portions sealed by the first insulating material 11 and the insulating plate 13 are provided in place of the above-described square cutouts 24a.
V-shaped notch 24b as shown in FIG.
The same effect can be obtained by providing a round notch 24c as shown in FIG. Further, the metal terminals 12a, 1
If the surface of the notch 2b is roughened, a greater anchor effect can be obtained.

FIGS. 3A to 3C are sectional views of the metal terminals 12a and 12b on which the metal plating 17 is applied.

Nickel is used as the metal terminals 12a and 12b.
If a material with poor solder wettability such as iron is used, copper, tin, lead, indium, silver, or any other metal plating on the entire surface or part of the surface, or two or more of these metals As shown in FIG. 3 (a), when metal plating made of an alloy or metal plating in the form of a layer is applied, when metal plating 17 is formed on the entire metal terminals 12a, 12b, the metal terminals 12a, 12b and the fuse are formed. The metal terminals 12a, 1 are connected to the element 14 by resistance welding or the like.
2b, the metal terminals 12a, 12b
Since the metal plating 17b has good wettability, the metal terminals 12a and 12b and the fuse element 14 can be easily welded. Further, as shown in FIGS. 3B and 3C, when the metal plating 17 is formed on at least one end of the metal terminals 12a and 12b (on the side protruding outward from the first insulating material 11), the temperature increases. Solderability at the time of attaching a fuse to an electronic device can be improved.

In the first embodiment of the present invention, an axial lead type thermal fuse in which a pair of metal terminals 12a and 12b are arranged on a straight line has been described. However, as shown in FIG. 12a, 12b
Can be applied to a radial lead type thermal fuse in which are arranged in parallel.

(Embodiment 2) Hereinafter, a thermal fuse according to Embodiment 2 of the present invention will be described with reference to the drawings.

FIGS. 4A and 4B are top views of the thermal fuse according to the second embodiment of the present invention.

The difference between the thermal fuse according to the second embodiment of the present invention and the thermal fuse according to the first embodiment of the present invention is that a pair of metal terminals 12a are provided as shown in FIGS. , 12b (the first insulating material 11).
The other point is that a slit 18 or a hole 19 is provided at the tip portion on the side that protrudes outward.

Generally, a thermal fuse using a plate-shaped metal terminal is attached to an electronic device by spot welding, soldering, or the like. However, in spot welding, welding is performed at a plurality of locations depending on the area (or width) of the metal terminal. At this time, the first spot-welded portion is fixed, so that the metal terminal is likely to bend. If the second spot-welding is performed in this bent state, 1
Stress may be applied to the spot-welded portion of the spot, and the welding strength between the metal terminal and the electronic device may be reduced.

However, in the configuration as in the second embodiment of the present invention, the slit 18 or the hole 1
If spot welding is performed on both sides of the portion provided with 9, the deflection can be eliminated by the slit 18 or the hole 19, so that the stress on the first spot welded portion due to the deflection of the pair of metal terminals 12a and 12b is reduced. Accordingly, the welding strength between the pair of metal terminals 12a and 12b and the electronic device can be increased. Further, the slit 18 or the hole 19 can be used for positioning when the thermal fuse is attached to the electronic device. Of course, if the slit 18 or the hole 19 is provided in the longitudinal direction of the pair of metal terminals 12a and 12b, the area that can be spot-welded is increased, which is advantageous in production.

[0044]

As described above, according to the present invention, the first insulating material and the one end are disposed on the upper surface of the first insulating material so as to protrude outward from the first insulating material. At least two metal terminals, an insulating plate disposed on the upper surface of the first insulating material so as to cover a part of the metal terminals located on the upper surface of the first insulating material, and having an opening; A fuse element located at the opening of the insulating plate and connected between the metal terminals, a flux applied so as to cover at least the fuse element, and a connection part between at least the fuse element and the metal terminal and A second insulating material disposed on the upper surface of the insulating plate so as to cover the flux,
According to this configuration, since the metal terminal is disposed between the first insulating material and the insulating plate, excellent sealing strength of the metal terminal can be obtained regardless of the size of the metal terminal.
Since the fuse element is connected between the metal terminals arranged on the upper surface of the first insulating material and includes the second insulating material so as to cover the fuse element, the fuse element is not exposed, and the electronic device and the fuse are not exposed. An advantageous effect that sufficient insulation between the elements can be obtained is obtained.

[Brief description of the drawings]

FIG. 1A is a top view in which a part of a thermal fuse according to a first embodiment of the present invention is cut away. FIG.

FIG. 2 (a) is a top view of a metal terminal partially provided with a rectangular notch in the first embodiment of the present invention; and (b) is a top view of a metal terminal having a V-shaped notch provided in the same part. Figure (c) Top view of a metal terminal having a round cutout in the same part

FIGS. 3A to 3C are cross-sectional views of metal terminals of the thermal fuse according to the first embodiment of the present invention.

FIGS. 4A and 4B are top views of a thermal fuse according to a second embodiment of the present invention;

FIG. 5 is a partially cutaway top view of a thermal fuse as a modification of the first embodiment of the present invention.

FIGS. 6A to 6E are process diagrams showing a method for manufacturing a thermal fuse according to the first embodiment of the present invention;

FIG. 7 is a sectional view showing another method of manufacturing the thermal fuse according to the first embodiment of the present invention.

FIG. 8 is a top view showing a state before the thermal fuse manufactured using the frame according to the first embodiment of the present invention is individually divided;

FIG. 9 is a top view showing a state in which the first insulating material according to the first embodiment of the present invention is formed of a continuous band-like material and the thermal fuse manufactured using the first insulating material is not divided yet.

FIG. 10 is a sectional view of a conventional thermal fuse.

11A to 11C are process diagrams showing a conventional method for manufacturing a thermal fuse.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 1st insulating material 12a, 12b Metal terminal 13 Insulating plate 13a Opening 14 Fuse element 15 Flux 16 2nd insulating material 17 Metal plating 18 Slit 19 Hole 23 Frame 24a Square notch 24b V-shaped notch 24c Round Shape cutout

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shinichi Otsuka 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 5G502 AA02 BA02 BB10 BB13 BC01 BD09 JJ01

Claims (8)

[Claims] A first insulating material; at least two metal terminals disposed on an upper surface of the first insulating material such that one end protrudes outward from the first insulating material; An insulating plate disposed on the upper surface of the first insulating material so as to cover a part of the metal terminal positioned on the upper surface of the first insulating material, and having an opening; and an insulating plate positioned at the opening of the insulating plate;
And a fuse element connected between the metal terminals, a flux applied so as to cover at least the fuse element, and at least a connection portion between the fuse element and the metal terminal and the insulating plate so as to cover the flux. And a second insulating material disposed on the upper surface. 2. The thermal fuse according to claim 1, wherein a width of a portion of the metal terminal sealed by the first insulating material and the insulating plate is smaller than a width of an unsealed portion. 3. The thermal fuse according to claim 1, wherein a metal plating is applied to a surface of the metal terminal. 4. The thermal fuse according to claim 1, wherein a slit or a hole is provided at one end of the metal terminal protruding outward from the first insulating material. 5. A step of arranging at least two metal terminals on an upper surface of the first insulating material such that one end protrudes outward from the first insulating material; Arranging an insulating plate having an opening on the upper surface of the first insulating material so as to cover a part of the metal terminal located on the upper surface; and providing the metal terminal so as to be positioned on the opening of the insulating plate. A step of connecting a fuse element therebetween, a step of applying a flux so as to cover at least the fuse element, and a step of applying a flux on the upper surface of the insulating plate so as to cover a connection between the fuse element and the metal terminal and the flux. 2. A method for manufacturing a thermal fuse, comprising the steps of: disposing an insulating material. 6. The method of manufacturing a thermal fuse according to claim 5, wherein the three members of the first insulating material, the metal terminal, and the insulating plate are joined by heat generation of the metal terminal. 7. The method of manufacturing a thermal fuse according to claim 5, wherein the thermal fuse is manufactured using a frame that connects two or more pairs of metal terminals. 8. The method according to claim 5, wherein at least one of the first insulating material, the second insulating material, and the insulating plate is formed of a continuous strip, and is manufactured using the same. 8. The method for manufacturing a thermal fuse according to any one of claims 1 to 7.