JPS6135345Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a soldering iron that uses a heat-generating semiconductor such as a thermistor having a positive temperature coefficient (PTC thermistor) as a heat source.

Conventionally, an electric soldering iron having a structure shown in FIG. 1 is known. In the figure, reference numeral 1 denotes a trowel member, which is sandwiched between heat generating plates 2, 2. Lead wires 4, 4 insulated by miniature tubes 3 are connected to the heating plates 2, 2. Reference numerals 5 and 5 denote metal cases, which fix and support the iron member 1 and heat generating plates 2, 2. Also,
Reference numeral 6 is a handle. The iron member 1 is made of steel with high thermal conductivity. Also, heat generating plate 2.
2 wraps a nichrome wire 2b around a mica thin plate 2a,
It is further coated with mica foil. The case 5 is made of a metal with good thermal conductivity, such as steel, in order to fix the iron member 1 and the heat generating plates 2, 2, support them, and radiate heat. However, the conventional electric soldering iron described above has a drawback in that the temperature rises to a temperature much higher than the temperature suitable for soldering. As a result, the solder becomes oxidized, its mechanical strength decreases, the surface loses its luster, and the soldering target, such as a printed circuit board or IC, may be damaged. In addition, since the temperature is higher than necessary, there is a drawback that the iron tip deteriorates rapidly. Furthermore, since more heat is generated than necessary, various disadvantages arise, such as extra power is consumed, a heat dissipation section must be provided, and this heat dissipation section must be provided in a large size. Therefore, as a solution to the above-mentioned drawbacks of the conventional electric soldering iron, a heat-generating semiconductor such as a thermistor (hereinafter referred to as a PTC thermistor) having a positive temperature coefficient generates heat when a voltage is applied to the semiconductor. Taking advantage of the property that resistance increases rapidly when a certain temperature is exceeded, a soldering iron using the above-mentioned heat-generating semiconductor as a heat source has been devised (Japanese Patent Publication No. 31579/1983). In the invention of this publication, in order to efficiently supply heat from the plate-shaped heat-generating semiconductor to the soldering iron tip, a current is passed through the plate-shaped heat-generating semiconductor in the direction of its thickness. The semiconductor is arranged with respect to the soldering iron tip so that the soldering iron tip is located in a direction perpendicular to the direction of electric current (the direction in which heat is released), which is a feature of the present invention. By the way, in order to efficiently generate heat in the above-mentioned heat-generating semiconductor, when connecting an electrode to the above-mentioned semiconductor, it is necessary to increase the contact area and density between the electrode and the semiconductor as much as possible. Here, the above-mentioned contact area is the side surface of the plate-shaped semiconductor, and cannot be made larger than this side surface. Therefore, the contact density, which is the other factor that efficiently causes the semiconductor to generate heat, must be increased. . The best way to maximize the contact density between the semiconductor and the electrode is to weld the electrode to the semiconductor. However, the semiconductor described above has the disadvantage that if heat is applied non-uniformly to the semiconductor, it will crack and be damaged, so electrodes cannot be welded to it. Furthermore, even when welding electrodes using chemical plating, the lead wires must be welded afterwards, and when welding the lead wires, heat is applied unevenly as described above, which can also damage the semiconductor. Resulting in. Therefore, welding by chemical plating is also not suitable. In this way, in order to increase the contact density between the semiconductor and the electrode, it is not possible to weld the electrode to the semiconductor, so other methods must be used to increase the contact density. Also, the upper limit of the operating temperature of the semiconductors mentioned above is around 300℃ at most.
To prevent the temperature from dropping, insulation must be applied, and in order to efficiently transfer heat to the tip of the soldering iron, the contact between the soldering iron and the semiconductor must be kept as close as possible. No. As described above, there are various problems that must be solved in order to put into practical use a soldering iron that uses a heat-generating semiconductor such as a PTC thermistor as a heat source. These problems to be solved are as follows in the invention of the above publication:
This is not mentioned at all, and the heating device (soldering iron) according to the invention of the above-mentioned publication has the drawback that it is difficult to put it into practical use.

This idea was made in view of the above circumstances, and its purpose was to provide an economical soldering iron that can maintain the optimum temperature for soldering, has a wide operating voltage range, and The heat source is a heat-generating semiconductor such as a PTC thermistor that can generate the optimum temperature for soldering, and the semiconductor, the electrode that supplies power to the semiconductor, and the iron member are integrally tightened and coated. By narrowing the middle part of the cylindrical body inward and narrowing the opening on the side where the tip of the iron member is located, the electrical contact density between the electrode and the semiconductor and the semiconductor The thermal contact density between the soldering iron and the soldering iron member is increased, and the heat of the semiconductor is efficiently transferred to the soldering iron tip.

This invention will be explained below with reference to the drawings.

FIGS. 2 to 4 are diagrams showing an embodiment of this invention. In the figure, reference numeral 10 denotes a heat-generating semiconductor, and this semiconductor 10 includes a PTC thermistor, which is formed into a rectangular parallelepiped thin plate as shown in FIG. 3A. Both sides 10 of the semiconductor 10
a, 10a has the largest area among the six side surfaces of the semiconductor 10;
An electrode 11 is arranged and pressed into contact with a and 10a. Lead wires 11b, 11b covered with insulated pipes 11a, 11a are connected to the electrodes 11, 11, as shown in FIG. 3B. The semiconductor 10 and electrode 11 are integrally covered with a film-like mica 12 as shown in FIG. 3C. The semiconductor 10 and electrode 11 integrally covered with this mica 12 are further covered with a polyimide film 13. This polyimide film 13 is made by winding a film into a cylindrical shape and then heat-sealing one end of the film as shown in FIG. 3D. In this way, the semiconductor 10 is integrally covered and insulated with the film-like mica 12 and the polyimide film 13.
The electrode 11 is press-fitted into the fitting portion 14a of the iron member 14, as shown in FIG. 3E. The circumferential surface of the iron member 14 is covered with a thin mica plate 15.
covered with. This mica thin plate 15 is
As shown in FIG. 3F, it is formed into a substantially cylindrical shape. The iron member 14 covered with the thin mica plate 15 is press-fitted into the cylindrical body 16. This cylinder 16 has a cylindrical shape as shown in FIG. The intermediate portion of the cylindrical body 16 is narrowed inward along its periphery to form a locking groove 16a that protrudes inward, and the cross-sectional shape of the locking groove 16a is As shown in Figure 2, it is approximately V-shaped. Further, the opening 16b at one end of the cylindrical body 16 is narrowed and made small. The opening 16a is formed by press-fitting the iron member 14 into the cylindrical body 16 provided with the locking groove 16a, and then narrowing the opening 16a. Further, the cylindrical body 16 is attached to a handle 17, as shown in FIG.

Next, the operation of the soldering iron according to the invention constructed as described above will be explained.

The heat-generating semiconductor 10 used as the heat source of this soldering iron has a property that as the temperature rises, the resistance decreases up to a certain set temperature, and increases rapidly when the set temperature is exceeded. Even if voltage continues to be applied, the heat generation temperature is automatically kept constant (240 to 270℃), and even if the voltage fluctuates, there is little variation in the heat generation temperature, and it has a wide operating voltage range. . Further, as described above, the electrodes 11 are arranged on both side surfaces 10a, 10a having the largest area among the side surfaces of the semiconductor 10,
In addition, since the soldering iron tip 14b is arranged in a direction perpendicular to the direction of the current, heat is efficiently supplied to the soldering iron tip 14b. Furthermore, the semiconductor 10 and the iron member 14 are integrally covered with the mica thin plate 15, and as a result, they are thermally insulated, so that there is little heat loss. In addition, the structure of the cylinder body 16 is first explained by the locking groove 1
6a is formed, and after the trowel member 14 is press-fitted into the cylindrical body 16 having the locking groove 16a, the opening 16b is narrowed down. Therefore, the iron member 14 is pressed toward the locking groove 16a. As described above, since the locking groove 16a has a V-shaped cross section, the iron member 14 is locked and simultaneously pushed down toward the center of the cylindrical body 16. As a result, the iron member 14 strongly pinches and presses the semiconductor 10 and the electrode 11, so that the contact density between the semiconductor 10 and the electrode 11 and the contact density between the semiconductor 10 and the iron member 14 via the insulator are is high, and the heat conduction is very good. Therefore, this soldering iron is
The above-mentioned good thermal efficiency and the above-mentioned heat source semiconductor 1
Coupled with the properties of 0, it has the excellent advantage of requiring very little power consumption.

FIG. 5 shows another embodiment. In this figure, the same reference numerals as in the first embodiment indicate the same constituent elements, and the explanation thereof will be omitted. This second embodiment is a soldering iron that is larger in size than the soldering iron of the first embodiment, and it is necessary to increase the amount of heat generated.
For this purpose, two semiconductors 10 are provided as heat sources. In order to lock these two semiconductors 10, the iron member 20 is provided with locking portions 20a and 20b. The iron member 20 includes a locking portion 20a,
Semiconductor 10 and electrode 11 integrally covered with film-like mica 12 and polyimide film 13 are locked to 20b, and after the circumferential surface of iron member 20 is covered and insulated with mica thin plate 21, cylindrical body 22 It is press-fitted and mated. This cylinder 22
has a cylindrical shape as shown in FIG. The intermediate portion of the cylindrical body 22 is a locking groove 22a that protrudes inwardly along its periphery, and the cross-sectional shape of the locking groove 22a is approximately V-shaped. Further, the opening 22b at one end of the cylindrical body 22 is narrowed and made small. The opening 22b is formed by press-fitting the iron member 20 into the cylindrical body 22 provided with the locking groove 22a and then narrowing the opening 22b. Even with this configuration, the same effects as in the first embodiment can be obtained.

In the above embodiments, film-like mica and polyimide film were used as the insulators, and mica thin plates were used as the insulating and heat-insulating materials, but other insulators and heat-insulating materials may be used.

As explained above, the soldering iron according to this invention uses a heat-generating semiconductor that can generate the optimum temperature for soldering as a heat source, and includes this semiconductor, an electrode that supplies power to this semiconductor, and this member. The intermediate part of the cylindrical body is tightened inward, and the opening on the side where the tip of the iron member is located is narrowed to prevent electrical contact between the electrode and the semiconductor. The density and thermal contact density between the semiconductor and the iron member can be increased. Also,
Semiconductors as a heat source automatically maintain a constant temperature even if the voltage is applied continuously, and even if the voltage fluctuates, the temperature does not fluctuate much, it has a wide operating voltage range, and it consumes less power. It is possible to make full use of its characteristics, such as being economical and having little energy. In addition, the temperature of the iron tip can be maintained at the optimum temperature for soldering (240 to 270 degrees Celsius), and the heat source does not overheat, ensuring high insulation with little deterioration of the insulation. For the same reason, when replacing parts of a printed circuit board, the copper foil does not peel off, and power consumption is low, which is economical.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing a conventional electric soldering iron, Figs. 2 to 4 show a first embodiment of this invention, and Fig. 2 shows a soldering iron according to this invention. 3 is a perspective view of each part, FIG. 4 is a perspective view of the whole, and FIG. 5 is a sectional view of main parts showing another embodiment of this invention. 10... Semiconductor, 11... Electrode, 12... Film-shaped mica, 13... Polyimide film,
14, 20... Trowel member, 14a... Fitting part, 1
4b, 20c... Soldering tip, 15, 21... Mica thin plate, 16, 22... Cylindrical body, 16a, 22a...
Locking groove, 16b, 22b...opening, 20a, 2
0b...Locking part.

Claims (1)

[Claims for Utility Model Registration] A heat-generating semiconductor such as a thermistor having a positive temperature coefficient, electrodes arranged to sandwich the semiconductor and supplying power to the semiconductor, and generating heat by receiving heat from the semiconductor. a soldering iron member, the semiconductor and the electrode are integrally covered with an insulating material, and the semiconductor and the electrode integrally covered with the insulating material are provided in a fitting part or a locking part provided on the ironing member. In a soldering iron that is fitted or locked, the periphery of the iron member is covered with an insulating and heat-insulating material, and the soldering iron is fitted into a cylindrical body, the middle part of the cylindrical body being connected to the distal end of the iron member. A soldering iron characterized in that it is narrowed inward so as to be locked, and one opening of the cylindrical body is narrowed so as to lock on the tip of a soldering iron member.