JPH0432201A - Manufacture of ptc element - Google Patents

Abstract

PURPOSE:To stick a constant quantity of solder by applying cream solder to the specified electrode faces of PTC elements, plating lead wires with solder having a higher melting point than the cream solder, applying the lead wires to the specified electrode faces of the PTC elements, and passing the PTC elements through a heater face for thermal welding. CONSTITUTION:PTC elements 1 with which various metallic oxides are mixed are sintered into disk form and silver thin films are attached to both faces thereof to form electrode faces 1a and 1b. Cream solder 2 with a low melting point is applied to one of the electrode faces 1a and 1b. Lead wires 3 are made of approximately U-shaped metallic wires and the tips of their parallel lead sections 3a are bent into cross form to make bends 3b and 3c and plated with solder 4 with a high melting point. The lead wires 3 are fixed to tape 5 at equal distances and the PTC elements 1 are inserted into the crosses of the bends 3b and 3c with the cream solder 2 on the upper face. The cream solder 2 with a low melting point is molten and the bends 3b of the lead wires 3 are welded by passing the PTC elements 1 through a heater 6 at the specified position by moving the tape 5. The unnecessary lead wires are cut to obtain PTC elements 1A having lead wires.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a PTC element in which a lead wire is welded to one side of a PTC element whose both sides are electrodes.

(Prior Art) Conventionally, when attaching a lead wire to one side of a PTC element having electrodes on both sides, as shown in FIG. They were in contact with each other and were welded one by one using thread solder 33 and soldering iron 34. This work was extremely complicated and required skill, and was not suitable for mass production.

For this reason, a batch method was considered. As shown in FIG. 5, a plurality of recesses 36 into which the PTC elements can be inserted are formed in a metal plate 35 such as a stainless steel plate or an aluminum plate to which solder does not adhere, and the PTC elements 30 are inserted into these recesses 36. is inserted and the lead wire 32 is attached, the lead wire 32 is held down by a holding jig 37, and the holding jig 37 and the metal plate 35 are fixed with a clip 38. And PTC element 30
and the lead wire 32 were immersed in a solder bath 39 to be welded.

(Problems to be Solved by the Invention) However, mass production is difficult with the above-mentioned batch method, and dipping into the solder bath is done manually, resulting in variations in the amount of solder adhering, variations in the dipping time, etc. There were problems such as silver corrosion on the electrode surface.

The present invention has been made in view of the above circumstances, and its purpose is to provide a method for manufacturing a PTC element that enables mass production, maintains a constant amount of solder adhesion, and is free from silver corrosion. It is something.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the method for manufacturing a PTC element of the present invention includes applying cream solder to a predetermined electrode surface of the PTC element, and applying a cream solder to a predetermined electrode surface of the PTC element. The present invention is characterized in that the lead wire is plated with melting point solder, and the lead wire is brought into contact with a predetermined electrode surface of the PTC element and passed through a heater surface to be thermally welded.

(Function) In the method for manufacturing a PTC element of the present invention using the above method, the low melting point solder on the predetermined electrode surface melts while passing through the heater surface and is welded to the high melting point solder on the lead wire, so that the PTC element is automatically manufactured. This makes it possible to weld the lead wire and the solder, making it possible to maintain a constant amount of solder and mass production.

(Example) An example of the present invention will be described below with reference to FIGS. 1 to 3.

Fig. 1 shows a PTC element, and Fig. 1 (a) is a plan view;
Figure (b) is a sectional view of the same. This PTC element 1 is made by mixing various metal oxides and sintering them into a disk shape, and electrode surfaces 1a and 1b coated with silver in a thin film form are provided on the front and back surfaces of the disk shape. A cream solder 2 having a melting point of 220° C. is applied on one side of these electrode surfaces 1a and 1b by a method such as printing, and this cream solder 2 is sufficiently dried to form a hardened layer on the surface. .

FIG. 2 is a perspective view of the lead wire. The lead wire 3 is formed by forming one metal wire into a substantially U-shape (clip shape), and the ends of the lead portions 3a that are parallel to each other are connected to the other end. Bent parts 3b and 3c are formed so as to intersect,
The bent portions 3b and 3c are shorter than the diameter of the PTC element 1 and come into elastic contact with each other. These bent portions 3b and 3C are coated with solder plating 4 having a high melting point (240° C. or higher).

FIG. 3(a) shows the lead wires 3 fixed to the tape 5 at equal intervals. This fixation is done by the lead part 3 of the lead wire 3.
By suppressing a, the elastic contact between the bent portions 3b and 3C becomes stronger, and the PTC element 1 is inserted into the intersection of the bent portions 3b and 30 with the cream solder 2 facing upward. As a result, the PTC element 1 is held by the lead wire 3 and is moved as the tape 5 moves without coming off.

By moving this tape 5, a third
By passing through the heater 6 as shown in FIG.
Weld b. In this case, if the temperature of the heater 6 is high, the solder plating 4 of the bent part 3b that is in contact with the electrode surface 1b may melt and stick to the electrode surface 1b, so the temperature of the heater 6 or the moving speed of the tape 5 may be increased. Adjust by doing.

Next, as shown in FIG. 3(C), by cutting off unnecessary lead wires, a PTC element IA provided with lead wires can be obtained. This PTC element IA is completely welded with the solder 4a also on the end surface side of the lead wire 3, as shown in FIG.
The solder plating 4 on the bent portion 3c does not melt onto the electrode surface 1b, and a finished product can be easily obtained.

[Effects of the Invention] As explained above, the method for manufacturing a PTC element of the present invention is as follows:
By applying cream solder to a predetermined electrode surface of the PTC element, applying solder plating with a higher melting point than the melting point of the cream solder to a lead wire, and bringing this lead wire into contact with the predetermined electrode surface and passing it through the heater surface. Since thermal welding is performed, it is possible to automatically weld the PTC element and the lead wire, and the amount of solder attached can be kept constant, which has the advantage of making mass production possible.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention, and FIG. 1 shows a PT
Figure (a) shows the C element; Figure (a) is a plan view, Figure (b) is a cross-sectional view, Figure 2 is a perspective view of the lead wire, Figure 3 is a manufacturing process diagram, and Figure (a) is a taping diagram. A process diagram of attaching a lead wire to the line tape and attaching a PTC element to this lead wire. Figure (b) is a process diagram of passing it through the heater surface. Figure (C) is a process diagram of cutting unnecessary lead wires. , the same figure (d
) is a side view of the finished product, FIGS. 4 and 5 are conventional examples, FIG. 4 is a manual lead wire installation diagram, and FIG. 5 is a process diagram using a batch method.

Claims (2)

[Claims] (1) Apply cream solder to the predetermined electrode surface of the PTC element,
The lead wire is plated with solder having a melting point higher than the melting point of the cream solder, and the lead wire is brought into contact with a predetermined electrode surface of the PTC element and passed through a heater surface to be thermally welded. A method for manufacturing a PTC element. (2) Apply cream solder to the predetermined electrode surface of the PTC element,
The intersection portions of the clip-shaped lead wires whose tips intersect are plated with solder having a melting point at least 20° C. higher than the melting point of the cream solder, and the PTC element is held between the intersection portions of the cream solder. A method for manufacturing a PTC element, which comprises cutting a lead wire located on one side of the PTC element after passing through a heater surface that heats the element to a level equivalent to its melting point.