JPS5951419A - Method of producing switch element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a switch element in which a space within a contact is completely sealed.

Traditionally, switch elements used in tact switches, etc.
A click spring that gives a click feeling to the push button is used as a movable contact, and this movable contact is arranged opposite to a fixed contact. In such a conventional switch element, a fixed contact and a movable contact are integrated by ultrasonic welding.

Ultrasonic welding is performed between a synthetic resin surface formed by insert molding on the fixed contact and an annular synthetic resin surface formed by separate insert molding on the flange of the movable contact. Since it is difficult to completely weld the entire circumference of the flange part, a gap is created in the welded part, making it impossible to completely seal the space formed between the fixed contact and the movable contact6. When cleaning the solder flux adhering to the surface with an organic solvent such as Freon or chlorocene, the solder flux dissolved in the organic solvent enters the space through the gap in the welded part, and
It may adhere to contacts and cause contact failure.

It is an object of the present invention to prevent foreign matter from entering the space between a fixed contact and a movable contact to eliminate contact failure, and to seal the space with a single insert molding. An object of the present invention is to provide a method for manufacturing a switch element that can realize a structure.

The method for manufacturing a switch element of the present invention includes the following steps. That is, the movable contact must have flexibility,
Since the terminal board of the movable contact must have a certain strength, both are formed separately and then integrated by spot welding or the like to form the movable contact side member.

Next, the fixed contact side member on which the terminal portion has been formed in advance and the movable contact side member manufactured in the previous step are superimposed with a spacer made of an electrically insulating material interposed therebetween, and the two members are integrated to form a contact wafer. At this time, hot melt, adhesive tape, etc. can be used as the unifying means. Then, the contact wafer thus formed is molded into a molding material with an insert 1 so as to cover the overlapping portion and the lower surface of the fixed contact side member, thereby completing a switch element. This insert molding realizes a completely sealed structure for the contact area, and
The contact wafer is reinforced, and furthermore, the fixed contact side member and the printed circuit board pattern surface are electrically insulated.

An embodiment of the present invention will be described below with reference to the drawings.

A movable contact terminal board 1 made of a material such as brass or phosphor bronze has terminal portions 1a and la on both sides thereof, and has an opening 1b in the center. And terminal board 1
Since the terminal portions 1a and 1a must have a certain strength, they are made of a material having a thickness of, for example, about 0.3I.

On the other hand, the movable contact 2 is made of phosphor bronze for springs, stainless steel for springs, etc., and has a dome-shaped curved part 2a in the center, and a flat peripheral flange part 2 around the curved part 2a.
It has b. Since the movable contact 2 must have flexibility, it is made of a material having a thickness of, for example, about 0.03 to 0.01 nwn.

The terminal board 1 and the movable contact 2 formed in this way are connected to the peripheral flange portion 2b of the movable contact 2, as shown in the third diagram.
are superimposed on the terminal board 1, and the overlapping portions are compressed using electrodes P and P of a spot welding machine, respectively, and welded through the slot 1, thereby being integrated. At this time, the curved portion 2a of the movable contact 2 is located within the opening 1b of the terminal board 1 and does not interfere with the terminal board l. In this way, the movable contact side member 3 is formed.

Next, the spacer 4 is made of an electrically insulating plastic material such as ABS resin or polycarbonate, and has an opening 4a formed in its center to avoid interference with the curved portion 2a of the movable contact 2. The front and back surfaces of the spacer 4 are coated with hot melt with a thickness of, for example, several 107i, i'ij degrees.

Reference numeral 5 indicates a fixed contact side member, and this fixed contact side member 5 has terminal portions 5a, 5a on both sides thereof, and has a protruding contact portion 5b at the center of its upper surface. The fixed contact side member 5 is made of a material such as bronze or phosphor bronze, and has a thickness of, for example, about 0.3+nm. The reason for forming the plate to such a thickness is to provide sufficient strength to the terminal portions 5a, 5a.

Then, the movable contact side member 3, which is formed by integrating the movable contact 2 with the terminal board 1, is superposed on the fixed contact side member 5'' through the spacer 4, as shown in Figure 6, and is used for hot melt melting. It is heated while being compressed from above and below by a heater 7. Then, the hot melt coated on the front and back surfaces of the spacer 4 melts, and the members 3 and 5 and the spacer 4 are integrated to form a contact wafer 6. The heating temperature by the heater 7 is usually about 70 to 80°C, and the heating time is about 1 to 2 seconds, but these temperatures and times vary depending on the type of hora 1-melt.

Note that adhesive tape or the like may be used as the joining means other than hot melt, and it is sufficient that the members 3, 5 and the spacer 4 are integrated.

Next, the contact wafer 6 is insert-molded into the molding material 8 so as to cover the overlapping part and the lower surface of the fixed contact side member 5 (see FIGS. 7 and 8), so that the space 9 within the contact is completely sealed.
The molded material 8 is sealed and reinforced, and the fixed contact side member 5 is insulated from the printed circuit board pattern surface (not shown). thus,
The switch element is completed.

As explained below, according to the method of manufacturing a switch element of the present invention, the space inside the contact is completely sealed, so foreign matter such as solder flux does not enter into this space, and the manufactured switch Since the occurrence of contact failure of the element can be reliably prevented and this complete sealing is achieved by just one insert molding, the effect of extremely high productivity can be obtained.

Moreover, the movable contact and its terminal board are made into separate members.

Since the terminal board is formed with the terminal board and then integrated with the terminal board, the strength of the terminal board can be sufficiently increased.

Furthermore, since the lower surface of the fixed contact side member is also covered with the molding material when the contact wafer is insert-molded into the molding material, it is possible to obtain an effect of excellent electrical insulation.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the terminal board of the movable contact, Fig. 2 is a plan view of the movable contact, Fig. 3 is a sectional view of the forming process of the movable contact side member, Fig. 4 (a) is a plan view of the spacer, (b) is (b)
5(A) is a plan view of the fixed contact side member, (B) is a front view of (A), FIG. 6 is a sectional view of the contact wafer forming process, and FIG. 7 is FIG. 8. FIG. 8 is a cross-sectional view of the insert molding process taken along line 1--2, and FIG. 8 is a plan view of the switch element of the present invention. DESCRIPTION OF SYMBOLS 1... Terminal board, 1a... Terminal part, 2... Movable contact, 2b... Peripheral flange part, 3... Movable contact side member, 4... Spacer, 5... Fixed contact Side member, 5a
...Terminal part, 6...Contact wafer, 8...Molding material. 7- Figure 1 ■ Figure 2 8- Figure 3 Figure 4 (A) (0)

Claims (1)

[Claims] A step of overlapping and integrating a peripheral flange portion of a movable contact with a terminal board of the movable contact to form a movable contact side member, a fixed contact side member having a terminal portion formed thereon, and the movable contact side member. a step of forming a contact wafer by overlapping the peripheral portion of the movable contact via a spacer made of an electrically insulating material and integrating the three, and the overlapping portion of the contact wafer and the lower surface of the fixed contact side member; A method for manufacturing a switch element, comprising the step of insert-molding the contact wafer in a molding material so as to cover the contact wafer.