KR900008564Y1 - Small push button - Google Patents

Abstract

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Description

Miniature push button switch

1 is a perspective view showing a first embodiment of the present invention.

2 is a cross-sectional view taken along the line A-A of FIG.

3 is a connection diagram of a switch of the present invention.

4 is a perspective view showing a second embodiment of the present invention.

5 is a plan view showing a third embodiment of the present invention.

6 is a sectional view taken along the line B-B in FIG.

7 is a perspective view showing a conventional example.

8 is a cross-sectional view taken along the line C-C in FIG.

* Explanation of symbols for main parts of the drawings

1: Case 2, 3: Contact

4: Contact terminal 5: Contact terminal

6: leaf spring 7: push button

7a: flange portion 7b: push-down portion

7c: head 8: heat-resistant film

9: cover 10: hole for insertion

11: Grounding terminal 12: Printed wiring board

13 wiring pattern 14 solder

51: case 52, 53: contact

54: contact terminal 56: leaf spring

57: push button 57a: flange

57b: Pushing part 57c: Head part

58: heat-resistant snow film 59: cover

60: through hole 61: ground terminal

62: printed wiring board 63: wiring pattern

64: solder

According to the present invention, when a small push button switch having a waterproof discharge structure is superimposed on a printed wiring board and soldered a terminal to a wiring pattern, the inside of the switch after installation is brought to a low pressure due to the high temperature, so that the switch works well. It relates to a small push button switch to prevent it from being adjusted.

In recent years, as the miniaturization of electronic devices has progressed, in order to increase the actual mounting density of the components on the printed wiring board, a small push button switch is placed on the printed wiring board and directly solders the terminal to the wiring pattern. It is used a lot.

And in order to improve reliability, the switch which implemented the waterproof discharge apparatus as disclosed, for example in Unexamined-Japanese-Patent No. 61-142617 is provided.

7 and 8 show an example of a conventional switch of this type, in which 51 is a case made of a box-shaped, heat-resistant electrical insulating material having an upper surface open, and a contact 52 formed on the inner bottom thereof. And 53 are respectively connected to the contact terminals 54 and 54 which are insert-molded on the side surface of the case 51, and the outer ends of both contact terminals 54 and 54 are the case 51, respectively. At the lower end of the side of the), it is bent in an "L" shape.

On the left and right contacts 52 in Fig. 8, a plate spring 56 made of phosphor bronze, for example, is placed on the left and right sides, and is usually slightly separated from the center contact 53.

The inner part of the case 51 has a hemispherical shape in which the flange portion 57a of the push button 57 made of the same material as the case is lifted and fitted freely, protruding from the center of the lower surface of the flange portion 57a. The pushing part 57b is in contact with the center of the upper surface of the leaf spring 56.

On the upper surface of the flange portion 57a of the push button 57 and the center head 57c, a flexible heat-resistant film 58 made of synthetic resin is superimposed, and its circumference is at the upper end surface of the case 51, It adhere | attaches as a heat resistant adhesive material and seals the inside of the case 51 airtightly.

The upper surface of the heat resistant film 58 is fixedly formed on the case 51 so that the cover 59 made of stainless steel sheet which has been soldered in advance is folded so as to be easily soldered, and the push button 57 is pressed upwards, The head portion 57c of the push button 57 covered with the heat-resistant film 58 protrudes from the through hole 60 formed by cutting in the center of the cover 59.

At one end of the cover 59, a ground terminal 61 bent in a "c" shape toward the bottom is successively formed, and a lower end thereof and a lower end of the contact terminals 54 and 54 are formed. , Are located at the same height.

As shown in FIG. 8, the switch as described above is placed on the wiring pattern 63 coated with the cream solder (not shown) of the printed wiring board 62 in a high-temperature atmosphere (200 占 폚 or higher). When heated, the molten solder 64 is welded to the respective terminals 54, 54, and 61, and is mounted on the printed wiring board 62, and the head 57c of the push button 57 is removed. By the push-pushing operation, the leaf spring 56 is elastically bent, so that both the contacts 52 and 53 are closed.

However, since the above-mentioned conventional switch is sealed with the heat resistant film 58 on the upper surface of the case 51, when the switch becomes hot at the time of soldering, the air inside the case 51 expands and high pressure is applied. At a minute interval between the case 51 and the penetrating portion of the case 51 of the contact terminals 54 and 54, air flows out.

As the soldering ends and the temperature of the switch decreases, the air inside the case contracts and becomes a lower pressure than the external air. Therefore, the contact terminals 54, 54 protruding from the case 51 and the case 51 are released. Flux of high temperature low clay in the cream solder adhering to the boundary of) is sucked into the gap together with the outside air and becomes high clay as it cools to close the gap, so that the inside of the case 51 is atmospheric pressure. There is a problem that the cover 59 is narrowed inwardly slightly, so that the operation of the switch mounted on the printed wiring board 62 is not adjusted well.

This invention solves the above-mentioned conventional problem by forming one or more contact terminals which are not soldered to a wiring pattern in the position which the flux which generate | occur | produces when soldering a terminal to a wiring pattern does not invade. It is.

The switch of the present invention is to form at least one terminal which is not soldered to the wiring pattern at a position where the flux generated when soldering the terminal to the wiring pattern does not penetrate. Away from the solder part, when soldering the switch, away from the cream solder part, so that there is no risk of flux entering into the gap between the case and the contact terminal, even after being installed on the printed wiring board. The inside and outside air flow is secured, and the inside of the case is always kept the same as the outside air pressure, so that the operation of the switch is not poorly adjusted.

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 show a first embodiment of the present invention, where (1) is the same case as in (51), (2) and (3) are (52) and (53), respectively. As the contacts similar to the above, the contacts 2 and 3 are connected to the "L" shaped contact terminals 4 insert-molded at the lower end of the side surface of the case 1 similarly to the above-mentioned (54). .

The contact terminal 5 is connected to the contact 2 and protrudes in the outward direction of the case.

(6) is a leaf spring similar to the above (56), (7) is a push button similar to the above (57), (7a) is a flange portion, (7b) is a push pressing portion, (7c) Is the head.

(8) is a heat-resistant film similar to the above (58), and (9), (10) and (11) are holes to be fitted into the cover, similar to the above (59), (60) and (61), respectively. And ground terminal.

The switch of the present invention described above is placed on the wiring pattern 13 coated with the cream solder (not shown) of the printed wiring board 12, as shown in FIG. When heated in the middle, the molten solder 14 welds the rulers 4 and 11 to the wiring pattern 13.

However, since the contact terminal 5 is remarkably separated from the wiring pattern 13, the terminals 4, and 11, the solder 14 is not attached and the high temperature low clay is formed around the solder 14. Even if the flux is diffused, the economics of the case 1 and the contact terminal 5 protruding from the case 1 are not reached. Therefore, even if the switch is cooled after the end of soldering, the flux remains in the case 1 and the contact terminal 5. The air permeability is ensured without being sucked at a minute interval between the two, and the case 1 inside is at a normal pressure, and the switch installed on the printed wiring board 12 is operated by the push button 7. Always open and close with the desired adjustment.

4 shows a second embodiment of the present invention. The same reference numerals are given to the same members as the first embodiment, and description thereof will be omitted.

In this embodiment, instead of the contact terminal 5, the contact terminal 21 is formed at a suitable place on the side without the contact terminal 4 of the case 1.

Even in this case, since the contact terminal 21 is remarkably separated from the contacts 4, 11 and the cream solder portion, the same effect as in the first embodiment can be obtained.

5 and 6 show a third embodiment of the present invention, and the same members as those in the first embodiment are denoted by the same reference numerals and the description thereof will be omitted.

In this embodiment, instead of the contact terminals 5 and 21, the contact terminal 31 protrudes slightly upward from the lower end of the contact terminal 4 and the copper plate side surface. A cutout 32 is formed below the contact terminal 31 of the.

In this way, even if there is a creme solder under the contact terminal 31, it is not attached to the contact terminal 31 and the distance on the surface of the case 1 between the contact terminal 31 and the cream solder is remarkable. Since it is so long, the flux of the high temperature low clay at the time of soldering does not spread below the contact terminal 31.

As described above, the switch of the present invention has a case and the above-mentioned when soldering the switch to the printed wiring board because at least one contact terminal is markedly separated from the other terminal which is directly soldered to the wiring pattern. Since there is no fear of flux entering between the contact terminals and air flows inside and outside the case of the switch even after being installed on the printed wiring board, the inside of the case is always maintained at the same input as outside air. The behavior of the thing is not to be adjusted well.

Claims (4)

In a small push button switch having a waterproof dustproof structure in which the terminals 54, 54, and 61 are soldered and laid on the printed wiring board 62 and directly mounted on the wiring pattern 63, the wiring pattern 13 And a terminal 5 which is not directly soldered to the wiring pattern 13 at a position where the flux generated when soldering the terminal 4 to the terminal 4 does not penetrate. The small push button switch according to claim 1, wherein a terminal (21) which is not soldered is formed on the upper side of the case (1). The small push button switch according to claim 2, wherein a terminal (31) which is not soldered is formed on the side surface of the case (1) in which the terminal (4) to be soldered is not formed. The small push button switch according to any one of claims 1 to 3, wherein the lower portions of the terminals (5), (21), and (31) which are not soldered in the case (1) are cut out.