JPH0411310Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a push button switch that is attached to a printed circuit board by soldering.

As a conventional push button switch of this type, the one shown in FIGS. 1 and 2, for example, is known. This push button switch 1 consists of a switch body 2 and a mounting plate 3, and is fixed to a printed circuit board 4 by soldering. The switch body 2 has a stem 6 that can freely protrude and retract from a case 5 that houses a switch element, and two terminal portions 7 that protrude downward from one side 5a of the lower surface in the figure. On the other hand, the mounting plate 3 includes a holding part 3a having a U-shaped cross section and a pair of leg parts 3 extending downward from the holding part 3a.
It consists of b. Holding portion 3a of this mounting plate 3
The switch body 2 is surrounded and held, and the leg portions 3b are
and the terminal portion 7 in the hole 4 of the printed circuit board 4, respectively.
a and through hole 4b, then turn the printed circuit board 4 upside down and hold it with the push button switch 1 facing down, and solder the leg portion 3b and terminal portion 7 to the printed circuit board 4 from above using the auto dip method or the like. The switch body 2 is arranged vertically so as to be substantially perpendicular to the printed circuit board 4.

However, in such a conventional push button switch 1, a portion of the switch body 2 including the protruding front surface 5b of the stem 6 is surrounded by the holding portion 3a of the mounting plate 3, and the mounting plate 3 is not exposed to heat. If it is made of a metal with high conductivity and is heated, it will easily reach a high temperature and the flux during soldering will be difficult to solidify, so the molten flux will pass through the hole 4a.
The water flows down the mounting plate 3 in the direction of arrow A and reaches the front surface 5b of the switch body 2. and,
This flux adheres to the periphery of the stem 6, significantly impairing the pressure feeling of the stem 6, and at the same time, there is a risk that it may enter the inside of the case 5 and cause contact failure.

This idea was made in view of the conventional situation, and by fixing the holding part of the mounting plate to the back side of the switch body opposite to the front side where the stem protrudes, the flux can be attached. To provide a push button switch which does not impair switch performance by preventing water from flowing through a plate to the front of a switch body, preventing it from adhering to a stem and infiltrating into a case.

This invention will be explained below based on the drawings.

3 to 6 are diagrams showing an embodiment of this invention.

First, to explain the configuration, the push button switch 11 is as follows.
Switch body 12 and mounting plate 1 with approximately U-shaped cross section
It consists of 3.

The switch main body 12 has a stem 15 provided in a resin case 14 so as to be freely retractable as in the conventional case. This case 14 has a pair of terminal portions 16 protruding from one side 14a facing the printed circuit board 4, and two caulking protrusions 14d protruding from the front 14b and the opposite back 14c. On the other hand, mounting plate 1
3 is made of metal material with good thermal conductivity,
A holding part 13d fixes the switch body 12 by making it come into contact with the protruding front face 14b and the back face 14c opposite to the protruding front face 14b. Both wing parts 13a are formed to bring the contact end 13b into contact with the printed circuit board 4, and the contact end 13b
A leg portion 13c is provided protruding from each of the legs 13c to be inserted and fixed to the printed circuit board 4. Furthermore, the stabilizing leg 13
The lower ends of both wing portions 13a extend toward the switch main body 12 so as not to protrude from the case 14, and the lower ends of the stabilizing legs 13f are formed to abut against the printed circuit board 4. Also, the holding part 13d of the mounting plate 13
is in surface contact with the back surface 14c of the case 14, and the caulking protrusion 14 of the case 14 is located there.
Two holes 13e are bored at positions corresponding to d. Furthermore, the aforementioned holding portion abutting end 13b is configured such that when the switch main body 12 is attached to the mounting plate 13,
It extends so as to protrude from one side surface 14a toward the printed circuit board 4 side.

And the case back 14c of the switch body 12
The caulking protrusion 14d is attached to the holding portion 13 of the mounting plate 13.
d is inserted into the hole 13e and caulked, with the case back surface 14c and the holding portion 13d in surface contact,
A switch body 12 is fixed to a mounting plate 13 to constitute a push button switch 11.

In order to mount this push button switch 11 on the printed circuit board 4, first, the leg portion 13c and the terminal portion 16 of the push button switch 11 are inserted into the hole 4a and through hole 4b drilled at predetermined positions on the printed circuit board 4, as in the conventional case. Penetrate it, then turn it over and solder using the auto dip method. In this state, the metal mounting plate 13 is attached to the front surface 14b of the switch body 12.
Since it is not provided so as to surround the sides, even if molten flux passes through the mounting plate 13, it will not adhere to the stem 15 or enter the case 14. In other words, due to the distance between the mounting plate 13 and the stem 15, even if the flux flows down the heated mounting plate 13 without solidifying, the case of the switch body 12 has low thermal conductivity and is unlikely to reach a high temperature. It begins to solidify at 14 and does not reach stem 15. Therefore, the switch function can be achieved without adhering to the stem 15 and impairing the pressing feeling, or penetrating inside the case 14 and causing poor contact of the contacts. Furthermore, when the push button switch 11 is attached to the printed circuit board 4, the contact end 13b of the mounting plate 13 is in contact with the printed circuit board 4, and one side 14a of the switch body 12 and the printed circuit board 4 are separated from each other. When the flux flows down through the leg portions 13c and the terminal portions 16, the flow is weakened, and in conjunction with the above, it is further prevented from adhering to the stem 15. That is, the push button switch 1 is connected to the printed circuit board 4.
Conventionally, one side 14 of the switch body 12
It is difficult to bring the printed circuit board 4 into contact with the printed circuit board 4 in a wet state, and a minute gap is created between the one side surface 14a and the printed circuit board 4. Therefore, the flux flowing down through the leg portions 13c and the terminal portions 16 passes through the minute gaps due to capillary action, and thus easily adheres to the stem 15. On the other hand, if the one side surface 14a and the printed circuit board 4 are actively separated by a certain distance, the effect of capillarity cannot be obtained, and moreover, it is easy to solidify while flowing down the spaced gap. Since the flow is weakened, adhesion to the stem 15 is further suppressed. Note that the stabilizing legs 13f are provided at the lower ends of both wing portions 13a, and are not provided up to the front side 14b of the case 14 as in the conventional case. There are almost no negative effects.

As explained above, according to this idea,
Since the holding part of the mounting plate is fixed to the back side of the switch body, it is possible to prevent flux from adhering to the stem, so that the function of the switch can be maintained in good condition. In addition, it has a simple structure, low cost, and can be easily and securely inserted into a printed circuit board together with the terminals of the switch body. Furthermore, since the wings extend on the opposite side from the stem, a stable posture can be maintained against the stem pressing operation. Furthermore,
Since the stabilizing legs are provided, a more stable posture can be obtained for insertion fixation and pressing operations. Since the tips of the stabilizing legs do not protrude beyond the case, the mounting plate and the switch body can be moved closer to the pressing operation side member, making it more compact. Furthermore, by separating the switch body from the printed circuit board, the effect of preventing flux from adhering to the stem is further improved.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams showing a conventional push button switch. Figure 1 is a side view of the push button switch mounted on a printed circuit board, Figure 2 is a perspective view of the push button switch, and Figure 3 is a perspective view of the push button switch. 6 to 6 are views showing one embodiment of the push button switch of this invention, FIG. 3 is a side view similar to FIG. 1, FIG. 4 is a front view of the same push button switch, and FIG. 5 is a view of the same push button switch. FIG. 6 is a perspective view of the mounting plate. 4...Printed circuit board, 11...Push button switch,
12...Switch body, 13...Mounting plate, 13a
... wing section, 13b ... contact end, 13c ... leg section,
13d...Holding part, 13f...Stabilizing leg, 14...
Case, 14a...One side, 14b...Front, 1
4c... Back, 15... Stem, 16... Terminal section.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A switch body in which a stem is provided in a resin case so as to be freely retractable and a terminal portion to be soldered to a printed circuit board protrudes from the case; A holding part that is fixed by coming into contact with the protruding front side and the back side opposite to the front side, and each side of the holding part is bent toward the side opposite to the switch body, and the lower end of the holding part is brought into contact with the printed circuit board. forming both wing parts and protruding from each of the corresponding contact ends a leg part to be inserted and fixed to the printed circuit board, and extending the lower ends of the both wing parts toward the switch main body side so as not to protrude from the case; 1. A push button switch comprising a mounting plate having a substantially U-shaped cross section and having a stabilizing leg whose lower end abuts the printed circuit board. (2) The mounting plate is arranged such that the contact end of the holder that contacts the printed circuit board is located closer to the printed circuit board than the one side surface, so that the one side of the switch main body that faces the printed circuit board is separated from the printed circuit board. A push button switch according to claim 1 of the utility model registration claim, characterized in that the push button switch protrudes from and extends to.