JPH04315717A - Push switch - Google Patents

Abstract

PURPOSE:To stabilize a function of a push switch and promote thinning thereof. CONSTITUTION:A recessed part 25 is formed in a fixed contact 13 with which a movable contact 16 is brought into contact so as to adopt multipoint contact or line contact for the contact between them. The fixed contact 13 provided on the upper surface of a base substrate 11 is continued to patterns 14, 14a, 20 on the rear surface of the base substrate 11 via through holes so that soldering can be applied. A spacer 17 is further placed on the upper surface of the base substrate 11 and a membrane sheet 18 is fixed to the spacer 17 so as to prevent the membrane sheet 18 from hindering an up-and-down motion of the movable contact 16.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a push switch, and more particularly to a push switch that prevents poor contact and promotes thinning.

0002

2. Description of the Related Art A conventional push switch of this type will be explained with reference to FIG. In the figure, reference numeral 1 denotes a push switch. In the push switch 1, a fixed contact 3 is insert-molded in a base mold 2, and the upper surface of the fixed contact 3 is exposed on the bottom surface of the base mold 2. Furthermore, a click spring 4 is accommodated within the base mold 2.

The center of the click spring 4 is curved upward to form a movable contact 5 at the center, and the periphery of the click spring 4 is placed on the fixed contact 3 outside the base mold 2. . Furthermore, a membrane sheet 6 is fixed to the side wall of the base mold 2 to cover the upper surface of the base mold 2. Further, the fixed contact 3 extends the terminal portion 7 and is exposed at the lower side of the base mold 2 to form an electrode 8. Then, the electrode 8 is soldered to the electrode of the circuit board 9.

[0004] When the top surface of the push switch 1 is pressed, the movable contact 5 of the click spring 4 descends and comes into contact with the fixed contact 3 at the center. Further, when the pressing is released, the elastic force of the click spring 4 returns to the original state, and the central fixed contact 3 and the movable contact 5 are separated.

[0005]

[Problems to be Solved by the Invention] In the conventional push switch described above, the fixed contacts and the terminals connected to the fixed contacts are insert-molded in the base mold.
The base mold becomes thick, which poses a problem in making the push switch thinner. Further, since the movable contact and the fixed contact are in one-point contact, contact failure is likely to occur due to the intrusion of unnecessary objects, which may cause quality problems.

[0006]Therefore, a technical problem arises that must be solved in order to stabilize the function of the push switch and promote thinning of the push switch.The present invention aims to solve this problem.

[0007]

[Means for Solving the Problems] The present invention has been proposed to achieve the above object, and it is possible to press a movable contact to contact a fixed contact, or to release the pressure and fix the movable contact. In a push switch that performs a switching operation by separating the contact, a fixed contact is provided on a base board, the fixed contact is electrically connected to a pattern on the back of the base board through a through hole, and a recess is formed in the fixed contact. Furthermore, the present invention provides a push switch characterized in that a spacer is mounted on the outer edge of the base substrate, and a membrane sheet is fixed to the spacer to cover the upper surface.

[0008]

[Operation] This invention is configured such that a fixed contact is provided on the base board, the fixed contact and the pattern on the back side are electrically connected through a through hole, and can be soldered to a circuit board of an electronic device, so insert molding is possible. By eliminating this, the push switch can be made thinner.

Furthermore, since the fixed contact is formed with a recess, the fixed contact and the movable contact are in multi-point contact or line contact, and unnecessary objects between the fixed contact and the movable contact can be removed from the recess. can be excluded. Therefore, the contact between the movable contact and the fixed contact is stable, and a reliable switching operation is possible. In addition, since the spacer is provided on the base substrate, the membrane sheet covering the top surface is prevented from interfering with the vertical movement of the movable contact.For example, when the movable contact is formed of a click spring, etc., the push switch It is possible to provide a good click feeling to the person typing the key.

0010

[Embodiment] An embodiment of the present invention will be described below with reference to FIG. 1 of the accompanying drawings.
This will be explained in detail with reference to FIGS. In the figure, 10 is a push switch, and as shown in FIG.
The push switch 10 is formed in a rectangular shape and performs a switching operation by pressing the center part of the upper surface.
The keypad is configured to give a click feeling to the person typing the key.

As shown in FIG. 2, the push switch 1
0 is the first fixed contact 12 on the upper side edge of the base board 11.
, and a second fixed contact 13 is arranged in the center. The first and second fixed contacts 12 and 13 are connected to electrode patterns 14 and 14a formed on the back surface of the base substrate 11. Further, the edge of a click spring 15 made of a conductive material is placed on the first fixed contact 12, and the center portion of the click spring 15, which can move up and down, serves as a movable contact 16. Further, a flat spacer 17 whose upper and lower surfaces are coated with adhesive is mounted on the upper surface of the base substrate 11, and the click spring 15 is accommodated in a large diameter accommodation hole 17a formed in the spacer 17. ing.

Then, the peripheral edge of the membrane sheet 18 is adhered to the upper surface of the spacer 17, and the push switch 1 is closed.
It covers the top surface of 0. Since the membrane sheet 18 is fixed to a flat surface, the pasting operation is easier than pasting the membrane sheet 18 onto the upper surface of the click spring 15. Further, by providing the spacer 17, the membrane sheet 18 can be accommodated in a predetermined position without coming into close contact with the click spring 15, so that the membrane sheet 18 prevents the vertical movement of the movable contact 16 of the click spring 15. This can be prevented and a good click feeling can be given to the person pressing the push switch 10. Furthermore, since the accommodation hole 17a of the spacer 17 serves as a guide when assembling the click spring 15, positioning becomes easy.
Simplify assembly work.

As shown in FIGS. 3 to 5, the base substrate 11 is formed by printing on a substrate 19 made of synthetic resin and having the first fixed contact 12, the second fixed contact 13, The electrode patterns 14, 14a and lead pattern 20 are formed on the back surface. The lead pattern 20 extends from the center to one electrode pattern 14a. In the figure, reference numerals 21 and 21a are conductive patterns provided on the edge of the upper surface of the substrate 19 to face the electrode patterns 14 and 14a.

Further, as shown in FIG. 3, the base substrate 11 is formed from a plurality of substrate sheets 22. As shown in FIG. Before the base substrate 11 is divided, through holes 23 and 23a are formed in the substrate sheet 22. The conductive pattern 2
Through holes 23 provided at positions 1 and 21a provide electrical continuity between the conductive patterns 21 and 21a and the electrode patterns 14 and 14a. On the other hand, a through hole 23a provided at the position of the second fixed contact 13 connects the second fixed contact 13 and the lead pattern 20.

Therefore, the first fixed contact 12 connects to the electrode pattern 14 via the conductive pattern 21 and the through hole 23.
The second fixed contact 13 is electrically connected to the electrode pattern 14a via the through hole 23a and the lead pattern 20. When the base substrate 11 is divided from the substrate sheet 22, a conductive groove 24 is formed at the edge of the base substrate 11. Furthermore, a cross-shaped recess 25 is formed in the center of the second fixed contact 13.

Further, as shown in FIG. 2, the space between the electrode patterns 14 and 14a on the back surface of the base substrate 11 is covered with an insulating resist 26. Then, the push switch 10 is placed on a circuit board 27 of an electronic device (not shown), and the electrode patterns 14 and 14a are soldered and surface-mounted. Even if the air between the membrane sheet 18 and the base board 11 expands during soldering, the outside air and the inside of the push switch 10 are ventilated through the through holes 22a, so there is no risk of the membrane sheet 18 peeling off, etc. The expanded air has no adverse effects.

When the upper surface of the push switch 10 is pressed, the middle portion of the click spring 15 is lowered to provide a good click feeling to the person pressing the key. Further, the movable contact 16 of the click spring 15 comes into contact with the second fixed contact 13, and the electrode patterns 14 and 14a are electrically connected. The contact is the second
Since a cross-shaped recess 25 is formed in the fixed contact 13, there is a four-point contact. Further, even if unnecessary objects such as dust enter between the click spring 15 and the second fixed contact 13, the unnecessary objects are accommodated in the recess 25 of the second fixed contact 13, thereby preventing contact failure. Then, when the pressure on the click spring 15 is released, the elastic force of the click spring 15 returns to the original state, and the second fixed contact 13 and the movable contact 16 are separated.
The push switch 10 performs a switching operation.

It should be noted that this invention can be modified in various ways without departing from the spirit of the invention, and it goes without saying that this invention extends to such modifications.

[0019]

According to the present invention, the movable contact and the fixed contact have a single point contact in the conventional type, but by forming a recess in the fixed contact, it is possible to make a multi-point contact or a line contact. Further, even if unnecessary objects enter between the fixed contact and the movable contact, the unnecessary objects are removed into the recess, thereby preventing contact failure and stabilizing the function of the push switch.

On the other hand, since the fixed contacts on the top surface of the base board are electrically connected to the pattern on the back surface of the base board through the through-holes, the push switch size is significantly reduced compared to the conventional type in which the fixed contacts are insert-molded in the base. It can be made thin. Furthermore, since a spacer is provided on the top surface of the base substrate to prevent the membrane sheet from interfering with the vertical movement of the movable contact, for example, when the movable contact is formed with a click spring, it is convenient for the person who presses the push switch. A click feeling can be given.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a push switch.

FIG. 2 is an enlarged sectional view of a push switch.

FIG. 3 is a plan view of the base substrate.

FIG. 4 is a back view of the base board.

FIG. 5 is a sectional view taken along line AA in FIG. 3;

FIG. 6 is a sectional view of a conventional push switch.

[Explanation of symbols]

10 Push switch 11
Base board 12 First fixed contact 13
Second fixed contact 16
Movable contact 17 Spacer 18 Membrane sheets 23, 23
a Through hole 25 recess

Claims (1)

[Claims] 1. A push switch in which a switching operation is performed by pressing a movable contact to contact a fixed contact, or releasing the pressure to separate the movable contact and the fixed contact, the fixed contact being mounted on a base substrate. , and conduct the fixed contact with the pattern on the back of the base board through the through hole.
A push switch characterized in that a recess is formed in the fixed contact, a spacer is further mounted on the outer edge of the base substrate, and a membrane sheet is fixed to the spacer to cover the upper surface.