JP2003031071A - Switch contact spring - Google Patents

Abstract

(57) Abstract: In order to reduce the manufacturing cost of a circuit board having a switch using a contact spring, a switch having a structure capable of forming a circuit only on one surface of the board and used in the switch It is to obtain a contact spring. A lead circuit is provided on one surface of a circuit board.
A first fixed contact 2 having a circular shape is formed on the outer side of the first fixed contact 2, which is separated from the first fixed contact 2. A second surface formed on one surface of the circuit board so as to surround the contact;
Are connected to the read circuit 5. Dome contact spring 6
By disposing the contact spring such that the opening 7 of the second fixed contact 4 and the separated portion of the second fixed contact 4 coincide with each other, the first fixed contact 2
The lead circuit 3 is pulled out through the space between the second fixed contacts 4 and is drawn out, and a circuit is formed on the same surface of the second fixed contacts 4 and the circuit board 1 without constantly contacting the contact spring 6. Switch can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact type switch used in a mobile phone, a portable audio device, a camera, a VTR, etc., and a contact spring used in this switch.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show a conventional switch of this type. In these drawings, reference numeral 1 indicates a circuit board. A first fixed contact 2 having a circular planar shape is formed on one surface of the circuit board 1. The circuit board 1 located substantially in the center of the first fixed contact 2 is provided with a through hole 10 for connection with the first fixed contact 2, and the first hole is provided on the other surface of the circuit board 1. Lead circuit 3
It is connected to the.

A ring-shaped second fixed contact 4 is formed outside the first fixed contact 2 on the circuit board 1 so as to surround the first fixed contact 2. A second lead circuit 5 connected to this second fixed contact 4 is formed. The contact spring 6 is made of phosphor bronze or the like and has a shallow dome shape with a diameter of about 5 mm. The peripheral portion of the contact spring 6 is attached to the second fixed contact 4 in a conductive state, and
It does not come into contact with the first fixed contact 2.

In the switch having such a structure, a push button (not shown) made of rubber, plastic, or the like is provided above the contact spring, and when this is pushed down and the top of the contact spring is pushed, when the pushing force increases to a certain extent, the contact spring 6 causes a kind of buckling, the central top part of the contact spring is inverted and faces downward, and contacts the first fixed contact 2. As a result, the first fixed contact 2 and the second fixed contact 4 are electrically connected via the contact spring 6.

[0005]

In the switch having such a structure, in order to form a circuit by electrical conduction through a contact spring, a through hole 3 is provided and one surface of the circuit board 1 and the other surface thereof are provided. It is necessary to make the surface conductive. Therefore, it is necessary to perforate the circuit board 1 by means such as machining, fill the entire through hole with solder or metal plating, or to provide electrical conduction by forming metal plating on the inner surface of the hole. There is.

Therefore, there is a problem that the manufacturing cost becomes higher than that in which a circuit is formed only on one surface of the circuit board. Therefore, the problem in this invention is
In order to reduce the manufacturing cost of such a circuit board,
It is to obtain a switch and a contact spring used for this switch, which is structured so that a circuit can be formed on only one surface of a substrate.

[0007]

The invention according to claim 1 for solving the above-mentioned problems is a contact for a switch, which has a shallow dome shape and whose outer peripheral part is cut off to provide an opening. Use as a spring. According to a second aspect of the invention, in the switch contact spring according to the first aspect, an edge portion is provided in a part of the peripheral portion of the dome.

According to a third aspect of the present invention, the first fixed contact and the first lead circuit connected to the first fixed contact are provided on one surface of the substrate, and the first fixed contact is provided outside the first fixed contact. A switch having a structure in which a second fixed contact that surrounds the fixed contact and a second lead circuit connected to the fixed contact are provided, and a dome-shaped contact spring is mounted on the second fixed contact, Has an opening formed by cutting off a part of its outer peripheral portion, and the second fixed contact is a substantially annular shape in which a part of an annular ring is cut off to form a separating portion. The contact spring is arranged so that the separated portion of the fixed contact and the opening of the contact spring coincide with each other, and the first lead circuit passes through the separated portion of the second fixed contact and is drawn to the outside. To do.

[0009]

1 and 2 are views showing an example of a switch of the present invention and a contact spring used for the switch. In the figure, reference numeral 1 is a circuit board, and a first fixed contact 2 having a circular surface shape is formed on one surface of the circuit board 1 and is connected to a lead circuit 3 on the same surface of the board 1. ing.

A ring-shaped second fixed contact 4 is formed outside the first fixed contact 2 on one surface of the circuit board 1 so as to surround the circular first fixed contact. And is connected to the second lead circuit 5 formed on the same substrate 1 surface. The second fixed contact 4 has a substantially annular structure in which a part of the annular portion is cut off to form a separated portion.

Reference numeral 6 is a shallow dome-shaped contact spring having a diameter of about 5 mm, and an opening 7 is provided by cutting off a part of the outer periphery of the dome. This opening 7
In the contact spring 6 provided with, the opening 7 of the contact spring and the separated portion of the second fixed contact 4 coincide with the second fixed contact 4 having a substantially annular shape in which a part of the annular portion is cut off. As described above, it is attached in a conductive state by soldering or the like. The lead circuit 3 connected to the first fixed contact 2 passes through the opening 7 of the contact spring 6 and is taken out to the outside so that the lead circuit 3 is not always in contact with the contact spring 6.

As in the conventional example, the push button is attached to the contact spring 6
When the top portion of the contact spring 6 is pushed above the center of the contact spring 6, the central top portion of the contact spring 6 is inverted and turned downward when the pressing force is increased to some extent, and the first fixed contact 2 is contacted.
As a result, the first fixed contact 2 and the second fixed contact 4 are electrically connected via the contact spring 6.

As described above, in the switch of this embodiment,
A second fixed contact is formed by cutting a part of the outer peripheral portion of the dome-shaped contact spring 6 to provide an opening 7 and attaching the opening 7 to the second fixed contact 4 which is formed by cutting a part of the annular portion in a conductive state. From the circular first fixed contact 2 located inside 4, there is a space for drawing the circuit outward on the same substrate 1 surface.

Since the lead circuit 5 from the first fixed contact 2 is formed by passing through the opening 7 of the contact spring, the second fixed contact 4 does not always come into contact with the contact spring 6.
It is possible to provide a switch having a circuit formed on the same surface of the circuit board 1. The shape of the opening obtained by cutting out a part of the outer peripheral portion of the dome-shaped contact spring in the present invention is determined in consideration of the shape of the contact spring, the shape and thickness of the fixed contact, and the like.

FIG. 3 shows another example of the switch contact spring of the present invention. The contact spring for the switch in this example is
An edge 9 is provided around the dome. The edge 9 has a shape in which the top of a cone is cut off, and is 5 to the surface of the circuit board.
It rises at an angle of 20 degrees and is connected to the dome-shaped portion 8. The dome-shaped portion 8 is formed with a dome in which the arc is shallower than that of the contact spring 6.

The contact spring provided with the edge portion 9 makes it possible to improve the feeling of operation when the button is pressed to push the top portion of the contact spring by the push button.

As the contact spring, a spring metal such as a stainless steel or a copper alloy such as phosphor bronze is used, but a metal or a metal laminated on a resin or rubber or a plated metal is also used.

[0018]

As described above, since the switch contact spring according to claim 1 has the outer peripheral portion partially cut off and the opening is provided, the lead circuit from the circular first fixed contact is removed. It becomes possible to draw it around. In addition, claim 2
The switch contact spring according to claim 1 is the switch contact spring according to claim 1, which has a structure in which an edge portion is provided in a part of the peripheral portion of the dome, so that the push button operation feeling is improved and stable switch operation is possible. .

In the switch of the third aspect, a part of the ring of the second fixed contact on the ring located outside is cut off,
Since it is attached in a conductive state with the contact spring provided with the opening, the lead circuit from the first fixed contact inside the second fixed contact does not always come into contact with the second fixed contact and the contact spring. A switch in which a circuit is formed on the same surface of the circuit board is possible without the need for a double-sided circuit board that is taken out toward the outside and perforated with through holes.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a switch of the present invention.

FIG. 2 is a side sectional view of the switch of the present invention.

FIG. 3 is a side sectional view showing an example of another contact spring of the present invention.

FIG. 4 is a plan view showing a conventional switch.

FIG. 5 is a side sectional view showing a conventional switch.

[Explanation of symbols]

1 ... Circuit board, 2 ... First fixed contact, 3 ... Lead circuit,
4 ... 2nd fixed contact, 5 ... Lead circuit, 6 ... Contact spring,
7 ... Contact spring opening, 8 ... Dome-shaped portion, 9 ... Edge

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tetsuya Kawahira             Fuji Co., Ltd. 1440 Rokuzaki, Sakura City, Chiba Prefecture             Kura Sakura Office F-term (reference) 5G006 AA02 AB25 AC01 BA01 FB04                 5G023 AA01 CA50

Claims (3)

[Claims] 1. A contact spring for a switch, which has a shallow dome shape and is provided with an opening by cutting a part of an outer peripheral portion thereof. 2. The switch contact spring according to claim 1, wherein the dome has a structure in which an edge portion is provided in a part of a peripheral portion of the dome. 3. A first fixed contact and a first lead circuit connected thereto are provided on one surface of the substrate, and a second fixed contact is provided outside the first fixed contact and surrounds the first fixed contact. Of the fixed contact and a second lead circuit connected to the fixed contact, and a dome-shaped contact spring is mounted on the second fixed contact. A part is cut out to form an opening, and the second fixed contact is a substantially ring-shaped part in which a part of the ring is cut out to form a separation part,
The contact spring is arranged so that the separated portion of the second fixed contact and the opening of the contact spring coincide with each other, and the first lead circuit passes through the separated portion of the second fixed contact and is drawn to the outside. A switch characterized by being.