KR20160004067U

KR20160004067U - Waterproof Board Switch

Info

Publication number: KR20160004067U
Application number: KR2020150003192U
Authority: KR
Inventors: 이수호
Original assignee: 이수호
Priority date: 2015-05-19
Filing date: 2015-05-19
Publication date: 2016-11-29

Abstract

A waterproofing substrate switch according to an embodiment of the present invention includes a printed circuit board on which an upper pattern having a central contact portion and an outer contact portion is formed on a front surface thereof and a lower pattern having a central contact terminal and an outer contact terminal on a rear surface thereof; A lower side cover provided on the back side of the printed circuit board to insulate the back side of the printed circuit board; An insulating adhesive film having a structure with a dome hole and thermocompression bonding to the front surface of the printed circuit board; A metal dome inserted into the dome hole so as to be in contact with the upper pattern; And a dome hole, and sealing the space where the metal dome is seated by covering both side surfaces of the insulating adhesive film, both side surfaces of the printed circuit board and the back surface of the printed circuit board, .

Description

Waterproof Board Switch

The present invention relates to a waterproof substrate switch, and more particularly, to a waterproof substrate switch capable of forming a waterproof structure while reducing the size of a tact switch.

The tact switch can be configured to place a conductive elastic contact or an elastic movable metal (also referred to as a 'metal dome') on a substrate having a predetermined pattern of terminals and to push and drop the contact to input an electrical signal between terminals connected to the contact Or to open or close the power.

Such a tact switch is provided on a keypad substrate or a printed circuit board (PCB) such as an MP3 player, an MP4 player (video player), a mobile communication terminal, a PDA or the like and a communication and information processing apparatus, The electric signal or the electric power is interrupted.

2. Description of the Related Art In recent years, portable communication devices and information processing devices such as mobile communication terminals and PDAs have become increasingly smaller and lighter, and tact switches used here have also been required to be reduced in size.

Conventionally, a tact switch having a width of x length x thickness of about 4 mm x 4 mm x 0.5 mm has a terminal pattern printed circuit in which switch terminals of the same pattern are continuously printed on an epoxy substrate or a phenol substrate (mainly an epoxy substrate is used) A PCB is formed and the remaining portion except for the terminal pattern portion is coated with an insulator. A contact is disposed on the terminal pattern and covered with a dust cover. The printed circuit board with the contact is connected to each contact unit .

As the width of 0.1mm is required to be different from that of competitors, there is a demand for a very small tact switch that has a width x length x thickness of 2mm x 3mm x 0.5mm and minimizes the width It is getting bigger. As a result, a product having a small width of 0.1 mm is thinner in the thickness of the portable device, which is an important factor in reducing the weight of the product.

1 shows a cross section of a tact switch 10 according to the prior art. 1, the tact switch 10 includes an insulating film 11, a printed circuit board 12, a base 13, a metal dome 14, and a top cover 16.

As the tact switch 10 is reduced in size, the size of the tact switch 10 is reduced by the size of the top cover laid on the base 13 to cover the base 13 containing the metal dome 14 and the metal dome 14 16 are affected by the watertightness by the thickness TO of the bonded portion.

That is, as shown in Fig. 1, when the outer cover of the top cover 16 does not come into contact with the outer periphery of the base 13 exactly, the outer cover of the top cover 16, The adhesive thickness T1 between the top coverlay 16 and the base 13 is narrower than the expected adhesive thickness T0 and the adhesive width is small so that it is vulnerable to waterproofing.

As a result, when repetitive force is applied to the top cover 16 due to repetitive use of the tact switch 10, a situation occurs in which an incomplete adhesion portion between the top cover 16 and the base 13 is heard The possibility may increase. As the number of times of use of the tact switch 10 is increased, the conventional top cover 16 is difficult to completely seal the internal space of the base 13 on which the metal dome 14 is seated, When water is introduced into the mounted electronic product, it is difficult to completely waterproof the printed circuit board 12.

In addition, due to the moisture introduced into the tact switch 10, a pop-up phenomenon caused by the printed circuit board 12 is caused, deformation and cracks are generated in each component, and a moisture sensitivity level (MSL) .

In addition, there is a difficulty in joining the base 13 and the top cover 16 so that the outer periphery of the base 13 and the outer periphery of the top cover 16 can be within 0.1 mm without any error.

As the tact switch 10 is smaller in size, the size of the metal dome 14 becomes smaller. When the size of the metal dome 14 is reduced, the metal dome 14 can be easily The lifetime of the metal dome 14 is reduced. As a result, there is a problem that the reliability of the product is lowered, which limits the reduction of the size of the metal dome.

Korean Patent Laid-Open No. 10-2005-0014359 discloses a tact switch for a keypad switch of a mobile phone.

The present invention seals a portion where a metal dome is electrically contacted with a printed circuit board and a printed circuit board to seal a portion of the printed circuit board and a metal dome, And to provide a highly reliable waterproof substrate switch.

In one embodiment of the present invention, it is preferable that the insulating adhesive film has a dome hole formed by opening upper and lower portions, and a structure in which one side of the dome hole is opened.

In one embodiment of the present invention, the top coverlay

Shaped cross-sectional structure.

In one embodiment of the present invention, the dome hole is preferably provided with a boss located between the metal dome and the top coverlay.

The present invention has a structure in which a top cover layer covers an upper portion of an insulating adhesive film, a side surface of an insulating adhesive film, a side surface of a substrate hole, and a back surface of a printed circuit board, And the substrate hole can be increased, thereby increasing the waterproof function of the dome hole.

The present invention has a structure in which a top cover layer covers an upper surface of a substrate having a metal dome and simultaneously covers a side surface of the substrate hole and a back surface of the printed circuit board, thereby reducing the bonding width T0 of the insulating adhesive film, It is possible to miniaturize the size of the miniature tact switch to be applied to a portable device such as a mobile phone and to form a complete waterproof structure.

1 schematically shows a cross-sectional view of a tact switch according to the prior art.
2 is a schematic exploded perspective view of a waterproofing substrate switch according to an embodiment of the present invention.
FIG. 3 is a schematic perspective view illustrating a waterproof substrate switch according to an embodiment of the present invention. Referring to FIG.
4 schematically shows a cross-sectional view of a waterproof substrate switch taken along the line XX in Fig.
Figure 5a schematically illustrates a perspective view of a printed circuit board according to one embodiment of the present invention, Figure 5b schematically shows a front view of a printed circuit board, Figure 5c schematically shows a rear view of a printed circuit board It is.

Hereinafter, a waterproofing substrate switch according to an embodiment of the present invention will be described with reference to FIGS. 2 to 4. FIG.

2, the waterproofing substrate switch 100a according to one embodiment of the present invention includes a printed circuit board 111, a lower coverlay 120, an insulating adhesive film 130a, a metal dome 140, And includes a top cover 160a and a boss 150.

5A, the printed circuit board 111 has a central contact portion 113 and an outer contact portion 114 formed on its front surface. 5C, a central contact terminal 115 and an outer contact terminal 116 are formed on the back surface of the printed circuit board 111. As shown in FIG.

Here, the central contact portion 113 and the outer peripheral contact portion 114 are electrically short-circuited. The central contact portion 113 is electrically connected to the central contact terminal 115 and the outer contact portion 114 is electrically connected to the outer contact terminal 116.

The central contact portion 113 is formed at the front center of the printed circuit board 111 as shown in Figs. 5A and 5B. The central contact portion 113 is electrically connected to the central contact terminal 115 formed on the opposite surface of the flexible printed circuit board 111 on which the central contact portion 113 is formed and the central contact portion 113 through the through hole 113a Lt; / RTI >

5A and 5B, the outer peripheral contact portion 114 is formed on the front surface of the printed circuit board 111 in such a shape as to surround the central contact portion 113. As shown in FIG. It is preferable that the outer contact point portion 114 is formed to be electrically short-circuited with the central contact point portion 113. The outer peripheral contact portion 114 is electrically connected to the outer peripheral contact terminal 116. Here, it is preferable that the outer contact point terminal 116 is provided on the back surface of the printed circuit board 111 in a structure in which it is short-circuited with the central contact point terminal 115.

As shown in FIGS. 2 to 4, the lower coverlay 120 is placed in contact with the back surface of the printed circuit board 111. The lower cover layer 120 is a kind of insulating film and is thermally bonded to the back surface of the printed circuit board 111 so that the portions excluding the central contact terminal 115 and the outer contact terminal 116 are electrically insulated, (Not shown).

In this embodiment, the lower coverlay 120 also prevents foreign matter, water, and the like from entering the printed circuit board 111. The lower coverlay 120 is coated with a thermosetting adhesive on the insulating film.

As shown in Figs. 2 to 4, the insulating adhesive film 130a is bonded to the front surface of the printed circuit board 111. Fig. The insulating adhesive film 130a has a dome hole 131a at the center thereof. As shown in Fig. 14, the insulating adhesive film 130a has a structure in which one side is opened. The dome hole 131a has a structure in which the upper part and the lower part are opened. A metal dome 140 may be installed on the dome hole 131a after the insulating adhesive film 130a is bonded to the front surface of the printed circuit board 111. [

As shown in FIG. 2, the metal dome 140 has a structure in which the center protrudes in a convex dome shape. This structure is for maintaining the elastic force of the metal dome 140.

The metal dome 140 is formed by coating a high-elasticity metal thin film, such as stainless steel, with a metal having a good silver-to-metal conductivity, and then punching the metal thin film in a form that can be restored upward when pressed.

The waterproofing substrate switch 100a according to the present embodiment may be provided with a plurality of metal domes 140 for contacting a larger force. In this embodiment, for convenience of explanation, a metal dome arranged to be in contact with the central contact portion 113 of the printed circuit board 111 is referred to as a 'first metal dome 141', and a first metal dome 141 will be referred to as a 'second metal dome 142'. In the present embodiment, the number of the metal domes provided in the substrate mount 110 is limited to two for convenience of explanation, but the present invention is not limited thereto.

In this embodiment, the reason for using the plurality of metal domes is to increase the force pressing the metal doms 140 against the substrate islands 110. [ The waterproofing substrate switch 100a according to an embodiment of the present invention is configured such that the life of the metal dome 140 is limited by the miniaturization of the tact switch and the miniaturization of the metal dome 140, To some extent.

2 and 4, the top cover 160a covers the upper portion of the insulating adhesive film 130a, and covers both sides of the insulating adhesive film 130a, both sides of the printed circuit board 111, It is preferable to have a structure that encloses a part of the rear surface of the circuit board 111 and seals the space where the metal dome 140 is seated. Illustratively, the top cover lay 160a according to this embodiment

Sectional structure.

The top cover 160a has a structure that completely covers the space formed by the dome hole 131a between the insulating adhesive film 130a and the printed circuit board 111 so that the top cover 160a can be electrically connected / disconnected by the metal dome 140 The foreign matter, moisture and the like can be prevented from flowing into the central contact portion 113 and the outer peripheral contact portion 114. [

Accordingly, the waterproofing substrate switch 100a according to an embodiment of the present invention can prevent an error or failure of an electric signal due to foreign matter and moisture, thereby achieving a highly reliable ultra-thin dustproof and waterproof structure.

In the present embodiment, it is preferable to use a material having excellent chemical resistance such as moisture resistance and excellent stretchability so that the top cover layer 160a does not come off or break even if the operation of pressing the metal dome 140 is repeated Do.

The waterproofing substrate switch 100a according to the present embodiment has a structure in which the top cover 160a covers the upper surface of the substrate substrate 110 and covers both sides of the substrate substrate 110, It is possible to prevent the occurrence of an error or failure of the electric signal due to the inflow, thereby achieving a highly reliable ultrathin dustproof waterproof structure.

The present invention has been described with reference to the embodiments. It will be apparent, however, to one skilled in the art, that the present invention may be embodied in various other forms without departing from the spirit or essential characteristics of the inventive concept. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. That is, the true scope of the present invention is indicated in the appended claims, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

100a: waterproof substrate switch 110: substrate ASI
120: lower coverlay 130a: insulating adhesive film
140: Metal Dome 150: Boss
160a: Top Cover Ray

Claims

A printed circuit board on which an upper pattern having a central contact portion and an outer contact portion is formed on a front surface thereof and a lower pattern having a central contact terminal and an outer contact terminal on a rear surface thereof;
A lower cover layer provided on a back surface of the printed circuit board to insulate a back surface of the printed circuit board;
An insulating adhesive film having a structure having a dome hole and being thermally pressed on the front surface of the printed circuit board;
A metal dome inserted into the dome hole to be in contact with the upper pattern; And
And a sealing member covering the dome hole and sealing the space where the metal dome is seated by covering both side surfaces of the insulating adhesive film, both side surfaces of the printed circuit board and the back surface of the printed circuit board, And a top cover layer connected to the top cover layer.

The method according to claim 1,
Wherein the insulating adhesive film has the dome hole formed by opening the upper and lower portions, and has a structure in which one side of the dome hole is opened.

The method according to claim 1,
The top coverlay

Sectional structure of the waterproof substrate switch.

The method according to claim 1,
Wherein the dome hole is further provided with a boss located between the metal dome and the top cover lay.