KR101711013B1

KR101711013B1 - Elastic electric contact terminal adapted to small size

Info

Publication number: KR101711013B1
Application number: KR1020150075077A
Authority: KR
Inventors: 김선기
Original assignee: 조인셋 주식회사; 김선기
Priority date: 2015-05-15
Filing date: 2015-05-28
Publication date: 2017-03-13
Also published as: JP2016219398A; JP6121583B2; KR20160134410A

Abstract

An elastic core formed to be recessed in a predetermined width and depth from an upper surface to a lower surface and having at least one channel extending along the longitudinal direction; A polymer film adhered to the core through an adhesive layer; And a solderable metal layer that is wrapped around the polymer film, wherein both side walls of the channel elastically support the object.

Description

[0001] The present invention relates to an elastic contact terminal adapted to a small size,

The present invention relates to an elastic electrical contact terminal, and more particularly to an elastic electrical contact terminal having a structure suitable for a small size.

Elastic electrical contact terminals, which are generally solderable, should have good electrical conductivity, good resilience, and be able to withstand soldering temperatures.

As an example of an elastic electrical contact terminal, Patent No. 783588 of the present inventor discloses an insulated foam rubber having a constant volume; An insulating nonfoaming adhesive layer which is wrapped around the insulating foam rubber; And a heat-resistant polymer film which is bonded to the insulating non-foaming adhesive layer so as to surround the insulating non-foaming adhesive layer on one side and the metal layer is integrally formed on the other side .

Further, Japanese Patent No. 1001354 discloses an elastic heat-resistant rubber core having a through hole formed therein in the longitudinal direction thereof; An insulating heat-resistant adhesive layer which is wrapped around the insulating elastic heat-resistant rubber core; And a heat-resistant polymer film having one surface bonded to the insulative heat-resistant adhesive layer so as to surround the insulative heat-resistant adhesive layer and having a metal layer integrally formed on the other surface thereof, wherein the polymer film is bonded to the insulative heat- And the lower surface of the insulating elastic heat-resistant rubber core is formed so as to be sloped in a fine shape toward the middle portion at both ends in the width direction.

In the case of the electrical contact terminal having the above-described structure, the through hole is formed in the longitudinal direction of the core or the core itself is formed into a tube shape so that the core has elasticity. As a result, As shown in FIG.

However, when the electrical contact terminal has a small size of 0.5 mm or less, it is difficult to form the through hole, and it is also difficult to manufacture the tube in the form of a tube, and the manufacturing efficiency is poor.

On the other hand, on the copper foil of the conventional electrical contact terminal, a metal plating layer having better environmental resistance than copper is formed so as to prevent corrosion and solder by the solder cream. However, in the process of manufacturing the electrical contact terminal, Therefore, the copper foil has to be exposed to the outside from the cut surface formed on the longitudinal side surface of the electrical contact terminal.

In other words, since the conventional electrical contact terminal is manufactured by wrapping a polymer film having a copper foil having a metal layer plated with a metal layer of tin or the like on the core and then cutting the copper foil, the copper foil is naturally exposed to the outside.

As a result, in the reliability test such as the salt water test, the salt water contacted to the copper foil exposed to the outside could not pass the salt water test due to the corrosion due to the brine, or the copper foil exposed to the outside easily rusted, The problem occurs.

Therefore, an object of the present invention is to provide an elastic electrical contact terminal having a structure suitable for a small size below a certain height.

Another object of the present invention is to provide a corrosion-resistant resilient electrical contact terminal.

Another object of the present invention is to provide an elastic electrical contact terminal having improved soldering strength and improved soldering reliability.

The above object is achieved by an elastic core comprising: an elastic core formed to be recessed from a top surface downward to a predetermined width and depth and having at least one channel extending along a longitudinal direction; A polymer film adhered to the core through an adhesive layer; And a solderable metal layer wrapped around the polymer film, the polymer film extending across the channel across the channel, and both side walls of the channel elastically supporting the object. Contact terminals.

Preferably, the plurality of channels may be formed, and a support wall protruding between the channels at a height corresponding to the both side walls and extending in the longitudinal direction may be further included.

Preferably, the vertical cross-sectional shape of the support wall may have a trapezoidal shape that becomes smaller toward the upper end.

Preferably, the channel side surfaces of the both side walls are inclined so that the both side walls can be inclined toward the channel side when the object is pressed by the object.

Preferably, the upper surface of the support wall may be bonded to the polymer film via the adhesive layer.

Preferably, the metal layer is composed of a copper foil and a metal plating layer surrounding the surface and the side surface of the copper foil, and the side surface of the copper foil may include both a longitudinal section and a transverse section.

Preferably, the thickness of the copper foil may be greater than the thickness of the metal plating layer, and the copper foil may be an electrolytic copper foil or a rolled copper foil. The copper foil may be coated with a liquid polymer corresponding to the polymer film, Or adhered to the polymer film through an adhesive.

Preferably, the metal plating layer is formed by electroless plating, and the surface roughness is increased, so that the soldering strength can be improved.

The above object is achieved by an elastic core comprising: an elastic core formed to be recessed from a top surface downward to a predetermined width and depth and having at least one channel extending along a longitudinal direction; An electrically conductive elastic rubber coating layer adhered to an outer surface of the elastic core; And a solderable metal foil adhered to a lower surface of the elastic rubber coating layer, wherein both side walls of the channel elastically support the object.

Preferably, the electrical contact terminal may have a width greater than the length.

Preferably, the electrical contact terminals are resiliently and electrically connected to an electrically conductive object that is soldered to the conductive pattern of the circuit board by solder cream.

According to the above-described structure, it is possible to easily and efficiently manufacture the electrical contact terminal of a size that is difficult to form a through hole in the core or to manufacture the core itself in a tube shape as in the prior art.

Further, by covering the copper foil exposed from the longitudinal cut surface with a metal plating layer having good environmental resistance, the contact between the brine and the copper foil can be fundamentally cut off in the reliability test, and the copper foil is not exposed to the outside during use, The reliability is improved.

Also, the solder cream spreads well over the metal plating layer formed to cover the copper foil at the longitudinal cut surface, increasing the soldering strength at the cut surface.

1 shows an electrical contact terminal according to an embodiment of the present invention.
2 shows the operation of the electrical contact terminal according to one embodiment.
Fig. 3 shows an electrical contact terminal according to another embodiment of the present invention. Fig. 3 (a) is a perspective view and Fig. 3 (b) is a front view.
4 shows an electrical contact terminal according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 shows an electrical contact terminal according to an embodiment of the present invention, and Fig. 2 shows an operation of an electrical contact terminal according to an embodiment.

The electrical contact terminal 100 is interposed between the circuit board and the electrically conductive object 10 and serves to electrically connect the circuit board to the circuit board. For example, the electrical contact terminal 100 may be forcibly inserted between the conductive pattern of the circuit board and the electrically conductive object, The pattern can be soldered by the solder cream to resiliently contact the opposing electrically conductive object 10.

In the case of reflow soldering, the electrical contact terminal 100 is reel taped to the carrier and reflow soldered by vacuum pick-up and solder cream.

1, the electrical contact terminal 100 includes an elastic core 110 having at least one channel 112 formed to be recessed in a predetermined width and depth downward from the top surface and extending in the longitudinal direction, A polymer film 130 which is wrapped around the core 110 with the adhesive layer 120 interposed therebetween and a solderable metal layer 140 which is wrapped around the polymer film 130.

According to this embodiment, both side walls 114,116 of the channel 112 elastically support the object on which it is located.

Hereinafter, the detailed structure of the electrical contact terminal 100 according to this embodiment will be described in detail.

1.1 Core (110)

The rubber core 110 has heat resistance and resiliency, preferably electrically insulating. As a result, it may be a non-foam silicone rubber that meets the reflow soldering and elastic conditions, or foam rubber, such as a sponge, but is not limited thereto.

The core 110 may be manufactured by, for example, an extrusion process, and may be symmetrically formed so as to be balanced in the horizontal direction at the time of soldering, thereby reducing lifting or sagging phenomenon during reflow soldering by the solder cream.

The core 110 is formed of a single body, and a channel 112 having a predetermined width and depth is formed, which is recessed downward from the upper surface and extends along the longitudinal direction. As a result, side walls 114 and 116 are formed on both sides of the channel 112 to be in contact with and supported by the upper object.

The core 110 is formed in a small size, for example, a width of 2 mm, a height of 0.5 mm, and a length of 1 mm, but is not limited thereto and has a size corresponding to or smaller than that.

As described above, when the through hole is formed in the core 110 or the core 110 itself is formed into a tube shape, it is difficult to set the height to 0.7 mm or less in the conventional core 110 As in this embodiment, since the channel 112 extending downward from the upper surface and having a predetermined width and depth and extending in the longitudinal direction can be formed, an electrical contact terminal having a height of 0.5 mm or less can be easily formed.

The upper and lower outer side walls 114 and 116 are formed in a rounded shape when the finished electrical contact terminal 100 is soldered to a printed circuit board or the like and then pressed by an opposing object It can be easily pressed inside and prevents external objects from being caught on both sides.

The side surfaces, i.e., the inner surfaces, of the side walls 114 and 116 on the side of the channel 112 may be inclined to be perpendicular or inclined toward the channel 112, and may be inclined toward the channel 112 side, The side walls 114 and 116 tend to be tilted toward the channel 112 when the object 10 is pressed by the object 10, so that the pressing force can be reduced.

The lower surface of the core 110 may be formed obliquely to the middle portion at both ends in the width direction. In other words, when the core 110 is vertically cut, the core 110 is formed to be inclined in the shape of a fins toward the lower center portion at both sides in the width direction so as to form a hypotenuse of an isosceles triangle. The inclination angle is not particularly limited, but it is sufficient to accommodate the adhesive leaking from the adhesive layer 120 to the lower surface of the bottom of the core 110 to form a space that does not affect soldering.

According to this structure, since the lower surface of the core 110 has a shape that is fined toward the middle portion from both ends, when both sides of the lower surface of the electrical contact terminal 100 are uniformly in contact with the molten solder during reflow soldering, It is possible to prevent the soldering lifting phenomenon. In addition, since the lower surface of the core 110 has a fine shape toward the middle portion at both ends thereof, it is possible to provide a space for receiving the adhesive that leaks to the outside from the adhesive layer 120 during the manufacturing process, Minimizing the phenomenon.

1.2 Adhesive layer (120)

The adhesive layer 120 has flexibility, elasticity, and insulation, and may have heat resistance when the electrical contact terminal 100 is applied to reflow soldering, and may be positioned between the core 110 and the polymer film 130, 110 and the polymer film 130 with reliability.

The adhesive layer 120 may be formed by, for example, thermosetting the liquid silicone rubber, and the liquid silicone rubber is adhered to the opposed object while being cured, and after the curing, the solid adhesive layer 120 is formed, It maintains the elasticity afterwards and maintains the adhesive force even when the heat is applied again.

Preferably, the adhesive layer 120 is formed by curing a self-adhesive silicone rubber adhesive and has a thickness of approximately 0.005 mm to 0.03 mm.

1.3 Polymer films (130)

The polymer film 130 may be, for example, a polyimide (PI) film or a heat-resistant polymer film having good heat resistance, and the thickness can be determined in consideration of flexibility and mechanical strength.

The polymer film 130 is a polymer film usually used in flexible flexible circuit boards.

For example, the polymer film 130 may be formed by curing after the liquid polymer is cast, and the thickness of the cured polymer film 130 is 0.007 mm to 0.030 mm.

1.4 Metal layer (140)

The metal layer 140 is adhered to one surface of the polymer film 130 so as to surround the polymer film 130. A metal plating layer 142 is formed on the copper layer 141 by plating and a copper layer 141 ), And the soldering is better.

According to this embodiment, a metal plating layer 142 is formed on all of the exposed surfaces of the copper layer 141, the exposed surface including the outer surface, i.e., the surface and the side surface, of the copper layer 141.

Referring to FIG. 1, the surface of the copper layer 141 refers to the outer surface that is visually recognized from the outside, and the side refers to both the longitudinally cut surface and both lateral surfaces in the width direction.

Here, the copper layer 141 is a copper foil of an electrolytic copper foil or a rolled copper foil, or a copper plating layer formed thereon by sputtering tungsten with a seed on one side of a polymer film. For example, a copper foil is used.

The thickness of the copper foil 141 is about 10 占 퐉, and the thickness of the copper plating layer is about 3 占 퐉.

It should be noted that the metal plating layer 142 is less corrosive than the copper foil 141 and the thickness of the copper foil 141 is thicker than the thickness of the metal plating layer 142.

The copper foil 141 may be bonded to the polymer film 130 with an adhesive interposed therebetween or the copper foil 141 may be bonded to the copper foil 141 on the copper foil 141 in such a manner that the metal film 140 covers the polymer film 130 The liquid polymer can be applied and cured to bond.

The metal plating layer 142 is formed by plating tin (Sn) or silver (Ag), or by plating with tin (Sn) or gold (Au) after nickel plating. Preferably, Is about 2 mu m, and in the case of nickel / gold, the thicknesses of nickel and gold are each 1 mu m or less.

Therefore, the metal layer 140 having the metal plating layer 142 is laminated on the polymer film 130 at the raw material level so that the electrical contact terminal 100 can be well-conducted and soldered, thereby preventing corrosion of the copper foil 141 prevent.

In addition, in the process of manufacturing the electrical contact terminal 100, since the copper foil 141 is directly exposed to the outside on the cut surface formed by cutting, it is necessary to prevent corrosion.

1, the metal plating layer 142 is formed on the copper foil 141 exposed from the cut surface of the contact terminal 100 to cover the copper foil 141. In this case, 1, the boundary between the copper foil 141 and the metal plating layer 142 is indicated by a dotted line, and the copper foil 141 is covered with the metal plating layer 142 on the cut surface.

Therefore, conventionally, the copper foil is exposed to the outside from the cut surface formed by cutting, so that the copper foil exposed in the reliability test such as the salt water test causes the brine to contact with the copper foil, The copper foil rusted and reliability decreased.

However, according to the present invention, covering the copper foil 141 exposed from the cut surface with the metal plating layer 142 can eventually block the contact of the brine in the reliability test, and the copper foil 141 is not exposed during use Since there is no risk of rusting, reliability is improved.

Moreover, the solder cream can spread more easily onto the metal plating layer 142 formed so as to cover the copper foil 141 at the cutting face at the time of reflow soldering, so that the soldering strength is inevitably increased, and in particular, the soldering strength is improved at the cut surface.

Especially, when the width of the contact terminal 100 is longer than the length, the soldering strength of the cut surface is very important, and the present invention is very useful in such a case.

In order to manufacture the electrical contact terminal 100 according to this embodiment, the core 110 is continuously wrapped around the liquid adhesive layer 120 with the polymer film 130 having the copper foil 141 adhered to one side thereof The supplied contact terminal bar is cut to a predetermined length. For example, the contact terminal bar may have a length of about 500 mm.

Thereafter, the contact terminal bar is cut to a desired length, for example, about 3 mm by the customer, to form a contact terminal. As described above, the contact terminal bar is formed of tin or silver or nickel / gold so as to cover the exposed surface of the copper foil 141 A plated metal plating layer 142 is formed to produce a final contact terminal 100.

Here, the specific gravity of the contact terminal 100 is smaller than the specific gravity of water by the core 110 made of silicone rubber, and thus the metal plating layer 142 can be formed by electroless plating in a bulk mode Electroplating may be applied without limitation.

Particularly, when the metal plating layer 142 is formed by electroless plating, the surface roughness of the metal plating layer 142 is increased and the surface becomes rough. As a result, the adhesion with the solder cream is improved and the soldering strength is increased.

As described above, the core 110 is made of a non-foamed silicone rubber or a foamed rubber, for example, a sponge. The adhesive layer 120 is formed by thermosetting the liquid silicone rubber, and the polymer film 130 is made of a polyimide film And the metal plating layer 142 is not formed on the cut surface by the plating process.

As described above, in the electrical contact terminal 100, the metal plating layer 142 is formed on the copper foil 141 exposed to the outside including both the cut surface in the longitudinal direction and both end faces in the width direction, 141 from the outside.

2, when the object 10 presses the electrical contact terminal 100, both side walls 114 and 116 are in contact with the object 10 to be pressed and displaced inward. In Fig. 2, the side walls 114a, 116a displaced for identification are shown by dotted lines.

At this time, as described above, the side faces of the side walls 114 and 116 are inclined to the side of the channel 112, and the side walls 114 and 116 are inclined when the object 10 is pressed by the object 10, 116 can be easily depressed toward the channel 112, so that the pressing force of the object 10 can be reduced.

Fig. 3 shows an electrical contact terminal according to another embodiment of the present invention. Fig. 3 (a) is a perspective view and Fig. 3 (b) is a front view.

In the elastic core 210 of the electrical contact terminal 200, a pair of channels 211 and 212 having a certain width and depth are formed downward from the upper surface and extend in the longitudinal direction, A support wall 218 is formed.

The polymer film 230 is bonded to the core 210 through the adhesive layer 220 and the solderable metal layer 240 is wrapped around the polymer film 230.

According to this embodiment, both sidewalls 214 and 216 of the channels 211 and 212 and the support wall 218 elastically support an object on which the upper side is located.

The structure of the core 210 and the metal layer 240 is different from that of the embodiment of FIG.

The core 210 is made of a single body and has a pair of channels 211 and 212 spaced downwardly from the upper surface thereof and having a predetermined width and depth and extending along the longitudinal direction, A support wall 218 is formed at approximately the same height as the side walls 214,

Referring to FIG. 3 (b), the bottoms of the channels 211 and 212 may be inclined upwardly from the bottom edge of the bottom of the core 210.

According to the above structure, the side walls 214 and 216 are formed on the outer sides of the channels 211 and 212 and the supporting wall 218 is formed on the inner side thereof, And a support wall 218,

The upper surface of the support wall 218 may be bonded to the polymer film 230 via the adhesive layer 220 like other portions of the core 210 to prevent the polymer film 230 from being lifted.

The cross-sectional shape of the support wall 218 is not particularly limited, but may be a trapezoid shape having a smaller size toward the upper surface, and both corners of the upper end may be rounded.

As shown in the above embodiment, both side walls 214 and 216 are formed in a rounded shape at an upper end outward when viewed from a cross section. This is because after the completed electrical contact terminal 200 is soldered to a printed circuit board or the like, So that it can be easily pushed inward when pressed by the pawl 10 and prevents external objects from being caught at both side edges.

According to this embodiment, since the polymer film 230 passing over the polymer film 230 is supported by the support wall 218 formed between the pair of channels 211 and 212, even if it is pressed by the object 10, 212 are not left behind by the object 10.

In addition, although a pair of channels 211 and 212 are formed as an example, a plurality of channels may be formed. In this case, a plurality of support walls 218 may be formed between the channels.

On both sides of the metal layer 240, openings 242 are formed at regular intervals along the longitudinal direction and extend in the height direction, so that the polymer film 230 can be exposed through the openings 242.

Here, the side surface refers to a region including a portion including a portion to be soldered at a lower end to an upper end excluding a vacuum pickup portion of the upper surface.

The opening 242 can be formed by etching, for example, a corresponding portion of the metal layer 240, wherein the width, length, and spacing of the opening 242 can be appropriately adjusted. In particular, since the openings 242 are formed symmetrically on both sides, the left and right soldering strengths can be made equal during soldering.

When the lower end of the opening 242 overlaps with the portion covered by the solder at the time of soldering, the molten solder contacts the polymer film 230 that is not soldered through the opening 242 in the overlapping portion, can do. In other words, when the electrical contact terminal 200 is soldered to the circuit board, the opening 242 can minimize the melting solder riding up the side surface of the metal layer 240.

By preventing the rising of the solder in this manner, the molten solder can not come up on the metal layer 240 and the elastic restoring force of the electrical contact terminal can be prevented from being reduced.

In addition, in a low electrical contact terminal having a height of 0.5 mm or less, since the pushing force is affected by the height of the lead rising, the pushing force of the electrical contact terminal can be greatly reduced by minimizing the rise of the lead.

4 shows an electrical contact terminal according to another embodiment of the present invention.

The electrical contact terminal 300 is composed of an electrically conductive elastic rubber coating layer 340 surrounding the elastic core 310 and the elastic core 310 and a metal foil 350 bonded to the lower surface of the elastic rubber coating layer 340.

The elastic rubber coating layer 340 is formed by coating a material having uniformly mixed metal powder of 50 占 퐉 or less, for example, with a liquid elastic rubber through the mold to the outside of the elastic core 310 and then curing .

The elastic rubber coating layer 340 may have a hardness of 40 to 70 Shore A, an electrical resistance of 1? Or less and a coating thickness of 10 to 40 占 퐉.

The metal foil 350 is preferably 8 to 200 占 퐉 or less, and copper may be used as a metal material. If necessary, gold or tin may be further coated to prevent corrosion or facilitate soldering.

The elastic core 310 is continuously produced by an extrusion and curing process, and a copper foil 350 is formed on the lower surface of the elastic core 310 while a material mixed with a metal powder is coated on the outer surface of the elastic core 310, And then hardened.

The liquid electroconductive liquid rubber is cured to form an elastic rubber coating layer 340. At the same time, the elastic rubber coating layer 340 and the copper foil 350 are mechanically and electrically bonded.

As in the above embodiment, in the electrical contact terminals having a small size of not more than 0.5 mm, which are difficult to form through holes in the core or to make the core itself into a tube shape, So that the object can be elastically supported by using the supporting walls formed between the side walls or the channels on both sides of the channel.

In the above embodiment, the electrical contact terminals 100, 200, and 300 are soldered to the conductive pattern of the circuit board by the solder cream to contact the opposing electrically conductive object. However, the present invention is not limited thereto, , It can be forcedly sandwiched between the conductive pattern of the circuit board and the electrically conductive object. In this case, the material of the component need not have heat resistance because there is no process such as reflow soldering.

As described above, at least one channel having a certain width and depth along the longitudinal direction downward from the upper surface of the core in the small-sized electrical contact terminal having a height of 0.5 mm or less is formed, So that the object can be elastically supported.

As a result, it is possible to easily and efficiently manufacture an electrical contact terminal of a size which is difficult to form a through hole in the core or to manufacture the core itself in a tube shape as in the conventional case.

Although the embodiments of the present invention have been described above, various modifications and changes may be made by those skilled in the art. Such changes and modifications are intended to fall within the scope of the present invention unless they depart from the scope of the present invention. The scope of the present invention should be determined by the following claims.

100, 200, 300: Electrical contact terminal
110, 210, 310: core
120, 220: adhesive layer
130, 230: Polymer film
140, 240: metal layer
141: Copper foil
142: metal plating layer
340: electrically conductive elastic rubber layer
350: Metal foil

Claims

An electrical contact terminal interposed between and contacting an object to form an electric path between the objects,
An elastic core formed to be recessed in a predetermined width and depth from an upper surface to a lower surface and having at least one channel extending along the longitudinal direction;
A polymer film adhered to the core through an adhesive layer; And
A solderable metal layer wrapped around the polymer film,
Wherein the polymer film extends over both side walls across the channel and both side walls of the channel elastically support the object.

In claim 1,
Wherein the plurality of channels are formed and further include a support wall protruding between the channels at a height corresponding to the both side walls and extending in the longitudinal direction.

In claim 2,
Wherein the vertical cross-sectional shape of the support wall is a trapezoidal shape having a smaller size toward the upper end.

In claim 1,
Wherein the channel side surfaces of the both side walls are inclined so that the both side walls are inclined toward the channel side when the object is pressed by the object.

In claim 2,
Wherein an upper surface of the support wall is bonded to the polymer film via the adhesive layer.

In claim 1,
Wherein the metal layer comprises a copper foil and a metal plating layer surrounding the surface and the side surface of the copper foil,
Wherein the side surface of the copper foil includes both a longitudinal cut surface and both widthwise end surfaces.

In claim 6,
Wherein the thickness of the copper foil is thicker than the thickness of the metal plating layer.

In claim 6,
Characterized in that the copper foil is an electrolytic copper foil or a rolled copper foil and is coated on the copper foil and a liquid polymer corresponding to the polymer foil is applied and cured to be adhered to the polymer film or via an adhesive, Terminals.

In claim 6,
Wherein the metal plating layer is formed by electroless plating to increase the surface roughness to improve the soldering strength.

delete

In claim 1,
Wherein the width of the electrical contact terminal is larger than the length of the elastic contact terminal.

In claim 1,
Wherein the electrical contact terminal is resiliently and electrically connected to an electrically conductive object that is soldered to the conductive pattern of the circuit board by the solder cream.