JP7289497B2 - surface mount contact - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount contact that is surface mounted on a substrate and electrically contacts a conductive member.

As a surface mount contact formed by bending a conductive plate material such as metal, it has a joint for surface mounting on the surface of the substrate with solder, etc., and an elastic deformation formed by bending so as to protrude upward from this joint. There are some with possible contacts. For example, the surface-mount contact disclosed in Patent Document 1 includes a substrate part whose lower surface is soldered to the substrate, and a spring contact that is folded upward from one end of the substrate part and makes electrical contact with a conductive member. Further, the surface mount contact of Patent Document 2 includes a solder joint portion fixed to a substrate and an elastic contact portion bent upward from one end of the solder joint portion. A contact portion is provided for making electrical contact with the conductive member.

In both the contacts of Patent Document 1 and Patent Document 2, a portion to be locked is provided at a distal end portion formed by bending a movable portion (a spring contact or a solder joint portion) downward. The structure is such that it is locked to a locking portion (engagement wall or spring tip hooking portion) provided on the board portion or solder joint portion). Such a structure for locking the tip of the movable portion prevents plastic deformation of the movable portion when an external force is applied to the movable portion.

Utility Model Registration No. 3064756 Japanese Patent No. 5228232

In both of the techniques disclosed in Patent Documents 1 and 2, a locked portion provided on a movable portion and a locking portion for locking the locked portion are provided at positions near the tip of the movable portion. Therefore, although the details will be described later, when the movable portion is elastically deformed by being brought into contact with the conductive member, the locked portion comes into contact with the fixed portion at an early initial point. Due to this collision, a drag force is generated in the engaged portion, and the movable portion is likely to be damaged by this drag force. Moreover, when this drag force is applied to the portion where the movable portion and the conductive member abut against each other, the conductive member may also be damaged, resulting in a problem of deterioration in the electrical characteristics of the contact. Furthermore, a problem arises that the workability when mounting the conductive member is deteriorated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a surface mount contact with improved electrical characteristics and improved workability.

The surface mount contact of the present invention comprises a base portion fixed to a substrate, and an elastically deformable contact portion that is bent to protrude from the base portion and electrically contacts a conductive member mounted on the substrate. , and a stopper portion provided on the base portion to stop the movement of the contact portion. The contact portion includes a base portion bent upward from one end of the base portion, a spring portion bent upward from the upper end of the base portion toward the other end of the base portion, and a spring portion extending from the tip of the spring portion. An attraction portion having an extended flat surface, a tip portion bent downward from the tip of the attraction portion toward the proximal portion, and a stopper provided at the tip of the tip portion and locked to the stopper portion. A locked part is provided. In addition, the boundary between the spring portion and the suction portion portion is configured as a contact portion, and the locked portion is configured as a portion elastically contacting the locking portion provided on the stopper portion in a normal state. A first distance from the part to the abutment part is longer than a second distance from the proximal part to the locked part.

According to the present invention, when the contact portion is brought into contact with the conductive member and is elastically deformed, the tip end portion or the engaged portion of the contact portion does not immediately contact the base portion, so that the contact portion contacts the base portion. Suppresses the drag generated by As a result, it is possible to prevent damage to the surface mount contacts and the conductive member caused by drag, improve electrical characteristics in contact, and improve workability when mounting the conductive member.

2 is an external perspective view of the surface mount contact of Embodiment 1. FIG. 3A, 3B, 3C, and 3C are a plan view, a front view, and a left side view of the surface mount contact of Embodiment 1. FIG. 4A and 4B are front views for explaining the operation of the surface mount contact according to the first embodiment; FIG. The front view explaining the operation|movement and subject of the surface mount contact of a reference example. FIG. 11 is a front view for explaining the structure and operation of the surface mount contact according to the second embodiment;

(Embodiment 1)
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view of a surface mount contact (hereinafter referred to as contact) according to Embodiment 1 of the present invention. The contact 1 is formed of a conductive metal plate and is surface-mounted on the ground pattern 21 of the printed wiring board 2 provided in the device by a reflow method using a conductive brazing material such as solder. A member (hereinafter referred to as a mounting member) 3 such as a liquid crystal display panel is mounted on the printed wiring board 2 . touched. As a result, the conductive pad 31 of the mounting member 3 is electrically connected to the ground pattern 21 of the printed wiring board 2 through the contact 1 and grounded.

2(a) to (c) are a plan view, a front view and a left side view of the contact 1. FIG. 1 and 2, the contact 1 is formed by bending an elastic, conductive metal plate. The contact 1 includes a base portion 11 mounted on the ground pattern 21 of the printed wiring board 2 and a contact portion 12 bent upward in FIG. 1 from the base portion 11 . A stopper portion 13 is formed on the base portion 11 . In the following, the vertical direction is based on FIG. 1, and the length direction is the horizontal direction in FIGS. 2(a) and 2(b).

The base portion 11 is formed in a generally rectangular flat plate shape, and the contact portion 12 extends upward from one longitudinal end (the right end in FIG. 1) of the base portion 11 and toward the opposite other end. are bent. Further, the stopper portions 13 are bent at both ends in the width direction of one end of the base portion 11 .

The contact portion 12 has a base portion 121 that is bent upward from one end of the base portion 11 in a generally arcuate shape, and a base portion 121 that extends obliquely upward from the base portion 121 toward the other end of the base portion 11 so as to be substantially straight. It has a bent back spring portion 122 . Further, it has a suction portion 123 which is bent in the horizontal direction from the spring portion 122 and straightly extended to a position substantially above the other end of the base portion 11 and whose upper surface is formed as a flat surface.

Further, the tip portion 124 is bent obliquely downward from the suction portion 123 toward the base end portion 121 at an acute angle and straight. Although the tip section 124 is formed substantially parallel to the spring section 122 here, it may have a desired angle with respect to the spring section 122 . The front end of the front end portion 124 is configured as a locked portion 125 in which both side edges in the width direction protrude outward. A bent portion of the boundary between the spring portion 122 and the suction portion 123 is configured as a contact portion 126 that electrically contacts the conductive pad 31 .

The stopper portions 13 are arranged at positions corresponding to the engaged portions 125 on both sides in the width direction of one end of the base portion 11 . Both edges of the base portion 11 in the width direction of the stopper portion 13 are bent upward into a crank shape, and the distal end of the stopper portion 13 is a hook-like locking member protruding horizontally toward the other end side. It is configured as a portion 131 and set at a predetermined height position with respect to the upper surface of the base portion 11 .

In addition, the engaged portion 125 is arranged below the engaging portion 131 and is in elastic contact with the lower surface of the engaging portion 131 . That is, when configuring the contact 1 , the contact portion 12 is elastically deformed downward, and in this elastically deformed state, the engaged portion 125 is arranged on the lower surface side of the engaging portion 131 . The contact portion 12 is returned upward by the elastic restoring force, but since the locked portion 125 is elastically contacted and locked to the lower surface of the locking portion 131, the contact portion 12 does not return upward. A locked steady state is assumed.

Here, as shown in FIG. 2B, the first distance Lc from the base end portion 121 to the contact portion 126 is the distance from the base end portion 121 to the tip of the tip portion 124, that is, the locked portion 125. 2 It is longer than the distance Ls. The ratio of these distances (Lc/Ls) is preferably designed to be a predetermined value, for example, about "1.5 to 3", but is designed to be approximately "2" in the first embodiment. Note that the starting points of these distances Lc and Ls are precisely positions that serve as fulcrums when the spring portion 122 is elastically deformed, but they are substantially located very close to the base end portion 121. The site 121 can be used as a starting point.

The positional relationship between the engaged portion 125 and the contact portion 126 is such that the engaged portion 125 is arranged closer to the base end portion 121 than the contact portion 126 on the surface of the base portion 11 . There may be. Here, the positions of the engaged portion 125 and the contact portion 126 on the surface of the base portion 11 are the positions when the engaged portion 125 and the contact portion 126 are projected onto the upper surface of the base portion 11 from the vertical direction. means.

Further, the height Hs of the engaging portion 131 of the stopper portion 13 with respect to the base portion 11 is set based on the distance between the mounting member 3 and the printed circuit board 2 when the mounting member 3 is mounted on the printed circuit board 2 . On the other hand, the height Hc of the contact portion 126 is sufficiently larger than the height dimension Hs of the locking portion 131, and the ratio of these heights (Hc/Hs) is equal to the ratio of the distances (Lc/ Ls), it is set to "1.5 to 3". Here, the ratio is approximately "2".

The contact 1 of Embodiment 1 having the above configuration is surface-mounted by fixing the lower surface of the base portion 11 onto the surface of the ground pattern 21 of the printed wiring board 2 shown in FIG. 1 by a reflow method using solder or the like. . At this time, a surface mounting method using vacuum suction may be applied by utilizing the fact that the upper surface of the suction portion 123 is a flat surface, but the present invention is not particularly limited to this.

In the normal state of the mounted contact 1, the locked portion 125 is in elastic contact with the lower surface of the locking portion 131 due to the elastic restoring force of the spring portion 122 as described above. Further, in this normal state, even if an external force is applied to the contact portion 12 , particularly even if an upward external force is applied to the tip portion 124 or the suction portion 123 , the locked portion 125 is locked by the locking portion 131 . As a result, excessive deformation of the contact portion 12 due to the external force is prevented, and plastic deformation of the contact portion 12 is prevented.

In this contact 1, as shown in FIG. 3(a), when a mounting component 3 such as a liquid crystal display panel is lowered from above the contact 1, a conductive member, that is, a conductive pad 31 provided on the mounting component. contacts the suction portion 123 of the contact portion 12, and the contact portion 12 is elastically deformed downward by this contact force.

When the conductive pad 31 is further lowered, as shown in FIG. 3(b), the contact portion 12 is elastically deformed downward to bring the conductive pad 31 into contact with the contact portion 126, so that an electric current is generated between the two. A conducting path is formed. At this time, the contact portion 12 maintains the contact state between the conductive pad 31 and the contact portion 126 by its own elastic restoring force.

When the conductive pad is further lowered, the contact portion 12 is elastically deformed to bring the tip of the tip portion 124, that is, the engaged portion 125, into contact with the upper surface of the base portion 11, as indicated by the chain line in FIG. 3(b). be. As a result, the contact 1 also forms an electrical conduction path between the tip portion 124 and the base portion 11, and the electrical contact resistance in the contact 1 is reduced.

Then, as shown in FIG. 3(c), the conductive pad 31 is lowered to a predetermined height position, here, to a height position where it substantially abuts on the upper surface of the locking portion 131 of the stopper portion 13, and the device is mounted at this height position. The component 3 is fixed to the printed wiring board 2 by a fixing member (not shown). At this time, the stopper portion 13 may be used as a fixing member that supports the mounting component 3 from below.

As described above, in the contact 1 of Embodiment 1, the component 3 is mounted and the conductive pad 31, which is a conductive member, is electrically connected to the ground pattern 21 of the printed circuit board 2 through the contact 1. It is possible to improve the electrical properties in the case. At the same time, workability in mounting can be improved. This will be described in comparison with the contact 1X of the reference example shown in FIG.

FIG. 4(a) shows the normal state of the contact 1X of the reference example. For this contact 1X, in order to facilitate comparison with the contact 1 of the first embodiment, parts equivalent to the contact 1 are the same. A sign is attached. Here, the heights (Hc, Hs) of the contact portion 126 and the locking portion 131 and the first distance (Lc) from the base end portion 121 to the contact portion 126 are the same as in the first embodiment. On the other hand, the second distance (Ls) from the proximal end portion 121 to the tip of the distal end portion 124, that is, the locked portion 125 is longer than in the first embodiment, and the ratio (Lc/Ls) is approximately "1" here. It's becoming It can be said that Patent Documents 1 and 2 also have the same configuration as this reference example.

As shown in FIG. 4B, when the conductive pad 31 is lowered to the contact 1X of this reference example, the contact portion 12 is brought into contact and elastically deformed downward. When the conductive pad 31 is lowered substantially by the height of the stopper portion 13, the tip portion 124 is also lowered and its tip, that is, the engaged portion 125 is brought into contact with the upper surface of the base portion 11, and this contact causes a drag force. occurs. That is, in this contact 1X, since the distance from the base end portion 121 to the contact portion 126 is substantially the same as the distance from the base end portion 121 to the engaged portion 125, the distance at which the contact portion 126 descends , the distance by which the member to be engaged 125 descends is substantially the same.

The generated drag is transmitted to the contact portion 12, and the contact portion 12 is likely to be plastically deformed. If part of the contact portion 12, particularly the contact portion 126, is plastically deformed, the electrical contact state with the conductive pad 31 may deteriorate. Further, this drag force is added to the contact force with the conductive pad 31 at the contact portion 126, and the contact force is increased. When the conductive pad 31 is lowered, the contact portion 126 is slid on the surface of the conductive pad 31, and the increase in the contact force increases the frictional force during the sliding, and the surface of the conductive pad 31 slides. may be worn out or otherwise damaged.

Furthermore, due to such an increase in contact force, the force required to lower the conductive pad 31, that is, the work force for mounting the component 3 is increased. This increase in working force can be said to be very small for one contact, but in practice there are many cases in which a plurality or a large number of contacts are mounted, and in such cases the working force increases. is multiplied by the number of contacts, the increase in total working force cannot be ignored, and workability may deteriorate.

Also in the contact 1X of the reference example, when the conductive pad 31 is lowered to a predetermined position, as shown in FIG. , electrical contact is made with the conductive pads 31 .

In contrast to the contact 1X of the reference example, in the contact 1 of the first embodiment, the tip of the tip portion 124, that is, the engaged portion 125 is closer to the proximal portion 121 than the contact portion 126, as shown in FIG. , that is, on one end side of the base portion 11, and the first distance Lc from the base end portion 121 to the contact portion 126 is the second distance Ls from the base end portion 121 to the engaged portion 125. , and the ratio of both (Lc/Ls) is designed to be approximately "2". Therefore, as shown in FIG. 3(b), when the contact portion 12 is elastically deformed and the abutting portion is lowered while rotating about the base end portion 121, the engaged portion 125 is brought into contact with the base end portion 121 as a fulcrum. It remains to be lowered by the reciprocal of the ratio (Lc/Ls) with respect to the portion 126 . Here, the distance by which the engaged portion 125 descends is approximately half the distance by which the contact portion 126 descends.

Therefore, the distance by which the contact portion 126 descends until the engaged portion 125 collides with the base portion 11 to generate a drag force is approximately double the distance in the contact 1X of the reference example. In other words, until the contact portion 126 reaches twice the lowering distance of the contact 1X of the reference example, the locked portion 125 does not come into contact with the base portion 11, and the locked portion 125 No drag occurs in As a result, there is no risk of plastic deformation of the contact portion 12 caused by drag force. Moreover, the contact force at the contact portion 126 does not increase, and damage to the conductive pad 31 when the contact portion 126 slides on the surface of the conductive pad 31 is prevented. Furthermore, since the contact force at the contact portion 126 is not increased, even when many contacts 1 are mounted, the work force in the mounting work is not increased and workability is not deteriorated.

When the conductive pad 31 is lowered to a height position substantially equal to the height Hs of the stopper portion, as shown in FIG. Occur. At this time, since the tip portion 124 has a shape substantially parallel to the spring portion 122 , the tip portion 124 abuts against the base portion 11 almost entirely. Therefore, the drag force generated in the tip portion 124 is dispersed in the tip portion 124 , the concentration of the drag force is prevented, and the plastic deformation of the contact portion 12 is prevented. On the other hand, the drag force generated by the collision between the tip portion 124 and the base portion 11 is added to the contact force with the conductive pad 31 at the contact portion 126 positioned directly above the tip portion 124, and the electrical characteristics are improved. be improved.

As described above, in the contact 1 of Embodiment 1, by appropriately designing the position of the engaged portion 125 provided at the tip of the tip portion 124 of the contact portion 12, the contact portion 126 of the contact portion 126, such as the conductive pad 31, etc. The contact force with the conductive member can be appropriately adjusted, the electrical characteristics of the electrical contact with the conductive member can be improved, and the workability in mounting the conductive member on the substrate can be improved. If the ratio (Lc/Ls) is less than 1.5, it will be difficult to obtain sufficient effects. Moreover, if it is larger than 3, the torque applied to the locking portion 131 of the stopper portion 13 increases when the contact portion 12 receives an external force, making it difficult to obtain the original stopper effect.

Further, since the height of the contact portion 126 and the amount of elastic deformation of the contact portion 126 in the vertical direction are not restricted by the height of the stopper portion 13, the shape, dimensions, etc. of the contact portion 12 can be arbitrarily designed. becomes possible. As a result, the degree of freedom in design can be increased when manufacturing contacts having preferable amounts of elastic deformation and contact forces corresponding to various different conductive members.

(Embodiment 2)
FIG. 5 is a front view of a surface mount contact 1A according to Embodiment 2. Parts equivalent to those of Embodiment 1 are assigned the same reference numerals and descriptions thereof are omitted. FIG. 5(a) shows the normal state of the contact 1A, which differs from the first embodiment in the shape of the tip portion 124A. That is, in the contact 1A of the second embodiment, the tip portion 124A is bent downward in the middle portion in the longitudinal direction, in other words, it is bent into a convex curved surface having a gentle curvature with respect to the spring portion 122. The configuration provided is different from that of the first embodiment.

Also in this contact 1A, similarly to the first embodiment, the locked portion 125, which is the tip of the tip portion 124A, is arranged closer to the base portion 121 than the contact portion 126, that is, to one end side of the base portion 11. . Specifically, the first distance Lc from the base end portion 121 to the contact portion 126 is made larger than the second distance Ls from the base end portion 121 to the engaged portion 125, which is the tip of the tip portion 124A, The ratio (Lc/Ls) is designed to be approximately "2" within the range of "1.5 to 3".

According to this contact 1A, the ratio (Lc/Ls) between the first distance Lc from the base end portion 121 to the contact portion 126 and the second distance Ls from the base end portion 121 to the engaged portion 125 is " 2", when the conductive pad 31 is lowered and the contact portion 12 is elastically deformed as shown in FIG. There is no contact with the base portion 11 and no drag occurs. As a result, an increase in the contact force between the conductive pad 31 and the contact portion 126 is prevented, there is no risk of plastic deformation in the contact portion 12, and damage to the conductive pad 31 is prevented. At the same time, it is possible to prevent an increase in work force when mounting the conductive member.

In this contact 1A, as shown in FIG. 5(c), when the contact 1A is lowered to a predetermined height position where the conductive pad 31 is mounted, the engaged portion 125 does not come into contact with the base portion 11. , the tip portion 124A having a convex curved surface slides on the surface of the base portion 11 and comes into contact therewith. As a result, the drag generated between the base portion 11 and the base portion 11 is dispersed in the longitudinal direction of the tip portion 124A, and concentration on a part of the contact portion 12 is alleviated, thereby preventing the contact portion 12 from being plastically deformed. On the other hand, by appropriately designing the curved shape of the tip portion 124A, the contact position between the tip portion 124A and the base portion 11 can be designed to be directly below the contact portion 126. It is also possible to apply the upward drag force to the contact portion 126 as it is, so that the contact force can be effectively increased.

As described above, the contact of Embodiment 2 can also improve the electrical characteristics with respect to the conductive member, and can improve the workability when mounting the conductive member on the substrate.

The present invention is not limited to the configurations and shapes of Embodiments 1 and 2, and the present invention can also be applied to contacts having different planar shapes of base portions. Further, the present invention can also be applied to contacts having different configurations and shapes of the base portion, spring portion, suction portion, tip portion, and engaged portion that constitute the contact portion.

1, 1A Surface mount contact 2 Printed wiring board 3 Mounting member 11 Base portion 12 Contact portion 13 Stopper portion 21 Ground pattern 31 Conductive pad (conductive member)
121 Base end portion 122 Spring portion 123 Adsorption portion 124 Tip portion 125 Locked portion 126 Contact portion 131 Locking portion Lc First distance Ls Second distance

Claims (2)

a base portion fixed to a substrate; an elastically deformable contact portion bent to protrude from the base portion and electrically contacting a conductive member mounted on the substrate; A surface mount contact comprising a stopper portion for locking movement of the contact portion, wherein the contact portion includes a proximal portion bent upward from one end of the base portion, and an upper end of the proximal portion. A spring portion bent upward toward the other end of the base portion, an adsorption portion having a flat surface extending from the tip of the spring portion, and a tip of the adsorption portion directed toward the proximal end portion. A tip portion bent downward and a locked portion provided at the tip of the tip portion and locked by the stopper portion are provided, and a boundary between the spring portion and the suction portion is configured as a contact portion. The locked portion is configured as a portion that is in elastic contact with a locking portion provided on the stopper portion in a normal state, and a first distance from the base end portion to the contact portion is equal to the base end portion. A surface mount contact, wherein the contact is longer than a second distance from a site to the latched site. 2. A surface mount contact according to claim 1, wherein said locked portion is arranged on the surface of said base portion at a position closer to said base end portion than said contact portion.

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