Contact

Abstract

To provide a highly reliable contact which prevents plastic deformation at a contact part for electric connection.SOLUTION: This connector is provided with a base part 2 fixed to a first conductive member K1, an elastically deformable contact part 3 extended and formed in a projecting state from the base part and electrically contacting with a second conductive member, and a stopper part 4 arranged in the base part 2 and locking elastic deformation of the contact part 3. The contact portion 3 includes a first locking portion (3544,) provided at a position close to the tip end in the extending direction, and a second locking portion (3643,) provided at a position closer to the base portion 2 than the first locking portion. Elastic deformation of the contact part 3 is locked at the first locking part and the second locking part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a contact for electrically connecting a plurality of conductive members to each other. [Background technology]

[0002] Contacts made by bending conductive plate material such as metal have been proposed as components for electrically connecting electronic components mounted on electronic devices to the electronic devices. One such contact is a surface-mount contact that includes a base portion fixed to an electrically conductive surface on the surface of the electronic device and a contact portion that is bent to protrude upward from the base portion and is elastically deformable. The contact in Patent Document 1 includes a base portion whose underside is surface-mounted to the electrically conductive surface by soldering or the like, and a contact portion that is bent upward from one end of the base portion. The elastic deformation force of the contact portion is utilized to electrically connect the contact to the electronic component, thereby electrically connecting the electronic component to the electronic device.

[0003] Furthermore, the contact of Patent Document 1 has a locking piece provided on a part of the contact portion, particularly on a part of the contact portion near the tip, and this locking piece is engaged with the base portion to form a locking structure that prevents the contact portion from elastically deforming. With this type of locking structure, it is expected that when an external force is applied to the contact portion, the contact portion will not be deformed beyond its limit of elastic deformation, and will therefore not be plastically deformed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-220426 Summary of the Invention [Problem to be solved by the invention]

[0005] The contacts in Patent Document 1 are designed to be electrically connected to the contact portion from a predetermined direction. The locking structure is provided on a portion of the contact portion, allowing elastic deformation in a predetermined direction and within a predetermined range, while preventing elastic deformation in other directions. However, during installation of electronic components in electronic devices, external forces may be applied to the contact from various directions other than the predetermined direction, which may cause excessive elastic deformation of the contact portion. Depending on the direction and magnitude of the external force, the contact portion may be elastically deformed beyond its elastic limit and even undergo plastic deformation. For example, the base end portion of the contact portion, which serves as a fulcrum for elastic deformation, may be plastically deformed, reducing the elasticity of the contact portion and causing it to no longer function as a contact, thereby reducing the reliability of the contact.

[0006] An object of the present invention is to provide a highly reliable contact that is prevented from plastic deformation in the contact. [Means for solving the problem]

[0007] The contact of the present invention comprises a base portion fixed to a first conductive member, an elastically deformable contact portion extending from the base portion and projecting therefrom to electrically contact a second conductive member, and a stopper portion provided on the base portion to prevent the contact portion from elastically deforming. The contact portion further comprises a first locking portion provided near the tip in the extension direction, and a second locking portion provided nearer to the base portion than the first locking portion. Elastic deformation of the contact portion is prevented by the first locking portion and the second locking portion.

[0008] In the present invention, the first and second locking portions are configured to prevent the contact portion from elastically deforming in opposite directions. For example, the contact portion includes a base portion formed at one end of the base portion, a spring portion bent upward from the base portion, an abutment portion extending from a tip of the spring portion, and a tip portion bent downward from the tip of the abutment portion, and the first locking portion is provided at the abutment portion or the tip portion, and the second locking portion is provided at the spring portion. [Effects of the Invention]

[0009] According to the present invention, the elastic deformation of the contact portion is prevented by the first and second locking portions provided at different positions on the contact portion, so that the contact portion is not subjected to excessive elastic deformation and plastic deformation can be prevented. In particular, since the first and second locking portions prevent elastic deformation in opposite directions, even when the contact portion is elastically deformed in opposite directions, excessive elastic deformation is not caused and plastic deformation can be prevented. This ensures elasticity in the contact portion and results in a highly reliable contact. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is an external perspective view of a contact according to an embodiment of the present invention. [Figure 2] 1A and 1B are a front view and a right side view of a contact according to an embodiment. [Figure 3] FIG. 10 is a perspective view of the contact with the stopper portion cut away. [Figure 4] FIG. 4 is a schematic right side view showing an electrical conduction state in the contact. [Figure 5] 5A and 5B are schematic right side views illustrating the operation of the contacts of the embodiment and the comparative example. [Figure 6] 5A and 5B are schematic right side views illustrating the operation of the contacts of the embodiment and the comparative example. [Figure 7] FIG. 10 is an external perspective view of a contact according to a modified example. [Figure 8]10A and 10B are a right side view and a rear view of a modified contact. DETAILED DESCRIPTION OF THE INVENTION

[0011] Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view of a contact according to an embodiment of the present invention. The contact 1 is configured as a surface-mount contact formed from a conductive and flexible metal plate. The contact 1 is surface-mounted on a ground pattern K11 of a wiring board K1 provided in an electronic device by a reflow method using a conductive brazing material such as solder. An electronic component K2, such as a liquid crystal display panel, is mounted on the wiring board K1, and the conductive surface of the electronic component K2 is electrically contacted with the contact 1. As a result, the electronic component K2 is electrically connected to the ground pattern K11 of the wiring board K1 via the contact 1, thereby grounding the electronic component K2. The wiring board K1 and the electronic component K2 in this embodiment are the first conductive member and the second conductive member, respectively, of the present invention, and the first conductive member K1 and the second conductive member K2 are electrically connected by the contact 1.

[0012] 2(a) and 2(b) are a front view and a right side view of the contact 1. Referring to Fig. 1 and Fig. 2, the contact 1 comprises a base portion 2 mounted on the ground pattern K11 of the wiring board K1, a contact portion 3 that is bent while extending from the base portion 2 upward in Fig. 1, and a stopper portion 4 that stops movement of the contact portion 3 when it elastically deforms. Note that, hereinafter, the up-down direction is based on Fig. 1, the length direction is the left-right direction in Fig. 2(b), and the width direction is the left-right direction in Fig. 2(a).

[0013] The base portion 2 is formed in the shape of a roughly rectangular flat plate. The contact portion 3 is bent upward from one longitudinal end of the base portion 2 (the left end in FIG. 1) to a required length and into a required shape. The stopper portion 4 is formed in the shape of a standing wall bent upward on both side edges in the width direction of the base portion 2. As described above, the base portion 2, contact portion 3, and stopper portion 4 are formed by bending a single elastic metal plate, but this configuration is not necessarily limited to this, and some portions may be configured by joining separate members.

[0014] FIG. 3 is a perspective view of the contact portion 3, with the stopper portion 4 cut away in FIG. 1, to illustrate the contact portion 3. The contact portion 3 includes a base end portion 31 that is continuous with one end of the base portion 2 and bent into a generally arcuate shape in the thickness direction. A spring portion 322 is bent diagonally upward from the base end portion 31 toward the other end of the base portion 2 by a required length and curved somewhat concavely. The spring portion 322 also includes an abutment portion 33 that is bent back from the tip of the spring portion 32 toward the other end and extends horizontally, i.e., in a direction generally parallel to the base portion 2, and has a flat upper surface. As described below, the abutment portion 33 abuts against the electronic component K2 to establish an electrical connection. However, since the contact portion 33 also serves as a vacuum suction portion when mounting the contact 1 on the wiring board K1, it can also be referred to as a suction portion, but here it is referred to as a contact portion. Furthermore, a tip portion 34 is bent downward from the tip of the abutment portion 33 toward the base portion 2.

[0015] The downward-facing tip of the tip portion 34 is provided with a locking pawl 35, which is reduced in width and bent substantially vertically toward one end. This locking pawl 35 may be bent so that the tip side is curved slightly upward. In addition, a pair of locking pieces 36 are provided at a midpoint in the extension direction of the spring portion 32, protruding outward in the width direction from both side edges of the spring portion 32. The pair of locking pieces 36 are set at substantially the same height as the locking pawl 35 relative to the base portion 2, but they do not necessarily have to be at the same height.

[0016] 1 and 2, the stopper portion 4 has a pair of side wall portions 41 erected on both widthwise edges of the base portion 2. The height of these side wall portions 41 is lower than the abutting portion 33 of the contact portion 3, and in this case is formed to be approximately half the height of the abutting portion 33. A locking window 43 is formed in an approximately central region in the longitudinal direction of the pair of side wall portions 41, cutting upward from the base portion. This locking window 43 is formed to required dimensions in both the longitudinal and vertical directions and is curved in an arc centered on the base end portion 31 of the contact portion 3. The height position of the upper edge of this locking window 43 is set to a height that regulates the height position of the locking piece 36 when the contact portion 3 is in the normal state, as will be described later.

[0017] The edges of one end of each of the pair of side wall portions 41 are bent inward in the thickness direction of the plate width to form end wall portions 42 whose tips are close to or in contact with each other. Both end wall portions 42 are formed only in regions toward the upper ends of the side wall portions 41, and the central regions in the width direction where they are close to or in contact with each other are cut downward to form a recessed locking groove 44 that opens downward. The width dimension of this locking groove 44 is slightly larger than the width dimension of the locking claw 35 described above. The height position of the upper edge of the locking groove 44 is set to a height that regulates the height position of the locking claw 35 when the contact portion 33 is in the normal state, as will be described later.

[0018] In the assembled contact 1, the contact portion 3 is elastically deformed in a direction reducing its height relative to the base portion 2, and the pair of locking pieces 36 provided on the spring portion 3 are inserted into the locking windows 43 and are brought into contact with the upper edges of the locking windows 43 from below by the elastic restoring force of the spring portion 32. Therefore, the spring portion 32 is prevented from elastically deforming toward one end by the engagement between the locking pieces 36 and the locking windows 43, and the contact portion 3 as a whole is prevented from elastically deforming toward the one end. Furthermore, the locking pawl 35 provided on the tip portion 34 is inserted into the locking groove 44 and is brought into contact with the upper edge of the locking groove 44 from below by the elastic restoring force of the spring portion 32. Therefore, the tip portion 34 is prevented from elastically deforming toward the other end by the engagement between the locking pawl 35 and the locking groove 44, and the contact portion 3 as a whole is prevented from elastically deforming toward the other end.

[0019] In this way, the abutment between the locking piece 36 and the locking window 43, and the abutment between the locking claw 35 and the locking groove 44, brings the contact portion 3 into a state in which the elastic deformation of the spring portion 32 is locked, and this state is the normal state of the contact portion 3. Here, locking the elastic deformation means that the elastic deformation is locked in a part of the contact portion. In this way, the locking structure in which the locking claw 35 and the locking groove 44 cooperate to perform the locking function, and the locking structure in which the locking piece 36 and the locking window 43 cooperate to perform the locking function are respectively configured as the first locking portion and the second locking portion in the present invention.

[0020] As shown in the right side view of FIG. 4 , the contact 1 configured as described above is surface-mounted by reflow soldering or the like onto the surface of the ground pattern K11 of the wiring board K1 shown in FIG. 1 . The contact 1 is electrically connected to the ground pattern K11. For this surface mounting, a vacuum surface mounting method may be used, taking advantage of the flat upper surface of the contact portion 33, but this is not particularly limited. An electronic component K2 to be electrically connected to the wiring board K1 is then placed on the contact 1 and lowered so that the conductive surface of the lower surface of the electronic component K2 abuts against the contact portion 3. This abutment occurs on the upper surface of the abutment portion 33 or in the boundary region with the bent spring portion 32. Alternatively, it may occur in the boundary region with the tip portion 34. When the electronic component K2 abuts against the contact portion 3, the spring portion 32 elastically deforms downward (toward the base portion 2), and the elastic restoring force associated with this elastic deformation establishes a suitable electrical connection between the abutment portion 33 and the electronic component K2.

[0021] When the electronic component K2 is normally mounted on the wiring board K1, as shown in Fig. 4, the contact portion 3 is elastically deformed such that the spring portion 32 falls toward the base portion 2, and the abutment portion 33 makes electrical contact with the electronic component K2. At this time, the locking piece 36 of the spring portion 32 moves downward within the locking window 43, causing elastic deformation at the spring portion 32. Furthermore, when the spring portion 32 elastically deforms, an upward reaction force acts on the locking claw 35 of the tip portion 34, so the locking claw 35 remains locked in the locking groove 44. Furthermore, even if a force acts in the width direction on the tip portion 34, the locking claw 35 will not come out of the locking groove 44 because the locking groove 44 is a concave groove. Therefore, a highly reliable electrical connection is obtained.

[0022] Here, when mounting the electronic component K2, it is conceivable that an unintended external force may be applied to the contact 1, particularly the contact portion 3. For example, as shown in FIGS. 5(a) and 5(b), when a lateral (horizontal or downward) external force F1 is applied to the contact portion 3 from one end, the contact portion 3 is deformed and falls toward the other end. If the locking claw 35 (first locking portion) were not present and only the locking piece 36 (second engaging portion) were present, as shown in FIG. 5(b), the locking piece 36 of the second locking portion would not be prevented from moving downward within the locking window 43. Therefore, the spring portion 32 and the abutment portion 33 would not be prevented from falling. This would result in excessive elastic deformation of the spring portion 32 and the base end portion 31, potentially resulting in plastic deformation of the contact portion 3. The technology of Patent Document 1 is similar to this situation.

[0023] The contact of the embodiment includes a first locking portion consisting of the locking pawl 35 and the locking groove 44 in addition to the second locking portion. Therefore, even if the spring portion 32 of the contact portion 3 is tilted toward the other end by an external force F1 as shown in FIG. 5(a), the reaction force generated by the first locking portion keeps the locking pawl 35 locked in the locking groove 44. This prevents the tip portion 34 from moving or deforming toward the other end, and also prevents excessive elastic deformation of the abutment portion 33, the spring portion 32, and the base end portion 31. This prevents plastic deformation of the contact portion 3, ensuring the reliability of the contact 1. In addition, even if the locking piece 36 moves within the locking window 43, the locking function of the second locking portion is not impaired after the locking piece 36 is released from the locking window 43.

[0024] 6(a) and 6(b), when a lateral external force F2 is applied to the contact portion 3 from the other end, the contact portion 3 will tilt toward one end. If the locking piece 36 (second locking portion) were not present at this time, as shown in FIG. 6(b), the locking claw 35 would be locked in the locking groove 44 in the first locking portion, preventing deformation toward the one end. However, the deformation of the spring portion 32 would not be prevented, and the collapse of the spring portion 32 or the abutment portion 33 would not be prevented, resulting in excessive elastic deformation. In particular, the elastic deformation of the base end portion 31 connected to the spring portion 32 would be excessive, and plastic deformation would occur in the spring portion 32 and the base end portion 31.

[0025] The contact of the embodiment has, in addition to the first locking portion, a second locking portion composed of the locking piece 36 and the locking window 43. Therefore, when the contact portion 3 is tilted toward one end, the locking piece 36 is locked by the locking window 43 in the second locking portion so as to prevent deformation toward the one end, and deformation of the spring portion 32 is prevented. Furthermore, in the first locking portion, the locking claw 35 is maintained in the locking groove 44 so that the abutment portion 33 and the tip portion 34 are prevented from tilting toward the one end. This prevents excessive elastic deformation of the spring portion 32 and the base end portion 31, preventing plastic deformation of the spring portion 32 and the base end portion 31 and thus preventing plastic deformation of the contact portion 3, ensuring the reliability of the contact 1.

[0026] As described above, by providing the contact 1 with the first locking portion and the second locking portion, even when an external force is applied from either one end or the other end, the locking action of either locking portion prevents excessive elastic deformation in the contact portion 3, preventing plastic deformation in the contact portion 1 and improving the reliability of the contact 1. Note that this effect of preventing plastic deformation in the contact 1 is not limited to when force is applied from an electronic component when the electronic component is being mounted, but also applies when an external force is applied to the contact by a tool or the like coming into contact with the contact during the mounting operation. Therefore, the reliability of the contact can be improved not only when mounting an electronic component on a wiring board, but also in other operations.

[0027] The contact of the present invention is not limited to the configuration described in the embodiment, and the shape of the spring portion may be different. Fig. 7 is an external perspective view of a modified contact 1A, and Figs. 8(a) and 8(b) are a right side view and a rear view thereof. In the modified contact 1A, portions equivalent to those of the contact 1 of the embodiment are given the same reference numerals, and detailed description thereof will be omitted. In the modified contact 1A, the spring portion 32 is bent in the plate thickness direction at an intermediate position 32a in the extension direction.

[0028] Furthermore, a locking piece 36 constituting a second locking portion is provided in the spring portion 32 at a position closer to the abutment portion 33 than the intermediate position 32a. In this contact 1A, the locking piece 36 extends downward from the spring portion 32 by a required length, and its tip 36a is bent. The tip 36a is inserted into a locking window 43 provided in a side wall portion 41 of the stopper portion 4, and is adapted to be locked by the locking window 43. The locking window 43 is formed in a rectangular shape that is longer in the longitudinal direction than in the embodiment.

[0029] In the contact 1A of this modification, the spring portion 32 is bent in a folded state, so that the abutting portion 33 and the tip portion 34 are directed toward the other end of the base portion 2. The abutting portion 33 is also bent so that a portion 33a on the other end side protrudes upward, and is configured as a contact point for establishing an electrical connection with the electronic component K2. The configuration of the tip portion 34 and the first locking portion provided thereon, i.e., the configuration of the locking pawl 35 and the locking groove 44, is the same as that of the contact 1 of the embodiment except that they are oriented in the opposite direction, but the depth of the locking groove 44 (the vertical dimension) is longer than that of the contact 1 of the embodiment.

[0030] In the contact 1A of the modified example, the spring portion 32 is bent, so that the length of the contact portion 32 in the extension direction can be increased even if the height dimension of the contact 1A is the same as that of the contact 1 of the embodiment. This increases the amount of deformation of the abutting portion 33 when the spring portion 32 is elastically deformed, i.e., the amount of deformation of the abutting portion 33 in the up-down direction, and increases the margin for the mounting position of the electronic component K2 to be mounted, i.e., the distance from the wiring board K1.

[0031] The contact 1A of the modified example also has substantially the same basic effect of improving the reliability of the contact as the contact 1 of the embodiment. That is, although there are differences in the configuration in that the amount of deformation at the spring portion 32 is increased and the tip portion 34 and the locking claw 35 are disposed on the other end side of the base portion 2 relative to the base end portion 31 of the contact portion 32 provided on one end side, the effect of preventing plastic deformation of the contact portion 3 by the first locking portion and the second locking portion against the external forces F1 and F2 shown in Figures 5 and 6 is the same. This can improve the reliability of the contact.

[0032] The present invention is not limited to the configurations and shapes of the embodiments and modified examples as long as the first and second locking portions are provided at two locations in the extension direction of the contact portion. Furthermore, the first and second locking portions are preferably provided at two locations sandwiching the abutment portion in the extension direction of the contact portion, but, for example, one of the locking structures may be a part of the abutment portion, such as a location near the tip portion. Furthermore, the first and second locking portions may be configured such that locking claws or locking pieces are provided on stopper portions, and these locking claws or locking pieces engage with the contact portion to lock the movement of the contact portion.

[0033] In the contact of the present invention, the planar shape of the base portion may be different from that of the embodiment, for example, the base portion may be fixed not by brazing but by screws, adhesive, etc. Furthermore, the configurations and shapes of the base end portion, spring portion, abutment portion, and tip portion that make up the contact portion may be different from those of the embodiment and modified examples. [Explanation of symbols]

[0034] 1,1A Contact 2 Base 3 Contact part 4 Stopper part 31 Proximal part 32 Spring part 33 Contact area 34 Tip part 35 Locking claw (first locking portion) 36 Locking piece (second locking portion) 41 Side wall part 42 End wall section 43 Locking window (second locking portion) 44 Locking groove (first locking portion) K1 Wiring board (first conductive member) K2 Electronic component (second conductive member)

Claims

1. A contact comprising: a base portion fixed to a first conductive member; an elastically deformable contact portion extending from the base portion and protruding to electrically contact a second conductive member; and a stopper portion provided on the base portion to lock the elastic deformation of the contact portion, wherein the contact portion has a first locking portion provided at a position near the tip in the extension direction, and a second locking portion provided at a position closer to the base portion than the first locking portion, and the elastic deformation of the contact portion is locked at the first locking portion and the second locking portion.

2. The surface mount contact according to claim 1 , wherein the contact portion is prevented from elastically deforming in opposite directions at the first and second locking portions.

3. 2. The contact according to claim 1, wherein the contact portion comprises a spring portion bent upward from a base end portion formed at one end of the base portion, an abutment portion having a flat surface extending from a tip of the spring portion, and a tip portion bent downward from the tip of the abutment portion, the first locking portion being provided at the abutment portion or the tip portion, and the second locking portion being provided at the spring portion.

4. 2. The contact according to claim 1, wherein the first engaging portion comprises an engaging claw provided on the contact portion and an engaging groove provided on the stopper portion for engaging the engaging claw, and the second engaging portion comprises an engaging piece provided on the contact portion and an engaging window provided on the stopper portion for engaging the engaging piece.

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