Device for temporarily fastening electronic component to circuit board

A fastening device for facilitating temporary fastening of an electronic component to a circuit board. The fastening device includes a base embedded in an electronic device and two elastic plates extending from the base. Each elastic plate includes a diagonal portion, which extend diagonally relative to the plane of the circuit board, and a leg, which extends continuously from the diagonal portion. When the legs are inserted through a connecting hole of the circuit board, the resilient force of the elastic plates presses the diagonal portions against the wall of the connecting hole.

BACKGROUND OF THE INVENTION

The present invention relates to a device for temporarily fastening electronic components, such as a connector, to a circuit board.

In the prior art, an electronic component, such as a connector, is temporarily fastened to a circuit board, such as a printed circuit board, at a predetermined connecting position before being securely fastened to the circuit board. As shown inFIG. 8, a threaded hole53is formed in the lower portion of an electronic component50. A printed circuit board51has a connecting hole52at a position where the electronic component50is connected to the circuit board51. To temporarily fasten the electronic component50to the circuit board51, the electronic component50is first arranged at the connecting position. Then, a fastener54, such as a screw, temporarily fastens the electronic component50to the printed circuit board51from the lower side of the circuit board51. Subsequently, the electronic component50is soldered to the printed circuit board51from the lower side of the circuit board51. Thus, the electronic component50is securely fastened to the printed circuit board51by solder3.

However, in the prior art, to connect the electronic component50to the printed circuit board51, a person must arrange the electronic component50on the printed circuit board51at the connecting position, reverse the circuit board51, and connect the electronic component50to the printed circuit board51with the fastener54. This increases the number of operations for connecting the electronic component50to the printed circuit board51and lowers working efficiency.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a device for facilitating temporary fastening of an electronic component to a printed circuit board.

To achieve the above object, the present invention provides a fastening device for temporarily fastening an electronic component to a circuit board. The circuit board has a connecting hole. The fastening device includes a base and at least two elastic plates formed integrally with the base and received in the connecting hole. The elastic plates each include a first portion, which is arranged outside a wall defining the connecting hole when the at least two elastic plates are received in the connecting hole, and a second portion, which extends diagonally relative to a plane of the circuit board when the at least two elastic plates are received in the connecting hole. The second portion has a section pressed against the wall of the connecting hole by the elastic force of the at least two elastic plates.

Another aspect of the present invention is an electronic component connected to a circuit board. The circuit board has a connecting hole. The electronic component includes a fastening portion for contacting a plane of the circuit board and a fastening device arranged in the fastening portion. The fastening device includes a base and at least two elastic plates formed integrally with the base and received in the connecting hole. The elastic plates each including a first portion, which is arranged outside a wall defining the connecting hole when the at least two elastic plates are received in the connecting hole, and a second portion, which extends diagonally relative to the plane of the circuit board when the at least two elastic plates are received in the connecting hole. The second portion has a section pressed against the wall of the connecting hole by the elastic force of the at least two elastic plates.

A further aspect of the present invention is a structure for fastening an electronic component to a circuit board. The circuit board has a connecting hole. The structure includes a fastening portion defined in the electronic component to contact a plane of the circuit board. A fastening device is attached to the fastening portion to temporarily fasten the electronic component to the circuit board. Solder securely fastens the temporarily fastened electronic device. The fastening device includes a base located in the fastening portion. At least two elastic plates are formed integrally with the base and received in the connecting hole. The elastic plates each include a first portion, which is arranged outside a wall defining the connecting hole when the at least two elastic plates are received in the connecting hole, and a second portion, which extends diagonally relative to the plane of the circuit board when the at least two elastic plates are received in the connecting hole. The second portion has a section pressed against the wall of the connecting hole by the elastic force of the at least two elastic plates.

A further aspect of the present invention is a method for manufacturing a fastening device that temporarily fastens an electronic component to a circuit board. The method includes forming a punched product including a base formed integrally with two elastic plates, which extend from opposite sides of the base, by punching the base and elastic plates out from a metal sheet, and bending the punched product so that the two elastic plates intersect each other at the center of the fastening device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of the present invention will now be discussed.

Referring toFIGS. 1 and 2, an electronic component, or a connector11, which is connected to a circuit board1, such as a printed circuit board, includes a housing12, and terminals13, which are accommodated in the housing12. The terminals13are bent at a right angle and inserted in terminal holes16, which extend through the circuit board1. A fastening portion17, which is fastened to the circuit board1, is defined at the lower part of the housing12.

At least one metal fastening device18is attached to the fastening portion17of the connector11to temporarily fasten the connector11to the circuit board1. As shown inFIG. 2, it is preferred that two fastening devices18be attached to the fastening portion17separated from each other by a predetermined distance and that the fastening devices18be attached near the ends of the fastening portion17. However, three or more fastening devices18may be attached to the connector11.

Referring toFIG. 3, each fastening device18has two elastic plates20. At least one connecting hole19used to connect the connector11to the circuit board1is provided on the circuit board1at a predetermined location. The number of connecting holes19is determined in accordance with the number of fastening devices18. The two elastic plates20are inserted into a connecting hole19from the upper surface, or connecting plane1a, of the circuit board1to temporarily fasten the connector11to the circuit board1. After temporarily fastening the connector11, the lower surface of the circuit board1, especially, legs24extending from the elastic plates20, undergo flow soldering. This fastens the fastening device18to the circuit board1with solder5and manufactures a unit, or board100, which includes the circuit board1and the connector11.

Each fastening device18includes a base21, which is embedded in the fastening portion17of the connector11. The two elastic plates20extend from the base21. The base21and the two elastic plates20are punched out of a sheet of metal with a pressing machine, or the like. For example, referring toFIG. 4A, a punched product22integrally including the base21and the two elastic plates20is first punched out of a metal sheet. Then, one of the elastic plates20is folded along a folding line21a, which is defined in the base21, so that the elastic plates20intersect each other at the center axis18aof the fastening device18, as shown in FIG.4B. The fastening device18is manufactured in this manner.

As shown inFIGS. 3 and 4B, each elastic plate20includes a diagonal portion23extending diagonally between the base21and the corresponding leg24. When the fastening device18is temporarily fastened in the connecting hole19, the resilient force of the elastic plates20press the diagonal portions23against the wall of the connecting hole19. The engagement between part of the elastic plates20and the wall of the connecting hole19temporarily fastens the connector11at its predetermined connecting position.

The portion of each leg24continuously extending from the corresponding diagonal portion23is slightly wider than the diagonal portion23. Further, each leg24becomes narrower at portions closer to its distal end24a. When the fastening device18is free from deformation, it is preferred that the distance between the distal ends24aof the two elastic plates20be smaller than the diameter of the connecting hole19and that the distance between the outer side surfaces24bof the two legs24be greater than the diameter of the connecting hole19. The tapered shape of each leg24facilitates insertion of the fastening device18into each connecting hole19.

The procedures for temporarily fastening the connector11incorporating the fastening device18will now be discussed.

Referring toFIG. 5A, the connector11is first arranged at its connecting position on the circuit board1and moved toward the connecting hole19. Referring toFIG. 5B, when the fastening device18is inserted into the connecting hole19, the elastic plates20are elastically deformed so that the two legs24move toward each other. Further advancement of the connector11toward the connecting hole19guides the outer side surfaces24bof the two legs24along the wall of the connecting hole19. Referring toFIG. 5C, when the legs24move out of the connecting hole19, the resilience of the elastic plates20moves the two legs24outward from the wall of the connecting hole19and presses the two diagonal portions23against the wall of the connecting hole19. As a result, the circuit board1is held between the fastening portion17of the connector11and the two diagonal portions23. This temporarily fastens the connector11to the circuit board1.

The preferred embodiment has the advantages described below.

The two elastic plates20are inserted into the connecting hole19of the circuit board1as the elastic plates20elastically deform about their basal ends. Upon completion of the insertion, the legs24of the elastic plates20move outward from the wall of the connecting hole19, and the elastic force of the elastic plates20press the diagonal portions23against the wall of the connecting hole19. Accordingly, the connector11incorporating the fastening device18is easily temporarily fastened to the circuit board1. The fastening device18is especially convenient in that it completes the temporary fastening of the connector11to the circuit board1with only one action.

The diagonal portions23of the elastic plates20enable application of the fastening device18when temporarily fastening the connector11to various types of circuit boards having different thicknesses. In other words, the connector11, which incorporates the fastening device18, may be applied for various types of circuit boards having different widths. This widens the application of the connector11.

Each elastic plate20is formed so that it becomes narrower at portions closer to its distal end24a. This facilitates the insertion of the fastening device18into the connecting hole19. Accordingly, the connector11incorporating the fastening device18is temporarily fastened to the circuit board1in a simple manner.

The fastening device18is manufactured by punching out the punched product22, which integrally includes the base21and the two elastic plates20, and bending the punched product22. The simplified manufacturing of the fastening device18increases the yield of the fastening device18.

The structure of the fastening device18is extremely simple, and the metal sheet is used efficiently when punching out the punched product22. Since the elastic plates20extend parallel to each other, many punched products22may be manufactured from a single sheet of metal. Accordingly, the fastening device18is manufactured at a low cost.

The two elastic plates20extend from the base21and intersect each other or overlap at the center axis18aof the fastening device. Accordingly, after insertion of the fastening device18into the connecting hole19, the diagonal portions23of the two elastic plates20are pressed against the wall of the connecting hole19by equal forces. This temporarily fastens the connector11, which incorporates the fastening device18, to the circuit board1in a stable manner.

The fastening device18of the preferred embodiment is manufactured by punching out the punched product22, which integrally includes the base21and the two elastic plates20, from a metal sheet and bending the punched product22to the predetermined shape. However, the fastening device18does not have to be manufactured in such a manner. For example, the fastening device18may be modified to fastening devices47and57shown respectively inFIGS. 6 and 7.

In the modification ofFIG. 6, the fastening device47includes a pentagonal base48and two elastic plates49, which extend away from each other from the lower end of the base48. In the modification ofFIG. 7, the fastening device57includes an elongated base58and two bent elastic plates59, which extend away from each other from the lower end of the base58. The elastic plates49and59of the fastening devices47and57respectively include diagonal portions49aand59a. The elastic forces of the elastic plates49and59press the diagonal portions49aand59aagainst the wall of the connecting hole19in the circuit board1.

The fastening device18may be incorporated in electronic components other than the connector11. Further, the fastening device18may be used to fasten components other than electronic components.