Fastening device and printed circuit board assembly having same

A printed circuit board (PCB) assembly includes a flexible printed circuit board (FPCB), a connector, a rigid PCB, and a fastening device. The rigid PCB includes a loading surface, a bottom surface opposite to the loading surface, and two pins protruding from the bottom surface. The loading surface contacts the FPCB. The FPCB is electrically connected to the rigid PCB through the connector. The fastening device includes a pressing plate, two fastening bars and two connecting arms. The pressing plate includes a pressing surface contacting the FPCB. The fastening bars are parallel to the pressing surface. Each fastening bar includes a hook grappling with a corresponding pin. Each hook includes a resisting surface resisting on the bottom surface. Each connecting arm connects the pressing plate and a corresponding fastening bar.

BACKGROUND

1. Technical Field

The present disclosure relates to printed circuit boards (PCBs) and, particularly, to a PCB assembly having a fastening device for fastening flexible printed circuit boards (FPCBs) on rigid printed circuit boards (PCBs).

2. Description of Related Art

FPCBs need fastening devices to be fastened on rigid PCBs to prevent separation from the rigid PCBs, when the FPCBs are electrically connected to the rigid PCBs. A fastening device includes a pressing plate for pressing the FPCB on the rigid PCB. The pressing plate is fastened on the rigid PCB with screws, thus some screw holes need to be formed in the pressing plate corresponding to the screws, which will occupy the area that is used for the wiring layout of the rigid PCB.

Therefore, it is desirable to provide a fastening device and a printed circuit board (PCB) assembly having same that can overcome the above-mentioned limitations.

DETAILED DESCRIPTION

Referring toFIGS. 1-3, a PCB assembly1, according to an exemplary embodiment, includes a fastening device100, an FPCB200, a rigid PCB300, a connector400, four screws500, and a fastening plate600. The FPCB200is electrically connected to a loading surface310of the rigid PCB300through the connector400. The rigid PCB300further includes a bottom surface320opposite to the loading surface310. Two pins321protrude from the bottom surface320. The four screws500are used for fastening the rigid PCB300on the fastening plate600. In this embodiment, the rigid PCB300is a computer motherboard. The fastening plate600is a part of a computer shell. The number of screws is not limited to this embodiment.

The fastening device100is used for fastening the FPCB200on the loading surface310, and includes a pressing plate10, two fastening bars30, and two connecting arms50.

The pressing plate10is substantially rectangular shaped, and includes a pressing surface11configured for pressing the FPCB200on the rigid PCB300.

The two fastening bars30are disposed on two opposite ends of the pressing surface11, and are parallel to the bottom surface320. Each fastening bar30includes an L-shaped handle31and a hook32extending outward from the handle31. A surface of the handle31opposite to the other handle31forms an anti-skid pattern to increase the force of friction between the handle31and the user's hand. Each hook32is used for grappling with the corresponding pin321, and includes a resisting surface34resisting on the bottom surface320. Along a direction perpendicular to the loading surface310, the distance between the pressing surface11and the resisting surface34is equal to the total thickness of the FPCB200, the connector400, and the rigid PCB300, and thus the FPCB200is firmly fixed on the rigid PCB300by the pressing plate10. In this embodiment, the distance between the two fastening bars30is larger than that of the two pins321when the two fastening bars30are at an original state. The two fastening bars30can make elastic deformation, and the distance between the two fastening bars30can be less than that of the two pins321when the two fastening bars30are pressed towards each other.

The two connecting arms50are respectively used for fastening the pressing plate10and the two fastening bars30. In this embodiment, one end of the connecting arm50is fixed on the pressing surface11, the other end of the connecting arm50is fixed on the adjoining portion between the handle31and the hook32.

Also referring toFIG. 4, in use, the pressing plate10is pressed on the FPCB200, one handle31are pressed towards the other handle31, the distance between the two handles31is reduced less than that of the two pins321. The hooks32can be inserted between the two pins321. The handles31are released, the two hooks32are resiled to grapple with the corresponding pin321, thus, the FPCB200is detachably fixed on the rigid PCB300through the fastening device100, and the rigid PCB300does not need to define screw holes to save the wiring layout space of the rigid PCB300. When the FPCB200needs to be dismantled from the rigid PCB300, the two handles31are pressed towards each other again, the two hooks32are separated from the corresponding pins321, then the fastening device100is removed, therefore, the FPCB200can be dismantled from the rigid PCB300easily.

In this embodiment, the extending directions of the two fastening bars30are parallel to each other. In other embodiments, the two fastening bars30also can form an acute angle or an obtuse angle.

In this embodiment, the extending directions of the two connecting arms50are substantially perpendicular to the pressing surface11. In other embodiments, the two extending directions of the two connecting arms50also can form a same acute/obtuse angle with the bottom surface320.

In this embodiment, the fastening device100is integrated, and is made of elastic material. In other embodiments, the fastening device100does not need to be integrated, the pressing plate10is made of rigid metal material, and the two fastening bars30and the two connecting arms50are made of elastic material.