Patent Publication Number: US-6902425-B2

Title: Electrical connector for flexible printed circuit board

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   The present invention relates to a co-pending U.S. Design Patent Application Ser. No. 29/191,239 filed on Oct. 1, 2003, entitled “FLEXIBLE PRINTED CIRCUIT BOARD CONNECTOR”, invented by CHIEN HSUN HUANG, and assigned to the same assignee as the present invention. 

   BACKGROUD OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to electrical connectors, and more particularly to a flexible printed circuit (FPC) connector for electrically interconnecting a printed circuit board (PCB) with an electrical interface such as a flexible printed circuit (FPC) board. 
   2. Description of the Prior Art 
   Flexible printed circuit connectors are widely used in electronic devices such as mobile telephones, keyboards, hard disk drives and fax machines etc. Such kind of FPC connectors is disclosed in “History of FFC/FPC” (Connector Specifier, February 2001, pp.18-20). The FPC connector comprises a housing, a plurality of terminals received in the housing, and an actuator rotatably mounted on the housing. Each terminal has a bifurcate contact section and a solder tail soldered onto a PCB. One end of an FPC board is inserted into an opening defined in the housing, for engaging the bifurcate contact sections of the terminals. Thus, mechanical and electrical engagement between the PCB and the FPC board is attained. 
   With the miniaturization of electronic system and the development of high-frequency signal transmission technology, An FPC connector used in such system needs to reliably transmit high-frequency signals. A shielding is commonly required to provided for the FPC connector, to prevent Electro Magnetic Interference (EMI) in relation to the external environment. Thus a reliable transmission of high-frequency signals within the system is ensured. 
   Conventional FPC connectors are disclosed in U.S. Pat. Nos. 5,580,272, 5,695,359 and 5,695,360. These connectors mainly comprise a housing, a plurality of terminals received in the housing, an actuator pivotably mounted on the housing, for pressing an FPC board against the terminals and solder pads mounted to the housing. However, these connectors have a shortcoming that there is no shielding means in these structures. When transmitting high-frequency signals, these connectors cannot provide effective EMI shielding. This thereby can effect a reliable transmission of the signals. 
   When the actuator is pivotably mounted on the housing at an open position, the FPC board is inserted into the housing with a zero insertion force (ZIF) thereby uniform pre-contact between the FPC board and the terminals. After that, the actuator is rotatable from the open position to a closed position thereby the actuator press the FPC board to engage with the terminals. Thus electrical engagement between the FPC board and the connector is attained. Because the housing is commonly formed from plastic material and only a part of the housing engaged with the actuator, after the actuator pivotably rotating round the housing for a long time, the housing crack from a portion connecting with the actuator. Thus, reliability mechanical and electrical engagement between the FPC board and the connector is decreased. 
   In view of the above, a new electrical connector that overcome above-mentioned disadvantages is desired. 
   SUMMARY OF THE INVENTION 
   Accordingly, a main object of the present invention is to provide an electrical connector for electrically connecting a sheet-like connection member such as a flexible printed circuit (FPC) or a flat cable with a circuit substrate such as a printed circuit board (PCB), and particularly to provide a connector that has an Electro Magnetic Interference (EMI) shielding to ensure reliable signal transmission between an FPC and a PCB. 
   Another object of the present invention is to provide an electrical connector, whereby the connector can reinforce a housing of the connector. 
   To achieve the above objects, an electrical connector in accordance with a preferred embodiment of the present invention is provided for electrically connecting an FPC or an FFC with a PCB. The connector comprises an elongated insulative housing, a plurality of electrical terminals received in the housing, an actuator pivotably mounted on the housing, and a shielding mounted on the housing, functioning as an EMI device. The housing comprises a main body and a pair of latching arms extending from two opposite ends of the main body. The main body has a lower surface and an upper surface opposite to the lower wall, and a plurality of passageway disposed between the lower surface and the upper surface, for receiving the corresponding terminals therein, respectively. A plurality of securing protrusions with T-shaped is formed on the main body, and a pair of grooves is defined in the main body. The shielding substantially surrounds the upper surface of the housing. A plurality of T-shaped securing slots is defined in the shielding, for engaging with the securing protrusions of the housing. A pair of grounding tabs extends from two opposite ends of the shielding, partly retained in the respective grooves of the housing, for mating with corresponding grounding pads of a PCB. A pair of clasping portions is formed on the shielding, surrounding the latching arms of the housing. This can also reinforce the strength of the housing. 
   Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded, isometric view of an FPC connector in accordance with the preferred embodiment of the present invention; 
       FIG. 2  is an assembled view of  FIG. 1 , showing a pressing member of the FPC connector at a closed position; 
       FIG. 3  is similar to  FIG. 1 , but viewed from another aspect; and 
       FIG. 4  is similar to  FIG. 2 , but viewed from another aspect. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION 
   Reference will now be made to the drawings to describe the present invention in detail. 
   Referring to  FIGS. 1 and 3 , an electrical connector  1  of the preferred embodiment of the present invention is provided for electrical connecting a sheet-like connection member such as a flexible printed circuit board (FPC) or a flexible flat cable (FFC) (not shown) with a circuit substrate such as a printed circuit board (PCB) (not shown). The connector  1  comprises an insulative housing  2 , a plurality of electrical terminals  3  received in the housing  2 , an actuator  4  rotatably mounted on the housing  2 , and a shielding  5  attached to the housing  2 . 
   The housing  2  is configured with a longitudinal main body  20 , and a pair of latching arms  21  extends from two opposite sides of the main body  20 . A plurality of spaced passageways  200  is defined in the main body  20 , for receiving the corresponding terminals  3  therein, respectively. The main body  20  has a top surface  201 , a bottom surface  203  opposite to the top surface  201 , and a sidewall  204  connecting the top and the bottom surfaces  201 ,  203 . The bottom surface  203  engages with the PCB, for fixing the connector on the PCB. A plurality of spaced protrusions  202  are formed on a back portion of the top surface  201  and arranged along a longitudinal direction. The protrusions  202  have a substantially “T” shaped configuration. A pair of tenons  205  is outwardly formed on two opposite end sides of the sidewall  204  respectively. A groove  206  is defined between each pair of tenons  205  therethrough. The side latching arms  21  each have a first arm  210  connecting with the main body  20 , and a smaller second arm  212  extending forwardly from a front end of the first arm  210 . A recess  211  is defined inwardly at one end portion of the first arm  210  near the second arm  212 . 
   The actuator  4  is pivotably mounted on the housing  2  and comprises a base portion  40 , a pair of latch blocks  41  formed outwardly on two opposite sides of the base portion  40 , and a metal sheet  42  longitudinally inlayed in the base portion  40 , for reinforcing the strength of the base portion  40 . A pressing surface  400  is formed on a bottom of the base portion  40 , for pressing the FPC against the terminals  3  (referring to FIG.  3 ). A convex  401  is protruded outwardly from the pressing surface  400  (referring to FIG.  3 ). A plurality of channels  402  is defined in the convex  401 , for accommodating the terminals  3  therein when the actuator  4  being mounted and pressed onto the housing  2 . The metal sheet  42  has a main portion (not labeled) and a pair of ears  421  extending and bending downwardly from two opposite sides of the main portion. The main portion is enchased within the base portion  40 . A protuberance  422  is formed outwardly on a middle portion of each of the ears  421 . The latch blocks  41  are configured to rotatably retain in the recess  211  of the respective latching arms  21 , and thereby mounting the actuator  4  to the housing  2  pivotably. 
   The shielding  5  is engaged with the housing  2  and has a planar plate portion  50 , and a pair of side clasping portions  51  extending forwardly from two opposite sides of the plate portion  50 . A plurality of “T” shaped securing slots  500  is defined in a back portion of the plate portion  50  therethough vertically. The slots  500  engage with the respective T-shaped protrusions  202  of the housing  2 , for positioning the plate portion  50  on the top surface  201  of the housing  2 . A pair of grounding tabs  501  extends downwardly from a back longitudinal side of the plate portion  50 , partly received in the respective grooves  206  of the housing  2 . The grounding tabs  501  each have a cantilever configuration. A mating portion (not labeled) is formed at a free end of the grounding tabs  501  each, for mating with the corresponding grounding pads of the PCB. A plurality of indents  502  is defined in a front portion of the plate portion  50 , perpendicular to and run through the plate portion  50  vertically. The indents  502  are above on and each communicate with the respective first passageways  200 , for avoiding the shielding  5  contacting with the terminals  3 . The clasping portion  51  each have a base portion  511 , a clasper  512  formed on the base portion  511  opposite to the plate portion  50 , and a strip clip  513  extending from the base portion  511  near the plate portion  50 . The clasper  512  extends and bends downwardly from a top edge of the base portion  511 . A cutout  514  is defined downwardly in the clasper  512 , for engaging with the respective protuberances  422  of the actuator  4 . 
   Referring also to  FIGS. 2 and 4 , in assembly, the terminals  3  are inserted into and retained in the respective passageways  200  of the housing  2 . Then the shielding  5  is attached to the housing  2 . The protrusions  202  of the housing  2  are locked into the respective slots  500  of the shielding  5 , to thereby position the shielding  5  on the top surface  201  of the housing  2 . The grounding tabs  501  are partly retained in the corresponding grooves  206  of the housing  2 , the mating portion thereof mating with the corresponding grounding pads of the PCB. Thus effective EMI protection is attained throughout the connector  1 . The clasper  512  and the strip clip  513  of clasping portion  51  embrace the first and second arm  212 ,  210  of the latching arms  21 , respectively. The base portion  511  of the clasping portion  51  abuts against outside wall (not labeled) of the latching arm  21 . This adversely can reinforce the strength of the latching arm  21  of the housing  2 . Finally, the latch blocks  41  of the actuator  4  are rotatably inserted into the recess  211  of the latching arms  21 . Thus, the actuator  4  is mounted to the housing  2  pivotably. 
   In use, the actuator  4  is firstly rotated to a vertical position stated as an open position. Then the FPC board is inserted into an opening (not labeled) of the housing  2  with zero insertion force (ZIF) from a front of the housing  2 , at that time the pads of the FPC board not engaging with the respective terminals  3 . When the FPC board is inserted completely into the opening of the housing  2 , and the actuator  4  is rotated downwardly from the vertical position to a horizontal position stated as a closed position, where the pressing surface  400  of the actuator  40  urges the FPC board to engage with the terminals  3 . During the rotation, the protuberances  422  of the actuator  4  are locked into the corresponding cutouts  514  of the shielding  5 , thereby the actuator  4  to hold at the horizontal position. As a result, the actuator  4  is firmly situated at the closed position, and liability mechanical and electrical engagement between the FPC board and the connector  1  is attained. 
   In the connector  1  of the present invention, the shielding  5  is attached to the housing  2 , the slots  500  thereof engaging with the protrusions  202  of the housing  2  thereby the shielding  5  substantially surrounding the housing  2 . Thus, EMI protection in housing  2  is established. Additionally, the grounding tabs  501  extend from the shielding  5 , partly retained in the grooves  206  of the housing  2 . The mating portion of the grounding tabs  501  mates with the corresponding grounding pads of the FPC board. This can reduces the static electricity accumulated in the shielding  5 . As a result, complete EMI protection throughout the connector  1  is provided. Furthermore, The plate portion  50  of the shielding  5  covers the main body  20  of the housing  2 , and the clasping portions  51  embrace the latching arms  21  of the housing  2 . This can prevent the housing  2  from damage caused by external forces, and thereby to reinforce the strength of the housing  2 . 
   While a preferred embodiment in accordance with the present invention has been shown and described, equivalent modifications and changes known to persons skilled in the art according to the spirit of the present invention are considered within the scope of the present invention as defined in the appended claims.