Abstract:
A connector for coupling a component to external circuitry, comprising a base, a guide for guiding the component along an axis towards the base, a first barb positioned to latch an edge of the component at a first distance along the axis from the base, and a second barb positioned to latch an edge of the component at a second distance along the axis from the base.

Description:
[0001]     This invention relates to a connector for connecting an electrical component such as a digital camera module to external circuitry.  
       BACKGROUND  
       [0002]     Digital camera modules have been developed as components for use in electronic apparatus such as personal digital assistants (PDAs) and mobile telephones.  
         [0003]     FIGS.  1  to  4  illustrate such a digital camera module  100 .  FIG. 1  is a perspective top view of the module,  FIG. 2  is a front side view of the module,  FIG. 3  is a top plan view of the module, and  FIG. 4  is a bottom plan view of the module. The module  100  comprises a substrate  110  and a lens structure  130 .  
         [0004]     The substrate  110  may be a rectangular-shaped ceramic substrate comprising electronic circuitry including an image sensor  116  on a top surface, and metallic terminals  114  on a bottom surface  112  for electrically coupling the module  100  to external circuitry.  
         [0005]     The lens structure  130  comprises a rectangular-shaped base portion  135 , and a turret portion  150  extending from the base portion  135 . The base portion  135  and the turret portion  150  may both be formed of a plastics material. The turret portion  150  defines an aperture  160  through which light is received into the camera module for detection by the image sensor  116 . A lens  170  is positioned within the aperture  160  for focusing received light onto the image sensor  116 .  
         [0006]     A drawback with known digital camera modules is that they are difficult to connect to printed wiring boards (PWBs). Reflow soldering of the ceramic substrate terminals  114  to a PWB is problematic as the plastics used in the lens  170  melt at temperatures less than the reflow temperatures. Reflow soldering may be possible if the lens is made from a glass material. However, glass lenses are expensive and are less suitable for mass production techniques.  
         [0007]     One method for connecting a digital camera module to a PWB involves using a flexible intermediate substrate. The flexible substrate is glued at one end to the bottom surface  112  of the ceramic substrate  110  with locally-conductive adhesive such that the substrate terminals  114  electrically couple to electrical traces in the flexible substrate. The other end of the flexible substrate is then connected to the PWB via a FPC connector. This method is labor intensive and does not lend itself to automated assembly easily.  
       SUMMARY OF THE INVENTION  
       [0008]     According to the present invention there is provided a connector for coupling a component to external circuitry, comprising a base, a guide for guiding the component along an axis towards the base, a first barb positioned to latch an edge of the component at a first distance along the axis from the base, and a second barb positioned to latch an edge of the component at a second distance along the axis from the base.  
         [0009]     A connector in accordance with the invention has the advantage that it is able to receive components along one axis which in turn enables simple assembly of the component to the connector. A connector in accordance with the invention also has the advantage that it is able to receive components that have housings of different height due to the two barb arrangement. In other words, the two barb arrangement enables a component to be retained by an edge of the component even when the height of that edge varies.  
         [0010]     The component is preferably a digital camera module.  
         [0011]     Suitably, the base includes electrical interconnects for coupling to the component/digital camera module.  
         [0012]     Preferably, the guide comprises side walls extending from a planar base. 
     
    
       [0013]     Embodiments of the invention will now be described in more detail, by way of example, with reference to the enclosed drawings, in which:  
         [0014]      FIG. 1  is a perspective top view of a camera module;  
         [0015]      FIG. 2  is a front side view of the module;  
         [0016]      FIG. 3  is a top plan view of the module;  
         [0017]      FIG. 4  is a bottom plan view of the module;  
         [0018]      FIG. 5  is a plan view of a connector in accordance with the invention;  
         [0019]      FIGS. 6 and 7  are side views of the connector and the module;  
         [0020]      FIG. 8  is a cross-sectional side view of the connector illustrating the position of retaining barbs;  
         [0021]      FIG. 9  is side view of two barbs;  
         [0022]      FIGS. 10 and 11  are schematic side views of the two barbs operating against a camera module; and  
         [0023]     FIGS.  12  to  17  are schematic side views of the four barbs of  FIG. 8  operating against a camera module.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0024]      FIG. 5  is a plan view of a connector  200  in accordance with the invention. The connector is made of a plastics material and is shaped generally like box having an open top. The connector  200  is further illustrated in  FIGS. 6 and 7 , which show a side view and an end view respectively.  
         [0025]     The connector  200  comprises a generally planar base portion  220  and four side walls  210  extending perpendicular to the base to form the open box shape.  
         [0026]     As shown in  FIG. 6 , the connector  200  is designed to receive the camera module  100  of  FIG. 1  along the Z-axis. Eight electrical interconnects  230  made of metal such as copper are embedded into the base  220  such that each interconnect has a internal portion extending to the inside of the box, and a external portion extending to the outside of the box. The internal portions are designed to couple to the terminals  114  of the camera module once it has been fully inserted into the connector  200 . The external portions are designed to be soldered to traces of a PWB (not shown) in order to provide electrical connections to external components. The connector  200  is preferably reflow soldered to the PWB before the camera module  100  is received into the connector. Other types of connection between the external portions and the PWB may also be used, such as pin and socket type connections.  
         [0027]     In an alternative embodiment, the internal portions of the interconnects may extend up the side walls  210  to couple with correspondingly positioned terminals on the camera module.  
         [0028]     As shown in  FIGS. 4 and 5 , the external dimensions x 1  and y 1  of the rectangular-shaped base portion  135  of the camera module  100  are slightly smaller than the internal dimensions x 2  and y 2  of the connector box opening defined by the side walls  210 . The side walls  210  thus act as guides to guide the camera module  100  into the connector along the Z-axis.  
         [0029]     It is important that the camera is held in the connector so that the terminals  114  remain coupled to the interconnects  230 .  FIG. 8  illustrate the barbs that form part of the connector  200  to achieve this function. The barbs need not be exactly the pointed shape illustrated in the Figures so long as they function to hold the camera module at the desired position. Accordingly, the term barb is intended to encompasses more rounded shapes than those illustrated.  
         [0030]      FIGS. 8 and 12  to  17  illustrate an embodiment of the connector with four barbs  241 ,  242 ,  243 ,  244 . An alternative embodiment of the connector with just two barbs is illustrated in FIGS.  9  to  11 . The barbs are supported by arms  251 - 254  that extend from the base  220  of the connector. The arms are coupled to the base  220  such that they can move independently of each other. Recesses  270  in the side walls  210  allow the arms and barbs to spring back as the camera module is received into the connector  200 .  
         [0031]     In  FIG. 8 , the two lower barbs  243 ,  244  of the of four barbs are positioned at a distance H 1  from the base  220 , while the two upper barbs  241 ,  242  are positioned at a distance H 2  from the base  220 .  
         [0032]     The height of the camera module H 3  (see  FIG. 2 ) is known to have a large tolerance due to variations in the alignment of the lens structure  130  to the substrate  110 . The use of barbs at different heights enables the connector  200  to receive and retain camera modules that vary greatly in height. Preferably the upper barb is positioned at a height H 2  that is near the maximum tolerance for H 3  while the lower barb is positioned at a height H 1  that is near the minimum tolerance for H 3 .  
         [0033]      FIG. 11  illustrates how the connector  200  according to the invention can retain a camera module  100  that has a large height H 3  by means of the upper barb  261 . The lower barb  262  is simply deflected out of the way.  FIG. 10  in contrast illustrates how the connector  200  according to the invention can retain a camera module that has a smaller height H 3  by means of the lower barb  262 .  
         [0034]     FIGS.  12  to  15  illustrate the sequence of deflections of the four barbs  241 - 244  (originally shown in  FIG. 8 ) as a camera module  100  with a small height is received by the connector  200  along the vertical z-axis.  FIGS. 16 and 17  illustrate a similar sequence for a camera module  100  with a larger height.  FIGS. 15 and 17  illustrate the camera module  100  fully inserted and retained in the connector  200 .  
         [0035]     In accordance with the invention, further barbs may be added at heights other than H 1  and H 2  to accommodate further variations in the height H 3  of the camera module, or to engage different edges of the camera module.  
         [0036]     Other components that may be retained by the connector include, for example, lamps, laser diodes etc.