Abstract:
A device and method are for increasing the normal force on a substrate power connector. The device includes an edge-type substrate, a socket housing and an actuator. The socket housing receives the edge-type substrate with a zero insertion force or a low insertion force, and the actuator increases a normal force between the socket housing and the substrate to electrically couple the socket and the substrate. A method of creating a power connection includes inserting an edge-type substrate into a socket housing and activating an actuator to increase a normal force between the socket the substrate.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a power connector for a substrate. More specifically, the present invention relates to a zero insertion force power connector for a substrate with an edge-type connector. The present invention further relates to a method for creating a power connection for a substrate and, more specifically, a method of using a zero insertion force socket by actuating an actuator to increase the normal force between the substrate metal contacts and the socket contacts.  
         BACKGROUND INFORMATION  
         [0002]    Edge-type power connections are commonly used for integrated circuits. These connections often consist of the edge of the substrate upon which an integrated circuit is etched, deposited or otherwise arranged. The substrate may have an organic composition and is generally planar. The substrate may be both flexible, with respect to bending or breaking forces, and rigid, with respect to compressive loads. Arranged on an edge of the substrate may be a metal contact area. This metal contact area may consist of a zone of metal plating on the surface of the substrate extending along the edge of the substrate. Alternatively, this metal zone may be situated on both sides of one edge of the substrate. This metal contact area is connected to the integrated circuit and provides power for the circuit.  
           [0003]    Power connections generally use a contact design in which a socket contact, or numerous socket contacts, engage a substrate metal contact, or numerous metal contacts, with some insertion force. Within the socket (socket housing), there may be spring loaded contacts (socket contacts) or fingers (socket fingers) that contact the metal pads (metal contacts) of the substrate to provide power delivery to the substrate. When the socket engages the substrate, the socket fingers are deformed, and an insertion force must be applied to the substrate in order to push the substrate further into the socket to overcome the resistance imposed by the deformation of the socket fingers. When the substrate bottoms out in the socket, the socket fingers reach their final positions. The deformation of the socket fingers provides a normal force between the substrate and the socket that reduces the DC resistance of the power connection.  
           [0004]    In certain substrate edge power delivery solutions, when the package edge connector is inserted into the socket, the contacts resist the substrate movement, thus creating an insertion force. This insertion force can bend or even break the substrate, thus damaging the integrated circuit. Since the insertion force is limited by the substrate mechanical strength, which is often limited by the integrated circuit manufacturing process, the normal force of the connector is also limited. Therefore, traditional edge type power connectors are limited in their ability to reduce the DC resistance at the contacts between the substrate and the socket.  
           [0005]    A conventional power connection is illustrated in FIGS. 1A and 1B. FIG. 1A illustrates a substrate  101  with an integrated circuit having metal contacts  102  on both sides of an edge to provide power to the integrated circuit. Two socket contacts  104 , also referred to as socket fingers, are enclosed within socket  103 . Socket contacts  104  are arranged in opposition to each other within socket  103 . Additional socket contacts may be situated adjacent to socket contacts  104 , such that a line of socket contacts extends on both sides of socket  103 , the two lines extending parallel to the opening of the socket and the edge of substrate  101 . The gap between socket contacts  104  is smaller than the width of substrate  101 . Therefore, an amount of force is required to insert substrate  101  into socket  103  when moving substrate  101  in the direction of arrow  105 . As metal contacts  102  on substrate  101  pass between socket contacts  104 , socket contacts  104  are deformed slightly since substrate  101  is not easily compressible. Therefore, as substrate  101  is pushed into socket  103 , socket contacts  104  are deformed outwardly. The deformation of socket contacts  104  provides a normal force in the power connection between socket contacts  104  and metal contacts  102 .  
           [0006]    [0006]FIG. 1B illustrates substrate  101  completely inserted into socket  103 . Socket contacts  104  have deformed slightly to allow passage of substrate  101  that includes metal contacts  102 . Socket contacts  104  resist deformation and therefore resist insertion of substrate  101 . Due to the limited rigidity of substrate  101 , the amount of deformation and resistance is therefore also limited. Thus, if the deformation, and therefore the resistance, is increased beyond a certain limit, substrate  101  may bend and/or break in response to the resistance to insertion imposed by socket contacts  104  when substrate  101  is inserted into socket  103 . This limitation on the deformation of socket contacts  104  translates into a limitation on the normal force between socket contacts  104  and metal contacts  102 .  
           [0007]    Zero insertion force (ZIF) connectors for pins have been utilized to increase the normal force on the pin and thereby decrease resistance to the signal being transmitted through the pin connector. ZIF pin connectors have included rings as the connectors for the pins. After insertion of the pin into the socket, actuation may either close the ring around the pin or move the pin against the substantially stationary ring. Increased normal force for pin connectors may lower DC resistance for a signal, which may result in a better signal to noise ratio.  
           [0008]    An object of the present invention is to provide a zero insertion force power connector for edge-type substrates, and to thereby decrease the mechanical strength requirements of the substrate and decrease the resistance, and therefore the power loss, in the power connection. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1A is a schematic side view of a prior art socket showing a substrate and a socket prior to the substrate being inserted into the socket.  
         [0010]    [0010]FIG. 1B is a schematic side view of the prior art socket illustrated in FIG. 1A showing the substrate and the socket after the substrate has been inserted into the socket.  
         [0011]    [0011]FIG. 2A is a schematic side view of an example embodiment of a connector according to the present invention showing a substrate and a socket prior to the substrate being inserted into the socket and showing an actuation arm on the socket in an unactuated position.  
         [0012]    [0012]FIG. 2B is a schematic side view of the connector illustrated in FIG. 2A showing the substrate and the socket after the substrate has been inserted into the socket and showing the actuation arm on the socket in the unactuated position.  
         [0013]    [0013]FIG. 2C is a schematic side view of the connector illustrated in FIGS. 2A and 2B showing the substrate and the socket after the substrate has been inserted into the socket and showing the actuation arm in an actuated position.  
         [0014]    [0014]FIG. 3A is a partial schematic side view of an example embodiment of a socket connector according to the present invention prior to actuation.  
         [0015]    [0015]FIG. 3B is a partial schematic side view of the socket connector illustrated in FIG. 3A showing the one side of the socket connector after actuation. 
     
    
     DETAILED DESCRIPTION  
       [0016]    An example embodiment of a connector according to the present invention is illustrated schematically in FIGS. 2A to  2 C. Substrate  101  may be at least partially composed of silicon and may be provided with an integrated circuit or other component. Substrate  101  includes metal contacts  102  on both sides of an edge to provide power to the component. Two socket contacts  107 , also referred to as socket fingers, are enclosed within socket  106 . Socket  106  also includes a lever  108 , shown in FIG. 2A in an unactuated position. Socket contacts  107  are arranged in opposition to each other within socket  106 . Additional socket contacts may be arranged adjacent to socket contacts  107 , such that a line of socket contacts extends on both sides of socket  106 , the two lines extending parallel to the opening of socket  106  and the edge of substrate  101 . In contrast to the connector illustrated in FIGS. 1A and 1B, the width gap between socket contacts  107  as illustrated in FIGS. 2A to  2 C is substantially the same as the width of substrate  101 . Because the width of the gap between socket contacts  107  is substantially the width of substrate  101 , little, if any, force is required to insert substrate  101  into socket  106  while the substrate is being moved in the direction of arrow  105 .  
         [0017]    [0017]FIG. 2B illustrates substrate  101  fully inserted into socket  106  but prior to actuation of lever  108 . Socket contacts  107  may or may not contact metal contacts  102  when substrate  101  is fully inserted into socket  106 . Socket contacts  107  do not deform, or are not substantially deformed, when substrate  101  is inserted into socket  106 . The normal force between socket contacts  107  and metal contacts  102  is small or zero prior to actuation of lever  108  on socket  106 .  
         [0018]    [0018]FIG. 2C illustrates lever  108  in an actuated position, in contrast to FIGS. 2A and 2B, which illustrate lever  108  in an unactuated position. Actuating lever  108  may, for example, be configured to move both socket contacts  107  towards substrate  101 . Alternatively, actuating lever  108  may be configured to move one socket contact  107 , arranged on one side of socket  106  (i.e., the socket contact  107  illustrated on the top in FIGS. 2A, 2B and  2 C or, alternatively, the socket contact  107  on the bottom in FIGS. 2A, 2B and  2 C), as well as any additional socket contacts arranged on the same side of socket  106  toward movable substrate  101 . In this alternative, the socket contacts  107  that are arranged opposite to the socket contacts  107  may remain substantially stationary or immovable. Therefore, actuation of the lever  108  increases the normal force between socket contacts  107  and metal contacts  102 , thereby decreasing the DC resistance between socket contacts  107  and metal contacts  102 .  
         [0019]    [0019]FIG. 3A illustrates an example embodiment of the edge-type power connector according to the present invention. FIG. 3A specifically illustrates a socket contact  107  including a movable socket part  109  and a spring contact  110  prior to actuation of an actuator. Movable socket part  109  is configured to be actuated by the actuator, which may include an arm, handle, lever, any other actuating device or combination thereof Movable socket part  109  moves in the direction of arrow  113  when actuated by the actuator. Spring contact  110  is configured to contact metal contacts on the substrate on a side opposite that of movable socket part  109 . Spring contact  110  is configured to be substantially immovable in the direction of arrow  113  and the reverse direction of arrow  113 . Movable socket part  109  includes a series of bumps  111  on a side adjacent to spring contact  110 . Likewise, spring contact  110  includes a series of bumps  112  on a side adjacent to movable socket part  109 . In the unactuated or rest position illustrated in FIG. 3A, bumps  111  and  112  together form a zig-zag pattern and exert little or no force against each other. Each of bumps  111  and  112  includes a sloped edge such that, when movable socket part  109  is actuated to move in the direction of arrow  113  (for example, when the substrate has been inserted into the socket), each bump  111  interacts with a corresponding bump  112  to urge movable socket part  109  away from spring contact  110 .  
         [0020]    [0020]FIG. 3B illustrates the edge-type power connector illustrated in FIG. 3A after actuation of the actuator. That is, FIG. 3B illustrates the edge-type power connector in the actuated position. Movable socket part  109  is substantially immovable in the direction of arrow  114  and the reverse direction of arrow  114 , while spring contact  110  is movable in the direction of arrow  114  and the reverse direction of arrow  114 . By actuating the actuator, movable socket part  109  moves in the direction of arrow  113 , forcing bumps  111  and  112  to interact. The interaction of bumps  111  with corresponding bumps  112 , and specifically the sloped edges of both bumps  111  and  112 , causes the separation of movable socket part  109  and spring contact  110 . Since movable socket part  109  is immovable in the direction of arrow  114  and the reverse direction of arrow  114 , actuation of the actuator causes spring contact  110  to move in the direction of arrow  114 . This movement of spring contact  110  is against the substrate when the substrate is inserted in the socket. Specifically, this movement of spring contact  110  translates into a normal force against the metal contacts on the substrate. So long as the substrate is constrained from moving away from the spring contact (i.e., the substrate is limited in its ability to move in the direction of arrow  114 ), the normal force between spring contact  110  and the metal contacts is increased by actuation of the socket. The substrate may be constrained against movement in the direction of arrow  114  by, for example, either a rigid barrier or an arrangement similar to that illustrated in FIGS. 3A and 3B arranged on the opposite side of the socket. The opposite arrangement may be provided on the other side of the substrate but oriented so that actuation of the actuator causes an opposite spring contact to move in a reverse direction of arrow  114 .