Abstract:
A technique connects a module to a connector. The technique involves inserting the module into a connector base of the connector, and moving a first connector lever of the connector against the module and a second connector lever of the connector against the module. The technique further involves installing a clip onto the connector such that the clip provides a first force on the first connector lever and a second force on the second connector lever to hold the module to the connector. The presence of the clip prevents the connector levers from moving away from the module (e.g., separating from the module sides) and allowing the module to escape from the connector.

Description:
BACKGROUND OF THE INVENTION 
     A typical circuit board includes a section of circuit board material (i.e., layers of conductive and non-conductive material sandwiched together) and a set of circuit board components (e.g., ICs, resistors, capacitors, connectors, etc.) mounted on one or more surfaces of the section of circuit board material. Some circuit boards include a module connector and a module that connects to the module connector. In some situations, the module is itself a circuit board, i.e., a section of circuit board material with circuit board components mounted thereon. 
     One conventional module connector includes a connecting portion that mounts to (e.g., solders to, press-fits and bolts to, etc.) a main circuit board. This connector further includes two connector levers that fasten to the connecting portion of the connector at respective hinges. Each connector lever includes a tab that aligns with a corresponding notch along a side of the module when the module connects with the module connector. 
     The conventional approach to installing a module within the module connector is commonly performed by a user. To install the module, the user typically (i) inserts a connecting edge of the module into the connector portion of the connector at an angle (e.g., at a 30 degree angle), and (ii) pivots the module to a lower angle (e.g., a 22.5 degree angle). The connector levers are spring loaded such that, when the module rotates downward, the connector levers deflect simultaneously past the sides of the module. As the module seats in the connector, the connector levers snap back locking the module in place. In particular, the connector levers close against the module such that the tabs of the connector levers insert into corresponding notches along the sides of the module. 
     At this point, the module is properly connected to the module connector, i.e., module contacts along the connecting edge of the module are now in electrical communication with corresponding connector contacts within the connecting portion of the connector. A module connector which is configured in a manner similar to the module connector described above, and which operates in a similar manner, is product number 74398-0002 manufactured by Molex, Inc. of Lisle, Ill. 
     SUMMARY OF THE INVENTION 
     Unfortunately, there are deficiencies to the above-described conventional approach to installing a module in a module connector. For example, the module can become disconnected from the module connector when exposed to certain types of shock or vibration. In particular, it is possible for the module to disconnect from the module connector during normal shipping. That is, the notched sides of the module escape the tabbed levers of the connector, and the module moves relative to the connector such that the module contacts no longer reliably connect with the connector contacts. Such disconnection can occur even if (i) the module connector and the module are installed on a main circuit board within an electronic device (e.g., a computer, a data communications device, etc.), and (ii) that electronic device passes a comprehensive shock and vibration test. 
     If disconnection occurs when the device ships from the device manufacturer to a customer, the customer may discover that the device does not work properly when installing the device at the customer&#39;s site, e.g., the customer might see that the device does not even pass self-test when turning on the device. Such situations may lead to additional time and costs incurred identifying and rectifying the failure (e.g., returning the device to the manufacturer for a new one, a field service call, etc.). Additionally, in some situations, the result may be lost customer goodwill and/or a lost reputation for quality. 
     In contrast to the above-described conventional approach to installing a module within a module connector, the invention is directed to techniques which utilize a clip that facilitates retention of a module within a connector. The clip is configured to install onto the connector and to provide force against levers of the connector to retain the module within the connector, i.e., to prevent the module from disconnecting from the connector. The use of such a clip on a circuit board assembly of a device decreases the likelihood of a device failure thus enhancing device reliability and customer goodwill. 
     One embodiment of the invention is directed to a method for connecting a module to a connector. The method includes the step of inserting the module into a connector base of the connector, and moving a first connector lever of the connector against the module and a second connector lever of the connector against the module. The method further includes the step of installing a clip onto the connector such that the clip provides a first force on the first connector lever and a second force on the second connector lever to hold the module to the connector. Accordingly, the presence of the clip prevents the connector levers from moving away from the module (e.g., separating from the module sides) and from allowing the module to escape from the connector. 
     The features of the invention, as described above, may be employed in systems, circuit board assemblies and methods, as well as other electronic components such as those of Cisco Systems, Inc. of San Jose, Calif. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects, features and advantages of the invention will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. 
     FIG. 1 is a perspective view of a clip which is suitable for use by the invention. 
     FIG. 2A is a top view of the clip of FIG.  1 . 
     FIG. 2B is a front view of the clip of FIG.  1 . 
     FIG. 3 is a perspective view of portions of a circuit board assembly which is suitable for use by the invention. 
     FIG. 4 is a perspective view of the portions of the circuit board assembly in a partially installed state. 
     FIG. 5 is a perspective view of the portion of the circuit board assembly in another partially installed state and with the clip of FIG.  1 . 
     FIG. 6 is a perspective view of the circuit board assembly in a fully installed state. 
     FIG. 7 is a flowchart of a procedure which is performed by a user when installing the portions of the circuit board assembly. 
    
    
     DETAILED DESCRIPTION 
     The invention is directed to techniques for connecting a module to a connector utilizing a clip that facilitates retention of the module within the connector. The clip is configured to install onto the connector and to provide force against levers of the connector to retain the module within the connector, i.e., to prevent the module from disconnecting from the connector. The use of such a clip on a device to retain a module within a connector of the device decreases the likelihood of a device failure thus enhancing device reliability and customer goodwill. 
     FIG. 1 shows a clip  20  which is suitable for use by the invention. The clip  20  is configured to hold a module to a module connector. A suitable module connector includes a connector base, and a pair of connector levers coupled to the connector base. That is, a first connector lever hinges to the connector base at a first end of the connector base, and a second connector lever hinges to the connector base at a second end of the connector base. 
     As shown in FIG. 1, the clip  20  includes a central portion  22 , a first arm portion  24 - 1  coupled to the central portion  22 , and a second arm portion  24 - 2  coupled to the central portion  22 . The arm portions  24 - 1 ,  24 - 2  are disposed relative to the central portion  22  such that, when the module connects with the connector base of the connector and when the clip  20  is installed onto the connector, (i) the central portion  22  of the clip  20  extends in a substantially parallel manner over a surface of the module, (ii) the first arm portion  24 - 1  provides a first force on the first connector lever, and (iii) the second arm portion  24 - 2  provides a second force on the second connector lever to hold the module to the connector. Further details of the invention will now be provided with reference to FIGS. 2A and 2B. 
     FIG. 2A shows a top view of the clip  20 , and FIG. 2B shows a front view of the clip  20 . As shown in FIGS. 1,  2 A and  2 B, the central portion  22  extends substantially in a central portion direction  30 , i.e., along a central portion axis  30 . The first arm portion  24 - 1  extends substantially in a first arm portion direction  32 - 1  that is substantially perpendicular to the central portion direction  30 . Similarly, the second arm portion  24 - 2  extends substantially in a second arm portion direction  32 - 2  that is substantially perpendicular to the central portion direction  30 . A distance D (e.g., 2.740 inches) separates the arm portion  24 - 1  and the arm portion  24 - 2  (see FIG.  2 A). As will be explained in further detail later, the perpendicular arrangement of the portions  22 ,  24 - 1 ,  24 - 2  prevents the clip  20  from inadvertently pivoting out of position relative to the module connector, and/or releasing connector levers of the module connector when the clip  20  is installed over the connector to retain a module within the connector. 
     Additionally, as further shown in FIGS. 1,  2 A and  2 B and as will be discussed in further detail later, the arm portions  24 - 1 ,  24 - 2  respectively define loop sections  34 - 1 ,  34 - 2 . Each loop section  34 - 1 ,  34 - 2  has a bend radius  36 - 1 ,  36 - 2  that conforms to a corresponding connector lever of the connector. Accordingly, the arm portions  24 - 1 ,  24 - 2  are configured to tightly fit around the connector levers for a robust compression fit around the connector. In one arrangement, each loop section  34 - 1 ,  34 - 2  has, as the bend radius  36 - 1 ,  36 - 2 , a minimum bend radius (e.g., each loop section  34 - 1 ,  34 - 2  defines a 0.060 inch gap). 
     Furthermore, as further shown in FIGS. 1 and 2B, the central portion  22  of the clip  20  is substantially C-shaped. In particular, the middle section of the central portion  22  extends in a direction that is up and away from the arm portions  24 - 1 ,  24 - 2 . As a result and as will be discussed in further detail later, the central portion  22  can avoid interfering with components of the module (e.g., physically hitting a component, electrically shorting a module contact, etc.). Moreover, the C-shape feature of the clip  20  makes the clip  20  easier to handle (e.g., more ergonomically and/or cosmetically attractive) during installation and removal. 
     In one arrangement, the central portion  22  and arm portions  24 - 1 ,  24 - 2  are formed as a single (i.e., unitary) member of rigid, resilient material such as sheet metal (e.g., a wire form clip), plastic, and the like. In one arrangement, the thickness of the portions  22 ,  24 - 1 ,  24 - 2  is substantially uniform (e.g., substantially 0.040 inches in diameter). Accordingly, these arrangements of the clip  20  are well suited for simple and straight-forward manufacturing processes such as cutting and bending sheet metal or wire, extruding plastic polymer material, etc. Further details of the invention will now be provided with reference to FIGS. 3 through 6 which show portions of a circuit board assembly in various stages of assembly. 
     FIG. 3 shows portions of a circuit board assembly  40  which are suitable for use by the invention. The circuit board assembly  40  includes a circuit board  42  (e.g., a section of circuit board material populated by circuit board components mounted thereon), a module connector  44  mounted to the circuit board  42 , and a module  46 . 
     As shown in FIG. 3, the module connector  44  includes a connector base  48  which is in electrical communication with conductive material of the circuit board  42 . In one arrangement, the connector base  48  is fastened to the circuit board  42  using hardware (e.g., bolted, screwed, etc.). In another arrangement, the connector base  48  is attached by other means (e.g., soldered, glued, etc.). The module connector  44  further includes a first connector lever  50 - 1  and a second connector lever  50 - 2 . The first connector lever  50 - 1  attaches to the connector base  48  at a first hinge  52 - 1 , and is configured to pivot relative to the connector base  48  about the hinge  52 - 1 . Similarly, the second connector lever  50 - 2  attaches to the connector base  48  at a second hinge  52 - 2 , and is configured to pivot relative to the connector base  48  about the hinge  52 - 2 . Each connector lever  52 - 1 ,  52 - 2  defines a respective tab  54 - 1 ,  54 - 2 . 
     As further shown in FIG.  3  and by way of example only, the module  46  includes a section of circuit board material  56  (e.g., layers of conductive and non-conductive material sandwiched together) and a set of circuit board components  58  (e.g., ICs) mounted to the circuit board section  56 . The circuit board section  56  has a connecting edge  60  (e.g., an array of contacts distributed along a periphery of the circuit board section  56 ), and sides defining notches (or grooves)  62 - 1 ,  62 - 2  which extend toward each other due to their orientation on opposing parallel sides of the circuit board section 
     The module  46  is configured to connect with the connector base  48  of the module connector  44  when the connecting levers  50 - 1 ,  50 - 2  are spread apart and when the module moves in a direction  64  as shown in FIG.  3 . In particular, metallic contacts of the circuit board section  56  along the connecting edge  60  of the module  46  are configured to electrically couple with corresponding connector contacts within the connector base  48  when the module moves in the direction  64  (e.g., in response to handling by a user). For illustration purposes only, the module connector  44  receives the module  46  at an angle  66  (e.g., at a 30 degree angle). 
     FIG. 4 shows portions of the circuit board assembly  40  when the module  46  is partially installed with the module connector  44 . In particular, the connecting edge  60  of the module  46  resides within the connector base  48 . At this point, the module connector  44  and the module  46  are configured to provide angular movement between the planes of the circuit board  42  and the module  46 . That is, the distal edge  70  of the module  46  is capable of arching toward the surface  72  of the circuit board  42  in a direction  74  while the connecting edge  60  of the module  46  remains within the connector base  48  of the module connector  44 . In one arrangement, the module  46  pivots about the connector base  48  from the initial angle  66  to a smaller angle (e.g., 22.5 degrees). 
     Furthermore, the connector levers  50 - 1 ,  50 - 2  of the module connector  44 , which are still spread apart in FIG. 4, are configured to move toward the module  46 . In particular, the tabs  54 - 1 ,  54 - 2  defined by the connector levers  50 - 1 ,  50 - 2  (FIG. 3) are configured to respectively engage the notches  62 - 1 ,  62 - 2  along the sides of the circuit board section  56  of the module  46 . 
     FIG. 5 shows portions of the circuit board assembly  40  with the module  46  pivoted toward the circuit board  42  to a smaller angle  80  (e.g., 22.5 degrees) and with the connector levers  50 - 1 ,  50 - 2  closed (or latched) against the sides of the module  46 . In one arrangement, each connector lever  50 - 1 ,  50 - 2  is configured to partially fit over a portion of a side of the module  46  to retain the module  46  at the smaller angle  80  within the module connector  44  (e.g., each lever  50 - 1 ,  50 - 2  has a U-shaped or L-shaped cross-section so that a lip of the lever  50 - 1 ,  50 - 2  interferes with the module  46  if a force attempts to pivot the module  46  back toward the initial angle  66 ). 
     At this point, the tabs  54 - 1 ,  54 - 2  defined by the connector levers  50 - 1 ,  50 - 2  respectively engage the notches  62 - 1 ,  62 - 2  along the sides of the circuit board section  56  of the module  46  (also see FIGS. 3 and 4 for comparison). Here, the module  46  is in electrical communication with the connector base  48  of the module connector  44 , and thus in electrical communication with other circuitry on the circuit board  42 . Additionally, the circuit board assembly  40  may be able to withstand particular vibrations without becoming disconnected (e.g., the assembly  40  may even be able to withstand a comprehensive vibration test). However, it may be possible to jostle the module  46  from the connector  44  with a particular shock or vibration such as those encountered during shipping by a conventional courier or shipping service. 
     As further shown in FIG. 5, the clip  20  of FIGS. 1,  2 A and  2 B is configured for installation over the module connector  44 . In particular, the arm portions  24 - 1 ,  24 - 2  of the clip  20  are oriented such that they extend toward and along the connector levers  50 - 1 ,  50 - 2 , and the portions  22 ,  24 - 1 ,  24 - 2  are oriented such that they are substantially parallel to the plane of the module  46 . At this point, the clip  20  is prepared to slide over the connector levers  50 - 1 ,  50 - 2  to further improve the ability of the circuit board assembly  40  to withstand shock and vibration. 
     FIG. 6 shows the circuit board assembly  40  with the clip  20  installed over the module connector  44  to hold the module  46  to the module connector  44  and thus prevent the module  46  from becoming electrically disconnected from the circuit board  42 . Here, the central portion  22  of the clip  20  extends in a substantially parallel manner over a surface  90  of the module  46 . Additionally, the arm portion  24 - 1  provides a force  92 - 1  on the connector lever  50 - 1  that pushes the connector lever  50 - 1  against the side of the module  46  and toward a central region  94  of the module  46 . Similarly, the arm portion  24 - 2  provides a force  92 - 2  on the connector lever  50 - 2  that pushes the connector lever  50 - 2  against the side of the module  46  and toward a central region  94  of the module  46  (the force  92 - 2  being in a direction that is substantially opposite that of the force  92 - 1 ). In particular, the forces  92 - 1 ,  92 - 2  provided by the arm portions  24 - 1 ,  24 - 2  urge the tabs  54 - 1 ,  54 - 2  defined by the connector levers  50 - 1 ,  50 - 2  tightly into the notches  62 - 1 ,  62 - 2  on the sides of the circuit board section  56  of the module  46  (FIG. 3) thus robustly retaining the module  46  within the connector  44 . 
     It should be understood that the clip  20  is preferably at least partially formed of material (e.g., sheet metal, plastic, etc.) that provides both resiliency and rigidness to continuously push the connecting levers  50 - 1 ,  50 - 2  toward each other and to continuously hold the connecting levers  50 - 1 ,  50 - 2  in place. The forces  92 - 1 ,  92 - 2 , which are in opposite directions and aimed toward the central region  94  of the module  46 , are at least in part due to spring action of the clip  20  resulting from the portion  22 ,  24 - 1 ,  24 - 2  being formed as a unitary member from such material. Such spring action facilitates holding the clip  20  in place when installed over the connector  44  (i.e., compresses the clip  20  onto the connector  44  to prevent the clip  20  from falling off or sliding out of its installed position), as well as enables easy installation and removal. 
     For example, a user can install the clip  20  simply by moving the clip  20  from its initial location (see FIG. 5) to its installed location (see FIG. 6) without exerting an uncomfortable amount of manual effort and without applying extreme forces that could perhaps damage the circuit board assembly  40 . As another example, the user can remove the clip  20  simply by moving the clip  20  from its installed location (FIG. 6) to its initial location (FIG. 5) in a similar manner. In both instances, the user simply provides enough force to overcome the frictional forces of the clip  20  against the connector  44 . 
     It should be understood that the amount of compression (see forces  92 - 1 ,  92 - 2  in FIG. 6) provided by the clip  20  is controllable in a variety of ways. For example, the forces  92 - 1 ,  92 - 2  can be controlled through control of the material used to form the portions  22 ,  24 - 1 ,  24 - 2  of the clip  20 , by controlling the distance D between the arm portions  24 - 1 ,  24 - 2  (FIG.  2 A), by changing the shape and locations of contact points (e.g., see subtle bends at the ends of the arm portions  24 - 1 ,  24 - 2  in FIG.  2 A), among others ways. 
     As mentioned earlier in connection with FIGS. 1,  2 A and  2 B, the arm portions  24 - 1 ,  24 - 2  respectively define loop sections  34 - 1 ,  34 - 2 . It should be understood that the bend radius  36 - 1 ,  36 - 2  of each loop section  34 - 1 ,  34 - 2  (see FIG. 2B) respectively conforms to connector levers  50 - 1 ,  50 - 2  of the connector  44  (see FIG.  6 ). As a result of this configuration in combination with the above-mentioned spring action provided by the clip  20 , the arm portions  24 - 1 ,  24 - 2  are configured to fit snuggly around the connector levers  50 - 1 ,  50 - 2  for a robust compression fit around the connector  44  and the module  46 . 
     As further mentioned above in connection with FIGS. 1 and 2B, the central portion  22  of the clip  20  is substantially C-shaped. That is, from the arm portions  24 - 1 ,  24 - 2 , the central portion  22  extends up and away from the arm portions  24 - 1 ,  24 - 2 . Accordingly, the central portion  22  avoids interfering with components of the module  46  (e.g., the central portion does not contact the components  58  of the module  46 , see FIG.  6 ). Furthermore, the C-shape of the clip  20  enables a user to easily handle the clip  20  during installation and removal (e.g., the user can easily grab the clip  20  without touching the components  58  of the module  46 , also see FIG.  6 ). Further details of the invention will now be provided with reference to FIG.  7 . 
     FIG. 7 is a flowchart of a procedure  100  which is performed by a user when installing the portions  42 ,  46 ,  20  of the circuit board assembly  40 . In step  102 , the user inserts the module  46  into the connector base  48  of the connector  44  (also see FIGS.  3  and  4 ). In particular, the user engages the connecting edge  60  of the module  46  with the connector base  48  to align module contacts along the connecting edge  60  with corresponding connector contacts within the connector base  48 . For some module connectors  44 , the user inserts the module  46  into the connector  44  at an initial angle  66  (FIG.  4 ), and then pivots or rotates the module  46  to a new angle  80  (FIG.  5 ). 
     In step  104 , the user moves the connector levers  50 - 1 ,  50 - 2  against the module  46 . In particular, the user pushes the connector lever  50 - 1  such that a tab  52 - 1  defined by the connector lever  50 - 1  inserts into a corresponding notch  62 - 1  of the circuit board section  56  of the module  46  (also see FIGS. 3 through 5) thus latching the lever  50 - 1  against the module  46 . Similarly, the user pushes the connector lever  50 - 2  such that a tab  52 - 2  defined by the connector lever  50 - 2  inserts into a corresponding notch  62 - 2  of the circuit board section  56 . At this point, the module connector  44  connects with the module  46 . 
     In step  106 , the user installs the clip  20  onto the module connector  44  such that the clip  20  provides a first force  92 - 1  on the connector lever  50 - 1  and a second force  92 - 1  on the second connector lever  92 - 2  to hold the module  46  to the module connector  44 . In particular, the user slides the clip  20  onto the connector  44  by moving the clip  20  from an initial location and orientation (see FIG. 5) to anew location and orientation (see FIG.  6 ). At this point, the clip  20  compresses the connector levers  50 - 1 ,  50 - 2  toward each other thus robustly retaining the module  46  within the connector  44 . Accordingly, the module  46  is less likely to disconnect from the connector  44  in response to vibration (e.g., shakes, shocks, jostles and other movements normally encountered by a device containing the circuit board assembly  40  during shipping). 
     As mentioned above, the invention is directed to techniques for connecting a module  46  to a module connector  44  utilizing a clip  20  that facilitates retention of the module  46  within the connector  44 . The clip  20  is configured to install onto the connector  44  and to provide forces  92 - 1 ,  92 - 2  against levers  50 - 1 ,  50 - 2  of the connector  44  to retain the module  46  within the connector  44 , i.e., to prevent the module  46  from disconnecting from the connector  44 . The use of such a clip  20  on a device to retain a module  46  within a connector  44  of the device decreases the likelihood of a device failure (e.g., preventing disconnection of the module  46  from the connector  44  during shipping) thereby promoting a reputation of reliability and enhancing customer goodwill. Such techniques are well suited for circuit board assemblies within particular types of devices having the above-described configuration, e.g., for retaining memory linecards (modules  46 ) within the connectors of motherboards (circuit boards  42 ) of data communications devices. 
     While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. 
     For example, it should be understood that the clip  20  was described above as being formed by sheet metal, wire or plastic by way of example only. Other materials are suitable for use as well, and combinations of materials are also suitable. For example, in one arrangement, an interior core of the clip  20  is formed by metal to provide rigidness and resiliency, and an outer softer, non-conductive coating of the clip  20  (e.g., a vinyl-bond coating of 0.005 inch thickness, a rubber sleeve, etc.) provides a more ergonomic feel for the user as well as prevents the clip  20  from inadvertently causing a short if the clip  20  makes contact with one or more electronic components. In some arrangements, the coating does not completely cover the clip  20  (e.g., only covers a portion of the clip such as part of the central portion  22 , see darken areas of the central portion  22  in FIG.  2 B). 
     Additionally, it should be understood that the clip  20  was described above as being installed by a user by way of example only. In other arrangements, the clip  20  is installed by other means, e.g., by automated equipment. 
     Furthermore, it should be understood that the central portion  22  of the clip  20  was described above as being C-shaped by way of example only in order to make the clip  20  easier to handle and so that the clip  20  was less likely to interfere with the components  58  of the module  46 . Other shapes are suitable for use as well. For example, in some arrangements, the central portion  22  of the clip  20  has a different shape (e.g., an overall M-shape, a relatively flat cross-section, etc.) to improve the users ability to handle (e.g., grab and move) the clip  20 . 
     Additionally, it should be understood that the clip  20  was described above as being well suited to hold a module  46  within a module connector  44 . It should be understood that the clip  20  is also well suited for holding other things to a connector. For example, the clip  20  is well suited for other types of devices to the connector  44  (e.g., other connectors, cable ends, components, etc.). 
     Furthermore, it should be understood that additional features can be added to the clip  20  to improve its performance. For example, bends, welds and other strengthening enhancements can be incorporated within the clip  20  to enable the clip  20  to provide additional force if necessary, and/or to enable the clip  20  to withstand counter forces and fatigue.