Abstract:
A zero or low insertion force socket coupling mechanism is actuated by rotation of a flat blade screwdriver or other like tool. The actuation device includes a receptacle in the shape of the arabic letter “S.” Placing the blade of the screwdriver in the receptacle and rotating the screwdriver moves the upper portion of the apparatus relative to the lower portion to line up the pins with the sockets. The shape of the receptacle enables the force created by the twisting motion of the screwdriver to be placed on the sides of the receptacle by the sides of the blade, rather than the ends of the blade, which could damage the molded plastic component. As a result, the actuation device avoids the waste of space of convention lever actuated devices. Moreover, the actuation device enables the use of a commonly available tool to actuate the coupling mechanism.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to zero or low insertion force sockets, and more particularly to an actuator for a zero or low insertion force socket. 
     A Pin Grid Array (PGA) package is a square or rectangular Integrated Circuit (IC) package with rigid pins coming out the bottom for inserting into sockets. Because a PGA package may be inserted into a socket, such as a Zero insertion Force (ZIF) socket, where it will be retained without soldering, PGA packages are readily interchangeable. When it is desired to replace a PGA package, the existing PGA package may be readily and quickly removed by simply popping the existing PGA package out of its socket and inserting a new PGA package in its place. PGA packages have been used for approximately 20 to 25 years and are especially popular in the Personal Computer (PC) industry due to the interchangeability they provide. As microprocessor IC chips become faster and faster, the PGA package in which they are housed may be easily removed and replaced with a PGA package housing a faster microprocessor IC chip. 
     Typical ZIF sockets include an actuation device for moving the attached CPU component. A known ZIF socket, for example, includes an actuation device that consists of an exposed lever and an embedded rotation bar wherein the rotation bar is joined with the lever at one end and the bar further includes multiple cam sections or crank shaft sections. When the bar is vertical in a right angle position with regard to the base, the pins of the CPU component can be inserted into a socket under ZIF conditions. Successively, the operator manually pushes the lever downward to the horizontal position, the cam sections or the crank shaft sections of the rotation bar move the CPU component horizontally, and the pins of the CPU component engage with the corresponding contacts of the socket. 
     In contrast, when the lever is moved from zero degrees (horizontal position) back to ninety degrees (vertical position), the cover may be moved horizontally in a reverse direction. Therefore, the engagement between the contacts of the socket and the corresponding pins of the CPU component may be released, and the CPU component can be detached from the socket. 
     When the lever is positioned in a horizontal position, some space on the PC board will be occupied because the lever is close to the PC board in this configuration, which wastes space on the PC board. From another viewpoint, there are many electrical components near the lever, thus resulting in inconvenience to operatively access the lever. 
     The present invention is therefore directed to the problem of developing a zero or low insertion force connection that does not require space above the actuator to actuate the connection. 
     SUMMARY OF THE INVENTION 
     The present invention solves this problem by providing an actuator for a zero or low insertion force connection that can be activated by using a screwdriver or other like tool. Moreover, by providing that the screwdriver or other like tool actuates the socket using the sides of the screwdriver or other like tool instead of the edges the present invention prevents damage to the socket actuator. 
     According to one aspect of the present invention, a socket assembly for receiving a pin grid array includes a cover, a housing and at least one receptacle. The cover includes multiple sockets for receiving pins in the pin grid array. The housing holds the cover, which is movable relative to the housing. Movement of the cover relative to the housing causes engagement and disengagement of the pins with the sockets. The receptacle is formed between the cover and the housing and has a curved shape for receiving a flat blade of a tool. 
     According to another aspect of the present invention, in the above socket assembly the cover is movable relative to the housing by rotation of the tool when the flat blade is inserted into the receptacle. 
     According to another aspect of the present invention, in the above socket assembly the first receptacle includes two shoulder portions. 
     According to another aspect of the present invention, in the above socket assembly the two shoulder portions receive a force applied by sides of the flat blade when the tool is rotated. 
     According to another aspect of the present invention, in the above socket assembly a second receptacle is provided with a shape for accepting a flat blade of a tool. 
     According to another aspect of the present invention, in the above socket assembly the second receptacle includes a curved shape. 
     According to another aspect of the present invention, in the above socket assembly a protrusion is disposed on the cover and two notches are disposed on the housing. 
     According to another aspect of the present invention, in the above socket assembly the protrusion travels from one of the two notches to the other notch when the cover travels from an open position to a closed position. 
     According to another aspect of the present invention, in the above socket assembly a locking icon is disposed adjacent to the first receptacle, which locking icon identifies a function of the receptacle. 
     According to another aspect of the present invention, in the above socket assembly a rotation icon is disposed adjacent to the first receptacle, which rotation icon indicates a direction of rotation of the tool to engage the pins of the pin grid array with the sockets. 
     According to another aspect of the present invention, in the above socket assembly an unlocking icon is disposed adjacent to the second receptacle, which identifies a function of the second receptacle. 
     According to another aspect of the present invention, in the above socket assembly a direction icon is disposed adjacent to the second receptacle, which direction icon indicates a direction of motion of the blade of the tool to disengage the pins of the pin grid array from the sockets. 
     According to another aspect of the present invention, a method for engaging pins of a pin grid array with sockets in a socket assembly includes at least three steps. First, a tool having a flat blade is inserted into a curve-shaped receptacle having two shoulders. Next, the tool is rotated so the sides of the flat blade push against the shoulders of the curve-shaped receptacle. Finally, a cover of the socket assembly is moved relative to the housing in response to the rotation of the tool thereby engaging the pins of the pin grid array in the sockets of the socket assembly. 
     According to another aspect of the present invention, the above method for engaging pins of a pin grid array with sockets in a socket assembly also preferably includes the step of moving a protrusion from a first cutout to a second cutout as the cover moves laterally relative to the housing. 
     According to another aspect of the present invention, the above method for engaging pins of a pin grid array with sockets in a socket assembly also preferably includes the step of providing a tactile feedback sensation to an operator of the tool upon reaching full travel of the cover relative to the housing. 
     According to another aspect of the present invention, the above method for engaging pins of a pin grid array with sockets in a socket assembly also preferably includes the step of providing a visual indicator indicating which direction the tool must be rotated to engage the pins in the sockets. 
     According to another aspect of the present invention, the above method for engaging pins of a pin grid array with sockets in a socket assembly also preferably includes the step of providing a visual icon indicating which receptacle engages the pins in the sockets and which receptacle disengages the pins from the sockets. 
     According to another aspect of the present invention, an apparatus for actuating a socket assembly having a cover and a housing includes several means. First, the apparatus includes a means for accepting a flat blade tool. In addition, the apparatus includes a means for transferring a force from the sides of the flat blade tool to the means for accepting the flat blade tool. Moreover, the apparatus includes a means for moving the cover of the socket assembly relative to the housing of the socket assembly in response to the force received means for accepting the flat blade tool. 
     According to another aspect of the present invention, the above apparatus also includes means for providing a tactile feedback sensation to an operator of the flat blade tool to indicate when the cover has completed its travel relative to the housing. 
     According to another aspect of the present invention, the above apparatus also includes means for indicating to the user a function of each of two receptacles and a direction of rotation of the flat blade tool to perform the associated function. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A depicts an exemplary embodiment of a micro pin grid array socket according to the present invention. 
     FIG. 1B depicts a portion of the exemplary embodiment of FIG. 1A in a top detail view. 
     FIG. 1C depicts a further detailed top view of a portion of the exemplary embodiment of FIG.  1 B. 
     FIG. 2 depicts a detailed view of an alternative embodiment of the socket actuator receptacle according to the present invention. 
     FIG. 3 depicts the socket actuator receptacle shown in FIG. 2 with the blade of a screwdriver or other like tool inserted into the actuation receptacle. 
     FIG  4 A depicts insertion of the pin grid array into the socket of the present invention. 
     FIG. 4B depicts the pin grid array mounted into the socket of the present invention in side view. 
     FIG. 5A depicts the use of a screwdriver tool to mate the pin grid array to the socket. 
     FIG. 5B depicts the use of a screwdriver tool to unmate the pin grid array from the socket. 
     FIG. 6A depicts a further detailed top view of a portion of the exemplary embodiment of FIG. 1C in the open position. 
     FIG. 6B depicts a further detailed top view of a portion of the exemplary embodiment of FIG. 1C in the closed position. 
     FIG. 7 depicts a conventional socket assembly for receiving a pin grid array, such as is used in CPU integrated circuits. 
    
    
     DETAILED DESCRIPTION 
     The present invention relates to a Screwdriver Actuated ZIF (SAZ) socket. This socket is designed to eliminate damage during installation and replacement of high pin count Micro PGA devices without the need for expensive insertion/extraction tools. The Micro Pin Grid Array (PGA) socket of the present invention features Zero Insertion Force (ZIF) mating and unmating. The SAZ socket features a cover that keeps the empty socket in the “OPEN” position. A standard 0.635[0.250] wide slotted screwdriver is all that is needed to actuate the socket. 
     Referring to FIG. 7, shown therein is a conventional socket assembly  70  for receiving the pins from a Pin Grid Array (PGA), for example. The assembly  70  consists of a cover  71  and a housing  72 . The cover  71  moves relative to the housing  72  to lock the PGA in place or to disengage the PGA. Only one row of sockets  73  and one column of sockets  74  are shown, however, conventional designs usually consist of many rows and columns, such as 24×26. 
     To move the cover  71  relative to the housing  72 , a lever and cam assembly (not shown) is used. Pushing the lever down rotates a cam into the slot  75  shown in FIG. 7, which moves the cover  71  in the direction shown by the arrow  18 . To move the cover  71  back, the lever is lifted, which rotates another cam and moves the cover  71  back. 
     Referring to FIG. 1A, an exemplary embodiment of the socket assembly  10  according to the present invention is shown. The socket assembly includes a cover  11  and a housing  12 . The socket assembly  10  includes 26 rows and 24 columns of sockets  16 , however, the actual number of sockets  16  is not limited to this embodiment. Any number of sockets  16  may be employed in the socket assembly  10  of the present invention without departing from the scope of the invention. 
     The pin grid array  41  (see FIG. 4A) is inserted, lightly pressed into place into the socket assembly  10  (see FIG. 4B) and locked in place by lateral movement of the cover  11  relative to the housing  12 . The lateral movement is caused by inserting a screwdriver or like tool (see FIGS. 5A and 5B) into the receptacle  13  and rotating the screwdriver clockwise (in this embodiment), which rotation moves the cover  11  laterally in the direction of the arrow  18  relative to the housing  12 , thereby engaging the pins of the pin grid array  41  with the sockets  16  in the socket assembly  10 . 
     Referring to FIG. 1B, shown therein is a detailed top view of a portion of the socket assembly  10 . When the socket assembly  10  is in the open position, i.e., the pins of the pin grid array  41  are not engaged with the sockets  16 , there is no space between the cover  11  and the housing  12  at the edge of the cover  12  where the socket receptacle  13  is disposed. 
     Also shown in FIG. 1B are visual directions or icons  14 ,  15 , (also see elements  20 ,  21  in FIG. 1A) indicating the direction of rotation of the screwdriver to lock the pin grid array  41  to the socket assembly  10 . Indicator  14  in the shape of a lock coupled with indicator  15  informs the user that rotation of the screwdriver in the clockwise direction locks the pins in the pin grid array  41  to the sockets  16  in the socket assembly  10 . Similarly, icons  20  and  21  indicate to the user that insertion of the screwdriver into the receptacle  19  and moving the cover  11  relative to the housing  12  in the direction indicated by icon  21  unlocks the pin grid array  41 . The unlock icon  20  indicates this to the user. 
     Referring now to FIG. 1C, shown therein is a further detailed top view of a portion of the socket assembly  10 . Detent assembly  17  provides a tactile feedback sensation to the user when the pins of the pin grid array  41  are completely engaged with the sockets  16 . When the cover  11  has moved as far laterally relative to the housing  12  in the direction of the arrow  18  as possible, the detent assembly  17  provides a click to the user to inform the user that further rotation of the screwdriver is not necessary, thereby preventing excess force from being exerted on the socket receptacle  13 . Further details of the detent assembly  17  can be seen in FIGS. 6A and 6B. 
     An alternative embodiment of the socket receptacle of the present invention is shown in FIG.  2 . In this alternative embodiment, the shape of the socket receptacle is such that rotation of the screwdriver is opposite to that of FIGS. 1A-C to engage the pin grid array  41 . In other words, in this embodiment to engage the pins of the pin grid array  41  with the sockets  16  of the socket assembly  10  the screwdriver must be rotated in the counter-clockwise direction. To disengage the pins of the pin grid array  41  from the sockets  16  of the socket assembly, the screwdriver must be rotated in the clockwise direction. 
     As can be seen in FIGS. 1A-1C and the alternative embodiment of FIG. 2, a specially-shaped receptacle  13  is used in place of the lever and cam assembly of the prior art. Several embodiments of the socket assembly  10  are possible. One of the specially-shaped receptacles  13  may be disposed on each side of the socket assembly  10 . One for engaging the pins of the pin grid array with the sockets  16  of the socket assembly  10 , and another for disengaging the pins of the pin grid array from the sockets  16  of the socket assembly  10 . 
     Alternatively, as shown in FIG. 1A, a rectangular receptacle  19  can be used to disengage the pins from the sockets  16 , as the forces required to disengage are much less than the forces necessary to engage the pins with the sockets  16 , which means that the specially shaped receptacle  13  is not as necessary for disengagement of the pin grid array  41 . The shape of the receptacle  13  is designed to minimize the forces from the screwdriver on the receptacle  13  to prevent damage to the plastic receptacle  13 . With a large number of pins, the forces to engage the pins to the sockets  16  can be rather large, and without the provision of the specially-shaped receptacle  13  one might damage the plastic receptacle  13 . 
     The receptacle  13  is formed by a space provided between the cover  11  and the housing  12 . Insertion of the blade of a screwdriver, for example, into the receptacle  13  and rotation of the blade will move the cover  11  relative to the housing  12 , thereby engaging the pins of the pin grid array  41  with the sockets  16  of the socket assembly in the known manner. Insertion of the blade of a screwdriver, for example, into the receptacle  19  on the opposite side and rotation of the blade will move the cover  11  relative to the housing  12 , thereby disengaging the pins of the pin grid array  41  with the sockets  16  of the socket assembly  10  in the known manner. 
     Referring to FIG. 3, shown therein is the embodiment of the receptacle of FIG. 2 with the blade  26  of the screwdriver inserted into the receptacle  13 . The shape of the receptacle  13  is selected to prevent damage to the molded plastic components of the housing  12  and cover  11 . By employing a receptacle  13  with shoulders  22 - 25 , the force applied to the shoulders  22 - 25  of the receptacle  13  can reach 45-50 lbs without damaging the molded plastic components, which force is necessary to engage the pins of the PGA with the sockets  16 . Due to the shape of the receptacle  13 , the force is applied by the sides  29  of the screwdriver blade  26  to the receptacle  13 , rather than by sharp edges  28  of the blade  26 . During rotation of the screwdriver blade  26 , the point at which the force is received by the receptacle  13  will move continuously along the shoulders  22 - 25  of the receptacle  13 . For example, during rotation of the blade  26  in the direction of the arrow  27  the force applied by the blade  26  is applied by the sides  29  of the blade  26  at shoulders  23  and  25 , while the sharp edges  28  are free to travel without contacting any part of the receptacle  13 . When rotating the blade  26  in a direction opposite to the arrow  27 , the force applied by the blade  26  to the receptacle  13  will be applied by the sides  29  of the blade  26  at shoulders  22  and  24 , and as before the sharp edges  28  of the blade  26  are free to travel without contacting any part of the receptacle  13 . Consequently, the shape of the receptacle  13  is designed to ensure that the shoulders  22 - 25  of the receptacle  13  remain in contact with the sides  29  of the blade  26 , thereby ensuring that the force applied by the blade  26  and received by the receptacle  13  will be felt at the shoulder portions  22 - 25  of the receptacle  13  at all times. Due to the design of the receptacle  13 , essentially a fulcrum is created where the one side  29  of the blade  26  touches the shoulders  22 - 25  of the receptacle  13 , allowing the force to be applied by the sides  29  of the screwdriver rather than the edges  28 , which might damage the plastic molded receptacle  13 . The design of the receptacle  13  is such that the edges  28  of the blade  26  can move without touching the receptacle  13 . 
     Alternate designs of the receptacle  13  include two shoulder sections with open ends, or two rounded bumps. Other possible designs would be evident to those of skill in the art based on this disclosure. 
     Referring to FIG. 4A, shown therein is the insertion of the pin grid array  41  into the socket assembly  10 . The corner marker  42  in the pin grid array  41  lines up with the missing sockets in the array of sockets  16  to enable the user to correctly line up the pins with the sockets  16 . 
     Referring to FIG. 4B, shown therein is a side view of the pin grid array  41  inserted into the socket assembly  10 . The finger  43  indicates that the user must apply a small force to the top of the pin grid array  41  to ensure that the pin grid array is flat against the bottom of the cover  11  of the socket assembly  10 . 
     Referring to FIG. 5A, once the pin grid array  41  is inserted into the socket assembly  10 , a screwdriver  51  is inserted into the socket and rotated (in this embodiment) clockwise to engage the pins with the sockets  16 . 
     Referring to FIG. 5B, to disengage the pins of the pin grid array  41  from the sockets  16  of the socket assembly  10 , the screwdriver  51  is placed in the receptacle  52  on the top of the socket assembly (opposite to the receptacle  13  used to engage the assembly) and the screwdriver  51  is rotated clockwise. 
     Referring to FIG. 6A, which is a detailed view of the detent assembly  17 , a protrusion  61  on the edge of the cover  11  moves between two cutouts  62 ,  63  in the housing  12  when the cover  11  moves relative to the housing  12 . FIG. 6A shows the detent assembly  17  when the socket assembly  10  is in the open position. In this position, the pins of the pin grid array  41  are not engaged with the sockets  16  of the socket assembly  10 . When the cover  11  moves relative to the housing  12  as a result of the screwdriver  51  action, the protrusion moves from cutout  63  to cutout  62 , as shown in. FIG. 6B, which depicts the detent assembly in the closed position. The closed position is when the pins of the pin grid array  41  are engaged with the sockets  16  of the socket assembly  10 . When the screwdriver  51  action disengages the pins from the sockets  16 , the detent assembly  17  changes from the position shown in FIG. 6B to the position shown in FIG.  6 A. When the protrusion moves from one cutout portion  62 ,  63  to the other, a tactile feedback sensation is provided to the user to indicate that the cover  11  has completed its travel relative to the housing  12 . This ensures that the user will not apply undue force to the socket actuator  13 . 
     In summary, the present invention provides a quick, easily manufactured technique to engage and disengage the pin grid array with the socket assembly without occupying additional space on the printed circuit board.