CHIP CARRIER EXTRACTION TOOL

Abstract: A tool (20) for extracting a microelectronic chip carrier from a receptacle to which it is connected. It includes left and right arms (26,28), each having coextensive members in the form of a substantially rigid tong and a flexible leg. Both arms are pivotally mounted at a common axis (30), for relative movement. A distant end of each tong terminates at a chip carrier engaging hook (48) and is slidably received in a channel formed in a tong support (32,34) at a far end of the leg. Each leg has a bearing surface at its extreme end and a hinge member (43) intermediate its ends and is bowed out­ wardly of its associated tong. With the bearing surface enga­ ged on the receptacle, the arms are opened sufficiently wide that the hooks which are extended from the bearing surface when the tool assumes its relaxed condition, straddle the chip carrier. As the arms are squeezed together, lateral move­ ment of the flexible leg members toward their associated tong members is effective to move the hooks, in a continuing sequence, first laterally toward and into engagement with the chip carrier, then longitudinally in a direction away from the receptacle until the chip carrier is dislodged from the recep­ tacle.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an improved tool for extracting a microelectronic chip carrier from a receptacle to which it is connected. 2. Description of the Prior Art Mounting of a chip carrier onto an appropriate receptacle is a relatively straight forward procedure. It merely requires an operator to align the contacts of the chip carrier with those of the mating receptacle, then press firmly against the receptacle until it is fully seated. In the instance in which the chip carrier has a plurality of outwardly extending pins, these pins must be firmly aligned with socket holes in the receptacle before pressing firmly against the chip carrier. However, extracting the chip carrier, is not nearly as simple a procedure for a number of reasons. In the first instance, the chip carriers are small and generally difficult to grasp. Furthermore, if too much pressure is applied to the outer casing of the carrier, it can become cracked and thereby probably rendered useless. Additionally, chip carriers are often mounted on densely packed receptacles, printed circuit boards, for example, such that they are closely surrounded by other components. Then, too, if the chip carrier is not drawn outwardly in a careful manner such that a plane of the chip carrier remains generally parallel with that of the circuit board, the contacts can become bent and therefore misaligned, such that, following a subsequent insertion, they will not operate in an effective manner. To effect extraction of a chip carrier from a receptacle without damage to either component, a number of tools have previously been devised. For example, Burndy Corporation, of Norwalk, Connecticut, presently manufactures and sells extraction tools referred to by catalog numbers QILE68EX-1 and QILE84EX-1. This design is of the screw type and requires a different size of extraction device for each different size of chip carrier. For example, in the instance of the first catalog number cited above, the tool is operable to extract 68 contact chip carriers while the latter design is effective to extract 84 contact tool carriers. Another extraction tool also manufactured by Burndy Corporation is that known by catalog number QILE68EX-2. In this instance, the tool includes a base with a depending skirt to define an underneath recess. Centrally upstanding from the upper surface of the base is an integral thumb receiving post. A spring member with a pair of opposed tong receiving loops located to either side of the post passes slidably through a vertical slot in the post. Each loop is curved outwardly and downwardly and extends through holes adjacent opposite corners in the base and terminates at a hook for engaging a chip carrier. When the base is grasped and the spring members pushed downwardly, the chip carrier engaging hooks extend beyond the terminal rim of the pending skirt. Then holding the tool by the sides of the springs, the tool is placed over the socket supporting a chip carrier and the hooks are appropriately positioned to straddle the chip carrier. Thereupon, the thumb receiving post is pushed downwardly toward the socket which serves to extend the tool skirt over the side of the socket and the socket into the recess defined by the skirt. While maintaining downward pressure on the knob, the operator then pulls the two loops of the spring member upwardly to extract the chip carrier from its socket. The tool is then lifted from the socket carrying with it the extracted chip carrier. Thereupon, the chip carrier is released from the tool by setting the tool on a soft surface and pushing down on the spring. Another known tool is manufactured and sold by AMP Inc. of Harrisburg, PA., known by catalog number 821566-1, also known as AMP "68", which is capable of extracting a carrier chip with 68 connectors. This tool, is capable of extracting only one size of chip carrier, for example, a carrier whose chip has 68 contacts. As with the other constructions, this tool also has a pair of spaced apart hooks extending from the main body of the tool. The hooks are operated by opposed handles which pivot on spaced apart axes. The handles have matingly engaging arcuate surfaces which operate a suitable cam and follower mechanism to cause the hooks to compress on the sides of the chip carrier; then, when the operator continues to squeeze the handles together, the hooks engage the undersurface of the chip carrier and draw it away from the receptacle in which it had been positioned. Still another extraction tool which has previously been used is a tweezers type tool which is manufactured by Microelectronics Supplies Inc., of Danbury, Connecticut and identified by catalog number QILE--EX-3. In this instance, inwardly directed hooks at the extreme ends of the device straddle the chip carrier and are moved by the operator to engage both the sides and the undersurface of the chip carrier. With the tool squeezed against the chip carrier, the operator pulls in a direction away from the receptacle on which the chip carrier is mounted to thereby extract the chip carrier from the receptacle. Still another extractor tool is manufactured by Techni -Tool of Plymouth Meeting, Pennsylvania under the trademark "LITTLE GRIPPER". This latter tool is a DIP (i.e. "dual in-line pin") extraction tool which has opposed rows of teeth which can be extended from a handle portion to engage the carrier unit when the teeth are aligned with spaces between the DIP leads. The extraction device is then locked onto the DIP and, by using a T-bar fixed to a slide member which extends through the housing and is integral with the tong member, is then raised to thereby draw the connector off the receptacle to which it was previously mounted. Yet another extractor tool known to the Inventor is manufactured by SAMTEC of New Albany, Indiana. This tool is cam actuated and acts on all four sides of a pin grid array at one time. It was with knowledge of the current state-of-the-art as represented by the extraction tools just described that the present invention was conceived and has now been reduced to practice. In United States patent specification No. 3,974,556, there is proposed a tool for extracting an integrated circuit package from a circuit board having one component that grasps the underside of the package and another component that produces a perpendicular force to effect the extraction. In United Kingdom patent application number 2,157,223, there is described a hand tool for extracting electronic components from sockets which has lever arms to engage the top side of a component and jaws to engage the underside of a component. SUMMARY OF THE INVENTION The present invention is directed toward a tool for extracting a mircroelectronic chip carrier from a receptacle to which it is connected. It includes right and left arms, each having coextensive members in the form of a substantially rigid tong and a flexible leg. The arms are pivotally mounted at a common axis for relative movement. A distant end of each tong terminates at a chip carrier engaging hook and is slideably received in a channel formed in a tong support at a far end of the leg. Each leg has a bearing surface at its extreme end and a hinge member intermediate its ends and is bowed outwardly of its associated tong. With the bearing surface engaged on the receptacle, the arms are opened sufficiently wide that the hooks which are extended from the bearing surface when the tool assumes its relaxed position, straddle the chip carrier. As the arms are squeezed together, lateral movement of the leg members toward their associated tong members effective to move the hooks, in a continuing sequence, laterally toward and into engagement with the chip carrier, then longitudinally in a direction away from the receptacle until the chip carrier is dislodged from the receptacle. The particular embodiment to be described below is of a simple construction such that it can be inexpensively manufactured and maintained. Additionally, it is of a generally universal design which enables it to be applicable for the removal of a large variety of sizes of chip carriers. The tool to be described is also substantially foolproof in its operation. To this end, it only lightly engages the sides of the carrier chip and applies virtually all of its force via the opposed hook members to draw the chip carrier away from the receptacle by gripping it from its underside. Opposed wing members which extend laterally outwardly from each tong support lightly engage the chip carrier whenever it tends to rotate about an axis defined by the opposed hooks as it is being drawn away from the receptacle. The tool assures a consistent operation each time it is used without regard to the particular operator of the tool. At the outset of a removal operation, it is inserted so that the hook members straddle the chip carrier. Its opposed arms are squeezed together, and, in a continuous operation, the hook engages the undersurface of the chip carrier then, with the application of a consistent force, draws the chip carrier away from its mating receptacle in a continuous operation until the chip carrier has been dislodged. Other and further features, objects, advantages, and benefits of the invention will become apparent from the following description taken in conjunction with the following drawings. It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory but are not to be restrictive of the invention. The accompanying drawings which are incorporated in and constitute a part of this invention, illustrate one of the embodiments of the invention and, together with the description, serve to explain the principles of the invention in general terms. Like numerals refer to like parts throughout the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a carrier chip extraction tool embodying the invention; FIG. 2 is a front elevation view of the extraction tool illustrated in FIG. 1; FIG. 3 is a side elevation view of the extraction tool illustrated in FIGS. 1 and 2; FIGS. 4a and 4b are detail side elevation views, certain parts being cut away and in section, illustrating, respectively, the relative positioning of the elements of the extraction tool immediately before, and immediately after, the extraction operation; FIG. 5 is a bottom view of the extraction tool of the invention; FIG. 6 is a detail side elevation view illustrating various positions of the extraction tool and thereby showing the manner in which the extraction tool can be operated to accommodate a wide variety of sizes of carriers; and FIG. 7 is a detail perspective view of a portion of the extraction tool. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Turn now to the drawings and initially to FIGS. 1 - 3 which illustrate a tool 20 for extracting a microelectronic chip carrier 22 (FIGS. 4a and 4b) from a receptacle 24 to which it is connected. The chip carrier 22 may be of the type commonly referred to by the term "chipak" and the receptacle 24 may be of the type commonly referred to by the term "chipak housing". The tool 20 is self adjusting, as illustrated in FIG. 6 to accommodate a wide variety of different sizes of chip carriers. For example, as seen in FIG. 6, the tool is operable on a chipak having as few as 20 contacts to a chipak having as many as 124 contacts and it can accommodate an infinite member of sizes within that range. Of course, the inventive concept need not be so limited, but is applicable to any size of chip carrier including those having fewer than 20 contacts or more than 124 contacts. Returning to FIGS. 1 - 3, the extraction tool is seen to include a left arm 26 and a right arm 28 which are pivotally mounted on a pivot pin 30 for relative movement between a widely spread condition and a narrowly spread condition. The widely spread condition is illustrated in FIG. 6 in which the tool is seen to accommodate a chip carrier 22 having 124 contacts. In the narrowly spread condition, the tool is seen to accommodate a chip carrier having only 20 contacts. Each of the arms 26 and 28 includes a tong support 32 and 34, respectively, at a working end distant from the common end as defined by the pivot pin 30 and each tong support terminates at respective surfaces 36 and 38. The tong supports 32 and 34 are actually terminal ends of flexible operative or leg members 40 and 42, respectively. The leg members 40 and 42 are composed of a suitable plastic material such as that manufactured and sold under the trademarks "DELRIN" or "LEXAN", each of which has an operative or "living" hinge 43 at a region intermediate a proximal end adjacent the pivot pin 30 and a far end at the tong supports. Each of the arms 26 and 28 also includes a substantially rigid tong member 44 and 45, respectively, composed, for example, of spring steel, which has a near end adjacent the pivot pin 30 for movement about an axis with the leg members 40 and 42, and a distant end 46, at a terminal location, is formed with a chip carrier engaging hook 48. Each of the tong supports 32 and 34 is formed with a longitudinally extending channel 50 which slideably receives the distant end 46 of each of the tong members 44 and 45. Both tong supports 32 and 34 include a transversely extending wing member 52 which is engageable with the chip carrier and cooperable with the hooks 48 for stabilizing the chip carrier at it is being dislodged from the receptacle 24. The wing members are suitably positioned to inhibit movement of the chip carrier 22, during the extraction process, about an axis defined by the spaced apart hooks 48. Each tong support 32 is also provided with a chip carrier receiving recess 54 appropriately sized to receive the chip carrier after it has been extracted from the receptacle. Each tong support 32 and 34 is also provided with a transversely extending metallic dowel pin 56 embedded in it and in communication with the channel 50 such that the associated tong member, 44, 45 is slideably engaged with the dowel pin. In this manner, the construction assures that the leg members 40, 42 will freely slide within the channels 50 and will not cause undue wear of the channels. The operation of the extraction tool 20 will now be described. The operator of the tool opens the arms 26 and 28 to an appropriate spacing (FIG. 6) to assure that the hooks 48 are properly received in slots 58 (FIG. 5) of the receptacle 24. The bearing surfaces 36 and 38 are appropriately positioned on an upper surface 60 of the receptacle. The operator then squeezes the arms, together at the intermediate region of the leg members 40 and 42, that is in the region of the hinges 43. As such squeezing is initiated, the chip carrier engaging hooks 48 are in their extended positions (see FIG. 4a) straddling the chip carrier. As force is applied to the leg members 40 and 42 by the operator to move them toward the tong members 44 and 45, the hooks 48 are moved in a continuous smooth operation longitudinally into engagement with the bottom surface of the chip carrier drawing it in a direction away from the receptacle 24, that is, in a direction substantially perpendicular to the receptacle. Simultaneously, the wing members 52 engage the upper surface of the chip carrier and prevent it from rotating or tilting about the axis defined by the hooks 48. When the legs have been moved to their inwardmost positions (FIG. 4b) the hooks 48 will have moved to a position generally coextensive of the bearing surfaces 36 and 38 of the tong supports 32 and 34, and the chip carrier 22 will be confined within the recess 54 and completely dislodged from the receptacle. The chip carrier 22 can then be fully released from the recess 54 by moving the leg members 40 and 42 to their original (FIG. 4a) positions relative to the tong members 44 and 45. While a preferred embodiment of the invention has been disclosed in detail, it should be understood by those skilled in the art that other various modifications may be made to the illustrated embodiment without departing from the scope of the invention as defined in the appended claims. For example, although the disclosure has been primarily directed toward a tool for extracting a microelectronic chip carrier from a receptacle to which it is connected, the invention is intended to encompass a tool for extracting from a receptacle any object which is resistive to removal but which, without harm to the object or to the receptacle, can be extracted by the application of sufficient force solely in a direction substantially perpendicular to the receptacle.

Claims: A tool (20) for extracting a microelectronic chip carrier from a receptacle to which it is connected, including a pair of substantially rigid mutually cooperating tong members (44, 45), each of the tong members having a near end and a distant end (46), and including a chip carrier engaging hook (48) at the distant end, a pair of leg members (40, 42), one of the leg members (40) being associated with one of the tong members (44), the other of the leg members (42) being associated with the other of the tong members (45), each of the leg members (40, 42) having a proximal end and a far end (32, 34), and including a tong support (32, 34) adjacent the far end and having a channel (50) to slidably receive the distant end (46) of its associated tong member (44, 45), characterised in that the tong members (44, 45) and the leg members (40, 42) are pivotally mounted for relative movement at their near and proximal ends respectively about a common axis, in that each of the leg members (40, 42) provides a bearing surface (36, 38) at the far end thereof, and in that each of the leg members (40, 42) includes hinge means (43) at a region intermediate the proximal end and the far end (32, 34) allowing for relative lateral movement between each of the intermediate regions and its associated one of the tong members (44, 45) and resulting in simultaneous relative longitudinal movement between the distant ends (46) of the tong members (44, 45) and the associated tong supports (32, 34), whereby each of the hooks (48) is in an extended position distant from an associated one of the bearing surfaces (50) when the hinge means (43) is broadly spaced from its associated tong, and whereby each of the hooks (48) is in a retracted position proximate to an associated one of the bearing surfaces when the hinge means is narrowly spaced from its associated tong member (44, 45). A tool as claimed in claim 1 characterised in that there are provided pin means (30) pivotally mounting the tong members (44, 45) and the leg members (40, 42) for relative movement about the common axis, and in that a first arm (26) comprising one of the tong members (44) and its associated one of the leg members (40) is relatively movable about the common axis relative to a second arm (28) comprising the other of said tong members (45) and its associated one of the leg members (42) to adjust the lateral distance between the hooks (48) to accommodate chip carriers of various sizes. A tool as claimed in Claim 2 characterised in that each of the tong supports (32, 34) defines a recess (54) therein for receiving a chip carrier, such that with the first and second arms (26, 28) sufficiently spaced that the hooks (48) in their extended positions straddle a chip carrier when the bearing surface (36, 38) engages a receptacle, as the arms (26, 28) are squeezed together, lateral movement of the leg members (40, 42) toward their associated tong members (44, 45) is effective to move, in a continuing sequence, the hooks (48) first laterally toward and into engagement with a chip carrier, and then longitudinally in a direction away from the receptable until the chip carrier is dislodged from the receptacle and firmly held within the recess (54).

Inventors: ERNEST, LOUIS, CHEH.
Applicants: BURNDY CORPORATION
Application year: 1987
Main classification: H05K13
IPC codes: H05K13, B25B27, H01L23