US20050287879A1 - Connector having improved contacts with fusible members - Google Patents

Abstract

An electrical connector includes a connector body, a plurality of cores and a plurality of electrically conductive contacts disposed in the cores of the connector body. Each of the contacts includes a fusible member attached thereto. Each of the fusible members includes an intermediate portion and two support members disposed on opposite sides of the intermediate portion. The support members are arranged to hang down below a tail portion of the contacts.

Description

BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to electrical connectors and more specifically, the present invention relates to connectors having a unique arrangement of contacts or terminals having a fusible member attached thereto, that allows for much higher coplanarity while simplifying the connector manufacturing and assembly procedures.
• 2. Description of the Related Art
• Electrical connectors are used to place electrical devices, such as printed circuit boards, in communication with one another. An electrical connector may be thought of as having two portions, one portion of which connects to a first electrical device and the second portion of which connects to a second electrical device to be put into communication with the first device. To connect the two devices, the two portions of the electrical connector are mated together.
• Each portion of the connector includes one set of contacts or terminals adapted to communicatively couple to an electronic device and a second set of contacts or terminals adapted to matingly couple to the other connector portion. This can be readily accomplished by designating one portion of the connector as having “male” contacts or terminals adapted to couple to the other connector portion's “female” contacts or terminals. Regardless of the specifics of the design of the contacts or terminals, the two connector portions should be adapted to be easily connected and disconnected from each other to respectively electrically link and unlink the electrical devices to which they are connected.
• Accordingly, each connector portion is fixedly connected to an electronic device through its remaining set of contacts or terminals. The contacts or terminals may be removably or permanently connectable to the electrical device; however, it is usually desired that the connector portion be secured to the electrical device through some physical mechanism. Typically, the connector portions are secured to electrical devices by fusing the contacts or terminals to contact pads or the like formed on the electrical device.
• Recently, there has been a trend toward miniaturization of most electrical devices. As electrical devices become smaller and more complex, the electrical connectors used with these devices must also become smaller and must be able to accommodate the more complex devices. One problem with miniaturized electrical connectors arises from the increased precision of placement necessary to produce the proper positioning and connection of the connector contacts or terminals onto the device. This problem is exacerbated by the ever increasing input/output (I/O) density requirements demanded of the progressively smaller electrical connectors by increasingly miniaturized electrical devices. With increased pin counts (e.g., greater number of terminals) in each connector, it becomes more and more difficult to maintain desired levels of co-planarity while maintaining contact of all of the terminals to a substrate or PCB.
• One means of addressing the need for increased I/O density is to provide an arrayed connector. Such a connector can provide a high-density two-dimensional array of contacts or terminals for interfacing with an electrical device. However, arrayed connectors present attachment difficulties regarding connection to devices (i.e., circuit boards or substrates) since most of the contacts or terminals must necessarily be positioned in the interior of the two-dimensional array area and are accordingly difficult to align upon connection, visually inspect, and/or repair.
• One attempt to provide a high-density electrical connector interface has been to use a ball grid array (BGA). The BGA offers the advantages of a precisely formed high-density array of contacts or terminals available to interconnect with a substrate. The use of a BGA is thought to overcome conventional problems with co-planarity (e.g., to maintain co-planarity at about 0.004″, for example) and to ensure that all contacts or terminals are securely soldered to pads on a PCB when the connector is mounted and reflowed to the PCB.
• However, the use of a BGA has many disadvantages. First of all, the use of solder balls greatly complicates the connector manufacturing process because an additional reflow step is required and the use of special equipment is also required. In addition, either the connector body and/or contacts or terminals must be modified to include recesses or solder ball holding structures, or special assembly equipment must be used to hold the solder balls in place until the solder balls can be reflowed to be connected to the tails of conductive contacts or terminals provided in the housing of the connector. After the solder balls have been reflowed a first time so as to be attached to the tails of the contacts or terminals, the entire connector must be reflowed again so that the solder balls can make the necessary electrical and mechanical attachments to conductive pads on a PCB upon which the connector is being mounted. A further problem may occur when the solder balls are attached to gold-plated tail portions of the contacts or terminals, during which process the gold of the tail portions of the contacts or terminals can mix with the tin/lead of the reflowed solder ball which can cause problems with gold embrittlement.
• In addition to the above-described problems, variations in the dimensions and/or placement of solder balls at the interface can lead to an uneven or non-coplanar interface and intermittent or poor electrical contact. Also, the presence of oversized or extra solder balls present in the connector interface, or the uncontrolled spreading of the solder balls during the multiple reflow steps can result in shorted connections and degraded connector performance. In addition, the tails of the contacts or terminals are inserted and attached at different depths within the various solder balls so as to create problems with co-planarity. Furthermore, the solder joints created by the solder balls between the contacts or terminals and the pads on the PCB is not as reliable and may not withstand twisting or distortion of the connector body which may occur. That is, the solder joints created using solder balls are not as flexible and may not withstand the stresses applied to the joints when the connector body bows, twists or is distorted in shape.
• One alternative to the use of a BGA is described in U.S. Pat. No. 6,679,709, in which circular columns ofsolder 6 are used instead of solder balls. The circular columns ofsolder 6 have an elongated cylindrical bar-shaped configuration and in fact are formed by cutting pieces of solder wire. These circular columns ofsolder 6 are inserted between a pair of bar-like pieces 12 which are then bent to allow claws 13 to grip and hold thesolder 6 on the respective terminal orpin 5 such that a longitudinal axis of the circular column ofsolder 6 is perpendicular to a mounting plane of a PCB or circuit board to which thesolder 6 and connector is to be attached. Thus, the solder holding assembly (elements 12, 13, 14) must be arranged perpendicular to themain body 10 of the contact orterminal 5, which complicates the manufacturing and assembly of the contacts orterminals 5 in the connector body. In addition, because the circular columns ofsolder 6 may have different lengths and may be mounted at different positions with the solder holding assembly (12, 13, 14) of each terminal, many problems with co-planarity may result. Thus, this complicated tail assembly of the contacts orterminals 5 makes manufacturing and assembly more difficult and may cause rather than solve co-planarity problems.
• Another alternative is the use of solder-bearing contacts in which the solder has been crimped to the contacts, as shown in U.S. Pat. No. 4,597,628, for example. In this patent, a solder bearingedge clip 10 has arms 15, 16 with arcuate fingers 18, 19 havingsolder wires 30 attached thereto. The attaching process involves insertingsolder wires 30 into openings at the ends of the fingers 18, 19, closing or crimping the fingers to close the openings so as to indent thesolder wires 30 as shown in FIGS. 3 and 12. The solder is then melted to attach the arms 15, 16 or 75, 76 to thepads 12 of the substrate 11 as seen in FIGS. 4 and 13. In most of the embodiments shown in this patent, the solder wire is spaced from the outer surfaces of the fingers 18, 19 or 68, 69 because the fingers 18, 19 or 68, 69 must be able to reliably hold the substrate. FIGS. 11A and 11B show an embodiment where the solder wire 71′ projects very slightly from the finger ends so that when the substrate is inserted, the solder wipes across thecontact pad 12 to improve the resulting solder joint. However, with this structure, there is no way to control how far the solder projects from the finger ends and thus, no way to ensure that the substrate is reliably held in the arms. If the finger ends are crimped too much, excessive solder will project from the finger ends and it may not be possible to reliably hold the substrate between the fingers. If the finger ends are not crimped enough, the solder will not project from the finger ends. In addition, if fingers 18, 19 or 68, 69 are bent, twisted or having varying dimensions due to manufacturing tolerances, there may be an air gap between thepads 12 and the fingers 18, 19 or 68, 69 and solder. This air gap may not be filled by the solder during reflow because the solder may not be sufficiently wicked or moved toward the pad during reflow. Thus, there may still be problems with reliably forming or soldering electrical connections between fingers 18, 19 or 68, 69 and thepads 12.
• In fact, this is one of the most significant problems with electrical connectors in which conductive contacts or terminals are to be joined to conductive elements on a substrate. Because of twisting or flexing of the connector or variations in size, shape, or arrangement of the contacts or terminals in a connector body, an air gap may exist between the contact or terminal and a conductive pad to which it is to be attached before the reflow process is performed. The current designs and arrangements of contacts or terminals in the connectors do not provide for a consistently reliable solution for eliminating the air gap during reflow, and do not ensure that each contact or terminal is securely connected to the conductive pad on a substrate to which the connector is mounted.
SUMMARY OF THE INVENTION
• In order to overcome the unsolved problems of the prior art described above, preferred embodiments of the present invention provide an electrical connector that allows for much greater co-planarity to be achieved and also allows for a much more reliable reflow process to be performed to reliably connect a connector to a substrate.
• According to a preferred embodiment of the present invention, an electrical connector includes a connector body, a plurality of contacts arranged in the connector body, each of the plurality of contacts having a tail portion with a fusible member attached thereto, wherein each of the fusible members includes an intermediate portion and two support members disposed on opposite sides of the intermediate portion, and the two support members extend below the tail portion of the contact.
• It is preferred that each of the two support members extends below the tail portion of the contact by a distance of about 0.004 inches to 0.014 inches, and that an outer periphery of each of the two support members is greater than an outer periphery of the tail portion of the contact.
• Furthermore, it is preferred that the two support members are arranged to wick up the tail portion of the contact in a direction toward the connector body during a reflow process. When this happens, the portions of the support portions that previously hung below the bottom tip of the tail portion moves up the tail portion such that there is no longer any portion of the fusible member that hangs down below the bottom tip of the tail portion. As a result, each contact or terminal and the entire connector is able to drop down such that the bottom tip of the tail portion is located very close to the substrate and is reliably attached to the substrate. This allows the connector to have much greater co-planarity and a much more reliable reflow process.
• The configuration and arrangement of the contact or terminals has additional unique features. It is preferred that the contact or terminal has a key hole defined by a first horizontally extending arc and two vertically extending arcs, such that the intermediate portion of the fusible member is fitted within the key hole. More specifically, the intermediate portion of the fusible member fills the keyhole defined by the first horizontally extending arc and the two vertically extending arcs. This allows the fusible member to be quickly and reliably attached to the contact or terminal and eliminates a reflow step required with BGA connectors.
• The contacts or terminals may also include a solder stop portion located at a medial portion thereof. In addition, the tail portions of the contacts are substantially straight and do not include a right angle portion as is required with some conventional contacts described above.
• The contacts or terminals may also include wings for engaging a core of the connector body to maintain a uniform distance between the tail portion of the contacts and the connector body.
• Also, the contacts or terminals may include wedges for engaging a side wall of a core of the connector body in order to fix the contact in the connector body.
• Furthermore, the contacts or terminals may include lead-in portions having coined edges arranged to position the contacts in the connector body.
• The contacts or terminals may also include bumps for positioning the contacts within the connector body.
• The fusible member also has unique features in addition to those described above. Each of the two support portions has one of a substantially flat bottom surface, a substantially rounded bottom surface, a substantially spherical bottom surface, a substantially conical bottom surface, a substantially rectangular bottom surface and a substantially square bottom surface. Also, the intermediate portion and the two support portions are integral and unitary, and the support portions are located on opposite sides of the tail portion of the contact.
• Each of the two support members extends from the intermediate portion and is larger than the intermediate portion. The two support members preferably have substantially the same size and shape.
• It should be noted that the above-described unique arrangement and construction of the fusible member attached to the contacts or terminals of a connector can be applied to any type of connector including a board-to-board mezzanine connector, a differential pair array connector, a single ended array connector, an edge card connector, a right angle connector, a wafer for use in a backplane connector system, a connector for use with an IC chip such as a microprocessor chip (e.g., a Pentium® socket) and any other type of connector.
• Another preferred embodiment relates to a connector assembly in which a connector according to the preferred embodiments described above is attached to a substrate, such as a PCB. In such a structure, the unique contacts or terminals with attached fusible members are arranged to be mounted on and attached to conductive elements on the substrate.
• A further preferred embodiment of the present invention provides a method of forming a connector including the steps of providing a contact having a tail portion, inserting a fusible member into the tail portion, pressing edges of the fusible member such that an intermediate portion and two support portions of the fusible member are formed such that the two support portions extend down below a bottom tip of the tail portion of the contact. The resulting intermediate portion, two support portions and the arrangement thereof on the tail portion of the contact preferably have the features described above with respect to the other preferred embodiments of the present invention described above.
• Yet another preferred embodiment of the present invention provides a method of mounting a connector to a substrate, in which the connector manufactured according to the method described in the preceding paragraph, is positioned above a substrate such that a respective one of the contacts is located directly above a respective one of a plurality of conductive elements formed on the substrate, and reflowing the connector and substrate such that the fusible members are melted causing the support portions of the fusible members to wick up the contacts away from the tail portions, resulting in the contacts and the connector dropping down toward the substrate, such that the contacts are electrically connected to the conductive elements formed on the substrate.
• Other features, elements, steps, characteristics, and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1A is an isometric view of a connector according to a preferred embodiment of the present invention.
• FIG. 1B is an end view of the connector ofFIG. 1A.
• FIG. 2A is an end view of a contact or terminal according to another preferred embodiment of the present invention.
• FIG. 2B is a side view of a contact or terminal according to the preferred embodiment of the present invention shown inFIG. 2A.
• FIG. 3 is an assembly view of a plurality of contacts or terminals on a carrier strip for use in preferred embodiments of the present invention.
• FIG. 4A shows a first assembly step for joining a fusible member to a tail of a contact or terminal wherein a fusible member is positioned at an opening in the carrier strip just below the tails of the contacts or terminals.
• FIG. 4B shows a second assembly step for joining a fusible member to a tail of a contact or terminal wherein the fusible member is inserted in the tails of the contacts or terminals.
• FIG. 4C shows a close-up detailed view of a fusible member having been joined to the tail of a contact or terminal as a result of the step shown inFIG. 4B being performed;
• FIG. 4D shows a third assembly step for joining a fusible member to a tail of a contact or terminal wherein the fusible member is pressed at opposite ends thereof;
• FIG. 4E shows a close-up detailed view of the resulting support portions formed by the step of pressing the opposite ends of the fusible member as a result of the step shown inFIG. 4D being performed;
• FIG. 4F shows a close-up detailed view of the resulting intermediate portion filling the arc portions of the tail of the contacts or terminals as a result of the step shown inFIG. 4D being performed;
• FIG. 4G shows a detailed section view of the fusible member bearing tails of the contacts or terminals as a result of the step shown inFIG. 4D being performed;
• FIG. 4H shows a detailed side view of the fusible member bearing tails of the contacts resulting from the step shown inFIG. 4D;
• FIG. 5A is an end view of a connector according to a preferred embodiment of the present invention being mounted on a PCB before a reflow process.
• FIG. 5B is a side view of a connector according to a preferred embodiment of the present invention being mounted on a PCB before a reflow process.
• FIG. 6A is an end view of a connector according to a preferred embodiment of the present invention being mounted on a PCB after a reflow process.
• FIG. 6B is a side view of a connector according to a preferred embodiment of the present invention being mounted on a PCB after a reflow process.
• FIG. 7A is a schematic view of a conventional connector having tail portions of the contacts or terminals aligned with pads of a PCB before a reflow process for joining the connector to the PCB is performed.
• FIG. 7B is a schematic view of a conventional connector having the tail portions of the contacts or terminals being attached to a PCB after a reflow process for joining the connector to the PCB is performed.
• FIG. 8A is a schematic view of a connector according to a preferred embodiment of the present invention having fusible member bearing tails being placed on a PCB before a reflow process for joining the connector to the PCB is performed.
• FIG. 8B is a schematic view of a connector according to a preferred embodiment of the present invention having fusible member bearing tails being connected to a PCB after a reflow process for joining the connector to the PCB is performed.
• FIG. 9 is an isometric view of a mezzanine connector according to a further preferred embodiment of the present invention, which includes fusible member bearing contacts or terminals of preferred embodiments of the present invention.
• FIG. 10 is an isometric view of an edge card wafer with fusible member bearing contacts or terminals of the preferred embodiments of the present invention for use in a backplane connector according to another preferred embodiment of the present invention.
• FIG. 11A is a side view of a connector for an IC chip according to another preferred embodiment of the present invention, which includes fusible member bearing contacts or terminals of preferred embodiments of the present invention.
• FIG. 11B is a top view of the connector ofFIG. 11A.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
• Preferred embodiments of the present invention will now be described with reference to the drawings.
• FIG. 1A is an isometric view andFIG. 1B is an end view of aconnector10 according to a first preferred embodiment of the present invention. Theconnector10 includes abody12 that is preferably made of an insulating material such as plastic, a plurality of cores (not shown inFIGS. 1A and 1B, but shown aselement14 inFIG. 9 which illustrates another preferred embodiment of the present invention) formed in theconnector body12 for receiving a plurality of contacts, and a plurality of contacts orterminals20 inserted into the cores and held in thebody12. It should be noted that theconnector10 is shown inFIGS. 1A and 1B in a state before being reflowed to be attached to a substrate such as a PCB.
• As seen inFIGS. 1A and 1B, each of the contacts orterminals20 includes afusible member40 that is fixed to atail portion22 of thecontact20. It should be noted that thefusible member40 can preferably be a conductive material that can be melted by a reflow process, such as solder or other suitable metal. In addition, thefusible member40 can be a flux coated solder material member or a flux core solder wire. Preferred embodiments of the present invention will be described with reference to solder wires constituting thefusible member40, but this is in no way limiting of the present invention.
• Eachfusible member40 has twosupport portions40a,40bwhich are connected to each other by anintermediate portion40c. The twosupport portions40a,40bare disposed opposite to each other and spaced from each other by a distance that is equal to a length of theintermediate portion40c. The twosupport portions40a,40bmay preferably have substantially flattened bottom surfaces as shown inFIG. 1B. However, the bottom surfaces of thesupport portions40a,40bmay also have other shapes such as rounded, spherical, conical, square, rectangular, and other suitable shapes.
• It is preferred that thesupport portions40a,40bbe formed such that an outer periphery of each of thesupport portions40a,40bis greater than an outer periphery of thetail portion22 of the contact or terminal20, as seen inFIGS. 1A and 1B, for example. This feature along with other unique features of the arrangement of thefusible member40 attached to the contact or terminal20 enables theconnector10 to achieve much greater co-planarity as will be described.
• One of the unique features of the combined contacts orterminals20 andfusible members40 is that the lower portions of the twosupport portions40a,40bextend or hang down well below the end or bottom tip of thetail portion22 of the contact or terminal20 as seen inFIGS. 1B and 2B. As will be described below, this is an important feature for allowing the much higher coplanarity and a much more effective reflow process for joining theconnector10 to a substrate such as a PCB.
• Theintermediate portion40cis fixedly held in thetail portion22 of thecontact20 and theopposed support portions40a,40bare disposed on opposite sides of thetail portion22 of thecontact20 as seen inFIG. 1B. The twosupport portions40a,40band theintermediate portion40care preferably integral and unitary, as a result of being formed from the same fusible member as will be described below.
• Before describing the preferred process for manufacturing theconnector10 shown inFIGS. 1A and 1B, a preferred construction of the contact or terminal20 will be described with reference toFIGS. 2A and 2B.
• FIG. 2A is an end view andFIG. 2B is a side view of the contact or terminal20 according to another preferred embodiment of the present invention, for use with theconnector10 shown inFIGS. 1A and 1B.FIG. 2A shows the contact or terminal20 without thefusible member40 affixed thereto andFIG. 2B shows the contact or terminal20 with thefusible member40 affixed thereto.
• The contacts orterminals20 preferably include acontact portion21 and thetail portion22 at the opposite end. In a medial portion of the contact or terminal20, asolder stop member23 is preferably provided to prevent the fusible material, such as solder, from wicking up toward thecontact portion21. Thesolder stop member23 may be formed of any suitable material such as nickel or bare copper alloy. Other anti-wicking agents like resist films or any other non-solder wettable material like flourine resist may also be used. In addition, the medial portion of the contact or terminal20 preferably includeswings24 for engaging the bottom of the core of theconnector body12 in order to maintain a consistent distance between thetail portion22 of the contact or terminal20 and theconnector body12.
• The medial portion of the contact or terminal20 may also preferably includewedges25 for engaging a side wall of a core in order to fix the position of the contact or terminal20 and retain the contact or terminal20 in the core of theconnector body12. Thewedges25 fix the contact or terminal20 in the core in the width direction of theconnector body12 so as to prevent stress from being applied in a length direction of theconnector body12 so as to prevent problems with co-planarity.
• The medial portion of thecontact20 also preferably includes lead-ins orchamfers26 which are formed by coined edges which facilitate insertion of the contacts orterminals20 into the cores of theconnector body12. Each of the contacts orterminals20 further preferably includes abump27 for positioning and stabilizing the contact or terminal20 in a desired position and orientation relative to theconnector body12.
• The contact or terminal20 also preferably includes akey hole28 at thetail portion22. Thekey hole28 has a unique configuration that serves a special function as will be described. Thekey hole28 is preferably defined by one horizontally extendingarc portion28aand two vertically extendingarc portions28bdisposed opposite to each other. Thearc portions28aand28bcut out of the tail portion form two retainingarms28c,28d. The tips of the two retainingarms28c,28dare preferably beveled so as to eliminate debris from thefusible member40 during the manufacture of the contact orterminal20. More specifically, the tips of thetail portion22 at the retainingarms28cand28dare preferably coined to a chamfered tip at the surfaces below the dotted lines on the retainingarms28cand28d. This is to facilitate the insertion and pushing through of thefusible member40 into thekeyhole28, and prevents the retainingarms28c,28dfrom removing or displacing portions of thefusible member40 that could build up at thetail portion22 or more specifically, at the two retainingarms28c,28d.
• FIG. 2B shows a side view of the contact orterminal20 ofFIG. 2A with afusible member40 being affixed thereto as will be described in more detail below. As seen inFIG. 2B, the lower portion of thesupport portions40a,40bextend down well below the bottom tip of thetail portion22 of the contact orterminal20.
• In preferred embodiments of the present invention, the distance between the bottom tip of thetail portion22 and the bottom surface of thesupport portions40a,40bis preferably in the range of about 0.004 to about 0.014 inches. This distance between the bottom tip of thetail portion22 and the bottom surface of thesupport portions40a,40ballows for the unique drop-down function of thefusible members40 and contacts orterminals20. The assembly shown inFIG. 2B is before a reflow process is performed during which thefusible member40 melts. Thus, when the assembly shown inFIG. 2B is placed on a substrate, such as a PCB, before reflow, thesupport portions40aand40brest on the substrate and the bottom tip of thetail portion22 is spaced from the substrate by about 0.004 to about 0.014 inches. During the reflow process, the fusible material fromsupport portions40a,40bwicks up thetail portion22 of the contact or terminal20 toward thesolder stop portion23. When this happens, the portion of thesupport portions40a,40bthat previously hung below the bottom tip of thetail portion22 moves up thetail portion22 such that there is no longer any portion of thefusible member40 that hangs down below the bottom tip of thetail portion22. As a result, each contact or terminal20 and theentire connector10 is able to drop down such that the bottom tip of thetail portion22 is located very close to the substrate and is reliably attached to the substrate. This will be described in more detail later.
• A preferred process for manufacturing and assembling the contacts orterminals20 having the unique fusible member bearingtail portions22 will now be described with reference toFIGS. 3-4H.
• As seen inFIG. 3, a plurality of contacts orterminals20 can be formed simultaneously and can be mass produced by stamping the contacts orterminals20 from a suitable material such as any copper alloy. The contacts orterminals20 are preferably held on acarrier strip30 for ease of assembling thefusible members40 to the contacts orterminals20. Thecarrier strip30 includes contact-holdingmembers36 arranged such that there is a space oropening34 between thecarrier strip30 and the contacts orterminals20. In addition, thecarrier strip30 includes a plurality ofholes32 which are used to position, hold and feed thecarrier strip30.
• As seen inFIG. 4A, thecarrier strip30 including a plurality of contacts orterminals20 is held in position such that afusible member40, in this case, preferably asolder wire49 for forming thefusible members40, can be moved into theopening34 to a location just below thekey hole28 of the contacts orterminals20. As seen inFIG. 4A, thesolder wire49 is inserted into theopening34 formed between thecarrier strip30 and the contacts orterminals20 so that thesolder wire49 can be inserted into thekey hole28. The insertion of thesolder wire49 into thekey hole28 preferably involves a press-fitting operation.
• As seen inFIG. 4B, thesolder wire49 is moved upwardly into thekey hole28 such that thesolder wire49 for forming thefusible member40 is press fit and held in thekey hole28 by the retainingarms28cand28d. It is not necessary bend or crimp the retainingarms28c,28dtoward each other to hold thefusible member40 because the dimensions of thekey hole28 allow for press-fitting of thefusible member40 into thearc portions28a,28bof thekey hole28 at thetail portion22. As can be seen inFIG. 4C, thesolder wire49 does not initially completely fill thearc portions28aand28b.
• As seen inFIG. 4D, the opposite ends of thesolder wire49 held in thetail portion22 of the contact or terminal20 are simultaneously pressed toward each other by a press or ram80 and asupport82, such that the two oppositely disposedsupport portions40a,40bare formed. Theram80 has a cut-outportion84 which corresponds to a desired shape of thesupport portions40a,40b. Thecarrier strip30 is held by apositioning pin86 for accurate positioning of the contact or terminal20 within thepress80. This is shown in more detail inFIG. 4E. The shape of thesupport portions40a,40bcan be changed as desired by changing the shape and configuration of the cut-outportion84 of theram80. Theintermediate portion40cof thefusible member40 between the twosupport portions40a,40bis held in thearc portions28a,28bof thetail portion22 during the pressing of the two opposite ends of thefusible member40. As a result of the forces applied by the press or ram80 and thesupport82 to form the twosupport portions40a,40b, theintermediate portion40cis distorted so as to fill thearc portions28a,28bof thetail portion22 as shown inFIG. 4F. This ensures that thefusible member40 is reliably held in thetail portion22 of the contact orterminal20.
• It is important to note inFIG. 4E that the pressing of thefusible member40 in the press or ram80 allows for highly precise control of the amounts of thesupport portions40a,40bthat hang down below the bottom tip of thetail portions22 of the contacts orterminals20. As seen inFIG. 4E, thesupport portions40a,40bare pressed against the cut-outportion84 such that the amount of thefusible member40 extending down below the bottom tip of thetail portion22 is precisely determined and formed, thereby enabling uniform assemblies offusible members40 attached to contacts orterminals20 to be formed. As a result, when aconnector10, which includes such unique assemblies of contacts orterminals20 havingfusible members40 attached thereto, is reflowed to aPCB60, much greater co-planarity is achieved.
• FIGS. 4G and 4H show the completion of the process for mounting thefusible member40 in the contact orterminal20. As seen in the detail ofFIG. 4G, the resultingfusible member40 is arranged in the contact or terminal20 such that the twosupport portions40a,40bextend well below the bottom tip or end of thetail portion22. This is very important for allowing for greatly increased co-planarity and ensuring a reliable reflow process when theconnector10 is joined to a substrate such as a PCB.
• As is seen in the detail ofFIG. 4F, the resultantfusible member40 has a unique shape and configuration. Theintermediate portion40chas a shape that substantially corresponds to the shape of thekey hole28. That is, theintermediate portion40cincludes a horizontally extendingarc portion40c1, two vertically extendingarc portions40c2,40c3, and substantiallyrectangular end portion40c4. The unique shape andvarious portions40c1,40c2,40c3 included in theintermediate portion40creliably holds thefusible member40 in thetail portion22 of the contact orterminal20.
• In addition, as seen inFIGS. 1A and 4E, the use of theram80 produces the unique shape of thesupport portions40a,40b. As noted above, in one preferred embodiment, thesupport portions40a,40bpreferably include a substantially flattened portion on the bottom surface thereof. However, other shapes of the bottom surfaces may also be used for the bottom surfaces of thesupport portions40a,40b. The unique shape of theintermediate portion40cis important for reliably holding thefusible member40 in thetail portion22 of the contact or terminal20, and allows for easy assembly of thefusible member40 to the contact orterminal20.
• The unique configuration of the twosupport portions40a,40bincluding the lower portions hanging down from theintermediate portion40cin relation to the bottom tips of thetail portions22 of the contact orterminals20 is very important for allowing the connector to drop down, due to gravity, during the reflow process, which allows for much higher than normal coplanarity and a much more effective reflow process because all of the contacts orterminals20 are successfully and reliably reflowed and electrically connected torespective pads62, as will be described below. This unique drop down action is not possible with conventional connectors described above.
• It is preferred that the distance between the bottom tip of thetail portion22 and the bottom surface of thesupport portions40a,40bis in the range of about 0.004 to about 0.014 inches. The reason this range is selected is as follows.
• When assembling thefusible member40 on the contact or terminal20, it is necessary to ensure that thefusible member40 is reliably held on the contact or terminal20 until the reflow process is performed. During assembly of thefusible member40 to the contact or terminal20, one of the goals is to fillkey hole28, and especially thekey hole portion28b(IS THIS RIGHT?) with the fusible material of thefusible member40, in order to prevent the fusible member from falling off of thetail portion22 of the contact orterminal20. If the amount of thefusible member40 hanging down below the bottom tip of thetail portion22 is greater than about 0.014 inches, it may not be possible to place thefusible member40 far enough into thekey hole28 to allow thekey hole28 to reliably hold the fusible member and thefusible member40 may fall off of the contact orterminal20. If the amount of thefusible member40 hanging down below the bottom tip of thetail portion22 is less than about 0.004 inches, the contacts orterminals20 and theentire connector10 may not experience an adequate amount of drop, as described above, which could result in a lack of connection between a contact or terminal20 and a conductive pad or element on a substrate.
• Once the unique construction of the contacts orterminals20 including thefusible members40 affixed thereto is completed as described above, the contacts orterminals20 are inserted and preferably press-fit into cores of theconnector body12 to complete theconnector10. Instead of being press fit in theconnector body12 as described above, the pins can also be insert-molded.
• In this manner, thefusible members40 are easily and securely press-fit and pressed to the contacts orterminals20 instead of being attached by reflowing a solder ball or other solder member thereto as in conventional methods, and then the contacts orterminals20 are easily inserted into theconnector body12. As a result, thetail portions22 of the contacts orterminals20 may be tin-plated, if desired, which eliminates or minimizes the gold embrittlement problems of the prior art.
• FIGS. 5A, 5B,6A, and6B show how theconnector10 having the contacts orterminals20 with the attachedfusible members40 described above is mounted to a substrate such as a PCB.FIGS. 5A and 5B show theconnector10 placed on thePCB60 before a reflow process is performed to join theconnector10 to thePCB60. As can be seen inFIGS. 5A and 5B, theconnector10 is placed on thePCB60 such that the twosupport portions40a,40bof each contact or terminal20 are placed on arespective pad62 of thePCB60. Flux or solder paste (not shown) may be applied on thepads62 prior to reflow for improving the connection between the contact or terminal20 and thePCB60.
• Agap64 exists between theconnector body12 and thePCB60. The unique structure of thefusible members40 allow for two different areas of contact and connection for securing eachfusible member40 to eachpad62 as seen inFIG. 5A. More specifically, the twosupport portions40a,40bare located on two different, spaced portions of arespective pad62. This increases the area of contact between thefusible member40 and thepad62, and enables each contact or terminal20 to be reliably and securely connected, both mechanically and electrically, to therespective pad62. Thus, by increasing the area of contact between thefusible member40 and thepad62, a stronger solder joint is ensured.
• When theconnector10 is placed on thePCB60 before the reflow process as shown inFIG. 5A, thesupport members40a,40ballow the fusible members to rest on thePCB60. Because thefusible members40 are reliably connected to the contacts orterminals20 via press-fitting and pressing to form thesupport members40a,40band theintermediate portion40cas described above, a reflow step for connecting thefusible members40 to the contacts orterminals20 is not required, as is conventionally necessary with BGA connectors. In addition, because the lower portions offusible members40 hang down well below the tip of thetail portion22 of the contacts orterminals20, a large portion of the contact or terminal20 extends outside of theconnector housing12 which increases the ability of the contacts orterminals20 to flex and endure thermal cycling and other forces applied to theconnector10 without experiencing any problems. Thus, the area of the solder joint formed between the contacts orterminals20 and thePCB pads62 via thefusible members40 is much greater and has a greater ability to flex and withstand forces applied thereto. In addition, because the contacts orterminals20 are formed by stamping and thefusible member40 is force-fit and compressed to be joined to the contact or terminal20, the contacts orterminals20 having thefusible members40 joined thereto can be formed much more easily and accurately. As a result, when the contacts orterminals20 with thefusible members40 are inserted into theconnector body12, the distance from theconnector body12 to the tips of thetail portions22 of thefusible members40 is uniform for all of the contacts orterminals20 which allows for the higher coplanarity achieved by preferred embodiments of the present invention.
• FIGS. 6A and 6B show theconnector10 andPCB60 after a reflow process has been performed. During the reflow process, thesupport portions40a,40bandintermediate portion40cmelt. The fusible material from theintermediate portion40ccompletely fills any remaining small voids in thekey hole28 of thetail portion22 thereby reinforcing the mounting of thefusible member40 to the contact or terminal20 and thereby increasing the strength of the resulting solder joint. The fusible material of the twosupport portions40a,40blocated below theintermediate portion40cwicks upward along thetail portion22 of thecontact20 allowing the twosupport members40a,40bto be secured directly on thePCB pads62. During the reflow process, because of thefusible members40 being press-fit to thetail portions22 of the contact orterminals20 and thefusible members40a,40bextending below thetail portions22, theconnector10 and contacts orterminals20 drop down such that the contacts orterminals20 are located much closer to thePCB pads62.
• As can be seen inFIG. 6B, all of the terminals orterminals20 are reliably connected to thepads62 of thePCB60 via the solder joints formed by the twosupport portions40a,40bof thefusible member40 because of the increased effectiveness of the reflow process due to the unique configuration of the contacts orterminals20 andfusible members40.
• FIGS. 7A and 7B show views of a conventional connector prior to the reflow process inFIG. 7A and after the reflow process inFIG. 7B. As seen inFIG. 7A, theconnector body12 has bowed or flexed such that many of the contacts orterminals20 are spaced from thepads62 on thePCB60. This bowing or flexing of theconnector10 can be caused by (1) bowing or flexing that may occur during molding of theconnector body12; (2) stress being relieved during either or both of the two separate reflow steps required with the prior art connector; (3) stress applied when press-fitting the contacts into the housing; and (4) manufacturing tolerances. As seen inFIG. 7A, when theconnector body12 is bowed or flexed, many of the contacts orterminals20 are unevenly spaced from thePCB60 before the reflow step.
• Even after reflow has been performed, as seen inFIG. 7B, many of the contacts orterminals20 are spaced a distance S frompads62 on thePCB60 such that many of the contacts orterminals20 are not connected to thepads62 on thePCB60. Thus, the co-planarity and electrical connections provided by the solder joint are very poor in the connector shown inFIGS. 7A and 7B.
• FIGS. 8A and 8B are similar figures toFIGS. 7A and 7B, but show how a preferred embodiment of the present invention is connected to aPCB60 and overcomes the problems with the connector shown inFIGS. 7A and 7B. As seen inFIG. 8A, theconnector body12 has bowed and distorted prior to reflow (FIG. 8A) in a manner similar to the conventional connector shown inFIG. 7A. Despite the presence of a bowed or flexedconnector body12, after the reflow process has been performed inFIG. 8B, each of the contacts orterminals20 are reliably connected topads62 on thePCB60 after reflow despite the bowing and flexing of theconnector body12.
• As seen by comparing the results shown inFIGS. 7B and 8B, theconnector10 according to preferred embodiments of the higher co-planarity and a much more reliable reflow process, and eliminates the problems with contacts orterminals20 not being connected to the respective conductive elements on thesubstrate60.
• Although theconnector10 shown inFIGS. 1-6B is preferably a board-to-board mezzanine type connector, the present invention is not limited thereto.
• The present invention can also be applied to other types of connectors including a single-endedarray connector10′ or differentialpair array connector10′ shown inFIG. 9, anedge card wafer10″ for use in a backplane connector as shown inFIG. 10, or asocket connector10′″ for use with an IC chip such as a microprocessor chip (e.g., a Pentium® socket connector) shown inFIGS. 11aand11b.
• It is possible to use standoffs, for example,element90 shown inFIG. 9, to maintain desired spacing between the connector and PCB. Another advantage of using thestandoff90 is the standoff reduces the stress applied at the solder joint between thecontacts20 and thepads62 on thePCB60.
• According to preferred embodiments of the present invention, the unique fusible member bearing contacts provided in the connector provide many advantages not achieved by conventional devices and overcome many problems not solved or recognized by the prior art.
• The connector having the unique fusible member bearing contacts allows for greater co-planarity and a more reliable reflow process. Also, the manufacturing process of the connector according to preferred embodiments of the present invention is much easier, cheaper and reliable since no special equipment is required, a reflow step is eliminated, the contact or terminal does not require a right-angle portion at the tail to hold the fusible member, and the connector housing does not require special features in the connector body for locating and holding solder balls.
• Furthermore, the method of attaching the fusible members to the contacts or terminals via the intermediate portion fitting in the unique key hole of the tail portions of the contacts or terminals and the unique construction of the two spaced opposed support portions being seated on a conductive pad or other attachment member, increases the strength of the solder joint, allows the contacts or terminals to be located much closer to the board or substrate upon which the connector is mounted, and allows the contacts or terminals to absorb more stress and flex more to avoid problems experienced by conventional connectors since the contacts or terminals are not rigidly held in the insulating body of the connector and are largely exposed from the insulating body.
• As a result, the overall height of the connector according to preferred embodiments of the present invention is more controllable and even allows for flattening of the field of contacts with a flat rigid surface, if desired, which is not possible with BGA connectors without compromising the solder joint. Furthermore, the plastic or insulating connector body can be spaced farther from the solder joint which allows for better air flow below the connector. In addition, the problems with gold embrittlement, solder wicking and solder joint weakness are eliminated or reduced in the connector according to preferred embodiments of the present invention.
• It should be noted that the preferred method of attaching the fusible members to the tails of the contacts or terminals has been described above. However, it is possible within the present invention to use alternative methods of attaching the fusible members to the contacts. In addition, the form, shape and arrangement of the support members can be changed as desired.
• It should be understood that the foregoing description is only illustrative of the present invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the present invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims.

Claims (114)

1. (canceled)

2. The electrical connector according toclaim 4, wherein each of the two support members extends below the tail portion of the contact by a distance of about 0.004 inches to 0.014 inches.

3. The electrical connector according toclaim 4, wherein an outer periphery of each of the two support members is greater than an outer periphery of the tail portion of the contact.

4. An electrical connector comprising:

a connector body;

a plurality of contacts arranged in the connector body, each of the plurality of contacts having a tail portion with a fusible member attached thereto; wherein

each of the fusible members includes an intermediate portion and two support members disposed on opposite sides of the intermediate portion, and the two support members extend below the tail portion of the contact; wherein

the two support members are arranged to wick up the tail portion of the contact in a direction toward the connector body during a reflow process.

5. An electrical connector comprising:

a connector body;

a plurality of contacts arranged in the connector body, each of the plurality of contacts having a tail portion with a fusible member attached thereto; wherein

each of the fusible members includes an intermediate portion and two support members disposed on opposite sides of the intermediate portion, and the two support members extend below the tail portion of the contact; wherein

the tail portion includes a key hole defined by a first horizontally extending arc and two vertically extending arcs.

6. The electrical connector according toclaim 5, wherein the intermediate portion is fitted within the key hole.

7. The electrical connector according toclaim 5, wherein the intermediate portion fills the keyhole defined by the first horizontally extending arc and the two vertically extending arcs.

8. An electrical connector comprising:

a connector body;

a plurality of contacts arranged in the connector body, each of the plurality of contacts having a tail portion with a fusible member attached thereto; wherein

each of the fusible members includes an intermediate portion and two support members disposed on opposite sides of the intermediate portion, and the two support members extend below the tail portion of the contact; wherein

the contacts include a solder stop portion located at a medial portion thereof.

9. The electrical connector according toclaim 4, wherein each of the two support members has one of a substantially flat bottom surface, a substantially rounded bottom surface, a substantially spherical bottom surface, a substantially conical bottom surface, a substantially rectangular bottom surface and a substantially square bottom surface.

10. The electrical connector according toclaim 4, wherein the tail portions of the contacts are substantially straight and do not include a right angle portion.

11. The electrical connector according toclaim 4, wherein the contacts include wings for engaging a core of the connector body to maintain a uniform distance between the tail portion of the contacts and the connector body.

12. The electrical connector according toclaim 4 wherein the contacts include wedges for engaging a side wall of a core of the connector body in order to fix the contact in the connector body.

13. The electrical connector according toclaim 4, wherein the contacts include lead-in portions having coined edges arranged to position the contacts in the connector body.

14. The electrical connector according toclaim 4, wherein the contacts include bumps for positioning the contacts within the connector body.

15. The electrical connector according toclaim 4, wherein the electrical connector is a board-to-board mezzanine connector.

16. The electrical connector according toclaim 4, wherein the electrical connector is a differential pair array connector.

17. The electrical connector according toclaim 4, wherein the electrical connector is a single ended array connector.

18. The electrical connector according toclaim 4, wherein the electrical connector is an edge card wafer for use with a backplane connector.

19. The electrical connector according toclaim 4, wherein the electrical connector is an IC chip socket.

20. The electrical connector according toclaim 4, wherein the intermediate portion and the two support members are integral and unitary.

21. The electrical connector according toclaim 4, wherein the support members are located on opposite sides of the tail portion of the contact.

22. The electrical connector according toclaim 4, wherein each of the two support members extends from the intermediate portion and are larger than the intermediate portion.

23. (canceled)

24. The electrical connector according toclaim 26, wherein each of the two support members extends below the tail portion of the contact by a distance of about 0.004 inches to 0.014 inches.

25. The electrical connector according toclaim 26, wherein an outer periphery of each of the two support members is greater than an outer periphery of the tail portion of the contact.

26. An electrical connector comprising:

a connector body;

a plurality of contacts arranged in the connector body and including fusible members attached to one end of the contacts; wherein

each of the fusible members includes two support members spaced from each other and extending below a tail portion of the respective contact; wherein

the two support members are arranged to wick up the tail portion of the contact in a direction toward the connector body during a reflow process.

27. The electrical connector according toclaim 26, wherein the two support members have substantially the same size and shape.

28. The electrical connector according toclaim 26, wherein the two support members have a substantially rounded shape with a substantially flattened bottom surface.

29. The electrical connector according toclaim 26, wherein the fusible member includes an intermediate portion located between the two support members.

30. An electrical connector comprising:

a connector body;

a plurality of contacts arranged in the connector body and including fusible members attached to one end of the contacts; wherein

each of the fusible members includes two support members spaced from each other and extending below a tail portion of the respective contact; wherein

the one end of the contacts includes a key hole defined by a first horizontally extending arc and two vertically extending arcs.

31. The electrical connector according toclaim 30, wherein a portion of the fusible member is fitted within the key hole.

32. The electrical connector according toclaim 30, wherein the fusible member includes an intermediate portion located between the two support members, and the intermediate portion fills the first horizontally extending arc and the two vertically extending arcs.

33. An electrical connector comprising:

a connector body;

a plurality of contacts arranged in the connector body and including fusible members attached to one end of the contacts; wherein

each of the fusible members includes two support members spaced from each other and extending below a tail portion of the respective contact; wherein

the contacts include a solder stop portion located at a medial portion thereof.

34. The electrical connector according toclaim 26, wherein the two support members extend below the one end of the contact.

35. The electrical connector according toclaim 26, wherein each of the two support members has one of a substantially flat bottom surface, a substantially rounded bottom surface, a substantially spherical bottom surface, a substantially conical bottom surface, a substantially rectangular bottom surface and a substantially square bottom surface.

36. The electrical connector according toclaim 26, wherein the one end of the contact is substantially straight and does not include a right angle portion.

37. The electrical connector according toclaim 26, wherein the contacts include wings for engaging a core of the connector body to maintain a uniform distance between the one end of the contacts and the connector body.

38. The electrical connector according toclaim 26, wherein the contacts include wedges for engaging a side wall of a core of the connector body in order to fix the contact in the connector body.

39. The electrical connector according toclaim 26, wherein the contacts include lead-in portions having coined edges arranged to position the contacts in the connector body.

40. The electrical connector according toclaim 26, wherein the contacts include bumps for positioning the contacts within the connector body.

41. The electrical connector according toclaim 26, wherein the electrical connector is a board-to-board mezzanine connector.

42. The electrical connector according toclaim 26, wherein the electrical connector is a differential pair array connector.

43. The electrical connector according toclaim 26, wherein the electrical connector is a single ended array connector.

44. The electrical connector according toclaim 26, wherein the electrical connector is an edge card wafer for use with a backplane connector.

45. The electrical connector according toclaim 26, wherein the electrical connector is an IC chip connector.

46. The electrical connector according toclaim 26, wherein the two members are disposed on opposite sides of the contact.

47. The electrical connector according toclaim 5, wherein each of the two support members extends below the tail portion of the contact by a distance of about 0.004 inches to 0.014 inches.

48. The electrical connector according toclaim 5, wherein an outer periphery of each of the two support members is greater than an outer periphery of the tail portion of the contact.

49. The electrical connector according toclaim 5, wherein each of the two support members has one of a substantially flat bottom surface, a substantially rounded bottom surface, a substantially spherical bottom surface, a substantially conical bottom surface, a substantially rectangular bottom surface and a substantially square bottom surface.

50. The electrical connector according toclaim 5, wherein the tail portions of the contacts are substantially straight and do not include a right angle portion.

51. The electrical connector according toclaim 5, wherein the contacts include wings for engaging a core of the connector body to maintain a uniform distance between the tail portion of the contacts and the connector body.

52. The electrical connector according toclaim 5, wherein the contacts include wedges for engaging a side wall of a core of the connector body in order to fix the contact in the connector body.

53. The electrical connector according toclaim 5, wherein the contacts include lead-in portions having coined edges arranged to position the contacts in the connector body.

54. The electrical connector according toclaim 5, wherein the contacts include bumps for positioning the contacts within the connector body.

55. The electrical connector according toclaim 5, wherein the electrical connector is a board-to-board mezzanine connector.

56. The electrical connector according toclaim 5, wherein the electrical connector is a differential pair array connector.

57. The electrical connector according toclaim 5, wherein the electrical connector is a single ended array connector.

58. The electrical connector according toclaim 5, wherein the electrical connector is an edge card wafer for use with a backplane connector.

59. The electrical connector according toclaim 5, wherein the electrical connector is an IC chip socket.

60. The electrical connector according toclaim 5, wherein the intermediate portion and the two support members are integral and unitary.

61. The electrical connector according toclaim 5, wherein the support members are located on opposite sides of the tail portion of the contact.

62. The electrical connector according toclaim 5, wherein each of the two support members extends from the intermediate portion and are larger than the intermediate portion.

63. The electrical connector according toclaim 8, wherein each of the two support members extends below the tail portion of the contact by a distance of about 0.004 inches to 0.014 inches.

64. The electrical connector according toclaim 8, wherein an outer periphery of each of the two support members is greater than an outer periphery of the tail portion of the contact.

65. The electrical connector according toclaim 8, wherein each of the two support members has one of a substantially flat bottom surface, a substantially rounded bottom surface, a substantially spherical bottom surface, a substantially conical bottom surface, a substantially rectangular bottom surface and a substantially square bottom surface.

66. The electrical connector according toclaim 8, wherein the tail portions of the contacts are substantially straight and do not include a right angle portion.

67. The electrical connector according toclaim 8, wherein the contacts include wings for engaging a core of the connector body to maintain a uniform distance between the tail portion of the contacts and the connector body.

68. The electrical connector according toclaim 8, wherein the contacts include wedges for engaging a side wall of a core of the connector body in order to fix the contact in the connector body.

69. The electrical connector according toclaim 8, wherein the contacts include lead-in portions having coined edges arranged to position the contacts in the connector body.

70. The electrical connector according toclaim 8, wherein the contacts include bumps for positioning the contacts within the connector body.

71. The electrical connector according toclaim 8, wherein the electrical connector is a board-to-board mezzanine connector.

72. The electrical connector according toclaim 8, wherein the electrical connector is a differential pair array connector.

73. The electrical connector according toclaim 8, wherein the electrical connector is a single ended array connector.

74. The electrical connector according toclaim 8, wherein the electrical connector is an edge card wafer for use with a backplane connector.

75. The electrical connector according toclaim 8, wherein the electrical connector is an IC chip socket.

76. The electrical connector according toclaim 8, wherein the intermediate portion and the two support members are integral and unitary.

77. The electrical connector according toclaim 8, wherein the support members are located on opposite sides of the tail portion of the contact.

78. The electrical connector according toclaim 8, wherein each of the two support members extends from the intermediate portion and are larger than the intermediate portion.

79. The electrical connector according toclaim 30, wherein each of the two support members extends below the tail portion of the contact by a distance of about 0.004 inches to 0.014 inches.

80. The electrical connector according toclaim 30, wherein an outer periphery of each of the two support members is greater than an outer periphery of the tail portion of the contact.

81. The electrical connector according toclaim 30, wherein the two support members have substantially the same size and shape.

82. The electrical connector according toclaim 30, wherein the two support members have a substantially rounded shape with a substantially flattened bottom surface.

83. The electrical connector according toclaim 30, wherein the fusible member includes an intermediate portion located between the two support members.

84. The electrical connector according toclaim 30, wherein the two members extend below the one end of the contact.

85. The electrical connector according toclaim 30, wherein each of the two support members has one of a substantially flat bottom surface, a substantially rounded bottom surface, a substantially spherical bottom surface, a substantially conical bottom surface, a substantially rectangular bottom surface and a substantially square bottom surface.

86. The electrical connector according toclaim 30, wherein the one end of the contact is substantially straight and does not include a right angle portion.

87. The electrical connector according toclaim 30, wherein the contacts include wings for engaging a core of the connector body to maintain a uniform distance between the one end of the contacts and the connector body.

88. The electrical connector according toclaim 30, wherein the contacts include wedges for engaging a side wall of a core of the connector body in order to fix the contact in the connector body.

89. The electrical connector according toclaim 30, wherein the contacts include lead-in portions having coined edges arranged to position the contacts in the connector body.

90. The electrical connector according toclaim 30, wherein the contacts include bumps for positioning the contacts within the connector body.

91. The electrical connector according toclaim 30, wherein the electrical connector is a board-to-board mezzanine connector.

92. The electrical connector according toclaim 30, wherein the electrical connector is a differential pair array connector.

93. The electrical connector according toclaim 30, wherein the electrical connector is a single ended array connector.

94. The electrical connector according toclaim 30, wherein the electrical connector is an edge card wafer for use with a backplane connector.

95. The electrical connector according toclaim 30, wherein the electrical connector is an IC chip connector.

96. The electrical connector according toclaim 30, wherein the two support members are disposed on opposite sides of the contact.

97. The electrical connector according toclaim 33, wherein each of the two support members extends below the tail portion of the contact by a distance of about 0.004 inches to 0.014 inches.

98. The electrical connector according toclaim 33, wherein an outer periphery of each of the two support members is greater than an outer periphery of the tail portion of the contact.

99. The electrical connector according toclaim 33, wherein the two support members have substantially the same size and shape.

100. The electrical connector according toclaim 33, wherein the two support members have a substantially rounded shape with a substantially flattened bottom surface.

101. The electrical connector according toclaim 33, wherein the fusible member includes an intermediate portion located between the two support members.

102. The electrical connector according toclaim 33, wherein the two support members extend below the one end of the contact.

103. The electrical connector according toclaim 33, wherein each of the two support members has one of a substantially flat bottom surface, a substantially rounded bottom surface, a substantially spherical bottom surface, a substantially conical bottom surface, a substantially rectangular bottom surface and a substantially square bottom surface.

104. The electrical connector according toclaim 33, wherein the one end of the contact is substantially straight and does not include a right angle portion.

105. The electrical connector according toclaim 33, wherein the contacts include wings for engaging a core of the connector body to maintain a uniform distance between the one end of the contacts and the connector body.

106. The electrical connector according toclaim 33, wherein the contacts include wedges for engaging a side wall of a core of the connector body in order to fix the contact in the connector body.

107. The electrical connector according toclaim 33, wherein the contacts include lead-in portions having coined edges arranged to position the contacts in the connector body.

108. The electrical connector according toclaim 33, wherein the contacts include bumps for positioning the contacts within the connector body.

109. The electrical connector according toclaim 33, wherein the electrical connector is a board-to-board mezzanine connector.

110. The electrical connector according toclaim 33, wherein the electrical connector is a differential pair array connector.

111. The electrical connector according toclaim 33, wherein the electrical connector is a single ended array connector.

112. The electrical connector according toclaim 33, wherein the electrical connector is an edge card wafer for use with a backplane connector.

113. The electrical connector according toclaim 33, wherein the electrical connector is an IC chip connector.

114. The electrical connector according toclaim 33, wherein the two support members are disposed on opposite sides of the contact.

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