Description:
This invention relates to a jumper for interconnecting electrical components such as dual-in-line sockets which are mounted on an integrated circuit board and, more particularly, to a jumper comprised of the combination of a flat multi-conductor cable terminated at opposite ends, or alternatively, at opposite ends and intermediate the ends thereof, with connecters adapted to be accommodated in standard dual-in-line sockets used in integrated circuit panel boards.
Miniaturized circuits are employed on an ever-increasing scale in complex electronic equipment. The practices in the technology have evolved such that it is now common practice to use what have become known as integrated circuits, or physically small units containing an entire circuit (rather than a single electric element), and to mount these integrated circuit packs or units to printed circuit boards and the like. It was early practice to mount the electrical contacts or terminals of these integrated circuits directly to points on the integrated circuit board. In other cases, the electronic circuit packs were mounted directly to a dielectric board, with the terminals extending through the board for connection to conductors by wire wrapping or soldering.
Through a gradual evolutionary use of these techniques, it is now more common and desirable to mount electronic integrated circuit packs to a terminal board or printed circuit board for easy removal and exchanging of individual units. Accordingly, sockets are now often provided for receiving the pins (contacts) of the integrated circuit pack. These sockets generally include a dielectric housing supporting electrical contacts for receiving the pins of the integrated circuit, the contacts having long pins, or posts, extending from the lower part of the housing for insertion through holes in the integrated or printed circuit board. Furthermore, the sockets are configured to include generally two rows of electrical contacts, whereby the term dual-in-line sockets is derived. When the socket is mounted in place on the integrated circuit board, the terminal posts extend to the back side of the printed circuit board, providing terminal posts for receiving wrapped wires or other common type of conductor connections for joining the integrated circuit to other components on the same or other circuit boards.
During the assembly of an integrated circuit board, and more particularly, during the assembly of the integrated circuit packs into the various dual-in-line sockets provided on an integrated circuit board, it is often desirable to interconnect two sockets with common electrical leads in order to test the sub-assembly. For this purpose, it is common practice to provide a jumper cable, commonly referred to as merely a jumper, which is terminated at its opposite ends with connecters adapted to be received within the dual-in-line sockets mounted on the integrated circuit board.
Heretofore, a common jumper employed in the industry consist of a plurality of wires extending between connecters having a plurality of terminals corresponding to the dual-in-line contacts of the sockets provided on the integrated circuit board. The individual wires are individually terminated to the terminals of the connecters, with the resulting assembly being extremely bulky and expensive to manufacture. With respect to the bulkiness of the resulting connecters, it must constantly be borne in mind that the jumper is to be employed with miniaturized circuitry, and accordingly miniaturization of all the components for use in the assembly is of utmost importance.
Along these lines, it is noted that there are several attributes considered desirable in a jumper for interconnecting the dual-in-line sockets, including miniaturization of the jumper, flexibility of the interconnecting leads or cable of the jumper to enable ease of assembly, reliability, and low cost. It is an object of the present invention to provide all of the attributes in a single jumper and, to this end, to overcome the failure of the prior art devices to satisfy one or more of these requirements.
SUMMARY OF THE INVENTION
In general, these and other objects of the invention are met by a jumper including a flat multi-conductor cable terminated at opposite ends with connecters, each including a base having a plurality of channels through which extend terminals that provide posts for interconnection to the sockets, and an integral contact portion extending partially along the upper surface of the base. The conductors of the flat multi-conductor cable are electrically and mechanically connected to the integral contact portions of the terminals, after which the upper cover structure of the connecter is bonded to said base to encase the electrical connections between the cable and terminals, and in addition, provide a strain relief for said electrical connections.
The use of a flat multi-conductor cable ensures flexibility of the jumper, and in addition, provides the required miniaturization for use in integrated circuit boards. In addition, each terminal of the connecters is in the form of an L-shaped member, one leg of which extend through the base and forms the terminal post, while the upper leg or integral contact portion is suitably configured so as to extend along the upper surface of the base in electrical isolation from adjacent terminals, with the resulting arrangement of the integral contact portions corresponding to the pitch or spacing between conductors of the multi-conductor cable, thereby enabling the multi-conductor cable to be bonded to the contact portions of the terminals using conventional mass bonding techniques, thereby significantly decreasing the cost of manufacture of the subject jumper. Another feature of the subject device is the provision of ribs on the upper portion of the base to further compartmentalize or electrically isolate the integral contact portions of the terminals from one another, thereby assuring electrical reliability of the connecter and the jumper.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention, together with the further objects and advantages thereof, the following detailed description of a preferred embodiment and the drawings may be referred to, in which:
FIG. 1 is a perspective view of several jumpers according to the invention, together with a representative integrated circuit board of the type with which the invention may be used;
FIG. 2 is an exploded perspective view of one end of the jumper of the subject invention, and illustrating a flat multi-conductor cable and the connecter for use therewith;
FIG. 3 is a plan view of a stamped strip of metal from which the terminals of the connecter of the subject invention are made;
FIG. 4 is a partial sectional view in plan form of one end of the jumper of the subject invention;
FIG. 5 is a view taken along the lines 5--5 in FIG. 4; and
FIG. 6 is a sectional view taken along lines 6--6 in FIG. 4.
DESCRIPTION OF PREFERRED EMBODIMENT
FIG. 1 illustrates the manner in which the jumper of the subject invention may be employed for interconnecting dual-in-line sockets of an integrated circuit board. Dual-in-line sockets 10 include posts 11 which extend through uniformly spaced holes in integrated circuit board 12 and protrude from the underside of the integrated circuit board 12 in order to provide a terminal connection for conductors and the like. In this matter, all conductor wiring (printed or otherwise) is made at the underside of the integrated circuit board 12. The sockets 10 are adapted to accommodate electronic integrated circuit components, such as the small rectangular integrated circuit packs 15, with the pins (not shown) of the integrated circuit packs 15 being fitted into receptacles in the intermediate sockets 10 thereby establishing electrical connection between the units 15 and the associated posts 12.
Several jumpers 20 made according to the teaching of the subject invention are illustrated in FIG. 1 as interconnecting a plurality of sockets 10 mounted on the integrated circuit board 12. Each jumper 20 includes flat multi-conductor cable 21 terminated at its opposite ends by connectors 22. If desired, an intermediate connecter 22 may be provided in a jumper 20 in order to establish a common connection between 3 sockets 10. Of course, additional connecters may also be provided intermediate the length of the flat multi-conductor cable 21 to interconnecting even a greater number of sockets 10. The jumper 20 shown in FIG. 1, which is the subject of the invention, will now be described in more detail.
FIG. 2 illustrates one end of the jumper 20 of the subject invention in exploded perspective view. The opposite end of the jumper 20 is of similar construction, and includes flat multi-conductor cable 21 consisting of a plurality of generally parallel conductors 41 embedded in a strip of insulating material, such as plastic polyethylene material. The conductors 41 may be round, or as shown, flat or rectangular in cross-section, with the lateral spacing between the conductors 41 being designated as the pitch p of the cable. In order to connect the cable 21 to the connecter 22 of the jumper 20, the insulation is stripped from the end of the cable thereby exposing conductors 41 which are then pre-tinned, for purposes to be more fully described hereinafter.
The connecter 22 generally comprises housing including base 50 and upper cover structure 52 and terminals 51. Base 50 is generally rectangular in configuration, and is made of a dielectric material such as glass filled nylon, and includes two upstanding walls or shoulders 61, each of which is provided with an alignment aperture, as at 62. The shoulders or supporting walls 61 of the base 50 extend up to an amount so as to properly locate the upper cover structure 52. More particularly, shoulders 61 provide sufficient clearance between the cover structure 52 and the upper surface of the base 50 in order to lightly grip the cable 40 thereby providing in effect a strain release against the pulling of the cable 21 from the connecter 22. Furthermore, shoulders 61 precisely locate the cable 21 in the base 50.
Base 50 also include a plurality of channels 63 arranged in two rows corresponding to the contacts in the dual-in-line sockets 10, with each channel 63 being specifically configured in a funnel-shape to accommodate the similarly configured terminals 51. FIG. 5 illustrates the configuration of the funnel-shaped channels 63, and it is noted that the configuration of the channels 63 along one row of the base 50 is identical to the configuration of the channels 63 in the opposite row. Also, the greater dimension of each funnel-shaped channel 63 is at the upper surface of the base 50. The funnel-shaped configuration of the channels 63 provides several advantages. First, it provides greater contact area between the terminals 51 and the base 50 in order to achieve greater rigidity of the terminals 51. Secondly, the funnel-shaped configuration aids in facilitating assembly of the miniaturized terminals 51 into the base 50, and finally, the different funnel-shapes of the channels 63 ensures proper assembly of the terminals 51 into the base 50.
Formed integral with the base 50 and disposed on the upper surface of the base 50 intermediate the rows of channels 63 are a plurality of generally parallel ribs 64 which are spaced on a pitch corresponding to the pitch of the flat multi-conductor cable 21. The pitch is indicated by the letter p, which corresponds to the "pitch" of cable 21. Disposed on the lower portion of the base 50 are two recesses 65 provided below the shoulders 61 in order to enable the connecter 22 to be gripped by a conventional tweezer-like device to facilitate extraction of the connecter from a socket 10.
Terminals 51 are adapted to the mounted within the channels 63 in the base 50, and are configurated to correspond to the funnel-shaped configuration of the channels 63. Each terminal 51 is L-shape in configuration, including a terminal post portion 73 which is adapted to extend through a channel 63 in the base 50 to provide a terminal post external of the connecter 22, and an integral contact portion 74 which is adapted to be disposed on the upper surface of the base 50 between the rows of channels 63, and between a pair of ribs 64, with the transverse spacing between the integral contact portions 74 corresponding to the pitch of the flat multi-conductor cable 21. In order to achieve this, the terminals 51 are formed in a manner so as to alternate with the terminals 21 extending from the channels 63 in the opposite side of the connecter 22.
As illustrated in FIG. 3, a convenient method of forming the terminals 21 is to provide a blank of electrically conductive material such as phosphor bronze or copper, and to form one row of terminals by a conventional stamping operation. The resulting stamped structure is illustrated in FIG. 3 and consists of a plurality of terminals 51 attached at their opposite ends by common carrier strips 71 and 72. Following stamping operation, the terminals 51 are bent at a 90° angle in order to form the L-shaped configuration, after which the stamping, in its configuration with the terminals 51 and the carrier strips 71, 72, is gold plated in a conventional batch process. The purpose of maintaining the carrier strips 71 and 72 on the terminals 51 is to facilitate handling of the latter. Following gold plating of the stamped structure, the stamping is coined along the extremities of the terminals 51 so as to enable the carrier strips 71 and 72 to be broken off quite easily.
In order to assemble the L-shaped terminals 51 into the base 50, carrier strip 72 disposed along the terminal post portions 73 of the terminals 51 is broken off from the stamping, followed by the insertion of the terminal posts 73 of the terminals 51 into channels 63. When the terminals 51 are fully seated into the channels 63, the remaining carrier strip 71 is broken off thereby enabling the integral contact portions 74 of the terminals 51 to be fully seated into place between alternating ribs 64. The terminals 51 for the opposite row of channels 63 are then assembled into the base in the same manner.
The cover structure 52 of the connecter is generally rectangular in plan form corresponding to the configuration of the base 50, and includes two depending studs 80 which are accommodated in the apertures 62 in base 50. As is conventional in electronic components used in integrated circuitry, one corner 81 of the cover structure is champfered in order to identify the proper alignment of the connecter in the dual-in-line socket 10. The cover 52 is preferably made of the same dielectric material as the base 50.
In the assembly of the jumper 20 of the subject invention, after the terminal pins 51 have been placed in the channels 63, the stripped end of the flat conductor cable 21 would be placed onto the base 50, with the exposed conductors 41 being aligned with the respective integral contact portions 74 of the terminals 51, and between the upstanding ribs 64 of the base 50. Preferably, both the exposed conductors 41 and the integral contact portions 74 of the terminals 51 are pre-tinned whereby, after the conductors 41 and integral contact portions 74 are aligned in the base 50, a soldered electrical connection is established between the conductors 41 and the terminals 51 by a conventional mass bonding technique. Next, a suitable adhesive such as epoxy would be applied to the upper portion of the base 50, and the cover 52 would be placed onto the base. The epoxy serves several functions, one of which is to hold the electrical contacts between the conductors 41 and terminals 51 in place; to provide strain relief for the cable 21; and to provide adhesive for glueing the cover 52 to the base 50.
FIGS. 4 through 6 illustrate the assembled connecter forming a portion of the subject jumper 20. As illustrated in FIG. 4, the pitch between the conductors 41, the integral contact portions 74 of terminals 51, and the ribs 64 of the base 50 is identical. Furthermore, the specific configuration of the terminals 51 enable complete electrical isolation between adjacent terminals. As shown in FIG. 5, the terminal post portions 73 of the terminals 51 are configurated to correspond to the funnel-shaped channels 63. Preferably, terminals 51 are inserted with a "clearance fit" into the channels 63 in order to facilitate rapid assembly of the connecter 22. FIG. 6 illustrates a cross section showing a conductor 41 soldered as at 90 to the integral contact portion 74 of a terminal 51, with the epoxy being indicated by the numeral 91.
The opposite end of the cable 21 is similarly terminated by a connecter 22, as illustrated in FIG. 2, thereby providing a jumper 20 adapted to be connected at its opposite ends to conventional dual-in-line sockets 10. If desired, a "daisy-chain" jumper may be readily manufactured using the connecter illustrated and described with reference to FIGS. 2 through 6. In such instance, the flat multi-conductor cable 21 would be terminated at opposite ends with connecters 22, and also intermediate the length of the cable 21. A portion of the insulation would be stripped from the cable 21 so as to expose a short length of conductors 41. The connecter 22 to be employed intermediate the length of the cable 21 is identical to that illustrated in FIG. 2, in which case the exposed conductors 41 would extend a distance respectively corresponding to the distance between the rows of channel 63 in base 50.
As is readily apparent, since the multi-conductor flat cable 21 is extremely flexible, the jumper 20 of the subject invention is readily adaptable for employment in miniaturized integrated circuit boards.
It should thus be appreciated that the invention offers many new advantages. The jumper 20 is extremely flexible; provides an extremely reliable and compact connecter for connection to sockets in an integrated circuit board; is cheap to manufacture; and is extremely reliable in that the conductors are soldered or welded to the terminals. Furthermore, the arrangement of the cover and the base of the housing of the connecter provide a strain relief means for ensuring reliability and ruggedness of the jumper.
Although the invention has been described with reference to a preferred embodiment, numerous modifications and variations, both in form and detail, might occur to those skilled in the art. For example, the conductors of the flat conductor cable may be welded to the terminal pins. Additionally, the invention applies to jumpers having contact configurations other than that illustrated in the preferred embodiment, as well as to sockets of various contact arrangements and geometries. Accordingly, all such modifications and variations are intended to be included within the scope and spirit of the appended claims.