US 3399372 A
Description (OCR text may contain errors)
1968 E. c. UBERBACHER 3,399,372
HIGH DENSITY CONNECTOR PACKAGE Filed April 15, 1966 EDWARD 0. UBERBACHER W mri ATTORNE United States Patent 3,399,372 HIGH DENSITY CONNECTOR PACKAGE Edward C. Uberbacher, Poughkeepsie, N.Y., assignor to International Business Machines Corporation, Armonk, N .Y., a corporation of New York Filed Apr. 15, 1966, Ser. No. 566,697 Claims. (Cl. 339-17) ABSTRACT OF THE DISCLOSURE A plurality of sheet metal ground contacts are formed in a general U-shape with these contacts having top and bottom contact buttons facing into theopening of the U-shape for top and bottom ground tabs of the printed circuit board wherein these contacts are slotted to provide spring action when mounted by projections in a box-like housing.
Prior art configurations are not suitable for use with the new printed circuit technology which gives very fine, closelyspaced printed circuit lines or conductors. These lines provide alternate ground and signal circuits which converge to the alternated ground and signal tabs. The spacing on the cards which is now possible is of the order of 0.012 (center-line) tab to tab. Accommodation of such spacing in prior connectors was not possible. Further, with closely spaced ground-signal tab alternation, additional problems arise. These other problems are prevention cross-talk, adequate insulation, relatively easy insertability of the card, and the proper retention of the card. Finally, even with prior art connectors having an unsatisfactory approach to such high density packaging, the required-center-line-to-center-line spacing was not achieved. Further, one insertion and removal of a card gave completely intolerable spacing due to more contacts.
Accordingly, it is an object of this invention to overcome the aforenoted disadvantages and to provide a highly reliable, high density connection package which is suitable for the present-day achievements in printed circuit technology and similar closely spaced electrical circuits.
Another object is to provide an arrangement of a printed circuit card having narrow, closely spaced, alternated ground and signal contact tabs and a socket receiving the card with the socket providing a common ground from ground connectors which provide electrical insulation and prevent cross-talk.
A further object is to provide such a socketconnection wherein the female-signal contacts are formed from wire and the female ground contacts are formed from sheet metal whereby inexpensive fabrication with closely spaced contacts results.
An additional object is the provision of such a socketcard arrangement wherein the card is accurately positioned by adjusting means so that the ground and signal contacts are center-lined with the respective card tabs.
In accordance with the disclosed embodiment of the invention, a plurality of sheet metal ground contacts are formed in a general U-shape. These contacts have top and bottom contact buttons facing into the opening of the U for top and bottom ground tabs of the printed circuit board. These contacts are slotted to provide spring action when mounted by projections in a box-like housing. The top and bottom signal contacts are formed from resilient wire and are so mounted in the housing to give a spring force and to prevent contact where the card is removed. Further, a screw-spring arrangement is provided for abutting the side edge of the card and giving proper center-line positioning.
The realization of the above objects, along with the features and advantages of the invention will be apparent from the following description and the accompanying drawing in which:
FIG. 1 is a perspective view of the multitop-andbottom, groundand signal-contact socket and a printed circuit card aligned to be inserted;
FIG. 2 is a cross-sectional view at plane 22 of FIG. 1 and shows the wire signal contacts engaging the card signal tabs;
FIG. 3 is a cross-sectional view at plane 3-3 of FIG. 1 and shows the operative positioning of the sheet-metal ground contacts;
FIG. 4 is a cross-sectional view at plane 44 of FIG. 1 and shows the adjustable means for positioning the board;
FIG. 5 is a cross-sectional view at plane 5-5 of FIG. 1 and shows the screw and W-shaped spring of the adjusting means; and
FIG. 6 is a schematic showing the operation of the adjusting means.
Referring to FIG. 1 of the drawing, a high density, printed circuit card 11 is shown at the right. It is in position to be inserted into a female-electrical-connection, card-holding socket (to be described). The card 11 includes an electrically insulating plastic base 13 and closely spaced printed circuit lines 15 and 17. Lines 15 and 17 are respectively signal lines and ground lines. Mirrorirnage lines are etched or plated on the bottom of the card, as is apparent, but do not appear. The signal and ground lines 15 and 16 respectively terminate in signal and ground tabs or lands 18 and 19.
The card-receiving socket 21 is comprised basically of a plastic housing 23, a plurality of top and bottom small-diameter, wire-like signal contacts 25 and a plurality of thin, sheet-metal type ground contacts 27. The housing 23 has slots 31 in its top and bottom walls 33 and 34 for positioning the ground contacts 27 therein. The housing side walls 35 and 36 also have slots 37 and 38. These slots are for guiding the board 11 which has shoulders 39 and 40 for abutting the housing side walls 35 and 36. The housing rear wall 41 has a recess 42 which receives a generally U-shaped ground wire or bus 43.
In FIG. 2, side plane views of the wire signal contacts 25 and 26 appear. The upper leg 51 of the upper contact 25 projects through, and is retained by, a positioning hole 53 in the housing rear wall 41. The end of the free lower leg 55 of the signal contact 25 is received in a recess 57 into the rear housing wall 41. The contact radius 59 engages the signal line land 19 with a self-generated spring force since the Phosphor-bronze wire contact has been flexed upwardly by insertion of the card 11. The lower signal contact 26 has essentially the same configuration as contact 25 except that its free leg 61 is shorter and overlies the central, projecting extension 63 of the housing rear wall. The outer, longer leg 65 is positioned and retained by extending through another closefitting hole 67 in the housing rear will. Radius 69 abuts the underside signal tab 19. It is to be understood that identical contacts can be paired, one above the other. As shown, it is clear that, upon removal of the card 11, contacts 25 and 26 will not abut or short out since the top free leg will be confined by recess 57 and the bottom free leg will rest on, and be limited by, ridge 63.
In FIG. 3, the sides of the sheet-metal ground contacts 27 appear. These contacts are generally U-shaped when viewed after a 90 counter-clockwise rotation and have upper and lower sections which include upper and lower self-biased contact buttons 71 and 73 engaging top and bottom ground tabs 19 of card 11. Both upper and lower sections of the ground contact 27 have slots 75 extending from the rear thereof at an angle toward the contact buttons 71 and 73 so that a self-generated spring force is provided upon insertion of card 11. The outer front parts or corners 74 of each ground contact section has a positioning-locking extension 77 which fits into housing slot 31. The ground contact 27 also has a central'rear projection 79 which extends through slots 81, in the housing rear wall 41. The ground wire or bus 43 is received in a notch 83 and soldered to the ground contacts 27."When the card 11 is removed, it is apparent that contact buttons 71 and 73 will pivot or move toward each other but will not touch. Upon insertion of a card, the top and bottom corner sections 74 of the unitary ground contacts 27 will pivot at the inner corners of rear wall slot 81 until limited by the inner edgeof housing front clots 31. The ground contacts 27 are made of Phosphor-bronze to prevent signal cross-talk. Contacts 27 are electrically insulated by being coated'with a suitable plastic (Teflon Du PontTM). Electrical conduction is provided at but tons 71 and 73 by grinding off the plastic to expose the Phosphor-bronze which is then gold-plated.
Referring to FIGS'. 4-6, means for adjusting to the very close tolerances required are shown'arid include a W- shaped spring 91, and an adjusting screw 93. The spring is mounted in cavity 94. The screw is threaded in a housing wall 95, extends through the spring 91, and is closely received in a cylindrical housing recess 96. The verticalextending center leaf section 97 extends toward the sides of the card 13 (FIG. The two outer leaves 98 of the spring loosely receive the screw while the two openings 99 of the center section provide non-contacting clearance for the screw. The inward movement of the screw and resulting functioning of the spring to contact and space the card and its lines relative to the ground and signal contacts to precise alignment is shown in FIG 6. The typical indicated tolerance of 0.012" is achieved and thus matches the center-line-to-center-line spacing of the printed circuit card signal and ground lines.
While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
What is claimed is:
1. An arrangement for electrically connecting a printed circuit into a socket comprised of:
a printed circuit card having top and bottom, alternated ground and signal tabs which are longitudinally staggered at a card end edge part,
a socket having ground and signal resilient contacts which correspond to the card tabs and a housing mounting the contacts,
said socket contacts being arranged side-by-side and insulated from each other,
said card being inserted in said socket,
adjusting means in said housing including a spring hav: ing a projecting bend,
said adjusting means being adapted to move said spring bend against a side end edge of the card to align the tabs for proper engagement with the tabs. 2. The arrangement according to claim 1 and being further characterized by:
said ground contacts being formed from sheet metal which prevents cross-talk and being coated with an electrical-insulating plastic material,
said signal and ground contacts being arranged in side abutting relation, and
said ground contacts having an engaging button which is plated with a non-corrosive metal. 3. A high density connector for receiving a printed circuit board having closely spaced alternate ground and signal terminal tabscomprised of:
a box-like housing means having an open side, top:
and bottom walls, two end walls and a back wall; said housing means being made from electrical insulating g ,7 plastic and have an opening in the back wall and recesses in the top and bottom walls; spaced barrier means formed of uniformly closely spaced, thin ground connector means inserted in said open side; said ground. connector means being formed from metal sheet-likematerial which bars ;-=..--cross-ta1k and so servesasa barrier to signals upon said'sig-nal connector means; at least one thin signal connector'means mounted in said hbusirig means'a'nd spaces between said barrier hieangieaciiofs'aid signal connector meansbeing a wire'formed into a generally J-shaped contact, having at least one straight end andta'loop end part and being mounted in the housing means by cooperation between said openings-and said straight ends and by cooperation between said recesses and said loop end paItsfa-nd i, w t jti M ,bothof said connector means being. constructed to resiliently receive and retain the end of a printed circuit board having closely spaced ground and signal ,tabs. 7 .l ,4. A,,high density,,connector for receiving a printed v circuit board having closely spaced alternate ground and l signal terminal tabs comprised of:
I signal terminal tabs comprised of:
a box-like housing having an open side, top and bottom walls, two end walls and a back wall, said housing means being made from an electrical insulating plastic and having openings in the back wall and recesses in the top and bottom walls; :spaced barrier means formed of uniformly closely spaced, thin ground connector means inserted in said open side; said ground connector means being formed to provide ground tab and conduction means from a location adjacent said open side to the back wall of said housing means and'said ground con- -nector means being further formed from metal-sheetlike material which bars cross-talk and so serves as the barrier to signals on said connector means;
at least one thin signal connector means mounted in said 'housing'means in spaces between said barrier means, each of said signal means being a wire formed I into a generally J-shapedcontact having 'a straight endand looped-end part and being mounted in the" housing means by cooperation between said opening and saidstraight ends and by cooperation between said recesses and said looped end parts; and
both of said connector means being constructed to resiliently receive and retain the end of a printed circuit board by the closely spaced ground and signal n tabs; a v 5. A high density connector for receiving a printed circuitboard having closely spaced alternate ground and a box-like housing means having an open side, top and bottom'walls, two end walls and aback wall, said housing means being made from an electrical insulating plastic and having openings in the back wall and recesses in the top and bottom walls; .spaced barrier means formed of uniformly closely spaced, thin ground connector means inserted in said: open side;.said:-ground connector means being formedfrom metal-sheet-like material which" bars cross-talk and so serves as a barrier to signals=upon saidwsignalconnector means; said ground connector means beingfurther formed to provide ground tabs and conduction .means from, alocation adjacent to vsaid open. sides to the back-walls-of said housing means; 1 at least one thinsignal-connectr meansmounted in ingka straightend ahd a loop end partand'being vmounted in -'-the-housing"means 'by cooperation be t -tween said openings and said straight-'endsandbycooperation between said recesses and said loop end parts; and,
both the thin ground connector means and the signal connector means being constructed to resiliently receive and retain the end of a printed circuit board having closely spaced ground and signal tabs where said ground signal tab means provide top and bottom contacts for a board having top and bottom tabs and further where said ground connector means is and a back grounding positioning projection.
References Cited UNITED STATES PATENTS Schweitzer et a1. 33917 X Raddin 33917 Dupre 33914 Mayon et al. 33917 Ecker 33917 MARVIN A. CHAMPION, Primary Examiner. O J. R. MOSES, Assistant Examiner.