Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R12/00—Structural associations of a plurality of mutually-insulated electrical connecting elements, specially adapted for printed circuits, e.g. printed circuit boards [PCB], flat or ribbon cables, or like generally planar structures, e.g. terminal strips, terminal blocks; Coupling devices specially adapted for printed circuits, flat or ribbon cables, or like generally planar structures; Terminals specially adapted for contact with, or insertion into, printed circuits, flat or ribbon cables, or like generally planar structures
  • H01R12/70—Coupling devices
  • H01R12/77—Coupling devices for flexible printed circuits, flat or ribbon cables or like structures
  • H01R12/79—Coupling devices for flexible printed circuits, flat or ribbon cables or like structures connecting to rigid printed circuits or like structures
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K3/00—Apparatus or processes for manufacturing printed circuits
  • H05K3/36—Assembling printed circuits with other printed circuits
  • H05K3/361—Assembling flexible printed circuits with other printed circuits
  • H05K3/365—Assembling flexible printed circuits with other printed circuits by abutting, i.e. without alloying process
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R12/00—Structural associations of a plurality of mutually-insulated electrical connecting elements, specially adapted for printed circuits, e.g. printed circuit boards [PCB], flat or ribbon cables, or like generally planar structures, e.g. terminal strips, terminal blocks; Coupling devices specially adapted for printed circuits, flat or ribbon cables, or like generally planar structures; Terminals specially adapted for contact with, or insertion into, printed circuits, flat or ribbon cables, or like generally planar structures
  • H01R12/70—Coupling devices
  • H01R12/77—Coupling devices for flexible printed circuits, flat or ribbon cables or like structures
  • H01R12/771—Details
  • H01R12/774—Retainers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
  • H01R13/02—Contact members
  • H01R13/22—Contacts for co-operating by abutting

Definitions

• the present invention relates to an electrical connector for coupling flexible flat cables and the like to like devices, such as other flat cables and printed wiring boards and, in particular, for ensuring electrical continuity between their mating electrical leads .
• the present invention constitutes an improvement over the prior art by utilizing a redundancy of protuberances or bumps on each circuit line, rather 5 than a single bump, and the bumps are made relatively rigid to avoid problems where too great a pressure thereon will flatten the bumps to preclude repeated mating and demating cycling.
• the bumps can be formed by several conven ⁇ tional processing operations. Harder metals, such as of nickel and beryllium copper, may be used because resiliency in the bumps is not needed. A wide range of unit pressures is allowable, up to near their yield 5 points, both to achieve gas-tight joints and to minimize contact discontinuities due to high vibration and shock environments. Because more than one bump contacts each circuit line, any open circuit, which might result from dirt or other contamination on one bump, is 0 avoided. The presence of redundant bumps assures the likelihood of electrical contact of at least one bump. Opens or discontinuties under severe vibration shock are also effectively eliminated. The redundant contacts can be placed on 8 mil centers or smaller.
• Backup pressurization hardware can be made of less expensive Q materials and processes, such as from injection-molded plastic parts.
• FIG. 1 is a cross-sectional view of an illustrative connector assembly embodying the present invention for coupling of a flexible flat cable to a printed wiring board, with FIG. la being an enlarged view of one bump in contact with a mating lead;
• FIG. 2 is a plan view of a flexible cable secured in the assembly shown in FIG. 1;
• FIG. 2a is an equivalent representation of an en ⁇ larged view of one end of the flexible cable depicted in FIG. 2;
• FIG. 3 is a side view in cross-section showing a modification of the present invention for doubling the interconnection capability of that depicted in FIG. 2;
• FIG. 4 is a top view of the modification illus ⁇ trated in FIG. 3.
• a connector assembly 10 com ⁇ prises a pair of pressure plates 14 and 16 for coupling therebetween a printed wiring board 18 and a flexible cable 20. While illustrated as a printed wiring board, printed wiring board 18 may comprise a similar flexible cable as cable 20 (e.g., cable 21 shown in FIG. 5).
• Pres ⁇ sure plates 14 and 16 are provided with aligned openings 22 and 24, respectively, numbering four in total, for example. Placed within each of these openings is an align ⁇ ment pin 26 having a head 28 at one end, a split dowel 30 at its other end, and a connecting shank 32 therebetween.
• Opening 24 is provided with a shoulder 34 onto which head 28 itself, or through the intermediary of a rubber spacer 36, rests. Thus, opening 24 narrows to a smaller sized opening 38, and opening 38 and opening 22 are approximately of the same dimension.
• Screws 40 for example four in number, pass through an opening 42 in plate 16 and threadedly engage threaded holes 44 in plate 14.
• Each screw 40 is provided with a head 46 which bears against a surface 48 of plate 16 through the intermediary of a lock, washer 49 so that, by turning of the screw, plates 16 and 14 are drawn together, and press cable 20 and printed wiring board 18 into secure contact with one another.
• a spring 50 is disposed between one of the plates and one of the cable and the printed wiring board.
• plate 16 is pro ⁇ vided with a cavity 52 which may include a spacer plate 54.
• Cavity 52 has a walled enclosure and is thereby adapted to receive and retain spring 50 so that the spring will not fall out of its retainment within plate 16.
• a second plate 56 is placed on the side of spring 50 opposite from plate 54 so that the pressure of the spring will be applied through plate 56 and, if desired, a conforming silicon rubber pad 58 against cable 20.
• Spring 50 may comprise a wave spring or an angled helical spring, and there may be a plurality of such springs placed in side by side relationship with one another and retained within cavity 52.
• flexible cable 20 is formed from a dielectric substrate 60 and electrical traces, leads or lines 62.
• FIG. 2a are a plurality of redundant bumps 66, e.g. 3 x 5 mils and 1 to 2 mils in height.
• a plurality of bumps 66a illustrated to be six in number, while for any other specific trace, denoted by indicium 62n, six redundant bumps 66n exist thereon.
• Bumps 66 are formed from an essentially incompressible metal, such as nickel and beryllium copper.
• each is provided with regis- tration holes 70 and 72.
• rings of circuitry metal or bushings surround the holes. These are precisely formed in their respective components and are sized to be slightly smaller than split dowels 30 of registration pins 26. The precision in sizing the openings and the dowels are made commensurate with the size of the traces and the bumps.
• FIGS. 3 and 4 A modification of cable 20 is shown in FIGS. 3 and 4 as a double sided flexible cable 78, in which conductors or leads 80 and 82 are formed on opposite sides of a dielectric substract 84.
• leads 82 are formed in two segments 82a and 82b with bumps 86a and 86b thereon. As shown, it may be desirable to
• SUBSTITUTE SHEET electrically couple one or more conductors 80 and 82 and, to this end, feedthrough vias 88 extend from conductor 80 to conductor 82b.
• Bumps 66 may be formed in any convenient manner, such as by a "plated-up” or an "etched bump” process.
• a 2 mil substrate of any suitable polymer such as of polyimide, has copper, nickel, beryllium copper, etc., cladding on one or both sides.
• the metal cladding may be deposited as a sheet, a vacuum deposit or sputtered film, etc.
• resist materials such as a dry film or liquid film resist may be utilized as conventional in the art. Suitable artwork for the leads and bumps is used. The following steps are employed. The metal surfaces are cleaned in preparation for application of the resist. They are then coated with a dry or liquid resist which is then exposed through the line pattern artwork.
• the line pattern on the resist is then developed and, after removal of portions thereof, the line pattern is etched into the metal by a suitable etchant.
• the resist is then stripped from the cladding and the line pattern metal is then cleansed, followed by drying and preheating of the thus far processed material.
• a further coating of resist is applied and a "bump" pattern artwork is aligned on the etched copper line pattern and exposed to form where the bump areas are to be placed.
• the resist is then developed and the bump areas are cleaned. It is important that the bump areas to be plated are completely clean of resist residue.
• the metal bumps are then plated to the desired height of the bump, typically 1 - 2 mils.
• the resist is then stripped from the cable. The bump and line dimensions are measured and adhesion of the bumps is tested.
• the bumps may be plated with a gold or other desired finish.
• the part is then trimmed.
• a polymer such as a polyimide, with metal cladding is cleaned, dried and coated with a resist.
• the resist is exposed under film artwork of the bump pattern and developed so that the remaining resist protects the bumps while leaving the remainder of the metal cladding exposed.
• the exposed metal cladding is then etched to leave the bumps at the desired height.
• the resist is stripped off, the metal surfaces are cleaned and the substrate is dried. Further resist, preferably liquid to ensure a conformance to the surface, is coated over the thus processed assembly, and artwork for the line pattern is placed thereover.
• the resist is developed and the line pattern is etched to the remaining sheet thickness of the metal.
• the resist is stripped, all important dimensions are measured and, if acceptable, gold or other metal is plated to form a finish, followed by trimming the part.

Landscapes

• Engineering & Computer Science (AREA)
• Metallurgy (AREA)
• Manufacturing & Machinery (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Coupling Device And Connection With Printed Circuit (AREA)
• Multi-Conductor Connections (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=25485931

Family Applications (1)

Country Status (7)

Families Citing this family (2)

Family Cites Families (2)

• 1987
  • 1987-11-13 WO PCT/US1987/002951 patent/WO1988005217A1/en not_active Application Discontinuation
  • 1987-11-13 JP JP88502266A patent/JPH01502466A/ja active Pending
  • 1987-11-13 EP EP88902070A patent/EP0294479A1/en not_active Withdrawn
  • 1987-11-26 GR GR871807A patent/GR871807B/el unknown
  • 1987-12-07 IL IL84743A patent/IL84743A0/xx unknown
  • 1987-12-28 ES ES8703727A patent/ES2006022A6/es not_active Expired
• 1988
  • 1988-08-29 DK DK480688A patent/DK480688A/da not_active Application Discontinuation

Non-Patent Citations (1)

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