Electrical connector

• US 20030092293A1
• Filed: 10/22/2002
• Published: 05/15/2003
• Est. Priority Date: 11/09/2001
• Status: Active Grant

• Current Assignee: Fujikura Limited
• Original Assignee: DDK Limited (Fujikura Limited)
• Inventors: Yamazaki, Yasue, Ohtsuki, Tomonari
• Granted Patent: US 6,857,880 B2
• Time in Patent Office: Days
• US Class Current: 439/66
• CPC Class Codes: H01R 12/52 connecting to other rigid printed circuits or like structures
• CPC Class Codes: H01R 13/2414 conductive elastomers
• CPC Class Codes: H05K 3/326 the printed circuit having integral resilient or deformable parts, e.g. tabs or parts of flexible circuits H05K3/365 takes precedence
• CPC Class Codes: H05K 3/3447 Lead-in-hole components H05K3/3415 takes precedence
• CPC Class Codes: H05K 3/365 by abutting, i.e. without alloying process

Abstract

An electrical connector includes an elastomer layer or board and a plurality of fine lead wires embedded in the elastomer layer and extending rectilinearly therein at right angles to both the surfaces of the elastomer layer. Recesses are formed in the elastomer layer around peripheries of openings of through-holes in which the fine lead wires are embedded. The electrical connector further includes two flexible printed circuit boards on both the sides, each including electric contacts to be connected to mating contacts, connection portions each formed with a through-hole passing therethrough, and conductors each electrically connecting the connection portion to the electric contact. When the flexible printed circuit boards and the fine lead wires are electrically connected by vapor reflow soldering, the flexible printed circuit boards and the elastomer layer having the fine lead wires embedded therein are clamped by restraining jigs to prevent from the flexible printed circuit boards from moving away from the elastomer layer. With this arrangement, reliable connection between the fine lead wires and the flexible printed circuit boards can be achieved without need to control the length of the fine lead wires without any risk of the flexible boards being deflected or warped during soldering even if circumferences of portions to be electrically connected are covered by the insulator.

Claims

1. An electrical connector having electric contacts on both surfaces, comprising an elastomer layer, and a plurality of fine lead wires embedded in said elastomer layer and extending rectilinearly therein at right angles to both surfaces of said elastomer layer, recesses being formed in said elastomer layer around peripheries of openings of through-holes in which said fine lead wires are embedded.

2. The electrical connector having electric contacts on both surfaces as set forth in claim 1, wherein said fine lead wires have a length substantially equal to the thickness of said elastomer layer.

3. The electrical connector having electric contacts on both surfaces as set forth in claim 1, wherein both ends of said fine lead wires extend slightly beyond said both surfaces of said elastomer layer.

4. The electrical connector having electric contacts on both surfaces as set forth in claim 2 or 3, further comprising flexible printed circuit boards each comprising electric contacts to be connected to mating contacts, connection portions each formed with a through-hole passing therethrough, and conductors each electrically connecting said connection portion to said electric contact, said flexible printed circuit boards being jointed to said elastomer layer each on one of said both surfaces such that ends of said fine lead wires are aligned with said through-holes of said flexible printed circuit boards.

5. The electrical connector having electric contacts on both surfaces as set forth in claim 1, wherein said recesses are substantially frustoconical.

6. The electrical connector having electric contacts on both surfaces as set forth in claim 1, wherein said recesses are of a substantially disc shape.

7. The electrical connector having electric contacts on both surfaces as set forth in claim 1, wherein said fine lead wires to be embedded in said elastomer layer each have at least one smaller diameter portion.

8. The electrical connector having electric contacts on both surfaces as set forth in claim 4, wherein said connection portions of said flexible printed circuit boards and said fine lead wires are soldered by vapor reflow soldering, while said flexible printed circuit boards are urged against said elastomer layer such that said connection portions of said flexible printed circuit boards are not moved away from the elastomer layer during said vapor reflow soldering.

9. An electrical connector having a required number of electric contacts adapted to contact mating contacts, wherein said electric contacts are electrically independent of one another after electrolytic surface treatment by cutting off electrical connections between said electric contacts for said electrolytic surface treatment.

10. An electrical connector having a required number of electric contacts adapted to contact mating contacts, wherein said electric contacts each form an electric contact element with a conductor electrically connecting said electric contact to the opposite side of a board through a through-hole formed in said board, and said electric contact elements are electrically independent of one another after electrolytic surface treatment by cutting off electrical connections between said electric contact elements for said electrolytic surface treatment.

11. The electrical connector as set forth in claim 9 or 10, wherein said electric contacts or said electric contact elements are electrically independent of one another by cutting off electrical connections therebetween by forming substantially U-shaped slits around said electric contacts after said electrolytic surface treatment.

12. A method for producing an electrical connector having a required number of electric contacts adapted to contact mating electric contacts, comprising an electric contact element producing step which comprises steps of forming a pattern on one surface of a board, removing unwanted copper foils by etching, applying a predetermined electrolytic surface treatment to electric contact elements, and cutting, off electrical connections between the electric contact elements by any one of laser beam machining, punching and the like to render said electric contact elements electrically independent of one another.

13. The method for producing an electrical connector as set forth in claim 12, wherein in said cutting off step, said electrical connections between the electric contact elements are cut off by forming substantially U-shaped slits around said electric contacts after said surface-treatment.

14. A method for producing an electrical connector having a required number of electric contacts adapted to contact mating contacts, including steps of forming electric contact elements, each having one electric contact and a conductor electrically connecting the electric contact to the opposite side of a board through a through-hole formed in said board;

electrically connecting said electric contact elements for performing electrolytic surface treatment; and

after the surface treatment, forming substantially U-shaped slits around said electric contacts to render said electric contact elements electrically independent of one another, wherein the step of forming said electric contact elements comprises steps of forming prepared through-holes, performing a surface treatment of said through-holes and a whole surface of said board, forming a pattern on the surface of the board, removing unwanted copper foils by etching, attaching a covering layer onto the whole surface, partly opening the covering layer at locations corresponding to the electric contacts to expose the board, then providing the electric contacts electrolytically, applying said electrolytic surface-treatment onto said electric contacts, opening said covering layer at said through-holes, and forming said substantially U-shaped slits around said electric contacts.