Method for manufacture of EMI reducing circuit card apparatus

• US 5,084,802 A
• Filed: 02/04/1991
• Issued: 01/28/1992
• Est. Priority Date: 05/16/1989
• Status: Expired due to Fees

• Current Assignee: AT&T, Inc.
• Original Assignee: AT&T, Inc.
• Inventors: Nguyenngoc, Kinhquoc
• Primary Examiner(s): Tolin, Gerald P.
• Application Number:
  US07/652,330
• Time in Patent Office: 358 Days
• Field of Search: 361/397, 361/415, 361/395, 361/399, 361/424, 361/212, 361/220, 174/35 R, 174/51, 174/66, 29/842, 29/846, 156/73.1
• US Class Current: 361/818
• CPC Class Codes: H05K 9/0062 Structures of standardised dimensions, e.g. 19" rack, chassis for servers or telecommunications
• CPC Class Codes: Y10T 29/49147 Assembling terminal to base

Abstract

A circuit card comprises a printed wiring board, a plastic faceplate therefor, and a resilient electroconductive sheet metal strip extending the length of such plate and fastened to its rear side. The strip at its opposite ends provides spring contacts electrically coupled by the strip'"'"'s middle part. The card is adapted to be inserted in a holding bay with a rectangular front opening of greater width than height and bordered at its top and bottom by designation strips for the cards to be put in such bay. Metallic structural means adjacent the opening provides an a.c. circuit path extending around the opening in a closed loop. When the card is inserted in the bay, the spring contacts engage with metal-surfaced regions on the designation strips to provide an electrical shunt across such loop and, thereby, to reduce electromagnetic interference radiating through such opening from the bay'"'"'s interior.

Claims

1. A method of adding electromagnetic interference ("EMI") reduction capability to a circuit card comprising an insulative board and a plastic faceplate fastened to the front of such board so that the respective centerplanes of such board and faceplate are at right angles to each other, and such faceplate having front and back sides, said method comprising:

providing on the back side of said faceplate a pair of plastic studs spaced from each other in the length of said faceplate and integral therewith and projecting rearward from said back side thereof, providing an elongated metallic constant thickness strip having front and back sides separated by the thickness of the strip, and having formed therein, laterally inwards of the ends thereof, a pair of holes spaced apart in the length of said strip by the same distance as that separating said studs and of diameters matching that of said studs, the front and back surface portions of said strip bordering said holes being parallel planar surface portions, flatly abutting the front side of said strip with the back side of said faceplate by passing said studs through said holes so that said studs fit therein without play and portions of said studs project outward of said strip, and upsetting said portions to transform them into enlarged heads holding said strip fast to and flat against said plate.