Electrostatically protected IC card

• US 5,319,516 A
• Filed: 06/28/1993
• Issued: 06/07/1994
• Est. Priority Date: 09/09/1991
• Status: Expired

• Current Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Original Assignee: ITT Corporation (ITT, Inc.)
• Inventors: Perkins, Carl C.
• Primary Examiner(s): Pellinen, A. D.
• Assistant Examiner(s): Elms, Richard T.
• Application Number:
  US08/084,034
• Time in Patent Office: 344 Days
• Field of Search: 361/212, 361/220, 361/728, 361/730, 361/736, 361/752, 361/816, 361/737, 174/35 R, 235/492, 235/495, 257/668, 257/728, 439/86
• US Class Current: 361/220
• CPC Class Codes: G06K 13/077 with intermittent movement; Braking or stopping movement
• CPC Class Codes: G06K 19/07735 the record carrier comprising means for protecting against electrostatic discharge
• CPC Class Codes: G06K 19/07743 External electrical contacts
• CPC Class Codes: Y10S 439/946 Memory card cartridge

Abstract

A system is provided wherein an IC memory card (10, FIG. 2) is inserted into a slot (12) of an electronic device (14), which discharges any static electric charge on the card. The card includes a frame that comprises a body having opposite side beams and top and bottom conductive covers mounted on the side beams, to enclose a circuit board. The circuit board has a ground plane, and a first of the side beams has an electrically conductive surface portion directly engaged with a peripheral portion of the ground plane and with one of the covers, to connect the cover to the side beam conductive portion. The body can be constructed of molded electrically conductive material.

Claims

1. An IC card which includes a frame having opposite sides, forward and rearward ends, and top and bottom cover regions, said card including a circuit board assembly which lies in said frame and which includes a circuit board having a ground plane and at least one circuit component mounted in said circuit board, said card being constructed to be inserted into a slot of an electronic device until card contacts at the front end of the card mate with device contacts in the device, characterized by:

at least said opposite sides of said frame are formed of molded electrically conductive plastic material having an electrical resistivity which is a plurality of times greater than that of copper, and said opposite sides of said frame are electrically connected to said ground plane of said circuit board.

2. The IC card described in claim 1 wherein:

said frame includes a connector lying at said forward end of said frame and comprising a housing constructed of molded dielectric material having a resistivity more than four orders fo magnitude greater than the resistivity of copper, said housing having a plurality of holes which hold said card contacts.

3. The IC card described in claim 1 wherein:

said frame includes a molded body of said electrically conductive plastic material, said body having opposite side edges forming at least part of said frame sides, and said frame also includes top and bottom covers mounted over said body and forming said top and bottom cover regions;

said circuit board has opposite faces and opposite edges, with a first of said circuit board edges lying adjacent to a first of said body edges, and said ground plane of said circuit board includes a portion lying on one of said circuit board faces adjacent to said first board edge;

a first of said covers has a primarily horizontally-extending face and has an edge portion bent to extend largely vertically, said edge portion having an extreme edge bearing against said ground plane portion on said circuit board.

4. An IC card comprising:

a frame having opposite sides and front and rear ends and having top and bottom conductive cover regions;

a circuit board assembly which includes a board and at least one circuit component mounted on said board, said board having a ground plane;

a connector which is mounted on said front end of said frame and which has a plurality of contacts;

said frame including a body extending at least along said opposite sides, said body being constructed of molded electrically conductive primarily polymeric material molded into the shape of said body and connected to said ground plane of said board.

5. The card described in claim 4 wherein:

said molded electrically conductive primarily polymeric material has a bulk resistivity which is at least one order to magnitude greater than that of copper, but less than 4 orders of magnitude greater than that of copper.

6. An IC card comprising:

a frame having opposite sides and front and rear ends and including a body having opposite body side beams;

said frame has first and second conductive covers that each has a peripheral cover portion, with one of said covers being a top cover that generally lies over said body and the other cover being a bottom cover that generally lies under said body;

a circuit board assembly mounted to said body side beams, said circuit board assembly including a board and at least one circuit component mounted on said board, said board assembly having a ground plane;

said board has a peripheral board portion, and said ground plane includes a peripheral ground plane lying at said board peripheral portion and electrically connected to both of said cover peripheral portions;

said body side beams each having an inner first portion sandwiched between said cover peripheral portions, said side beams each having an outer second portion which lies outside said board and said cover peripheral portions to protect the edges of said board and of said covers;

at least one of said body side beams having an electrically conductive surface portion directly engaged with said peripheral ground plane portion; and

one of said covers having a vertically bent edge directly engaged with said side beam conductive surface portion.

7. The IC card described in claim 6 wherein:

said outer second portions of said body side beams each have inner surfaces where they merge with said inner first portions, and said vertically bent edge of said one cover lies substantially against the inner surface of said outer second portion of said one body side beam.

8. An IC card comprising:

a frame which includes a body having opposite sides and forming opposite side beams at said opposite sides, said body also having opposite forward and rearward ends with the distance between said opposite ends being greater than the distance between said opposite sides, said body having upper and lower surfaces, said frame including top and bottom conductive covers that lie respectively over said body upper and lower surfaces and that each has a peripheral cover portion;

a connector mounted on a first of said frame ends and having contacts positioned to mate when the card moves in a forward direction;

a circuit board assembly mounted to said frame, said circuit board assembly including a board with a peripheral portion mounted on said body side beams and with most of said board lying between said body side beams, said board having a ground plane with a peripheral ground plane portion lying at said board peripheral portion; and

a first of said body beams having an electrically conductive surface portion directly engaged with said board ground plane peripheral portion and with a first of said covers, to electrically connect said board ground plane peripheral portion to said first of said covers.

9. An IC card comprising:

a frame having opposite sides and front and rear ends and including a body having opposite side beams, said body including upper and lower surfaces and top and bottom conductive covers that lie respectively over said body upper and lower surfaces and that each has a peripheral cover portion;

a circuit board assembly mounted to said frame, said circuit board including a board mounted on said body side beams, said board lying between said body side beams and having a peripheral board portion and at least one circuit component mounted on said board, said board having a ground plane with a peripheral ground plane portion lying at said board peripheral portion;

at least one of said body beams having an electrically conductive surface portion directly engaged with said peripheral ground plane portion; and

a first of said covers has a primarily horizontally extending face and has an edge portion which is bent to extend vertically and directly engages said side beam conductive surface portion.

10. The combination of components which when assembled, forms the frame of an IC card that is adapted to contain a circuit board assembly, said combination comprising:

a body for supporting the circuit board assembly of said IC card, said body having a top and a bottom, opposite sides, and front and rear ends, with said ends spaced apart by a greater distance than said sides;

a pair of covers for mounting respectively at said top and bottom of said body to enclose the circuit board assembly;

said body having spaced opposite side beams at said sides, with each of said side beams having upwardly and downwardly-facing surfaces;

at least a first of said body side beams has an electrically conductive surface portion, with parts of said conductive surface portion lying at the outside of said first side beam at said body side, and at both said upwardly and downwardly-facing surfaces of said first side beam;

a first of said covers has a peripheral cover portion that directly engages said electrically conductive surface portion when said covers are mounted on said body.

11. The combination described in claim 10 wherein:

first cover has a vertically bent edge which forms said peripheral cover portion that directly engages one of said parts of said electrically conductive surface portion when said covers are mounted on said body.

12. The combination described in claim 10 wherein:

said body is constructed of a molded electrically conductive polymeric material.