Spread spectrum radio incorporated in a PCMCIA Type II card holder

• US 5,519,577 A
• Filed: 12/23/1993
• Issued: 05/21/1996
• Est. Priority Date: 12/23/1993
• Status: Expired due to Term

• Current Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Wallace, Pat, Hutton, Tom, Nelson, Norm, Dudas, Errol
• Primary Examiner(s): SPARKS, DONALD ALAN
• Application Number:
  US08/173,249
• Time in Patent Office: 880 Days
• Field of Search: 174/35 R, 174/35 TS, 174/35 GC, 174/51, 174/255, 235/488, 235/489, 235/490, 235/492, 235/1 D, 257/678, 361/212, 361/220, 361/684, 361/737, 361/686, 361/753, 361/755, 361/780, 361/792, 361/793-795, 361/816, 361/818, 439/607, 439/609, 455/90, 455/106, 455/300, 455/311, 455/303, 455/347, 455/348, 455/349, 343/880-882, 343/841, 343/887, 343/878, 343/872
• US Class Current: 361/737
• CPC Class Codes: H05K 1/0218 by printed shielding conductors, ground planes or power plane H05K1/0236 takes precedence
• CPC Class Codes: H05K 5/0269 Card housings therefor, e.g. covers, frames, PCB
• CPC Class Codes: H05K 5/0273 having extensions for peripherals, e.g. LAN, antennas details of antennas H01Q1/2275
• CPC Class Codes: H05K 9/0039 Galvanic coupling of ground layer on printed circuit board [PCB] to conductive casing printed shielding conductors, ground planes or power planes for reduction of cross-talk or noise in printed circuits H05K1/0218
• CPC Class Codes: Y10S 174/34 PCB in box or housing

Abstract

This invention is directed to a PCMCIA Type II memory card holder assembly for a spread spectrum radio communication card that provides radio frequency interference shielding, electrostatic discharge resistance and heat dissipation. The card holder assembly consists of a multilayer circuit board and a card holder. The multilayer circuit board has a ground plane disposed between a plurality of analog circuit layers and a plurality of digital circuit layers. The ground plane is connected by through vias to ground traces on the surfaces of the circuit board. The card holder consists of a card holder frame in which the memory card is slidably and rotatably mounted so that the ground traces continuously contact the frame, and two outer cover plates which are adhered to the opposing surfaces of the card holder frame.

Claims

1. An electrically shielded and grounded, electrostatic discharge resistant memory card assembly comprising:

a memory card circuit board formed from a plurality of layers of circuit planes having a top surface and a bottom surface, all of the circuit planes on one side of a ground plane are digital circuits planes and all of the circuit planes on the opposing side of the ground plane are analog circuits planes; and

a perimeter ground trace on three sides of each said surface and a connector on a fourth side, where the ground plane is disposed between said top and bottom surfaces;

a memory card holder comprising an open connector end, an opposing end having a closed mating header and a pair of side rails for slidably and rotatably receiving a memory card there between, said rails extending between the closed mating header end and the connector end to form a card holder frame having an inward side, an outward side, an upper surface and a lower surface, where each said rail has an inward transverse slot at about the midpoint and each rail is defined by an outer wall having an inwardly directed lower wall extending between said open connector end and said transverse slot and an inwardly directed upper wall between said transverse slot and said closed mating header, where each said lower wall is connected by a rib and where a lower joint between said outer wall and said inwardly directed lower wall is characterized by a recess extending a predetermined distance along said lower joint and an upper joint between said outer wall and said inwardly directed upper wall is characterized by a recess extending a predetermined distance along said upper joint; and

a pair of cover plates disposed on either side of said card holder frame having an exterior surface and an interior surface and a raised central area extending from the exterior surface;

wherein said card holder frame and cover plates are constructed of electrically conductive and heat conductive materials and said memory card assembly is formed by mounting said memory card in said card holder so that said ground trace continuously contacts said lower and upper walls of said card frame and tightly contacting the cover plates on said upper surface and said lower surface of said card holder frame to form two electrically isolated compartments.

2. The memory card assembly of claim 1, wherein said memory card is a PCMCIA memory card.

3. The memory card assembly of claim 2, wherein, said analog circuits are radio communication circuits.

4. The memory card assembly of claim 3, wherein said analog circuits are spread spectrum radio circuits.

5. The memory card assembly of claim 4, wherein said closed mating header has an aperture.

6. The memory card assembly of claim 5, wherein, a layer of non-electrically conductive material extending to all edges of said circuit board is adhered to said interior surface of each said cover plate.

7. The memory card assembly of claim 6, wherein said card holder frame is a die cast metal, said cover plates are stainless steel and said electrically conductive adhesive is a conductive glue.

8. The memory card assembly of claim 7, wherein said lower walls of said side rails slope upwardly from said connector end to said transverse slot and said upper walls of said side rails slope upwardly from said transverse slot to said mating header.

9. The memory card assembly of claim 8, wherein said closed mating header has an aperture and an antenna is connected to said memory card holder on said outward side of said closed mating header.

10. The memory card assembly of claim 4, wherein said rib is electrically non-conductive.

11. The memory card assembly of claim 4, wherein said closed mating header has an aperture and an antenna is connected to said memory card holder on said outward side of said closed mating header.

12. The memory card assembly of claim 1, wherein said closed mating header has an aperture.

13. The memory card assembly of claim 12, wherein a layer of non-electrically conductive material extending to all edges of said circuit board is adhered to said interior surface of each said cover plate.

14. The memory card assembly of claim 13, wherein each said cover plate is secured to said upper and lower surfaces of said card holder frame by an electrically conductive adhesive.

15. The memory card assembly of claim 14, wherein said card holder frame is a die cast metal, said cover plates are stainless steel and said electrically conductive adhesive is a conductive glue.

16. The memory card assembly of claim 15, wherein said lower walls of said side rails slope upwardly from said connector end to said transverse slot and said upper walls of said side rails slope upwardly from said transverse slot to said mating header.

17. The memory card assembly of claim 16, wherein said closed mating header has an aperture and an antenna is connected to said memory card holder on said outward side of said closed mating header.

18. The memory card assembly of claim 1, wherein said rib is electrically non-conductive.

19. The memory card assembly of claim 1, wherein said lower walls of said side rails slope upwardly from said connector end to said transverse slot and said upper walls of said side rails slope upwardly from said transverse slot to said mating header.

20. The memory card assembly of claim 1, wherein said closed mating header has an aperture and an antenna is connected to said memory card holder on said outward side of said closed mating header.

21. An electrically shielded and grounded, electrostatic discharge resistant PCMCIA memory card holder comprising:

an open connector end for mounting a connector;

an opposing end having a closed mating header;

a pair of side rails for slidably and rotatably receiving a memory card there between, said rails extending between said closed mating header end and said connector end to form a card holder frame having an inward side, an outward side, an upper surface and a lower surface, where each said rail has an inward transverse slot at about the midpoint and each rail is defined by an outer wall having an inwardly directed lower wall extending between said open connector end and said transverse slot and an inwardly directed upper wall between said transverse slot and said closed mating header, where a lower joint between said outer wall and said inwardly directed lower wall is characterized by a recess extending a predetermined distance along said lower joint and an upper joint between said outer wall and said inwardly directed upper wall is characterized by a recess extending a predetermined distance along said upper joint;

a rib connecting said inward sides of said lower walls of said side rails; and

a pair of cover plates disposed on either side of said card holder frame having an exterior surface, an interior surface and a raised central area extending from said exterior surface;

wherein said side rails, closed mating header, rib and cover plates are constructed of electrically conductive and heat conductive materials.

22. The memory card holder of claim 21, wherein said closed mating header has an aperture.

23. The memory card holder of claim 22, wherein said rib is constructed of non-electrically conductive material.

24. The memory card holder of claim 22, wherein a layer of non-electrically conductive material extending to all edges of said circuit board is adhered to said interior surface of said raised area of each said cover plate.

25. The memory card holder of claim 24, wherein each cover plate is secured to said upper and lower surfaces of said card holder frame by an electrically conductive adhesive.

26. The memory card holder of claim 25, wherein said card holder frame is a die cast metal, said covers plates are stainless steel and said electrically conductive adhesive is a conductive glue.

27. The memory card holder of claim 25, wherein said lower walls of said side rails slope upwardly from said connector end to said transverse slot and said upper walls of said side rails slope upwardly from said transverse slot to said mating header end.

28. The memory card holder of claim 27, wherein said closed mating header has an aperture and an antenna is connected to said memory card holder on said outward side of said closed mating header.

29. The memory card holder of claim 21, wherein said rib is constructed of non-electrically conductive material.

30. The memory card holder of claim 21, wherein a layer of non-electrically conductive material extending to all edges of said circuit board is adhered to said interior surface of said raised area of each said cover plate.

31. The memory card holder of claim 21, wherein each cover plate is secured to said upper and lower surfaces of said card holder frame by an electrically conductive adhesive.

32. The memory card holder of claim 31, wherein said card holder frame is a die cast metal, said covers plates are stainless steel and said electrically conductive adhesive is a conductive glue.

33. The memory card holder of claim 21, wherein said lower walls of said side rails slope upwardly from said connector end to said transverse slot and said upper walls of said side rails slope upwardly from said transverse slot to said mating header end.

34. The memory card holder of claim 21, wherein said closed mating header has an aperture and an antenna is connected to said memory card holder on said outward side of said closed mating header.