SNAP INSTALL EMI SHIELDS WITH PROTRUSIONS AND ELECTRICALLY-CONDUCTIVE MEMBERS FOR ATTACHMENT TO SUBSTRATES

• US 20080106884A1
• Filed: 04/16/2007
• Published: 05/08/2008
• Est. Priority Date: 11/03/2006
• Status: Active Grant

• Current Assignee: Laird Technologies Incorporated (DuPont de Nemours, Inc.)
• Original Assignee: Laird Technologies Incorporated (DuPont de Nemours, Inc.)
• Inventors: English, Gerald Robert, Wrona, Timothy M.
• Granted Patent: US 7,534,968 B2
• Time in Patent Office: Days
• US Class Current: 361/818
• CPC Class Codes: H05K 9/0032 having multiple parts, e.g. frames mating with lids

Abstract

Various embodiments provide EMI shields for substrates having at least one electrical component disposed thereon. In one embodiment, an EMI shield generally includes a cover having first and second protrusions and at least one electrically-conductive member disposed along an inner side of the cover. The electrically-conductive member may be compressed generally between the substrate and the cover when the substrate is captured generally between the electrically-conductive member and the first protrusion. In addition, a compressive clamping force may be generated by the engagement of the first protrusion with the substrate and the compression of the electrically-conductive member. This compressive clamping force may mechanically retain the cover to the substrate, and also compress the electrically-conductive member against at least one electrically-conductive surface disposed on the substrate, to establish electrical conductivity therebetween that is sufficient for EMI shielding performance.

Claims

1. An EMI shield for a substrate having at least one electrical component disposed thereon, the EMI shield comprising:

a cover having at least a first protrusion and a second protrusion spaced apart from the first protrusion to allow for positioning of the first and second protrusions respectively along generally opposite first and second sides of the substrate;

at least one resilient electrically-conductive member disposed along an inner side of the cover, and configured to be compressed generally between the substrate and the cover when at least a portion of the substrate is captured generally between the at least one resilient electrically-conductive member and the first protrusion;

the second protrusion operable as a stop for inhibiting relative movement of the cover towards the substrate beyond a predetermined amount to thereby help prevent over-compression of the at least one resilient electrically-conductive member when the substrate contacts the second protrusion;

whereby engagement of the first protrusion with the substrate and compression of the at least one resilient electrically-conductive member generates a compressive clamping force for mechanically retaining the cover to the substrate, and for compressing the at least one resilient electrically-conductive member against at least one electrically-conductive surface disposed on the substrate, to establish electrical conductivity therebetween that is sufficient for EMI shielding performance.

2. The EMI shield of claim 1, wherein the at least one resilient electrically-conductive member intervenes between one or more areas partitioned by the at least one resilient electrically-conductive member, to provide for an attenuation of transfer of electromagnetic energy from the one or more partitioned areas that is sufficient for EMI shielding applications.

3. The EMI shield of claim 1, wherein the at least one resilient electrically-conductive member comprises silicone-based elastomer and electrically-conductive particles dispersed within the silicone-based elastomer.

4. The EMI shield of claim 1, wherein the electrical conductivity established by the at least one resilient electrically-conductive member between the cover and the at least one electrically-conductive surface is at least a minimal level sufficient for EMI shielding applications.

5. The EMI shield of claim 1, wherein the at least one resilient electrically-conductive member has a cross-section that increases in width from a free end portion to a base portion coupled to the cover.

6. The EMI shield of claim 1, wherein the at least one resilient electrically-conductive member is at least one or more of molded onto the cover or adhesively bonded to the cover.

7. The EMI shield of claim 1, wherein the at least one resilient electrically-conductive member provides an area of contact with the at least one electrically-conductive surface and provides an electrical impedance between the at least one electrically-conductive surface and the cover that is sufficient for EMI shielding applications.

8. The EMI shield of claim 1, wherein the cover comprises first and second covers for respectively shielding electrical components disposed on first and second sides of the substrate.

9. The EMI shield of claim 1, further comprising a plurality of EMI shielding compartments configured for covering a plurality of electrical components disposed on the substrate.

10. The EMI shield of claim 9, wherein the at least one resilient electrically-conductive member defines at least a portion of at least one of the EMI shielding compartments.

11. The EMI shield of claim 1, wherein the substrate includes generally opposite first and second sides defining a thickness therebetween, and wherein the first and second protrusions are spaced apart a distance greater than the thickness to thereby allow the first and second protrusions to be respectively positioned along the substrate'"'"'s first and second sides.

12. An electronic device including the EMI shield of claim 1, a printed circuit board having electrical components on generally opposite first and second sides of the printed circuit board, wherein the cover comprises first and second covers for shielding the electrical components on the respective first and second sides of the substrate.

13. The EMI shield of claim 1, wherein the cover is removably attachable to the substrate.

14. The EMI shield of claim 1, wherein the EMI shield is mechanically retained to the substrate without any frame.

15. The EMI shield of claim 1, wherein the EMI shield is mechanically retained to the substrate solely by the compressive clamping force generated by engagement of the first protrusion with the substrate and compression of the at least one resilient electrically-conductive member caused thereby.

16. The EMI shield of claim 1, wherein the cover includes a generally planar portion, and at least one tab downwardly depending relative to the generally planar portion, the at least one tab having the first and second protrusions and configured for extending across a thickness defined between the substrate'"'"'s first and second sides to thereby allow positioning of the second protrusion on a side of the substrate opposite that of the generally planar portion.

17. The assembly of claim 16, wherein the at least one tab includes at least one camming surface for urging the tab outwardly to thereby facilitating the positioning of the second protrusion on the substrate'"'"'s side opposite that of the generally planar portion.

18. The EMI shield of claim 1, wherein the first and second protrusions comprise inwardly extending half-dimples defining detents configured for engagement with the substrate.

19. A method of providing EMI shielding for a substrate having at least one electrical component disposed thereon, the method comprising attaching a cover to a substrate by capturing at least a portion of the substrate generally between at least a first protrusion of the cover and at least one electrically-conductive member disposed along an inner side of the cover to thereby engage the first protrusion with the substrate and compress the at least one electrically-conductive member for generating a compressive clamping force for mechanically retaining the cover to the substrate, and for compressing the at least one electrically-conductive member against at least one electrically-conductive surface disposed on the substrate, to establish electrical conductivity therebetween that is sufficient for EMI shielding performance.

20. The method of claim 19, further comprising detaching the cover from the substrate to access one or more electrical components on the substrate.

21. The method of claim 20, further comprising reusing the removed cover, or using a replacement cover.

22. The method of claim 19, wherein the step of attaching a cover includes attaching a first cover to the substrate for shielding one or more electrical components disposed on a first side of the substrate, and attaching a second cover to the substrate for shielding one or more electrical components on the second side of the substrate.

23. An EMI shield for a substrate having at least one electrical component disposed thereon, the EMI shield comprising.

a cover having at least a first protrusion;

at least one electrically-conductive member disposed along an inner side of the cover, and configured to be compressed generally between the substrate and the cover when at least a portion of the substrate is captured generally between the first protrusion and the electrically-conductive member;

whereby engagement of the first protrusion with the substrate and the compression of the electrically-conductive member generates a compressive clamping force for mechanically retaining the cover to the substrate, and for compressing the electrically-conductive member against at least one electrically-conductive surface disposed on the substrate, to establish electrical conductivity therebetween that is sufficient for EMI shielding performance.

24. The EMI shield of claim 23, wherein the cover includes a portion configured to be captured generally between spaced-apart first and second protruding portions of the substrate, such that contact between the cover'"'"'s portion and the substrate'"'"'s first protruding portion inhibits the cover from sliding in a first direction along the substrate, and such that contact between the cover'"'"'s portion and the substrate'"'"'s second protruding portion inhibits the cover from sliding in a second direction along the substrate.

25. The EMI shield of claim 23, wherein the cover and the substrate cooperatively define means for inhibiting sliding of the cover relative to the substrate.

26. The EMI shield of claim 23, further comprising at least one thermally-conductive compliant material disposed relative to an inner surface of the cover and to the at least one electrical component for forming a thermally-conducting heat path from the at least one electrical component to the cover.

27. The EMI shield of claim 23, wherein the at least one electrically-conductive member comprises at least one flexible electrically-conductive member.

28. The EMI shield of claim 23, wherein the at least one electrically-conductive member comprises at least one elastomeric electrically-conductive member.