Combination parallel path heatsink and EMI shield
Electronic devices have a PCB with a heat-generating component (e.g., POP or SOC), a heat sink, and an EMI shielding structure. A combination structure can include a top heat spreader/EMI shield located above and in thermal contact with the POP/SOC top, a bottom heat spreader/EMI shield located below and in thermal contact with the POP/SOC bottom, and a heat-directing component located on the PCB, laterally surrounding a majority of the POP/SOC sides, and between and in thermal contact with the top and bottom heat spreaders. Resulting heat paths for the POP/SOC include one through its top to the top heat spreader, another through its bottom to the bottom heat spreader, and others through its sides through the PCB through the heat-directing component to the top and bottom heat spreaders. The heat-directing component can be a metal horseshoe shaped pad integrally formed onto the PCB.
1. An electronic device, comprising: an outer housing arranged to enclose and support a plurality of internal components; a printed circuit board having a plurality of electronic elements located within the outer housing; a heat-generating component located on the printed circuit board, wherein the heat-generating component includes a top surface, a bottom surface, and multiple side surfaces; and a heat sink structure configured to dissipate heat from the heat-generating component, wherein the heat sink structure is in thermal contact with and surrounds the heat generating component at the top surface, the bottom surface, and a majority of the one or more side surfaces, wherein the heat sink structure includes a heat-directing pad extending normal to the printed circuit board, and wherein the heat-directing pad extends laterally about all but one side surface[s] of the heat generating component and is directly adjacent each side of the plurality of sides without intervening components.
2. The electronic device of claim 1 , wherein the printed circuit board includes a plurality of electromagnetic interference (“EMI”) shielding frame walls that extend away from both a top surface and a bottom surface of the printed circuit board.
3. The electronic device of claim 1 , wherein the heat sink structure includes:
a top heat spreader located above and in thermal contact with the heat-generating component top surface, the top heat spreader being adapted to provide EMI shielding for at least some of the electronic elements,
a bottom heat spreader located below and in thermal contact with the heat-generating component bottom surface, the bottom heat spreader being adapted to provide EMI shielding for at least some of the electronic elements, and
wherein the heat-directing pad is located on the printed circuit board and between and in thermal contact with the top heat spreader and the bottom heat spreader, and wherein the heat-directing pad directs heat from the printed circuit board into the top heat spreader and the bottom heat spreader.
4. The electronic device of claim 3 , wherein the at least one heat-directing pad comprises a copper pad that is integrally formed on the printed circuit board and that surrounds the heat-generating component on three sides.
5. The electronic device of claim 3 , wherein the printed circuit board includes a plurality of EMI frame walls that extend away from a top surface of the printed circuit board to contact the top heat spreader and away from a bottom surface of the printed circuit board to contact the bottom heat spreader to forth collectively one or more Faraday cages that surround the plurality of electronic elements.
6. The electronic device of claim 3 , wherein the top heat spreader and the bottom heat spreader are formed from aluminum.
7. The electronic device of claim 3 , wherein one or both of the top heat spreader and the bottom heat spreader defines an area that is larger than an area defined by the printed circuit board.
8. The electronic device of claim 3 , wherein resulting heat paths for the heat-generating component include a heat path through the top surface to the top heat spreader, a heat path through the bottom surface to the bottom heat spreader, and heat paths through at least a portion of the multiple side surfaces through the printed circuit board through the at least one heat-directing pad to the top heat spreader and the bottom heat spreader.
9. The electronic device of claim 1 , wherein the printed circuit board comprises a plurality of layers and a plurality of heat-directing vias thermally coupling two or more of the plurality of layers.
10. The electronic device of claim 1 , wherein the heat-directing pad is characterized by a U-shape extending about the heat-generating component.
11. The electronic device of claim 1 , wherein EMI shielding is positioned in contact with the printed circuit board laterally outward from and extending about the heat-directing pad.
12. The electronic device of claim 11 , wherein the EMI shielding includes a gasket extending orthogonally to a vertical wall in contact with the printed circuit board.
13. The electronic device of claim 1 , wherein the heat-directing pad extends about and adjacent to all but one lateral side of the heat-generating component.
14. An electronic device, comprising: a printed circuit board having a plurality of electronic elements including a heat generating component having a top surface, a bottom surface, and multiple side surfaces; and a heat sink structure configured to dissipate heat from the heat-generating component, the heat sink structure including one or more heat spreaders, a heat-directing component, and a portion of the printed circuit board between the heat-generating component and the heat-directing component, wherein the heat-directing component extends normal to the printed circuit board, and wherein the heat-directing component extends laterally about all but one side surface[s] of the heat-generating component, and is adjacent each of the side surfaces without intervening components.
15. The electronic device of claim 14 , wherein the heat-directing component comprises a metal pad that is integrally formed on the printed circuit board.
16. The electronic device of claim 14 , wherein the heat-generating component comprises four sides, and the heat-directing component surrounds the heat-generating component on three of the four sides.
17. The electronic device of claim 14 , wherein the heat sink structure further includes:
a top heat spreader located above and in thermal contact with the heat-generating component top surface, and
a bottom heat spreader located below and in thermal contact with the heat-generating component bottom surface, the bottom heat spreader being adapted to provide EMI shielding for at least some of the electronic elements.
18. The electronic device of claim 17 , wherein the heat-directing component directs heat received from the heat-generating component via the printed circuit board into the top heat spreader and the bottom heat spreader.
19. The electronic device of claim 17 , wherein the top beat spreader and bottom heat spreader substantially surround the printed circuit board.
20. The electronic device of claim 14 , wherein resulting heat paths for the heat-generating component include a beat path through its top surface, a heat path through its bottom surface, and heat paths through at least a portion of the multiple side surfaces through the printed circuit board and to the heat-directing component.