| 摘要 |
A system and method are presented for forming a grid array device package around an integrated circuit (i.e., chip), the packaged device incorporating electromagnetic shielding. Embodiments of the packaged device include an integrated circuit, a substrate, and a thermally and electrically conductive heat spreader. The integrated circuit includes multiple input/output (I/O) pads on an underside surface divided into a central portion and a surrounding peripheral portion. Members of the central portion are connected to corresponding bonding pads on an upper surface of the substrate using the controlled collapse chip connection (C4) method. Members of the peripheral portion are connected to an electrical ground potential. One end of a grounding lead is attached to each member of the peripheral portion of the I/O pads such that the remaining free end extends outward from the integrated circuit. The grounding leads may be, for example, metal foil strips or wires. The free ends of the grounding leads are electrically coupled to the heat spreader, maintaining the heat spreader at the ground potential and forming an electromagnetic shield about the integrated circuit. In two embodiments, the packaged device includes an electrically conductive stiffener used to help the substrate maintain its planar shape during and after C4 heating. The grounding leads maintain the heat spreader and the stiffener at the ground potential. In another embodiment, the stiffener is omitted, the integrated circuit resides within a cavity of the heat spreader, and the grounding leads maintain the heat spreader at the ground potential.
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