| 摘要 |
A grid array (GA) package for holding a die therein, the die accessing its operational power from a printed circuit board through the GA package, the GA package comprises a substrate with a die cavity. A first conductive layer is provided on a top surface of the substrate, a ring is provided surrounding the die cavity whereby the die electrically connects the first conductive layer via the ring. A second conductive layer is provided on a bottom surface of the substrate. A plurality of vias are provided within the substrate to connect the first conductive layer with the second conductive layer. A plurality of solder balls are provided on the bottom surface of the second conductive layer to connect the second conductive layer with the printed circuit board. Individual solder ball is horizontally closer to the die cavity in comparison with at least one associated via. Therefore when power transfers from individual solder ball through the second conductive layer, at least one associated via, the first conductive layer, and the ring, finally to the die. The direction of current that flow through the second conductive layer is opposite to the direction of current that flow through the first conductive layer, so as that the magnetic field produced by the current flow through the second conductive layer cancels out the magnetic field produced by the current flow through the first conductive layer, to decrease the power and ground impedance of the substrate.
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