Method and apparatus for delivering power to semiconductors
A semiconductor package includes a VLSI semiconductor die and one or more output circuits connected to supply power to the die mounted to a package substrate. The output circuit(s), which include a transformer and rectification circuitry, provide current multiplication at an essentially fixed conversion ratio, K, in the semiconductor package, receiving AC power at a relatively high voltage and delivering DC power at a relatively low voltage to the die. The output circuits may be connected in series or parallel as needed. A driver circuit may be provided outside the semiconductor package for receiving power from a source and driving the transformer in the output circuit(s), preferably with sinusoidal currents. The driver circuit may drive a plurality of output circuits. The semiconductor package may require far fewer interface connections for supplying power to the die.
1. A method of supplying power received from an input source at an input voltage, Vin, for delivery to circuitry on a semiconductor chip at a DC output voltage, Vchip, comprising:
providing a first power conversion circuit having an input for receiving power from the source at the input voltage, Vin, and an output for delivering power at a second voltage, V 2 ;
providing a point of load (“POL”) module that includes a point of load circuit, wherein the point of load module is located outside of the semiconductor chip, the POL circuit having a POL input connected to receive power from the first power conversion circuit at the second voltage, V 2 , the POL circuit having second power conversion circuitry configured to convert power received from the POL input at the second voltage, V 2 , for delivery at the output voltage, Vchip, via a POL output to the semiconductor chip, wherein the point of load module and the semiconductor chip are both mounted on a substrate;
providing heat conductors through the POL module using through-module terminations that enhance thermal conductivity; and
providing a path for heat flow from the semiconductor chip through the substrate to the point of load module using the heat conductors, and dissipating at least a portion of heat generated by the semiconductor chip through the point of load module.
2. The method of claim 1 wherein the point of load module and the semiconductor chip are mounted on a same side of the substrate.
3. The method of claim 1 wherein a lid made of thermally conductive material is attached to the point of load module, the point of load module is configured to provide thermally conductive conduits between the substrate and the lid, facilitating removal of at least a portion of heat generated by the semiconductor chip through the substrate, the point of load module, and the lid.
4. The method of claim 3 wherein a first portion of the lid is attached to the semiconductor chip, and a second portion of the lid is attached to the point of load module, a first thermal path is provided from the semiconductor chip directly to the lid, and a second thermal path is provided from the semiconductor chip through the substrate and the thermally conductive conduits of the point of load module to the lid.
5. The method of claim 1 wherein the semiconductor chip is mounted on a first side of the substrate, a first side of the point of load module is mounted on a second side of the substrate, a second side of the point of load module is mounted on a system board; and
wherein the method comprises providing a path for heat flow from the semiconductor chip through the substrate and the point of load module to the system board, and dissipating at least a portion of heat generated by the semiconductor chip through the system board.
6. The method of claim 1 wherein the semiconductor chip comprises at least one of a processor core or an application specification integrated circuit.
7. The method of claim 1 wherein the semiconductor chip comprises at least one of a central processing unit or a graphics processing unit.
8. The method of claim 1 wherein the path for heat flow also allows heat generated by the point of load module to be conducted to the semiconductor chip, wherein the method comprises dissipating at least a portion of heat generated by the point of load module through the semiconductor chip.
9. The method of claim 1 wherein the POL circuit provides at least 5 to 1 current multiplication from the POL input to POL output in a single power conversion stage.
10. The method of claim 1 wherein the input voltage is greater than 40 VDC.
11. The method of claim 10 wherein the second voltage, V 2 , is greater than 20 VDC and the output voltage, Vchip, is less than 3 VDC.
12. The method of claim 1 wherein the second voltage, V 2 , is greater than 5 VDC and the output voltage is 1 VDC or less.
13. A method of supplying power received from an input source at an input voltage, Vin, for delivery to circuitry on a semiconductor chip at a DC output voltage, Vchip, comprising:
providing a first power conversion circuit having an input for receiving power from the source at the input voltage, Vin, and an output for delivering power at a second voltage, V 2 ;
providing a point of load (“POL”) module that includes a point of load circuit, wherein the point of load module is located outside of the semiconductor chip, the POL circuit having a POL input connected to receive power from the first power conversion circuit at the second voltage, V 2 , the POL circuit having second power conversion circuitry configured to convert power received from the POL input at the second voltage, V 2 , for delivery at the output voltage, Vchip, via a POL output to the semiconductor chip;
wherein the semiconductor chip is mounted on a first side of a substrate, and the point of load module is mounted on a second side of the substrate, the substrate having conductive vias that provide thermal paths through the substrate; and
providing a path for heat flow from the point of load module through the conductive vias of the substrate to the semiconductor chip, and through the semiconductor chip to a heat sink or a lid attached to the semiconductor chip, and dissipating at least a portion of heat generated by the point of load module through the heat sink or lid, in which the lid is made of a thermally conductive material.
14. The method of claim 13 wherein conductive pads on a bottom surface of the semiconductor chip are electrically and thermally connected to conductive pads on a top surface of the substrate;
conductive pads on a bottom surface of the substrate are electrically and thermally connected to conductive pads on a top surface of the point of load module; and
conductive pads on the top surface of the substrate are electrically and thermally connected to respective conductive pads on the bottom surface of the substrate through the respective conductive vias.
15. The method of claim 14 wherein conductive pads on a bottom surface of the point of load module are electrically and thermally connected to respective conductive pads on a system board; and
wherein the method comprises providing a path for heat flow from the point of load module to the system board, and dissipating at least a portion of heat generated by the point of load module through the system board.
16. The method of claim 13 wherein the first power conversion circuit is further adapted to regulate the output voltage, Vchip.
17. The method of claim 13 wherein the second power conversion circuit further comprises voltage transformation at an essentially fixed ratio, K=Vchip/V 2 .
18. The method of claim 13 , comprising delivering the output voltage, Vchip, from the POL output to a plurality of integrated circuit (IC) power terminations on the semiconductor chip, wherein the IC power terminations comprise a plurality of first polarity power terminations and a plurality of second polarity power terminations arranged in a first pattern including alternation of the first polarity power terminations and the second polarity power terminations on a surface of the semiconductor chip and being electrically connected to conduct electrical power to circuitry in the semiconductor chip.
19. The method of claim 18 wherein the alternating arrangement of the first pattern includes a juxtaposition of each first polarity power termination adjacent to a respective second polarity power termination and each second polarity power termination adjacent to a respective first polarity power termination.
20. The method of claim 19 wherein the first pattern comprises an array of rows and columns of integrated circuit power terminations, each row and column including a plurality of the first polarity power terminations and the second polarity power terminations, each first polarity power termination within a selected row or column being adjacent to a respective second polarity power termination within the selected row or column.