Packaged integrated circuit with enhanced thermal dissipation
View Patent ↗A semiconductor package ( 10 ) uses a plurality of thermal conductors ( 56 - 64 ) that extend upward within an encapsulant ( 16 ) from one or more thermal bond pads ( 22, 24, 26 ) on a die ( 14 ) to disperse heat. The thermal conductors may be bond wires or conductive stud bumps and do not extend beyond a lateral edge of the die. One or more of the thermal conductors may be looped within the encapsulant and exposed at an upper surface of the encapsulant. In one form a heat spreader ( 68 ) is placed overlying the encapsulant for further heat removal. In another form the heat spreader functions as a power or ground terminal directly to points interior to the die via the thermal conductors. Active bond pads may be placed exclusively along the die's periphery or also included within the interior of the die.
1. A method of packaging an integrated circuit comprising:
providing a semiconductor die comprising a plurality of active bond pads having an electrical function associated therewith and comprising a plurality of thermal bond pads;
locating the plurality of thermal bond pads within an inner region of the semiconductor die;
placing the semiconductor die overlying a substrate;
connecting one or more thermal conductors to each of the plurality of thermal bond pads, each of the one or more thermal conductors extending upward from the semiconductor die, each of the one or more thermal conductors not extending beyond a peripheral edge of the semiconductor die; and
surrounding the semiconductor die, the plurality of thermal bond pads, the plurality of active bond pads and the one or more thermal conductors with an encapsulant to permit the thermal conductors to conduct heat from the semiconductor die to an upper surface of the encapsulant.
2. The method of claim 1 further comprising:
providing at least one conductive heat spreader overlying the one or more thermal conductors for conducting heat from the one or more thermal conductors.
3. The method of claim 2 further comprising:
coupling the conductive heat spreader to at least one of the one or more thermal conductors for use as a signal conductor for either conducting a power supply voltage or providing a ground reference potential to the semiconductor die via the at least one of the one or more thermal conductors.
4. The method of claim 1 further comprising:
locating at least one of the plurality of active bond pads within a central region of the semiconductor die and locating a remainder of the plurality of active bond pads within a peripheral region of the semiconductor die.
5. The method of claim 1 further comprising:
providing at least one of the one or more thermal conductors as a thermal bond wire that forms a loop within the encapsulant and contacts one or more of the plurality of thermal bond pads, the loop reaching an upper surface of the encapsulant.
6. A method of making a packaged integrated circuit comprising:
providing a semiconductor die overlying a substrate, wherein the semiconductor die has active circuitry;
forming a plurality of thermal bond pads over the active circuitry;
forming a plurality of thermal bond wires that are connected to the thermal bond pads and extend upward from the semiconductor die and terminating without extending beyond a perimeter of the semiconductor die; and
surrounding the semiconductor die and the plurality of thermal bond wires with an encapsulant.
7. The method of claim 6 wherein the step of surrounding is further characterized by one or more of the plurality of thermal bond wires extending to an upper surface of the encapsulant.
8. The method of claim 6 wherein the step of forming a plurality of thermal bond wires is further characterized by at least one of the plurality of thermal bond wires being connected to two thermal bond pads by extending from a first of the two thermal bond pads away from a surface of the semiconductor die and returning toward the surface of the semiconductor die to connect to a second of the two thermal bond pads.
9. The method of claim 6 further comprising:
forming a conductive heat spreader overlying at least one of the plurality of thermal bond wires for conducting heat from the at least one of the plurality of thermal bond wires and radiating the heat from the packaged integrated circuit.
10. The method of claim 9 wherein the step of forming the conductive heat spreader is further characterized by at least one of the plurality of thermal bond wires being connected to the at least one conductive heat spreader to function as a power conductor or a ground conductor overlying the semiconductor die.
11. The method of claim 6 wherein the step of forming the plurality of thermal bond pads is further characterized by a portion of the plurality of thermal bond pads not being connected to any active circuitry within the semiconductor die.
12. The method of claim 11 wherein the portion is substantially all of the plurality of thermal bond pads.
13. The method of claim 6 wherein the step of forming the plurality of thermal bond pads is further characterized by at least one of the plurality of thermal bond pads being connected to a power or a ground terminal within the active circuitry.
14. The method of claim 6 further comprising:
forming a plurality of active bond pads positioned around a periphery of the semiconductor die within a pad ring region and electrically connected to respective package bond pads outside the perimeter of the semiconductor die.
15. A method of making a packaged integrated circuit comprising:
providing a semiconductor die overlying a substrate;
forming an active bond pad having an electrical function associated therewith and a first thermal bond pad not having an electrical function associated therewith overlying the semiconductor die;
forming an active conductor and a thermal conductor connected to the active bond pad and the first thermal bond pad, respectively, and extending upward from the semiconductor die; and
surrounding the semiconductor die, the active bond pad, the first thermal bond pad, the active conductor, and the thermal conductor with an encapsulant, whereby the thermal conductor conducts heat from the semiconductor die to an upper surface of the encapsulant.
16. The method of claim 15 wherein the step of forming the active conductor and a thermal conductor is further characterized by the thermal conductor comprising one of a group consisting a conductive stud bump and a bond wire.
17. The method of claim 15 wherein the step of forming the active bond pad and the first thermal bond pad further comprises forming a second thermal bond pad overlying the semiconductor die and wherein the step of forming the active conductor and a thermal conductor is further characterized by the thermal conductor extending from the first thermal bond pad away from the semiconductor die and returning toward the semiconductor die to connect to the second thermal bond pad.
18. The method of claim 15 further comprising:
forming a conductive heat spreader on the upper surface of the encapsulant and contacting the thermal conductor for conducting heat from the thermal conductor.
19. The method of claim 18 wherein the step of forming the conductive heat spreader is further characterized by the conductive heat spreader being a signal conductor for conducting either a power supply voltage or a ground reference potential.
20. The method of claim 15 wherein the step of forming the active bond pad and the first thermal bond pad is further characterized by the of active bond pad being located within a peripheral region of the packaged integrated circuit and the first thermal bond pad is located within a central region of the packaged integrated circuit.