Heat transfer structures and methods for IC packages
A method of transferring heat in a package includes conducting heat from a first device to a second device by a low thermal resistance substrate path in a chip layer of the package, conducting heat from an integrated circuit (IC) to a first package layer of the package, conducting heat from the first package layer of the package to at least a first set of through-vias positioned in the chip layer, and conducting heat from the first set of through-vias to a surface of a second package layer opposite the chip layer. The first device and the second device is part of the IC chip. The first package layer is adjacent to the chip layer.
1. A package structure comprising:
a first package layer comprising an electrical signal structure and a first set of redistribution lines electrically isolated from the electrical signal structure;
a second package layer comprising a second set of redistribution lines, and the second package layer being over the first package layer;
a heat spreader over the second package layer;
a chip layer between the first package layer and the second package layer, the chip layer comprising:
a molding material; and
an integrated circuit (IC) chip in the molding material, and being electrically coupled to the electrical signal structure, the IC chip comprising:
a first device and a second device thermally coupled to the first device by a first low thermal resistance path,
wherein the first set of redistribution lines and the second set of redistribution lines are configured as a second low thermal resistance path from the IC chip to a surface of the second package layer opposite the chip layer.
2. The package structure of claim 1 , further comprising:
a set of through-vias extending through the chip layer and the second package layer to the surface of the second package layer opposite the chip layer,
wherein the set of through-vias are configured as part of the second low thermal resistance path from the IC chip to the surface of the second package layer opposite the chip layer.
3. The package structure of claim 1 , further comprising:
a printed circuit board (PCB) coupled to a surface of the first package layer opposite the chip layer.
4. The package structure of claim 3 , further comprising:
a set of electrical connectors on the surface of the first package layer opposite the chip layer, and being coupled to the electrical signal structure; and
a set of under-bump metallurgies (UBMs) positioned between the PCB and the set of electrical connectors,
wherein the set of electrical connectors and the set of UBMs electrically couple the PCB to the electrical signal structure.
5. The package structure of claim 1 , wherein the IC chip further comprises:
an electrical signal path from the first device to a first surface of the IC chip, the electrical signal path being electrically coupled to the electrical signal structure, and the electrical signal structure extending through the first package layer.
6. The package structure of claim 5 , wherein the IC chip further comprises:
a third low thermal resistance path extending from the second device to the first surface of the IC chip, the third low thermal resistance path being thermally coupled to the first set of redistribution lines.
7. The package structure of claim 6 , wherein
the first device and the electrical signal path are part of an integrated voltage regulator;
the second device comprises a dummy transistor comprising a gate, a source, and a drain; and
the third low thermal resistance path is thermally coupled to each of the gate, the source, and the drain by a corresponding low thermal resistance path.
8. A package structure comprising:
a first package layer comprising an electrical signal structure, a first thermal conduction structure and a second thermal conduction structure, the first thermal conduction structure and the second thermal conduction structure being electrically isolated from the electrical signal structure;
a second package layer over the first package layer;
a chip layer over the first package layer, the chip layer comprising:
an integrated circuit (IC) chip electrically coupled to the electrical signal structure;
a first set of through-vias coupled to the first thermal conduction structure, and extending through at least the chip layer and the second package layer; and
a second set of through-vias coupled to the second thermal conduction structure, extending through at least the chip layer and the second package layer, and being separated from the first set of through-vias in a first direction,
wherein the first thermal conduction structure and the first set of through-vias are configured as a first low thermal resistance path from the IC chip to a surface of the second package layer opposite the chip layer, and
the second thermal conduction structure and the second set of through-vias are configured as a second low thermal resistance path from the IC chip to the surface of the second package layer.
9. The package structure of claim 8 , further comprising:
a heat spreader over the second package layer; and
a set of under-bump metallurgies (UBMs) positioned between the heat spreader and the second package layer.
10. The package structure of claim 8 , further comprising:
a set of under-bump metallurgies (UBMs) coupled to the first package layer; and
a printed circuit board (PCB) electrically coupled to the electrical signal structure by at least the set of UBMs.
11. The package structure of claim 8 , wherein the second package layer comprises:
a set of thermal conduction structures extending in the first direction, and being coupled to the first set of through-vias and the second set of through-vias.
12. The package structure of claim 1 , further comprising:
a set of under-bump metallurgies (UBMs) positioned between the heat spreader and the second package layer.
13. A package structure comprising:
a first package layer comprising an electrical signal structure and a first set of redistribution lines electrically isolated from the electrical signal structure;
a set of under-bump metallurgies (UBMs) coupled to the first package layer;
a second package layer comprising a second set of redistribution lines, and the second package layer being above the first package layer;
a chip layer between the first package layer and the second package layer, the chip layer comprising:
a molding material; and
an integrated circuit (IC) chip embedded in the molding material, and being electrically coupled to the electrical signal structure, the IC chip comprising:
a first device and a second device thermally coupled to the first device by a first low thermal resistance path,
wherein the first set of redistribution lines and the second set of redistribution lines are configured as a second low thermal resistance path from the IC chip to a surface of the second package layer opposite the chip layer.
14. The package structure of claim 13 , further comprising:
a printed circuit board (PCB) coupled to the set of UBMs.
15. The package structure of claim 13 , further comprising:
a first set of through-vias coupled to the first set of redistribution lines, and extending through at least the chip layer and the second package layer.
16. The package structure of claim 15 , wherein the first package layer further comprises:
a third set of redistribution lines electrically isolated from the electrical signal structure.
17. The package structure of claim 16 , further comprising:
a second set of through-vias coupled to the third set of redistribution lines, and extending through at least the chip layer and the second package layer, and being separated from the first set of through-vias in a first direction.
18. The package structure of claim 17 , wherein the second set of redistribution lines are electrically coupled to the first set of through-vias and the second set of through-vias.
19. The package structure of claim 13 , wherein the package structure is part of an integrated fan-out package.
20. The package structure of claim 13 , wherein
the first device is part of an integrated voltage regulator; and
the second device comprises a dummy transistor comprising a gate, a source, and a drain.