Structures for improving heat dissipation in stacked semiconductor packages
View Patent ↗Semiconductor packages including at least two semiconductor dies are disclosed. A first die is mounted on a substrate, which may be a metallized laminate or a leadframe. A rigid support structure is mounted on the substrate over the first die. The support structure may be thermally coupled to the substrate, and also may be electrically coupled to the substrate. A second die is mounted on the support structure, which spaces the second die away from the first die. Encapsulant fills the volume within the support structure, including the vertical space between the pair of dies. In an alternative package embodiment, a heat spreader formed of a flexible metal sheet may be thermally coupled between the two stacked dies. The heat spreader transfers heat from the first and second dies to a heat sink of the substrate. The support structure and the heat spreader mitigate the transfer of heat between the first and second dies.
1. A semiconductor package comprising:
a substrate;
a first die electrically coupled to the substrate;
a second die electrically coupled to the substrate and superimposed over the first die; and
a metal heat spreader disposed between the first and second dies, thermally coupled to the first and second dies by respective thermally conductive layers, and thermally coupled to the substrate, wherein the second die is electrically coupled to the substrate through at least one aperture in the heat spreader; and
a unitary body of a hardened encapsulant covering the first and second dies and filling an internal cavity of the heat spreader.
2. The semiconductor package of claim 1 , wherein the first die is electrically coupled to the substrate in a flip chip connection.
3. The semiconductor package of claim 2 , wherein the second die is electrically coupled to the substrate by conductive wires.
4. The semiconductor package of claim 1 , wherein the first and second dies are electrically coupled to the substrate by conductive wires.
5. The semiconductor package of claim 1 , further comprising a metal second heat spreader superimposed over the first and second dies, and thermally coupled between the second die and the substrate.
6. The semiconductor package of claim 5 , wherein the second heat spreader is thermally coupled to an active surface of the second die.
7. The semiconductor package of claim 6 , wherein the first die is electrically coupled to the substrate in a flip chip connection.
8. The semiconductor package of claim 7 , wherein the second die is electrically coupled to the substrate by at least two conductive wires each of which extends through a respective said aperture in the heat spreader, and by at least one conductive wire that contacts the substrate outward of a perimeter of the heat spreader.
9. The semiconductor package of claim 7 , wherein the second die is electrically coupled to the substrate by at least two conductive wires each of which extends through a respective said aperture in the heat spreader.
10. The semiconductor package of claim 5 , wherein the first and second dies are electrically coupled to the substrate by conductive wires.
11. The semiconductor package of claim 10 , wherein the second die is electrically coupled to the substrate by at least two conductive wires each of which extends through a respective said aperture in the heat spreader.
12. A semiconductor package comprising:
a substrate;
a first die electrically coupled to the substrate;
a second die superimposed over the first die; and
a metal first heat spreader, wherein the first heat spreader is thermally coupled between the inactive surface of the first die and the inactive surface of the second die, and is thermally coupled to the substrate, and the second die is electrically coupled to the substrate through at least one aperture in the heat spreader; and
a unitary body of a hardened encapsulant covering the first and second dies and filling an internal cavity of the first heat spreader.
13. The semiconductor package of claim 12 , wherein the second die is electrically coupled to the substrate by at least two conductive wires each of which extends through a respective said aperture in the heat spreader.
14. The semiconductor package of claim 13 , wherein the second die also is electrically coupled to the substrate by at least one conductive wire that does not extend through any aperture in the first heat spreader.
15. The semiconductor package of claim 13 , wherein the second die also is electrically coupled to the substrate by at least one conductive wire that contacts the substrate outward of a perimeter of the heat spreader.
16. The semiconductor package of claim 12 , further comprising a metal second heat spreader superimposed over the first and second dies, and thermally coupled between the active surface of the second die and the substrate, wherein the encapsulant fills an internal cavity of the second heat spreader.
17. The semiconductor package of claim 12 , further comprising a metal second heat spreader superimposed over the first and second dies, and thermally coupled between the active surface of the second die and the substrate.
18. A semiconductor package comprising:
a substrate;
a first die electrically coupled to the substrate by conductive wires;
a second die superimposed over the first die and electrically coupled to the substrate by conductive wires; and
a metal first heat spreader, wherein the first heat spreader is thermally coupled between the active surface of the first die and the inactive surface of the second die, and is thermally coupled to the substrate, and the second die is electrically coupled to the substrate through at least one aperture in the heat spreader; and
a unitary body of a hardened encapsulant covering the first and second dies and filling an internal cavity of the first heat spreader.
19. The semiconductor package of claim 18 , wherein the second die is electrically coupled to the substrate by at least two conductive wires each of which extends through a respective said aperture in the heat spreader.
20. The semiconductor package of claim 19 , wherein the second die also is electrically coupled to the substrate by at least one conductive wire that does not extend through any aperture in the first heat spreader.
21. The semiconductor package of claim 19 , wherein the second die also is electrically coupled to the substrate by at least one conductive wire that contacts the substrate outward of a perimeter of the heat spreader.
22. The semiconductor package of claim 18 , further comprising a metal second heat spreader superimposed over the first and second dies, and thermally coupled between the active surface of the second die and the substrate, wherein the encapsulant fills an internal cavity of the second heat spreader.
23. The semiconductor package of claim 18 , further comprising a metal second heat spreader superimposed over the first and second dies, and thermally coupled between the active surface of the second die and the substrate.
24. The semiconductor package of claim 23 , wherein the second die is electrically coupled to the substrate by at least two conductive wires each of which extends through a respective said aperture in the heat spreader.