Electrical-circuit assembly with heat-sink
An electrical-circuit assembly includes an electrical-device and a heat-sink. The heat-sink has a base having a first-surface and a second-surface. The first-surface is in thermal communication with the electrical-device. The heat sink also has a lid having a third-surface and a fourth-surface. The third-surface faces toward the second-surface. The heat sink also has side-walls disposed between the base and the lid extending from the second-surface to the third-surface. The base, the lid, and the side-walls define a cavity. The heat sink also has a porous-structure extending from the second-surface toward the third-surface terminating a portion of the distance between the second-surface and the third-surface thereby defining a void between the porous-structure and the third-surface. The base, the side-walls, and the porous-structure are integrally formed of a common material. The porous-structure is characterized as having a contiguous-porosity network. The heat sink also has a heat-transfer-fluid disposed within the cavity.
1. An electrical-circuit assembly, the assembly comprising:
a heat-sink having:
a base formed of a die cast aluminum alloy, the base having a first-surface and a second-surface opposite the first-surface, the first-surface in thermal communication with an electrical-device;
a lid having a third-surface and a fourth-surface opposite the third-surface, the lid arranged so the third-surface faces toward the second-surface;
side-walls formed of the die cast aluminum alloy integral to the base and disposed between the base and the lid extending from the second-surface to the third-surface, wherein the base, the lid, and the side-walls cooperate to define a cavity;
a porous-structure formed of the die cast aluminum alloy integral to the base and the side-walls, and extending from the second-surface toward the third-surface, the east porous-structure terminating a portion of a distance between the second-surface and the third-surface thereby defining a void between the east porous-structure and the third-surface;
the void extending along the entire east porous-structure and terminating on the side-walls;
the porous-structure having a contiguous-porosity network; and
a heat-transfer-fluid disposed within the cavity and the contiguous-porosity network of the porous-structure.
2. The assembly in accordance with claim 1 , wherein the heat-transfer-fluid occupies a portion of the cavity and a portion of the porous-structure.
3. The assembly in accordance with claim 1 , wherein a depth of the porous-structure is in a range from about 1.0 millimeters to about 4.0 millimeters.
4. The assembly in accordance with claim 1 , wherein the fourth-surface is configured to dissipate heat generated by the electrical-device to a surrounding environment.
5. The assembly in accordance with claim 1 , wherein the fourth-surface includes cooling-fins extending beyond the fourth-surface.
6. The assembly in accordance with claim 1 , wherein the contiguous-porosity network is characterized by a percent-porosity in a range from about 48 percent to about 74 percent.
7. The assembly in accordance with claim 1 , wherein the porous-structure defines an exposed-surface that is adjacent to the void.
8. The assembly in accordance with claim 7 , wherein the exposed-surface is a planar-surface.
9. The assembly in accordance with claim 7 , wherein the exposed-surface has undulations.
10. The assembly in accordance with claim 9 , wherein the undulations include at least one of ribs or dimples.
11. A heat-sink comprising:
a base formed of a die cast aluminum alloy, the base having a first-surface and a second-surface opposite the first-surface, the first-surface configured for thermal communication with an electrical-device;
a lid having a third-surface and a fourth-surface opposite the third-surface, the lid arranged so the third-surface faces toward the second-surface;
side-walls formed of the die cast aluminum alloy integral to the base and disposed between the base and the lid extending from the second-surface to the third-surface, wherein the base, the lid, and the side-walls cooperate to define a cavity;
a single porous-structure formed of the die cast aluminum alloy integral to the base and the side-walls, and extending from the second-surface toward the third-surface, the single porous-structure terminating a portion of a distance between the second-surface and the third-surface thereby defining a void between the single east porous-structure and the third-surface;
the void extending along the entire porous-structure and terminating on the side-walls;
the single porous-structure having a contiguous-porosity network; and
a heat-transfer-fluid disposed within the cavity and the contiguous-porosity network of the porous-structure.
12. The heat-sink in accordance with claim 11 , wherein the single porous-structure defines an exposed-surface adjacent to the void.
13. The heat-sink in accordance with claim 12 , wherein the exposed-surface is a planar-surface.
14. The heat-sink in accordance with claim 12 , wherein and the exposed-surface has undulations.
15. The heat-sink in accordance with claim 14 , wherein the undulations include at least one of ribs or dimples.
16. A method of making a heat-sink, comprising:
die-casting, from an aluminum alloy, a base;
the base having a first-surface and a second-surface opposite the first-surface, a single porous-structure, and side-walls;
the first-surface, second-surface, single porous-structure, and side-walls formed integral to the base and defining a cavity;
the first-surface configured for thermal communication with an electrical-device;
the single porous-structure having a contiguous-porosity network;
die-casting a lid;
the lid having a third-surface and a fourth-surface opposite the third-surface;
exposing a surface of the porous-structure;
dispensing a heat-transfer-fluid within the cavity and the contiguous-porosity network of the porous-structure; and
joining the lid to the side-walls;
the lid arranged such that the third-surface faces toward the second-surface of the base;
the single east porous-structure extending from the second-surface of the base toward the third-surface of the lid;
the single porous-structure terminating a portion of a distance between the second-surface and the third-surface thereby defining a void between the single porous-structure and the third-surface;
the void extending along the entire porous-structure and terminating on the side-walls.
17. A method of cooling an electrical-circuit assembly, comprising:
providing a heat-sink having:
a base formed of a die cast aluminum alloy, the base having a first-surface and a second-surface opposite the first-surface, the first-surface in thermal communication with an electrical-device;
a lid having a third-surface and a fourth-surface opposite the third-surface, the lid arranged so the third-surface faces toward the second-surface;
side-walls formed of the die cast aluminum alloy integral to the base and disposed between the base and the lid extending from the second-surface to the third-surface, wherein the base, the lid, and the side-walls cooperate to define a cavity;
a porous-structure formed of the die cast aluminum alloy integral to the base and the side-walls, and extending from the second-surface toward the third-surface, the porous-structure terminating a portion of a distance between the second-surface and the third-surface thereby defining a void between the porous-structure and the third-surface;
the void extending along the entire porous-structure and terminating on the side-walls;
the porous-structure having a contiguous-porosity network; and
disposing a heat-transfer-fluid within the cavity and the contiguous-porosity network of the porous-structure.