Electronic device assemblies and vehicles employing dual phase change materials

1. An electronic device assembly comprising:

a semiconductor device comprising a surface, wherein the semiconductor device operates in a transient heat flux state and a normal heat flux state;

a housing configured to receive a coolant fluid thermally coupled to the surface of the semiconductor device;

one or more thermally conductive features thermally coupled to the surface of the semiconductor device and disposed within the housing; and

a phase change material disposed within the one or more thermally conductive features, the phase change material thermally coupled to the surface of the semiconductor device, the phase change material having a phase change temperature at which the phase change material changes from a first phase to a second phase, wherein the phase change material absorbs heat flux at least when the semiconductor device operates in the transient heat flux state.

2. The electronic device assembly of claim 1 , wherein the phase change material is a solid when it is at a temperature below the phase change temperature.

3. The electronic device assembly of claim 1 , wherein the one or more thermally conductive features are located at one or more edges of the surface of the semiconductor device.

4. The electronic device assembly of claim 1 , wherein the one or more thermally conductive features comprises a plurality of radially arranged thermally conductive features.

5. The electronic device assembly of claim 1 , wherein the one or more thermally conductive features are not rigidly coupled to the surface of the semiconductor device.

6. The electronic device assembly of claim 1 , wherein the phase change material comprises paraffin wax.

7. The electronic device assembly of claim 1 , further comprising a jet impingement nozzle configured to direct the coolant fluid toward the surface of the semiconductor device.

8. The electronic device assembly of claim 7 , wherein the coolant fluid impinges a central region of the surface of the semiconductor device.

9. The electronic device assembly of claim 1 , wherein:

the coolant fluid has a fluid phase change temperature at which the coolant fluid changes to a vapor; and

the fluid phase change temperature is reached when the semiconductor device operates at the normal heat flux state or the transient heat flux state.

10. The electronic device assembly of claim 1 , further comprising a cold plate comprising a heated surface and a cooling surface, wherein the surface of the semiconductor device is thermally coupled to the heated surface of the cold plate, and the coolant fluid and the phase change material are thermally coupled to the cooling surface of the cold plate.

11. An electronic device assembly comprising:

a semiconductor device comprising a surface, wherein the semiconductor device operates in a transient heat flux state and a normal heat flux state;

a housing configured to receive a coolant fluid thermally coupled to the surface of the semiconductor device, the coolant fluid having a fluid phase change temperature at which the coolant fluid changes to a vapor;

one or more thermally conductive features thermally coupled to the surface of the semiconductor device, wherein each thermally conductive feature of the one or more thermally conductive features defines an enclosure and the one or more thermally conductive features are disposed within the housing; and

a phase change material disposed within the enclosures of the one or more thermally conductive features, the phase change material having a phase change temperature at which the phase change material changes from a solid to a liquid.

12. The electronic device assembly of claim 11 , wherein the one or more thermally conductive features are made of copper.

13. The electronic device assembly of claim 11 , wherein the one or more thermally conductive features are located at one or more edges of the surface of the semiconductor device.

14. The electronic device assembly of claim 11 , wherein the one or more thermally conductive features comprises a plurality of radially arranged thermally conductive features.

15. The electronic device assembly of claim 11 , wherein the one or more thermally conductive features are not rigidly coupled to the surface of the semiconductor device.

16. The electronic device assembly of claim 11 , wherein the phase change material comprises paraffin wax.

17. The electronic device assembly of claim 11 , further comprising a jet impingement nozzle configured to spray the coolant fluid toward the surface of the semiconductor device.

18. A vehicle comprising:

an electric motor; and

a power electronics module comprising an electronic device assembly, wherein the power electronics module is electrically coupled to the electric motor, and the electronic device assembly comprises:

a semiconductor device comprising a surface, wherein the semiconductor device operates in a transient heat flux state and a normal heat flux state;

a housing configured to receive a coolant fluid thermally coupled to the surface of the semiconductor device;

one or more thermally conductive features thermally coupled to the surface of the semiconductor device and disposed within the housing; and

a phase change material disposed within the one or more thermally conductive features, the phase change material thermally coupled to the surface of the semiconductor device, the phase change material having a phase change temperature at which the phase change material changes from a first phase to a second phase, wherein the phase change material absorbs heat flux at least when the semiconductor device operates in the transient heat flux state.

19. The vehicle of claim 18 , wherein:

the phase change material is a solid when it is at a temperature below the phase change temperature.