Immersion cooling electronic devices
Embodiments have two approaches as follows: (1) Embedded PCB-based fabrication and (2) PCB assembly-based fabrication. An embedded printed circuit board (PCB) type approach involves the creation of a space of coolant direct interconnection, using immersion cooling to link on any type of power semiconductor device hot spots to convectively and evaporatively cool directly. This means fabricating PCB embedded channels, to utilize the microgap between die and PCB as the cooling channel. A printed circuit board (PCB) assembly embodiment includes a PCB having at least one heat generating component. A lid is mounted to the PCB, wherein the lid defines a cooling path therein extending in a coolant flow direction from an inlet end of the cooling path to an outlet end of the cooling path.
1. An embedded printed circuit board (PCB) assembly comprising:
a first PCB including at least one heat generating component;
a cooling path extending in a coolant flow direction from an inlet end of the cooling path to an outlet end of the cooling path, wherein the cooling path is in fluid communication with the at least one heat generating component;
a second PCB defining a perimeter wall about the cooling path, the second PCB sealed to the first PCB;
a third PCB including an inlet and an outlet for the cooling path, the third PCB sealed to the second PCB, the cooling path defined in an interior space bounded by the first, the second, and the third PCBs; and
one or more vias extending from an exterior surface of the third PCB, through the third PCB, through the second PCB, and through the first PCB to an exterior surface of the first PCB.
2. The assembly as recited in claim 1 , wherein at least one of the second PCB and the third PCB forms a lid, and wherein the lid defines the cooling path.
3. The assembly as recited in claim 2 , wherein the lid includes a unitary polymer element defining the inlet and the outlet for the cooling path.
4. The assembly as recited in claim 3 , wherein the lid is joined to the first PCB with one or more fasteners.
5. The assembly as recited in claim 4 , wherein the one or more fasteners each extend through the first PCB and into the lid.
6. The assembly as recited in claim 2 , wherein the lid includes electronic devices mounted thereto.
7. The assembly as recited in claim 1 , wherein:
the second PCB is sealed to the first PCB with a first seal element; and
the third PCB is sealed to the second PCB with a second seal element.
8. The assembly as recited in claim 7 , wherein the first and the second seal elements are laser cut.
9. The assembly as recited in claim 7 , wherein the first and the second seal elements include Indium.
10. The assembly as recited in claim 1 , wherein:
the at least one heat generating component includes a die inside a package;
the die is configured to generate heat; and
the package is in direct fluid communication with the cooling path.
11. The assembly as recited in claim 1 , wherein the at least one heat generating component includes a die in direct fluid communication with the cooling path without an intervening package.
12. The assembly as recited in claim 11 , wherein the die is embedded in the first PCB.
13. The assembly as recited in claim 1 , wherein the at least one heat generating component includes a die embedded in the first PCB with a direct bonded copper (DBC) packaging intervening between the die and direct fluid communication with the cooling path.
14. The assembly as recited in claim 1 , wherein the first PCB includes an electronic device mounted to an external surface thereof, opposite an interior surface of the first PCB that bounds the cooling path.
15. The assembly as recited in claim 14 , wherein the electronic device mounted to the external surface includes a capacitor.
16. The assembly as recited in claim 14 , wherein the electronic device mounted to the external surface is electrically connected to the at least one heat generating component.
17. The assembly as recited in claim 16 , wherein the one or more vias through the first PCB electrically connect the at least one heat generating component to the electronic device mounted to the external surface.
18. The assembly as recited in claim 1 , further comprising a cryogenic and non-conductive fluid coolant in the cooling path.
19. An embedded printed circuit board (PCB) assembly comprising:
a first PCB with an embedded electronics device PCB packaging and including at least one heat generating component;
a cooling path extending in a coolant flow direction from an inlet end of the cooling path to an outlet end of the cooling path, wherein the cooling path is in fluid communication with the at least one heat generating component;
a second PCB defining a perimeter wall about the cooling path, which includes a micro cooling channel;
a third PCB that includes an inlet and an outlet for the cooling path, wherein the second PCB is sealed with a first seal element to the first PCB, wherein the third PCB is sealed to the second PCB with a second seal element, and wherein the cooling path is defined in an interior space bounded by the first, the second, and the third PCBs; and
one or more vias extending from an exterior surface of the third PCB, through the third PCB, through the second PCB, and through the first PCB to an exterior surface of the first PCB.
20. The assembly as recited in claim 19 , wherein the third PCB includes a unitary polymer element defining the inlet and the outlet for the cooling path.
21. The assembly as recited in claim 19 , wherein the first and the second seal elements include Indium.