A vapor-chamber that includes a porous microstructure sheet with varying surface energy across different regions to optimize utilization of a working fluid. Modulating the surface energy of the porous microstructure sheet can minimize the amount of the working fluid that becomes trapped in the condenser region(s) and maximize an aggregate thin-film evaporation area of the working fluid in the evaporator region(s). The condenser region of the vapor-chamber is treated so that the internal surfaces have low surface energy. For example, the treatment may cause the condenser region to become hydrophobic to minimize the amount of fluid that becomes trapped in the condenser. The evaporator region is treated so that the internal surfaces have high surface energy. For example, the treatment may cause the evaporator region to become hydrophilic to induce the formation of large numbers of robust (e.g., dry-out resistant) thin-film evaporation sites.

An apparatus includes first and second microchannel heat exchangers and first and second pipes. The first heat exchanger includes a first inlet, a second inlet, a first tube, a second tube, a first outlet, and a second outlet. Refrigerant at the first inlet is directed through the first tube to the first outlet and the first pipe. Refrigerant at the second inlet is directed through the second tube to the second outlet and the second pipe. The second heat exchanger includes a third inlet, a fourth inlet, a third tube, a fourth tube, a third outlet, and a fourth outlet. The third inlet directs refrigerant from the first pipe through the third tube towards the third outlet. The fourth inlet directs the refrigerant from the second pipe through the fourth tube towards the fourth outlet. The first pipe overlaps the second pipe between the two heat exchangers.

A vapor-chamber that includes a porous microstructure sheet with varying surface energy across different regions to optimize utilization of a working fluid. Modulating the surface energy of the porous microstructure sheet can minimize the amount of the working fluid that becomes trapped in the condenser region(s) and maximize an aggregate thin-film evaporation area of the working fluid in the evaporator region(s). The condenser region of the vapor-chamber is treated so that the internal surfaces have low surface energy. For example, the treatment may cause the condenser region to become hydrophobic to minimize the amount of fluid that becomes trapped in the condenser. The evaporator region is treated so that the internal surfaces have high surface energy. For example, the treatment may cause the evaporator region to become hydrophilic to induce the formation of large numbers of robust (e.g., dry-out resistant) thin-film evaporation sites.

A polymer-based heat transfer device comprising a polymer-based housing having housing walls defining a working fluid chamber, a porous structure extending in the working fluid chamber from at least one of the two opposed ones of the housing walls, and a plurality of housing wall spacers, such as support posts, extending between the two housing walls to maintain the two housing walls in a spaced-apart configuration with the working fluid chamber extending in between is provided. Also described is a polymer-based heat transfer device comprising a polymer-based housing having housing walls defining a working fluid chamber and a porous structure extending in the working fluid chamber from at least one of the two opposed ones of the housing walls, and heat-conductive metal or ceramic-based foam contacting at least one of the housing walls. A process for manufacturing the polymer-based heat transfer device is provided.

The present invention provides a PCB assembly. The PCB assembly comprises a PCB board element comprising an outer surface, and a micro heat pipe configured for heat transport. The micro heat pipe has a pipe wall and at least a section of the pipe wall is connected to the outer surface of the PCB board element in a thermally conductive manner. The thermally conductive connection may comprise a solder connection. Thus, a corresponding micro heat pipe may comprise a pipe wall, wherein at least a section of the pipe wall is configured to be soldered to a PCB element. Furthermore, the present invention provides a corresponding method of manufacturing a PCB assembly.

In one general aspect, a microelectronics cooling device can include a microchannel heat exchanger within an enclosure that houses the device at a heat absorbing end and another heat exchanger which is optionally also a microchannel heat exchanger at a heat sink end outside the enclosure. One or more pipes flowably connect the two ends for transporting liquid working fluid to the heat absorber and vaporized working fluid to the heat sink. The heat pipes may also be used to transfer heat outside a room that contains the electronic devices.

A cooling device for a heat source, such as an electronic component, has a single or set of nano- and/or micro-sized channel(s) connected to a single or multiple reservoir(s). The heat source causes nucleation within a channel, and a vapor bubble forms removing heat from the heat source via evaporation of liquid to vapor in the bubble and condensation of the generated vapor at the cooler ends of the bubble. Thus, the channel operates as a passive heat pipe and removes heat from the source by passively circulating the cooling fluid between the vapor bubble and the reservoir(s).

A heat pipe device includes an outer pipe and at least one first capillary structure. The outer pipe is a hollow pipe and has a defined lengthwise direction, and the first capillary structure is accommodated along the lengthwise direction and positioned in the outer pipe, and at least one steam channel is formed between the first capillary structure and the outer pipe. Even if the heat pipe device is upside down, the heat pipe still can resist gravity and work normally to achieve the effect of using the heat pipe without being limited by the using direction.

An example apparatus is disclosed that includes a base and a wickless capillary driven constrained vapor bubble heat pipe carried by the base. The wickless capillary driven constrained vapor bubble heat pipe includes a capillary, and the capillary has a longitudinal axis and a cross-sectional shape orthogonal to the longitudinal axis. The cross-sectional shape includes a first curved wall, a second curved wall, a first corner between a first straight wall and a second straight wall, and a second corner between a third straight wall and a fourth straight wall.

A thermal ground plane (TGP) is disclosed. A TGP may include a first planar substrate member comprising copper and a second planar substrate member comprising a metal, wherein the first planar substrate member and the second planar substrate member enclose a working fluid. The TGP may include a first plurality of pillars disposed on an interior surface of the first planar substrate and a mesh layer disposed on the top of the first plurality of pillars, wherein the mesh layer comprises at least one of copper, polymer encapsulated with copper, or stainless steel encapsulated with copper. The TGP may also include a second plurality of pillars disposed on an interior surface of the second planar substrate member within an area defined by the perimeter of the second planar substrate member and the second plurality of pillars extend from the second planar substrate member to the mesh layer.