Diffusion bonded wire mesh heat sink

a heat sink and wire mesh technology, applied in the field of heat sinks, can solve the problems of insufficient effectiveness of conventional cooling methods, injurious to equipment or its environment, and insufficient heat, so as to reduce the size and power of the pump, and facilitate fluid push.

Inactive Publication Date: 2005-10-13
PAR TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0012] The monolithic heat sink comprises a wire mesh formed into a tightly wound spiral which is fused by diffusion bonding (rather than by soldering) onto the thermal transfer plate, as well as being fused to itself. The diffusion bonding of the wires provides the wire mesh structure with many and appropriately sized interstices, making it easier to push the fluid through the heat sink assembly and thereby significantly reducing the size and power of the pump which pushes the fluid. Stated differently, the diffusion bonded mesh functions similarly to the microchannel, but with, e.g., greater numbers of fluidic paths and thus far less pressure drop. Further, the heat transfer efficiency is increased due to the fact that the diffusion bonded wire mesh structure has such a large surface area, up to five to ten times more that a standard microchannel heat sink
[0013] The wire mesh structure can be secured or adhered to the thermal transfer plate by numerous conventional techniques such as (for example) soldering, welding, radio frequency (RF) melting, and adhesives which are cured or activated (e.g., by heat, by voltage, etc.). Preferably the wire mesh structure is diffusion bonded to the thermal transfer plate in a same operation in which the wires of the wire mesh structure are bonded together. The diffusion bonding of the wire mesh structure to the thermal transfer plate to create the monolith allows for higher efficiency in transferring heat from the thermal transfer plate to the wire mesh structure.

Problems solved by technology

In some cases the heat can be injurious to the equipment or its environment (e.g., other equipment or components in proximity to the heat-generating or heat-releasing equipment).
In fact, the heat can become so great in many chips that conventional means of cooling (e.g., fans and heat pipes) are not sufficiently effective.
Despite their proven potential for handling high heat fluxes, microchannel-based heat sinks have not found widespread commercial use, possibly due to the very high pressure drops encountered in the microchannels.
High pressure drops necessitate the use of relatively large pumps with significant power requirements, noise, reliability issues, and associated costs.
Moreover, there can be a problem if bubbles form in microchannel-type heat sinks.
If the hot spot grows significantly, the device being cooled may fail.

Method used

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Examples

Experimental program
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Effect test

first embodiment

[0044] Like covers of other example embodiments illustrated herein, the cover 22-1 is essentially a parallelepiped. In fact, the cover 22-1 of the first embodiment is a rectangular parallelepiped having one open face. As such, the cover 22-1 has five walls. The walls of the cover 22-1 include side walls 31-1, 32-1, 33-1, and 34-1, as well as cover wall 35-1. The cover wall 35-1 lies in a plane which is parallel to thermal transfer plate 25-1. When the heat sink assembly is assembled, the open face of cover 22—is closed by thermal transfer plate 25-1. FIG. 1A, FIG. 1B, and FIG. 1C show the heat sink assembly 20-1 with thermal transfer plate 25-1 surmounting the cover 22-1.

[0045] The thermal transfer plate 25-1 can be secured to cover 22 by any suitable fasteners or adhesives such as, e.g., threaded fasteners. FIG. 1B shows the interior of the chamber looking up from cover wall 35-1 toward the underside of thermal transfer plate 30-1, thereby also permitting a view of the diffusion bo...

second embodiment

[0054] As in the other embodiments, the diffusion bonded wire mesh structure 26-2 is situated in the chamber 24-2 to transfer heat acquired from the thermal transfer plate 30-2 to the fluid in the chamber 24-2 as the fluid is pumped through interstices of the diffusion bonded wire mesh structure 26-2. As mentioned previously, preferably the diffusion bonded wire mesh structure is formed integrally with or bonded to the thermal transfer plate 30-2 (e.g., diffusion bonded in the same operation in which the wires of the wire mesh structure are bonded). As shown in FIG. 2C, the diffusion bonded wire mesh structure 26-2 of the second embodiment has an essentially spiral configuration within the chamber. The spiral pattern of the diffusion bonded wire mesh structure 26-2 has a first end near the center of the chamber 24-2 (e.g., near the inlet 40-2), and spirals radially outward toward the side walls of chamber 22-2.

[0055] Due to pumping action, in operation a fluid enters the chamber 24-...

third embodiment

[0057] As in the other embodiments, the diffusion bonded wire mesh structure 26-3 is situated in the chamber 24-3 to transfer heat acquired from the thermal transfer plate 30-3 to the fluid in the chamber 24-3 as the fluid first impinges upon thermal transfer plate 25-3 and then is pumped through interstices of the diffusion bonded wire mesh structure 26-3. As mentioned previously, preferably the diffusion bonded wire mesh structure is formed integrally with or bonded to the thermal transfer plate 30-3 (e.g., diffusion bonded in the same operation in which the wires of the wire mesh structure are bonded). As shown in FIG. 3C, the diffusion bonded wire mesh structure 26-3 of the third embodiment has an essentially circular configuration within the chamber, and preferably is configured to comprise plural concentric rings within the chamber.

[0058]FIG. 4A-FIG. 4F illustrate components of a fourth example embodiment of a heat sink assembly. Unless otherwise excepted specifically or by co...

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Abstract

A heat sink (20) comprises a heat sink monolith (23) and a cover (22). The heat sink monolith (23) comprises a thermal transfer plate (25) and a wire mesh structure (26). The thermal transfer plate (25) of the monolith (23) and the cover (22) cooperate to define a heat transfer chamber (24). The wire mesh structure (26) of the monolith (23) is configured and positioned in the chamber (24) to provide a tortuous, heat conduction path for fluid (e.g., a coolant) which turbulently travels from an inlet (40) of the chamber to one or more outlets (42) of the chamber (24). The wire mesh structure comprises wires which are fused by diffusion bonding (rather than by soldering) into a mesh. The diffusion bonding of the wires provides the wire mesh structure with many and appropriately sized interstices, making it easier to push the fluid through the heat sink assembly and thereby significantly reducing the size and power of the pump which pushes the fluid. Preferably the diffusion bonded wire mesh structure is integral with or diffusion bonded to the thermal transfer plate. Within the chamber the diffusion bonded wire mesh (26) structure can have various configurations for providing an exposure interface between fluid pumped through the chamber and the diffusion bonded wire mesh.

Description

BACKGROUND [0001] 1. Field of the Invention [0002] This invention pertains to heat sinks, and particularly to heat sinks which are cooled by a circulating fluid. [0003] 2. Related Art and Other Considerations [0004] Various types of equipment create or release heat during operation. In some cases the heat can be injurious to the equipment or its environment (e.g., other equipment or components in proximity to the heat-generating or heat-releasing equipment). Accordingly, attempts have been made in some such cases to cool the equipment and / or its environs. Common cooling techniques include circulation of a cooling fluid around or near the source of heat. For example, fans have been used to blow cooling air around a heat-generating component of a system. Alternatively, heat pipes or other types of heat sinks have been placed in contact or nearby the heat source for the purpose of dissipating the heat using, e.g., circulating air. [0005] Among the types of equipment prone to heat gener...

Claims

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Application Information

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IPC IPC(8): H01L23/473F28F3/02B23K20/02F28F7/00
CPCB23K20/02F28F3/022H01L23/473B23K2101/14H01L2924/0002H01L2924/00
InventorEAST, W. JOE
OwnerPAR TECH