1. Technical Field
The present disclosure relates to heat pipes and, more particularly, to a plate-type heat pipe having good heat dissipation efficiency and stable and reliable performance.
2. Description of Related Art
Generally, plate-type heat pipes efficiently dissipate heat from heat-generating components such as a central processing unit (CPU) of a computer. A conventional plate-type heat pipe comprises a top plate and a bottom cover hermetically contacting the top plate to form a container. A continuous wick structure is adhered to inner surfaces of the top plate and the bottom cover. Working fluid is contained in the container. All parts of the wick structure have the same thickness. When the bottom cover of the plate-type heat pipe absorbs heat of the heat-generating component, the working fluid is vaporized and transfers heat to the ambient environment at the wick structure mounted on the top plate.
The wick structure intervenes between the vaporized working fluid and the inner surface of the top plate at which the vaporized working fluid can release its latent heat of vaporization and change into condensate. Therefore, the wick structure tends to retard the phase change occurring at the top plate. The heat may transfer to the ambient environment too slowly, and is thus liable to accumulate on the container formed by the top plate and the bottom cover. In due course, the plate-type heat pipe may be overheat, and the heat dissipation efficiency of the plate-type heat pipe is reduced.
What is needed, therefore, is a plate-type heat pipe having good heat dissipation efficiency and stable, reliable performance.
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The container 10 is made of copper, aluminum, or an alloy thereof, and comprises an elongated condensing plate 11 and a bowl-shaped evaporating plate 13 hermetically contacting the condensing plate 11. The evaporating plate 13 absorbs heat generated by one or more components (not shown) such as electronic devices. The condensing plate 11 dissipates heat transferred from the evaporating plate 13 to the ambient environment.
The evaporating plate 13 comprises an elongated heat absorbing portion 131, two transition portions 133, two extending portions 134, and two sidewalls 135. The transition portions 133 extend outwardly and upwardly from opposite ends of the heat absorbing portion 131, respectively, and are symmetrically opposite each other. The extending portions 134 extend outwardly along opposite horizontal directions from outer ends of the transition portions 133, respectively. The sidewalls 135 extend upwardly from outer ends of the extending portions 134, respectively. In the illustrated embodiment, top ends of the sidewalls 135 are integrally formed with two ends of the condensing plate 11. That is, the evaporating plate 13 and the condensing plate 11 are a single body of the same material without any seams.
The wick structure 30 is made of metallic powder by a sintering process. The wick structure 30 comprises a first wick member 31 and a second wick member 33. The first wick member 31 is adhered to an inner surface of the condensing plate 11. The second wick member 33 is adhered to an inner surface of the evaporating plate 13. Opposite ends of the second wick member 33 connect opposite ends of the first wick member 31, respectively, thereby forming the continuous wick structure 30.
The second wick member 33 comprises an elongated first wick portion 331, two second wick portions 333, two third wick portions 335, and two fourth wick portions 337. The first wick portion 331 is adhered to a top surface of the heat absorbing portion 131 of the evaporating plate 13. The first wick portion 331 is thinner than each of the second wick portions 333. Thus, in general, the working fluid contained in the first wick portion 331 is vaporized faster than the working fluid contained in the second wick portion 333. Accordingly, the heat of the heat absorbing portion 131 is transferred by the first wick portion 331 quickly. The second wick portions 333 extend upwardly and outwardly from opposite ends of the first wick portion 331, respectively, and are symmetrically opposite each other. The second wick portions 333 are adhered to top surfaces of the transition portions 133 of the evaporating plate 13. The third wick portions 335 are horizontal, and extend outwardly from the second wick portions 333, respectively. The third wick portions 335 are adhered to top surfaces of the extending portions 134 of the evaporating plate 13. Each fourth wick portion 337 is adhered to an inner surface of the corresponding sidewall 135 of the evaporating plate 13, and fills a corner formed by the sidewall 135 and the corresponding extending portion 134. A cross-section of each fourth wick portion 337 is substantially triangular. That is, a transverse thickness (horizontal, from left to right, as viewed in
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It is to be understood, however, that even though numerous characteristics and advantages of various embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
Number | Date | Country | Kind |
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200910308310.9 | Oct 2009 | CN | national |