1. Field of the Invention
The invention relates to plate-type heat pipes and, more particularly, to a plate-type heat pipe with enhanced heat dissipation efficiency. The plate-type heat pipe has a wick structure therein; the wick structure has a cross-section with a varied thickness.
2. Description of Related Art
Generally, plate-type heat pipes efficiently dissipate heat from components such as central processing units (CPU). Referring to
It is therefore desirable to provide a plate-type heat pipe which has a wick structure of optimum thickness to engage the plate-type heat pipe.
Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Referring to
A bowl-shaped base plate 11 and a covering plate 13 are provided. The base plate 11 comprises a central heat absorbing plate 112, a pair of extending plates 114 angling upwardly from opposite ends of the heat absorbing plate 112, two engaging plates 116 extending outwardly from ends of the extending plates 114 respectively and facing apart, and two sidewalls 118 extending upwardly from ends of the engaging plates 116.
A mold 15 is provided. The mold 15 comprises a first mold 151 and a second mold 153. The first mold 151 encloses the base plate 11 therein. The first mold 151 and the base plate 11 define a first cavity 152 therebetween. The second mold 153 encloses the covering plate 13 therein. The second mold 153 and the covering plate 13 define a second cavity 154 therebetween. A cross-section of the second cavity 154 is rectangular. The first cavity 152 comprises a first receiving portion 1522 corresponding to a central portion of the heat absorbing plate 112 of the base plate 11, two second receiving portions 1524 angling outwardly from opposite ends of the first receiving portion 1522 and corresponding to lateral portions of the heat absorbing plate 112 and the extending plates 114 of the base plate 11, and two third receiving portions 1526 extending outwardly from ends of the second receiving portions 1524 and corresponding to the engaging plates 116 of the base plate 11. The first, second and third receiving portions, 1522, 1524, 1526 connect and communicate with each other in series. A cross-section of the first receiving portion 1522 is rectangular. A cross-section of the second receiving portion 1524 is pentagonal. The third receiving portion 1526 comprises a first connecting portion 1526a angling outwardly from an end of the second receiving portion 1524 and a second connecting portion 1526b extending outwardly from an end of the first connecting portion 1526a. A cross-section of the first connecting portion 1526a of the third receiving portion 1526 is trapezoidal. A cross-section of the second connecting portion 1526b of the third receiving portion 1526 is rectangular. The second receiving portion 1524 of the first cavity 152 is deeper than the first receiving portion 1522. Depth of the second receiving portion 1524 first increases and then decreases along a laterally outwardly direction. The third receiving portion 1526 is deeper than the second receiving portion 1524 of the first cavity 152. Depth of the first connecting portion 1526a of the third receiving portion 1526 of the first cavity 152 increases from an inner end connected with the second receiving portion 1524 to an outer end opposite to the inner end. An inner end of the second connecting portion 1526b is of the same depth as the outer end of the first connecting portion 1526a.
A first metal powder is filled into the first cavity 152 and a second metal powder is filled into the second cavity 154. The first and second metal powder are copper powder. Particle size of the first metal powder is less than that of the second metal powder. The first metal powder filled in the first cavity 152 and the second metal powder filled in the second cavity 154 are heated to a high temperature, sufficient to execute sintering, to obtain a sintered first wick structure 16 securely fixed to a top surface of the base plate 11 and a sintered second wick structure 17 securely fixed to a bottom surface of the covering plate 13. The first wick structure 16 and the second wick structure 17 are porous, with apertures of the first wick structure 16 fewer than those of the second wick structure 17. The first wick structure 16 comprises a first adhering portion 161 securely fixed to a top surface of the central portion of the heat absorbing plate 112 of the base plate 11, two second adhering portions 163 securely fixed to top surfaces of the lateral portions of the heat absorbing plate 112 and the extending plates 114 of the base plate 11, and two third adhering portion 165 securely fixed to top surfaces of the engaging plates 116 of the base 11. The third adhering portion 165 receives a first joining portion 1651 in the first connecting portion 1526a and a second joining portion 1653 in the second connecting portion 1526b of the third receiving portion 1526 of the first cavity 152. A top surface of the second adhering portion 163 and a top surface of the first joining portion 1651 of the third adhering portion 165 of the first wick structure 16 are coplanar.
The first mold 151 and the second mold 153 of the mold 15 are removed from the first and second wick structures 16, 17 respectively. The base plate 11 with the first wick structure 16 attached thereto and the covering plate 13 with the second wick structure 17 attached thereto are assembled together. A chamber 18 is defined between the first and second wick structures 16, 17 and the chamber 18 is vacuumed and filled with a working fluid (not shown) such as water, alcohol, methanol, or the like, and sealed. The disclosed plate-type heat pipe 10 is thus obtained. In this state, opposite ends of the second wick structure 17 and the second joining portions 1653 of the third adhering portions 165 of the first wick structure 16 are combined.
In this embodiment, a cross-section of the first adhering portion 161 of the first wick structure 16 is rectangular. A cross-section of the second adhering portion 163 of the first wick structure 16 is pentagonal. A cross-section of the first joining portion 1651 of the third adhering portion 165 of the first wick structure 16 is trapezoidal. A cross-section of the second joining portion 1653 of the third adhering portion 165 of the first wick structure 16 is rectangular. A cross-section of the second wick structure 17 is rectangular. The first adhering portion 161 of the first wick structure 16 is thinner than the second wick structure 17. Work fluid contained in the first adhering portion 161 of the first wick structure 16 absorbs heat and is vaporized quickly to generate vapor. The vapor then reaches the second wick structure 17. The second adhering portion 163 of the first wick structure 16 is thicker than the first adhering portion and thins from a central portion to distal ends thereof. Third adhering portion 165 thickens from an inner end connected with the second adhering portion 163 to an outer end opposite to the inner end. The second and third adhering portions 163, 165 collect condensate work fluid from the second wick structure 17. When generated heat enters the plate-type heat pipe 10 via heat absorbing portion 112, the work fluid contained in the first adhering portion 161 of the first wick structure 16 absorbs the heat and vaporizes, and the working fluid contained in the second and third adhering portions 163, 165 of the first wick structure 16 flows to the first adhering portion 161.
Referring to
Referring to
It is believed that the disclosed embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the disclosure.
Number | Date | Country | Kind |
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200810305727.5 | Nov 2008 | CN | national |