Patent Publication Number: US-2012031588-A1

Title: Structure of heat plate

Description:
FIELD OF THE INVENTION 
     The present invention relates to a structure of heat plate, and in particular to a structure of heat plate applicable to an electronic device. 
     BACKGROUND OF THE INVENTION 
     An electronic device often generates a great amount of heat during a long term operation. A common solution for handling such a great amount of heat is installation of a heat plate that dissipates the heat. A heat plate is advantageous in respect of high heat conductivity, light weight, and simple construction and can carry out transfer of a large amount of heat without consuming electrical power. 
     A conventional heat plate structurally comprises a board, which has a hollow interior forming a chamber that receives and retains therein a capillary tissue and is filled with a working fluid. Mounted to one side of the board is a sealing tube (or referred to an opening sealing tube, a degassing tube, or a filling and degassing tube), which has an end mounted to the board and communicating the hollow interior chamber, so that the working fluid can be filled from the outside into the interior (namely the chamber) of the board through the sealing tube and degassing and air evacuation operations can also be performed through the sealing tube in order to realize the destination function of removal of heat from an electronic device. 
     Thus, the present invention aims to provide a structure of heat plate that helps increasing the efficiency of reduction of temperature in order to extend the lifespan of an electronic device. 
     SUMMARY OF THE INVENTION 
     A primary objective of the present invention is to provide a structure of heat plate that improves temperature reduction efficiency of the heat plate. 
     To realize the above objectives, the present invention provides a structure of heat plate that comprises two boards, which mate and are coupled to each other to define therebetween an accommodation chamber, and a plurality of first capillary layers, which is arranged in the accommodation chamber in such a way that the first capillary layers are set on a common horizontal plane and the first capillary layers form therebetween a plurality of passages. As such, the efficiency of diffusion of vapor of a working fluid is increased and the uniformity of distribution of the working fluid is improved, so that the efficiency of temperature reduction is improved to thereby offer practicability, novelty, improvement, and convenience. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be apparent to those skilled in the art by reading the following description of preferred embodiments thereof with reference to the drawings, in which: 
         FIG. 1A  is an exploded view of a structure of heat plate according to a first embodiment of the present invention; 
         FIG. 1B  is a perspective view of the heat plate according to the first embodiment of the present invention in an assembled form; 
         FIG. 2  is an exploded view of a structure of heat plate according to a second embodiment of the present invention; 
         FIG. 3  is an exploded view of a structure of heat plate according to a third embodiment of the present invention; 
         FIG. 4  is an exploded view of a structure of heat plate according to a fourth embodiment of the present invention; 
         FIG. 5A  is an exploded view of a structure of heat plate according to a fifth embodiment of the present invention; 
         FIG. 5B  is a perspective view of the heat plate according to the fifth embodiment of the present invention in an assembled form; 
         FIG. 5C  is a cross-sectional view taken along line A-A′ of  FIG. 5B ; and 
         FIG. 5D  is a cross-sectional view taken along line B-B′ of  FIG. 5B . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the drawings and in particular to  FIGS. 1A-3 , which respectively show an exploded view and an assembled perspective view of a structure of heat plate according to a first embodiment of the present invention and exploded views of structures of heat plate according to second and third embodiments of the present invention, the heat plate constructed in accordance with the present invention comprises two boards  100 , a sealing tube  110 , and a plurality of first capillary layers  210 , and is provided for installation on an electronic device to realize functions of lowering temperature of a heat source, performing effective heat transfer, and improving temperature reduction efficiency. 
     The two boards  100  are mated and coupled to each other so that the two boards  100  defined an accommodation chamber  101  therebetween. In a practical arrangement, one of the two boards  100  can be structured to form a recess  102 , or alternatively, both boards  100  are structured to form corresponding recesses  102 , so that when the two boards  100  are coupled to each other, an accommodation chamber  101  that is in a vacuum condition and receives a working fluid therein is formed. The two boards  100  can be coupled in various ways, such as being jointed with copper paste or silver paste through blazing, diffusion bounding, or welding. 
     The sealing tube  110 , which is a hollow tubular body, is mounted to any side or any corner of the two coupled boards  100 . The sealing tube  110  has an end communicating the accommodation chamber  101  to allow the working fluid to be filled from the outside through the sealing tube  110  into the accommodation chamber  101 , whereby through changes between two phases of the working fluid and circulation of the working fluid conducted by the capillary structure arranged between the two boards  100 , the functions of lowering temperature of heat source and performing effective heat transfer and dissipation can be realized. 
     The first capillary layers  210  are arranged in the accommodation chamber  101 . Preferably, the first capillary layers  210  are set on a common horizontal plane in such a way to form a plurality of passages  211  between the first capillary layers  210 . The passages  211  between the first capillary layers  210  can be arranged parallel to each other (see  FIG. 1 ), or perpendicular to each other (see  FIG. 2 ), or in a radial pattern (see  FIG. 3 ). In other words, the passages  211  between the first capillary layers  210  can be arranged in arbitrary directions. The first capillary layers  210  can be metal net or an object formed of sintered powders (such as metal powders). The first capillary layers  210  are of a thickness that is substantially identical to a depth of the accommodation chamber  101 , so that the capillary layers can be snugly, or even tightly, received in the accommodation chamber  101  to improve structural stability for positioning and supporting the capillary layers. 
     As shown in  FIG. 1 , in the instant embodiment, two boards  100  and a plurality of first capillary layers  210  are included, wherein one of the two boards  100  forms a recess  102  so that the two boards  100 , when mating and coupled to each other, form an accommodation chamber  101  therebetween, and a sealing tube  110  is mounted to a corner of the two coupled boards  100  and has an end communicating the accommodation chamber  101 . The first capillary layers  210  are received in the accommodation chamber  101  and the first capillary layers  210  form therebetween a plurality of passages  211 , which is arranged parallel to each other. Through the sealing tube  110 , a working fluid (such as water) is filled into the chamber between the two boards  100 , whereby through changes between two phases, the working fluid is circulated through the first capillary layers  210  arranged between the two boards  100 , and the functions of lowering temperature of heat source and performing effective heat transfer can be realized. Meanwhile, when the working fluid undergoes changes between two phases (such as liquid water and vapor), the passages  211  serve as passageways for the vapor to allow the vapor phase of the working fluid (such as water vapor) to be quickly diffused to the upper board  100 , thereby improving vapor diffusion efficiency, and, on the other hand, the liquid phase of the working fluid (such as water) is caused by the first capillary layers  210  to uniformly distribute over the lower board  100  to improve uniformity of distribution of the working fluid, thereby improving temperature reduction efficiency. 
     Referring to  FIG. 4 , an exploded view of a structure of heat plate according to a fourth embodiment of the present invention is shown. The fourth embodiment is substantially similar to the first embodiment with a major difference residing in that the heat plate of the fourth embodiment further comprises a plurality of second capillary layers  220 , which form therebetween a plurality of passages  221 . The first capillary layers  210  are metal nets, and the second capillary layers  220  can be metal nets (or objects formed of sintered powders (such as metal powders)). The second capillary layers  220  and the first capillary layers  210  are stacked over each other. In other words, the second capillary layers  220  are stacked on or under the first capillary layers  210 . In the instant embodiment, the second capillary layers  220  are stacked under the first capillary layers  210  and the passages  221  between the second capillary layers  220  and the passages  211  between the first capillary layers  210  are set to correspond to each other or alternate or intersect each other. Further, the first capillary layers  210  has a thickness that is greater than a thickness of the second capillary layers  220  (namely, the first capillary layers  210  can be “coarse” capillary layers, while the second capillary layers  220  are “fine” capillary layers). The first capillary layers  210 , which are metal nets, are of a mesh that is different from mesh of the second capillary layers  220 . 
     Referring to  FIGS. 5A-5D , which respectively show an exploded view, an assembled perspective view, and two cross-sectional views of a structure of heat plate according to a fifth embodiment of the present invention, the fifth embodiment is substantially similar to the fourth embodiment with a major difference residing in that besides being stacked on a first surface (such as top or bottom) of the first capillary layers  210 , the second capillary layers  220  are also stacked on the opposite surface of the first capillary layers  210 . In the instant embodiment, the second capillary layers  220  stacked on the top surface of the first capillary layers  210  form therebetween a plurality of passages  221 , but those stacked under the bottom of the first capillary layers  210  do not. The overall height of the stacked first and second capillary layers  210 ,  220  is substantially identical to a depth of the accommodation chamber  101 , so that the capillary layers can be snugly, or even tightly, received in the accommodation chamber  101  to improve structural stability for positioning and supporting the capillary layers, as shown in  FIGS. 5C and 5D , wherein  FIG. 5C  is a view taken along a cross-section of the heat plate passing through the first capillary layers  210  and the second capillary layers  220  and  FIG. 5D  is a view taken along a cross-section extending through the passages  221  of the top second capillary layers  220 , the passages  211  of the first capillary layers  210 , and the bottom second capillary layers  220 . 
     The present invention provides a structure of heat plate of which the features are that two boards  100  mate and are coupled to each other to form an internal accommodation chamber  101  and a plurality of first capillary layers  210  is received in the accommodation chamber  101  in such a way that the first capillary layers  210  form therebetween a plurality of passages  211 , whereby when a working fluid contained in the accommodation chamber  101  undergoes phase change, the passages  211  serve as passageways for vapor or gaseous phase of the working fluid to allow the vapor of the working fluid (such as water vapor) to be quickly diffused to the upper board  100 , thereby improving vapor diffusion efficiency, and, on the other hand, the liquid phase of the working fluid (such as water) is caused by the first capillary layers  210  to uniformly distribute over the lower board  100  to improve uniformity of distribution of the working fluid, thereby improving temperature reduction efficiency. 
     Although the present invention has been described with reference to the preferred embodiments thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.