Abstract:
A fin structure is disclosed. The fin structure includes a first concavo-convex portion formed with a concave on a first surface of the fin in the direction of thickness and a corresponding convex on a second surface of the fin in the direction of thickness. Besides, a second concavo-convex portion formed with a first concave and second concave on the first surface of the fin in the direction of thickness and a corresponding first convex and a corresponding second convex on the second surface of the fin in the direction of thickness is included as well. Specifically, the first and second concavo-convex portions are symmetrical respect to the center of the fin. Furthermore, the second convex of the second concavo-convex portion on one fin can be exactly received by the concave of the first concavo-convex portion on another fin.

Description:
FIELD OF THE INVENTION 
     This invention relates to a fin structure and, more particularly, to a heat-dissipating fin structure to be assembled for heat dissipation and the assembly thereof. 
     DESCRIPTION OF THE PRIOR ART 
     When using electronic products, the heat produced therefrom is usually removed by a heat sink, and the operating efficiency of the electronic products is thereby increased and prevented from damaging. For example, the central processing unit (CPU) of a computer system may be provided with a high-density heat-dissipating fin assembly on it. 
     Usually, the heat from a heat source is transferred to a heat sink and then taken away by heat convection. In this case, a heat sink must have a large area for improving the heat convection effect and further raising the heat dissipating efficiency. Accordingly, it is preferable to maximize the number of the fins on a substrate for the high-density heat-dissipating fin assembly. 
     Up to now, however, the fabricating techniques for fins and the limitations on fastening and assembling fins have prevented the space between two adjacent fins from being further reduced. Therefore, it is difficult to achieve a maximum fin number. 
     For example, the published Taiwan patent No. 365411 has disclosed a heat-dissipating fin assembly composed of a front fin, a rear fin, and a plurality of middle fins. In this case, since the space between any two adjacent fins is determined by the thickness of an extra concave portion on the fin, the space cannot be reduced as desired. 
     Still an example, the published Taiwan Patent No. 506247 has disclosed a heat sink composed of a plurality of high-density heat-dissipating fins. In this case, since the plurality of fins are assembled by employing hooks and grooves provided thereon, the space between any two adjacent fins still can not be effectively reduced due to the hook length required to assemble the fins. 
     According to the above-mentioned drawbacks of the conventional fin assemblies, the invention provides a fin structure being capable of minimizing the space between two adjacent fins in an assembly. Thus, the number of the fins on a substrate can be effectively increased and the heat-dissipating efficiency of a heat sink can be improved. 
     SUMMARY OF THE INVENTION 
     To solve the above-mentioned problems, one object of the invention is to provide a fin structure to minimize the space of two adjacent fins in an assembly. 
     Another object of the invention is to provide a fin structure to maximize the number of the fins of a fin assembly. 
     In one aspect of the invention, the invented fin structure includes a first concavo-convex portion and a second concavo-convex portion. The first concavo-convex portion is formed with a concave on a first surface of the fin in the direction of thickness, and a corresponding convex on a second surface of the fin in the direction of thickness. The second concavo-convex portion is formed with a first concave and a second concave on the first surface of the fin in the direction of thickness, and a corresponding first convex and a corresponding second convex on the second surface of the fin in the direction of thickness. Wherein, the first concavo-convex portion and the second concavo-convex portion are symmetrical with respect to a center of the fin, and the second convex of the second concavo-convex portion can be exactly received by the concave of the first concavo-convex portion. 
     In another aspect of the invention, the fin structure of the invention further includes a plurality of protruding sheets provided on two sides of the fin. In addition, one fin is clasped and mounted with another fin by riveting the concave of the first concavo-convex portion on one fin and the second convex of the second concavo-convex portion on another fin and by bending the protruding sheets. 
     The invention discloses a fin assembly assembled by clasping a plurality of fins. Each of the fins has a characterization the same as the above described fin structure. 
     To be emphasized in this aspect is that the first convex of the second concavo-convex portion has a height equaling to a space between two adjacent fins. In addition, the protruding sheets are bent in a cross manner. 
     The invention has the following advantages. First, the formation of the concavo-convex portions are easy to control, therefore, a minimum space between two adjacent fins can be achieved. Secondly, it is convenient to clasp the concavo-convex portions and the protruding sheets, and the assembled assembly would not depart easily. Thirdly, the invention uses only one fin structure and therefore enables a more simplified and effective assembly. Fourthly, the fin structure designed in the invention is appropriate for formations of common aluminum and copper materials. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front view showing a fin structure in accordance with a first embodiment of the invention. 
     FIG. 2 is a cross-sectional view taken along a line C—C in FIG. 1, showing the concavo-convex portion of the fin structure in accordance with the first embodiment of the invention. 
     FIG. 3 is a simplified schematic diagram showing the alignment of a plurality of the fins having the structure in accordance with the first embodiment of the invention. 
     FIG. 4 is a simplified schematic diagram showing the assembly of the plurality of fins in accordance with the first embodiment of the invention. 
     FIG. 5 is an enlarged diagram showing the protruding sheets provided on sides of the fins after a plurality of fins are assembled in accordance with the first embodiment of the invention. 
     FIG. 6 is a front view showing a fin structure in accordance with a second embodiment of the invention. 
     FIG. 7 is a cross-sectional view taken along a line D—D in FIG. 6, showing the concavo-convex portion of the fin structure in accordance with the second embodiment of the invention. 
     FIG. 8 is a simplified schematic diagram showing the alignment of a plurality of fins having the structure in accordance with the second embodiment of the invention in the assembly. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A fin structure and a fin assembly in accordance with preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. 
     Referring to FIGS. 1 and 2, a fin  100  according to the first embodiment of the invention is provided with two concavo-convex portions  12  and  13  having a cylindrical shape. The concavo-convex portions  12  and  13  are formed on a transverse central line  15  of the fin  100 , respectively, and arranged to be symmetrical with respect to a longitudinal central line  14  of the fin  100 . Herein, the concavo-convex portion  12  is formed by stamping the lower surface  11  to depress toward the upper surface  10 . Thus, the concavo-convex portion  12  forms a concave  121  on the lower surface  11  of the fin  100  and a corresponding convex  122  on the upper surface  10  of the fin  100 . 
     Similarly, the concavo-convex portion  13  is formed by stamping the lower surface  11  to depress toward the upper surface  10  of the fin  100 . Thus, a first concave  131  and a second concave  132  are formed on the lower surface  11  of the fin  100  and corresponding first convex  133  and second convex  134  are formed on the upper surface  10  of the fin  100 . 
     Especially, these concavo-convex portions  12  and  13  are so designed that the second convex  134  of the first concavo-convex portion  13  on one fin is received by the concave  121  of the concavo-convex portion  12  on another fin. In other words, the second convex  134  of the first concavo-convex portion  13  on one fin and the concave  121  of the concavo-convex portion  12  on another fin are closely fit. Moreover, the height h 2  between the upper surface of the first convex  133  of the concave-convex portion  13  and the upper surface  10  of the fin  100  is designed to equal a desired space between any two adjacent fins after being assembled. In addition, the height h 2  is equal to or larger than the height h 1  between the upper surface of the convex  122  of the concave-convex portion  12  and the upper surface  10  of the fin  100 . 
     Consequently, as shown in FIG. 3, a plurality of the fins with such a structure can be assembled one by one that the convex  134  of the concavo-convex portion  13  on the odd fins N 1 , N 3  . . . are riveted with the concave  121  of the concavo-convex portion  12  on the even fins N 2 , N 4  . . . respectively. Meanwhile, since the height h 1  and H of the concavo-convex portions  12  and  13  are determined by the thickness t of the fins (see FIG.  2 ), the space between two adjacent fins can be minimized in an assembly. Therefore, the object for maximizing the fin number on a substrate (not shown) can be achieved. 
     On the other hand, as shown in FIG. 1, the fin according to the first embodiment of the invention is further provided with protruding sheets  16  and  17  at the central part of the sides  18  and  19  of the fin  100 . Among these protruding sheets  16  and  17 , the short sheets  161 ,  162 ,  171  and  172  are bent to be substantially perpendicular to the fin before a plurality of the fins are assembled (see FIG.  3 ). Thereby, the plurality of fins can be effectively clasped in the assembly. 
     Subsequently, after the plurality of fins are clasped (see FIG.  4 ), the long sheets  163 ,  164 ,  173  and  174  are bent to L-shapes for further fixing the clasped short protruding sheets  161 ,  162 ,  171  and  172  and completing the assembly. 
     As shown in FIG. 5, the protruding sheets are bent in a cross manner, that is, the directions of short protruding sheets  161 ,  162 ,  171  and  172  are perpendicular with the directions of long protruding sheets  163 ,  164 ,  173  and  174 . 
     As shown in FIGS. 6 and 7, the fin  200  is provided with two concavo-convex portions  22  and  23 . These concavo-convex portions  22  and  23  are formed on a transverse central line  25  of the fin  200 , respectively, and arranged to be symmetrical with respect to a longitudinal central line  24  of the fin  200 . Herein, the concavo-convex portion  22  is formed by stamping the lower surface  21  of the fin  200  to depress toward the upper surface  20  of the fin  200 . Consequently, the concavo-convex portion  22  forms a concave  221  on the lower surface  21  of the fin  200  and forms a convex  222  on the upper surface  20  of the fin  200 . 
     Similarly, the concavo-convex portion  23  is formed by stamping the lower surface  21  of the fin  200  to depress toward the upper surface  20  of the fin  200 . Thus, a first concave  231  and a second concave  232  are formed on the lower surface  21  of the fin  200  while a corresponding first convex  233  and a corresponding second convex  234  are formed on the upper surface  20  of the fin  200 . 
     Especially, these concavo-convex portions  22  and  23  are characterized by the following arrangement. First, the second convex  234  of the first concavo-convex portion  23  is designed to be received by the concave  221  of the concavo-convex portion  22 . That is, the second convex  234  of the concavo-convex portion  23  and the concave  221  of the concavo-convex portion  22  can be closely fit with each other. Secondly, the height h 2 ′ between the upper surface of the first convex  233  of the concavo-convex portion  23  and the upper surface  20  of the fin  200  is designed to be a desired space between any two adjacent fins after being assembled. In addition, the height h 2 ′ is equal to or larger than the height h 1 ′ between the upper surface of the convex  222  of the concave-convex portion  22  and the upper surface  20  of the fin  200 . Thirdly, the first concave  231  of the concavo-convex portion  23  has been transversely punched for airflow pass so that heat resistance can be reduced (see FIGS.  7  &amp;  8 ). Fourthly, the concavo-convex portion  22  and the second convex  234  of the concavo-convex portion  23  are shaped to be cylindrical while the first convex  233  of the concavo-convex portion  23  is shaped to be prismatic (see FIGS.  7  &amp;  8 ). 
     Consequently, as shown in FIG. 8, a plurality of fins can be assembled so that the convex  234  of the concavo-convex portion  23  on the odd fins M 1 , M 3  . . . are riveted with the concave  221  of the concavo-convex portion  22  on the even fins M 2 , M 4  . . . , respectively. Meanwhile, since the heights h 1 ′ and H′ of the concavo-convex portions  22  and  23  are determined by the thickness t′ (see FIG. 7) of the fins, the space between two adjacent fins can be minimized in the assembly. Therefore, one can design a preferred fin thickness t′ so as to achieve the object of maximizing the fin number on a substrate (not shown). 
     On the other hand, as shown in FIG. 6, the fin  200  in accordance with the second embodiment of the invention is further provided with protruding sheets  26  and  27  at the central part of the sides  28  and  29  of the fin  200 . Among these protruding sheets  26  and  27 , the short protruding sheets  261 ,  262 ,  271  and  272  are pre-bent to be substantially perpendicular to the fin (see FIG. 3) before a plurality of fins are assembled. Thereby, a plurality of fins can be effectively clasped in the assembly. 
     Subsequently, after the plurality of fins are clasped (not shown), the long protruding sheets  263 ,  264 ,  273  and  274  are bent to L-shapes (see FIG.  5 ), as the case in the first embodiment, for further fixing the clasped short protruding sheets  261 ,  262 ,  271  and  272 . Herein, the protruding sheets are bent in a cross manner, as shown in FIG.  5 . 
     Summing up the above, a plurality of fins are assembled by at least two concavo-convex portions arranged to be symmetrical with respect to the center of each fin and a plurality of protruding sheets provided on sides of each fin. In this way, not only the plurality of fins can be clasped firmly but also the space between any two adjacent fins can be minimized. Therefore, the fin number on a heat dissipating substrate can be maximized. Furthermore, comparing with the conventional case of using three kinds of fin structures to accomplish the assembly, the invention uses only one fin structure and therefore enables a more convenient way to assemble the fins. In addition, although methods for fabricating fins vary with the materials used, the fin structure of the invention does not have any problems in formation with regard to common aluminum- and copper-based materials. 
     It should be noted that the number of the concavo-convex portions on the fin of the invention is not limited to two. However, it is preferred that the concavo-convex portions are in an even number and are arranged to be symmetrical with respect to the center of the fins. Similarly, the number of the protruding sheets of the fin structure in accordance with the invention is not limited by the embodiments described above, however, an even number would be preferred. 
     The invention has been clearly described by each embodiment and the accompanying figures, however, it is apparent for those skilled in the art that each embodiment of the invention is not limited but exemplary. That is, various changes or modifications can be made without departing from the spirit and scope of the invention as defined by the appended claims. For example, the first convex of the second concavo-convex portion in the first and second embodiments of the invention can be shaped to be cylindrical, prismatic or other shapes.