Patent Publication Number: US-9897390-B2

Title: Fixing structure for heat dissipation element

Description:
FIELD OF THE INVENTION 
     The present invention relates to a heat dissipation element, and more specifically, to a fixing structure for heat dissipation element. 
     BACKGROUND OF THE INVENTION 
     Generally, a fixing structure for heat dissipation element includes a base plate and a heat pipe. The base plate defines a receiving recess for receiving the heat pipe therein. The heat pipe is connected to the receiving recess by tight fitting or loose fitting. In the case of tight fitting, the heat pipe has an outer diameter or a width larger than an inner diameter or a width of the receiving recess, so the heat pipe tends to be damaged when being connected to the receiving recess or could not be easily successfully connected to the receiving recess. On the other hand, in the case of loose fitting, glue or solder is needed to bond or weld the heat pip to the receiving recess. In other words, additional steps are required in the whole manufacturing process to connect the heat pipe to the receiving recess. Therefore, there are problems of lengthened production process, increased manufacturing cost and potential environmental pollution. 
     It is therefore tried by the inventor to develop an improved fixing structure for heat dissipation element that can prevent the heat pipe from being damaged when being connected to the receiving recess, and shorten the production process, as well as reduce the manufacturing cost. 
     SUMMARY OF THE INVENTION 
     To solve the above problems, a primary object of the present invention is to provide a fixing structure for heat dissipation element that enables a heat transfer element to be tightly fitted in a receiving recess by inserting a fixing member into at least one clearance between the receiving recess and the heat transfer element. 
     Another object of the present invention is to provide a fixing structure for heat dissipation element that can prevent a heat transfer element from being damaged when being connecting to a receiving recess, and enables shortened manufacturing process and reduced manufacturing cost of the fixing structure. 
     A further object of the present invention is to provide a fixing structure for heat dissipation element that has a base plate provided with a shallow recess for receiving at least one fixing member therein. 
     To achieve the above and other objects, the fixing structure for heat dissipation element according to the present invention includes a heat transfer element, a base plate, and at least one fixing member. The heat transfer element has two opposite outer lateral sides, and a width of the heat transfer element is defined between the two opposite outer lateral sides. The base plate has a top surface, on which a receiving recess is defined for receiving the heat transfer element therein. The receiving recess has a top opening and two opposite inner lateral sides located corresponding to the two opposite outer lateral sides of the heat transfer element, and a width of the receiving recess is defined between the two opposite inner lateral sides and is larger than the width of the heat transfer element. At least one clearance is defined between the two inner lateral sides of the receiving recess and the two outer lateral sides of the heat transfer element. The at least one fixing member has a fixing portion connected to the top surface of the base plate, and an extended portion extended from the fixing portion. The extended portion is bent and inserted into the clearance to locate between the receiving recess and the heat transfer element, bringing the heat transfer element to be tightly held in the receiving recess. 
     More specifically, the fixing structure for heat dissipation element according to the present invention includes a heat transfer element, a base plate, and a first fixing member. The heat transfer element has an outer surface, on which a first and a second outer lateral side are defined, and a width of the heat transfer element is defined between the first and the second outer lateral side. The base plate has a top surface, on which a receiving recess is defined for receiving the heat transfer element therein. The receiving recess has a top opening, a first inner lateral side, and a second inner lateral side located opposite to the first inner lateral side. The first inner lateral side is located corresponding to the first outer lateral side of the heat transfer element, whereas the second inner lateral side is located corresponding to the second outer lateral side of the heat transfer element. A width of the receiving recess is defined between the first and the second inner lateral side and is larger than the width of the heat transfer element, such that a first clearance is defined between the first inner lateral side of the receiving recess and the first outer lateral side of the heat transfer element. The first fixing member is connected to the top surface of the base plate, and has a first fixing portion and a first extended portion extended from the first fixing portion. The first fixing portion is connected to the top surface of the base plate, whereas the first extended portion is bent and inserted into the first clearance, such that the first extended portion is tightly fitted between the first inner lateral side of the receiving recess and the first outer lateral side of the heat transfer element. 
     In an embodiment of the present invention, the base plate further has a first shallow recess defined on the top surface and located adjacent to one outer side of the top opening of the receiving recess. The receiving recess has a depth larger than a depth of the first shallow recess; and the first fixing portion of the first fixing member is fitted in the first shallow recess. 
     In an embodiment of the present invention, the fixing structure for heat dissipation element further includes a second fixing member, which has a second fixing portion connected to the top surface of the base plate and a second extended portion extended from the second extended portion into the top opening of the receiving recess. 
     In an embodiment of the present invention, a second clearance is defined between the second inner lateral side of the receiving recess and the second outer lateral side of the heat transfer element; and the second extended portion of the second fixing member is bent and inserted into the second clearance, such that the second extended portion is tightly fitted between the second inner lateral side of the receiving recess and the second outer lateral side of the heat transfer element. 
     In an embodiment of the present invention, the base plate further has a first and a second shallow recess defined on the top surface and located adjacent to two outer sides of the top opening of the receiving recess. The first and the second shallow recess respectively have a depth smaller than that of the receiving recess; and the first fixing portion of the first fixing member is fitted in the first shallow recess, whereas the second fixing portion of the second fixing member is fitted in the second shallow recess. 
     In an embodiment of the present invention, the second extended portion of the second fixing member has a free edge pressed against the outer surface of the heat transfer element. 
     In an embodiment of the present invention, the heat transfer element is a heat pipe or a vapor chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein 
         FIG. 1A  is a fully exploded perspective view of a fixing structure for heat dissipation element according to a first embodiment of the present invention; 
         FIG. 1B  is a partially assembled perspective view of  FIG. 1A ; 
         FIG. 1C  is a fully assembled perspective view of  FIG. 1A ; 
         FIG. 2A  is a fragmentary assembled sectional view taken along line  2 A- 2 A of  FIG. 1C ; 
         FIG. 2B  is a fragmentary assembled sectional view of the fixing structure for heat dissipation element according to a second embodiment of the present invention; 
         FIG. 3A  is a fully exploded perspective view of the fixing structure for heat dissipation element according to a third embodiment of the present invention; 
         FIG. 3B  is a partially assembled perspective view of  FIG. 3A ; 
         FIG. 3C  is a fully assembled perspective view of  FIG. 3A ; 
         FIG. 4A  is a fragmentary sectional view taken along line  4 A- 4 A of  FIG. 3C ; 
         FIG. 4B  is a fragmentary assembled sectional view of the fixing structure for heat dissipation element according to a fourth embodiment of the present invention; 
         FIG. 5A  is a fragmentary assembled sectional view of the fixing structure for heat dissipation element according to a fifth embodiment of the present invention; 
         FIG. 5B  is a fragmentary assembled sectional view of the fixing structure for heat dissipation element according to a sixth embodiment of the present invention; 
         FIGS. 6A to 6D  are perspective views showing four variants of a first and a second fixing member included in the fixing structure of the present invention; 
         FIG. 7  shows the manner in which the fixing structure for heat dissipation element of  FIG. 4A  is assembled; and 
         FIG. 8  shows the manner in which the fixing structure for heat dissipation element of  FIG. 5A  is assembled. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention relates to a fixing structure for heat dissipation element that includes a heat transfer element, a base plate, and at least one fixing member. The heat transfer element has two opposite outer lateral sides, and a width of the heat transfer element is defined between the two opposite outer lateral sides. The base plate has a top surface, on which a receiving recess is defined for receiving the heat transfer element therein. The receiving recess has a top opening and two opposite inner lateral sides located corresponding to the two opposite outer lateral sides of the heat transfer element. A width of the receiving recess is defined between the two opposite inner lateral sides and is larger than the width of the heat transfer element. At least one clearance is defined between the two opposite inner lateral sides of the receiving recess and the two outer lateral sides of the heat transfer element. The at least one fixing member has a fixing portion connected to the top surface of the base plate and an extended portion extended from the fixing portion. The extended portion is bent and inserted into the clearance to locate between the receiving recess and the heat transfer element, bringing the heat transfer element to be tightly held in the receiving recess. 
     The present invention will now be described with some preferred embodiments thereof and by referring to the accompanying drawings. For the purpose of easy to understand, elements that are the same in the preferred embodiments are denoted by the same reference numerals. 
     Please refer to  FIGS. 1A to 1C , which are fully exploded, partially assembled, and fully assembled perspective views, respectively, of a fixing structure for heat dissipation element according to a first embodiment of the present invention, and to  FIG. 2A , which is a fragmentary assembled sectional view taken along line  2 A- 2 A of  FIG. 1C . For the purpose of conciseness, the present invention is also briefly referred to as the fixing structure herein. As shown, the fixing structure in the first embodiment includes a heat transfer element  11 , a base plate  12 , and a first fixing member  13 . The heat transfer element  11  has an outer surface  111 ; two opposite sides of which are defined as a first and a second outer lateral side  112 ,  113 ; and a heat transfer element width HB is defined between the first and the second outer lateral side  112 ,  113 . The first outer lateral side  112  of the heat transfer element  11  can be, for example but not limited to, a rightmost side of the heat transfer element  11 , whereas the second outer lateral side  113  of the heat transfer element  11  can be, for example but not limited to, a leftmost side of the heat transfer element  11 . The heat transfer element  11  can be, for example but not limited to, a heat pipe or a vapor chamber and internally defines a chamber  114 , in which a wick structure  115  and a working fluid  116  are provided. Either the heat pipe or the vapor chamber dissipates heat mainly through a vapor-liquid circulation occurred therein. More specifically, both the heat pipe and the vapor chamber have an evaporating and a condensing end. The evaporating end is in contact with a heat generating element, such that the working fluid  116  located at the evaporating end is heated and vaporized. The vaporized working fluid  116  flows through the chamber  114  to the condensing end, at where the working fluid  116  is condensed into liquid. The liquid working fluid  116  then flows back to the evaporating end with the help of a capillary force of the wick structure  115 . Since the heat pipe and the vapor chamber are known in the art, they are not discussed in more details herein. 
     The base plate  12  can be, for example but not limited to, a middle frame or a back case of a cell phone or a tablet computer, or a heat spreader provided in an electronic device, such as a personal computer (PC) or a smart wearable device. The base plate  12  has a top surface  121 , on which a receiving recess  122  is defined for receiving the heat transfer element  11  therein. The receiving recess  122  has a top opening  1221 , a first inner lateral side  1222  and a second inner lateral side  1223  opposite to the first inner lateral side  1222 . The first inner lateral side  1222  is located corresponding to the first outer lateral side  112  of the heat transfer element  11 , whereas the second inner lateral side  1223  is located corresponding to the second outer lateral side  113  of the heat transfer element  11 . A receiving recess width CB is defined between the first and the second inner lateral side  1222 ,  1223  and is slightly larger than the heat transfer element width HB, as can be seen in  FIG. 2A . Furthermore, in the illustrated first embodiment, a first clearance g 1  is defined between the first inner lateral side  1222  of the receiving recess  122  and the first outer lateral side  112  of the heat transfer element  11 , and the second outer lateral side  113  of the heat transfer element  11  is in contact with the second inner lateral side  1223  of the receiving recess  122 . 
     The first fixing member  13  is connected to the top surface  121  of the base plate  12  to locate adjacent to one side of the top opening  1221  of the receiving recess  122 . In the illustrated first embodiments, the first fixing member  13  is located to a right side of the top opening  1221  of the receiving recess  122 . The first fixing member  13  has a first fixing portion  131  and a first extended portion  132  extended from one side of the first fixing portion  131 . The first fixing portion  131  is connected to the top surface  121  of the base plate  12 , whereas the first extended portion  132  of the first fixing member  13  is bent and inserted into the first clearance g 1 , such that the first extended portion  132  of the first fixing member  13  is tightly fitted between the first inner lateral side  1222  of the receiving recess  122  and the first outer lateral side  112  of the heat transfer element  11 . 
     Furthermore, a first shallow recess  126   a  is also defined on the top surface  121  of the base plate  12  to locate adjacent to one outer side of the top opening  1221  of the receiving recess  122 . In the illustrated first embodiment, the first shallow recess  126   a  is located adjacent to a right outer side of the top opening  1221  of the receiving recess  122 . The receiving recess  122  has a depth d 1  defined between the top surface  121  of the base plate  12  and a bottom of the receiving recess  122 , whereas the first shallow recess  126   a  has a depth d 2  defined between the top surface  121  of the base plate  12  and a bottom of the first shallow recess  126   a . Moreover, the depth d 1  of the receiving recess  122  is larger than the depth d 2  of the first shallow recess  126   a . The first fixing portion  131  of the first fixing member  13  is fitted in the first shallow recess  126   a , and has a thickness equal to or smaller than the depth d 2  of the first shallow recess  126   a , so that a top surface of the first fixing portion  131  of the first fixing member  13  fitted in the first shallow recess  126   a  is not higher than the top surface  121  of base plate  12 . 
     Alternatively, as shown in  FIG. 2B , which is a fragmentary assembled sectional view of the fixing structure for heat dissipation element according to a second embodiment of the present invention, the first fixing portion  131  of the first fixing member  13  can be directly connected to the top surface  121  of the base plate  12  without the need of providing a shallow recess on the base plate  12 . 
     More specifically, the first fixing portion  131  of the first fixing member  13  is connected to the top surface  121  of the base plate  12  or fitted in the first shallow recess  126   a  by riveting, welding, bonding, spot welding, hooking, or snap fitting. 
     In the illustrated first embodiment, the first extended portion  132  of the first fixing member  13  is tightly fitted between the first inner lateral side  1222  of the receiving recess  122  and the first outer lateral side  112  of the heat transfer element  11 , causing the heat transfer element  11  to be tightly held in the receiving recess  122 . In other words, a sum of a thickness of the first extended portion  132  and the width HB of the heat transfer element  11  is slightly larger than the width CB of the receiving recess  122 , so that the first extended portion  132  and the heat transfer element  11  can be tightly fitted in the receiving recess  122 . 
     Please refer to  FIGS. 3A to 3C , which are fully exploded, partially assembled, and fully assembled perspective views, respectively, of the fixing structure according to a third embodiment of the present invention, and to  FIG. 4A , which is a fragmentary assembled sectional view taken along line  4 A- 4 A of  FIG. 3C . As shown, the fixing structure in the third embodiment further includes a second fixing member  15 . In the illustrated third embodiment, the first and the second fixing member  13 ,  15  are respectively located to a right and a left outer side of the top opening  1221  of the receiving recess  122 . The second fixing member  15  has a second fixing portion  151  and a second extended portion  152 . The second fixing portion  151  is connected to the top surface  121  of the base plate  12 , whereas the second extended portion  152  is extended from the second fixing portion  151  into the top opening  1221  of the receiving recess  122 , as shown in  FIG. 4A . The second extended portion  152  is extended beyond a contact surface between the second inner lateral side  1223  of the receiving recess  122  and the second outer lateral side  113  of the heat transfer element  11 , such that a free edge  1521  of the second extended portion  152  is pressed against the outer surface  111  of the heat transfer element  11 , preventing the second outer lateral side  113  of the heat transfer element  11  from moving out of the receiving recess  122 . 
     Moreover, a first and a second shallow recess  126   a ,  126   b  are defined on the top surface  121  of the base plate  12  to locate adjacent to two lateral outer sides of the top opening  1221  of the receiving recess  122 . The first and the second shallow recess  126   a ,  126   b  respectively have a depth d 2  defined between the top surface  121  of the base plate  12  and a bottom of the first and of the second shallow recess  126   a ,  126   b.    
     Further, the depth d 1  of the receiving recess  122  is larger than the depth d 2  of the first and the second shallow recess  126   a ,  126   b . The first fixing portion  131  of the first fixing member  13  and the second fixing portion  151  of the second fixing member  15  are respectively fitted in the first and the second shallow recess  126   a ,  126   b . The first fixing member  13  and the second fixing member  15  respectively have a thickness equal to or smaller than the depth d 2  of the first and the second shallow recess  126   a ,  126   b , so that top surfaces of the first and second fixing portions  131 ,  151  fitted in the first and second shallow recesses  126   a ,  126   b  are not higher than the top surface  121  of the base plate  12 . 
     Alternatively, as shown in  FIG. 4B , which is a fragmentary assembled sectional view of the fixing structure according to a fourth embodiment of the present invention, the first fixing portion  131  of the first fixing member  13  and the second fixing portion  151  of the second fixing member  15  can be directly connected to the top surface  121  of the base plate  12  without the need of providing two shallow recesses on the base plate  12 . 
     Like the first fixing member  13 , the second fixing portion  151  of the second fixing member  15  is connected to the top surface  121  of the base plate  12  or fitted in the second shallow recess  126   b  by riveting, welding, bonding, spot welding, hooking, or snap fitting. 
     In the third and fourth embodiments illustrated in  FIGS. 4A and 4B , respectively, the second outer lateral side  113  of the heat transfer element  11  is in contact with the second inner lateral side  1223  of the receiving recess  122 . However, in a fifth and a sixth embodiment illustrated in  FIGS. 5A and 5B , respectively, a second clearance g 2  is defined between the second inner lateral side  1223  of the receiving recess  122  and the second outer lateral side  113  of the heat transfer element  11 . In this case, like the first fixing member  13 , the second extended portion  152  of the second fixing member  15  is bent and inserted into the second clearance g 2 , such that the second extended portion  152  of the second fixing member  15  is tightly fitted between the second inner lateral side  1223  of the receiving recess  122  and the second outer lateral side  113  of the heat transfer element  11 . 
     In the illustrated fifth and sixth embodiments, the first extended portion  132  of the first fixing member  13  is tightly fitted between the first inner lateral side  1222  of the receiving recess  122  and the first outer lateral side  112  of the heat transfer element  11 , and the second extended portion  152  of the second fixing member  15  is tightly fitted between the second inner lateral side  1223  of the receiving recess  122  and the second outer lateral side  113  of the heat transfer element  11 , causing the heat transfer element  11  to be tightly held in the receiving recess  122 . In other words, a sum of the thickness of the first and second extended portions  132 ,  152  and the width HB of the heat transfer element  11  is slightly larger than the width CB of the receiving recess  122 , so that the first and second extended portions  132 ,  152  and the heat transfer element  11  can be tightly fitted in the receiving recess  122 . 
     Please refer to  FIGS. 6A to 6D , which are perspective views showing four variants of the first and the second fixing member  13 ,  15  included in the fixing structure of the present invention. As shown, both the first extended portion  132  of the first fixing member  13  and the second extended portion  152  of the second fixing member  15  can be differently configured. For example, the first and the second extended portion  132 ,  152  may respectively be a plurality of continuously arranged saw teeth, as shown in  FIG. 6A , or be a plurality of equally spaced teeth, as shown in  FIG. 6B , or be a plurality of irregularly spaced teeth, as shown in  FIG. 6C , or simply be a long strip, as shown in  FIG. 6D . The configurations of the first and the second extended portion  132 ,  152  can be changed according to the width HB of the heat transfer element  11 , as shown in  FIGS. 2A, 2B, 4A, 4B, 5A, and 5B , or a wall thickness of the heat transfer element  11  defined between the outer surface  111  and the chamber  114  of the heat transfer element  11  for isolating the chamber  114  from external environment, or can be determined according to the manner in which the heat transfer element  11  is to be fitted in the receiving recess  122 . 
     The following is a description of the manner in which the fixing structure of the present invention is assembled. 
     Please refer to  FIG. 7 , which shows the manner in which the fixing structure of  FIG. 4A  is assembled. As shown, the first and the second fixing member  13 ,  15  are first respectively connected to the top surface  121  of the base plate  12 , such that the first and the second fixing portion  131 ,  151  are fixedly fitted in the first and the second shallow recess  126   a ,  126   b , respectively, and the first and the second extended portion  132 ,  152  are horizontally extended beyond the first and the second inner lateral side  1222 ,  1223  of the receiving recess  122  into the top opening  1221 . It is noted a distance between a free edge  1321  of the first extended portion  132  and a free edge  1521  of the second extended portion  152  is smaller than the receiving recess width CB. Then, the heat transfer element  11  is slantingly directed into the receiving recess  122 , such that the second outer lateral side  113  of the heat transfer element  11  can be moved into the receiving recess  122  to press against the second inner lateral side  1223  of the receiving recess  122  without being interfered by the second extended portion  152  of the second fixing member  15 . 
     Then, the first outer lateral side  112  of the heat transfer element  11  is downwardly pressed into the receiving recess  122 . When doing so, the first outer lateral side  112  of the heat transfer element  11  naturally presses the first extended portion  132  of the first fixing member  13  downwardly to bend the same by an angle equal to or larger than 90 degrees, such that the first extended portion  132  of the first fixing member  13  is located between the first inner lateral side  1222  of the receiving recess  122  and the heat transfer element  11 . After the heat transfer element  11  is fitted in the receiving recess  122 , the first clearance g 1  is defined between the first outer lateral side  112  of the heat transfer element  11  and the first inner lateral side  1222  of the receiving recess  122 , and the first extended portion  132  is inserted in the first clearance g 1 , bringing the heat transfer element  11  to be tightly held in the receiving recess  122 . 
     Please refer to  FIG. 8 , which shows the manner in which the fixing structure of  FIG. 5A  is assembled. As shown, the first and the second fixing member  13 ,  15  are first respectively connected to the top surface  121  of the base plate  12 , such that the first and the second fixing portion  131 ,  151  are fixedly fitted in the first and the second shallow recess  126   a ,  126   b , respectively, and the first and the second extended portion  132 ,  152  are horizontally extended beyond the first and the second inner lateral side  1222 ,  1223  of the receiving recess  122  into the top opening  1221 . It is noted a distance between a free edge  1321  of the first extended portion  132  and a free edge  1521  of the second extended portion  152  is smaller than the receiving recess width CB. Then, the heat transfer element  11  is horizontally positioned and downwardly pressed into the receiving recess  122 . When doing so, the first outer lateral side  112  of the heat transfer element  11  naturally presses the first extended portion  132  of the first fixing member  13  downwardly to bend the same by an angle equal to or larger than 90 degrees, whereas the second outer lateral side  113  of the heat transfer element  11  naturally presses the second extended portion  152  of the second fixing member  15  downwardly to bend the same by an angle equal to or larger than 90 degrees, such that the first extended portion  132  of the first fixing member  13  and the second extended portion  152  of the second fixing member  15  are respectively located between the receiving recess  122  and the first and second outer lateral sides  112 ,  113  of the heat transfer element  11 . 
     After the heat transfer element  11  is fitted in the receiving recess  122 , the first clearance g 1  is defined between the first outer lateral side  112  of the heat transfer element  11  and the first inner lateral side  1222  of the receiving recess  122 , whereas the second clearance g 2  is defined between the second outer lateral side  113  of the heat transfer element  11  and the second inner lateral side  1223  of the receiving recess  122 , and the first extended portion  132  is inserted in the first clearance g 1  while the second extended portion  152  is inserted in the second clearance g 2 , bringing the heat transfer element  11  to be tightly held in the receiving recess  122 . 
     By inserting the fixing member in at least one clearance formed between the receiving recess and the heat transfer element, the heat transfer element can be tightly fitted in the receiving recess without causing damage to it, while the production process can be shortened and the manufacturing cost can be reduced. 
     Furthermore, in an operable embodiment of the present invention, the first and the second fixing member  13 ,  15  can be integrally formed, such that the first extended portion  132  of the first fixing member  13  and the second extended portion  152  of the second fixing member  15  are connected to each other. 
     The present invention has been described with some preferred embodiments thereof and it is understood that many changes and modifications in the described embodiments can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.