Patent Publication Number: US-2012044641-A1

Title: Electronic device

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to device cooling, more particularly to an electronic device dissipating heat from a central processing unit. 
     2. Description of Related Art 
     Heat dissipating devices often include one or more fans and heat sinks corresponding thereto. For example, a central processing unit (CPU) in an all-in-one (AIO) computer can experience deteriorated operational stability and damage associated electronic components if heat is not dissipated efficiently. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the embodiments can be better understood with references 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 embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an exploded, isometric view of an electronic device in accordance with an embodiment as disclosed. 
         FIG. 2  is similar to  FIG. 1 , but shows a first and second heat devices fixed to a circuit board. 
         FIG. 3  is an assembled view of  FIG. 1 . 
         FIG. 4  is a diagram showing a software-generated relationship between temperature and distances between two adjacent first fins. 
     
    
    
     DETAILED DESCRIPTION 
     The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one. 
     Referring to  FIGS. 1 and 2 , an electronic device in accordance with an embodiment includes an enclosure  10  and a casing  30  received in the enclosure  10 . In one embodiment, the electronic device is an AIO. 
     The enclosure  10  includes a main body  11  and a cover  13  attached to the main body  11 . A first heat device  20  and a circuit board  40  are attached to the main body  11 . The first heat device  20  is located on one side of the circuit board  40 , and includes a plurality of first fins  21  and a first base  23  configured for securing the plurality of first fins  21 . The plurality of first fins  21  cooperatively defines a plurality of first air path for air passing through. A distance of every two adjacent first fins  21  equals or exceeds 5.3 mm, but less than or equal to 5.7 mm. In one embodiment, the distance of two adjacent first fins  21  is 5.5 mm. A CPU  41  is disposed on the circuit board  40 , and four securing holes  43  are defined in the circuit board  40 , surrounding CPU  41 . 
     A second heat device  50  is attached to the CPU  41 , and includes a second base  51  and a plurality of second fins  53 . The plurality of second fins  53  cooperatively define a plurality of second air path for air passing through. Four mounting holes  511  are respectively defined in four corners of the base, corresponding to the four securing holes  43 . 
     A heat pipe  60  is located between the first heat device  20  and the second heat device  50 . In one embodiment, the heat pipe  60  is L-shaped, a first end of the heat pipe  60  is substantially perpendicularly secured to the plurality of first fins  21 , and a second end of the heat pipe  60  is located between two adjacent second fins  53 . 
     A plurality of first air intakes (not shown) is defined in the bottom of the cover  13 , and a plurality of first air outlets  133  is defined in the center of the cover  13 . 
     A plurality of through holes  31  is defined in the casing  30 . The casing  30  includes first flanges (not shown) and an opposite second flange  33 . A plurality of second air intakes (not shown) is defined in the first flange, and a plurality of second air outlets  331  is defined in the second flange  33 . 
     Referring to  FIGS. 2 and 3 , in assembly, the first heat device  20  is placed on one side of the circuit board  40 , and the second heat device  50  is placed on the CPU  41 . The four securing holes  43  of the main body  11  are aligned with the four mounting holes  511  of the second heat device  50 . Four fixing members  70  are received in the four securing holes  43  and the four mounting holes  511 . Thus, the second heat device  50  is mounted to the main body  11 . In one embodiment, the first heat device  20  is mounted to the main body  11  by fasteners or clasps. The casing  30  is attached to the main body  11 , and the circuit board  40 , the first heat device  20  and the second heat device  50  are accommodated in the casing  30 . 
     In use, the second heat device  50  absorbs heat from the CPU, and some heat is transmitted to the first heat device  20  by the heat pipe  60 . The air flows into the enclosure  10  from the first air intakes of the enclosure  10 , and passes through the through holes  31  and the second intakes of the casing  30 . Then, the air flows to the CPU  41 , the first heat device  20  and the second heat device  50 , and out of the second air outlets  331  of the casing  30 , the first air outlets  133  of the enclosure  10 . Accordingly, heat is dissipated from the first heat device  20  and the second heat device  50 . 
     Referring to  FIG. 4 , a simulation application of an embodiment such as Icepak generates a working temperature of the CPU  41  under conditions in which a normal temperature is 35° C. and the distance between adjacent first fins  21  is in a range of 5.0-6.0 mm. The lowest temperature of the CPU  41  is 86° C. when the distance between the two adjacent first fins  21  is 5.5 mm. When the distance between the two adjacent first fins  21  is from 5.1 to 5.5 mm, the temperature of the CPU  41  drops to 86° C. from 90.3° C. When the distance between the two adjacent first fins  21  is from 5.5 to 5.9 mm, the temperature of the CPU  41  increases to 90.8° C. from 86° C. In one embodiment, when the temperature of the CPU  41  is in a range 86-86.6° C., the CPU  41  operates stably. Referring to  FIG. 4 , when the distance between the two adjacent first fins  21  is 5.3 mm or 5.7 mm, the temperature of the CPU  41  for both is 86.6° C. When the distance between the two adjacent first fins  21  is increased to 5.5 mm from 5.3 mm, the temperature of the CPU  41  is decreased to 86° C. from 86.6° C. When the distance between the two adjacent first fins  21  is increased to 5.7 mm from 5.5 mm, the temperature of the CPU  41  is increased to 86.6° C. from 86° C. Therefore, when the distance between the two adjacent first fins  21  is in the 5.3-5.7 mm range, the temperature of the CPU  41  is in a range 86-86.6° C., and the CPU  41  can operate stably. When the distance between the two adjacent first fins  21  is 5.5 mm, the temperature of the CPU  41  is 86° C. Thus, the 5.5 mm is shown to be an optimum distance between the two adjacent first fins  21 . 
     It is to be understood, however, that even though numerous characteristics and advantages have been set forth in the foregoing description of embodiments, 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.