TWI491341B - Plate type heat pipe and heat dissipation device having the same - Google Patents

Description

Flat heat pipe and heat dissipation module using the same

The invention relates to a heat dissipation module, in particular to a flat heat pipe and a heat dissipation module using the heat pipe.

With the rapid development of the computer industry, the CPU pursues high speed, and the heat dissipation problem caused by multi-function and miniaturization becomes more and more serious, which is more prominent in electronic devices with narrow internal space such as notebook computers. If the heat generated by the electronic components such as the CPU in the notebook cannot be dissipated in a timely and effective manner, the performance of the electronic component will be greatly affected, and the service life of the electronic component will be reduced. Therefore, the electronic component must be dissipated.

At present, in a small electronic device such as a notebook computer, since the space is limited by a small space, the heat dissipation module used usually uses a plate type heat pipe for heat transfer. 1 shows a conventional plate type heat pipe 70 placed on a circuit board 80 provided with heat generating electronic components 90. The upper plate 71 and the lower plate 72 of the plate type heat pipe 70 are both planar and parallel to each other, and the height of the vapor cavity 75 of the heat pipe 70 is unchanged in the heat pipe 70. The heat-generating electronic component 90 is protruded above the circuit board 80. The lower plate 72 of the heat pipe 70 is in contact with the heat-generating electronic component 90, so that the design space of the heat pipe 70 is limited to the top plane 92 of the heat-emitting electronic component 90. Space, such that the volume of the vapor cavity 75 of the heat pipe 70 is limited in a small space, thereby limiting the heat pipe 70 The heat transfer efficiency ultimately affects the heat dissipation efficiency of the heat dissipation module.

In view of this, it is necessary to provide a flat heat pipe which still has excellent heat transfer efficiency in a small space and a heat dissipation module using the heat pipe.

A flat heat pipe for conducting heat generated by a heat-generating electronic component, the flat heat pipe including a casing internally forming a vapor cavity and a capillary structure housed in the casing, the casing being combined with heat-generating electronic components Forming at least one inner recess toward the vapor cavity, the inner recess for receiving the heat-generating electronic component, the inner recess comprising a bottom wall and a sidewall surrounding the periphery of the bottom wall, the heat-generating electronic component and the inner recess The outer surface of the bottom wall is in contact with the inner wall of the top plate and the inner surface of the bottom wall of the inner recess, the bottom of the capillary structure surrounding the outer periphery of the inner wall of the inner recess, the bottom of the capillary structure The central portion is in contact with the inner surface of the bottom wall of the inner recess, the peripheral portion of the bottom of the capillary structure surrounding the inner wall of the side wall of the inner recess and extending downwardly to contact the inner wall of the bottom plate, the top of the capillary structure being from the bottom Extending into contact with the inner wall of the top panel, the capillary structure is spaced from the side panel to form a vapor passage through which vapor can pass.

A heat dissipation module for dissipating heat to a heat-generating electronic component, comprising a flat heat pipe and a heat sink, the flat heat pipe comprising an evaporation section and a condensation section for contacting the heat-generating electronic component, a condensation section is coupled to the heat sink, the flat heat pipe including a housing internally forming a vapor cavity and a capillary structure housed within the housing, the surface of the housing coupled to the heat generating electronic component facing the vapor cavity The recess forms at least one inner recess for receiving the heat-generating electronic component, the inner recess includes a bottom wall and a sidewall surrounding the periphery of the bottom wall, and the heat-generating electronic component is attached to the outer surface of the bottom wall of the inner recess The capillary structure and the inner wall and inner portion of the top plate The inner surface of the bottom wall of the recess is in contact with the bottom of the capillary structure surrounding the periphery of the entire inner wall of the inner recess, and the central portion of the bottom of the capillary structure is in contact with the inner surface of the bottom wall of the inner recess, the bottom of the capillary structure a peripheral portion surrounding an inner wall of the side wall of the inner recess and extending downwardly into contact with an inner wall of the bottom plate, the top of the capillary structure extending from the bottom to be in contact with an inner wall of the top plate, the capillary structure being spaced apart from the side plate to form A vapor passage through which steam can pass.

The inner concave portion of the flat heat pipe accommodates the heat-generating electronic component therein, and the flat heat pipe sufficiently utilizes a space around the heat-generating electronic component to expand the volume of the vapor cavity. In the same space, the volume of the vapor cavity of the flat heat pipe is larger than the volume of the steam cavity of the conventional heat pipe, and a large vapor cavity can be ensured in a small space inside a notebook computer, thereby increasing The heat transfer efficiency of the heat pipe is large.

10‧‧‧ Centrifugal fan

12‧‧‧Fan frame

120‧‧‧First air inlet

122‧‧‧air outlet

14‧‧‧ Impeller

20‧‧‧ radiator

30, 50‧‧‧ flat heat pipe

31‧‧‧Evaporation section

32, 52‧‧‧ top board

33‧‧‧Condensation section

34, 54‧‧‧ side panels

35, 55‧‧‧Vapor passage

36, 56‧‧‧ bottom plate

360, 560‧ ‧ inner recess

361, 561‧‧‧ bottom wall

362, 562‧‧‧ side walls

37, 57‧‧‧ shell

38‧‧‧through holes

39, 59‧‧‧Capillary structure

70‧‧‧ plate type heat pipe

71‧‧‧Upper board

72‧‧‧ Lower board

75‧‧‧Vapor Cavity

80‧‧‧ boards

90‧‧‧Electronic components

92‧‧‧ top surface

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic cross-sectional view showing a conventional flat heat pipe placed on a circuit board provided with heat generating electronic components.

2 is a perspective assembled view of the inverted state of the first embodiment of the heat dissipation module of the present invention.

Fig. 3 is an exploded perspective view of Fig. 2;

4 is a cross-sectional view of the flat type heat pipe of FIG. 2 placed on a circuit board provided with heat generating electronic components.

Figure 5 is a cross-sectional view showing a second embodiment of the flat heat pipe of the present invention.

Referring to FIG. 2 and FIG. 3 together, the heat dissipation module includes a centrifugal fan 10, a heat sink 20 and a flat heat pipe 30.

The centrifugal fan 10 includes a frame 12 and an impeller 14. An accommodating space is formed in the fan frame 12 , and the impeller 14 is received in the accommodating space. A first air inlet 120 and a second air inlet (not shown) are formed on the opposite sides of the axial direction of the fan frame 12, and a fan outlet 122 is formed laterally of the fan frame 12.

The heat sink 20 is formed by stacking a plurality of heat dissipation fins. The heat sink 20 has a rectangular shape and is located at the air outlet 122 of the centrifugal fan 10.

Referring to FIG. 4 together, the heat pipe 30 has a plate shape including a hollow casing 37, a capillary structure 39 disposed in the casing 37, and a working liquid injected into the casing 37. The housing 37 includes a top plate 32, a bottom plate 36 opposite the top plate 32, and side plates 34. The side panel 34 is located between the top panel 32 and the bottom panel 36 and is connected to the periphery of the top panel 32 and the bottom panel 36. The top plate 32, the bottom plate 36 and the side plates 34 are enclosed such that the housing 37 forms a hollow sealed chamber such that a vapor cavity is formed inside the housing 37. In the present embodiment, the casing 37 is formed by closing the upper and lower casings. Of course, the housing 37 can also be formed by flattening a hollow circular tube.

The heat pipe 30 has a substantially "Z" shape and includes an L-shaped evaporation section 31 and a linear condensation section 33 along the extending direction thereof, and the condensation section 33 is connected to the heat sink 20 and has a shape corresponding thereto.

The bottom plate 36 of the evaporation section 31 of the heat pipe 30 is recessed toward the vapor cavity to form four inner recesses 360 for accommodating a plurality of heat-generating electronic components, and the four inner recesses 360 can be set differently according to the heights of different heat-generating electronic components. Depth to allow simultaneous thermal conduction of different heat-generating electronic components. In this embodiment, only a heat-generating electronic component 90 is combined with one of the inner recesses 360 of the heat pipe 30 as an example. The inner recesses 360 are generally square or rectangular. Each inner recess 360 includes a bottom wall 361 and four side walls 362. The bottom wall 361 is parallel to the bottom plate 36 and sinks a distance from the bottom plate 36 toward the vapor cavity, the bottom wall 361 being spaced from the top plate 32. The four side walls 362 surround the bottom wall 361 The circumference is connected to the bottom plate 36 at the periphery of the recess 360. The heat-generating electronic component 90 has a top surface 92 that conforms to the outer surface of the bottom wall 361 of the inner recess 360, and the side surface of the heat-generating electronic component 90 is spaced from the sidewall 362 of the inner recess 360.

In other embodiments, the inner recesses 360 may also have other shapes, such as circular, trapezoidal, etc., the specific shape of which corresponds to the shape of the heat-generating electronic component 90 and slightly larger than the size of the heat-generating electronic component 90. In addition, the extent to which the recessed portions 360 are recessed depends on the height of the heat-generating electronic component 90 protruding from the circuit board 80, and the recessed portion 360 corresponding to the relatively large heat-generating electronic component 90 is recessed deep, and the heat-emitting electronic component having a small height is small. The depression of the corresponding concave portion 360 of 90 is shallow.

The capillary structure 39 extends from the evaporation section 31 to the condensation section 33 along the direction in which the heat pipe 30 extends, and the working liquid is contained in the capillary structure 39. The bottom of the capillary structure 39 surrounds the periphery of the entire inner wall of the inner recess 360. The central portion of the bottom of the capillary structure 39 is in contact with the inner surface of the bottom wall 361 of the inner recess 360. The peripheral portion of the bottom of the capillary structure 39 surrounds the inner wall of the side wall 362 of the inner recess 360 and extends downwardly to the bottom plate 36. The inner wall is in contact with the top of the capillary structure 39 extending upwardly from the bottom to contact the inner wall of the top plate 32. The capillary structure 39 is spaced from the side panels 34 of the housing 37 to form a vapor passage 35 through which vapor can pass, the capillary structure 39 contacting the inner surface of the bottom wall 361 of the inner recess 360 to ensure that the inner surface has working fluid To ensure normal operation of the heat pipe 30, the bottom of the capillary structure 39 is in contact with the inner wall of the bottom plate 36 to absorb the working liquid that is converged by gravity to the inner wall of the bottom plate 36 to the inside of the capillary structure 39. In addition, the capillary structure 39 is in contact with the inner wall of the top plate 32 and the bottom plate 36 of the housing 37 to support the housing 37, thereby preventing deformation of the top plate 32 and the bottom plate 36 and affecting the performance of the heat pipe 30.

The evaporation section 31 of the heat pipe 30 is provided with four through holes penetrating the heat pipe 30 up and down. 38. The periphery of the through holes 38 forms a wall portion to seal the casing 37 of the periphery of the through hole 38 so as not to affect the sealing property of the casing 37. The through holes 38 are permeable to a fixing member (not shown) to fix the heat pipe 30 to the circuit board 80.

When assembled, the heat sink 20 is disposed at the air outlet 122 of the centrifugal fan 10. The condensation section 33 of the heat pipe 30 is disposed above the heat sink 20, and the concave portion 360 of the evaporation section 31 of the heat pipe 30 will heat the electrons. The component 90 is received therein, and the top surface 92 of the heat-generating electronic component 90 is attached to the bottom wall 361 of the recessed portion 360. To reduce the thermal resistance, the top surface 92 of the heat-generating electronic component 90 and the bottom wall 361 may be A thermal paste (not shown) is applied between the outer surfaces, and finally the heat pipe 30 is fixed to the circuit board 80 through the through holes 38 of the heat pipe 30 by the fixing members.

When the heat dissipation module is in operation, the bottom wall 361 of the inner recess 360 of the heat pipe 30 absorbs heat from the heat-generating electronic component 90 and transfers heat to the inside of the casing 37, so that the capillary structure 39 surrounding the inner wall of the inner recess 360 is provided. The working liquid contained therein is vaporized, with heat transferred to the condensation section 33 via the vapor passage 35, and the condensation section 33 transfers heat to the radiator 20 located below it, and the impeller 14 of the centrifugal fan 10 draws in airflow from the inlet 104 and blows To the heat sink 20, the heat on the fins is dissipated, thereby lowering the temperature of the condensation section 33, causing the vapor in the condensation section 33 to liquefy and condense, and returning to the evaporation section 31 under the action of the capillary structure 39 to continue vaporization and liquefaction. The condensation causes the working medium to circulate inside the heat pipe 30, and the heat generated by the heat-generating electronic component 90 is continuously emitted.

Since the inner recessed portion 360 of the heat pipe 30 can accommodate the heat-generating electronic component 90 protruding from the circuit board 80, the flat heat pipe 30 of the present invention makes full use of the flat heat pipe 70 of the present invention as compared with the conventional flat heat pipe 70 shown in FIG. The space around the heat-generating electronic component 90 expands the volume of the vapor cavity, and the flat heat guide of the present invention is in the same installation space. The volume of the vapor cavity of the tube 30 is larger than the volume of the vapor cavity 75 of the conventional flat heat pipe 70, and a large vapor cavity can be secured in a small space, especially in a case where the internal installation space of the notebook computer is small. The heat transfer efficiency of the flat heat pipe 30 can be increased, thereby improving the heat dissipation efficiency of the heat dissipation module of the present invention.

5 is a flat heat pipe 50 according to a second embodiment of the present invention, which is different from the heat pipe 30 of the first embodiment in that a capillary structure 59 of the heat pipe 50 is attached to the case. The top plate 52 of the body 57 and the entire inner wall of the side plate 54. The portion of the capillary structure 59 disposed on the inner wall of the top plate 52 is in contact with the inner surface of the bottom wall 561 of the inner recess 560, thereby ensuring a working liquid at the inner surface of the bottom wall 561 to ensure heat transfer performance of the heat pipe 50. The portion of the capillary structure 59 attached to the inner wall of the side plate 54 is spaced from the side wall 562 of the inner recess 560 to leave a vapor passage 55 for vapor to pass therethrough. The portion of the capillary structure 59 provided on the inner wall of the side plate 54 extends down the inner wall of the side plate 54 to contact the inner wall of the bottom plate 56 to absorb the working liquid of the inner wall of the bottom plate 56.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10‧‧‧ Centrifugal fan

12‧‧‧Fan frame

120‧‧‧First air inlet

122‧‧‧air outlet

14‧‧‧ Impeller

20‧‧‧ radiator

30‧‧‧flat heat pipe

31‧‧‧Evaporation section

32‧‧‧ top board

33‧‧‧Condensation section

34‧‧‧ side panels

36‧‧‧floor

360‧‧‧ recess

361‧‧‧ bottom wall

362‧‧‧ side wall

37‧‧‧Shell

38‧‧‧through holes

Claims (5)

A flat heat pipe for conducting heat generated by a heat-generating electronic component, the flat heat pipe including a casing internally forming a vapor cavity and a capillary structure housed in the casing, the casing including a top plate, a bottom plate opposite to the top plate, and two side plates, the side plate is located between the top plate and the bottom plate and connected to the periphery of the top plate and the bottom plate, the top plate, the bottom plate and the side plates are enclosed to form a hollow sealed chamber, and the improvement is that the top plate is a horizontal plate, the casing is recessed from the bottom plate toward the vapor cavity to form at least one inner recess for receiving the heat-generating electronic component, the inner recess comprising a bottom wall and a side wall surrounding the periphery of the bottom wall, the heat The electronic component is in contact with an outer surface of the bottom wall of the inner recess, the capillary structure being in contact with an inner wall of the top plate and an inner surface of the bottom wall of the inner recess, the bottom of the capillary structure surrounding the entire inner wall of the inner recess a peripheral portion, a central portion of the bottom of the capillary structure is in contact with an inner surface of the bottom wall of the inner concave portion, and a peripheral portion of the bottom portion of the capillary structure surrounds an inner wall of the side wall of the inner concave portion The inner wall extends downwardly into contact with the bottom plate, the top of the capillary structure extending from the bottom to the top plate contact the inner wall of the capillary structure and the spacer plate to form a vapor phase for vapor passage therethrough. The flat type heat pipe according to claim 1, wherein the inner concave portion has a square shape, a rectangular shape, or a circular shape. The flat type heat pipe according to claim 1, wherein the inner recess is provided in plurality for receiving a plurality of heat-generating electronic components, and the depth of each recess depends on the height of the corresponding heat-generating electronic component. A heat dissipation module for dissipating heat to a heat-generating electronic component, comprising a flat heat pipe and a heat sink, the flat heat pipe comprising an evaporation section and a condensation section for contacting the heat-generating electronic component, The condensing section is connected to the heat sink, wherein the flat type heat pipe is the flat type heat pipe according to any one of claims 1 to 3. The heat dissipation module of claim 4, wherein the heat dissipation module further comprises a centrifugal fan, and an air outlet is formed on the centrifugal fan, and the radiator is disposed at an air outlet of the centrifugal fan.