TWM664018U - Heat dissipation device - Google Patents

Abstract

A heat dissipation device is adapted to dissipate a heat source. The heat dissipation device includes a casing, a heat conducting base, a heat conducting block, multiple heat dissipation pipes, at least one first heat dissipation fins assembly and a heat dissipation medium. The heat source is disposed inside the casing. The heat conducting base is disposed inside the casing and thermally coupled to the heat source, and has a cavity and a side part which encircles the cavity. The heat conducting block is disposed inside the cavity and thermally coupled to the heat source. The multiple heat dissipation pipes are inserted into the casing. Each of the multiple heat dissipation pipes has a first end and a second end which is relative to the first end. The first end of each of the multiple heat dissipation pipes is inserted into the side part and interconnected with the cavity. The second end of each of the multiple heat dissipation pipes is interconnected to the cavity. The at least one first heat dissipation fins assembly is disposed on the casing and partially covered the cavity. The multiple heat dissipation pipes are thermally coupled to the at least one first heat dissipation fins assembly. The heat dissipation medium is stored inside the cavity and immerses at least part of the heat conducting block.

Description

Heat sink

The invention relates to a heat dissipation device, and in particular to a heat dissipation device applied to a heat source on a circuit board.

Generally speaking, the heat dissipation of fanless heat sinks currently on the market is easily limited by the structure and has poor results. Moreover, if a pump is set to enhance the convection cycle in order to improve the heat dissipation, the power consumption of the heat sink will increase and the life of the heat sink will be affected by the pump. Therefore, how to make the heat sink have a good heat dissipation effect without increasing the power consumption of the heat sink and maintaining the life of the heat sink is an issue that this field is committed to exploring.

The present invention provides a heat dissipation device which has a good heat dissipation effect.

A heat dissipation device of the novel invention is suitable for dissipating heat from a heat source, wherein the heat dissipation device includes a housing, a heat-conducting seat, a heat-conducting block, a plurality of heat-dissipating pipes, at least a first heat-dissipating fin set and a heat-dissipating medium. The heat source is disposed in the housing. The heat-conducting seat is disposed in the housing, wherein the heat-conducting seat is thermally coupled to the heat source and has a groove and a side surrounding the groove. The heat-conducting block is disposed in the groove and is thermally coupled to the heat-conducting seat. A plurality of heat-dissipating pipes are penetrated in the housing, each heat-dissipating pipe has a first end and a second end opposite to the first end, the first end of each heat-dissipating pipe is penetrated in the side and connected to the groove, and the second end of each heat-dissipating pipe is connected to the groove. At least one first heat dissipation fin assembly is arranged on the housing and partially covers the groove, wherein the heat dissipation pipes are thermally coupled to the at least one first heat dissipation fin assembly. The heat dissipation medium is stored in the groove and immerses at least part of the heat conduction block.

Based on the above, in the heat dissipation device of the present invention, the heat generated by the heat source will be transferred to the heat dissipation medium through the heat conductive seat and the heat conductive block. After the heat dissipation medium absorbs a certain amount of heat, the heat dissipation medium will undergo a phase change and change from liquid to gas. The gaseous heat dissipation medium will flow upward from the top opening through the second end into the multiple heat dissipation pipes due to the pressure difference and the temperature difference, and will exchange heat with the first heat dissipation fin assembly in the process of flowing through the heat dissipation pipes. Finally, the heat dissipation medium flows out of the heat dissipation pipe from the first end and flows into the groove, completing the cycle. Accordingly, the heat dissipation device of the present invention does not require an additional pump to circulate the heat dissipation medium, so as to effectively transfer the heat generated by the heat source to the outside, thereby having a good heat dissipation effect.

FIG. 1A to FIG. 1C are schematic diagrams of a heat sink of an embodiment of the present invention at different viewing angles. FIG. 2 is an exploded view of the heat sink of FIG. 1A. FIG. 3 is a cross-sectional view of the heat sink of FIG. 1B along line A-A. Referring to FIG. 1A to FIG. 3, the heat sink 100 of the present embodiment is suitable for cooling a heat source 10 disposed on a circuit board 20 as shown in FIG. 3. The heat source 10 is, for example, a central processing unit (CPU) or a graphics processing unit (GPU), but is not limited thereto. The structure of the heat sink 100 is described in detail below.

FIG4 is a cross-sectional view of the heat sink of FIG1B along line B-B. Referring to FIG1A, FIG2, FIG3 and FIG4, the heat sink 100 includes a housing 110, a heat-conducting base 120, a heat-conducting block 130, a plurality of heat-dissipating pipes 140, at least one first heat-dissipating fin assembly 150 (two are shown) and a heat-dissipating medium 160. The heat source 10 is disposed in the housing 110. The heat-conducting base 120 is disposed in the housing 110. The heat-conducting base 120 is thermally coupled to the heat source 10 and has a groove 121 and a side portion 123 surrounding the groove 121. The heat-conducting block 130 is disposed in the groove 121 as shown in FIG4 and is thermally coupled to the heat-conducting base 120. As shown in FIG. 3 , a plurality of heat dissipation pipes 140 are disposed through the housing 110. As shown in FIG. 3 , each heat dissipation pipe 140 has a first end 141 and a second end 143 opposite to the first end 141. The first end 141 of each heat dissipation pipe 140 is disposed through the side 123 and communicates with the groove 121. The second end 143 of each heat dissipation pipe 140 is communicated with a top opening 1215 of the groove 121. At least one first heat dissipation fin assembly 150 is disposed on the housing 110 and partially covers the groove 121. These heat dissipation pipes 140 are thermally coupled to at least one first heat dissipation fin assembly 150. The heat dissipation medium 160 is stored in the groove 121 and immerses at least a portion of the heat conductive block 130.

As described above, in the heat dissipation device 100 of the present embodiment, the heat generated by the heat source 10 is transferred to the heat dissipation medium 160 through the heat conductive seat 120 and the heat conductive block 130. After the heat dissipation medium 160 absorbs a certain amount of heat, the heat dissipation medium 160 undergoes a phase change and changes from a liquid state to a gas state. The gaseous heat dissipation medium 160 flows upward from the top opening 1215 through the second end 143 into the plurality of heat dissipation pipes 140 due to the pressure difference and the temperature difference, and exchanges heat with the first heat dissipation fin assembly 150 while flowing through the heat dissipation pipes 140. Finally, the heat dissipation medium 160 flows out of the heat dissipation pipe 140 from the first end 141 and flows into the groove 121, completing the cycle. Accordingly, the heat dissipation device 100 of the present invention can circulate the heat dissipation medium 160 without an additional pump, so as to effectively transfer the heat generated by the heat source 10 to the outside, thereby having a good heat dissipation effect.

In this embodiment, the circuit board 20 is disposed in the housing 110, and the heat source 10 is located between the heat conducting base 120 and the circuit board 20. In this embodiment, the first heat sink fin set 150 includes a plurality of first fins 151, and the number of first fins 151 of each first heat sink fin set 150 is twelve, and each first fin 151 extends along the axis X and the axis Z (i.e., each first fin 151 is parallel to the XZ plane), and these first fins 151 are arranged at intervals along the axis Y, but the novel creation does not limit the arrangement direction and number of the first fins 151. In this embodiment, the heat sink medium 160 is, for example, water, but the novel creation does not limit this either.

The distribution state and position of the heat dissipation medium 160 in the groove 121 are described in detail below.

FIG5 is a cross-sectional view of the heat sink of FIG1C along the C-C line. In order to clearly illustrate the heat conducting block 130 of FIG5, the number of the second heat dissipation fin set 132 and the fourth heat dissipation fin set 138 of FIG5 is schematically illustrated. Referring to FIG3 and FIG5, the heat conducting seat 120 includes a top opening 1215 connected to the groove 121, a top space 1211 is formed between the heat conducting block 130 and the top opening 1215, and a side space 1213 is formed between the heat conducting block 130 and the side 123. The top space 1211 is connected to the top opening 1215 as shown in FIG3, and the top space 1211 and the side space 1213 are connected to each other as shown in FIG5. In this embodiment, the liquid heat dissipation medium 160 is present in the lower area of the lateral space 1213 and is shown as a horizontal short line distribution in Figures 3 and 5. The gaseous heat dissipation medium 160 is present in the upper area of the lateral space 1213 and in the top space 1211. More specifically, the gaseous heat dissipation medium 160 is located above a liquid surface 161 (see Figure 3) of the liquid heat dissipation medium 160.

Please refer to FIG3 . In order to make the heat dissipation device 100 of this embodiment have a good heat dissipation effect, the first end 141 of each heat dissipation pipe 140 of this embodiment includes a communication port 1411. As shown in FIG3 , a distance D1 from a center 1411a of the communication port 1411 to a bottom 1217 of the groove 121 is less than a height H1 from a liquid surface 161 of the liquid heat dissipation medium 160 in the lateral space 1213 to the bottom 1217. In other embodiments, the distance D1 from the center 1411a to the bottom 1217 may also be equal to the height H1 from the liquid surface 161 to the bottom 1217, and the present invention is not limited thereto. The heat dissipation device 100 of this embodiment can increase the heat potential of the heat dissipation medium 160 for absorbing heat energy by making the height H1 of the liquid heat dissipation medium 160 higher than the distance D1 from the center 1411a to the bottom 1217, thereby further improving the heat dissipation effect of the heat dissipation device 100.

The structure of the heat conductive block 130 is described in detail below.

6A to 6C are schematic diagrams of the heat conducting block of FIG3 at different viewing angles. Referring to FIG3 and FIG6A, the heat conducting block 130 has a top surface 131 facing the top opening 1215 as shown in FIG3, and the top surface 131 has at least one recess 1311, and the recess 1311 is connected to the top space 1211 as shown in FIG3. As shown in FIG6A, the heat conducting block 130 is provided with at least one second heat dissipation fin assembly 132 (shown as two) on the top surface 131, and the at least one second heat dissipation fin assembly 132 is located on one side of the recess 1311. In this embodiment, there are three recesses 1311, the left second heat sink fin set 132 is located on the left side of the leftmost recess 1311, and the right second heat sink fin set 132 is located on the right side of the rightmost recess 1311, but the number of recesses 1311, the number of second heat sink fin sets 132 and the setting positions are not limited to the above.

In detail, please refer to FIG. 6A , at least one second heat sink fin assembly 132 includes a plurality of second fins 1321 arranged in parallel, and a first slit S1 between two adjacent second fins 1321 extends from the lateral space 1213 shown in FIG. 5 to the recess 1311. Accordingly, the gaseous heat sink 160 in the lateral space 1213 can move along the first slit S1 to the recess 1311, and then move to the top space 1211 shown in FIG. 3 . In this embodiment, each second fin 1321 is perpendicular to the top surface 131 and extends along the axis Y (ie, each second fin 1321 is parallel to the YZ plane). The second fins 1321 are arranged at intervals along the axis X, and the first slit S1 is parallel to the axis Y, but not limited thereto.

6A to 6C, the heat conducting block 130 further has a first side surface 133 facing the side space 1213 shown in FIG5, a second side surface 134 opposite to the first side surface 133, a third side surface 135, and a fourth side surface 136 opposite to the third side surface 135. As shown in FIG5, the side space 1213 surrounds the first side surface 133, the second side surface 134, the third side surface 135, and the fourth side surface 136. The heat conducting block 130 is provided with a third heat sink fin assembly 137 on at least one of the first side surface 133 and the second side surface 134. In this embodiment, the heat conducting block 130 is provided with a third heat dissipating fin assembly 137 on both the first side surface 133 and the second side surface 134 , but the present invention is not limited thereto.

In detail, please refer to FIG. 6A , the third heat sink fin assembly 137 includes a plurality of third fins 1371 arranged in parallel, and each third fin 1371 is perpendicular to the first side surface 133 or the second side surface 134. In addition, as shown in FIG. 6B , the recess 1311 extends from the first side surface 133 to the second side surface 134 and passes through the first side surface 133 and the second side surface 134, and at least a portion of the third fins 1371 of the third heat sink fin assembly 137 spans one side of the recess 1311. Accordingly, the gaseous heat dissipation medium 160 in the lateral space 1213 can move to the recess 1311 along a second slit S2 between the two third fins 1371, and then move to the top space 1211 as shown in FIG3. In this embodiment, each third fin 1371 extends along the axis X and the axis Y (i.e., each third fin 1371 is parallel to the XY plane), and these third fins 1371 are arranged at intervals along the axis Z, and the second slit S2 is parallel to the axis Y, but not limited thereto.

6A to 6C , as shown in FIG. 6A , the heat conducting block 130 is further provided with at least one fourth heat dissipation fin set 138 (shown as two) on the top surface 131, and the recess 1311 is located between at least one second heat dissipation fin set 132 and at least one fourth heat dissipation fin set 138. Accordingly, at least part of the gaseous heat dissipation medium 160 that moves to the recess 1311 through the first slit S1 and the second slit S2 can move to the middle recess 1311 along a third slit S3. In this embodiment, the number of the fourth heat sink fin set 138 is not limited thereto. In other embodiments, the number of the fourth heat sink fin set 138 may be, for example, one or three, or the heat conductive block 130 may not have the fourth heat sink fin set 138. In addition, in this embodiment, the fourth heat sink fin set 138 is parallel to the second heat sink fin set 132, and the direction of each fourth fin 1381 is the same as the direction of the second fin 1321, and the third slit S3 is parallel to the axial direction Y.

In this embodiment, the distance between two adjacent second fins 1321, the distance between two adjacent third fins 1371, and the distance between two adjacent fourth fins 1381, that is, the width of the first slit S1, the second slit S2, and the third slit S3, respectively, are less than or equal to 0.5 mm, but not limited thereto.

The heat dissipation device 100 of this embodiment can perform heat exchange with the heat dissipation medium 160 by disposing the second heat dissipation fin set 132 , the third heat dissipation fin set 137 and the fourth heat dissipation fin set 138 , thereby further improving the heat dissipation effect of the heat dissipation device 100 .

FIG7 is a cross-sectional view of the heat conducting block of FIG6C along the D-D line. Referring to FIG6A and FIG7, the heat conducting block 130 is provided with at least one tapered hole 139 on at least one of the third side surface 135 and the fourth side surface 136. In the present embodiment, six tapered holes 139 are provided in the third side surface 135 and the fourth side surface 136, respectively, but the number of tapered holes 139 is not limited thereto. An opening 1391 of at least one tapered hole 139 faces the first ends 141 of the heat dissipating pipes 140 as shown in FIG3. For example, the opening 1391 on the right side faces the first end 141 of the heat dissipating pipe 140 on the right side, and the opening 1391 on the left side faces the first end 141 of the heat dissipating pipe 140 on the left side.

7, at least one tapered hole 139 further has a bottom surface 1393 relative to the opening 1391, and a hole diameter 1391a of the opening 1391 gradually decreases from the opening 1391 to the bottom surface 1393. The heat sink 100 of this embodiment can increase the return speed of the liquid heat dissipation medium 160 from the heat dissipation pipe 140 by configuring the tapered hole 139 and the gradually decreasing hole diameter 1391a.

Referring to FIG. 6A , the surface of the heat conducting block 130 located in the groove 121 shown in FIG. 3 is provided with a capillary structure layer. For example, the surface of the top surface 131 of the heat conducting block 130, the surface of the first side surface 133, the surface of the second side surface 134, the surface of the third side surface 135, the surface of the fourth side surface 136, the surface of the second heat dissipating fin assembly 132, the surface of the third heat dissipating fin assembly 137, the surface of the fourth heat dissipating fin assembly 138, and the inner wall of the tapered hole 139 are all provided with a capillary structure layer, but the present invention is not limited thereto. Accordingly, the heat sink 100 of the present embodiment can guide the liquid heat sink 160 to flow back to the lateral space 1213 of the groove 121 through the capillary structure layer, and can ensure that the gaseous and liquid heat sinks 160 are separated from each other. In addition, the heat sink 100 can also ensure that the liquid heat sink 160 can flow along the first slit S1, the second slit S2, and the third slit S3 through the capillary structure layer, so that the heat sink 160 can exchange heat with the second heat sink fin assembly 132, the third heat sink fin assembly 137, and the fourth heat sink fin assembly 138, and flow back to the lateral space 1213.

Please refer to FIG. 3 , the heat sink 100 of the present embodiment further includes a cover plate 170, which is disposed on one side of at least one first heat sink fin assembly 150 and closes the top opening 1215 with at least one first heat sink fin assembly 150. The second end 143 of each heat sink pipe 140 is passed through the cover plate 170. The cover plate 170 is located opposite to the recess 1311, that is, the recess 1311 is located within the projection range of the cover plate 170. Accordingly, the heat sink 100 of the present embodiment closes the top opening 1215 by the cover plate 170 and the first heat sink fin assembly 150, so that the gaseous heat sink medium 160 in the groove 121 will not be lost. In addition, the heat dissipation device 100 allows the gaseous heat dissipation medium 160 to smoothly move from the top space 1211 to the second end 143 by positioning the cover plate 170 in the recess 1311. In this embodiment, the cover plate 170 is disposed between the two first heat dissipation fin assemblies 150, but the present invention is not limited thereto.

The heat dissipation mechanism of the heat dissipation device 100 of this embodiment is described in detail below.

When the heat source 10 generates heat, first, the heat of the heat source 10 is transferred to the heat conductive block 130 through the heat conductive base 120. Then, the heat is exchanged with the heat dissipation medium 160 through the surface of the heat conductive block 130, the second heat dissipation fin set 132, the third heat dissipation fin set 137, and the fourth heat dissipation fin set 138 as shown in FIG. 6A, and is absorbed by the heat dissipation medium 160 and converted into latent heat of the heat dissipation medium 160. When the heat source 10 is in low power mode, the above heat dissipation mechanism can enable the heat dissipation device 100 to have a good heat dissipation effect.

When the heat source 10 is in high power mode, after the heat generated by the heat source 10 exceeds the latent heat that the liquid heat dissipation medium 160 can absorb, the liquid heat dissipation medium 160 begins to undergo a phase change and transforms from a liquid state to a gas state. Then, the heat dissipation medium 160 transformed into a gas state moves from the lateral space 1213 shown in FIG. 3 to the recess 1311 through the first slit S1 in the second heat dissipation fin assembly 132, the second slit S2 in the third heat dissipation fin assembly 137, and the third slit S3 in the fourth heat dissipation fin assembly 138 shown in FIG. 6A. Then, the gaseous heat dissipation medium 160 leaves the groove 121 from the depression 1311 through the top space 1211 and the top opening 1215 and enters the second end 143 of the heat dissipation pipe 140 and moves toward the first end 141. Then, the gaseous heat dissipation medium 160 in the heat dissipation pipe 140 exchanges heat with the first heat dissipation fin assembly 150 connected to the heat dissipation pipe 140, so that the heat dissipation medium 160 is converted from a high-pressure gas state to a low-pressure gas state or a liquid state. Since the inner wall of the heat dissipation pipe 140 is a smooth surface, the heat dissipation medium 160 converted into low-pressure gas or liquid will continue to move toward the first end 141 of the heat dissipation pipe 140 and flow back into the groove 121 to complete the cycle and re-exchange heat with the heat conductive block 130.

That is, the heat sink 100 of the present embodiment can circulate the heat sink 160 as described above without an additional pump because the pressure and temperature of the gaseous heat sink 160 at the recess 1311 are higher than the pressure and temperature of the heat sink 160 at the second end 143 of the heat sink 140.

In summary, in the heat dissipation device of the present invention, the heat generated by the heat source will be transferred to the heat dissipation medium through the heat conductive seat and the heat conductive block. After the heat dissipation medium absorbs a certain amount of heat, the heat dissipation medium will undergo a phase change and change from liquid to gas. Due to the pressure difference and temperature difference, the gaseous heat dissipation medium will flow upward from the top opening through the second end into the multiple heat dissipation pipes, and exchange heat with the first heat dissipation fin assembly in the process of flowing through the heat dissipation pipes. Finally, the heat dissipation medium flows out of the heat dissipation pipe from the first end and flows into the groove, completing the cycle. Accordingly, the heat dissipation device of the present invention does not require an additional pump to circulate the heat dissipation medium, so as to effectively transfer the heat generated by the heat source to the outside, thereby having a good heat dissipation effect. In addition, in one embodiment, the heat conducting block has a second heat dissipating fin set, a third heat dissipating fin set and a fourth heat dissipating fin set, which can further enhance the heat dissipation effect of the heat dissipation device.

10: heat source 20: circuit board 100: heat sink 110: housing 120: heat conducting seat 121: groove 123: side 130: heat conducting block 131: top surface 132: second heat sink fin set 133: first side surface 134: second side surface 135: third side surface 136: fourth side surface 137: third heat sink fin set 138: fourth heat sink fin set 139: conical hole 140: heat sink pipe 141: first end 143: second end 150: first heat sink fin set 151: first fin 160: heat sink medium 161: Liquid level 170: Cover plate 1211: Top space 1213: Side space 1215: Top opening 1217: Bottom 1311: Depression 1321: Second fin 1371: Third fin 1381: Fourth fin 1391: Opening 1391a: Aperture 1393: Bottom surface 1411: Connection port 1411a: Center D1: Distance H1: Height S1: First slit S2: Second slit S3: Third slit X, Y, Z: Axis

Figures 1A to 1C are schematic diagrams of a heat sink of an embodiment of the present invention at different viewing angles. Figure 2 is an exploded view of the heat sink of Figure 1A. Figure 3 is a cross-sectional view of the heat sink of Figure 1B along line A-A. Figure 4 is a cross-sectional view of the heat sink of Figure 1B along line B-B. Figure 5 is a cross-sectional view of the heat sink of Figure 1C along line C-C. Figures 6A to 6C are schematic diagrams of the heat conducting block of Figure 3 at different viewing angles. Figure 7 is a cross-sectional view of the heat conducting block of Figure 6C along line D-D.

10: Heat source

20: Circuit board

110: Shell

120: Thermal seat

121: Groove

123: Side

131: Top

132: Second heat sink fin assembly

135: Third side

136: Fourth side

137: Third heat sink fin assembly

138: The fourth heat sink fin assembly

139: Conical hole

140: Heat sink

141: First end

143: Second end

150: First heat sink fin assembly

151: First fin

160: Heat dissipation medium

161: Liquid level

170: Cover plate

1211: Top space

1213: Lateral space

1215: Top opening

1217: Bottom

1311: Depression

1391: Open mouth

1393: Bottom

1411:Connection port

1411a: Center

D1: Distance

H1: Height

X, Y, Z: axial direction

Claims (13)

A heat dissipation device is suitable for dissipating heat from a heat source, wherein the heat dissipation device comprises: a shell, wherein the heat source is arranged in the shell; a heat-conducting seat, arranged in the shell, wherein the heat-conducting seat is thermally coupled to the heat source and has a groove and a side surrounding the groove; a heat-conducting block, arranged in the groove and thermally coupled to the heat-conducting seat; a plurality of heat dissipation pipes, which are passed through the shell, each heat dissipation pipe has a first end and a second end opposite to the first end, the first end of each heat dissipation pipe is passed through the side and connected to the groove, and the second end of each heat dissipation pipe is connected to the groove; At least one first heat sink fin assembly is disposed on the housing and partially covers the groove, wherein the heat sink pipes are thermally coupled to the at least one first heat sink fin assembly; and A heat sink medium is stored in the groove and immerses at least a portion of the heat conductive block. A heat dissipation device as described in claim 1, wherein the heat conductive seat includes a top opening connected to the groove, a top space is formed between the heat conductive block and the top opening, a side space is formed between the heat conductive block and the side, the top space and the side space are interconnected, and the liquid heat dissipation medium is stored in the side space. A heat dissipation device as described in claim 2, wherein the first end of each heat dissipation tube includes a communication port, and a distance from a center of the communication port to a bottom of the groove is less than or equal to a height from a liquid level of the heat dissipation medium to the bottom. A heat dissipation device as described in claim 2, wherein the heat conductive block has a top surface facing the top opening, and the top surface has at least one recess, the at least one recess is connected to the top space, and the top space is connected to the top opening. As described in claim 4, the top surface of the heat conductive block is provided with at least one second heat dissipation fin assembly, and the at least one second heat dissipation fin assembly is located on one side of the at least one recess. A heat dissipation device as described in claim 5, wherein the heat conductive block has a first side surface facing the lateral space and a second side surface opposite to the first side surface, and at least one of the first side surface and the second side surface is provided with a third heat dissipation fin assembly. As described in claim 6, the top surface of the heat conductive block is further provided with at least one fourth heat dissipation fin set, and the at least one recess is located between the at least one second heat dissipation fin set and the at least one fourth heat dissipation fin set. A heat sink as described in claim 6, wherein the third heat sink fin set includes a plurality of fins arranged in parallel, and each of the fins is perpendicular to the first side surface or the second side surface. The heat sink as described in claim 8, wherein the at least one recess extends from the first side surface to the second side surface and passes through the first side surface and the second side surface, and at least a portion of the fins of the third heat sink fin assembly spans across a side of the at least one recess. A heat sink as described in claim 5, wherein the at least one second heat sink fin set includes a plurality of fins arranged in parallel, and a slit between two adjacent fins extends from the lateral space toward the at least one recess. The heat dissipation device as described in claim 4 further includes: A cover plate, disposed on one side of the at least one first heat dissipation fin assembly, and sealing the top opening together with the at least one first heat dissipation fin assembly, wherein the second end of each heat dissipation tube is passed through the cover plate, and the cover plate is aligned with the at least one recess. A heat dissipation device as described in claim 2, wherein the heat conductive block has a first side, a second side opposite to the first side, a third side and a fourth side opposite to the third side, and the lateral space surrounds the first side, the second side, the third side and the fourth side, the heat conductive block is provided with at least one tapered hole on at least one of the third side and the fourth side, and an opening of the at least one tapered hole faces the first end of the heat dissipation pipes, the at least one tapered hole has a bottom surface opposite to the opening, and a hole diameter of the opening gradually decreases from the opening to the bottom surface. A heat dissipation device as described in claim 1, wherein a surface of the heat conductive block located in the groove is provided with a capillary structure layer.