Heat dissipation device

This disclosure provides a heat dissipation device configured to be in thermal contact with a heat source. The heat dissipation device includes a heat dissipation body and a cover plate. The heat dissipation body has at least one vertical channel. The heat dissipation body is configured to be in thermal contact with the heat source. The cover plate includes a first layer and a second layer that are stacked on each other. The first layer is stacked on the heat dissipation body and covers the at least one vertical channel. A thermal conductivity of the first layer is larger than a thermal conductivity of the second layer. The cover plate has at least one first through hole penetrating through the first layer and the second layer and connecting to the at least one vertical channel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 108119018 filed in Taiwan, R.O.C. on May 31, 2019, the entire contents of which are hereby incorporated by reference.

TECHNICAL FIELD

The disclosure relates to a heat dissipation device, more particularly to a heat dissipation device having at least one vertical channel.

BACKGROUND

In recent years, electronic devices, such as laptop computers, tablet computers, and cellular phones, have become compact and slim yet powerful, so internal heat dissipation devices for such electronic devices have become smaller than before. Therefore, it is always desirable to find a way to effectively cool the electronic devices by small sized heat dissipation devices.

In general, the conventional heat dissipation device includes a copper or aluminum made base plate and heat dissipation fins disposed on the base plate. The heat dissipation device has a limited thermal contact surface, so it is known that increasing the flow rate of working fluid flowing over the heat dissipation device is one of the critical factors to improve the cooling efficiency of the heat dissipation device. For example, some use a fan to increase the flow rate of working fluid, but a slim and compact electronic device does not have an enough space for accommodating a fan, so such electronic device still uses natural convection for cooling. Therefore, the disclosure seeks to overcome one or more of the above disadvantages.

SUMMARY

The disclosure relates to a heat dissipation device for improving the cooling efficiency of heat dissipation component under natural convection.

An embodiment of the disclosure provides a heat dissipation device configured to be in thermal contact with a heat source. The heat dissipation device includes a heat dissipation body and a cover plate. The heat dissipation body has at least one vertical channel and is configured to be in thermal contact with the heat source. The cover plate includes a first layer and a second layer that are stacked on each other. The first layer is stacked on the heat dissipation body and covers the at least one vertical channel. A thermal conductivity of the first layer is larger than a thermal conductivity of the second layer. The cover plate has at least one first through hole penetrating through the first layer and the second layer and connecting to the at least one vertical channel.

Another embodiment of the disclosure provides a heat dissipation device configured to be in thermal contact with a heat source. The heat dissipation device includes a heat dissipation body and a cover plate. The heat dissipation body has at least one vertical channel and is configured to be in thermal contact with the heat source. The cover plate is stacked on the heat dissipation body and covers the at least one vertical channel. A thermal conductivity of the heat dissipation body is larger than the thermal conductivity of the cover plate. The cover plate has at least one first through hole connecting to the at least one vertical channel.

Still another embodiment of the disclosure provides a heat dissipation device configured to be in thermal contact with a heat source. The heat dissipation device includes a heat dissipation body and a heat insulation film. The heat dissipation body includes a first thermally conductive plate, a second thermally conductive plate and a plurality of fins that are integrally formed with one another. The plurality of fins are located between the first thermally conductive plate and the second thermally conductive plate. The first thermally conductive plate, the second thermally conductive plate and the plurality of fins form a plurality of vertical channels therebetween. The first thermally conductive plate is configured to be in thermal contact with the heat source. The second thermally conductive plate has a plurality of first through holes connecting to the plurality of vertical channels. The heat insulation film has a plurality of second through holes and is stacked on a side of the second thermally conductive plate facing away from the first thermally conductive plate. The plurality of second through holes are respectively connected to the plurality of vertical channels via the plurality of first through holes.

According to the heat dissipation devices discussed above, due to the composite material of the cover plate or the heat dissipation body, or the thermal insulation part, the amount of heat transferred to the fluid inside the vertical channels will be more than that transferred to the fluid outside the vertical channels, such that the fluid inside the vertical channels will flow faster than the fluid outside the vertical channels. According to the Bernoulli's equation, the higher velocity of the fluid inside the vertical channels will result in a pressure lower than that in the space outside the vertical channels, and which will draw the air outside the vertical channels into the vertical channels to increase the flow rate of the fluid in the vertical channels. Therefore, during the operation of the heat source, the flow rate of the fluid flowing through the vertical channels can be increased. The increased flow rate of the fluid in the vertical channels can help improve the cooling efficiency of the heat dissipation device to the heat source under natural convection.

The above embodiments and following detailed descriptions are considered as examples of the application of the principles of the disclosure, which help to facilitate comprehension of the claims but are not limited to any specific details of these embodiments.

DETAILED DESCRIPTION

Please refer toFIG. 1andFIG. 2.FIG. 1is a perspective view of a heat dissipation device according to a first embodiment of the disclosure.FIG. 2is an exploded view of the heat dissipation device inFIG. 1.

This embodiment provides a heat dissipation device10configured to be in thermal contact with a heat source11. The heat dissipation device10includes a heat dissipation body110and a cover plate120. The heat dissipation body110may include copper and have a thermal conductivity of approximately 390 W/mk to 401 W/mk. The heat dissipation body110is configured to be in thermal contact with the heat source11. The heat source11may be a central processing unit, battery or light emitting diode. The heat dissipation body110has at least one vertical channel S. In detail, the heat dissipation body110includes a base111and a plurality of heat dissipation fins112. The heat dissipation fins112protrude from the base111, and every two adjacent heat dissipation fins112are spaced apart by a vertical channel S. As can be seen, the heat dissipation body110has a plurality of vertical channels S, but it is noted that the disclosure is not limited to the quantity or size of the vertical channels S.

Each vertical channel S has an extension direction E parallel to a vertical direction V, where the vertical direction V is the direction of gravitational force. However, the disclosure is not limited thereto; in other embodiments, the extension direction of the vertical channels may have an acute angle to the vertical direction. It is noted that the extension direction of the vertical channels is not limited to be parallel to or has an acute angle to the vertical direction as long as it is not perpendicular to the vertical direction.

The cover plate120is stacked on the heat dissipation fins112, and the cover plate120and the base111are respectively located on two opposite sides of the heat dissipation fins112. The cover plate120may be connected to the heat dissipation fins112by press fit, riveting or welding. In the case that the cover plate is connected to the heat dissipation fins by press fit, the cover plate may have slots respectively for the heat dissipation fins to mount on the cover plate. The cover plate120may have a thickness T ranging approximately between 1 millimeter and 5 millimeters. In detail, the cover plate120includes a first layer121and a second layer122. The first layer121may include copper and have a thermal conductivity of approximately 390 W/mk to 401 W/mk. The first layer121is stacked on the heat dissipation body110to cover the vertical channels S. The second layer122may include plastic and have a thermal conductivity lower than 1 W/mk. The second layer122is stacked on a side of the first layer121facing away from the heat dissipation body110, that is, the first layer121is located between the heat dissipation body110and the second layer122. In this embodiment, the thermal conductivity of the first layer121is at least one hundred times higher than that of the second layer122, but the disclosure is not limited thereto. In other embodiments, the thermal conductivity of the first layer may be at least twenty times higher than that of the second layer. In addition, in this embodiment, the first layer121and the heat dissipation body110have the same material, but the disclosure is not limited thereto. In other embodiments, the first layer and the heat dissipation body may be made of different materials so that the first layer may have a thermal conductivity higher or lower than that of the heat dissipation body.

The cover plate120has a plurality of first through holes O penetrating through the first layer121and the second layer122and connecting to some of or all of the vertical channels S.

Please refer toFIG. 3.FIG. 3is a planar view of a cover plate inFIG. 2. In this embodiment, each first through hole O may have a diameter D approximately larger than or equal to 2 millimeters, and every two adjacent second through holes O may be spaced apart by a gap G approximately larger than or equal to 3 millimeters. It is noted that the diameter D and gap G are one of the ways to explain the empty spaces in the cover plate120. The porosity can be another way to explain the empty spaces in the cover plate120, where the porosity is the percentage of empty space in the cover plate120and, in this or some other embodiments, can be defined as the ratio of the total volume of the empty spaces divided by the total volume of the cover plate. In this embodiment, the porosity of the cover plate120may be approximately ranging between 20% and 50%.

In addition, in this embodiment, the first through hole O is a circular through hole, but the disclosure is not limited to the shape of the second through hole. For example, in other embodiments, the first through hole may be a square, triangular, or hexagonal through hole.

Please refer toFIG. 4.FIG. 4is a cross-sectional view of the heat dissipation device inFIG. 1. The base111of the heat dissipation body110is in thermal contact with the heat source11so that heat generated by the heat source11will be transferred to the heat dissipation body110and thus will heat the fluid F1in the vertical channels S, thereby causing the fluid F1to flow upwards. Within a short time period, the heat generated by the heat source11will be transferred to the cover plate120via the heat dissipation body110and thus heating the fluid F2outside the cover plate120, thereby causing the fluid F2to flow upwards. Since the first layer121has a higher thermal conductivity than the second layer122, more heat will be transferred towards the fluid F1. As a result, the fluid F1will flow faster than the fluid F2. According to the Bernoulli's equation, if the velocity increases, then the pressure decreases. Therefore, the higher velocity of the fluid F1will result in a pressure in the vertical channels S lower than that in the space in which the fluid F2flows, causing the air outside the vertical channels S to flow into the vertical channels S (e.g., fluid F3shown inFIG. 4). Such movement of air is known as the stack effect.

Accordingly, during the operation of the heat source11, the flow rate of the fluid flowing through the vertical channels S can be increased with the help of the first through holes O of the cover plate120and the different thermal conductivities between the first layer121and the second layer122. The increased flow rate of the fluid in the vertical channels S can help improve the cooling efficiency of the heat dissipation device10to the heat source11under natural convection.

It is noted that the flow rate of the fluid F3will be increased if any one of the porosity of the cover plate, the diameter D of the first through holes O, and the gap G between the first through holes O meets the aforementioned conditions.

Please refer toFIG. 5.FIG. 5is a cross-sectional view of a heat dissipation device according to a second embodiment of the disclosure.

This embodiment provides a heat dissipation device20including a heat dissipation body210and a cover plate220. The heat dissipation body210may include copper and have a thermal conductivity of approximately 390 W/mk to 401 W/mk. The heat dissipation body210includes a base211and a plurality of heat dissipation fins212, and has a plurality of vertical channels S. Every two adjacent heat dissipation fins212are spaced apart by a vertical channel S. The heat dissipation body210and the heat dissipation body110of the previous embodiment are similar in configuration, so the heat dissipation body210will not be described in detail below.

The cover plate220is stacked on the heat dissipation fins212, and the cover plate220and the base211are respectively located on two opposite sides of the heat dissipation fins212. The cover plate220may include plastic and have a thermal conductivity lower than 1 W/mk. The cover plate220is stacked on a side of the heat dissipation fins212facing away from the base211. In this embodiment, the thermal conductivity of the heat dissipation body210is at least one hundred times higher than that of the cover plate220, but the disclosure is not limited thereto. In other embodiment, the thermal conductivity of the heat dissipation body may be at least twenty times higher than that of the cover plate. In addition, the cover plate220has a plurality of first through holes O connecting to some of or all of the vertical channels S.

The base211of the heat dissipation body210is in thermal contact with a heat source (not shown) so that heat generated by the heat source will be transferred to the heat dissipation body210and thus will heat the fluid F1in the vertical channels S, thereby causing the fluid F1to flow upwards. Within a short time period, the heat generated by the heat source will be transferred to the cover plate220via the heat dissipation body210and thus heating the fluid F2outside the cover plate220, thereby causing the fluid F2to flow upwards. Since the heat dissipation body210has a higher thermal conductivity than the cover plate220, more heat will be transferred toward the fluid F1. As a result, the fluid F1will flow faster than the fluid F2. According to the Bernoulli's equation, if the velocity increases, then the pressure decreases. Therefore, the higher velocity of the fluid F1will result in a pressure in the vertical channels S lower than that in the space where the fluid F2flows, thereby causing the air outside the vertical channels S to flow into the vertical channels S (e.g. fluid F3shown inFIG. 5).

Accordingly, during the operation of the heat source, the flow rate of the fluid flowing through the vertical channels S can be increased with the help of the first through holes O of the cover plate220and the different thermal conductivities between the heat dissipation body210and the cover plate220. The increased flow rate of the fluid in the vertical channels S can help improve the cooling efficiency of the heat dissipation device20to the heat source.

Please refer toFIG. 6.FIG. 6is a cross-sectional view of a heat dissipation device according to a third embodiment of the disclosure. This embodiment provides a heat dissipation device30including a heat dissipation body310and a cover plate320. The heat dissipation body310includes a base311and a plurality of heat dissipation fins312and has a plurality of vertical channels S. Every two adjacent heat dissipation fins312are spaced apart by a vertical channel S. The heat dissipation body310and the heat dissipation body110of previous embodiment are similar in configuration, so the heat dissipation body310will not be described in detail below.

The cover plate320is stacked on the heat dissipation fins312, and the cover plate320and the base311are respectively located on two opposite sides of the heat dissipation fins312. In detail, the cover plate320includes a first layer321, a second layer322and a thermal insulation part323. The first layer321may include copper and have a thermal conductivity of approximately 390 W/mk to 401 W/mk. The first layer321is stacked on the heat dissipation body310to cover the vertical channels S. The second layer322may include plastic and have a thermal conductivity lower than 1 W/mk. The second layer322is stacked on a side of the first layer321facing away from the heat dissipation body310; that is, the first layer321is located between the heat dissipation body310and the second layer322. In this embodiment, the thermal conductivity of the first layer321is at least one hundred times higher than that of the second layer322, but the disclosure is not limited thereto. In other embodiment, the thermal conductivity of the first layer may be at least twenty times higher than that of the second layer.

The thermal insulation part323is located between the first layer321and the second layer322. Also, the thermal insulation part323may be an empty space filled with air, in such a case, the thermal insulation part323can be considered as an air layer and the thermal insulation part323may have a thermal conductivity of approximately 0.024 W/mk, but the disclosure is not limited thereto. For example, in other embodiments, the thermal insulation part may be a vacuum space, that is, the thermal insulation part has no air inside and can be considered as a vacuum layer.

The cover plate320has a plurality of first through holes O penetrating through the first layer321and the second layer322and connecting to some of or all of the vertical channels S.

The base311of the heat dissipation body310is in thermal contact with a heat source so that heat generated by the heat source will be transferred to the heat dissipation body310and thus will heat the fluid F1in the vertical channels S, thereby causing the fluid F1to flow upwards. Meanwhile, most of the heat in the fluid F1is blocked by the thermal insulation part323of the cover plate320, so the heat that is transferred to and makes the fluid F2flow upwards is decreased. Also, because the thermal insulation part323is located between the first layer321and the second layer322, and the first layer321has higher thermal conductivity than the second layer322, more heat will be transferred to the fluid F1. As a result, the fluid F1will flow faster than the fluid F2. According to the Bernoulli's equation, if the velocity increases, then the pressure decreases. Therefore, the higher velocity of the fluid F1will result in a pressure in the vertical channels S lower than that in the space where the fluid F2flows, thereby causing the air outside the vertical channels S to flow into the vertical channels S (e.g. fluid F3shown inFIG. 6).

Accordingly, during the operation of heat source, the flow rate of the fluid flowing through the vertical channels S can be increased with the help of the first through holes O of the cover plate320, the thermal insulation part323and the different thermal conductivities between the first layer321and the second layer322. The increased flow rate of the fluid in the vertical channels S can help to improve the cooling efficiency of the heat dissipation device30to the heat source.

Please refer toFIG. 7.FIG. 7is a cross-sectional view of a heat dissipation device according to a fourth embodiment of the disclosure. This embodiment provides a heat dissipation device40including a heat dissipation body410and a cover plate420. The heat dissipation body410includes a base411and has a plurality of vertical channels S. Every two adjacent heat dissipation fins412are spaced apart by a vertical channel S. The heat dissipation body410and the heat dissipation body110of previous embodiment are similar in configuration, so the heat dissipation body410will not be described in detail below.

The cover plate420is stacked on the heat dissipation fins412and the cover plate420and the base411are respectively located on two opposite sides of the heat dissipation fins412. In detail, the cover plate420includes a first layer421, a second layer422and a thermal insulation part423. The first layer421may include copper and have a thermal conductivity of approximately 390 W/mk to 401 W/mk. The first layer421is stacked on the heat dissipation body410to cover the vertical channels S. The second layer422may include plastic and have a thermal conductivity lower than 1 W/mk. The second layer422is stacked on a side of the first layer421facing away from the heat dissipation body410. In this embodiment, the thermal conductivity of the first layer421is at least one hundred times higher than that of the second layer422, but the disclosure is not limited thereto; in other embodiments, the thermal conductivity of the first layer may be at least twenty times higher than that of the second layer.

The thermal insulation part423is located inside the second layer422. Also, the thermal insulation part423may be an empty space filled with air, in such case, the thermal insulation part423can be considered as an air layer, and the thermal insulation part423may have a thermal conductivity of approximately 0.024 W/mk, but the disclosure is not limited thereto; in other embodiments, the thermal insulation part may be a vacuum space, that is, the thermal insulation part has no air inside and can be considered as a vacuum layer.

The cover plate420has a plurality of first through holes O penetrating through the first layer421and the second layer422and connecting to some of or all of the vertical channels S.

The base411of the heat dissipation body410is in thermal contact with a heat source so that heat generated by the heat source will be transferred to the heat dissipation body410and thus will heat the fluid F1in the vertical channels S, thereby causing the fluid F1to flow upwards. Meanwhile, most of the heat in the fluid F1is blocked by the thermal insulation part423of the cover plate420, so the heat that is transferred to and makes the fluid F2flow upwards is decreased. Also, because the thermal insulation part423is located inside the second layer422and the first layer421has higher heat conductivity than the second layer422, more heat will be transferred toward the fluid F1. As a result, the fluid F1will flow faster than the fluid F2. According to the Bernoulli's equation, if the velocity increases, then the pressure decreases. Therefore, the higher velocity of the fluid F1will result in a pressure in the vertical channels S lower than that of the space where the fluid F2flows, thereby causing the air outside the vertical channels S to flow into the vertical channels S (e.g. fluid F3shown inFIG. 7).

Accordingly, during the operation of the heat source, the flow rate of the fluid flowing through the vertical channels S can be increased with the help of the first through holes O of the cover plate420, the thermal insulation part423and the difference thermal conductivities between the first layer421and the second layer422. The increased flow rate of the fluid in the vertical channels S can help improve the cooling efficiency of the heat dissipation device40to the heat source.

Please refer toFIG. 8.FIG. 8is a cross-sectional view of a heat dissipation device according to a fifth embodiment of the disclosure.

This embodiment provides a heat dissipation device50including a heat dissipation body510and a cover plate520. The heat dissipation body510may include copper and have a thermal conductivity of approximately 390 W/mk to 401 W/mk. The heat dissipation body510includes a base511and a plurality of heat dissipation fins512, and has a plurality of vertical channels S. Every two adjacent heat dissipation fins512are spaced apart by a vertical channel S. The heat dissipation body510and the heat dissipation body110of previous embodiment are similar in configuration, so the heat dissipation body510will not be described in detail below.

The cover plate520is stacked on the heat dissipation fins512, and the cover plate520and the base511are respectively located on two opposite sides of the heat dissipation fins512. The cover plate520includes an outer heat insulation part521and an inner heat insulation part522. The outer heat insulation part521may include plastic and have a thermal conductivity lower than 1 W/mk. The outer heat insulation part521is stacked on a side of the heat dissipation fins512facing away from the base511. The inner heat insulation part522may be an empty space filled with air, in such case, the inner heat insulation part522can be considered as an air layer, and the inner heat insulation part522may have a thermal conductivity of approximately 0.024 W/mk, but the disclosure is not limited thereto. For example, in other embodiments, the inner heat insulation part may be a vacuum space, that is, the inner heat insulation part has no air inside and can be considered as a vacuum layer. The cover plate520has a plurality of first through holes O connecting to some of or all of the vertical channels S.

In this embodiment, the inner heat insulation part522is to improve the thermal isolation of the cover plate520so as to increase the difference of heat amount between the fluid F1and the fluid F2, thereby improving the cooling efficiency of the heat dissipation device50to the heat source.

Please refer toFIG. 9andFIG. 10.FIG. 9is a perspective view of a heat dissipation device according to a sixth embodiment of the disclosure.FIG. 10is a cross-sectional view of the heat dissipation device inFIG. 9.

This embodiment provides a heat dissipation device60including a heat dissipation body610and a heat insulation film620. The heat dissipation body610may include copper and have a thermal conductivity of approximately 390 W/mk to 401 W/mk. The heat dissipation body610includes a first thermally conductive plate611, a second thermally conductive plate612and a plurality of fins613that are integrally formed with one another. The fins613are located between the first thermally conductive plate611and the second thermally conductive plate612. The first thermally conductive plate611, the second thermally conductive plate612and the fins613form a plurality of vertical channels S therebetween. The first thermally conductive plate611is configured to be in thermal contact with a heat source. The second thermally conductive plate612has a plurality of first through holes O1connecting to some of or all of the vertical channels S.

The heat insulation film620has a plurality of second through holes O2. The heat insulation film620is stacked on a side of the second thermally conductive plate612facing away from the first thermally conductive plate611. The second through holes O2are respectively connected to some of or all of the vertical channels S via the first through holes O1. The heat insulation film620may be insulation paint and may have a thermal conductivity lower than 0.03 W/mk.

The first thermally conductive plate611of the heat dissipation body610is in thermal contact with the heat source (not shown) so that heat generated by the heat source will be transferred to the heat dissipation body610and thus will heat the fluid F1in the vertical channels S, thereby causing the fluid F1to flow upwards. Meanwhile, most of the heat in the fluid F1is blocked by the heat insulation film620, so the heat that is transferred to and makes the fluid F2flow upwards is decreased. With the help of the heat insulation film620, more heat is transferred toward the fluid F1than the fluid F2. As a result, the fluid F1will flow faster than the fluid F2. According to the Bernoulli's principle, if the velocity increases, then the pressure decreases. Therefore, the higher velocity of the fluid F1will result in a pressure in the vertical channels S lower than that of the space where the fluid F2flows, thereby causing the air outside the vertical channels S to flow into the vertical channels S (e.g. fluid F3shown inFIG. 10).

In this case, during the operation of the heat source, the flow rate of the fluid flowing through the vertical channels S can be increased with the help of the first through holes O of the second thermally conductive plate612, the second through holes O2of the heat insulation film620, and the heat insulation film620. The increased flow rate of the fluid flowing through the vertical channels S can help improve the cooling efficiency of the heat dissipation device60to the heat source.

Please refer toFIG. 11.FIG. 11is a cross-sectional view of a heat dissipation device according to a seventh embodiment of the disclosure.

This embodiment provides a heat dissipation device70including a heat dissipation body710and a cover plate720. The heat dissipation body710may include copper and have a thermal conductivity of approximately 390 W/mk to 401 W/mk. The heat dissipation body710includes a first thermally conductive plate711, a second thermally conductive plate712and a plurality of fins713that are integrally formed with one another. These fins713are located between the first thermally conductive plate711and the second thermally conductive plate712. The first thermally conductive plate711, the second thermally conductive plate712and the fins713form a plurality of vertical channels S therebetween. The first thermally conductive plate711is configured to be in thermal contact with a heat source. The second thermally conductive plate712has a plurality of first through holes O1connecting to some of or all of the vertical channels S.

The heat insulation film720has a plurality of second through holes O2. The heat insulation film720is stacked on a side of the second thermally conductive plate712facing away from the first thermally conductive plate711. The second through holes O2are respectively connected to some of or all of the vertical channels S via the first through holes O1. The heat insulation film720may be insulation print, and may have a thermal conductivity lower than 0.03 W/mk. The heat insulation film720includes an outer heat insulation part721and an inner heat insulation part722. The outer heat insulation part721surrounds the inner heat insulation part722and a thermal conductivity of the outer heat insulation part721is higher than that of the inner heat insulation part722. The outer heat insulation part721and the inner heat insulation part722may respectively be insulation print and an empty space filled with air, in such case, the inner heat insulation part722can be considered as an air layer, but the disclosure is not limited thereto. In other embodiments, the inner heat insulation part may be a vacuum space, that is, the inner heat insulation part has no air inside and can be considered as a vacuum layer.

According to the heat dissipation devices discussed above, due to the composite material of the cover plate or the heat dissipation body, or the thermal insulation part, the amount of heat transferred to the fluid inside the vertical channels will be more than that transferred to the fluid outside the vertical channels, such that the fluid inside the vertical channels will flow faster than the fluid outside the vertical channels. According to the Bernoulli's equation, the higher velocity of the fluid inside the vertical channels will result in a pressure lower than that in the space outside the vertical channels, and which will draw the air outside the vertical channels into the vertical channels to increase the flow rate of the fluid in the vertical channels. Therefore, during the operation of the heat source, the flow rate of the fluid flowing through the vertical channels can be increased. The increased flow rate of the fluid in the vertical channels can help improve the cooling efficiency of the heat dissipation device to the heat source under natural convection.