TWI486543B - Flat type heat pipe - Google Patents

Description

Flat thin heat pipe

The present invention relates to a heat pipe, and more particularly to a flat thin heat pipe.

At this stage, the heat pipe has been widely used in electronic components with large heat generation because of its high heat transfer capacity. When the heat pipe is in operation, the low-boiling working medium filled inside the pipe body absorbs the heat generated by the heat-generating electronic component in the evaporation portion, and then evaporates and vaporizes, the vapor moves with heat to the condensation portion, and condenses and condenses in the condensation portion to release the heat. , heat dissipation of electronic components. The liquefied working medium is returned to the evaporation portion under the action of the capillary structure of the heat pipe wall, and further evaporative vaporization and liquefaction condensation are performed, so that the working medium circulates inside the heat pipe, and the heat generated by the electronic component is continuously emitted.

Today's electronic products are continually inclined to develop in a light, short, and short direction. The problem of heat dissipation in electronic products is becoming more and more important in ever-shrinking spaces. This requires heat-dissipating products to be lighter and shorter, and more need to have higher heat transfer and heat dissipation performance.

Conventional heat pipes use only a single capillary structure, and the capillary structure can be generally divided into a groove type, a sintered type, a fiber type, a wire mesh type, etc., and the capillary structure is disposed on the pipe wall of the heat pipe or closely adheres to the pipe wall. In the circular heat pipe, the working medium of the condensation portion can be timely returned to the evaporation portion of the heat pipe. However, when the heat pipe is flattened, especially when it is flattened to a very thin thickness, the capillary structure is liable to be deformed, disintegrated, etc., so that the liquid transporting ability is greatly reduced, and the liquid transporting ability of the entire heat pipe cannot be It is supplemented by other means, resulting in a large drop in the maximum heat transfer of the heat pipe and an increase in the thermal resistance. At the same time, because the thickness of the heat pipe is very thin, the use of the conventional capillary structure makes the vapor passage inside the heat pipe narrow, and it is impossible to transport the vapor from the evaporation section to the condensation section in time, which also largely leads to the maximum heat pipe. The amount of heat transfer has dropped dramatically.

In view of this, it is necessary to provide a flat thin heat pipe with high heat transfer performance.

A flat thin heat pipe comprising a hollow flat tube body and a first capillary structure and a second capillary structure disposed in the tube body, the tube body comprising an evaporation section and a condensation section, the first capillary structure being formed by a wire The second capillary structure is formed by sintering a powder, the second capillary structure is attached to an inner wall of the evaporation section of the tubular body, and a first vapor passage for vapor passage is formed in the evaporation section, the first capillary structure The first capillary structure includes a first portion that is bonded to the inner wall of the tubular body and a second portion that is not attached to the inner wall of the tubular body, and the first capillary structure A second vapor passage for vapor passage is formed between the two portions and the inner wall of the tubular body in the condensation section, the first vapor passage and the second vapor passage are in communication with each other, and the first capillary structure is condensed from the tubular body The section extends to the junction of the condensation section and the evaporation section and is joined to the second capillary structure at the junction.

Compared with the prior art, the thickness of the flat thin heat pipe of the present invention is thin, and the second capillary structure of the sintered powder type is disposed on the inner wall of the evaporation section of the pipe body, and the space occupied by the condensation section is relatively small. a capillary structure, which relatively increases the internal vapor passage of the condensation section for the smooth flow of the vapor, and the working medium condensed in the condensation section can be returned to the evaporation section through the first capillary structure and the second capillary structure, thereby ensuring flat and thin heat Good heat dissipation of the catheter, especially suitable for small internal space Child device.

10, 20, 30, 40‧‧‧ flat thin heat pipes

11, 21, 31, 41‧‧‧ body

12, 13, 22, 32, 33, 35‧‧‧ first capillary structure

14, 44‧‧‧Second capillary structure

17‧‧‧ overall structure

70‧‧‧Fever electronic components

111,411‧‧‧Evaporation section

113, 213, 313‧‧ ‧ Condensation section

114, 214, 414‧‧‧ top board

115, 215, 415‧‧ ‧ bottom plate

116, 117, 216, 217‧‧‧ side panels

118, 418‧‧‧ inner wall

121, 131‧‧‧ top wall

122, 132‧‧‧ bottom wall

123, 133‧‧‧ left wall

124, 134‧‧‧ right side wall

125, 135‧‧‧ first part

126, 136‧‧‧ Part II

140‧‧‧ channel

141, 441‧‧‧ first vapor channel

142, 242, 342‧‧‧ second vapor channel

148‧‧‧End

149‧‧‧ junction

2421, 2422, 3421, 3422‧ ‧ sub-vapor channel

Fig. 1 is a side view of a flat thin heat pipe according to a first embodiment of the present invention.

2 is a transverse cross-sectional view along the II-II of the flat thin heat pipe of FIG. 1.

3 is a schematic cross-sectional view along the III-III of the flat thin heat pipe shown in FIG. 1.

4 is a schematic longitudinal cross-sectional view of the flat thin heat pipe of FIG. 1 taken along line IV-IV.

Figure 5 is a transverse cross-sectional view showing a condensation section of a flat thin heat pipe in a second embodiment of the present invention.

Figure 6 is a transverse cross-sectional view showing a condensation section of a flat thin heat pipe according to a third embodiment of the present invention.

Fig. 7 is a transverse cross-sectional view showing an evaporation section of a flat thin heat pipe according to a fourth embodiment of the present invention.

Referring to FIGS. 1 to 4 , the flat thin heat pipe 10 includes a hollow flat tube body 11 , two first capillary structures 12 , 13 , a second capillary structure 14 , and an appropriate amount of working medium injected into the tube body 11 ( The figure is not shown).

The tube body 11 is made of a material having good thermal conductivity such as copper, and heat from the outside thereof can be transmitted to the inside thereof. The tube body 11 is vertically long and sealed, and includes an evaporation section 111 and a condensation section 113 along the longitudinal direction thereof. The evaporation section 111 and the condensation section 113 are respectively located at longitudinal ends of the tube body 11. The tube body 11 is a hollow sealed cavity which is formed by flattening a hollow tube and includes a top plate 114, a bottom plate 115 and two side plates 116, 117. The top plate 114 and the bottom plate 115 are parallel to each other and face up and down, and the two side plates 116, 117 are curved. They are respectively located on both sides of the pipe body 11 and connected to the top plate 114 and the bottom plate 115, so that the pipe body 11 forms a runway-like profile on a lateral cross section perpendicular to the longitudinal direction. The tube body 11 has a smooth inner wall 118.

The second capillary structure 14 is a capillary structure formed by sintering a metal powder such as copper. The second capillary structure 14 is disposed in the evaporation section 111 of the tubular body 11 and is attached to the inner wall 118 of the evaporation section 111 of the tubular body 11. In the present embodiment, the second capillary structure 14 is disposed on the entire inner wall 118 of the evaporation section 111, and the second capillary structure 14 encloses a first vapor passage 141 through which the vapor can pass, that is, the evaporation section 111. A first vapor passage 141 is formed therein.

Each of the first capillary structures 12, 13 has an elongated hollow tubular structure, and the wires made of a plurality of materials such as copper or stainless steel are woven to form a single-layer mesh, and a longitudinal length is formed inside the tubular body. The passage 140 forms a plurality of fine pores in the wall portion of the tubular body, and the pores are formed by weaving the yarn. In other embodiments, each of the first capillary structures 12, 13 can also be woven to form a multilayer screen that is laminated to one another in its radial direction.

The first capillary structures 12, 13 are disposed in the condensation section 113 of the tubular body 11, and are respectively located on both sides of the tubular body 11. Each of the first capillary structures 12, 13 is extruded flat by the inner wall 118 of the tubular body 11, and the outer wall of the hollow tubular body of each of the first capillary structures 12, 13 includes a top wall 121, 131, a bottom wall 122, 132, left side walls 123, 133 and right side walls 124, 134. The first capillary structure 12 is disposed on the right side of the tubular body 11, and the top wall 121, the bottom wall 122, and the right side wall 124 of the first capillary structure 12 are attached to the inner wall 118 of the tubular body 11 to form an inner wall 118 with the tubular body 11. A U-shaped first portion 125 that fits. The left side wall 123 of the first capillary structure 12 is not attached to the inner wall 118 of the tubular body 11 to form a C-shaped second portion 126 that is not attached to the inner wall 118 of the tubular body 11.

The first capillary structure 13 is disposed on the left side of the tubular body 11, and the top wall 131, the bottom wall 132, and the left side wall 133 of the first capillary structure 13 are attached to the inner wall 118 of the tubular body 11 to form an inner wall 118 with the tubular body 11. The first portion 135 of the U shape is fitted. The right side wall 134 of the first capillary structure 13 is not attached to the inner wall 118 of the tubular body 11 to form a C-shaped second portion 136 that is not attached to the inner wall 118 of the tubular body 11.

The first portions 125, 135 of each of the first capillary structures 12, 13 are attached to the inner wall 118 of the tubular body 11, i.e., the side panels 116, 117 of the tubular body 11 and the top panel 114 and the bottom panel that are in close contact with the side panels 116, 117. Part of the wall of 115 is fitted. The second portions 126, 136 are oriented toward the center of the tubular body 11 and are not attached to the inner wall 118 of the tubular body 11. The right side wall 134 of the first capillary structure 13 is opposite the left side wall 123 of the first capillary structure 12 and is spaced apart from each other within the condensation section 113 to form a second vapor passage 142. The first vapor passage 141 and the second vapor passage 142 communicate with each other in the longitudinal direction.

The first capillary structure 12, 13 extends longitudinally in the condensation section 113 of the tubular body 11 and is joined to the second capillary structure 14 at the junction 149 of the evaporation section 111 of the tubular body 11 with the condensation section 113, i.e., the first capillary structure 12 13, extends in the longitudinal direction of the condensation section 113 of the tubular body 11 to the end 148 of the second capillary structure 14 adjacent to the condensation section 113 and is connected thereto. During the sintering process of the second capillary structure 14, the first capillary structures 12, 13 and the second capillary structure 14 are sintered at the junction 149 and the second capillary structure 14 into a unitary structure 17. The apertures of the channels 140 of the first capillary structures 12, 13 are larger than the wall thickness of the second capillary structure 14, such that the channels 140 of the first capillary structures 12, 13 are in communication with the first vapor channels 141.

The working medium is a substance having a lower boiling point such as water, alcohol or methanol. When the evaporation section 111 of the pipe body 11 is in contact with the heat source, the working medium absorbs heat from the evaporation section 111 to evaporate into a vapor, and the vapor overflows to the first vapor passage 141 located in the evaporation section 111, and the vapor zone The heat is transported from the first vapor passage 141 to the condensation section 113, and enters the passage 140 and the second vapor passage 142 from the junction 149, and finally condenses into a liquid after the condensation section 113 releases heat, releasing the heat to complete the heating element. Heat dissipation (not shown). The first capillary structure 12, 13 and the second capillary structure 14 provide a capillary force to cause the working medium formed by the condensation of the condensation section 113 of the pipe body 11 to flow back to the evaporation section 111, thereby realizing the circulation movement of the working medium in the pipe body 11 to complete Continuous heat dissipation of the heating element.

The second capillary structure 14 of the sintered powder type is disposed in the evaporation section 111 of the pipe body 11, effectively increasing the capillary force of the evaporation section 111, so that the liquid condensed by the condensation section 113 can be transported back to the evaporation section 111 in time to prevent dry burning phenomenon; At the same time, the first capillary structure 12, 13 occupying a relatively small space is disposed in the condensation section 113, which can relatively increase the internal vapor passage of the condensation section 113 for the smooth flow of the vapor while ensuring that the working medium condensed in the condensation section 113 passes through the first The capillary structures 12, 13 are returned to the evaporation section 111. The second capillary structure 14 is sinteredly joined to the first capillary structure 12, 13 at the junction 149 such that the first capillary structure 12, 13 is tightly coupled to the second capillary structure 14, and the working medium is reflowed through the first capillary structure 12, 13. After the junction 149, it can quickly penetrate into the second capillary structure 14. The flat thin heat pipe 10 of the present embodiment can reach 2 mm or less, and even when the flat thin heat pipe 10 has a thickness of 1.5 mm, the flat thin heat pipe 10 can ensure good performance, and is suitable for electronic devices with small internal space such as notes. Computer, etc.

5 is a schematic transverse cross-sectional view showing a condensation section 213 of the flat thin heat pipe 20 of the second embodiment of the present invention, which differs from the first embodiment in that the number of the first capillary structures 22 disposed in the heat pipe 20 is One, the first capillary structure 22 is sandwiched in the center of the condensation section 213 of the flat thin heat pipe 20, and the first capillary structure 22 divides the second vapor passage 242 of the condensation section 213 into a vapor-distributing passage located on the left side of the first capillary structure 22. Lane 2421 and a steam dividing passage 2422 located to the right of the first capillary structure 22. The top and bottom of the first capillary structure 22 are respectively connected between the top plate 214 of the tubular body 21 and the bottom plate 215, and the first capillary structure 22 is spaced apart from the side plate 217 on the left side of the tubular body 21 to form a vapor dividing passage 2421 through which the vapor can pass. A capillary structure 22 is spaced from the side panels 216 on the right side of the tubular body 21 to form a vapor dividing passage 2422 through which vapor can pass. The structure of the evaporation section of the heat pipe 20 is the same as that of the first embodiment, and is not described here, wherein the first capillary structure 22 is also connected to the second capillary structure of the evaporation section at the intersection of the evaporation section of the heat pipe 20 and the condensation section 213. . The working principle of the heat pipe 20 is the same as that of the first embodiment, and will not be described herein.

6 is a transverse cross-sectional view showing a condensation section 313 of the flat thin heat pipe 30 of the third preferred embodiment of the present invention, which is different from the first embodiment in that three first capillary structures 32 are disposed in the heat pipe 30. 33, 35, wherein one of the first capillary structures 35 is located at the center of the condensation section 313 of the heat pipe 30, and the other two first capillary structures 32, 33 are respectively located at the condensation section 313 on both sides of the pipe body 31, at the center A capillary structure 35 is spaced apart from the first capillary structure 33 on the left side to form a vapor-dividing channel 3421 through which the vapor passes, and the centrally located first capillary structure 35 is spaced from the first capillary structure 32 on the right side to form a vapor-permeable passage. A vapor dividing channel 3422 through which the vapor passes. The second vapor passage 342 in the condensation section 313 is comprised of sub-vapor passages 3421, 3422. The structure of the evaporation section of the heat pipe 30 is the same as that of the first embodiment, and the details of the first capillary structure 32, 33, 35 at the intersection of the evaporation section of the heat pipe 30 and the condensation section 313 are also the same as those of the evaporation section. Two capillary structures are connected. The working principle of the heat pipe 30 is the same as that of the first embodiment, and will not be described here.

7 is a transverse cross-sectional view showing an evaporation section 411 of a flat thin heat pipe 40 according to a fourth preferred embodiment of the present invention, which is different from the first embodiment in that a second The capillary structure 44 is attached to the inner side of the bottom plate 415 of the evaporation section 411 of the pipe body 41, that is, the second capillary structure 44 is attached to a portion of the inner wall 418 of the evaporation section 411 of the pipe body 41. The heat-generating electronic component 70 is attached to the outside of the bottom plate 415. Since the second capillary structure 44 is not disposed on the inner side of the top plate 414 of the evaporation section 411, the volume of the first vapor passage 441 in the evaporation section 411 can be further increased, and the heat generated by the heat-generating electronic component 70 is quickly transmitted via the tube 41. It is transferred to the second capillary structure 44, thereby improving the heat dissipation performance of the flat thin heat pipe 40.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art will be included in the following claims.

11‧‧‧Body

12.13‧‧‧First capillary structure

14‧‧‧Second capillary structure

17‧‧‧ overall structure

111‧‧‧Evaporation section

113‧‧‧Condensation section

141‧‧‧First vapor channel

142‧‧‧Second vapor channel

148‧‧‧End

149‧‧‧ junction

Claims (16)

A flat thin heat pipe comprising a hollow flat tube body and a first capillary structure and a second capillary structure disposed in the tube body, the tube body comprising an evaporation section and a condensation section, wherein the first capillary structure is a wire formation, the second capillary structure being formed by sintering of a powder, the second capillary structure being attached to an inner wall of the evaporation section of the tubular body, the evaporation section forming a first vapor passage through which the vapor passes, The first capillary structure is disposed on the condensation section of the tubular body, and the first capillary structure includes a first portion that is in contact with the inner wall of the tubular body and a second portion that is not attached to the inner wall of the tubular body, the first portion A second vapor passage for vapor passage is formed in the condensation section between the second portion of the capillary structure and the inner wall of the tubular body, the first vapor passage and the second vapor passage being in communication with each other, the first capillary structure being a condensation section of the tubular body extending to an intersection of the condensation section and the evaporation section and connected to the second capillary structure at the junction, wherein a diameter of the passage of the first capillary structure is greater than a wall thickness of the second capillary structure, To make the first Fine channel structure with the first vapor passage. The flat thin heat pipe of claim 1, wherein the first capillary structure and the second capillary structure are sintered together at an intersection of an evaporation section and a condensation section of the pipe body. The flat thin heat pipe of claim 1, wherein the first capillary structure is joined to the end of the second capillary structure adjacent to the condensation section. The flat thin heat pipe of claim 1, wherein the first capillary structure is a hollow tubular body formed by wire weaving. The flat thin heat pipe according to claim 4, wherein the hollow tubular body is extruded into a flat shape by an inner wall of the pipe body. The flat thin heat pipe according to claim 4, wherein the hollow tubular body comprises a top wall, a bottom wall and two side walls, the top wall, the bottom wall and one of the side walls and the inside of the tube body The wall is fitted, the other side wall of the tubular body is not attached to the inner wall of the tubular body, and the second vapor passage is formed between the other side wall of the hollow tubular body and the tubular body. The flat thin heat pipe according to claim 4, wherein the hollow tubular body comprises a top wall, a bottom wall and two side walls, the top wall and the bottom wall being attached to the inner wall of the pipe body, The two side walls of the tubular body are not attached to the inner wall of the tubular body, and the second vapor passage is formed between the two side walls and the tubular body. The flat thin heat pipe according to claim 1, wherein the second capillary structure is sintered and integrated with the first capillary structure in a sintering process. The flat thin heat pipe of claim 1, wherein the second capillary structure is looped and attached to the entire inner wall of the evaporation section of the pipe body. The flat thin heat pipe of claim 1, wherein the second capillary structure is attached to a portion of the inner wall of the evaporation section of the pipe body. A flat thin heat pipe according to claim 1, wherein the number of the first capillary structures is one, and the first capillary structure is located at a center of the pipe body in the condensation section. The flat thin heat pipe according to claim 1, wherein the number of the first capillary structures is two, and the two first capillary structures are respectively disposed at two sides of the tubular body at a condensation section, A second vapor passage is formed between the two first capillary structures. The flat thin heat pipe according to claim 1, wherein the number of the first capillary structures is three, wherein one of the first capillary structures is located at the center of the pipe body in the condensation section, and the other two first capillary structures are The condensing sections are respectively located on both sides of the tubular body, and the second vapor passage is formed between the centrally located first capillary structure and the other two first capillary structures located on both sides. The flat thin heat pipe according to claim 1, wherein the first capillary structure is a single layer mesh or a multilayer mesh laminated in the radial direction. The flat thin heat pipe according to claim 1, wherein the pipe body has a smooth inner wall in the evaporation section and the condensation section. The flat thin heat pipe according to any one of claims 1 to 15, wherein the heat pipe has a thickness of 2 mm or less.