JP2016050682A - Sheet-type heat pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet-type heat pipe having enough heat-transport capacity and capable of being naturally placed even in a thin casing.SOLUTION: A sheet body 12 forming an outer bailey of a container includes a steam passage 20 and a wick 22. The steam passage 20 forms a second steam passage 20B as a radial passage running in a radial state when seen from a heat-receiving part 33 thermally connected to an external heat source H. When operating fluid in a container 15 is evaporated due to heat transferred to the heat-receiving part 33 from the heat source H, steam is flown in a radial state through the second steam passage 20B from the heat-receiving part 33. As a result, favorable heat diffusion can be performed in the container furthermore in a broad region of the casing, and performance of the heat source H such as a CPU can be satisfactorily exerted.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a sheet-type heat pipe that can be mounted on a portable information terminal such as a smartphone or a tablet terminal and can obtain a sufficient amount of heat transport while being small.

  Conventionally, in order to diffuse the heat generation of a CPU mounted on a portable device such as a tablet terminal, for example, a heat dissipation structure in which graphite having high thermal conductivity as shown in Patent Document 1 is mixed in a heat dissipation sheet has been proposed. .

JP 2012-186692 A

  However, in the conventional configuration, heat diffusion is not sufficient, and the CPU exceeds the limit temperature, or a heat spot is generated in the outline of the portable device, so that the heat generation of the CPU has to be limited. For this reason, the CPU's ability could not be used to the maximum.

  On the other hand, a heat dissipation structure that diffuses the heat generated by the CPU with a round heat pipe is also known. It is difficult to secure enough space for storage. In particular, in portable information terminals such as smartphones, the thickness of the casing is limited due to the pursuit of ease of use, and it is difficult to install a heat pipe. In addition, with a pipe-shaped heat pipe, good heat diffusion cannot be performed over a wide area of the portable information terminal, and as a portable information terminal, the performance of thermal components such as a CPU cannot be sufficiently exhibited.

  In view of the above problems, an object of the present invention is to provide a sheet-type heat pipe that has sufficient heat transport capability and can be installed without difficulty in a thin casing.

  The present invention is a sheet-type heat pipe formed by stacking two or more metal foil sheets to form a sealed container by joining, wherein the metal foil sheet has a steam passage and a wick, and the steam passage Is characterized in that a radial passage is formed in a radial direction when viewed from a heat receiving portion thermally connected to an external heat source.

  Further, the present invention is a sheet-type heat pipe formed by stacking two or more metal foil sheets and forming a sealed container by joining, wherein the metal foil sheet has a steam passage and a wick, and the wick Has a plurality of pattern portions formed inside the container and a connecting portion that connects the plurality of pattern portions, and the connecting portion is formed in a heat receiving portion that is thermally connected to an external heat source. And

  According to the first aspect of the present invention, by stacking two or more metal foil sheets, it is possible to form fine vapor passages and wicks having sufficient heat transport capability on the inner surface of the container. Further, by stacking and joining metal foil sheets to form a sealed container, it is possible to provide a sheet-type heat pipe that is thinner than a round heat pipe and has sufficient heat transport capability. For this reason, the sheet-type heat pipe can be easily and easily installed in a thin casing such as a portable information terminal. Furthermore, when the hydraulic fluid inside the container evaporates due to heat transmitted from an external heat source to the heat receiving portion, steam flows radially from the heat receiving portion through the radiation passage. Therefore, good thermal diffusion can be performed over the container and thus the wide area of the housing, and the performance of, for example, a CPU serving as a heat source can be sufficiently exhibited.

  According to the invention of claim 2, by forming at least two or more radiation passages, steam can be sent from the heat receiving portion in various directions inside the container, and good thermal diffusion can be performed throughout the container. It becomes possible.

  According to the invention of claim 3, when the working fluid inside the container evaporates, the steam flows toward the outer corner of the container located far from the heat source. Can be performed.

  According to the invention of claim 4, by forming the width of the radiation passage in the range of 1 mm to 3 mm, it becomes possible to smoothly send the steam from the heat receiving portion through the radiation passage to the inside of the container.

  According to the invention of claim 5, by stacking two or more metal foil sheets, it is possible to form a fine steam passage and a wick groove having sufficient heat transport capability on the inner surface of the container. Further, by stacking and joining metal foil sheets to form a sealed container, it is possible to provide a sheet-type heat pipe that is thinner than a round heat pipe and has sufficient heat transport capability. For this reason, the sheet-type heat pipe can be easily and easily installed in a thin casing such as a portable information terminal. Furthermore, reviewing the pattern shape of the wick, at the part away from the heat receiving part, the working fluid remaining inside the container is collected at each pattern part of the wick and collected in the connecting part, which is the heat receiving part that tends to run out of hydraulic fluid So that the working fluid inside the container can be used effectively. As a result, the temperature distribution and local hot spots of the entire container can be improved, and the performance of, for example, a CPU serving as a heat source can be sufficiently exhibited.

  According to the invention of claim 6, it becomes possible to collect the hydraulic fluid collected in each pattern part without any delay in the wider connecting part and supply it to the heat receiving part, and the temperature distribution of the entire container and the local hot water The spot improvement can be effectively promoted.

It is the top view and side view in the completion state of a basic sheet type heat pipe. It is a side view and a top view of a 2nd sheet | seat body same as the above. FIG. 3 is an enlarged detailed view of the wick portion A shown in FIG. FIG. 3 is an enlarged detailed view of the wick portion B shown in FIG. FIG. 3 is an enlarged detailed view of the wick portion C shown in FIG. FIG. 3 is an enlarged detailed view of the wick portion D shown in FIG. FIG. 7 is a cross-sectional view taken along line AA in FIG. 6. It is a top view in the completed state of the sheet type heat pipe which shows the 1st example of the present invention. It is a top view of a 2nd sheet | seat body same as the above. FIG. 10 is an enlarged detailed view of the wick portion E shown in FIG. FIG. 9 is a sectional view taken along line BB in FIG. It is a top view in the completed state of the sheet type heat pipe which shows the 2nd example of the present invention. It is a top view of a 2nd sheet | seat body same as the above. It is a top view of the 2nd sheet | seat body which shows another modification same as the above. It is a figure which shows various experimental results by the comparison with the seat pipe of the conventional sheet | seat type heat pipe and a present Example. As yet another modification, it is a diagram showing various experimental results in comparison between a conventional sheet heat pipe and the seat pipe of the present modification.

  Hereinafter, a preferred embodiment of the present invention will be described by taking a sheet-type heat pipe mounted on a portable device such as a tablet terminal as an example. Here, after first explaining the structure of a basic sheet type heat pipe, the sheet type pipe of each example relevant to the present invention will be explained. Accordingly, in the following descriptions, common portions are denoted by common reference numerals, and descriptions of common portions are omitted as much as possible to avoid duplication.

  1 to 7 show a basic sheet-type heat pipe 1. In each of these drawings, the sheet-type heat pipe 1 is constituted by a container 15 in which a first sheet body 11 and a second sheet body 12 which are two copper foil sheets are diffusion bonded. These sheet bodies 11 and 12 may use other metal sheets that have good thermal conductivity and can be etched or pressed, such as aluminum. As shown in FIG. 1, the sheet-type heat pipe 1 in a completed state has a substantially rectangular flat plate shape, and has an external shape that matches the internal shape of the case of a portable information terminal such as a smartphone. Part 16 is formed. Further, in order to enclose a working fluid (not shown) such as pure water in a vacuum state inside the container 15, a cylindrical liquid injection nozzle 17 that can be welded is formed in the container 15. The thickness t1 of the container 15 sealed by the liquid injection nozzle 17, and consequently the sheet-type heat pipe 1, is 0.4 mm.

  At the four corners of the container 15, attachment portions 18 are disposed. The attachment portion 18 is formed as a through hole, and enables the portable information terminal to be attached to the housing. For example, the attachment portion 18 is aligned with a screw hole (not shown) formed in the housing, and is not shown. The sheet-type heat pipe 1 can be easily attached and fixed at a desired position with respect to a housing such as a portable information terminal by passing a screw as a fitting member through the attachment portion 18 and screwing it into the screw hole. it can. In addition, the attachment part 18 is not limited to a through-hole, You may employ | adopt another structure which exhibits an equivalent function.

  FIG. 2 is a side view and a plan view of the second sheet body 12. In addition, since the 1st sheet | seat body 11 is the same shape as the 2nd sheet | seat body 12, illustration is abbreviate | omitted. In the figure, the thickness t2 of the sheet bodies 11 and 12 is both 0.2 mm. Here, the thickness of the sheet bodies 11 and 12 is half-etched only on one side surface which finally becomes the inner surface of the container 15. Etching is performed halfway to form a vapor passage 20 that transports the vapor of the working liquid evaporated in the heat receiving part to the heat radiating part, and a wick 22 that returns the working liquid condensed in the heat radiating part to the heat receiving part. In addition to the vapor passage 20 and the wick 22, convex side walls 30 that are not etched by etching are formed on the inner surfaces of the sheet bodies 11 and 12 along the outer periphery of the sheet bodies 11 and 12. This side wall 30 which is a convex wall is in a position where it overlaps when the inner surfaces of the sheet bodies 11 and 12 face each other, and finally forms a part of the outer peripheral portion of the container 15 by diffusion bonding. In FIG. 2, the wick 22 and the side wall 30 are indicated by hatching.

  In order to manufacture the sheet-type heat pipe 1 shown in FIG. 1, two sheets 11 and 12 having the same shape are overlapped with the inner surfaces thereof inward to form a container 15 that contains a working fluid. Next, a part of the wick 22 and the side wall 30 are joined. At that time, after joining the side wall 30 which becomes the outer peripheral portion, and then injecting and degassing the working liquid using the liquid injection nozzle 17, the liquid injection nozzle 17 is closed to close the sheet type heat pipe 1. The function as the container 15 can be obtained by sealing the inside.

  Inside the container 15, a sealed chamber 13 in a deaerated state in which a working fluid is sealed is formed. Here, only one sealed chamber 13 is formed inside the container 15, and all the vapor passages 20 and wicks 22 are disposed in the sealed chamber 13. The sealed chamber 13 includes the above-described liquid injection nozzle 17, and a cylindrical liquid injection passage 17 </ b> A formed in the liquid injection nozzle 17 is provided in communication with the inside of the sealed chamber 13. The liquid injection passage 17A is provided alone and is closed in the completed state shown in FIG. 1, thereby maintaining the sealed chamber 13 in a sealed state.

  By the way, in a heat pipe having a round cross section, a thickness of 0.9 mm is a limit from the viewpoint of manufacturability and heat transport capability. Therefore, if the container 15 shown in FIG. 1 and the thickness t1 of the sheet-type heat pipe 1 are 0.9 mm or less, the sheet-type heat pipe 1 is thinner than the round heat pipe and has sufficient heat transport capability. Can provide. Further, when the thickness t1 of the sheet type heat pipe 1 is set to 0.9 mm at the maximum, the thickness t2 (see FIG. 7) of each of the sheet bodies 11 and 12 is 0.45 mm per sheet. Good.

  When the vapor passage 20 and the wick 22 are formed in the sheet bodies 11 and 12 by photoetching, the sheet bodies 11 and 12 require a thickness t2 of at least 0.05 mm. On the other hand, the number of sheets 11, 12,... May be three or more. However, if the number of sheets increases excessively, it is difficult to align all the sheets 11, 12,. become. In consideration of the manufacturability of the sheet-type heat pipe 1 and to obtain a sheet-type heat pipe 1 that is thinner than the round heat pipe, the number of the sheet bodies 11, 12,. , 12,... Is preferably 0.1 mm or more per sheet. Therefore, by etching the surfaces of the sheet bodies 11, 12,... Having a thickness t2 of 0.1 mm to 0.45 mm, the thickness t1 of the completed sheet heat pipe 1 is set to 0.9 mm or less. In addition, a fine steam passage 20 and a wick 22 having sufficient heat transport capability can be formed on the inner surface of the container 15, and the sheet-type heat pipe 1 is thinner than a round heat pipe in a thin housing such as a portable information terminal. Can be installed without difficulty.

  The steam passage 20 communicates with the concave first passage portion 21A formed in a plurality along the longitudinal direction of the sheet bodies 11 and 12 and the plurality of first passage portions 21A inside the sealed container 15. And a single concave second passage portion 21B formed. The first passage portion 21A is formed in a straight line shape in plan view, whereas the second passage portion 21B is formed in an inverted V shape in plan view, and the first passage portion 21A is formed near the center of the sheet bodies 11 and 12. Although the passage portion 21A and the second passage portion 21B cross each other obliquely, they may be communicated at any position in any shape. When the side surfaces of the sheet bodies 11 and 12 are stacked so as to face each other, the first passage portions 21A of the sheet bodies 11 and 12 face each other, so that a hollow cylindrical first steam passage 20A is formed. , 12 of the second passage portions 21B face each other, thereby forming a hollow cylindrical second steam passage 20B. At this time, a steam passage 20 including a first steam passage 20 </ b> A and a second steam passage 20 </ b> B is disposed inside the container 15, and a plurality of first steam passages 20 </ b> A formed along the longitudinal direction of the sheet type heat pipe 1. Communicates with the second steam passage 20B formed into one.

  The wick 22 is formed in a portion excluding the vapor passage 20 and the side wall 30 inside the container 15. More specifically, the outer periphery of the container 15 together with the side wall 30 is formed, and the sheet bodies 11 and 12 and the outer periphery of the container 15 are removed except for the portion of the steam passage 20 extending toward the liquid injection passage 17A of the liquid injection nozzle 17. The first wick 22A formed on substantially the entire circumference of the section, and the sheet bodies 11 and 12, and then along the longitudinal direction of the container 15, respectively, from one side and the other side of the first wick 22A toward the center of the container 15 respectively. All the wicks 22 are constituted by a plurality of second wicks 22B formed side by side. Each of the second wicks 22B is linear, and there are twelve second wicks 22B from one side of the first wick 22A toward the center, and twelve second wicks 22B from the other side of the first wick 22A toward the center. The above-mentioned second passage portion 21B is formed between them. Further, the first passage portion 21A is formed between the first wick 22A and the second wick 22B arranged side by side or between the two second wicks 22B and 22B.

  3 is an enlarged view of the wick portion A of the second sheet body 12 in FIG. 2, and FIG. 4 is an enlarged view of the wick portion B of the second sheet body 12 in FIG. In each of these drawings, the second wick 22B constituting the wick 22 is constituted by a concave groove 26 etched by an etching process and a convex wall 27 not etched, and is in the region of the second wick 22B. A plurality of grooves 26 serving as hydraulic fluid passages are formed in a desired shape by the walls 27. Such a structure in which the fine groove 26 and the wall 27 are combined is common at any position of the wick 22.

  The grooves 26 are located along both side portions and end portions of the steam passage 20, and a plurality of first grooves 26 </ b> A arranged at regular intervals perpendicular to the direction of the steam passage 20, and the first grooves 26 </ b> A. The plurality of second grooves 26B, which are arranged at a constant interval smaller than the first groove 26A and arranged at a constant interval smaller than the first groove 26A, and the first groove 26A and the second groove 26B are connected to the steam path 20. And a third groove 26 </ b> C as a vertical groove that communicates with each other along the direction. Further, the depth t2 of the groove 26 (see FIG. 7) is 0.1 mm to 0.13 mm, and the width d1 of the groove 26 is set to be 0.1 mm in any of the first groove 26A, the second groove 26B, and the third groove 26C. 12 mm. Here, if the width d1 of the groove 26 is in the range of 0.05 mm to 0.3 mm, the capillary force by the wick 22 can be increased. Further, the number of the first grooves 26A is larger than the number of the second grooves 26B, and the first grooves 26A that are finer than the second grooves 26B are located on both sides of the steam passage 20 and directly with the steam passage 20. Communicate.

  The wall 27 formed between the grooves 26 includes a plurality of first walls 27A for forming the first grooves 26A at finer intervals than the second grooves 26B, and a second groove 26B. The first wall 27A has at least a plurality of second walls 27B and third walls 27C having different shapes. The first wall 27A has a width d2 along the direction orthogonal to the steam passage 20 of 0.1 mm, while the third wall 27C has a width d3 along the direction orthogonal to the steam passage 20. The first wall 27A and the second wall 27B are formed to be 0.3 mm wider than the width d2. Here, the second walls 27B are arranged in parallel so as to face both outer sides of the third walls 27C arranged in a row perpendicular to the direction of the steam passage 20, and a plurality of first walls are arranged outside the second walls 27B. 27A is juxtaposed. Preferably, the width d2 of the first wall 27A and the second wall 27B is less than 0.25 mm, and the width d3 of the third wall 27C is 0.25 mm or more, so that the third wall 27C where the sheet bodies 11 and 12 overlap each other. Using the surface, diffusion bonding at the portion of the wick 22 becomes possible.

  The first wick 22A constituting the wick 22 is also constituted by a concave groove 26 and a convex wall 27, and a large number of fine grooves 26 serving as a passage for the hydraulic fluid are formed in the region of the first wick 22A. The wall 27 is formed into a desired shape. The groove 26 of the first wick 22A includes the first groove 26A, the second groove 26B, and the third groove 26C described above, but the wall 27 of the first wick 22A includes a plurality of first grooves. It consists only of the wall 27A and the plurality of second walls 27B. And while arrange | positioning the side wall 30 in the one side of the 2nd wall 27B arranged in multiple rows toward the vapor | steam path | route 20, while arranging the some 1st wall 27A in parallel in the other side, those A plurality of third grooves 26C are formed at regular intervals between them.

  Here, there are 12 rows of third grooves 26C as the peripheral grooves of the first wick 22A, and in order to form the third grooves 26C, there are 12 rows of first walls 27A and second walls 27B in total as convex walls. And a convex side wall 30 on the outer side of the first wick 22A.

  The sheet bodies 11 and 12 as the metal foil sheets constituting the container 15 are formed on the surface of the side wall 30 that contacts the outer peripheral wall outside the first wick 22A when the two sheet bodies 11 and 12 are overlapped. The width d4 is formed to have a dimension in the range of 0.2 mm to 1.9 mm. Thereby, in the state of the completed sheet type heat pipe 1, it is possible to obtain the necessary degree of sealing and proper strength as the container 15. On the other hand, the first wall 27A and the second wall 27B that only form the groove 26 of the first wick 22A are preferable as the width d5 is narrower, which leads to the refinement of the groove 26. Here, it is set to 0.1 mm, which is the same as the aforementioned width d2, and is narrower than the width d6 of the third groove 26C. This width d6 is 0.12 mm, similar to the aforementioned width d1. That is, in the first wick 22A, the dimensions of the width d6 of the third groove 26C, the width d5 of the first wall 27A and the second wall 27B, and the width d4 of the side wall 30 formed outside the first wick 22A are as follows. , D4> d6> d5. By maintaining such a dimensional relationship, the surface area where the liquid phase comes into contact with the groove 26 of the first wick 22A and the gas phase of the steam passage 20 flow while ensuring the strength of the container 15 while ensuring the hermeticity of the container 15. The cross-sectional area becomes optimum, and the heat transport capability of the sheet heat pipe 1 can be improved.

  FIG. 5 is an enlarged view of the wick portion C of the second sheet body 12 in FIG. 2, and FIG. 6 is an enlarged view of the wick portion D of the second sheet body 12 in FIG. In FIG. 5, the tip of the second wick 22B is enlarged, and in FIG. 6, the substantially middle portion of the first steam passage 20A and the second wick 22B is enlarged. As described in 4. In particular, on the tip side of the second wick 22B shown in FIG. 5, in addition to the first wall 27A, the second wall 27B, and the third wall 27C, the third wall 27C is arranged in the same row as the third wall 27C. A fourth wall 27D having the same width d3 and shorter in the direction along the steam passage 20 than the third wall 27C, and fan-shaped fifth walls on both sides of the fourth wall 27D. 27E is arranged as a wall 27, thereby forming a first groove 26A, a second groove 26B, and a third groove 26C.

  Referring to FIG. 6, there are four rows of third grooves 26C as vertical grooves of the second wick 22B, and one row of third walls is formed as a wide convex wall to form the third grooves 26C. 27C and a total of four rows of the first wall 27A and the second wall 27B having a narrow width are provided.

  The sheet bodies 11 and 12 as the metal foil sheets constituting the container 15 are the surfaces of the third wall 27C that contacts as the first convex wall of the second wick 22B when the two sheet bodies 11 and 12 are overlapped. The width d3 is formed in a dimension in the range of 0.2 mm to 1.9 mm. Thereby, in the state of the completed sheet type heat pipe 1, it is possible to obtain the necessary degree of sealing and proper strength as the container 15. On the other hand, the first wall 27A and the second wall 27B, which are the second convex walls that only form the groove 26 of the first wick 22A, are preferably as the width d2 becomes narrower, leading to the refinement of the groove. 1 mm, which is narrower than the width d1 of the third groove 26C. That is, in the first wick 22B, the width d1 of the third groove 26C, the width d2 of the first wall 27A and the second wall 27B, and the width d3 of the third wall 27C are in a relationship of d3> d1> d2. It becomes. By maintaining such a dimensional relationship, the surface area where the liquid phase comes into contact with the groove 26 of the second wick 22B and the vapor phase of the vapor passage 20 flow while ensuring the strength of the container 15 while ensuring the hermeticity. The cross-sectional area becomes optimum, and the heat transport capability of the sheet heat pipe 1 can be improved.

  In addition, although the sheet-type heat pipe 1 as shown in FIG. 1 changes in each position of the heat receiving part and the heat radiating part depending on which part is thermally connected to the heat source, a plurality of sheet type heat pipes 1 are formed inside the container 15. Since the first steam passage 20A communicates with the second steam passage 20B formed as one, even if the heat receiving portion and the heat radiating portion are located in any part of the sheet type heat pipe 1, each steam passage By communicating 20A and 20B with each other, the entire surface of the sheet-type heat pipe 1 can be soaked.

  FIG. 7 is a cross-sectional view taken along line AA of the second sheet body 12 shown in FIG. In the figure, a region of a steam passage 20 having a width d7 is formed between the end portion of one adjacent second wick 22B and the end portion of the other second wick 22B. The thickness k1 of the region to be 20 has a dimension in the range of 0.03 mm to 0.14 mm.

  The cross-sectional area of the steam passage 20 is large, and as the aspect ratio, which is the ratio of the depth t4 and the width d7 of the steam passage 20, is the same, the surface area of the working fluid that passes through the steam passage 20 is reduced in surface area. , Heat transport ability is improved. On the other hand, in order to install the sheet type heat pipe 1 in a thin casing such as a portable information terminal without difficulty, the container 15 shown in FIG. 1 and the thickness t1 of the sheet type heat pipe 1 must be 0.5 mm or less. There is. Therefore, in order to achieve both the heat transport capability of the completed sheet-type heat pipe 1 and the thickness limitation of the entire container 15, the dimension of the wall thickness k1 in the region serving as the steam passage 20 is suppressed to 0.14 mm or less. . On the other hand, when the dimension of the wall thickness k1 is less than 0.03 mm, the container 15 is crushed by the external atmospheric pressure because the inside of the container 15 is evacuated. Therefore, it is preferable that the dimension of the wall thickness k1 in the region serving as the steam passage 20 is 0.03 mm or more.

  On the other hand, if the width d7 of the steam passage 20 is smaller than 0.5 mm, the cross-sectional area of the steam passage 20 is reduced, and the intended heat transport capability cannot be obtained. On the other hand, when the width d7 of the steam passage 20 is larger than 2.7 mm, the container 15 is crushed by the external atmospheric pressure because the inside of the container 15 is evacuated. Therefore, it is preferable that the width d7 of the region serving as the steam passage 20 of the sheet bodies 11 and 12 has a dimension in the range of 0.5 mm to 2.7 mm.

  Regarding the steam passage 20, when an appropriate ratio of the wall thickness k1 and the width d7 is obtained for the reason described above, the ratio is in the range of 1: 4 to 1:90. For example, when the thickness k1 is 0.03 mm, if the width d4 is 0.03 × 90 = 2.7 mm or less, there is no possibility that the container 15 is crushed by the external atmospheric pressure. When the thickness k1 is 0.14 mm, the target heat transport capability can be obtained if the width d4 is 0.14 × 4 = 0.56 mm or more.

  The thickness k1 of the region that becomes the steam passage 20 of the sheet bodies 11 and 12 is not constant in any part, and is closer to the region where the groove 26 that becomes the wick 22 is formed than the central portion of the steam passage 20. Both sides are thick and formed so that the whole changes into a gentle, generally arched shape. This is because the inside of the container 15 is at the saturated vapor pressure of the hydraulic fluid, and stress due to atmospheric pressure is applied to the wall surface of the vapor passage 20, so that a groove 26 that becomes the wick 22 is formed in the vapor passage 20. If the thickness k1 of the both side portions with large stress close to the region is increased while the thickness k1 of the central portion with small stress is decreased, there is no possibility that the container 15 is crushed by the external atmospheric pressure, and the steam passage 20 This is because it is possible to secure a cross-sectional area that provides the desired heat transport capability.

  As described above, a large number of grooves 26 to be the wicks 22 are formed in the sheet bodies 11 and 12 by etching or pressing. The fine groove 26 that becomes the wick 22 has a greater heat transport capability as the surface area that the liquid phase of the working fluid touches in the container 15 is larger. Therefore, the ratio of the width d1 and the depth t3 of the groove 26 per sheet of the sheet members 11 and 12 is 1: 1 to 2: 2 so that the surface area touched by the liquid phase can be increased while maintaining a certain cross-sectional area. A range of 1 is preferable. Thereby, the heat transport capability in the wick 22 can be improved.

  The ratio of the width d1 of the groove 26 per sheet of the sheet bodies 11 and 12 to the depth t4 of the steam passage 20 is preferably in the range of 1: 0.8 to 1: 1.6. . Within this range, the surface area in which the liquid phase of the working fluid touches the groove 26 of the wick 22 can be increased, and the cross-sectional area of the vapor passage 20 through which the gas phase flows can be increased. As the mold heat pipe 1, the heat transport capability can be improved.

  Next, the effect when the sheet-type heat pipe 1 described above is mounted on a thin portable information terminal will be described.

  As described above, the sheet-type heat pipe 1 has an external shape that matches the internal shape of the portable information terminal, and is installed as it is inside the portable information terminal. At this time, one side of the sheet-type heat pipe 1 serves as a heat source, a part of which serves as a heat receiving portion and is thermally connected in contact with a mother board (none of which is shown) including a CPU installed inside the housing. A heat dissipating part is formed at a part away from (a part of one side of the sheet-type heat pipe 1 or the other side). Then, when the CPU or the like generates heat inside the casing and the temperature rises, the heat from the CPU is transmitted to the heat receiving portion of the sheet type heat pipe 1, and the working fluid evaporates in the heat receiving portion and receives heat through the vapor passage 20. Steam flows from the part toward the heat radiating part having a low temperature, and heat is transported inside the sheet type heat pipe 1. The heat transported to the heat radiating portion is thermally diffused in a wide planar area of the sheet type heat pipe 1 and is radiated from both the front and back sides of the sheet type heat pipe 1, that is, both the one side and the other side. Thereby, since the portable information terminal can thermally diffuse heat generated in the CPU or the like over a wide area, the heat spot generated on the outer surface of the portable information terminal is alleviated and the temperature rise of the CPU can be suppressed.

  On the other hand, in the heat radiating portion of the sheet type heat pipe 1, the vapor is condensed and the working liquid is accumulated. However, the operation is performed by the strong capillary force of the wicks 22 formed on both sides of the vapor passage 20 inside the sheet type heat pipe 1. The liquid is transferred from the liquid flow path formed by the first groove 26A and the second groove 26B orthogonal to the vapor passage 20 through the liquid flow path formed by the third groove 26C along the vapor path 20 and returned from the heat radiating unit to the heat receiving unit. Therefore, the hydraulic fluid does not disappear in the heat receiving portion, and the hydraulic fluid evaporates and travels through the vapor passage 20 and is guided to the heat radiating portion by capillary force. Performance is demonstrated.

  In addition, the thickness t1 of the sheet type heat pipe 1 itself is 0.9 mm or less, more preferably 0.5 mm or less, which is thinner than the round type heat pipe, and is particularly easy to use in a portable information terminal such as a smartphone. It is possible to cope with the limitation of the thickness of the casing in pursuit of thickness, and to quickly diffuse the heat of the CPU 54 and the like over a wide area while taking advantage of the characteristics of the sheet-type heat pipe 1 having extremely good thermal conductivity as compared with the graphite sheet. It becomes possible.

  As described above, the sheet-type heat pipe 1 is a sheet-type heat pipe 1 in which two or more sheet bodies 11 and 12 as metal foil sheets are stacked to form a sealed container 15 by bonding. In the sheet bodies 11 and 12, the groove 26 which becomes the vapor passage 20 and the wick 22 is formed by half-etching processing, and the sheet bodies 11 and 12 are stacked and joined, so that the thickness t1 is 0.9 mm or less. The formed container 15 is formed.

  In this case, by performing half-etching on the surfaces of the sheet bodies 11 and 12, the fine vapor passage 20 having sufficient heat transport capability and the groove 26 of the wick 22 can be formed on the inner surface of the container 15. Further, by forming the thickness of the container in which the sheet bodies 11 and 12 are stacked to be 0.9 mm or less, the sheet-type heat pipe 1 is thinner than a round-shaped heat pipe and has a sufficient heat transport capability. Can provide. Therefore, the sheet-type heat pipe 1 can be easily and easily installed in a thin casing such as a portable information terminal.

  In addition, the half etching process here does not chemically etch and etch the same pattern shape from both surfaces of the sheet bodies 11 and 12 as processing materials, but intentionally controls the etching balance of each surface. In addition, it refers to an etching process in which a pattern shape is formed only on one side of the sheet bodies 11 and 12, or different arbitrary pattern shapes are formed on both sides of the sheet bodies 11 and 12.

  The sheet-type heat pipe 1 is formed such that the thickness t2, which is the thickness of each of the sheet bodies 11 and 12, is in the range of 0.1 mm to 0.45 mm.

  When stacking two sheet bodies 11 and 12 as metal foil sheets, if the thickness t2 of each sheet body 11 and 12 is formed to 0.45 mm or less, the thickness t1 of the container 15 is set to a desired 0.9 mm. The following can be formed. Further, due to manufacturing restrictions of the sheet-type heat pipe 1, if the thickness t2 of each of the sheet bodies 11 and 12 is 0.1 mm or more, the vapor passage 20 and the wick 22 are formed in the sheet bodies 11 and 12 by photoetching. The thickness t1 of the container 15 can be formed to a desired value of 0.9 mm or less even when the number of stacked sheets 11 and 12 is nine.

  Next, the details of the sheet-type heat pipe 2 suitable as the first embodiment of the present invention will be described with reference to FIGS. In each of these drawings, the completed sheet heat pipe 2 shown in FIG. 8 is provided on one side in the short direction of the container 15 formed in a substantially rectangular flat plate shape so that the liquid injection nozzle 17 does not protrude, Further, corner portions 32 where the attachment portion 18 does not exist are provided at the four corners of the sheet-type heat pipe 2 having a substantially rectangular flat plate shape. However, like the basic sheet-type heat pipe 1, the attachment portion 18 may be provided at the corner portion 32. H is a heat source that is thermally connected to the surface of the container 15, and as described above, this is composed of a CPU or the like disposed inside the casing of the portable information terminal. Therefore, in the sheet-type heat pipe 2 of the present embodiment, the central portion closer to the one side in the short direction of the container 15 to which the heat source H is thermally connected becomes the heat receiving portion 33, and around the corner portion 32 of the container 15 away from the heat source H. The part becomes the heat radiation part 34. Other external configurations are generally the same as those of the basic sheet type heat pipe 1.

  FIG. 9 is a plan view of the second sheet body 12 that faces and overlaps the first sheet body 11, and FIG. 10 is an enlarged view of the wick portion E of the sheet heat pipe 2 shown in FIG. 11 is a cross-sectional view of the sheet-type heat pipe 2 shown in FIG. In this case, the first sheet body 11 has the same shape as the second sheet body 12.

  In the present embodiment, in the sealed container 15, a plurality of concave first passage portions 21A formed side by side along the longitudinal direction and the short side direction of the sheet bodies 11 and 12, and the respective first passage portions. Three concave second passage portions 21 </ b> B formed to communicate with the plurality of first passage portions 21 </ b> A so as to be connected to one end of 21 </ b> A are configured as passage portions of the steam passage 20. Also in this case, when the sheet bodies 11 and 12 are stacked facing each other, the first passage portions 21A of the sheet bodies 11 and 12 face each other, so that a hollow cylindrical first steam passage 20A is formed. As the second passage portions 21B of the sheet bodies 11 and 12 face each other, a hollow cylindrical second steam passage 20B is formed. At this time, a steam passage 20 including a first steam passage 20A and a second steam passage 20B is disposed inside the container 15.

  Here, with reference to FIG. 9, focusing on the arrangement shape of the steam passage 20 inside the container 15, the base ends of the three second steam passages 20 </ b> B are located in the region of the heat receiving portion 33 having a shape corresponding to the heat source H. Are connected to each other, and the second steam passages 20B extend radially or in a Y-shape toward the outer shape of the container 15 when viewed from the passage base 35. That is, it can be said that the steam passage 20 of the present embodiment forms the linear second steam passage 20 </ b> B inside the container 15 as a radiation passage that goes radially as viewed from the heat receiving portion 33 thermally connected to the external heat source H.

  Of the two second steam passages 20B, the two second steam passages 20B are provided on a straight line connecting the heat receiving portion 33 and the corner portion 32 forming the outer shape of the container 15, and these two The tips of the second steam passages 20 </ b> B are all arranged around the corners 32 corresponding to the heat radiating portions 34. On the other hand, the remaining one second steam passage 20B communicates with the liquid injection passage 17A at the tip thereof. A large number of first steam passages 20A are formed as branch passages from the second steam passage 20B in the respective regions inside the container 15 partitioned by these three second steam passages 20B. Each base end of the passage 20A is connected to one of the three second steam passages 20B. Each tip of the first steam passage 20A extends toward the outer shape of the container 15, and the first steam passage 20A and the second steam passage 20B are arranged so that the steam reaches every corner inside the container 15. Has been.

  The width d8 of the second steam passage 20B shown in FIG. 9 is constant, and is preferably formed in a range of 1 mm to 3 mm (for example, 2 mm). In contrast, the width d9 of the first steam passage 20A is constant, but is equal to or less than the width d8 of the second steam passage 20B (d9 ≦ d8). In this way, when the working fluid in the container 15 evaporates by heat transmitted from the heat source H to the heat receiving unit 33, the steam is smoothly transported to the first steam passage 20A branched from the second steam passage 20B without any delay. It becomes possible to do. Further, when a part of the second steam passage 20B is communicated with the liquid injection passage 17A as in the present embodiment, the second steam passage 20B is not simply used as a steam radiation passage from the heat receiving portion 33, but inside the container 15. Therefore, it can be effectively used as an injection path and a deaeration path for the working fluid radiating to each part, and the manufacturability of the sheet type heat pipe 2 is also improved. Note that the number of the second steam passages 20B is not particularly limited, but preferably two or more.

  Inside the container 15, a wick 22 is formed at a portion excluding the steam passage 20 and the side wall 30. The wick 22 includes the first wick 22A described above, and a second wick 22B that is formed in a straight line with a plurality of the first wick 22A connected to the first wick 22A toward the second passage portion 21B. Everything is configured. For this reason, wicks 22 (first wick 22A and second wick 22B) on which the capillary force acts are formed on both sides of the first steam passage 20A. In particular, in this embodiment, the wick 22 is formed so that all of the first wick 22A and the second wick 22B are connected to the heat receiving portion 33 without being interrupted in the middle. Even if the fluid is condensed, the hydraulic fluid can be returned to the heat receiving portion 33 by the capillary force of the wick 22.

  In this embodiment, a part of the wick 22 and the side wall are formed such that two sheets 11 and 12 having the same shape are overlapped with the inner surfaces thereof inward to form a container 15 for containing the working fluid. 30 is joined and the sheet type heat pipe 2 shown in FIG. 8 is manufactured. At that time, after joining the side wall 30 which becomes an outer peripheral part and performing injection | pouring and deaeration of a hydraulic fluid using the injection nozzle 17 next, this injection nozzle 17 is obstruct | occluded and the sheet | seat type heat pipe 2 is made. The function as the container 15 can be obtained by sealing the inside.

  Inside the container 15, a sealed chamber 13 in a deaerated state in which a working fluid is sealed is formed. Also in this embodiment, only one sealed chamber 13 is formed inside the container 15, and all the steam passages 20 and wicks 22 are disposed in the sealed chamber 13. The sealed chamber 13 includes the above-described liquid injection nozzle 17, and a cylindrical liquid injection passage 17 </ b> A formed in the liquid injection nozzle 17 is provided in communication with the inside of the sealed chamber 13. In the completed state shown in FIG. 8, the liquid injection passage 17A is closed, thereby maintaining the sealed chamber 13 in a sealed state.

  As shown in FIGS. 10 and 11, the detailed configuration of the steam passage 20 and the wick 22 is generally the same as that of the sheet-type heat pipe 1 described above, but the first wick 22A around the corner portion 32 has a flat surface. In addition to the rectangular second wall 27B, the second wall 27B having a different L shape or square shape is also formed. Other configurations are the same as those of the sheet type heat pipe 1.

  As described above, also in this embodiment, the two sheet bodies 11 and 12 are overlapped to form the container 15, and the liquid injection nozzle 17 provided in the container 15 is used to inject and degas the working fluid. Thereafter, the liquid injection nozzle 17 is closed, and the sheet-type heat pipe 2 in which the working liquid is sealed in the sealed chamber 13 inside the container 15 in a vacuum state is manufactured. In the completed sheet heat pipe 2, the heat receiving part 33 and the heat radiating part 34 are naturally formed by installing the heat source H such as a CPU on the outer surface of the container 15. The action of the steam passage 20 and the wick 22 inside the container 15 is as described in the above-described sheet-type heat pipe 1, but the heat transmitted from the external heat source H to the heat receiving part 33 of the sheet-type heat pipe 2 When the internal working fluid evaporates, the steam flows radially from the heat receiving portion 33 through the respective second steam passages 20B with the passage base portion 35 as a base point.

  In particular, in this embodiment, regardless of the orientation of the sheet type heat pipe 2, the two linear second steam passages 20 </ b> B from the heat receiving portion 33 toward the corner portion 32 of the container 15 are configured to receive heat. The steam generated in the portion 33 is transported to the heat radiating portion 34 at the shortest distance, and the condensed hydraulic fluid is again received by the capillary force of the wick 22 in which a number of second wicks 22B are connected to the common first wick 22A. Therefore, it is possible to quickly diffuse the heat from the heat receiving portion 33 to the heat radiating portion 34 in spite of the flat sheet type heat pipe 2. Each of the second steam passages 20B is formed with a large number of first steam passages 20A directed toward the outer shape of the container 15, and the steam generated in the heat receiving portion 33 passes through the second steam passage 20B. Not only the corner portion 32 but also the outer portion other than the corner portion 32 of the container 15 is carried almost evenly through the first steam passage 20A. Moreover, no matter where the steam condenses into the working fluid, the working fluid can be smoothly returned to the heat receiving portion 33 again by the capillary force of the wick 22. In particular, it is possible to perform good thermal diffusion over the container 15 and a wide area of the casing of the portable information terminal that accommodates the container 15.

  The second steam passage 20 </ b> B of the present embodiment extends in different directions inside the container 15 with the passage base portion 35 as a base point. In this way, if at least two or more second steam passages 20B serving as radiation passages are extended, steam can be sent from the heat receiving portion 33 in various directions inside the container 15, It is possible to perform good thermal diffusion with 15 as a whole.

  Further, in the present embodiment, the second steam passages 20B are respectively arranged toward the two corners 32 located on the other side in the short direction of the container 15 when viewed from the heat receiving part 33, and the heat source H moves from the heat source H to the heat receiving part 33. When the working fluid inside the container 15 evaporates due to the transmitted heat, the steam directly flows toward the corner portion 32 that forms the outer shape of the container 15 located far from the heat source H. Preferably, when these second steam passages 20B are formed in a straight line, the steam is transported to the heat radiating portion 34 around the corner portion 32 at the shortest distance, so that better thermal diffusion can be performed throughout the container 15. It becomes possible. Although not specifically shown, the second steam passage 20B may extend toward any corner 32 of the container 15. By forming the width d8 of all the second steam passages 20B in the range of 1 mm to 3 mm, it is possible to smoothly send the steam from the heat receiving portion 33 to the corners in the container 15 through the second steam passage 20B. Become.

  As described above, the sheet-type heat pipe 2 of the present embodiment has two or more sheets 11 and 12 which are metal foil sheets stacked in addition to the features described in the above-described sheet-type heat pipe 1, and is diffusion bonded. And the like. In particular, a steam passage 20 and a wick 22 are formed in the sheet bodies 11 and 12, and the steam passage 20 is formed from a heat receiving portion 33 that is thermally connected to an external heat source H. Thus, a second steam passage 20B serving as a radiation passage going radially, and a plurality of first steam passages 20A branching from the second steam passage 20B toward the outer peripheral portion of the container 15 are formed.

  In this case, by stacking two or more sheet bodies 11 and 12, the fine vapor passage 20 and the wick 22 having sufficient heat transport capability can be formed on the inner surface of the container 11. Moreover, the sheet-type heat pipe 2 which is thinner than a round heat pipe and has sufficient heat transport capability can be provided by stacking and joining the sheet bodies 11 and 12 to form a sealed container 15. Therefore, the sheet-type heat pipe 2 can be easily and easily installed in a thin casing such as a portable information terminal. Furthermore, when the hydraulic fluid inside the container 15 evaporates due to the heat transmitted from the external heat source H to the heat receiving unit 33, the steam flows radially from the heat receiving unit 33 through the second vapor passage 20B. Therefore, good heat diffusion can be performed over the container 15 and thus a wide region of the housing that accommodates the container 15, and the performance of, for example, a CPU serving as the heat source H can be sufficiently exhibited.

  In this embodiment, a plurality of the second steam passages 20B are formed in at least two or more.

  In this case, by forming at least two or more second steam passages 20B instead of one, steam can be sent from the heat receiving portion 33 in various directions inside the container 15, and the container 15 as a whole is good. Thermal diffusion can be performed.

  In the present embodiment, the second steam passage 20B is formed on a line connecting the heat receiving portion 33 and the corner portion 32 which is the outer shape of the container 15.

  In this case, when the working fluid inside the container evaporates, the steam flows toward the corner 32 of the container 15 located far from the heat source H, so that the entire container 15 can perform better thermal diffusion. Is possible.

  Furthermore, in this embodiment, the width d8 of the second steam passage 20B is formed in the range of 1 mm to 3 mm.

  In this case, by forming the width d8 of the second steam passage 20B in the range of 1 mm to 3 mm, it becomes possible to smoothly send the steam from the heat receiving portion 33 through the second steam passage 20B to the inside of the container 15 without delay. .

  FIGS. 12-14 has shown the sheet | seat type heat pipe 3 in 2nd Example of this invention. In each of these drawings, the completed sheet-type heat pipe 3 shown in FIG. 12 is provided with a liquid injection nozzle 17 projecting from one end in the longitudinal direction of a container 15 formed in a substantially rectangular flat plate shape. However, as described above, the liquid injection nozzle 17 that does not protrude from the container 15 or the attachment portion 18 may be provided. H is the heat source described in the first embodiment, and is arranged at a substantially central portion of the container 15 in this embodiment. Therefore, in the sheet-type heat pipe 3 of the second embodiment, the central portion of the container 15 to which the heat source H is thermally connected becomes the heat receiving portion 33, and for example, both longitudinal end portions of the container 15 away from the heat source H become the heat radiating portion 34. . The other external configuration is the same as that of the sheet type heat pipe 2 of the first embodiment.

  FIG. 13 is a plan view of the second sheet body 12, and FIG. 14 is a plan view of the second sheet body 12 showing another modification. In this case, the first sheet body 11 has the same shape as the second sheet body 12.

  The second sheet body 12 of FIG. 13 will be described. Here, in the sealed container 15, a plurality of concave first passage portions 21A formed side by side along the longitudinal direction of the sheet bodies 11 and 12, and the container A concave second passage portion 21B formed in the four directions from the center of the 15 and a third passage formed along the outer periphery of the container 15 and connected to one end of all the first passage portions 21A and the second passage portions 21B The portion 21 </ b> C is configured as a passage portion of the steam passage 20. Then, when the sheet bodies 11 and 12 are stacked with the one side facing each other, the first passage portions 21A of the sheet bodies 11 and 12 face each other, thereby forming a hollow cylindrical first steam passage 20A. When the second passage portions 21B of the bodies 11 and 12 face each other, a hollow cylindrical second steam passage 20B is formed, and when the third passage portions 21C of the sheet bodies 11 and 12 face each other, a hollow tubular shape is formed. The third steam passage 20C is formed. At this time, a steam passage 20 including a first steam passage 20A, a second steam passage 20B, and a third steam passage 20C is disposed inside the container 15.

  In the region of the heat receiving part 33 having a shape corresponding to the heat source H, a passage base part 35 to which the base ends of the four second steam passages 20B are connected is arranged, and viewed from the passage base part 35 toward the outer shape part of the container 15. Thus, each of the second steam passages 20B extends radially or in a cross shape. That is, it can be said that the steam passage 20 of the present embodiment forms the linear second steam passage 20 </ b> B inside the container 15 as a radiation passage that goes radially as viewed from the heat receiving portion 33 thermally connected to the external heat source H. In the present embodiment, the liquid injection passage 17A communicates with the third steam passage 20C.

  All the second steam passages 20 </ b> B have their tips connected to the third steam passage 20 </ b> C, and the third steam passages 20 </ b> C are continuously formed along the outer periphery of the container 15 without being interrupted. In addition, a large number of first steam passages 20A are formed as branch passages in each of the four regions inside the container 15 partitioned by the second steam passages 20B, and the base ends of all the first steam passages 20A are 3 is connected to the steam passage 20C. Thus, the first steam passage 20A, the second steam passage 20B, and the third steam passage 20C are arranged so that the steam reaches every corner in the container 15.

  Inside the container 15, a wick 22 is formed at a portion excluding the steam passage 20 and the side wall 30. In particular, in the present embodiment, the pattern of the wick 22 is used for the purpose of sufficiently equalizing the sheet type heat pipe 3 itself and reducing the temperature difference (heat resistance of heat connection) between the heat source H and the heat receiving portion 33. The shape is reviewed. Specifically, the first wick 22A formed on substantially the entire circumference of the outer periphery of the sheet bodies 11 and 12 and the container 15 except for the portion of the liquid injection passage 17A communicating with the third steam passage 20C, the container 15 In addition to a plurality of second wicks 22B that are formed in a straight line along the longitudinal direction, a plurality of second wicks 22B are provided for each of the four regions inside the container 15 defined by the second steam passage 20B. All the wicks 22 are constituted by the third wick 22C for connecting the one ends thereof. In the first embodiment, the first wick 22A and the second wick 22B are connected. In the present embodiment, the first wick 22A is connected to the second wick 22B or the third wick 22C because the third steam passage 20C is disposed. Not connected to wick 22C. However, as a modification, the first wick 22A may be connected to the second wick 22B or the third wick 22C.

  The wick 22 of the present embodiment includes a plurality of second wicks 22B that are pattern portions arranged at regular intervals, four third wicks 22C that are connecting portions that connect the second wicks 22B, and second wicks 22B. In addition, it can be said that the first wick 22A serving as a circulating portion surrounding the entire third wick 22C is provided. In particular, any part of the second wick 22B extends to the area of the heat receiving portion 33. Even if the steam is condensed in any place in the steam passage 20, the working liquid is obtained. Can be collected in the heat receiving portion 33 by capillary force from the second wick 22B to the third wick 22C.

  The width d11 of the third wick 22C is wider than the width d10 of the second wick 22B (d11> d10), and preferably the width d11 of the third wick 22C is twice the width d10 of the second wick 22B. Formed. This is because, when a plurality of second wicks 22B are connected to one third wick 22C, the hydraulic fluid recovered by the second wick 22B having the narrow width d11 is kept in the third wick 22C having the wide width d10. This is because they are smoothly collected and returned to the heat receiving portion 33. The width d10 of the second wick 22B and the width d11 of the third wick 22C are formed with constant dimensions at any location, but may be formed with partially different dimensions.

  Next, a modification of the second sheet body 12 shown in FIG. 14 will be described. Here, two second steam passages 20 </ b> B extend radially toward one end and the other end of the outer shape of the container 15 when viewed from the passage base 35. Moreover, the 3rd wick 22C which connects the end of several 2nd wick 22B for every 2 area | region inside the container 15 divided by the 2nd steam channel | path 20B is arrange | positioned. Here, all of the third wick 22C extends in the region of the heat receiving portion 33, and the operation of the third wick 22C is performed regardless of where the steam condenses into the working fluid. The liquid can be collected in the heat receiving portion 33 by the capillary force of the wick 22 through the third wick 22C from the second wick 22B adjacent thereto. That is, the second sheet body 12 shown in FIG. 14 is different from the second sheet body 12 shown in FIG. 13 except for the number of second steam passages 20B and third wicks 22C.

  In addition, since the manufacturing method of the sheet-type heat pipe 3 is the same as that of the first embodiment, the description thereof is omitted. In addition, the configuration of the sheet type heat pipe 3 including details of the steam passage 20 and the wick 22 is generally the same as that of the sheet type heat pipe 2 of the first embodiment.

 In the completed sheet heat pipe 3, the heat receiving part 33 and the heat radiating part 34 are naturally formed by installing a heat source H such as a CPU on the outer surface of the container 15. The action of the steam passage 20 and the wick 22 inside the container 15 is as described in the above-described sheet type heat pipes 1 and 2, but with heat transmitted from the external heat source H to the heat receiving part 33 of the sheet type heat pipe 3, When the working fluid inside the container 15 evaporates, steam flows radially from the heat receiving portion 33 through the respective second steam passages 20B from the passage base 35 to the third steam passage 20C. As a result, the steam circulates along the outer shape of the container 15 and flows into the first steam path 20A from the third steam path 20C. As a result, the steam generated in the heat receiving section 33 is transferred to the heat radiating section 34 in the container 15. Can be spread throughout.

  In addition, the hydraulic fluid is scarce in the heat receiving portion 33 that receives the heat supply from the heat source H, while the hydraulic fluid is excessive in a portion such as the heat radiating portion 34 that is away from the heat receiving portion 33. Therefore, in this embodiment, the pattern shape of the wick 22 inside the container 15 is completely reviewed, and the steam generated in the heat receiving portion 33 is transferred to the steam path inside the container 15 regardless of the posture of the sheet heat pipe 3. Even if it is condensed in any part of 20 to become a working fluid, the working fluid is collected by the second wick 22B by the capillary force of the wick 22, and collected in the third wick 22C connected to each second wick 22B. The heat receiving section 33 can be supplied. Therefore, the hydraulic fluid remaining in the container 15 is collected by the second wick 22B of the wick and collected in the third wick 22C at a site away from the heat receiving portion 33, and this is collected in the heat receiving portion 33 where the hydraulic fluid tends to be insufficient. By supplying, the working fluid inside the container 15 can be effectively used to make the temperature distribution of the entire container 15 uniform and to improve local hot spots in the heat receiving section 33. Therefore, the arrangement of the steam passage 20 described above, together with the distribution of steam from the heat receiving portion 33 to the entire inside of the container 15, makes it possible to sufficiently exhibit the performance of, for example, a CPU serving as the heat source H. Become.

  FIG. 15 shows various experimental results by comparing the “before improvement” sheet type heat pipe 3 ′ as the conventional example with the “after improvement” sheet type heat pipe 3 as the present example shown in FIG. 13. Is shown.

  In these drawings, the outer dimensions of the sheet-type heat pipes 3 and 3 ′ are 130 mm in the longitudinal direction, 46 mm in the lateral direction, and 0.4 mm in thickness. The pattern shape of the wick 22 is “Wick As shown in “Pattern”. In the drawing, some symbols are omitted.

  The “IR image” shows the temperature distribution of the sheet-type heat pipes 3 and 3 ′ when 6 W is input to the CPU with the heat source H as the CPU. In the figure, “a” is the temperature of the heat receiving portion 33 of the sheet type heat pipes 3 and 3 ′, and other “b” to “g” are the temperatures at the respective outer peripheral portions of the sheet type heat pipes 3 and 3 ′. is there.

  The “CPU temperature” is the temperature of the CPU serving as the heat source H. The sheet-type heat pipe 3 ′ of the conventional example is 78.2 ° C., whereas the sheet-type heat pipe 3 of the present embodiment is 70.2 ° C. Thus, a temperature drop of 8 ° C. was confirmed. The “SHP heat receiving part temperature” is the temperature of the heat receiving part 33 corresponding to the “a” part, and the sheet type heat pipe 3 ′ of the conventional example has a temperature of 67.2 ° C., whereas the sheet type of the present example. The heat pipe 3 was 61.0 ° C.

  The “heat receiving heat resistance” is the heat resistance of the heat receiving unit 33, and is calculated as a value obtained by subtracting the “SHP heat receiving unit temperature” from the “CPU temperature” divided by the input wattage (6 W in this case). The sheet type heat pipe 3 ′ of the conventional example has a heat resistance of the heat receiving portion 33 of 1.83 ° C./W, whereas the sheet type heat pipe 3 of the present embodiment has a heat resistance of the heat receiving portion 33 of 1. It was 0.53 ° C / W, an improvement of 16.4%. That is, the sheet-type heat pipe 3 of the present embodiment is devised in the pattern shape of the wick 22 facing the heat source H, and the above-described third wick 22C is arranged there, so that the sheet-type heat pipe 3 ′ of the conventional example is arranged. As a result, the temperature difference between the heat source H and the heat receiving portion 33 can be reduced, and as a result, improvement of the heat spot in the heat receiving portion 33 was confirmed. The reason is that in the conventional sheet-type heat pipe 3 ′, the wicks 22 are not connected to each other, so that the hydraulic fluid does not sufficiently return to the heat receiving portion 33 corresponding to the heat source H. This is because in the sheet type heat pipe 3, the second wicks 22 </ b> B are connected by the heat receiving unit 33 by the third wicks 22 </ b> C so that a large amount of hydraulic fluid is supplied to the heat receiving unit 33.

  In addition, the “SHP right end temperature” is the temperature in the “g” part, and “ΔT1” is a value obtained by subtracting the “SHP right end temperature” from the “SHP heat receiving part temperature”. The sheet-type heat pipe 3 ′ of the conventional example has a temperature at the “g” portion of 54.0 ° C. and a difference from the “SHP heat receiving portion temperature” of 13.2 ° C. In the pipe 3, the temperature in the “g” part was 56.6 ° C., and the difference from the “SHP heat receiving part temperature” was relaxed to 4.4 ° C.

  The “SHP left end temperature” is the temperature in the “e” part, and “ΔT2” is a value obtained by subtracting the “SHP left end temperature” from the “SHP heat receiving part temperature”. The sheet-type heat pipe 3 ′ of the conventional example has a temperature at the “e” portion of 56.2 ° C. and a difference from the “SHP heat receiving portion temperature” of 11.0 ° C. The temperature of the pipe 3 at the “e” portion was 56.4 ° C., and the difference from the “SHP heat receiving portion temperature” was relaxed to 4.6 ° C. again. From the above results, the sheet type heat pipe 3 of this example has a smaller temperature difference between the heat receiving portion 33 and the outer peripheral end than the sheet type heat pipe 3 ′ of the conventional example, and the sheet type heat pipe 3 itself. It was confirmed that soaking was sufficiently improved.

  As described above, the sheet-type heat pipe 32 of the present embodiment has, in addition to the features described in the above-described sheet-type heat pipe 1, two or more sheet bodies 11 and 12 serving as metal foil sheets are stacked to perform diffusion bonding or the like. The sealed container 15 is formed by joining, and in particular, the steam passages 20 and the wicks 22 are formed in the sheet bodies 11 and 12, and the wick 22 is a first pattern portion formed in the container 15. The second wick 22B has a third wick 22C as a connecting portion that connects the plurality of second wicks 22B. The third wick 22C is formed in a heat receiving portion 33 that is thermally connected to an external heat source H.

  In this case, the pattern shape of the wick 22 is reviewed, and the working fluid remaining in the container 15 is collected by the second wick 22B of the wick 22 and collected in the third wick 22C at a site away from the heat receiving portion 33, and this is operated. The liquid is supplied to the heat receiving part 33 that tends to be deficient so that the working liquid inside the container 15 can be used effectively. As a result, the temperature distribution and local hot spots of the entire container 15 can be improved, and the performance of the heat source H, such as a CPU, can be sufficiently exhibited.

  In the present embodiment, the pattern shape of the wick 22 in which the width d11 of the third wick 22C is formed wider than the width d10 of the second wick 22B is employed.

  In this case, the hydraulic fluid collected by each second wick 22B can be collected without delay in the wider third wick 22C and supplied to the heat receiving unit 33, and the temperature distribution and local distribution of the entire container 15 can be reduced. Improvement of hot spots can be effectively promoted.

  The pattern shape of the wick 22 proposed in the present embodiment can be variously modified depending on the position of the heat receiving portion 33 in the container 15. In FIG. 16, as another modified example, a comparison is made between the “before improvement” sheet type heat pipe 4 ′ as a conventional example and the “after improvement” sheet type heat pipe 4 as this modification example. The overall temperature distribution and numerical values of each part are shown as experimental results. The outer dimensions of the sheet type heat pipes 4 and 4 ′ are 150 mm in the longitudinal direction and 136 mm in the short direction.

  First, the “pattern arrangement” in the figure will be described. A conventional sheet type heat pipe 4 ′ has a pattern shape in which the wicks 22 are not connected to each other like the sheet type heat pipe 3 ′. On the other hand, in the sheet type heat pipe 4 of the present modification, the pattern shape in which the second wicks 22B are connected to the heat receiving unit 33 by the third wicks 22C so that a large amount of hydraulic fluid is supplied to the heat receiving unit 33. It has become. In this case as well, some symbols are omitted from the drawing.

  The “temperature distribution” indicates the temperature distribution of the sheet type heat pipes 4 and 4 ′ when 8 W is input to the heat source H. In the figure, “A” is the temperature of the heat receiving part 33 of the sheet type heat pipes 4, 4 ′, and “B” to “K” other than that are the temperatures in each part other than the heat receiving part 33. Regarding the temperature of the heat source H, the sheet type heat pipe 4 ′ of the conventional example is 88.8 ° C., whereas the sheet type heat pipe 3 of the present modification is 83.5 ° C., which is a temperature of 4.5 ° C. A decrease was confirmed. Further, the temperature of the heat receiving portion 33 corresponding to the “A” portion is 60.01 ° C. in the sheet heat pipe 4 ′ of the conventional example, whereas it is 52.69 ° C. in the sheet heat pipe 3 of the present embodiment. It was confirmed that the heat spot in the heat receiving portion 33 was improved.

  Regarding the temperature difference between the heat receiving part 33 and other parts, the sheet-type heat pipe 4 ′ of the conventional example is the most among the temperatures of the “A” part corresponding to the heat receiving part 33 and the parts other than the heat receiving part 33. The difference between the low "K" temperature is 26.67 ° C, while the difference between the "A" temperature and the "K" temperature is relaxed to 16.53 ° C. Also here, it was confirmed that the soaking of the sheet type heat pipe 4 itself was sufficiently improved.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of this invention. For example, in the above embodiment, the sheet bodies 11 and 12 are diffusion-bonded, but another bonding method such as ultrasonic bonding may be adopted, and three or more sheet bodies 11 and 12 are overlapped and bonded. May be. The shapes and dimensions of the respective parts described above are merely examples, and can be appropriately changed without departing from the gist of the present invention. Further, the sheet bodies 11 and 12 do not need to have the same shape. Furthermore, it is good also as a sheet | seat type heat pipe which combined suitably the characteristic of each part demonstrated in each said Example.

2,3,4 sheet heat pipe 11,12 sheet body (metal foil sheet)
15 Container 20 Steam passage 20A First steam passage (radiation passage)
22 wick 22B 2nd wick (pattern part)
22C 3rd wick (connection part)
32 Corner 33 Heat-receiving part H Heat source

Claims (6)

A sheet type heat pipe formed by stacking two or more metal foil sheets and forming a sealed container by bonding,
The metal foil sheet is formed with a steam passage and a wick,
The sheet-type heat pipe is characterized in that the steam passage is formed with a radial passage as seen from a heat receiving portion thermally connected to an external heat source.   The sheet-type heat pipe according to claim 1, wherein a plurality of the radiation paths are formed in at least two or more.   The sheet-type heat pipe according to claim 1 or 2, wherein the radiation passage is formed on a line connecting the heat receiving portion and an outer corner portion of the container.   The sheet-type heat pipe according to any one of claims 1 to 3, wherein a width of the radiation passage is in a range of 1 mm to 3 mm.   A sheet-type heat pipe formed by stacking two or more metal foil sheets to form a sealed container by bonding, wherein the metal foil sheet is formed with a steam passage and a wick, and the wick is disposed inside the container. The sheet-type heat is characterized in that a large number of pattern portions are formed on the substrate and a plurality of connection portions that connect the plurality of pattern portions to each other, and the connection portions are formed in a heat receiving portion that is thermally connected to an external heat source. pipe. 6. The sheet-type heat pipe according to claim 5, wherein a width of the connecting portion is formed wider than a width of the pattern portion.