Manufacturing method of sheet-shaped heat pipe and sheet-shaped heat pipe

Abstract

To provide a manufacturing method of a reasonable sheet-shaped heat pipe having sufficient heat diffusion performance, and simplified in the manufacturing method.SOLUTION: In a sheet-shaped heat pipe 1 molded by pressing first sheet bodies 11 and second sheet bodies 12 whose materials are stainless steel, or alloy metals with the stainless steel as main components, and having a hollow vessel 15 into which a working fluid is sealed by laminating and joining two pieces or more of the first sheet bodies 11 and the second sheet bodies 12 including the moldings, a flat plate-shaped wick 31 containing a metal of copper, stainless steel or titanium is provided in the vessel 15, columns 11C which are formed by recessing surface side parts of the first sheet bodies 11 by press throttle processing are provided at least at either of the first sheet bodies 11 and the second sheet bodies 12, and a wick 31 is pressed by the columns 11C.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a sheet-shaped heat pipe that can be mounted on a mobile device such as a smartphone or a tablet terminal, and that is small yet provides a sufficient amount of heat transport, and to a manufacturing method thereof and a sheet-shaped heat pipe. [Background technology]

[0002] Conventionally, in order to dissipate heat generated by a CPU mounted on a mobile device such as a smartphone or tablet terminal, a heat dissipation structure incorporating a sheet-shaped heat pipe has been proposed, as shown in Patent Documents 1 to 4, for example. In such a sheet-shaped heat pipe, a sealed container is formed by overlapping and bonding two or more sheets made of metal foil, and the working fluid is circulated between the heat receiving part and the heat dissipating part of the sheet-shaped heat pipe by utilizing the capillary force of a wick provided inside the container, and the heat from the CPU thermally connected to the heat receiving part is transported to the heat dissipating part and dissipated to the outside of the mobile device. In order to easily mount a sheet-shaped heat pipe inside a mobile device that is becoming thinner, it has been desired to make the sheet-shaped heat pipe thinner without impairing its heat diffusion performance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-050682 A [Patent Document 2] JP 2016-017702 A [Patent Document 3] JP 2018-204841 A [Patent Document 4] JP 2018-189320 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional sheet-type heat pipes, etching is performed on sheet-type metal foil to form the space inside the container in which the working fluid is sealed, which requires technical skills for part processing and leads to increased costs. Also, in order to achieve sufficient thermal diffusion performance as a sheet-type heat pipe, it is necessary to secure a certain amount of space volume inside the container, and such sufficient thermal diffusion is difficult. It has been difficult to simplify the production method while maintaining the dispersion performance.

[0005] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to solve the above problems and provide a sheet-shaped heat pipe that has sufficient thermal diffusion performance and is manufactured in a simplified manner at a reasonable cost, and to provide a manufacturing method thereof and a sheet-shaped heat pipe. [Means for solving the problem]

[0006] The sheet-shaped heat pipe according to the present invention is a sheet-shaped heat pipe having a hollow container in which a working fluid is sealed, which is formed by pressing a metal foil made of stainless steel or an alloy metal mainly composed of stainless steel, stacking two or more sheets of the metal foil including the formed product, and joining flange parts, and is characterized in that a flat wick made of any metal of copper, stainless steel, or titanium is provided inside the container, and at least one of the metal foils has a column formed by recessing the surface side of the metal foil by press drawing, and the column holds the wick. Also, the manufacturing method of the sheet-shaped heat pipe according to the present invention is characterized in that a metal foil made of stainless steel or an alloy metal mainly composed of stainless steel is pressed, stacking two or more sheets of the metal foil including the formed product, and joining flange parts to form a hollow container in which a working fluid is sealed, and a flat wick made of any metal of copper, stainless steel, or titanium is provided inside the container, and at least one of the metal foils has a column formed by recessing the surface side of the metal foil by press drawing, and the column holds the wick. Effect of the Invention

[0007] According to the present invention, it is possible to provide an etching-less sheet-shaped heat pipe that has sufficient heat diffusion performance and can be manufactured by a simplified method at reasonable cost. [Brief description of the drawings]

[0008] [Figure 1] 1 is a longitudinal sectional view of a main portion of a sheet-shaped heat pipe according to a first embodiment of the present invention. [Diagram 2] FIG. 4 is a plan view of the first sheet body before bonding according to the first embodiment. [Diagram 3] FIG. 3 is an enlarged perspective view of a main part of FIG. 2 according to the first embodiment. [Figure 4] FIG. 11 is a plan view of a first sheet body before bonding in a sheet-shaped heat pipe of another shape according to the first embodiment. [Diagram 5] FIG. 13 is a front view of a sheet-shaped heat pipe having a different shape, in which a heat dissipation component and a heat generating component are thermally connected to a container. [Figure 6] FIG. 11 is a plan view of the sheet-shaped heat pipe of the second embodiment before the nozzle tip is cut off. [Figure 7] FIG. 11 is a vertical cross-sectional view of two adjacent pillars. [Figure 8] FIG. 11 is a vertical cross-sectional view of an example pillar. [Figure 9] FIG. 11 is a vertical cross-sectional view of another example of a pillar according to the same embodiment. [Figure 10] FIG. 11 is a vertical cross-sectional view of yet another example of a pillar according to the same embodiment. [Figure 11] FIG. 11 is a longitudinal sectional view of a main part of a sheet-shaped heat pipe in which one pressed molded piece and one non-pressed non-molded piece are stacked together. [Figure 12] FIG. 11 is a longitudinal sectional view of a main portion of a sheet-shaped heat pipe formed by stacking two pressed molded pieces. [Figure 13] FIG. 2 is a longitudinal cross-sectional view of a main portion of a sheet-shaped heat pipe having a pillar disposed on the heat dissipation side according to the first embodiment. [Figure 14] FIG. 2 is a longitudinal cross-sectional view of a main portion of a sheet-shaped heat pipe in which a pillar is arranged on the heat receiving portion side of the sheet-shaped heat pipe of the first embodiment. [Figure 15]FIG. 11 is a longitudinal cross-sectional view of a main portion of a sheet-shaped heat pipe having pillars on both the heat dissipation side and the heat reception side. [Figure 16] FIG. 4 is a partially enlarged view of the mesh wick of the same embodiment. [Figure 17] FIG. 4 is a plan view of the metal foil wick of the same embodiment. [Figure 18] FIG. 2 is a right side view of the metal foil wick of the same embodiment. [Figure 19] FIG. 4 is a bottom view of the metal foil wick of the same embodiment. [Figure 20] 18 is a cross-sectional view taken along line XX in FIG. 17. [Figure 21] 13 is a photograph showing a wick made of nonwoven fabric after sintering a metal wire. [Figure 22] 22A and 22B are partially enlarged photographs of the surfaces of the nonwoven fabric shown in FIG. 21, showing (A) the web fiber side and (B) the straight fiber side. [Diagram 23] 4 is a photograph of the first sheet body shown in FIG. 2 and FIG. [Figure 24] FIG. 24 shows the temperature distribution at each part of a sheet-shaped heat pipe completed using the first sheet body of FIG. 23, which is an experimental result. [Diagram 25] FIG. 6 is a longitudinal sectional view of a main part of a sheet-type heat pipe according to a second embodiment of the present invention. [Figure 26] This is a photo of multiple wicks stacked and stored in the wick storage compartment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In the following, several preferred embodiments of the present invention will be described using as examples a sheet-shaped heat pipe (hereinafter referred to as "SHP") mounted on a mobile device such as a smartphone, tablet terminal, etc. In the description of each embodiment, common parts are given common reference numerals, and descriptions of common parts are omitted as much as possible to avoid duplication.

[0010] 1 to 4 show the external configuration of the SHP1 in the first embodiment of the present invention. In each of these figures, the SHP1 is composed of a container 15 formed by overlapping and bonding two sheets of metal foil, a first sheet 11 and a second sheet 12. The sheets 11 and 12 forming the outer shell of the SHP1 are formed into a desired shape from metal foil having a certain degree of thermal conductivity as a metal and a hardness (rigidity) that makes the SHP1 easy to handle and not easily deform before the completed SHP1 is incorporated into the housing of a mobile device (not shown). The material of the metal foil that meets these requirements is preferably, for example, stainless steel, titanium, copper, or an alloy metal containing these as a main component. Also, two or more sheets of metal foil, for example, three sheets of metal foil, may be stacked and bonded to form the hollow container 15. The thicknesses of the metal foils that form the sheets 11 and 12, i.e., wall thicknesses t1 and t2, are preferably less than 0.1 mm in order to accommodate the thinning of mobile devices.

[0011] As shown in Fig. 2 and Fig. 4, a cylindrical nozzle 17 is extended from the container 15 in order to seal and store a liquid-phase working fluid (not shown) such as pure water in a vacuum state inside the container 15. Although not shown in Fig. 2, the nozzle 17 has an opening 17A that communicates the inside and outside of the container 15, and by finally closing the opening 17A, the thickness T0 of the sealed container 15 and therefore the SHP 1 is made less than 0.4 mm in response to the trend toward thinner mobile devices. This thickness T0 corresponds to the total thickness of the entire SHP 1, which is made by stacking two or more metal foils. After the opening 17A is closed, the tip 17B of the nozzle 17 is cut off leaving the base end, and the SHP 1 is completed with the container 15 still sealed. The completed SHP1 has an outer shape that matches the internal shape of the housing of a mobile device such as a smartphone or tablet terminal. For example, when the shape of the first sheet body 11 is as shown in Figures 2 and 4, the SHP1 has a roughly rectangular flat plate shape when viewed from above. However, an SHP1 having a polygonal flat plate shape when viewed from above may be completed from a first sheet body 11 of a different shape (not shown).

[0012] As described above, the completed SHP1 is installed as it is inside the housing of the mobile device. At this time, the surface portion of the SHP1 that is in thermal contact with the heat source (e.g., CPU) of the mobile device is formed as a heat receiving portion (not shown), and a portion of the SHP1 that is in thermal contact with the heat diffusion member of the mobile device (e.g., touch panel or back cover) is formed as a heat dissipation portion (not shown) at a location separate from the heat receiving portion. The location on the surface portion of the SHP1 where the heat receiving portion that receives heat from the heat source and the heat dissipation portion that transfers heat to the heat diffusion member are formed depends on the internal configuration of the mobile device.

[0013] The first sheet body 11 forming one side of the SHP1 is composed of a concave sheet surface portion 11A forming one side of the outer shell of the bag-shaped container 15, a frame-shaped flange portion 11B formed around the entire periphery of the sheet surface portion 11A in a plan view, and a plurality of supports 11C formed in spots protruding inward from the sheet surface portion 11A. Among these, the sheet surface portion 11A and the supports 11C are formed by drawing a flat metal foil without any unevenness before processing into a desired shape by press drawing, which is a type of press processing. At the same time as forming the sheet surface portion 11A and the supports 11C, a groove portion that becomes the opening 17A of the nozzle 17 can also be formed.

[0014] The second sheet body 12 forming the other side of the SHP1 is composed of a flat sheet surface portion 12A forming the other outer side surface of the container 15, and a frame-shaped flange portion 12B formed around the entire periphery of the sheet surface portion 12A in a plan view. The second sheet body 12 shown in Fig. 1 is a flat metal foil without any unevenness before processing, which is stacked on the first sheet body 11 without processing. In this case, the portion facing the sheet surface portion 11A of the first sheet body 11 becomes the sheet surface portion 12A of the second sheet body 12, and the portion facing and abutting the flange portion 11B of the first sheet body 11 becomes the flange portion 12B of the second sheet body 12.

[0015] In this embodiment, the first sheet body 11 and the second sheet body 12 are stacked so that the opening of the sheet surface portion 11A of the first sheet body 11 is closed by the sheet surface portion 12A of the second sheet body 12, and a concave steam passage 21 for circulating the working fluid mainly in the gas phase and a wick storage portion 22 for storing the wick 31 for circulating the working fluid mainly in the liquid phase are formed inside the container 15 in which the working fluid is sealed. These steam passage 21 and wick storage portion 22 are formed by press drawing to form the concave sheet surface portion 11A in the above-mentioned metal foil. The wick storage portion 22 corresponds to a portion corresponding to the outer shape of the wick 31 arranged inside the container 15, and the other internal portion of the container 15 becomes the steam passage 21.

[0016] The flange portions 11B, 12B are positioned so that they come into contact and overlap when the inner surfaces of the sheet bodies 11, 12 are placed facing each other, and by joining these together without any gaps using either brazing, laser welding, or diffusion bonding, an outer periphery 16 is formed that surrounds the container 15 of the SHP1.

[0017] Inside the container 15, a sealed chamber in a degassed state in which the working fluid is sealed is formed. This sealed chamber is composed of a vapor passage 21 for transporting the working fluid in the gas phase evaporated in the heat receiving section to the heat dissipating section, and a wick storage section 22 equipped with a sheet-like wick 31 for returning the working fluid in the liquid phase condensed in the heat dissipating section to the heat receiving section. The wick 31 is, for example, a sheet having a thickness of 0.1 mm or less, and is enclosed in the wick storage section 22 separately from the container 15. In order to generate a strong capillary force in the working fluid in the liquid phase, the wick 31 is made of a porous body including powder sintered from a metal such as copper, stainless steel, or titanium, and is configured to have gaps 32 that become fine holes evenly throughout the entire wick. In this embodiment, in order to prevent the container 15 from being crushed by atmospheric pressure, a large number of support columns 11C that abut against the wick 31 arranged in the wick storage section 22 are formed at the same height only in the first sheet body 11 toward the sheet surface section 12A of the second sheet body 12. The specific configurations of the wick 31 and the support 11C will be described in detail later.

[0018] In this embodiment, first, two flat sheets of metal foil, each with a thickness of less than 0.1 mm, are prepared. One of the metal foils is shaped by press drawing to form an uneven molded product having a first sheet surface portion 11A and support pillars 11C as the first sheet body 11, while the other metal foil is left as a non-molded product to be made into the second sheet body 12.

[0019] Next, a flat wick 31 is placed on the inner surface of the second sheet body 12 at a portion corresponding to the wick storage section 22, and the sheet bodies 11 and 12 obtained from two metal foils having the same outer shape in a planar view are stacked so that the inner surfaces of the sheets face inward and the sheet surface portions 11A and 11B face each other, sandwiching the wick 31. Then, the flange portions 11B and 12B of the sheet bodies 11 and 12 are joined so that a bag-shaped container 15 with a hollow interior is formed, and the SHP1 is manufactured. At this time, the flange portions 11B and 12B that form the outer periphery of the SHP1 are joined, and then the nozzle 17 that communicates with the interior of the container 15 is used to inject a liquid-phase working fluid and degas (evacuate), and then the nozzle 17 is closed to seal the interior of the SHP1, thereby obtaining the function of the container 15, and the tip portion 17B of the nozzle 17 is cut off to complete the final manufacture of the SHP1. Therefore, in the completed SHP 1, a sealing portion 18 (see FIG. 6) for keeping the inside of the container 15 sealed is provided at the base end of the nozzle 17 as a mark for closing the opening 17A of the nozzle 17.

[0020] The completed SHP1 can have any shape that matches the internal shape of the housing of the mobile device, other than a substantially rectangular or polygonal plate shape in plan view. The SHP1 shown in Fig. 1 is formed to have a uniform thickness T0, preferably less than 0.4 mm, in all areas other than where the pillars 11C of the container 15 are provided, but by taking advantage of the press drawing process, the thickness T0 of the SHP1 may be changed in stages and / or continuously.

[0021] For example, in the SHP1 shown in FIG. 5, when the heat source 41 that becomes a heat-generating component and the heat-dissipating member 42 that becomes a heat-dissipating component are arranged at different heights within the housing 43 of the portable device, the SHP1 installed within the housing 43 of the portable device as well has different thicknesses T0a of the container 15 on the heat-receiving portion 44 side that contacts the heat source 41 and T0b of the container 15 on the heat-dissipating portion 45 side that contacts the heat-dissipating member 42 so as to be in close contact with and thermally connect to these heat source 41 and heat-dissipating member 42 (T0a < T0b). Further, as going from the heat-receiving portion 44 to the heat-dissipating portion 45 of the SHP1, the thickness Toc of the container 15 continuously changes so as to gradually increase. Such thickness of the container 15 can be easily obtained simply by appropriately adjusting the depth of the concave sheet surface portion 11A with a press machine (not shown) when forming the first sheet body 11 by press drawing from a metal foil having a constant thickness. With the conventional etching process, it is not possible to obtain the shape of the container 15 as shown in FIG. 5 from a metal foil having a constant thickness.

[0022] FIG. 6 shows the SHP1 before separating the tip portion 17B of the nozzle 17 in the manufacturing process of the SHP1. However, two or more nozzles 17 may be provided at any position of one container 15. In the example shown in FIG. 6, nozzles 17 having the same shape are respectively provided on one short side and the other short side which are different sides of the container 15 in plan view. Further, the tip portion 17B of the nozzle 17 is formed in a cylindrical shape protruding outward from the short side of the container 15 so that the injection of the working fluid and the evacuation can be easily performed in the manufacturing process of the SHP1. The opening 17A of the nozzle 17 described above also extends to the tip portion 17B to communicate the inside and outside of the container 15, and the base of the tip portion 17B has a configuration that can be separated relatively easily, for example, by forming a notch.

[0023] In this embodiment, the working fluid can be injected into the container 15 and the container 15 can be evacuated from the inside not only at the same place but also at a plurality of different places. When an oxide film for improving wettability is to be attached to the inner surface of the container 15, if an oxide film material is injected from the nozzle 17 at one place of the container 15, the oxide film will only be attached around the nozzle 17, resulting in uneven attachment. However, if the oxide film material is injected from the nozzle 17 at a plurality of places of the container 15, the uneven attachment of the oxide film on the inner surface of the container 15 can be improved. After such operations are completed, the opening 17A of the nozzle 17 is closed with the sealing part 18 and the tip part 17B is cut off from its base, so that the nozzle 17 does not protrude from the container 15 in the SHP 1 in the product state after the manufacturing process is completed, and the sealing parts 18 provided on each nozzle 17 keep the inside of the container 15 sealed.

[0024] In the manufacturing method of the SHP1 described above, the flange portions 11B, 12B may be joined by brazing or laser welding instead of diffusion bonding. For example, if the material of the metal foil that forms the sheets 11, 12 is stainless steel, laser welding will improve the adhesion between the flange portions 11B, 12B, and if the material of the metal foil is copper, brazing will improve the adhesion between the flange portions 11B, 12B. In this way, when joining the flange portions 11B, 12B, any joining method depending on the material of the metal foil can be used to meet the requirement of improving the adhesion between the flange portions 11, 12.

[0025] Furthermore, when the two sheets 11, 12 are overlapped, the width d of the flanges 11B, 12B as the outer periphery 16 surrounding the container 15 is formed to a dimension of less than 2 mm, for example, 1.5 mm or more. This makes it possible to maximize the internal volume of the container 15 while ensuring the required airtightness for the container 15 in the completed SHP1 state.

[0026] In the press drawing process, the depth of the sheet surface portion 11A formed on the sheet body 11 can be easily adjusted to provide the concave steam passage 21 and the wick storage portion 22 inside the container 15, but in order to correspond to the thinning of the housing 43 of the portable device, the thicknesses t1 and t2 of the metal foils that become the sheet bodies 11 and 12 are made less than 0.1 mm, and the thickness T0 of the SHP1 in the completed state is made less than 0.4 mm at most. The thicknesses t1 and t2 of the sheet bodies 11 and 12 do not necessarily have to be the same dimension, and for example, by making the dimension of the thickness t1 of the metal foil that becomes the sheet body 11 by the press drawing process larger than the dimension of the thickness t2 of the metal foil that becomes the sheet body 12 without the press drawing process, the sheet surface portion 11A and the support 11C formed on the sheet body 11 are less likely to deform, and the handling of the SHP1 becomes easier.

[0027] Thus, in this embodiment, no etching is performed in the series of manufacturing steps, and a molded product of metal foil formed by press drawing is used as the first sheet 11, and two or more sheets of metal foil including another second sheet 12 are stacked in addition to this first sheet 11, and then flanges 11B, 12B formed with a width d of less than 2 mm are joined to form a hollow container 15 through which the working fluid circulates, thereby easily obtaining an SHP1 with sufficient thermal diffusion performance by increasing the internal volume of the container 15 as much as possible using a reasonable etching-free manufacturing method. Also, a thin SHP1 can be provided that has a thickness T0 of less than 0.4 mm without etching, and is equipped with a concave vapor passage 21 through which the gas-phase working fluid passes and a wick storage section 22 that stores a sheet-like wick 31.

[0028] In the present embodiment, in order to surely prevent the phenomenon that the container 15 collapses under atmospheric pressure, a plurality of support columns 11C are arranged at equal intervals in the vertical and horizontal directions from the region that becomes the vapor passage 21 inside the sheet surface portion 11A of the first sheet body 11 toward the surface of the wick 31 housed in the wick housing portion 22 of the second sheet body 12. As shown in FIG. 7, each support column 11C has the same shape, and the gap L, which is the shortest distance from the base end of one support column 11C to the base end of the adjacent support column 11C in the vertical and horizontal directions, is 5 mm or less, and it is integrally formed with the sheet surface portion 11A. By setting the gap L1 between the support columns 11C to 5 mm or less, while the entire support column 11C supports the sheet surface portion 11A of the first sheet body 11 so that the container 15 does not collapse under atmospheric pressure, a vapor passage 21 can be secured through which the vapor-phase working fluid can sufficiently pass inside the container 15.

[0029] FIGS. 8 to 10 show preferred cross-sectional shapes of the support columns 11C formed on the first sheet body 11 by press drawing. FIG. 8 shows a support column 11C having a hemispherical outer shape, FIG. 9 shows a support column 11C having a cylindrical outer shape, and FIG. 10 shows a support column 11C having a mortar-like outer shape. All of these support columns 11C are formed in a convex shape from the sheet surface portion 11A of the first sheet body 11 toward the inside of the container 15. Various different-shaped support columns 11C, including the spherical support column 11C shown in FIG. 1 and the support columns 11C shown in FIGS. 8 to 10, may be formed on the first sheet body 11 in a single operation by press drawing. Also in that case, the respective support columns 11C are arranged at intervals so that the gap L between the support columns 11C is 5 mm or less.

[0030] The second sheet body 12 effectively functions as a reinforcing member that prevents deformation of the sheet surface portion 12A by the flat wick 31 housed in the wick housing portion 22. Therefore, even if the thickness t2 of the second sheet body 12 is formed to be thinner than the thickness t1 of the first sheet body 11 (that is, even if t2 < t1), collapse of the container 15 on the sheet surface portion 12A side of the second sheet 12 can be avoided. Also, accordingly, the thickness T0 of the SHP1 can be made thinner, and an SHP1 having a preferable thickness T0 corresponding to the thinning of the housing 43 of the portable device can be provided.

[0031] Furthermore, as shown in Fig. 11, in order to meet the requirement that the thickness T0 of the SHP1 be as thin as possible, it is preferable to stack one side of the metal foil as a first sheet 11 that will be a formed product obtained by press drawing, and the other side of the metal foil as a second sheet 12 that will be a flat, non-formed product that has not been press drawn, and to manufacture the SHP1. Alternatively, as shown in Fig. 12, if one side of the metal foil is the first sheet 11 that will be a formed product obtained by press drawing, and the other side of the metal foil is also the second sheet 12 that will be a formed product by press drawing, and to manufacture the SHP1 by stacking these, it is possible to meet the requirement that the thickness T0 of the SHP1 be a little thicker. In this case, the second sheet body 12 is formed with a sheet surface portion 12A that is not flat but concave by press drawing, and this sheet surface portion 12A faces the sheet surface portion 11A of the first sheet body 11 that is also formed with a concave shape, thereby forming a concave steam passage 21 and a wick storage portion 22 for storing the wick 31 inside the container 15. In FIG. 12, the wick storage portion 22 is provided on the sheet surface portion 12A side of the second sheet body 12, and the sheet-like wick 31 stored therein is held down by a support 11C protruding from the sheet surface portion 11A of the first sheet body 11, but the wick storage portion 22 may be provided on the sheet surface portion 11A side of the first sheet body 11, and the sheet-like wick 31 stored therein may be held down by a support (not shown here) protruding from the sheet surface portion 12A of the second sheet body 12.

[0032] The pillars (pillars 11C) protruding toward the inside of the container 15 are arranged on the heat dissipation side, the heat receiving side, or both the heat dissipation side and the heat receiving side depending on the conditions of use of the SHP1, and have the function of preventing the container 15, which is the outer shell of the SHP1, from collapsing and holding down the wick 31 arranged in the wick storage section 22 inside the container 15. For example, in the SHP1 shown in Fig. 13, pillars 11C are arranged from the sheet surface section 11A of the first sheet body 11 on the heat dissipation section 45 side that contacts the above-mentioned thermal diffusion member 42 (not shown here), and the tip of this pillar 11C comes into contact with the wick 31, thereby preventing the container 15 from collapsing and holding down the wick 31 so that it does not move inside the container 15. The sheet surface portion 12A of the second sheet body 12 on which the wick 31 is placed functions as the heat receiving portion 44 that contacts the aforementioned heat source 41 (not shown here), but the support pillar 11C is positioned only on the heat dissipation portion 45 side, not on the heat receiving portion 44 side.

[0033] 14 shows an SHP1 in which one side of a metal foil is a second sheet body 12 that is a formed product obtained by press drawing, and the other side of the metal foil is a second sheet body 11 that is a non-formed product that is a flat plate that is not press drawn, which are stacked together, and a concave sheet surface portion 12A formed in the second sheet body 12 by press drawing is used as a heat receiving portion 44, from which a plurality of supports 12C are arranged toward the sheet surface portion 11A of the first sheet body 11. In addition, the first sheet body 11 and the second sheet body 12 are stacked together such that the opening of the sheet surface portion 12A of the second sheet body 12 is blocked by the sheet surface portion 11A of the first sheet body 11, thereby forming a steam passage 21 for circulating the gas phase working fluid and a wick storage portion 22 for storing a wick 31 for circulating the liquid phase working fluid inside the container 15 in which the working fluid is sealed. The wick 31 is provided with holes 33 through which the support posts 12C pass, so that the tips of the support posts 12C come into direct contact with the inner surface of the sheet surface portion 11A of the first sheet body 11, preventing the container 15 from being crushed. Furthermore, by inserting the support posts 12C into the holes 33 of the wick 31, the wick 31 is not held down by the support posts 12C, but is positioned by restricting a certain degree of movement from the wick storage portion 22. The sheet surface portion 12A of the second sheet body 12 on which the wick 31 is placed functions as a heat receiving portion 44, and the sheet surface portion 11A of the first sheet body 11 against which the tips of the support posts 12C come into contact functions as a heat dissipation portion, but the support posts 12C are positioned only on the heat receiving portion 44 side, not on the heat dissipation portion 45 side.

[0034] The SHP1 shown in Figure 15 has a first sheet body 11 in which one side of a metal foil is a molded product obtained by press-drawing, and a second sheet body 12 in which the other side of the metal foil is also a molded product obtained by press-drawing, stacked together, and a concave sheet surface portion 11A formed in the first sheet body 11 by press-drawing serves as a heat dissipation portion 45, with multiple pillars 11C arranged from this toward the sheet surface portion 12A of the second sheet body 12, and a concave sheet surface portion 12A formed in the second sheet body 12 by press-drawing serves as a heat receiving portion 44, with multiple pillars 12C arranged from this toward the sheet surface portion 11A of the first sheet body 11. Moreover, by stacking the first sheet body 11 and the second sheet body 12 with the sheet surface portion 12A of the second sheet body 12 facing the sheet surface portion 11A of the first sheet body 11, a steam passage 21 for circulating the gas phase working fluid and a wick storage portion 22 for storing the wick 31 for circulating the liquid phase working fluid are formed inside the container 15 in which the working fluid is sealed. The wick 31 has a hole 33 through which the support 12C of the second sheet body 12 is inserted, so that the tip of the support 12C directly contacts the tip of the opposing support 11C of the first sheet body 11, preventing the container 15 from being crushed. Also, by inserting the support 12C into the hole 33 of the wick 31, the wick 31 is not held down by the support 12C, but is positioned by restricting some movement from the wick storage portion 22. Here, pillars 11C and 12C are arranged on both the heat dissipating portion 45 side and the heat receiving portion 44 side.

[0035] Various configurations of the wick 31 will now be described in detail with reference to the accompanying drawings.

[0036] FIG. 16 is an enlarged view of the wick 31 made of a mesh 51. In the figure, the wick 31 here is composed of a flat mesh 51 having a diameter D1 of 0.05 mm or less, in which metal wires 52 such as copper, stainless steel, or titanium are aligned lengthwise and widthwise, and woven so that the openings H1 are 200 um or less. By reducing the diameter D1 of the metal wires 52 that are components of the mesh 51 to 0.05 mm or less, a strong capillary force can be obtained when used as the wick 31, and even if the thickness T0 of the SHP1 is reduced to less than 0.4 mm, the wick 31 can be easily stored in the wick storage section 22. The openings H1 are the distance from the inner end of one adjacent metal wire 52 to the inner end of the other metal wire 52, and by making the openings H1 200 um or less, a strong capillary force can be exerted by the gaps 32 formed between the metal wires 52.

[0037] 17 to 20 show wicks 31 made of metal foil 61. In each of these figures, the wick 31 has a thickness T2 of 0.1 mm or less and is composed of a flat metal foil 61 made of copper, stainless steel, titanium, or the like having fine grooves 62 that cross each other vertically and horizontally on its surface and generate capillary forces, and holes 63 that are arranged at appropriate positions in the grooves 62 at equal intervals. The concave grooves 62 are arranged in a lattice pattern only on the surface of the metal foil 61, but they may also be similarly arranged on the back surface of the metal foil 61 to increase the capillary forces. The holes 63 that penetrate the front and back surfaces of the metal foil 61 correspond to the gaps 32 of the wick 31, and the liquid phase working fluid that flows along the grooves 62 by capillary forces can be guided to the holes 63 by even stronger capillary forces and diffused throughout the entire back surface of the metal foil 61, and a strong capillary force can be exerted by the combination of the grooves 62 and the holes 63. Furthermore, by setting the thickness T2 of the metal foil 61 to 0.1 mm or less, the wick 31 can be stored in the wick storage section 22 without difficulty even if the thickness T0 of the SHP 1 is reduced to less than 0.4 mm.

[0038] 21 and 22 each show a wick 31 made of a nonwoven fabric 71. In the figures, the wick 31 here is composed of a nonwoven fabric 71 in which metal wires 72, 73 having a diameter D2 of 0.03 mm or less are arranged at a density of 100 g / m2 to 350 g / m2. The nonwoven fabric 71 is formed by overlapping metal wires 72 as long straight fibers arranged uniformly in almost one direction and metal wires 73 as web fibers that are shorter than the metal wires 72 and arranged in a random direction almost uniformly, and by intertwining these metal wires 72, 73 rather than weaving them, into a sheet shape. This is different from the mesh 51 in which vertical metal wires 52 and horizontal metal wires 52 are woven in a net shape. In addition, since the metal wires 72, 73 are simply intertwined, the metal wires 73 of the web fibers are likely to come off from the metal wires 72 of the straight fibers, the nonwoven fabric 71 may be formed by bonding the metal wires 72, 73 to each other by sintering. By reducing the diameter D2 of the metal wires 72, 73 that are components of the nonwoven fabric 71 to 0.03 mm or less, a strong capillary force can be obtained when this is used as the wick 31, and even if the thickness T0 of the SHP1 is reduced to less than 0.4 mm, the wick 31 can be easily stored in the wick storage section 22. Furthermore, in the nonwoven fabric 71 combining the metal wires 72, 73, gaps 32 of an appropriate size range according to the density of the metal wires 72, 73 are formed, so that the liquid-phase working fluid that flows between the metal wires 72, 73 by capillary force can be guided to the gaps 32 by even stronger capillary force and diffused throughout the entire nonwoven fabric 71, allowing the wick 31 to exert a strong capillary force.

[0039] Next, the operation and effect of the SHP1 configured as above when mounted on a thin mobile device will be described. The SHP1 of this embodiment has an outer shape that matches the internal shape of the housing 43 of the mobile device shown in FIG. 5, and is installed as it is in the housing 43. At this time, one side of the SHP1 is in contact with a heat source 41 such as a CPU installed inside the housing 43 as a heat receiving part 44, and is thermally connected to the heat source 41, and a heat dissipation part 45 is formed at a part (another part of one side of the SHP1 or the other side) away from the CPU that is the heat source. Then, when the heat source 41 generates heat inside the housing 43 and the temperature rises, heat is transferred from the heat source 41 to the heat receiving part 44 of the SHP1, and the liquid phase working fluid evaporates in the heat receiving part 44, and the vapor that becomes the gas phase working fluid flows from the heat receiving part to the heat dissipation part with a low temperature through the hollow vapor passage 21 formed inside the container 15, and heat is transported inside the SHP1. The heat transported to heat dissipation section 45 is thermally diffused to heat diffusion member 42 that is in contact with and thermally connected to heat dissipation section 45, and is then dissipated from there to the outside of housing 43. This allows the portable device to efficiently diffuse heat generated from heat source 41 such as a CPU to heat diffusion member 42, thereby mitigating heat spots that occur on the outer surface of the portable device and suppressing a rise in temperature of heat source 41 such as a CPU.

[0040] On the other hand, in the heat dissipation section 45 of the SHP1, the vapor condenses inside the container 15 and the liquid phase working fluid accumulates, but the strong capillary force of the wick 31 arranged opposite the vapor passage 21 returns the liquid phase working fluid from the heat dissipation section 45 to the heat receiving section 44. The wick 31 having the fine gaps 32 smoothly flows the liquid phase working fluid from the heat dissipation section 45 to the heat receiving section 44 by the strong capillary force, regardless of the configuration of the porous body, mesh 51, metal foil 61, or nonwoven fabric 71 described above, so that a high capillary force can be obtained even with a thin wick 31, and high thermal diffusion performance of the SHP1 is ensured. Therefore, the liquid phase working fluid does not disappear in the heat receiving section 44, and the liquid phase working fluid evaporates again here, travels through the vapor passage 21, and is led to the heat dissipation section 45, thereby continuing heat transport and demonstrating the original performance of the SHP1.

[0041] Fig. 23 is a plan view of the actual first sheet body 11 shown in Fig. 2 and Fig. 3. Fig. 24 shows the temperature distribution when a heat source 41 was thermally connected in an experiment to an SHP1 completed using the first sheet body 11 in Fig. 23. In this experiment, a completed SHP1 manufactured as described above by stacking two sheet bodies 11 and 12 including the first sheet body 11 formed by press drawing was prepared, and a heat source 41 was attached to the right part "a" of one side of the SHP1, and the temperature of each part of the SHP1 due to the heat generated by the heat source 41 was measured.

[0042] As a result, the temperature of the right side "a" of the SHP1 with the heat source 41 attached was 66.0°C, while the temperature of the center part "b" of the SHP1 side was 65.7°C, and the temperature of the left side "c" of the SHP1 was 65.5°C. In other words, the surface temperature difference over the entire SHP1 was only about 0.5°C, confirming that the SHP1 of this embodiment exhibits sufficient thermal diffusion performance.

[0043] As described above, in this embodiment, a manufacturing method for an SHP1 is provided in which a metal foil is formed by pressing such as press drawing, and two or more metal foils including this formed product, for example two sheets of a first sheet body 11 and a second sheet body 12, are stacked, and flange portions 11B, 12B having a width d of less than 2 mm are joined to form a hollow container 15 in which a liquid-phase working fluid is sealed.

[0044] In this case, metal foil formed by press processing is used to stack first sheet 11 and second sheet 12, which are two or more pieces of metal foil, and in order to maximize the internal volume of container 15, flange portions 11B, 12B, which are formed with a width d of less than 2 mm, are joined to form hollow container 15 through which the working fluid circulates, thereby providing a reasonable etching-less SHP1 that has sufficient thermal diffusion performance and a simplified manufacturing method.

[0045] In addition, in this embodiment, the thicknesses t1, t2 of the sheet bodies 11, 12 that become the metal foil are both less than 0.1 mm, a concave steam passage 21 and wick storage section 22 are formed inside the container 15 by press processing, the wick storage section 22 is provided with a sheet-like wick 31 having fine gaps 32, and a manufacturing method for the SHP1 is provided in which the total thickness T0 of the SHP1 is less than 0.4 mm in response to the trend toward thinner portable devices.

[0046] In this case, it is possible to provide a thin SHP1 that is etch-free and has a thickness T0 of less than 0.4 mm, yet includes a concave vapor passage 21 through which the gas-phase working fluid passes, and a wick storage section 22 that stores a sheet-like wick 31. In addition, by storing a sheet-like wick 31 having fine gaps 32 that generate capillary force in the wick storage section 22 inside the container 15, it becomes possible to smoothly circulate the liquid and gas-phase working fluids between the wick 31 and the vapor passage 21, and it is possible to provide an SHP1 that has sufficient thermal diffusion performance.

[0047] Furthermore, in this embodiment, a manufacturing method for SHP1 is provided in which concave steam passage 21 is formed inside container 15 by press processing, and in the region that will become steam passage 21, supports 11C that serve as convex columns such as hemispherical, cylindrical, or mortar-shaped supports are formed by press processing to prevent container 15 from being crushed by atmospheric pressure, and gaps L between supports 11C, 11C are arranged at intervals of 5 mm or less.

[0048] In this way, by providing support pillars 11C that prevent container 15 from collapsing, a vapor passage 21 that allows sufficient passage of gas-phase working fluid inside container 15 can be secured even when container 15 is pressed by atmospheric pressure.

[0049] In addition, in the manufacturing method of the SHP1 of this embodiment, the container 15 is provided with two or more nozzles 17 at any position that communicate with the inside of the container 15 in order to inject the working fluid and perform vacuum drawing during the manufacturing process, and these nozzles 17 are provided with sealing parts 18 for sealing the container 15.

[0050] In this case, in the manufacturing process of the SHP1, it becomes possible to inject the working fluid into the inside of the container 15 or to evacuate the inside of the container 15 at a plurality of different points of the container 15. Furthermore, in the product state after the manufacturing process of the SHP1 is completed, by providing sealing portions 18 on each nozzle 17, the inside of the container 15 can be kept sealed, ensuring high thermal diffusion performance even in a thin type.

[0051] In the manufacturing method of the SHP 1 of this embodiment, the flange portions 11B, 12B of the sheets 11, 12 are joined by using any one of brazing, laser welding, and diffusion bonding.

[0052] As a result, when joining the flange portions 11B, 12B of the sheet bodies 11, 12, any joining method can be used according to requirements based on the material of the sheet bodies 11, 12, for example, and the degree of freedom in designing the SHP 1 can be increased.

[0053] Furthermore, in the manufacturing method of the SHP1 of this embodiment, for example, as shown in FIG. 11, one of the stacked metal foils may be a first sheet 11 that is a pressed molded product, and the other of the metal foils may be a second sheet 12 that is a non-molded product that becomes a flat plate.

[0054] In this case, one of the stacked metal foils is made into a first sheet 11 that will be a press-processed molded product, and the other of the metal foils is made into a second sheet 12 that will be a flat plate, making it possible to design according to the thickness requirements of the SHP1, thereby increasing the design freedom.

[0055] Alternatively, as shown in FIG. 12, for example, one side and the other side of the stacked metal foils may be a first sheet body 11 and a second sheet body 12, both of which are formed by pressing.

[0056] In this case, by making one side of the stacked metal foil into a first sheet 11 and a second sheet 12, both of which are press-processed molded products, it becomes possible to design SHP1 according to the thickness requirements, thereby increasing the design freedom.

[0057] Furthermore, in the manufacturing method of the SHP1 of this embodiment, a concave steam passage 21 and wick storage section 22 are formed inside the container 15 by press processing, and the wick storage section 22 is provided with a sheet-like wick 31 having fine gaps 32. For example, as shown in Figures 13 to 15, pillars 11C, 12C are formed by press processing, and the pillars 11C, 12C are arranged on the heat dissipation section 45 side, the heat receiving section 44 side, or both the heat dissipation section 45 side and the heat receiving section 44 side of the SHP1 so as to have the function of preventing the container 15 from being crushed and the function of holding down the wick 31.

[0058] In this way, by providing the supports 11C, 12C on the heat dissipation section 45 side, the heat receiving section 44 side, or both the heat dissipation section 45 side and the heat receiving section 44 side of the SHP 1 and giving the supports 11C, 12C a function to prevent the container 15 from collapsing or a function to hold down the wick 31 as necessary, it becomes possible to design the SHP 1 according to the performance requirements, and the degree of freedom in design can be increased. In addition, by storing the sheet-like wick 31 having the fine gaps 32 that generate capillary force in the wick storage section 22 inside the container 15, it becomes possible to smoothly circulate the liquid and gas phase working fluid between the wick 31 and the steam passage 21, and it is possible to provide an SHP 1 that has sufficient thermal diffusion performance.

[0059] In the method for producing the SHP 1 of this embodiment, the material of the metal foil that becomes the sheets 11 and 12 is preferably any one of stainless steel, titanium, copper, and alloy metals containing these as main components.

[0060] In this case, the metal foil that forms the sheets 11 and 12 that form the outer contour of the SHP 1 can be made of any material to meet requirements, allowing for greater freedom in design.

[0061] In the manufacturing method of the SHP1 of this embodiment, the wick 31 provided inside the container 15 is preferably, for example, a mesh 51 woven from metal wires 52 such as copper, stainless steel, or titanium having a diameter D1 of 0.05 mm or less and an opening H1 of 200 um or less. This allows the mesh 51 to provide a high capillary force despite the thin wick 31, ensuring high thermal diffusion performance for the SHP1.

[0062] Alternatively, the wick 31 of this embodiment may be a metal foil 61 made of copper, stainless steel, titanium, or the like, with a thickness T2 of 0.1 mm or less and fine intersecting grooves 62 and holes 63 on its surface that generate capillary force. This allows the wick 31 to have a thin shape but still obtain a high capillary force due to the metal foil 61, ensuring high thermal diffusion performance as an SHP1.

[0063] Alternatively, the wick 31 of this embodiment may be a sheet of a porous material containing sintered powder of a metal such as copper, stainless steel, or titanium, having a thickness of 0.1 mm or less and having fine pores serving as gaps 32. This allows the wick 31 to be thin yet have a high capillary force due to the porous material, ensuring high thermal diffusion performance for the SHP1.

[0064] Furthermore, the wick 31 of this embodiment may be made of metal wires 72, 73 each having a diameter D2 of 0.03 mm or less, and nonwoven fabric 71 having a density of 100 g / m2 to 350 g / m2. This allows the wick 31 to be thin, yet obtains high capillary force due to the nonwoven fabric 71, ensuring high thermal diffusion performance as an SHP1.

[0065] Next, the SHP1 in the second embodiment of the present invention will be described in detail with reference to the attached FIG. 25. In the figure, in this embodiment, inside the container 15, a plurality of pillar members 35, which replace the pillars 11C and 12C shown in the first embodiment, are arranged at equal intervals vertically and horizontally from the surface of the wick 31 toward the concave sheet surface portion 11A formed in the first sheet body 11. Therefore, the sheet surface portion 11A of the first sheet body 11 is formed flat without any unevenness without the pillars 11C. This increases the contact area and improves adhesion, particularly when the heat source 41 and the heat diffusion member 42 are thermally connected to the outer surface of the sheet surface portion 11A, which is the outer surface of the SHP1. In addition, after the completed SHP1 is installed in the housing 43 of the mobile device, when the user applies pressure with a finger or the like to the display portion of the mobile device, if the outer surface of the SHP1 located below is a flat surface without any unevenness, there is an advantage that no distortion of the screen occurs.

[0066] Other configurations and manufacturing methods related to the SHP1, as well as the dimensions of each part, are the same as in the first embodiment, but in this embodiment, it is preferable to provide two or more nozzles 17 at any position in one container 15, as shown in Fig. 6. In this case as well, by using each nozzle 17 to inject the oxide film and working fluid or to draw a vacuum, and then sealing the opening 17A of the nozzle 17 with the sealing part 18, and then cutting off the tip part 17B from its base, the inside of the container 15 can be kept sealed by the sealing part 18 provided on the nozzle 17, without the nozzle 17 protruding from the container 15.

[0067] The convex columnar member 35 is made of a porous powder sintered product made of a material having excellent thermal conductivity, such as copper, iron, stainless steel, or an alloy metal mainly composed of copper or iron, or a separate part that is not limited to powder sintered. Each columnar member 35 is joined to the surface of the wick 31 in the same columnar shape such as a cylinder, or in a combination of multiple columnar shapes. In other words, since the wick 31 and the columnar member 35 are separate members, it is possible to provide a large number of porous columns 35 in any shape on the sheet-like wick 31 without being restricted in position or height by the support 11C. In addition, by setting the gap between the adjacent columnar members 35, 35 to the same conditions as the above-mentioned supports 11C and 12C, the entire columnar member 35 supports the sheet surface portion 11A of the first sheet body 11 so that the container 15 does not collapse under atmospheric pressure, while securing the steam passage 21 that allows the gaseous working fluid to pass sufficiently inside the container 15.

[0068] Each columnar member 35 has many fine gaps (not shown) that generate capillary force, similar to the gaps 32 of the wick 31. Therefore, the columnar members 35 here not only function to prevent the container 15 from collapsing, but also function to cause the liquid phase working fluid to flow mainly toward the vapor passage 21 by strong capillary force. By providing a wick structure in which multiple columnar members 35 are joined to the wick 31 inside the container 15, sufficient heat diffusion performance can be obtained due to the strong capillary force of the wick structure. In addition, the wick 31 can be made of the above-mentioned porous body, mesh 51, metal foil 61, or nonwoven fabric 71 as it is.

[0069] FIG. 26 shows an example of a wick 31 in which multiple sheets are stacked and stored in the wick storage section 22. The wick 31 here is composed of two meshes 51A and 51B shown in FIG. 16. In FIG. 26, a part of the mesh 51A is folded back to show that there are multiple wicks 31, but in reality, the meshes 51A and 51B of the same shape are not folded back and are completely overlapped and arranged in the wick storage section 22. The two or more wicks 31 may be any of the above-mentioned porous bodies, metal foils 61, and nonwoven fabrics 71 in addition to the mesh 51 shown here, and may also be a combination of one wick 31 equipped with a columnar member 35 and one or more other wicks 31 not equipped with a columnar member 35.

[0070] In this way, by storing multiple wicks 31 in a stacked manner in the wick storage section 22, the amount of liquid-phase working fluid that the wick 31 can hold (liquid retention amount) can be increased in proportion to the number of wicks 31, improving the performance of the SHP 1. In particular, there is a limit to the amount of liquid that a single wick 31 can hold, and if liquid-phase working fluid remains in a portion of the steam passage 21 like a liquid pool, the flow of the gas-phase working fluid is hindered there, significantly reducing the performance of the SHP 1. However, by using multiple wicks 31, such liquid pools can be eliminated, making it possible to smoothly circulate the gas-phase working fluid throughout the entire steam passage 21.

[0071] As described above, in this embodiment, a wick 31 is provided inside the container 15, and this wick 31 is equipped with a pillar member 35 made of a powder sintered product or a separate part to prevent the container 15 from being crushed by atmospheric pressure, and a manufacturing method for SHP1 is provided in which the surface of the sheet surface portion 11A of the first sheet body 11 is flat as the outer surface of the metal foil facing the pillar member 35.

[0072] In this case, by making the surface of the sheet surface portion 11A of the first sheet 11 flat, the adhesion to the heat diffusion member 42, which is a heat dissipation component, and the heat source 41, which is a heat generating component, can be improved, and high performance can be ensured even if the SHP1 is thin.

[0073] Furthermore, this embodiment provides a method for manufacturing an SHP 1 having multiple wicks 31 instead of one.

[0074] In this case, the more wicks 31 are used, the greater the amount of liquid working fluid held in the wicks 31. Therefore, instead of only a portion of the liquid working fluid being locally trapped inside the container 15, the entire liquid working fluid can be circulated without waste through the wicks 31, ensuring even higher thermal diffusion performance for the SHP1.

[0075] The present invention is not limited to the above-mentioned embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, the pillars 11C and 12C in the first embodiment and the porous pillars 35 in the second embodiment may be configured so that their individual shapes and arrangement intervals are changed in accordance with the positions of the heat receiving portion 44 and the heat dissipating portion 45 of the SHP1. [Explanation of symbols]

[0076] 1. Sheet-type heat pipe 11 First sheet body (metal foil) 11B Flange part 11C,12C Pillar 12 Second sheet body (metal foil) 12B Flange part 15 Container 17 Nozzle 17A opening 18 Sealing part 21 Steam passage 22 Wick storage section 31 Wick 44 Heat receiving part 45 Heat radiation part T0a: Thickness of the container 15 of the heat receiving part 44 (thickness of the container of the heat receiving part) T0b Thickness of the container 15 of the heat dissipation part 45 (thickness of the container of the heat dissipation part)

Claims

1. A sheet-like heat pipe having a hollow vessel in which a working fluid is sealed, the hollow vessel being formed by pressing a metal foil made of stainless steel or an alloy metal mainly composed of stainless steel, and stacking and bonding two or more sheets of the metal foil including the formed product, A flat wick containing any one of copper, stainless steel, and titanium is provided inside the container, A sheet-like heat pipe characterized in that at least one side of the metal foil has a pillar formed by recessing the surface side of the metal foil by press drawing, and the pillar holds down the wick.

2. The sheet-type heat pipe of claim 1, characterized in that the container is formed with a thickness that increases continuously from the flange portion which is the outer periphery, and one of the metal foils is recessed to form a wick storage section for storing the wick and a steam passage through which the working fluid flows, and the total thickness is the thickness of the two or more metal foils and the amount of recession of the wick storage section and the steam passage.

3. A heat receiving portion and a heat dissipating portion are formed in the metal foil where the columns are not formed, 2. The sheet-shaped heat pipe according to claim 1, wherein a thickness of said container in said heat receiving portion is different from a thickness of said container in said heat radiating portion.

4. 2. The sheet-shaped heat pipe according to claim 1, further comprising a plurality of sealing portions for closing the openings of the nozzle.

5. A metal foil made of stainless steel or an alloy metal mainly composed of stainless steel is formed by pressing, and two or more sheets of the metal foil including the formed product are stacked and joined to form a hollow container in which a working fluid is sealed; A flat wick containing any one of copper, stainless steel, and titanium is provided inside the container; A method for manufacturing a sheet-type heat pipe, comprising forming a pillar on at least one side of the metal foil by pressing the surface side of the metal foil using a press drawing process, and using the pillar to hold down the wick.

Images