Core sheet for evaporation chamber, evaporation chamber, and electronic device

Abstract

The core piece for the evaporation chamber of the present invention is interposed between a first piece and a second piece of the evaporation chamber in which a working fluid is enclosed. The core piece for the evaporation chamber includes: a piece main body having a first main surface and a second main surface; a through space penetrating the piece main body; a first groove aggregate communicating with the through space and provided on the second main surface; and a second groove aggregate communicating with the through space and provided on the first main surface. The flow path cross-sectional area of the second main flow groove of the second groove aggregate is larger than the flow path cross-sectional area of the first main flow groove of the first groove aggregate.

Description

Technical Field

[0001] The present invention relates to a core sheet for an evaporation chamber, an evaporation chamber, and an electronic device. Background Art

[0002] In electronic devices such as mobile terminals, electronic devices that generate heat are used. Examples of such electronic devices include a central processing unit (CPU), a light-emitting diode (LED), or a power semiconductor. Examples of mobile terminals include a portable terminal or a tablet terminal.

[0003] Such electronic devices are cooled by a heat dissipation device such as a heat pipe (for example, refer to Patent Document 1). In recent years, due to the thinning of electronic devices, heat dissipation devices are required to be thinner. As a heat dissipation device, the development of an evaporation chamber that can be made thinner than a heat pipe is being promoted. In the evaporation chamber, the enclosed working fluid absorbs the heat of the electronic device and diffuses it, thereby cooling the electronic device.

[0004] More specifically, the working fluid in the evaporation chamber is heated by the electronic device through a portion (evaporation portion) close to the electronic device. As a result, the working fluid evaporates and changes into a working vapor. The working vapor diffuses in the vapor flow path portion formed in the evaporation chamber in a direction away from the evaporation portion and is cooled. Then, the working vapor condenses and changes back into a working fluid. A liquid flow path portion serving as a capillary structure (also referred to as a core) is provided in the evaporation chamber. Thus, the working fluid enters the liquid flow path portion from the vapor flow path portion. Then, the working fluid flows in the liquid flow path portion and is transported toward the evaporation portion. And the working fluid transported to the evaporation portion is heated and evaporated again in the evaporation portion. Thus, the working fluid repeats phase change (i.e., evaporation and condensation) while circulating in the evaporation chamber. In this way, the heat of the electronic device is diffused. As a result, the heat dissipation efficiency of the evaporation chamber is improved.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2008-82698 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] An object of the present invention is to provide a core sheet for an evaporation chamber, an evaporation chamber, and an electronic device that can suppress performance degradation.

[0010] Means for Solving the Problems

[0011] As a first solution means, the present invention provides a core sheet for an evaporation chamber, which is interposed between a first sheet and a second sheet of the evaporation chamber, and a working fluid is enclosed in the evaporation chamber.

[0012] Among them,

[0013] the core piece for the evaporation chamber includes:

[0014] a piece main body having a first main surface and a second main surface provided on the side opposite to the first main surface;

[0015] a through space that penetrates the piece main body;

[0016] a first groove assembly communicating with the through space and provided on the second main surface; and

[0017] a second groove assembly communicating with the through space and provided on the first main surface,

[0018] the first groove assembly includes a plurality of first main flow grooves extending in a first direction,

[0019] the second groove assembly includes a plurality of second main flow grooves extending in the first direction,

[0020] the flow path cross-sectional area of the second main flow groove is larger than that of the first main flow groove.

[0021] Moreover, in the core piece for the evaporation chamber of the above first solution, it is possible that the width of the second main flow groove is larger than the width of the first main flow groove.

[0022] In addition, in the core piece for the evaporation chamber of the above first solution, it is possible that the depth of the second main flow groove is larger than the depth of the first main flow groove.

[0023] In addition, in the core piece for the evaporation chamber of the above first solution, it is possible that

[0024] the piece main body has a plurality of platform portions that divide the through space into a plurality of passages,

[0025] the plurality of platform portions are separated from each other in a second direction perpendicular to the first direction,

[0026] the width of the second main flow groove is smaller than the gap between a pair of adjacent platform portions.

[0027] In addition, in the core piece for the evaporation chamber of the above first solution, it is possible that

[0028] the piece main body has a plurality of platform portions that divide the through space into a plurality of passages,

[0029] the first groove assembly and the second groove assembly are provided on at least one of the plurality of platform portions,

[0030] The number of the second main flow grooves provided in the platform portion is smaller than the number of the first main flow grooves provided in the platform portion.

[0031] In addition, in the core chip for the evaporation chamber of the first solution means described above, it may be that

[0032] The chip body has a plurality of platform portions extending in the first direction and dividing the through space into a plurality of passages.

[0033] The second groove assembly is disposed on one side of the platform portion in the first direction.

[0034] In addition, in the core chip for the evaporation chamber of the first solution means described above, it may be that

[0035] The chip body has a plurality of platform portions dividing the through space into a plurality of passages.

[0036] The second groove assemblies adjacent to each other in the second direction perpendicular to the first direction are provided in a pair of the platform portions adjacent to each other in the second direction.

[0037] The length in the first direction of the second main flow grooves of the second groove assembly provided in one of the platform portions is longer than the length in the first direction of the second main flow grooves of the second groove assembly provided in the other platform portion.

[0038] In addition, in the core chip for the evaporation chamber of the first solution means described above, it may be that

[0039] The chip body has a plurality of platform portions dividing the through space into a plurality of passages.

[0040] A plurality of the second groove assemblies are provided in at least one of the plurality of platform portions.

[0041] In addition, in the core chip for the evaporation chamber of the first solution means described above, it may be that

[0042] The core chip for the evaporation chamber includes a communication portion provided in the chip body and communicating with the first groove assembly and the second groove assembly.

[0043] In addition, in the core chip for the evaporation chamber of the first solution means described above, it may be that

[0044] The communication portion includes a communication recess provided on the wall surface of the through space and extending from the first groove assembly to the second groove assembly.

[0045] In addition, in the core chip for the evaporation chamber of the first solution means described above, it may be that

[0046] The first groove assembly includes a first connection groove communicating with the first main groove, and the first connection groove extends along a direction different from the first direction.

[0047] The second groove assembly includes a second connection groove communicating with the second main groove, and the second connection groove extends along a direction different from the first direction.

[0048] The communicating recess extends to at least one of the first connection groove and the second connection groove.

[0049] In addition, in the core chip for the evaporation chamber of the above first solution, it may be that

[0050] The communicating portion includes a through hole that penetrates the chip body and extends from the first groove assembly to the second groove assembly.

[0051] In addition, in the core chip for the evaporation chamber of the above first solution, it may be that

[0052] The first groove assembly includes a first connection groove communicating with the first main groove, and the first connection groove extends along a direction different from the first direction.

[0053] The first main groove includes a first intersection portion communicating with the first connection groove.

[0054] The second groove assembly includes a second connection groove communicating with the first main groove, and the second connection groove extends along a direction different from the first direction.

[0055] The second main groove includes a second intersection portion communicating with the second connection groove.

[0056] The through hole extends to at least one of the first intersection portion and the second intersection portion.

[0057] As a second solution, the present invention provides an evaporation chamber.

[0058] The evaporation chamber includes:

[0059] A first chip;

[0060] A second chip; and

[0061] The core chip for the evaporation chamber of the above first solution, which is interposed between the first chip and the second chip.

[0062] As a third solution, the present invention provides an electronic device.

[0063] The electronic device includes:

[0064] A housing;

[0065] An electronic device housed in the housing; and

[0066] The evaporation chamber of the second solution means in thermal contact with the electronic device.

[0067] Moreover, in the electronic device of the third solution means described above, it may be that

[0068] When looking down on the evaporation chamber, the second groove assembly is arranged in a region different from the region overlapping with the electronic device.

[0069] In addition, in the evaporation chamber of the second solution means described above, it may be that the working fluid has freeze expansion property.

[0070] As a fourth solution means, the present invention is an electronic device

[0071] The electronic device includes:

[0072] A housing;

[0073] An electronic device housed in the housing; and

[0074] The evaporation chamber of the second solution means in thermal contact with the electronic device.

[0075] Moreover, in the electronic device of the fourth solution means described above, it may be that

[0076] When looking down on the evaporation chamber, the second groove assembly is arranged in a region overlapping with the electronic device.

[0077] In addition, in the electronic device of the fourth solution means described above, it may be that

[0078] The second groove assembly extends outward beyond the electronic device in the first direction.

[0079] In addition, in the electronic device of the fourth solution means described above, it may be that

[0080] The sheet body has a first overlapping platform portion and a second overlapping platform portion that divide the through space into a plurality of passages,

[0081] The first overlapping platform portion and the second overlapping platform portion are separated from each other in a second direction perpendicular to the first direction,

[0082] The second groove assembly is provided on the first overlapping platform portion and the second overlapping platform portion,

[0083] The second groove assembly disposed on the first overlapping platform portion and the second groove assembly disposed on the second overlapping platform portion are arranged in a region that coincides with the electronic device when looking down at the evaporation chamber.

[0084] When looking down at the evaporation chamber, the second groove assembly disposed on the first overlapping platform portion is located closer to the center side of the electronic device in the second direction perpendicular to the first direction than the second groove assembly disposed on the second overlapping platform portion.

[0085] The length of the second groove assembly disposed on the first overlapping platform portion in the first direction is longer than the length of the second groove assembly disposed on the second overlapping platform portion in the first direction.

[0086] In addition, in the electronic device of the fourth solution means described above, it may be that

[0087] The sheet body has overlapping platform portions and non-overlapping platform portions that divide the through space into a plurality of passages.

[0088] The overlapping platform portions and the non-overlapping platform portions are separated from each other and adjacent to each other in a second direction perpendicular to the first direction.

[0089] The second groove assembly is provided in the overlapping platform portions and the non-overlapping platform portions.

[0090] The second groove assembly disposed on the overlapping platform portion is arranged in a region that coincides with the electronic device when looking down at the evaporation chamber.

[0091] The second groove assembly disposed on the non-overlapping platform portion is arranged in a region different from the region that coincides with the electronic device when looking down at the evaporation chamber.

[0092] In addition, in the electronic device of the fourth solution means described above, it may be that

[0093] The length of the second groove assembly disposed on the overlapping platform portion in the first direction is longer than the length of the second groove assembly disposed on the non-overlapping platform portion in the first direction.

[0094] As a fifth solution means, the present invention provides an evaporation chamber.

[0095] The evaporation chamber includes:

[0096] A first sheet;

[0097] A second sheet; and

[0098] The core sheet for the evaporation chamber of the first solution means described above, which is interposed between the first sheet and the second sheet.

[0099] The working fluid has freeze expansion properties.

[0100] As a sixth solution means, the present invention provides an electronic device,

[0101] The electronic device includes:

[0102] A housing;

[0103] A plurality of electronic components housed in the housing; and

[0104] The evaporation chamber of the above-mentioned fifth solution means, which is in thermal contact with the plurality of electronic components,

[0105] The plurality of electronic components are arranged in different regions in the first direction,

[0106] A plurality of the second groove aggregates corresponding to the respective electronic components are provided on the first main surface,

[0107] The second groove aggregate is arranged in a region that coincides with the corresponding electronic component when the evaporation chamber is viewed from above.

[0108] As a seventh solution means, the present invention provides a core sheet for an evaporation chamber, which is interposed between a first sheet and a second sheet of the evaporation chamber, and a working fluid is sealed in the evaporation chamber. Among them,

[0109] The core sheet for the evaporation chamber includes:

[0110] A sheet main body having a first main surface and a second main surface provided on the side opposite to the first main surface;

[0111] A vapor flow path portion for allowing the gas of the working fluid to pass through, which penetrates from the first main surface of the sheet main body to the second main surface;

[0112] A liquid flow path portion for allowing the liquid of the working fluid to pass through, which is provided on the second main surface and communicates with the vapor flow path portion; and

[0113] A liquid storage portion for storing the liquid of the working fluid, which is provided on the first main surface and communicates with the vapor flow path portion.

[0114] And, in the core sheet for the evaporation chamber of the above-mentioned seventh solution means, it may be that

[0115] The liquid flow path portion has a plurality of liquid flow path main grooves for allowing the liquid of the working fluid to pass through,

[0116] A plurality of liquid storage protrusions protruding from the sheet main body and abutting against the first sheet are provided in the liquid storage portion,

[0117] The gap between a pair of adjacent ones of the liquid storage protrusions is larger than the width of the main flow channels of the liquid flow path.

[0118] Further, in the core piece for the evaporation chamber of the above-described seventh solution means, it may be that

[0119] The liquid flow path portion has a plurality of main flow channels for the liquid of the working fluid to pass through, extending in the first direction.

[0120] The liquid storage portion has a plurality of main flow channels extending in the first direction, which are provided between the liquid storage protrusions adjacent to each other in the second direction perpendicular to the first direction.

[0121] Further, in the core piece for the evaporation chamber of the above-described seventh solution means, it may be that

[0122] The piece main body has a plurality of platform portions that divide the vapor flow path portion into a plurality of vapor passages.

[0123] The gap between a pair of adjacent ones of the liquid storage protrusions is smaller than the gap between a pair of adjacent ones of the platform portions.

[0124] Further, in the core piece for the evaporation chamber of the above-described seventh solution means, it may be that

[0125] The piece main body has a plurality of platform portions that divide the vapor flow path portion into a plurality of vapor passages.

[0126] The liquid storage portion is provided on each of the platform portions.

[0127] Further, in the core piece for the evaporation chamber of the above-described seventh solution means, it may be that

[0128] The piece main body has a plurality of platform portions that divide the vapor flow path portion into a plurality of vapor passages, extending in the first direction.

[0129] The liquid storage portion is arranged on one side of the platform portion in the first direction.

[0130] Further, in the core piece for the evaporation chamber of the above-described seventh solution means, it may be that

[0131] It further includes a communication portion provided on the piece main body and communicating with the liquid flow path portion and the liquid storage portion.

[0132] Further, in the core piece for the evaporation chamber of the above-described seventh solution means, it may be that

[0133] The communication part includes a communication recess provided on the wall surface of the vapor flow path part and extending from the liquid flow path part to the liquid storage part.

[0134] In addition, in the core piece for the evaporation chamber of the above-described seventh solution means, it may be that

[0135] The liquid flow path part has:

[0136] A plurality of liquid flow path main grooves through which the liquid of the working fluid passes, which extend in the first direction; and

[0137] Liquid flow path connection grooves communicating with the liquid flow path main grooves, which extend in a direction different from the first direction,

[0138] The liquid storage part has:

[0139] A plurality of liquid storage main grooves extending in the first direction; and

[0140] Liquid storage connection grooves communicating with the liquid storage main grooves, which extend in a direction different from the first direction,

[0141] The communication recess extends to at least one of the liquid flow path connection groove and the liquid storage connection groove.

[0142] In addition, in the core piece for the evaporation chamber of the above-described seventh solution means, it may be that

[0143] The communication part includes a through hole that penetrates the piece main body and extends from the liquid flow path part to the liquid storage part.

[0144] In addition, in the core piece for the evaporation chamber of the above-described seventh solution means, it may be that

[0145] The liquid flow path part has:

[0146] A plurality of liquid flow path main grooves through which the liquid of the working fluid passes, which extend in the first direction; and

[0147] Liquid flow path connection grooves communicating with the liquid flow path main grooves, which extend in a direction different from the first direction,

[0148] The liquid flow path main groove further includes a liquid flow path intersection part communicating with the liquid flow path connection groove,

[0149] The liquid storage part has:

[0150] A plurality of liquid storage main grooves extending in the first direction; and

[0151] A liquid storage connection tank communicating with the liquid storage main tank, which extends in a direction different from the first direction,

[0152] The liquid storage main tank further includes a liquid storage intersection communicating with the liquid storage connection tank,

[0153] The through hole extends to at least one of the liquid flow path intersection and the liquid storage intersection.

[0154] In addition, as an eighth solution, the present invention provides an evaporation chamber,

[0155] The evaporation chamber includes:

[0156] A first sheet;

[0157] A second sheet; and

[0158] The core sheet for the evaporation chamber of the above seventh solution, which is interposed between the first sheet and the second sheet.

[0159] Moreover, in the evaporation chamber of the above eighth solution, it may be that

[0160] An evaporation area for evaporating the working fluid is provided,

[0161] The liquid storage portion is arranged in an area different from the evaporation area.

[0162] In addition, in the evaporation chamber of the above eighth solution, it may be that the working fluid has freeze expansion property.

[0163] In addition, in the evaporation chamber of the above eighth solution, it may be that

[0164] An evaporation area for evaporating the working fluid is provided,

[0165] The liquid storage portion is arranged in the evaporation area.

[0166] In addition, as a ninth solution, the present invention provides an electronic device,

[0167] The electronic device includes:

[0168] A housing;

[0169] Electronic components housed in the housing; and

[0170] The evaporation chamber of the above eighth solution in thermal contact with the electronic components.

[0171] Effects of the Invention

[0172] According to the present invention, performance degradation can be suppressed. Brief Description of the Drawings

[0173] Figure 1 It is a schematic perspective view for explaining the electronic device according to the first embodiment of the present invention.

[0174] Figure 2 It is a top view showing the evaporation chamber according to the first embodiment of the present invention.

[0175] Figure 3 It shows Figure 2 A cross-sectional view of the evaporation chamber along line A-A.

[0176] Figure 4 It is Figure 3 A top view of the lower side piece of.

[0177] Figure 5 It is Figure 3 A bottom view of the upper side piece of.

[0178] Figure 6 It is Figure 3 A top view of the core piece of.

[0179] Figure 7 It is Figure 3 A bottom view of the core piece of.

[0180] Figure 8A It is Figure 3 A partially enlarged cross-sectional view of.

[0181] Figure 8B It shows Figure 8A Another example of a partially enlarged cross-sectional view of.

[0182] Figure 8C It shows Figure 8A Another example of a partially enlarged cross-sectional view of.

[0183] Figure 9 It is in Figure 6 A partially enlarged top view of the liquid flow path portion shown in.

[0184] Figure 10 It is in Figure 7 A partially enlarged bottom view of the liquid storage portion shown in.

[0185] Figure 11 It is along Figure 7 A partial cross-sectional view along line B-B in.

[0186] Figure 12 It is a diagram for explaining the preparation process of the core piece in the manufacturing method of the evaporation chamber according to the first embodiment.

[0187] Figure 13 It is a diagram for explaining the etching process in the manufacturing method of the evaporation chamber according to the first embodiment.

[0188] Figure 14 This is a diagram for explaining the bonding process in the manufacturing method of the evaporation chamber according to the first embodiment.

[0189] Figure 15 This is a partially enlarged top view showing the liquid flow path portion as a first modification example.

[0190] Figure 16 This is a partially enlarged bottom view showing the liquid storage portion as a first modification example.

[0191] Figure 17 This is a partially enlarged top view showing the liquid flow path portion as a second modification example.

[0192] Figure 18 This is a partially enlarged bottom view showing the liquid storage portion as a second modification example.

[0193] Figure 19 This is a partially enlarged bottom view showing the liquid storage portion as a third modification example.

[0194] Figure 20 This is a partially enlarged bottom view showing the liquid storage portion as a third modification example.

[0195] Figure 21 This is a partially enlarged bottom view showing the liquid storage portion as a third modification example.

[0196] Figure 22 This is the Figure 3 bottom view of the core sheet as a fifth modification example.

[0197] Figure 23 This is the Figure 3 bottom view of the core sheet as a sixth modification example.

[0198] Figure 24 This is the bottom view showing the core sheet in the evaporation chamber according to the second embodiment of the present invention.

[0199] Figure 25 This is a partial cross-sectional view along the Figure 24 C-C line in

[0200] Figure 26 This is a schematic diagram for explaining the state of the return flow of the working fluid when the heat generation amount of the electronic device is relatively large in a general evaporation chamber.

[0201] Figure 27 This is a schematic diagram for explaining the state of the return flow of the working fluid when the heat generation amount of the electronic device is relatively small in a general evaporation chamber. Detailed Description of the Invention

[0202] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings attached to this specification, for the convenience of illustration and understanding, the scale, the aspect ratio between the vertical and horizontal dimensions, etc. are appropriately changed according to the actual object and exaggeratedly shown.

[0203] In addition, regarding the geometric conditions, physical properties, terms specifying the degree of geometric conditions or physical properties, and numerical values representing geometric conditions or physical properties used in this specification, they can be interpreted without being bound by strict meanings. And regarding these geometric conditions, physical properties, terms, and numerical values, they can be interpreted to include ranges to the extent that the same functions can be expected. As examples of terms specifying geometric conditions, "length", "angle", "shape", or "configuration", etc. can be cited. As examples of terms specifying geometric conditions, "parallel", "perpendicular", or "identical", etc. can be cited. In addition, for the sake of clarity of the drawings, the shapes of multiple parts that can be expected to have the same function are regularly described. However, without being bound by strict meanings, within the range where this function can be expected, the shapes of these parts can also be different from each other. In addition, in the drawings, for convenience, only straight lines are used to show the boundary lines indicating the joint surfaces between components, etc., but it is not limited to strict straight lines, and within the range where the desired joint performance can be expected, the shape of this boundary line is arbitrary.

[0204] (First Embodiment)

[0205] Using Figures 1 - 21 , the core sheet for the evaporation chamber, the evaporation chamber, and the electronic device in the first embodiment of the present invention will be described. The evaporation chamber 1 in this embodiment is housed together with the electronic device D accompanied by heat generation in the housing H of the electronic device E, and is a device for cooling the electronic device D. As examples of the electronic device E, mobile terminals such as portable terminals or tablet terminals can be cited. As examples of the electronic device D, a central processing unit (CPU), a light-emitting diode (LED), or a power semiconductor, etc. can be cited. Sometimes the electronic device D is also referred to as the device to be cooled.

[0206] Here, first, for the electronic device E equipped with the evaporation chamber 1 of this embodiment, a tablet terminal will be taken as an example for description. As Figure 1 shown, the electronic device E includes: a housing H; an electronic device D housed in the housing H; and an evaporation chamber 1. In Figure 1In the electronic device E shown, a touch panel display TD is provided on the front surface of the housing H. The evaporation chamber 1 is housed within the housing H and is configured to be in thermal contact with the electronic device D. Thereby, the evaporation chamber 1 can receive the heat generated by the electronic device D when the electronic device E is in use. The heat received by the evaporation chamber 1 is released to the outside of the evaporation chamber 1 via the working fluids 2a and 2b described later. In this way, the electronic device D is effectively cooled. When the electronic device E is a tablet terminal, the electronic device D corresponds to a central processing unit or the like.

[0207] Next, the evaporation chamber 1 of the present embodiment will be described. As shown in Figure 2 and Figure 3 the evaporation chamber 1 has a sealed space 3 in which the working fluids 2a and 2b are enclosed, and the working fluids 2a and 2b in the sealed space 3 repeatedly undergo a phase change, whereby the above-described electronic device D is cooled. Examples of the working fluids 2a and 2b include pure water, ethanol, methanol, acetone, etc., and mixtures thereof. Further, the working fluids 2a and 2b may have freeze expansion properties. That is, the working fluids 2a and 2b may be fluids that expand when frozen. Examples of the working fluids 2a and 2b having freeze expansion properties include pure water, or an aqueous solution obtained by adding an additive such as alcohol to pure water.

[0208] As shown in Figure 2 and Figure 3 the evaporation chamber 1 includes a lower side plate 10, an upper side plate 20, and a core plate 30 for the evaporation chamber. The lower side plate 10 is an example of the first plate. The upper side plate 20 is an example of the second plate. The core plate 30 for the evaporation chamber is interposed between the lower side plate 10 and the upper side plate 20. Hereinafter, the core plate for the evaporation chamber will be simply described as the core plate 30. In the present embodiment, the lower side plate 10, the core plate 30, and the upper side plate 20 are stacked in this order.

[0209] The evaporation chamber 1 is formed in a substantially thin plate shape. The planar shape of the evaporation chamber 1 can be arbitrary and can be Figure 2 a rectangular shape as shown in. The planar shape of the evaporation chamber 1 can be, for example, a rectangle with one side being 1 cm and the other side being 3 cm, or a square with each side being 15 cm, and the planar size of the evaporation chamber 1 is arbitrary. In the present embodiment, as an example, an example in which the planar shape of the evaporation chamber 1 is a rectangular shape with the length direction being the X direction described later will be described. In this case, as shown in Figures 4 - 7 the lower side plate 10, the upper side plate 20, and the core plate 30 may have the same planar shape as the evaporation chamber 1. Further, the planar shape of the evaporation chamber 1 is not limited to a rectangular shape and may be an arbitrary shape such as a circular shape, an elliptical shape, an L-shaped, or a T-shaped.

[0210] As shown in Figure 2As shown, the evaporation chamber 1 has an evaporation region SR where the working fluids 2a and 2b evaporate, and a condensation region CR where the working fluids 2a and 2b condense.

[0211] The evaporation region SR is a region that coincides with the electronic device D in a top view and is a region where the electronic device D is mounted. The evaporation region SR can be arranged at any position in the evaporation chamber 1. In the present embodiment, the evaporation region SR is formed on one side in the X direction of the evaporation chamber 1 ( Figure 2 the left side in the figure). Heat from the electronic device D is transferred to the evaporation region SR, and the liquid of the working fluid evaporates in the evaporation region SR due to this heat. The heat from the electronic device D can be transferred not only to the region that coincides with the electronic device D in a top view but also to the periphery of the region that coincides with the electronic device D. Therefore, the evaporation region SR includes the region that coincides with the electronic device D in a top view and its peripheral region. Here, the top view means a state of observing from a direction perpendicular to the surface of the evaporation chamber 1 that receives heat from the electronic device D and the surface that releases the received heat. The heat-receiving surface corresponds to the second upper surface 20b of the upper side plate 20 described later. The surface that releases heat corresponds to the first lower surface 10a of the lower side plate 10 described later. For example, as Figure 2 shown, the state of observing the evaporation chamber 1 from above or from below corresponds to the top view. Also, the gas of the working fluid is denoted as the working vapor 2a, and the liquid of the working fluid is denoted as the working liquid 2b.

[0212] The condensation region CR is a region that does not coincide with the electronic device D in a top view and is a region mainly for the working vapor 2a to release heat and condense. The condensation region CR can also be said to be the surrounding region of the evaporation region SR. In the condensation region CR, the heat from the working vapor 2a is released to the lower side plate 10, and the working vapor 2a is cooled and condensed in the condensation region CR.

[0213] Moreover, when the evaporation chamber 1 is provided in a tablet terminal, there are cases where the up-down relationship does not hold depending on the posture of the tablet terminal. However, in the present embodiment, for convenience, the plate that receives heat from the electronic device D is called the upper side plate 20 described above, and the plate that releases the received heat is called the lower side plate 10 described above. Therefore, the structure of the evaporation chamber 1 will be described in a state where the lower side plate 10 is arranged on the lower side and the upper side plate 20 is arranged on the upper side.

[0214] As Figure 3As shown, the lower side piece 10 has: a first lower side surface 10a provided on the side opposite to the core piece 30; and a second lower side surface 10b provided on the side opposite to the first lower side surface 10a. The second lower side surface 10b is provided on one side of the core piece 30. The lower side piece 10 can be formed in a flat shape as a whole. The lower side piece 10 can have a fixed thickness as a whole. A housing member Ha that forms part of the above-described housing H is mounted on the first lower side surface 10a. The entire first lower side surface 10a can be covered by the housing member Ha. As Figure 4 shown, alignment holes 12 can be provided at the four corners of the lower side piece 10.

[0215] As Figure 3 shown, the upper side piece 20 has: a first upper side surface 20a provided on one side of the core piece 30; and a second upper side surface 20b provided on the side opposite to the first upper side surface 20a. The first upper side surface 20a is provided on one side of the core piece 30. The upper side piece 20 can be formed in a flat shape as a whole. The upper side piece 20 can have a fixed thickness as a whole. The above-described electronic device D is mounted on the second upper side surface 20b. As Figure 5 shown, alignment holes 22 can be provided at the four corners of the upper side piece 20.

[0216] As Figure 3 shown, the core piece 30 includes: a piece main body 31; and a vapor flow path portion 50, a liquid flow path portion 60, and a liquid storage portion 70 provided on the piece main body 31. The piece main body 31 has: a first main surface 31a; and a second main surface 31b provided on the side opposite to the first main surface 31a. The first main surface 31a is disposed on one side of the lower side piece 10. The second main surface 31b is disposed on one side of the upper side piece 20. The above-described sealed space 3 is formed by the vapor flow path portion 50, the liquid flow path portion 60, and the liquid storage portion 70.

[0217] The second lower side surface 10b of the lower side piece 10 and the first main surface 31a of the piece main body 31 can be diffusion-bonded together. The second lower side surface 10b and the first main surface 31a can also be permanently bonded to each other. Similarly, the first upper side surface 20a of the upper side piece 20 and the second main surface 31b of the piece main body 31 can be diffusion-bonded together. The first upper side surface 20a and the second main surface 31b can also be permanently bonded to each other. And, if the lower side piece 10, the upper side piece 20, and the core piece 30 can be permanently bonded together instead of diffusion-bonded, they can also be joined by other means such as brazing. And, the term "permanently bonded" is not limited to the strict meaning, but is used as a term indicating the degree of bonding such that the sealing property of the sealed space 3 can be maintained when the evaporation chamber 1 is operating. As long as the lower side piece 10 and the core piece 30 are permanently bonded and the bonding between the lower side piece 10 and the core piece 30 can be maintained when the evaporation chamber 1 is operating. As long as the upper side piece 20 and the core piece 30 are permanently bonded and the bonding between the upper side piece 20 and the core piece 30 can be maintained when the evaporation chamber 1 is operating.

[0218] The piece main body 31 of the core piece 30 in the present embodiment includes a frame portion 32 and a plurality of platform portions 33. As Figure 3 , Figure 6 and Figure 7 shown, the frame portion 32 is formed in a rectangular frame shape in a plan view. The platform portions 33 are provided inside the frame portion 32. The frame portion 32 and the platform portions 33 are parts where the material of the core piece 30 remains without being etched in the etching process described later. The vapor flow path portion 50 is defined inside the frame portion 32. That is, the working vapor 2a flows inside the frame portion 32 and around the platform portions 33.

[0219] In the present embodiment, the platform portions 33 can extend in an elongated shape with the X direction as the length direction in a plan view. The planar shape of the platform portions 33 can be an elongated rectangular shape. The X direction is an example of the first direction. The X direction corresponds to the left-right direction in Figure 6 . In addition, the respective platform portions 33 are separated at equal intervals in the Y direction. The Y direction is an example of the second direction. The Y direction corresponds to the up-down direction in Figure 6 . The respective platform portions 33 can be arranged parallel to each other. The working vapor 2a flows around the respective platform portions 33 and is delivered toward the condensation region CR. Thereby, the situation where the flow of the working vapor 2a is obstructed is suppressed. The width w1 (refer to Figure 8A ) of the platform portion 33 can be, for example, 100 μm to 1500 μm. Here, the width w1 of the platform portion 33 is the dimension of the platform portion 33 in the Y direction. The width w1 refers to the dimension at a position where a through portion 34 described later exists in the thickness direction of the core piece 30.

[0220] The frame portion 32 and each platform portion 33 are diffusion-bonded to the lower side piece 10 and are also diffusion-bonded to the upper side piece 20. Thereby, the mechanical strength of the evaporation chamber 1 can be improved. The wall surface 53a of the lower steam flow path recess 53 and the wall surface 54a of the upper steam flow path recess 54, which will be described later, constitute the side walls of the platform portion 33. The first main surface 31a and the second main surface 31b of the piece main body 31 can be formed in a flat shape over the frame portion 32 and each platform portion 33.

[0221] The steam flow path portion 50 is an example of a through space that penetrates the piece main body 31. The steam flow path portion 50 is a flow path mainly for the working steam 2a to pass through. The steam flow path portion 50 penetrates from the first main surface 31a to the second main surface 31b.

[0222] As Figure 6 and Figure 7 shown, the steam flow path portion 50 in the present embodiment has a first steam passage 51 and a plurality of second steam passages 52. The first steam passage 51 is formed between the frame portion 32 and the platform portion 33. The first steam passage 51 is continuously formed inside the frame portion 32 and outside the platform portion 33. The planar shape of the first steam passage 51 is a rectangular frame shape. The second steam passages 52 are formed between adjacent platform portions 33. The planar shape of the second steam passages 52 is an elongated rectangular shape. The steam flow path portion 50 is divided into the first steam passage 51 and a plurality of second steam passages 52 by a plurality of platform portions 33.

[0223] As Figure 3 shown, the first steam passage 51 and the second steam passages 52 extend from the first main surface 31a to the second main surface 31b of the piece main body 31. The first steam passage 51 and the second steam passages 52 are each composed of the following parts: a lower steam flow path recess 53 provided on the first main surface 31a; and an upper steam flow path recess 54 provided on the second main surface 31b. The lower steam flow path recess 53 and the upper steam flow path recess 54 communicate with each other, and the first steam passage 51 and the second steam passages 52 of the steam flow path portion 50 extend from the first main surface 31a to the second main surface 31b.

[0224] The lower steam flow path recess 53 is formed by etching from the first main surface 31a of the core piece 30 in an etching process to be described later. The lower steam flow path recess 53 is formed in a concave shape on the first main surface 31a. Thereby, as Figure 8A shown, the lower steam flow path recess 53 has a wall surface 53a formed in a curved shape. The wall surface 53a defines the lower steam flow path recess 53 and is curved in a shape that bulges toward the second main surface 31b. Such a lower steam flow path recess 53 constitutes a part (lower half) of the first steam passage 51 and a part (lower half) of the second steam passages 52.

[0225] The upper steam flow path recess 54 is formed by etching from the second main surface 31b of the core piece 30 in the etching process described later. The upper steam flow path recess 54 is formed in a concave shape on the second main surface 31b. Thus, as Figure 8A shown, the upper steam flow path recess 54 has a wall surface 54a formed in a curved shape. The wall surface 54a defines the upper steam flow path recess 54 and is curved in a shape that bulges toward the first main surface 31a. Such an upper steam flow path recess 54 constitutes a part (upper half) of the first steam passage 51 and a part (upper half) of the second steam passage 52.

[0226] As Figure 8A shown, the wall surface 53a of the lower steam flow path recess 53 and the wall surface 54a of the upper steam flow path recess 54 are connected to form a through portion 34. The wall surface 53a and the wall surface 54a are respectively curved toward the through portion 34. Thus, the lower steam flow path recess 53 and the upper steam flow path recess 54 communicate with each other. In the present embodiment, the planar shape of the through portion 34 in the first steam passage 51 is a rectangular frame shape that is the same as that of the first steam passage 51. The planar shape of the through portion 34 in the second steam passage 52 is an elongated rectangular shape that is the same as that of the second steam passage 52. It is possible that the wall surface 53a of the lower steam flow path recess 53 and the wall surface 54a of the upper steam flow path recess 54 converge and are defined by a ridge line. As Figure 8A shown, this ridge line can be formed to protrude inwardly into the steam passages 51, 52. At this through portion 34, the planar area of the first steam passage 51 becomes the smallest, and the planar area of the second steam passage 52 becomes the smallest. The width w2 of such a through portion 34 (refer to Figure 8A ) can be, for example, 400 μm to 1600 μm. Here, the width w2 of the through portion 34 corresponds to the gap between the platform portions 33 adjacent to each other in the Y direction.

[0227] The position of the through portion 34 in the Z direction can be the intermediate position between the first lower side surface 10a and the second upper side surface 20b. Alternatively, the position of the through portion 34 can be a position offset downward from the intermediate position, or can also be a position offset upward. As long as the lower steam flow path recess 53 and the upper steam flow path recess 54 communicate, the position of the through portion 34 in the Z direction is arbitrary.

[0228] In addition, in the present embodiment, the cross-sectional shapes of the first steam passage 51 and the second steam passage 52 are formed to include the through portion 34, which is defined by a ridge line formed to protrude inwardly, but it is not limited thereto. For example, the cross-sectional shapes of the first steam passage 51 and the second steam passage 52 can be trapezoidal or rectangular, or can also be a barrel shape.

[0229] The vapor flow path section 50 including the first vapor path 51 and the second vapor path 52 configured as such forms a part of the above-described sealed space 3. As Figure 3 shown, the vapor flow path section 50 of the present embodiment is mainly defined by the lower side piece 10, the upper side piece 20, and the frame portion 32 and the platform portion 33 of the above-described piece main body 31. Each of the vapor paths 51, 52 has a relatively large flow path cross-sectional area for the working vapor 2a to pass through.

[0230] Here, for the sake of clarity of the drawings, Figure 3 the first vapor path 51 and the second vapor path 52 are shown enlarged. The number or arrangement of these vapor paths 51, 52 is different from Figure 2 、 Figure 6 and Figure 7 .

[0231] In addition, although not shown, a plurality of support portions for supporting the platform portion 33 on the frame portion 32 may be provided in the vapor flow path section 50. In addition, support portions for supporting the adjacent platform portions 33 may be provided. These support portions may be provided on both sides of the platform portion 33 in the X direction or on both sides of the platform portion 33 in the Y direction. Preferably, the support portions are formed so as not to obstruct the flow of the working vapor 2a diffusing in the vapor flow path section 50. For example, they may be arranged on one side of the first main surface 31a and the second main surface 31b of the piece main body 31 of the core piece 30, and a space forming the vapor flow path recess may be formed on the other side. Thereby, the thickness of the support portions can be made thinner than the thickness of the piece main body 31, and the first vapor path 51 and the second vapor path 52 can be prevented from being disconnected in the X direction and the Y direction.

[0232] As Figure 6 and Figure 7 shown, calibration holes 35 may be provided at the four corners of the piece main body 31 of the core piece 30.

[0233] In addition, as Figure 2 shown, the evaporation chamber 1 may further include an injection portion 4 for injecting the working liquid 2b into the sealed space 3 at one end edge in the X direction. In the Figure 2 shown configuration, the injection portion 4 is arranged on one side of the evaporation region SR. The injection portion 4 protrudes outward from the end edge on the evaporation region SR side.

[0234] More specifically, the injection portion 4 may include: a lower injection protrusion 11; an upper injection protrusion 21; and a core piece injection protrusion 36. As Figure 4 shown, the lower injection protrusion 11 is a part constituting the lower side piece 10. As Figure 5 shown, the upper injection protrusion 21 is a part constituting the upper side piece 20. As Figure 6 and Figure 7As shown, the core chip injection protrusion 36 is a part that constitutes the chip main body 31. An injection flow path 37 is formed in the core chip injection protrusion 36. The injection flow path 37 extends from the first main surface 31a of the chip main body 31 to the second main surface 31b, thereby penetrating the chip main body 31 (more specifically, the core chip injection protrusion 36) in the Z direction. In addition, the injection flow path 37 communicates with the vapor flow path portion 50. The working fluid 2b is injected into the sealing space 3 through the injection flow path 37. And it can be that the injection flow path 37 communicates with the liquid flow path portion 60 through the arrangement of the liquid flow path portion 60. The upper surface and the lower surface of the core chip injection protrusion 36 are formed in a flat shape. The upper surface of the lower injection protrusion 11 and the lower surface of the upper injection protrusion 21 are also formed in a flat shape. The planar shapes of the respective injection protrusions 11, 21, 38 may be the same.

[0235] And, in the present embodiment, an example is shown in which the injection portion 4 is provided at one end edge of a pair of end edges of the evaporation chamber 1 in the X direction. However, it is not limited thereto, and the injection portion 4 can be provided at any position. In addition, for the injection flow path 37 provided in the core chip injection protrusion 36, as long as the working fluid 2b can be injected, it may not penetrate the chip main body 31. In this case, by etching only from one of the first main surface 31a and the second main surface 31b of the chip main body 31, the injection flow path 37 communicating with the vapor flow path portion 50 can be formed.

[0236] As Figure 3 , Figure 6 and Figure 8A shown, the liquid flow path portion 60 is provided on the second main surface 31b of the chip main body 31 of the core chip 30. The liquid flow path portion 60 may be a flow path mainly for the working fluid 2b to pass through. The liquid flow path portion 60 constitutes a part of the above-mentioned sealing space 3. The liquid flow path portion 60 communicates with the vapor flow path portion 50. The liquid flow path portion 60 is configured as a capillary structure for transporting the working fluid 2b to the evaporation region SR. Sometimes the liquid flow path portion 60 is also called the core. In the present embodiment, the liquid flow path portion 60 is provided on the second main surface 31b of each platform portion 33 of the core chip 30. The liquid flow path portion 60 may be formed over the entire second main surface 31b of each platform portion 33. On the first main surface 31a of each platform portion 33, the liquid flow path portion 60 may not be provided.

[0237] As Figure 9As shown, the liquid flow path portion 60 is an example of the first groove assembly. More specifically, the liquid flow path portion 60 includes a plurality of main liquid flow path grooves 61 and a plurality of liquid flow path connection grooves 65. The main liquid flow path groove 61 is an example of the first main groove. The liquid flow path connection groove 65 is an example of the first connection groove. The main liquid flow path groove 61 and the liquid flow path connection groove 65 are grooves through which the working liquid 2b passes. The liquid flow path connection groove 65 communicates with the main liquid flow path groove 61.

[0238] As Figure 9 shown, each main liquid flow path groove 61 extends in the X direction. The main liquid flow path groove 61 has a flow path cross-sectional area that mainly allows the working liquid 2b to flow by capillary action. The flow path cross-sectional area of the main liquid flow path groove 61 is smaller than the flow path cross-sectional areas of the vapor passages 51 and 52. Thus, the main liquid flow path groove 61 is configured to transport the working liquid 2b condensed from the working vapor 2a to the evaporation region SR. It is possible that the main liquid flow path grooves 61 are arranged at equal intervals in the Y direction perpendicular to the X direction.

[0239] The main liquid flow path groove 61 is formed by etching from the second main surface 31b of the sheet main body 31 of the core sheet 30 in an etching process described later. Thus, as Figure 8A shown, the main liquid flow path groove 61 has a wall surface 62 formed in a curved shape. The wall surface 62 defines the main liquid flow path groove 61 and is curved in a shape that bulges toward the first main surface 31a.

[0240] As Figure 8A and Figure 9 shown, the width w3 of the main liquid flow path groove 61 can be, for example, 5 μm to 150 μm. The width w3 of the main liquid flow path groove 61 refers to the dimension on the second main surface 31b. The width w3 corresponds to the dimension in the Y direction. In addition, as Figure 8A shown, the depth h1 of the main liquid flow path groove 61 can be, for example, 3 μm to 150 μm. The depth h1 corresponds to the dimension in the Z direction.

[0241] As Figure 9As shown, each liquid flow path connection groove 65 extends in a direction different from the X direction. In the present embodiment, each liquid flow path connection groove 65 extends in the Y direction. The liquid flow path connection groove 65 is formed perpendicular to the main liquid flow path groove 61. Several liquid flow path connection grooves 65 communicate the main liquid flow path grooves 61 adjacent to each other. Other liquid flow path connection grooves 65 communicate the first vapor passage 51 or the second vapor passage 52 with the main liquid flow path groove 61. That is, the liquid flow path connection groove 65 extends from the end edge of the platform portion 33 in the Y direction to the main liquid flow path groove 61 adjacent to the end edge. Thus, the first vapor passage 51 and the main liquid flow path groove 61 are communicated, and the second vapor passage 52 and the main liquid flow path groove 61 are communicated.

[0242] The liquid flow path connection groove 65 has a flow path cross-sectional area that mainly allows the working liquid 2b to flow by capillary action. The flow path cross-sectional area of the liquid flow path connection groove 65 is smaller than the flow path cross-sectional areas of the vapor passages 51 and 52. Each liquid flow path connection groove 65 can be arranged at equal intervals in the X direction.

[0243] The liquid flow path connection groove 65 is formed by etching in the same manner as the main liquid flow path groove 61. The liquid flow path connection groove 65 has a wall surface (not shown) formed in the same curved shape as the main liquid flow path groove 61. As Figure 9 shown, the width w4 of the liquid flow path connection groove 65 can be equal to the width w3 of the main liquid flow path groove 61. However, the width w4 can also be larger than the width w3, or can be smaller than it. The width w4 corresponds to the dimension in the X direction. The depth of the liquid flow path connection groove 65 can be equal to the depth h1 of the main liquid flow path groove 61. However, the depth of the liquid flow path connection groove 65 can also be deeper than the depth h1, or can be shallower than it.

[0244] As Figure 9 shown, a convex portion row 63 is provided between the main liquid flow path grooves 61 adjacent to each other. Each convex portion row 63 includes a plurality of convex portions 64 arranged in the X direction. The convex portion 64 is an example of a liquid flow path protruding portion. The convex portion 64 is provided in the liquid flow path portion 60. The convex portion 64 protrudes from the sheet main body 31 and abuts against the upper sheet 20. Each convex portion 64 is formed in a rectangular shape with the X direction being the length direction in a plan view. The main liquid flow path groove 61 is interposed between the convex portions 64 adjacent to each other in the Y direction. The liquid flow path connection groove 65 is interposed between the convex portions 64 adjacent to each other in the X direction. The liquid flow path connection groove 65 extends in the Y direction and communicates the main liquid flow path grooves 61 adjacent to each other in the Y direction. Thereby, the working liquid 2b can travel between these main liquid flow path grooves 61.

[0245] The convex portion 64 is a portion where the material of the core sheet 30 remains without being etched in the etching process described later. In the present embodiment, as Figure 9As shown, the planar shape of the convex portion 64 is rectangular. The planar shape of the convex portion 64 corresponds to the planar shape at the position of the second main surface 31b of the sheet main body 31.

[0246] In the present embodiment, the convex portions 64 are arranged in a staggered pattern. More specifically, the convex portions 64 of the convex portion columns 63 adjacent to each other in the Y direction are arranged so as to be offset from each other in the X direction. The offset amount can be half of the arrangement pitch of the convex portions 64 in the X direction. The width w5 of the convex portion 64 can be, for example, 5 μm to 500 μm. The width w5 of the convex portion 64 refers to the dimension on the second main surface 31b. The width w5 corresponds to the dimension in the Y direction. Further, the arrangement of the convex portions 64 is not limited to the staggered pattern, and they may be arranged side by side. In this case, the convex portions 64 of the convex portion columns 63 adjacent to each other in the Y direction are also aligned in the X direction (refer to Figure 19 ).

[0247] The liquid flow path main channel 61 includes a liquid flow path crossing portion 66. The liquid flow path crossing portion 66 is an example of the first crossing portion. The liquid flow path crossing portion 66 is a portion of the liquid flow path main channel 61 that communicates with the liquid flow path connection groove 65. At the liquid flow path crossing portion 66, the liquid flow path main channel 61 and the liquid flow path connection groove 65 communicate in a T shape. Thereby, it is possible to avoid the following situation: at the liquid flow path crossing portion 66 where one liquid flow path main channel 61 communicates with the liquid flow path connection groove 65 on one side, the liquid flow path connection groove 65 on the other side communicates with the liquid flow path main channel 61. Thereby, at this liquid flow path crossing portion 66, it is possible to prevent the wall surface 62 of the liquid flow path main channel 61 from being cut off on both sides, and one side of the wall surface 62 can be left remaining. For example, it is possible to avoid the following situation: at one liquid flow path crossing portion 66, Figure 9 the upper liquid flow path connection groove 65 and the lower liquid flow path connection groove 65 in Figure 9 communicate with the liquid flow path main channel 61. In this case, at this liquid flow path crossing portion 66, it is possible to prevent

[0248] both the upper wall surface 62 and the lower wall surface 62 in Figure 3 from being cut off. Thereby, even at the liquid flow path crossing portion 66, it is possible to impart a capillary action to the working liquid in the liquid flow path main channel 61. Therefore, it is possible to suppress the following situation: the propulsive force of the working liquid 2b toward the evaporation region SR decreases at the liquid flow path crossing portion 66.

[0248] As shown in Figure 3 , Figure 7 and Figure 8AAs shown, the liquid storage section 70 is provided on the first main surface 31a of the sheet main body 31 of the core sheet 30. The liquid storage section 70 may be a part mainly storing the working liquid 2b. The liquid storage section 70 forms a part of the above-described sealed space 3. The liquid storage section 70 communicates with the vapor flow path section 50 and communicates with the liquid flow path section 60 via the vapor flow path section 50. In the present embodiment, the liquid storage section 70 is provided on the first main surface 31a of each platform section 33 of the core sheet 30.

[0249] As Figure 7 and Figure 11 shown, the liquid storage section 70 of the present embodiment may be arranged on one side of the platform section 33 in the X direction. The liquid storage section 70 may also be formed on this side closer to the center of the platform section 33 in the X direction. The liquid storage section 70 may be arranged on the evaporation region SR side and may be arranged on the left side of the platform section 33 as Figure 7 shown. More specifically, the liquid storage section 70 is continuously formed from the end edge on the evaporation region SR side of the pair of end edges of the platform section 33 in the X direction toward the other end edge to a specified position. In Figure 7 , the liquid storage section 70 is formed from the left end edge toward the right end edge to a specified position. The liquid storage section 70 of the present embodiment may be arranged in the evaporation region SR. However, it is not limited thereto, and a part of the liquid storage section 70 may also extend outside the evaporation region SR. When at least a part of the liquid storage section 70 is arranged in the evaporation region SR, the working liquid 2b stored in the liquid storage section 70 is heated by the electronic device D and easily evaporates. In addition, the liquid storage section 70 may be arranged in a region overlapping the electronic device D.

[0250] As Figure 10 shown, the liquid storage section 70 is an example of the second groove aggregate. More specifically, the liquid storage section 70 includes a plurality of liquid storage main grooves 71 and a plurality of liquid storage connection grooves 75. The liquid storage main groove 71 is an example of the second main groove. The liquid storage connection groove 75 is an example of the second connection groove. The liquid storage main groove 71 and the liquid storage connection groove 75 are grooves through which the working liquid 2b passes. The liquid storage connection groove 75 communicates with the liquid storage main groove 71.

[0251] As Figure 10 shown, each liquid storage main groove 71 extends in the X direction. As Figure 7 and Figure 11As shown, the liquid storage main flow channel 71 is continuously formed from the edge of the platform portion 33 on the evaporation region SR side in the X direction toward the other edge to a specified position. The liquid storage main flow channel 71 defines the X-direction range of the liquid storage portion 70. The liquid storage main flow channel 71 has a flow path cross-sectional area that mainly allows the working fluid 2b to flow by capillary action. The flow path cross-sectional area of the liquid storage main flow channel 71 is smaller than that of the vapor passages 51 and 52. However, the flow path cross-sectional area of the liquid storage main flow channel 71 may also be larger than that of the above-described liquid flow path main channel 61. The capillary force acting on the working fluid 2b in the liquid storage main flow channel 71 may be smaller than the capillary force acting on the working fluid 2b in the liquid flow path main channel 61. In this way, the liquid storage main flow channel 71 can introduce the working fluid 2b into the liquid storage portion 70 and can ensure the storage amount of the working fluid 2b. It is possible that the liquid storage main flow channels 71 are arranged at equal intervals in the Y direction perpendicular to the X direction.

[0252] The liquid storage main flow channel 71 is formed by etching from the first main surface 31a of the sheet main body 31 of the core sheet 30 in the etching process described later. Thus, as Figure 8A shown, the liquid storage main flow channel 71 has a wall surface 72 formed in a curved shape. The wall surface 72 defines the liquid storage main flow channel 71 and is curved in a shape that bulges toward the second main surface 31b.

[0253] As Figure 8A and Figure 10 shown, the width w6 of the liquid storage main flow channel 71 may be larger than the width w3 of the above-described liquid flow path main channel 61. The width w6 may be, for example, 10 μm to 250 μm. And the width w6 of the liquid storage main flow channel 71 refers to the dimension on the first main surface 31a. The width w6 corresponds to the dimension in the Y direction. In addition, as Figure 8A shown, the depth h2 of the liquid storage main flow channel 71 may be larger than the depth h1 of the above-described liquid flow path main channel 61. The depth h2 may be, for example, 5 μm to 200 μm. The depth h2 corresponds to the dimension in the Z direction.

[0254] As Figure 10As shown, each liquid storage connection groove 75 extends in a direction different from the X direction. In the present embodiment, each liquid storage connection groove 75 extends in the Y direction. The liquid storage connection groove 75 is formed perpendicular to the liquid storage main flow groove 71. Several liquid storage connection grooves 75 communicate the liquid storage main flow grooves 71 adjacent to each other. Other liquid storage connection grooves 75 communicate the first vapor passage 51 or the second vapor passage 52 with the liquid storage main flow groove 71. That is, the liquid storage connection groove 75 extends from the end edge of the platform portion 33 in the Y direction to the liquid storage main flow groove 71 adjacent to the end edge. In this way, the first vapor passage 51 and the liquid storage main flow groove 71 are communicated, and the second vapor passage 52 and the liquid storage main flow groove 71 are communicated.

[0255] The liquid storage connection groove 75 has a flow path cross-sectional area that mainly allows the working fluid 2b to flow by capillary action. The flow path cross-sectional area of the liquid storage connection groove 75 is smaller than the flow path cross-sectional areas of the vapor passages 51 and 52. However, the flow path cross-sectional area of the liquid storage connection groove 75 can be larger than the flow path cross-sectional area of the above-mentioned liquid flow connection groove 65. The capillary force acting on the working fluid 2b in the liquid storage connection groove 75 can be smaller than the capillary force acting on the working fluid 2b in the liquid flow connection groove 65. In this way, the liquid storage connection groove 75 can introduce the working fluid 2b into the liquid storage portion 70 and can ensure the storage amount of the working fluid 2b. Each liquid storage connection groove 75 can be arranged at equal intervals in the X direction.

[0256] The liquid storage connection groove 75 is formed by etching in the same manner as the liquid storage main flow groove 71. The liquid storage connection groove 75 has a wall surface (not shown) formed in the same curved shape as the liquid storage main flow groove 71. As Figure 10 shown, the width w7 of the liquid storage connection groove 75 can be equal to the width w6 of the liquid storage main flow groove 71. However, the width w7 can also be larger than the width w6, or can be smaller than it. The width w7 corresponds to the dimension in the X direction. The depth of the liquid storage connection groove 75 can be equal to the depth h2 of the liquid storage main flow groove 71. However, the depth of the liquid storage connection groove 75 can also be deeper than the depth h2, or can be shallower than it.

[0257] As Figure 10As shown, between the main liquid storage channels 71 adjacent to each other, there are provided convex portion columns 73. Each convex portion column 73 includes a plurality of convex portions 74 arranged in the X direction. The convex portion 74 is an example of a liquid storage protruding portion. The convex portion 74 is provided within the liquid storage portion 70. The convex portion 74 protrudes from the sheet main body 31 and abuts against the lower sheet 10. Each convex portion 74 is formed in a rectangular shape such that the X direction is the longitudinal direction in a plan view. The main liquid storage channels 71 are interposed between the convex portions 74 adjacent to each other in the Y direction. The liquid storage connection channels 75 are interposed between the convex portions 74 adjacent to each other in the X direction. The liquid storage connection channels 75 extend in the Y direction and communicate with each other the main liquid storage channels 71 adjacent to each other in the Y direction. Thus, the working liquid 2b can flow back and forth between these main liquid storage channels 71.

[0258] The convex portion 74 is a portion where the material of the core sheet 30 remains without being etched in the etching process described later. In the present embodiment, as Figure 10 shown, the planar shape of the convex portion 74 is rectangular. The planar shape of the convex portion 74 corresponds to the planar shape at the position of the first main surface 31a of the sheet main body 31.

[0259] In the present embodiment, the convex portions 74 are arranged in a staggered manner. More specifically, the convex portions 74 of the adjacent convex portion columns 73 are arranged so as to be offset from each other in the X direction. The offset amount can be half of the arrangement pitch of the convex portions 74 in the X direction. The width w8 of the convex portion 74 can be, for example, 10 μm to 100 μm. The width w8 of the convex portion 74 refers to the dimension on the first main surface 31a. The width w8 corresponds to the dimension in the Y direction. And, the arrangement of the convex portions 74 is not limited to the staggered shape, and they may be arranged side by side. In this case, the convex portions 74 of the convex portion columns 73 adjacent to each other in the Y direction are also aligned in the X direction (refer to Figure 19 ).

[0260] Thus, the width w6 of the main liquid storage channel 71 can be larger than the w3 of the main liquid flow channel 61. The width w6 corresponds to the gap between a pair of convex portions 74 adjacent to each other in the Y direction. In addition, the width w6 of the main liquid storage channel 71 can be smaller than the width w2 of the through portion 34. The width w2 corresponds to the gap between a pair of platform portions 33 adjacent to each other in the Y direction.

[0261] In the present embodiment, as described above, the flow cross-sectional area of the main liquid storage channel 71 of the liquid storage portion 70 is larger than the flow cross-sectional area of the main liquid flow channel 61 of the liquid flow path portion 60. In order to satisfy this relationship of the flow cross-sectional area, in Figure 8AIn the example shown, the width w6 of the liquid storage main channel 71 is greater than the width w3 of the liquid flow path main channel 61, and the depth h2 of the liquid storage main channel 71 is greater than the depth h1 of the liquid flow path main channel 61. However, it is not limited to this. As long as the flow path cross-sectional area of the liquid storage main channel 71 is greater than the flow path cross-sectional area of the liquid flow path main channel 61, the relationship between the width and the depth can be arbitrary. For example, as Figure 8B shown, if the width w6 is greater than the width w3, the depth h2 can be equal to the depth h1. Even in this case, it is possible to make the flow path cross-sectional area of the liquid storage main channel 71 greater than the flow path cross-sectional area of the liquid flow path main channel 61. In addition, as Figure 8C shown, if the depth h2 is greater than the depth h1, the width w6 can be equal to the width w3. Even in this case, it is possible to make the flow path cross-sectional area of the liquid storage main channel 71 greater than the flow path cross-sectional area of the liquid flow path main channel 61. And the flow path cross-sectional area of the groove in this specification corresponds to the area occupied by the groove in the cross-section along the direction perpendicular to the direction in which the groove extends. For example, the flow path cross-sectional area of the liquid flow path main channel 61 corresponds to the area occupied by the groove 61 (or the space defined by the wall surface 62 of the groove 61) in the cross-section of the liquid flow path main channel 61 along the Y direction.

[0262] In addition, the number of the liquid storage main channels 71 provided in the platform portion 33 can be less than the number of the liquid flow path main channels 61 provided in the platform portion 33. In the present embodiment, the platform portion 33 extends in the X direction and has an elongated rectangular shape. And the width of the platform portion 33 on the first main surface 31a is equal to the width of the platform portion 33 on the second main surface 31b. In this case, it is possible to make the flow path cross-sectional area of the liquid storage main channel 71 greater than the flow path cross-sectional area of the liquid flow path main channel 61.

[0263] The liquid storage main channel 71 includes a liquid storage crossing portion 76. The liquid storage crossing portion 76 is an example of the second crossing portion. The liquid storage crossing portion 76 is a part of the liquid storage main channel 71 that communicates with the liquid storage connection groove 75. At the liquid storage crossing portion 76, the liquid storage main channel 71 and the liquid storage connection groove 75 are connected in a T shape. Thereby, it is possible to avoid the following situation: at the liquid storage crossing portion 76 where one liquid storage main channel 71 communicates with one side of the liquid storage connection groove 75, the other side of the liquid storage connection groove 75 communicates with the liquid storage main channel 71. Thereby, at the liquid storage crossing portion 76, it is possible to prevent the wall surface 72 of the liquid storage main channel 71 from being cut off on both sides and to leave one side of the wall surface 72. For example, it is possible to avoid such a situation: at one liquid storage crossing portion 76, Figure 10 the upper liquid storage connection groove 75 and the lower liquid storage connection groove 75 inFigure 10 Both the upper and lower wall surfaces 72 are cut away. As a result, even at the liquid storage intersection 76, capillary action can be imparted to the working fluid in the liquid storage main flow channel 71.

[0264] In addition, regarding the materials constituting the lower side piece 10, the upper side piece 20, and the core piece 30, as long as they are materials with good thermal conductivity, they are not particularly limited. The lower side piece 10, the upper side piece 20, and the core piece 30 may include, for example, copper or a copper alloy. In this case, the thermal conductivity of each of the pieces 10, 20, 30 can be improved, thereby improving the heat dissipation efficiency of the evaporation chamber 1. In addition, when using pure water as the working fluids 2a, 2b, corrosion can be prevented. And as long as the desired heat dissipation efficiency can be obtained and corrosion can be prevented, other metal materials such as aluminum or titanium, or other metal alloy materials such as stainless steel can also be used for these pieces 10, 20, 30.

[0265] In addition, Figure 3 The thickness t1 of the evaporation chamber 1 shown can be, for example, 100 μm to 1000 μm. By setting the thickness t1 of the evaporation chamber 1 to 100 μm or more, the vapor flow path portion 50 can be appropriately ensured. Therefore, the function of the evaporation chamber 1 can be appropriately exerted. On the other hand, by setting the thickness t1 to 1000 μm or less, the thickness t1 of the evaporation chamber 1 can be suppressed from becoming thick.

[0266] The thickness t2 of the lower side piece 10 can be, for example, 6 μm to 100 μm. By setting the thickness t2 of the lower side piece 10 to 6 μm or more, the mechanical strength of the lower side piece 10 can be ensured. On the other hand, by setting the thickness t2 of the lower side piece 10 to 100 μm or less, the thickness t1 of the evaporation chamber 1 can be suppressed from becoming thick. Similarly, the thickness t3 of the upper side piece 20 can be set in the same manner as the thickness t2 of the lower side piece 10. The thickness t3 of the upper side piece 20 and the thickness t2 of the lower side piece 10 may also be different.

[0267] The thickness t4 of the core piece 30 can be, for example, 50 μm to 400 μm. By setting the thickness t4 of the core piece 30 to 50 μm or more, the vapor flow path portion 50 can be appropriately ensured. Therefore, the function of the evaporation chamber 1 can be appropriately exerted. On the other hand, by setting it to 400 μm or less, the thickness t1 of the evaporation chamber 1 can be suppressed from becoming thick.

[0268] Next, regarding the manufacturing method of the evaporation chamber 1 of the present embodiment configured as such, it will be described using Figures 12 - 14 And in Figures 12 - 14 a cross-section identical to the cross-sectional view of Figure 3 is shown.

[0269] Here, first, the manufacturing process of the core piece 30 will be described.

[0270] First, as shown in Figure 12 , as a preparation process, a flat metal material sheet M is prepared. The metal material sheet M includes a first material surface Ma and a second material surface Mb. The metal material sheet M can be formed from a rolled product having a desired thickness.

[0271] After the preparation process, as an etching process, as shown in Figure 13 , the metal material sheet M is etched from the first material surface Ma and the second material surface Mb. Thereby, a vapor flow path portion 50, a liquid flow path portion 60, and a liquid storage portion 70 are formed on the metal material sheet M.

[0272] More specifically, a patterned resist film (not shown) is formed on the first material surface Ma and the second material surface Mb of the metal material sheet M by photolithography. Next, the first material surface Ma and the second material surface Mb of the metal material sheet M are etched through the openings of the patterned resist film. Thereby, the first material surface Ma and the second material surface Mb of the metal material sheet M are etched into a pattern shape to form Figure 13 the vapor flow path portion 50, the liquid flow path portion 60, and the liquid storage portion 70 as shown. And, as the etching solution, a ferric chloride-based etching solution such as an aqueous ferric chloride solution, or a cupric chloride-based etching solution such as an aqueous cupric chloride solution can be used.

[0273] Regarding the etching, the first material surface Ma and the second material surface Mb of the metal material sheet M can be etched simultaneously. However, it is not limited thereto, and the etching of the first material surface Ma and the second material surface Mb can also be performed as separate processes. In addition, the vapor flow path portion 50, the liquid flow path portion 60, and the liquid storage portion 70 can be formed simultaneously by etching, or can be formed by separate processes.

[0274] In addition, in the etching process, by etching the first material surface Ma and the second material surface Mb of the metal material sheet M, a Figure 6 and Figure 7 prescribed outer contour shape as shown can be obtained. That is, the edge of the core sheet 30 is formed.

[0275] In this way, the core sheet 30 of the present embodiment can be obtained.

[0276] After the manufacturing process of the core sheet 30, as a bonding process, as shown in Figure 14 , the lower sheet 10, the upper sheet 20, and the core sheet 30 are bonded together. And, the lower sheet 10 and the upper sheet 20 can be formed from rolled products having a desired planar shape and a desired thickness.

[0277] More specifically, first, the lower side piece 10, the core piece 30, and the upper side piece 20 are stacked in this order. In this case, the first main surface 31a of the core piece 30 coincides with the second lower side surface 10b of the lower side piece 10, and the first upper side surface 20a of the upper side piece 20 coincides with the second main surface 31b of the core piece 30. At this time, the pieces 10, 20, 30 are aligned using the alignment holes 12 of the lower side piece 10, the alignment holes 35 of the core piece 30, and the alignment holes 22 of the upper side piece 20.

[0278] Next, the lower side piece 10, the core piece 30, and the upper side piece 20 are temporarily fastened. For example, these pieces 10, 20, 30 can be temporarily fastened by performing resistance welding in a dot pattern, or these pieces 10, 20, 30 can be temporarily fastened by laser welding.

[0279] Next, the lower side piece 10, the core piece 30, and the upper side piece 20 are permanently joined together by diffusion bonding. Diffusion bonding is a method in which, in a controlled atmosphere such as a vacuum or an inert gas, the lower side piece 10, the core piece 30, and the upper side piece 20 are pressurized in the stacking direction and heated, and bonding is performed using the diffusion of atoms occurring at the bonding surface. When pressurizing, the lower side piece 10 and the core piece 30 are in close contact, and the core piece 30 and the upper side piece 20 are in close contact. In diffusion bonding, although the materials of the pieces 10, 20, 30 are heated to a temperature close to the melting point, since it is lower than the melting point, it is possible to avoid the situation where the pieces 10, 20, 30 melt and deform. More specifically, the first main surface 31a of the core piece 30 in the frame portion 32 and each platform portion 33 is diffusion bonded to the second lower side surface 10b of the lower side piece 10. In addition, the second main surface 31b of the core piece 30 in the frame portion 32 and each platform portion 33 is diffusion bonded to the first upper side surface 20a of the upper side piece 20. In this way, the pieces 10, 20, 30 are diffusion bonded together, and a sealed space 3 having a vapor flow path portion 50, a liquid flow path portion 60, and a liquid storage portion 70 is formed between the lower side piece 10 and the upper side piece 20. At this stage, the injection flow path 37 described above may not be sealed for the sealed space 3. In the above-described injection portion 4, the lower injection protrusion 11 of the lower side piece 10 and the core piece injection protrusion 36 of the core piece 30 are diffusion bonded together. In addition, the core piece injection protrusion 36 and the upper injection protrusion 21 of the upper side piece 20 are diffusion bonded together.

[0280] After the joining process, the working fluid 2b is injected into the sealed space 3 from the injection portion 4. At this time, the working fluid 2b can be injected in an injection amount larger than the total volume of the space formed by the main liquid flow grooves 61 and the liquid flow connection grooves 65 of each liquid flow path in the liquid flow path portion 60.

[0281] Then, seal the above-mentioned injection flow path 37. For example, it can be that the injection portion 4 is irradiated with a laser to partially melt the injection portion 4 and seal the injection flow path 37. Thus, the communication between the sealed space 3 and the outside is blocked, and the sealed space 3 filled with the working fluid 2b is obtained. Therefore, the leakage of the working fluid 2b in the sealed space 3 to the outside is prevented. And, in order to seal the injection flow path 37, the injection portion 4 can be caulked (or can be extruded to cause plastic deformation), or can also be brazed.

[0282] Through the above content, the evaporation chamber 1 of the present embodiment is obtained.

[0283] Next, the working method of the evaporation chamber 1, that is, the cooling method of the electronic device D, will be described.

[0284] The evaporation chamber 1 obtained as described above is provided in the housing H of a mobile terminal or the like. Electronic devices D such as a CPU to be cooled are mounted on the second upper side surface 20b of the upper side plate 20. The working fluid 2b in the sealed space 3 adheres to the wall surface of the sealed space 3 due to its surface tension. More specifically, the working fluid 2b adheres to the wall surface 53a of the lower side vapor flow path recess 53, the wall surface 54a of the upper side vapor flow path recess 54, the wall surface 62 of the liquid flow path main groove 61 of the liquid flow path portion 60, and the wall surface of the liquid flow path connection groove 65. In addition, the working fluid 2b also adheres to the portion of the second lower side surface 10b of the lower side plate 10 that is exposed in the lower side vapor flow path recess 53. In addition, the working fluid 2b also adheres to the portion of the first upper side surface 20a of the upper side plate 20 that is exposed in the upper side vapor flow path recess 54, the liquid flow path main groove 61, and the liquid flow path connection groove 65.

[0285] If the electronic device D generates heat in this state, the working fluid 2b present in the evaporation region SR (refer to Figure 6 and Figure 7 ) is heated by the electronic device D. The received heat is absorbed as latent heat to cause the working fluid 2b to evaporate, thereby generating working vapor 2a. Most of the generated working vapor 2a diffuses in the lower side vapor flow path recess 53 and the upper side vapor flow path recess 54 that constitute the sealed space 3 (refer to the solid line arrows in Figure 6 ). The working vapor 2a in each vapor flow path recess 53, 54 leaves the evaporation region SR. Most of the working vapor 2a is transported to the condensation region CR with a lower temperature. In Figure 6 and Figure 7 , most of the working vapor 2a is transported to the right side portion in the vapor flow path portion 50. In the condensation region CR, the working vapor 2a is mainly cooled by dissipating heat in the lower side plate 10. The heat received by the lower side plate 10 from the working vapor 2a is transferred to the outside air through the housing member Ha (refer to Figure 3 ).

[0286] The working vapor 2a dissipates heat to the lower side plate 10 in the condensation region CR. As a result, the working vapor 2a loses the latent heat absorbed in the evaporation region SR and condenses, thereby generating the working liquid 2b. The generated working liquid 2b adheres to the wall surfaces 53a, 54a of the respective vapor flow path recesses 53, 54, the second lower side surface 10b of the lower side plate 10, and the first upper side surface 20a of the upper side plate 20. Here, in the evaporation region SR, the working liquid 2b continuously evaporates. Therefore, the working liquid 2b in the region of the liquid flow path portion 60 other than the evaporation region SR (i.e., the condensation region CR) is transported toward the evaporation region SR by the capillary action of each liquid flow path main groove 61 (see the dashed arrow in Figure 6 ). As a result, the working liquid 2b adhering to the respective wall surfaces 53a, 54a, the second lower side surface 10b, and the first upper side surface 20a moves in the liquid flow path portion 60. At this time, the working liquid 2b enters the liquid flow path main groove 61 through the liquid flow path connection groove 65. In this way, the working liquid 2b is filled in each liquid flow path main groove 61 and each liquid flow path connection groove 65. Therefore, the filled working liquid 2b obtains a propulsive force toward the evaporation region SR by the capillary action of each liquid flow path main groove 61. In this way, the working liquid 2b is smoothly transported toward the evaporation region SR.

[0287] In the liquid flow path portion 60, each liquid flow path main groove 61 communicates with other adjacent liquid flow path main grooves 61 via the corresponding liquid flow path connection grooves 65. As a result, the working liquid 2b travels back and forth in the adjacent liquid flow path main grooves 61, suppressing the occurrence of dry-out in the liquid flow path main grooves 61. Therefore, the capillary action is imparted to the working liquid 2b in each liquid flow path main groove 61, and the working liquid 2b is smoothly transported toward the evaporation region SR.

[0288] And, a part of the working liquid 2b condensed in the condensation region CR is not transported to the liquid flow path portion 60, but is transported to the liquid storage portion 70 provided on the first main surface 31a of the core plate 30. More specifically, a part of the working liquid 2b adhering to the respective wall surfaces 53a, 54a, the second lower side surface 10b, and the first upper side surface 20a enters the liquid storage main groove 71 through the liquid storage connection groove 75. In this way, the working liquid 2b is filled in each liquid storage main groove 71 and each liquid storage connection groove 75. Therefore, the working liquid 2b obtains a propulsive force by the capillary action of each liquid storage main groove 71 and the capillary action of each liquid storage connection groove 75, and smoothly moves toward the inside of the liquid storage portion 70.

[0289] The working fluid 2b that reaches the evaporation region SR through the liquid flow path portion 60 is heated again by the electronic device D and evaporates. The working vapor 2a evaporated from the working fluid 2b moves through the liquid flow path connection groove 65 in the evaporation region SR to the lower vapor flow path recess 53 and the upper vapor flow path recess 54 with a larger flow path cross-sectional area. Then, the working vapor 2a diffuses within each of the vapor flow path recesses 53, 54. On the other hand, the liquid storage portion 70 is disposed in the evaporation region SR. Thus, the working fluid 2b in the liquid storage portion 70 also evaporates and diffuses within each of the vapor flow path recesses 53, 54. In this way, the working fluids 2a, 2b reflux in the sealed space 3 while repeating phase changes (i.e., evaporation and condensation). Thereby, the heat of the electronic device D is transported and released. As a result, the electronic device D is cooled.

[0290] During the period when the electronic device D stops generating heat, the working fluid 2b in the evaporation region SR does not evaporate but fills and stays in the liquid flow main groove 61 and the liquid flow path connection groove 65 of the liquid flow path portion 60. Therefore, the working fluid 2b in the condensation region CR stops without being transported toward the evaporation region SR. A part of the working fluid 2b in the liquid flow path portion 60 flows on the wall surface 53a of the lower vapor flow path recess 53 or the wall surface 54a of the upper vapor flow path recess 54 and moves to the liquid storage main groove 71 and the liquid storage connection groove 75 of the liquid storage portion 70. Thereby, the working fluid 2b fills and stays in these grooves 71, 75. When the amount of the working fluid 2b enclosed in the sealed space 3 is more than the total volume of the space formed by the liquid flow main groove 61 and the liquid flow path connection groove 65, a part of the working fluid 2b is easily filled in the liquid storage main groove 71 and the liquid storage connection groove 75. Therefore, the working fluid 2b can not only disperse and stay in the liquid flow path portion 60 but also disperse and stay in the liquid storage portion 70.

[0291] In this state, even when the electronic device E equipped with the evaporation chamber 1 is placed in a temperature environment lower than the freezing points of the working fluids 2a and 2b, causing the working fluid 2b in the liquid flow path portion 60 to freeze and expand, the expansion forces of the working fluids 2a and 2b will weaken. Thereby, it is possible to suppress the following situation: the upper side plate 20 is deformed by the force caused by the expansion. Therefore, it is possible to suppress the reduction in flatness of the second upper side surface 20b of the upper side plate 20 on which the electronic component D is mounted, and thereby it is possible to suppress the formation of a gap between the second upper side surface 20b and the electronic component D. In this case, it is possible to suppress the obstruction of heat conduction from the electronic component D, and thereby it is possible to suppress the performance degradation of the evaporation chamber 1. Similarly, even when the working fluid 2b in the liquid storage portion 70 freezes and expands, the expansion force will weaken. Thereby, it is possible to suppress the following situation: the lower side plate 10 is deformed by the force caused by the expansion. Therefore, it is possible to suppress the reduction in flatness of the first lower side surface 10a of the lower side plate 10.

[0292] Thus, according to the present embodiment, the liquid flow path portion 60 is provided on the second main surface 31b of the plate main body 31 of the core plate 30, and the liquid storage portion 70 is provided on the first main surface 31a located on the side opposite to the second main surface 31b. The flow path cross-sectional area of the liquid storage main flow channel 71 of the liquid storage portion 70 is larger than the flow path cross-sectional area of the liquid flow path main flow channel 61 of the liquid flow path portion 60. Thereby, during the period when the electronic component D stops generating heat, it is possible to disperse and store the working fluid 2b not only in the liquid flow path portion 60 but also in the liquid storage portion 70. Therefore, even when the working fluid 2b in the liquid flow path portion 60 freezes and expands in a temperature environment lower than the freezing point of the working fluid 2b, it is possible to reduce the expansion force acting on the upper side plate 20. In this case, it is possible to suppress the deformation of the upper side plate 20. In addition, even when the working fluid 2b in the liquid storage portion 70 freezes and expands, it is possible to reduce the expansion force acting on the lower side plate 10. In this case, it is possible to suppress the deformation of the lower side plate 10. As a result, it is possible to suppress the deformation of the evaporation chamber 1, and thereby it is possible to suppress the performance degradation of the evaporation chamber 1. In addition, during the period when the electronic component D generates heat, the working fluid 2b in the liquid storage portion 70 receives heat from the electronic component D and can evaporate. Therefore, it is possible to further spread the heat of the electronic component D, and thereby it is possible to improve the cooling efficiency of the electronic component D.

[0293] In addition, according to the present embodiment, the liquid flow path portion 60 is provided on the second main surface 31b of the sheet main body 31 of the core portion sheet 30, and the liquid storage portion 70 is provided on the first main surface 31a located on the side opposite to the second main surface 31b. The flow path cross-sectional area of the liquid storage main flow channel 71 of the liquid storage portion 70 is larger than the flow path cross-sectional area of the liquid flow path main flow channel 61 of the liquid flow path portion 60. Thereby, the capillary force acting on the working fluid 2b in the liquid storage main flow channel 71 can be made smaller than the capillary force acting on the working fluid 2b in the liquid flow path main flow channel 61. During the period when the electronic device D generates heat, the amount of movement of the working fluid 2b toward the liquid storage portion 70 can be reduced. Therefore, it is possible to suppress a decrease in the transport function of transporting the working fluid 2b to the evaporation region SR, and thus it is possible to suppress a decrease in the heat transport efficiency. In addition, as described above, by making the flow path cross-sectional area of the liquid storage main flow channel 71 larger than the flow path cross-sectional area of the liquid flow path main flow channel 61, the total volume of the space formed by each liquid storage main flow channel 71 can be increased. Therefore, during the period when the electronic device D stops generating heat, the storage amount of the working fluid 2b in the liquid storage portion 70 can be increased.

[0294] In addition, according to the present embodiment, the width of the liquid storage main flow channel 71 is larger than the width of the liquid flow path main flow channel 61. Thereby, the flow path cross-sectional area of the liquid storage main flow channel 71 can be made larger than the flow path cross-sectional area of the liquid flow path main flow channel 61. Therefore, it is possible to suppress a decrease in the heat transport efficiency and increase the storage amount of the working fluid 2b.

[0295] In addition, according to the present embodiment, the depth of the liquid storage main flow channel 71 is larger than the depth of the liquid flow path main flow channel 61. Thereby, the flow path cross-sectional area of the liquid storage main flow channel 71 can be made larger than the flow path cross-sectional area of the liquid flow path main flow channel 61. Therefore, it is possible to suppress a decrease in the heat transport efficiency and increase the storage amount of the working fluid 2b.

[0296] In addition, according to the present embodiment, the liquid flow path portion 60 and the liquid storage portion 70 are provided on each platform portion 33, and the number of the liquid storage main flow channels 71 provided on the platform portion 33 is smaller than the number of the liquid flow path main flow channels 61 provided on the platform portion 33. Thereby, the flow path cross-sectional area of the liquid storage main flow channel 71 can be made larger than the flow path cross-sectional area of the liquid flow path main flow channel 61. Therefore, it is possible to suppress a decrease in the heat transport efficiency and increase the storage amount of the working fluid 2b.

[0297] In addition, according to the present embodiment, a liquid flow path portion 60 through which the working fluid 2b passes is provided on the second main surface 31b of the sheet main body 31 of the core sheet 30, and a liquid storage portion 70 is provided on the first main surface 31a located on the side opposite to the second main surface 31b. The liquid storage portion 70 is arranged in the evaporation region SR in a plan view. Thus, during the period when the electronic device D stops generating heat, the working fluid 2b can be dispersed and stored not only in the liquid flow path portion 60 but also in the liquid storage portion 70. Therefore, even when the working fluid 2b in the liquid flow path portion 60 freezes and expands in a temperature environment lower than the freezing point of the working fluid 2b, the expansion force acting on the upper sheet 20 can be reduced. In this case, deformation of the upper sheet 20 can be suppressed. In addition, even when the working fluid 2b in the liquid storage portion 70 freezes and expands, the expansion force acting on the lower sheet 10 can be reduced. In this case, deformation of the lower sheet 10 can be suppressed. As a result, deformation of the evaporation chamber 1 can be suppressed, and thus a decrease in the performance of the evaporation chamber 1 can be suppressed. In addition, during the period when the electronic device D generates heat, the working fluid 2b in the liquid storage portion 70 receives heat from the electronic device D and can evaporate. Therefore, heat of the electronic device D can be further diffused, and thus the cooling efficiency of the electronic device D can be improved.

[0298] In addition, according to the present embodiment, a plurality of convex portions 74 are provided in the liquid storage portion 70, and they protrude from the sheet main body 31 of the core sheet 30 and abut against the lower sheet 10. The gap (corresponding to the width w6 of the liquid storage main flow channel 71) between a pair of adjacent convex portions 74 is larger than the width of the liquid flow path main flow channel 61 of the liquid flow path portion 60. Thus, the capillary force acting on the working fluid 2b in the liquid storage portion 70 can be made smaller than the capillary force acting on the working fluid 2b in the liquid flow path portion 60 (in the liquid flow path main flow channel 61). During the period when the electronic device D generates heat, the amount of movement of the working fluid 2b toward the liquid storage portion 70 can be reduced. Therefore, a decrease in the conveying function for conveying the working fluid 2b to the evaporation region SR can be suppressed, and thus a decrease in the heat transfer efficiency can be suppressed. In addition, by making the gap between the convex portions 74 larger than the width of the liquid flow path main flow channel 61 as described above, the total volume of the space formed by each liquid storage main flow channel 71 and each liquid storage connection channel 75 of the liquid storage portion 70 can be increased. Therefore, during the period when the electronic device D stops generating heat, the storage amount of the working fluid 2b in the liquid storage portion 70 can be increased.

[0299] In addition, according to the present embodiment, the liquid storage portion 70 has a liquid storage main flow channel 71 that is provided between the convex portions 74 adjacent to each other in the Y direction perpendicular to the direction in which the liquid flow path main flow channel 61 of the liquid flow path portion 60 extends (i.e., the X direction), and the liquid storage main flow channel 71 extends in the X direction. After the electronic device D stops generating heat, although the working fluid 2b generally flows in the X direction from the condensation region CR toward the evaporation region SR, the working fluid 2b that reaches the liquid storage portion 70 can easily enter the liquid storage main flow channel 71. And it can flow smoothly in the X direction within the liquid storage main flow channel 71 and can easily reach the end edge on the evaporation region SR side of the liquid storage portion 70. Therefore, the working fluid 2b can be quickly introduced into the liquid storage portion 70, and thus the storage amount of the working fluid 2b can be rapidly increased. When the ambient temperature around the evaporation chamber 1 drops sharply, the working fluid 2b can be quickly introduced into the liquid storage portion 70. Thereby, when the working fluid 2b freezes, the expansion force acting on the upper side plate 20 and the lower side plate 10 can be effectively reduced. Therefore, the deformation of the evaporation chamber 1 can be effectively suppressed.

[0300] In addition, according to the present embodiment, the gap between a pair of adjacent convex portions 74 is smaller than the gap between a pair of adjacent platform portions 33 (corresponding to the width w2 of the through portion 34). Thereby, capillary force can act on the working fluid 2b within the liquid storage portion 70. Therefore, the working fluid 2b can be introduced into the liquid storage portion 70, and the working fluid 2b can be stored during the period when the electronic device D stops generating heat.

[0301] In addition, according to the present embodiment, the liquid storage portion 70 is provided on the first main surface 31a of each platform portion 33. Thereby, the working fluid 2b can be dispersed and stored in each liquid storage portion 70. Therefore, even when the working fluid 2b in the liquid flow path portion 60 freezes and expands in a temperature environment lower than the freezing point of the working fluid 2b, the deformation of the upper side plate 20 can be further suppressed. In addition, even when the working fluid 2b in the liquid storage portion 70 freezes and expands, the deformation of the lower side plate 10 can be further suppressed.

[0302] In addition, according to the present embodiment, the liquid storage portion 70 is arranged on one side of the platform portion 33 in the X direction. Thereby, when the evaporation region SR is formed on one side of the evaporation chamber 1 in the X direction, the liquid storage portion 70 can be arranged in the evaporation region SR. Therefore, during the period when the electronic device D generates heat, the working fluid 2b in the liquid storage portion 70 can evaporate, and thus the heat of the electronic device D can be further diffused. As a result, the cooling efficiency of the electronic device D can be improved.

[0303] (First Modified Example)

[0304] Further, in the above-described embodiment, the following example was described: during the period when the electronic device D stops generating heat, a part of the working fluid 2b in the liquid flow path portion 60 moves to the liquid storage portion 70 and is stored. In this example, the working fluid 2b flows on the wall surface 53a of the lower vapor flow path recess 53 or the wall surface 54a of the upper vapor flow path recess 54. However, not limited thereto, a plurality of communication portions 80 communicating the liquid flow path portion 60 and the liquid storage portion 70 may be provided on the sheet main body 31. The communication portion 80 may be located within the evaporation region SR. Further, the communication portion 80 may be located within a region that coincides with the electronic device D in a plan view.

[0305] For example, as Figure 15 and Figure 16 shown in the first modification example, it may be that the communication portion 80 includes a communication recess 81 provided on the wall surface of the vapor flow path portion 50. The communication recess 81 may extend from the liquid flow path portion 60 to the liquid storage portion 70. In Figure 15 and Figure 16 shown in the first modification example, a communication recess 81 extending in the Z direction is provided along the wall surface 53a of the lower vapor flow path recess 53 and the wall surface 54a of the upper vapor flow path recess 54.

[0306] The communication recess 81 may extend to at least one of the liquid flow path connection groove 65 of the liquid flow path portion 60 and the liquid storage connection groove 75 of the liquid storage portion 70. In Figure 15 and Figure 16 shown in the first modification example, one end of the communication recess 81 extends to the liquid flow path connection groove 65, and the other end of the communication recess 81 extends to the liquid storage connection groove 75. Further, the communication recess 81 may not communicate with the liquid flow path connection groove 65, or may not communicate with the liquid storage connection groove 75. Moreover, the communication recess 81 may not communicate with both the liquid flow path connection groove 65 and the liquid storage connection groove 75. The cross-sectional shape of the flow path of the communication recess 81 may be Figure 15 and Figure 16 shown as a rectangular shape, or may be formed into a curved shape such as a semicircular shape or a semi-elliptical shape. The cross-sectional shape of the flow path of the communication recess 81 corresponds to the shape in a plan view.

[0307] As Figure 15 shown, the width w9 of the communication recess 81 may be greater than the width w4 of the liquid flow path connection groove 65 (refer to Figure 9)。The width w9 corresponds to the dimension in the X direction. Thus, the capillary force acting on the working fluid 2b in the communication recess 81 can be made smaller than the capillary force acting on the working fluid 2b in the liquid flow path connection groove 65. In this case, the situation where the working fluid 2b stays in the communication recess 81 can be suppressed. In addition, in this case, the communication recess 81 is formed in a manner that cuts off the convex portion 64. In addition, the width w9 of the communication recess 81 can be smaller than the width w7 of the liquid storage connection groove 75 (refer to Figure 10 ). Thus, the capillary force can act on the working fluid 2b in the communication recess 81, and the working fluid 2b can move to the liquid storage portion 70. The width w9 of the communication recess 81 can be, for example, 20 μm to 300 μm. And, the width w9 of the communication recess 81 refers to the dimension on the second main surface 31b of the core piece 30.

[0308] In this way, according to the first modification example, during the period when the electronic device D stops generating heat, a part of the working fluid 2b in the liquid flow path portion 60 can move to the liquid storage portion 70 through the communication portion 80. Thus, the amount of movement of the working fluid 2b from the liquid flow path portion 60 toward the liquid storage portion 70 increases, and the storage amount of the working fluid 2b in the liquid storage portion 70 can be increased.

[0309] In addition, according to the first modification example, the communication portion 80 includes a communication recess 81 provided on the wall surface of the vapor flow path portion 50 and extending from the liquid flow path portion 60 to the liquid storage portion 70. Thus, the flow path resistance of the working fluid 2b from the liquid flow path portion 60 toward the liquid storage portion 70 can be reduced. Therefore, the amount of the working fluid 2b staying in the liquid flow path portion 60 can be reduced. Even when the working fluid 2b in the liquid flow path portion 60 freezes and expands, the expansion force can be weakened. In addition, even when the working fluid 2b in the liquid storage portion 70 freezes and expands, the expansion force can be weakened. As a result, the situation where the upper side piece 20 and the lower side piece 10 are deformed by the force caused by the expansion can be suppressed. And, according to the first modification example, since the communication recess 81 extends to the liquid flow path connection groove 65 and the liquid storage connection groove 75, the flow path resistance of the working fluid 2b from the liquid flow path portion 60 toward the liquid storage portion 70 can be further reduced.

[0310] (Second Modification Example)

[0311] In addition, different from the Figure 15 and Figure 16 shown first modification example, as in the Figure 17 and Figure 18 shown second modification example, the communication portion 80 may include a through hole 82 that penetrates the piece main body 31 and extends from the liquid flow path portion 60 to the liquid storage portion 70. In Figure 17 and Figure 18In the second modified example shown, the through hole 82 is not located on the wall surface 53a of the lower steam flow path recess 53 or the wall surface 54a of the upper steam flow path recess 54, but is located inside the platform portion 33 in a plan view. The through hole 82 is formed at a position where the wall surface 53a of the lower steam flow path recess 53 and the wall surface 54a of the upper steam flow path recess 54 are not cut off. That is, the through hole 82 has a closed contour shape in a plan view. In Figure 17 and Figure 18 , an example in which the through hole 82 is formed in a rectangular shape is shown. However, the planar shape of the through hole 82 may be an arbitrary shape such as a circular shape.

[0312] The through hole 82 may extend to at least one of the liquid flow path intersection portion 66 of the liquid flow path portion 60 and the liquid storage intersection portion 76 of the liquid storage portion 70. In Figure 17 and Figure 18 In the second modified example shown, one end of the through hole 82 extends to the liquid flow path intersection portion 66 and is located at the above-mentioned liquid flow path intersection portion 66. The other end of the through hole 82 extends to the liquid storage intersection portion 76. And, as long as the through hole 82 communicates with the liquid flow path main groove 61 or the liquid flow path connection groove 65, it may not communicate with the liquid flow path intersection portion 66. Or, as long as the through hole 82 communicates with the liquid storage main groove 71 or the liquid storage connection groove 75, it may not communicate with the liquid storage intersection portion 76. The flow path cross-sectional shape of the through hole 82 may be rectangular as shown in Figure 17 and Figure 18 , or may be formed in a curved shape such as a circular shape or an elliptical shape. The flow path cross-sectional shape of the through hole 82 corresponds to the shape in a plan view.

[0313] As shown in Figure 17 , the width w10 of the through hole 82 may be larger than the width w4 of the liquid flow path connection groove 65 (refer to Figure 9 ). The width w10 corresponds to the dimension in the X direction. Thereby, the capillary force acting on the working fluid 2b in the through hole 82 can be made smaller than the capillary force acting on the working fluid 2b in the liquid flow path connection groove 65. In this case, the situation where the working fluid 2b stays in the through hole 82 can be suppressed. In addition, in this case, the through hole 82 is formed by cutting off the convex portion 64. In addition, the width w10 of the through hole 82 may be smaller than the width w7 of the liquid storage connection groove 75 (refer to Figure 10 ). Thereby, the capillary force can act on the working fluid 2b in the through hole 82, and the working fluid 2b can move to the liquid storage portion 70. The width w10 of the through hole 82 may be, for example, 10 μm to 100 μm. And, the width w10 of the through hole 82 refers to the dimension on the second main surface 31b of the core piece 30. In addition, as shown in Figure 18As shown, an example is shown in which the through-hole 82 is formed so as to extend beyond the liquid storage intersection 76 according to the relationship between the arrangement pitch of the main flow channels 61 of the liquid flow path in the Y direction and the arrangement pitch of the main flow channels 71 of the liquid storage in the Y direction. However, it is not limited to this. Although it also depends on the arrangement pitch of these channels 61 and 71, the through-hole 82 may not extend beyond the liquid storage intersection 76.

[0314] Thus, according to the second modification, during the period when the electronic device D stops generating heat, a part of the working fluid 2b in the liquid flow path portion 60 can move to the liquid storage portion 70 through the through-hole 82. As a result, the amount of movement of the working fluid 2b from the liquid flow path portion 60 toward the liquid storage portion 70 increases, and the storage amount of the working fluid 2b in the liquid storage portion 70 can be increased. In particular, since the through-hole 82 is located inside the platform portion 33 in a plan view, the flow path resistance of the working fluid 2b from the liquid flow path portion 60 toward the liquid storage portion 70 can be reduced. Therefore, the retention amount of the working fluid 2b in the liquid flow path portion 60 can be reduced. Even when the working fluid 2b in the liquid flow path portion 60 freezes and expands, the expansion force can be weakened. As a result, it is possible to suppress the situation where the upper side plate 20 is deformed by the force caused by the expansion. In addition, even when the working fluid 2b in the liquid storage portion 70 freezes and expands, the expansion force can be weakened. As a result, it is possible to suppress the situation where the lower side plate 10 is deformed by the force caused by the expansion.

[0315] In addition, according to the second modification, the communication portion 80 includes the through-hole 82 that penetrates the sheet body 31 and extends from the liquid flow path portion 60 to the liquid storage portion 70. As a result, the flow path resistance of the working fluid 2b from the liquid flow path portion 60 toward the liquid storage portion 70 can be further reduced. Therefore, the retention amount of the working fluid 2b in the liquid flow path portion 60 can be further reduced. Even when the working fluid 2b in the liquid flow path portion 60 freezes and expands, the expansion force can be further weakened. Moreover, according to the second modification, since the through-hole 82 extends to the liquid flow path intersection 66 and the liquid storage intersection 76, the flow path resistance of the working fluid 2b from the liquid flow path portion 60 toward the liquid storage portion 70 can be further reduced.

[0316] (Third modification)

[0317] In addition, in the above-described embodiment, an example is described in which the convex portion 74 provided in the liquid storage portion 70 is formed in a rectangular shape with the X direction as the longitudinal direction in a plan view. However, it is not limited to this, and the planar shape of the convex portion 74 is arbitrary.

[0318] For example, as Figure 19As shown, the convex portion 74 can be formed in a circular shape when viewed from above, or, although not shown, it can also be formed in an elliptical shape. In addition, in Figure 19 the example shown, an example is shown in which the convex portions 74 are arranged side by side. More specifically, the convex portions 74 of the convex portion columns 73 adjacent to each other in the Y direction are also aligned in the X direction.

[0319] In addition, for example, as Figure 20 shown, the convex portion 74 can also be formed in a square shape when viewed from above. In Figure 20 the example shown, an example is shown in which the convex portions 74 are arranged in a staggered manner, but they can also be arranged side by side.

[0320] In addition, for example, as Figure 21 shown, the convex portion 74 can also be formed in a cross shape when viewed from above. In Figure 21 the example shown, the planar shape of the convex portion 74 is formed in a cross shape with arcs. In addition, in Figure 21 the example shown, an example is shown in which the convex portions 74 are arranged in a staggered manner, but they can also be arranged side by side. In addition, the convex portion 74 can also be formed in a star-shaped polygon shape when viewed from above.

[0321] (Fourth Modification Example)

[0322] In addition, in the above-described present embodiment, an example has been described in which the liquid storage portion 70 is provided on the first main surface 31a of each platform portion 33 of the core portion sheet 30. However, it is not limited thereto, and the liquid storage portion 70 may not be provided on all the platform portions 33. For example, the liquid storage portion 70 may be provided only on any one of the platform portions 33, and the liquid storage portion 70 may also be provided on several platform portions 33. For example, when the planar shape of the electronic device D is small, the liquid storage portion 70 can be selectively provided on any platform portion 33 according to the area covered by the electronic device D. The same applies when the evaporation chamber 1 is not simply rectangular.

[0323] (Fifth Modification Example)

[0324] In addition, as Figure 22 shown, the liquid storage portion 70 can be arranged in a region that coincides with the electronic device D when the evaporation chamber 1 is viewed from above.

[0325] In Figure 22 the example shown, the liquid storage portion 70 is provided on a part of the platform portions 33 among the plurality of platform portions 33. The electronic device D coincides with the plurality of platform portions 33. The electronic device D is arranged across the plurality of platform portions 33. In Figure 22In it, seven platform parts 33 are shown, and the electronic device D overlaps with three platform parts 33. The electronic device D does not overlap with the remaining four platform parts 33. The three platform parts 33 that overlap with the electronic device D are called overlapping platform parts 91 and 92, and the platform parts 33 among the four platform parts 33 that do not overlap with the electronic device D and are adjacent to the overlapping platform parts 91 and 92 are called first non-overlapping platform parts 93. The platform parts 33 among the four platform parts 33 that do not overlap with the electronic device D and are not adjacent to the overlapping platform parts 91 and 92 are called second non-overlapping platform parts 94.

[0326] The first non-overlapping platform parts 93 are arranged on both sides in the Y direction of the three overlapping platform parts 91 and 92. The second non-overlapping platform parts 94 are arranged on the side opposite to the overlapping platform parts 91 and 92 with respect to the first non-overlapping platform parts 93. The second non-overlapping platform parts 94 are arranged at Figure 22 the lowermost side and the uppermost side in, and the two first non-overlapping platform parts 93 are arranged between the two second non-overlapping platform parts 94. Moreover, the three overlapping platform parts 91 and 92 are arranged between the two first non-overlapping platform parts 93. In Figure 22 the lowermost overlapping platform part (the second overlapping platform part 92 described later) among the three overlapping platform parts 91 and 92 and the lower first non-overlapping platform part 93 are adjacent to each other in the Y direction. Similarly, in Figure 22 the uppermost overlapping platform part (the second overlapping platform part 92 described later) among the three overlapping platform parts 91 and 92 and the upper first non-overlapping platform part 93 are adjacent to each other in the Y direction.

[0327] The liquid storage parts 70 are provided on each of the overlapping platform parts 91 and 92. The liquid storage parts 70 provided on the overlapping platform parts 91 and 92 are arranged in the region that overlaps with the electronic device D in a plan view. These liquid storage parts 70 can extend outward beyond the electronic device D in the X direction. The liquid storage parts 70 provided on the overlapping platform parts 91 and 92 extend outward beyond the electronic device D on both sides in the X direction. In Figure 22 the example shown, the liquid storage parts 70 provided on the overlapping platform parts 91 and 92 extend beyond the electronic device D to the left and to the right.

[0328] The three overlapping platform parts 91 and 92 include one first overlapping platform part 91 and two second overlapping platform parts 92. The second overlapping platform parts 92 are arranged on both sides of the first overlapping platform part 91 in the Y direction. Each second overlapping platform part 92 is adjacent to the first overlapping platform part 91 in the Y direction. The liquid storage part 70 provided on the first overlapping platform part 91 and the liquid storage part 70 provided on the second overlapping platform part 92 are adjacent to each other in the Y direction. When viewed from above, the liquid storage part 70 provided on the first overlapping platform part 91 is located on the center side of the electronic device D in the Y direction compared to the liquid storage part 70 provided on the second overlapping platform part 92. That is, the liquid storage part 70 provided on the second overlapping platform part 92 is farther from the center of the electronic device D than the liquid storage part 70 provided on the first overlapping platform part 91. In Figure 22 , the liquid storage part 70 provided on the first overlapping platform part 91 coincides with the center of the electronic device D. The length L1 of the liquid storage part 70 provided on the first overlapping platform part 91 in the X direction is longer than the length L2 of the liquid storage part 70 provided on the second overlapping platform part 92 in the X direction. Compared with the liquid storage part 70 provided on the second overlapping platform part 92, the amount by which the liquid storage part 70 provided on the first overlapping platform part 91 extends outward from the electronic device D is larger. The lengths L1 and L2 may be the lengths of the liquid storage main channels 71 of the liquid storage part 70 in the X direction. When the liquid storage part 70 includes a plurality of liquid storage main channels 71, it may be the maximum value of the lengths of the liquid storage main channels 71.

[0329] A liquid storage part 70 is provided on each of the first non-overlapping platform parts 93. The liquid storage part 70 provided on the first non-overlapping platform part 93 is arranged in a region different from the region that coincides with the electronic device D when viewed from above. That is, this liquid storage part 70 does not coincide with the electronic device D. The liquid storage part 70 provided on the second overlapping platform part 92 and the liquid storage part 70 provided on the first non-overlapping platform part 93 are adjacent to each other in the Y direction. The length L2 of the liquid storage part 70 provided on the second overlapping platform part 92 in the X direction is longer than the length L3 of the liquid storage part 70 provided on the first non-overlapping platform part 93 in the X direction. And, in Figure 22 an example in which the length L3 is equal to the length of the electronic device D is shown. However, it is not limited to this, and this liquid storage part 70 may also extend outward from the electronic device D in the X direction. Or, the length of this liquid storage part 70 in the X direction may also be shorter than the length of the electronic device D in the X direction. Similar to the lengths L1 and L2, the length L3 may be the length of the liquid storage main channel 71 of the liquid storage part 70 in the X direction.

[0330] As Figure 22As shown, the liquid storage portion 70 may not be provided in the second non-overlapping platform portion 94. However, without being limited thereto, the liquid storage portion 70 may also be provided in the second non-overlapping platform portion 94.

[0331] Thus, according to the fifth modification, the liquid storage portion 70 is disposed in a region that coincides with the electronic device D when the evaporation chamber 1 is viewed from above. Thereby, the liquid storage portion 70 can be disposed in a region that is easily heated by the electronic device D. Therefore, during the period when the electronic device D generates heat, the working fluid 2b in the liquid storage portion 70 receives heat from the electronic device D and can evaporate. Therefore, the heat of the electronic device D can be further diffused, and thus the cooling efficiency of the electronic device D can be improved.

[0332] In addition, according to the fifth modification, the liquid storage portion 70 extends outward in the X direction beyond the electronic device D. Thereby, in the vicinity of the region that coincides with the electronic device D, the working fluid 2b in the liquid storage portion 70 can evaporate by using the heat transferred from the electronic device D. More specifically, in the region in the X direction adjacent to the region that coincides with the electronic device D, the working fluid 2b in the liquid storage portion 70 can evaporate by using the heat of the electronic device D. Therefore, the evaporation amount of the working fluid 2b can be increased. As a result, the heat of the electronic device D can be further diffused, and thus the cooling efficiency of the electronic device D can be further improved.

[0333] In addition, according to the fifth modification, when viewed from above, the liquid storage portion 70 provided in the first overlapping platform portion 91 is located closer to the center side of the electronic device D in the Y direction than the liquid storage portion 70 provided in the second overlapping platform portion 92. And, the length L1 of the liquid storage portion 70 provided in the first overlapping platform portion 91 in the X direction is longer than the length L2 of the liquid storage portion 70 provided in the second overlapping platform portion 92 in the X direction. Thereby, the length of the liquid storage portion 70 located on the center side of the electronic device D in the X direction can be increased. Therefore, the filling amount of the working fluid 2b in the liquid storage main flow channel 71 that coincides with the vicinity of the center of the electronic device D can be increased. As a result, in the vicinity of the center of the electronic device D, the evaporation amount of the working fluid 2b can be increased, and thus the vicinity of the center of the electronic device D can be efficiently cooled.

[0334] In addition, according to the fifth modification example, liquid storage portions 70 are respectively provided in a pair of adjacent second overlapping platform portions 92 and first non-overlapping platform portions 93. The liquid storage portion 70 provided in the second overlapping platform portion 92 is disposed in a region overlapping with the electronic device D, and the liquid storage portion 70 provided in the first non-overlapping platform portion 93 is disposed in a region different from the region overlapping with the electronic device D. Thus, around the region overlapping with the electronic device D, the working fluid 2b in the liquid storage portion 70 can be evaporated by the heat transferred from the electronic device D. More specifically, in a region adjacent to the region overlapping with the electronic device D in the Y direction, the working fluid 2b in the liquid storage portion 70 can be evaporated by the heat of the electronic device D. Therefore, the evaporation amount of the working fluid 2b can be increased. As a result, the heat of the electronic device D can be further diffused, and thus the cooling efficiency of the electronic device D can be further improved.

[0335] In addition, according to the fifth modification example, the length L2 of the liquid storage portion 70 provided in the second overlapping platform portion 92 in the X direction is longer than the length L3 of the liquid storage portion 70 provided in the first non-overlapping platform portion 93 in the X direction. Thus, the length of the liquid storage portion 70 overlapping with the electronic device D in the X direction can be increased. Therefore, the filling amount of the working fluid 2b in the liquid storage main flow channel 71 overlapping with the electronic device D can be increased. As a result, in the region overlapping with the electronic device D, the evaporation amount of the working fluid 2b can be increased, and thus the electronic device D can be efficiently cooled.

[0336] Moreover, in the above-described fifth modification example, an example has been described in which the liquid storage portion 70 provided in the second overlapping platform portion 92 entirely overlaps with the electronic device D in the Y direction. However, it is not limited thereto, and the liquid storage portion 70 provided in the second overlapping platform portion 92 may overlap with the electronic device D within a partial range in the Y direction (refer to Figure 23 ). In this case, the liquid storage portion 70 does not overlap with the electronic device D within the remaining range in the Y direction. In addition, in Figure 22 , an example has been shown in which the electronic device D extends outward in the Y direction beyond the liquid storage portion 70 provided in the second overlapping platform portion 92. However, it is not limited thereto, and the electronic device D may also coincide with the edge of the second overlapping platform portion 92. In this case, the edge of the electronic device D coincides with the edge of the wall surface 54a of the upper steam flow path recess 54 in the second main surface 31b.

[0337] In addition, in the above-described fifth modification example, the following example was described: the electronic device D is superposed on the liquid storage section 70 provided on the three superposed platform sections 91 and 92. However, it is not limited thereto, and the number of the superposed platform sections 91 and 92 provided with the liquid storage section 70 superposed on the electronic device D is arbitrary. In addition, the following example was described: two non-superposed platform sections 93 and 94 are respectively provided on both sides in the Y direction of the three superposed platform sections 91 and 92. However, it is not limited thereto, and the number of the non-superposed platform sections 93 and 94 respectively provided on both sides in the Y direction of the three superposed platform sections 91 and 92 may be one, or may be three or more.

[0338] (Sixth Modification Example)

[0339] In addition, as Figure 23 shown, the evaporation chamber 1 can be in thermal contact with a plurality of electronic devices D.

[0340] More specifically, as Figure 23 shown, a plurality of electronic devices D are mounted on the second main surface 31b. Here, as an example, an example in which two electronic devices D1 and D2 are mounted on the second main surface 31b is shown, but the number of the electronic devices D may be three or more. The two electronic devices D are arranged in regions different from each other in the X direction. The Figure 23 left-side electronic device D in is referred to as the first electronic device D1, and the right-side electronic device D is referred to as the second electronic device D2.

[0341] A plurality of liquid storage sections 70 respectively corresponding to the electronic devices D1 and D2 can be provided on the first main surface 31a. In this case, the liquid storage sections 70 can be arranged in regions that overlap the corresponding electronic devices D1 and D2 in a plan view.

[0342] The liquid storage sections 70 are provided on a part of the plurality of platform sections 33. Similar to the Figure 22 example shown, each of the electronic devices D1 and D2 overlaps the plurality of platform sections 33. Similar to the Figure 22 example shown, the plurality of platform sections 33 include: three superposed platform sections 91 and 92; two first non-superposed platform sections 93; and two second non-superposed platform sections 94. The liquid storage sections 70 overlapping the first electronic device D1 and the liquid storage sections 70 overlapping the second electronic device D2 are respectively provided on the three superposed platform sections 91 and 92. In the first non-superposed platform section 93, similar to the Figure 22 example shown, a liquid storage section 70 overlapping the first electronic device D1 is provided. However, in the first non-superposed platform section 93, no liquid storage section 70 overlapping the second electronic device D2 is provided. No liquid storage section 70 is provided in the second non-superposed platform section 94.

[0343] The sizes of the two electronic devices D1 and D2 in the X direction may be different from each other. In this case, the lengths of the two liquid storage portions 70 in the X direction may also be different from each other. And, in Figure 23 an example is shown in which, for each electronic device D, the length of the liquid storage portion 70 in the X direction is equal. More specifically, the liquid storage portion 70 that coincides with the first electronic device D1 will be described. The lengths L1 and L2 of the liquid storage portions 70 provided on the coincidence platform portions 91 and 92 in the X direction are equal to each other. The lengths L1 and L2 and the length L3 of the liquid storage portion 70 provided on the first non-coincidence platform portion 93 in the X direction are also equal. However, not limited thereto, the lengths L1, L2, and L3 of the liquid storage portion 70 in the X direction may also be different for each platform portion as Figure 22 shown. The same applies to the liquid storage portion 70 that coincides with the second electronic device D2.

[0344] Thus, according to the sixth modification example, the evaporation chamber 1 is in thermal contact with the plurality of electronic devices D1 and D2, and a plurality of liquid storage portions 70 corresponding to the respective electronic devices D1 and D2 are provided on the first main surface 31a. And, the liquid storage portion 70 is disposed in a region that coincides with the corresponding electronic device D1 or D2 when the evaporation chamber 1 is viewed from above. Thereby, each liquid storage portion 70 can be disposed in a region that is easily heated by the corresponding electronic device D1 or D2. Therefore, during the period when the respective electronic devices D1 and D2 generate heat, the working fluid 2b in each liquid storage portion 70 receives heat from the respective electronic devices D1 and D2 and can evaporate. Therefore, the heat of each electronic device D1 and D2 can be further diffused, and thus the cooling efficiency of each electronic device D1 and D2 can be improved.

[0345] In addition, according to the sixth modification example, the plurality of liquid storage portions 70 that coincide with the corresponding electronic devices D1 and D2 are provided on at least one of the plurality of platform portions 33. Thereby, the liquid storage portion 70 can be respectively provided in a region of the platform portion 33 that coincides with the corresponding electronic device D1 or D2. Therefore, each liquid storage portion 70 can be disposed in a region that is easily heated by the corresponding electronic device D1 or D2.

[0346] Here, in the sixth modification example, the two electronic devices D1 and D2 may not generate heat at the same time. For example, when the first electronic device D1 generates heat and the second electronic device D2 stops generating heat, the working fluid 2b in the liquid storage portion 70 that coincides with the first electronic device D1 receives heat from the first electronic device D1 and can evaporate. The working fluid 2b in the liquid storage portion 70 that coincides with the second electronic device D2 can continue to be stored.

[0347] Further, in the above-described sixth modification example, an example was described in which two liquid storage portions 70 are provided in each of the three overlapping platform portions 91 and 92. However, the present invention is not limited thereto, and the number of the overlapping platform portions 91 and 92 provided with the two liquid storage portions 70 is arbitrary and is not limited to three. For example, the number of such overlapping platform portions 91 and 92 may be one. For example, two liquid storage portions 70 may be provided in the first overlapping platform portion 91, and one liquid storage portion 70 may be provided in the second overlapping platform portion 92. In this case, the liquid storage portion 70 overlapping with the first electronic device D1 and the liquid storage portion 70 overlapping with the second electronic device D2 may be provided in the first overlapping platform portion 91. One of the liquid storage portions 70 overlapping with the first electronic device D1 may be provided in one of the second overlapping platform portions 92, and the liquid storage portion 70 overlapping with the second electronic device D2 may not be provided. The other liquid storage portion 70 overlapping with the second electronic device D2 may be provided in the other of the second overlapping platform portions 92, and the liquid storage portion 70 overlapping with the first electronic device D1 may not be provided. That is, at least one of the liquid storage portion 70 overlapping with the first electronic device D1 and the liquid storage portion 70 overlapping with the second electronic device D2 may be provided in the overlapping platform portions 91 and 92.

[0348] In addition, in the above-described sixth modification example, an example was described in which a plurality of liquid storage portions 70 are provided on the first main surface 31a so as to overlap the corresponding electronic devices D1 and D2 in a plan view. However, the present invention is not limited thereto. For example, when a liquid storage portion 70 overlapping with one of the two electronic devices D1 and D2 is provided on the first main surface 31a, the liquid storage portion 70 overlapping with the other may not be provided. The same applies when the number of the electronic devices D is three or more. That is, a plurality of liquid storage portions 70 may be provided on the first main surface 31a so as to overlap all the electronic devices D. However, a liquid storage portion 70 overlapping with a part of the electronic devices D may be provided on the first main surface 31a, and the liquid storage portion 70 overlapping with the other part of the electronic devices D may not be provided.

[0349] (Second Embodiment)

[0350] Next, Figures 24 - 27 will be used to describe the core piece for the evaporation chamber, the evaporation chamber, and the electronic device in the second embodiment of the present invention.

[0351] In Figures 24 - 27 the second embodiment shown, the main difference is that the liquid storage portion is disposed in a region different from the evaporation region in a plan view, and other structures are substantially the same as those in Figures 1 - 23 the first embodiment shown. And in Figures 24 - 27 , for Figures 1 - 23Parts identical to those of the first embodiment shown are denoted by the same reference numerals, and detailed description thereof is omitted.

[0352] In the present embodiment, as Figure 24 shown, the liquid storage unit 70 of the present embodiment can be arranged on one side of the platform unit 33 in the X direction. The liquid storage unit 70 can also be formed at a position closer to this side than the center of the platform unit 33 in the X direction. The liquid storage unit 70 can be arranged on the side opposite to the evaporation region SR, and can be arranged on the right side of the platform unit 33 as Figure 24 shown. The liquid storage unit 70 is arranged in a region different from the evaporation region SR when viewed from above. The liquid storage unit 70 is arranged in the condensation region CR. In this case, the liquid storage unit 70 is arranged in a region different from the region overlapping with the electronic device D. More specifically, as Figure 24 and Figure 25 shown, the liquid storage unit 70 is arranged in a portion of the platform unit 33 on the side opposite to the evaporation region SR in the X direction. The main liquid storage groove 71 of the liquid storage unit 70 is continuously formed from the end edge on the side opposite to the evaporation region SR of the platform unit 33 toward the end edge on the evaporation region SR side to a predetermined position in the X direction. In Figure 24 , the liquid storage unit 70 is formed from the right end edge to the left end edge to a predetermined position. Thus, the range of the liquid storage unit 70 in the X direction is defined. The other structure of the liquid storage unit 70 has the same structure as the liquid storage unit 70 in the first embodiment, and thus detailed description thereof is omitted here.

[0353] In a general evaporation chamber 1, as described above, the working fluids 2a and 2b circulate in the sealed space 3 while undergoing a phase change (i.e., evaporation and condensation), thereby transporting and releasing the heat of the electronic device D. The circulation of the working fluids 2a and 2b can be formed within the entire range of the evaporation chamber 1. Thereby, the working vapor 2a can release heat within the entire range of the evaporation chamber 1, and thus the heat release region can be expanded. Therefore, the heat dissipation efficiency of the evaporation chamber 1 can be improved, and the electronic device D can be cooled efficiently. In this case, the temperature difference of the evaporation chamber 1 can be reduced, and the temperature can be made uniform.

[0354] However, when the calorific value of the electronic device D is relatively large, as Figure 26As shown, the working fluid 2b condensed in the condensation region CR is difficult to be transported to the center of the evaporation region SR. That is, since the heat generation amount of the electronic device D is relatively large, the working fluid 2b is likely to evaporate before reaching the center of the evaporation region SR. As a result, a reflux of the working fluids 2a and 2b is formed in a range other than near the center of the evaporation region SR, and thus the temperature at the center of the evaporation region SR rises. Therefore, the cooling efficiency of the electronic device D decreases. As a result, a high-temperature region TH and a low-temperature region TL are formed in the evaporation chamber 1, and the temperature difference becomes large.

[0355] On the other hand, when the heat generation amount of the electronic device D is small, as Figure 27 shown, a part of the working fluid 2b condensed in the condensation region CR is likely to stay in the liquid flow path portion 60 of the evaporation region SR. That is, since the heat generation amount of the electronic device D is small, the evaporation amount of the working fluid 2b in the evaporation region SR decreases. As a result, the transport amount of the working fluid 2b toward the evaporation region SR decreases, and the working fluid 2b is likely to stay in the liquid flow path portion 60 of the condensation region CR. As a result, a reflux of the working fluids 2a and 2b is formed in a range other than near the end portion on the condensation region CR side ( Figure 27 the right end portion in the figure), and the working fluid 2b near the end portion stays in the liquid flow path portion 60. Therefore, the region where the working vapor 2a releases heat becomes small, and thus the heat dissipation efficiency of the evaporation chamber 1 decreases. As a result, a high-temperature region TH and a low-temperature region TL are formed in the evaporation chamber 1, and the temperature difference becomes large.

[0356] In contrast, in the evaporation chamber 1 of the present embodiment, during the period when the electronic device D generates heat, a part of the working fluid 2b condensed in the condensation region CR is not transported to the evaporation region SR but is transported to the liquid storage portion 70 provided on the first main surface 31a of the core piece 30. Thus, the working fluid 2b is stored in the liquid storage portion 70. Since the liquid storage portion 70 of the present embodiment is arranged in the condensation region CR, the working fluid 2b in the liquid storage portion 70 is difficult to evaporate and remains in the liquid storage portion 70.

[0357] When the heat generation amount of the electronic device D is relatively large, the working fluid 2b condensed in the condensation region CR can be transported to the center of the evaporation region SR. That is, when the heat generation amount of the electronic device D is relatively large, not only the working fluid 2b in the liquid flow path portion 60 but also the working fluid 2b stored in the liquid storage portion 70 can be transported toward the center of the evaporation region SR, so that the transport amount of the working fluid 2b transported toward the evaporation region SR can be increased. Thereby, even the center of the evaporation region SR can be reached by the working fluid 2b, and thus a reflux of the working fluids 2a and 2b can be formed within the entire range of the evaporation chamber 1. Therefore, the temperature at the center of the evaporation region SR can be reduced, and thus the cooling efficiency of the electronic device D can be improved. As a result, the temperature difference in the evaporation chamber 1 can be reduced, and thus the temperature can be made uniform.

[0358] On the other hand, when the heat generation amount of the electronic device D is relatively small, a part of the working fluid 2b condensed in the condensation region CR can be stored in the liquid storage portion 70, so that the situation where the working fluid 2b stays in the liquid flow path portion 60 in the evaporation region SR can be suppressed. Thereby, a reflux of the working fluids 2a and 2b can be formed within the entire range of the evaporation chamber 1. Therefore, the region where the working vapor 2a releases heat can be expanded, and thus the heat dissipation efficiency of the evaporation chamber 1 can be improved. As a result, the temperature difference in the evaporation chamber 1 can be reduced.

[0359] Thus, according to the present embodiment, the liquid flow path portion 60 through which the working fluid 2b passes is provided on the second main surface 31b of the sheet main body 31 of the core sheet 30, and the liquid storage portion 70 is provided on the first main surface 31a located on the side opposite to the second main surface 31b. The liquid storage portion 70 is arranged in a region different from the evaporation region SR in a plan view. Thereby, the working fluid 2b can be dispersed and stored not only in the liquid flow path portion 60 but also in the liquid storage portion 70. When the heat generation amount of the electronic device D is relatively large, the working fluid 2b stored in the liquid storage portion 70 can be fed into the evaporation region SR, so that the range of the reflux of the working fluids 2a and 2b can be increased. Therefore, the cooling efficiency of the electronic device D can be improved. In addition, when the heat generation amount of the electronic device D is relatively small, the situation where the working fluid 2b stays in the liquid flow path portion 60 in the evaporation region SR can be suppressed, and thus the range of the reflux of the working fluids 2a and 2b can be increased. Therefore, the region where the working vapor 2a releases heat can be expanded, and thus the heat dissipation efficiency of the evaporation chamber 1 can be improved. As a result, a decrease in the performance of the evaporation chamber 1 can be suppressed regardless of the heat generation amount of the electronic device D.

[0360] In addition, according to the present embodiment, as described above, the working fluid 2b can be stored in the liquid storage portion 70. Thus, during the period when the electronic device D stops generating heat, the working fluid 2b can be dispersed and stored not only in the liquid flow path portion 60 but also in the liquid storage portion 70. Therefore, even when the working fluid 2b in the liquid flow path portion 60 freezes and expands in a temperature environment lower than the freezing point of the working fluid 2b, the expansion force acting on the upper side plate 20 can be reduced, and thus deformation of the upper side plate 20 can be suppressed. In addition, even when the working fluid 2b in the liquid storage portion 70 freezes and expands, the expansion force acting on the lower side plate 10 can be reduced, and thus deformation of the lower side plate 10 can be suppressed. As a result, deformation of the evaporation chamber 1 can be suppressed.

[0361] In addition, according to the present embodiment, a plurality of convex portions 74 are provided in the liquid storage portion 70, which protrude from the sheet main body 31 of the core sheet 30 and abut against the lower side plate 10. The gap between a pair of adjacent convex portions 74 (corresponding to the width w6 of the liquid storage main flow channel 71) is larger than the width w3 of the liquid flow path main flow channel 61 of the liquid flow path portion 60. Thereby, the capillary force acting on the working fluid 2b in the liquid storage portion 70 can be made smaller than the capillary force acting on the working fluid 2b in the liquid flow path portion 60 (in the liquid flow path main flow channel 61). During the period when the electronic device D generates heat, the amount of movement of the working fluid 2b toward the liquid storage portion 70 can be reduced. Therefore, reduction of the transport function for transporting the working fluid 2b to the evaporation region SR can be suppressed, and thus reduction of the heat transport efficiency can be suppressed. In addition, by making the gap between the convex portions 74 larger than the width w3 of the liquid flow path main flow channel 61 as described above, the total volume of the space formed by the respective liquid storage main flow channels 71 and the respective liquid storage connection channels 75 of the liquid storage portion 70 can be increased. Therefore, the storage amount of the working fluid 2b in the liquid storage portion 70 can be increased, and in the case where the heat generation amount of the electronic device D is small, the following situation can be further suppressed: the working fluid 2b stays in the liquid flow path portion 60 of the condensation region CR.

[0362] In addition, according to the present embodiment, the liquid storage portion 70 has a liquid storage main flow channel 71 that is provided between the convex portions 74 adjacent to each other in the Y direction perpendicular to the direction (i.e., the X direction) in which the liquid flow path main flow channel 61 of the liquid flow path portion 60 extends, and the liquid storage main flow channel 71 extends in the X direction. Thereby, the working fluid 2b in the liquid storage portion 70 can flow in the X direction, and the working fluid 2b flowing out of the liquid storage portion 70 can have a propulsive force in the X direction. Therefore, the working fluid 2b flowing out of the liquid storage portion 70 can be smoothly transported to the evaporation region SR.

[0363] In addition, according to the present embodiment, the gap between a pair of adjacent convex portions 74 is smaller than the gap between a pair of adjacent platform portions 33 (equivalent to the width w2 of the through portion 34). Thus, capillary force can act on the working fluid 2b in the liquid storage portion 70. Therefore, the working fluid 2b can be introduced into the liquid storage portion 70 and stored therein.

[0364] In addition, according to the present embodiment, the liquid storage portion 70 is provided on the first main surface 31a of each platform portion 33. Thus, the working fluid 2b can be dispersed and stored in each liquid storage portion 70. Therefore, when the heat generation amount of the electronic device D is relatively large, the amount of the working fluid 2b fed into the evaporation region SR can be increased, thereby further improving the cooling efficiency of the electronic device D. When the heat generation amount of the electronic device D is relatively small, the situation where the working fluid 2b stays in the liquid flow path portion 60 can be further suppressed, thereby further improving the heat dissipation efficiency of the evaporation chamber 1.

[0365] In addition, according to the present embodiment, the liquid storage portion 70 is arranged on one side of the platform portion 33 in the X direction. Thus, when the evaporation region SR is formed on one side of the evaporation chamber 1 in the X direction, the liquid storage portion 70 can be arranged in a region different from the evaporation region SR. Therefore, when the heat generation amount of the electronic device D is relatively large, the amount of the working fluid 2b fed into the evaporation region SR can be increased, thereby further improving the cooling efficiency of the electronic device D. When the heat generation amount of the electronic device D is relatively small, the situation where the working fluid 2b stays in the liquid flow path portion 60 can be further suppressed, thereby further improving the heat dissipation efficiency of the evaporation chamber 1.

[0366] Moreover, in the above-described present embodiment, the first modification, the second modification, the third modification, and the fourth modification described as modification examples of the first embodiment can be applied in the same manner as the first embodiment.

[0367] For example, in the second embodiment, by providing the communication part 80 as in the first modification example, the working fluid 2b can smoothly move between the liquid flow path part 60 and the liquid storage part 70. As a result, the amount of movement of the working fluid 2b from the liquid flow path part 60 toward the liquid storage part 70 increases, and the storage amount of the working fluid 2b in the liquid storage part 70 can be increased. In addition, when the heat generation amount of the electronic device D is large, the working fluid 2b stored in the liquid storage part 70 can be smoothly fed into the evaporation region SR. The range of the reflux of the working fluids 2a and 2b can be effectively increased. Therefore, the cooling efficiency of the electronic device D can be further improved. In addition, when the heat generation amount of the electronic device D is small, the situation where the working fluid 2b stays in the liquid flow path part 60 in the evaporation region SR can be further suppressed, and thus the range of the reflux of the working fluids 2a and 2b can be increased. Therefore, the heat dissipation efficiency of the evaporation chamber 1 can be further improved.

[0368] In addition, by making the communication part 80 include the communication recess 81 as in the first modification example, the flow path resistance of the working fluid 2b between the liquid flow path part 60 and the liquid storage part 70 can be reduced. As a result, when the heat generation amount of the electronic device D is large, the cooling efficiency of the electronic device D can be further improved. When the heat generation amount of the electronic device D is small, the heat dissipation efficiency of the evaporation chamber 1 can be further improved. Moreover, according to the first modification example, since the communication recess 81 extends to the liquid flow path connection groove 65 and the liquid storage connection groove 75, the flow path resistance of the working fluid 2b between the liquid flow path part 60 and the liquid storage part 70 can be further reduced.

[0369] For example, in the second embodiment, by making the communication part 80 include the through hole 82 as in the second modification example, the flow path resistance of the working fluid 2b between the liquid flow path part 60 and the liquid storage part 70 can be reduced. As a result, when the heat generation amount of the electronic device D is large, the cooling efficiency of the electronic device D can be further improved, and when the heat generation amount of the electronic device D is small, the heat dissipation efficiency of the evaporation chamber 1 can be further improved. Moreover, according to the second modification example, since the through hole 82 extends to the liquid flow path intersection 66 and the liquid storage intersection 76, the flow path resistance of the working fluid 2b between the liquid flow path part 60 and the liquid storage part 70 can be further reduced.

[0370] In addition, the liquid storage unit 70 of the present embodiment described above and the liquid storage unit 70 of the first embodiment can be combined. In this case, two liquid storage units 70 are provided on each platform portion 33 of the core sheet 30. One liquid storage unit 70 is disposed in the evaporation region SR in a plan view, and the other liquid storage unit 70 is disposed in the condensation region CR in a plan view. The liquid storage unit 70 in the evaporation region SR and the liquid storage unit 70 in the condensation region CR can be separated from each other in the X direction. In this case, the effects obtained by the liquid storage unit 70 of the first embodiment and the effects obtained by the liquid storage unit 70 of the second embodiment can both be obtained.

[0371] The present invention is not fixedly limited to the above-described embodiments and each modification. At the implementation stage, the components can be deformed and embodied within the scope not departing from the gist thereof. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the above-described embodiments and each modification. Some components can also be eliminated from all the components shown in the embodiments and each modification.

Claims

1. A core piece for an evaporation chamber, in which a working fluid is sealed in the evaporation chamber, wherein, the core piece for the evaporation chamber includes: a piece main body having a first main surface and a second main surface provided on a side opposite to the first main surface; a through space penetrating the piece main body; a first groove assembly communicating with the through space and provided on the second main surface; and a second groove assembly communicating with the through space and provided on the first main surface, the first groove assembly includes a plurality of first main grooves extending in a first direction, the second groove assembly includes a plurality of second main grooves extending in the first direction, the flow path cross-sectional area of the second main groove is larger than that of the first main groove, when looking down at the core piece, the entire area of the second groove assembly on the first main surface is smaller than the entire area of the first groove assembly on the second main surface.

2. The core piece for the evaporation chamber according to claim 1, wherein, the width of the second main groove is larger than the width of the first main groove.

3. The core piece for the evaporation chamber according to claim 1 or 2, wherein, the depth of the second main groove is larger than the depth of the first main groove.

4. The core piece for the evaporation chamber according to claim 1 or 2, wherein, the piece main body has a plurality of platform portions dividing the through space into a plurality of passages, the plurality of platform portions are separated from each other in a second direction perpendicular to the first direction, the width of the second main groove is smaller than the gap between a pair of adjacent platform portions.

5. The core piece for the evaporation chamber according to claim 1, wherein, the piece main body has a plurality of platform portions dividing the through space into a plurality of passages, the first groove assembly and the second groove assembly are provided on at least one of the plurality of platform portions, the number of the second main grooves provided on the platform portion is smaller than the number of the first main grooves provided on the platform portion.

6. The core piece for the evaporation chamber according to claim 1 or 2, wherein, the piece main body has a plurality of platform portions extending in the first direction and dividing the through space into a plurality of passages, the second groove assembly is arranged on one side of the platform portion in the first direction.

7. The core piece for the evaporation chamber according to claim 1 or 2, wherein, the piece main body has a plurality of platform portions dividing the through space into a plurality of passages, the second groove assemblies adjacent to each other in the second direction perpendicular to the first direction are provided on a pair of platform portions adjacent to each other in the second direction, the length of the second main groove of the second groove assembly provided on one platform portion in the first direction is longer than the length of the second main groove of the second groove assembly provided on the other platform portion in the first direction.

8. The core piece for the evaporation chamber according to claim 1 or 2, wherein, the piece main body has a plurality of platform portions dividing the through space into a plurality of passages, a plurality of the second groove assemblies are provided on at least one of the plurality of platform portions.

9. The core piece for an evaporation chamber according to claim 1 or 2, wherein, the core piece for the evaporation chamber is provided with a communication part, and the communication part is arranged on the piece main body and communicates with the first groove assembly and the second groove assembly.

10. The core piece for an evaporation chamber according to claim 9, wherein, the communication part includes a communication recess, and the communication recess is arranged on the wall surface of the through space and extends from the first groove assembly to the second groove assembly.

11. The core piece for an evaporation chamber according to claim 10, wherein, the first groove assembly includes a first connection groove communicating with the first main flow groove, and the first connection groove extends along a direction different from the first direction, the second groove assembly includes a second connection groove communicating with the second main flow groove, and the second connection groove extends along a direction different from the first direction, the communication recess extends to at least one of the first connection groove and the second connection groove.

12. The core piece for an evaporation chamber according to claim 9, wherein, the communication part includes a through hole, and the through hole penetrates the piece main body and extends from the first groove assembly to the second groove assembly.

13. The core piece for an evaporation chamber according to claim 12, wherein, the first groove assembly includes a first connection groove communicating with the first main flow groove, and the first connection groove extends along a direction different from the first direction, the first main flow groove includes a first intersection part communicating with the first connection groove, the second groove assembly includes a second connection groove communicating with the second main flow groove, and the second connection groove extends along a direction different from the first direction, the second main flow groove includes a second intersection part communicating with the second connection groove, the through hole extends to at least one of the first intersection part and the second intersection part.

14. An evaporation chamber, wherein, the evaporation chamber includes: a first piece; a second piece; and the core piece for the evaporation chamber according to claim 1 or 2, which is interposed between the first piece and the second piece.

15. The evaporation chamber according to claim 14, wherein, the working fluid has freeze expansion property.

16. An electronic device, wherein, the electronic device includes: a housing; electronic components housed in the housing; and the evaporation chamber according to claim 14, which is in thermal contact with the electronic components.

17. The electronic device according to claim 16, wherein, when looking down on the evaporation chamber, the second groove assembly is arranged in a region different from the region overlapping with the electronic components.

18. An electronic device, wherein, the electronic device includes: a housing; electronic components housed in the housing; and the evaporation chamber according to claim 15, which is in thermal contact with the electronic components.

19. The electronic device according to claim 18, wherein, when looking down on the evaporation chamber, the second groove assembly is arranged in the region overlapping with the electronic components.

20. The electronic device according to claim 19, wherein, in the first direction, the second groove assembly extends outward beyond the electronic components.

21. The electronic device according to claim 18, wherein, the sheet body has a first overlapping platform portion and a second overlapping platform portion that divide the through space into a plurality of passageways, the first overlapping platform portion and the second overlapping platform portion are separated from each other in a second direction perpendicular to the first direction, the second groove assembly is provided in the first overlapping platform portion and the second overlapping platform portion, when the evaporation chamber is viewed from above, the second groove assembly provided in the first overlapping platform portion and the second groove assembly provided in the second overlapping platform portion are arranged in a region overlapping with the electronic device, when the evaporation chamber is viewed from above, the second groove assembly provided in the first overlapping platform portion is located closer to the center side of the electronic device in the second direction perpendicular to the first direction than the second groove assembly provided in the second overlapping platform portion, the length of the second groove assembly provided in the first overlapping platform portion in the first direction is longer than the length of the second groove assembly provided in the second overlapping platform portion in the first direction.

22. The electronic device according to claim 18, wherein, the sheet body has an overlapping platform portion and a non-overlapping platform portion that divide the through space into a plurality of passageways, the overlapping platform portion and the non-overlapping platform portion are separated and adjacent to each other in a second direction perpendicular to the first direction, the second groove assembly is provided in the overlapping platform portion and the non-overlapping platform portion, when the evaporation chamber is viewed from above, the second groove assembly provided in the overlapping platform portion is arranged in a region overlapping with the electronic device, when the evaporation chamber is viewed from above, the second groove assembly provided in the non-overlapping platform portion is arranged in a region different from the region overlapping with the electronic device.

23. The electronic device according to claim 22, wherein, the length of the second groove assembly provided in the overlapping platform portion in the first direction is longer than the length of the second groove assembly provided in the non-overlapping platform portion in the first direction.

24. An evaporation chamber, wherein, the evaporation chamber includes: a first sheet; a second sheet; and a core sheet for the evaporation chamber according to claim 8, which is interposed between the first sheet and the second sheet, the working fluid has freeze expansion property.

25. An electronic device, wherein, the electronic device includes: a housing; a plurality of electronic devices housed in the housing; and the evaporation chamber according to claim 24, which is in thermal contact with the plurality of electronic devices, the plurality of electronic devices are arranged in different regions in the first direction, a plurality of the second groove assemblies corresponding to the respective electronic devices are provided on the first main surface, when the evaporation chamber is viewed from above, the second groove assembly is arranged in a region overlapping with the corresponding electronic device.

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