Spring material

Abstract

To improve the heat radiation performance of a heat generating element with a simple configuration.SOLUTION: A spring member comprises a support plate 11 and a heat pipe member 12 formed of a material that has a lower Young's modulus and higher thermal conductivity than those of the material forming the support plate. The heat pipe member is formed in a box shape having a bottom wall 12 and opened upward. The upper end opening portion of the heat pipe member is joined to at least a pressing portion 14 of the support plate to be closed, so that an internal space S of the heat pipe member is divided into a heat receiving space Sr, a heat radiating space Sd, a large flow passage P1, and a small flow passage P2. A working fluid is sealed in the internal space, the heat receiving space is located directly above a heat generating element X, and the heat radiating space is located apart from the heat receiving space and the heat generating element as viewed in a vertical direction. The large flow passage and the small flow passage having a smaller flow passage cross sectional area than that of the large flow passage individually provide communication between the heat receiving space and the heat radiating space, respectively.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a spring member. [Background technology]

[0002] For example, as a spring member for pressing a heat generating body such as a semiconductor device against a heat sink, a configuration is known which includes a fixed portion, a pressing portion that is pressed against the heat sink or the heat generating body, and an elastic portion that connects the fixed portion and the pressing portion to each other, as shown in Patent Document 1 below. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5530517 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to improve the heat dissipation performance of the heat generating element, for example, it may be necessary to provide an additional heat dissipation element, which may lead to a complicated structure.

[0005] An object of the present invention is to provide a spring member that can improve the heat dissipation performance of a heat generating body with a simple configuration. [Means for solving the problem]

[0006] A spring member according to one aspect of the present invention comprises a support plate and a heat pipe member formed of a material having a lower Young's modulus and higher thermal conductivity than a material forming the support plate, the heat pipe member being formed in a box shape having a bottom wall and opening upward, the support plate comprising a fixing portion, a pressing portion that presses at least a part of the lower surface of the bottom wall of the heat pipe member against a heat generating element, and an elastic portion that connects the fixing portion and the pressing portion to each other, and an upper end opening of the heat pipe member is joined to at least the pressing portion of the support plate and closed, thereby dividing the internal space of the heat pipe member into a heat receiving space, a heat dissipation space, and The internal space is divided into a large flow path and a small flow path, and a working fluid is sealed in the internal space, the heat receiving space is located directly above the heat generating element, and the heat dissipation space is located away from the heat receiving space and the heat generating element when viewed from above and below, the large flow path and the small flow path, which has a smaller cross-sectional area than the large flow path, each separately connect the heat receiving space and the heat dissipation space, and the vapor of the working fluid that is heated and evaporated in the heat receiving space flows from the heat receiving space toward the heat dissipation space in the large flow path, and the working fluid that has been cooled and condensed in the heat dissipation space and returned to liquid flows from the heat dissipation space toward the heat receiving space by capillary force in the small flow path.

[0007] The working fluid sealed in the internal space evaporates in the heat-receiving space heated by the heating element (absorbing latent heat), and the resulting vapor flows through the large flow path into the heat-dissipating space, where it is cooled and condensed, returning to a liquid state (releasing latent heat). The working fluid, which has returned to a liquid state, then returns to the heat-receiving space through the small flow path due to capillary force. In this way, the working fluid moves back and forth between the heat-receiving space and the heat-dissipating space, releasing heat from the heating element and improving the heat-dissipating performance of the heating element. By joining and closing the upper end opening of the heat pipe member to the support plate, the internal space is divided into a heat receiving space, a heat dissipation space, a large flow path, and a small flow path, and the working fluid is sealed in the internal space, so that the support plate and the heat pipe member are provided as a single unit, thereby reducing the complexity of the structure. Since the entire upper end opening of the heat pipe member is closed by the support plate, no gap is formed in the vertical direction between the heat pipe member and the support plate, making it possible to reduce the occurrence of dead space.

[0008] When viewed from the top and bottom, the direction in which the pressing portion, the elastic portion, and the fixing portion are arranged in this order may coincide with the direction in which the heat receiving space and the heat dissipation space are arranged in this order and the direction in which the large flow path and the small flow path extend.

[0009] When viewed from the top and bottom, the direction in which the pressing portion, elastic portion, and fixed portion are arranged in this order coincides with the direction in which the heat receiving space and heat dissipation space are arranged in this order and the direction in which the large flow path and small flow path extend, making it possible to easily ensure a long distance between the heat receiving space and the heat dissipation space, and reliably improving the heat dissipation performance of the heat-generating element.

[0010] A partition wall that partitions the internal space of the heat pipe member into the heat receiving space, the heat dissipation space, the large flow path, and the small flow path may be formed integrally with the heat pipe member.

[0011] The partition walls that divide the internal space of the heat pipe member into a heat receiving space, a heat dissipation space, a large flow path, and a small flow path are formed integrally with the heat pipe member, which has a high thermal conductivity, so that the heat dissipation performance of the heat generating element can be reliably improved with a simple configuration without impairing the springiness of the support plate. [Effects of the Invention]

[0012] According to this invention, the heat dissipation performance of the heat generating element can be improved with a simple configuration. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view taken along the longitudinal direction (one direction) of a spring member of a first embodiment. [Figure 2A] FIG. 2 is a cross-sectional view taken along line 2A-2A in FIG. [Figure 2B] FIG. 2B is a cross-sectional view taken along line 2B-2B in FIG. [Figure 3A] FIG. 2B shows a second embodiment of FIG. 2A. [Figure 3B] FIG. 2C shows a second embodiment of FIG. 2B. [Figure 4A] FIG. 2B shows a third embodiment of FIG. 2A. [Figure 4B] FIG. 2C shows a third embodiment of FIG. 2B. [Figure 5] FIG. 2C shows a fourth embodiment of FIG. 2B. [Figure 6A] FIG. 10 is a cross-sectional view taken along the longitudinal direction (one direction) of a spring member according to a fifth embodiment. [Figure 6B] FIG. 6B is a cross-sectional view taken along line 6B-6B in FIG. 6A. DETAILED DESCRIPTION OF THE INVENTION

[0014] A first embodiment of the spring member will be described below with reference to FIGS. 1, 2A, and 2B. The spring member 1 is used by being housed in a case body C that also houses a heat generating element X. The heat generating element X is, for example, a semiconductor device or the like, and includes a chip x1 that generates heat. The spring member 1 includes a support plate 11 and a heat pipe member 12. The heat pipe member 12 is made of a material that has a lower Young's modulus and higher thermal conductivity than the material that forms the support plate 11. For example, the support plate 11 is made of iron, stainless steel, or the like, and the heat pipe member 12 is made of copper, aluminum, or the like. The heat pipe member 12 is formed in a box shape as will be described later, and hereinafter, the direction in which the box-shaped heat pipe member 12 opens will be referred to as the upper side, and the opposite direction will be referred to as the lower side.

[0015] The support plate 11 includes a fixed portion 13, a pressing portion 14, and an elastic portion 15. The fixed portion 13, the pressing portion 14, and the elastic portion 15 are integrally formed. The support plate 11 has a rectangular shape that is long in one direction when viewed from the top to bottom. The fixed portion 13, the elastic portion 15, and the pressing portion 14 are aligned in this order along the one direction when viewed from the top to bottom.

[0016] The fixing portion 13 is fixed to the inner surface of the case body C. The pressing portion 14 is biased downward toward the heat generating element X by the elastic portion 15. The pressing portion 14 presses at least a part of the heat pipe member 12 against the heat generating element X. The fixed portion 13 and the pressing portion 14 are formed in a flat plate shape with the front and back surfaces facing up and down. The fixed portion 13 abuts uniformly without any gaps against the inner surface of the case body C. Note that the fixed portion 13 may be curved, for example, to fit the shape of the portion of the inner surface of the case body C with which the fixed portion 13 abuts.

[0017] The elastic portion 15 connects the fixed portion 13 and the pressing portion 14 to each other. The elastic portion 15 is composed of an inclined portion 15a that extends upward from the pressing portion 14 toward the fixed portion 13 along the one direction, a rising portion 15b that extends upward from the fixed portion 13, and a top portion 15c that connects the inclined portion 15a and the rising portion 15b to each other and has a curved surface that protrudes upward. The elastic deformation of the elastic portion 15 urges the pressing portion 14 downward.

[0018] The heat pipe member 12 has a bottom wall 12a and is formed in a box shape that is open upward. When viewed from above, the heat pipe member 12 has a rectangular shape that is long in the one direction. The lower surface of the bottom wall 12a of the heat pipe member 12 is in uniform contact with the upper surface of the heat generating element X without any gap. The heat pipe member 12 and the pressing portion 14 may be curved to fit the shape of the upper surface of the heat generating element X, for example.

[0019] The upper end opening of the heat pipe member 12 is joined and closed to at least the pressing portion 14 of the support plate 11 by, for example, diffusion bonding, brazing, or adhesive. This seals the internal space S of the heat pipe member 12, sealing the working fluid in the internal space S and dividing the internal space S into a heat receiving space Sr, a heat dissipation space Sd, a large flow path P1, and a small flow path P2. The internal space S is sealed in a reduced pressure state lower than atmospheric pressure. Note that the internal pressure of the internal space S may be set to atmospheric pressure or higher.

[0020] The heat receiving space Sr is located directly above the heating element X. In the illustrated example, the heat receiving space Sr is located directly above the chip x1 of the heating element X. The center of the heating element X in the one direction is located on the opposite side of the elastic portion 15 along the one direction relative to the center of the pressing portion 14 in the one direction. The heat dissipation space Sd is located away from the heat receiving space Sr and the heating element X when viewed from the top and bottom. Due to the heat from the heating element X, the temperature of the heat receiving space Sr becomes higher than the temperature of the heat dissipation space Sd. The internal volumes of the heat receiving space Sr and the heat dissipation space Sd are the same.

[0021] The large flow path P1 and the small flow path P2 each connect the heat receiving space Sr and the heat dissipation space Sd. The small flow path P2 has a smaller flow path cross-sectional area than the large flow path P1. The groove width and depth of the small flow path P2 are smaller than the groove width and depth of the large flow path P1. The large flow path P1 and the small flow path P2 have the same flow path length. In the large flow path P1, the vapor of the working fluid that has been heated and evaporated in the heat receiving space Sr flows from the heat receiving space Sr to the heat dissipation space Sd. In the small flow path P2, the working fluid that has been cooled and condensed in the heat dissipation space Sd and turned back into a liquid flows from the heat dissipation space Sd to the heat receiving space Sr by capillary force.

[0022] When viewed from the top-bottom direction, a plurality of small flow paths P2 are provided at intervals in another direction perpendicular to the one direction. When viewed from the top-bottom direction, a plurality of small flow paths P2 (the same number) are provided on both sides of the large flow path P1 in the other direction. The large flow path P1 is provided in the middle of the internal space S in the other direction. When viewed from the top and bottom, the direction in which the pressing portion 14, the elastic portion 15, and the fixed portion 13 are arranged in this order coincides with the direction in which the heat receiving space Sr and the heat dissipation space Sd are arranged in this order and the direction in which the large flow path P1 and the small flow path P2 extend. In the illustrated example, these directions coincide with the one direction. However, these directions may be different from each other. FIG. 1 shows a cross-sectional view of the central portion of the spring member 1 in the other direction, taken along the one direction.

[0023] Raising protrusions (compartment walls) 17 are provided on both sides of the upper surface of the bottom wall 12a of the heat pipe member 12 in the other direction. The raising protrusions 17 are formed integrally with the heat pipe member 12 and are connected to both end faces of the inner surface of the heat pipe member 12 in the other direction. The top surfaces of the raising protrusions 17 are located below the upper end opening edge of the heat pipe member 12. The top surfaces of the raising protrusions 17 form the bottom surfaces of the small flow paths P2. As a result, the bottom surfaces of the small flow paths P2 are located above the bottom surface of the large flow path P1. The raising protrusions 17 are spaced apart in the one direction from both end faces of the inner surface of the heat pipe member 12 in the one direction.

[0024] In the internal space S, the portions sandwiched in one direction between both end faces of the inner surface of the heat pipe member 12 and the protrusions 17 form a heat receiving space Sr and a heat dissipation space Sd. In the internal space S, the portion sandwiched in the other direction between the two protrusions 17 forms a large flow path P1.

[0025] A plurality of protrusions (compartment walls) 16, which protrude upward and extend continuously over the entire length in the one direction, are formed on the top surface of the raised protrusion 17 at intervals in the other direction. The portions located between adjacent protrusions 16 in the other direction form small flow paths P2. The upper end surfaces of the protrusions 16 are located at the same vertical position as the upper end opening edge of the heat pipe member 12. The upper end surfaces of the protrusions 16 abut against the lower surface of the support plate 11 in a sealed state. The upper end surfaces of the protrusions 16 may or may not be joined to the lower surface of the support plate 11.

[0026] As described above, the raising protrusions 17 and the protruding ridges 16 divide the internal space S into a heat receiving space Sr, a heat dissipation space Sd, a large flow path P1, and a small flow path P2, and are formed integrally with the heat pipe member 12. Note that the raising protrusions 17 and the protruding ridges 16 may be formed integrally with the support plate 11. In the illustrated example, the entire upper end opening of the heat pipe member 12 is closed by the pressing portion 14. The lower surface of the portion of the bottom wall 12a of the heat pipe member 12 that straddles the heat receiving space Sr and the ends of the large flow path P1 and the small flow path P2 on the heat receiving space Sr side abuts against the upper surface of the heat-generating element X, and the lower surface of the portion where the heat receiving space Sr is located abuts against the upper surface of the chip x1.

[0027] For example, the upper end opening of the heat pipe member 12 where the heat receiving space Sr is located may be blocked by the pressing portion 14, and the upper end opening of the heat dissipation space Sd may be blocked by the elastic portion 15 or the fixed portion 13. The upper end opening of the heat pipe member 12 where the large flow path P1 and the small flow path P2 are located may be blocked by, for example, both the pressing portion 14 and the elastic portion 15, all of the pressing portion 14, the elastic portion 15, and the fixed portion 13, or both the elastic portion 15 and the fixed portion 13, depending on the position of the heat dissipation space Sd relative to the support plate 11 in the one direction.

[0028] As described above, in the spring member 1 according to this embodiment, the working fluid sealed in the internal space S evaporates (absorbs latent heat) in the heat receiving space Sr heated by the heating element X, and the resulting vapor flows through the large flow path P1 into the heat dissipation space Sd, where it is cooled and condensed to return to a liquid state (releases latent heat). The working fluid that has returned to a liquid state returns to the heat receiving space Sr through the small flow path P2 by capillary force. In this way, the working fluid moves back and forth between the heat receiving space Sr and the heat dissipation space Sd, thereby dissipating heat from the heating element X and improving the heat dissipation performance of the heating element X.

[0029] By joining and closing the upper end opening of the heat pipe member 12 to the support plate 11, the internal space S is divided into a heat receiving space Sr, a heat dissipation space Sd, a large flow path P1, and a small flow path P2, and the working fluid is sealed in the internal space S, so that the support plate 11 and the heat pipe member 12 are provided as a single unit, thereby reducing the complexity of the structure. Since the entire upper end opening of the heat pipe member 12 is blocked by the support plate 11, no gap is formed between the heat pipe member 12 and the support plate 11 in the vertical direction, making it difficult for dead space to occur.

[0030] When viewed from the top and bottom, the direction in which the pressing portion 14, elastic portion 15, and fixed portion 13 are arranged in this order coincides with the direction in which the heat receiving space Sr and heat dissipation space Sd are arranged in this order and the large flow path P1 and small flow path P2 extend, so it is possible to easily ensure a long distance between the heat receiving space Sr and the heat dissipation space Sd, and the heat dissipation performance of the heating element X can be reliably improved.

[0031] The raised protrusions 17 and protruding portions 16 that divide the internal space S of the heat pipe member 12 into a heat receiving space Sr, a heat dissipation space Sd, a large flow path P1, and a small flow path P2 are formed integrally with the heat pipe member 12, which has high thermal conductivity, so that the heat dissipation performance of the heat generating element X can be reliably improved with a simple configuration without impairing the spring properties of the support plate 11.

[0032] Next, a spring member 2 according to a second embodiment of the present invention will be described with reference to FIGS. 3A and 3B. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, with only the differences being described.

[0033] In the spring member 2 of this embodiment, a plurality of small flow paths P2 are provided at intervals not only in the other direction but also in the up-down direction. In the illustrated example, the heat pipe member 12 is made up of a first divided member 21 and a plurality of second divided members 22 stacked in the vertical direction.

[0034] The first divided member 21 has a bottom wall 21a and is formed in a box shape that opens upward, and constitutes the lowest layer of the heat pipe member 12. When viewed from the top-bottom direction, the first divided member 21 has a rectangular shape that is long in one direction. The upper end opening of the first divided member 21 is joined to the underside of the bottom wall 22a of the second divided member 22 and is closed.

[0035] A plurality of first protrusions (compartment walls) 23a protruding upward and extending in the one direction are formed at intervals in the other direction on both sides of the upper surface of the bottom wall 21a of the first divided member 21. The upper end faces of the first protrusions 23a are located at the same vertical position as the upper opening edge of the first divided member 21. The upper end faces of the first protrusions 23a abut in a sealed state against the lower surface of the bottom wall 22a of the second divided member 22. The upper end faces of the first protrusions 23a may or may not be joined to the lower surface of the bottom wall 22a of the second divided member 22. The portions located between adjacent first protrusions 23a in the other direction form small flow paths P2. The first protrusions 23a are spaced apart in the one direction from both end faces of the inner surface of the first divided member 21 in the one direction.

[0036] The second divided members 22 are formed in a box shape with a bottom wall 22a and an upward opening, and are stacked on the first divided member 21. When viewed from the top and bottom, the second divided members 22 are rectangular in shape and are long in the one direction. The second divided members 22 are formed to have the same shape and size as each other.

[0037] Through-holes are formed integrally over the entire bottom wall 22a of the second divided member 22 in a portion of the first divided member 21 other than the first protrusions 23a and the small passages P2, i.e., in a portion that faces vertically the portions that define the heat receiving space Sr, the heat dissipation section Sd, and the large passage P1. As a result, the heat receiving space Sr, the heat dissipation section Sd, and the large passage P1 are provided integrally across the first divided member 21 and the multiple second divided members 22 in the vertical direction.

[0038] Of the multiple second divided members 22, the upper end opening of the second divided member 22 that constitutes the uppermost layer of the heat pipe member 12 is joined to at least the pressing portion 14 of the support plate 11 and closed, and the upper end opening of the second divided member 22 located below this is joined to the underside of the bottom wall 22a of the second divided member 22 located directly above and closed.

[0039] A plurality of second protrusions (compartment walls) 23b protruding upward and extending in the one direction are formed at intervals in the other direction on both sides of the upper surface of bottom wall 22a of second divided member 22. Second protrusions 23b are located at the same positions in both the one direction and the other direction relative to first protrusions 23a. The portions located between adjacent second protrusions 23b in the other direction form small flow paths P2.

[0040] Of the multiple second divided members 22, the upper end surface of the second protrusions 23b formed on the second divided member 22 constituting the uppermost layer of the heat pipe member 12 abuts in a sealed state against the underside of the support plate 11, and the upper end surfaces of the second protrusions 23b formed on the second divided members 22 positioned below this abut in a sealed state against the underside of the bottom wall 22a of the second divided member 22 positioned immediately above. The upper end surface of the former second protrusions 23b may or may not be joined to the underside of the support plate 11, and the upper end surface of the latter second protrusions 23b may or may not be joined to the underside of the bottom wall 22a of the second divided member 22 positioned immediately above.

[0041] As described above, according to the spring member 2 of this embodiment, in addition to the effects obtained by the spring member 1 of the first embodiment, multiple small flow paths P2 are provided at intervals not only in the other directions but also in the vertical direction, making it easier to immediately return the working fluid condensed and produced in the heat dissipation space Sd to the heat receiving space Sr, thereby reliably improving the heat dissipation performance of the heating element X.

[0042] Next, a spring member 3 according to a third embodiment of the present invention will be described with reference to FIGS. 4A and 4B. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, with only the differences being described.

[0043] In the spring member 3 of this embodiment, one small flow passage P2 is provided on each side of the large flow passage P1 in the other direction. The groove width of the small flow passage P2 is wider than the groove width of the large flow passage P1. The depth of the small flow passage P2 is shallower than the depth of the large flow passage P1. Only one protrusion 16 is provided on the inner end of the top surface of each raised protrusion 17 in the other direction.

[0044] As described above, according to the spring member 3 of this embodiment, the same effects as those of the spring member 1 of the first embodiment can be obtained.

[0045] Next, a spring member 4 according to a fourth embodiment of the present invention will be described with reference to FIG. In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, with only the differences being described.

[0046] In the spring member 4 of this embodiment, a fitting protrusion 41 is provided on the underside of the support plate 11. The fitting protrusion 41 fits into the upper end opening of the heat pipe member 12 and closes the upper end opening of the heat pipe member 12. The upper end surface of the protrusion 16 is located below the edge of the upper end opening of the heat pipe member 12 and abuts in a sealed state against the underside of the fitting protrusion 41. Not only the lower surface of the fitting protrusion 41 but also the outer peripheral surface of the fitting protrusion 41 are joined to the upper end of the heat pipe member 12.

[0047] As described above, according to the spring member 4 of this embodiment, in addition to the effects obtained by the spring member 1 of the first embodiment, not only the lower surface of the fitting protrusion 41 but also the outer surface of the fitting protrusion 41 are joined to the upper end of the heat pipe member 12, so that the support plate 11 and the heat pipe member 12 can be firmly joined to each other and the internal space S can be reliably sealed.

[0048] Next, a spring member 5 according to a fifth embodiment of the present invention will be described with reference to Figures 6A and 6B. Figure 6A shows a cross-sectional view of the central portion of spring member 5 in the other direction, taken along the one direction. In the fifth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, with only the differences being described.

[0049] In the spring member 5 of this embodiment, the heat dissipation space Sd, the large flow path P1, and the small flow path P2 are separately arranged on both sides of the heat receiving space Sr. In the example shown in the figure, the heat dissipation space Sd, the large flow path P1, and the small flow path P2 are separately arranged on both sides of the heat receiving space Sr in the one direction. The support plate 11 is provided with an extension portion 51 that extends from the pressing portion 14 toward the opposite side of the elastic portion 15 along the one direction. In the example shown, the extension portion 51 extends upward along the one direction as it moves away from the pressing portion 14, but it may also extend downward as it moves away from the pressing portion 14, or it may extend straight in the one direction.

[0050] The center of the heat generating element X in the one direction coincides with the center of the pressing portion 14 in the one direction. The upper end opening of the heat pipe member 12 where the heat receiving space Sr is located is blocked by the pressing portion 14, and the upper end openings of the portions where the two heat dissipation spaces Sd are located are blocked separately by the elastic portion 15 and the extension portion 51. The upper end openings of the heat pipe member 12 where the two sets of large flow paths P1 and small flow paths P2 are located are blocked separately by both the pressing portion 14 and the elastic portion 15, and both the pressing portion 14 and the extension portion 51. The heat pipe member 12 has a central portion extending straight in the one direction, and both side portions extending upward toward the outside in the one direction. In a cross-sectional view along the one direction, the heat pipe member 12 has a symmetrical shape with respect to a line that passes through the central portion in the one direction and extends vertically.

[0051] As described above, according to the spring member 5 of this embodiment, in addition to the effects obtained by the spring member 1 of the first embodiment, the heat dissipation space Sd, the large flow path P1, and the small flow path P2 are arranged separately on both sides of the heat receiving space Sr, so that the heat dissipation performance of the heat-generating body X can be reliably improved.

[0052] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0053] For example, the number and relative positions of the large flow paths P1 and the small flow paths P2 may be changed as appropriate, such as by providing a large flow path P1 at each end of the internal space S in the other direction, and providing a plurality of small flow paths P2 spaced apart in the other direction in the middle of the internal space S in the other direction.

[0054] In the heat pipe member 12, cooling fins that protrude toward the outside of the internal space S may be formed on the wall surfaces that define the heat dissipation space Sd. In this case, since the cooling fins are provided on the heat pipe member 12 rather than on the support plate 11, the spring properties of the support plate 11 are not impaired and the heat dissipation performance of the heat generating element X can be reliably improved. The direction in which the cooling fins protrude from the heat pipe member 12 may be changed as appropriate, for example, to the one direction, the other direction, or downward.

[0055] The small flow passage P2 may be provided with a wick such as a mesh or wire.

[0056] In addition, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, without departing from the spirit of the present invention, and the above-described embodiments and variations may be combined as appropriate. [Explanation of symbols]

[0057] 1, 2, 3, 4, 5 Spring members 11 Support plate 12 Heat pipe components 12a Bottom wall 13 Fixed part 14 Pressing part 15 Elastic part 16 Protrusion (compartment wall) 17 Raised protrusion (compartment wall) 23a First protrusion (compartment wall) 23b Second protrusion (compartment wall) P1 Large flow path P2 small channel S interior space Sd Heat dissipation space Sr heat receiving space X heating element

Claims

1. A support plate; a heat pipe member formed of a material having a lower Young's modulus and higher thermal conductivity than a material forming the support plate, The heat pipe member is formed in a box shape having a bottom wall and an opening facing upward, The support plate is A fixed portion; a pressing portion that presses at least a portion of the lower surface of the bottom wall of the heat pipe member against a heat generating body; an elastic portion connecting the fixing portion and the pressing portion to each other, an upper end opening of the heat pipe member is joined to at least the pressing portion of the support plate and closed, thereby dividing the internal space of the heat pipe member into a heat receiving space, a heat dissipation space, a large flow path, and a small flow path, and a working fluid is sealed in the internal space; The heat receiving space is located directly above the heating element, the heat dissipation space is located away from the heat receiving space and the heat generating body when viewed from above and below, the large flow path and the small flow path, which has a flow path cross-sectional area smaller than that of the large flow path, respectively communicate with the heat receiving space and the heat dissipation space; In the large flow path, the vapor of the working fluid that has been heated and evaporated in the heat receiving space flows from the heat receiving space toward the heat dissipation space, The small flow path includes a spring member that allows the working fluid, which has been cooled from its vapor in the heat dissipation space and condensed to return to a liquid state, to flow from the heat dissipation space toward the heat receiving space by capillary force.

2. 2. The spring member according to claim 1, wherein, when viewed from the top-bottom direction, the direction in which the pressing portion, the elastic portion, and the fixing portion are arranged in this order coincides with the direction in which the heat receiving space and the heat dissipation space are arranged in this order and the direction in which the large flow path and the small flow path extend.

3. 3. The spring member according to claim 1, wherein a partition wall that divides the internal space of the heat pipe member into the heat receiving space, the heat dissipation space, the large flow path, and the small flow path is formed integrally with the heat pipe member.

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