JP2009024933A - Thermal diffusion device and manufacturing method for it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal diffusion device capable of forming a groove having a steep wall surface with favorable accuracy to improve thermal diffusion. <P>SOLUTION: In this thermal diffusion device, first and second metal thin plates 22, 23 having a difference in dimension are alternately stacked and diffusion-joined to upper and lower sealing metal thin plates 25 and 26 to form a sealed space 45 inside, the groove 44 having a steep wall surface generated by a difference in dimension between the first and the second metal thin plates 22, 23 is formed on the wall surface of the sealed space 45, and liquid is sealed in the groove 44 at reduced pressure in an initial state. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermal diffusion device that diffuses heat from a heat source in, for example, electronic devices and other devices, and suppresses the temperature of the heat source to a required temperature or less, and a method for manufacturing the same.

  Conventionally, for example, electronic devices such as personal computers and projectors (display devices) require a heat diffusing device for radiating heat from a heat source. As this heat diffusion device, what is called a heat pipe is known. For example, as shown in FIG. 23, the heat pipe is formed with a plurality of parallel grooves 3 along the longitudinal direction so that the cross section in the circumferential direction is concave and convex inside the metal pipe 2, and a wire mesh on the inner surface. The wick 4 formed in the above is arranged, and the water 4 is sealed in the groove 3. In the heat pipe 1, when one end is brought into contact with the heat generation source, the water in the groove 3 evaporates at the one end, and the steam is instantly spread to the other end. Since the other end is in contact with the outside air, the heat is exchanged, the steam is cooled and condensed, and returned to water. This water flows back to one end through wick 4. By repeating the evaporation, condensation, and reflux of the water, the temperature rise of the heat source is suppressed.

Document 1 discloses an example of a heat pipe.
JP 2004-198098 A

  In the heat pipe 1 described above, as shown in FIG. 22, if the groove 3 is formed with a steep wall surface, that is, a right-angle wall surface, the contact angle θ with the wall surface 3a of the water 10 enclosed in the groove 3. And the thin portion 9 of the water 10 is likely to evaporate, and the wall surface of this portion 9 can be made extremely cold. At the same time, the water 10 aggregated by capillary action can be refluxed to the evaporation part side through the groove 3. However, in practice, the pipe 2 having a plurality of grooves 3 is formed by drawing, so that the groove 3 having a steep wall surface cannot be formed. Therefore, a wick 4 formed of a wire mesh is required. Become.

  On the other hand, as shown in FIG. 21A, a plurality of grooves 13 are formed on the surface of the first metal thin plate 12 by etching, and a second metal thin plate 14 serving as a lid is joined to the groove 13, whereby a sealed space by each groove 13 is formed. A flat type thermal diffusion device 11 in which water 15 is sealed in the groove 13 under a reduced pressure in an initial state can be considered. However, as shown in FIG. 21B, when the groove 13 is formed by etching, the cross section becomes a groove having a curved surface, and a groove having a steep wall surface cannot be formed.

  In view of the above, the present invention provides a thermal diffusion device and a manufacturing method thereof in which a groove having a steep wall surface is accurately formed and thermal diffusion is improved.

  The thermal diffusion device according to the present invention is formed by alternately laminating first and second thin metal plates having a dimensional difference and diffusion-bonding them so that a sealed space is formed inside with upper and lower sealing metal thin plates. A groove having a steep wall surface is formed on the wall surface of the space due to a dimensional difference between the first and second metal thin plates, and liquid is sealed in the groove under reduced pressure in an initial state.

  In the present invention, since the first and second thin metal plates having a dimensional difference are alternately laminated, a groove having a steep wall surface is accurately formed on the wall surface of the sealed space. Since the contact angle θ of the liquid with respect to the groove wall surface can be reduced, water is efficiently evaporated.

  The manufacturing method of the heat diffusing device according to the present invention includes a step of alternately laminating first and second metal thin plates having a dimensional difference, and arranging sealing metal thin plates on the upper and lower sides, and the first and second metals. The thin plate and the metal thin plate for sealing are diffusion-bonded to form an integral laminate, and a sealed space is formed inside the laminate, and the dimensional difference between the first and second metal thin plates on the wall of the sealed space A step of forming a groove having a steeper wall surface, and a step of enclosing a liquid in the groove in an initial state in which the inside of the sealed space is decompressed.

  In the manufacturing method of the thermal diffusion device of the present invention, a groove having a steep wall surface can be accurately formed on the wall surface of the sealed space by alternately laminating the first and second metal thin plates having a dimensional difference. it can. By enclosing the liquid in the groove, it is possible to enclose the liquid in a state in which the contact angle θ of the liquid with respect to the groove wall surface is reduced.

According to the heat diffusing device according to the present invention, a groove having a steep wall surface can be obtained, and the liquid enclosed in the groove can be efficiently evaporated. Therefore, a heat diffusing device with good heat diffusion is provided. be able to.
According to the method of manufacturing a thermal diffusion device according to the present invention, a groove having a steep wall surface can be formed with high accuracy, and thus a thermal diffusion device with good thermal diffusion can be manufactured.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 5 show a first embodiment of a thermal diffusion device and a manufacturing method thereof according to the present invention. As shown in FIGS. 1A and 1B, the thermal diffusion device 21 according to the present embodiment includes a first metal thin plate 22 having a rectangular shape when viewed from above, and a square having the same size in this example, and this A laminate 24 in which second metal plates 23 having a dimensional difference with the first metal thin plate 22 are alternately laminated, and metal thin plates 25 and 26 for sealing that seal the top and bottom of the laminate 24 are provided. It is configured. The 1st, 2nd metal thin plates 22 and 23 are formed with a thin plate with a uniform film thickness. The upper and lower sealing metal thin plates 25 and 26 are also formed from thin plates having a uniform film thickness.

  As shown in FIGS. 3A and 3B, the first thin metal plate 22 includes a central portion 31, a square frame-shaped peripheral portion 32, and a plurality of radiating portions that communicate from the central portion 31 to the peripheral portion 32. It is formed in a pattern having four radiating portions 33 [331, 332, 333, 334] that radiate in a cross shape that divides the four sides into two equal parts. The peripheral portion 32 is formed with the same width over the entire periphery, and the width is selected as the required width w1. Each of the radiating portions 331 to 334 is formed with the same width d1 from the peripheral portion 32 to the middle, and is formed in a tapered shape such that the width gradually decreases from the middle toward the central portion 31. In this example, each radiation | emission part 33 [331-334] is each formed in line symmetry. Each of the four radiating portions 331 to 334 is formed with a through hole 35 into which a support column provided integrally with a lower sealing metal thin plate 26 described later is inserted. The first metal thin plate 22 can be formed by pressing one metal thin plate.

  As shown in FIGS. 4A and 4B, the second thin metal plate 23 includes a central portion 36, a square frame-shaped peripheral portion 37, and a plurality of radiating portions communicating from the central portion 36 to the peripheral portion 37, in this example. Two diagonal lines intersect to form a pattern having four radiation portions 38 [381, 382, 383, 384] that radiate in a cross shape. That is, the pattern of the second metal thin plate 23 is different from the pattern of the first metal thin plate 22 in the radiation portion. The peripheral portion 37 is formed with the same width over the entire periphery, and the width is selected as a required width w2 (w1> w2) smaller than the width w1 of the first metal thin plate 22. Each of the radiating portions 381 to 384 is formed with the same width d2 from the peripheral portion 37 to the middle, and is formed in a tapered shape such that the width gradually decreases from the middle toward the central portion 36. In this example, each radiation part 38 [381-384] is formed in line symmetry, respectively. Each of the four radiating portions 381 to 384 is formed with a through hole 39 into which a support column provided integrally with the lower sealing metal thin plate 26 described later is inserted. The first metal thin plate 23 can be formed by pressing one metal thin plate.

  The width d1 of the radiating portion 33 of the first thin metal plate 22 and the width d2 of the radiating portion 38 of the second thin metal plate 23 may be the same dimension (d1 = d2) or may be different dimensions (d1). ≠ d2). The through holes 35 and 39 formed in the radiation portions 33 and 38 of the first and second thin metal plates 22 and 23 preferably have the same diameter.

  Since the widths w1 and w2 of the peripheral portions 32 and 37 of the first and second thin metal plates 22 and 23 are different from each other, there is a dimensional difference Δw = w1−w2 in the peripheral portions 32 and 37 when stacked. It comes to occur.

  As shown in FIG. 2, the upper sealing metal thin plate 25 has a square shape, and corresponds to the radiating portions 33 and 38 in the first and second metal thin plates 22 and 23, that is, the lower sealing metal thin plate. A through hole 41 into which the tip of the column is inserted is formed at a position corresponding to the column that is integral with the column 26. In this example, eight through holes 41 are formed.

  As shown in FIG. 5, the lower sealing metal thin plate 26 has a square shape, and each of the through holes 35 and 39 of the radiation portions 33 and 38 in the first and second metal thin plates 22 and 23 and the upper sealing metal. A column 42 is integrally planted and formed at a position corresponding to the through hole 41 of the metal thin plate 25. In this example, eight struts 42 are formed. The support column 42 has a large-diameter portion 42a inserted into the through holes 35 and 39 provided in the radiation portions 33 and 38 of the first and second thin metal plates 22 and 23, and the upper sealing thin metal plate 25 at the tip thereof. The small-diameter portion 42b inserted into the through-hole 41 is formed. The struts 42 are for enduring internal pressure and maintaining the distance between the lower sealing metal thin plate 26 and the upper sealing metal thin plate 25. The support column 42 does not need to be joined to the radiating portions 33 and 38, and penetrates the radiating portions 33 and 38. The column 42b can be omitted, and the eight columns are connected to the upper and lower planes by diffusion bonding simultaneously with the laminated structure. The figure shows the possibility that a caulking structure can be used together to ensure strength.

  The first and second metal thin plates 22 and 23 and the upper and lower sealing metal thin plates 25 and 26 are formed using a metal that can be diffusion bonded, for example, a metal such as copper or beryllium copper, in this example, copper.

  In the present embodiment, the first metal thin plate 22 and the second metal thin plate 23 are stacked by alternately laminating a plurality of, for example, 21 sheets so that the uppermost layer and the lowermost layer are the first metal thin film. A body 24 is formed, and this laminated body 24 is disposed on the lower sealing metal thin plate 26. That is, the laminated body 24 is arranged on the lower sealing metal thin plate 26 so that the large-diameter portion 42a of the column 42 of the lower sealing metal thin plate 26 is inserted into the through holes 35 and 39 of the radiation portions 33 and 38, respectively. Placed in. An upper sealing metal thin plate 25 is disposed on the laminate 24. The upper sealing metal thin plate 25 is disposed on the laminated body 24 so that the small diameter portion 42b at the tip of the column 42 integral with the lower sealing metal thin plate 26 is inserted into each through hole 41 thereof.

  And in this Embodiment, the laminated body 24 which has arrange | positioned the metal thin plates 25 and 26 for sealing up and down is integrated by diffusion joining by pressurization and heating in a vacuum in this state, and is airtight and liquidtight Sealed. The column 42 is diffusion-bonded to the upper sealing metal thin plate in a state where the stepped surface at the tip thereof is in contact with the back surface of the upper sealing metal thin plate 25. At the same time, a liquid serving as a refrigerant under reduced pressure in an initial state is sealed in a groove, which will be described later, formed on the side wall surface in the sealed space in the laminated body 24, thereby configuring the heat diffusion device 21.

  The thermal diffusion device 21 according to the first embodiment has dimensions of the first and second metal thin films 22 and 23 on the side wall surface of the peripheral portion 28 in the sealed space 45 in FIG. Due to the difference Δw, a groove 44 having a steep wall surface is formed. That is, when viewed in the cross section of the groove, a U-shaped groove 44 having upper and lower wall surfaces perpendicular to the inner wall surface is formed. Further, in the central portion 27 in the sealed space 45, as shown in FIGS. 7A and 7B, a groove 44 having a steep wall surface due to a dimensional difference Δw between the first and second metal thin films 22 and 23 on the side wall surface. Is formed. That is, when viewed in the cross section of the groove, a U-shaped groove 44 having upper and lower wall surfaces perpendicular to the inner wall surface is formed. In the central portion 27, the groove 44 is formed along the star shape of the central portion 27 as indicated by a chain line 29 when viewed from above.

  On the other hand, in the 1st metal thin film 22 arrange | positioned up and down on both sides of the 2nd metal thin film 23, the reflux liquid (it mentions later) which has a capillary action between the upper and lower radiation | emission parts 33 [331-334]. ) Is formed. In addition, in the second metal thin film 23 disposed above and below the first metal thin film 22, a narrowly spaced reflux liquid having a capillary action is similarly provided between the upper and lower radiation portions 38 [381 to 384]. Are formed (see FIG. 8).

  For example, water (pure water) is preferably used as the liquid serving as the refrigerant. As shown in FIG. 11, the groove width t1 of the groove 44 (that is, the plate thickness of the second metal thin plate 23) and the depth Δw can be freely set according to the refrigerant. For example, when water is used as the coolant, the groove width t1 is optimally 20 μm to 100 μm, but is not necessarily limited to this value depending on the surface tension of the coolant.

  Next, the operation | work which encloses a liquid specifically in the thermal-diffusion apparatus 21 is demonstrated with reference to FIG.9 and FIG.10. As shown in FIG. 9, a liquid supply unit 54 and a liquid / gas discharge unit 55 are provided in advance in, for example, opposite corners on a diagonal line with respect to the heat diffusion device integrated by diffusion bonding. As shown in FIGS. 10A and 10B, the liquid supply unit 54 and the liquid / gas discharge unit 55 are formed to have the same structure. The liquid supply unit 54 and the liquid / gas discharge unit 55 are formed by forming, for example, notches 56a and 56b communicating with the sealed space 45 in two places on the first metal thin film 22 in the uppermost layer of the laminate 24, A groove 57 is formed on the lower surface of the metal thin plate 25 to communicate with the notches 56a and 56b at both ends, and a through-hole 58 is formed from the groove 57 to the outside.

  After the upper sealing metal thin plate 25, the laminate 24, and the lower sealing metal thin plate 26 are stacked and diffusion bonded as described above to obtain a sealed state, the through hole 58 of one liquid supply unit 54 is provided. A liquid such as water is supplied into the sealed space 45 through the groove 57 and the notches 56a and 56b. The liquid can be supplied so as to fill the sealed space 45. In this state, both sides of the liquid supply part 54 sandwiching the through hole 58 of the groove 57 are once crushed by caulking, for example, to seal the liquid supply part 81. Next, the liquid in the sealed space 45 is sucked and discharged from the through hole 58 of the other liquid / gas discharge portion 55 and exhausted, and the inside of the sealed space 45 is in a decompressed state, and is partially in the groove 44 on the wall surface of the sealed space. Allow the liquid to remain. In this state, both sides sandwiching the through hole 58 of the groove 57 in the liquid / gas discharge portion 55 are crushed by, for example, caulking, and the liquid / gas discharge portion 82 is sealed. Reference numeral 59 in FIG. 10A indicates a caulking position. At the end of this process, the thermal diffusion device 21 of the first embodiment is completed.

  Next, the operation of the thermal diffusion device 21 according to the first embodiment will be described. First, in the heat diffusing device 21, the groove 44 formed on the wall surface of the sealed space has an ideal groove shape with a rectangular cross section having a vertical wall surface as shown in FIG. When water 100 serving as a refrigerant is sealed in the groove 44, the contact angle θ of the water 100 with respect to the wall surface 44a is 40 ° or less (θ <40 °). Since the contact angle θ of the water 100 becomes small, the water 100 is easily evaporated at the thinly attached portion 101 on the opening side.

  In the heat diffusing device 21, a heat source is disposed at the central portion 27. A so-called point heat source is arranged. The peripheral part 28 of the heat diffusing device 21 acts as a heat exhausting part, that is, a cooling part. When the central portion 27 of the heat diffusing device 21 is heated by the heat source, the water 100 in the groove 44 corresponding to the central portion 27 evaporates and radiates to the wide sealed space 45 (see FIG. 1) as steam. It instantaneously scatters to the part 28 side. The steam is cooled at the peripheral portion 28 (that is, the steam heat is exhausted at the exhaust heat section at the other end) and condensed to return to water. The returned water enters the groove 44 in the peripheral portion 28. When the width t1 of the square-shaped groove 44 shown in FIG. 11 is formed to be about 20 μm to 100 μm, the water that has entered the linear groove 44 spreads into the groove 44 by capillary action. Therefore, the water as the reflux liquid that has entered the groove 44 in the peripheral portion 28 passes through the groove 44 and flows through the gap between the radiating portions 33 and 33 configured as the reflux path and between the radiating portions 38 and 38 by capillary action. It is returned to the groove 44 in the central portion 27. A narrow space between the radiating portions 33 and 33 and between the radiating portions 38 and 38 has a so-called wick function that diffuses water widely.

  According to this thermal diffusion device 21, by repeating the evaporation, condensation, and reflux of the water, the heat heated at the central point is diffused to the entire area up to the periphery and heated above the required temperature. There is no. Therefore, the temperature rise at the heat source can be suppressed.

  12 to 17 show a second embodiment of the thermal diffusion device and the manufacturing method thereof according to the present invention. As shown in FIGS. 12 and 13, the heat diffusing device 61 according to the present embodiment includes a first metal thin plate 62 that has a rectangular shape with a long side sufficiently longer than a short side as viewed from above. And the laminated body 64 which laminated | stacked alternately the 2nd metal thin plate 63 which has a dimensional difference between this 1st metal thin plate 62, and the metal thin plates 65 and 66 for sealing which seal the upper and lower sides of the laminated body 64 And is configured. The first and second metal thin plates 62 and 63 are formed of thin plates having a uniform film thickness. The upper and lower sealing metal thin plates 65 and 66 are also formed of thin plates having a uniform film thickness.

  14A to 14C, the first metal thin plate 62 is formed in a pattern in which a plurality of elongated openings 68 extending along the long side direction are formed in parallel in the short side direction. In the peripheral portion 67, the width on the long side is selected as the required width w3, and the width on the short side is selected as the required width w4. In this case, when the same width is set over the entire periphery of the peripheral portion 67, the width w3 = the width w4. The width of the partition 69 that partitions each opening 68 is selected to be a required width w5. In addition, each width | variety of the both sides of the short side in the peripheral part 67 and each width | variety of both sides of a long side can also be selected as an appropriate width | variety as needed. The first metal thin plate 62 can be formed by pressing one metal thin plate.

  As shown in FIGS. 15A to 15C, the second thin metal plate 63 has a plurality of elongated openings 71 which are similarly extended along the long side direction at positions corresponding to the elongated openings 68 of the first thin metal plate 62. The pattern is formed in parallel in the short side direction. The second metal thin plate 63 is generally similar in pattern shape to the first metal thin plate 62, but has a different pattern dimension and has a different pattern from the first metal thin plate 62.

  That is, the width of the peripheral portion 72 and the partition portion 73 of the second thin metal plate 63 is smaller than the width of the peripheral portion 67 and the partition portion 69 of the first thin metal plate 62. With a dimensional difference.

  As shown in FIGS. 15A to 15C, in the second metal thin plate 63, the peripheral portion 72 has a required width w6 (w3> w6) whose width on the long side is smaller than the width w3 of the first metal thin plate 62. The width of the short side is selected to be a required width w7 (w4> w7) smaller than the width w4 of the first metal thin plate 62. In this case, when the same width is set over the entire periphery of the peripheral portion 72, the width w6 = the width w7. The width of the partition 73 that partitions each opening 71 is selected to be a required width w8 (w5> w8) that is smaller than the width w5 of the first metal thin plate 62. In addition, each width | variety of the both sides of the short side in the peripheral part 72 and each width | variety of both sides of a long side can also be selected as an appropriate width | variety as needed. The second metal thin plate 63 can be formed by pressing one metal thin plate.

  The first and second metal thin plates 62 and 63 have different widths w3 and w6 on the long sides of the peripheral portions 67 and 72, different widths w4 and w7 on the short sides, and a width w5 of the partition portions 69 and 73. , W8 are different from each other, a difference in dimension Δw = w3-w6, Δw = w4-w7, Δw = w5-w8 is generated on the side wall surfaces of the elongated openings 69, 71 when they are stacked. That is, the same dimensional difference Δw is generated over the entire circumference of the wall surface of the elongated opening.

  As shown in FIG. 16, the upper sealing metal thin plate 65 is formed of a rectangular thin plate having an outline shape having the same size as the first and second metal thin plates 62 and 63. The upper sealing metal thin plate 65 can be formed by pressing one metal thin plate.

  As shown in FIGS. 17A and 17B, the lower sealing metal thin plate 66 is formed of a rectangular thin plate having the same outline shape as the first and second metal thin plates 62 and 63, and both ends of the rectangle on the upper surface thereof. On the side, a plurality of lateral grooves 75 are formed so as to communicate with the openings 68 and 71 of the first and second thin metal plates 62 and 63 described above. The lower sealing metal thin plate 66 can be formed by pressing one metal thin plate.

  The first and second metal thin plates 62 and 63 and the upper and lower sealing metal thin plates 65 and 66 are formed using a metal that can be diffusion bonded, for example, a metal such as copper or beryllium copper, in this example, copper.

  In the present embodiment, the first metal thin plate 62 and the second metal thin plate 63 are stacked alternately, for example, 21 sheets so that the uppermost layer and the lowermost layer are the first metal thin plate 62. A laminated body 64 is formed, and a sealing metal thin plate 65 and a sealing metal thin plate 66 are disposed above and below the laminate 64. The upper sealing metal thin plate 65, the laminated body 64, and the lower sealing metal thin plate 66 are integrated by diffusion bonding by pressurization and heating in a vacuum, and are hermetically and liquid tightly sealed. . At the same time, a liquid serving as a refrigerant under reduced pressure in an initial state is sealed in a groove, which will be described later, formed in the side wall surface of the sealed space 77 by the openings 68 and 71 in the stacked body 64, thereby configuring the heat diffusion device 61. .

  The heat diffusing device 61 according to the second embodiment is steep due to the dimensional difference Δw between the first and second metal thin films 62 and 63 over the side wall surface of each sealed space 77 formed by the elongated openings in FIG. A groove 78 having a wall surface (see FIGS. 13A and 13B) is formed. The groove 78 is formed in an annular shape continuously around the entire circumference of each sealed space 77, and is formed in a U-shape having upper and lower wall surfaces perpendicular to the inner wall surface when viewed in the groove cross section, as in the first embodiment. Is done.

  As the liquid serving as the refrigerant, for example, water (pure water) is preferably used, as described above.

  Next, the operation | work which encloses a liquid specifically in the thermal-diffusion apparatus 61 is demonstrated with reference to FIGS. In the present embodiment, with respect to the thermal diffusion device 61 integrated by diffusion bonding, a liquid supply unit 81 is provided in advance on one end side in the longitudinal direction, and a liquid / gas discharge unit 82 is provided on the other end side. It is done. The liquid supply unit 81 and the liquid / gas discharge unit 82 have the same structure. As shown in FIG. 18, the liquid supply unit 81 and the liquid / gas discharge unit 82 are provided with cutout portions 83a and 83b communicating with the first metal thin plate 62 on the uppermost layer of the laminate 64, for example, in two places with the sealed space 77. In the upper sealing metal thin plate 65, a groove 84 having both ends communicating with the notches 83a and 83b is formed on the lower surface thereof, and a through-hole 85 communicating from the groove 84 to the outside is formed. .

  After the upper sealing metal thin plate 65, the laminate 64, and the lower sealing metal thin plate 66 are stacked and diffusion bonded as described above to obtain a sealed state, the through hole 85 of one liquid supply unit 81 is provided. A liquid such as water is supplied into the sealed space 77 through the groove 84 and the notches 83a and 83b. Water is supplied to all the sealed spaces 77 (see FIG. 12) partitioned by the partition portions 68 and 73 through the lateral grooves 75 formed on the inner surface of the lower sealing metal thin plate. Water can be supplied so as to fill all the enclosed spaces 77. In this state, the liquid supply part 81 is sealed by once crushing the through holes 85 of the groove 84 in the liquid supply part 81 by, for example, caulking. Next, the liquid in the sealed space 77 is sucked and discharged from the through hole 85 of the other liquid / gas discharge portion 82 and exhausted, and the inside of the sealed space 77 is in a reduced pressure state, and the inside of the groove 78 around the entire wall surface of the sealed space 77. So that some liquid remains on the surface. In this state, both sides sandwiching the through hole 85 of the groove 84 in the liquid / gas discharge portion 82 are crushed by, for example, caulking, and the liquid / gas discharge portion 82 is sealed. Reference numeral 89 in FIG. 20 indicates a caulking position. At the end of this process, the thermal diffusion device 61 of the second embodiment is completed.

  Next, the operation of the thermal diffusion device 61 according to the second embodiment will be described. In the heat diffusing device 61, the grooves 78 formed on the entire circumference of the side wall surfaces of the plurality of sealed spaces 77 configured in parallel are ideal in a quadrangular cross section having a vertical wall surface as described with reference to FIG. It becomes a typical groove shape. When, for example, water 100 serving as a coolant is seen in the groove 78, the contact angle θ of water with respect to the groove wall surface is 40 ° or less (θ <40 °) (see FIG. 11). As described above, since the contact angle θ of the water 100 is small, the water 100 is easily evaporated at the thinly attached portion on the opening side.

  In the thermal diffusion device 61 of the second embodiment, a heat source is disposed on one end side thereof. The other end side of the heat diffusing device 61 acts as a heat exhausting part, that is, a cooling part. Further, the linear sealed space 77 becomes a gas phase flow path, and the groove 78 on the side wall surface becomes a liquid phase reflux path. When one end of the heat diffusing device 61 is heated by the heat source, the water in the groove 78 corresponding to the one end side evaporates, becomes steam and is radiated to each wide sealed space 77 and instantaneously scatters to the other end side. The steam is cooled by the cooling section at the other end (that is, the steam heat is exhausted by the exhaust heat section at the other end) and condensed to return to water. The returned water enters the groove 78 at the other end. When the width of the groove 78 having a square cross section is formed to be about 20 μm to 100 μm, the water that has entered the groove 78 spreads into the groove 78 having a longer side than the short side by capillary action, and is constituted by the groove 78 having a longer side. It is returned to the groove 78 at one end through the reflux path.

  According to this heat diffusing device 61, by repeating the evaporation, condensation and reflux of the water, the heat heated at one end is diffused to the entire area up to the other end, and the heat diffusing device 61 has a required temperature. No more heating. Therefore, the temperature rise at the heat source can be suppressed.

  The diffusion device 61 can form the groove 78 having a steep wall surface by a laminated structure in which the first and second metal thin plates are alternately laminated. The groove 78 has a wick function for widely diffusing water. In the wick structure by the groove 78, the wall surface rises more steeply than etching or machining, so that the heat transport capacity can be increased by reducing the liquid contact angle θ.

  The above-described heat diffusion device according to the embodiment of the present invention can be applied to, for example, suppression of heat generation in an electronic device. For example, the present invention is suitable for suppressing heat generation of a central processing unit (CPU) in a personal computer and light emission diodes in a projector.

FIGS. 1A and 1B are a partially broken plan view and side view showing a first embodiment of a thermal diffusion device according to the present invention. FIGS. A, B It is a top view of the metal sheet for top sealing of a 1st embodiment, and its sectional view on the aa line. A and B are a plan view of a first metal thin plate according to the first embodiment and a cross-sectional view taken along the line aa. A and B are a plan view of a second thin metal plate of the first embodiment and a cross-sectional view taken along the line aa. A and B are a plan view of a lower sealing metal thin plate according to the first embodiment and a cross-sectional view taken along the line aa. It is an expanded sectional view of the peripheral part in the thermal diffusion apparatus of a 1st embodiment. FIGS. 3A and 3B are an enlarged cross-sectional view and an enlarged plan view of a central portion in the thermal diffusion device of the first embodiment. FIGS. It is a perspective view of the radiation | emission part in the thermal diffusion apparatus of 1st Embodiment. It is the partially broken top view including the liquid supply part and liquid / gas discharge part of the thermal diffusion apparatus of 1st Embodiment. A and B are an exploded perspective view showing an example of a liquid supply unit and a liquid / gas discharge unit, and a cross-sectional view along the line XX. It is sectional drawing of the principal part which shows the relationship between the groove | channel where the wall surface formed by this invention was steep, and the sealed. It is the partially broken top view which shows 2nd Embodiment of the thermal-diffusion apparatus which concerns on this invention. A and B It is sectional drawing on the AA line of FIG. 12, and sectional drawing on the BB line. A, B and C It is a perspective view of the 1st metal thin plate of 2nd Embodiment, sectional drawing on the AA line, and sectional drawing on the BB line. A, B and C It is a perspective view of the 2nd metal thin plate of 2nd Embodiment, sectional drawing on the AA line, and sectional drawing on the BB line. It is a perspective view of the metal sheet for top sealing of a 2nd embodiment. A and B are a perspective view and a cross-sectional view along the line DD of the lower sealing metal thin plate according to the second embodiment. It is a disassembled perspective view of the principal part which shows an example of the liquid supply part in the thermal diffusion apparatus of 2nd Embodiment, and a liquid and gas discharge part. It is sectional drawing of the principal part of the liquid supply part and the liquid / gas discharge part in the thermal diffusion apparatus of 2nd Embodiment. It is a perspective view of the principal part after sealing of the liquid supply part and liquid / gas discharge part in the thermal diffusion apparatus of 2nd Embodiment. A and B It is the perspective view which fractured | ruptured partially and the sectional view on the AA line of the thermal-diffusion apparatus of a comparative example. It is sectional drawing which shows an ideal groove shape. It is a perspective view made into the partial cross section which shows the heat pipe of a prior art example.

Explanation of symbols

  21, 61 .. Thermal diffusion device, 22... First metal sheet, 23.. Second metal sheet, 24 .. Laminate, 25, 26 .. Upper and lower sealing metal sheets, 27. .., 28..Peripheral part, 32, 37..Peripheral part, 33 [331-334], 38 [381-384] .. Radiation part, 31, 36..Central part, 35, 39, 41..Penetration Holes 42 .. struts 44 .. grooves 44 a .. groove walls 45, 77 .. sealed spaces 51, 52 .. reflux paths 54.. Liquid supply sections 55 .. liquid and gas discharge sections, 56a, 56b, ... notches, 57, grooves, 58, through holes, 59, caulking position, 62, first metal thin plate, 63, second metal thin plate, 65, 66, upper and lower Metal thin plate for sealing, 67, 72 ... Peripheral part, 68, 71 ... Rectangular opening, 69, 73 ... Partition part, 75 ... , 78 .. Groove, 81 .. Liquid supply part, 82 .. Liquid / gas discharge part, 83 a, 83 b .. Notch part, 84 .. Groove, 85 .. Through hole, 89. ·water

Claims (10)

First and second metal thin plates having a dimensional difference are alternately laminated, and diffusion bonded so that a sealed space is formed inside with the upper and lower metal thin plates for sealing,
A groove having a steep wall surface due to a dimensional difference between the first and second metal thin plates is formed on the wall surface of the sealed space,
A heat diffusion apparatus, wherein a liquid is sealed in the groove under reduced pressure in an initial state. The sealed space is formed in a rectangular shape,
The groove is formed to communicate with the entire circumference of the sealed space;
The heat diffusing apparatus according to claim 1, wherein one end side in the longitudinal direction of the sealed space is an evaporation unit, and the other end side is configured as an exhaust heat unit. The thermal diffusion device according to claim 2, wherein a plurality of the rectangular sealed spaces are formed in parallel. Each of the first and second metal thin plates has a plurality of radiating portions communicating from the central portion to the peripheral portion,
The radiation pattern of the first and second metal thin plates is different,
A flow path of the reflux liquid is formed between the radiating portions of the other metal plate laminated with the one metal thin plate interposed therebetween,
The thermal diffusion device according to claim 1, wherein the central portion is an evaporation portion, and the peripheral portion is configured as an exhaust heat portion. The heat diffusion device according to claim 1, wherein the first and second metal thin plates and the sealing metal thin plate are formed of the same material. Alternately laminating first and second thin metal plates having a dimensional difference, and arranging sealing thin metal plates on the top and bottom;
The first and second metal thin plates and the sealing metal thin plate are diffusion bonded to form an integral laminate, forming a sealed space inside the laminate, and on the wall of the sealed space, Forming a groove having a steep wall due to a dimensional difference between the first and second metal thin plates;
A method for manufacturing a thermal diffusion device, comprising: enclosing a liquid in the groove in an initial state in which the inside of the sealed space is decompressed. As the first and second metal thin films, a thin plate having a rectangular opening and a dimensional difference in the width of the periphery of the opening is used.
The upper and lower metal thin plates for sealing use thin plates having an area that closes the opening,
The method of manufacturing a heat diffusing device according to claim 6, wherein the groove communicating with the entire periphery of the sealed space by the opening is formed. The method of manufacturing a heat diffusing apparatus according to claim 7, wherein the first and second metal thin plates are thin plates each having a plurality of rectangular openings arranged in parallel. As the first and second metal thin plates, a plurality of radiating portions communicating from the central portion to the peripheral portion are formed, openings are formed between the radiating portions, and thin plates having different radiating portion patterns are used. ,
A closed space is formed by the opening,
The method for manufacturing a thermal diffusion device according to claim 6, wherein the groove is formed in the central portion and the peripheral portion. The heat diffusion device according to claim 6, wherein the first and second metal thin plates and the sealing metal thin plate are formed of a thin plate of the same material.

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