Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W40/00—Arrangements for thermal protection or thermal control
  • H10W40/70—Fillings or auxiliary members in containers or in encapsulations for thermal protection or control
  • H10W40/73—Fillings or auxiliary members in containers or in encapsulations for thermal protection or control for cooling by change of state

Definitions

• This disclosure relates to a cooling device and an electronic device.
• Some electronic devices have a cooling device thermally connected to the heat-generating electronic components to prevent damage to the electronic components due to heat generated when power is applied.
• the cooling device cools the electronic components by dissipating heat transferred from the electronic components into the surrounding air.
• An example of this type of cooling device is disclosed in Patent Document 1.
• the tower-type heat sink disclosed in Patent Document 1 comprises a heat pipe that is inserted from the bottom of the base, penetrates the base, and comes into contact with the heat-generating CPU (Central Processing Unit), and multiple fins attached to the heat pipe.
• CPU Central Processing Unit
• the heat pipes provided in the tower-type heat sink disclosed in Patent Document 1 are U-shaped, so the bent portions do not come into contact with either the base or the heat-generating element.
• heat from the CPU is transferred directly only to the straight pipe portion of the heat sink that is in contact with the CPU.
• Increasing the capacity of the power conversion device increases the amount of heat generated by the switching elements, so it is necessary to improve the cooling performance of the cooling device.
• This disclosure has been made in consideration of the above circumstances, and aims to provide a cooling device and electronic device with high cooling performance.
• the cooling device of the present disclosure comprises a base plate and at least one vapor chamber. At least one recess is formed in the first main surface of the base plate, and at least one through-hole is formed extending from the bottom of the recess toward a second main surface opposite the first main surface.
• the vapor chamber has a base portion that has a first cavity therein and is housed in the recess; a pipe portion that has a second cavity therein that communicates with the first cavity and has at least one pipe extending from the base portion and inserted into the through-hole; and a refrigerant that is sealed in the first cavity and the second cavity.
• the vapor chamber dissipates heat transferred from a heating element attached to the first main surface while in surface contact with the base portion to the surrounding air via the base portion and the pipe portion.
• the cooling device disclosed herein comprises a vapor chamber having a base portion housed in a recess formed in the base plate and a pipe portion extending from the base portion.
• the vapor chamber dissipates heat transferred from a heating element attached to the base plate while in surface contact with the base portion into the surrounding air, resulting in a cooling device with high cooling performance.
• FIG. 1 is a perspective view of a cooling device according to a first embodiment
• FIG. 1 is a perspective view of a base plate according to a first embodiment
• 1 is a perspective view of a vapor chamber according to a first embodiment
• 1 is a front view of a cooling device according to a first embodiment
• FIG. 1 is a diagram showing an example of mounting an electronic component to a cooling device according to a first embodiment
• 6 is a cross-sectional view of the cooling device according to the first embodiment taken along line VI-VI in FIG. 1 is a cross-sectional view of an electronic device according to a first embodiment
• FIG. 10 is a perspective view of a cooling device according to a second embodiment.
• FIG. 10 is a perspective view of a base plate according to a second embodiment;
• FIG. 10 is a perspective view of a base plate according to a second embodiment
• FIG. 10 is a perspective view of a first modified example of the cooling device according to the embodiment;
• FIG. 10 is a perspective view of a modified example of the base plate according to the embodiment;
• FIG. 10 is a front view of a second modified example of the cooling device according to the embodiment;
• FIG. 10 is a rear view of a third modified example of the cooling device according to the embodiment.
• the cooling device 1 shown in Figure 1 comprises a base plate 11 to which a heat generating element is attached, and a vapor chamber 12 that dissipates heat transferred from the heat generating element into the surrounding air.
• At least one recess 11c are formed in the first main surface 11a of the base plate 11.
• the recess 11c has a shape that is recessed in a direction perpendicular to the first main surface 11a.
• the recesses 11c are arranged two-dimensionally.
• the base plate 11 has at least one through hole 11d, for example, nine through holes 11d, which extend from the bottom surface of the recess 11c toward the second main surface 11b opposite the first main surface 11a.
• one through hole 11d is formed in each recess 11c.
• the base plate 11 is preferably formed from a heat-conductive material, for example, a metal such as copper, aluminum, or iron.
• the X-axis and Z-axis are defined as axes included in the first main surface 11a and perpendicular to each other.
• the Y-axis is defined as an axis parallel to the penetration direction of the through-hole 11d penetrating the base plate 11 and perpendicular to both the X-axis and Z-axis.
• the X-axis and Z-axis each extend parallel to different side surfaces of the base plate 11.
• the side surfaces are surfaces that are continuous with the first main surface 11a and the second main surface 11b. The same applies to subsequent figures.
• the vapor chamber 12 has a base portion 13 housed in the recess 11c, and a pipe portion 14 having at least one, for example, four pipes 14a extending from the base portion 13 and inserted into the through-hole 11d.
• the base portion 13 and pipe portion 14 are integrally formed.
• each pipe 14a is attached to the base portion 13 by brazing.
• the vapor chamber 12, while in contact with the base portion 13, radiates heat transferred from a heating element attached to the first main surface 11a of the base plate 11 to the surrounding air via the base portion 13 and pipe portion 14.
• the vapor chamber 12 is preferably formed from a heat-conductive material, for example, a metal such as copper, aluminum, or iron.
• each vapor chamber 12 is spaced apart from one another.
• the electronic component 21, which is a heating element is attached to the first main surface 11a of the base plate 11, for example, by a fastening member (not shown), in face-to-face contact with the base portion 13.
• the electronic component 21 is preferably attached to the first main surface 11a with the casing 22, which has, for example, a switching element therein, in face-to-face contact with the base portion 13.
• the surface of the casing 22 facing the base portion 13 and the end surface 13a of the base portion 13 facing the electronic component 21 abut against each other.
• the base portion 13 is preferably accommodated in the recess 11c in a state of surface contact with the bottom surface of the recess 11c.
• the end surface 13c of the base portion 13 facing the pipe portion 14 is preferably accommodated in the recess 11c in a state of surface contact with the bottom surface of the recess 11c, specifically, the periphery of the through-hole 11d on the surface of the recess 11c facing in the negative Y-axis direction.
• the base portion 13 has a flat plate shape, and the bottom surface of the recess 11c is flat, so that the base portion 13 is accommodated in the recess 11c in a state of surface contact with the bottom surface of the recess 11c. In other words, the bottom surface of the recess 11c and the end surface 13c of the base portion 13 abut against each other on a surface.
• the base portion 13 is attached to the base plate 11 by any method, such as soldering, friction stir welding, or bonding with an adhesive.
• the end surface 13a of the base portion 13 that abuts the electronic component 21 is located on the same plane as the first main surface 11a of the base plate 11.
• the pipe 14a of the pipe section 14 extends in a direction perpendicular to the first main surface, in other words, in a direction tilted from the Y-axis direction, and away from the base plate 11.
• the pipe 14a extends in both the positive Y-axis direction and the positive Z-axis direction.
• the base portion 13 has a first cavity 13b inside.
• the pipe 14a has a second cavity 14b inside that is connected to the first cavity 13b.
• the cooling device 1 is equipped with a refrigerant 15 sealed in the first cavity 13b and the second cavity 14b.
• the refrigerant 15 exists in a gas-liquid two-phase state at room temperature.
• the refrigerant 15 is, for example, water.
• the cooling device 1 is attached to the housing 31 of the electronic device 101 that includes the electronic component 21.
• the cooling device 1 is attached to the housing 31 in a position where the base plate 11 covers the opening 31a formed in the housing 31.
• the cooling device 1 preferably includes a sealing member 16 that abuts against the base portion 13 and the base plate 11 in the through-hole 11d of the base plate 11.
• the sealing member 16 is applied to the inside of the through-hole 11d from the positive Y-axis side, for example, after the vapor chamber 12 is attached to the base plate 11.
• the sealing member 16 is, for example, a caulking agent.
• the cooling device 1 preferably further comprises a plurality of fins 17 attached to the pipe portion 14.
• the cooling device 1 is attached, for example, under the floor of the railway vehicle with the Y-axis direction coinciding with the width direction of the railway vehicle and the X-axis direction coinciding with the direction of travel of the railway vehicle.
• the cooling air specifically the running air generated when the railway vehicle is moving, flows in the X-axis direction.
• the direction of the cooling air passing between the pipes 14a is the X-axis direction.
• the fins 17 are preferably formed from a heat-conductive material, for example, a metal such as copper, aluminum, or iron.
• the cooling device 1 having the above configuration cools the electronic component 21.
• the heat is transferred from the electronic component 21 to the refrigerant 15 via the base portion 13.
• the temperature of the refrigerant 15 rises, and part of the refrigerant 15 vaporizes.
• the vaporized refrigerant 15 flows into the pipe 14a and moves further inside the pipe 14a toward the tip of the pipe 14a, specifically the end of the pipe 14a on the positive Y-axis direction.
• the refrigerant 15 As the refrigerant 15 travels through the pipe 14a, it transfers heat to the air surrounding the cooling device 1 via the pipe 14a and fins 17. As a result, the temperature of the refrigerant 15 drops, and the refrigerant 15 liquefies. The liquefied refrigerant 15 returns to the base 13 by capillary action, passing through gaps in the wick, sintered copper powder, etc., inside the pipe 14a. When the liquefied refrigerant 15 receives heat from the electronic component 21 via the base 13, it vaporizes again, flows into the pipe 14a, and travels inside the pipe 14a toward the tip of the pipe 14a.
• the heat generated in the electronic component 21 is dissipated into the air surrounding the cooling device 1, specifically the air around the pipe 14a and fins 17, thereby cooling the electronic component 21.
• the base portion 13 of the vapor chamber 12 is housed in the recess 11c of the base plate 11 provided in the cooling device 1 according to the first embodiment.
• the vapor chamber 12, in face-to-face contact with the base portion 13, dissipates heat transferred from the electronic component 21 attached to the first main surface 11a of the base plate 11 to the surrounding air via the base portion 13 and the pipe portion 14. Because the electronic component 21 is in face-to-face contact with the base portion 13, the cooling device 1 receives heat from the electronic component 21 more efficiently than a heat sink having a U-shaped heat pipe in which only the straight pipe portion receives heat directly from the heat generating element.
• the cooling performance of the cooling device 1 is higher than that of a heat sink having a U-shaped heat pipe in which only the straight pipe portion receives heat directly from the heat generating element. Furthermore, even if the refrigerant 15 freezes in a low-temperature environment, the cooling device 1 can transfer heat to the frozen refrigerant 15 and melt it more quickly than a heat sink having the above-mentioned U-shaped heat pipe.
• the vapor chamber 12 may have any shape as long as it can radiate heat transferred from the electronic component 21 in surface contact to the surrounding air.
• a cooling device equipped with a vapor chamber 12 having a structure different from that of the first embodiment will be described in the second embodiment, focusing on the differences from the first embodiment.
• the vapor chamber 12 provided in the cooling device 2 according to embodiment 2 shown in Figure 8 has a base portion 13 on which multiple electronic components 21 are attached, and which are aligned in the direction of the cooling air flowing between the pipes 14a, i.e., the X-axis direction. Similar to embodiment 1, the electronic components 21 are attached to the cooling device 2. In other words, three electronic components 21 are attached to one base portion 13.
• Electronic device 101 is, for example, a power conversion device that converts input power into power to be supplied to a load device and supplies the converted power to the load device.
• Electronic component 21 is, for example, a switching element provided in the power conversion device.
• Electronic components 21 provided in surface contact with the same base portion 13 are switching elements that correspond to the same phase of the AC power input to or output from the power conversion circuit provided in the power conversion device and are electrically connected in parallel. Switching elements that correspond to the same phase and are electrically connected in parallel are switched on and off at the same timing. For this reason, multiple electronic components 21 provided in surface contact with the same base portion 13 generate heat at the same timing.
• the base plate 11 provided in the cooling device 2 has three recesses 11c formed therein, and one through-hole 11d formed in each recess 11c.
• a pipe portion 14 of one vapor chamber 12 is inserted into each through-hole 11d.
• the three electronic components 21 are attached to the first main surface 11a of the base plate 11 with the electronic components 21 in surface contact with the base portion 13 of each vapor chamber 12.
• the vapor chamber 12 provided in the cooling device 2 radiates heat transferred from adjacent electronic components 21 arranged in surface contact with the same base portion 13 in the X-axis direction to the surrounding air via the base portion 13 and the pipe portion 14.
• the multiple electronic components 21 arranged in surface contact with the same base portion 13 are uniformly heated by the base portion 13. Electrical resistance changes with temperature, but uniformly heating the electronic components 21 arranged in surface contact with the same base portion 13 reduces differences in resistance values.
• differences in current values flowing through the electronic components 21, which are switching elements electrically connected in parallel and correspond to the same phase of the AC power input to or output from the power conversion circuit of the power conversion device are reduced. This reduces overcurrents caused by increased current in some electronic components 21 and shortens the lifespan of semiconductor elements.
• the present disclosure is not limited to the above-described embodiment.
• the number, placement position, and shape of the vapor chambers 12 are arbitrary as long as they can dissipate heat transferred from the electronic components 21 into the surrounding air.
• the multiple base portions 13 provided in the cooling device 3 are housed in abutting contact with each other in multiple recesses 11c adjacent to each other in the direction of the cooling air passing between the pipes 14a, i.e., in the X-axis direction, and are in surface contact with multiple electronic components 21 (not shown) that are electrically connected in parallel to each other.
• the multiple electronic components 21 are provided in surface contact with the multiple base portions 13, which are housed in the recess 11c in abutting contact with each other. Because the multiple base portions 13 uniformly heat the multiple electronic components 21, the differences in resistance values of the multiple electronic components 21 are reduced. As a result, for example, the differences in current values flowing through electronic components 21, which are switching elements that correspond to the same phase of the AC power input to or output from the power conversion circuit of the power conversion device and are electrically connected in parallel, are reduced. This prevents overcurrents caused by an increase in current through some electronic components 21, shortening the lifespan of semiconductor elements, and other problems.
• the shape of the base plate 11 is not limited to a plate-like shape, and can be any shape as long as it allows the electronic component 21 to be attached to the first main surface 11a and the vapor chamber 12 to be accommodated in the recess 11c.
• the shape of the pipe portion 14 may be any shape that can dissipate heat transferred from the electronic component 21 via the base portion 13.
• the pipe 14a shown in Figure 10 may extend in a direction perpendicular to the first main surface, i.e., in the positive direction of the Y axis.
• the shape of the recess 11c formed in the base plate 11 may be any shape, as long as it allows the vapor chamber 12 to make surface contact with the bottom surface.
• the vapor chamber 12 may be formed with a recess 11c in which multiple through holes 11d are formed.
• each recess 11c has multiple through holes 11d aligned in the X-axis direction.
• the pipe portion 14 of the vapor chamber 12 is inserted into each through hole 11d.
• the electronic component 21 is not limited to a switching element, but may be any electronic component that generates heat and is housed inside the housing 31, such as a thyristor or diode.
• the electronic device 101 is not limited to a power conversion device, but may be any electronic device that houses a heat generating element inside the housing 31. Furthermore, the method of attaching the cooling device 1 to the housing 31 of the electronic device 101 is not limited to the above example. As an example, the cooling device 1 may be attached to the housing 31 with the base plate 11 oriented so as to block the opening 31a from inside the housing 31.
• the installation location of electronic device 101 is not limited to under the floor of the railway vehicle, but may also be on the roof of the railway vehicle.
• electronic device 101 is attached to the roof of the railway vehicle with the X-axis direction coinciding with the width direction of the railway vehicle and the Z-axis direction coinciding with the direction of travel of the railway vehicle.
• Electronic device 101 is not limited to railway vehicles, and may be mounted on any moving object that generates wind due to running, such as a trolleybus or tram.
• Electronic device 101 may also be installed outdoors or indoors.
• the end surface 13a of the base portion 13 that abuts the electronic component 21 does not have to be flush with the first main surface 11a of the base plate 11.
• the end surface 13a may be located on the negative Y-axis side of the first main surface 11a.
• the cooling device 1 may further include, as an example, a heat transfer member 18 that extends in the direction of the cooling air passing between the pipes 14a and transfers heat in the extension direction, as shown in FIG. 12.
• the heat transfer member 18 is, for example, a heat pipe.
• the heat transfer member 18 is arranged in contact with the end face 13a of the base portion 13 opposite the pipe portion 14. By providing the heat transfer member 18, the heat is more uniformly distributed between adjacent base portions 13 in the direction of the cooling air.
• the cooling device 1 may further include a heat transfer member 19 that extends in the direction of cooling air flow passing between the pipes 14a and transfers heat in that direction.
• the heat transfer member 19 is, for example, a heat pipe.
• the heat transfer member 19 is arranged through a groove formed in the second main surface 11b of the base plate 11, in contact with the end face 13c of the base portion 13 that faces the pipe portion 14. By providing the heat transfer member 19, adjacent base portions 13 in the direction of cooling air flow are more uniformly heated.
• the cross-sectional shape of the heat transfer members 18, 19 perpendicular to the extension direction is not limited to a circle, but may be a flattened shape.
• a flattened shape is a shape obtained by deforming a circle so that the width of a portion of the circle is narrower than the original circle, and includes ellipses, streamlines, ovals, etc.
• An oval shape refers to a shape obtained by connecting the outer edges of two circles of the same diameter with two straight lines.
• Cooling device 11: Base plate, 11a: First main surface, 11b: Second main surface, 11c: Recess, 11d: Through hole, 12: Vapor chamber, 13: Base portion, 13a, 13c: End surface, 13b: First cavity, 14: Pipe portion, 14a: Pipe, 14b: Second cavity, 15: Refrigerant, 16: Sealing member, 17: Fins, 18, 19: Heat transfer members, 21: Electronic component, 22: Casing, 31: Housing, 31a: Opening, 101: Electronic device.

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• Cooling Or The Like Of Electrical Apparatus (AREA)

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Citations (4)

• 2024
  • 2024-04-22 JP JP2026516709A patent/JPWO2025224805A1/ja active Pending
  • 2024-04-22 WO PCT/JP2024/015785 patent/WO2025224805A1/ja active Pending

Patent Citations (4)

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