JP4663440B2 - Liquid-cooled heat dissipation device - Google Patents

Description

  The present invention relates to a liquid-cooled heat radiating device that radiates heat generated from a heating element such as a heat generating electronic component of an electronic device such as a notebook personal computer, a two-dimensional display device, or a projector, and a method for manufacturing the same.

  In this specification and claims, the term “aluminum” includes aluminum alloys in addition to pure aluminum.

  Conventionally, as a method of dissipating heat generated from a heat generating electronic component in an electronic device, an aluminum heat dissipating substrate whose one side is a heat receiving surface that is brought into thermal contact with the heat generating electronic component and a heat dissipating substrate integrally provided on the other surface The heat dissipation electronic component is attached to the heat receiving surface of the heat dissipation board, and the heat is applied to the heat dissipation fin by the cooling fan, so that the heat generated from the heat generation electronic component is removed from the heat dissipation substrate and the heat dissipation fin. The method of escaping into the air through the air has been widely adopted.

  However, in recent electronic devices, the amount of heat generated by heat-generating electronic components tends to increase due to downsizing and high performance, and sufficient heat dissipation performance cannot be obtained by conventional methods. In addition, in notebook personal computers, two-dimensional display devices, projectors, and the like, noise from the cooling fan increases, and the quietness that has been required for these devices cannot be satisfied.

  Therefore, in order to solve these problems, for example, in a notebook personal computer, a liquid cooling system is employed. This liquid cooling system includes a heat receiver that is composed of a water jacket filled with a coolant and fixed to a CPU (heat generating electronic component), and a coolant circulation tube that has both ends connected to the heat receiver and circulates the coolant. The heat receiver is arranged in a personal computer main body having a keyboard, and the cooling liquid circulation tube is extended to a display device provided in the personal computer main body so as to be freely opened and closed (see Patent Document 1).

However, in the liquid cooling system described in Patent Document 1, there is a problem that the heat radiation area is insufficient because only heat is radiated from the coolant circulation tube, resulting in poor heat radiation efficiency.
JP 2002-182797 A

  An object of the present invention is to provide a liquid-cooled heat radiating device that solves the above problems and has improved heat radiating efficiency.

  In order to achieve the above object, the present invention comprises the following aspects.

1) It includes a substrate made of two or more metal plates joined together in a laminated form, and a cooling fluid circulation path is formed between at least one set of two adjacent metal plates among all the metal plates , A cooling fluid is enclosed in the cooling fluid circulation path, and the cooling fluid is circulated in the cooling fluid circulation path by a circulation pump, and the cooling fluid circulation path has a plurality of linear shapes arranged at intervals. Between the adjacent linear portions, and only one metal plate of the set of two metal plates between which the cooling fluid circulation path is formed is included in the linear portion. A liquid-cooled heat radiating device that is formed so that one through-hole for short circuit prevention that extends in the longitudinal direction and prevents a short circuit in the cooling fluid circulation path is exposed to the outside .

2) The substrate is made of two metal plates, and a cooling fluid circulation path is formed by expanding at least one of the two metal plates, and only one of the two metal plates. The liquid-cooled heat radiating device according to 1) , wherein a through hole for preventing a short circuit is formed in

According to the liquid cooling type heat dissipation device of 1) and 2) above, the heat of the cooling fluid circulating in the cooling fluid circulation path is radiated to the outside through the entire substrate, so the heat dissipation area is the patent document 1 increases as compared with the apparatus described, to improve the heat dissipation efficiency.

In addition, according to the liquid cooling type heat radiating device of the above 1) and 2) , for example, when a helium leak test is performed after joining the metal plates, the cooling fluid circulation path is connected between the metal plates to the outer edge portion of the substrate. However, if a joint failure that causes a short circuit in the cooling fluid circulation path occurs, leakage of helium to the outside through the through hole for short circuit prevention is detected. I understand. Therefore, it is possible to prevent a decrease in heat dissipation performance due to occurrence of a short circuit in the cooling fluid circulation path. When the through hole for preventing a short circuit is not formed, the cooling fluid circulation path is not allowed to pass between the metal plates to the outer edge portion of the substrate, but there is a bonding failure that causes a short circuit in the cooling fluid circulation path. Even if a helium leak test is performed, leakage of helium to the outside cannot be detected. When such a joint failure occurs, a short circuit occurs in the cooling fluid circulation path, and the cooling fluid may not flow through the entire cooling fluid circulation path, which may reduce the heat dissipation performance. Moreover, since the through hole for short circuit prevention is formed in either metal plate, it becomes possible to achieve weight reduction of a board | substrate.

Furthermore, according to the above 1) and 2) of the liquid-cooled heat radiator, since a metal plate only the through hole for preventing a short circuit is formed, it is possible to prevent a reduction in the strength of the substrate.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the left and right sides in FIG. Also, the top and bottom in FIG.

  1 and 2 show the overall configuration of the liquid-cooled heat dissipation device according to the present invention, and FIG. 3 shows the configuration of the main part thereof.

  1 to 3, the liquid-cooled heat radiating device (1) is a flat substrate composed of two upper and lower high thermal conductive plates, in this case, aluminum metal plates (3) and (4) joined together in a laminated manner. (2), and a cooling fluid circulation path (5) is formed between both metal plates (3) and (4) of the substrate (2). The cooling fluid circuit (5) of the substrate (2) is filled with a cooling fluid that is non-corrosive to aluminum, such as antifreeze, and the cooling fluid is attached to the lower surface of the substrate (2). The circulation pump (6) can circulate the cooling fluid circuit (5). A heat receiving part (7), a heat radiating part (8) and an expansion tank part (9) are provided in the middle of the cooling fluid circulation path (5).

  At least one of the two metal plates (3) and (4) constituting the substrate (2) is made of an aluminum brazing sheet having a brazing filler metal layer on the surface facing the other metal plate. The plates (3) and (4) are brazed using a brazing material layer of an aluminum brazing sheet.

  The upper metal plate (3) includes a plurality of lateral straight portions (11a) extending in the left-right direction and spaced apart in the front-rear direction, and a lateral straight portion (11a) extending in the front-rear direction and adjacent in the front-rear direction. ) And a plurality of vertically extending straight lines extending in the front-rear direction and spaced apart in the left-right direction. A second meandering upward bulging portion (12a), and a horizontal linear portion (12b) extending in the left-right direction and connecting the vertical linear portions (12a) adjacent in the left-right direction alternately in the front-rear direction ( 12) and are formed. In both meandering upward bulging portions (11) and (12), the connecting portions of the horizontal linear portions (11a) and (12b) and the vertical linear portions (11b) and (12a) are rounded, respectively. Yes.

  The right end portion of the laterally linear portion (11a) at the rear end of the first serpentine upward bulging portion (11) is narrower than the other portions. The left end vertical straight portion (12a) in the second meandering upward bulging portion (12) and the rear end portion of the right next vertical straight portion (12a) are narrower than other portions. The width of the horizontal linear portion (12b) connecting these vertical linear portions (12a) is the same as the width of the narrow linear portions (12a). Further, the rear end portion of the vertical linear portion (12a) at the right end of the second meandering upward bulge portion (12) is narrower than the other portions. The front end of the vertical straight portion (12a) at the left end of the second meandering upward bulging portion (12) is connected to the front end of the first meandering upward bulging portion (11) via the rounded connecting portion. It is connected to the right end of the part (11a). The first and second meandering upper bulges (11) and (12) have a large number of inwardly protruding top ends and brazed to the lower metal plate (4), except for the narrow part. The protrusion (13) is formed. The top wall of the vertical linear portion (12a) at the left end of the second meandering upward bulging portion (12) has a portion where no projection (13) is formed, and this portion is the upward bulging for forming the heat receiving portion. Part (14).

  Further, an upper bulge for forming an expansion tank portion that is long in the left-right direction is formed on the right side of the laterally linear portion (11a) at the rear end of the first serpentine upper bulge portion (11) in the upper metal plate (3). The portion (15) is formed at a distance from the rear end laterally linear portion (11a). Further, on the right side of the upper bulging portion for forming the expansion tank (15), the upper bulging portion for forming the heat radiation portion (16 ) Is formed.

  The lower metal plate (4) includes the right end of the laterally linear portion (11a) at the rear end of the first serpentine upper bulge portion (11) of the upper metal plate (3) and the upper bulge for forming the heat radiating portion. A downward bulging portion (25) is formed through the left end of the portion (16). The lower metal plate (4) has the rear end of the vertical straight portion (12a) at the right end of the second meandering upper bulging portion (12) of the upper metal plate (3) on the lower surface of the substrate (2). A through hole (17) for opening and a through hole (18) for opening the right end of the heat radiating portion forming upward bulging portion (16) on the lower surface of the substrate (2) are formed. One through hole is connected to the discharge port of the circulation pump (6), and the other through hole is connected to the suction port of the circulation pump (6).

  The upper bulging portion (11) (12) (15) (16) of the upper metal plate (3) and the lower bulging portion (25) of the lower metal plate (4) form a cooling fluid circulation path (5). Is formed.

  Here, an aluminum corrugated heat transfer fin (19) (heat transfer member) is disposed in the upper bulging portion (14) for forming the heat receiving portion of the upper metal plate (3), and the heat transfer fin (19) At least the lower metal plate (4) of the upper and lower metal plates (4) is brazed, whereby a heat receiving portion (7) is formed in the middle of the cooling fluid circulation path (5). The wave head and wave bottom of the heat transfer fin (19) are arranged with their length directions in the front-rear direction. The heat generating electronic component (20) is in thermal contact with the portion corresponding to the heat receiving portion (7) on the lower surface of the substrate (2).

  In addition, the corrugated heat dissipating fin (21) made of aluminum is formed on the lower metal plate (4) including the intermediate portion in the length direction of the upper bulging portion (16) for forming the heat dissipating portion of the upper metal plate (3) on the lower surface. As a result, the heat radiating portion (8) is formed in the middle of the cooling fluid circulation path (5). The wave head and the wave bottom of the radiating fin (21) are arranged with their length directions in the front-rear direction.

  Further, the upper bulging portion (15) for forming the expansion tank portion of the upper metal plate (3) and the lower bulging portion (25) of the lower metal plate (4) are placed in the middle of the cooling fluid circulation path (5). An expansion tank portion (9) is formed. Although not shown, the expansion tank section (9) can take in and hold air contained in a bubble state in the cooling fluid, and when the cooling fluid is heated and expanded, the cooling fluid is introduced to increase the internal pressure. The cooling fluid circuit (5) is prevented from being damaged by the above. Further, by placing an excess cooling fluid in the expansion tank section (9), it is possible to prevent a decrease in cooling efficiency when the cooling fluid is reduced.

  Between the adjacent linear straight portions (11a) of the first serpentine upward bulging portion (11) in the upper metal plate (3), the adjacent vertical linear portions of the second meandering upward bulging portion (12) ( 12a), and the vertical linear portion (11b) on the right side of the first serpentine upper bulge portion (11) and the vertical linear portion (12a) on the left end of the second serpentine upper bulge portion (12). Are formed with through-holes (22), (23) and (24) for preventing short-circuits for detecting leakage from the cooling fluid circulation path (5). In addition, the through-hole (22) for short circuit prevention between the horizontal linear parts (11a) adjacent in the front-rear direction connected at the left end is a vertical linear part on the right side of the first meandering upper bulging part (11). (11b) and a through hole (24) for preventing a short circuit between the second meandering upward bulging portion (12) and the vertical straight portion (12a) at the left end.

  The liquid-cooled heat dissipation device (1) described above is, for example, a notebook personal computer including a personal computer main body having a keyboard and a display device provided in the personal computer main body so as to be freely opened and closed. The CPU (20) (heat-generating electronic component) is placed in thermal contact with the lower surface of the substrate (2) in the heat receiving part (7) of the cooling fluid circulation path (5) of the liquid-cooled heat dissipation device (1). When the notebook personal computer is activated, the cooling fluid is circulated in the cooling fluid circulation path (5) by the circulation pump (6). The heat generated from the CPU (20) is transferred to the heat transfer fin (19) through the lower metal plate (4), and is transferred from the heat transfer fin (19) to the cooling fluid. And until the cooling fluid circulates through the cooling fluid circulation path (5) and returns to the heat receiving section (7), the heat of the cooling fluid is radiated to the outside through the upper and lower metal plates (3) (4). In particular, heat is radiated to the outside through the lower metal plate (4) and the heat radiating fin (21) in the heat radiating portion (8), and as a result, the cooling fluid is cooled. By repeating such an operation, heat generated from the CPU (20) is dissipated.

  The liquid cooling type heat dissipation device (1) is manufactured by the method described below.

  By pressing the upper metal plate (3) made of an aluminum brazing sheet having a brazing filler metal layer on the lower surface, the first and second meandering upper bulges (11) (12), protrusions (13), expansion The tank portion forming upward bulging portion (15), the heat radiating portion forming upward bulging portion (16) and the short-circuit preventing through holes (22), (23), and (24) are formed simultaneously. On the other hand, by pressing the lower metal plate (4) made of an aluminum brazing sheet having a brazing filler metal layer on the upper surface, the lower bulging portion (25) and the through holes (17) and (18) are formed simultaneously.

  Next, a heat transfer fin (19) is formed in the upper bulging portion (14) for forming the heat receiving portion of the vertical linear portion (12a) at the left end of the second meandering upward bulging portion (12) of the upper metal plate (3). Then, the two metal plates (3) and (4) are overlapped so that the openings of the respective bulging portions (11), (12) and (25) are closed by the other metal plate. Next, a heat radiating fin (21) made of an aluminum brazing sheet having a brazing filler metal layer on both sides is provided at a position corresponding to the middle portion of the length of the upper bulging portion (16) for forming the heat radiating portion in the lower metal plate (4). Deploy. After that, temporarily fix both metal plates (3) and (4) and radiating fins (21) by appropriate means, and connect both metal plates (3) and (4) to each other and lower metal plate (4) and radiating fins (21). Are brazed at the same time, preferably vacuum without using flux. Thus, the liquid cooling type heat radiating device (1) is manufactured.

  After manufacturing the liquid-cooled heat dissipation device (1), a helium leak test is performed. When there is a bonding failure between the metal plates (3) and (4) that causes the cooling fluid circulation path (5) to communicate with the outer peripheral edge of the substrate (2), the outer peripheral edge of the substrate (2) Helium leakage from the outside is detected. Also, if the cooling fluid circulation path (5) does not lead to the outer peripheral edge of the substrate (2), but a joint failure that causes a short circuit in the cooling fluid circulation path (5) occurs, Helium leakage from the through holes (22), (23) and (24) is detected.

  In the above embodiment, the upper and lower metal plates (3) and (4) are joined by brazing, but the present invention is not limited to this, and may be joined by other methods such as crimping. In the above embodiment, the substrate (2) is flat. However, the present invention is not limited to this, and at least a portion may be curved or bent. Furthermore, in the above embodiment, the substrate (2) is formed from two upper and lower metal plates (3) and (4), but is not limited to this, and is formed from three or more metal plates. It may be. Also in this case, a cooling fluid circulation path is formed between at least one set of two adjacent metal plates among all the metal plates, and at least one of the two metal plates forming the cooling fluid circulation path. It is only necessary to form a through hole for short-circuit prevention for detecting leakage of the cooling fluid from the cooling fluid circulation path so as to be exposed to the outside.

It is a top view of the liquid cooling type heat radiating device by this invention. It is a disassembled perspective view of the liquid cooling type heat radiating device shown in FIG. It is the III-III line expanded sectional view of FIG.

(1): Liquid-cooled heat dissipation device
(2): Board
(3) (4): Metal plate
(5): Cooling fluid circuit
(6): Circulation pump
(7): Heat receiving part
(11) (12): Upper bulge
(13): Projection
(19): Heat transfer fin (heat transfer member)
(20): Heat-generating electronic parts
(22) (23) (24): Through hole for short circuit prevention
(25): Downward bulge

Claims (2)

A substrate comprising two or more metal plates joined in a laminated form is provided, and a cooling fluid circulation path is formed between at least one set of two adjacent metal plates among all the metal plates, and the cooling fluid A cooling fluid is enclosed in the circulation path, and the cooling fluid is circulated in the cooling fluid circulation path by a circulation pump. The cooling fluid circulation path includes a plurality of linear portions arranged at intervals. And between the adjacent linear portions, the longitudinal direction of the linear portion is only on one of the two metal plates of the pair of cooling fluid circulation paths formed between the adjacent linear portions. A liquid-cooled heat radiating device in which one through-hole for short circuit prevention that extends and prevents the occurrence of a short circuit in the cooling fluid circuit is exposed to the outside . The substrate is composed of two metal plates, and a cooling fluid circulation path is formed by expanding at least one of the two metal plates, and only one of the two metal plates is short-circuited. The liquid-cooled heat dissipation device according to claim 1, wherein a prevention through hole is formed .

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