JP4687541B2 - Liquid cooling jacket - Google Patents

Description

  The present invention relates to a liquid cooling jacket for cooling a heat generating body such as a CPU.

  In recent years, as the performance of electronic devices typified by personal computers has improved, the amount of heat generated by a CPU (heat generating body) mounted has increased, and cooling of the CPU has become increasingly important. Conventionally, air-cooled fan type heat sinks have been used to cool CPUs, but problems such as fan noise and cooling limit in air-cooled systems have come to be highlighted. Jackets (also called water-cooled jackets or liquid-cooled modules) are attracting attention.

With regard to such a technique, for example, Patent Document 1 proposes a liquid cooling jacket that includes a metal tube that is formed in a meandering shape and is provided with intake ports and discharge ports at both ends thereof.
JP-A-63-293865 (2nd page, upper right column, second line to lower left column, 15th line, FIGS. 1 and 2)

  However, as in the liquid cooling jacket described in Patent Document 1, when the number of passages through which the cooling water flows is one, the pressure loss that the cooling water receives increases. As a result, there is a problem that not only the CPU cannot be efficiently cooled, but also the output of the pump that supplies the cooling water has to be increased.

  Therefore, an object of the present invention is to provide a liquid cooling jacket capable of efficiently cooling a heat generating body such as a CPU in order to solve the above-described problem.

As a means for solving the above-mentioned problems, the present invention provides a heat generating body attached to a predetermined position, and heat generated by the heat generating body is supplied from an external heat transport fluid supply means and flows through the inside. A liquid cooling jacket to be transferred to the transport fluid, the first flow path on the heat transport fluid supply means side, a second flow path group consisting of a plurality of second flow paths branched from the first flow path, A plurality of metal fins arranged at predetermined intervals on the downstream side of the plurality of second channels, the third channel collecting the plurality of second channels, and between adjacent fins Is the second flow path, the width W of the second flow path is 0.2 to 1.1 mm, the width W of the second flow path, and the fins between the adjacent second flow paths The thickness T satisfies the following formula (1),
−0.375 × W + 0.875 ≦ T / W ≦ −1.875 × W + 3.275 (1)
Furthermore, the depth D and the width W of the second flow path satisfy the following expression (2):
5 × W + 1 ≦ D ≦ 16.25 × W + 2.75 (2)
The heat generating body mainly performs heat exchange in the second flow path group.

According to such a liquid cooling jacket, the heat transport fluid from the external heat transport fluid supply means is supplied to the first flow path. Then, it distribute | circulates in order of a 2nd flow path group and a 3rd flow path. And the heat which a heat generating body generates is transmitted to a heat transport fluid mainly by exchanging heat in the 2nd channel group. As a result, the heat generator is suitably cooled. In addition, by using the second flow path between adjacent fins, the heat from the heat generating body can be transmitted to the heat transport fluid flowing through the second flow path via the plurality of fins. Furthermore, by setting the width W of the second flow path to 0.2 to 1.0 mm, it is possible to make the thermal resistance and the pressure loss received by the heat transport fluid passing through the inside a favorable range. Further, by limiting the relationship between the width W of the second channel and the thickness T of the fin and the relationship between the depth D and the width W of the second channel, the thermal resistance is reduced, Good heat exchange with the heat transport fluid can be achieved.

Here, the second flow path group is composed of a plurality of second flow paths branched from the first flow path, and since the plurality of second flow paths are gathered by the third flow path, the second flow path is Compared with the case where it is formed in a single meandering shape, the length of each second flow path is dramatically shortened. As a result, the pressure loss of the heat transport fluid flowing through the plurality of second flow paths is significantly smaller than the pressure loss of the heat transport fluid flowing through the second flow path having the one long flow path length. . Further, in the present invention, the adjacent second flow paths are not completely isolated like the second flow paths B5a and B5a related to the liquid cooling jacket J6 according to the sixth embodiment described later (see FIG. 26). It is also good.
Therefore, according to such a liquid cooling jacket, an external heat transport fluid supply means (for example, a pump) with a small output is used to supply the heat transport fluid and circulate in the liquid cool jacket, and the like. This heat generator can be efficiently cooled.

Further, the present invention provides a liquid cooling jacket in which a heat generating body is attached at a predetermined position, and heat generated by the heat generating body is supplied from an external heat transport fluid supply means and transmitted to a heat transport fluid flowing through the inside. In this case, a plurality of first flow paths, a plurality of second flow path groups including a plurality of second flow paths, and a third flow path are arranged toward the downstream side, and arranged at predetermined intervals. Metal fins are provided, the gap between adjacent fins is the second flow path, the width W of the second flow path is 0.2 to 1.1 mm, the width W of the second flow path, The fin thickness T between the adjacent second flow paths satisfies the following equation (1):
−0.375 × W + 0.875 ≦ T / W ≦ −1.875 × W + 3.275 (1)
Furthermore, the depth D and the width W of the second flow path satisfy the following expression (2):
5 × W + 1 ≦ D ≦ 16.25 × W + 2.75 (2)
The heat generating body mainly exchanges heat in the second flow path group, and the adjacent second flow path groups are connected in series via a connection flow path. .
That is, the second flow path group has a plurality of second flow path group parts, and the plurality of second flow path group parts are liquid cooling jackets arranged in series.

According to such a liquid cooling jacket, by providing a plurality of second flow path groups (second flow path group) connected in series via a connection flow path, a plurality of second flow path groups, Heat can be exchanged with the heat generator. In addition, by using the second flow path between adjacent fins, the heat from the heat generating body can be transmitted to the heat transport fluid flowing through the second flow path via the plurality of fins. Furthermore, by setting the width W of the second flow path to 0.2 to 1.0 mm, it is possible to make the thermal resistance and the pressure loss received by the heat transport fluid passing through the inside a favorable range. Further, by limiting the relationship between the width W of the second channel and the thickness T of the fin and the relationship between the depth D and the width W of the second channel, the thermal resistance is reduced, Good heat exchange with the heat transport fluid can be achieved.

Further, the present invention provides a liquid cooling jacket in which a heat generating body is attached at a predetermined position, and heat generated by the heat generating body is supplied from an external heat transport fluid supply means and transmitted to a heat transport fluid flowing through the inside. In this case, a plurality of first flow paths, a plurality of second flow path groups including a plurality of second flow paths, and a third flow path are arranged toward the downstream side, and arranged at predetermined intervals. Metal fins are provided, the gap between adjacent fins is the second flow path, the width W of the second flow path is 0.2 to 1.1 mm, the width W of the second flow path, The fin thickness T between the adjacent second flow paths satisfies the following equation (1):
−0.375 × W + 0.875 ≦ T / W ≦ −1.875 × W + 3.275 (1)
Furthermore, the depth D and the width W of the second flow path satisfy the following expression (2):
5 × W + 1 ≦ D ≦ 16.25 × W + 2.75 (2)
The heat generating body mainly exchanges heat in the second channel group, and the adjacent second channel groups are arranged side by side, and one downstream end and the other upstream end are on the same side. This is a liquid cooling jacket characterized by the above.
That is, the adjacent second flow path group portions are juxtaposed, and one downstream end and the other upstream end are liquid cooling jackets on the same side.

According to such a liquid cooling jacket, the heat exchange fluid meanders through one of the second flow path groups adjacent in the flow direction of the heat exchange fluid, the connection flow path, and the other of the adjacent second flow path groups. Circulate like Therefore, when the size of the liquid cooling jacket in a plan view is constant, the number of second flow path groups can be increased by changing the number of second flow path groups without changing the number of second flow paths constituting each second flow path group. The channel cross-sectional area of each second channel constituting the second channel group is reduced. Therefore, when the flow rate of the heat transport fluid flowing through the liquid cooling jacket is constant, the flow rate of the heat transport fluid in each second flow channel increases as the number of second flow channel groups increases. Therefore, the heat transfer rate from the liquid cooling jacket to the heat transport fluid increases, and as a result, the thermal resistance of the liquid cooling jacket decreases.
On the other hand, adjacent second flow path groups are not arranged side by side, for example, when arranged in a line in the flow path direction, even if the number of second flow path groups increases, Only the flow path length of each second flow path constituting each second flow path group is shortened, the cross-sectional area thereof is not reduced, and the flow rate of the heat exchange fluid is not increased. Therefore, the thermal resistance of the liquid cooling jacket does not decrease.
Further, if the number of second flow path groups is an even number, the inlet and outlet of the heat transport fluid to the liquid cooling jacket can be arranged on the same side, and as a result, the piping connected to the liquid cooling jacket can be routed. Becomes easy.
Furthermore, by using the second flow path between adjacent fins, the heat from the heat generating body can be transmitted to the heat transport fluid flowing through the second flow path via the plurality of fins. Furthermore, by setting the width W of the second flow path to 0.2 to 1.0 mm, it is possible to make the thermal resistance and the pressure loss received by the heat transport fluid passing through the inside a favorable range. Further, by limiting the relationship between the width W of the second channel and the thickness T of the fin and the relationship between the depth D and the width W of the second channel, the thermal resistance is reduced, Good heat exchange with the heat transport fluid can be achieved.

  A fin member configured to include the plurality of metal fins; a base plate on which the plurality of metal fins are erected; and a jacket body that accommodates the fin members; The base plate is fixed to the jacket body so as to be capable of heat exchange.

Such a liquid cooling jacket, for example, cuts a metal extrusion mold member having a base plate serving as a base plate and a plurality of strips serving as a plurality of fins erected on the base plate. After producing a fin member including fins, a liquid cooling jacket can be configured by fixing the fin member to, for example, a box-shaped jacket body.
For example, a fin member provided with a plurality of metal fins can be produced by forming a plurality of grooves in a metal block.

  A jacket body having a fin housing chamber for housing the plurality of metal fins; and a sealing body for sealing the fin housing chamber; and a peripheral wall of the jacket body surrounding the fin housing chamber; The mating portion with the sealing body is friction stir welded, and the start end and the end of the friction stir weld overlap.

According to such a liquid cooling jacket, the peripheral wall of the jacket main body and the sealing body can be satisfactorily joined by overlapping the start end and the end of the friction stir welding. This makes it difficult for the heat transport fluid to leak to the outside.
Further, since the sealing body and the jacket main body are joined by friction stir welding without using a brazing material or the like, there is no possibility that the heat transport fluid (refrigerant) is contaminated by the brazing material or the like. There is no possibility that the devices such as the micro pump and the radiator constituting the cooling system are corroded by the brazing material.

  Further, the plurality of metal fins are erected on the sealing body and are integral with the sealing body.

According to such a liquid cooling jacket, since the plurality of metal fins and the sealing body are integrated, the fin housing chamber is sealed with the sealing body, and at the same time, the plurality of metal fins are accommodated in the fins. It can be arranged at a predetermined position in the chamber. That is, the production process of the liquid cooling jacket can be reduced, the production can be easily performed, and the production cost can be reduced. Further, in the case where the plurality of metal fins and the sealing body are integrated as described above, for example, as described in a fifth embodiment described later, a plate (plate material) made of an aluminum alloy is skived. Can be obtained at
In addition, as described above, if the fin and the sealing body are integrally formed by skive processing or the like, it is naturally not necessary to join the fin and the sealing body with a brazing material or the like. In addition, contamination of the heat transport fluid can be prevented.
Furthermore, since the fin and the sealing body are integral, heat transfer between them is high. Therefore, if a heat generating body such as a CPU is attached to the sealing body, the heat of the heat generating body is favorably transmitted to the plurality of fins through the sealing body. As a result, the heat dissipation performance of the heat generating body in the liquid cooling jacket is enhanced.

  Further, the friction stir welding is performed while applying a jig to the peripheral wall so that the peripheral wall does not deform outward.

  According to such a liquid cooling jacket, the peripheral wall is hardly deformed to the outside by the friction stir welding by performing the friction stir welding while applying a jig to the peripheral wall. Further, by applying the jig in this manner, the peripheral wall is thin, and the distance (gap) between the outer peripheral surface of the shoulder and the outer peripheral surface of the peripheral wall in the tool used for friction stir welding is, for example, 2.0 mm or less. However, friction stir welding can be performed without deforming the peripheral wall.

  Moreover, the length of the pin of the tool used in the friction stir welding is 60% or less of the thickness of the sealing body.

  According to such a liquid cooling jacket, since the length of the pin of the tool is 60% or less of the thickness of the sealing body, the sealing body is hardly deformed to the fin housing chamber side by friction stir welding. Thereby, it is prevented that the capacity | capacitance of a fin storage chamber becomes small.

  In the friction stir welding, the tool extraction position is removed from the mating portion.

  According to such a liquid cooling jacket, the removal position of the tool is removed from the mating portion, so that no pin trace is formed in the mating portion. Thereby, a jacket main body and a sealing body can be joined suitably.

  The metal is aluminum or an aluminum alloy.

  According to such a liquid cooling jacket, the weight is reduced by using aluminum or an aluminum alloy as the metal.

  The heat transport fluid intake port communicating with the first flow path and the heat transport fluid discharge port communicating with the third flow path are arranged symmetrically with the heat generating body as a center. It is characterized by that.

  According to such a liquid cooling jacket, the heat transport fluid supplied from the intake port to the first flow path can easily flow through the second flow path near the heat generator. Thereby, heat exchange can be performed between the heat transport fluid and the heat generator.

  Further, the intake port and the discharge port are arranged so as to be relatively distant from each other.

  According to such a liquid cooling jacket, the heat transport fluid supplied from the intake port to the first flow path can easily flow through the plurality of second flow paths. Thereby, heat exchange can be suitably performed between the heat transport fluid that flows through the entire plurality of second flow paths and the heat generator.

  Further, the intake port and the discharge port are arranged so as to approach the heat generating body.

  According to such a liquid cooling jacket, the heat transport fluid supplied from the intake port to the first flow path can easily flow through the second flow path near the heat generating body at a high flow rate. Thereby, heat exchange can be suitably performed between the heat transport fluid that circulates at this fast flow rate and the heat generator. That is, for example, a heat generating body such as a CPU is not attached to the liquid cooling jacket via a heat diffusion sheet 102 (see FIG. 3) called a heat spreader, and the heat of the heat generating body is the whole of the liquid cooling jacket. When it is difficult to transmit the heat to the heat generating fluid, the heat transport fluid can be efficiently radiated by circulating the heat transport fluid through the second flow path in the vicinity of the heat generator at a high flow rate.

  The heat generator is a CPU.

  According to such a liquid cooling jacket, it is possible to efficiently exchange heat between the CPU and the heat transport fluid to cool the CPU.

  ADVANTAGE OF THE INVENTION According to this invention, the liquid cooling jacket which can cool efficiently heat generating bodies, such as CPU, can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with appropriate reference to the drawings.

<< First Embodiment >>
First, a liquid cooling system and a liquid cooling jacket according to a first embodiment will be described with reference to FIGS. FIG. 1 is a configuration diagram of a liquid cooling system according to the first embodiment. FIG. 2 is an overall perspective view of the liquid cooling jacket according to the first embodiment. FIG. 3 is an overall perspective view from below of the liquid cooling jacket according to the first embodiment. FIG. 4 is a perspective view of the liquid cooling jacket according to the first embodiment, showing a state where the lid unit is omitted. FIG. 5 is a plan view of the liquid cooling jacket according to the first embodiment, omitting the intake pipe and the discharge pipe. 6 is an XX cross-sectional view of the liquid cooling jacket according to the first embodiment shown in FIG. FIG. 7 is an exploded perspective view of the liquid cooling jacket according to the first embodiment. FIG. 8 is a graph schematically showing the effect of the liquid cooling jacket according to the first embodiment.

≪Configuration of liquid cooling system≫
As shown in FIG. 1, the liquid cooling system S <b> 1 according to the first embodiment is a system mounted on a personal computer main body 120 (electronic equipment) of a tower-type personal computer, and includes a CPU 101 constituting the personal computer main body 120. This is a system for cooling the (heat generating body). The liquid cooling system S1 includes a liquid cooling jacket J1 (see FIG. 3) to which the CPU 101 is attached at a predetermined position, a radiator 121 (heat radiating means) that releases heat transported by the cooling water (heat transport fluid), and cooling water. A micropump 122 (heat transport fluid supply means) that circulates, a reserve tank 123 that absorbs expansion / contraction of cooling water due to temperature changes, a flexible tube 124 that connects them, and cooling water that transports heat. Mainly prepared. For example, an ethylene glycol antifreeze is used as the cooling water.
And if the micropump 122 act | operates, cooling water will circulate through these apparatuses.

≪Composition of liquid cooling jacket≫
Next, the liquid cooling jacket J1 constituting the liquid cooling system S1 will be described in detail.
As shown in FIGS. 2 and 3, the liquid cooling jacket J <b> 1 has a CPU 101 attached to the center (predetermined position) on the lower side (back side) via a thermal diffusion sheet 102 (heat spreader). With the CPU 101 attached in this manner, the cooling water flows through the liquid cooling jacket J1, so that the liquid cooling jacket J1 receives the heat generated by the CPU 101 and exchanges heat with the cooling water flowing through the inside. As a result, the heat received from the CPU 101 is transmitted to the cooling water, and as a result, the CPU 101 is efficiently cooled. The thermal diffusion sheet 102 is a sheet for efficiently transferring the heat of the CPU 101 to the bottom wall 11 of the jacket body 10 to be described later, and is made of a metal having high thermal conductivity such as copper.

  Such a liquid cooling jacket J1 mainly includes a jacket body 10, a flat tube bundle 20 (tube bundle), and a lid unit 30 as shown in FIGS. The jacket body 10, the flat tube bundle 20, and the lid unit 30 are made of aluminum or an aluminum alloy unless otherwise specified. Thereby, the liquid cooling jacket J1 is reduced in weight and is easy to handle.

<Jacket body>
The jacket main body 10 is a shallow box body whose upper side (one side) is open (see FIG. 7), has a bottom wall 11 and a peripheral wall 12, and accommodates the flat tube bundle 20 inside thereof. A storage chamber is provided (see FIG. 7). Such a jacket main body 10 is produced by, for example, die casting (die casting), casting, forging, or the like. Moreover, the jacket main body 10 has the alignment part 14 of the shape corresponding to the notch part 31c of the cover main body 31 mentioned later in a part of opening edge.

<Flat tube bundle>
The flat tube bundle 20 has a space 10a and a space 10c on both end sides thereof in the jacket body 10 (see FIGS. 4 and 5), and a brazing material made of an aluminum alloy such as Al—Si—Zn, etc. It is joined and fixed to the bottom wall 11 of the jacket body 10 so that heat exchange (heat transfer) is possible (see FIG. 6). The space 10a functions as the first flow path A1, and the space 10c functions as the third flow path C1.

  The flat tube bundle 20 is obtained by bundling and joining a predetermined number of flat tubes 21 in the thickness direction (see FIGS. 6 and 7). Each flat tube 21 has one or a plurality (two in the first embodiment) of hollow portions 21a. Each hollow portion 21a functions as a second flow path B1a through which cooling water flows. That is, each of the second flow paths B1a is rectangular in cross-sectional view, and is located on the side walls (second flow path constituent parts) composed of the peripheral walls 21b and 21b of the flat tube 21 located on both sides thereof and on the upper and lower sides thereof. The peripheral wall 21b or the partition wall 21c is surrounded by an upper wall portion (second flow path constituting portion) or a lower wall portion (second flow passage constituting portion). Accordingly, the flat tube bundle 20 has a plurality of second flow paths B1a, that is, a second flow path group B1 including a plurality of second flow paths B1a.

Here, as described above, the CPU 101 is attached to a substantially central position on the lower side (outside) of the bottom wall 11 (see FIG. 3). Thereby, the heat of the CPU 101 is transmitted via the bottom wall 11 to the peripheral wall 21b that surrounds the hollow portion 21a (second flow path B1a) of each flat tube 21 and the partition wall 21c that partitions the adjacent hollow portions 21a. It is like that. And the heat transmitted to the surrounding wall 21b and the partition wall 21c (heat exchange part) is transmitted to the cooling water which distribute | circulates each 2nd flow path B1a. In this way, the CPU 101 mainly exchanges heat with the cooling water flowing through the second flow path group B1.
Further, since the flat tube bundle 20 is configured by bundling a plurality of flat tubes 21, heat from the CPU 101 is transmitted, and the peripheral wall 21b (heat exchanging portion) that directly exchanges heat with the cooling water increases. Thus, heat can be efficiently exchanged between the CPU 101 and the cooling water. Thereby, the CPU 101 can be efficiently cooled.

[First channel, second channel group (a plurality of second channels), third channel]
Here, the first channel A1, the second channel group B1 (a plurality of second channels B1a), and the third channel C1 will be further described.
The first flow path A1 is a flow path to which cooling water is supplied from the micro pump 122, and is disposed on the micro pump 122 side (upstream side of the second flow path group B1).
The second flow path group B1 is disposed on the downstream side of the first flow path A1, and each second flow path B1a constituting the second flow path group B1 is branched from the first flow path A1. Thus, the cooling water is distributed from the first flow path A1 and flows into each second flow path B1a.
The third flow path C1 is disposed downstream of the second flow path group B1, that is, the plurality of second flow paths B1a, and collects the plurality of second flow paths B1a. Thus, the cooling water flowing out from each second flow path B1a is collected in the third flow path C1, and then discharged to the outside of the liquid cooling jacket J1.

The channel cross-sectional areas of the first channel A1 and the third channel C1 are set larger than the channel cross-sectional areas of the second channels B1a. The flow path length of each second flow path B1a (the length of each flat tube 21) is relative to one flow path meandering through all of the portions corresponding to the flat tube bundle 20 according to the conventional technology. It has become dramatically shorter.
Therefore, the pressure loss experienced by the cooling water flowing in the order of the first flow path A1, each second flow path B1a, and the third flow path C1 hardly occurs in the first flow path A1 and the third flow path C1. In each second flow path B1a, the pressure loss received from one meandering flow path is drastically reduced. As a result, the rated output of the micropump 122 that supplies cooling water to the liquid cooling jacket J1 can be reduced, and the micropump 122 can be reduced in size and noise.

<Lid unit>
As shown in FIG. 7, the lid unit 30 mainly includes a lid body 31, an intake pipe 32, and a discharge pipe 33.

[Cover body]
The lid body 31 is joined and fixed to the jacket body 10 so as to cover the jacket body 10 containing the flat tube bundle 20. The lid main body 31 is formed with an intake port 31a communicating with the first flow path A1 (space 10a) and a discharge port 31b communicating with the third flow path C1 (space 10c) (see FIG. 7).
The lid body 31 has a cutout portion 31 c that is cut out, and the shape of the cutout portion 31 c matches the alignment portion 14 of the jacket body 10. Thereby, the lid body 31 (lid unit 30) is combined with the jacket body 10 only in a predetermined direction.

(Take-in port, discharge port)
As shown in FIG. 5, the intake port 31 a and the discharge port 31 b are arranged symmetrically with respect to the CPU 101 in plan view, and are arranged so as to be relatively distant from each other. In other words, the intake port 31a, the discharge port 31b, and the CPU 101 are arranged on a diagonal line of the liquid cooling jacket J1 having a square shape in plan view. More specifically, the intake port 31a is disposed on the upper left side in FIG. 5, while the discharge port 31b is disposed on the lower right side in FIG. 5, and is substantially intermediate between the intake port 31a and the discharge port 31b. The CPU 101 is arranged at a position (substantially the center of the liquid cooling jacket J1 having a square shape).
Therefore, the cooling water from the intake pipe 32 is supplied substantially uniformly to the entire second flow path group B1 (the entire plurality of second flow paths B1a) via the intake port 31a and the first flow path A1. It has come to be. Then, heat exchange is efficiently performed between the CPU 101 and the entire cooling water flowing through the entire second flow path group B1.
Next, the cooling water flowing out from the plurality of second flow paths B1a is collected in the third flow path C1, and then discharged to the outside of the liquid cooling jacket J1 via the discharge port 31b and the discharge pipe 33. ing.

[Intake pipe and discharge pipe]
The intake pipe 32 is fixed to the lid body 31. Connected to the intake pipe 32 is a flexible tube 124 that communicates with the micropump 122 (see FIG. 1) on the upstream side of the liquid cooling jacket J1. The cooling water from the micropump 122 is supplied to the first flow path A1 through the hollow portion of the intake pipe 32 and the intake port 31a.
The discharge pipe 33 is fixed to the lid body 31. Connected to the discharge pipe 33 is a flexible tube 124 that leads to a radiator 121 (see FIG. 1) on the downstream side of the liquid cooling jacket J1. Then, the cooling water gathered in the third flow path C1 is discharged to the outside of the liquid cooling jacket J1 through the discharge port 31b and the hollow portion of the discharge pipe 33.

  The intake pipe 32 and the discharge pipe 33 are fixed to the upper surface side of the lid body 31 in a standing state. Accordingly, the flexible tubes 124 and 124 can be connected to the intake pipe 32 and the discharge pipe 33 only from the upper surface side of the liquid cooling jacket J1. That is, in the personal computer main body 120 with limited space (see FIG. 1), the flexible tubes 124 and 124 (see FIG. 1) connected to the liquid cooling jacket J1 can be easily routed.

≪Function and effect of liquid cooling jacket≫
Next, the function and effect of the liquid cooling jacket J1 will be described.
When the power source of the personal computer main body 120 (FIG. 1) is turned on, the CPU 101 operates and starts to generate heat. Then, the heat of the CPU 101 is transmitted to the bottom wall 11 of the jacket body 10 via the thermal diffusion sheet 102 and further transmitted to the peripheral wall 21b and the partition wall 21c of each flat tube 21 that mainly forms the flat tube bundle 20.

  On the other hand, in conjunction with turning on the power of the personal computer main body 120, the micropump 122 operates to circulate cooling water. Then, in the liquid cooling jacket J1, the cooling water flows in the order of the first flow path A1, the second flow path group B1 (a plurality of second flow paths B1a), and the third flow path C1.

Then, heat is exchanged between the peripheral wall 21b and the partition wall 21c of each flat tube 21 and the cooling water flowing through each second flow path B1a, and the heat of the CPU 101 transmitted to the peripheral wall 21b and the partition wall 21c is the cooling water. Is transmitted (moved) to the cooling water and receives heat.
Next, the cooling water received in each second flow path B1a is collected in the third flow path C1, and then discharged to the outside of the liquid cooling jacket J1 via the discharge port 31b and the discharge pipe 33. The discharged cooling water is supplied to the radiator 121 through the flexible tube 124, and the heat of the cooling water is radiated from the radiator 121. Then, the cooling water whose temperature has decreased flows through the reserve tank 123 and the flexible tube 124 to the micropump 122, and is then supplied again to the liquid cooling jacket J1.

Such (1) heat transfer from the CPU 101 to the thermal diffusion sheet 102, the bottom wall 11, the peripheral wall 21b and the partition wall 21c of each flat tube 21, and (2) from the peripheral wall 21b and the partition wall 21c to the cooling water. The CPU 101 is efficiently cooled by the continuous heat transfer and (3) the heat dissipation of the cooling water in the radiator 121.
Further, the heat of the CPU 101 is distributed and transmitted to the peripheral wall 21b and the partition wall 21c of the plurality of flat tubes 21, and the heat of each peripheral wall 21b and the partition wall 21c is transmitted to the cooling water flowing through each second flow path B1a. Therefore, the CPU 101 can be efficiently cooled.

Further, the cooling water supplied to the liquid cooling jacket J1 has a short flow path length and a main heat exchange through the first flow path A1 having a large flow path cross-sectional area in the liquid cooling jacket J1. After being circulated through the second flow path B1a (second flow path group B1), the pressure is lost to the cooling water in the liquid cooling jacket J1 because it collects and is discharged in the third flow path C1 having a large cross-sectional area. Is getting smaller. Thereby, the micro pump 122 can be reduced in size and the application range of liquid cooling system S1 becomes wide.
Furthermore, according to such a liquid cooling jacket J1 (product of the present invention), as shown in FIG. 8, compared to a conventional liquid cooling jacket (conventional product) having one long meandering second flow path. Cooling water can be passed with low pressure loss and high flow rate. That is, as shown in FIG. 8, with respect to the intersection M1 between the pressure loss-flow curve of one micropump and the flow curve according to the conventional product, the pressure loss-flow curve and the flow curve according to the present invention The intersection M2 is shifted to the lower right side, and according to the liquid cooling jacket J1 (product of the present invention), it is understood that the pressure loss is small and the flow rate is high.

≪Production method of liquid cooling jacket≫
Next, a method for manufacturing (manufacturing) the liquid cooling jacket J1 will be described with reference mainly to FIG. The manufacturing method of the liquid cooling jacket J1 mainly includes a first step of manufacturing the flat tube bundle 20 and a second step of joining and fixing the flat tube bundle 20 to the jacket body 10.

<First step>
A plurality of flat tubes 21 are bundled while being joined by an appropriate means. Next, both ends of the bundle are cut and ground to prepare a flat tube bundle 20.

<Second step>
The flat tube bundle 20 is joined and fixed to a predetermined position of the bottom wall 11 of the jacket body 10 by an appropriate means (a brazing material such as Al—Si—Zn and a flux) so as to allow heat exchange. In addition, when fixing the flat tube bundle 20 to the jacket main body 10, the above-mentioned space 10a (1st flow path A1) and the space 10c (3rd flow path C1) are ensured at the both ends of the flat tube bundle 20.

Thereafter, the lid main body 31 with the intake pipe 32 and the discharge pipe 33 fixed at predetermined positions is joined and fixed to the jacket main body 10 by an appropriate means. In this way, the liquid cooling jacket J1 can be obtained.
Note that the intake pipe 32 and the discharge pipe 33 may be fixed to the lid body 31 after the lid body 31 is fixed to the jacket body 10.

  As described above, according to the method for producing the liquid cooling jacket J1 according to the first embodiment, the flat tube bundle 20 is fixed to the jacket main body 10 and the lid main body 31 is fixed. With this simple process, the liquid cooling jacket J1 can be obtained.

<< Second Embodiment >>
Next, a liquid cooling jacket according to the second embodiment will be described with reference to FIGS. FIG. 9 is an overall perspective view of the liquid cooling jacket according to the second embodiment, showing a state in which the lid unit is omitted. 10 is a YY sectional view of the liquid cooling jacket according to the second embodiment shown in FIG.

  As shown in FIGS. 9 and 10, the liquid cooling jacket J2 according to the second embodiment includes a flat tube bundle 23 instead of the flat tube bundle 20 of the liquid cooling jacket J1 according to the first embodiment. To do. The flat tube bundle 23 has the same external dimensions as the flat tube bundle 20 according to the first embodiment, but is configured by stacking a plurality of thin plate-like flat tubes 24 (three in FIG. 9 and FIG. 10). Has been. Each flat tube 24 has a plurality (12 in FIGS. 9 and 10) of hollow portions 24a therein, and each hollow portion 24a serves as a second flow path B2a. As a result, the flat tube bundle 23 has a second flow path group B2 composed of a plurality of second flow paths B2a.

  Here, since each flat tube 24 has a thin plate shape, the number of hollow portions 24a formed therein (12 in FIG. 9) is the number of hollow portions formed in the flat tube 21 according to the first embodiment. More than the number (2) of 21a. Thereby, the number (three) of the flat tubes 24 which comprise the flat tube bundle 23 becomes smaller than the number (refer FIG. 7, 20 pieces) of the flat tubes 21 which comprise the flat tube bundle 20 which concerns on 1st Embodiment. That is, the flat tube bundle 23 according to the second embodiment can reduce the number of flat tubes 24 to be bundled (stacked) on the flat tube bundle 20 according to the first embodiment, and can be easily configured without taking time and effort. be able to.

«Third embodiment»
Next, a liquid cooling jacket according to a third embodiment will be described with reference to FIGS. FIG. 11 is an overall perspective view of the liquid cooling jacket according to the third embodiment. FIG. 12 is a plan view of a liquid cooling jacket according to the third embodiment.

≪Composition of liquid cooling jacket≫
As shown in FIGS. 11 and 12, the liquid cooling jacket J3 according to the third embodiment is formed at a position where the intake port 34a and the discharge port 34b are different from the liquid cooling jacket J1 according to the first embodiment. The lid body 34 is provided.
The intake port 34a communicates with a substantially central position of the space 10a (first flow path A1), and cooling water is supplied to a substantially central position of the space 10a. The discharge port 34b communicates with a substantially central position of the space 10c (third flow path), and cooling water is discharged from the substantially central position. The intake port 34a and the discharge port 34b are arranged symmetrically with the CPU 101 as a center in a plan view, and are arranged at positions close to the CPU 101.
Note that the lid body 34 also has a cutout 34 c having a shape corresponding to the alignment portion 14 of the jacket body 10, similarly to the lid body 31 according to the first embodiment.

≪Function and effect of liquid cooling jacket≫
Next, the effect of the liquid cooling jacket J3 will be briefly described.
Since the intake port 34a and the discharge port 34b are arranged at positions close to the CPU 101, the cooling water supplied from the intake port 34a to the first flow path A1 (space 10a) is in the vicinity of the CPU 101. It becomes easy to preferentially flow through the second flow path B1a. Thereby, heat exchange can be suitably performed between the cooling water and the CPU 101, and the CPU 101 can be efficiently cooled.

<< Fourth Embodiment >>
Next, a liquid cooling jacket according to a fourth embodiment will be described with reference to FIGS. FIG. 13 is an overall perspective view of the liquid cooling jacket according to the fourth embodiment, showing a state in which the lid unit is omitted. FIG. 14 is a ZZ sectional view of the liquid cooling jacket according to the fourth embodiment shown in FIG. FIG. 15 is an enlarged view of the ZZ cross-sectional view shown in FIG. FIGS. 16A and 16B are perspective views illustrating a first manufacturing method of the fin member of the liquid cooling jacket according to the fourth embodiment, where FIG. 16A shows before cutting and FIG. 16B shows after cutting. FIGS. 17A and 17B are perspective views showing a second method for producing the fin member of the liquid cooling jacket according to the fourth embodiment, where FIG. 17A shows before cutting and FIG. 17B shows after cutting. FIG. 18 is a perspective view showing friction stir welding according to the fourth embodiment. FIG. 19 is a cross-sectional view showing friction stir welding according to the fourth embodiment. FIG. 20 is a plan view showing the movement of the tool in the friction stir welding according to the fourth embodiment.

≪Composition of liquid cooling jacket≫
As shown in FIGS. 13 and 14, the liquid cooling jacket J4 according to the fourth embodiment includes a fin member 25 made of aluminum or aluminum alloy instead of the flat tube bundle 20 of the liquid cooling jacket J1 according to the first embodiment. It is characterized by having.
Note that the jacket body 10 according to the fourth embodiment includes a fin housing chamber that houses the fin member 25 on the inside thereof, and the fin housing chamber is surrounded by the peripheral wall 12. The fin member 25 is brazed and fixed to the bottom wall 11 and is accommodated in the fin accommodating chamber. The lid main body 31 (sealing body) covers the opening of the jacket main body 10, thereby the fin accommodating chamber. Is sealed (see FIG. 14).

<Fin member>
As shown in FIG. 14, the fin member 25 includes a base plate 25a and a plurality of fins 25b erected on the base plate 25a. The base plate 25a is joined and fixed to the bottom wall 11 of the jacket body 10 so that heat exchange is possible. Therefore, the heat of the CPU 101 is transmitted to the fins 25b via the thermal diffusion sheet 102 and the bottom wall 11. Further, the upper end of each fin 25 b is in contact with the back surface of the lid body 31. In addition, it is preferable that the base plate 25a and the jacket main body 10 are reliably joined to each other by a brazing material made of an aluminum alloy such as Al—Si—Zn.
And between the adjacent fins 25b and 25b becomes the 2nd flow path B3a, respectively. That is, the fin member 25 has a plurality of second flow paths B3a, that is, a second flow path group B3 including a plurality of second flow paths B3a.

  As shown in FIG. 15, the distance between the adjacent fins 25b, 25b, that is, the groove width W1, which is the width of the second flow path B3a, is designed to be 0.2 to 1.1 mm. As a result, the thermal resistance of the liquid cooling jacket J4 and the pressure loss experienced by the cooling water passing through the liquid cooling jacket J4 can be in a favorable range as will be described in the examples described later.

Further, the groove width W1 and the thickness T1 of the fin 25b, that is, the thickness T1 of the fin 25b between the adjacent second flow paths B3a and B3a satisfy the relationship of the following expression (1). Thereby, the thermal resistance of the liquid cooling jacket J4 is reduced, and heat can be exchanged favorably between the CPU 101 and the cooling water.
−0.375 × W1 + 0.875 ≦ T1 / W1 ≦ −1.875 × W1 + 3.275 (1)

Further, the groove width W1 and the depth D1 (depth of the second flow path B3a) satisfy the relationship of the following expression (2). Thereby, the thermal resistance of the liquid cooling jacket J4 can be optimized.
5 × W1 + 1 ≦ D1 ≦ 16.25 × W1 + 2.75 (2)

≪Function and effect of liquid cooling jacket≫
Next, the effect of the liquid cooling jacket J4 will be briefly described.
The cooling water flows in the order of the first flow path A1, the second flow path group B3 (a plurality of second flow paths B3a), and the third flow path C1. And heat exchange is mainly carried out between the cooling water which distribute | circulates 2nd flow-path group B3, and the several fin 25b. As a result, the CPU 101 can be efficiently cooled.

≪Method of manufacturing fin member of liquid cooling jacket≫
Next, a method for manufacturing (manufacturing) the fin member 25 of the liquid cooling jacket J4 will be illustrated.

<First production method of fin member>
First, the 1st production method of the fin member 25 is demonstrated with reference to FIG.
As shown in FIG. 16A, a metal extrusion die 41 having a bottom plate 42 and a plurality of strips 43 standing on the bottom plate 42 is produced using a predetermined mold. And the fin member 25 provided with the base plate 25a (a part of the bottom plate 42) and a plurality of fins 25b (a part of the plurality of strips 43) is produced by cutting the extruded mold member 41 at a predetermined cutting surface. (See FIG. 16B).

<The 2nd preparation method of a fin member>
Next, a second manufacturing method of the fin member 25 will be described with reference to FIG.
As shown in FIG. 17A, a plurality of grooves 44a are formed in a metal block 44 having a size corresponding to the outer shape of the fin member 25 using an appropriate cutting tool. Then, the fin member 25 including the base plate 25a and the plurality of fins 25b can be manufactured (see FIG. 17B).

≪Assembly of liquid cooling jacket≫
Next, in the assembly of the liquid cooling jacket J4, friction stir welding between the jacket main body 10 to which the fin member 25 is fixed and the lid unit 30 will be described with reference mainly to FIGS.
As shown in FIG. 18, the cover unit 30 is put on the jacket body 10 to which the fin member 25 is fixed by brazing while aligning the notch 31 c and the alignment portion 14. In addition, as shown in FIG. 19, the opening edge of the jacket main body 10 is uneven, and the lid main body 31 is placed on the stepped portion 15 that is lowered by one step. The width W11 of the step portion 15 is set as small as possible in order to secure the volumes of the first flow path A1 and the third flow path C1 through which the cooling water flows, and specifically, set to about 0.1 to 0.5 mm. Is preferred.

Then, the joint portion P <b> 1 between the peripheral wall 12 and the lid main body 31 is friction stir welded using the friction stir welding tool 200. Then, a friction stir welding portion K (see FIG. 15) is formed behind the tool 200, and the peripheral wall 12 and the lid body 31 are joined. Here, the length L5 of the pin 201 of the tool 200 is preferably 60% or less of the thickness T2 of the lid body 31 that is a member to be joined. In this way, by setting it to 60% or less, although depending on the material of the lid main body 31, even if the width W11 of the stepped portion 15 is small, the mating portion P1 is located inside the jacket main body 10 by the pressing force of the tool 200. It becomes difficult to deform.
The tool 200 is controlled by a machine tool (not shown) such as an NC and is rotated and moved along the mating portion P1 (see FIG. 18).

In addition, when performing friction stir welding, an appropriate jig 210 is applied to the peripheral surface of the peripheral wall 12 of the jacket body 10. Thereby, even if the distance L6 (gap) between the outer peripheral surface of the shoulder 202 of the tool 200 and the outer peripheral surface of the peripheral wall 12 is 2.0 mm or less, the peripheral wall 12 is thin due to the pressing force of the tool 200. 12 becomes difficult to deform | transform outside.
In addition to this, when the peripheral wall 12 is thin like this, the surface of the jig 210 is set to 1.0 to 2.0 mm with respect to the surface of the mating portion P1 in order to avoid contact between the tool 200 and the jig 210. It is preferable to lower the degree.

  Furthermore, as shown in FIG. 20, the tool 200 is moved so that the start end and the end end in the friction stir welding overlap (refer to reference sign Q). Thereby, the jacket main body 10 and the lid main body 31 are joined without a gap, and the cooling water hardly leaks to the outside. Next, the tool 200 is removed from the mating portion P1, and the pin 201 is removed. Thereby, the trace of the pin 201 is not formed on the mating portion P1.

«Fifth embodiment»
Next, a liquid cooling jacket according to a fifth embodiment will be described with reference to FIGS. FIG. 21 is a cross-sectional view of a liquid cooling jacket according to the fifth embodiment. FIG. 22 is an enlarged view of the cross-sectional view shown in FIG. FIGS. 23A and 23B are diagrams showing a method for manufacturing the fin member of the liquid cooling jacket according to the fifth embodiment. FIG. 23A shows a state during skive processing, and FIG. 23B shows a state after skive processing. FIG. 24 is a view showing a method for producing the fin member of the liquid cooling jacket according to the fifth embodiment, after a part of the skive fin shown in FIG. FIG. 25 is a cross-sectional view showing friction stir welding according to the fifth embodiment.
In addition, a different part is demonstrated with respect to the liquid cooling jacket J4 which concerns on 4th Embodiment.

≪Composition of liquid cooling jacket≫
As shown in FIG. 21, the liquid cooling jacket J5 according to the fifth embodiment mainly includes a jacket body 10C and a fin member 29 made of aluminum or aluminum alloy, and the CPU 101 has a bottom wall 29a of the fin member 29. It becomes the structure attached to (sealing body).

The jacket main body 10C is a thin box having an opening on the lower side of FIG. 21 and having a fin housing chamber inside.
As will be described later, the fin member 29 is obtained by skiving a single plate 61 (see FIG. 23A), and includes a bottom wall 29a and a plurality of metal fins 29b. The plurality of fins 29b are erected on the bottom wall 29a, and are configured integrally with the bottom wall 29a. Thereby, heat is transmitted favorably between the bottom wall 29a and the fins 29b.

  Further, the bottom wall 29a functions as a sealing body that seals the fin housing chamber. Furthermore, the space between the adjacent fins 29b and 29b functions as the second flow path B4a (see FIG. 22). And the liquid cooling jacket J5 has 2nd flow-path group B4 comprised by several 2nd flow-path B4a. In the state where the fin member 29 is attached to the jacket main body 10C, the first flow path A1 and the third flow path C1 are formed in the liquid cooling jacket J5 as in the fourth embodiment. (See FIG. 13).

≪Function and effect of liquid cooling jacket≫
Next, the effect of the liquid cooling jacket J5 will be briefly described.
The cooling water flows in the order of the first channel A1 (see FIG. 13), the second channel group B4 (the plurality of second channels B4a), and the third channel C1 (see FIG. 13). And it is mainly heat-exchanged between the cooling water which distribute | circulates 2nd flow-path group B4, and the several fin 25b, and can cool CPU101 efficiently. Here, since the bottom wall 29a and the fins 29b are integrally formed, the heat of the CPU 101 can be transferred well to the plurality of fins 29b, and as a result, heat can be radiated well.

≪Method of manufacturing fin member of liquid cooling jacket≫
Next, a manufacturing (manufacturing) method of the fin member 29 of the liquid cooling jacket J5 using skive processing will be described with reference to FIGS.
As shown in FIG. 23 (a), the plate-like plate 61 is skived as described in JP 2001-326308 A, JP 2001-352020 A, and the like. Specifically, the cutting tool 62 is cut into the plate 61 at an acute angle, and a part of the plate 61 is cut and raised to form a plurality of skive fins 63. This is repeated a plurality of times to produce a skive intermediate 64 having a plurality of skive fins 63 (see FIG. 23B). Incidentally, the portion of the plate 61 that is not cut and raised serves as the bottom wall 29 a (sealing body) of the fin member 29.

  Subsequently, the outer periphery of the plurality of skive fins 63 is formed so that the first flow path A1 and the third flow path C1 are formed in the liquid cooling jacket J5 when the liquid cooling jacket J5 is assembled with the jacket body 10C. Remove the side part with a cutting tool. If it does so, as shown in FIG. 24, the fin member 29 provided with the bottom wall 29a and the several fin 29b erected integrally with this can be obtained.

  However, the production method of the fin member 29 is not limited to this, and the fin member 25 (see FIG. 16) after cutting the extruded die 41 according to the fourth embodiment or the fin member 25 formed by grooving (FIG. 17)), a part of the fin 25b may be removed.

≪Assembly of liquid cooling jacket≫
Then, as shown in FIG. 25, the jacket main body 10 </ b> C and the fin member 29 are combined, and the mating portion P <b> 2 is friction stir welded while applying the jig 210 in the same manner as in the fourth embodiment. The length L5 of the pin 201 of the tool 200 is preferably 60% or less of the thickness T3 of the bottom wall 29a (sealing body) of the fin member 29 which is a member to be joined.

<< Sixth Embodiment >>
Next, a liquid cooling jacket according to a sixth embodiment will be described with reference to FIG. FIG. 26 is a cross-sectional view of the liquid cooling jacket according to the sixth embodiment, where (a) shows a completed state after assembly, and (b) shows before assembly.

≪Composition of liquid cooling jacket≫
As shown in FIG. 26 (a), the liquid cooling jacket J6 according to the sixth embodiment includes a jacket body 10A (first fin member), a lid unit, and the liquid cooling jacket J1 according to the first embodiment. 35 (second fin member). The jacket body 10 </ b> A includes a bottom wall 11 (first base plate) and a plurality of fins 13 erected on the bottom wall 11 at a predetermined interval. On the other hand, the lid unit 35 includes a lid body 36 (second base plate) and a plurality of fins 37 erected on the lid body 36 at a predetermined interval.

  The jacket body 10A and the lid unit 35 are combined so that the plurality of fins 13 and the plurality of fins 37 are engaged with each other, and the lid body 36 is joined and fixed to the jacket body 10A. The entire fin of the liquid cooling jacket J6 is composed of a plurality of fins 13 and a plurality of fins 37 engaged with each other. And between the adjacent fin 13 and the fin 37 becomes 2nd flow path B5a, and liquid cooling jacket J6 has 2nd flow path group B5 which consists of several 2nd flow path B5a.

  As described above, the plurality of fins 13 and the plurality of fins 37 are meshed to form the entire fin, thereby increasing the interval d1 between the plurality of fins 13 and the interval d2 between the plurality of fins 37. And groove processing with a cutting tool or the like becomes easy.

The protruding length L1 of the plurality of fins 13 from the bottom wall 11 is set to be the same as or shorter than the protruding length L2 of the plurality of fins 37 from the lid body 36, as shown in FIG. And the several fin 37 and the bottom wall 11 are joined and fixed so that heat exchange is possible by an appropriate means, and is thermally connected. Thereby, the heat of the CPU 101 on the jacket main body 10 </ b> A side (first base plate side) is transmitted not only to the plurality of fins 13 but also to the plurality of fins 37.
That is, by setting the protruding length L1 of the plurality of fins 13 to be the same as or shorter than the protruding length L2 of the plurality of fins 37, when the jacket body 10A and the lid unit 35 are assembled, the plurality of fins 37 The tip (top) reliably contacts the bottom wall 11 of the jacket body 10A, and the plurality of fins 37 and the bottom wall 11 can be reliably connected thermally.

≪Function and effect of liquid cooling jacket≫
Next, the effect of the liquid cooling jacket J6 will be briefly described.
According to such a liquid cooling jacket J6, when the cooling water flows through the second flow path group B5, the heat of the CPU 101 transmitted to the plurality of fins 13 and the plurality of fins 37 is transmitted to the circulating cooling water, and the CPU 101 Is efficiently cooled.

<< Seventh Embodiment >>
Next, a liquid cooling jacket according to a seventh embodiment will be described with reference to FIG. FIG. 27 is a cross-sectional view of a liquid cooling jacket according to the seventh embodiment, where (a) shows a completed state after assembly, and (b) shows before assembly.

≪Composition of liquid cooling jacket≫
As shown in FIGS. 27 (a) and 27 (b), the liquid cooling jacket J7 according to the seventh embodiment has a plurality of pores instead of the flat tube bundle 20 of the liquid cooling jacket J1 according to the first embodiment. A metal honeycomb body 26 having 26a is provided.

<Honeycomb body>
The honeycomb body 26 is joined and fixed to the bottom wall 11 of the jacket main body 10 so as to allow heat exchange by an appropriate means. Therefore, the heat of the CPU 101 is transmitted to the peripheral wall 26b surrounding the pore 26a. Each pore 26a functions as a second flow path B6a through which cooling water flows. That is, the honeycomb body 26 has a second flow path group B6 including a plurality of second flow paths B6a. Here, as shown in FIG. 27, the honeycomb body 26 having the pores 26a having a rectangular cross-sectional view is illustrated, but the shape of the pores 26a is not limited to this, and other shapes such as a hexagonal shape may be used. Also good. Moreover, it is preferable that the honeycomb body 26 and the bottom wall 11 of the jacket main body 10 are bonded to each other by a brazing material so as to be surely heat exchangeable.

≪Function and effect of liquid cooling jacket≫
Next, the effect of the liquid cooling jacket J7 will be briefly described.
The cooling water flows in the order of the first flow path A1, the second flow path group B6 (a plurality of second flow paths B6a), and the third flow path C1. And heat exchange is mainly performed between the peripheral wall 26b of the honeycomb body 26 and the cooling water flowing through the second flow path B5a, and the heat of the peripheral wall 26b is transmitted to the cooling water. As a result, the CPU 101 is efficiently cooled.

<< Eighth Embodiment >>
Next, a liquid cooling jacket according to an eighth embodiment will be described with reference to FIG. FIG. 28 is a cross-sectional view of the liquid cooling jacket according to the eighth embodiment, where (a) shows a completed state after assembly, and (b) shows before assembly.

≪Composition of liquid cooling jacket≫
As shown in FIGS. 28A and 28B, the liquid cooling jacket J8 according to the eighth embodiment has a wavy cross section instead of the flat tube bundle 20 of the liquid cooling jacket J1 according to the first embodiment. A metal heat exchange sheet 27 (brazing sheet) is provided.

<Heat exchange sheet>
The heat exchange sheet 27 includes a sheet main body 27a formed from an aluminum alloy such as Al-Mn or Al-Fe-Mn, and a brazing material formed from an aluminum alloy such as Al-Si-Zn on the lower surface side. Layer 27b. The heat exchange sheet 27 is joined and fixed to the bottom wall 11 of the jacket main body 10 so that heat exchange is possible because the brazing material layer 27b is partially melted and cured. Therefore, the heat of the CPU 101 is transmitted to the heat exchange sheet 27 through the bottom wall 11.

  A plurality of second flow paths B7a are formed between the heat exchange sheet 27 and the jacket body 10 or the lid body 31. That is, the liquid cooling jacket J8 has a second channel group B7 including a plurality of second channels B7a.

≪Function and effect of liquid cooling jacket≫
Next, the effect of the liquid cooling jacket J8 will be briefly described.
The cooling water flows in the order of the first flow path A1, the second flow path group B7 (a plurality of second flow paths B7a), and the third flow path C1. And heat exchange is carried out between the heat exchange sheet 27 and the cooling water flowing through the second flow path B7a, and the heat of the heat exchange sheet 27 is transmitted to the cooling water. As a result, the CPU 101 is efficiently cooled.

<< Ninth embodiment >>
Next, a liquid cooling jacket according to a ninth embodiment will be described with reference to FIG. FIG. 29 is a plan view of a liquid cooling jacket according to the ninth embodiment. In FIG. 29, the lid body is removed for easy understanding.

≪Composition of liquid cooling jacket≫
As shown in FIG. 29, the liquid cooling jacket J9 according to the ninth embodiment includes one flat tube bundle 20 while the liquid cooling jacket J1 according to the first embodiment includes three flat tube bundles 20. The three flat tube bundles 20 are arranged in a row in the jacket body 10B so that the hollow portions 21a (second flow paths B1a) of the flat tube bundles 20 are in the same direction. The three flat tube bundles 20 include a space 10d between the upstream flat tube bundle 20 and the midstream flat tube bundle 20 in the jacket body 10B, and a space between the midstream flat tube bundle 20 and the downstream flat tube bundle 20. 10d is provided and fixed to the bottom wall 11 of the jacket main body 10B so as to allow heat exchange.

  The spaces 10d and 10d function as fourth flow paths E1 and E1 (connection flow paths) that communicate the second flow path group B1 of the flat tube bundle 20 in series. The channel cross-sectional area of the fourth channel E1 is set to be larger than the channel cross-sectional area of the second channel B1a constituting each second channel group B1. That is, the liquid cooling jacket J9 has three second flow path groups B1, B1, and B1 (second flow path group portions) arranged in series.

≪Function and effect of liquid cooling jacket≫
Next, the effect of the liquid cooling jacket J9 will be briefly described.
The cooling water includes a first flow path A1, an upstream second flow path group B1, a fourth flow path E1, a middle flow second flow path group B1, a fourth flow path E1, a downstream second flow path group B1, It circulates in order of 3 flow paths C1. That is, the cooling water flows in series through the three second flow path groups B1, B1, and B1. Here, when the cooling water passes through the fourth flow path E1 between the adjacent second flow path groups B1 and B1, the pressure loss received by the cooling water in the fourth flow path E1 is reduced. That is, by interposing the fourth channel E1 having a large channel cross-sectional area between the second channel groups B1 and B1, the second channel group having a long channel length without the fourth channel E1 and Compared to the case, the load acting on the micropump 122 can be reduced.

«Tenth embodiment»
Next, a liquid cooling jacket according to the tenth embodiment will be described with reference to FIGS. 30 and 31. FIG. 30 is a plan view of a liquid cooling jacket according to the tenth embodiment. FIG. 31 is a graph showing the relationship between the number of turns and the thermal resistance.

  As shown in FIG. 30, the liquid cooling jacket J10 according to the tenth embodiment is similar to the liquid cooling jacket J9 according to the ninth embodiment in three second flow path groups B1, B1, B1 connected in series. (Second flow path group), and in the flow direction of the cooling water, adjacent second flow path groups B1 and B1 are connected in series via the fourth flow path E1 (connection flow path). ing.

However, in the liquid cooling jacket J10, adjacent second flow path groups B1 and B1 are arranged side by side, and among the adjacent second flow path groups B1, the downstream end of the upstream side and the upstream end of the downstream side Is arranged on the same side, and the downstream end and the upstream end are connected in series via the fourth flow path E1. Specifically, as shown in FIG. 30, the second flow path group B1 at the upstream position and the second flow path group B1 at the midstream position are adjacent to each other in the flow direction of the cooling water. They are juxtaposed in the horizontal direction. For example, the downstream end of the second flow path group B1 at the upstream position and the upstream end of the second flow path group B1 at the midstream position face the lower side in FIG. 30, which is the same side.
Here, in this specification, the state in which the adjacent second flow path groups B1 and B1 are arranged side by side is expressed as “folded” with respect to the ninth embodiment.

  Therefore, according to such a liquid cooling jacket J10, the cooling water meanders and flows through the inside. Then, the thermal resistance of the liquid cooling jacket J10 is smaller than that of the liquid cooling jacket J9 that is not folded back.

  More specifically, when the size of the liquid cooling jacket in a plan view is constant, the number of turns is increased without changing the number of second flow paths constituting each second flow path group B1, and the second flow is increased. If the number of path groups B1 is increased, the channel cross-sectional area of each second channel constituting each second channel group B1 is reduced. Therefore, when the flow rate of the cooling water flowing through the liquid cooling jacket is constant, the flow rate of the cooling water passing through each second flow path increases as the number of the second flow path groups B1 increases. Therefore, heat is efficiently transferred from the liquid cooling jacket to the cooling water, and the thermal resistance of the liquid cooling jacket is reduced.

  As mentioned above, although an example was described about suitable embodiment of the present invention, the present invention is not limited to each of the above-mentioned embodiments, and various embodiments may be appropriately combined without departing from the gist of the present invention, For example, it can be modified as follows.

  In each of the above-described embodiments, the case where the heat generating body is the CPU 101 has been described. However, the type of the heat generating body is not limited thereto, and may be, for example, a power module, an LED lamp, or the like.

  In the first embodiment described above, the flat tube bundle 20 is configured by bundling a plurality of flat tubes 21 in the thickness direction, but may be configured by further bundling in the width direction.

  The liquid cooling jacket J1 according to the first embodiment has been described with respect to the case where a plurality of flat tubes 21 are bundled to provide the flat tube bundle 20 (see FIG. 6). In addition, for example, as shown in FIG. Moreover, it may replace with the flat tube bundle 20, and may be the liquid cooling jacket J11 provided with the flat tube 28 which has the some hollow part 28a divided by the some partition wall. In this case, each hollow portion 28a functions as a second flow path B8a, and the flat tube 28 has a second flow path group B8 including a plurality of second flow paths B8a.

  In the liquid cooling jacket J1 according to the first embodiment described above, the case where the intake port 31a and the discharge port 31b are formed in the lid body 31 has been described, but the positions of the intake port 31a and the discharge port 31b are limited to this. For example, the case where it forms in the surrounding wall 12 of the jacket main body 10 may be sufficient. Concomitantly, the positions of the intake pipe 32 and the discharge pipe 33 are not limited to the upper surface side of the liquid cooling jacket J1, and may be positioned on the side surface side.

  In the liquid cooling jacket J6 according to the sixth embodiment described above, the fin 13 is erected on the jacket body 10A and the fin 37 is erected on the lid body 36 (see FIG. 26), but FIG. 33 (a). As shown in FIG. 33B, a first fin member 50 including a first base plate 51 and a plurality of first fins 52 erected on the first base plate 51, and a second base plate 56. And a liquid cooling jacket J12 including a plurality of second fins 57 provided upright on the second base plate 56.

  The liquid cooling jacket J12 shown in FIG. 33 will be further described. The first fin member 50 and the second fin member 55 are combined such that the plurality of first fins 52 and the plurality of second fins 57 are engaged with each other. The whole of the plurality of metal fins in the liquid cooling jacket J12 includes a plurality of first fins 52 and a plurality of second fins 57, and the first fins 52 and the second fins 57 adjacent to each other. A second flow path B9a is formed between the two. The first fin member 50 is located on the CPU 101 side, and the first base plate 51 is fixed to the bottom wall 11 of the jacket body 10 so that heat exchange is possible.

  The liquid cooling jacket J12 has a second flow path group B9 including a plurality of second flow paths B9a. The protruding length L3 of the plurality of first fins 52 from the first base plate 51 is set to be the same as or shorter than the protruding length L4 of the plurality of second fins 57 from the second base plate 56. The plurality of second fins 57 and the first base plate 51 are joined and fixed so as to be capable of heat exchange by an appropriate means, and are thermally connected.

  In the first embodiment described above, the first flow path A1 and the third flow path C1 are formed by providing the spaces 10a and 10c between the jacket body 10 and the flat tube bundle 20, respectively (see FIG. 5). In addition, for example, the spaces 10a and 10c are not provided, the outer side of the jacket body 10 is provided with a branch pipe on the upstream side, the hollow portion is used as the first flow path, and the collecting pipe is provided on the downstream side. The hollow portion may be used as the third flow path.

  In the liquid cooling jacket J4 (see FIG. 14) according to the above-described fourth embodiment, the fin member 25 is fixed to the jacket main body 10, but as shown in FIG. It may be a liquid cooling jacket J13 in which the fin member 25 is fixed to the side surface. Further, as shown in FIG. 34, the CPU 101 may be attached to the lid body 31. Furthermore, the structure which the intake pipe 32 used as the cooling water intake port in the liquid cooling jacket J13 and the discharge pipe 33 used as a discharge port were attached to the jacket main body 10 may be sufficient. In addition, the structure by which the fin was integrally formed in the jacket main body 10 side surface of the lid | cover main body 31 may be sufficient.

Furthermore, as shown in FIG. 35, the jacket main body 10 includes four leg portions 16 having insertion holes 16a, screws 125 are inserted into the respective insertion holes 16a, and the liquid cooling jacket J13 is connected to the personal computer main body 120 (FIG. 1). In the case where the tool 200 is attached to the casing 126, the tool 200 is preferably removed at a position corresponding to the insertion hole 16a. And after extracting the tool 200 in such a position, the trace of the tool 200 can be hidden by forming the insertion hole 16a in the trace part.
34 is an X1-X1 cross section of FIG.

  Hereinafter, based on an Example, this invention is demonstrated further more concretely.

(1) Example 1, examination of groove width W1 of second flow path B3a For liquid cooling jacket J4 (see FIG. 13 and the like) according to the fourth embodiment, groove width W1 of second flow path B3a (see FIG. 15). Were made of an aluminum alloy having a thickness of 0.2 mm, 0.5 mm, and 1.0 mm. Table 1 shows the specifications of the liquid cooling jacket J4 produced.
In Table 1, the overall flow path width W0 is the width of the first flow path A1 and the third flow path C1. The total flow path length L0 is the sum of the length of the first flow path A1, the length of the second flow path B3a, and the length of the third flow path C1 (see FIGS. 13 and 14).

  Then, water is used as the cooling water, and the micropump 122 (see FIG. 1) is operated so that the water flows at 5 (L / min) (see Table 2), and the groove width W1 of the second flow path B3a And the relationship between the thermal resistance and pressure loss of the liquid cooling jacket J4. Thermal resistance and pressure loss were measured by appropriate methods. In the liquid cooling jacket J4 of this specification, the target thermal resistance is set to 0.008 (° C./W) or less.

As shown in FIG. 36, as the groove width W1 of the second flow path B3a is reduced, the contact area between the liquid cooling jacket J4 and the cooling water is increased, so that the thermal resistance of the liquid cooling jacket J4 is reduced. On the other hand, it was confirmed that when the groove width W1 of the second flow path B3a is larger than 1.1 mm, the thermal resistance is larger than the target of 0.008 (° C./W).
Further, it was confirmed that the pressure loss that the cooling water receives by the liquid cooling jacket J4 is larger than 0.01 (° C./W) when the groove width W1 of the second flow path B3a is smaller than 0.2 mm.
Therefore, it is considered that the groove width W1 of the second flow path B3a is preferably 0.2 to 1.1 mm.

(2) Examination of the relationship between the thickness T1 of the fin 25b and the groove width W1 of the second flow path B3a in the second embodiment Next, as in the first embodiment, the groove width W1 of the second flow path B3a is set to 0. Three types of 2 mm, 0.5 mm, and 1.0 mm are set (see Table 1), and the thickness T1 of the fin 25b is appropriately changed with respect to the groove width W1 of each of the second flow paths B3a. The relationship between the “ratio between the thickness T1 of 25b and the groove width W1 (T1 / W1)” and “thermal resistance” was examined.

As shown in FIG. 37, in each groove width W1, there was a range of “T1 / W1” in which the thermal resistance was reduced. This range was set to a value that is 5% or less of the minimum thermal resistance in each groove width W1.
Specifically, when the groove width W1 of the second flow path B3a is 1.0 mm, the minimum thermal resistance is 0.0073 (° C./W), so the value increased by 5% is 0.0073 × 1. 0.05 = 0.0076 (° C / W). The range of 0.0076 (° C./W) or less is 0.5 ≦ T1 / W1 ≦ 1.4.
Similarly, when the groove width W1 of the second flow path B3a is 0.5 mm, the range is 0.7 ≦ T1 / W1 ≦ 2.1. When the groove width W1 of the second flow path B3a is 0.2 mm, 0.8 ≦ T1 / W1 ≦ 2.9.

Based on this, the graph shown in FIG. 38 was obtained by rewriting the X-axis as “groove width W1” and the Y-axis as “fin thickness T1 / groove width W1”. As shown in FIG. 38, it was confirmed that “groove width W1” and “fin thickness T1 / groove width W1” preferably satisfy the following expression (1).
−0.375 × W1 + 0.875 ≦ T1 / W1 ≦ −1.875 × W1 + 3.275 (1)

(3) Third Example, Investigation of Relationship Between Groove Width W1 and Depth D1 of Second Channel B3a Next, in the liquid cooling jacket J4 according to the fourth embodiment, the groove width W1 of the second channel B3a. Is set to three types of 0.2 mm, 0.5 mm, and 1.0 mm (see Table 1), and the depth D1 is appropriately changed with respect to the groove width W1 of each second flow path B3a, The relationship between “depth D1” and “thermal resistance” was examined.

  As shown in FIG. 39, as in Example 2, it was confirmed that each groove width W1 had a range of groove depth D1 in which the thermal resistance was reduced. When this range is obtained in the same manner as in Example 2, when the groove width W1 is 0.2 mm, 2 ≦ D1 ≦ 6, when the groove width W1 is 0.5 mm, 4 ≦ D2 ≦ 11, and the groove width W1 is 1. At 0 mm, 6 ≦ D1 ≦ 18.

Based on this, the graph shown in FIG. 40 was obtained by rewriting the X axis as “groove width W1” and the Y axis as “groove depth D1”. As shown in FIG. 40, it was confirmed that “groove width W1” and “groove depth D1” preferably satisfy the following expression (2).
5 × W + 1 ≦ D ≦ 16.25 × W + 2.75 (2)

(4) Example 4, Examination of Effectiveness of Jig Next, in the friction stir welding between the jacket body 10 and the lid body 31 in the fourth embodiment, the jig 210 is applied to the peripheral wall 12 of the jacket body 10. The effectiveness was examined. In this examination, two types of tools 200 shown in Table 3 were used. Then, as shown in Table 4, the distance L6 between the outer peripheral surface of the shoulder 202 and the outer peripheral surface of the peripheral wall 12 of the jacket body 10 in the A tool or B tool is changed (see FIG. 19), and the jig 210 is present. The peripheral wall 12 and the lid main body 31 were friction stir welded while changing / no. And the quality of the junction part was evaluated visually. ○ indicates good and × indicates poor bonding.
The rotation speed of the tool 200 was 6000 rpm, and the joining speed was 200 mm / min. Moreover, thickness T11 (refer FIG. 19) of the surrounding wall 12 was 4 mm.

  As is apparent from Table 4, it was confirmed that when the jig 210 was used, the lid body 31 could be satisfactorily joined without deforming the peripheral wall 12 even when the peripheral wall 12 was thin and the distance L6 was 0.5 mm.

(5) Example 5, relationship between pin length L5 and lid body 31 thickness T2 Next, the relationship between pin 201 length L5 of tool 200 and lid body 31 thickness T2 was examined. (See FIG. 19). In this examination, as shown in Table 5, the length L5 of the pin 201 was fixed to 2.0 mm, the thickness T2 of the lid body 31 was changed, and the joint quality was visually evaluated.

  As shown in Table 5, when the length L5 of the pin 201 is 60.0% or less of the thickness T2 of the lid body 31 that is the member to be joined, the peripheral wall 12 and the lid body 31 can be satisfactorily joined. confirmed.

It is a lineblock diagram of the liquid cooling system concerning a 1st embodiment. 1 is an overall perspective view of a liquid cooling jacket according to a first embodiment. It is a whole perspective view from the lower part of the liquid cooling jacket concerning a 1st embodiment. It is a perspective view of the liquid cooling jacket which concerns on 1st Embodiment, and shows the state which abbreviate | omitted the cover unit. It is a top view of the liquid cooling jacket which concerns on 1st Embodiment. It is XX sectional drawing of the liquid cooling jacket which concerns on 1st Embodiment shown in FIG. It is a disassembled perspective view of the liquid cooling jacket which concerns on 1st Embodiment. It is a graph which shows typically the effect of the liquid cooling jacket concerning a 1st embodiment. It is a whole perspective view of the liquid cooling jacket concerning a 2nd embodiment, and shows the state where a lid unit was omitted. It is YY sectional drawing of the liquid cooling jacket which concerns on 2nd Embodiment shown in FIG. It is a whole perspective view of the liquid cooling jacket which concerns on 3rd Embodiment. It is a top view of the liquid cooling jacket which concerns on 3rd Embodiment. It is a whole perspective view of the liquid cooling jacket concerning a 4th embodiment, and shows the state where a lid unit was omitted. It is ZZ sectional drawing of the liquid cooling jacket which concerns on 4th Embodiment shown in FIG. It is an enlarged view of ZZ sectional drawing shown in FIG. It is a perspective view which shows the 1st preparation method of the fin member of the liquid cooling jacket which concerns on 4th Embodiment, (a) shows before cutting, (b) shows after cutting. It is a perspective view which shows the 2nd production method of the fin member of the liquid cooling jacket which concerns on 4th Embodiment, (a) shows before cutting, (b) shows after cutting. It is a perspective view which shows the friction stir welding which concerns on 4th Embodiment. It is sectional drawing which shows the friction stir welding which concerns on 4th Embodiment. It is a top view which shows the motion of the tool in the friction stir welding which concerns on 4th Embodiment. It is sectional drawing of the liquid cooling jacket which concerns on 5th Embodiment. It is an enlarged view of sectional drawing shown in FIG. It is a figure which shows the preparation methods of the fin member of the liquid cooling jacket which concerns on 5th Embodiment, (a) is during skive processing, (b) shows after skive processing. It is a figure which shows the preparation methods of the fin member of the liquid cooling jacket which concerns on 5th Embodiment, and shows after removing a part of skive fin shown in FIG.23 (b). It is sectional drawing which shows the friction stir welding which concerns on 5th Embodiment. It is sectional drawing of the liquid cooling jacket which concerns on 6th Embodiment, (a) is after an assembly | attachment, (b) shows before an assembly | attachment. It is sectional drawing of the liquid cooling jacket which concerns on 7th Embodiment, (a) is after an assembly | attachment, (b) shows before an assembly | attachment. It is sectional drawing of the liquid cooling jacket which concerns on 8th Embodiment, (a) is after an assembly | attachment, (b) shows before an assembly | attachment. It is a top view of the liquid cooling jacket which concerns on 9th Embodiment. It is a top view of the liquid cooling jacket which concerns on 10th Embodiment. It is a graph which shows the relationship between the number of folding | turns, and thermal resistance. It is sectional drawing of the flat tube bundle which concerns on a modification. It is sectional drawing of the liquid cooling jacket which concerns on a modification, (a) shows after an assembly | attachment, (b) shows before an assembly | attachment. It is sectional drawing of the liquid cooling jacket which concerns on a modification. It is a perspective view of the liquid cooling jacket which concerns on a modification. It is a graph which shows the relationship between groove width W1, thermal resistance, and pressure loss. It is a graph which shows the relationship between the thickness T1 / groove width W1 of a fin, and thermal resistance. It is a graph which shows the relationship between groove width W1 and fin thickness T1 / groove width W1. It is a graph which shows the relationship between the depth D1 of a groove | channel, and thermal resistance. It is a graph which shows the relationship between groove width W1 and groove depth D1.

Explanation of symbols

A1 1st flow path B1 2nd flow path group B1a 2nd flow path C1 3rd flow path J1 Liquid cooling jacket 10 Jacket body 10a Space 10c Space 11 Bottom wall 12 Peripheral wall 15 Stepped portion 20 Flat tube bundle 21 Flat tube 21a Hollow portion 21b Peripheral wall 21c Partition wall 31 Lid body 31a Intake port 31b Outlet port 101 CPU (heat generating body)
200 Tool 201 Pin 202 Shoulder 210 Jig K Friction stir welding part L5 Pin length L6 Distance between the outer peripheral surface of the tool and the outer peripheral surface of the peripheral wall P1 Matching part Q Overlapping part T1 Fin thickness T2 Lid body thickness T11 Perimeter wall thickness W1 Groove width W11 Step width

Claims (14)

A liquid cooling jacket that is attached to a predetermined position and heat generated by the heat generating body is supplied from an external heat transport fluid supply means and is transmitted to the heat transport fluid flowing through the inside,
A first flow path on the heat transport fluid supply means side;
A second flow path group consisting of a plurality of second flow paths branched from the first flow path;
A third flow path for collecting the plurality of second flow paths downstream of the plurality of second flow paths;
Have
Provided with a plurality of metal fins arranged at a predetermined interval, between the adjacent fins is the second flow path,
The width W of the second flow path is 0.2 to 1.1 mm,
The width W of the second flow path and the thickness T of the fin between the adjacent second flow paths satisfy the following formula (1):
−0.375 × W + 0.875 ≦ T / W ≦ −1.875 × W + 3.275 (1)
Furthermore, the depth D and the width W of the second flow path satisfy the following expression (2):
5 × W + 1 ≦ D ≦ 16.25 × W + 2.75 (2)
The liquid cooling jacket, wherein the heat generating body mainly exchanges heat in the second flow path group. A liquid cooling jacket that is attached to a predetermined position and heat generated by the heat generating body is supplied from an external heat transport fluid supply means and is transmitted to the heat transport fluid flowing through the inside,
Toward the downstream side, the first flow path, a plurality of second flow path groups consisting of a plurality of second flow paths, and a third flow path,
Provided with a plurality of metal fins arranged at a predetermined interval, between the adjacent fins is the second flow path,
The width W of the second flow path is 0.2 to 1.1 mm,
The width W of the second flow path and the thickness T of the fin between the adjacent second flow paths satisfy the following formula (1):
−0.375 × W + 0.875 ≦ T / W ≦ −1.875 × W + 3.275 (1)
Furthermore, the depth D and the width W of the second flow path satisfy the following expression (2):
5 × W + 1 ≦ D ≦ 16.25 × W + 2.75 (2)
The heat generating body mainly exchanges heat in the second flow path group,
The adjacent second flow path group is connected in series via a connection flow path. A liquid cooling jacket that is attached to a predetermined position and heat generated by the heat generating body is supplied from an external heat transport fluid supply means and is transmitted to the heat transport fluid flowing through the inside,
Toward the downstream side, the first flow path, a plurality of second flow path groups consisting of a plurality of second flow paths, and a third flow path,
Provided with a plurality of metal fins arranged at a predetermined interval, between the adjacent fins is the second flow path,
The width W of the second flow path is 0.2 to 1.1 mm,
The width W of the second flow path and the thickness T of the fin between the adjacent second flow paths satisfy the following formula (1):
−0.375 × W + 0.875 ≦ T / W ≦ −1.875 × W + 3.275 (1)
Furthermore, the depth D and the width W of the second flow path satisfy the following expression (2):
5 × W + 1 ≦ D ≦ 16.25 × W + 2.75 (2)
The heat generating body mainly exchanges heat in the second flow path group,
Adjacent second flow path groups are arranged side by side, and one downstream end and the other upstream end are on the same side. A fin member including the plurality of metal fins and a base plate on which the plurality of metal fins are erected;
A jacket body that houses the fin member;
With
The liquid cooling jacket according to any one of claims 1 to 3, wherein the base plate is fixed to the jacket main body so as to allow heat exchange. A jacket body having a fin housing chamber for housing the plurality of metal fins;
A sealing body for sealing the fin housing chamber;
With
While the peripheral wall of the jacket body surrounding the fin housing chamber and the sealing body are joined by friction stir welding,
The liquid cooling jacket according to any one of claims 1 to 3, wherein a start end and a terminal end of the friction stir welding overlap each other . The liquid cooling jacket according to claim 5, wherein the plurality of metal fins are erected on the sealing body and are integral with the sealing body. The liquid cooling jacket according to claim 5 or 6, wherein the friction stir welding is performed while applying a jig to the peripheral wall so that the peripheral wall is not deformed to the outside. The liquid cooling according to any one of claims 5 to 7 , wherein a length of a pin of a tool used in the friction stir welding is 60% or less of a thickness of the sealing body. Jacket. The liquid cooling jacket according to any one of claims 5 to 7, wherein in the friction stir welding, a drawing position of the tool is removed from the mating portion. The liquid cooling jacket according to any one of claims 1 to 9, wherein the metal is aluminum or an aluminum alloy. The intake port of the heat transport fluid communicating with the first flow path and the discharge port of the heat transport fluid communicating with the third flow path are disposed symmetrically with respect to the heat generator. The liquid cooling jacket according to any one of claims 1 to 10, wherein the jacket is a liquid cooling jacket. The liquid cooling jacket according to claim 11, wherein the intake port and the discharge port are disposed so as to be relatively distant from each other. The liquid cooling jacket according to claim 11, wherein the intake port and the discharge port are disposed so as to approach the heat generating body. The liquid cooling jacket according to any one of claims 1 to 13, wherein the heat generating body is a CPU.

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