JP6311279B2 - Heat dissipation member, manufacturing method thereof, and structure using heat dissipation member - Google Patents

Description

  The present invention relates to a heat radiating member and a structure, and more particularly to a heat radiating member and a structure that can be used for a heat pipe to which evaporation and condensation of hydraulic fluid are applied, and a method for manufacturing the heat radiating member.

A heat pipe is a fluid that evaporates (absorbs latent heat) in the high-temperature part, condenses (releases latent heat) in the low-temperature part, and circulates in the heat pipe, causing heat transfer from the high-temperature part to the low-temperature part. It is. Utilizing such vaporization (absorption of latent heat) and condensation (release of latent heat) of hydraulic fluid for heat dissipation and heat transport, heat pipes are used for various purposes such as cooling of devices such as CPUs.
In such a heat pipe, efficient circulation of the hydraulic fluid is important, and in order to disperse the condensed hydraulic fluid quickly in the high temperature part in the heat pipe without stagnation in the low temperature part, for example, It has been proposed to arrange the linear body along the inner wall surface (Patent Document 1) or to roughen the inner wall surface of the heat pipe (Patent Document 2).
On the other hand, portable devices typified by PCs and smartphones are becoming more sophisticated year by year, and the amount of heat generated from electronic components tends to increase. In particular, main semiconductor elements that operate portable devices are highly integrated with increasing functionality, and the amount of heat generated is increased. In addition, the amount of electric power required for the operation of the electronic device is also increasing, and the amount of heat generated from the battery is also increasing.

JP-A-5-106976 Japanese Unexamined Patent Publication No. 8-75381

However, in the heat pipe disclosed in Patent Document 1, a part of the hydraulic fluid passes over the striatum and flows down in a streak shape, and does not spread into a liquid film, thereby narrowing the area where the hydraulic fluid evaporates. There was a problem of becoming. Further, even in the heat pipe disclosed in Patent Document 2, when the roughening becomes large, there is a problem that the return of the hydraulic fluid is delayed, and the circulation efficiency of the hydraulic fluid is lowered, and heat exchange is hindered. It was. Moreover, the heat pipe of the structure currently disclosed by patent document 1 and patent document 2 also had the problem that thickness reduction for using for portable apparatuses, such as PC and a smart phone, was difficult.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a heat radiating member, a manufacturing method thereof, and a structure that enable a heat pipe having good circulation due to evaporation and condensation of hydraulic fluid. And

To solve such problems, the heat radiation member of the present invention comprises a substrate, and at least one through-hole penetrating the base material, the inner wall of the pre-Symbol through-holes are roughened and has a plan view shape of the opening of the through hole was to be such a structure in a shape portion which is bent inwardly in an arcuate portion of the sector is present two or more locations.

Another aspect of the present invention, a plurality of the through holes was the direction a so that is arranged by changing the 180 ° alternating structure of the plan view shape of the opening.
As another aspect of the present invention, the roughened inner wall has a configuration in which the surface roughness Ra is in the range of 1 to 3 μm.
As another aspect of the present invention, the roughened inner wall has a surface area ratio in the range of 1.5 to 2.5.
Another aspect of the present invention, the base material, the inner wall is configured so as to have a protrusion protruding into said through hole.

The method for manufacturing a heat radiating member of the present invention includes a step of forming a resist layer having openings in a planar view in which two or more portions bent inwardly exist in a fan-shaped arc portion on both surfaces of the substrate, and the resist layer Etching the base material from both sides via a step, forming a through hole, and applying a roughening treatment to the inner wall of the base material exposed in the through hole with the resist layer left And a step of removing the resist layer.

Another aspect of the present invention, has a configuration so as to form the resist layer as the plan view shape of the opening that faces through the substrate coincident.
Another aspect of the present invention, a plurality of the through hole is configured so as to form the resist layer so that are arranged while changing the direction of the plan view shape of the opening in the 180 ° turn.
As another aspect of the present invention, the roughening treatment is performed so that the surface roughness Ra of the inner wall is in the range of 1 to 3 μm and the surface area ratio is in the range of 1.5 to 2.5. did.

  The structure of the present invention includes a main body having an internal space along the stacking direction in which a plurality of the heat dissipation members of the present invention described above are stacked so that the positions of the through holes coincide with each other. Cover members respectively disposed so as to seal the internal space are provided on the two end faces where the openings are exposed.

As another aspect of the present invention, one of the cover members is configured to have a cooling fin.
As another aspect of the present invention, the heat radiating member has a plurality of through holes, and at least one of the cover members has a flow path for communicating the plurality of internal spaces of the main body with the main body. It was set as the structure which has in the surface side.

In the heat radiating member of the present invention, the inner wall of the base material in the through hole is roughened, and the plan view shape of the opening of the through hole has two or more portions bent inward. Therefore, in the heat pipe or the like manufactured using the heat radiating member, good circulation by evaporation and condensation of the working fluid can be obtained.
The structure of the present invention functions as a heat pipe or the like capable of efficiently radiating heat and transporting heat by encapsulating the working fluid in a sealed space present inside, thereby obtaining good circulation of the working fluid by evaporation and condensation. can do. Further, a thin structure can be formed by setting the size, shape, and number of layers of the heat dissipating member constituting the main body, and it can be used as a heat pipe in a portable device such as a PC or a smartphone.
The manufacturing method of the heat radiating member of the present invention forms through holes in the base material such that the opening shape has two or more portions bent inward, and the inner wall is roughened while the inner wall is roughened. Since the other parts are not roughened, good bonding properties can be obtained when the heat dissipation member is laminated by diffusion bonding.

FIG. 1 is a plan view for explaining an embodiment of a heat radiating member of the present invention. 2 is a longitudinal sectional view taken along line II of the heat dissipating member shown in FIG. FIG. 3 is a plan view for explaining another embodiment of the heat dissipation member of the present invention. FIG. 4 is a partial cross-sectional view for explaining another embodiment of the heat radiating member of the present invention. FIG. 5 is a partial cross-sectional view for explaining an embodiment of the structure of the present invention. FIG. 6 is a partial cross-sectional view for explaining another embodiment of the structure of the present invention. FIG. 7 is a partial cross-sectional view for explaining another embodiment of the structure of the present invention. FIG. 8 is a partial cross-sectional view for explaining another embodiment of the structure of the present invention. FIG. 9 is a process diagram for explaining an embodiment of a method for producing a heat radiating member of the present invention. FIG. 10 is a process diagram for explaining another embodiment of the method for producing a heat radiating member of the present invention. FIG. 11 is a process diagram for explaining another embodiment of the method for manufacturing a heat dissipation member of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Note that the drawings are schematic or conceptual, and the dimensions of each member, the ratio of sizes between the members, etc. are not necessarily the same as the actual ones, and represent the same members. However, in some cases, the dimensions and ratios may be different depending on the drawing.
[Heat dissipation member]
FIG. 1 is a plan view for explaining an embodiment of a heat radiating member of the present invention, and FIG. 2 is a longitudinal sectional view taken along line II of the heat radiating member shown in FIG. 1 and 2, the heat radiating member 11 has a base material 12 and a through hole 14 penetrating the base material 12, and the base material 12 has a roughened inner wall 12 'in the through hole 14. The plan view shape of the opening of the through hole 14 has two or more portions 15 (four in the illustrated example) that are bent inward. In addition, although the number of through-holes 14 penetrating the base material 12 is one in the illustrated example, two or more through-holes 14 may be provided.

The base material 12 constituting the heat radiating member 11 may be a material such as copper, copper alloy, aluminum, aluminum alloy, iron, iron alloy, brass, nickel, nickel alloy, chromium alloy, stainless steel, etc. In particular, any one of copper, copper alloy, aluminum, aluminum alloy and the like is preferable. The thickness of the base material 12 can be set in consideration of the structure produced using the heat dissipation member 11, the structure of a heat pipe, the strength of the material used, the thermal conductivity, and the like. It can set suitably in the range of 500 micrometers.
The rough surface of the inner wall 12 ′ in the through-hole 14 in the substrate 12 preferably has a surface roughness Ra in the range of 1 to 3 μm. The surface roughness Ra can be measured using a contact type surface roughness meter or an optical interference type three-dimensional shape measuring instrument. When the surface roughness Ra is less than 1 μm, the effect of making the inner wall 12 ′ rough is not achieved, and when the surface roughness Ra exceeds 3 μm, condensed hydraulic fluid is required for the inner wall 12 ′ in the through hole 14. There is a possibility that the fluid stays in the above and adversely affects the circulation of the hydraulic fluid.

  The rough surface of the inner wall 12 ′ in the through-hole 14 in the substrate 12 preferably has a surface area ratio in the range of 1.5 to 2.5. The surface area ratio is a ratio of the actually measured surface area including the shape of the surface roughness to the apparent area, and is a parameter called S-Ratio, and is a light interference type three-dimensional shape measuring instrument such as Ryoka System (stock) ) Manufactured by Bartscan R3300H Lite. If the surface area ratio is less than 1.5, the effect of roughening the inner wall 12 'is not achieved. If the surface area ratio exceeds 2.5, condensed hydraulic fluid is required for the inner wall 12' in the through hole 14. There is a possibility that the fluid stays in the above and adversely affects the circulation of the hydraulic fluid.

As described above, the plan view shape of the opening of the through hole 14 constituting the heat radiating member 11 has the inner bent portions 15 at four locations. As described above, the plan view shape of the opening of the through hole 14 has two or more portions bent inward, so that the perimeter of the shape in plan view increases compared to the case where there is no portion bent inward. In addition, the area of the inner wall 12 ′ of the base material 12 in the through hole 14 is increased, and the working fluid is more easily spread. Here, the circumference when there is no part that bends inward is a simple circular shape determined by the remaining part from which the part to be bent is removed, or a circumference in a shape that connects straight lines, for example, It is a circular perimeter as shown by a dotted line in FIG. In the present invention, the peripheral length at the opening of the through hole 14 with the inner bent portion 15 is 1.1 times the peripheral length at the opening of the through hole 14 without the inner bent portion 15. Above, preferably 1.6 times or more is suitable.
There is no particular limitation on the shape of the opening of the through hole 14 having two or more inner bent portions 15. For example, as shown in FIG. The shape may be evenly positioned. In this example, the circumference when the inner bending portion 15 does not exist is a circular circumference as shown by a dotted line. 3B, the inner bent portion 15 may be located in the fan-shaped arc portion. In this example, the plurality of through-holes 14 are alternately oriented 180 ° in plan view. It is arranged while changing. In this example, the circumference when the inner bent portion 15 does not exist is a fan-shaped circumference as indicated by a dotted line in one through hole in the figure. In FIG. 3, the rough surface state of the inner wall 12 ′ of the base 12 is omitted.

When the heat radiating member 11 has a plurality of through holes 14 as in the above example, all the openings in the plan view of the through holes 14 may have the same shape, and the arrangement of the through holes 14 in the heat radiating member 11, etc. Depending on the case, the plan view shape of the opening of the through hole 14 may be set differently.
Moreover, in this invention, as FIG. 4 shows, the wall surface 12 'in the through-hole 14 of the base material 12 may have the protrusion part 13 which protrudes to the through-hole 14. As shown in FIG. In the heat radiating member 11 ′ shown in FIG. 4A, the position of the tip 13 a that protrudes most through the through hole 14 is the depth of the through hole 14 among the protrusions 13 provided on the inner wall 12 ′ of the base material 12. In the middle of the direction. That is, in the depth direction of the through-hole 14, a distance d1 from the tip 13a to the opening in the one surface 12a of the substrate 12 and a distance d2 from the tip 13a to the opening in the other surface 12b of the substrate 12 are It is equal. In the present invention, the position of the tip 13a of the protrusion 13 provided on the inner wall 12 'of the base 12 may be out of the middle of the through hole 14 in the depth direction. That is, in the heat dissipating member 11 ″ shown in FIG. 4B, the distance d1 from the tip 13a to the opening on the one surface 12a of the base 12 is such that the opening on the other surface 12b of the base 12 from the tip 13a. In addition, in the heat dissipating member 11 ″ shown in FIG. 4C, the distance d1 from the tip 13a to the opening on one surface 12a of the substrate 12 is the tip. It is smaller than the distance d2 from 13a to the opening on the other surface 12b of the substrate 12. In this way, the retention of the working fluid can be controlled by appropriately setting the position of the tip 13a of the protrusion 13 provided on the inner wall 12 'of the base material 12. In addition, when the heat radiating member 11 has a plurality of through holes 14, the position of the tip 13a of the protruding portion 13 may be the same in all the through holes, and depending on the arrangement of the through holes 14 in the heat radiating member 11, etc. The position of the tip 13a of the protrusion 13 may be different.

  Thus, by providing the protrusion 13 so that the inner wall 12 ′ of the substrate 12 protrudes into the through hole 14, as shown in FIG. 4A, the tip of the protrusion 13 inside the through hole 14. The opening dimension W in the part where 13a exists is smaller than the opening dimension Wa of the through hole 14 on the surface 12a of the base 12 and the opening dimension Wb of the through hole on the surface 12b of the base 12. The opening dimensions Wa and Wb of the through-hole 14 take into consideration the structure manufactured using the heat radiating member 11, the structure of a heat pipe, the working fluid used, the strength of the material of the base material 12, the thermal conductivity, and the like For example, it can be appropriately set within a range of 50 μm to 2 mm. Moreover, the opening dimension W in the site | part in which said front-end | tip 13a exists can be set so that the difference (Wa-W, Wb-W) with opening dimension Wa and Wb may be set to about 15-200 micrometers. If the difference between the opening dimension W and the opening dimensions Wa and Wb is less than 15 μm, the effect of providing the protruding portion 13 is not achieved, and if it exceeds 200 μm, the condensed hydraulic fluid is more than necessary in the protruding portion 13. There is a possibility that it may stay and adversely affect the circulation of the hydraulic fluid. The above-mentioned measurement of the opening dimensions W, Wa, Wb is a two-dimensional shape measuring instrument that can recognize the outline of the opening using reflected light and transmitted light, for example, a CNC image measuring system NEXI series manufactured by Nikon Corporation. Can be used. When the heat dissipating member 11 has a plurality of through holes 14, the opening dimensions W, Wa, Wb of all the through holes may be the same, and according to the arrangement of the through holes 14 in the heat dissipating member 11, etc. The through-holes 14 may have different opening dimensions W, Wa, Wb.

In the heat radiating member 11 of the present invention, the inner wall 12 ′ of the base material 12 in the through hole 14 is roughened, and the plan view shape of the opening of the through hole 14 has a portion 15 bent inward. Since it has two or more locations, it becomes possible for the hydraulic fluid to stay and spread appropriately on the inner wall 12 ′, and in the structure, heat pipe, etc. produced using the heat radiating member 11, good by evaporation and condensation of the hydraulic fluid. A good circulation.
The above-mentioned embodiment is an illustration and the heat radiating member of this invention is not limited to these embodiment.

[Structure]
FIG. 5 is a partial cross-sectional view for explaining an embodiment of the structure of the present invention. In FIG. 5, the structure 31 is formed by laminating a plurality (four in the illustrated example) of the above-described heat radiation member 11 of the present invention so that the positions of the through holes 14 coincide with each other. A main body 32 having an internal space 34 along the direction indicated by (2), and two end faces 32a and 32b at which the openings of the internal space 34 are exposed in the main body 32 so as to seal the internal space 34, respectively. Cover members 35, 37. In addition, the joining surface of the heat radiating members 11 and the joining surface of the main body 32 and the cover members 35 and 37 are shown by chain lines. The same applies to the following embodiments.
The number of stacked heat dissipating members 11 constituting the main body 32 of the structure 31 can be appropriately set in consideration of the thickness of the heat dissipating member 11, the thickness required for the main body 32, the volume required for the internal space 34, and the like. In addition, lamination | stacking of the thermal radiation member 11 can be performed by diffusion bonding, for example.
The cover members 35 and 37 constituting the structure 31 may be made of copper, copper alloy, aluminum, aluminum alloy, iron, iron alloy, brass, nickel, nickel alloy, chromium alloy, stainless steel, or the like, and conduct heat. In particular, it is preferably any one of copper, copper alloy, aluminum, aluminum alloy and the like, and the same material as the heat radiating member 11 is preferable. In the illustrated example, the cover members 35 and 37 have concave portions 35 a and 37 a at positions corresponding to the internal space 34 of the main body 32, and a sealed space is formed by the concave portions 35 a and 37 a and the internal space 34. . The main body 32 and the cover members 35 and 37 can be joined by diffusion joining, for example. In addition, the inner wall of any one of the recessed parts 35a and 37a may be roughened.

In the illustrated example, the main body 32 is composed of the same heat radiating member 11. For example, the main body 32 is configured by stacking the heat radiating member 11 ′ or the heat radiating member 11 ″ as shown in FIG. 4 described above. Furthermore, the number, position, and shape of the opening in the plan view of the through hole are the same, but a plurality of types of heat dissipating members are different in the position of the tip 13a of the protrusion 13 provided on the inner wall 12 'of the base 12 The main body 32 may be configured by appropriately combining the above.
Moreover, the structure of this invention may have a fin for cooling in one cover member. A structure 31 shown in FIG. 6 includes a cooling fin 36 on the cover member 35. Such a cooling fin 36 may be made of copper, copper alloy, aluminum, aluminum alloy, iron, iron alloy, brass or the like, and is particularly made of copper, copper alloy, aluminum, aluminum alloy from the viewpoint of thermal conductivity. Either of them is preferable, and the same material as the cover member 35 is preferable. The number, shape, thickness, area, and arrangement pitch of the cooling fins 36 can be appropriately set in consideration of the material, the use of the structure, and the like.

In the example of the structure 31 described above, the main body 32 has one internal space 34, but may include two or more internal spaces 34. FIG. 7 is a partial cross-sectional view for explaining an example of such a structure of the present invention. In FIG. 7, a structure 41 is formed by laminating a plurality (four in the illustrated example) of the heat dissipating member 11 of the present invention having a plurality of through holes so that the positions of the through holes coincide with each other. The inner space 44 is sealed to the main body 42 having a plurality of inner spaces 44 along the direction indicated by the arrow a) and the two end faces 42a, 42b at which the openings of the inner space 44 are exposed. Cover members 45 and 47 arranged respectively.
The cover members 45 and 47 constituting the structure 41 have recesses 45a and 47a at positions corresponding to the plurality of internal spaces 44 of the main body 42, and a sealed space composed of the recesses 45a and 47a and the internal space 44. A plurality of are formed. The main body 42 and the cover members 45 and 47 can be joined by, for example, diffusion joining. The material of the cover members 45 and 47 can be the same as that of the cover members 35 and 37 described above. One cover member, for example, the cover member 45 may have cooling fins.

FIG. 8 is a partial cross-sectional view for explaining another embodiment of the structure of the present invention. In FIG. 8, the structure 51 is formed by laminating a plurality (four in the illustrated example) of the heat dissipating member 11 of the present invention having a plurality of through holes so that the positions of the through holes coincide with each other. The main body 52 having a plurality of internal spaces 54 along the direction indicated by the arrow a) and the two end faces 52a, 52b at which the openings of the internal space 54 are exposed in the main body 52 are sealed. Cover members 55 and 57 arranged respectively.
The cover members 55 and 57 constituting the structure 51 have flow paths 55A and 57A for communicating with the plurality of internal spaces 54 of the main body 52 on the contact surface side with the end surfaces 52a and 52b of the main body 52. ing. That is, the cover members 55 and 57 have a structure in which the lid portions 55b and 57b are joined to the base portions 55a and 57a having shapes corresponding to the end faces 52a and 52b of the main body 52 via the pillar portions 55c and 57c. Channels 55A and 57A are configured between 57a and lid portions 55b and 57b. As a result, a sealed space including the flow paths 55A and 57A and the plurality of internal spaces 54 is formed, and the internal spaces 54 are in communication with each other via the flow paths 55A and 57A.

Such joining of the main body 52 and the cover members 55 and 57 can be performed by diffusion joining, for example. The material of the cover members 55 and 57 can be the same as that of the cover members 35 and 37 described above. Further, one cover member, for example, the cover member 55 may have a cooling fin.
Such a structure of the present invention is a heat pipe which can efficiently radiate heat and transport heat by enclosing the working fluid in a sealed space existing inside, thereby obtaining good circulation of the working fluid by evaporation and condensation. And so on. Further, a thin structure can be formed by setting the size, shape, and number of layers of the heat dissipating member constituting the main body, and it can be used as a heat pipe in a portable device such as a PC or a smartphone.
The above-described embodiments are examples, and the structure of the present invention is not limited to these embodiments.

[Method of manufacturing heat dissipation member]
FIG. 9 is a process diagram for explaining an embodiment of a method for producing a heat radiating member of the present invention. In FIG. 9, the production of the above-described heat radiation member 11 of the present invention will be described as an example.
In the manufacturing method of the present invention, resist layers 21 and 22 having desired openings 21a and 22a are formed on both surfaces 12a and 12b of the substrate 12 (FIG. 9A). The openings 21a and 22a in plan view have two or more portions bent inward. Further, in the present invention, the circumferential lengths of the openings 21a and 22a in the case of having the inwardly bent portions are different from the peripheral lengths of the openings 21a and 22a in the case of not having the inwardly bent portions. It is suitable that it is 1 time or more, preferably 1.6 times or more.
As described above, the base material 12 may be made of copper, copper alloy, aluminum, aluminum alloy, iron, iron alloy, brass or the like.
The resist layers 21 and 22 can be formed, for example, by applying a photosensitive resist on the substrate 12, exposing through a desired mask, and developing. Alternatively, it can be formed by laminating a photosensitive dry film on the substrate 12, and then exposing and developing through a desired mask. The resist layers 21 and 22 are formed so that the planar views of the openings 21 a and 22 a that are opposed to each other with the base material 12 in between match.

Next, the base material 12 is simultaneously etched from both sides through the resist layers 21 and 22 to form the through holes 14 (FIG. 9B). In the illustrated example, the inner wall 12 ′ in the through hole 14 is substantially straight and does not have a protruding portion that protrudes into the through hole 14. When the through hole 14 having such a shape is formed, it is preferable that the substrate 12 is etched by a spray method, and a high concentration etching solution kept at a high temperature is sprayed at a relatively high pressure. For example, cupric chloride, ferric chloride, etc. are used as the etching solution, these are adjusted to a concentration of about 35 to 45 Baume, and the temperature of the solution is set in the range of 45 to 55 ° C., and 4 kg / cm. ^The substrate 12 can be sprayed at a pressure of ² or more.
Next, with the resist layers 21 and 22 left, a roughening process is performed on the inner wall 12 ′ of the substrate 12 exposed in the through hole 14 (FIG. 9C). In this roughening treatment, a treatment liquid according to the material of the base material 12, for example, when the base material 12 is copper, a treatment liquid such as MEC etch bond CZ series manufactured by MEC Co., Ltd. can be used. When the substrate 12 is aluminum, a processing solution such as Mec Almat AR series manufactured by Mec Co., Ltd. can be used. Thus, by performing the roughening treatment without removing the resist layers 21 and 22, the both surfaces 12a and 12b of the substrate 12 can be protected. When the members are laminated by diffusion bonding, good bondability is obtained.
Thereafter, the resist layers 21 and 22 are removed to obtain the heat dissipating member 11 of the present invention (FIG. 9D).

FIG. 10 is a process diagram for explaining another embodiment of the method for producing a heat radiating member of the present invention. In FIG. 10, the production of the heat radiating member 11 ′ (see FIG. 4A) of the present invention will be described as an example.
In the manufacturing method of the present invention, resist layers 21 and 22 having desired openings 21a and 22a are formed on both surfaces 12a and 12b of the substrate 12 (FIG. 10A). The formation of the resist layers 21 and 22 can be the same as the above-described manufacturing method.
Next, the base material 12 is simultaneously etched from both sides through the resist layers 21 and 22 to form the through holes 14 (FIG. 10B). The substrate 12 is etched by wet etching such as a dipping method or a spray method. In the etching by the spray method, a high-temperature, high-concentration etching solution and high-pressure spray as in the etching by the above manufacturing method (see FIG. 9B) are unnecessary.
Thereafter, as in the above-described embodiment, the inner wall 12 ′ of the base material 12 exposed in the through hole 14 is subjected to a roughening process (see FIG. 9C), and then the resist layers 21 and 22 are formed. By removing, the heat radiating member 11 ′ of the present invention is obtained (see FIGS. 9D and 4A).

Moreover, FIG. 11 is process drawing for demonstrating other embodiment of the manufacturing method of the thermal radiation member of this invention. Also in FIG. 11, the production of the heat radiating member 11 ′ of the present invention described above (see FIG. 4A) will be described as an example.
In the manufacturing method of the present invention, the resist layers 21 and 22 having desired openings 21 a and 22 a are formed on both surfaces 12 a and 12 b of the substrate 12, and then the surface of the substrate 12 is covered with the resist layer 22. An etching barrier layer 23 is formed on 12b (FIG. 11A). The formation of the resist layers 21 and 22 can be the same as the above-described manufacturing method. The etching barrier layer 23 has a barrier property against the etching process of the base material 12 in a subsequent process, and can be formed of a material that can be removed while the resist layer 22 remains, for example, EC series manufactured by Sumilon Co., Ltd. Etc. can be used.
Next, the hole 14a is formed by etching from the surface 12a side of the substrate 12 to a desired depth through one resist layer 21 (FIG. 11B). The substrate 12 is etched by wet etching such as a dipping method or a spray method. In the etching by the spray method, a high-temperature, high-concentration etching solution and high-pressure spray as in the etching by the above manufacturing method (see FIG. 9B) are unnecessary.

Next, the etching barrier layer 24 is formed so as to cover the resist layer 21 on the surface 12a of the substrate 12 in which the hole 14a is formed, and the etching barrier layer 23 formed on the surface 12b of the substrate 12 is removed. The resist layer 22 is exposed. The etching barrier layer 24 can be the same as the etching barrier layer 23 described above.
Next, etching is performed from the surface 12b side of the substrate 12 through the resist layer 22, and etching is performed until the etching barrier layer 24 is exposed in a desired range to form the hole 14b (FIG. 11C). Etching of the base material 12 can also be wet etching such as a dipping method or a spray method. In the etching by the spray method, a high temperature and high temperature as in the etching by the above manufacturing method (see FIG. 9B). Concentration etchant and high-pressure spray are not required. In this etching, since the etching barrier layer 24 exists in the hole 14a formed in the previous step, the etching liquid is prevented from entering the hole 14a.

Next, by removing the etching barrier layer 24, the through hole 14 in which the hole 14a and the hole 14b communicate with each other is obtained, and the inner wall 12 ′ of the base material 12 thus etched is penetrated. A protruding portion 13 protruding into the hole 14 is formed (FIG. 11D). As described above, in the formation of the hole 14b, the etching liquid is prevented from entering the hole 14a, so that the etching that rounds the tip 13a is suppressed, whereby the tip 13a of the protrusion 13 is prevented. Becomes a sharp shape. Further, the position of the tip 13a of the protruding portion 13 in the depth direction of the through hole 14 can be controlled by adjusting the formation depth of the hole portion 14a.
Thereafter, as in the above-described embodiment, the inner wall 12 ′ of the base material 12 exposed in the through hole 14 is subjected to a roughening process (see FIG. 9C), and then the resist layers 21 and 22 are formed. By removing, the heat radiating member 11 ′ of the present invention is obtained (see FIGS. 9D and 4A).

The manufacturing method of the heat radiating member of the present invention is such that through holes having two or more portions where the opening shape is bent inward are formed in the base material, and the inner wall is roughened, Since the surface roughening treatment is not performed on the other part of the base material, good bondability can be obtained when the heat dissipation member is laminated by diffusion bonding.
The above-mentioned embodiment is an illustration and the manufacturing method of the heat radiating member of this invention is not limited to these embodiment.

Next, the present invention will be described in more detail by showing specific examples.
(Preparation of sample 1)
An oxygen-free copper base material (300 mm × 300 mm) having a thickness of 150 μm was prepared.
After laminating a photosensitive dry film (AQ-2558 manufactured by Asahi Kasei Co., Ltd.) on both surfaces of this substrate, the resist layer was formed by exposing through a desired mask and developing. The formed resist layer has 40000 openings having a shape having four inner bent portions as shown in FIG. 1 in a circle having a diameter of 200 μm so as to be positioned at each intersection of the lattice shape at a pitch of 500 μm. there were. Moreover, the opening part of each resist layer existed in the position which opposes through a base material. In addition, the circumference in the opening part which has an inner side bending part in four places was 1.6 times with respect to the circumference in the circle of diameter 200 micrometers.

Next, a ferric chloride solution (40 Baume) is used as an etchant, and the substrate is simultaneously etched from both sides through a resist layer by spray etching at a liquid temperature of 55 ° C. and a pressure of 4 kg / cm ^2. Through holes were formed.
Next, with the resist layer left, the inner wall of the base material exposed in the through hole was roughened. As the surface roughening treatment solution, Mec Etch Bond CZ manufactured by Mec Co., Ltd. was used.
Thereafter, the resist layer was removed using an aqueous 3% sodium hydroxide solution at a temperature of 50 ° C. to obtain a heat radiating member (sample 1).
About the rough surface of the inner wall of the base material exposed to the through hole of the manufactured heat radiating member (sample 1), the surface roughness Ra was measured using an optical interference type three-dimensional shape measuring instrument (Bartscan R3300H Lite manufactured by Ryoka System Co., Ltd.). ) To be 2 μm. Moreover, as a result of measuring the surface area ratio in the rough surface of the inner wall using the above-described optical interference type three-dimensional shape measuring instrument, the surface area ratio was 2.

(Preparation of sample 2)
The mask used for forming the resist layer was changed to form a resist layer having an opening having a shape having two inner bent portions in a circle having a diameter of 200 μm. Sample 2 was prepared. In addition, the circumference in the opening part which has an inner side bending part in two places was 1.2 times with respect to the circumference in the circle | round | yen 200 micrometers in diameter.

(Preparation of sample 3)
In addition to changing the mask used when forming the resist layer, a resist layer having openings having a shape having eight inner bent portions in a circle having a diameter of 200 μm as shown in FIG. Produced Sample 3 in the same manner as Sample 1 described above. In addition, the circumference in the opening part which has an inner side bending part in two places was 2.0 time with respect to the circumference in the circle of diameter 200 micrometers.
(Preparation of sample 4)
Sample 4 was prepared in the same manner as Sample 1 above, except that the mask used for forming the resist layer was changed to form a resist layer having a circular opening with a diameter of 200 μm.

(Preparation of Sample 5 to Sample 8)
Surface roughness Ra, surface area ratio of the inner wall rough surface of the base material is changed by changing the conditions (temperature of the processing solution and processing time) when the inner surface of the base material exposed to the through hole is roughened. The four types of heat dissipating members (Sample 5 to Sample 8) were prepared in the same manner as Sample 1 except that the value was as shown in Table 1 below.

(Preparation of sample 9)
A ferric chloride solution (40 Baume) is used as the etching solution, and the substrate temperature is simultaneously etched from both sides through the resist layer by spray etching at 55 ° C. and a pressure of 1 kg / cm ^2. A heat radiating member (Sample 9) was produced in the same manner as Sample 1 described above except that was formed. A protrusion that protrudes into the through hole is formed on the inner wall of the base material exposed in the through hole of the heat radiating member (sample 9), and the position of the tip of the protrusion is in the depth direction of the through hole. It was in the middle.
(Preparation of sample 10)
A heat radiating member (sample 10) was produced in the same manner as the sample 1 except that the inner wall of the base material exposed in the through hole was not roughened.

(Evaluation)
Ten types of structures for evaluation were produced using the heat radiating members of Sample 1 to Sample 10. That is, 20 heat dissipating members are processed into dimensions that match the size of the following measurement block, these are stacked so that the positions of the through holes coincide with each other, and integrated by diffusion bonding to produce a main body. A cover member is joined to one end surface of the main body by diffusion bonding, pure water is injected as working fluid into the internal space of the main body, and a cover member is immediately bonded to the other end surface of the main body by diffusion bonding to seal the inner space. And it was set as the structure for evaluation.
Next, a copper measuring block of 100 mm × 100 mm and a height of 20 mm is prepared, the entire block is uniformly heated to 60 ° C., the periphery excluding the upper surface is covered with a heat insulating material, and the exposed upper surface is a structure for evaluation. One cover member side of the body was fixed with a heat conductive adhesive, left in the atmosphere at 20 ° C., and the temperature of the block after 3 minutes was measured. The results are shown in Table 1 below. The block temperature is the temperature at the center of gravity of the block, and was measured by installing a thermocouple in the measurement hole.

Sample 1 to Sample 4 change the circumference of the opening of the through hole without changing the surface roughness and the surface area ratio of the inner wall of the through hole (the circumference of the opening relative to the circumference when there is no inner bending portion) This is the result of testing the heat dissipation effect by displaying the magnification. As the perimeter of the opening of the through-hole increases, that is, as the above-mentioned magnification increases, it is confirmed that the heat dissipation effect for lowering the block temperature is improved, and the magnification of the perimeter of the opening of the sample 4 is 1 time. In this case, it was confirmed that the heat dissipation effect was small.
Samples 5 to 10 are the results of testing the heat dissipation effect by changing the surface roughness and surface area ratio of the inner wall of the through hole without changing the peripheral length of the opening of the through hole. Sample 9 is an example having a protruding portion inside the through hole, and sample 10 is an example in which the inner wall of the through hole is not roughened. Sample 5 (surface roughness Ra is 1 μm, surface area ratio is 1.5) having a slightly roughened surface and sample 6 (surface roughness Ra is 3 μm, surface area ratio is 2) having a slightly roughened surface. .5) had a large and sufficient heat dissipation effect to lower the block temperature. However, the sample 10 in which the inner wall of the through hole was not roughened, or the sample 7 with a small degree of roughening (surface roughness Ra is 0.5 μm, surface area ratio is 1) is a heat dissipation effect that lowers the block temperature. Was small. On the other hand, the heat radiation effect of sample 8 (surface roughness Ra is 4 μm, surface area ratio 3) having a larger degree of roughening is lower than that of sample 6, surface roughness Ra is 3 μm, and surface area ratio exceeds 2.5. It was confirmed that the heat dissipation effect could not be enhanced even with such surface treatment.
Sample 9 has a protruding portion formed in the cross section of the etched through hole, and a higher heat dissipation effect is obtained than Sample 1 having no protruding portion inside the through hole, and the protruding portion is provided in the cross section of the through hole. It was confirmed that the heat dissipation effect was improved.

  It can be used to manufacture various devices and equipment that require heat dissipation and heat transport.

DESCRIPTION OF SYMBOLS 11, 11 ', 11 "... Radiation member 12 ... Base material 12' ... Inner wall 13 ... Protrusion part 13a ... Tip of protrusion part 14 ... Through-hole 15 ... Inner bending part 31, 41, 51 ... Structure 32, 42, 52 ... Main body 34, 44, 54 ... Internal space 35, 37, 45, 47, 55, 57 ... Cover member 36 ... Cooling fins 55A, 57A ... Flow path

Claims (13)

A substrate and at least one through-hole penetrating the substrate;
The inner wall of the front Symbol through hole are roughened,
The plan view shape of the opening of the through hole, the heat radiating member, characterized in that part that bends inwardly arc portion of the sector is shaped to present more than two places. Radiating member according to claim 1 a plurality of said through holes, characterized by Rukoto the orientation of the plan view shape of the opening is arranged by changing the 180 ° turn.   The heat radiating member according to claim 1 or 2, wherein the roughened inner wall has a surface roughness Ra in a range of 1 to 3 µm.   The heat radiating member according to claim 1, wherein the roughened inner wall has a surface area ratio in a range of 1.5 to 2.5. The substrate, the heat radiating member according to any one of claims 1 to 4 wherein the inner wall and having a projection projecting into the through-hole. Forming a resist layer on both sides of the base material having openings in a planar view in which there are two or more portions that are bent inwardly in a fan-shaped arc portion ;
Etching the substrate from both sides through the resist layer to form a through hole;
Applying a roughening treatment to the inner wall of the base material exposed in the through-hole with the resist layer left;
And a step of removing the resist layer.   The method of manufacturing a heat radiating member according to claim 6, wherein the etching of the base material is spray etching using a high-viscosity etching solution maintained at a high temperature. Method for producing a heat radiation member according to claim 6 or claim 7, characterized in that to form the resist layer as the plan view shape of the opening that faces through the substrate coincident. According to any one of claims 6 to 8 a plurality of said through holes and forming the resist layer so that are arranged while changing the direction of the plan view shape of the opening to 180 ° alternately Manufacturing method of heat dissipation member.   10. The surface roughening treatment is performed so that the surface roughness Ra of the inner wall is in a range of 1 to 3 [mu] m and a surface area ratio is in a range of 1.5 to 2.5. The manufacturing method of the heat radiating member in any one of. The heat radiating member according to any one of claims 1 to 5, made by stacking a plurality of such positions of the through hole coincides, a body having an internal space along the stacking direction,
And a cover member disposed on each of the two end faces of the main body where the opening of the internal space is exposed to seal the internal space.   The structure according to claim 11, wherein one of the cover members has a cooling fin.   The heat dissipation member has a plurality of through holes, and at least one of the cover members has a flow path on the contact surface side with the main body for communicating with the plurality of internal spaces of the main body. The structure according to claim 11 or claim 12.

Images