Heat sink and method for manufacturing the same

Abstract

The present invention provides a heat spreader and a method for manufacturing the same for efficiently dissipating heat from heat-generating electronic components mounted on a thin, high-density electronic circuit board. The electronic components and the heat spreader are connected via a circuit board heat dissipation path formed on the electronic circuit board to efficiently dissipate heat. The circuit board heat dissipation path and the heat spreader are integrated without connecting materials. The heat is further efficiently dissipated by roughening the concave surface of the enclosed space constituting the heat spreader. In addition, by using an etching stop layer, a thin heat spreader with high productivity and stable quality and good heat dissipation efficiency can be provided.

Description

Technical Field

[0001] The invention relates to a thin heat spreader and a method for manufacturing the same. Background Art

[0002] In the past, the general method of heat dissipation for semiconductors was to use a high thermal conductivity paste or solder as a patch material on the back of the semiconductor and guide it to a heat conductor such as a cold plate or a heat spreader. Another method is to form a thermal via on the active surface of the semiconductor and guide it to the heat conductor through an electronic circuit substrate by soldering. In recent years, mobile devices, centered on smartphones, have sought to be further miniaturized and thin. In addition, the heat generation problem associated with the large-scale transmission and high-speed of semiconductor signals has surfaced, and various heat dissipation countermeasures for semiconductors have been studied.

[0003] In mobile devices such as smartphones, the thickness of the installation is limited, and graphite sheets are used as a heat dissipation countermeasure for semiconductors. Furthermore, in order to improve the heat dissipation capacity of semiconductors in smartphones, the introduction of heat spreaders has also been discussed. However, in smartphones, since the thickness of the shell is restricted, the thickness of the heat spreader is required to be less than 0.3 mm, and the use of heat spreaders less than 0.3 mm has not yet been realized (Non-Patent Document 1).

[0004] The vapor chamber is a planar heat dissipation device that utilizes the principle of a heat pipe and is a radiator that dissipates heat. The interior of the vapor chamber is a closed space that is decompressed and contains a working fluid that is used to move heat. If the working fluid is heated by a heat source, the working fluid absorbs latent heat and evaporates. The evaporated steam diffuses in the closed space, and if it reaches the upper inner wall surface that is connected to the heat sink, it releases the latent heat and returns to the liquid. A structure called a capillary wick that generates capillary force is arranged on the inner wall or in the closed space of the vapor chamber, and the working fluid that returns to the liquid moves through the capillary phenomenon. The capillary wick is shaped to guide the working fluid toward the heat source, and the working fluid that moves toward the heat source absorbs heat again and evaporates, repeating this cycle. In this way, the heat generated from a small heat source can be diffused to a large area.

[0005] Since the heat spreader dissipates heat by circulating the working fluid, the structural design of the capillary wick has a great influence on the performance of the heat spreader. The prior art related to the heat spreader includes the following technologies. For example, Patent Document 1 describes a heat spreader that forms a capillary flow path by stacking multiple intermediate plates in a closed space. The structure is as follows: fine holes are set in each intermediate plate as a flow path, and the working fluid is guided to the heat source through the capillary phenomenon.

[0006] In addition, Patent Document 2 describes a heat sink having protrusions (fins) provided on the upper and lower sides in a closed space. This heat sink has a feature that a capillary wick integrated with a metal plate can be formed by grinding the metal plate.

[0007] In addition, Patent Document 3 describes a heat spreader having a capillary wick formed by thermally spraying molten copper powder on an aluminum shell. Since the capillary wick is formed by thermal spraying, the heat spreader has the characteristic of not having to go through the process of forming a fine structure compared to the above-mentioned scheme.

[0008] Patent Document 4 discloses a heat spreader in which a housing formed of a resin material and having a space for circulating a working fluid and a capillary wick formed integrally with the housing are coated with metal by metal plating.

[0009] Patent Document 5 describes that a space for circulating a working fluid can be formed by etching or pressing. The capillary wicks of these heat spreaders have different structures, but they are all formed to direct the working fluid toward the heat source.

[0010] Prior Art Literature

[0011] Patent Literature

[0012] Patent Document 1: JP Patent Publication No. 2010-28055

[0013] Patent Document 2: JP Patent Publication No. 2007-3164

[0014] Patent Document 3: JP Patent Publication No. 2011-102691

[0015] Patent Document 4: JP Patent Publication No. 2015-10765

[0016] Patent Document 5: JP Patent No. 6151813

[0017] Non-patent document 1: Is it possible to use a heat spreader for mobile terminals in Apple iPhone to improve thermal conductivity and introduce a cooling system with good efficiency? May 25.2017 Correiente.Top Summary of the invention

[0018] Problems to be solved by the invention

[0019] Due to the high functionality and miniaturization of semiconductors, the heat generation of semiconductor chips has become a problem, and a more efficient and good heat dissipation method for heat-generating semiconductors is needed. That is, as mentioned above, the current situation mainly uses a method of releasing heat from the back side of the semiconductor (the opposite side of the active surface). It is often used to connect the thermal conductor and the heat sink to the back side of the semiconductor via bonding materials such as heat dissipation grease, silver paste, and solder. However, in the above method, the heat transfer resistance will increase due to the distance from the component to the heat sink and the thermal conductivity of the bonding material, so a more efficient heat dissipation mechanism is sought.

[0020] Furthermore, silicon is the main component material of semiconductors at present, but silicon carbide is receiving much attention in the next generation of semiconductor component materials. Compared with silicon, silicon carbide can operate at a higher temperature, so it can improve the efficiency of heat dissipation compared with semiconductors made of silicon. In addition, as a heat dissipation method for components, in order to dissipate heat efficiently, heat is also dissipated from the active surface of the semiconductor component close to the heat source. There is a solution to dissipate heat efficiently through a circuit board heat dissipation path formed on an electronic circuit board and using a connecting material to dissipate heat efficiently to a heat conductor or a heat sink.

[0021] Here, the circuit board heat dissipation path refers to a heat dissipation path with good heat conduction, such as thermal vias, metal pillars, and circuit wiring formed on the electronic circuit board, which is used to dissipate the heat of the semiconductor to the heat spreader through the electronic circuit board. The method of using the circuit board heat dissipation path will generate heat transfer resistance due to the distance between the component and the heat sink and the thermal conductivity of the bonding material, so a more efficient heat dissipation method is sought.

[0022] In particular, when considering mobile devices such as smartphones, which have a limited thickness, as mentioned above, in addition to the issue of heat dissipation efficiency, thinning has also become a major issue. Although heat dissipation using a vapor chamber is excellent in cooling efficiency, it cannot currently achieve the thinness required for smartphones. In order to use a vapor chamber for cooling the internal components of a smartphone, the vapor chamber needs to be thinned. In fact, it is necessary to make the total thickness of a smartphone, which is equipped with heat-generating components (such as application processors, power elements), electronic circuit boards, and vapor chambers, thin. At present, there is a limit to thinning because the vapor chamber and the electronic circuit board are made separately and glued together.

[0023] In addition, it is difficult to form a circuit board heat dissipation path such as thermal vias that release heat efficiently from the heat-generating components by separately manufacturing the heat spreader and the electronic circuit board. The circuit board heat dissipation path is a structure that conducts the heat of the heating element to the heat spreader through the electrodes of the heating element and the electronic circuit board, and the thermal resistance needs to be small. For example, in the case where the circuit board heat dissipation path is a thermal via, although the heat transfer resistance is affected by the thermal conductivity, cross-sectional area, and distance of the metal of the thermal via, the thermal conduction of the material connecting the electronic circuit board and the heat spreader also becomes a major factor in determining the heat dissipation efficiency. If an organic substance such as an adhesive exists between the electronic circuit board and the heat spreader, the heat transfer resistance will increase, and even an adhesive with high thermal conductivity cannot ignore the increase in heat transfer resistance.

[0024] In addition, the closed space and the capillary wick of the heat spreader are made as described above, and the capillary wick is formed by other methods after the space is made. The process of forming the capillary wick is complicated. In addition, the heat generating components, electronic circuit boards and heat spreaders are generally made as single pieces, and the productivity during installation is low. At present, the thermal vias of the electronic circuit board and the heat spreader are joined with a bonding material, so the heat transfer resistance of the bonding material is large, the thickness of the electronic circuit board and the heat spreader combined becomes thicker, and the processing difficulty caused by the heating of solder etc. has become a problem. Since the heat spreader has good heat conduction, the heat dissipation is good, and the solder etc. is a cooling block during soldering, so the joining processing based on solder etc. is not easy. In addition, when manufacturing the heat spreader, it is desired to achieve a processing method that can achieve thinness, good dimensional accuracy, and good efficiency.

[0025] Means for solving problems

[0026] The heat spreader involved in the invention of the present application comprises: a first component comprising metal; and a second component comprising metal that forms a closed space for enclosing a working fluid together with the first component. The heat spreader is characterized in that the first component or the second component, or the first component and the second component have a recess formed by etching, and the surface of the recess formed by the etching has a fine roughened surface.

[0027] In the heat spreader according to the present invention, preferably, the first member or the second member, or both the first member and the second member, has an electronic circuit board on a surface opposite to a surface forming the sealed space.

[0028] In the heat spreader according to the present invention, preferably, the electronic circuit board has a circuit board heat dissipation path.

[0029] In the heat spreader according to the present invention, preferably, metal is filled inside via holes of the circuit board heat dissipation path formed in a cross-sectional direction of the electronic circuit board.

[0030] In the heat spreader according to the present invention, preferably, at least one of the circuit board heat dissipation paths is in contact with an electronic component connected to the electronic circuit board.

[0031] In the heat spreader according to the present invention, preferably, the etched surface includes an etching stopper layer below the etched layer.

[0032] In the heat spreader according to the present invention, preferably, the etching stop layer is not provided in a part of the etching stop layer, and a surface formed by the etching in the part without the etching stop layer has a finely roughened surface.

[0033] The manufacturing method of the heat spreader involved in the present invention forms a closed space for enclosing a working fluid by joining a first component comprising a metal and a second component comprising a metal. The manufacturing method of the heat spreader is characterized in that a recess is formed by etching the first component or the second component, or the first component and the second component, and the recess forms the closed space, and the surface of the recess is set to a fine roughened surface.

[0034] In the method for manufacturing a heat spreader according to the present invention, preferably, the first member or the second member, or both the first member and the second member, has an electronic circuit board disposed on a surface opposite to a surface forming the enclosed space.

[0035] In the method for manufacturing a vapor chamber according to the present invention, preferably, a circuit board heat dissipation path is provided on the electronic circuit board.

[0036] In the method for manufacturing a vapor chamber according to the present invention, preferably, the circuit board heat dissipation path is provided by forming a via hole in a cross-sectional direction of the electronic circuit board and filling the via hole with metal.

[0037] In the method for manufacturing a vapor chamber according to the present invention, preferably, at least one of the circuit board heat dissipation paths is brought into contact with an electronic component connected to the electronic circuit board.

[0038] In the method for manufacturing a heat spreader according to the present invention, preferably, an etching stopper layer is provided on the lower side of the etched layer on the etched surface.

[0039] In addition, in the manufacturing method of the heat spreader involved in the present invention, suitably, the etching stop layer is not provided on a part of the etching stop layer, the layer in contact with the etching stop layer is removed by the etching, an opening is provided in the etching stop layer, and a fine roughened surface is formed on the opening surface by the etching.

[0040] Effects of the Invention

[0041] According to the present invention, a heat spreader can be provided that can efficiently dissipate heat from an electronic circuit board on which heat-generating electronic components are mounted. In addition, the manufacturing method of the heat spreader of the present invention can achieve thinning and can manufacture the heat spreader with good dimensional accuracy and good efficiency.

[0042] The heat spreader obtained by the present invention can dissipate heat within a device with limited space, and therefore is used in the heat dissipation of devices having heat-generating components such as LED-using devices, high-frequency devices, IGBTs, and MOSFETs, including mobile devices represented by smartphones. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1The following are diagrams of a heat spreader according to an embodiment of the present invention. (A) shows a cross-sectional structural example of a heat spreader according to an embodiment of the present invention, and (B) shows a cross-sectional structural example of a heat spreader according to another embodiment of the present invention.

[0044] Figure 2 A method for forming an electronic circuit board of a heat spreader involved in an embodiment of the present invention is shown, (C) indicates a first component, (D) indicates a state in which an insulating member and copper foil are formed on the first component, (E) indicates a state in which vias are formed in the insulating member and copper foil formed on the first component and the formed vias are plated, (F) indicates a state in which an electronic circuit board is continuously formed on the first component, and (G) indicates a state in which an electronic circuit board is formed on the first component involved in the embodiment of the present invention.

[0045] Figure 3 The method for forming a closed space involved in embodiment 1 of the present invention is shown, (H) a state in which a resist layer is formed on the opposite side of the first component forming the electronic circuit board, on which the electronic circuit board is formed; (I) a state in which the opposite side of the first component forming the electronic circuit board, on which the electronic circuit board is formed, is etched; (J) a state in which the resist on the opposite side of the first component forming the electronic circuit board, on which the electronic circuit board is formed, is removed to form a recess; (K) a state in which a bonding material is formed on the opposite side of the first component forming the electronic circuit board, on which the electronic circuit board is formed; (L) a state in which the first component in which the recess is formed on the opposite side of the first component forming the electronic circuit board, is bonded to the second component to form a closed space.

[0046] Figure 4 The cross section of a heat spreader involved in an embodiment of the present invention of the present invention with electronic components installed is shown, (M) shows a cross section in which an electronic circuit board is formed on the heat spreader and electronic components are installed on the formed electronic circuit board, and (N) shows a cross section in which an electronic circuit board is formed on another heat spreader and electronic components are installed on the formed electronic circuit board.

[0047] Figure 5 A method for forming a closed space of a heat spreader according to embodiment 2 of the present invention is shown, wherein (O) shows a cross-sectional structure of a first component having an etching stop layer, (P) shows a state in which an etching mask is formed on the first component having the etching stop layer, (Q) shows a state in which the first component having the etching stop layer is etched, and (R) shows a state in which a recess is formed on the first component having the etching stop layer.

[0048] Figure 6A method for forming a closed space of a heat spreader involved in embodiment 3 of the present invention is shown, (S) shows a state in which an etching stop layer is provided on a portion of the first component where no etching stop layer is provided, (T) shows a plane in a state in which the first component in which the etching stop layer is provided on a portion where no etching stop layer is provided is etched, (U) shows a cross-section in a state in which the first component in which the etching stop layer is provided on a portion where no etching stop layer is provided is etched, and (V) shows an enlarged cross-section of the portion in which the first component in which the etching stop layer is provided on a portion where no etching stop layer is provided is etched.

[0049] Figure 7 A method for forming a closed space of a heat spreader involved in embodiment 4 involved in an embodiment of the present invention is shown, (W) indicates a first component in which an etching stop layer is provided on a portion of the first component without an etching stop layer, and further an etching stop layer is provided on a lower portion of a metal layer of the first component, (X) indicates an enlarged cross-section of a portion of the first component in which no etching stop layer is provided, after etching the first component in which an etching stop layer is provided on a portion of the first component without an etching stop layer, and further an etching stop layer is provided on a lower portion of the metal layer of the first component, and (Y) indicates a state in which the etching stop layer in (X) is removed.

[0050] Figure 8 The heat spreader according to the embodiment of the present invention is a cross-sectional view showing a state in which a first member and a second member having an etching stopper layer are etched and the formed concave surfaces are bonded to each other to form a closed space. DETAILED DESCRIPTION

[0051] The present invention relates to a heat spreader for rapidly dissipating heat generated in an electronic component such as a semiconductor mounted on an electronic circuit board, and a method for manufacturing the heat spreader.

[0052] In order to rapidly vaporize and liquefy the working fluid in the vapor chamber, the vapor chamber of the present invention is characterized in that the surface of the enclosed space forming the vapor chamber is roughened. As a result, the vapor chamber involved in the present invention can efficiently absorb and dissipate heat. In addition, in the present invention, what hinders the heat dissipation of the electronic components is the electronic circuit board and bonding materials between the electronic components and the vapor chamber, and the feature is that a circuit board heat dissipation path is formed between the electronic components and the vapor chamber, so that direct heat conduction between the electronic components and the vapor chamber is achieved through materials with good thermal conductivity.

[0053] The so-called circuit board heat dissipation path refers to a heat path with good heat conduction such as thermal vias, metal columns, and circuit wiring formed on the electronic circuit board for dissipating heat from electronic components to the heat spreader through the electronic circuit board.

[0054] Furthermore, the present invention reduces the heat transfer resistance from the circuit board heat dissipation path of the electronic circuit board to the heat spreader, and reduces the thickness of the electronic circuit board and the heat spreader together. In addition, by connecting the ground of the semiconductor to the circuit board heat dissipation path, the shell (container) of the heat spreader can be used as a ground, thereby contributing to the stabilization of the function of the electronic circuit board.

[0055] Hereinafter, a thin vapor chamber integrated with an electronic circuit board and a method for manufacturing the same according to the present invention will be described with reference to the accompanying drawings.

[0056] Figure 1 The cross-sectional structure diagram of the heat spreader 1 having the electronic circuit board 2 on the opposite side of the surface of the heat spreader 1 forming the enclosed space 3 according to the first embodiment of the present invention, wherein (A) shows a state in which the electronic circuit board 2 is provided on the entire surface of the first member 4 on the opposite side of the surface forming the enclosed space 3, wherein the first member 4 has a recessed portion formed by etching the heat spreader 1 and contains metal, and (B) shows a state in which the electronic circuit board 2a is provided on a portion of the first member 4 on the opposite side of the surface forming the enclosed space 3. In addition, Figure 1 (A) and Figure 1 In (B), an electrode 11 for electrically connecting to a heat generating component such as an electronic component, that is, a semiconductor, is provided. Figure 1 (A) is a cross-sectional structural example of the case of flip chip installation, in which the heat spreader 1 and the electronic circuit board 2 are integrated. Since the heat spreader 1 and the electronic circuit board 2 are integrated, the heat spreader 1 and the electronic component are directly bonded by metal without passing through a bonding layer through the metal constituting the first component 4 and the circuit board heat dissipation path 8, that is, the via filled with metal. That is, the thermal via of one of the circuit board heat dissipation paths 8 of the electronic circuit board 2 and the first component 4 are bonded by metal, thereby the circuit heat dissipation path 8 of the electronic circuit board 2 and the heat spreader 1 are integrated to form a heat spreader 1 having the electronic circuit board 2 of the present invention. That is, the metal forming the circuit heat dissipation path 8 can directly contact the electronic component 19 and the heat spreader 1.

[0057] The first member 4 and the second member 17 are bonded together by the bonding material 16 to form the heat spreader 1 .

[0058] One side of the circuit board heat dissipation path 8 of the electronic circuit board 2 is integrated with the heat spreader 1, and an electrode 11 for connecting to an electronic component is formed on the electronic circuit board 2 having the circuit board heat dissipation path 8. Figure 1As shown in the figure, in order to reduce the total thickness of the mounting form of the stacked components such as the heat generating electronic components (for example, application processors), the electronic circuit board 2 and the heat spreader 1, the electronic circuit board 2 with the heat spreader 1 can be made thinner by forming the electronic circuit board 2 and the heat spreader 1 as one. In addition, by integrating the electronic circuit board 2 with the heat spreader 1, a circuit board heat dissipation path 8 such as a thermal via, a heat conductor, etc. can be formed to efficiently release heat from the heat generating electronic components to the heat spreader.

[0059] Here, the circuit board heat dissipation path 8 is, as mentioned above, a heat path with good heat conduction such as a thermal via, a metal column, or a circuit wiring formed on the electronic circuit board 2 for dissipating the heat of the electronic components to the heat spreader 1 through the electronic circuit board 2. Since the circuit board heat dissipation path 8 of the electronic circuit board 2 and the heat spreader 1 are directly joined without using a connecting material, the thickness of the electronic circuit board 2 and the heat spreader 1 combined can be made thin.

[0060] use Figure 2 A method for manufacturing the heat spreader 1 according to the embodiment of the present invention will be described. Figure 2 The method of forming an electronic circuit board 2 with a metal member 12 before etching for forming a concave portion for forming a closed space 3 of the present invention is shown. The electronic circuit board 2 includes an insulating member 13, an outer wiring conductor 10, vias 9 for interlayer connection, electrodes 11, a solder resist layer 7, and the like, which are the same structures as those of a general electronic circuit board, and a circuit board heat dissipation path 8.

[0061] The electronic circuit board 2 is formed using materials and processes generally used in semiconductor mounting. That is, materials used in the manufacture of hard wiring boards, such as CCL, prepreg, copper foil, and insulating films, and materials used in the manufacture of flexible wiring boards, such as heat-resistant films and copper foils such as polyimide and LCP, can be used. In addition, the process can use a process for manufacturing electronic circuit boards such as a subtractive process, a semi-additive process, a layer-building process, and a coreless process.

[0062] Although the electronic circuit board 2 can also Figure 2 As shown in the figure, the electronic circuit board formed in the middle process is sequentially formed on one side of the metal component 12, but the electronic circuit board formed in the middle process can also be attached to the metal component 12 using an adhesive. In the case where the electronic circuit board in the middle process is formed and attached to the metal component 12 using an adhesive, after the electronic circuit board in the middle process is attached to the metal component 12, a via hole reaching the metal component 12 is formed in the cross-sectional direction of the electronic circuit board in the middle process, and metal is filled in the via hole by plating or the like, thereby forming the circuit board heat dissipation path 8.

[0063] After the electronic circuit board 2 is formed on one side of the metal component 12, the metal component 12 forming the electronic circuit board 2 can be etched to form a recess, thereby making the first component. Alternatively, after the metal component 12 is etched to form a recess, the electronic circuit board 2 can be set on the opposite side of the recess forming the enclosed space 3.

[0064] After the metal member 12 is formed into the circuit board heat dissipation path 8, the formation of the electronic circuit board 2 including the circuit board heat dissipation path 8 is completed. The following is a specific example of a method that can be actually implemented.

[0065] Figure 2 (C) is a metal member 12. The metal member 12 is formed into a concave portion by etching, thereby becoming the first member 4 having the enclosed space 3, and can be set to a copper plate with a thickness of 200 μm. The metal member 12 can use a thermal conductivity of 10 W / m at the temperature used. 2 Metals above K are suitable for copper, copper-molybdenum alloys, and aluminum. However, copper is more suitable from the perspective of processability and conductivity such as plating and etching. The thickness of the metal component 12 is suitable for 9μm to 10000μm, and more suitable for 50μm to 500μm. If it is less than 9μm, the volume of the enclosed space 3 of the formed heat spreader 1 will become smaller, and it will be difficult to ensure the flow path for sealing the working fluid in the enclosed space 3. If it exceeds 10000μm, the etching efficiency will be poor when the heat spreader is formed, and the productivity will be significantly reduced. Furthermore, if processability is taken into consideration, 50μm to 500μm is suitable.

[0066] A copper plate can be used as the metal member 12 . For example, a rolled copper foil produced by Fukuda Metal Foil Co., Ltd. can be used as the copper plate. However, the present invention is not limited thereto.

[0067] Figure 2 (D) is a diagram showing the insulating member 13 and the metal foil 14 being bonded to the metal component 12. As the insulating member 13, for example, Hitachi Chemical GEA-679 with a thickness of 40 μm can be used. The insulating member 13 has a resistivity of 10 to the 10th power Ωm or more, and can be used as long as it functions as an adhesive. As other examples, prepregs with epoxy resin impregnated in glass cloth substrates, prepregs with polyimide resin impregnated in glass cloth substrates, interlayer insulating materials such as Ajinomoto Fine Chemicals ABF series, and polyimide films such as APICAL of Kaneka Co., Ltd. can be used. In order to improve the adhesion between the insulating member 13 and the metal foil 14, an adhesive can also be placed between the insulating member 13 and the metal foil 14. The thickness of the insulating member 13 is preferably 3 μm to 200 μm. When it is less than 3 μm, the interlayer insulation is reduced, causing circuit failure. If it exceeds 200 μm, the heat transfer resistance from the electronic component, i.e., the semiconductor, to the heat spreader 1 becomes larger.

[0068] As the metal foil 14, a copper foil of Mitsui Mining & Smelting Co., Ltd. with a thickness of 12 μm can be used. The so-called metal foil 14 refers to a film-like metal. The metal foil 14 can use copper foil and metal foil commonly used in electronic circuit boards, and examples thereof include electrolytic copper foil, rolled copper foil, copper foil with carrier, copper foil with resin, and aluminum foil.

[0069] When the metal component 12 is bonded to the insulating member 13, the surface of the metal component 12 is cleaned by pretreatment as needed. When the metal component 12 is copper, the pretreatment can use chemical grinding based on acid treatment and microetching agent; physical grinding such as polishing, brushing or scrubbing, and washing and drying after grinding. These treatments are commonly performed in the manufacture of electronic circuit boards. In addition, although pretreatment can be performed for the above-mentioned surface cleaning, the record of pretreatment is omitted hereafter. The metal component 12, the insulating member 13 and the copper foil 14 are overlapped in a vacuum forming press, and heat and pressure are applied while bonding under conditions sufficient to harden the resin contained in the insulating member 13. It is also possible to bond while applying heat and pressure through a heating roller instead of a vacuum forming press.

[0070] Figure 2 (E) is a diagram showing the following: a via hole reaching the metal member 12 is formed in the cross-sectional direction of the metal foil 14 and the insulating member 13, and metal is filled inside the formed via hole to form the circuit heat dissipation path 8 and the electronic circuit board 12. In order to set the via hole, a laser hole opening machine manufactured by Via Machine Co., Ltd. is used to open the via hole reaching the metal member 12. In order to fill the metal inside the formed via hole, copper is filled in the via hole that becomes the circuit board heat dissipation path 8 by copper plating using a vertical plating device manufactured by Chemitron Co., Ltd. Through the formed circuit board heat dissipation path 8, the copper plate of the metal member 12 and the circuit heat dissipation path 8 are bonded by copper. That is, the circuit heat dissipation path 8 of the electronic circuit board 2 and the metal member 12 are bonded by metal, and the heat spreader 1 formed by the circuit heat dissipation path 8 of the electronic circuit board 2 and the metal member 12 can be formed as a whole. The metal filled in the metal heat dissipation path 8 and the heat spreader 1 come into contact.

[0071] The process of forming a via hole that reaches the metal member 12 in the cross-sectional direction of the metal foil 14 and the insulating member 13 and filling the formed via hole with metal requires hole opening by laser drilling, hole cleaning by permanganate, formation of a catalyst layer on the inner surface of the hole, electroless plating, and electroplating. These processes, and the devices and materials used in the processes are those used in the manufacture of ordinary electronic circuit boards.

[0072] The shape of the via hole can be any shape such as circular, square, polygonal, elliptical, etc. The cross-sectional area of ​​the via hole is preferably 0.02 mm 2 ~400mm 2, further preferably 0.05mm 2 ~50mm 2 If the area is 0.02mm 2 If the area is smaller than 400mm, the heat dissipation effect will be small and it will be difficult to fill the via hole with plating. 2 If the heat capacity of the vias is too large, the balance with the heat capacity of the bumps for circuit connection will be poor during solder bonding, and stable soldering cannot be performed. In addition, the total cross-sectional area of ​​the vias is preferably 1 / 20 to 4 / 5 of the heat generation area of ​​the electronic component, and more preferably 1 / 10 to 1 / 2. When it is less than 1 / 20, the temperature of the electronic component rises due to the slow heat dissipation rate. When it exceeds 4 / 5, the area for the bumps for circuit connection can no longer be ensured.

[0073] The metal foil 14 is etched to form a wiring circuit, such as Figure 2 The outer wiring conductor 10 is formed as shown in (E).

[0074] The wiring circuit formation is performed by forming a plating resist, exposing, developing, plating, stripping the plating resist, and removing the seed layer.

[0075] like Figure 2 As shown in (F), in the Figure 2 The exterior wiring conductor 10 on the surface of the insulating material 13 of (E) is further overlapped with the insulating material 13 and the metal foil 14, and the wiring layers may be overlapped in two layers, three layers or more layers.

[0076] Figure 2 (G) is a diagram showing a state where a solder resist layer 7 is formed on an electronic circuit board 2 formed on a metal member 12 .

[0077] Figure 3 This is the manufacturing method of the first embodiment for forming the vapor chamber 1 by forming the metal member 12 of the electronic circuit board 2 .

[0078] Figure 3 (H) is a diagram showing an etching mask (also called resist) 15 formed on the surface of the electronic circuit board 2 on the opposite side of the metal component 12 forming the electronic circuit board 2. As the etching mask 15, a Photec film with a thickness of 40 microns produced by Hitachi Chemical Industries can be used. The portion around the wall that encloses the working fluid in the enclosed space 3 of the heat spreader 1 and the portion of the passage through which the working fluid passes are formed by etching. First, pretreatment is performed on the surface of the metal component 12 that forms the etching mask 15. The pretreatment is generally acid treatment, scrubbing surface treatment, polishing and grinding, soft etching, and brushing surface treatment alone or in combination, but it is not limited to this if the surface of the metal component 12 becomes clean. For example, a pretreatment machine of Tokyo Chemical Industry Co., Ltd. can be used. After the pretreatment, an etching mask 15 is formed on the surface of the metal component 12.

[0079] The formation method of the etching mask 15 is generally a photo method and a printing method. In the photo method, after forming a photosensitive layer on the surface of the metal component 12 by forming a dry film on the metal component 12 with a dry film laminator, a method of applying a photosensitive film with a roller, etc., a protective film is attached to the photosensitive layer, and exposure is performed via an exposure mask. After the protective film is peeled off, it is carried out in the order of development, etching, and dry film peeling. Regarding materials and devices, for example, the dry film can use the Photec series of Hitachi Chemical Industries, the dry film laminator can use the Hitachi Plant Mechanics Co., Ltd., the exposure machine can use the manual exposure machine of ORC Manufacturing Co., Ltd., and the development, etching, and dry film peeling can use the device of Chemitron Co., Ltd., but these are examples and are not limited to these. In addition, the etching liquid can be exemplified by ferric chloride solution, MEC Co., Ltd. EXE series, and JCU Co., Ltd. HE-500, but these are examples and are not limited to these. In addition, the photolithography method can form a complex shape because it uses an exposure mask. Since complex concave and convex shapes can be formed around the wall that seals the working fluid and the passage through which the working fluid passes, it is easy to form a capillary wick.

[0080] In the printing method, after pre-processing, the screen method generally uses a screen printer and a screen mask to print etching ink on the surface of the metal member 12, and then hardens it to form an etching mask 15. Development, etching, and peeling can be performed by the same method as the photographic method.

[0081] Figure 3 (I) is a diagram of a first component 4 having a recessed portion forming a confined space 3 by etching a metal component 12. By etching the metal component 12 using the above-mentioned etching method, a portion of the confined space 3 can be formed. Furthermore, the etched surface is roughened using MEC's ​​Etch Bond CZ to form a capillary wick. By using an etching-based roughening treatment liquid, a fine roughened surface can be formed on the surface of the recessed portion formed by etching of the wall of the confined space 3 that becomes the first component 4, and a capillary wick can be easily formed on the surface forming the confined space 3. During the etching, the electronic circuit board 2 is treated as needed, and a protective film or the like is used to prevent it from being etched.

[0082] The surface roughness of the roughened surface is preferably an average roughness of 0.2 μm to 5 μm and a maximum roughness of 20 μm or less, and more preferably an average roughness of 0.5 μm to 3.0 μm and a maximum roughness of 8 μm or less. When the average roughness is less than 0.2 μm and the maximum roughness is less than 0.3 μm, a good capillary wick cannot be formed, the heat conduction capacity is poor, and the function of the heat spreader 1 is significantly poor. When the average roughness is greater than 5 μm and the maximum roughness is greater than 20 μm, the strength of the metal at the bottom of the heat spreader 1 is reduced, which becomes a cause of defects such as leakage.

[0083] By forming a fine roughened surface on the surface of the concave portion formed by etching, which becomes the wall of the enclosed space 3, the area of ​​the working fluid enclosed in the heat spreader 1 that contacts the wall forming the enclosed space 3 becomes larger. As a result, the efficiency of heat absorption and heat dissipation of the working fluid can be improved. By setting the first member 4 having the concave portion forming the enclosed space 3 of the heat spreader 1 or the concave portion formed in the second member 17 by etching as a fine roughened surface, the surface area of ​​the enclosed space 3 is increased, and the efficiency of heat absorption and heat dissipation of the working fluid can be improved.

[0084] Figure 3 (J) is a diagram showing the removal of the etching mask 15. The etching mask 15 is removed using an alkaline solution such as an aqueous sodium hydroxide solution or an organic solvent.

[0085] Figure 3 (K) is a diagram showing a bonding material 16 formed on the first member 4 in which a recess is formed in the metal member 12 by etching. The bonding material 16 can be formed by applying solder paste using a dispenser. The bonding material 16 can also be formed by a printing method or solder flow. As the bonding material 16, solder such as solder paste and solder plating is generally used, but a heat-resistant adhesive such as epoxy resin can also be used.

[0086] Figure 3(L) is a diagram of a heat spreader 1 in which the electronic circuit board 2 on the opposite side of the surface of the first member 4 having the concave portion forming the enclosed space 3 is integrated by bonding the first member 4 having the concave portion forming the enclosed space 3 and the second member 17 via a bonding material 16. The bonding of the first member 4 having the concave portion forming the enclosed space 3 and the second member 17 is performed via a bonding material 16, and a reflow device, a laser heating device, and an oven can be used for bonding based on the bonding material 16. The bonding material 16 can be any material as long as it has good thermal conductivity and is not destroyed by the internal pressure of the heat spreader 1 during operation, and solder or an organic adhesive can be exemplified. The solder can use the commonly used SnAgCu system, SnPb, etc., but low-temperature solder and high-temperature solder can also be used. The method of soldering can be exemplified by a manual method; a method using solder paste to perform metal mask printing, heating through a reflow furnace, and laser; and a method based on flow soldering. In the joining step, a jig or a robot is used as necessary to closely fix the first member 4 and the second member 17 .

[0087] The first member 4 and the second member 17 having the recessed portion forming the sealed space 3 are bonded by the bonding material 16 to form the sealed space 3. As described above, the bonding material 16 needs to have sufficient strength to form the sealed space 3 and not be broken by the internal pressure during the operation of the heat spreader.

[0088] Figure 4 This is an example of mounting electronic component 19, which is a heat source, on heat spreader 1 having electronic circuit board 2 of the present invention. Electronic component 19 is a semiconductor element or semiconductor package having electrodes on the same surface as a bare chip, BGA, CSP, WLP, etc.

[0089] Figure 4 (M) is a diagram of flip-chip mounting of an electronic component 19, in which the external electrode of the semiconductor bare chip and the electrode 11 of the electronic circuit board 2 are joined with solder 18. A thermal via, which is one of the circuit board heat dissipation paths 8, is formed at a portion of the electrode 11 of the electronic circuit board 2. The thermal path from the electrode 11 of the electronic circuit board 2 through the circuit board heat dissipation path 8 to the heat spreader 1 is connected by metal without passing through a connecting material, so as to form an integral whole. Since the ground of the electronic component 19 is connected to the electrode 11 of the electronic circuit board 2 forming the circuit board heat dissipation path 8, it is electrically at the same potential as the heat spreader 1, and therefore the first member and the second member that form the heat spreader 1 and contain metal and have a recessed portion that becomes the enclosed space 3 can be used as grounding, thereby contributing to the stability of the grounding.

[0090] Figure 4(N) is a diagram showing that a CSP (Chip Scale Package) 19a as an electronic component and a semiconductor bare chip 19b connected to an electrode 11 by wire bonding are mounted on an electronic circuit board 2. The external electrodes of the semiconductor bare chip 19b and the electrodes 11 of the electronic circuit board 2 are bonded with aluminum wires. Gold wires and copper wires are also used as the wires. Both CSP 19a and the semiconductor bare chip 19b are connected to the circuit board heat dissipation path 8. The circuit board heat dissipation path 8 is formed by a metal columnar circuit board heat dissipation path 23 formed by relatively large through holes, and the electronic components 19a and 19b are connected to the heat spreader 1.

[0091] use Figure 5 as well as Figure 6 A method for manufacturing the heat spreader 1 according to the second embodiment of the present invention will be described.

[0092] Figure 5 The present invention is a method for manufacturing an electronic circuit board 2 constituting a heat spreader 1 , and shows a method for manufacturing a first member 4 having a recess serving as a sealed space 3 by forming a recess in a metal member 12 a . Figure 5 (O) represents a metal component 12a having an etching stopper layer 21, and the metal component 12a has the etching stopper layer 21 between the metal layer 29 and the metal layer 30. The metal layer 29 and the metal layer 30 are copper, and the etching stopper layer 21 can be made of nickel. The etching stopper layer 21 is formed on one surface of the metal layer 29 by plating or vapor deposition, and the metal layer 30 is further formed on the etching stopper layer 21 by plating or vapor deposition, thereby obtaining the metal component 12a.

[0093] The metal layer 29 forms a recessed portion by etching with the etching liquid. The metal layer 29 that does not form the etching mask 15 by etching is dissolved into the etching stop layer 21. That is, since the dissolution is stopped by the etching stop film 21 that is not dissolved by the etching liquid, the metal layer 3 of the metal member 12a on the opposite side of the dissolution surface of the etching stop layer 21 is not dissolved and can remain.

[0094] After the metal layer 29 is dissolved, an etching mask is formed on the exposed etching stop layer 21 , and the surface of the etching stop layer 21 can be etched by selecting an etching solution.

[0095] The metal layer 29 and the metal layer 30 can be used with a thermal conductivity of 10 W / m at the temperature of the heat spreader 1. 2Metals of K or higher. As materials for the metal layer 29 and the metal layer 30, copper, copper-molybdenum alloy, and aluminum are suitable, and copper is more suitable from the viewpoint of adaptability to processing such as plating and etching and thermal conductivity. When the metal layer 29 and the metal layer 30 are copper or copper-molybdenum alloy, nickel, aluminum, and tin are suitable for the etching stop layer 21. When the metal layer 29 and the metal layer 30 are aluminum, copper, nickel, and tin are suitable for the etching stop layer 21.

[0096] The thickness of the etching stop layer 21 is preferably 0.1 μm to 5 μm, more preferably 0.5 μm to 2 μm. If it is thinner than 0.1 μm, it will not fully function as an etching stopper due to pinholes, etc. On the other hand, if it exceeds 5 μm, it will be difficult to remove the etching stop layer 21.

[0097] Figure 5 (P) is a diagram showing an etching mask 15 formed on a metal member 12a having a metal layer 29, an etching stopper layer 21, and a metal layer 30. The etching mask 15 is formed on the entire surface of the metal layer 30 which does not need to be etched. Figure 3 (H) An etching mask 15 is formed in the same manner as in (H).

[0098] Figure 5 (Q) is an etching pattern of a metal component 12a having a metal layer 29, an etching stopper layer 21 and a metal layer 30 forming an etching mask 15. When the metal layer 29 and the metal layer 30 are copper and the etching stopper layer 21 is nickel, the desired treatment can be performed if an alkaline etching solution is used as the etching solution for the metal layer 29. Since nickel is not corroded by the alkaline etching solution, the etching stopper layer 21 containing nickel functions as an etching stopper layer. The etching efficiency of the alkaline etching solution is poor compared with the ferric chloride etching solution and the cupric chloride etching solution. For this reason, it is also possible to use a ferric chloride etching solution and a cupric chloride etching solution to etch first and then switch to an alkaline etching solution in the middle.

[0099] In order to dissolve the metal layer 29 and roughen the exposed etching stop layer 21, the etching stop layer 21 must be etched. The etching stop layer 21 containing nickel can be etched with sulfuric acid. The nickel film can be dissolved by immersing it in sulfuric acid. Since sulfuric acid dissolves nickel, but copper is insoluble in sulfuric acid, the above-mentioned treatment can be performed. Furthermore, the surface of the etching stop layer 21 can be roughened with a roughening treatment liquid such as MEC's ​​Etch BondCZ to form a capillary wick. By using an etching-based roughening treatment liquid, the surface of the etching stop layer 21 exposed after the metal layer 29 of the metal component 12 having the etching stop layer 21 is dissolved can be simply roughened to form a capillary wick. The formation of the roughened surface can also use roughening plating.

[0100] Figure 5(R) indicates the first member 4 formed by removing the etching mask.

[0101] exist Figure 6 A method for manufacturing the heat spreader 1 according to the third embodiment of the present invention will be described.

[0102] Figure 6 (S) is a cross-sectional structural diagram of a metal member 12b having a metal layer 29a, an etching stopper layer 21a having an opening 22, and a metal layer 30a. The etching stopper layer 21a partially has an opening 22, and when the etching liquid reaches the opening 22, etching is advanced from the opening 22, and the surface of the opening 22 of the metal layer 30a into which the etching liquid has penetrated can be etched to form a concave portion 24. Furthermore, the concave portion 24 and the roughening treatment can be combined to form a good capillary wick.

[0103] An etching stop layer 21a is formed on one surface of the metal layer 29a by plating or vapor deposition, an etching mask is formed on the portion of the etching stop layer 21a other than the opening 22, and then etching is performed to form the opening 22. Thereafter, a metal layer 30a is formed by plating, thereby obtaining a metal component 12b.

[0104] The surface energy of the etching stop layer 21a exposed by the dissolution of the metal layer 29a is Figure 5 The surface shown in (Q) is also set as a roughened surface.

[0105] Figure 6 (S) shows a cross section of the metal member 12b including the metal layer 29a, the etching stopper layer 21a having the opening 22, and the metal layer 30a.

[0106] Figure 6 (T) is a top view of a first member 4b having a concave portion forming a closed space 3, wherein the first member 4b is obtained by forming a metal member 12b having a metal layer 29a, an etching stopper layer 21a having an opening 22, and a metal layer 30a. Figure 6 The etching mask 15 as shown in (S) is etched to remove the etching mask 15, and a part of the metal layer 29a is dissolved to form a recessed portion.

[0107] The metal member 12b is etched to form a recess in the metal member 12b, but an etching mask 15a is formed in the center of the metal member 12b, which is separated from the etching mask 15 formed in the periphery of the metal member 12b, so that an island 20 of the metal layer 29a can be formed in the center of the recess of the first member 4b having the recess that becomes the closed space 3. By forming the island 20 of the metal layer 29a, a wall that separates the portion where the working fluid is liquefied and vaporized can be provided, so that the liquid working fluid and the gaseous working fluid are not mixed, and heat absorption and heat dissipation can be performed smoothly.

[0108] Figure 6 (U) is a cross-sectional structural diagram of a first member 4b having a concave portion forming a closed space 3, wherein the first member 4b is obtained by forming a metal member 12b having a metal layer 29a, an etching stopper layer 21a having an opening 22, and a metal layer 30a. Figure 6 The etching mask 15 as shown in (S) is etched to remove the etching mask 15, and a part of the metal layer 29a is dissolved to form a recessed portion.

[0109] The metal in the opening 22 formed in the etching stopper layer 21a is dissolved by the etching solution, and a part of the metal layer 30a is also dissolved. The shape of the opening 22 is preferably circular in order to make the depth of the bottom surface of the recess 24 constant. The opening diameter of the opening 22 is preferably T / 5 to T with respect to the thickness T of the metal layer 30a, and more preferably T / 3 to T / 2.

[0110] Figure 6 (V) is a partially enlarged view of the first member 4b having a concave portion that becomes the closed space 3, showing a state in which a portion of the metal layer 30a in contact with the opening 22 is etched and dissolved. By roughening the surface of the concave portion 24 formed in the metal layer 30a, the first member 4b can have a capillary wick with a large surface area that combines the concave portion 24 formed in the metal layer 30a in contact with the opening 22 and the roughened surface formed on the surface of the concave portion 24 formed in the metal layer 30a.

[0111] Figure 7 A method for forming a closed space of a heat spreader according to Embodiment 4 of the present invention will be described.

[0112] Figure 7 (W) is a cross-sectional structural diagram of a metal component 12c having a metal layer 29, an etching stop layer 21a having an opening 22, a metal layer 30b, an etching stop layer 21, and a metal layer 30. The metal component 12c is obtained by combining the methods described in the metal components 12 and the metal components 12a. By further adding an etching stop layer 21 to the etching stop layer 21a having the opening 22, a recess 24a formed in the metal layer 30b in contact with the opening 22 can be formed more precisely than in the third embodiment. The first component 12c can also be formed by the etching stop layers 21 and 21a being nickel and the metal layers 29, 30b, and 30 being copper.

[0113] Figure 7 (X) indicates that the metal layer 30b in contact with the etching stop layer 21a having the opening 22 is completely dissolved and the etching stop layer 21 is exposed. The metal member 12c is etched to form a concave portion that becomes the closed space 3, and a portion of the bottom surface of the concave portion of the first member 4c having the formed concave portion is removed. Figure 7By further providing the etching stopper layer 21 below the etching stopper layer 21a having the opening 22, etching can be stopped reliably regardless of the opening shape and opening diameter of the etching stopper layer 21a having the opening 22.

[0114] The surface of the concave portion 24 a formed in the metal layer 30 b in contact with the opening 22 of the first member 4 c and the exposed etching stopper layer 21 can be roughened by the surface roughening treatment.

[0115] Figure 7 (Y) means Figure 7 The etching stopper layers 21a and 21 of (X) are dissolved and removed by etching. Figure 7 The bottom surface of the recessed portion formed in the first member 12c as shown in (X) is Figure 7 The bottom surface shown in (Y) can further increase the surface area.

[0116] Figure 8 The heat spreader 1 is shown, and the heat spreader 1 is formed by forming the first member 4b having the island 20 of the metal layer described in the third embodiment, and the second member 17a having no island 20 of the metal layer and the same as the first member 4b in other parts, and bonding the first member 4b having the concave portion forming the enclosed space 3 and the second member 17a having the concave portion forming the enclosed space 3 by bonding material 16. The second member 17a can be formed as follows. Figure 3 It may be plate-shaped as shown in (L), or may be Figure 8 As shown in the figure, the second member 17a is formed with the recessed portion 24 by etching. Furthermore, the electronic circuit board 2 may be formed on the opposite side to the surface on which the sealed space 3 is formed.

[0117] The method of filling the working fluid in the heat spreader 1 is the same general method as heat pipes and other heat spreaders. The working fluid is injected from the filling port while cooling as needed, the filling port is physically flattened, and then sealed by soldering, brazing, welding, etc. The filling port can be set in the first component or the second component, and can also be formed in both the first component and the second component.

[0118] -Explanation of symbols-

[0119] 1: Vapor chamber

[0120] 2: Electronic circuit board

[0121] 3: Confined Space

[0122] 4: Component 1

[0123] 7: Solder mask

[0124] 8: Circuit heat dissipation path

[0125] 9: Vias for inter-layer connections

[0126] 10: Outer wiring conductor

[0127] 11: Electrode

[0128] 12: Metal components

[0129] 13: Insulation

[0130] 14: Metal foil

[0131] 15: Etching mask

[0132] 16: Joining materials

[0133] 17: Component 2

[0134] 18: Solder

[0135] 19: Electronic components

[0136] 20: Island of metal layer

[0137] 21: Etching stop layer

[0138] 22: Opening

[0139] 23: Metal columnar circuit heat dissipation path

[0140] 29: Metal layer

[0141] 30: Metal layer.

Claims

1. A heat spreader, wherein a first member made of metal and a second member made of metal are joined together to form a closed space for enclosing a working fluid, The heat sink is characterized in that: The first member, or the first member and the second member, comprises a first metal layer, a first etching stopper layer having an opening, and a second metal layer in order, wherein the first metal layer of the first member, or the first member and the second member, is dissolved by etching, and the second metal layer in contact with the opening of the first etching stopper layer having an opening is etched, A recessed portion is provided which includes a side surface formed by the first metal layer, a surface on the first metal layer side of the first etching stop layer having an opening, and a concave surface formed by dissolution of the second metal layer by etching, the first component and the second component are joined with the recessed portion as an inner side, and the working fluid is sealed in the enclosed space including the recessed portion.

2. A heat spreader, wherein a first member made of metal and a second member made of metal are joined together to form a closed space enclosing a working fluid, The heat sink is characterized in that: The first member, or the first member and the second member, comprises a first metal layer, a first etching stopper layer having an opening, a second metal layer, a second etching stopper layer, and a third metal layer in order, wherein the first metal layer of the first member, or the first member and the second member, is dissolved by etching, and the second metal layer in contact with the opening of the first etching stopper layer having an opening is dissolved by etching until the second etching stopper layer is reached, A recess is provided that includes the side surface formed by the first metal layer, the surface of the first etching stop layer having an opening on the first metal layer side, the side surface formed by the second metal layer by etching, and the surface of the second etching stop layer on the first metal layer side, the first component and the second component are joined with the recess as the inner side, and the working fluid is sealed in the enclosed space including the recess.

3. A heat spreader, wherein a first member made of metal and a second member made of metal are joined together to form a closed space enclosing a working fluid, The heat sink is characterized in that: The first member, or the first member and the second member, comprises a first metal layer, a first etching stopper layer having an opening, a second metal layer, a second etching stopper layer, and a third metal layer in order, the first metal layer of the first member, or the first member and the second member is dissolved by etching, the second metal layer in contact with the opening of the first etching stopper layer having an opening is dissolved by etching until the second etching stopper layer is reached, and the second etching stopper layer is further dissolved by etching, A recess is provided that includes a side surface formed by the first metal layer, a surface on the first metal layer side of the first etching stop layer having an opening, a side surface formed by the second metal layer by etching, and a surface on the first metal layer side of the third metal layer, the first component and the second component are joined with the recess as an inner side, and the working fluid is sealed in the enclosed space including the recess.

4. The vapor chamber according to any one of claims 1 to 3, characterized in that: The surface forming the enclosed space is a roughened surface obtained by a roughening treatment.

5. A method for manufacturing a heat spreader, comprising: bonding a first member made of metal and a second member made of metal to form a closed space enclosing a working fluid; The method for manufacturing the vapor chamber is characterized in that: The first member, or the first member and the second member, comprises a first metal layer, a first etching stopper layer having an opening, and a second metal layer in order, wherein the first metal layer of the first member, or the first member and the second member, is dissolved by etching, and the second metal layer in contact with the opening of the first etching stopper layer having an opening is etched, A recessed portion is provided which includes a side surface formed by the first metal layer, a surface on the first metal layer side of the first etching stop layer having an opening, and a concave surface formed by dissolution of the second metal layer by etching, the first component and the second component are joined with the recessed portion as an inner side, and the working fluid is sealed in the enclosed space including the recessed portion.

6. A method for manufacturing a heat spreader, comprising: bonding a first member made of metal and a second member made of metal to form a closed space enclosing a working fluid; The method for manufacturing the vapor chamber is characterized in that: The first member, or the first member and the second member, comprises a first metal layer, a first etching stopper layer having an opening, a second metal layer, a second etching stopper layer, and a third metal layer in order, wherein the first metal layer of the first member, or the first member and the second member, is dissolved by etching, and the second metal layer in contact with the opening of the first etching stopper layer having an opening is dissolved by etching until the second etching stopper layer is reached, A recess is provided that includes the side surface formed by the first metal layer, the surface of the first etching stop layer having an opening on the first metal layer side, the side surface formed by the second metal layer by etching, and the surface of the second etching stop layer on the first metal layer side, the first component and the second component are joined with the recess as the inner side, and the working fluid is sealed in the enclosed space including the recess.

7. A method for manufacturing a vapor chamber, comprising: bonding a first member made of metal and a second member made of metal to form a closed space enclosing a working fluid, The method for manufacturing the vapor chamber is characterized in that: The first member, or the first member and the second member, comprises a first metal layer, a first etching stopper layer having an opening, a second metal layer, a second etching stopper layer, and a third metal layer in order, the first metal layer of the first member, or the first member and the second member is dissolved by etching, the second metal layer in contact with the opening of the first etching stopper layer having an opening is dissolved by etching until the second etching stopper layer is reached, and the second etching stopper layer is further dissolved by etching, A recess is provided that includes a side surface formed by the first metal layer, a surface on the first metal layer side of the first etching stop layer having an opening, a side surface formed by the second metal layer by etching, and a surface on the first metal layer side of the third metal layer, the first component and the second component are joined with the recess as an inner side, and the working fluid is sealed in the enclosed space including the recess.

8. The method for manufacturing a vapor chamber according to any one of claims 5 to 7, characterized in that: The surface forming the enclosed space is a roughened surface obtained by a roughening treatment.

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