JPWO2020255836A1 - A copper composite plate material, a vapor chamber using a copper composite plate material, and a method for manufacturing a vapor chamber. - Google Patents

Abstract

The second copper layer is pressure-welded to one surface of the first copper layer, the first copper layer is composed of a precipitation-reinforced copper alloy, and the second copper layer is made of pure copper having a Cu content of 99.9% by mass or more. It is a copper composite plate material which is composed of or is composed of a non-precipitation reinforced copper alloy in which Si is less than 0.1% by mass.

Description

The present invention relates to a copper composite plate material and a method for manufacturing a vapor chamber using the same.

In recent years, mobile devices such as notebook PCs, mobile notebook PCs (mobile PCs), tablet terminals, phablet terminals and smartphones (mobile phone terminals) have become smaller, thinner and lighter, as well as more sophisticated and sophisticated. Performance has been improved. CPUs mounted on such mobile devices are rapidly increasing in speed and density, and their heat generation is increasing. Excessive temperature rise in mobile devices can cause CPU malfunctions (malfunctions, thermal runaway, etc.), so there is an urgent need to improve the heat dissipation effect from the CPU and other semiconductor devices installed in mobile devices. It has become.

As a heat dissipation means considered to be effective for miniaturization, thinning, and weight reduction of mobile devices, a vapor chamber in which a refrigerant is vacuum-sealed inside a flat plate-shaped housing is being studied. The vapor chamber is a flat plate-shaped heat pipe having a high heat dissipation effect, and is a heat diffusion component capable of conducting heat by evaporating and condensing the refrigerant sealed inside. As the refrigerant of the vapor chamber, pure water is exclusively used for the reasons of safety, low cost, easy handling and the like.

For example, Japanese Patent Application Laid-Open No. 2017-172871 discloses a vapor chamber in which a flat plate-shaped upper plate member and a flat plate-shaped lower plate member are joined to form a housing. In this vapor chamber, the upper plate member and the lower plate member, which are the housings, are precipitation-hardened copper alloys (Cu-Ni-Si type, Cu-Fe-P type, Cu-Fe-Ni-P type, Cu-Cr type). And Cu-Cr-Zr system), the mechanical strength and thermal conductivity of the housing (upper plate member and lower plate member) lowered by joining heated to 650 ° C or higher are aged (precipitated). It is improved by curing treatment). The Cu—Ni—Si based copper alloy described above is called a Corson alloy. The members made of this Corson alloy are the Journal of the Copper Society of Japan, "Copper and Copper Alloy", Vol. 57, No. 1, 2018, Paper "Diffusive Bondability and Mechanical Properties of Copper-Coated Copper Alloy Plate", Daisuke Hashimoto (Kobe Co., Ltd.) Steelworks) As disclosed, it is possible to coat the surface with a copper plating process.

For example, in Japanese Patent Application Laid-Open No. 2007-315745, a flat plate-shaped upper plate member, a flat plate-shaped middle plate member having micropores serving as a flow path for a refrigerant, and a flat plate-shaped lower plate member are joined to form a chamber. The vapor chambers that make up the body are disclosed. Since the upper plate member, middle plate member, and lower plate member of this vapor chamber are made of copper (pure copper), a high heat dissipation effect (thermal conductivity) can be expected. Further, in this vapor chamber, a groove-shaped recess is provided inside the upper plate member and the lower plate member that come into contact with the refrigerant, and the contact area with the refrigerant is increased, so that the heat dissipation effect (thermal conductivity) is further improved. Will be improved.

Japanese Unexamined Patent Publication No. 2017-172871 Japanese Unexamined Patent Publication No. 2007-315745

Journal of the Copper Society of Japan, "Copper and Copper Alloy", Vol. 57, No. 1, 2018, Paper "Diffusive Bondability and Mechanical Properties of Copper-Coated Copper Alloy Plate", by Daisuke Hashimoto (Kobe Steel, Ltd.)

Recently, when constructing the housing of the vapor chamber, the bonding means using a bonding agent such as silver wax has been replaced from the viewpoint of preventing contamination inside the housing, improving the bonding strength, and improving the reliability of decompression sealing of the refrigerant. Therefore, a means for joining surfaces to be joined, that is, diffusion joining, is being applied by utilizing a diffusion phenomenon generated by heating a surface to be joined with a load applied. Although it depends on the material of the surface to be joined, it is generally required to heat and hold at 600 ° C. or higher and 1000 ° C. or lower for diffusion bonding. However, if the member constituting the housing is copper (pure copper), the mechanical strength of the housing is reduced, and increasing the thickness of the member hinders the thinning and weight reduction of the above-mentioned portable device. It will be.

In order to ensure the mechanical strength of the housing after diffusion bonding from the viewpoint of material, precipitation hardening of a Corson alloy (Cu—Ni—Si system) or Cu—Co—Si system disclosed in Patent Document 1 is required. The application of cupronickel alloy is conceivable. When the member constituting the housing is a precipitation hardening type copper alloy, aging treatment (precipitation hardening treatment) can be performed by utilizing the heat retention of the diffusion bonding. It should be noted that the inside (inner surface) of the housing of the vapor chamber is required to have no particular reaction even if it comes into contact with the refrigerant, for example, no gas is generated and corrosion does not proceed. However, Si contained in the above-mentioned Corson alloy or the like may react with pure water or an aqueous solution to generate _{silicon dioxide (SiO 2} ) and hydrogen (H _2). Further, if Si is present at the bonding interface that comes into contact with oxygen during diffusion bonding, it may react to form a brittle structure (SiO _{2 phase) containing silicon dioxide (SiO 2).}

From the viewpoint of preventing the reaction between Si and water and preventing the reaction between Si and oxygen, the copper plating treatment disclosed in Non-Patent Document 1 is applied to cover the surface of the member made of the above-mentioned Corson alloy or the like. It is conceivable that Si is not exposed. However, the copper plating film formed by a general copper plating process may have pinholes or partial peeling, so that the base (Colson alloy) may be exposed. In addition, the surface of the copper-plated film formed with a current density suitable for mass production is rougher than the surface roughness of general finish rolling, so the load applied to the surface to be joined during diffusion bonding must be increased, resulting in higher productivity. descend. The surface roughness of the copper plating film is improved by adding an additive such as S, but the additive element such as S may react with the refrigerant. Further, when the groove-shaped recesses are provided inside the upper plate member and the lower plate member described above, an etching process may be performed. However, with a thin copper plating film, the substrate (Corson alloy) may be exposed by etching, and if a thick copper plating film is formed, the plating time increases and the productivity decreases.

One of the objects of the present invention is to provide a copper-based plate material having diffusion bonding property, corrosion resistance and 0.2% proof stress suitable as a constituent member (housing etc.) of a vapor chamber, and to use this copper-based plate material. It is to provide a method for manufacturing a copper chamber that has been used.

The present inventor has found that the above-mentioned problems can be solved by combining a copper-based plate material whose mechanical strength is secured after diffusion bonding and a copper-based plate material which does not easily react with the solvent used in the vapor chamber. I was able to come up with this invention.

The copper composite plate material according to the first aspect of the present invention is a copper composite plate material in which a second copper layer is pressed against one surface of the first copper layer, and the first copper layer is made of a precipitation-reinforced copper alloy. The second copper layer is a copper composite plate material in which Cu is composed of 99.9% by mass or more of pure copper or Si is composed of a non-precipitation reinforced copper alloy of less than 0.1% by mass. Is.

In the copper composite plate material according to the first aspect of the present invention, when the thickness of the first copper layer is T1 and the thickness of the second copper layer is T2, T2 / (T1 + T2) × 100 ≦ 30% and It is preferable to satisfy T2> 1 μm. Further, it is preferable that the second copper layer has a surface roughness R _ZJIS of 0.8 μm or less and a kurtosis Rku of 4 or less.

Further, the copper composite plate material according to the second aspect of the present invention is copper formed by pressing a second copper layer on one surface of the first copper layer and pressing a third copper layer on the other surface of the first copper layer. In the composite plate material, the first copper layer is composed of a precipitation-reinforced copper alloy, and the second copper layer and the third copper layer are both composed of pure copper having Cu of 99.9% by mass or more. It is a copper composite plate material which is made of a non-precipitation reinforced copper alloy in which Si is less than 0.1% by mass.

In the copper composite plate material according to the second aspect of the present invention, when the thickness of the first copper layer is T1, the thickness of the second copper layer is T2, and the thickness of the third copper layer is T3. , (T2 + T3) / (T1 + T2 + T3) × 100 ≦ 30% and preferably satisfy T2> 1 μm and T3> 1 μm. Further, it is preferable that the second copper layer and the third copper layer have a surface roughness R _ZJIS of 0.8 μm or less and a kurtosis Rku of 4 or less.

In the copper composite plate material according to the first aspect and the second aspect of the present invention, the copper alloy constituting the first copper layer is 0.8% by mass or more and 5.0% by mass or less of Ni, 0.2% by mass. It may be a copper alloy composed of Si, the balance Cu, and unavoidable impurities of 1.5% by mass or more. Further, in the copper composite plate material according to the first aspect and the second aspect of the present invention, the copper alloy constituting the first copper layer further contains Co, Sn, Zn, in the range of 2.0% by mass or less. It can contain one or more of Mg, Fe, Ti, Zr, Cr, Al, P, Mn, B and Ag.

The vapor chamber according to the third aspect of the present invention comprises an upper plate member and a lower plate member formed by using the copper composite plate material of the first aspect or the second aspect, and together with the second copper layer of the upper plate member. The upper plate member and the lower plate member are diffusion-bonded so as to form a space surrounded by the second copper layer of the lower plate member.

A vapor chamber can be manufactured using either or both of the copper composite plates according to the first aspect and the second aspect of the present invention.
That is, the method for manufacturing a vapor chamber according to the first aspect of the present invention is an upper plate formed by using either or both of the copper composite plate materials according to the first aspect and the second aspect of the present invention. It is a method of manufacturing a vapor chamber including a member and a lower plate member, and the upper plate member and the lower plate member are diffusion-bonded, wherein (1) a first heat treatment, (2) a second heat treatment and ( 3) By performing any one of the third heat treatments, the second copper layer of the copper composite plate material constituting the upper plate member and the second copper composite plate material constituting the lower plate member are second. This is a method for manufacturing a vapor chamber, which comprises a step of diffusion-bonding the copper layer and making the 0.2% resistance of the upper plate member and the lower plate member 240 MPa or more.

(1) The first heat treatment includes a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, cooling to 100 ° C. at a cooling rate of 25 ° C. or lower per minute, and then cooling to room temperature.
(2) The second heat treatment is a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, cooling to 100 ° C. or lower, then heating and holding at 400 ° C. or higher and 550 ° C. or lower, and then cooling to room temperature. including.
(3) The third heat treatment includes a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, cooling and holding at 400 ° C. or higher and 550 ° C. or lower, and then cooling to room temperature.

Further, the step of diffusion-bonding the second copper layer of the copper composite plate material constituting the upper plate member and the second copper layer of the copper composite plate material constituting the lower plate member is the copper composite plate material constituting the upper plate member. Includes a step of forming a space between the second copper layer of the above and the second copper layer of the copper composite plate material constituting the lower plate member.

The method for manufacturing a vapor chamber according to the second aspect of the present invention is a top plate member and a top plate member formed by using either or both of the copper composite plate materials according to the first aspect and the second aspect of the present invention. It comprises a lower plate member and a middle plate member in which Cu is composed of 99.9% by mass or more of pure copper or Si is composed of a non-precipitation reinforced copper alloy of less than 0.1% by mass. A method for manufacturing a vapor chamber in which the upper plate member and the middle plate member are diffusion-bonded, and the middle plate member and the lower plate member are diffusion-bonded, wherein (1) the first heat treatment is performed. By performing any one of (2) second heat treatment and (3) third heat treatment, the second copper layer of the copper composite plate material constituting the upper plate member and the middle plate member are separated from each other. The second copper layer of the copper composite plate material constituting the lower plate member and the middle plate member are diffusion-bonded, and the upper plate member and the lower plate member have a 0.2% resistance. It is a method of manufacturing a vapor chamber including a step of making it 240 MPa or more.

(1) The first heat treatment includes a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, cooling to 100 ° C. at a cooling rate of 25 ° C. or lower per minute, and then cooling to room temperature.
(2) The second heat treatment is a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, cooling to 100 ° C. or lower, then heating and holding at 400 ° C. or higher and 550 ° C. or lower, and then cooling to room temperature. including.
(3) The third heat treatment includes a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, cooling and holding at 400 ° C. or higher and 550 ° C. or lower, and then cooling to room temperature.

Further, the step of diffusion-bonding the second copper layer of the copper composite plate material constituting the upper plate member and the second copper layer of the copper composite plate material constituting the lower plate member is the copper composite plate material constituting the upper plate member. Includes a step of forming a space between the second copper layer of the above and the second copper layer of the copper composite plate material constituting the lower plate member.

According to the above-mentioned invention relating to the copper composite plate material, it is possible to provide a copper composite plate material having diffusion bonding property, corrosion resistance and 0.2% proof stress suitable as a constituent member (housing or the like) of a vapor chamber. Further, according to the invention relating to the above-mentioned method for manufacturing a vapor chamber, the vapor chamber has a mechanical strength suitable for a copper-based housing and a suitable corrosion resistance that does not easily react with a solvent (particularly pure water). Can be manufactured.

It is a figure which shows the layer structure of one Embodiment (the 1st Embodiment) of the copper composite plate material according to 1st aspect of this invention schematically. It is a figure which shows typically the layer structure of one Embodiment (second Embodiment) of the copper composite plate material by the 2nd aspect of this invention. It is a figure which shows typically the cross-sectional structure of the main part about one Embodiment (1st configuration example) of a vapor chamber using the copper composite plate material (1st Embodiment) of this invention. It is a figure which shows typically the cross-sectional structure of the main part about one Embodiment (second composition example) of a vapor chamber using the copper composite plate material (second embodiment) of this invention. It is a figure which shows typically the cross-sectional structure of the main part about one Embodiment (third configuration example) of a vapor chamber using the copper composite plate material (1st Embodiment) of this invention. It is a figure which shows typically the cross-sectional structure of the main part about one Embodiment (4th configuration example) of a vapor chamber using the copper composite plate material (2nd Embodiment) of this invention. It is a figure which shows typically the cross-sectional structure of the main part about one Embodiment (fifth configuration example) of a vapor chamber using the copper composite plate material (1st Embodiment and 2nd Embodiment) of this invention. It is a figure which shows typically the cross-sectional structure of the main part about one Embodiment (sixth structural example) of a vapor chamber using the copper composite plate material (2nd Embodiment) of this invention.

Hereinafter, embodiments of the copper composite plate material according to the present invention will be described with reference to the drawings as appropriate.

<First Embodiment>
The copper composite plate material according to the first aspect of the present invention is a copper composite plate material in which a second copper layer is pressure-welded to one surface of the first copper layer, and the first copper layer is composed of a precipitation-reinforced copper alloy. The second copper layer is a copper composite plate material in which Cu is composed of 99.9% by mass or more of pure copper or Si is composed of a non-precipitation reinforced copper alloy of less than 0.1% by mass. .. In the copper composite plate material according to the first aspect of the present invention, the copper alloy constituting the first copper layer is, for example, 0.8% by mass or more and 5.0% by mass or less of Ni, 0.2% by mass or more and 1 It may be a copper alloy consisting of 5.5% by mass or less of Si, the balance Cu and unavoidable impurities. The copper composite plate material having the above-mentioned structure is hereinafter referred to as the first embodiment.

FIG. 1 schematically shows the layer structure of the first embodiment of the copper composite plate material according to the first aspect of the present invention.
The copper composite plate material 10 shown in FIG. 1 is a copper composite plate material formed by pressing a second copper layer 12 onto one surface of the first copper layer 11. In the copper composite plate material 10 shown in FIG. 1, the first copper layer 11 is made of a precipitation-strengthened copper alloy. The precipitation-strengthened copper alloy is, for example, 0.8% by mass or more and 5.0% by mass or less of Ni (nickel), 0.2% by mass or more and 1.5% by mass or less of Si (silicon), and the balance Cu (copper). ) And a copper alloy consisting of unavoidable impurities. The precipitation-strengthened copper alloy described above has higher mechanical properties such as tensile strength, 0.2% proof stress and elongation than pure copper, and also secures bending workability, stress relaxation properties and thermal conductivity. The copper alloy having this composition includes a copper alloy generally called a Corson alloy. The first copper layer 11 made of a copper alloy having this composition is precipitation-hardened by a first heat treatment, a second heat treatment or a third heat treatment, which will be described later. For example, a vapor chamber can be manufactured by using the copper composite plate material 10 provided with the first copper layer 11 made of such a copper alloy. In that case, the heat retention performed in the diffusion bonding when forming the housing of the vapor chamber causes precipitation hardening and improves the mechanical strength of the first copper layer 11, so that the first copper layer 11 has good mechanical strength. A housing can be formed.

The copper alloy constituting the first copper layer 11 shown in FIG. 1 is a precipitation-strengthened copper alloy. The copper alloy constituting the first copper layer 11 is, for example, 0.8% by mass or more and 5.0% by mass or less of Ni, 0.2% by mass or more and 1.5% by mass or less of Si, the balance Cu, and unavoidable impurities. It may be a copper alloy made of. In this copper alloy, Ni is 0.8% by mass or more and 5.0% by mass or less, and Si is 0.2% by mass or more and 1.5% by mass or less. In this copper alloy, Ni and Si are important additive elements for improving mechanical strength by precipitation hardening action. If the Ni content ratio is too small (less than 0.8% by mass) or the Si content ratio is too small (less than 0.2% by mass _{), the formation of precipitates (Ni 2} Si) becomes insufficient, and the copper alloy It is difficult to improve the mechanical strength of. Further, if the Ni content ratio is excessive (more than 5.0% by mass) or the Si content ratio is excessive (more than 1.5% by mass _{), the formation of precipitates (Ni 2} Si) becomes excessive and the copper alloy is formed. It becomes brittle and it becomes difficult to manufacture plate materials by rolling or the like.

Further, in the above-mentioned copper alloy, the balance except Ni and Si is composed of Cu and unavoidable impurities. Cu is a basic element constituting the parent phase of the copper alloy constituting the first copper layer 11. Cu is an element that is particularly important for forming the first copper layer 11 having a high thermal conductivity. From the viewpoint of thermal conductivity and bendability, the Cu content ratio is preferably as large as possible.

Further, in the above-mentioned copper alloy, the balance other than Ni, Si and Cu is an unavoidable impurity. If the content ratio of unavoidable impurities is excessive (for example, more than 0.1% by mass), the processability of the first copper layer 11 is lowered, so that the content ratio of unavoidable impurities is made as small as possible. The content ratio of the unavoidable impurities is, for example, preferably 0.1% by mass or less, more preferably 0.05% by mass or less. As the unavoidable impurities (elements), for example, S, Pb and the like can be considered.

Further, in the above-mentioned copper alloy, additive elements other than Ni and Si can be further contained in the range of 2.0% by mass or less with respect to Cu. Specifically, the above-mentioned copper alloys include Co (cobalt), Sn (tin), Zn (zinc), Mg (magnesium), Fe (iron), Ti (titanium), Zr (zirconium), and Cr (chromium). ), Al (aluminum), P (phosphorus), Mn (manganese), B (boron), and Ag (silver), which may contain one or more of them in a range of 2.0% by mass or less. can. In the above-mentioned copper alloy, by containing one or more of the above-mentioned Co to Ag in the range of 2.0% by mass or less, the mechanical strength is further improved and the bending workability is improved. Improvements can be made.

In the copper composite plate material 10 shown in FIG. 1, the second copper layer 12 is composed of pure copper having a Cu content of 99.9% by mass or more or a non-precipitation reinforced copper alloy having a Si content of less than 0.1% by mass. Has been done. That is, the second copper layer 12 made of pure copper or a non-precipitation reinforced copper alloy has a Si content ratio of less than 0.1% by mass even if it contains Si. It is considered that the exposed surface of the second copper layer 12 having a Si content ratio of less than 0.1% by mass has substantially the same properties as pure copper having more stable electrochemical properties such as corrosion resistance. When, for example, a vapor chamber is manufactured using a copper composite plate material provided with a second copper layer 12 composed of such pure copper or a non-precipitation reinforced copper alloy, the Si content ratio is inside (inner surface) of the housing of the vapor chamber. By using the second copper layer 12 having a value of less than 0.1% by mass, a special reaction is less likely to occur even if a refrigerant composed of pure water or an aqueous solution sealed inside the chamber comes into contact with the reaction. It is possible to form a highly reliable housing in which sex gas is less likely to be generated and corrosion is less likely to proceed. If a copper layer having a Si content ratio of 0.1% by mass or more is used on the inside (inner surface) of the housing of the vapor chamber, copper is held by heating performed by diffusion bonding when forming the housing of the vapor chamber. Precipitates may form on the exposed surface of the layer. If deposits are present on the inside (inner surface) of the housing, corrosion starting from the deposits may progress, the mechanical strength of the housing may be lowered, and the life of the vapor chamber may be deteriorated.

When the second copper layer 12 is made of pure copper, C10200 (oxygen-free copper), C10300 (low phosphorus deoxidized copper), C11000 (tough pitch copper) and the like of UNS regulation No. can be used as the pure copper. When the second copper layer 12 is composed of a non-precipitation reinforced copper alloy in which Si is less than 0.1% by mass, the non-precipitation reinforced copper alloy is C15150 (Cu-Zr) represented by UNS regulation No. System), C14415 (Cu-Sn system), C10700 (Cu-Ag system), C18665 (Cu-Mg system), C70200 (Cu-Ni system), C40410 (Cu-Zn system) and the like can be used. When a vapor chamber is manufactured using a copper composite plate material provided with a second copper layer 12 made of such pure copper or a non-precipitation reinforced copper alloy, diffusion bonding is performed when forming the housing of the vapor chamber. No precipitate is formed on the surface of the second copper layer 12 even by the heat holding.

In the copper composite plate material according to the first aspect of the present invention, when the thickness of the first copper layer is T1 and the thickness of the second copper layer is T2, T2 / (T1 + T2) × 100 ≦ 30% and T2> It is preferable to satisfy 1 μm. In the copper composite plate material 10 shown in FIG. 1, the total thickness is T, the thickness of the first copper layer 11 is T1, and the thickness of the second copper layer 12 is T2. In the copper composite plate material 10, the first copper layer 11 and the second copper layer 12 satisfy the relationship of T2 / (T1 + T2) × 100 ≦ 30% and T2> 1 μm (preferably T2 ≧ 2 μm). The total thickness T of the copper composite plate 10 is equal to T1 + T2. In the copper composite plate material 10 provided with the second copper layer 12 having such a configuration, the thickness T2 of the second copper layer 12 occupying the total thickness T becomes smaller, and the thickness T2 of the first copper layer 11 occupying the total thickness T becomes smaller. The thickness T1 increases.

Further, in the case of manufacturing a vapor chamber using the copper composite plate material 10, for example, as described above, the second copper that does not undergo precipitation hardening due to the heat holding performed by the diffusion joining when forming the housing of the vapor chamber. The mechanical strength of the first copper layer 11 that causes precipitation hardening is greater than the mechanical strength of the layer 12. For example, in the case of manufacturing a vapor chamber, good mechanical strength is obtained by forming a housing of the vapor chamber using a copper composite plate material 10 in which the first copper layer 11 having a large mechanical strength occupies a large proportion. It is possible to form a housing having. Further, the 0.2% proof stress of the housing of the vapor chamber is preferably 240 MPa or more, and more preferably 300 MPa or more. From this point of view, in the copper composite plate material 10 constituting the housing of the vapor chamber, the first copper layer 11 and the second copper layer 12 may be configured to satisfy T2 / (T1 + T2) × 100 ≦ 30%. preferable. The copper composite plate material 10 configured in this way can have a 0.2% proof stress of 240 MPa or more.

Further, for example, in the case of manufacturing a vapor chamber, the inside (inner surface) of the housing of the vapor chamber may be subjected to uneven processing by etching. By using the copper composite plate material 10 having the thickness structure described above, the second copper layer 12 satisfying the relationship of T2> 1 μm (preferably T2 ≧ 2 μm) is arranged inside (inner surface) of the housing of the vapor chamber. It is possible to prevent a problem that the second copper layer 12 is removed by excessive etching and the first copper layer 11 is exposed. When etching the surface of the second copper layer 12, when the removal amount (maximum depth) by the etching is D (unit: μm), the thickness T2 of the second copper layer 12 is T2 ≧. It is preferable to satisfy D + 1 μm, and more preferably T2 ≧ D + 2 μm.

In the copper composite plate material according to the first aspect of the present invention, it is preferable that the second copper layer has a surface roughness R _ZJIS of 0.8 μm or less and a kurtosis Rku of 4 or less. The second copper layer 12 of the copper composite plate material 1 shown in FIG. 1 has a surface roughness (ten-point average roughness) R _ZJIS of 0.8 μm or less and a kurtosis Rku of 4 or less. The surface roughness R _ZJIS and the kurtosis Rku conform to JIS B0601: 2013 (or JIS B0601: 2001). When, for example, a vapor chamber is manufactured using the copper composite plate material 1 shown in FIG. 1, a _{second copper layer 12 having a surface roughness R ZJIS} of 0.8 μm or less and a kurtosis Rku of 4 or less is used as a housing. By arranging it on the inner side (inner surface) and performing diffusion bonding by heating and holding, the contact state between the second copper layer 12 and the member to be bonded approaches surface contact, the degree of adhesion is improved, and the bonding strength by diffusion bonding is improved. Therefore, it is possible to form a housing (joining member) having good mechanical strength.

In the first embodiment described above, the thickness T of the copper composite plate material 10 may be, for example, 0.01 mm or more and 1 mm or less, preferably 0.02 mm or more and 0.3 mm or less, and more preferably 0.02 mm or more and 0. It is 1 mm or less. The thickness T1 of the first copper layer 11 may be, for example, 0.007 mm or more and 0.999 mm or less, preferably 0.014 mm or more and 0.299 mm or less, and more preferably 0.014 mm or more and 0.099 mm or less. be. The difference between the thickness T and the thickness T1 described above corresponds to the thickness T2 of the second copper layer 12. Further, the thickness T2 of the second copper layer 12 is preferably set in consideration of the relationship between the thickness T of the copper composite plate 10 and the thickness T1 of the first copper layer 11.

<Second Embodiment>
The copper composite plate material according to the second aspect of the present invention is a copper composite plate material in which the second copper layer is pressed against one surface of the first copper layer and the third copper layer is pressed against the other surface of the first copper layer. Therefore, the first copper layer is composed of a precipitation-reinforced copper alloy, and the second copper layer and the third copper layer are both composed of pure copper having a Cu content of 99.9% by mass or more, or Si. It is a copper composite plate material composed of a non-precipitation reinforced copper alloy of less than 0.1% by mass. In the copper composite plate material according to the second aspect of the present invention, the copper alloy constituting the first copper layer is, for example, 0.8% by mass or more and 5.0% by mass or less of Ni, 0.2% by mass or more and 1 It may be a copper alloy consisting of 5.5% by mass or less of Si, the balance Cu and unavoidable impurities. The copper composite plate material having the above-mentioned structure is hereinafter referred to as a second embodiment.

FIG. 2 schematically shows the layer structure of the second embodiment of the copper composite plate material according to the second aspect of the present invention.
The copper composite plate 20 shown in FIG. 2 is a copper composite plate in which the second copper layer 22 is pressed against one surface of the first copper layer 21 and the third copper layer 23 is pressed against the other surface of the first copper layer 21. Is. In this second embodiment, when the configuration of the second copper layer 22 and the configuration of the third copper layer 23 are equivalent or substantially equivalent, for example, the thickness of each layer (T2, T3), surface texture and various properties are included. When the composition of the material and the like is the same or substantially the same, the front and back sides of the copper composite plate 20 can be used without any particular distinction, which is convenient for production. Further, from the viewpoint of aiming for further thinning, it is preferable that the thickness T2 of the second copper layer 22 and the thickness T3 of the third copper layer 23 are equal to or substantially the same, and a large warp occurs during rolling. It can be easily thinned without any particular inconvenience.

In the copper composite plate 20 shown in FIG. 2, the first copper layer 21 is made of a precipitation-strengthened copper alloy. The precipitation-strengthened copper alloy is, for example, 0.8% by mass or more and 5.0% by mass or less of Ni (nickel), 0.2% by mass or more and 1.5% by mass or less of Si (silicon), and the balance Cu (copper). ) And a copper alloy consisting of unavoidable impurities. The configuration and the preferred configuration of the first copper layer 21 are the same as the configuration of the first copper layer 11 in the above-described first embodiment, including the action exerted by the configuration. Therefore, the description of the configuration of the first copper layer 21 will refer to the description of the first embodiment described above, and the description thereof will be omitted here.

In the copper composite plate 20 shown in FIG. 2, the second copper layer 22 is composed of pure copper having a Cu content of 99.9% by mass or more or a non-precipitation reinforced copper alloy having a Si content of less than 0.1% by mass. Has been done. That is, even if the second copper layer 22 made of pure copper or a non-precipitation reinforced copper alloy contains Si, its Si content ratio is less than 0.1% by mass. The configuration and the preferred configuration of the second copper layer 22 are the same as the configuration of the second copper layer 12 in the above-described first embodiment, including the action exerted by the configuration. Therefore, the description of the configuration of the second copper layer 22 will refer to the description of the first embodiment described above, and the description thereof will be omitted here.

In the copper composite plate 20 shown in FIG. 2, the third copper layer 23 is composed of pure copper having a Cu content of 99.9% by mass or more or a non-precipitation reinforced copper alloy having a Si content of less than 0.1% by mass. Has been done. That is, the configuration of the third copper layer 23 is the same as the configuration of the second copper layer 22. That is, like the second copper layer 22, the third copper layer 23 made of pure copper or a non-precipitation reinforced copper alloy contains Si even if it contains Si by 0.1 mass. Less than%. The configuration and preferable configuration of the third copper layer 23 are equivalent to the configuration of the second copper layer 22 described above, including the action exerted by the configuration, that is, equivalent to the configuration of the second copper layer 12 in the first embodiment. Is. Therefore, the description of the configuration of the third copper layer 23 will refer to the description of the first embodiment described above, and the description thereof will be omitted here.

In the second embodiment described above, the thickness T of the copper composite plate 20 may be, for example, 0.01 mm or more and 1 mm or less, preferably 0.02 mm or more and 0.3 mm or less, and more preferably 0.02 mm or more and 0. .1 mm or less. The thickness T1 of the first copper layer 21 may be, for example, 0.007 mm or more and 0.998 mm or less, preferably 0.014 mm or more and 0.298 mm or less, and more preferably 0.014 mm or more and 0.098 mm or less. be. The difference between the thickness T and the thickness T1 described above corresponds to the total of the thickness T2 of the second copper layer 22 and the thickness T3 of the third copper layer 23. Further, the thickness T2 of the second copper layer 22 and the thickness T3 of the third copper layer 23 take into consideration the relationship between the thickness T of the copper composite plate 20 and the thickness T1 of the first copper layer 21 described above. It is preferable to set it. Further, it is preferable to set the thickness T2 of the second copper layer 22 and the thickness T3 of the third copper layer 23 to be the same or substantially the same, and the copper composite plate material 20 can be used without distinguishing between the front and back sides.

A vapor chamber can be manufactured using either the first embodiment or the second embodiment of the copper composite plate material described above, or using both the first embodiment and the second embodiment.
Hereinafter, a configuration example of the vapor chamber will be described with reference to the drawings as appropriate.

<First configuration example>
FIG. 3 schematically shows a configuration example (first configuration example) of a cross section of a main part of the vapor chamber. The vapor chamber 100 shown in FIG. 3 has a flat plate-like appearance as a whole, and is configured by using the copper composite plate material 10 (first embodiment) shown in FIG. Specifically, in the vapor chamber 100, the upper plate member 101 configured by using the copper composite plate material 10 and the lower plate member 102 configured by using the copper composite plate material 10 are joined at the joint portion 105. There is. The interior 106 of the vapor chamber 100 is a space surrounded by the second copper layer 12 constituting the copper composite plate material 10, and the first copper layer 11 constituting the copper composite plate material 10 is not exposed. A refrigerant (for example, pure water) can be vacuum-sealed in the inside 106 of the vapor chamber 100. In the second copper layer 12 constituting the upper plate member 101, a part of the surface opposite to the surface on which the first copper layer 11 is pressed is removed. Further, in the second copper layer 12 constituting the lower plate member 102, a part of the surface opposite to the surface on which the first copper layer 11 is pressed is removed. As a result, when the upper plate member 101 and the lower plate member 102 are diffusion-bonded, a space (inside 106) surrounded by the second copper layer 12 is formed.

The upper plate member 101 and the lower plate member 102 constituting the vapor chamber 100 are cut into individual pieces by cutting the copper composite plate material 10 into a predetermined shape, and the end portion of the individualized copper composite plate material 10 is bent. It is formed by a manufacturing method. The copper composite plate material 10 is rolled in a state where the first copper plate material for forming the first copper layer 11 and the second copper plate material for forming the second copper layer 12 are laminated, and finally a predetermined value is obtained. It can be formed by a manufacturing method for forming to a thickness (for example, the thickness T shown in FIG. 1).

The joint portion 105 of the vapor chamber 100 is formed by diffusion bonding according to a predetermined heating pattern. Specifically, the lower plate member 102 is arranged below, and heating and holding is performed in a state where a load is applied to the surface to be joined (see the joint portion 105) from above the upper plate member 101. During this heating and holding, a diffusion phenomenon occurs between the surface to be joined of the upper plate member 101 and the surface to be joined of the lower plate member 102, so that the surfaces to be joined are joined (diffusion joining) to form a joint portion 105. Will be done. In this heat treatment, one of (1) first heat treatment, (2) second heat treatment, and (3) third heat treatment, which will be described later, may be performed. If any of the heat treatments is performed in a non-oxidizing atmosphere using, for example, nitrogen gas, argon gas, or a mixed gas of nitrogen and argon, the surface roughness of the material to be heat-treated due to heat oxidation is suppressed. preferable.

(1) The first heat treatment includes a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, cooling to 100 ° C. at a cooling rate of 25 ° C. or lower per minute, and then cooling to room temperature.
(2) The second heat treatment is a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, cooling to 100 ° C. or lower, then heating and holding at 400 ° C. or higher and 550 ° C. or lower, and then cooling to room temperature. including.
(3) The third heat treatment includes a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, cooling and holding at 400 ° C. or higher and 550 ° C. or lower, and then cooling to room temperature.

In any of the first heat treatment, the second heat treatment, and the third heat treatment described above, the second copper layer 12 of the copper composite plate material 10 constituting the upper plate member 101 and the copper composite plate material 10 constituting the lower plate member 102 are the first. 2 The copper layer 12 is diffusion-bonded. Similarly, the first copper layer 11 of the copper composite plate material 10 constituting the upper plate member 101 and the first copper layer 11 of the copper composite plate material 10 constituting the lower plate member 102 are diffusion-bonded. Further, the 0.2% proof stress of the upper plate member 101 and the lower plate member 102 can be set to 2400 MPa or more, further 300 MPa or more. Further, a space (inside 106) for decompressing and sealing the refrigerant is formed between the second copper layer 12 of the upper plate member 101 and the second copper layer 12 of the lower plate member 102.

In the first heat treatment, the second heat treatment, and the third heat treatment described above, the first heat treatment is to heat and hold at 600 ° C. or higher and 1000 ° C. or lower. The copper composite plate material 10 constituting the upper plate member 101 and the lower plate member 102 is made of pure copper and / or a copper alloy as described above. Therefore, excessive heat retention exceeding 1000 ° C. tends to reduce the mechanical strength (0.2% proof stress, etc.) obtained as pure copper and / or copper alloy, and the mechanical strength of the vapor chamber 100 (0.2%). % Strength, etc.) and other characteristics are likely to be insufficient. If the temperature is kept below 600 ° C., the above-mentioned diffusion bonding becomes insufficient, and the copper alloy constituting the first copper layer 11 of the copper composite plate 10 is not precipitation-hardened. Therefore, the mechanical strength of the vapor chamber 100 ( 0.2% proof stress, etc.) and the joint strength of the joint portion 105, etc. become insufficient.

The holding time in the first heat holding described above is not particularly limited, but is preferably 0 hours or more and 4 hours or less, and more preferably 0 hours or more and 2 hours or less. The holding time can be set according to a desired configuration with respect to, for example, the mechanical strength of the vapor chamber 100, the joint strength of the joint portion 105, the surface texture of the inner 106, and the like. In this case, if it is considered that only the predetermined holding temperature needs to be reached, the holding time may be 0 hours. It should be noted that the mechanical strength (0.2% proof stress) obtained as pure copper and / or a copper alloy when excessive holding is performed for more than 4 hours in an atmosphere of relatively high temperature (for example, 900 ° C. or higher and 1000 ° C. or lower). Etc.) and other characteristics are likely to be insufficient. Further, even if excessive holding is performed for more than 4 hours in an atmosphere of a relatively low temperature (for example, 600 ° C. or higher and 900 ° C. or lower), it is difficult to improve various properties obtained as pure copper and / or a copper alloy.

Further, in the first heat treatment, after the above-mentioned first heat retention, the mixture is cooled to 100 ° C. at a cooling rate of 25 ° C. or less per minute. If the cooling rate exceeds 25 ° C. per minute, various characteristics such as mechanical strength (0.2% proof stress, etc.) of the vapor chamber 100 tend to be insufficient.

Further, in the second heat treatment, after the first heating and holding described above, the mixture is cooled to 100 ° C. or lower, and then heated to 400 ° C. or higher and 550 ° C. or lower for holding. From the viewpoint of improving various characteristics such as mechanical strength (0.2% proof stress, etc.) of the vapor chamber 100, the holding temperature is preferably 400 ° C. or higher and 550 ° C. or lower, more preferably 450 ° C. or higher and 540 ° C. or lower. And. The holding time is preferably 10 minutes or more and 4 hours or less, and more preferably 30 minutes or more and 2 hours or less.

Further, in the third heat treatment, after the first heating and holding described above, the heat is cooled to 400 ° C. or higher and 550 ° C. or lower and held. From the viewpoint of improving various characteristics such as mechanical strength (0.2% proof stress, etc.) of the vapor chamber 100, the holding temperature (cooling holding temperature) when cooling and holding is preferably 400 ° C. or higher and 550 ° C. or lower. Is 450 ° C. or higher and 540 ° C. or lower. The holding time (cooling holding time) is preferably 10 minutes or more and 4 hours or less, and more preferably 30 minutes or more and 2 hours or less.

<Second configuration example>
FIG. 4 schematically shows a configuration example (second configuration example) of a cross section of a main part of the vapor chamber. The vapor chamber 200 shown in FIG. 4 has a flat plate-like appearance as a whole, and is configured by using the copper composite plate material 20 (second embodiment) shown in FIG. Specifically, in the vapor chamber 200, the upper plate member 201 made of the copper composite plate material 20 and the lower plate member 202 made of the copper composite plate material 20 are joined at the joint portion 205. There is. The interior 206 of the vapor chamber 200 is a space surrounded by the second copper layer 22 constituting the copper composite plate material 20, and the first copper layer 21 constituting the copper composite plate material 20 is not exposed. A refrigerant (for example, pure water) can be vacuum-sealed in the inside 206 of the vapor chamber 200. In the second copper layer 22 constituting the upper plate member 201, a part of the surface opposite to the surface on which the first copper layer 21 is pressed is removed. Further, in the second copper layer 22 constituting the lower plate member 202, a part of the surface opposite to the surface on which the first copper layer 21 is pressed is removed. As a result, when the upper plate member 201 and the lower plate member 202 are diffusion-bonded, a space (inside 206) surrounded by the second copper layer 22 is formed.

The upper plate member 201 and the lower plate member 202 constituting the vapor chamber 200 are cut into a predetermined shape of the copper composite plate material 20 to be individualized, and the end portion of the individualized copper composite plate material 20 is bent. It is formed by a manufacturing method. The copper composite plate material 20 is for forming the first copper plate material for forming the first copper layer 21, the second copper plate material for forming the second copper layer 22, and the third copper layer 23. The third copper plate material is rolled in a state of being laminated so as to sandwich the first copper plate material between the second copper plate material and the third copper plate material, and finally a predetermined thickness (for example, the thickness T shown in FIG. 2) is obtained. ) Can be formed by the manufacturing method.

The joint portion 205 of the vapor chamber 200 is formed by diffusion bonding according to a predetermined heating pattern. Specifically, the lower plate member 202 is arranged below, and heating and holding is performed in a state where a load is applied to the surface to be joined (see the joint portion 205) from above the upper plate member 201. During this heating and holding, a diffusion phenomenon occurs between the surface to be joined of the upper plate member 201 and the surface to be joined of the lower plate member 202, so that the surfaces to be joined are joined (diffusion joining) to form the joint portion 205. Will be done. In this heat treatment, it is preferable to perform any one of the above-mentioned (1) first heat treatment, (2) second heat treatment, and (3) third heat treatment as in the first configuration example. In any of the first heat treatment, the second heat treatment, and the third heat treatment, the second copper layer 22 and the third copper layer 23 of the copper composite plate material 20 constituting the upper plate member 201 and the copper composite constituting the lower plate member 202 are used. The second copper layer 22 of the plate material 10 is diffusion-bonded. Similarly, the first copper layer 21 of the copper composite plate material 20 constituting the upper plate member 201 and the first copper layer 21 of the copper composite plate material 20 constituting the lower plate member 202 are diffusion-bonded. Further, the 0.2% proof stress of the upper plate member 201 and the lower plate member 202 can be 240 MPa or more, further 300 MPa or more. Further, a space (inside 206) for decompressing and sealing the refrigerant is formed between the second copper layer 22 constituting the upper plate member 201 and the second copper layer 22 constituting the lower plate member 202. ..

<Third configuration example>
FIG. 5 schematically shows a configuration example (third configuration example) of a cross section of a main part of the vapor chamber. The vapor chamber 300 shown in FIG. 5 has a flat plate-like appearance as a whole, and is configured by using the copper composite plate material 10 (first embodiment) shown in FIG. Specifically, in the vapor chamber 300, the upper plate member 301 made of the copper composite plate material 10 and the lower plate member 302 made of the copper composite plate material 10 are joined at the joint portion 305a. At the same time, a plurality of middle plate members 303 arranged between the second copper layer 12 constituting the upper plate member 301 and the second copper layer 12 constituting the lower plate member 302 are provided at the joint portion 305b. It is joined. The plurality of middle plate members 303 may be made of pure copper or a non-precipitation hardening type copper alloy, and are preferably made of a material equivalent to or substantially equivalent to that of the second copper layer 12. The interior 306 of the vapor chamber 300 is a space surrounded by the second copper layer 12 constituting the copper composite plate material 10, and the first copper layer 11 constituting the copper composite plate material 10 is not exposed. A refrigerant (for example, pure water) can be vacuum-sealed in the inside 306 of the vapor chamber 300. In the second copper layer 12 constituting the upper plate member 301, a part of the surface opposite to the surface to which the first copper layer 11 is pressed is removed. Further, in the second copper layer 12 constituting the lower plate member 302, a part of the surface opposite to the surface on which the first copper layer 11 is pressed is removed. As a result, when the upper plate member 301 and the lower plate member 302 are diffusion-bonded, a space (inside 306) surrounded by the second copper layer 12 is formed. Further, the internal 306 of the vapor chamber 300 is divided into a plurality of spaces by a plurality of middle plate members 303, and the plurality of spaces are connected by a plurality of holes 303a provided so as to penetrate the plurality of middle plate members 303. .. The plurality of holes 303a allow the refrigerant to move inside the vapor chamber 300 (in the plurality of spaces).

The upper plate member 301 and the lower plate member 302 constituting the vapor chamber 300 are cut into individual pieces by cutting the copper composite plate material 10 into a predetermined shape, and the end portions of the individualized copper composite plate materials 10 are bent. It is formed by a manufacturing method. The copper composite plate material 10 is rolled in a state where the first copper plate material for forming the first copper layer 11 and the second copper plate material for forming the second copper layer 12 are laminated, and finally a predetermined value is obtained. It can be formed by a manufacturing method for forming to a thickness (for example, the thickness T shown in FIG. 1).

The joint portions 305a and 305b of the vapor chamber 300 are formed by diffusion bonding according to a predetermined heating pattern. Specifically, the lower plate member 302 is arranged below, and heating and holding is performed in a state where a load is applied to the surface to be joined (see the joint portions 305a and 305b) from above the upper plate member 301. During this heating and holding, a diffusion phenomenon occurs between the surface to be joined of the upper plate member 301 and the surface to be joined of the lower plate member 302, so that the surfaces to be joined are joined (diffusion joining) to form a joint portion 305a. Will be done. At the same time, during this heating and holding, the surface (bonded surface) of the second copper layer 12 of the copper composite plate material 10 constituting the upper plate member 301 and the lower plate member 302 and the bonded surface of the plurality of middle plate members 303 Due to the diffusion phenomenon occurring between them, the surfaces to be joined are joined (diffusion joining) to form the joint portion 305b. In this heat treatment, it is preferable to perform any one of the above-mentioned (1) first heat treatment, (2) second heat treatment, and (3) third heat treatment as in the first configuration example. In any of the first heat treatment, the second heat treatment, and the third heat treatment, the second copper layer 12 of the copper composite plate material 10 constituting the upper plate member 301 and the second copper of the copper composite plate material 10 constituting the lower plate member 302 are used. The layer 12 is diffusion-bonded. Similarly, the first copper layer 11 of the copper composite plate material 10 constituting the upper plate member 301 and the first copper layer 11 of the copper composite plate material 10 constituting the lower plate member 302 are diffusion-bonded. Further, the 0.2% proof stress of the upper plate member 301 and the lower plate member 302 can be 240 MPa or more, further 300 MPa or more. Further, a space (inside 306) for decompressing and sealing the refrigerant is formed between the second copper layer 12 constituting the upper plate member 301 and the second copper layer 12 constituting the lower plate member 302.

<Fourth configuration example>
FIG. 6 schematically shows a configuration example (fourth configuration example) of a cross section of a main part of the vapor chamber. The vapor chamber 400 shown in FIG. 6 has a flat plate-like appearance as a whole, and is configured by using the copper composite plate material 20 (second embodiment) shown in FIG. Specifically, in the vapor chamber 400, the upper plate member 401 configured by using the copper composite plate material 20 and the lower plate member 402 configured by using the copper composite plate material 20 are joined at the joint portion 405a. At the same time, a plurality of middle plate members 403 arranged between the second copper layer 22 constituting the upper plate member 401 and the second copper layer 22 constituting the lower plate member 402 are formed at the joint portion 405b. It is joined. The plurality of middle plate members 403 may be made of pure copper or a non-precipitation hardening type copper alloy, and are preferably made of a material equivalent to or substantially equivalent to that of the second copper layer 22. The internal 406 of the vapor chamber 400 is a space surrounded by the second copper layer 22 constituting the copper composite plate material 20, and the first copper layer 21 constituting the copper composite plate material 20 is not exposed. A refrigerant (for example, pure water) can be vacuum-sealed in the internal 406 of the vapor chamber 400. The second copper layer 22 constituting the upper plate member 401 has a part of the surface opposite to the surface to which the first copper layer 21 is pressure-welded removed. Further, in the second copper layer 22 constituting the lower plate member 402, a part of the surface opposite to the surface on which the first copper layer 21 is pressed is removed. As a result, when the upper plate member 401 and the lower plate member 402 are diffusion-bonded, a space (inside 406) surrounded by the second copper layer 22 is formed. Further, the internal 406 of the vapor chamber 400 is divided into a plurality of spaces by a plurality of middle plate members 403, and the plurality of spaces are connected by a plurality of holes 403a provided through the plurality of middle plate members 403. .. The plurality of holes 403a allow the refrigerant to move inside the vapor chamber 400 (in the plurality of spaces).

The upper plate member 401 and the lower plate member 402 constituting the vapor chamber 400 are made by cutting the copper composite plate material 20 into a predetermined shape and individualizing it, and bending the end portion of the individualized copper composite plate material 20. It is formed by a manufacturing method. The copper composite plate material 20 is for forming the first copper plate material for forming the first copper layer 21, the second copper plate material for forming the second copper layer 22, and the third copper layer 23. The third copper plate material is rolled in a state of being laminated so as to sandwich the first copper plate material between the second copper plate material and the third copper plate material, and finally a predetermined thickness (for example, the thickness T shown in FIG. 2) is obtained. ) Can be formed by the manufacturing method.

The joint portions 405a and 405b of the vapor chamber 400 are formed by diffusion bonding according to a predetermined heating pattern. Specifically, the lower plate member 402 is arranged below as in the third configuration example, and heat holding is performed in a state where a load is applied to the bonded surface (see the joint portions 405a and 405b) from above the upper plate member 401. conduct. During this heating and holding, a diffusion phenomenon occurs between the surface to be joined of the upper plate member 401 and the surface to be joined of the lower plate member 402, so that the surfaces to be joined are joined (diffusion joining) to form a joint portion 405a. Will be done. At the same time, during this heating and holding, the surface (bonded surface) of the second copper layer 22 of the copper composite plate material 20 constituting the upper plate member 401 and the lower plate member 402 and the bonded surface of the plurality of middle plate members 403 Due to the diffusion phenomenon occurring between them, the surfaces to be joined are joined (diffusion joining) to form the joint portion 405b. In this heat treatment, it is preferable to perform any one of the above-mentioned (1) first heat treatment, (2) second heat treatment, and (3) third heat treatment as in the first configuration example. In any of the first heat treatment, the second heat treatment, and the third heat treatment, the second copper layer 22 of the copper composite plate material 20 constituting the upper plate member 401 and the second copper of the copper composite plate material 20 constituting the lower plate member 402 are used. The layer 22 is diffusion-bonded. Similarly, the first copper layer 21 of the copper composite plate material 20 constituting the upper plate member 401 and the first copper layer 21 of the copper composite plate material 20 constituting the lower plate member 402 are diffusion-bonded. Further, the second copper layer 22 of the copper composite plate material 20 constituting the upper plate member 401 and the middle plate member 403 are diffusion-bonded to each other, and the second copper layer 22 of the copper composite plate material 20 constituting the lower plate member 402 is formed. The middle plate member 403 is diffusion-bonded. Further, the 0.2% proof stress of the upper plate member 401 and the lower plate member 402 can be 240 MPa or more, further 300 MPa or more. Further, a space (inside 406) for decompressing and sealing the refrigerant is formed between the second copper layer 22 constituting the upper plate member 401 and the second copper layer 22 constituting the lower plate member 402.

<Fifth configuration example>
FIG. 7 schematically shows a configuration example (fifth configuration example) of a cross section of a main part of the vapor chamber. The vapor chamber 500 shown in FIG. 7 has a flat plate-like appearance as a whole, and has the copper composite plate material 10 (first embodiment) shown in FIG. 1 and the copper composite plate material 20 (second embodiment) shown in FIG. It is configured using. Specifically, in the vapor chamber 500, the upper plate member 501 made of the copper composite plate material 20 and the lower plate member 502 made of the copper composite plate material 10 are joined at the joint portion 505. There is. The interior 506 of the vapor chamber 500 is a space surrounded by a second copper layer 12 constituting the copper composite plate material 10 and a second copper layer 22 constituting the copper composite plate material 20, and is a first space constituting the copper composite plate material 10. The first copper layer 21 constituting the copper layer 11 and the copper composite plate material 20 is not exposed. A refrigerant (for example, pure water) can be vacuum-sealed in the inside 506 of the vapor chamber 500. In the second copper layer 22 constituting the upper plate member 501, a part of the surface opposite to the surface on which the first copper layer 21 is pressed is removed. Further, in the second copper layer 12 constituting the lower plate member 502, a part of the surface opposite to the surface on which the first copper layer 11 is pressed is removed. As a result, when the upper plate member 501 and the lower plate member 502 are diffusion-bonded, a space (inside 506) surrounded by the second copper layer 12 and the second copper layer 22 is formed.

Further, a plurality of recesses 504 are provided on the wall surface of the inside 506 of the vapor chamber 500. Specifically, a plurality of recesses 504 are provided on the surface (wall surface of the inner surface 506) of the second copper layer 22 of the copper composite plate material 20 constituting the upper plate member 501 of the vapor chamber 500. Since the surface area of the wall surface of the inner 506 is increased by providing the plurality of recesses 504 on the wall surface of the inner 506 of the vapor chamber 500, the surface area to which the refrigerant can come into contact can be increased. By increasing the contact area of the refrigerant by the amount of the plurality of recesses 504, the thermal conductivity between the refrigerant and the upper plate member 501 is improved, and the heat diffusion performance of the vapor chamber 500 can be expected to be improved.

The plurality of recesses 504 correspond to the plurality of recesses 504 on the surface of the second copper layer 22 by etching the surface of the second copper layer 22 of the copper composite plate 20 before forming the vapor chamber 500. It can be formed by a manufacturing method that removes the position by a predetermined depth. When etching is performed on the surface of the second copper layer 22 constituting the wall surface of the inner 506 of the vapor chamber 500, the second copper layer 22 is completely removed and the first copper layer 21 is exposed on the surface. Appropriately control the etching conditions so that there is no such thing. Further, the plurality of recesses 504 are not limited to the forming method by etching, but can also be formed by plastic working such as press working.

The upper plate member 501 before etching constituting the vapor chamber 500 is formed by a manufacturing method in which the copper composite plate material 20 is cut into a predetermined shape and individualized. Further, the lower plate member 502 constituting the vapor chamber 500 is manufactured by a manufacturing method in which the copper composite plate material 10 is cut into a predetermined shape to be individualized, and the end portion of the individualized copper composite plate material 10 is bent. , Is formed. The copper composite plate material 10 can be formed by the same manufacturing method as the copper composite plate material 10 in the above-mentioned first configuration example. Further, the copper composite plate material 20 can be formed by the same manufacturing method as the copper composite plate material 20 in the above-mentioned second configuration example.
can do.

The joint portion 505 of the vapor chamber 500 is formed by diffusion bonding according to a predetermined heating pattern. Specifically, the lower plate member 502 is arranged below, and heating and holding is performed in a state where a load is applied to the surface to be joined (see the joint portion 505) from above the upper plate member 501. During this heating and holding, a diffusion phenomenon occurs between the surface (bonded surface) of the second copper layer 22 of the copper composite plate 20 constituting the upper plate member 501 and the bonded surface of the lower plate member 502. The joint surfaces are joined (diffusion joint) to form a joint portion 505. In this heat treatment, it is preferable to perform any one of the above-mentioned (1) first heat treatment, (2) second heat treatment, and (3) third heat treatment as in the first configuration example. In any of the first heat treatment, the second heat treatment, and the third heat treatment, the second copper layer 22 of the copper composite plate material 20 constituting the upper plate member 501 and the second copper of the copper composite plate material 10 constituting the lower plate member 502. The layer 22 is diffusion-bonded. Similarly, the second copper layer 22 of the copper composite plate material 20 constituting the upper plate member 501 and the first copper layer 11 of the copper composite plate material 10 constituting the lower plate member 502 are diffusion-bonded. Further, the 0.2% proof stress of the upper plate member 501 and the lower plate member 502 can be 240 MPa or more, further 300 MPa or more. Further, a space (inside 506) for decompressing and sealing the refrigerant is formed between the second copper layer 22 constituting the upper plate member 501 and the second copper layer 12 constituting the lower plate member 502.

<Sixth configuration example>
FIG. 8 schematically shows a configuration example (sixth configuration example) of a cross section of a main part of the vapor chamber. The vapor chamber 600 shown in FIG. 8 has a flat plate-like appearance as a whole, and is configured by using the copper composite plate material 20 (second embodiment) shown in FIG. Specifically, in the vapor chamber 600, the upper plate member 601 and the middle plate member 603 made of the copper composite plate material 20 and the lower plate member 602 and the middle plate member 602 made of the copper composite plate material 20 are used. The plate members 603 are joined at the joining portion 605, respectively. The middle plate member 603 may be made of pure copper or a non-precipitation hardening type copper alloy, and is preferably made of a material equivalent to or substantially equivalent to that of the second copper layer 22. The interior 606 of the vapor chamber 600 is a space surrounded by the second copper layer 22 constituting the copper composite plate material 20, and the first copper layer 21 constituting the copper composite plate material 20 is not exposed. A refrigerant (for example, pure water) can be vacuum-sealed in the inside 606 of the vapor chamber 600. Further, the internal 606 of the vapor chamber 600 is divided into a plurality of spaces by a plurality of holes 603a and 603b provided in the middle plate member 603, and the plurality of spaces are provided in the upper plate member 601 and the lower plate member 602. It is connected by a plurality of recesses 604a and 604b. The plurality of holes 603a, 603b and the plurality of recesses 604a, 604b allow the refrigerant to move inside the vapor chamber 600 (in the plurality of spaces).

Further, a plurality of recesses 604a and 604b are provided on the wall surface of the inner 606 of the vapor chamber 600. Specifically, a plurality of recesses 604a are provided on the surface (wall surface of the inner surface 606) of the second copper layer 22 of the copper composite plate material 20 constituting the upper plate member 601 of the vapor chamber 600. Further, a plurality of recesses 604b are provided on the surface (wall surface of the inner surface 606) of the second copper layer 22 of the copper composite plate material 20 constituting the lower plate member 602 of the vapor chamber 600. Since the surface area of the wall surface of the inner 606 is increased by providing the plurality of recesses 604a and 604b on the wall surface of the inner 606 of the vapor chamber 600, the surface area to which the refrigerant can come into contact can be increased. The contact area of the refrigerant is increased by the amount of the plurality of recesses 604a of the upper plate member 601 and further increased by the amount of the plurality of recesses 604b of the lower plate member 602, whereby the refrigerant and the upper plate member 601 and the lower plate member 602 are increased. The thermal conductivity between the two is further improved, and further improvement in the heat diffusion performance of the vapor chamber 600 can be expected.

These plurality of recesses 604a and 604b are etched into the surface of the second copper layer 22 of the copper composite plate 20 before forming the vapor chamber 600, and the plurality of recesses 604a on the surface of the second copper layer 22 are etched. It can be formed by a manufacturing method in which the position corresponding to 604b is removed by a predetermined depth. When etching the surface of the second copper layer 22 constituting the wall surface of the inner 606 of the vapor chamber 600, the second copper layer 22 is completely removed and the first copper layer 21 is exposed on the surface. Appropriately control the etching conditions so that there is no such thing. Further, the plurality of recesses 604a and 604b are not limited to the forming method by etching, but can also be formed by plastic working such as press working.

The pre-etched upper plate member 601 constituting the vapor chamber 600 is formed by a manufacturing method in which the copper composite plate 20 is cut into a predetermined shape and individualized. Further, the lower plate member 602 constituting the vapor chamber 600 is manufactured by a manufacturing method in which the copper composite plate 20 is cut into a predetermined shape to be individualized, and the end portion of the individualized copper composite plate 20 is bent. , Is formed. The copper composite plate material 20 constituting the upper plate member 601 can be formed by the same manufacturing method as the copper composite plate material 20 in the above-mentioned second configuration example. Further, the copper composite plate material 20 constituting the lower plate member 602 can be formed by the same manufacturing method as the copper composite plate material 20 in the above-mentioned second configuration example.

The joint portions 605a and 605b of the vapor chamber 600 are formed by diffusion bonding according to a predetermined heating pattern. Specifically, the lower plate member 602 is arranged below, and heating and holding is performed in a state where a load is applied to the surface to be joined (see the joint portion 605) from above the upper plate member 601. During this heating and holding, a diffusion phenomenon occurs between the surface (bonded surface) of the second copper layer 22 of the copper composite plate 20 constituting the upper plate member 601 and the surface (bonded surface) of the middle plate member 603. As a result, similarly, a diffusion phenomenon occurs between the surface (bonded surface) of the second copper layer 22 of the copper composite plate material 20 constituting the lower plate member 602 and the surface (bonded surface) of the middle plate member 603. As a result, the surfaces to be joined are joined (diffusion joining) to form a joining portion 605. In this heat treatment, it is preferable to perform any one of the above-mentioned (1) first heat treatment, (2) second heat treatment, and (3) third heat treatment as in the first configuration example. In any of the first heat treatment, the second heat treatment, and the third heat treatment, the second copper layer 22 of the copper composite plate material 20 constituting the upper plate member 601 and the middle plate member 603 are diffusion-bonded. Similarly, the second copper layer 22 of the copper composite plate material 20 constituting the lower plate member 602 and the middle plate member 603 are diffusion-bonded. Further, the 0.2% proof stress of the upper plate member 601 and the lower plate member 602 can be 240 MPa or more, further 300 MPa or more. Further, by intermittently providing the middle plate member 603 between the upper plate member 601 and the lower plate member 602, when the upper plate member 601 and the lower plate member 602 are diffusion-bonded, the second copper layer is formed. A space (inside 606) surrounded by the 22 and the middle plate member 601 is formed.

<Evaluation of copper composite plate material>
Next, various evaluations were performed to confirm whether the copper composite plate material according to the present invention has diffusion bonding property, corrosion resistance and 0.2% proof stress suitable as a constituent member of a vapor chamber (housing), for example. rice field. Specifically, using the copper composite plate material according to the present invention, a copper composite plate material for comparison, a copper alloy plate material, and a copper-plated coated copper alloy material, test specimens suitable for various evaluations were prepared. For these test pieces, the surface texture, 0.2% proof stress and corrosion resistance were examined using the test pieces before the heat treatment shown in Table 2, and the test pieces before the heat treatment shown in Table 1 were used in the table. The diffusion bonding property when diffusion bonding was performed in the same heating step as the heat treatment shown in 2 was investigated, and the compatibility of the vapor chamber with structural members (housing and the like) was evaluated. Various evaluations of the copper composite plate material were performed using the copper composite plate material 10 having a two-layer structure shown in FIG. This is because the second copper layer 12 of the copper composite plate material 10 having a two-layer structure shown in FIG. 1 and the second copper layer 22 and the third copper layer 23 of the copper composite plate material 20 shown in FIG. 2 are made of the same material ( Since it is composed of pure copper having Cu of 99.9% by mass or more or non-precipitation reinforced copper alloy having Si of less than 0.1% by mass), the copper composite plate material 10 having a two-layer structure shown in FIG. 1 is the first. This is because it is considered possible to be represented by the 2 copper layer 12.

For example, the test piece using the copper composite plate material according to the present invention was produced by producing the copper composite plate material 10 having a two-layer structure shown in FIG. 1 and cutting out individual pieces having a predetermined shape from the copper composite plate material 10. .. Specifically, first, a first copper plate material for forming the first copper layer 11 of the copper composite plate material 10 and a second copper plate material for forming the second copper layer 12 were produced. The first copper plate material is made by hot rolling a plate material made of a copper alloy, which is a kind of Corson alloy, consisting of 2.5% by mass of Ni, 0.5% by mass of Si, the balance Cu and impossible impurities. Further, by combining cold rolling and annealing, a product having a predetermined thickness (about 1.235 mm) was produced. The first copper plate contains 1.7% by mass of Zn (zinc) and 0.3% by mass of Sn (tin), which are additive elements other than the above-mentioned Ni and Si. Further, as the second copper plate material, a plate material made of oxygen-free copper, which is a kind of pure copper having Cu of 99.9% by mass or more, is prepared, and has a predetermined thickness by the same manufacturing method as the above-mentioned first copper plate material. (Approximately 0.065 mm) was manufactured. Subsequently, the first copper plate material and the second copper plate material are joined (press-welded) by rolling at a rolling reduction ratio of about 60% in a state where the first copper plate material and the second copper plate material are laminated. A copper composite plate material having a two-layer structure with a thickness of about 0.52 mm was produced. Subsequently, using this copper composite plate material, diffusion annealing (holding condition: about 1 minute at about 900 ° C.) and then cold rolling are performed to form a two-layer structure having a predetermined thickness (about 0.1 mm). A copper composite plate material was produced.

Next, the prepared copper composite plate was heat-treated including a specific step to prepare a copper composite plate having a two-layer structure for evaluation. Specifically, the copper composite plate is heated in a nitrogen atmosphere, heated from room temperature to 900 ° C. in a heating time of about 30 minutes, held for about 5 minutes after reaching 900 ° C., and then every time. The figure is shown by performing a heat treatment (see the first heat treatment shown in Table 2) including a step of cooling to 100 ° C. at a cooling rate of about 6.7 ° C. (cooling time of about 2 hours) and then cooling to room temperature. It is a configuration corresponding to the copper composite plate material 10 shown in No. 1, and has a thickness T of about 0.1 mm, a thickness T1 of the first copper layer of about 95 μm, and a thickness T2 of the second copper layer of about 5 μm. A copper composite plate having a two-layer structure for evaluation was produced.

<Test piece No. 1>
By cutting out individual pieces having a predetermined shape from the copper composite plate material for evaluation produced by the above-mentioned manufacturing method, No. 1 shown in Table 1 was obtained. 1 test piece was prepared. In addition, T2 / (T1 + T2) × 100 (%) is 5%.

<Test piece No. 2>
Specimen No. shown in Table 1. No. 2 is the test body No. 2 described above. In the manufacturing method 1, the ratio of the thickness of the first copper layer to the second copper layer is changed so that the thickness T1 of the first copper layer is about 98 μm and the thickness T2 of the second copper layer is about 2 μm. It was made as follows. In addition, T2 / (T1 + T2) × 100 (%) is 2%.

<Test piece No. 3>
Specimen No. shown in Table 1. No. 3 is the test body No. 3 described above. In the manufacturing method 1, the ratio of the thickness of the first copper layer to the second copper layer is changed so that the thickness T1 of the first copper layer is about 75 μm and the thickness T2 of the second copper layer is about 25 μm. It was made as follows. In addition, T2 / (T1 + T2) × 100 (%) is 25%.

<Test piece No. 4>
Specimen No. shown in Table 1. No. 4 is the test body No. 4 described above. In the manufacturing method 1, the ratio of the thickness of the first copper layer to the second copper layer is changed so that the thickness T1 of the first copper layer is about 70 μm and the thickness T2 of the second copper layer is about 30 μm. It was made as follows. In addition, T2 / (T1 + T2) × 100 (%) is 30%.

<Test piece No. 5-8>
Specimen No. shown in Table 1. Each of 5 to 8 has the above-mentioned test piece No. In the manufacturing method 1, the material of the second copper layer is changed to pure copper or a non-precipitation reinforced copper alloy shown in Table 1, the thickness T1 of the first copper layer is about 95 μm, and the thickness T2 of the second copper layer is It was prepared to be about 5 μm. In addition, T2 / (T1 + T2) × 100 (%) is 5% in each case.

<Test piece No. 9-11>
Specimen No. shown in Table 1. 9 to 11 are the test body Nos. 9 to 11 described above, respectively. In the production method 1, as shown in Table 1, the additive element (Sn) other than Ni and Si constituting the first copper layer is replaced with Mg, Co or Cr, and the thickness T1 of the first copper layer is about 95 μm. , The thickness T2 of the second copper layer was about 5 μm. In addition, T2 / (T1 + T2) × 100 (%) is 5% in each case.

<Test piece No. 12-20>
Specimen No. shown in Table 1. 12 to 20 are the test body Nos. 12 to 20 described above, respectively. In the heat treatment including a specific step in the production method 1, the heat treatment step is changed to the heat treatment step shown in Table 2, so that the thickness T1 of the first copper layer is about 95 μm and the thickness T2 of the second copper layer is about 5 μm. Made. In addition, T2 / (T1 + T2) × 100 (%) is 5% in each case. In addition, the test piece No. shown in Table 2 The enclosing of the double line in 17 to 20 indicates that the treatment conditions of the first heat treatment, the second heat treatment, or the third heat treatment are deviated.

<Test piece No. 21>
Specimen No. shown in Table 1. Reference numeral 21 is the above-mentioned test piece No. 21. In the manufacturing method of No. 1, the second copper layer was not used and was changed to the precipitation-strengthened copper alloy (C19400) shown in Table 1, and the thickness T1 of the first copper layer was about 95 μm and the thickness T2 of the second copper layer was about 95 μm. It was prepared to be about 5 μm. In addition, T2 / (T1 + T2) × 100 (%) is 5%. In addition, the test piece No. shown in Table 1 The enclosing of the double wire in 21 indicates that it is out of the scope of the invention relating to this copper composite plate material.

<Test piece No. 22>
Specimen No. shown in Table 1. 21 forms a copper plating layer corresponding to the second copper layer on the surface of the copper alloy plate material corresponding to the first copper layer of the copper composite plate material by a general copper plating treatment in which the current density is suitable for mass production. It was done. Specifically, first, the test piece No. A plate material made of a copper alloy, which is one of the Corson alloys used in No. 1, was rolled to finally produce a copper alloy plate material having a thickness T1 of about 98 μm. Subsequently, a copper plating layer having a thickness of about 2 μm was formed on the surface of the copper alloy plate by a general copper plating treatment to produce a copper plating-coated copper alloy plate. Next, the test piece No. In the same manner as in No. 1, after performing the heat treatment step (first heat treatment) shown in Table 2 on the copper-plated-coated copper alloy plate material, individual pieces having a predetermined shape were cut out from the copper-plated-coated copper alloy plate material, and the test piece No. 21 was produced. In addition, T2 / (T1 + T2) × 100 (%) is 2%. In addition, the test piece No. shown in Table 1 The enclosing of the double wire in 22 indicates that it is out of the scope of the invention relating to this copper composite plate material.

<Test piece No. 23>
Specimen No. shown in Table 1. Reference numeral 23 is a copper alloy plate material having a thickness T, which comprises only a portion having a thickness T1 corresponding to the first copper layer of the copper composite plate material and does not have a portion having a thickness T2 corresponding to the second copper layer. Specifically, first, the test piece No. A plate material made of a copper alloy, which is one of the Corson alloys used in No. 1, was rolled to finally prepare a copper alloy plate material having a thickness T of about 100 μm. Next, the test piece No. In the same manner as in No. 1, after performing the heat treatment step (first heat treatment) shown in Table 2, individual pieces having a predetermined shape are cut out, and the test piece No. 23 was made. In addition, T2 / (T1 + T2) × 100 (%) is 0%. In addition, the test piece No. shown in Table 1 The enclosing of the double wire in 23 indicates that it is out of the scope of the invention relating to this copper composite plate material.

<Test piece No. 24>
Specimen No. shown in Table 1. No. 24 is the test body No. 24 described above. In the manufacturing method of 1, the ratio of the thickness of the first copper layer and the second copper layer is changed, the thickness T1 of the first copper layer is about 99.5 μm, and the thickness T2 of the second copper layer is about 0. It was made to be .5 μm. In addition, T2 / (T1 + T2) × 100 (%) is 0.5%. In addition, the test piece No. shown in Table 1 The enclosing of the double line in 24 indicates that T2 / (T1 + T2) × 100 ≦ 30% and T2> 1 μm are not satisfied.

Hereinafter, the above-mentioned test piece No. Various evaluations performed using 1 to 24 and the results thereof will be described with reference to Table 3. In addition, the test body No. shown in Table 3 was used. The enclosing of the double lines in 21 to 24 represents the evaluation result that caused the compatibility of the vapor chamber with the constituent members (housing and the like) to be impaired.

<Surface texture>
Specimen No. after the heat treatment shown in Table 2. _{The surface texture (10-point average roughness R ZJIS} , kurtosis Rku) was examined using a sample corresponding to 1 to 24 (hereinafter, simply referred to as test body Nos. 1 to 24). The surface texture was determined by using a laser microscope (VK-8710) manufactured by KEYENCE CORPORATION, which conforms to JIS B0601: 2001. In 1 to 22 and the test body 24, the surface of the second copper layer was subjected to the test body No. In No. 22, the surface of the copper plating layer was subjected to the test piece No. In No. 23, the surface of the copper alloy plate having a thickness T was measured.

As a result, the test piece No. having a copper plating layer was obtained. _{It was confirmed that all the test pieces} except 22 had an R ZJIS of 0.8 μm or less and an Rku of 4 or less. This tendency is the same as the surface texture of the test piece before the heat treatment shown in Table 2. Further, _{from the viewpoint that R ZJIS} and Rku are excessive, the test piece No. having a copper plating layer. It is predicted that the diffusion bondability of 22 cannot be expected. In addition, the test piece No. having a copper plating layer. The _reason why R ZJIS and Rku of 22 became excessive is due to variations in the growth of crystal grains constituting the copper plating layer (copper plating film) and pinholes.

<0.2% proof stress>
Specimen No. after the heat treatment shown in Table 2. The 0.2% proof stress was examined using a sample corresponding to 1 to 24 (hereinafter, simply referred to as Specimen Nos. 1 to 24). Specifically, the test piece No. Each copper composite plate material for which 1 to 21 and the test body 24 were prepared, the test body No. The copper-plated coated copper alloy plate material for which 22 was produced, and the test piece No. From the copper alloy plate material from which 23 was produced, a plate-shaped test piece (No. 13A) specified in JIS Z2241: 2011 was produced so that its longitudinal direction was parallel to the rolling direction. Using each plate-shaped test piece (test body Nos. 1 to 24), a room temperature tensile test based on JIS Z2241: 2011 was performed to obtain a 0.2% proof stress.

As a result, the 0.2% proof stress was obtained by the test body Nos. 1 to 3 and the test body Nos. 5-16 and test piece No. In 21 to 24, it is 300 MPa or more, and the test piece No. 4 and test piece No. It was confirmed that it was less than 300 MPa in 17 to 20. In addition, the test piece No. 1-4 and test piece No. At 24, a remarkable tendency is confirmed that the 0.2% proof stress decreases with the decrease in the thickness of the first copper layer (increase in the thickness of the second copper layer). This is because the mechanical strength of the first copper layer made of the precipitation-strengthened copper alloy was improved by the precipitation hardening action by the heat treatment shown in Table 2. In addition, the test piece No. In 9 to 12, it was confirmed that the 0.2% proof stress differs depending on the difference in the additive elements (Mg, Co, Cr and Sn) other than Ni and Si with respect to Cu. In this case, it was found that the 0.2% proof stress became 350 MPa or more by adding an appropriate amount of Mg, Co or Cr. In addition, the test body No. The reason why the 0.2% proof stress in 17 to 20 was less than 300 MPa is that the heat treatment conditions shown in Table 2 are the range of (1) first heat treatment, (2) second heat treatment and (3) third heat treatment described above. This is because it is outside and the precipitation hardening action of the first copper layer is insufficient.

<Corrosion resistance>
Specimen No. after the heat treatment shown in Table 2. Corrosion resistance was examined using a sample corresponding to 1 to 24 (hereinafter, simply referred to as Specimen Nos. 1 to 24). The corroded surface targeted for investigation was the test piece No. In 1 to 21, the surface of the second copper layer, the test piece No. No. 22 is the surface of the copper plating layer and No. Reference numeral 23 is a surface of a copper alloy plate having a thickness of T. In the corrosion test, the test piece was left in a state of being immersed in pure water kept at about 50 ° C., taken out after 24 hours, and dried. Subsequently, the surface color of the test piece after drying was observed, and the degree of change in the surface color before and after immersion was observed. If the change in the surface color (copper color) before immersion is not visible, the corrosion resistance is evaluated as "○", and if the change in the surface color (copper color) before immersion is not visible, the corrosion resistance is evaluated. Was evaluated as "x" because it was inferior.

As a result, the test piece No. 1 to 20 and test piece No. All 24 were marked with "○", confirming that they had good corrosion resistance. This is because there is no precipitate that easily reacts with pure water on the surface of the second copper layer made of pure copper or a non-precipitation reinforced copper alloy. In addition, the test piece No. All of 21 to 23 became "x", and it was confirmed that the corrosion resistance was inferior. Specimen No. In the case of 21, it is because the second copper layer was composed of C19400 which is not a non-precipitation reinforced copper alloy. Specimen No. In the case of 22, the presence of defects such as pinholes in the copper plating layer exposed the precipitation-strengthened copper alloy as a base, and the presence of precipitates easily reacting with pure water was present on the surface thereof. Specimen No. In the case of 23, it is because the precipitate easily reacts with pure water was present on the surface composed of the precipitation hardening copper alloy.

<Diffusion bondability>
The test piece No. before the heat treatment shown in Table 2. Diffusion bondability was examined using samples corresponding to 1 to 24 (hereinafter, simply referred to as test specimens No. 1 to 24). The surface to be investigated was the test piece No. In 1 to 21, the surface of the second copper layer, the test piece No. No. 22 is the surface of the copper plating layer and No. Reference numeral 23 is a surface of a copper alloy plate having a thickness of T. Specifically, the test piece No. Each copper composite plate material for which 1 to 21 and the test body 24 were prepared, the test body No. The copper-plated coated copper alloy plate material for which 22 was produced, and the test piece No. A rectangular piece (10 mm × 50 mm) was cut out from the copper alloy plate material for which 23 was prepared, and a test piece to be joined was prepared. Further, a rectangular piece (10 mm × 50 mm) was cut out from a 100 μm-thick pure copper plate material composed of C10200 to prepare a joining standard piece to be a joining partner of the test piece to be joined. Diffusion bonding is arranged so that the overlap amount of the overlapping portion where the test piece to be bonded and the bonding standard piece are overlapped in the longitudinal direction is about 10 mm, and a pressure of about 3 MPa acts on the overlapping portion. It was carried out under load. The heating step for performing diffusion bonding was the same as the heat treatment shown in Table 2 corresponding to each of the test pieces to be bonded (test pieces No. 1 to 24). In this case, diffusion proceeds in the holding state (900 ° C., 5 minutes) of the first step of the heat treatment shown in Table 2.

The diffusion bondability was evaluated by performing a room temperature tensile test using a general tensile tester. In the room temperature tensile test, a load was applied until the test piece to be joined and the standard piece to be joined were broken in parallel with the longitudinal direction so that a shear force (shear stress) was applied to the overlapped portion. In addition, the case where the material is broken (broken base material) at a place other than the overlapped part is evaluated as "○" because the diffusion bonding property is good, and the case where the overlapping part is peeled and broken (joint part is peeled off) is diffused bonded. It was evaluated as "x" because of its inferior sex. As a result, the test piece No. All of 1 to 21 became "○", and it was confirmed that the diffusion bondability was good. In addition, the test piece No. All of 22 to 24 became "x", and it was confirmed that the diffusion bondability was inferior. Specimen No. _{In the case of 22, diffusion was difficult to proceed because the R ZJIS} and Rku of the copper plating layer (copper plating film) to be joined were excessive, and the copper plating layer (copper plating film) and precipitation-reinforced copper were used. This is because the adhesion strength with the copper alloy plate made of alloy is relatively small and the copper plating layer (copper plating film) is peeled off. Specimen No. In the case of 23, a Si oxide film was formed on the surface of the test piece composed of the precipitation hardening copper alloy, and this film inhibited the diffusion. Specimen No. In the case of 24, the first copper layer made of a precipitation hardening copper alloy is covered with a second copper layer made of pure copper, and the second copper layer is present on the surface of the test piece. However, the thickness (0.5 μm) of the second copper layer was thin, and Si contained in the first copper layer diffused and reached the surface of the second copper layer (the surface of the test piece), so that the surface of the test piece was reached. This is due to the formation of a Si oxide film, which inhibited diffusion.

<Vapor chamber compatibility>
Specimen No. For each of 1 to 24, the compatibility of the vapor chamber with the structural members (housing and the like) was evaluated based on the evaluation results of the above-mentioned surface properties, 0.2% proof stress, corrosion resistance and diffusion bonding property. Regarding the compatibility of the vapor chamber in the present invention, when all of the conditions A to D described later are "good compatibility", the compatibility with the vapor chamber is evaluated as "○", and the condition B is "compatibility". If "Yes" and "Compatibility is good" in other cases, it is evaluated as "△" as being compatible with the vapor chamber, and "Compatibility" with any one or more of Conditions A to D. When there was "None", it was evaluated as "x" because it was not compatible with the vapor chamber.

As condition A, in the surface texture shown in Table 3, when the ten-point average roughness R _ZJIS is 0.8 μm or less and the kurtosis Rku is 4 or less, it is regarded as “good compatibility”, and in other cases, it is “compatible”. No sex. "
As condition B, when the 0.2% proof stress shown in Table 3 is 300 MPa or more, it is regarded as "good compatibility", when it is 240 MPa or more, it is regarded as "compatible", and when it is less than 240 MPa, it is "not compatible". And.
As the condition C, in the corrosion resistance shown in Table 3, the case where the evaluation is "○" is "good compatibility", and the case where the evaluation is "x" is "no compatibility".
As the condition D, in the diffusion bondability shown in Table 3, when the evaluation is "◯", it is regarded as "good compatibility", and when the evaluation is "x", it is regarded as "not compatible".

As a result, the test piece No. 1-3 and test specimen No. All of 5 to 16 were marked with "○", and it was confirmed that the vapor chamber had good compatibility with structural members (housing, etc.). In addition, the test piece No. 4 and test piece No. All of 17 to 20 were "Δ", and it was confirmed that they were compatible with the structural members (housing, etc.) of the vapor chamber. In addition, the test body No. All of 21 to 24 were "x", and it was confirmed that they were not compatible with the structural members (housing, etc.) of the vapor chamber. As a result, the copper composite plate material of the present invention, that is, the second copper layer is pressed against one surface of the first copper layer, and the first copper layer is made of 0.8% by mass or more and 5.0% by mass or less of Ni. , 0.2% by mass or more and 1.5% by mass or less of Si, the balance Cu and a copper alloy composed of unavoidable impurities, and the second copper layer is composed of pure copper with Cu of 99.9% by mass or more. It was confirmed that the copper composite plate material, which is composed of a non-precipitation reinforced copper alloy in which Si is less than 0.1% by mass, has compatibility with structural members (housing and the like) of a vapor chamber.

The present invention is capable of providing a copper composite plate material applicable to a vapor chamber, and is also used in various applications other than the vapor chamber, such as, for example, a heat conductive member or a heat radiating member, a conductive member, a chassis, a case and a frame. It also has industrial applicability in that it can provide applicable copper composite plates.

Claims (13)

A copper composite plate material (10) in which a second copper layer is pressure-welded to one surface of the first copper layer.
The first copper layer (11) is made of a precipitation-strengthened copper alloy.
The second copper layer (12) is a copper composite plate material in which Cu is composed of 99.9% by mass or more of pure copper or Si is composed of a non-precipitation reinforced copper alloy of less than 0.1% by mass. .. The copper according to claim 1, wherein when the thickness of the first copper layer is T1 and the thickness of the second copper layer is T2, T2 / (T1 + T2) × 100 ≦ 30% and T2> 1 μm are satisfied. Composite board material. The copper composite plate material according to claim 1 or 2, wherein the second copper layer has a surface roughness R _ZJIS of 0.8 μm or less and a kurtosis Rku of 4 or less. A copper composite plate material (20) in which a second copper layer (22) is pressure-welded to one surface of the first copper layer (21) and a third copper layer (23) is pressure-welded to the other surface of the first copper layer. There,
The first copper layer is made of a precipitation-strengthened copper alloy.
Both the second copper layer and the third copper layer are composed of pure copper having a Cu content of 99.9% by mass or more, or a non-precipitation-reinforced copper alloy having a Si content of less than 0.1% by mass. Copper composite plate material. When the thickness of the first copper layer is T1, the thickness of the second copper layer is T2, and the thickness of the third copper layer is T3, (T2 + T3) / (T1 + T2 + T3) × 100 ≦ 30%. The copper composite plate material according to claim 4, which also satisfies T2> 1 μm and T3> 1 μm. The copper composite plate material according to claim 4 or 5, wherein the second copper layer and the third copper layer have a surface roughness R _ZJIS of 0.8 μm or less and a kurtosis Rku of 4 or less. The copper alloy constituting the first copper layer is composed of 0.8% by mass or more and 5.0% by mass or less of Ni, 0.2% by mass or more and 1.5% by mass or less of Si, the balance Cu, and unavoidable impurities. The copper composite plate material according to any one of claims 1 to 6, which is a precipitation-strengthened copper alloy. The copper alloy constituting the first copper layer further comprises Co, Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, B and Ag in the range of 2.0% by mass or less. The copper composite plate material according to any one of claims 1 to 7, which comprises one or more of them. The upper plate member and the lower plate member formed by using the copper composite plate material according to any one of claims 1 to 8 are provided.
The upper plate member and the lower plate member are diffusely joined so as to form a space surrounded by the second copper layer of the upper plate member and the second copper layer of the lower plate member. , Vapor chamber. The upper plate member and the lower plate member formed by using the copper composite plate material according to any one of claims 1 to 8 are provided, and the upper plate member and the lower plate member are diffusion-bonded to each other. It is a manufacturing method of the vapor chamber.
By performing any one of the first heat treatment, the second heat treatment, and the third heat treatment, the second copper layer of the copper composite plate material constituting the upper plate member and the lower plate member constituting the lower plate member. A step of diffusion-bonding the second copper layer of the copper composite plate material and making the 0.2% withstand strength of the upper plate member and the lower plate member 240 MPa or more is provided.
The first heat treatment comprises a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, then cooling to 100 ° C. at a cooling rate of 25 ° C. or lower per minute, and then cooling to room temperature.
The second heat treatment includes a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, cooling to 100 ° C. or lower, then heating and holding at 400 ° C. or higher and 550 ° C. or lower, and then cooling to room temperature. ,
The third heat treatment method comprises a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, cooling and holding at 400 ° C. or higher and 550 ° C. or lower, and then cooling to room temperature. The step of diffusion-bonding the second copper layer of the copper composite plate material constituting the upper plate member and the second copper layer of the copper composite plate material constituting the lower plate member constitutes the upper plate member. The method for manufacturing a vapor chamber according to claim 10, further comprising a step of forming a space between the second copper layer of the copper composite plate material and the second copper layer of the copper composite plate material constituting the lower plate member. .. The upper plate member and the lower plate member formed by using the copper composite plate material according to any one of claims 1 to 8, and whether Cu is composed of 99.9% by mass or more of pure copper or Si is A middle plate member made of a non-precipitation reinforced copper alloy of less than 0.1% by mass is provided, the upper plate member and the middle plate member are diffusion-bonded, and the middle plate member and the said It is a method of manufacturing a vapor chamber configured by diffusion-bonding a lower plate member.
By performing any one of the first heat treatment, the second heat treatment, and the third heat treatment, the second copper layer of the copper composite plate material constituting the upper plate member and the middle plate member are diffusion-bonded. In addition, the second copper layer of the copper composite plate material constituting the lower plate member and the middle plate member are diffusion-bonded, and the 0.2% strength of the upper plate member and the lower plate member is increased to 240 MPa or more. With a process to do
The first heat treatment comprises a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, then cooling to 100 ° C. at a cooling rate of 25 ° C. or lower per minute, and then cooling to room temperature.
The second heat treatment includes a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, cooling to 100 ° C. or lower, then heating and holding at 400 ° C. or higher and 550 ° C. or lower, and then cooling to room temperature. ,
The third heat treatment method comprises a step of heating and holding at 600 ° C. or higher and 1000 ° C. or lower, cooling and holding at 400 ° C. or higher and 550 ° C. or lower, and then cooling to room temperature. The step of diffusion-bonding the second copper layer of the copper composite plate material constituting the upper plate member and the second copper layer of the copper composite plate material constituting the lower plate member constitutes the upper plate member. The method for manufacturing a vapor chamber according to claim 12, further comprising a step of forming a space between the second copper layer of the copper composite plate material and the second copper layer of the copper composite plate material constituting the lower plate member. ..

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