WO2017209157A1

WO2017209157A1 - Metal multilayer material formed from copper and magnesium and method for producing same

Info

Publication number: WO2017209157A1
Application number: PCT/JP2017/020174
Authority: WO
Inventors: 哲平黒川; 橋本　裕介
Original assignee: 東洋鋼鈑株式会社
Priority date: 2016-05-31
Filing date: 2017-05-31
Publication date: 2017-12-07
Also published as: JP2017213759A; JP6813961B2

Abstract

The purpose of the present invention is to provide a metal multilayer material using a magnesium alloy, which achieves a good balance between high heat dissipation performance and lightweightness, while additionally having electrical conductivity. A metal multilayer material 1 which has a two-layer structure composed of a copper layer 10 and a magnesium alloy layer 20, and which does not have an intermetallic compound at the interface.

Description

Metal laminate made of copper and magnesium and method for producing the same

The present invention relates to a metal laminate made of copper and magnesium and a method for producing the same.

A metal laminate (cladding material) is a material in which two or more different metals are bonded together, and is a highly functional metal material having composite characteristics that cannot be obtained by a single material. Conventionally, such a metal laminated material is manufactured by passing through each process, such as washing | cleaning of a joining surface, and rolling joining.

As an example of a metal laminate, a metal laminate of stainless steel and aluminum is known. This metal laminate material has both the characteristics of lightness of aluminum and the strength of stainless steel, and is widely used because it has higher moldability and heat dissipation than each single material.

For example, Patent Document 1 discloses a heat sink material for electronic equipment having a three-layer clad structure characterized in that an outer layer material is an aluminum material and a core material is made of stainless steel.

Patent Document 2 discloses a clad material in which a hard aluminum plate made of an Al-based metal containing Al as a main component is bonded to one surface of a stainless steel plate, the hardness of the stainless steel plate being Hv400 or less, An aluminum / stainless steel clad material is described in which the hardness of the hard aluminum plate is Hv40 or higher and the bonding strength between the stainless steel plate and the hard aluminum plate is 0.3 kgf / cm or higher.

However, considering the application to various electronic devices such as mobile electronic devices, if the electronic devices are further enhanced in function and weight, the metal laminate material of stainless steel and aluminum has a high level of lightness and heat dissipation. Balancing is difficult.

Under such circumstances, the present inventors paid attention to a magnesium alloy as a constituent material of the metal laminate. Magnesium alloys have the advantage that they are excellent in heat dissipation and light weight, and have a higher specific strength than aluminum. However, magnesium alloy has poor corrosion resistance, and has a problem that orientation is low due to a small slip surface, and the workability in biaxial direction is extremely low. Is very limited compared to metal laminates using aluminum.

As an example of the metal laminated material using the magnesium alloy, Patent Literature 3 discloses a bonding method for bonding a first member made of steel and a second member made of a magnesium alloy. An insertion step of installing an insertion member between the first member and the second member; and the insertion member melts the first member and the second member with the insertion member installed. And a step of heating to a predetermined temperature, thereby disclosing an intermetallic compound Fe ₂ Al ₅ at the interface between the first member and the second member. In this joining method, it is necessary to heat the insertion member separately to a melting temperature, and the laminated material obtained has a problem that the thickness is very large and the use of the laminated material is limited to the structural member.

Patent Document 4 is composed of a magnesium alloy plate and a steel plate material, and is laminated with a one-component thermosetting adhesive interposed between the surface of the magnesium alloy plate and the surface of the steel plate material, A metal alloy laminate is described in which the one-component thermosetting adhesive is cured by heating while applying pressure. In this example, since the adhesive is used, there is a defect that the heat dissipation is reduced, and it is expected that the decrease in the heat dissipation becomes more remarkable in the range where the thickness of the laminated material is thin.

Japanese Patent Laying-Open No. 2015-62922 JP 2000-312979 A Japanese Patent No. 5323927 Japanese Patent No. 5372469

As described above, the use of a magnesium alloy as a metal laminate has been studied, but all the conventional magnesium alloy laminates have problems and still need to be improved. In addition, electrical conductivity may be required in order to enhance the functionality of electronic equipment, but it cannot be handled with a magnesium alloy alone. Therefore, an object of the present invention is to provide a metal laminate using a magnesium alloy that achieves both high heat dissipation and light weight and also has electrical conductivity, and a method for manufacturing the same.

As a result of intensive studies by the present inventors, it has been found that the above problems can be solved by laminating copper on a magnesium alloy and controlling the interface state thereof, and the present invention has been completed. That is, the gist of the present invention is as follows.
(1) A metal laminate having a two-layer structure of copper layer / magnesium alloy layer and having no intermetallic compound at the interface.
(2) The metal laminate according to (1), wherein the thickness is 0.03 mm to 1 mm.
(3) The metal laminate according to (1) or (2), wherein the thickness ratio of the copper layer is 5% to 70% of the whole.
(4) The metal laminate according to any one of (1) to (3), wherein an oxide layer of a magnesium alloy is present at the interface.
(5) The metal laminate according to any one of (1) to (4), which has a thermal conductivity of 1.2 times or more of the thermal conductivity of the magnesium alloy layer.
(6) The metal laminate material according to any one of (1) to (5), wherein the volume resistivity of the magnesium alloy layer is 2/3 or less.
(7) The method for producing a metal laminate according to (1),
A step of sputter etching a copper plate or foil;
A step of sputter etching a magnesium alloy plate or foil;
Pressing the sputter-etched surface of the copper or magnesium alloy plate or foil to form a two-layer structure of copper layer / magnesium alloy layer;
The manufacturing method of the said metal laminated material containing.
(8) The method for producing a metal laminate according to (4),
A step of sputter etching a copper plate or foil to remove the oxide layer on the surface;
A step of sputter etching the magnesium alloy plate or foil while leaving the oxide layer on the surface;
Pressing the sputter-etched surface of the copper or magnesium alloy plate or foil to form a two-layer structure of copper layer / magnesium alloy layer;
The manufacturing method of the said metal laminated material containing.
(9) A method for producing a metal laminate comprising a step of subjecting the metal laminate obtained by the production method according to (7) or (8) to a heat treatment at 100 ° C. to 200 ° C. for 10 minutes to 6 hours. Production method.

This specification includes the disclosure of Japanese Patent Application No. 2016-108764, which is the basis of the priority of the present application.

According to the present invention, a magnesium alloy having the lightest and highest specific strength among practical alloys is used, and copper having excellent thermal conductivity and electrical conductivity is used, and no intermetallic compound is present at the interface. By laminating in a state, it is possible to obtain a metal laminate having excellent lightness and heat dissipation and further imparted with electrical conductivity. Such a metal laminate can be obtained by laminating a magnesium alloy and copper by a surface activated bonding method.

It is sectional drawing which shows typically one Embodiment of the metal laminated material of this invention. It is a graph which shows the relationship between the thickness ratio of a magnesium alloy layer, and a thermal conductivity improvement magnification. It is a graph which shows the relationship between the heat processing time and peel strength in different heat processing temperature. 2 is a focused ion beam scanning electron microscope (FIB-SEM) image of a metal laminate according to Example 1. FIG. 2 is a focused ion beam scanning electron microscope (FIB-SEM) image of a metal laminate according to Example 1. FIG. 2 is a focused ion beam scanning electron microscope (FIB-SEM) image of a metal laminate according to Comparative Example 1. It is a scanning electron microscope (SEM) image of the surface of the copper layer after peeling off the metal laminated material which concerns on Example 4 by a peel strength test. It is a figure which shows the energy-dispersive X-ray (EDX) analysis result of the surface of the copper layer after peeling off the metal laminated material which concerns on Example 4 by a peel strength test. It is a scanning electron microscope (SEM) image of the surface of the copper layer after peeling off the metal laminated material which concerns on the comparative example 1 by a peel strength test. It is a figure which shows the energy dispersive X-ray (EDX) analysis result of the surface of the copper layer after peeling off the metal laminated material which concerns on the comparative example 1 by a peel strength test. It is a figure which shows the X-ray photoelectron spectroscopy (XPS) analysis result in the interface of the metal laminated material which concerns on Example 1. FIG.

Hereinafter, the present invention will be described in detail.

As shown in FIG. 1, the metal laminate 1 of the present invention has a two-layer structure in which a magnesium alloy layer 20 is laminated on a copper layer 10 and has no intermetallic compound at the interface. To do. As examples of intermetallic compounds, Mg ₂ Cu, Cu ₂ Mg, and the like are assumed. The metal laminate of FIG. 1 is a high-performance material that exhibits excellent heat dissipation, is lightweight, and has electrical conductivity because it has the properties of copper and magnesium alloy. Here, “having no intermetallic compound at the interface” means that the presence or absence of a product at the interface can be confirmed by observing the interface at a magnification of 5000 to 10,000 times. In the present invention, 0.1 μm or more In this state, no product is formed. Specifically, when the metal laminate was peeled off from the copper layer and the magnesium alloy layer with a peel strength tester, and the surface of the peeled copper layer was subjected to energy dispersive X-ray (EDX) analysis, the fracture occurred. Is the interfacial debonding, that is, when the strength of magnesium observed is less than 1/1000 of the strength of copper, that is, when there is no intermetallic compound at the interface. Suppose that it is in a state. When magnesium is contained in the base copper alloy, it is compared with the result of EDX analysis of the copper alloy alone, and after specifying the amount of magnesium derived from the magnesium alloy layer, it is compared with the strength of copper. Also, the difference between fracture in the base metal and interfacial delamination is, for example, in the case where there is a fracture in the base metal in the magnesium alloy layer, the magnesium alloy layer is analyzed when analyzed by Auger electron spectroscopy on the peeled surface on the copper layer side. Judgment can be made by the absence of detection of elements other than those contained (for example, copper).

As the copper layer 10, a copper plate material or foil can be used. Although depending on the use of the metal laminate, copper preferably has a high purity in order to further improve heat dissipation, electrical conductivity, etc., specifically 99.0% by mass or more, more preferably 99.5. Although it is more than mass%, it is not limited to this. As copper foil, rolled copper foil, electrolytic copper foil, copper foil by metallization, etc. can be used. When an alloy element is added to copper to obtain a copper alloy, the total content of these additive elements and inevitable impurities is preferably less than 1.0% by mass. In particular, when at least one selected from the group consisting of Sn, Mn, Cr, Zn, Zr, Ni, Si, Mg and Ag is added to copper in a total amount of 200 to 2000 ppm by mass, the elongation is improved compared to pure copper. Therefore, it is preferable. The thickness of the copper plate or foil is usually 0.01 mm or more, and is applicable from the viewpoint of mechanical strength and workability of the obtained metal laminate. The thickness is preferably 0.01 mm to 0.7 mm, but is not limited to this range. The “thickness” of the plate material or foil in the present invention can be measured with a micrometer or the like, and means an average value of thicknesses measured at 10 points randomly selected from the entire range of the target material. Moreover, about the copper plate material or foil to be used, it is preferable that the deviation from the average value of 10 measured values (hereinafter referred to as “thickness unevenness”) is within 10% in all measured values. In particular, when a thin foil having a thickness of less than 1 mm is used, if the value of the thickness unevenness is large, there is a concern that the heat dissipation may vary. Therefore, it is preferable that the thickness unevenness value is small.

As the magnesium alloy layer 20, a magnesium alloy plate or foil can be used. Specific examples of the magnesium alloy include AZ31, AZ61, AZ91, and LZ91. Further, the surface hardness Hv of the magnesium alloy plate or foil is appropriately selected in consideration of the fact that if it is too large, the formability of the metal laminated material after joining is lowered, and conversely if it is too small, handling becomes difficult. Is done. Preferably, 30 ≦ Hv ≦ 100, but not limited thereto. Furthermore, the thickness of the magnesium alloy plate or foil is usually 0.01 mm or more, and is applicable from the viewpoint of mechanical strength and workability of the obtained metal laminate, and is 0.01 mm to 0.99 mm. Although it is preferable, it is not limited to this range. When the purpose is to reduce the thickness of the metal laminate, the thickness of the magnesium alloy plate or foil is preferably 0.01 mm to 0.7 mm, and preferably 0.01 mm to 0.5 mm. Is more preferable. As in the case of the copper layer, the thickness unevenness is preferably within 10% in all measured values.

If the thickness of the metal laminate 1 (a + b in FIG. 1) is too thin, handling becomes difficult. On the other hand, if the thickness of the copper layer is too thick, the merit of weight reduction becomes small. When the thickness is large, continuous production from reel to reel becomes difficult, and accordingly, the thickness is set appropriately in consideration of these balances. Specifically, it is preferably 0.03 mm to 1 mm, particularly 0.05 mm to 0.7 mm.

Further, the thickness ratio (a / (a + b) × 100) of the copper layer 10 with respect to the entire metal laminate 1 is not particularly limited, but is 5% in order to take advantage of the respective characteristics of the copper layer and the magnesium alloy layer. The range of ˜70% is suitable, and the range of 8% ˜50% is particularly preferable. In addition, in this invention, the thickness of each layer of a copper layer and a magnesium alloy layer says the average value of the thickness measured in 10 points | pieces selected at random from the whole range of the metal laminated material of width 1mm x length 1m made into object. . The thickness of each layer can be measured by using, for example, a length measuring function of a focused ion beam scanning electron microscope (FIB-SEM). When the reduction ratio of the metal laminate is 0%, the thickness of the copper or magnesium alloy plate or foil used for the production of the metal laminate can be used as it is as the thickness of each layer in the metal laminate. it can.

In the metal laminate 1, when the magnesium alloy layer and the copper layer have thickness ratios a _Mg and a _Cu , respectively, and the magnesium alloy layer and the copper layer have thermal conductivities K _Mg and K _Cu , respectively, the heat conduction of the metal laminate material The rate K _CLAD is expressed by the following equation.
K _CLAD = a _Mg · K _Mg + a _Cu · K _Cu

Based on the above formula, when the thickness ratio of the magnesium alloy layer (AZ31) is 100% (ie, the magnesium alloy layer alone), the decrease in the thickness ratio of the magnesium alloy layer (the thickness of the copper layer) FIG. 2 shows the change in the thermal conductivity improvement magnification accompanying the increase in the ratio. As shown in FIG. 2, the overall thermal conductivity can be improved by increasing the thickness ratio of the copper layer 10. In consideration of application to electronic equipment, the thermal conductivity of the metal laminate 1 is preferably 1.2 times or more, and particularly preferably 1.5 times or more that of the magnesium alloy layer.

Also, by laminating a copper layer on a magnesium alloy layer, the volume resistivity of the resulting metal laminate can be reduced and electrical conductivity can be imparted. The decrease in volume resistivity increases as the thickness ratio of the copper layer increases and can be appropriately designed according to the application. In particular, the volume resistivity of the metal laminate is 2/3 or less of the magnesium alloy layer. It is preferable that

Further, the surface of the copper layer 10 and the surface of the magnesium alloy layer 20 on the opposite side of the interface in the metal laminate 1 may have corrosion resistance, oxidation, and so on as long as they do not hinder the intended conductivity and heat dissipation. A protective layer can be provided for the purpose of prevention and discoloration prevention. Examples of the protective layer for the copper layer 10 include a chemical conversion treatment layer and a Ni plating layer. Examples of the protective layer for the magnesium alloy layer 20 include a metal layer such as copper and aluminum, a chemical conversion treatment layer such as a phosphoric acid type, a chromate type, and an anodizing treatment. The magnesium alloy layer is the outermost layer. If it is necessary, there is no need to provide it.

When the metal laminate 1 is manufactured, a copper plate or foil and a magnesium alloy plate or foil are prepared, and these are bonded to each other by various methods such as cold rolling bonding, hot rolling bonding, and surface activation bonding. It can be performed by bonding. In the case of cold rolling joining, if the rolling reduction is increased, the magnesium alloy layer is cracked and joining becomes difficult. Therefore, it is necessary to join under conditions where the magnesium alloy layer does not break. Moreover, it is preferable to perform stabilization heat processing after joining. Hot rolling joining is a method of rolling joining while applying heat above the recrystallization temperature of the joining material, and can be joined with a lower force than cold rolling joining, but generates an intermetallic compound at the joining interface. Easy to do. Therefore, attention should be paid to the selection of the heating temperature and heating time conditions so as not to generate intermetallic compounds.

Preferred embodiments of the method for producing the metal laminate 1 are as follows. First, a copper plate material or foil (hereinafter, sometimes referred to as “foil”) is sputter etched and a magnesium alloy plate material or foil is sputter etched. The metal laminate 1 shown in FIG. 1 can be manufactured by press-contacting the sputter-etched surface of the plate material or foil to form a two-layer structure of copper layer / magnesium alloy layer. This method is preferable because the rolling reduction can be lowered (several percent or less), and the magnesium alloy layer can be joined without cracking even at room temperature.

For the sputter etching process, for example, a copper foil or a magnesium alloy foil is prepared as a long coil having a width of 100 mm to 600 mm, and copper and magnesium alloy having a joint surface are respectively grounded as one electrode and insulated. An alternating current of 1 MHz to 50 MHz is applied to the supported other electrode to generate a glow discharge, and the area of the electrode exposed in the plasma generated by the glow discharge is set to 1 of the area of the other electrode. / 3 or less. During the sputter etching process, the grounded electrode is in the form of a cooling roll to prevent the temperature of each conveying material from rising.

In the sputter etching process, the adsorbed material on the surface is completely removed by sputtering the surface where the copper and magnesium alloy are joined with an inert gas under vacuum, and part or all of the oxide layer on the surface is removed. . Particularly in the case of a magnesium alloy, it is not always necessary to completely remove the oxide layer, and a sufficient bonding force can be obtained even in a partially remaining state. By performing the sputter etching while leaving the oxide layer, the sputter etching processing time can be greatly reduced as compared with the case where the oxide layer is completely removed, and the productivity of the metal laminate can be improved. On the other hand, it is preferable to completely remove the copper oxide layer. As the inert gas, argon, neon, xenon, krypton, or a mixed gas containing at least one of these can be used. For both copper and magnesium alloys, the adsorbate on the surface can be completely removed with an etching amount of about 1 nm, and the copper oxide layer can usually be removed with about 5 nm to 12 nm (in terms of SiO ₂ ). is there.

The sputter etching process for copper can be performed under vacuum, for example, with a plasma output of 100 W to 10 kW and a line speed of 0.5 m / min to 30 m / min. The degree of vacuum at this time is preferably higher in order to prevent re-adsorption on the surface, but it may be, for example, 1 × 10 ⁻⁵ Pa to 10 Pa. In the sputter etching process, the temperature of copper is preferably kept at room temperature to 150 ° C.

The sputter etching process for the magnesium alloy can be performed under vacuum, for example, with a plasma output of 100 W to 10 kW and a line speed of 0.5 m / min to 30 m / min. The degree of vacuum at this time is preferably higher in order to prevent re-adsorbed substances on the surface, but may be 1 × 10 ⁻⁵ Pa to 10 Pa.

The pressure welding between the copper foil or the like and the magnesium alloy foil or the like can be performed by roll pressure welding. The rolling line load for roll pressure welding is not particularly limited, and can be set, for example, within a range of 0.1 to 10 tf / cm. The temperature at the time of joining by roll pressure welding is not particularly limited, and is, for example, from room temperature to 150 ° C.

Since the rolling reduction at the time of pressure contact exceeds 10%, the thickness unevenness tends to deteriorate, so it is preferably 8% or less, more preferably 5% or less. In addition, since the thickness does not need to change before and after the pressing, the lower limit value of the rolling reduction is 0%.

Bonding by roll pressure welding is performed in a non-oxidizing atmosphere, for example, an inert gas atmosphere such as Ar, in order to prevent the bonding strength between the two from decreasing due to re-adsorption of oxygen to the copper and magnesium alloy surfaces. preferable.

It is preferable that the metal laminated material having a two-layer structure obtained by pressure welding is further heat-treated as necessary. By heat treatment, the processing strain of the magnesium alloy layer is removed, and the adhesion between the layers can be improved. When this heat treatment is carried out at a high temperature for a long time, an intermetallic compound is formed at the interface, and the adhesion (peel strength) tends to be lowered. Therefore, it is necessary to carry out under appropriate conditions. For example, it is preferable to perform heat treatment at 100 ° C. to 200 ° C. for 10 minutes to 6 hours.

Through the above steps, a metal laminate having a two-layer structure can be obtained.

Hereinafter, the present invention will be described in more detail based on examples and comparative examples, but the present invention is not limited to these examples.

(Volume resistivity survey)
A copper foil having a thickness of 16 μm, 50 μm, and 100 μm, respectively, and AZ31 having a thickness of 44 μm were used as a magnesium alloy foil. In press-contacting them, the copper foil and the magnesium alloy foil were sputter-etched. Sputter etching for copper foil was performed under conditions of 0.1 Pa and plasma output of 700 W for 20 minutes, and sputter etching for magnesium alloy foil was performed under 0.1 Pa of plasma output of 700 W and 20 minutes. It implemented on condition, and the adsorbate of the surface of copper foil and the foil of a magnesium alloy was removed completely. The copper foil after the sputter etching treatment and the magnesium alloy foil were joined by roll pressure welding at a normal temperature and a rolling line load of 1.5 tf / cm to produce a metal laminate having a two-layer structure. The rolling reduction of the finally obtained laminated material was calculated by the following formula 1, and was 0% for all the copper foils having thicknesses of 16 μm, 50 μm, and 100 μm.
(Sum of thicknesses of test materials−thickness of laminated materials) / (Sum of thicknesses of test materials) × 100 (%) Formula (1)

The volume resistivity (μΩcm) of the obtained metal laminate was measured using a Milliohm HiTester 3540 manufactured by Hioki Electric. The results are shown in Table 1 together with the volume resistivity of the magnesium alloy foil alone. From the results of Table 1, it was found that the volume resistivity can be reduced to 60% or less of the magnesium alloy layer alone by laminating the copper layer on the magnesium alloy layer. Further, it has been clarified that the volume resistivity is as small as that when the thickness ratio of the copper layer is 27% and 53%.

(Investigation of the effects of heat treatment)
Next, the above metal laminate produced from a copper foil having a thickness of 16 μm and a magnesium alloy foil having a thickness of 44 μm was used as Example 1, and this metal laminate was subjected to heat treatment under the conditions shown in Table 2. After the heat treatment, the peel strength (180 °) was measured using a Tensilon universal testing machine RTC-1210A manufactured by Orientec, and the adhesion was examined. The results are shown in Table 2 and FIG. Further, a focused ion beam scanning electron microscope (FIB-SEM) image (FIB-SEM: JEM-9320FIB manufactured by JEOL Ltd.) of a cross section of the metal laminate of Example 1 (no heat treatment) is shown in FIGS. FIG. 6 shows FIB-SEM images of the cross section of the metal laminate material (heat treatment at 300 ° C. for 6 hours).

As shown in FIGS. 4 and 5, in the metal laminate of Example 1 where no heat treatment was performed, no product was confirmed at the interface between the copper layer and the magnesium alloy layer. On the other hand, in the metal laminate of Comparative Example 1 subjected to heat treatment at 300 ° C. for 6 hours, a product layer having a thickness of 0.1 μm or more was observed at the interface as shown in FIG. Moreover, as shown in FIG. 3, the peel strength of the metal laminate of Comparative Example 1 was lower than that of the metal laminate of Example 1 that was not subjected to heat treatment. This result is considered to be due to the product layer at the interface appearing by heat treatment at 300 ° C. for 6 hours.

Next, SEM observation of the peeled surface on the copper layer side after the peel test was performed on the metal laminate of Example 4 that was heat-treated at 100 ° C. for 6 hours (SEM: SU8020 manufactured by Hitachi High-Technologies). The result is shown in FIG. Moreover, energy dispersive X-ray (EDX) analysis was performed on the peeled surface (EDX: OCTENE SUPER made by AMETEK). The result is shown in FIG. Similarly, FIG. 9 shows an SEM image of the peeled surface of Comparative Example 1 subjected to heat treatment at 300 ° C. for 6 hours, and FIG. 10 shows the EDX analysis result.

In Example 4 (FIG. 7) and Comparative Example 1 (FIG. 9), Comparative Example 1 was clearly more uneven on the surface after peeling, and the fracture mode was considered brittle fracture. As shown in FIGS. 8 and 10, only Cu was detected in Example 4, whereas both elements of Cu and Mg were detected in Comparative Example 1. From these observation results, it was considered that the heat treatment at 300 ° C. for 6 hours in Comparative Example 1 produced an intermetallic compound of copper and magnesium at the interface, which caused brittle fracture, resulting in a decrease in peel strength.

(Measurement of oxide layer)
About the oxide layer in the interface of a metal laminated material, it confirmed using XPS (X-ray photoelectron spectroscopy) (PHI5000VersaProbeII by ULVAC-PHI).

FIG. 11 shows the results measured by etching from the copper layer side in the metal laminate of Example 1. In the measurement by XPS, etching was started after the copper layer was polished to some extent.

As shown in FIG. 11, oxygen was not detected in the copper layer, but the detection of oxygen increased with an increase in the detected value of magnesium, and the detection of oxygen decreased as etching progressed from the interface into the magnesium alloy layer. From this, it is considered that the oxide layer on the surface of the copper layer was removed by sputter etching at the time of bonding, and oxygen derived from the oxide layer on the surface of the magnesium alloy layer was detected. It was confirmed that exists at the interface of the metal laminate.

Although the thickness of the oxide layer of the magnesium alloy cannot be measured strictly, the thickness of the oxide layer calculated by multiplying the etching rate in terms of SiO _{2 in} XPS and the etching time was about 2000 nm to 5000 nm.

1 Metal laminate 10 Copper layer 20 Magnesium alloy layer

All publications, patents and patent applications cited in this specification are incorporated herein by reference in their entirety.

Claims

A metal laminate having a two-layer structure of copper layer / magnesium alloy layer and no intermetallic compound at the interface.
The metal laminate according to claim 1, wherein the thickness is 0.03 mm to 1 mm.
The metal laminate according to claim 1 or 2, wherein the thickness ratio of the copper layer is 5% to 70% of the whole.
4. The metal laminate according to claim 1, wherein a magnesium alloy oxide layer is present at the interface.
The metal laminate according to any one of claims 1 to 4, which has a thermal conductivity of 1.2 times or more of the thermal conductivity of the magnesium alloy layer.
The metal laminate according to any one of claims 1 to 5, which has a volume resistivity of 2/3 or less with respect to a volume resistivity of the magnesium alloy layer.
It is a manufacturing method of the metal laminated material of Claim 1,
A step of sputter etching a copper plate or foil;
A step of sputter etching a magnesium alloy plate or foil;
Pressing the sputter-etched surface of the copper or magnesium alloy plate or foil to form a two-layer structure of copper layer / magnesium alloy layer;
The manufacturing method of the said metal laminated material containing.
It is a manufacturing method of the metal laminated material of Claim 4, Comprising:
A step of sputter etching a copper plate or foil to remove the oxide layer on the surface;
A step of sputter etching the magnesium alloy plate or foil while leaving the oxide layer on the surface;
Pressing the sputter-etched surface of the copper or magnesium alloy plate or foil to form a two-layer structure of copper layer / magnesium alloy layer;
The manufacturing method of the said metal laminated material containing.
A method for producing a metal laminate, further comprising a step of heat-treating the metal laminate obtained by the production method according to claim 7 or 8 at 100 ° C to 200 ° C for 10 minutes to 6 hours.