JP2021186867A - Component for electric and electronic equipment - Google Patents

Abstract

To provide a component for electric/electronic equipment in which a plurality of plate materials made of copper-based materials are welded to each other by welding, in which strength of a welded part is high.SOLUTION: The component for electric/electronic equipment comprises a welded part, constituted of a plurality of plate materials containing Cu of 90 mass% or more, in which the plurality of plate materials are joined to each other in a linear shape or in a point shape while butting the plate materials to each other or while overlapped the materials with each other to be integrated with each other. The welded part extends across the whole thickness of the plate materials, where when measuring a GAM value obtained from crystalline orientation analysis data of SEM-EBSD method, in a rectangular region sectioned by a welding width and a thickness of the plate material, on a cross section of the welded part cut in a direction in which the plurality of welded plate materials extend, a rear ratio of crystalline grain whose GAM values are 0.5° or more and less than 2.0° to all crystalline grain existing in a measured area is 20% or more, and an average crystalline grain size determined from all crystalline grain existing in the measured area is a dimension equal to or shorter than a thickness of the thinner plate material of the plurality of plate materials.SELECTED DRAWING: None

Description

The present invention relates to parts for electrical and electronic devices.

In recent years, the amount of heat generated tends to increase due to higher functionality and higher performance of electric and electronic devices. In addition, as the miniaturization of electric and electronic devices progresses, the heat generation density increases, so it is becoming important to cool the generated heat. Examples of the member for cooling the generated heat include a vapor chamber which is a planar heat pipe. As the material of the vapor chamber, it is desirable to use a copper-based material (pure copper, copper alloy) having high thermal conductivity.

Here, the vapor chamber has a hermetically sealed structure in which a working liquid is put into an internal space formed by joining the outer peripheral portions in a state where a plurality of plates are stacked, and then sealed under reduced pressure. Examples of such a joining method include laser welding, resistance welding, diffusion welding, and TIG welding.
When joining by these welds, the welded part is formed by melting once by heating to a high temperature and then re-solidifying, so that it is softened and the plate itself is softened as in the case of annealing. There is a problem that it becomes softer than the strength and the strength becomes low. The lower the strength, the easier it is to deform.

To deal with such problems, Patent Document 1 describes a method of manufacturing a vapor chamber by joining a plurality of parts by diffusion joining or brazing, using a precipitation hardening copper alloy as a material of a housing and aging treatment. Then, a technique for improving the strength of the housing and the like by precipitation hardening is disclosed.
However, in the technique of Patent Document 1, it is necessary to use a precipitation hardening type copper alloy, and there is a problem that it cannot be applied to a non-precipitation type copper alloy or pure copper. Further, in the technique of Patent Document 1, it is necessary to perform aging treatment, and there is a problem that productivity is lowered due to an increase in the number of steps.
Therefore, it is desired to increase the strength of the welded portion by a method other than the method of precipitation hardening using a precipitation hardening type copper alloy by aging treatment.

The above-mentioned problem of low strength of the welded portion exists not only in the vapor chamber but also in other electric / electronic devices such as a bus bar.

Note that Patent Document 2 discloses a technique for improving the bonding strength by irradiating a laser with a specific trajectory, but the technique of Patent Document 2 is a technique relating to bonding between aluminum and copper. It is difficult to apply to joining copper-based materials. More specifically, the copper-based material has a high thermal conductivity, so that heat easily escapes, and the laser beam is easily reflected. Therefore, the copper-based material is a material that is difficult to join by laser welding. Therefore, as in Patent Document 2, simple welding using a laser beam has low bonding strength and cannot be sufficiently bonded.

International Publication No. 2017/164013 Japanese Unexamined Patent Publication No. 2017-168340

The present invention has been made in view of the above circumstances, and is a component for an electric / electronic device in which a plurality of plates made of copper-based materials are joined by welding, and the electric / electronic device having a high weld strength. The subject is to provide parts for use.

As a result of diligent studies, the present inventors control the GAM value and the average crystal grain size of the welded portion by controlling the laser welding conditions using a plate material having a component composition containing 90% by mass or more of Cu. It was found that the Vickers hardness HV of the welded portion could be increased, and the present invention was completed.

That is, the gist structure of the present invention is as follows.
(1) It is composed of a plurality of plate materials containing 90% by mass or more of Cu, and the plurality of plate materials are joined and integrated by welding in a state of being abutted against each other or in a state of being overlapped with each other. The weld has a welded portion, and the welded portion extends over the entire thickness of the plate material, and the weld is formed in a cross section when the welded portion is cut in a direction in which the plurality of joined plate materials extend. When the GAM value obtained from the crystal orientation analysis data of the SEM-EBSD method is measured in the rectangular region partitioned by the weld width of the portion and the thickness of the plate material, the GAM value is 0.5 ° or more. The crystal grains having a temperature of less than 0 ° have an area ratio of 20% or more to all the crystal grains existing in the measurement area, and the average crystal grain size obtained from all the crystal grains existing in the measurement area is Parts for electrical and electronic equipment having dimensions equal to or less than the thickness of the thinner plate material among the plurality of plate materials.
(2) The electricity according to (1) above, wherein the plate material contains one or more elements selected from the group consisting of Ag, Fe, Ni, Co, Si, Cr, Sn, Zn, Mg and P. Parts for electronic devices.
(3) The crystal grains having a GAM value of 0.5 ° or more and less than 2.0 ° have an area ratio of 42% or more to all the crystal grains existing in the measurement area, and the average crystal grain size is The component for electrical / electronic equipment according to (2) above, which has a dimension of 60% or less of the thickness of the plate material.
(4) The component for electrical / electronic equipment according to (1) above, wherein the plate material is 99.96% by mass or more of Cu and unavoidable impurities.
(5) The component for electrical / electronic equipment according to any one of (1) to (4) above, wherein the component for electrical / electronic equipment is a vapor chamber.
(6) The component for electrical / electronic equipment according to any one of (1) to (4) above, wherein the component for electrical / electronic equipment is a bus bar.

According to the present invention, a component for electrical / electronic equipment in which a plurality of plates made of a copper-based material containing 90% by mass or more of Cu are joined by welding, and for electrical / electronic equipment having a high weld strength. Parts can be provided.

(A) is a schematic perspective view when two Cu plates are abutted and laser-welded linearly, and (b) is a linear laser weld in a state where two Cu plates are overlapped. It is a schematic perspective view at the time of this. It is an optical micrograph when observing the surface state of the laser-irradiated side of a Cu joint body (a joint body of two Cu plate materials) obtained by laser-welding a butt Cu plate material from the Z-axis. It is an optical micrograph when observing the surface state of the Cu junction body which laser-welded the butt Cu plate material on the side opposite to the side irradiated with the laser. It is an optical micrograph when observing the cross-sectional state of the Cu joint body which laser-welded the Cu plate material from the X-axis. (A) is a schematic perspective view when two Cu plates are abutted and laser-welded in a dot shape, and (b) is a case where two Cu plates are laser-welded in a dot-like state in a superposed state. It is a schematic perspective view of the above, and in each case, the welded portion is shown in a state where the cross section can be seen when the Cu joint is cut in the extending direction. It is a figure which shows the schematic structure of the laser welding apparatus. It is a figure which shows the spot diameter of the laser beam of a laser welding apparatus.

Hereinafter, embodiments of the present invention will be described. The following description is an example of an embodiment of the present invention and does not limit the scope of claims.

The component for electric / electronic equipment according to the embodiment of the present invention is composed of a plurality of plate materials containing 90% by mass or more of Cu, and the plurality of plate materials are welded together in a state of being abutted against each other or in a state of being overlapped with each other. It has a welded part that is joined and integrated in a shape or a dot shape, and the welded part extends over the entire thickness of the plate material, and the welded part is cut in the direction in which the plurality of joined plate materials extend. When the GAM value obtained from the crystal orientation analysis data of the SEM-EBSD method is measured in the rectangular region divided by the weld width of the weld and the thickness of the plate in the cross section, the GAM value is 0.5. The crystal grains having a temperature of ° or more and less than 2.0 ° have an area ratio of 20% or more to all the crystal grains existing in the measurement area, and the average crystal grain size obtained from all the crystal grains existing in the measurement area. Is a dimension equal to or less than the thickness of the thinner plate material among the plurality of plate materials.

FIG. 1A is a schematic perspective view when a Cu joint body 10 (a joint body of two Cu plate materials) is formed by laser welding linearly with two Cu plate materials 1 and 2 abutted against each other. FIG. 1B is a schematic perspective view of a Cu bonded body 10A formed by linear laser welding in a state where two Cu plates 1 and 2 are overlapped with each other. In the embodiment shown in FIG. 1 (a), the Cu plate members 1 and 2 have a welded portion 3 that is linearly joined and integrated in a state where the Cu plates 1 and 2 are butted against each other, and the portions are joined by laser welding. Further, in the embodiment shown in FIG. 1 (b), there is a welded portion 3A in which Cu plate materials 1 and 2 are integrated in a superposed state, and the portions are joined by laser welding. The welded portion 3 extends over the entire thickness of the plate members 1 and 2. That is, in FIGS. 1 (a) and 1 (b), the welded portion 3 is melted and solidified so as to melt from the surface on the side irradiated with the laser to the surface (back surface) on the opposite side, and the plate materials 1 and 2 are formed. Exists so as to penetrate in the thickness direction. The term "Cu plate material" as used herein means a plate material containing 90% by mass or more of Cu (copper).

Here, the "plate material containing 90% by mass or more of Cu" may be any plate material having a Cu content of 90% by mass or more, and may be pure Cu or any Cu alloy, and is not particularly limited.
When the plate material is a Cu alloy, the plate material contains one to two or more elements selected from Ag, Fe, Ni, Co, Si, Cr, Sn, Zn, Mg, and P as alloy components, and the balance of Cu. It is preferable to have a component composition in which is 90% by mass or more. The Cu alloy may be a precipitation hardening type Cu alloy or a non-precipitation hardening type Cu alloy. When the plate material is a Cu alloy, the Vickers hardness HV of the plate material is not particularly limited because it varies depending on the type and amount of the alloy component to be added, but is generally 75 or more and 240 or less.

When the plate material is pure Cu, the plate material has a Cu content of 99.96% by mass or more, and Cd, Mg, Pb, Sn, Cr, Bi, Se and Te as unavoidable impurities are 5 ppm in total. The total of Ag and O is 400 ppm or less. Pure Cu has excellent thermal conductivity, so it can exhibit excellent performance as a heat dissipation / cooling member. Examples of so-called pure Cu include electrolytic copper, oxygen-free copper (OFC), and TPC. When the plate material is pure Cu, the Vickers hardness of the plate material is not particularly limited, but is generally 65 or more and 120 or less.

Further, the "plate material" as used in the present invention is a material processed into a predetermined shape, for example, a plate, a strip, a foil, a rod, a flat wire, etc., and has a predetermined thickness, in a broad sense. Means to include strips. In the present invention, the thickness (plate thickness) of the plate material is not particularly limited, but is preferably 0.05 to 1.0 mm, more preferably 0.1 to 0.8 mm. The shape of the plurality of plate materials to be joined and the thickness (plate thickness) of the plate materials may be the same or different.

FIG. 2 is a photograph showing the surface state of the Cu-bonded body 10 obtained by laser-welding two butted Cu plates 1 and 2 on the side irradiated with the laser. It shows that the X-axis direction is the laser sweep direction, that is, the welding direction. In addition, it can be seen that there is a portion where the processing marks of rolling of the Cu plate material have disappeared due to the irradiation of the laser beam. Further, there is a portion where the Cu plate materials 1 and 2 are melted and solidified again, and this is referred to as a welded portion 3.
FIG. 3 is an optical microscope photograph when observing the surface state of the Cu junction 10 obtained by laser-welding two butted Cu plates 1 and 2 on the side opposite to the laser-irradiated side, and is the back surface of FIG. It is an optical microscope photograph when observing the surface state of.
As shown in FIGS. 2 and 3, since the welded portion 3 extends over the entire thickness of the plate materials 1 and 2, the laser welding mark is on the side irradiated with the laser of the Cu junction 10. It appears on the surface (front) and the surface (back) opposite to the side irradiated with the laser. Then, as shown in FIGS. 2 and 3, the width of the laser welding mark on the surface on the laser-irradiated side is wider than the laser welding mark on the surface opposite to the laser-irradiated side. The width of the laser welding mark on the surface irradiated with this laser was defined as the welding width in the present invention, and the cross-sectional structure was observed by cutting at the dotted cross-sectional observation position.
FIG. 4 is an optical micrograph showing a cross-sectional state when a Cu plate material is laser welded to form a Cu bonded body. As shown in FIG. 4, the width of the surface of the welded portion that has been irradiated with the laser and melted and solidified again on the side irradiated with the laser corresponds to the weld width. The welding width can also be recognized from the cross-sectional view shown in FIG.

In the present invention, in the cross section when the welded portion is cut in the direction in which the plurality of joined plate materials extend, the SEM-EBSD method is performed in a rectangular region divided by the weld width of the welded portion and the thickness of the plate material. When the GAM value obtained from the crystal orientation analysis data of is measured, the crystal grains having a GAM value of 0.5 ° or more and less than 2.0 ° have an area ratio of 20% or more to all the crystal grains existing in the measurement area. Is.

Further, in the present invention, the average crystal grain size obtained from all the crystal grains existing in the above-mentioned measurement area of the GAM value in the cross section when the welded portion is cut in the direction in which the plurality of joined plates extend. , The size is equal to or less than the thickness of the thinner plate material among the plurality of joined Cu plate materials.

As described above, a specific crystal structure having a GAM value of 0.5 ° or more and less than 2.0 °, an area ratio of crystal grains of 20% or more, and an average crystal grain size equal to or less than the thickness of the plate material. As shown in Examples described later, the Vickers hardness of the welded portion can be increased, and for example, the Vickers hardness of the welded portion can be 60 or more, further 100 or more.

The above-mentioned Vickers hardness is measured at a position corresponding to half the thickness of the plate material of the welded portion in the cross section when the welded portion is cut in the direction in which the two joined plates extend. Vickers hardness. In this specification, the Vickers hardness HV is measured according to the method specified in JIS Z2244 (2009).

More specifically, as shown in FIG. 1 (a), when the welded portion 3 is provided by linearly joining and integrating the two Cu plates 1 and 2 in a state of being butted against each other, the welding direction (laser sweep direction). ) Is the X-axis direction, the direction perpendicular to the welding direction (width direction of the plate material) is the Y-axis direction, and the normal direction of the plate material (thickness direction of the plate material) is the Z-axis direction. The direction L in which the plate members 1 and 2 extend is the direction in which the plate members are brought closer to each other in order to bring them into a butt state, that is, the Y-axis direction. In the case of the electric / electronic device parts of the present embodiment having such a structure of the bonded body 10, the welded portion 3 existing in the cross section A when the Cu bonded body 10 is cut in the Y-axis direction is the Cu plate material 1. The Vickers hardness can be 60 or more at the position b corresponding to the half dimension of the thickness a of 2.

Further, as shown in FIG. 1 (b), when the welded portion 3A is formed by linearly joining and integrating the two Cu plates 1 and 2 in a state of being overlapped with each other, the two joined plates are joined. The direction in which 1 and 2 extend is the direction perpendicular to the welding direction, that is, the Y-axis direction. For parts for electrical and electronic equipment of the present embodiment having the configuration of such a conjugate 10A, when cutting the Cu assembly 10A in the Y axis direction, welds present in cross-section A ₁ of the Cu plate 1 _{Position b 1} corresponding to half the size of the thickness a ₁ of the Cu plate material 1 and the position corresponding to half the size of _{the thickness a 2} of the Cu plate material 2 of the welded portion existing in _{the cross section A 2 of the Cu plate material 2.} in both the b _2, the Vickers hardness can be 60 or more.

In the above, the case of linear laser welding has been described, but the case of point laser welding is shown in FIGS. 5 (a) and 5 (b). FIG. 5 (a) is a schematic perspective view of the case where two Cu plates 1 and 2 are abutted and laser welded in a dot shape to form a Cu bonded body 10B, and FIG. 5 (b) is a schematic perspective view of 2. It is a schematic perspective view when the Cu bonded body 10C is formed by laser welding in the form of dots in the state where the Cu plates 1 and 2 are laminated.

As shown in FIG. 5A, in the case of the parts for electrical and electronic equipment of the present embodiment having the configuration of the Cu joint body 10B having the welded portions 3B that are joined and integrated in a dot shape in a state of being butted against each other. , Half the thickness a of the plate material of the welded portion 3B existing in the cross section A when the bonded body 10B is cut in the extending direction L of the Cu plate materials 1 and 2 through the center c of the welded portion 3B on the plate material surface. At the position b corresponding to, the Vickers hardness can be 60 or more.

Further, as shown in FIG. 5B, the parts for electrical and electronic equipment of the present embodiment having the configuration of the Cu joint body 10C having the welded portions 3B which are joined and integrated in a dot shape in a state of being overlapped with each other. for passes through the center c of the welded portion in the plate surface, obtained by cutting the welded portion in the stacking direction of the plate, the Cu plate 1 of the welded portion present in the cross section a ₁ of the Cu plate 1 having a thickness of a ₁ a position b ₁ corresponding to half the size, in both positions b ₂ corresponding to half of the thickness dimension a ₂ of Cu plate 1 of the welded portion present in the cross section a ₂ of the Cu plate 2, the Vickers hardness It can be 60 or more.

In the present specification, the Vickers hardness HV in the case of linear laser welding is measured in five cross sections A (YZ planes) cut at intervals of 1 mm in the welding direction (X-axis direction), and these measurements are taken. Calculate as the average value of the results.

Next, the GAM value will be described. The GAM (grain average misorientation) value is a value obtained from the crystal orientation analysis data of the SEM-EBSD method, and is a value between measurement points in a crystal grain distinguished by a large angle grain boundary having an orientation difference of 15 ° or more. The distance (hereinafter, also referred to as step size) is measured at 0.1 μm, the orientation difference between adjacent measurement points is calculated, and the calculated orientation difference is a value calculated as an average value within the same crystal grain.

A small GAM value means that the average orientation difference in the crystal grains is small, the uniform crystal grains have very little strain, the crystal grains have a continuous azimuth gradient, and the like, and the locality in one crystal grain. Indicates that the strain is small. On the other hand, a large GAM value means that the average orientation difference in the crystal grains is large, and indicates that the local strain in one crystal grain is large. Crystal grains having a GAM value of 0.5 ° or more and less than 2.0 ° are crystal grains having characteristics between them, and indicate that local strain is large to some extent within one crystal grain. When the plate material is annealed, the GAM value is usually 0 ° or more and less than 0.5 °, and the local strain in one crystal grain becomes small.

The GAM value is analyzed from the crystal orientation data continuously measured using the EBSD detector attached to the high-resolution scanning analysis electron microscope (JSM-7001FA, manufactured by Nippon Denshi Co., Ltd.) (OIM Analysis, manufactured by TSL). It can be obtained from the crystal orientation analysis data calculated using. "EBSD" is an abbreviation for Electron Backscatter Diffraction, which is a crystal orientation analysis technique using reflected electron Kikuchi line diffraction generated when a copper plate material as a sample is irradiated with an electron beam in a scanning electron microscope (SEM). Is. "OIM Analysis" is data analysis software measured by EBSD.
In the present invention, the measurement region is the _{entire rectangular region of the surfaces of the cross sections A, A 1} , and A ₂ which is divided by the weld width of the welded portion and the thickness of the plate material on the surface mirror-finished by electrolytic polishing. be. The area ratio of crystal grains with GAM values within the specified range is defined as the first category with GAM values of 0 ° or more and less than 0.25 °, 15 categories in 0.25 ° increments, and 0 ° or more and less than 3.75 °. The GAM value is used as a measurement target, and it can be calculated from the total area ratio of crystal grains in each category to the entire SEM image obtained by the SEM-EBSD method.

Next, the average crystal grain size will be described. In the present invention, the crystal grain size is the cross section when the welded portion is cut in the direction in which the plurality of joined plates extend, that is, the cross sections A, A ₁ , A used in the measurement of the Vickers hardness and the GAM value. ₂ by observing, ask. Specifically, OIM analysis defines an orientation difference of 15 ° or more as a grain boundary, and creates a diagram depicting the crystal grain boundary. From the figure, based on the crystal grain size measurement method (cutting method) specified in JIS H0501-1986 for the plate thickness direction (Z-axis direction) and the direction perpendicular to the plate thickness direction (Y-axis direction), respectively. , Measure the crystal grain size. The average of the measured crystal grain size in the plate thickness direction and the crystal grain size in the direction perpendicular to the plate thickness direction is defined as the average crystal grain size.
In the present invention, the average crystal grain size thus obtained is a dimension equal to or less than the thickness of the thinner plate material among the plurality of bonded Cu plates.

When joining by welding, the welded part is formed by melting once by heating to a high temperature and then re-solidifying. Therefore, in the conventional joining method, the structure is similar to that when the plate is annealed. There is a problem that it changes and becomes soft, and becomes softer and lower in strength than the strength of the plate itself. The lower the strength, the easier it is to deform.
However, as shown in Examples described later, by using a plate material having a composition containing 90% by mass or more of Cu and controlling the laser welding conditions, the GAM value, which is the structure of the welded portion, is 0.5 ° or more 2 It is possible to control the area ratio of crystal grains having a temperature of less than 0.0 ° and the average crystal grain size, and it is possible to suppress a decrease in strength due to softening of the welded portion.
Therefore, in the present embodiment, the Vickers hardness of the welded portion can be increased, and the Vickers hardness of the welded portion can be 60 or more, further 100 or more. Since the welded portion in the present invention has a high Vickers hardness, it is possible to provide parts for electrical and electronic devices having high strength and excellent deformation resistance. Since there is a proportional relationship between Vickers hardness and strength, the strength can be increased by increasing the Vickers hardness. When the aging treatment is performed as in Patent Document 1, the entire Cu joint including the welded portion tends to be heated and softened unless a curable copper alloy is used. Therefore, the Vickers hardness of the welded portion is present. It is considered difficult to maintain 60 or more, and even 100 or more.

When a Cu alloy is used as the plate material, the above-mentioned crystal grains having a GAM value of 0.5 ° or more and less than 2.0 ° have an area ratio of 42% or more to all the crystal grains existing in the measurement area, and the above-mentioned The average crystal grain size of is preferably 60% or less of the thickness of the thinner plate material. The above-mentioned crystal grains having a GAM value of 0.5 ° or more and less than 2.0 ° have an area ratio of 42% or more to all the crystal grains existing in the measurement area, and the above-mentioned average crystal grain size is thin. If the size is 60% or less (for example, 80 μm or less) of the thickness of the plate material, the Vickers hardness of the welded portion is 100 or more in the case of Cu alloy, although it depends on the total amount of elements added as alloy components. Can be. In the case of a Cu alloy, the inclusion of the alloy components Ag, Fe, Ni, Co, Si, Cr, Sn, Zn, Mg and P strengthens the solid solution and increases the hardness of the plate material. In such a plate material made of Cu alloy, the difference in hardness between the welded portion and the plate material tends to be large, but the above-mentioned crystal grains having a GAM value of 0.5 ° or more and less than 2.0 ° have a measurement area. When the area ratio to all the existing crystal grains is 42% or more and the above-mentioned average crystal grain size is 60% or less of the thickness of the thinner plate material, the hardness of the welded portion and the plate material is The difference between can be reduced. The total amount of the elements added as the alloy component is preferably 1.30% by mass or more.

The upper limit of the Vickers hardness HV of the welded portion is not particularly limited, but is, for example, 110 or less in the case of pure Cu, and is, for example, 130 or less in the case of Cu alloy.

The Cu plate material used for this component for electrical and electronic equipment is a Cu alloy containing 90% by mass or more of Cu and containing other metal elements, or 99.96% by mass or more of Cu and pure Cu which is an unavoidable impurity. It is preferable to have. Thermal conductivity can be provided by using a Cu plate material of 90% by mass or more. Originally, Cu has high thermal conductivity, but the amount of added elements increases, and the appearance of the second phase lowers the thermal conductivity. Therefore, the Cu plate material used for the parts for electric and electronic devices of the present embodiment contains 90% by mass or more of Cu, so that deterioration of thermal conductivity can be suppressed and high strength can be provided.

Next, the reasons for limiting the suitable component composition of the plate material constituting the parts for electric and electronic devices of the present invention will be described below.
The plate material constituting the parts for electric and electronic devices of the present invention may be any plate material containing 90% by mass or more of Cu, and may be either a Cu alloy or pure Cu.

First, the component composition when the plate material is a Cu alloy will be described.
(1) When the plate material is a Cu alloy The plate material preferably contains one or more elements selected from the group consisting of Ag, Fe, Ni, Co, Si, Cr, Sn, Zn, Mg and P.

(Ag: 0.05 to 5.00% by mass)
Ag (silver) is a component having an action of improving mechanical properties without impairing electrical properties, and in order to exert such actions, the Ag content is preferably 0.05% by mass or more. .. Further, it is not necessary to set an upper limit of the Ag content in particular, but since Ag is expensive, it is preferable to set the upper limit of the Ag content to 5.0% by mass from the viewpoint of material cost.

(Fe: 0.05 to 0.50% by mass)
Fe (iron) is a component having an action of improving mechanical properties. In order to exert such an effect, the Fe content is preferably 0.05% by mass or more. However, even if Fe is contained in an amount of more than 0.50% by mass, no further improvement effect can be expected, and there is a concern that the corrosion resistance is further lowered. Therefore, the Fe content is preferably 0.05 to 0.50% by mass.

(Ni: 0.05 to 5.00% by mass)
Ni (nickel) is finely precipitated in the matrix of Cu as a precipitate of second-phase particles composed of a simple substance or a compound with Si, for example, in a size of about 50 to 500 nm, and this precipitate is formed. It is a component having an action of precipitation hardening by suppressing dislocation movement, further suppressing grain growth, and increasing material strength by refining crystal grains. In order to exert such an effect, the Ni content is preferably 0.05% by mass or more. On the other hand, when the Ni content exceeds 5.00% by mass, the conductivity and the thermal conductivity are significantly lowered. Therefore, the upper limit of the Ni content is preferably 5.00% by mass.

(Co: 0.05 to 2.00% by mass)
Co (cobalt) is finely precipitated in the matrix of Cu as a precipitate of second-phase particles composed of a simple substance or a compound with Si, for example, in a size of about 50 to 500 nm, and this precipitate is formed. It is a component having an action of precipitation hardening by suppressing dislocation movement, further suppressing grain growth, and increasing material strength by refining crystal grains. In order to exert such an effect, the Co content is preferably 0.05% by mass or more. On the other hand, when the Co content exceeds 2.00% by mass, the conductivity and the thermal conductivity are significantly lowered. Therefore, the upper limit of the Co content is preferably 2.00% by mass or less.

(Si: 0.05 to 1.10% by mass)
Si (silicon) is finely precipitated in the matrix of Cu as a precipitate of second-phase particles composed of compounds together with Ni and Co, and this precipitate is precipitated and hardened by suppressing dislocation movement. Furthermore, it is an important component having an action of suppressing grain growth and increasing the material strength by refining the crystal grains. In order to exert such an effect, the Si content is preferably 0.05% by mass or more. On the other hand, when the Si content exceeds 1.10% by mass, the conductivity and the thermal conductivity are significantly lowered. Therefore, the upper limit of the Si content is preferably 1.10% by mass.

(Cr: 0.05 to 0.50% by mass)
Cr (chromium) is finely precipitated in the matrix of Cu as a compound or a single substance in the form of a precipitate having a size of, for example, about 10 to 500 nm, and this precipitate suppresses dislocation movement. It is a component that has the effect of precipitating and hardening, further suppressing grain growth, and increasing the material strength by refining the crystal grains. In order to exert this effect, the Cr content is preferably 0.05% by mass or more. Further, when the Cr content exceeds 0.50% by mass, the conductivity and the thermal conductivity are significantly lowered. Therefore, the Cr content is preferably 0.05 to 0.50% by mass.

(Sn: 0.05 to 9.50% by mass)
Sn (tin) is a component that is solid-solved in the matrix of Cu and contributes to the improvement of the strength of the Cu alloy, and the Sn content is preferably 0.05% by mass or more. On the other hand, when the Sn content exceeds 9.50% by mass, embrittlement is likely to occur. Therefore, the Sn content is preferably 0.05 to 9.50% by mass. Further, since the Sn content tends to decrease the conductivity and the thermal conductivity, the Sn content is set to 0.05 to 0.50% by mass in the case of suppressing the decrease in the conductivity and the thermal conductivity. Is more preferable.

(Zn: 0.05 to 0.50% by mass)
Zn (zinc) is a component having an effect of improving the adhesion and migration characteristics of Sn plating and solder plating. In order to exert such an effect, the Zn content is preferably 0.05% by mass or more. On the other hand, if the Zn content exceeds 0.50% by mass, the amount of zinc vapor increases during welding, which may cause defects in the welded portion. Therefore, the Zn content is preferably 0.05 to 0.50% by mass.

(Mg: 0.01 to 0.50% by mass)
Mg (magnesium) is a component having an action of improving mechanical properties. In order to exert such an effect, the Mg content is preferably 0.01% by mass or more. On the other hand, when the Mg content exceeds 0.50% by mass, the conductivity and the thermal conductivity tend to decrease. Therefore, the Mg content is preferably 0.01 to 0.50% by mass.

(P: 0.01 to 0.50% by mass)
P (phosphorus) not only contributes as a deoxidizing material for Cu alloys, but also finely precipitates in the form of precipitates having a size of about 20 to 500 nm as compounds with Fe, Ni, etc., and these precipitates suppress dislocation movement. By doing so, precipitation hardening can be performed, and further, grain growth is suppressed and the material strength can be increased by refining the crystal grains. In order to exert such an effect, the P content is preferably 0.01% by mass or more. On the other hand, when the P content exceeds 0.50% by mass, cracks tend to easily occur in the solidified portion after welding. Therefore, the P content is set to 0.01 to 0.50% by mass.

(2) When the plate material is pure Cu with excellent conductivity and heat dissipation The plate material is 99.96% or more Cu and, as unavoidable impurities, for example, Cd, Mg, Pb, Sn, Cr, Bi, Se, Te. Is preferably 5 ppm or less in total, and pure Cu having a component composition in which Ag and O are each 400 ppm or less is preferable.

(Manufacturing method of parts for electrical and electronic equipment)
In the method for manufacturing a component for an electric / electronic device according to an embodiment of the present invention, a plurality of plate materials containing 90% by mass or more of Cu are set in a state of being abutted against each other or in a state of being overlapped with each other, and then joined. A plurality of plate materials are welded by irradiating a plurality of laser beams having a wavelength of 400 to 1200 nm and having different spot diameters and injecting a gas containing a non-oxidizing gas as a main component to the molten portion. It includes a welding process in which they are linearly joined together and integrated.

As for the plurality of laser beams to be irradiated in the welding process, the smaller the wavelength of the laser beam, the larger the spot diameter, and the spot of the laser beam other than the laser beam having the minimum wavelength and the maximum spot diameter (that is, the irradiation range) has the minimum wavelength and the maximum spot. It should be included in the spot of the laser beam of the diameter. The plurality of laser beams irradiated in the welding step include a laser beam having a wavelength of at least 400 to 500 nm and a laser beam having a wavelength of 800 to 1200 nm. Further, the plurality of laser beams irradiated in the welding process are the ratio _{of the spot diameter Φ max} of the laser beam having the minimum wavelength and the maximum spot diameter to _{the spot diameter Φ min} of the laser beam having the maximum wavelength and the minimum spot diameter _{Φ min} / Φ _max. However, it is 0.05 to 0.25. The spot diameter is the diameter of the irradiated laser beam on the surface of the plate material.

For example, when two laser beams having a wavelength of 400 to 500 nm and a second laser beam having a wavelength of 800 to 1200 nm are used as a plurality of laser beams to be irradiated, the spot diameter of the first laser beam is the first. (2) A spot of a laser beam other than the spot of the first laser beam (that is, a spot of the second laser beam) having a diameter larger than the spot diameter of the second laser beam is included in the spot of the first laser beam. Then, the ratio Φ _min / Φ _{of the spot diameter Φ max} of the first laser beam which is the laser beam having the minimum wavelength and the maximum spot diameter _{and the spot diameter Φ min} of the second laser beam which is the laser beam having the maximum wavelength and the minimum spot diameter. _{Make max} so that it satisfies 0.05 to 0.25.
The case of irradiating two laser beams has been described, but the relationship between the above-mentioned spots (irradiation range) and spot diameters of three or more laser beams having a wavelength of 400 to 1200 nm and different spot diameters is described. You may irradiate three or more laser beams that satisfy the condition.

The gas containing a non-oxidizing gas as a main component sprayed on the molten portion in the welding step contains 50% by volume or more of the non-oxidizing gas. The gas containing a non-oxidizing gas as a main component preferably contains 99.0% by volume or more of the non-oxidizing gas. The non-oxidizing gas is a gas that does not oxidize the plate material, and can be appropriately selected from argon, helium, nitrogen and the like. The gas containing a non-oxidizing gas as a main component may contain oxygen as long as it is a small amount.

While simultaneously irradiating a plurality of laser beams having a specific wavelength and satisfying the relationship between a specific spot (irradiation range) and a spot diameter, and injecting a gas containing a non-oxidizing gas as a main component into the molten portion. Welding facilitates welding of Cu plates, which was difficult in the past, and all existing in the measured area of crystal grains with a GAM value of 0.5 ° or more and less than 2.0 ° in the welded part. The area ratio to the crystal grains is 20% or more, and the average crystal grain size obtained from all the crystal grains existing in the measurement area is equal to or less than the plate thickness of the thinner plate material among the plurality of plate materials. It becomes a dimension. Such a welded portion has a high Vickers hardness, for example, the Vickers hardness of the welded portion can be 60 or more, and a welded portion having high strength can be obtained.

By irradiating a plurality of laser beams having a wavelength of 400 to 1200 nm and having different spot diameters, it becomes possible to generate a local temperature gradient in the molten pool, and an appropriate strain is introduced during solidification. .. Further, the uniformity of the welded portion surface can be improved by including the spot (irradiation range) of the laser light other than the laser light having the minimum wavelength and the maximum spot diameter in the spot of the laser light having the minimum wavelength and the maximum spot diameter. Can be enhanced. Further, by irradiating a laser beam having a wavelength of 400 to 500 nm and a laser beam having a wavelength of 800 to 1200 nm, a temperature difference can be generated during laser welding.

In the welded part where the crystal grains have grown, one crystal grain occupies the plate thickness, and further, the crystal grains may grow to a size larger than the plate thickness in the in-plane direction of the plate material and become coarse, and welding is performed. It causes a decrease in the rigidity of the part. However, by injecting a non-oxidizing gas into the molten portion, heat can be efficiently dissipated and cooling can be performed, thereby suppressing the growth of crystal grains. Further, the injection of the non-oxidizing gas into the molten portion also has a function of suppressing the oxidation of the molten portion.

Although the details are unknown, the GAM value is 0.5 ° or more and less than 2.0 ° at the welded part due to the action of the irradiation laser beam, the action of the gas containing non-oxidizing gas as the main component, and the interaction between them. The area ratio to all the crystal grains existing in the measured area of the crystal grains is 20% or more, and the average crystal grain size obtained from all the crystal grains existing in the measured area is among the plurality of plate materials. It is estimated that the dimensions will be equal to or less than the thickness of the thinner plate.

(Laser welding method)
The laser welding method is a welding method in which light having a wavelength with good directivity and concentration is collected by a lens and laser light having an extremely high energy density is used as a heat source. By adjusting the output of the laser beam, penetration welding with a narrow width with respect to the depth is also possible. In addition, the laser beam can be narrowed down to a very small size as compared with the arc of arc welding. With the energy densified by the condenser lens, the laser welding device can perform local welding and joining materials with different melting points. It is suitable for fine welding because it has little heat effect due to welding, the welding pattern is fine, and no processing reaction force is generated.

(Laser welding equipment)
FIG. 6 is a diagram showing an example of a schematic configuration of a laser welding apparatus. The laser welding apparatus 20 includes a laser control unit 21, oscillators 221 and 222, a laser head 29, a processing table (not shown), and a gas supply nozzle 30. Cu plate materials 111 and 112, which are the materials to be processed, are arranged on the processing table in a butt or overlapped state. The laser control unit 21 controls laser oscillators 221 and 222 that oscillate laser light, a scanner (not shown), a laser head 29, a processing table, and the like. The control unit 21 controls the course directions of the Cu plate members 111 and 112, which are the workpieces, by controlling the rotation of the X-axis motor and the Y-axis motor (not shown), for example. Further, the control unit 21 may move and control the laser beams 231 and 232. This can be appropriately selected depending on the size of the work material. The control unit 21 oscillates a plurality of first and second laser beams 231 and 232 oscillated from the oscillators 221 and 222. The oscillated first and second laser beams 231 and 232 are collected in parallel light through the glass fiber 25 by the first and second condenser lenses 261 and 262 in the laser head 29, respectively. The first and second laser beams 231 and 232 are changed in the direction of the processing table by the first and second mirrors 271 and 272, and the first and second laser beams 231 and 232 are passed through the focusing lens 28 to the Cu plate material 111. Welding is performed by focusing and irradiating the positions of 112 to be joined. At this time, a gas containing a non-oxidizing gas as a main component is supplied from the gas supply nozzle 30.

The laser can be appropriately selected from those known as welding lasers. Examples of _{lasers include CO 2} lasers, Nd: YAG lasers, semiconductor lasers, fiber lasers and the like. It is preferable to use a fiber laser from the viewpoint of output and condensing property of laser light. Other configurations of the laser welder can be selected from any conventionally known configuration.

(Laser welding)
FIG. 7 is a diagram showing the spot diameter of the laser beam of the laser welding apparatus. When irradiating the first laser light 231 having a wavelength of 400 to 500 nm and the second laser light 232 having a wavelength of 800 to 1200 nm, as shown in FIG. 7, the spot diameter of the first laser light 231 is the second. The spot (irradiation range) of the second laser beam 232, which is larger than the spot diameter of the laser beam 232, is included in the spot of the first laser beam 231. The ratio of the spot diameter Φ _max of the first laser beam to the spot diameter Φ _{min of the second laser beam Φ min} / Φ _max is in the range of 0.25 to 0.75. FIG. 7 shows an example in which the first laser beam 231 and the second laser beam 232 are irradiated so as to be concentric circles on the surface of the plate material and overlap each other. The spot diameter of the first laser beam having a wavelength of 400 to 500 nm is, for example, 150 to 650 μm, and the spot diameter of the second laser beam having a wavelength of 800 to 1200 nm is, for example, 20 to 60 μm.

(Application to electrical and electronic equipment)
The parts for electrical and electronic devices of the present invention can be considered to be used in semiconductor devices, LSIs, or many electronic devices using these, and further, for example, homes that need to be particularly miniaturized and highly integrated. Use for electrical and electronic equipment such as game consoles, medical equipment, workstations, servers, personal computers, car navigation systems, mobile phones, robot connectors, battery terminals, jacks, relays, switches, autofocus camera modules, lead frames, etc. Is possible.

(Vapor chamber)
The parts for electric and electronic devices of the present invention are made of pure Cu or Cu alloy having excellent thermal conductivity, and have high strength and excellent deformation resistance, so that they are preferably applied to heat pipes and vapor chambers.

(Busbar)
Further, the component for electric / electronic equipment of the present invention is made of pure Cu or Cu alloy having excellent thermal conductivity, and is suitable as a bus bar because of its high strength and excellent deformation resistance. The bus bar can be applied as an electric path for electrically connecting and as a transportation path for heat dissipation. In particular, the bus bar can also be used as a cooling device by connecting the bus bar from the heat generating portion and providing a path to the heat dissipation portion or the outside. Applicable.

Examples of the present invention will be described below. Various embodiments are possible in the present invention, and the present invention is not limited to the following examples.

(Examples 1 to 10 and Comparative Examples 1 to 17 (butt welding), Examples 11 to 20 and Comparative Examples 18 to 27 (lap welding)) Joining of two identical plates made of Cu alloy Examples 1 to In 10 and Comparative Examples 1 to 17, two plates made of Cu alloy having the component compositions shown in Table 1 were cut out into a thickness of 0.15 mm, a width of 20 mm, and a length of 1000 mm. The two cut out plates were moved in a direction in which the end faces extending in the length direction were brought closer to each other, and arranged in a butt state as shown in FIG. 1 (a). The first laser beam having a wavelength of 400 to 500 nm and a spot diameter (hereinafter, may be referred to as “beam diameter”) Φ _max is 150 to 660 μm, and a wavelength of 800 to 1200 nm and a spot diameter of Φ _min of 25. Laser welding was performed by irradiating with a second laser beam having a wavelength of about 40 μm while sweeping at 50 mm / sec while maintaining the positional relationship of the spot diameter as shown in FIG. The laser conditions are shown in Tables 1 and 2. Laser welding was performed while supplying a gas containing a non-oxidizing gas to the molten portion. As a gas containing a non-oxidizing gas, 99.9995 Vol% N ₂ was used.
Further, in Examples 11 to 20 and Comparative Examples 18 to 27, laser welding was performed under the same conditions as in Example 1 by using the overlapping arrangement shown in FIG. 1B instead of the butt arrangement.

Then, the GAM value and the average crystal grain size of the welded portion were measured by the following methods. Further, the Vickers hardness of the welded portion is measured, and when the Vickers hardness is 100 or more, it is described as "◎" as having excellent deformation resistance, and when the Vickers hardness is 60 or more, the deformation resistance is described. When the Vickers hardness is less than 60, it is described as "x" as the deformation resistance is poor. The results are shown in Table 1. In addition, the comparative example which could not be welded was not measured and was described as "-" in the table.

[Vickers hardness]
Vickers hardness HV was measured according to the method specified in JIS Z2244 (2009). The load (test force) at this time was selected from between 20 and 100 gf within a range in which the diagonal length of the indentation did not exceed 0.03 mm and tested. The pressing time (pushing time) of the indenter is 15 sec.
In the examples and comparative examples in which the plate materials are butted, as shown in FIG. 1A, the welding direction is the X-axis direction, the direction perpendicular to the welding direction is the Y-axis direction, and the plate normal direction is the Z-axis direction. Then, the Vickers hardness was measured at the position b corresponding to the half dimension of the thickness a of the plate material of the welded portion existing in the cross section A when the welded portion was cut in the Y-axis direction. Measurements were made on five cross sections A (YZ planes) cut at intervals of 1 mm in the welding direction (X-axis direction), and the average values of those measurement results were obtained.
Further, in the Examples and Comparative Examples were overlapped plate, FIG. 1, as shown in (b), Y the thickness of the sheet material of the welded portion present in the cross section A ₁ obtained by cutting the weld axis a ₁ position b ₁ corresponding to half the size _of, and in the position b ₂ corresponding to half the dimension of the thickness of a ₂ plate material welded portions existing section a ₂ obtained by cutting the welded portion in the Y-axis direction , Vickers hardness was measured. Measured in the welding direction (X axis direction) respectively were cut at intervals of 1mm to five cross A _1, A 2 _(YZ plane) was determined as an average of the measurement results.

[GAM value]
The GAM value is analyzed from the crystal orientation data continuously measured using the EBSD detector attached to the high-resolution scanning analysis electron microscope (JSM-7001FA, manufactured by Nippon Denshi Co., Ltd.) (OIM Analysis, manufactured by TSL). It was obtained from the crystal orientation analysis data calculated using. The measurement was performed in a visual field region of 400 μm × 800 μm with a step size of 0.1 μm. The measurement region is the _{entire rectangular region of the surfaces of the cross sections A, A 1} , and A ₂ which is divided by the weld width of the welded portion and the thickness of the plate material on the surface mirror-finished by electrolytic polishing.
The area ratio of crystal grains with GAM values within the specified range is defined as the first category with GAM values of 0 ° or more and less than 0.25 °, 15 categories in 0.25 ° increments, and 0 ° or more and less than 3.75 °. The GAM value was used as a measurement target, and it was calculated from the total area ratio of crystal grains in each category to the entire SEM image obtained by the SEM-EBSD method. Crystal grains consisting of 2 pixels or more are the targets of analysis.
When the plate materials were overlapped, the average value of the area ratio of the crystal grains of the GAM value measured for each of the two plate materials was obtained, and this average value is shown in the table.

[Average crystal grain size]
_{With respect to the cross sections A, A 1} and A ₂ used in the measurement of the Vickers hardness and the GAM value, the orientation difference of 15 ° or more was defined as the grain boundary, and a diagram depicting the grain boundary was created. From the figure, the crystal grain size was measured in the direction perpendicular to the plate thickness direction and the direction perpendicular to the plate thickness direction, respectively, based on the method for measuring the crystal grain size (cutting method) specified in JISH0501-1986. The average value of the measured crystal grain size in the plate thickness direction and the crystal grain size in the direction perpendicular to the plate thickness direction was taken as the average crystal grain size.

According to Examples 1 to 20, in the joining of two identical plates made of Cu alloy, a plurality of laser beams having a specific welding condition, that is, a wavelength of 400 to 1200 nm and different spot diameters are applied. At the same time, the multiple laser beams that are welded and welded while injecting a gas containing a non-oxidizing gas as the main component onto the molten portion have a larger spot diameter as the laser beam has a smaller wavelength, and other than the laser beam having the minimum wavelength and the maximum spot diameter. The spot of the laser beam is included in the spot of the laser beam having the minimum wavelength and the maximum spot diameter, and includes the laser beam having a wavelength of 400 to 500 nm and the laser beam having a wavelength of 800 to 1200 nm, and the minimum wavelength and the maximum spot. The ratio Φ _min / Φ _max of the spot diameter Φ _{max of the laser beam having a diameter to the spot diameter Φ min} of the laser beam having the maximum wavelength and the minimum spot diameter is 0.05 to 0.25, so that the GAM value is 0. The area ratio of the crystal grains of .5 ° or more and less than 2.0 ° can be 20% or more, and the average crystal grain size can be the same as or less than the plate thickness of the plate material. It can be seen that the hardness could be 60 or more. Among them, Examples 3 to 6 in which the area ratio of the crystal grains having a GAM value of 0.5 ° or more and less than 2.0 ° is 42% or more and the average crystal grain size is 60% or less of the plate thickness. 10 and 14 to 17 had a Vickers hardness of 100 or more, which was particularly high.
On the other hand, in Comparative Examples 1 to 27 which did not satisfy the above specific welding conditions, internal oxidation became excessive and embrittlement occurred and the damage was large (Comparative Example 1), no bonding (Comparative Example 13), and fusing (Comparative Example 14). ), Or welding was possible, but the area ratio of crystal grains with a GAM value of 0.5 ° or more and less than 2.0 ° is 20% or more, and the average crystal grain size is the plate thickness of the plate material. Did not satisfy that the dimensions were equal to or less than. Therefore, the Vickers hardness of the welded portion was less than 60.

(Examples 21 to 24 and Comparative Examples 28 to 33 (butt welding), Example 25 and Comparative Example 34 (lap welding)) Joining of two identical plates made of pure Cu Examples 21 to 24 and Comparative Example 28 to 33 are the same as in Example 1 (butt welding) except that two plates made of pure Cu having the component compositions shown in Table 3 were used and welded under the welding conditions shown in Table 3. did.
In Example 25 and Comparative Example 34, except that two plates made of pure Cu having the component compositions shown in Table 4 were used and welded under the welding conditions shown in Table 4, Example 11 (superimposition). Welding) was the same.

According to Examples 21 to 25, in the joining of two identical plates made of pure Cu, a crystal having a GAM value of 0.5 ° or more and less than 2.0 ° by welding under the above-mentioned specific welding conditions. The area ratio of the grains was 20% or more, and the average crystal grain size could be the same as or less than the plate thickness of the plate material, and as a result, the Vickers hardness of the welded part could be 60 or more. I understand.
On the other hand, Comparative Examples 28 to 34 that did not satisfy the above specific welding conditions could not be welded without joining (Comparative Example 33), or could be welded but had a GAM value of 0.5 ° or more and 2.0 °. It did not satisfy that the area ratio of the crystal grains less than 20% and the average crystal grain size were equal to or less than the plate thickness of the plate material. Therefore, the Vickers hardness of the welded portion was less than 60.

(Examples 26 to 28 and Comparative Examples 35 to 38) Welding of two plates made of Cu alloy and having different component compositions In Examples 26 to 28 and Comparative Examples 35 to 38, Cu having the component compositions shown in Table 5 is used. The same procedure as in Example 1 was carried out except that a plate material made of an alloy was used and welded under the welding conditions shown in Table 5. The results are shown in Table 5.

According to Examples 26 to 28, in the joining of two plates made of Cu alloy and having different component compositions, the GAM value is 0.5 ° or more and less than 2.0 ° by welding under the above-mentioned specific welding conditions. The area ratio of the crystal grains is 20% or more, and the average crystal grain size can be set to a size equal to or less than the plate thickness of the plate material, whereby the Vickers hardness of the welded portion can be set to 60 or more. You can see that it was done.
On the other hand, in Comparative Examples 35 to 38 which did not satisfy the above specific welding conditions, the area ratio of the crystal grains having a GAM value of 0.5 ° or more and less than 2.0 ° was 20% or more and the average crystal grain size was a plate material. It did not satisfy that the dimensions were equal to or less than the plate thickness of. Therefore, the Vickers hardness of the welded portion was less than 60.

(Examples 29 to 30 and Comparative Examples 39 to 41) Welding of two plates made of pure Cu and having different component compositions In Examples 29 to 30 and Comparative Examples 39 to 41, pure Cu having the component composition shown in Table 6 is used. The same procedure as in Example 1 was carried out except that a plate material made of Cu was used and welded under the welding conditions shown in Table 6. The results are shown in Table 6.

According to Examples 29 to 30, in the joining of two plates made of pure Cu and having different component compositions, the GAM value is 0.5 ° or more and less than 2.0 ° by welding under the above-mentioned specific welding conditions. The area ratio of the crystal grains is 20% or more, and the average crystal grain size can be set to a size equal to or less than the plate thickness of the plate material, whereby the Vickers hardness of the welded portion can be set to 60 or more. You can see that it was done.
On the other hand, in Comparative Examples 39 to 41 which did not satisfy the above specific welding conditions, the area ratio of the crystal grains having a GAM value of 0.5 ° or more and less than 2.0 ° was 20% or more and the average crystal grain size was a plate material. It did not satisfy that the dimensions were equal to or less than the plate thickness of. Therefore, the Vickers hardness of the welded portion was less than 60.

(Example 31 and Comparative Examples 42 to 44) Welding of a plate material made of pure Cu and a plate material made of Cu alloy In Examples 31 and Comparative Examples 42 to 44, a plate material made of pure Cu having the component composition shown in Table 7 The same as in Example 1 was carried out except that a plate material made of Cu alloy was used and welded under the welding conditions shown in Table 7. The results are shown in Table 7.

According to Example 31, in the joining of the plate material made of pure Cu and the plate material made of Cu alloy, the GAM value is 0.5 ° or more and less than 2.0 ° by welding under the above-mentioned specific welding conditions. The area ratio of the crystal grains can be 20% or more, and the average crystal grain size can be set to a size equal to or less than the plate thickness of the plate material, whereby the Vickers hardness of the welded portion can be set to 60 or more. You can see that.
On the other hand, in Comparative Examples 42 to 44 which did not satisfy the above specific welding conditions, the area ratio of the crystal grains having a GAM value of 0.5 ° or more and less than 2.0 ° was 20% or more and the average crystal grain size was a plate material. It did not satisfy that the dimensions were equal to or less than the plate thickness of. Therefore, the Vickers hardness of the welded portion was less than 60.

1, 2 Plate material 3, 3A, 3B, 3C Welding part 10, 10A, 10B, 10C Joined body 20 Laser welding device 21 Laser control part 25 Glass fiber 26 Condensing lens 28 Focusing lens 29 Laser head 30 Gas supply nozzle 221,222 Laser oscillator 231 1st laser beam 232 2nd laser beam 261 1st condensing lens 262 2nd condensing lens 271 1st mirror 272 2nd mirror

Claims (6)

It is composed of a plurality of plate materials containing 90% by mass or more of Cu.
It has a welded portion in which the plurality of plate materials are joined to each other in a linear or dot shape by welding in a state of being abutted against each other or in a state of being overlapped with each other.
The weld extends over the entire thickness of the plate.
In the cross section when the welded portion is cut in the direction in which the plurality of joined plates extend.
When the GAM value obtained from the crystal orientation analysis data of the SEM-EBSD method is measured in the rectangular area partitioned by the welding width of the welded portion and the thickness of the plate material, the GAM value is 0.5 ° or more. Crystal grains having a temperature of less than 2.0 ° have an area ratio of 20% or more to all crystal grains existing in the measured area, and the area ratio is 20% or more.
A component for electrical / electronic equipment in which the average crystal grain size obtained from all the crystal grains existing in the measured area is equal to or less than the thickness of the thinner plate material among the plurality of plate materials. The component for electrical / electronic equipment according to claim 1, wherein the plate material contains one or more elements selected from the group consisting of Ag, Fe, Ni, Co, Si, Cr, Sn, Zn, Mg and P. .. The crystal grains having a GAM value of 0.5 ° or more and less than 2.0 ° have an area ratio of 42% or more to all the crystal grains existing in the measurement area, and the average crystal grain size is smaller. The component for electrical / electronic equipment according to claim 2, which has a dimension of 60% or less of the thickness of the plate material. The component for electrical / electronic equipment according to claim 1, wherein the plate material is 99.96% by mass or more of Cu and unavoidable impurities. The component for electrical / electronic equipment according to any one of claims 1 to 4, wherein the component for electrical / electronic equipment is a vapor chamber. The component for electrical / electronic equipment according to any one of claims 1 to 4, wherein the component for electrical / electronic equipment is a bus bar.

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