JP6101513B2 - Metal foil lap joint method and joint structure - Google Patents

Description

  The present invention relates to a metal foil lap joining method and a joining structure in which a plurality of metal foils are temporarily fixed and then contactlessly welded.

  Conventionally, metal foils such as aluminum foil and copper foil are widely joined in the manufacturing process of lithium ion batteries, capacitors, capacitors and the like. Generally, this type of metal foil lap bonding is performed by ultrasonic bonding or resistance welding.

  However, when metal foils are lap-joined by ultrasonic joining or resistance welding, there is a problem that joining is difficult when the number of laminated metal foils increases (for example, 60 or more). In other words, when metal foils are laminated by ultrasonic bonding, the metal foil tends to be damaged because it is necessary to increase the pressing force of the horn and the vibration energy of the ultrasonic waves by increasing the number of laminated metal foils. . In addition, when metal foils are joined by resistance welding, it is necessary to increase the resistance welding current value or set the energization time longer due to the increase in the number of laminated metal foils. It becomes easy and sufficient joint strength may not be obtained.

  In addition, since ultrasonic bonding is diffusion bonding that does not involve melting of the metal foil, it is not easy to evaluate whether or not all of the plurality of metal foils are securely bonded. The same applies to resistance welding (resistance bonding) of copper foil accompanied by diffusion bonding.

  Furthermore, when aluminum foil is lap-joined by resistance welding, an electrode composed of chromium copper, tungsten, or the like becomes an aluminum alloy, and the life of the electrode is remarkably shortened, which is not rational.

  In order to solve such a problem, in recent years, it has been studied to perform lap joining of metal foils by non-contact welding such as laser welding. However, in this case, since a large number of gaps are formed between adjacent metal foils, through holes are formed in the metal foil, or welding defects such as blow holes are generated.

  For example, Patent Document 1 has a technical idea of welding by irradiating a laser beam to a contact portion in a state where adjacent metal foils are in close contact with each other by applying a pressure roller and a pressure gas to the stacked metal foils. Proposed.

  In addition, for example, in Patent Document 2, a plurality of aluminum foils are stably resisted by applying ultrasonic vibration to the laminated aluminum foils to remove the oxide film of each aluminum foil and then performing resistance welding. A technical idea of welding has been proposed.

JP 2009-119465 A JP 2010-184260 A

  The prior art described in Patent Document 1 described above requires a special laser welding apparatus provided with a pressing means such as a pressing roller or a device for jetting pressurized gas, so that the apparatus becomes complicated and large. . Moreover, since the prior art described in Patent Document 2 described above is to remove the oxide film of the aluminum foil by applying ultrasonic vibration to the aluminum foil for the purpose of obtaining stable resistance welding, Problems such as electrode oxidation and aluminum alloying in the welding process are not solved.

  The present invention has been made in consideration of such problems, and provides a metal foil lap joining method and a joining structure capable of reliably performing metal foil lap joining using a general-purpose non-contact welding apparatus. The purpose is to provide.

The metal foil lap joining method according to the present invention is such that the metal plate and the metal foil are in close contact with each other and the adjacent metal foils are in contact with each other with the metal plate stacked on the outermost side of one side of the plurality of metal foils. Performing a first step of temporarily fixing and bonding so as to closely contact each other, and a second step of performing non-contact welding of the plurality of the metal foils and the metal plate temporarily bonded to each other from the metal foil side. It is characterized by.

According to the metal foil lap joining method according to the present invention, a first step of temporarily fixing and bonding so that adjacent metal foils are in close contact with each other, and a second step of non-contact welding the temporarily bonded bonding portion. Therefore, it is possible to suppress the formation of through holes in the metal foil or the occurrence of welding defects such as blow holes during non-contact welding. In addition, since temporary bonding is performed in advance, there is no need to provide pressing means in the non-contact welding apparatus itself as in the above-described prior art. Therefore, it is possible to reliably perform metal foil lap joining using a general-purpose non-contact welding apparatus. In addition, since the metal plate and the metal foil are in close contact with each other and the adjacent metal foils are temporarily bonded so that they are in close contact with each other, the contact portions are non-contact welded. It can be reliably joined. Further, for example, when laser welding is used as the non-contact welding in the second step, the laser beam is irradiated from the metal foil side to the close contact portion in a state where the condensing point of the laser beam is set inside the metal plate. Can do. If it carries out like this, it can suppress that a sputter | spatter generate | occur | produces from the back surface (surface by the side of a metal plate) of metal foil adjacent to a metal plate.

The joining method of the above SL, in the first step, the resistance joining, a plurality of the metal foil by at least one of ultrasonic bonding and caulking joint can be temporarily fixed joint.

  According to such a joining method, in the first step, the plurality of metal foils are temporarily bonded by at least one of resistance joining, ultrasonic joining, and caulking joining. Can be adhered to. In addition, since the first step may be temporary bonding that allows adjacent metal foils to be in close contact with each other, resistance bonding or ultrasonic bonding can be used even when the number of stacked metal foils is increased. It is. That is, when resistance bonding is used in the first step, the operating temperature of the electrode can be lowered compared to the case where a plurality of metal foils are completely bonded only by resistance bonding. As a result, it is possible to prolong the life of the electrode. In addition, when ultrasonic bonding is used in the first step, the pressing force and vibration energy of the horn can be reduced as compared with the case where a plurality of metal foils are completely bonded only by ultrasonic bonding. Therefore, it is possible to suppress the metal foil from being damaged by this ultrasonic bonding.

The metal foil lap bonding method according to the present invention includes a first step of temporarily bonding by resistance bonding so that the adjacent metal foils are in close contact with each other in a state where a plurality of metal foils are stacked, and a plurality of the metal foils performs a second step of non-contact welding tacking bonded adhesion portion of the metal foil, each of the metal foil is constituted by aluminum, electrodes used in the resistance junction that consists of carbon It is characterized by that .

  According to such a joining method, since each metal foil made of aluminum is resistance-bonded by an electrode made of carbon, the electrode does not become an aluminum alloy. In addition, since the electrode can be used at a relatively low temperature, it is possible to suitably suppress oxidation of the electrode even when the electrode is made of carbon.

The joining method of the above SL, in the first step to obtain a temperature of the electrode in the resistance junction with a radiation thermometer may be used to control the energization condition of the resistor junction on the basis of the acquired temperature.

  According to such a joining method, since the energization conditions for resistance joining are controlled based on the temperature of the electrodes acquired by the radiation thermometer, temporary fixing joining of a plurality of metal foils can be performed efficiently. In addition, since an electrode made of carbon is close to a black body, the temperature of the electrode can be obtained with high accuracy by a radiation thermometer.

The joining method of the above SL, in the second step, the laser welding may be non-contact welding the contact portions by at least one of TIG welding and electron beam welding.

  According to such a joining method, in the second step, the contact portions of the plurality of metal foils are non-contact welded by at least one of laser welding, TIG welding, and electron beam welding. The foil can be reliably melt-bonded.

The joining method of the above SL, in the second step, the plurality of positions of the contact portion may be a non-contact welding.

  According to such a joining method, since a plurality of close contact portions are welded in a non-contact manner, the joining strength of the plurality of metal foils can be increased.

The joining method of the above SL, in the second step, by changing the irradiation position with respect to the contact portion of the laser light a plurality of locations of the contact portions may be laser welded by galvanometer scanner.

  According to such a joining method, since the galvano scanner is used, it is possible to efficiently change the irradiation position of the laser beam on the close contact portion.

The metal foil bonding method according to the present invention, adjacent with in a state of overlapping metal plate portion on the outermost sides of the double number of sheets of gold Shokuhaku, and the said metal foil and each of said plate in close contact There a first step of temporarily stop engagement to close contact with each other, to carry out the second step of non-contact welding tacking bonded contact portion of the metal foil and the said plate of several sheets double Features .

  According to such a joining method, since the flat plate portion and the metal foil are brought into close contact with each other and the adjacent metal foils are temporarily bonded so that they are brought into close contact with each other, the contact portions are non-contact welded. The flat plate portion and the plurality of metal foils can be reliably bonded. Further, for example, in the first step, when caulking bonding is used for temporary bonding, a plurality of metal foils can be caulked securely and firmly as compared with the case where no flat plate portion is provided. The adhesion strength of the part can be increased. Thereby, since it can suppress further that a welding defect generate | occur | produces when non-contact welding a close_contact | adherence site | part, it becomes possible to improve the joint quality of a close_contact | adherence site | part.

In the bonded structure according to the present invention, a plurality of stacked metal foils, a metal plate stacked on the outermost side of one side of the plurality of metal foils, and the metal plate and the metal foil are in close contact with each other. A contact portion formed by temporarily bonding the plurality of metal foils so that adjacent metal foils are in close contact with each other, and the metal plate and the plurality of metal foils are contactlessly welded at the contact portion. And a welded portion formed in the above manner.

According to the bonded structure according to the present invention, since the adjacent metal foil is provided with a tightly bonded portion temporarily bonded so that the adjacent metal foils are in close contact with each other, and a welded portion formed by non-contact welding the tightly bonded portion, A bonded structure in which a plurality of metal foils are surely laminated and bonded can be obtained. In addition, it is possible to obtain a bonded structure in which a metal plate and a plurality of metal foils are securely overlapped and bonded. Thereby, joining strength can be raised compared with the case where a metal plate is not provided.

In the joined structure of the upper SL, the adhesion sites resistor junction may be formed by tacking joining a plurality of the metal foil by at least one of ultrasonic bonding and caulking joint.

  According to such a configuration, since the plurality of metal foils are temporarily bonded to each other by at least one of resistance bonding, ultrasonic bonding, and caulking bonding, the adhesion portion is formed. The joint quality of the welded portion formed by contact welding can be improved.

In the joined structure of the upper SL, the weld laser welding, may be formed in a non-contact welding the contact portions by at least one of TIG welding and electron beam welding.

  According to such a configuration, since the welded portion is formed by non-contact welding of at least one of laser welding, TIG welding, and electron beam welding, the plurality of metal foils are reliably melted. A bonded bonded structure can be obtained.

Junction structure according to the present invention includes a plurality of metal foils stacked, a plurality of the metal plate portion superimposed on the outermost sides of the metal foil, said metal foil and each of said plate a plurality of the metal and the contact portion formed by tacking bonded foil, before Symbol the metal foil of the plurality and each said plate in close contact portion such that the metal foil is in close contact with each other adjacent with but close contact And a welded portion formed by non-contact welding.

  According to such a configuration, it is possible to obtain a bonded structure in which a plurality of flat plate portions and a plurality of metal foils are securely overlapped and bonded. Thereby, joining strength can be raised compared with the case where a flat plate part is provided only on the outermost side of one side of a plurality of metal foils.

In the joined structure of the upper SL, a plurality of said plate may be integrally formed.

  According to such a configuration, since the plurality of flat plate portions are integrally formed, the rigidity of the joint structure can be increased as compared with the case where these flat plate portions are provided separately. In addition, for example, when the junction structure is used as a junction between a plurality of current collectors (metal foils) and electrode tabs (metal plates) constituting a lithium ion battery, both sides of the plurality of metal foils Since current can be collected from each flat plate portion stacked on the outermost surface of the metal, current collection efficiency can be increased.

  According to the metal foil lap-joining method of the present invention, since the adhering portions temporarily bonded together so that adjacent metal foils are in close contact with each other are non-contact welded, a plurality of metals are used using a general-purpose non-contact welding apparatus. It is possible to obtain a bonded structure in which the foils are securely lap bonded.

It is block explanatory drawing of the resistance welding apparatus used for the lap joining method of the metal foil which concerns on 1st Embodiment of this invention. 2A is a partially omitted cross-sectional view for explaining a temporary fixing process of the lap joining method, and FIG. 2B is a partially omitted cross-sectional view showing a state in which the temporary fixing process is completed. It is block explanatory drawing of the laser welding apparatus used for the said lap joining method. 4A is a partially omitted cross-sectional perspective view for explaining a welding process of the lap joining method, and FIG. 4B is a partially omitted cross-sectional perspective view of a workpiece in a state where the welding process is completed. It is a top view of the joined structure obtained by the lap joining method. FIG. 3 is a partially omitted cross-sectional view for explaining the structure of a lithium ion battery including the joint structure according to the first embodiment. It is a partially-omission perspective view for demonstrating the structure of the lithium ion battery which concerns on the modification provided with the joining structure body which concerns on 1st Embodiment. FIG. 8A is a partially omitted cross-sectional view for explaining a temporary fixing process of the metal foil lap joining method according to the second embodiment of the present invention, and FIG. 8B is a diagram for explaining a welding process of the lap joining method. FIG. 8C is a partially omitted cross-sectional view of the bonded structure obtained by the lap bonding method. FIG. 9A is a partially omitted cross-sectional view for explaining a temporary fixing step of the metal foil lap joining method according to the third embodiment of the present invention, and FIG. 9B is a diagram for explaining a welding step of the lap joining method. FIG. 9C is a partially omitted cross-sectional view of the bonded structure obtained by the lap bonding method. FIG. 10A is a partially omitted cross-sectional view showing a first state for explaining a temporary fixing process of the metal foil lap bonding method according to the fourth embodiment of the present invention, and FIG. 10B explains the temporary fixing process. It is a partially abbreviated sectional view showing the 2nd state for doing. FIG. 11A is a partially omitted cross-sectional perspective view for explaining a welding process of the lap joining method, and FIG. 11B is a partially omitted cross-sectional perspective view of a joint structure obtained by the lap joining method. FIG. 12A is a partially omitted cross-sectional view showing a first state for explaining a temporary fixing process of the metal foil lap bonding method according to the fifth embodiment of the present invention, and FIG. 12B explains the temporary fixing process. It is a partially abbreviated sectional view showing the 2nd state for doing. FIG. 13A is a partially omitted cross-sectional perspective view for explaining a welding process of the lap joining method, and FIG. 13B is a partially omitted cross-sectional perspective view of a joined structure obtained by the lap joining method. FIG. 14A is a partially omitted cross-sectional view for explaining a welding process of a metal foil lap joining method according to a modification of the fifth embodiment of the present invention, and FIG. 14B is obtained by the lap joining method according to the modification. FIG. 6 is a partially omitted cross-sectional view of the obtained bonded structure. FIG. 15A is a partially omitted cross-sectional view for explaining a temporary fixing process of a metal foil lap joining method according to a sixth embodiment of the present invention, and FIG. 15B is a diagram for explaining a welding process of the lap joining method. FIG. 15C is a partially omitted cross-sectional view of the bonded structure obtained by the lap bonding method.

  Hereinafter, a metal foil lap joining method and a joining structure according to the present invention will be described in detail with reference to the accompanying drawings by illustrating preferred embodiments.

(First embodiment)
A method for lap joining of metal foils 12 and a joint structure 200 according to a first embodiment of the present invention will be described with reference to FIGS. The method for lap joining of metal foils 12 according to the present embodiment (hereinafter sometimes simply referred to as “lap joining method”) is a resistance welding apparatus for a workpiece W in which a plurality of metal foils 12 are stacked on a metal plate 10. This is a method in which the workpiece W is welded by a laser welding apparatus (non-contact welding apparatus) 40 after temporary bonding is performed by the (resistance bonding apparatus) 20.

  First, the workpiece | work W which concerns on this embodiment is demonstrated. As shown in FIG. 1, the workpiece W is formed by laminating a plurality of metal foils 12 on a single metal plate 10. In other words, the workpiece W has the metal plate 10 stacked on the outermost side on one side of the plurality of stacked metal foils 12. The constituent material of each of the metal plate 10 and each metal foil 12 is not particularly limited, and examples thereof include aluminum and copper. Moreover, the metal plate 10 and each metal foil 12 may be comprised with the same material, and may be comprised with a different material. If the metal plate 10 and each metal foil 12 are comprised with the same material, weldability will become high compared with the case where it comprises with a different material.

  Of course, the metal plate 10 is formed thicker than the metal foil 12. The thickness of each metal foil 12 is set in the range of 0.006 mm to 0.2 mm, for example. In the present embodiment, the thickness of each metal foil 12 is set in the range of 0.007 mm to 0.02 mm. Further, the number of laminated metal foils 12 can be arbitrarily set, and is set to 60 or more, for example. In FIG. 1, illustration of some metal foils 12 is omitted for convenience, and the same applies to other drawings. In the workpiece W configured as described above, a gap S is formed between the metal plate 10 and the metal foil 12 and between the adjacent metal foils 12.

  Then, each structure of the resistance welding apparatus 20 and the laser welding apparatus 40 used by this embodiment is demonstrated.

  The resistance welding apparatus 20 is for performing temporary fixing joining of the workpiece W, and includes a pair of electrodes 22, 24, a radiation thermometer 26, and a control unit 28. The pair of electrodes 22 and 24 are arranged to face each other in a state of being movable along the axial direction. Each of the electrodes 22 and 24 can be made of a material such as nickel copper, tungsten, or carbon. In addition, when the metal plate 10 and each metal foil 12 are comprised with aluminum, it is preferable to comprise each electrode 22 and 24 with carbon. This is because it is possible to prevent the electrodes 22 and 24 from being alloyed with aluminum during resistance welding.

  The radiation thermometer 26 acquires the temperature of one electrode 22 and outputs the acquired temperature to the control unit 28. The radiation thermometer 26 may acquire the temperature of the other electrode 24 or may acquire the temperatures of both electrodes 22 and 24.

  The control unit 28 includes a pressurization control unit 30 that controls pressurization of the pair of electrodes 22 and 24 against the work W, an energization control unit 32 that controls energization time and current value between the pair of electrodes 22 and 24, and radiation. An energization condition setting unit 34 that sets energization conditions such as the energization time and the current value based on the temperature acquired by the thermometer 26 is provided. The energization control unit 32 controls the energization time and current value between the pair of electrodes 22 and 24 based on the energization condition set by the energization condition setting unit 34.

  As shown in FIG. 3, the laser welding apparatus 40 is a general-purpose laser apparatus having a general configuration for laser welding a workpiece W that is temporarily bonded. That is, the laser welding apparatus 40 includes a laser oscillator 42, an optical fiber 44 that transmits the laser light L oscillated from the laser oscillator 42, and a laser head 46 that guides the laser light L emitted from the optical fiber 44 to the workpiece W. It has.

  The laser head 46 includes a collimating lens 48 that collimates the laser light L emitted from the optical fiber 44, a mirror 50 that reflects the collimated laser light L toward the work W, and an irradiation position of the laser light L on the work W. And a fθ lens 54 that focuses the laser light L guided from the galvano scanner 52 onto the workpiece W. As the galvano scanner 52, for example, a known scanner including a pair of movable mirrors (not shown) capable of swinging in two orthogonal directions is used.

  Next, the lap joint of this embodiment using the resistance welding apparatus 20 and the laser welding apparatus 40 described above will be described. In the following, an example in which the metal plate 10 and each metal foil 12 are made of aluminum and the electrodes 22 and 24 are made of carbon will be described, but it goes without saying that the present invention is not limited to this example.

  In the lap joint of the present embodiment, first, a temporary fixing process (first process) of the workpiece W is performed. Specifically, the pair of electrodes 22 and 24 are arranged so as to sandwich the welding target portion of the workpiece W, and the pressurization control unit 30 brings the pair of electrodes 22 and 24 close to each other to apply the workpiece W at a predetermined pressure. Press. Then, since each metal foil 12 is deformed along the tip shape of the electrode 24, the adjacent metal foil 12 comes into contact with no gap and the metal foil 12 and the metal plate 10 come into contact with no gap (see FIG. 2A). At this time, in this embodiment, the metal plate 10 is hardly deformed due to its high rigidity with respect to each metal foil 12, but may be deformed along the tip shape of the electrode 22.

  Subsequently, the energization control unit 32 energizes between the pair of electrodes 22 and 24. As a result, Joule heat is generated and brought into close contact with the contact portion 14 of the metal foil 10 and the contact portion 16 of the adjacent metal foil, and the close contact portion 18 is formed on the workpiece W. At this time, the energization condition setting unit 34 sets the energization condition based on the temperature of the heated electrode 22 acquired by the radiation thermometer 26, and the energization control unit 32 sets the energization condition set by the energization condition setting unit 34. The energization time and the current value between the pair of electrodes 22 and 24 are controlled based on the conditions.

  As a result, the contact portion 14 of the metal plate 10 and the metal foil 12 and the contact portion 16 of the adjacent metal foil 12 can be reliably adhered, and the excessive heating of the electrodes 22 and 24 can be suppressed. it can. That is, the oxidation of the electrodes 22 and 24 is suppressed, and as a result, the life of the electrodes 22 and 24 can be extended.

  When the energization between the pair of electrodes 22 and 24 is completed, the pressurization control unit 30 separates the pair of electrodes 22 and 24. At this time, as understood from FIG. 2B, the metal plate 10 and the metal foil 12 are in close contact with each other and the adjacent metal foils 12 are in close contact with each other. Never formed.

  Thereafter, a welding process (second process) is performed. Specifically, the workpiece W is set in the laser welding apparatus 40 so that the laser beam L can be irradiated from the metal foil 12 side to the tightly bonded portion 18 of the workpiece W that is temporarily fixed. In this embodiment, the condensing point of the laser beam L is set inside the metal plate 10 (see FIG. 3). The condensing point of the laser beam L can be set at an arbitrary position according to the number of the metal foils 12, the thickness of the metal plate 10, and the like.

  Then, the laser oscillator 42 is driven to oscillate the laser light L. The laser light L oscillated from the laser oscillator 42 is incident on the optical fiber 44 and transmitted to the laser head 46. The laser light L emitted from the optical fiber 44 is collimated by the collimator lens 48, then reflected by the mirror 50, passes through the galvano scanner 52, and the contact portion 18 (indentation is formed on the workpiece W by the fθ lens 54. (Refer to FIG. 4A).

  When the laser beam L is irradiated to the close contact portion 18 of the workpiece W, the metal plate 10 and the metal foil 12 are in close contact with each other and the adjacent metal foils 12 are in close contact with each other without any clearance. In this way, the metal plate 10 and the plurality of metal foils 12 are welded without forming a through hole or generating a welding defect such as a blow hole (see FIG. 4B). As a result, the welded part P that has melted into the metal plate 10 is formed on the workpiece W. In addition, it is desirable to set the laser light L irradiated to the adhesion | attachment site | part 18 of the workpiece | work W on the conditions which are irradiated from the metal foil 12 side and do not penetrate the metal plate 10. FIG. If it carries out like this, it can prevent that a sputter | spatter generate | occur | produces under the workpiece | work W. FIG. However, the output of the laser beam L and the condensing point may be set so as to melt up to the back surface of the workpiece W (metal plate 10). In this case, since the welded part P can be visually recognized from both sides of the workpiece W, it becomes easy to determine whether the welded part P is welded.

  In the welding process (laser welding process), laser welding is performed a plurality of times (in this embodiment, five times) on one contact portion 18. At this time, the irradiation position of the laser beam L on the contact portion 18 is changed by swinging a pair of movable mirrors (not shown) of the galvano scanner 52. Thereby, the joining structure 200 which has the some welding part P in the one adhesion | attachment site | part 18 is formed (refer FIG. 5).

  The bonded structure 200 obtained in this way has a plurality of metal foils 12, a metal plate 10 stacked on the outermost side of one side of the plurality of metal foils 12, and a metal plate 10 and a metal foil 12. Formed by laser welding (non-contact welding) of the metal plate 10 and the plurality of metal foils 12 at the close contact portion 18, which are in close contact with each other and are temporarily bonded so that the adjacent metal foils 12 are in close contact with each other. And a plurality of welded portions P.

  The junction structure 200 can be applied to various products such as a lithium ion battery, a capacitor, and a capacitor. Next, the case where the junction structure 200 according to the present embodiment is applied to a lithium ion battery (secondary battery) 202 will be described.

  As shown in FIG. 6, the lithium ion battery 202 is configured as a so-called laminated type (laminated type) lithium ion battery. The laminated electrode group 204 formed in a rectangular shape and the laminated electrode group 204 are sealed together with an electrolyte. A sealing member (laminate film) 206 to be stopped, a first joined structure 200a located on one side of the laminated electrode group 204, and a second joined structure 200b located on the other side of the laminated electrode group 204 I have.

  The stacked electrode group 204 is configured by stacking a plurality of positive electrodes 208 and negative electrodes 210 with a separator 212 interposed therebetween. The positive electrode 208 is formed by applying a positive electrode active material (not shown) to the surface of the positive electrode current collector 214 made of aluminum foil, and the negative electrode 210 is formed by applying a negative electrode active material (not shown) to the surface of the negative electrode current collector 216 made of copper foil. It is formed by coating.

  The first bonded structure 200a has the same configuration as the bonded structure 200, and a first connection between a positive electrode tab 218 made of an aluminum plate and a plurality of positive electrode current collectors 214 stacked on the positive electrode tab 218. Portion (portion where positive electrode active material is not applied in positive electrode current collector 214) 220, positive electrode tab 218, and first connection portions 220 of a plurality of positive electrode current collectors 214 are in close contact with each other and the first connection is made The first contact portion 222 is temporarily bonded so that the portions 220 are in close contact with each other, and the first weld portion Pa is formed by laser welding the first contact portion 222. A part of the sealing member 206 is thermally bonded to the positive electrode tab 218.

  The second bonding structure 200b has the same configuration as that of the bonding structure 200, and includes a negative electrode tab 224 made of a copper plate and a second connection portion of a plurality of negative electrode current collectors 216 stacked on the negative electrode tab 224. (A portion of the negative electrode current collector 216 where the negative electrode active material is not applied) 226, the negative electrode tab 224, and the second connection portions 226 of the plurality of negative electrode current collectors 216 are in close contact with each other and the second connection portions. It has the 2nd close_contact | adherence site | part 228 temporarily bonded so that 226 may mutually adhere | attach, and the 2nd welding part Pb formed by laser-welding the 2nd close_contact | adherence site | part 228. A part of the sealing member 206 is thermally bonded to the negative electrode tab 224.

  According to the lithium ion battery 202 configured as described above, in the first bonding structure 200a, the positive electrode tab 218 and the first connection portions 220 of the plurality of positive electrode current collectors 214 are in close contact with each other, and the first connection portions. A first welded portion Pa is formed in a first contact portion 222 that is temporarily fixed and joined so that 220 are in close contact with each other. Therefore, for example, compared with the case where the positive electrode tab 218 and the first connection portions 220 of the plurality of positive electrode current collectors 214 are diffusion bonded by ultrasonic bonding, the bonding strength of the first bonding structure 200a can be increased. Since it is possible (a highly reliable joint can be obtained), the first joint structure 200a can be made more compact (the dimension along the left-right direction in FIG. 6 is shortened). The same applies to the second bonded structure 200b. As a result, the stacked electrode group 204 can be enlarged by the amount that the first bonded structure 200a and the second bonded structure 200b can be made compact. That is, the battery capacity can be increased without increasing the overall dimensions of the lithium ion battery 202.

  In addition, since the bonding strength of each of the first bonding structure 200a and the second bonding structure 200b can be increased, the lithium ion battery 202 can be used even when the lithium ion battery 202 is mounted on a vehicle, an aircraft, or the like. It is possible to suitably prevent the joint portions of the first joint structure 200a and the second joint structure 200b from being damaged by vibrations transmitted to

  The bonded structure 200 can also be applied to, for example, a lithium ion battery (secondary battery) 230 shown in FIG. As shown in FIG. 7, in the lithium ion battery 230, both the first bonded structure 200 a and the second bonded structure 200 b having the same configuration as the bonded structure 200 are provided on one side of the stacked electrode group 204. This is different from the lithium ion battery 202 shown in FIG. Of course, even such a lithium ion battery 230 has the same effect as the lithium ion battery 202 described above.

  As described above, according to the method for lap joining of the metal foils 12 according to the present embodiment, the temporary fixing for temporarily bonding the metal plate 10 and the metal foil 12 so that the adjacent metal foils 12 are in close contact with each other. Since the process and the welding process in which the metal plate 10 and the plurality of metal foils 12 are welded by irradiating the laser beam L to the adhesion part 18 that is temporarily bonded are penetrated, the metal foil 12 is penetrated during laser welding. It is possible to suppress the formation of holes and the occurrence of welding defects such as blow holes. In addition, since temporary bonding is performed in advance, there is no need to provide pressing means or the like for pressing the metal foil 12 on the laser welding apparatus 40 itself. Therefore, the metal foil 12 can be securely joined by using the general-purpose laser welding apparatus 40. Thereby, the joining structure 200 with favorable joining quality can be obtained.

  In addition, since the work W is temporarily fixed and joined by resistance welding (resistance joining), the metal plate 10 and the metal foil 12 can be securely adhered and the adjacent metal foils 12 can be reliably adhered to each other. Furthermore, since the resistance welding may be performed so long as the metal plate 10 and the metal foil 12 are in close contact with each other and the adjacent metal foils 12 can be temporarily bonded to each other, the number of laminated metal foils 12 is increased. However, the operating temperature of each electrode 22 and 24 can be made low compared with the case where the several metal foil 12 is completely welded only by resistance welding. Thereby, the oxidation of the electrodes 22 and 24 at the time of resistance welding can be suitably suppressed, and the life of the electrodes 22 and 24 can be extended.

  In the case of this embodiment, since the metal plate 10 and each metal foil 12 are made of aluminum and the electrodes 22 and 24 are made of carbon, the electrodes 22 and 24 are not alloyed with aluminum during resistance welding. . Moreover, since each electrode 22 and 24 can be used at comparatively low temperature, even when each electrode 22 and 24 is made from carbon, it can suppress suitably that these electrodes 22 and 24 oxidize.

  In the case of the present embodiment, since the energization conditions for resistance welding are controlled based on the temperature of the electrode 22 acquired by the radiation thermometer 26, the work W can be temporarily fixed and joined efficiently. Further, since the carbon electrodes 22 and 24 are close to a black body, the temperature of the electrode 22 can be obtained with high accuracy by the radiation thermometer 26.

  In the case of the present embodiment, since the welded portion P is formed at a plurality of locations of one close contact portion 18, the bonding strength between the metal plate 10 and each metal foil 12 can be increased. Moreover, since the galvano scanner 52 is used, the irradiation position of the laser beam L with respect to the contact | adherence site | part 18 can be changed efficiently.

  In the case of the present embodiment, the laser light L is irradiated from the metal foil 12 side to the contact portion 18 on which the work W is temporarily fixed in a state where the condensing point of the laser light L is set inside the metal plate 10. It is possible to suppress the occurrence of spatter from the back surface of the outermost metal foil 12 (the metal foil 12 in contact with the metal plate 10).

  According to the bonded structure 200 according to the present embodiment, the metal plate 10 is stacked on the outermost side of one side of the plurality of metal foils 12, so that the bonded structure 200 is compared with the case where the metal plate 10 is not provided. It is possible to increase the bonding strength.

(Second Embodiment)
Next, a lap joining method of the metal foil 12 and the joining structure 250 according to the second embodiment of the present invention will be described with reference to FIGS. 8A to 8C. In the present embodiment, components having the same or similar functions and operations as those of the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted. The same applies to a third embodiment, a fourth embodiment, and a sixth embodiment described later.

  The lap joining method is a method in which the workpiece W is welded with the laser welding device 40 after temporarily bonding with the ultrasonic bonding device 60 to the workpiece W in which a plurality of metal foils 12 are stacked on the metal plate 10. is there. That is, in the present embodiment, the same workpiece W as in the first embodiment is used, and the same welding process as in the first embodiment is performed. In other words, in the present embodiment, the temporary fixing process is different from the temporary fixing process of the first embodiment. The same applies to a third embodiment to be described later.

  Specifically, as illustrated in FIG. 8A, in the temporary fixing process of the workpiece W, the welding target portion of the workpiece W is pressed by the horn 64 while being set on the angel 62 of the ultrasonic bonding apparatus 60. Then, since each metal foil 12 is deformed along the tip shape of the horn 64, the adjacent metal foils 12 are in contact with each other without a gap, and the metal foil 12 and the metal plate 10 are in contact with each other without a gap. At this time, the metal plate 10 is hardly deformed because of its high rigidity with respect to each metal foil 12.

  Subsequently, each metal foil 12 is vibrated by ultrasonically vibrating the horn 64. Then, frictional heat is generated at the contact portion 14 between the metal plate 10 and the metal foil 12 and the contact portion 16 between the adjacent metal foils 12, so that the contact portions 14 and 16 are brought into close contact with each other to form a close contact portion 18.

  Then, a welding process is performed. That is, the laser beam L is irradiated from the metal foil 12 side to the adhesion part 18 temporarily bonded with the laser welding apparatus 40 set so that the condensing point of the laser beam L is located inside the metal plate 10 ( (See FIG. 8B). When the laser beam L is irradiated to the contact portion 18 of the workpiece W, the metal plate 10 and the plurality of metal foils 12 are formed without forming through holes in the metal foils 12 or generating welding defects such as blow holes. It will be welded (refer FIG. 8C).

  In the welding process, laser welding is performed a plurality of times on one contact portion 18, whereby a joint structure having a plurality (only one is shown in FIG. 8C) of welds P in one contact portion 18. The body 250 is formed. The bonded structure 250 obtained in this way has the same configuration as the bonded structure 200 described above. The junction structure 250 can be applied to, for example, the lithium ion batteries 202 and 230 shown in FIGS. 6 and 7 described above. The same applies to the joint structures 252, 254, 256, and 258 according to third to sixth embodiments to be described later.

  As described above, according to the present embodiment, since the workpiece W is temporarily bonded by ultrasonic bonding, the metal plate 10 and the metal foil 12 can be securely adhered to each other, and the adjacent metal foils 12 can be connected to each other. It is possible to ensure close contact.

  In addition, since this ultrasonic bonding is a temporary bonding that allows the metal plate 10 and the metal foil 12 to be in close contact with each other and the adjacent metal foils 12 to be in close contact with each other, the number of laminated metal foils 12 is increased. In addition, the pressing force and vibration energy of the horn 64 can be reduced as compared with the case where the metal plate 10 and the plurality of metal foils 12 are completely joined by ultrasonic joining. Therefore, it is possible to prevent the metal foil 12 from being damaged in the temporary fixing step. Thereby, the lap joining of the metal foil 12 can be reliably performed using the general-purpose laser welding apparatus 40. Therefore, it is possible to obtain a bonded structure 250 having good bonding quality.

(Third embodiment)
Next, a method for joining the metal foils 12 and the joining structure 252 according to the third embodiment of the present invention will be described with reference to FIGS. 9A to 9C. The lap joining method is a method in which the workpiece W is welded by the laser welding device 40 after temporarily fixing the workpiece W with the plurality of metal foils 12 on the metal plate 10 by the crimping device 70. .

  Specifically, as illustrated in FIG. 9A, in the temporary fixing process of the workpiece W, the workpiece 74 is pressed by the punch 74 in a state where the welding target portion of the workpiece W is set on the die 72 of the caulking device 70. Then, since the metal plate 10 and each metal foil 12 are deformed so as to be pushed into the recess 76 formed in the die 72, the contact portion 14 between the metal plate 10 and the metal foil 12 and the contact portion of the adjacent metal foil 12. 16 adheres to each other without a gap, and a contact portion 18 is formed on the workpiece W.

  Then, a welding process is performed. That is, the laser beam L is irradiated from the metal foil 12 side to the adhesion part 18 temporarily bonded with the laser welding apparatus 40 set so that the condensing point of the laser beam L is located inside the metal plate 10 ( (See FIG. 9B). When the laser beam L is irradiated to the contact portion 18 of the workpiece W, the metal plate 10 and the plurality of metal foils 12 are welded without forming a through hole in each metal foil 12 or generating a welding defect such as a blow hole. (See FIG. 9C).

  In the welding process, laser welding is performed a plurality of times on one contact portion 18, whereby a joint structure having a plurality (only one is shown in FIG. 9C) of welds P in one contact portion 18. The body 252 is formed. The bonded structure 252 thus obtained has the same configuration as the bonded structure 200 described above.

  As described above, according to the present embodiment, since the work W is temporarily fixed by caulking, the metal plate 10 and the metal foil 12 can be securely adhered to each other, and the adjacent metal foils 12 can be reliably connected to each other. Can be adhered to. Thereby, the lap joining of the metal foil 12 can be reliably performed using the general-purpose laser welding apparatus 40. Therefore, it is possible to obtain a bonded structure 252 having good bonding quality.

(Fourth embodiment)
Next, a lap joint method and a joint structure 254 of the metal foil 12 according to the fourth embodiment of the present invention will be described with reference to FIGS. 10A to 11B. In the lap joining method, the laser welding apparatus 40 performs temporary fastening joining to the workpiece W1 in which the pair of metal plates 10 and 80 are stacked on the outermost sides of both sides of the plurality of metal foils 12 by the crimping device 82. This is a method of welding the workpiece W1.

  That is, in this embodiment, a workpiece W1 different from the workpiece W of the first to third embodiments described above is used. As shown in FIG. 10A, the metal plate 80 constituting the workpiece W1 has the same material, size, and shape as the metal plate 10. However, the metal plate 80 may have a material, size, and shape different from those of the metal plate 10.

  In the caulking device 82 used in the temporary fixing process of the workpiece W1 of the present embodiment, the side surface of the concave portion 86 formed in the die 84 expands in a tapered shape toward the punch 88 side, and the convex portion 90 of the punch 88 is formed. Is formed in a tapered shape that tapers toward the tip.

  In the temporary fixing process, when the place to be welded of the workpiece W1 is pressed by the punch 88 in a state where it is set on the die 84 of the caulking device 82, the metal plates 10, 80 and the metal foil 12 are brought into contact with the recess 86 and the punch 88 of the die 84. It deform | transforms along the shape of the convex part 90 (refer FIG. 10B). At this time, the metal plates 10 and 80 are plastically deformed to have a substantially U-shaped cross section, so that the metal plate 10 and the metal foil 12, the adjacent metal foil 12, and the metal plate 80 and the metal foil 12 are firmly adhered without gaps. Then, a close contact portion 92 is formed on the workpiece W1 (see FIG. 10B).

  Then, a welding process is performed. That is, the workpiece W1 is placed on the support base 41 of the laser welding apparatus 40 so that the convex metal plate 10 is positioned on the irradiation side of the laser beam L, and the contact portion 92 of the workpiece W1 is irradiated with the laser beam L. (See FIG. 11A). Specifically, the laser beam L is applied to the convex portion 96 of the metal plate 10 constituting the workpiece W1 so as to melt up to the bottom surface of the concave portion 94 of the metal plate 80 constituting the workpiece W1 (the back surface of the workpiece W1).

  When the contact portion 92 is irradiated with the laser beam L, the pair of metal plates 10 and 80 and the plurality of metal foils 12 are formed without forming through holes in the metal foils 12 or causing welding defects such as blow holes. It will be welded (refer FIG. 11B). At this time, since a predetermined gap is formed between the support base 41 on which the work W1 is placed and the bottom surface of the concave portion 94 of the metal plate 80, the work W1 is welded to the support base 41 in the welding process. There is no.

  As understood from FIGS. 11A and 11B, in the welding process, laser welding is performed a plurality of times on one contact portion 92, and thereby, a joint structure having a plurality of welds P in one contact portion 92. The body 254 is formed.

  The bonded structure 254 thus obtained includes a plurality of metal foils 12, metal plates 10 and 80 stacked on the outermost sides of both sides of the plurality of metal foils 12, and the metal plates 10 and 80. Formed by laser welding a pair of metal plates 10, 80 and a plurality of metal foils 12 at the close contact portion 92 where the metal foil 12 is in close contact and adjacent metal foils 12 are formed in close contact with each other. And a plurality of welded portions P.

  As described above, according to the method of laminating and joining the metal foils 12 according to the present embodiment, the metal plates 10 and 80 and the metal foil 12 are brought into close contact with each other and the adjacent metal foils 12 are brought into close contact with each other by caulking joining. After the temporary bonding is performed, the contact portion 92 is laser welded, so that the pair of metal plates 10 and 80 and the plurality of metal foils 12 are reliably bonded using the general-purpose laser welding apparatus 40. be able to. Therefore, the bonded structure 254 having good bonding quality can be obtained.

  In addition, since the metal plates (flat plate portions) 10 and 80 are stacked on the outermost sides of both sides of the plurality of metal foils 12, for example, in the case where the metal plates 10 and 80 are not provided in the temporary fixing step by caulking and joining In comparison, since the plurality of metal foils 12 can be caulked securely and firmly, the adhesion strength of the adhesion part 92 can be increased. Thereby, since it is possible to further suppress the occurrence of welding defects when laser welding the close contact portion 92, it is possible to further improve the joint quality of the joint structure 254.

  The present embodiment is not limited to the configuration or method described above. For example, in the welding process, the contact portion 92 may be laser welded by irradiating the laser beam L from the concave portion 94 side of the metal plate 80 constituting the workpiece W1. In this case, since heat generated during welding is easily spilled into the concave portion 94, the welded portion P can be efficiently formed with respect to the close contact portion 92.

(Fifth embodiment)
Next, a lap joining method and a joining structure 256 of the metal foil 12 according to the fifth embodiment of the present invention will be described with reference to FIGS. 12A to 14B. In the present embodiment, components having the same or similar functions and operations as those of the above-described fourth embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, the configuration of the workpiece W2 is different from the workpiece W1 according to the fourth embodiment. Specifically, as shown in FIG. 12A, a workpiece W2 includes a plurality of stacked metal foils 12 and a metal plate 100 that is bent in a triple manner so as to sandwich the end portions of these metal foils 12 from both sides. And have.

  Although the constituent material of the metal plate 100 is not specifically limited, For example, the material similar to the metal plate 10 mentioned above can be used. The metal plate 100 includes a first flat plate portion 102, a second flat plate portion 106 that is connected to the first flat plate portion 102 via the first bent portion 104 and faces the first flat plate portion 102, and an end portion of the metal plate 100. And a third flat plate portion 110 that is connected to the second flat plate portion 106 through the second bent portion 108 and faces the second flat plate portion 106.

  The length dimension of the second flat plate part 106 (the dimension between the first bent part 104 and the second bent part 108) is the length dimension of the third flat plate part 110 (from the second bent part 108 to the metal plate). (Dimensions up to 100 ends). Further, the first flat plate portion 102 and the second flat plate portion 106 are in contact with each other, and a gap is formed between the second flat plate portion 106 and the third flat plate portion 110 so that a plurality of metal foils 12 can be arranged. ing. That is, the workpiece W <b> 2 according to the present embodiment has a configuration in which the second flat plate portion 106 and the third flat plate portion 110 are overlapped on the outermost sides of both sides of the plurality of metal foils 12.

  The lap joining method of this embodiment is a method in which the workpiece W2 is welded by the laser welding device 40 after temporarily joining the workpiece W2 by the crimping device 82. In the temporary fixing process according to the present embodiment, the first flat plate portion 102 is pressed by the punch 88 in a state where the third flat plate portion 110 constituting the workpiece W2 is set on the die 84 of the caulking device 82.

  If it does so, the 1st-3rd flat plate part 102,106,110 and each metal foil 12 will deform | transform along the shape of the recessed part 86 of the die | dye 84, and the convex part 90 of the punch 88 (refer FIG. 12B). At this time, each of the first to third flat plate portions 102, 106, and 110 is plastically deformed to have a substantially U-shaped cross section. And the metal foil 12 are in close contact with each other without a gap, and a close contact portion 112 is formed on the workpiece W2.

  In the subsequent welding process, the workpiece W2 is placed on the support base 41 of the laser welding apparatus 40 so that the third flat plate portion 110 is positioned on the irradiation side of the laser beam L, and the laser beam L is applied to the contact portion 112 of the workpiece W2. Irradiate (see FIG. 13A). Specifically, the projection 116 of the third flat plate part 110 constituting the work W2 is irradiated with the laser beam L so as to melt up to the bottom surface of the concave part 114 (the back surface of the work W2) of the first flat plate part 102 constituting the work W2. .

  When the contact portion 112 is irradiated with the laser light L, the first to third flat plate portions 102, 106, 110 and the plurality of sheets are formed without forming a through hole in each metal foil 12 or generating a welding defect such as a blow hole. The metal foil 12 will be welded (see FIG. 13B). At this time, since a predetermined gap is formed between the support base 41 on which the work W2 is placed and the bottom surface of the recess 114 of the first flat plate portion 102, the work W2 is placed on the support base 41 in the welding process. There is no welding.

  As understood from FIGS. 13A and 13B, in the welding process, laser welding is performed a plurality of times on one contact portion 112, and thereby, a joint structure having a plurality of welds P in one contact portion 112. A body 256 is formed.

  The joined structure 256 thus obtained includes a plurality of metal foils 12, the second flat plate portion 106 and the third flat plate portion 110 that are stacked on the outermost sides of both sides of the plurality of metal foils 12, 2 The flat plate portion 106 and the metal foil 12 are in close contact with each other, the third flat plate portion 110 and the metal foil 12 are in close contact with each other, and the adjacent metal foil 12 is in close contact with each other. -3rd flat plate part 102,106,110 and the some metal foil 12 are provided with the some welding part P formed by laser welding.

  As described above, according to the lap joining method of the metal foil 12 according to the present embodiment, the same effects as those of the fourth embodiment described above can be achieved. In addition, according to the present embodiment, the first to third flat plate portions 102, 106, 110 are integrally formed, so that separate metal plates are provided on the outermost sides of the plurality of metal foils 12. Compared to the case, the rigidity of the joined structure 256 can be increased.

  Furthermore, for example, when the junction structure 256 is applied to the lithium ion batteries 202 and 230 shown in FIGS. 6 and 7 described above, the second flat plates stacked on the outermost sides of both sides of the plurality of metal foils 12. Since current can be collected from both the portion 106 and the third flat plate portion 110, the current collection efficiency can be increased.

  The present embodiment is not limited to the configuration or method described above. For example, in the joining method according to the present embodiment, as shown in FIG. 14A, TIG welding may be used instead of laser welding in the welding process.

  Here, the TIG welding apparatus 120 is provided so as to surround the rod-shaped TIG welding electrode 122, the collet 124 for holding the TIG welding electrode 122, and the TIG welding electrode 122, and is inert such as argon or helium. And a gas nozzle 126 for supplying gas to the welding target portion. In the TIG welding apparatus 120 according to the present embodiment, the TIG welding electrode 122 is made of tungsten, the collet 124 is made of copper, and the gas nozzle 126 is made of ceramics.

  In this modification, the temporarily bonded workpiece W2 is disposed on the support 128 of the TIG welding apparatus 120 so that the third flat plate portion 110 is positioned on the side where the TIG welding electrode 122 is positioned, and the first flat plate portion The arc is discharged to the convex portion 116 of the third flat plate portion 110 so as to melt up to the bottom surface of the concave portion 114 of 102. As a result, the first to third flat plate portions 102, 106, 110 and the plurality of metal foils 12 are TIG welded without forming through holes in each metal foil 12 or generating welding defects such as blow holes. (See FIG. 14B). At this time, since a predetermined gap is formed between the support base 128 on which the work W2 is placed and the bottom surface of the recess 114 of the first flat plate portion 102, the work W2 is placed on the support base 128 in the welding process. There is no welding.

  In the welding process, a plurality of spot-like TIG weldings are performed on one contact portion 112, and thereby, the joint structure 258 having a plurality of (only one is shown in FIG. 14B) welds Pc. Will be formed. The bonded structure 258 thus obtained has the same configuration as the above-described bonded structure 256.

  Thus, in the welding process, even when TIG welding is used, the same effect as that obtained when laser welding is used is produced. In other words, the metal foil 12 can be lap-joined reliably using a general-purpose TIG welding apparatus (non-contact welding apparatus) 120.

  In the present embodiment, in the welding process, the close contact portion 112 may be welded by irradiating the laser beam L (arc discharge) from the concave portion 114 side of the first flat plate portion 102 constituting the workpiece W2. In this case, the welds P and Pc can be efficiently formed with respect to the close contact portion 112.

(Sixth embodiment)
Next, a lap joint method and a joint structure 260 of the metal foil 12 according to the sixth embodiment of the present invention will be described with reference to FIGS. 15A to 15C. The lap joining method is a method in which the workpiece W3 is welded by the laser welding device 40 after the temporary welding is performed by the resistance welding device 20 to the workpiece W3 in which a plurality of metal foils 12 are laminated. That is, the workpiece W3 of the present embodiment is composed of a plurality of metal foils 12 and does not have the metal plate 10 described above.

  In the temporary fixing process of the present embodiment, since a plurality of metal foils 12 are pressed with a pair of electrodes 22 and 24 and energized, the workpiece W3 is deformed along the tip shape of each electrode 22 and 24 and adjacent. Joule heat is generated and brought into close contact with the contact portion 16 of the metal foil 12, and a close contact portion 130 is formed on the workpiece W3 (see FIGS. 15A and 15B).

  Then, in the welding process, the workpiece W3 that is temporarily bonded is disposed on the support base 41 of the laser welding apparatus 40, and the contact portion 130 is irradiated with the laser beam L so as to melt to the back surface of the workpiece W3 (FIG. 15B). reference). When the laser beam L is applied to the contact portion 130, a plurality of metal foils 12 are welded without forming through holes in the metal foils 12 or causing welding defects such as blow holes (FIG. 15C).

  In this welding process, laser welding is performed a plurality of times on one contact portion 130, thereby joining a plurality of weld portions P (only one is shown in FIG. 15C) on one contact portion 130. The structure 260 is formed.

  The bonded structure 260 obtained in this way includes a plurality of metal foils 12, a contact part 130 formed by adhering adjacent metal foils 12 to each other, and a plurality of metal foils 12 in the contact part 130. And a plurality of welds P formed by laser welding.

  According to the bonding method of the metal foil 12 and the bonding structure 260 according to the present embodiment, the same effects as those of the first embodiment described above can be achieved.

  Each embodiment is not limited to the configuration or method described above. For example, in each embodiment, in the temporary fixing process, the temporary bonding can be performed by at least one of resistance bonding, ultrasonic bonding, and caulking bonding, and in the welding process, laser welding, TIG welding, and electron beam can be performed. Non-contact welding can be performed by at least one of the welding.

  The present invention is not limited to the above-described embodiment, and it is naturally possible to adopt various configurations without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10,80 ... Metal plate 12 ... Metal foil 14, 16 ... Contact part 18, 92, 112, 130 ... Contact | adherence part 20 ... Resistance welding apparatus 22, 24 ... Electrode 26 ... Radiation thermometer 34 ... Current supply condition setting part 40 ... Laser Welding device 60 ... Ultrasonic bonding device 62 ... Angel 64 ... Horn 70, 82 ... Caulking device 200, 250, 252, 254, 256, 258, 260 ... Joining structure L ... Laser light P, Pa, Pb, Pc ... Welded part S ... Gap W, W1-W3 ... Workpiece

Claims (13)

A first step of temporarily bonding the metal plate and the metal foil so that the adjacent metal foils are in close contact with each other in a state where the metal plate is stacked on the outermost side of one side of the plurality of metal foils. When,
Performing a second step of non-contact welding a plurality of the metal foil and the metal plate and the adhesion part temporarily bonded to each other from the metal foil side ;
A metal foil lap joining method characterized by the above. In the metal foil lap joining method according to claim 1,
In the first step, the plurality of metal foils are temporarily bonded by at least one of resistance bonding, ultrasonic bonding, and caulking bonding.
A metal foil lap joining method characterized by the above. A first step of temporarily bonding by resistance bonding so that the adjacent metal foils in close contact with each other in a state where a plurality of metal foils are stacked;
Performing a second step of non-contact welding the adhesion part temporarily bonded among the plurality of metal foils,
Each of the metal foils is made of aluminum,
The electrode used for the resistance bonding is made of carbon,
A metal foil lap joining method characterized by the above. In the metal foil lap joining method according to claim 3,
In the first step, the temperature of the electrode during the resistance bonding is acquired with a radiation thermometer, and the energization condition of the resistance bonding is controlled based on the acquired temperature.
A metal foil lap joining method characterized by the above. In the metal foil lap joining method according to any one of claims 1 to 4,
In the second step, the contact portion is non-contact welded by at least one of laser welding, TIG welding, and electron beam welding.
A metal foil lap joining method characterized by the above. In the metal foil lap joining method according to claim 5,
In the second step, non-contact welding is performed on a plurality of the close contact portions.
A metal foil lap joining method characterized by the above. The metal foil lap joining method according to claim 6,
In the second step, the laser beam is welded at a plurality of locations of the close contact portion by changing the irradiation position of the laser light to the close contact portion with a galvano scanner,
A metal foil lap joining method characterized by the above. In a state where the outermost sides of the double number of sheets of gold Shokuhaku superimposed metallic flat plate portion, temporarily fixed such that the metal foil is in close contact with each other for each said plate and the metal foil are adjacent with close contact A first step of joining;
Performing a second step of non-contact welding the metal foil of several sheets double and tacking bonded adhesion portion of each said plate,
A metal foil lap joining method characterized by the above. A plurality of stacked metal foils,
A metal plate stacked on the outermost side of one side of the plurality of metal foils;
The contact portion formed by temporarily bonding the plurality of metal foils so that the metal plate and the metal foil are in close contact and the adjacent metal foils are in close contact with each other;
A welded portion formed by non-contact welding the metal plate and the plurality of metal foils at the close contact portion,
A bonded structure characterized by that. The bonded structure according to claim 9 , wherein
The adhesion part is formed by temporarily bonding a plurality of the metal foils by at least one of resistance bonding, ultrasonic bonding, and caulking bonding,
A bonded structure characterized by that. In the junction structure according to claim 9 or 10 ,
The weld is formed by non-contact welding of the contact portion by at least one of laser welding, TIG welding, and electron beam welding.
A bonded structure characterized by that. A plurality of stacked metal foils,
A metal flat plate portion stacked on the outermost sides of both sides of the plurality of metal foils ;
A close contact portion formed by temporarily fixing and joining a plurality of the metal foils so that each of the flat plate portions and the metal foil are in close contact and the adjacent metal foils are in close contact with each other;
A welding portion formed by non-contact welding and a plurality of the metal foil each said plate before Symbol adhesion sites, Ru provided with,
A bonded structure characterized by that. The joined structure according to claim 12 ,
The plurality of flat plate portions are integrally formed.
A bonded structure characterized by that.

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