JPH11221682A - Method and device for ultrasonic joining of metallic foil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute an effective and high quality welding and at the same time to enable excellently applying to repeated use. SOLUTION: An anvil 16 on which a metallic foil 12 and a metallic lead 14 are placed overlapped, and an ultrasonic horn 18 to weld an overlapped part of the metallic lead 14 and the metallic foil 12 on the anvil 16 which is pressed and given ultrasonic vibration from the side of the metallic lead 14 are provided. The anvil 16 is made from die steel or high speed steel, and a smooth finished surface 20a-20d of the anvil 16 is ground into the surface roughness not more than the thickness of the metallic foil 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for ultrasonically joining metal foils to a metal foil for welding a metal foil to a metal plate using an anvil and an ultrasonic horn.

[0002]

2. Description of the Related Art For example, when a secondary battery such as a lithium ion battery is manufactured, a positive electrode plate and a negative electrode plate (hereinafter referred to as a current collector) are provided by providing an active material on a metal foil such as an aluminum foil or a copper foil. ) Is formed, a strip-shaped metal lead (a nickel plate, an aluminum plate, or the like) is welded to the current collector.

In this case, an ultrasonic horn is widely used for welding a metal lead to a current collector. That is, the current collector and the metal lead are placed on the processed surface of the anvil in a superposed manner, and the superposed portion of the current collector and the metal lead is pressed while being pressed by the ultrasonic horn processed surface. Welding is performed by applying vibration.

[0004] Incidentally, since the metal lead is easily slipped on the current collector, if the pressing force of the ultrasonic horn is weak, the metal lead is welded in a state where the metal lead is displaced on the current collector. There is. Therefore, Japanese Patent Laid-Open No. 7-105
As disclosed in Japanese Patent No. 946, a large number of fine irregularities are provided on the processing surface of the anvil, while the processing surface of the ultrasonic horn has a plurality of squares each having a size matching the exposed portion of the current collector. There is known a method of manufacturing a battery electrode plate in which a plurality of convex portions are arranged in a row at intervals, and a number of fine irregularities are provided on the surface of each convex portion, and welding is performed by the anvil and the ultrasonic horn. I have.

[0005]

However, according to the above-mentioned prior art, when a current collector having a thickness of 50 μm or less is used, the current collector may be damaged by uneven portions provided on a processed surface of the anvil. There is a problem that is easily caused.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. H6-155051, the processed surface of the anvil is a rough surface subjected to sandblasting, and the processed surface of the ultrasonic horn is formed of irregularities processed at a constant pitch. An ultrasonic bonding method of a metal foil, which is a surface and is welded by the anvil and the ultrasonic horn, is known.

However, in the above-mentioned prior art, the sandblasted rough surface is significantly worn by 200 to 300 welding operations, and the processed surface is smoothed. As a result, a problem has been pointed out that a desired welding operation cannot be efficiently performed, such as a change in welding conditions every time welding is performed, and a change in the range of welding conditions.

SUMMARY OF THE INVENTION The present invention solves this kind of problem, and realizes an ultrasonic bonding method of a metal foil, which can perform an efficient and high-quality welding operation and can be applied well to repeated use. It is intended to provide a device.

[0009]

In order to solve the above-mentioned problems, in the ultrasonic bonding method and apparatus for metal foil according to the present invention, the processed surface of the anvil has a smooth surface having a surface roughness equal to or less than the thickness of the metal foil. In the state where the metal foil and the metal plate are superimposed and placed on the smooth processing surface, the processing surface of the ultrasonic horn in which the uneven surface is formed at a constant pitch is set on the processing surface. Ultrasonic vibration is applied and welded while pressurizing the overlapping portion of the metal plate and the metal foil on the anvil from the side. Therefore, even when a metal foil having a thickness of 50 μm or less is used, it is possible to reliably prevent the metal foil from being damaged by the smooth processed surface of the anvil.

[0010] Furthermore, the surface condition of the smooth machined surface of the anvil is less likely to change and the pressure applied to the machined surface of the ultrasonic horn is uniform as compared with the case where the uneven surface or the sand blast surface is provided on the machined surface of the anvil. Become Therefore, while suppressing the change in the range of welding conditions, it prevents uneven wear of the ultrasonic horn and the anvil, and is suitable for stable welding work and repeated use. Further, in the case of an anvil having a smooth processed surface, manufacturing costs can be effectively reduced, and a rise in equipment costs can be suppressed.

Further, a pressing member is provided for pressing and holding the metal foil when welding is performed by applying ultrasonic vibration while applying pressure to the overlapped portion of the metal plate and the metal foil by the ultrasonic horn. Therefore, slippage between the smoothed surface of the anvil and the metal foil is reliably prevented, and a more stable welding operation is performed.

[0012]

FIG. 1 is a schematic perspective explanatory view of an ultrasonic bonding apparatus 10 for performing an ultrasonic bonding method for metal foil according to a first embodiment of the present invention. The ultrasonic bonding apparatus 10 is configured to weld a metal lead (metal plate) 14 to a predetermined position of a metal foil 12. In the first embodiment, the metal foil 12 is formed of a copper foil having a thickness of 17 μm. And
The metal lead 14 is formed of a nickel plate having a thickness of 100 μm.

The ultrasonic bonding apparatus 10 includes an anvil 16 on which a metal foil 12 and a metal lead 14 are placed on top of each other, and a connection between the metal lead 14 and the metal foil 12 on the anvil 16 from the metal lead 14 side. Ultrasonic horn 18 for welding by applying ultrasonic vibration while pressurizing the overlapping portion
And

The anvil 16 is made of die steel or high-speed steel, and as shown in FIGS.
The smooth processing surfaces 20a to 20d are set on the four surfaces of No. 6. The smoothed surfaces 20a to 20d are ground to a surface roughness equal to or less than the thickness of the metal foil 12, and specifically, since the thickness of the metal foil 12 is 17 μm, the surface roughness is R _MAX. = 8 μm. In the anvil 16,
A plurality of holes 21 are formed for fixing the anvil 16.

As shown in FIGS. 1, 3 and 4, the ultrasonic horn 18 has first and second processing surfaces 22, 24 on both surfaces, respectively. As shown in FIG.
2 has a wide first pressing part 26 and a narrow second pressing part 28 connecting the first pressing parts 26 to each other. The first and second pressing portions 26 and 28 are arranged at a predetermined pitch interval at an angle of 45 ° in the longitudinal direction (arrow A direction) and in the transverse direction (arrow B direction) of the first processing surface 22. A plurality of fine uneven portions 30 are provided. The second processing surface 24 has the same configuration as the first processing surface 22, and the same components are denoted by the same reference characters, and detailed description thereof will be omitted.

The ultrasonic bonding apparatus 10 constructed as described above
The operation will be described below in relation to the ultrasonic bonding method according to the first embodiment.

First, as shown in FIG. 1, after the metal foil 12 is placed on the smoothed surface 20a of the anvil 16, the strip-shaped metal leads 14 are arranged on the metal foil 12.
Next, the superposed portion of the metal foil 12 and the metal lead 14 is welded by applying ultrasonic vibration while applying pressure to the first processing surface 22 of the ultrasonic horn 18 from the metal lead 14 side. In the ultrasonic horn 18, when welding by the first processing surface 22 becomes impossible, the upper and lower surfaces are switched, and the welding operation is performed by the second processing surface 24.

In this case, in the first embodiment, the smooth processing surface 20a of the anvil 16 is
m) is set to the following surface roughness (R _MAX = 8 μm), and in a state where the metal foil 12 and the metal lead 14 are superposed and placed on the smooth processing surface 20a, the first ultrasonic horn 18 The overlapping portion of the metal lead 14 and the metal foil 12 is welded on the processing surface 22. For this reason,
For example, even when the metal foil 12 having a thickness of 50 μm or less is used, an effect is obtained that the smooth processing surface 20 a of the anvil 16 can reliably prevent the metal foil 12 from being damaged.

Further, the surface condition of the smooth processing surface 20a of the anvil 16 is less likely to change than that of the conventional anvil processing surface provided with the uneven portion and the sand blast surface, and the first and second processing of the ultrasonic horn 18 are also performed. The pressure applied to the surfaces 22, 24 becomes uniform. Therefore, there is an advantage that the change of the welding condition range is suppressed, the uneven horn 18 and the anvil 16 are prevented from being unevenly worn, and the welding is suitable for stable welding operation and repeated use. In addition, the smooth processing surface 20a
In the anvil 16 having the above, the manufacturing cost can be effectively reduced as compared with the conventional uneven portion and the sand blast surface, and it is possible to suppress the increase in the equipment cost.

FIG. 5 is a schematic perspective explanatory view of an ultrasonic bonding apparatus 40 for performing an ultrasonic bonding method of metal foil according to a second embodiment of the present invention. Note that the same components as those of the ultrasonic bonding apparatus 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

This ultrasonic bonding apparatus 40 performs welding when applying ultrasonic vibration while applying pressure to the overlapping portion of the metal lead 14 and the metal foil 12 by the ultrasonic horn 18.
A holding member 42 for holding the metal foil 12 is provided. The pressing member 42 has a substantially U-shape, and is disposed on the smooth processing surface 20 a of the anvil 16 over the entire periphery of a portion pressed by the ultrasonic horn 18. Note that the pressing member 42 may be set so as to be disposed at a part around a part to be pressed by the ultrasonic horn 18.

The ultrasonic bonding apparatus 40 constructed as described above
Then, the metal foil 12 is placed on the smoothed surface 20 a of the anvil 16.
Is placed, a strip-shaped metal lead 14 is arranged on the metal foil 12. Next, with the pressing member 42 pressing and holding the metal foil 12 over the entire periphery of the portion to be pressed by the ultrasonic horn 18, the overlapping portion of the metal foil 12 and the metal lead 14 is moved to the ultrasonic horn 1.
8 while applying ultrasonic pressure while applying pressure to the first processing surface 22 for welding.

In this case, in the second embodiment, in particular, since the metal foil 12 is pressed and held by the pressing member 42, when the metal foil 12 is pressed by the ultrasonic horn 18,
Slip between the smoothed surfaces 20a to 20d of the anvil 16 and the metal foil 12 can be reliably prevented. Therefore,
The effect that the welding work by the anvil 16 and the ultrasonic horn 18 is performed more stably and with high quality can be obtained.

[0024]

In the method and apparatus for ultrasonically bonding metal foil according to the present invention, the processed surface of the anvil is set to a smooth processed surface having a surface roughness equal to or less than the thickness of the metal foil. Even when a foil, for example, a metal foil having a thickness of 50 μm or less is used, it is possible to reliably prevent the metal foil from being damaged.

Further, since the surface condition of the smooth processed surface of the anvil is unlikely to change and the pressure applied to the processed surface of the ultrasonic horn is made uniform, the change in the welding condition range is suppressed, and the ultrasonic horn and It prevents uneven wear of the anvil and is suitable for stable welding operation and repeated use. Further, in the case of an anvil having a smooth processed surface, manufacturing costs can be effectively reduced, and a rise in equipment costs can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic perspective explanatory view of an ultrasonic bonding apparatus for performing an ultrasonic bonding method of metal foil according to a first embodiment of the present invention.

FIG. 2 is an explanatory front view of an anvil constituting the ultrasonic bonding apparatus.

FIG. 3 is an explanatory plan view of an ultrasonic horn constituting the ultrasonic bonding apparatus.

FIG. 4 is an explanatory side view of the ultrasonic horn.

FIG. 5 is a schematic perspective explanatory view of an ultrasonic bonding apparatus for performing an ultrasonic bonding method of a metal foil according to a second embodiment of the present invention.

[Explanation of symbols]

10, 40 ... ultrasonic bonding apparatus 12 ... metal foil 14 ... metal lead 16 ... anvil 18 ... ultrasonic horn 20a-20d ... smooth processing surface 22, 24 ... processing surface 42 ... holding member

Claims (4)

[Claims] 1. A step of superposing and placing said metal foil and a metal plate on a smooth-worked surface of an anvil set to a surface roughness equal to or less than the thickness of the metal foil; Applying ultrasonic vibration while pressurizing a superposed portion of the metal plate and the metal foil on the anvil from the metal plate side on the processed surface of the ultrasonic horn, and welding. Characteristic ultrasonic bonding method of metal foil. 2. The ultrasonic bonding method according to claim 1, wherein
While holding the metal foil placed on the smooth processing surface of the anvil by a holding member, the ultrasonic horn processing surface presses the superposed portion of the metal plate and the metal foil while applying ultrasonic waves. An ultrasonic bonding method of metal foil, wherein welding is performed by applying vibration. 3. An anvil in which a processing surface on which a metal foil and a metal plate are stacked and placed is a smooth processing surface having a surface roughness equal to or less than the thickness of the metal foil, and the anvil from the metal plate side. An ultrasonic horn having a processed surface on which irregularities are formed at a constant pitch while applying ultrasonic vibration and welding while applying pressure to the overlapping portion of the metal plate and the metal foil. Ultrasonic bonding apparatus for metal foils. 4. The ultrasonic bonding apparatus according to claim 3, wherein
A metal foil, comprising: a pressing member that presses and holds the metal foil when welding is performed by applying ultrasonic vibration while applying pressure to the overlapping portion of the metal plate and the metal foil by the ultrasonic horn. Ultrasonic bonding equipment.