Ultrasonic welding horn

Abstract

To provide a horn for ultrasonic joining which can control heights of burrs occurring during ultrasonic joining.SOLUTION: A horn 100 for ultrasonic joining disclosed herein enables ultrasonic vibration in a predetermined vibration direction and includes: a base part 110; a mounting part 130 erected from an upper surface of the base part 110; and a pressure contact part 150 formed of multiple projections 152 protruding from an upper surface 131 of the mounting part 130. The multiple projections 152 forming the pressure contact part 150 are formed in a pyramid shape or a truncated pyramid shape and arranged in a line. At least a part of a peripheral edge of an arrangement portion of the multiple projections 152 has a zigzag shape in a plan view. The zigzag shaped portion is formed along at least one of the vibration direction and a direction perpendicular to the vibration direction. The upper surface of the base part 110 has an exposed surface 112 where the mounting part 130 is not formed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic bonding horn. [Background technology]

[0002] Ultrasonic bonding has long been known as a method for joining metal members together. For example, Patent Document 1 discloses a horn for ultrasonic bonding. This horn has multiple protrusions on the surface that presses the materials to be joined, and ultrasonic bonding is achieved by applying ultrasonic vibrations while pressing the materials to be joined via these multiple protrusions. The protrusions are hexagonal pyramid-shaped, and are configured so that the opposing direction of a pair of opposing surfaces is perpendicular to the vibration direction. This horn is said to be able to suppress the generation and scattering of burrs and to reduce shape changes due to wear of the protrusions.

[0003] Furthermore, Patent Document 2 discloses an ultrasonic welding tool that directly bonds metal members together or a metal electrode provided with a circuit or the like to a lead-shaped metal plate through which electricity flows. This ultrasonic welding tool has a tool welding section that presses multiple metal members together, and the pressure welding section of the tool welding section that comes into contact with the metal members has a quadrangular pyramidal protrusion with a rectangular flat surface. The protrusion extends toward a horn that transmits ultrasonic vibrations, and the rectangular flat surface of the pressure welding section of the protrusion is configured so that it is parallel to the direction of ultrasonic vibrations. This is said to enable long-term stable bonding in the ultrasonic welding process. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-330851 [Patent Document 2] Japanese Patent Application Publication No. 2018-69308 Summary of the Invention [Problem to be solved by the invention]

[0005] In ultrasonic bonding, burrs are formed around the area where the horn is pressed against the materials to be bonded (contact area). The burrs are generated when the materials to be bonded are scraped by the horn, and are formed disorderly around the contact area. If burrs remain on the materials to be bonded, they may become contaminated as foreign matter when peeled off in electronic devices that use the materials to be bonded, which can cause malfunctions in the electronic devices. For this reason, burrs are generally removed by cleaning or other processes. However, such additional processes are undesirable because they increase costs and manufacturing time.

[0006] The present inventors have been studying the possibility of forming a recess in the workpieces and performing ultrasonic welding in the recess to keep the burrs inside the recess. If the burrs can be kept inside the recess, the recess can be sealed with another member, which would eliminate the need for additional processing such as cleaning the burrs. As one approach to keeping the burrs inside the recess, it is desirable to develop a mechanism for controlling the burr height.

[0007] The present invention has been made in view of the above circumstances, and has as its object to provide an ultrasonic bonding horn that is capable of controlling the height of burrs that occur during ultrasonic bonding. [Means for solving the problem]

[0008] In order to achieve the above object, the ultrasonic bonding horn disclosed herein is an ultrasonic bonding horn capable of ultrasonic vibration in a predetermined vibration direction, and includes a base portion, a platform portion rising from the upper surface of the base portion, and a pressure-welding portion consisting of a plurality of protrusions protruding from the upper surface of the platform portion. The plurality of protrusions constituting the pressure contact portion are arranged in a pyramidal or truncated pyramidal shape, and in a plan view, at least a portion of the periphery of the arrangement of the plurality of protrusions is zigzag, and the zigzag portion is formed along at least one of the vibration direction and a direction perpendicular to the vibration direction. The upper surface of the base portion has an exposed surface on which the platform portion is not formed.

[0009] With this configuration, the periphery of the arrangement of the horn protrusions in a plan view has a zigzag portion, which makes it easier for burrs generated during ultrasonic bonding to be guided into the zigzag valleys. Furthermore, a horn with this configuration has a platform between the base and the pressure-welding portion, and the base has an exposed surface where the platform is not formed. As a result, burrs generated by ultrasonic bonding (particularly burrs guided into the valleys of the zigzag portion) are suppressed in the vertical direction by the exposed surface, thereby controlling the height of the burrs.

[0010] In a preferred embodiment of the horn disclosed herein, at least a portion of the peripheral wall of the base is formed in a corrugated shape, and the corrugated portion corresponds to the zigzag portion of the peripheral edge of the arrangement of the plurality of protrusions. This allows burrs guided into the valleys of the zigzag portion of the peripheral edge of the arrangement of the protrusions to smoothly enter the recessed spaces of the corrugated shape of the peripheral wall of the base. As a result, the spread of the burrs is more appropriately controlled, and the burr height can be more efficiently controlled.

[0011] In a preferred embodiment of the horn disclosed herein, the recessed portion of the corrugated portion formed on the peripheral wall of the base is formed in an arc shape in plan view, which makes it difficult for sharp-tipped burrs to form, thereby reducing the likelihood of burrs penetrating the horn and more efficiently controlling burrs.

[0012] In a preferred embodiment of the horn disclosed herein, the protrusions are arranged adjacent to one another so that there are no flat grooves between the protrusions, thereby preventing burrs from getting between the protrusions and providing better burr control.

[0013] In a preferred embodiment of the horn disclosed herein, the peripheral edge of the arrangement of the plurality of protrusions has no sides extending in the vibration direction or perpendicular to the vibration direction in plan view, which prevents burrs from spreading randomly and more effectively controls the height of the burrs.

[0014] In a preferred embodiment of the horn disclosed herein, the exposed surface is provided around the entire periphery of the base in a plan view, thereby effectively controlling the height of burrs in any direction around the ultrasonic bonded portion.

[0015] In a preferred embodiment of the horn disclosed herein, the boundary between the upper surface of the base and the peripheral wall of the stand is formed in a slope, which makes it difficult for burrs to penetrate into the exposed surface.

[0016] In a preferred embodiment of the horn disclosed herein, the ratio of the height T1 of the stand from the top surface of the base to the height T2 of the protrusion from the top surface of the stand is 5:1 to 1:1, which allows for more appropriate control of the height of burrs. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view schematically illustrating a configuration of a horn according to an embodiment. [Figure 2] FIG. 1 is a plan view schematically illustrating the configuration of a horn according to an embodiment. [Figure 3] FIG. 1 is a side view schematically illustrating a configuration of a horn according to an embodiment. [Figure 4] FIG. 10 is a perspective view schematically showing the configuration of a horn according to Modification 1. [Figure 5] FIG. 10 is a plan view schematically showing the configuration of a horn according to Modification 1. [Figure 6] FIG. 10 is a side view schematically showing the configuration of a horn according to Modification 2. [Figure 7A] FIG. 2 is a schematic diagram showing the configuration of the terminal component before ultrasonic bonding. [Figure 7B] 1A to 1C are schematic diagrams illustrating an ultrasonic bonding process. [Figure 8] FIG. 1 is a partial cross-sectional view of a lithium-ion secondary battery. [Figure 9] FIG. 9 is a cross-sectional view showing a cross section taken along line IX-IX in FIG. 8. [Figure 10] 10 is a cross-sectional view schematically illustrating a configuration in which a terminal part manufactured using a horn according to one embodiment is used as an external terminal of a negative electrode terminal of a lithium ion secondary battery. FIG. [Figure 11] FIG. 10 is a plan view schematically showing the configuration of the horn used in Comparative Example 1. [Figure 12A] 1 is an image showing the shape of the vicinity of the ultrasonic bonded portion of the terminal component for evaluation in Example 1. [Figure 12B] 4 is a graph showing the cross-sectional shape of the terminal component for evaluation in Example 1. [Figure 13A] 10 is an image showing the shape of the vicinity of the ultrasonic bonded portion of the terminal component for evaluation in Example 2. [Figure 13B] 10 is a graph showing the cross-sectional shape of an evaluation terminal component of Example 2. [Figure 14A] 10 is an image showing the shape of the vicinity of the ultrasonic bonded portion of the terminal part for evaluation of Comparative Example 1. [Figure 14B] 10 is a graph showing the cross-sectional shape of an evaluation terminal component of Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0018] Below, we will explain an embodiment of the ultrasonic bonding horn (hereinafter simply referred to as the "horn") disclosed herein, and a terminal component used in a secondary battery as an example of an article that is suitably manufactured using the horn disclosed herein. Matters necessary for implementation, even if not specifically mentioned in this specification, can be understood as design matters for those skilled in the art based on the prior art in the relevant field. The content of the technology disclosed herein can be implemented based on the content disclosed in this specification and common technical knowledge in the relevant field.

[0019] It should be noted that each drawing is a schematic drawing, and the dimensional relationships (length, width, thickness, etc.) do not reflect the actual dimensional relationships. Furthermore, in the drawings described below, the same reference numerals are used to designate components and parts that perform the same functions, and redundant explanations may be omitted or simplified. In this specification, when a numerical range is described as A to B (where A and B are arbitrary numerical values), this is the same as the general interpretation, meaning A or more and B or less (including a range greater than A but less than B).

[0020] In this specification, the term "secondary battery" refers generally to an electricity storage device in which charge carriers move between a pair of electrodes (positive and negative electrodes) via an electrolyte, resulting in a charge-discharge reaction. Such secondary batteries include so-called storage batteries such as lithium-ion secondary batteries, nickel-metal hydride batteries, and nickel-cadmium batteries, as well as capacitors such as electric double-layer capacitors.

[0021] One embodiment of horn 100 disclosed herein is shown in Figures 1 to 3. Figure 1 is a perspective view schematically showing the configuration of horn 100. Figure 2 is a plan view schematically showing the configuration of horn 100. Figure 3 is a side view schematically showing the configuration of horn 100. In the following description, the symbols F, B, L, R, U, and D in the drawings represent front, rear, left, right, top, and bottom, respectively. However, these directions are used merely for convenience and do not limit the installation form of horn 100 in any way.

[0022] As shown in FIG. 1 , horn 100 includes base 110, support 130, and pressure-welding portion 150. Horn 100 can be attached to an ultrasonic oscillator (not shown) to generate ultrasonic vibrations in a predetermined direction. This transmits the ultrasonic vibrations to the workpieces, achieving ultrasonic welding. In the following description, the direction of the ultrasonic vibrations (hereinafter simply referred to as the "vibration direction") will be described as the front-to-rear direction. In this specification, the term "plan view" is generally interpreted as referring to the field of view when horn 100 is viewed from the top (U side in the figure) toward the bottom (D side in the figure), i.e., the field of view when viewed from the pressure-welding portion 150 toward base 110.

[0023] The base portion 110 is a portion that is connected to an ultrasonic oscillator. As shown in FIG. 2, the base portion 110 has a rectangular surface in a plan view. A platform portion 130 is formed rising from the surface (top surface) of the base portion 110. In a plan view, the top surface of the base portion 110 has a larger area than the platform portion 130 and has an exposed surface 112 where the platform portion 130 is not formed. In this embodiment, the base portion 110 is formed in a rectangular parallelepiped shape, but the overall shape of the base portion 110 is not particularly limited as long as the platform portion 130 has a rising top surface. The shape of the top surface of the base portion 110 in a plan view is also not particularly limited and may be, for example, a polygonal shape, a circle, an ellipse, or the like. The base portion 110 may be made of a material that is conventionally used for horns, such as cemented carbide, die steel, or high-speed steel.

[0024] The base portion 130 is a portion that rises from the surface of the base portion 110, and is present between the base portion 110 and the pressure-contact portion 150. As shown in FIG. 2, the base portion 130 is formed with an area smaller than the surface of the base portion 110 in a plan view. In this embodiment, the upper surface 131 of the base portion 130 has an area larger than that of the pressure-contact portion 150 in a plan view. Here, the upper surface 131 of the base portion 130 is parallel to the upper surface of the base portion 110.

[0025] 2, in this embodiment, the outer shape of the base portion 130 is a hexagon with long sides in the left-right direction in a plan view. A peripheral wall 132 is formed between an upper surface 131 of the base portion 130 and an upper surface of the base portion 110. The peripheral wall 132 has a pair of wide surfaces 132a and four narrow surfaces 132b that face each other in the vibration direction. The external shape of the base 130 is not particularly limited, and may be polygonal, circular, elliptical, or the like in a plan view. The base 130 may be made of the same material as the base 110. A coating such as a diamond-like carbon (DLC) coating or a titanium nitride (TiN) coating may be applied to a portion of the base 130 that may come into contact with the workpiece (e.g., the upper surface 131 of the base 130). This can reduce adhesion of the metal (e.g., aluminum) that constitutes the workpiece. Furthermore, the coating can improve wear resistance.

[0026] The pressure welding portion 150 is composed of a plurality of protrusions 152 protruding from the upper surface 131 of the base portion 130. The plurality of protrusions 152 are arranged on the upper surface 131 of the base portion 130. The pressure welding portion 150 is the portion that is pressed against the materials to be joined, and transmits ultrasonic vibrations to the materials to be joined.

[0027] As shown in FIGS. 1 and 2 , in this embodiment, the pressure-contact portion 150 has ten protrusions 152. The number of protrusions 152 may be two or more, for example, five or more, eight or more, ten or more, or twelve or more. The number of protrusions 152 can be changed appropriately depending on the area to be ultrasonically bonded, and there is no particular upper limit. For example, the number may be 100 or less, 50 or less, or 20 or less. The protrusions 152 may be made of the same material as the base portion 110 and the platform portion 130. The protrusions 152 may be subjected to the above-described coating treatment, similar to the platform portion 130.

[0028] As shown in FIGS. 1 to 3, in this embodiment, the protrusion 152 is formed in a quadrangular pyramid shape. Here, the protrusion 152 has a square top surface 152a, a square bottom surface 152b, and four side surfaces 152c formed between the top surface 152a and the bottom surface 152b. The top surface 152a has a smaller area than the bottom surface 152b. Note that the shape of the protrusion 152 is not limited to this and may be, for example, a triangular pyramid, a quadrangular pyramid, a hexagonal pyramid, or another pyramid, or a triangular pyramid, a hexagonal pyramid, or another pyramid. Furthermore, the shapes of the multiple protrusions 152 do not necessarily all have to be the same shape.

[0029] 2, in a plan view, a zigzag portion 154 is formed on at least a portion of the periphery of the arrangement of the plurality of protrusions 152. In this embodiment, the zigzag portion 154 is formed by the bottom surfaces 152b of three protrusions 152 arranged along a direction perpendicular to the vibration direction. As shown in FIGS. 1 and 2, the zigzag portion 154 typically has a zigzag shape with each vertex connected by a straight line, but is not limited to this and may have a shape in which each vertex is rounded, for example.

[0030] The zigzag portion 154 is formed by arranging at least two protrusions 152, but the number of protrusions 152 constituting the zigzag portion 154 is not particularly limited and may be, for example, 3 or more, 4 or more, or 5 or more. The number of protrusions 152 constituting the zigzag portion 154 is limited by the area of ​​the upper surface 131 of the base portion 130 and is not particularly limited, but may be, for example, 20 or less, 15 or less, or 10 or less.

[0031] Horn 100, with its base portion 130 and exposed surface 112 of base portion 110, can control the height of burrs generated during ultrasonic bonding. While the details of this mechanism are unclear, it is presumed to be as follows: Burrs are generated where pressure-welding portion 150 of horn 100 is pressed against the workpieces and formed around that area. The burrs are formed by the transmission of ultrasonic vibrations from pressure-welding portion 150 of horn 100 to the workpieces, scraping the surface of the workpieces and extending in the vertical (upward) and horizontal directions. Because horn 100 has exposed surface 112, burrs that extend in the vertical direction come into contact with exposed surface 112, thereby suppressing their extension in the vertical direction. This allows the height of the burrs to be controlled to the height from the surface of the workpieces to exposed surface 112.

[0032] Furthermore, because horn 100 has zigzag portion 154 on the periphery of the arrangement of multiple protrusions 152, burrs generated during ultrasonic bonding are easily guided to the valleys of zigzag portion 154. This prevents burrs from spreading horizontally, making them more likely to extend in the height direction. Burrs that extend in the height direction are then easily suppressed by exposed surface 112. As a result, it is possible to effectively prevent burrs from forming randomly not only in the height direction but also in the horizontal direction. In this specification, the valleys of the zigzag portion 154 refer to the spaces between adjacent protrusions 152 among the protrusions 152 that make up the zigzag portion 154 in a plan view.

[0033] In plan view, zigzag portion 154 is preferably formed along at least one of the vibration direction (here, the front-rear direction) and the direction perpendicular to the vibration direction (here, the left-right direction), and it is particularly preferable that zigzag portion 154 be formed along the direction perpendicular to the vibration direction. Burrs tend to occur in the vibration direction, so by forming zigzag portion 154 along the direction perpendicular to the vibration direction, burrs that occur in the vibration direction can be more reliably controlled.

[0034] Furthermore, in a plan view, it is preferable that the periphery of the arrangement of the multiple protrusions 152 has neither a side extending in the vibration direction nor a side extending in a direction perpendicular to the vibration direction. With the above configuration, in the vibration direction and in a direction perpendicular to the vibration direction, the side (corner) connecting the top surface 152a and the bottom surface 152b of the protrusion 152 comes into contact with the workpiece before the side surface 152c of the protrusion 152 comes into contact with the workpiece. This prevents the burrs from being pushed straight in the vibration direction by the side surface 152c of the protrusion 152, making it easier for the burrs to be guided into the valleys of the zigzag portion 154.

[0035] Burrs generated during ultrasonic bonding are efficiently accumulated in the burr accumulation portion 170. Roughly speaking, the burr accumulation portion 170 refers to the space above the exposed surface 112 up to the height T1 of the base portion 130 (see FIG. 3). Note that the height T1 of the base portion 130 refers to the height from the upper surface (exposed surface 112) of the base portion 110.

[0036] The volume of the burr accumulation portion 170 is preferably larger than the volume of the entire protrusion 152 (pressure-welded portion 150). It is estimated that the volume of burrs generated by ultrasonic welding is the volume of the horn 100 that penetrates into the materials to be joined. In other words, it is estimated that burrs equivalent to the entire volume of the protrusion 152 may be generated. Therefore, by making the volume of the burr accumulation portion 170 larger than the entire volume of the protrusion 152, the height of the burr can be more reliably controlled. The volume of the burr accumulation portion 170 can be roughly calculated by multiplying the area of ​​the exposed surface 112 by the height T1 of the base portion 130. However, the method for calculating the volume may be changed as appropriate depending on the shape of the exposed surface 112, the shape of the base portion 130, etc.

[0037] The ratio of the height T1 of the base portion 130 to the height T2 of the protrusion 152 (pressure-contact portion 150) can be, for example, 5:1 to 1:1, preferably 4:1 to 1:1, more preferably 3:1 to 1:1, and can be, for example, 2:1 to 1:1. If the height T1 of the base portion 130 is too large relative to the height T2 of the protrusion 152, the rigidity and durability of the base portion 130 may decrease. Furthermore, if the height T1 of the base portion 130 is too small relative to the height T2 of the protrusion 152, burrs held down by the exposed surface 112 tend to extend horizontally, resulting in disorderly burrs, which is undesirable. The height T2 of the protrusion 152 refers to the height from the top surface 131 of the base portion 130 (the bottom surface 152b of the protrusion 152) to the top surface 152a of the protrusion 152 (the apex if the protrusion 152 is pyramidal).

[0038] Although not particularly limited, the height T1 of the base 130 may be, for example, 0.1 mm or more, and may be 0.3 mm or more. The height T1 of the base 130 may be, for example, 1.5 mm or less, and may be 1 mm or less, or 0.5 mm or less.

[0039] If the height T2 of the protrusions 152 is too low, the contact area between the protrusions 152 and the workpieces increases, making it easier for components of the workpieces (e.g., aluminum) to adhere to the protrusions 152. Therefore, the height T2 of the protrusions 152 is preferably, for example, 0.03 mm or more, and can be 0.1 mm or more, or 0.2 mm or more. If the height T2 of the protrusions 152 is too high, the rigidity of the protrusions 152 decreases, thereby reducing their durability. Therefore, the height T2 of the protrusions 152 is preferably, for example, 0.3 mm or less, and can be 0.25 mm or less. Note that the height T2 of the protrusions 152 is not limited to the above numerical range and can be changed as needed depending on the material and thickness of the workpieces and the ultrasonic bonding conditions.

[0040] 1 and 2, the protrusions 152 are preferably arranged adjacent to each other so that there are no flat grooves between them. In other words, in a plan view, the bottom surfaces 152b of the protrusions 152 are adjacent to each other so that there are no gaps between them, so that the top surface 131 of the base portion 130 is not visible between the protrusions 152. This reduces the amount of burrs that get between the protrusions 152, and makes it possible to more appropriately guide the burrs into the valleys of the zigzag portions 154. Note that the arrangement of the protrusions 152 is not limited to this, and for example, there may be gaps (grooves) between the protrusions 152.

[0041] 2, in this embodiment, the exposed surface 112 of the base portion 110 is provided around the entire periphery of the platform portion 130 in a plan view. In other words, the platform portion 130 is formed inside the edge (outer shape) of the top surface of the base portion 110. This allows the height of burrs to be suitably controlled in any direction around the ultrasonic bonded portion.

[0042] As shown in FIG. 3 , the width W1 of the exposed surface 112 may be, for example, 1 / 3 or more times the height T2 of the protrusion 152, or may be 1 / 2 or more, 1 or more, 2 or more, or 4 or more times the height T2 of the protrusion 152. This allows burrs to be more reliably accumulated in the burr accumulation portion 170, and the burr height is suitably controlled. Here, the width W1 of the exposed surface 112 refers to the distance measured vertically from the peripheral wall 132 of the base portion 130 to the outer shape of the exposed surface. The width W1 may vary for each face of the peripheral wall 132 (here, the wide face 132a and the narrow face 132b). Furthermore, the width W1 of the exposed surface 112 is not limited to the above ratio and may be varied as appropriate depending on the height T1 of the base portion 130. In other words, the volume of the burr accumulation portion 170 may be designed to be larger than the volume of the entire protrusion 152 (the pressure-contact portion 150).

[0043] It is preferable that the width W1 of exposed surface 112 in the vibration direction be wider than the width of exposed surface 112 in the direction perpendicular to the vibration direction (left-right direction in the figure). Because a large amount of burrs can be generated in the vibration direction, with this configuration, the volume of burr accumulation portion 170 in the vibration direction becomes larger, and burrs can be controlled more reliably.

[0044] While one embodiment of the horn disclosed herein has been described above, the above embodiment is merely an example, and various other embodiments are possible. Below, we will describe Modification 1 (horn 100A) and Modification 2 (horn 100B) as other embodiments of horn 100.

[0045] FIG. 4 is a perspective view schematically illustrating the configuration of horn 100A. FIG. 5 is a plan view schematically illustrating the configuration of horn 100A. Horn 100A has corrugated portion 134 formed in a corrugated shape on at least a portion of peripheral wall 132 of base portion 130. Here, corrugated portion 134 is formed on wide surface 132a of peripheral wall 132. The shape of corrugated portion 134 corresponds to zigzag portion 154 on the periphery of the arrangement of multiple protrusions 152. In other words, the valleys of zigzag portion 154 correspond to the positions of the recesses of corrugated portion 134 of peripheral wall 132 of base portion 130. This allows the volume of flash accumulation portion 170 to be increased. Furthermore, with this configuration, burrs guided into the valleys of the zigzag portion 154 can smoothly enter the recesses of the corrugated portion 134 of the peripheral wall 132 of the base portion 130, and are guided to extend in the height direction (upward). This makes it easier for the burrs to come into contact with the exposed surface 112, and therefore the height of the burrs is more efficiently reduced. Note that in this specification, the term "corrugated" is a term that encompasses a zigzag shape and a wave-like shape composed of curves.

[0046] In horn 100A, the recessed portion of corrugated plate portion 134 formed on peripheral wall 132 of base portion 130 is formed in an arc shape in a plan view. This makes it difficult for sharp burrs to be formed during ultrasonic bonding, reducing the risk of burrs penetrating. In this specification, the term "arc shape" does not refer only to a strict arc shape, but also encompasses rounded shapes that do not have corners (for example, a semi-elliptical shape, a curved shape, etc.). The shape of the recesses in corrugated plate portion 134 in plan view is not limited to an arc shape, and may be formed by cutting out a triangle, square, polygon, etc. Horn 100A is configured so that top surface 131 of base portion 130 is exposed in plan view, but the shape of zigzag portion 154 on the periphery of the arrangement of multiple protrusions 152 may be made to completely correspond to the shape of corrugated plate portion 134 of peripheral wall 132 of base portion 130 so that top surface 131 is not exposed.

[0047] 6 is a side view showing a schematic configuration of horn 100B. In horn 100B, a sloped portion 136 is formed at the boundary between stand portion 130 and base portion 110. In other words, the boundary between the upper surface of base portion 110 and peripheral wall 132 of stand portion 130 is formed to be rounded. This makes it easier for the tip of the burr to curl when it comes into contact with exposed surface 112, thereby effectively preventing the burr from penetrating exposed surface 112.

[0048] Horns 100A and 100B have been described above as modified examples, but these are merely examples of embodiments and do not limit the form of the horn disclosed herein. It is also possible to replace part of the above-described embodiment with other modified forms. For example, in horns 100 and 100A, the boundary between pedestal 130 and base 110 may be formed in a sloped shape.

[0049] Hereinafter, a method of using the horn disclosed herein will be described using an example of manufacturing terminal components used in secondary batteries.

[0050] 7A and 7B are schematic diagrams roughly illustrating the process of ultrasonically bonding a first member 210 and a second member 220 of a terminal part 200. Fig. 7A is a schematic diagram illustrating the configuration of the terminal part 200 before ultrasonic bonding. Fig. 7B is a schematic diagram illustrating the ultrasonic bonding process.

[0051] 7A, the terminal component 200 includes a first member 210 and a second member 220 overlapped on the first member 210. In this embodiment, the first member 210 is made of copper, and the second member 220 is made of aluminum.

[0052] In this embodiment, the first member 210 has a shaft portion 212 and a flange portion 214 extending radially outward from one end of the shaft portion 212. An end portion 212a of the first member 210 on the side where the flange portion 214 is provided is circular. The flange portion 214 is formed continuously in the circumferential direction of the shaft portion 212. The outer edge of the flange portion 214 is formed perpendicular to the end portion 212a. Furthermore, the shaft portion 212 is provided on the side opposite the side where the flange portion 214 is provided with a tubular portion 216, which is a portion to be crimped to another member.

[0053] In this embodiment, the second member 220 is plate-shaped. The second member 220 has a recess 222 on its surface 221 facing the first member 210, into which the flange portion 214 of the first member 210 is fitted. The recess 222 has a shape corresponding to the outer shape of the flange portion 214. The bottom 222a of the recess 222 is circular, corresponding to the shape of the end portion 212a of the first member 210. The side surface 222b of the recess 222 is formed perpendicularly from the bottom 222a toward the opening. The second member 220 has a recess 224 on its surface 223 opposite the first member 210, into which the horn 100 is abutted. The horn 100 abuts against the bottom 224a of the recess 224. In this embodiment, the recess 224 is formed by cutting out a rectangular parallelepiped shape from the surface 223. The side surface 224b of the recess 224 is formed perpendicularly from the bottom 224a toward the opening. Depth T3 of recess 224 is set to be greater than height T1 of base portion 130 of horn 100. Note that depth T3 of recess 224 refers to the height from bottom 224a of recess 224 to surface 223 of second member 220. In this case, since recess 224 is formed in a rectangular parallelepiped shape, depth T3 refers to the height from bottom 224a to side peripheral surface 224b of recess 224. Note that the shape of recess 224 is not particularly limited, and may be, in addition to a rectangular parallelepiped shape, a cube, a hemisphere, a cylinder, a triangular pyramid, a prism, a pyramid, a truncated pyramid, or the like.

[0054] 7A and 7B, ultrasonic bonding is performed on the first member 210 and the second member 220 in a state where they are overlapped. The horn 100 is attached to an ultrasonic oscillator (not shown). The horn 100 is pressed against the bottom 224a of the recess 224 of the second member 220. Meanwhile, the anvil 300 is pressed against the horn 100 from the side of the tubular portion 216 of the first member 210. As a result, the first member 210 and the second member 220 are sandwiched between the horn 100 and the anvil 300 from above and below. Then, ultrasonic vibrations from the ultrasonic oscillator are transmitted to the horn 100, and the horn 100 applies ultrasonic vibrations to the second member 220 while applying pressure to the second member 220, thereby bonding the first member 210 and the second member 220 and forming a bonded portion 230.

[0055] The various conditions for ultrasonic bonding are not particularly limited, as they are set appropriately depending on the metal type and dimensions of the materials to be bonded (here, first member 210 and second member 220), the shape of horn 100, etc. For example, if first member 210 is copper and second member 220 is aluminum, the amplitude can be about 20 μm to 50 μm, the frequency about 19 kHz to 21 kHz, the load with which horn 100 is pressed against the materials to be bonded (second member 220) about 30 N to 200 N, and the amount of energy applied to the materials to be bonded about 30 J to 200 J.

[0056] As shown in FIG. 7B, ultrasonic bonding results in the formation of raised portion 225, which is formed by the accumulation of burrs. Because pressure is applied to pressure-contact portion 150 of horn 100 as it is pressed against second member 220 during ultrasonic vibration, pressure-contact portion 150 penetrates into bottom portion 224a of recess 224 of second member 220, forming contact portion 226 at bottom portion 224a. Contact portion 226 is a depression that resembles the shape of the portion of pressure-contact portion 150 that penetrates into bottom portion 224a. Burrs are formed around contact portion 226, but because the height of the burr is controlled by exposed surface 112 of horn 100, height T4 of raised portion 225, which is formed by the accumulation of burrs, is controlled to be equal to or less than height T1 of base portion 130. Height T4 of raised portion 225 is thereby controlled so as not to exceed depth T3 of recess 224, thereby confining the burr within recess 224. It should be noted that height T4 of raised portion 225 refers to the height from bottom 224a of recess 224 where horn 100 is not pressed.

[0057] The manufactured terminal component 200 can retain the burrs (protrusions 225) within the recesses 224, and can be used in secondary batteries without the need for a burr cleaning process by joining an external member (for example, a bus bar) to seal the recesses 224. Below, a lithium-ion secondary battery 10 will be described as an example of a secondary battery in which the terminal component 200 can be used.

[0058] <Lithium-ion secondary battery 10> FIG. 8 is a partial cross-sectional view of a lithium-ion secondary battery 10. FIG. 8 illustrates a state in which the interior is exposed along one wide surface of a substantially rectangular parallelepiped battery case 41. The lithium-ion secondary battery 10 illustrated in FIG. 8 is a so-called sealed battery. FIG. 9 is a cross-sectional view showing the IX-IX cross section of FIG. 8. FIG. 9 schematically illustrates a partial cross-sectional view of a state in which the interior is exposed along one narrow surface of a substantially rectangular parallelepiped battery case 41.

[0059] As shown in FIG. 8, the lithium ion secondary battery 10 includes an electrode assembly 20, a battery case 41, a positive electrode terminal 42, and a negative electrode terminal 43.

[0060] <Electrode body 20> The electrode assembly 20 is housed in a battery case 41 while being covered with an insulating film (not shown) or the like. The electrode assembly 20 includes a positive electrode sheet 21 as a positive electrode element, a negative electrode sheet 22 as a negative electrode element, and separator sheets 31 and 32 as separators. The positive electrode sheet 21, the first separator sheet 31, the negative electrode sheet 22, and the second separator sheet 32 ​​are each a long, strip-shaped member.

[0061] The positive electrode sheet 21 has a positive electrode current collector foil 21a (e.g., aluminum foil) of a predetermined width and thickness, and a positive electrode active material layer 21b containing a positive electrode active material formed on both sides thereof, except for an unformed portion 21a1 set at one end of the width direction with a fixed width. In a lithium-ion secondary battery, the positive electrode active material is, for example, a material that can release lithium ions during charging and absorb lithium ions during discharging, such as a lithium transition metal composite material. Generally, various positive electrode active materials have been proposed in addition to lithium transition metal composite materials, and there is no particular limitation to the positive electrode active material.

[0062] The negative electrode sheet 22 has a negative electrode current collector foil 22a (copper foil in this case) of a predetermined width and thickness, and a negative electrode active material layer 22b containing a negative electrode active material formed on both sides thereof, except for an unformed portion 22a1 set at a fixed width on one edge in the width direction. In a lithium-ion secondary battery, the negative electrode active material is, for example, a material such as natural graphite that can absorb lithium ions during charging and release the absorbed lithium ions during discharging. Generally, various negative electrode active materials other than natural graphite have been proposed, and there is no particular limitation.

[0063] For example, a porous resin sheet having required heat resistance and allowing the electrolyte to pass through is used for the separator sheets 31, 32. Various separator sheets 31, 32 have been proposed, and there is no particular limitation.

[0064] Here, the width of the negative electrode active material layer 22b is formed to be wider than that of the positive electrode active material layer 21b, for example. The width of the separator sheets 31 and 32 is wider than that of the negative electrode active material layer 22b. The unformed portion 21a1 of the positive electrode current collector foil 21a and the unformed portion 22a1 of the negative electrode current collector foil 22a are oriented on opposite sides of each other in the width direction. The positive electrode sheet 21, the first separator sheet 31, the negative electrode sheet 22, and the second separator sheet 32 ​​are aligned in the length direction and stacked in order and wound. The negative electrode active material layer 22b covers the positive electrode active material layer 21b with the separator sheets 31 and 32 interposed therebetween. The negative electrode active material layer 22b is covered by the separator sheets 31 and 32. The unformed portion 21a1 of the positive electrode current collector foil 21a protrudes from one widthwise side of the separator sheets 31 and 32. The unformed portion 22a1 of the negative electrode current collector foil 22a protrudes from the separator sheets 31 and 32 on the opposite widthwise side.

[0065] 8, the electrode body 20 described above is flattened along a plane including the winding axis so that it can be housed in the case body 41a of the battery case 41. At the end of the winding axis of the electrode body 20, the unformed portion 21a1 of the positive electrode current collector foil 21a is arranged on one side, and the unformed portion 22a1 of the negative electrode current collector foil 22a is arranged on the other side.

[0066] <Battery Case 41> As shown in Fig. 8, the battery case 41 houses the electrode assembly 20. The battery case 41 has a case body 41a having a substantially rectangular parallelepiped shape with one side open, and a lid 41b attached to the opening. In this embodiment, the case body 41a and the lid 41b are each made of aluminum or an aluminum alloy mainly containing aluminum, from the viewpoints of reducing weight and ensuring the required rigidity.

[0067] <Case body 41a> The case body 41a has a generally rectangular parallelepiped shape with one side open. The case body 41a has a generally rectangular bottom surface 61, a pair of wide surface portions 62, 63 (see FIG. 9), and a pair of narrow surface portions 64, 65. The pair of wide surface portions 62, 63 each rise from a long side of the bottom surface 61. The pair of narrow surface portions 64, 65 each rise from a short side of the bottom surface 61. An opening 41a1 surrounded by the pair of wide surface portions 62, 63 and the pair of narrow surface portions 64, 65 is formed on one side of the case body 41a.

[0068] <Lid 41b> The lid 41b is attached to the opening 41a1 of the case body 41a, which is surrounded by the long sides of the pair of wide surface portions 62, 63 (see FIG. 9) and the short sides of the pair of narrow surface portions 64, 65. The peripheral edge of the lid 41b is then joined to the edge of the opening 41a1 of the case body 41a. This joining may be achieved, for example, by continuous welding without any gaps. This welding may be achieved, for example, by laser welding.

[0069] In this embodiment, a positive electrode terminal 42 and a negative electrode terminal 43 are attached to the lid 41b. The positive electrode terminal 42 includes an internal terminal 42a and an external terminal 42b. The negative electrode terminal 43 includes an internal terminal 43a and an external terminal 43b. The internal terminals 42a, 43a are each attached to the inside of the lid 41b via an insulator 72. The external terminals 42b, 43b are each attached to the outside of the lid 41b via a gasket 71. The internal terminals 42a, 43a each extend into the case body 41a. The positive electrode internal terminal 42a is connected to the unformed portion 21a1 of the positive electrode current collector foil 21a. The negative electrode internal terminal 43a is connected to the unformed portion 22a1 of the negative electrode current collector foil 22a.

[0070] The required level of oxidation-reduction resistance for the positive electrode internal terminal 42a is not as high as that for the negative electrode. Furthermore, from the viewpoints of the required oxidation-reduction resistance and weight reduction, aluminum, for example, may be used for the positive electrode internal terminal 42a (see FIG. 8). In contrast, the required level of oxidation-reduction resistance for the negative electrode internal terminal 43a is higher than that for the positive electrode. From this viewpoint, copper, for example, may be used for the negative electrode internal terminal 43a.

[0071] As shown in FIG. 8 , the unformed portion 21a1 of the positive electrode current collector foil 21a of the electrode assembly 20 and the unformed portion 22a1 of the negative electrode current collector foil 22a are attached to internal terminals 42a, 43a attached to both longitudinal sides of the lid 41b, respectively. The electrode assembly 20 is housed in the battery case 41 in a state where it is attached to the internal terminals 42a, 43a attached to the lid 41b. Note that a wound-type electrode assembly 20 is illustrated here. The structure of the electrode assembly 20 is not limited to this form. The structure of the electrode assembly 20 may be, for example, a layered structure in which positive electrode sheets and negative electrode sheets are alternately stacked with separator sheets interposed therebetween. Furthermore, a plurality of electrode assemblies 20 may be housed in the battery case 41.

[0072] The battery case 41 may also contain an electrolyte (not shown) together with the electrode assembly 20. A non-aqueous electrolyte in which a supporting salt is dissolved in a non-aqueous solvent can be used as the electrolyte. Examples of non-aqueous solvents include carbonate-based solvents such as ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate. Examples of supporting salts include fluorine-containing lithium salts such as LiPF6.

[0073] Fig. 10 is a cross-sectional view schematically illustrating a configuration in which the terminal component 200 is used as the external terminal 43b of the negative electrode terminal 43. As shown in Fig. 10, the lid 41b has a mounting hole 41b1 for mounting the terminal component 200. The mounting hole 41b1 penetrates the lid 41b at a predetermined position on the lid 41b. The negative electrode internal terminal 43a and the terminal component 200 are mounted in the mounting hole 41b1 of the lid 41b with a gasket 71 and an insulator 72 interposed therebetween.

[0074] 10, the second member 220 of the terminal part 200 is disposed outside the lid 41b. The shaft portion 212 of the first member 210 is attached to the mounting hole 41b1 via a gasket 71. The cylindrical portion 216 is crimped to the negative electrode internal terminal 43a inside the lid 41b, and a rivet portion 218 is formed at the tip of the cylindrical portion 216. This establishes electrical continuity between the terminal part 200 and the internal terminal 43a.

[0075] <Gasket 71> As shown in FIG. 10 , the gasket 71 is a component attached to the mounting hole 41b1 of the lid 41b and the outer surface of the lid 41b. In this embodiment, the gasket 71 includes a seat 71a, a boss 71b, and a sidewall 71c. The seat 71a is attached to the outer surface of the lid 41b. The seat 71a has a substantially flat surface that matches the outer surface of the lid 41b. The boss 71b protrudes from the bottom surface of the seat 71a. The boss 71b has an outer shape that conforms to the inner surface of the mounting hole 41b1 of the lid 41b so that it can be attached to the mounting hole 41b1. The inner surface of the boss 71b forms an attachment hole into which the shaft 212 of the first member 210 is attached. The sidewall 71c rises upward from the periphery of the seat 71a. The second member 220 is attached to the portion of the gasket 71 surrounded by the sidewall 71c.

[0076] The gasket 71 is disposed between the lid 41b and the terminal component 200, and ensures insulation between the lid 41b and the terminal component 200. The gasket 71 also ensures airtightness of the mounting hole 41b1 of the lid 41b. From this perspective, it is preferable to use a material that is excellent in chemical resistance and weather resistance. In this embodiment, PFA is used for the gasket 71. PFA is a copolymer of tetrafluoroethylene and perfluoroalkoxyethylene (tetrafluoroethylene-perfluoroalkylvinylether copolymer). However, the material used for the gasket 71 is not limited to PFA.

[0077] <Insulator 72> The insulator 72 is a member attached to the inside of the lid 41b around the mounting hole 41b1 of the lid 41b. The insulator 72 has a bottom wall 72a and a hole 72b. The bottom wall 72a is a portion disposed along the inner surface of the lid 41b. In this embodiment, the bottom wall 72a is a substantially flat plate-shaped portion. The bottom wall 72a is disposed along the inner surface of the lid 41b. The hole 72b is a hole provided corresponding to the inner surface of the boss portion 71b of the gasket 71. Since the insulator 72 is disposed inside the battery case 41, it is preferable that the insulator 72 has required chemical resistance. In this embodiment, PPS is used for the insulator 72. PPS is polyphenylene sulfide resin. Note that the material used for the insulator 72 is not limited to PPS.

[0078] The negative electrode internal terminal 43a includes a base 43a1 and a connecting piece 43a2 (see FIGS. 8 and 9). The base 43a1 is attached to the bottom wall 72a of the insulator 72. The connecting piece 43a2 extends from one end of the base 43a1, extends into the case body 41a, and is connected to the unformed portion 22a1 of the negative electrode current collector foil 22a (see FIGS. 8 and 9).

[0079] In this embodiment, the gasket 71 is attached to the outside of the lid 41b while the boss portion 71b is attached to the mounting hole 41b1. Next, the terminal component 200 is attached to the gasket 71. At this time, the shaft portion 212 of the first member 210 is inserted into the boss portion 71b of the gasket 71, and the second member 220 is placed on the seat portion 71a of the gasket 71. On the inside of the lid 41b, the internal terminal 43a is attached to the insulator 72. Then, as shown in FIG. 10 , the tubular portion 216 of the first member 210 is bent radially outward and crimped to the internal terminal 43a. The tubular portion 216 of the first member 210 and the internal terminal 43a may be partially joined by welding or metal joining to improve conductivity.

[0080] As shown in FIG. 10 , a bus bar 80, as an example of an external member, is superimposed on an upper surface 223 of a second member 220 of a terminal component 200 and joined by a weld 82. In this embodiment, the weld 82 is formed by laser welding. The bus bar 80 is joined to the surface 223 of the second member 220 so as to seal a recess 224 therein. This allows burrs (protrusions 225) to be sealed within the recess 224, allowing the terminal component 200 to be used in a secondary battery without cleaning the burrs. In this embodiment, the bus bar 80 is made of aluminum. Using the same type of metal for the bus bar 80 and the second member 220 improves conductivity and joint strength. In this embodiment, the bus bar 80 is welded, but the recess 224 may be sealed with an external member other than the bus bar.

[0081] In this embodiment, the first member 210 of the terminal component 200 is made of copper, the second member 220 is made of aluminum, and the bus bar 80 is made of aluminum, but this is not particularly limited. The first member 210, the second member 220, and the bus bar may each be made of, for example, copper, a copper-based alloy, aluminum, an aluminum-based alloy, nickel, or the like. The first member 210 and the second member 220 may be made of different metals or the same type of metal. The terminal component 200 may also be suitably employed as the external terminal 42b of the positive electrode terminal 42. In this specification, "aluminum-based alloy" refers to an alloy composed of at least 50% aluminum. Other elements that may be contained in the aluminum material are not particularly limited, but examples include silicon, iron, copper, manganese, magnesium, zinc, chromium, titanium, lead, and zirconium. In this specification, "copper-based alloy" refers to an alloy composed of at least 50% copper. Other elements that may be contained in the material are not particularly limited, but examples include silicon, iron, manganese, magnesium, zinc, chromium, titanium, lead, tin, phosphorus, aluminum, nickel, cobalt, beryllium, and zirconium.

[0082] Although the use of the horn 100 disclosed herein has been described above using the manufacture of the terminal component 200 as an example, the use of the horn 100 is not limited to the manufacture of the terminal component 200.

[0083] As specific examples, test pieces simulating the terminal components disclosed herein were prepared and the bonding strength of the bonded portions was evaluated. Note that it is not intended that the technology disclosed herein be limited to such examples.

[0084] Example 1 A copper test piece having the same shape as the first member 210 described above and an aluminum test piece having the same shape as the second member 220 described above were prepared. An aluminum test piece was placed on top of the copper test piece and secured to an anvil. The horn was attached to an ultrasonic oscillator. A horn having the same shape as the horn 100 shown in FIGS. 1 to 3 was used. The horn had a base 130 height T1 of 0.2 mm, a protrusion 152 height T2 of 0.2 mm (i.e., T1:T2 = 1:1), and the exposed surface 112 had a minimum width W1 approximately twice T2. The pressure-welding portion of the horn was placed against the bottom of the recess of the aluminum test piece, and ultrasonic bonding was performed under conditions of an amplitude of 20 μm, a frequency of 20 kHz, and energy of 100 J while applying a load of 100 N. This produced the terminal component for evaluation of Example 1.

[0085] Example 2 The terminal component for evaluation of Example 2 was manufactured in the same manner as Example 1 using a horn having the same configuration as that used in Example 1, except that the shortest width W1 of the exposed surface 112 was approximately 1 time the height T2 of the base portion 130.

[0086] Comparative Example 1 FIG. 11 is a plan view schematically illustrating the configuration of ultrasonic bonding horn 400 (hereinafter also referred to as "horn 400") used to fabricate Comparative Example 1. FIG. 11 shows the shape of pressure-welding portion 450 of horn 400 that is brought into contact with the workpieces to be joined. As shown in FIG. 11, the pressure-welding portion of horn 400 is composed of eight protrusions 452. Each protrusion 452 has a truncated quadrangular pyramid shape with a square top surface 452a and a square bottom surface. The bottom surfaces of adjacent protrusions 452 are adjacent to each other with no gaps between them. In horn 400, protrusions 452 are formed to rise from the surface of the base portion, and do not have a pedestal portion. In Comparative Example 1, a terminal component for evaluation of Comparative Example 1 was manufactured in the same manner as in Example 1, except that horn 400 was used.

[0087] <Measuring the shape of burrs> To observe the shape of burrs around the ultrasonic bonded portion of each terminal component for evaluation, the cross-sectional shape near the bonded portion was analyzed using a non-contact three-dimensional measuring machine (VR-5000, manufactured by Keyence Corporation). The cross-sections were prepared along the direction of ultrasonic vibration. FIG. 12A is an image showing the shape of the vicinity of the ultrasonic bonded portion (near the area where the pressure-contact portion of the horn was pressed) of the terminal component for evaluation in Example 1. FIG. 12B is a graph showing the cross-sectional shape of the terminal component for evaluation in Example 1. FIG. 13A is an image showing the shape of the vicinity of the ultrasonic bonded portion of the terminal component for evaluation in Example 2. FIG. 13B is a graph showing the cross-sectional shape of the terminal component for evaluation in Example 2. FIG. 14A is an image showing the shape of the vicinity of the ultrasonic bonded portion of the terminal component for evaluation in Comparative Example 1. FIG. 14B is a graph showing the cross-sectional shape of the terminal component for evaluation in Comparative Example 1. Note that FIGS. 12A, 13A, and 14A are all images taken from a plan view near the ultrasonic bonded portion of an aluminum test piece, and the vibration direction of the ultrasonic vibration is indicated by the arrows in the figures.

[0088] Comparing Figures 12A, 13A, and 14A, it is observed that in Comparative Example 1, burrs are formed randomly around the ultrasonic bond (see Figure 14A), whereas in Examples 1 and 2, which used the horn disclosed herein, it is observed that burrs are accumulated in a controlled manner around the ultrasonic bond (see Figures 12A and 13A).

[0089] In the graphs shown in Figures 12B, 13B, and 14B, the height around 600 nm indicates the surface height of the bonded materials, and the height around 0 to 100 μm indicates a shape in which the protrusions have embedded into the test piece. As shown in Figure 12B, in Example 1, a step (protrusion) with a nearly flat upper surface formed by burrs accumulated at a height of around 400 μm is formed near the ultrasonic bonded portion. Also, as shown in Figure 13B, in Example 2, a step (protrusion) formed by burrs accumulated near the ultrasonic bonded portion is also formed. On the other hand, Figure 14B shows the presence of relatively sharp burrs biased to one side (the left side of the graph) near the ultrasonic bonded portion.

[0090] From the above, it can be seen that the use of the horn disclosed herein effectively controls the height of burrs formed near the ultrasonic bonded portion, suppresses the random spreading of burrs, and forms a controlled, stepped protrusion around the ultrasonic bonded portion.

[0091] While specific examples of the technology disclosed herein have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology disclosed herein includes various modifications and variations of the above specific examples. [Explanation of symbols]

[0092] 10 Lithium-ion secondary battery 20 Electrode body 21 Positive electrode sheet 21a Positive electrode current collector foil 21a1 Unformed part 21b Positive electrode active material layer 22 Negative electrode sheet 22a Negative current collector foil 22a1 Unformed part 22b Negative electrode active material layer 31,32 Separator sheet 41 Battery case 41a Case body 41a1 opening 41b Lid 41b1 Mounting hole 42 Positive terminal 42a Positive internal terminal 42b Positive external terminal 43 Negative terminal 43a Negative internal terminal 43a1 base 43a2 Connecting piece 43b Negative external terminal 61 Bottom part 62,63 Wide surface section 64,65 Narrow side part 71 Gasket 71a Seat part 71b boss part 71c side wall 72 Insulator 72a bottom wall 72b hole 80 Bus Bar 82 Welded parts 100, 100A, 100B Horn 110 Base 112 Exposed surface 130 Daibu 131 Top surface 132 Peripheral wall 132a Wide surface 132b narrow side 134 Corrugated sheet section 136 Slope section 150 Pressure welding part 152 Protrusion 152a top surface 152b bottom 152c side 154 Zigzag section 170 Burr accumulation section 200 terminal parts 210 First member 212 Shaft 212a End 214 Flange 216 Cylinder part 218 Stud part 220 Second member 221 Surface 222 recess 222a bottom 222b Side surface 223 Surface 224 recess 224a bottom 224b Side surface 225 Ridge 226 Contact area 230 Joint 300 Anvil 400 Horn 450 Pressure welding part 452 Protrusion 452a top side T1 Base height T2 protrusion height T3 Recess depth T4 Ridge Height W1 width of exposed surface

Claims

1. An ultrasonic bonding horn capable of ultrasonic vibration in a predetermined vibration direction, a base portion connected to an ultrasonic oscillator; a platform portion rising from the upper surface of the base portion; a pressure welding portion that is formed by a plurality of protrusions protruding from an upper surface of the base portion and that is pressed against the workpiece; Equipped with The plurality of protrusions constituting the pressure contact portion are formed and arranged in a pyramidal or truncated pyramidal shape, In a plan view, at least a part of the periphery of the arrangement portion of the plurality of protrusions is zigzag-shaped, the zigzag portion is formed along at least one of the vibration direction and a direction perpendicular to the vibration direction, an upper surface of the base portion has an exposed surface on which the platform portion is not formed; The width of the exposed surface in the vibration direction is wider than the width in a direction perpendicular to the vibration direction. Horn for ultrasonic welding.

2. In a plan view, the exposed surface is provided so as to surround the base portion.

2. The ultrasonic bonding horn according to claim 1.

3. The width of the exposed surface in the vibration direction is equal to or greater than a height T2 of the protrusion from the upper surface of the base portion.

3. The ultrasonic bonding horn according to claim 2.

4. a volume of a burr accumulation portion defined as a space above the exposed surface up to a height T1 from the upper surface of the base portion of the platform portion is larger than a volume of the pressure-welded portion; 4. The ultrasonic bonding horn according to claim 2 or 3.

5. the plurality of protrusions are disposed adjacent to one another such that there are no planar grooves between the protrusions; The ultrasonic bonding horn according to any one of claims 1 to 4.

6. In a plan view, a periphery of an arrangement portion of the plurality of protrusions has neither a side extending in the vibration direction nor a side extending in a direction perpendicular to the vibration direction. The ultrasonic bonding horn according to any one of claims 1 to 5.

7. The boundary between the upper surface of the base portion and the peripheral wall of the platform portion is formed in a sloped shape. The ultrasonic bonding horn according to any one of claims 1 to 6.

8. a ratio of a height T1 of the platform from the top surface of the base to a height T2 of the protrusion from the top surface of the platform is 2:1 to 1:1; The ultrasonic bonding horn according to any one of claims 1 to 7.

9. A method for manufacturing a terminal component for a secondary battery, comprising joining a first metal member and a second metal member using the ultrasonic joining horn according to any one of claims 1 to 8.

10. The first member and the second member are made of different metals. The method of claim 9.

Images