Ultrasonic bonding tip and ultrasonic bonding apparatus and method using the same

Abstract

To provide an ultrasonic bonding tip and the like capable of improving quality of a plurality of joint bodies of metal foils.SOLUTION: A horn tip 40 has a tip base part 41 and a protrusion 422 protruding from the tip base part 41. The protrusion 422 pressed against a plurality of metal foils is composed of at least one of cemented carbide, polycrystalline diamond, CBN (cubic boron nitride), ceramic, and carbon steel. Thus, even when the plurality of metal foils are sticky metal foils such as aluminum foils or copper foils after ultrasonic bonding is performed while the plurality of laminated metal foils are pressed by the protrusion 422 of the horn tip 40 in a lamination direction, the possibility for a part of the plurality of metal foils to adhere to the protrusion 422 is reduced.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic bonding tip for bonding multiple workpieces made of various materials such as metals using ultrasonic vibrations, and to an ultrasonic bonding technique using the ultrasonic bonding tip. [Background technology]

[0002] The present applicant has proposed a technology for joining multiple workpieces using ultrasonic complex vibration (see, for example, Patent Document 1). Ultrasonic complex vibration is achieved by combining ultrasonic vibrations in two directions perpendicular to the axial direction of an ultrasonic joining tip. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7219495 Summary of the Invention [Problem to be solved by the invention]

[0004] The ultrasonic bonding tip is pressed against the topmost metal foil of a stack of metal foils, and ultrasonic complex vibrations are applied to the metal foils while applying pressure to the metal foils in the stacking direction using the ultrasonic bonding tip. However, if the metal foils are relatively sticky, such as aluminum foil, copper foil, or an alloy foil of these, portions of the metal foils tend to adhere or stick to the ultrasonic bonding tip, making it difficult to separate the ultrasonic bonding tip from the bonded assembly of the metal foils. This results in a deterioration in the quality of the bonded assembly of the metal foils.

[0005] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an ultrasonic bonding tip or the like that can improve the quality of a bonded body of a plurality of metal foils. [Means for solving the problem]

[0006] The ultrasonic bonding chip of the present invention is an ultrasonic bonding chip having a chip base and a convex portion protruding from the chip base, and the convex portion is at least partially made of at least one of cemented carbide, polycrystalline diamond and CBN (cubic boron nitride), ceramic and carbon steel.

[0007] In the ultrasonic bonding tip (hereinafter sometimes simply referred to as "tip") having this configuration, the protrusion is at least partially made of at least one of cemented carbide, polycrystalline diamond, CBN (cubic boron nitride), ceramic, and carbon steel. This reduces the possibility that multiple metal foils or parts of the bonded body thereof will adhere to the protrusion, making it easier to separate the protrusion from the bonded body and ultimately improving the quality of the bonded body.

[0008] The ultrasonic bonding device of the present invention comprises: The ultrasonic bonding tip; an ultrasonic complex vibration element configured to induce ultrasonic complex vibration by combining longitudinal vibration and torsional vibration and propagate the ultrasonic complex vibration to the ultrasonic bonding tip; a control device for controlling the complex vibration of the ultrasonic complex vibration element; It is equipped with:

[0009] The ultrasonic bonding method of the present invention comprises: The laminated metal foils are bonded together using an ultrasonic bonding device. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating the configuration of an ultrasonic bonding device according to an embodiment of the present invention. [Figure 2A] 1 is an exploded explanatory view of an ultrasonic bonding tip according to a first embodiment of the present invention; [Figure 2B] FIG. 1 is a diagram illustrating the configuration of an ultrasonic bonding tip according to a first embodiment of the present invention. [Figure 3A]FIG. 4 is an exploded explanatory view of an ultrasonic bonding tip according to a second embodiment of the present invention. [Figure 3B] FIG. 4 is an explanatory diagram of the configuration of an ultrasonic bonding tip according to a second embodiment of the present invention. [Figure 4] 3 is a flowchart showing the function of the ultrasonic bonding device. [Figure 5A] FIG. 10 is an exploded explanatory view of an ultrasonic bonding tip according to another embodiment of the present invention. [Figure 5B] FIG. 10 is a diagram illustrating the configuration of an ultrasonic bonding tip according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] (Configuration of ultrasonic bonding device) The ultrasonic bonding device according to one embodiment of the present invention shown in Fig. 1 includes an ultrasonic complex vibration device 10, a horn tip 40 (ultrasonic bonding tip), and an anvil 18. The anvil 18 may be omitted. For the purpose of explaining the configuration, a three-dimensional Cartesian coordinate system (x, y, z) as shown in Fig. 1 will be used as appropriate.

[0012] The ultrasonic complex vibration device 10 includes a first vibration element 110 having a substantially cylindrical shape, an intermediate vibration element 100 having a substantially cylindrical, cylindrical, or bottomed cylindrical shape, and a second vibration element 120 having a substantially cylindrical or bottomed cylindrical shape. The first vibration element 110, the intermediate vibration element 100, and the second vibration element 120 constitute "vibration elements."

[0013] The first vibration element 110 and the intermediate vibration element 100 are coaxially connected by a mechanical connecting mechanism (such as a bolt and / or a clamp mechanism) at the middle or intermediate portion of the ultrasonic complex vibration device 10. The intermediate vibration element 100 and the second vibration element 120 are coaxially connected by a mechanical connecting mechanism at the middle portion of the ultrasonic complex vibration device 10. The first vibration element 110, the intermediate vibration element 100, and the second vibration element 120 may be integrally configured rather than being mechanically connected.

[0014] The intermediate vibration element 100 may be a component of the first vibration element 110. That is, the first vibration element 110 may be composed of two vibration elements. In this case, the first vibration element 110 and the intermediate vibration element 100 may be integrally configured rather than being mechanically connected. The intermediate vibration element 100 may be a component of the second vibration element 120. That is, the second vibration element 120 may be composed of two vibration elements. In this case, the second vibration element 120 and the intermediate vibration element 100 may be integrally configured rather than being mechanically connected.

[0015] As shown in FIG. 1, the first vibration element 110 is provided with a piezoelectric body 112 whose axial direction (parallel to the first axis) is the piezoelectric polarization direction.

[0016] As shown in FIG. 1 , the intermediate vibration element 100 is formed with a substantially annular plate-shaped intermediate flange 102 that protrudes radially around its entire circumference at a central position in the axial direction. The intermediate vibration element 100 is configured to be clamped or supported around its entire circumference by a clamping mechanism (not shown) at least at the intermediate flange 102. If it is ensured that the intermediate vibration element 100 is supported by a mechanical support mechanism, the intermediate flange 102 may be omitted. As shown in FIG. 1 , the intermediate vibration element 100 has a substantially cylindrical shape with a substantially constant outer diameter in the axial direction behind the intermediate flange 102 (leftward in FIG. 1 ). As shown in FIG. 1 , the intermediate vibration element 100 has a substantially cylindrical shape (a shape in which a substantially truncated conical shape and a substantially cylindrical shape are coaxially connected) with a substantially constant outer diameter after continuously tapering partway toward the tip of the intermediate vibration element 100 ahead of the intermediate flange 102 (+x direction in FIG. 1 ).

[0017] 1, the second vibration element 120 is provided with a frequency adjustment element 122 in the shape of a generally regular octagonal plate with rounded corners, which extends radially around the entire circumference at a midpoint in the axial direction of the second vibration element 120. The frequency adjustment element 122 adjusts the resonance frequencies of the longitudinal vibration component and the torsional vibration component of the ultrasonic vibration. The outer shape of the frequency adjustment element 122 may be a generally circular, generally elliptical, or generally regular n-polygonal plate (e.g., n = 4, 6, 8, 12, 16, etc.) plate, columnar, or frustum shape, which shares a common central axis with the second vibration element 120, or any combination thereof.

[0018] 1, the second vibration element 120 has a plurality of slits 124 formed on its outer surface behind the frequency adjustment element 122. A plurality of slits 124 may be formed on the outer surface of the second vibration element 120 ahead of the frequency adjustment element 122. The slits 124 extend obliquely in the second vibration element 120 when viewed from the side, or extend in the axial direction while being displaced in the circumferential direction in phase with each other. N (N=2, 3, ...) slits 124 may be arranged to have N-fold rotational symmetry (e.g., N=8, 12, or 16) around the central axis of the second vibration element 120.

[0019] 1, the second vibration element 12 is provided with a tip portion 126 of a generally regular octagonal shape with rounded corners that protrudes radially around the entire circumference at the tip position in the axial direction. Holes 128 (or through holes) are formed in the tip portion 126 at a plurality of locations spaced apart in the circumferential direction. The M (N=2, 3, ...) holes 128 may be arranged to have M-fold rotational symmetry (e.g., M=4) about the central axis of the second vibration element 12. A female thread is provided on the inner surface of the hole 128.

[0020] The balancer for adjusting the phase difference between the longitudinal vibration and the torsional vibration at the tip 126 of the second vibration element 12, and hence at the horn tip 40, may be removably fixed to the tip 126 of the second vibration element 12 by screwing the male thread of the balancer into the female thread of the hole 128.

[0021] Anvil 18 is disposed so as to face the front end of horn tip 40 in the vertical direction. A plurality of metal foils W (for example, a workpiece formed by laminating a plurality of aluminum foils, copper foils, aluminum alloy foils, and / or copper alloy foils, each having a thickness of 3 to 50 μm) are placed on the upper surface of anvil 18. Anvil 18 may be configured to be displaced vertically, either passively or actively, in response to the pressure of horn tip 40 received through the plurality of metal foils W.

[0022] As shown in FIG. 1, the ultrasonic bonding apparatus according to one embodiment of the present invention further includes an operating device 20, a control device 22, a high-frequency power supply device 221, a translational drive device 222, and a status sensor 224.

[0023] The operation device 20 is configured, for example, by a display, and displays or outputs on the display the displacement amount of the pressure block and / or the time series of the pressure according to the output signal of the status sensor 224. The display may be configured by a touch panel display, and may be configured to accept a setting operation for allowing the user to directly or indirectly specify parameters, such as one of a plurality of bonding modes that determine a time series pattern of the target pressure.

[0024] The control device 22 is configured to include a microcomputer, an arithmetic processing unit (CPU, microprocessor, processor core, etc.), and a storage device (memory such as ROM and RAM). The control device 22 is configured to read software such as an ultrasonic bonding program stored in the storage device, and to control the displacement operation of the pressure block by the translation drive device 222 in accordance with the program based on, for example, a time series of the displacement amount of the pressure block represented by the output signal of a stroke sensor constituting the status sensor 224. The control device 22 is configured to control the power supplied to the piezoelectric body 112 based on the amplitude (corresponding to a specified parameter) of the horn tip 40 represented by the output signal of an amplitude sensor constituting the status sensor 224, and thereby to control the ultrasonic vibration power of the vibration elements (first vibration element 110, intermediate vibration element 100, and second vibration element 120) and the ultrasonic vibration power of the horn tip 40.

[0025] The high-frequency power supply device 221 is configured to excite the first vibration element 110 in the axial direction by applying a high-frequency AC voltage to the piezoelectric element 112 of the first vibration element 110 in accordance with power supplied from a commercial power source (not shown).

[0026] The translational drive device 222 is equipped with a pressure block and is configured to apply pressure from the horn tip 40 to the multiple metal foils W by displacing a support mechanism such as a clamp mechanism that supports the intermediate vibration element 100 using the pressure block.

[0027] The status sensor 224 includes a stroke sensor that outputs a signal corresponding to the displacement of the pressure block that constitutes the translational drive device 222, as well as an amplitude sensor that outputs a signal corresponding to the amplitude (corresponding to a specified parameter) of the horn tip 40. The amplitude sensor may be a sensor module configured with an imaging device and a device that calculates the amplitude by analyzing an image captured by the imaging device. The status sensor 224 may be provided with a pressure sensor that outputs a signal corresponding to the pressure acting on the intermediate vibration element 100 from the pressure block of the translational drive device 222 (i.e., the pressure applied by the horn tip 40 or its protrusions 422 to the multiple metal foils W), and the control device 22 may control the time series of the pressure to be constant or in a specified manner based on the output signal of the pressure sensor.

[0028] (Ultrasonic bonding tip (first embodiment)) Horn tip 40 (ultrasonic bonding tip) according to the first embodiment of the present invention shown in FIG. 2B includes tip base 41 and a plurality of protrusions 422. Tip base 41 is formed of a substantially rectangular plate made of, for example, at least one of pre-hardened steel, carbon steel, and stainless steel. Tip base 41 may also be made of a non-ferrous metal. Protrusions 422 are formed in a substantially conical or truncated conical shape made of, for example, at least one of cemented carbide, polycrystalline diamond (PCD), CBN (cubic boron nitride), ceramic, and carbon steel. Carbon steel The chip base 41 has three recesses arranged along the longitudinal direction and through-holes 410 formed at approximately the centers of the three recesses, penetrating the chip base 41 in the z-direction. A bolt passing through the through-holes 410 is screwed into the female thread of the hole 128 in the tip end 126 of the second vibration element 12, thereby attaching the chip base 41 to the second vibration element 12.

[0029] A plurality of (eight in the example of FIG. 4B ) protrusions 422 protrude in the −z direction from a substantially flat reference surface 412 extending in the longitudinal direction of the chip base 41, and are arranged at substantially equal intervals in the longitudinal direction (±x direction) of the chip base 41. The arrangement of the plurality of protrusions 422 may be changed in various ways, such as being arranged substantially linearly, being arranged regularly such as in a substantially lattice pattern, or being arranged irregularly.

[0030] The shape of the chip base 41 may be changed to various shapes such as a substantially rectangular plate, a substantially trapezoidal plate, a substantially circular plate, a substantially elliptical plate, a substantially rectangular body, a substantially truncated cone, etc. The shape of the protrusion 422 may be changed to various shapes such as a substantially cylindrical shape, a substantially prismatic shape (for example, a regular N-sided prism (N=6, 8, 12, etc.)), a substantially pyramidal shape, a substantially truncated pyramidal shape, a substantially elliptical cylinder, etc.

[0031] As shown in FIG. 2A, the chip base 41 is provided with a plurality of recesses 411 (eight in the example of FIG. 4A) that are recessed in a generally cylindrical shape from a reference surface 412. The recesses 411 are arranged at generally equal intervals in the longitudinal direction of the chip base 41. As shown in FIG. 2A, the convex member 42 is formed in a shape that is coaxially continuous with a generally cylindrical convex base 421 and a conical or truncated conical convex portion 422 whose bottom surface has a generally identical diameter to that of the convex base 421. Of the convex member 42, the convex base 421 is fitted into the recess 411 and then fixed to the chip base 41 by brazing, soldering, or welding. The portion of the convex member 42 that protrudes from the reference surface 412 of the chip base 41 constitutes the convex portion 422.

[0032] The protrusion member 42 is entirely made of at least one of cemented carbide, polycrystalline diamond (PCD), CBN (cubic boron nitride), ceramic (e.g., alumina (Al2O3), zirconia (ZrO), aluminum nitride (AlN), silicon nitride (Si3N4), silicon carbide (SiC)), and carbon steel (e.g., die steel, high-speed steel). The protrusion 422 of the protrusion member 42 may be entirely made of at least one of cemented carbide, polycrystalline diamond, CBN (cubic boron nitride), ceramic (e.g., alumina (Al2O3), zirconia (ZrO), aluminum nitride (AlN), silicon nitride (Si3N4), silicon carbide (SiC)), and carbon steel (e.g., die steel, high-speed steel). A part (for example, a surface layer or a tip portion) of the convex portion 422 of the convex portion member 42 may be made of at least one of cemented carbide, polycrystalline diamond, CBN (cubic boron nitride), ceramic, and carbon steel.

[0033] The shapes of recess 411 and protrusion base 421 fitted therein may be changed to various shapes such as a substantially rectangular column, a substantially elliptical column, a substantially (inverted) truncated cone, or a substantially (inverted) truncated pyramid.

[0034] (Ultrasonic bonding tip (second embodiment)) The horn tip 40 (ultrasonic bonding tip) of the second embodiment of the present invention shown in Figure 3B has a configuration (and a configuration related to a modified form) that is approximately the same as the horn tip 40 of the first embodiment (see Figure 2B), and includes a tip base 41 and multiple protrusions 422.

[0035] As shown in FIG. 3A, the chip base 41 has a single recess 411 recessed below the reference surface 412 in the shape of a substantially elongated cylinder or a substantially rectangular cylinder with rounded corners. As shown in FIG. 3A, the convex member 42 is formed in a continuous shape, with a substantially elongated cylinder-shaped convex base 421 and multiple conical or truncated conical convex portions 422 arranged along the longitudinal direction of the convex base 421. Of the convex member 42, the convex base 421 is fitted into the recess 411 and then fixed to the chip base 41 by brazing, soldering, or welding. Multiple portions of the convex member 42 protruding from the reference surface 412 of the chip base 41 constitute multiple convex portions 422.

[0036] (Ultrasonic bonding method) The procedure of an ultrasonic bonding method according to one embodiment of the present invention using the ultrasonic bonding apparatus 1 will be described with reference to the flowchart of Fig. 4. As shown in Fig. 1, a plurality of metal foils W are placed on an anvil 18 in a stacked or laminated state in the z direction.

[0037] The ultrasonic complex vibration device 10 and the horn tip 40 are moved in the radial direction by the translational drive device 222 so as to approach the plurality of metal foils W (FIG. 4 / STEP 112).

[0038] Furthermore, it is determined whether the pressure P that horn tip 40 receives from the multiple metal foils W has reached or exceeded a first specified pressure P1 (FIG. 4 / STEP 114). The pressure P that horn tip 40 receives from the multiple metal foils W is measured based on the output signal of a pressure sensor that constitutes status sensor 224. When convex portion 422 of horn tip 40 is separated from the multiple metal foils W, P=0. When convex portion 422 of horn tip 40 comes into contact with the uppermost metal foil W of the multiple stacked metal foils W, a reaction force is received, so that P>0.

[0039] If the determination result is negative (FIG. 4 / STEP 114...NO), the translational driver 222 moves the ultrasonic complex vibration device 10 and the horn tip 40 in the radial direction so as to approach the metal foils W (FIG. 2 / connector X1 →STEP 112). As a result, the position of the horn tip 40, and therefore the static pressure applied from the horn tip 40 to the metal foils W, is adjusted to be within a specified static pressure range (e.g., 200 N to 800 N).

[0040] If the determination result is affirmative (FIG. 4 / STEP 114...YES), ultrasonic vibrations are generated in the vibration elements (FIG. 4 / STEP 116). Specifically, in response to power being supplied to the high-frequency power supply device 221 from a commercial power source (not shown) via a slip ring or the like, the high-frequency power supply device 221 applies a high-frequency AC voltage to the piezoelectric body 112 of the first vibration element 110. This causes the first vibration element 110 to vibrate in its axial direction at, for example, approximately 20 KHz, generating ultrasonic vibrations. The ultrasonic vibrations are transmitted from the first vibration element 110 to the intermediate vibration element 100 in its axial direction, and the amplitude of the ultrasonic vibrations is amplified. Furthermore, the ultrasonic vibrations with amplified amplitude are transmitted from the intermediate vibration element 100 to the second vibration element 120 in its axial direction.

[0041] In this way, a portion of the longitudinal vibration component (axial component of the second vibration element 120) of the ultrasonic vibration transmitted to the second vibration element 120 is converted into a torsional vibration component by the multiple slits 124 formed on the outer surface of the second vibration element 120. Then, a composite vibration generated by combining the longitudinal vibration component and the torsional vibration component is transmitted to the horn tip 40 fixed to the tip of the second vibration element 120.

[0042] In response, the horn tip 40 displaces or vibrates along a circular or elliptical orbit in a plane perpendicular to the contact or pressing direction against the multiple metal foils W (the uppermost metal foil W among them). As a result, the amplitude and ultrasonic vibration power of the horn tip 40 gradually increase from the vibration start time t=t0. During this process, impurities are removed from the mutual contact surfaces of the multiple metal foils W, further promoting plastic deformation of the mutual contact surfaces of the multiple metal foils W. After the rate of increase in the amplitude and ultrasonic vibration power of the horn tip 40 significantly decreases at time t=t1, the amplitude and ultrasonic vibration power of the horn tip 40 gradually increase. This is because the oxide coatings and other metals constituting the joining surfaces of the multiple metal foils W are removed, revealing clean, activated metal atoms at the joining surfaces. The temperature rise due to frictional heat activates the atomic movement, generating mutual attractive forces between the atoms.

[0043] At this time, the composite vibration is applied to the plurality of metal foils W while adjusting the amount of pressing of the plurality of metal foils W by the horn tip 40 and / or the static pressure applied to the plurality of metal foils W. This allows the plurality of metal foils W to be solid-state joined to one another.

[0044] It is determined whether the time derivative δA (= current amplitude A(k) - previous amplitude A(k-1)) of the amplitude A of the horn tip 40 is negative and whether the amplitude A is equal to or less than the reference amplitude A0 (FIG. 4 / STEP 118). An amplitude sensor constituting the state sensor 224 optically measures the amplitude A at a specified location (e.g., a location where the amplitude is relatively large) of the horn tip 40. Instead of this determination process, it may be determined whether the amplitude A has decreased by the reference amplitude A0 (or a reference ratio based on the maximum value) using the maximum value at the time when the amplitude A started to decrease as a reference. For example, the reference amplitude A0, such as one of multiple joining modes for which the reference amplitude A0 is determined, may be directly or indirectly specified via a touch panel display constituting the operation device 20.

[0045] If the determination result is negative (FIG. 4 / STEP 118...NO), ultrasonic vibrations are continuously generated in the vibration element (FIG. 2 / connector X2 →STEP 116). On the other hand, if the determination result is positive (FIG. 4 / STEP 118...YES), the translational drive device 222 moves the ultrasonic complex vibration device 10 and the horn tip 40 away from the metal foils W (FIG. 4 / STEP 122).

[0046] Furthermore, it is determined whether the pressure P that the horn tip 40 receives from the multiple metal foils W has become equal to or less than a second designated pressure P2 (FIG. 4 / STEP 124). The second designated pressure P2 is set to a value smaller than the first designated pressure P1, for example, 0 or a very small value.

[0047] If the determination result is negative (FIG. 4 / STEP 124...NO), the translational driver 222 moves the ultrasonic complex vibration device 10 and the horn tip 40 away from the metal foils W (FIG. 2 / connector X4 →STEP 122). This adjusts the radial position of the horn tip 40, and therefore the static pressure applied from the horn tip 40 to the metal foils W, so as to decrease.

[0048] If the determination result is positive (FIG. 4 / STEP 124...YES), the generation of ultrasonic vibrations in the vibration element is stopped (FIG. 4 / STEP 126). For example, after the time t=t2 when the amplitude of the horn tip 40 changes from increasing to decreasing and falls below the reference amplitude A0, the ultrasonic power of the horn tip 40 is controlled to become 0 with a slight response delay. This stops the series of processes.

[0049] (Action and effect) According to the horn tip 40 (ultrasonic bonding tip) used in the ultrasonic bonding device configured as described above, the convex portion 422 pressed against the plurality of metal foils W is made of at least one of cemented carbide, polycrystalline diamond, CBN (cubic boron nitride), ceramic, and carbon steel. As a result, after the plurality of metal foils W are ultrasonically bonded while being pressed in the stacking direction by the convex portion 422 of the horn tip 40 in a stacked state, even if the plurality of metal foils W are sticky metal foils such as aluminum foil or copper foil, the possibility of parts of the plurality of metal foils W adhering to the convex portion 422 is reduced, thereby improving the quality of the bonded body of the plurality of metal foils W.

[0050] (Another embodiment of the present invention) In the above embodiment, the amplitude A of the horn tip 40 was measured as a specified parameter that changes depending on the progress of joining multiple metal foils W, but in other embodiments, the axial displacement amount, displacement speed and / or displacement acceleration of the vibration element (e.g., the second vibration element 12) may be measured as a specified parameter.

[0051] Horn tip 40 (ultrasonic bonding tip) according to another embodiment of the present invention shown in FIG. 5B includes a substantially cylindrical tip base 41 and a protrusion 422. As shown in FIG.

[0052] As shown in FIG. 5A, the chip base 41 has a recess 411 that is recessed in an approximately cylindrical shape from a reference surface 412, which is one end face of the approximately annular shape, and a hole 410 that is recessed in an approximately cylindrical shape from the other end face of the approximately annular shape.

[0053] As shown in FIG. 5A, the protrusion member 42 includes a generally cylindrical or disc-shaped protrusion base 421 having a diameter generally equal to that of the recess 411 of the tip base 41; a generally cylindrical or disc-shaped first protrusion 4221 having a diameter larger than that of the protrusion base 421 and generally equal to the outer diameter of the tip base 41; and a generally rectangular second protrusion 4222 protruding from the first protrusion 4221 in the −z direction. These components are formed in a continuous shape, with their central axes aligned coaxially or aligned. The end surface of the second protrusion 4222 is provided with a plurality of small protrusions 4220 having a generally hemispherical or truncated conical shape. The small protrusions 4220 may be omitted from the end surface of the second protrusion 4222, and the end surface may be formed as a flat or convex curved surface. As shown in FIG. 5B, the protrusion 422 is composed of the first protrusion 4221 and the second protrusion 4222. In this other embodiment, of the convex portion 422, the first convex portion 4221 has its end surface pressed against the plurality of metal foils W. Of the convex portion member 42, the convex portion base 421 is fitted into the concave portion 411 and then fixed to the chip base 41 by brazing, soldering, or welding.

[0054] The tip base 41 is attached to the second vibration element 12 by threading a headless bolt into the female thread provided in the hole 410 and threading into the female thread of the hole 128 in the tip end 126 of the second vibration element 12. The hole 410 and the recess 411 may be connected to each other to form a through hole that passes through the tip base 41 in the axial direction. The hole 410 may be omitted, and a male thread may be formed on the outer periphery of the tip base 41, and the male thread may be threaded into the female thread of the hole 128 in the tip end 126 of the second vibration element 12, thereby attaching the tip base 41 to the second vibration element 12. [Explanation of symbols]

[0055] 10. Ultrasonic complex vibration device 100...Intermediate vibration element 102...Intermediate flange 110...First vibration element 112. Piezoelectric material 120...Second vibration element 122...Frequency adjustment element 124. Slit 14‥Base 142... Female thread 14C‥Bottom surface (boundary surface) 18. Anvil 20‥Operation device 22. Control device 221‥High frequency power supply equipment 222...Translation drive device 224...Status sensor 40. Horn tip (tip for ultrasonic bonding) 41. Tip base 410...Through hole 411. Recess 412‥Reference plane 42. Convex part 421. Base of convex part 422‥Convex part W: Metal foil (workpiece).

Claims

1. An ultrasonic bonding tip having a tip base and a protrusion protruding from the tip base, The protrusions are at least partially made of at least one of cemented carbide, polycrystalline diamond, CBN (cubic boron nitride), ceramic, and carbon steel. Ultrasonic bonding tip.

2. 2. The ultrasonic bonding tip according to claim 1, The protrusion is partially fitted into a recess provided in the tip base, and is brazed, soldered, or welded to the tip base, with the protrusion being a portion that protrudes from the tip base. Ultrasonic bonding tip.

3. 3. The ultrasonic bonding tip according to claim 2, The plurality of protrusions are formed by the portions of the plurality of protrusion members that are partially fitted into the plurality of recesses provided in the chip base and brazed, soldered, or welded to the chip base and that protrude from the chip base. Ultrasonic bonding tip.

4. 3. The ultrasonic bonding tip according to claim 2, The plurality of protrusions are constituted by a plurality of portions of the protrusion members that are partially fitted into the single recess provided in the tip base and brazed, soldered or welded to the tip base and protrude from the tip base. Ultrasonic bonding tip.

5. 2. The ultrasonic bonding tip according to claim 1, The tip base is made of at least one of pre-hardened steel, carbon steel, stainless steel, and non-ferrous metal. Ultrasonic bonding tip.

6. The ultrasonic bonding tip according to any one of claims 1 to 5, an ultrasonic complex vibration element configured to induce ultrasonic complex vibration by combining longitudinal vibration and torsional vibration and propagate the ultrasonic complex vibration to the ultrasonic bonding tip; a control device for controlling the complex vibration of the ultrasonic complex vibration element; An ultrasonic bonding device comprising:

7. A method for joining a plurality of stacked metal foils using the ultrasonic joining device according to claim 6. Ultrasonic bonding method.

8. The ultrasonic bonding method according to claim 7, A plurality of aluminum foils or a plurality of copper foils are bonded together as the plurality of metal foils. Ultrasonic bonding method.

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