Tip structure for ultrasonic joining, ultrasonic joining device, and ultrasonic joining program

Abstract

To provide a structure etc. in which a tip for ultrasonic joining is fixed to a base part of an ultrasonic complex vibration element etc. more securely.SOLUTION: In a tip structure for ultrasonic joining comprising a horn tip 40 (a tip for ultrasonic joining) and a base part 14, the base part 14, formed by a stainless steel material, and the horn tip 40, formed by a laser shaped body including a high speed steel material having a lower melting point than that of the stainless steel material, are integrally formed.SELECTED DRAWING: Figure 2

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] When the ultrasonic bonding tip is connected to the ultrasonic composite vibration element by a mechanical fixing mechanism such as a screw fastening mechanism, the fixing strength may be insufficient, and therefore, the ultrasonic bonding tip may be partially or entirely displaced relative to the ultrasonic composite vibration element after repeated joining of workpieces.

[0005] Therefore, it is conceivable to improve the fixing strength between the ultrasonic bonding tip and the ultrasonic composite vibration element by not only mechanically connecting the tip to the ultrasonic composite vibration element but also welding the tip to the element.

[0006] However, depending on the type of welding, the fixing strength of the ultrasonic welding tip to the ultrasonic composite vibration element may still be insufficient, and repeated welding of workpieces may cause cracks to appear in the welded area.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a structure in which an ultrasonic bonding tip is more reliably fixed to a base of an ultrasonic composite vibration element or the like. [Means for solving the problem]

[0008] The ultrasonic bonding chip structure of the present invention comprises: An ultrasonic bonding tip structure including an ultrasonic bonding tip and a base for propagating ultrasonic vibrations to the ultrasonic bonding tip, The base is made of stainless steel, and the ultrasonic bonding chip is made of a laser-shaped body including high-speed steel having a lower melting point than the stainless steel, which is integrally formed on the surface of the base.

[0009] In the ultrasonic bonding chip structure having this configuration, the base made of stainless steel and the ultrasonic bonding chip made of a laser-shaped body including high-speed steel with a lower melting point than the stainless steel are integrally formed, thereby improving the fixing strength of the chip to the base and improving the mechanical strength of the chip structure as a whole.

[0010] The ultrasonic bonding device of the present invention comprises: an 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; An ultrasonic bonding apparatus comprising: The ultrasonic bonding chip structure according to the present invention is composed of a base portion that is a part of the ultrasonic complex vibration element, and the ultrasonic bonding chip.

[0011] The ultrasonic bonding program of the present invention includes: An ultrasonic bonding program that gives a computer constituting the control device a function of performing an ultrasonic bonding method for bonding one workpiece and another workpiece using the ultrasonic bonding device according to the present invention, The ultrasonic bonding method comprises: a step of determining whether or not the joining of the one workpiece and the other workpiece has been completed based on a signal corresponding to a value of a designated parameter that changes depending on the progress of joining of the one workpiece to the other workpiece while the ultrasonic joining tip is in contact with the one workpiece to be joined; and stopping the complex vibration of the ultrasonic complex vibration element when it is determined that the joining of the one workpiece and the other workpiece has been completed.

[0012] According to the ultrasonic bonding program of the present invention and the ultrasonic bonding method implemented by a computer constituting a control device with the functions provided by the ultrasonic bonding program, it is possible to accurately determine whether the bonding is complete or not based on the change in the value of a specified parameter, such as the amplitude of ultrasonic vibration of the ultrasonic bonding tip of the present invention, which changes depending on the progress of the bonding of the one workpiece and the other workpiece. If the determination result indicates that the bonding of the one workpiece and the other workpiece is complete, the ultrasonic vibration of the ultrasonic bonding tip is stopped, and as a result, the period during which the ultrasonic bonding tip is ultrasonically vibrated can be appropriately controlled from the perspective of improving the quality of the bonding of the one workpiece and the other workpiece. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating the configuration of an ultrasonic bonding device according to an embodiment of the present invention. [Figure 2] 1 is a diagram illustrating the configuration of an ultrasonic bonding chip structure according to a first embodiment of the present invention; [Figure 3] 3 is a flowchart showing the function of the ultrasonic bonding device. [Figure 4] FIG. 4 is a diagram illustrating the configuration of an ultrasonic bonding chip structure according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] (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.

[0015] 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."

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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 ).

[0020] 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.

[0021] 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.

[0022] As shown in FIG. 1, the second vibration element 12 has a base 14 at its axial tip. The base 14 has a generally rectangular cross section from the proximal end (left end in FIG. 2) to the distal end (right end in FIG. 2), and is formed so that the length of the long side of the rectangle remains generally constant, the length of the short side of the rectangle decreases relatively abruptly, and then continues to a constant length (see FIGS. 2 and 3). The base 14 may be formed integrally with the second vibration element 12, or may be removably fixed or connected to the second vibration element 12. The base 14 is made of stainless steel. Examples of stainless steel include nickel-molybdenum-chromium steel. The melting point of stainless steel is, for example, within a temperature range of 1400°C to 1500°C.

[0023] The base 14 may be provided with a female thread extending downward from its upper surface (or extending laterally from its side surface). The male thread of a balancer for adjusting the phase difference between the longitudinal vibration and the torsional vibration in the horn tip 40 may be screwed into the female thread, thereby removably fixing the balancer to the base 14 of the second vibration element 12.

[0024] The anvil 18 is disposed so as to face the tip of the horn tip 40 in the vertical direction. A first workpiece W1 and a second workpiece W2 as multiple workpieces are placed on the upper surface of the anvil 18. The anvil 18 may be configured to passively or actively displace up and down in response to the pressure of the horn tip 40 received through the first workpiece W1 and the second workpiece W2.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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).

[0029] The translational drive device 222 is equipped with a pressure block and is configured to apply pressure from the horn tip 40 to the first workpiece W1 and the second workpiece W2 by displacing a support mechanism such as a clamping mechanism that supports the intermediate vibration element 100 using the pressure block.

[0030] 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 that the horn tip 40 applies to the first workpiece W1 and the second workpiece W2), 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.

[0031] (Ultrasonic bonding chip structure (first embodiment)) The ultrasonic bonding tip structure according to the first embodiment of the present invention, as shown schematically in FIG. 2, is composed of an integrally formed base 14 and horn tip 40. The horn tip 40 is composed of a laser-formed body of high-speed steel, which has a lower melting point than the stainless steel that constitutes the base 14. Examples of high-speed steel include tungsten-based steel and molybdenum-based steel. The melting point of high-speed steel is lower than that of stainless steel, and is within the temperature range of 1300°C to 1500°C, for example. Because high-speed steel is in a powder state when formed, it is more easily melted by laser light irradiation than stainless steel.

[0032] The horn tip 40 has a first tip portion 41 in the shape of a substantially rectangular plate, and a second tip portion 42 in the shape of a substantially rectangular plate or a substantially oval plate that is continuous with the first tip portion 41 at the distal end of its lower end. The first tip portion 41 has a countersunk hole 402 that extends from its lower surface to its upper surface 40C. The second tip portion 42 abuts against one of the first workpieces W1 and the second workpieces W2, that is the uppermost workpiece W1. The abutting portion of the second tip portion 42 against the one workpiece W1 may be a flat surface or a convex curved surface, and may have one or more convex portions and / or one or more concave portions formed thereon.

[0033] The first tip portion 41 may be configured as a substantially circular cylinder, a substantially elliptical cylinder, a substantially n-sided prism (regular n-sided prism), a substantially truncated cone, or a substantially n-sided truncated pyramid (regular n-sided truncated pyramid). The second tip portion 42 may be configured as a connected body in which a substantially circular cylinder, a substantially elliptical cylinder, a substantially n-sided prism (regular n-sided prism), a substantially truncated cone, or a substantially n-sided truncated pyramid (regular n-sided truncated pyramid), or any combination thereof, are connected so as to be stacked coaxially.

[0034] The ultrasonic bonding chip structure having this configuration is fabricated using an inkjet laser shaping device (3D printer device). Specifically, raw material powder (high-speed steel powder) is sprayed onto the surface of base 14, and laser light is irradiated onto the raw material powder, gradually building up layers or objects of the raw material powder on the surface of base 14. The laser-shaped body is then subjected to a finishing process by machining, and further subjected to a surface treatment (wear-resistant treatment), thereby fabricating the ultrasonic bonding chip structure.

[0035] (Ultrasonic bonding method) The procedure of an ultrasonic bonding method according to one embodiment of the present invention using the ultrasonic bonding device 1 will be described with reference to the flowchart of Fig. 2. As shown in Fig. 3, a first workpiece W1 and a second workpiece W2 are placed on the anvil 18 in a stacked state from top to bottom.

[0036] 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 first workpiece W1 and the second workpiece W2 (FIG. 3 / STEP 112).

[0037] Furthermore, it is determined whether the pressure P that horn tip 40 receives from first workpiece W1 (and second workpiece W2) is equal to or greater than first specified pressure P1 (FIG. 3 / STEP 114). The pressure P that horn tip 40 receives from first workpiece W1 is measured based on the output signal of a pressure sensor that constitutes state sensor 224. When the tip of horn tip 40 is separated from workpiece W1, P=0. For example, as shown in FIG. 3, when the tip of horn tip 40 comes into contact with first workpiece W1 that is inserted into through-hole W20 of second workpiece W2, a reaction force is received, so that P>0.

[0038] If the determination result is negative (FIG. 3 / STEP 114...NO), the translational drive device 222 moves the ultrasonic complex vibration device 10 and the horn tip 40 in the radial direction so as to approach the first workpiece W1 inserted into the through-hole W20 of the second workpiece W2 (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 first workpiece W1 and the second workpiece W2, is adjusted to be within a specified static pressure range (e.g., 200 N to 800 N).

[0039] If the determination result is affirmative (FIG. 3 / STEP 114...YES), ultrasonic vibrations are generated in the vibration elements (FIG. 3 / 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.

[0040] 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.

[0041] In response, the horn tip 40 displaces or vibrates in a circular or elliptical orbit on a plane perpendicular to the contact direction of the first workpiece W1. 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 contact surface between the first workpiece W1 and the second workpiece W2, further promoting plastic deformation of the contact surface between the first workpiece W1 and the second workpiece W2. 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 due to the removal of oxide coatings and other metals constituting the joining surfaces of the first workpiece W1 and the second workpiece W2, revealing clean, activated metal atoms at the joining surfaces. The temperature rise due to frictional heat activates the atomic movement, generating mutual attraction between the atoms.

[0042] At this time, the composite vibration is applied to the first workpiece W1 and the second workpiece W2 while adjusting the amount of pressing of the first workpiece W1 and the second workpiece W2 by the horn tip 40 and / or the static pressure applied to the first workpiece W1 and the second workpiece W2. As a result, as shown in Fig. 4, the outer surface and the peripheral edge of the lower surface of the first workpiece W1 can be solid-state welded to the stepped portion W22 of the second workpiece W2 over the entire circumference.

[0043] 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. 3 / 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.

[0044] If the determination result is negative (FIG. 3 / 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. 3 / STEP 118...YES), the translational drive device 222 moves the ultrasonic complex vibration device 10 and the horn tip 40 away from the first workpiece W1 and the second workpiece W2 (FIG. 3 / STEP 122).

[0045] Furthermore, it is determined whether the pressure P that the horn tip 40 receives from the first workpiece W1 (and the second workpiece W2) has become equal to or less than a second designated pressure P2 (FIG. 3 / 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.

[0046] If the determination result is negative (FIG. 3 / STEP 124...NO), the translational drive device 222 moves the ultrasonic complex vibration device 10 and the horn tip 40 away from the first workpiece W1 and the second workpiece W2 (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 first workpiece W1 and the second workpiece W2, so as to decrease.

[0047] If the determination result is positive (FIG. 3 / STEP 124...YES), the generation of ultrasonic vibrations in the vibration element is stopped (FIG. 3 / STEP 126). For example, after the amplitude of horn tip 40 changes from increasing to decreasing and becomes equal to or less than reference amplitude A0 at time t=t2, the ultrasonic power of horn tip 40 is controlled to become 0 with a slight response delay. This stops the series of processes.

[0048] (Action and effect) In the ultrasonic bonding tip structure used in the ultrasonic bonding device configured as described above, which is composed of a horn tip 40 (ultrasonic bonding tip) and a base 14, the base 14, which is made of stainless steel, and the horn tip 40, which is made of a laser-shaped body containing high-speed steel that has a lower melting point than the stainless steel, are integrally formed. As a result, the fixing strength of the horn tip 40 to the base 14 is improved, and the mechanical strength of the ultrasonic bonding tip structure as a whole is improved.

[0049] (Ultrasonic bonding chip structure (second embodiment)) According to the ultrasonic bonding chip structure of the second embodiment of the present invention, the essential parts of which are shown schematically in Figure 4, a concave-convex structure 140 is formed on the surface of the base 14 on which the ultrasonic bonding chip is formed. The concave-convex structure 140 has a plurality of convex portions 141 that are approximately conical (tapered). The laser-shaped body that constitutes the horn tip 40 at least partially penetrates into the concave-convex structure 140. The height of the convex portions 141 or the depth of the concave portions 142 is within the range of, for example, 50 µm to 2 mm, 200 µm to 1.5 mm, or 500 µm to 1.0 mm.

[0050] The protrusions 141, and thus the uneven structure 140, may be formed by forming grooves that form the recesses 142 on the surface of the base 14. The uneven structure 140 may be formed by forming the protrusions 141 as a laser-shaped object on the surface of the base 14. The protrusions 141 may be formed in a tapered shape such as a substantially conical shape, a substantially truncated cone shape, a substantially truncated pyramid shape, a substantially hemispherical shape, or a substantially hemi-elliptical sphere shape, in addition to a substantially conical shape. The protrusions 141 may also be formed in a non-tapered shape such as a square shape or a rectangular parallelepiped shape. The laser-shaped object that forms the horn tip 40 is formed in the same manner as in the first embodiment.

[0051] With this configuration of the ultrasonic bonding chip structure, the anchoring effect of the uneven structure 140 formed on the surface of the base 14 and the laser-shaped body that forms the horn tip 40 that is inserted into the recess 142 that forms the uneven structure 140 further improves the fixing strength of the horn tip 40 to the base 14 and further improves the overall mechanical strength of the ultrasonic bonding chip structure.

[0052] Furthermore, since the convex portions 141 of the uneven structure 140 are tapered, when the initial laser-shaped layer that penetrates into the concave portions 142 is formed, the stainless steel at the tip of the convex portions 141 is melted by the laser light, forming a portion that is mixed with the high-speed steel that makes up the laser-shaped layer.

[0053] In this portion, it is preferable that the amount of components derived from the high-speed steel material that constitutes horn tip 40 is greater than the amount of components derived from the stainless steel material that constitutes base 14 (protrusions 141 on its surface). Compared to when the amount of components derived from high-speed steel material is equal to the amount of components derived from stainless steel material in this portion, or when the amount of components derived from high-speed steel material is less than the amount of components derived from stainless steel material in this portion, the strength of this portion is higher when the amount of components derived from high-speed steel material in this portion is greater than the amount of components derived from stainless steel material in this portion. This improves the fixing strength of horn tip 40 to base 14 and the mechanical strength of the tip structure as a whole.

[0054] (Another embodiment of the present invention) In the first or second embodiment of the present invention, the laser-shaped object constituting the horn tip 40 may be made of stainless steel and high-speed steel, and may be formed so that the stainless steel content decreases while the high-speed steel content increases with increasing distance from the surface of the base 14. A laser-shaped object of this configuration can be produced by adjusting the mixing ratio of the stainless steel powder and the high-speed steel powder in the raw material powder so that it changes during the lamination process of the laser-shaped layers.

[0055] 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 one workpiece W1 and the other workpiece W2, 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. [Explanation of symbols]

[0056] 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 140‥Uneven structure 141. Convex part 142. Recess 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. First tip part 42. Second chip part W1: First work W2: Second work.

Claims

1. An ultrasonic bonding tip structure including an ultrasonic bonding tip and a base for propagating ultrasonic vibrations to the ultrasonic bonding tip, The base is made of stainless steel, and the ultrasonic bonding tip is made of a laser-shaped body that is integrally formed on the surface of the base and includes high-speed steel that has a lower melting point than the stainless steel. Tip structure for ultrasonic bonding.

2. 2. The ultrasonic bonding chip structure according to claim 1, A concave-convex structure is formed on the surface of the base on which the ultrasonic bonding chip is formed, and the laser-shaped body constituting the ultrasonic bonding chip is at least partially embedded in a concave portion constituting the concave-convex structure. Tip structure for ultrasonic bonding.

3. 3. The ultrasonic bonding chip structure according to claim 2, The uneven structure has a plurality of tapered convex portions. Tip structure for ultrasonic bonding.

4. 2. The ultrasonic bonding chip structure according to claim 1, The laser-shaped body is made of the stainless steel material and the high-speed steel material, and is formed so that the content of the stainless steel material decreases and the content of the high-speed steel material increases with increasing distance from the surface of the base. Tip structure for ultrasonic bonding.

5. an 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; An ultrasonic bonding apparatus comprising: The ultrasonic bonding chip structure according to any one of claims 1 to 4 is configured by a base portion that is a part of the ultrasonic composite vibration element and the ultrasonic bonding chip. Ultrasonic bonding equipment.

6. An ultrasonic bonding program that provides a computer constituting the control device with a function of performing an ultrasonic bonding method for bonding one workpiece and another workpiece using the ultrasonic bonding device according to claim 5, The ultrasonic bonding method comprises: a step of determining whether or not the joining of the one workpiece and the other workpiece has been completed based on a signal corresponding to a value of a designated parameter that changes depending on the progress of joining of the one workpiece to the other workpiece while the ultrasonic joining tip is in contact with the one workpiece to be joined; and stopping the complex vibration of the ultrasonic complex vibration element when it is determined that the joining of the one workpiece and the other workpiece is completed. Ultrasonic welding program.

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