Ultrasonic welding device

Abstract

Provided is an ultrasonic welding device comprising a detachable horn tip with which it is possible to obtain an excellent joining finish without affecting the resonance frequency of ultrasonic vibration using a simple configuration.　Each of a pair of opposing inner surfaces 32a2, 32a3 of a recess in a horn 32 is inclined so that the distance between one ends thereof is greater than the distance between the other ends thereof. The inclination angle of each of the pair of opposing inner surfaces 32a2, 32a3 is 30° within the range of 20-60° from one end toward the other end. Two side surfaces 34a2, 34a3 of an attachment part 34a of a horn tip 34, said side surfaces 34a2, 34a3 being in surface contact with the pair of opposing inner surfaces 32a2, 32a3 of the recess 32a, are inclined at the same inclination angle as each of the pair of opposing inner surfaces 32a2, 32a3 of the recess. Thus, a longitudinal vibration component of the horn tip 34 in a direction orthogonal to the center line of the horn is reduced, and it is possible to reduce loss of ultrasonic vibration energy and generation of heat.

Description

Ultrasonic bonding equipment

[0001] The present invention relates to an ultrasonic bonding apparatus that bonds objects to be bonded by applying ultrasonic vibrations to the objects.

[0002] Conventionally, an apparatus for joining objects to be joined using ultrasonic vibration energy is disclosed, for example, in Patent Document 1. This type of apparatus joins the objects to be joined by applying ultrasonic vibrations from an ultrasonic vibration means to a resonator while sandwiching and pressurizing the objects to be joined, such as overlapping metal foils, metal plates, or wires, between a support surface of a support body and a pressing surface provided on a horn.

[0003] However, in the above-mentioned conventional devices, when the horn needs to be replaced due to wear on the pressing surface, etc., the entire horn must be replaced, which is a problem that the replacement cost is high. Therefore, as described in Patent Document 2, for example, it has been considered to make part of the horn detachable and replaceable.

[0004] JP 11-198233 A JP 2023-26474 A

[0005] However, in the configuration described in Patent Document 2, a portion of the horn is detachable and replaceable, but this detachable portion is intended to be inserted inside the cylindrical workpiece in a special joining process in which a linear workpiece such as a wire is joined to the inner periphery of the cylindrical workpiece. Therefore, when the configuration is applied to general joining processes other than such special joining, the configuration does not include measures to prevent fluctuations in the resonance frequency or a decrease in joining strength or joining accuracy.

[0006] Therefore, there is a need for a detachable structure that does not affect the resonant frequency of the ultrasonic vibration of the horn and that can achieve a good bonded finish.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide an ultrasonic bonding device equipped with a detachable horn tip that has a simple configuration and is capable of obtaining a good bonding finish without affecting the resonance frequency of ultrasonic vibrations.

[0008] In order to solve the above-mentioned problems, an ultrasonic bonding apparatus according to the present invention is an ultrasonic bonding apparatus that bonds objects to be bonded by pressing them while applying ultrasonic vibrations, and includes: a support that supports the objects to be bonded; ultrasonic vibration means having a vibrator and a horn; a horn tip that is detachably attached to the horn and to which ultrasonic vibrations are applied by the ultrasonic vibration means while the objects to be bonded are sandwiched and pressed between the horn tip and the support; and pressure means that presses and applies pressure to the objects to be bonded sandwiched between the ultrasonically vibrating horn tip and the support, the horn tip having a mounting part that is fitted into a recess formed in the shape of a groove on the mounting surface of the horn and is detachably fixed to the horn by a fixing means; and a pressure means that is attached to the mounting part. the recess has a bottom surface and a pair of opposing inner surfaces, one end of which rises from each end of the bottom surface toward the other end, and each of the pair of opposing inner surfaces is inclined so that the distance between the other ends of the pair of opposing inner surfaces is larger than the distance between the one ends, and the inclination angle of each of the pair of opposing inner surfaces is the same angle within a range of 20° to 60° from the one end to the other end; the attachment portion has a bottom surface opposite the bottom surface of the recess, and two side surfaces that are continuous with the bottom surface and in surface contact with each of the pair of opposing inner surfaces of the recess, and the two side surfaces of the attachment portion that are in surface contact with each of the pair of opposing inner surfaces are inclined at the same inclination angle as each of the pair of opposing inner surfaces.

[0009] With this configuration, the pair of opposing inner surfaces of the recess of the horn are inclined so that the distance between their other ends is greater than the distance between their one ends, the inclination angle of each of the pair of opposing inner surfaces is the same angle within a range of 20° to 60° from one end to the other, and the two side surfaces of the horn tip that come into surface contact with each of the pair of opposing inner surfaces of the recess of the mounting portion are inclined at the same inclination angle as each of the pair of opposing inner surfaces of the recess. Therefore, compared to when the inclination angle is less than 20° or more than 60°, the longitudinal vibration component of the ultrasonic vibration of the horn tip in the direction perpendicular to the center line of the horn can be made smaller, reducing ultrasonic vibration energy loss and heat generation, and achieving a good joining finish without affecting the resonant frequency of the ultrasonic vibration.

[0010] The horn tip may be fixed to the horn with a gap between the bottom surface of the mounting portion and the bottom surface of the recess. The gap is preferably 10 μm or more, for example, and may be 10 μm or less if the recess of the horn and the horn tip are machined with high precision.

[0011] In this way, the bottom surface of the mounting portion of the horn tip is separated from the bottom surface of the recess in the horn, allowing for firm surface contact between the side of the horn tip and the inner surface of the recess in the horn, and the surface contact state to be firmly maintained, thereby reducing the loss of ultrasonic vibration energy and heat generation.

[0012] The horn may be formed to have a length of approximately one wavelength of the ultrasonic vibration generated by the ultrasonic vibration means and have a maximum amplitude point at the center, and the horn tip may be attached to the horn at the position of the maximum amplitude point and have a width of 1 / 4 to 1 / 40 of the wavelength in the longitudinal direction of the horn.Furthermore, the horn tip may have a length of 1 / 2 to 1 / 24 of the wavelength in a direction perpendicular to the longitudinal direction of the horn.

[0013] In this way, when the horn tip has a width of ¼ to 1 / 40 of a wavelength in the longitudinal direction of the horn, there is no risk of the resonant frequency due to ultrasonic vibrations being shifted, as occurs when the horn tip width is longer than ¼ of a wavelength, and it is possible to prevent a situation in which the joining width is too small to achieve the desired joining finish, as occurs when the horn tip width is shorter than 1 / 40 of a wavelength.Furthermore, when the horn tip has a length of ½ to 1 / 24 of a wavelength in the direction perpendicular to the longitudinal direction of the horn, a sufficiently large horn tip can be used to achieve a good joining finish without affecting the resonant frequency of the ultrasonic vibrations.

[0014] Furthermore, it is preferable to further provide a cooling device that cools the horn tip and the vicinity of the horn attachment portion while the horn tip is attached to the horn. In this case, it is preferable that the cooling device blows cooling air through ventilation holes provided in the horn tip and ventilation holes provided in the vicinity of the horn attachment portion. In this case, the horn and horn tip are cooled by the cooling device, thereby enabling stable continuous joining.

[0015] The fixing means may include a through hole formed on the side of the horn opposite to the side where the horn tip is attached, a screw hole formed in the horn tip, and a bolt that is inserted through the through hole and threaded into the screw hole to fix the horn tip to the horn. In this case, the horn tip can be easily attached to the horn by the bolt.

[0016] It is also preferable to further include an exchange means that detects the bolt, rotates the bolt in the opposite direction to the bolt's screwing direction to unscrew it, removes the horn tip from the horn, and automatically replaces it with a new horn tip. In this way, the exchange means can unscrew the bolt and automatically replace the horn tip, thereby improving the efficiency of the joining work.

[0017] The horn tips may be attached to at least two longitudinal surfaces of the horn. In this case, multiple horn tips can be detachably attached to the horn. For example, when a horn tip on one surface needs to be replaced, a new horn tip on the other surface can be used for joining. When both horn tips need to be replaced, both horn tips can be replaced at the same time, thereby reducing the number of horn tip replacement operations. Note that horn tips may be detachably attached to three or more surfaces parallel to the center line of the horn.

[0018] The horn and the horn tip may be made of different materials, which allows the horn tip to be made of a material stronger than the horn itself, thereby extending the replacement interval for the horn tip and reducing costs, compared to when the horn and horn tip are made of the same material.

[0019] It is also preferable to further provide a storage means provided in the horn in which usage history data such as the number of times the horn tip has been used, frequency of use, and duration of use is readably written, and an alarm means for determining when it is time to replace the horn tip based on the usage history data read from the storage means and notifying the user.

[0020] In this way, the notification means determines and notifies the user when it is time to replace the pressing body based on the usage history data read from the storage means, which is convenient for the user as it allows the user to easily know when it is time to replace the pressing body.

[0021] The replacement means may store usage history data such as the number of times the horn tip has been used, the frequency of use, and the duration of use, and may determine whether it is time to replace the horn tip based on the stored usage history data, and automatically replace the horn tip when it is determined that it is time to replace it. In this way, when it is time to replace the horn tip, the replacement means can automatically replace the horn tip, which is convenient and does not require manual labor.

[0022] According to the present invention, an ultrasonic bonding device equipped with a detachable horn tip can be provided, which has a simple configuration and does not affect the resonant frequency of the ultrasonic vibration, can reduce the loss of ultrasonic vibration energy and heat generation, and can obtain a good bonding finish.

[0023] 1 is a side view of a first embodiment of the ultrasonic bonding device of the present invention; FIG. 2 is a front view of FIG. 1; FIG. 3 is a perspective view of a horn portion which is a part of FIG. 1; FIG. 4 is an enlarged view of a part of FIG. 3; FIG. 5 is a perspective view showing a state in which a horn tip is attached to the horn of FIG. 1; (a) is a front view of a state before the horn tip is attached to the horn of FIG. 1, and (b) is a front view of a state after attachment; FIG. 6 is a graph showing changes in lateral amplitude, vertical amplitude, load under no load, and temperature when the inclination angle of the side surface of the horn tip in the first embodiment is changed; and FIG. 7 is a front view of a part of a second embodiment of the ultrasonic bonding device of the present invention, showing a modified example of the horn tip.

[0024] First Embodiment A first embodiment of an ultrasonic bonding device according to the present invention will be described with reference to FIGS. 1 to 7. FIG.

[0025] 1 and 2 show an ultrasonic bonding device 1, in which objects to be bonded are sandwiched between a support surface 21 of a support body 2 and a horn of a head unit 3 that ultrasonically vibrates in a horizontal direction (the Y-axis direction in FIGS. 1 and 2 ) parallel to the support surface 21, and a pressure means 5 controlled by a control device 4 configured as a microcomputer having a CPU and memory applies pressure to the objects to be bonded (not shown) in the vertical direction (the Z-axis direction) while applying ultrasonic vibration energy in the form of so-called lateral vibration in the left-right direction (the Y-axis direction), thereby bonding the objects to be bonded. Here, the objects to be bonded are stacked metal foils, metal plates, wires, etc., and these objects are not limited to being of the same type, but different types may also be bonded.

[0026] 1 and 2, which is the pressure direction, a mother horn (hereinafter simply referred to as "horn") 32 connected to one end of the vibrator 31, and a support means 33 for supporting the vibrator 31 and the horn 32 so that they can move freely in the up-down direction (Z-axis direction) which is perpendicular to the left-right direction (Y-axis direction), which is the vibration direction. The vibrator 31 ultrasonically vibrates the horn 32, thereby applying ultrasonic vibrations to the objects to be bonded, and the objects to be bonded are bonded. Here, the horn 32 has a detachable horn tip 34, and the vibrator 31 and the horn 32 correspond to the ultrasonic vibration means in the present invention.

[0027] Specifically, the horn 32 resonates with ultrasonic vibrations generated by the vibrator 31 controlled by the control device 4 and ultrasonically vibrates in the left-right direction (the Y-axis direction in FIGS. 1 and 2 ), which is the direction of its central axis. The horn 32 is formed to a length of one wavelength of the resonant frequency so that its approximate center in the Y-axis direction and its two opposite ends have maximum amplitude points. A horn tip 34 made of the same material as the horn 32 is detachably attached to the maximum amplitude point at the center of the horn 32. Two positions spaced a quarter wavelength from each maximum amplitude point in the left-right direction (the Y-axis direction) correspond to first and second minimum amplitude points of the horn 32, respectively, and the horn 32 is supported by support means 33 at these first and second minimum amplitude points. The horn 32 is formed in the shape of a column with a cross section that is, for example, octagonal, and the vibrator 31 is connected to the right end of the horn 32 by a headless screw or the like so that it is coaxial with the central axis of the horn 32.

[0028] Horn 32 may be made of any of a variety of metal materials commonly used to form resonators, such as titanium, titanium alloys, iron, stainless steel, aluminum, and aluminum alloys such as duralumin. Horn 32 is preferably configured so that its resonance frequency is approximately 15 kHz to approximately 60 kHz and its vibration amplitude (the amplitude of expansion and contraction in the Y-axis direction in FIGS. 1 and 2) is approximately 1 μm to approximately 300 μm.

[0029] Support means 33 includes a base 33a, a vertical support pillar 33b (in the Z-axis direction in FIGS. 1 and 2) whose upper end is connected to base 33a, a support portion 33c connected to the lower end of support pillar 33b, and a pair of clamp portions 33d connected to the lower surface of support portion 33c. Support means 33 supports horn 32 by using both clamp portions 33d to grip gripped portions of horn 32 at positions corresponding to the first and second minimum amplitude points.

[0030] Here, each of the clamping portions 33d is made up of two, upper and lower, separable gripping members 33d1 and 33d2, and the upper gripping member 33d1 is fixed to the underside of the support portion 33c, and the upper and lower gripping members 33d1 and 33d2 clamp and grip the gripped portion at positions corresponding to the first and second minimum amplitude points of the horn 32.

[0031] The gripped portion of the horn 32 may be supported by the support means 33 via an elastic member such as an O-ring or a diaphragm.

[0032] The pressure applying means 5 moves the support means 33 that supports the horn 32 in the vertical direction (Z-axis direction), thereby moving the horn 32 in the vertical direction so as to move the horn 32 closer to or further away from the support 2. The pressure applying means 5 includes a drive motor 51, a vertical (Z-axis) ball screw 52 that is rotated by the drive motor 51, a base 53 that is U-shaped in a side view and that rotatably supports the upper and lower ends of the ball screw 52, ​​and a rectangular parallelepiped movable support 54 that has a base 33a of the support means 33 connected to its front side and has a vertical female screw formed in its center and into which the ball screw 52 is threaded.

[0033] The base 53 includes a flat plate portion 53a that is long in the vertical direction (Z-axis direction), horizontal extension portions 53b that are integral with the upper and lower ends of the flat plate portion 53a and rotatably support the upper and lower ends of the ball screw 52, ​​and a vertical (Z-axis) guide rail 53c that is attached to the front side of the flat plate portion 53a between the upper and lower extension portions 53b and along the flat plate portion 53a. Here, the drive motor 51 is placed on the upper surface of the upper extension portion 53b, and the guide rail 53c is inserted into a vertical (Z-axis) guide groove formed on the rear side of the movable support 54. The drive motor 51 is controlled by the control device 4 to rotate, which rotates the ball screw 52, ​​thereby moving the movable support 54 in the vertical direction (Z-axis direction) along the guide rail 53c.

[0034] At this time, movable support 54 moves upward or downward according to the rotation direction of ball screw 52, ​​causing base 33a of support means 33 connected to movable support 54 to move up and down, and horn 32 moves closer to support 2 and away from support 2. Then, the downward movement of base 33a caused by the downward movement of movable support 54 applies pressure to the object to be welded that is held between horn tip 34 attached to horn 32 and support 2.

[0035] Incidentally, a pressure sensor (not shown) constituted by a load cell or the like is provided on the support body 2 or the head portion 3, and the pressure applied by the pressure means 5 to the object to be joined, which is held between the horn tip 34 and the support body 2, is detected by the pressure sensor. Also, a linear encoder 6 (see FIG. 1) is provided on the movable support body 54, which detects the height of the head portion 3 in the vertical direction (Z-axis direction). Here, the control device 4 controls the drive motor 51 based on the detection signal of the linear encoder 6, thereby adjusting the height of the head portion 3 and thereby adjusting the height of the horn 32 relative to the support body 2.

[0036] The most significant feature of the present invention is that the horn tip 34 is detachably attached to the horn 32, as shown in FIG.

[0037] 3 and 4, the top surface (the surface on the positive side of the Z axis) of horn 32, which is the mounting surface, has a groove-like recess 32a for mounting horn tip 34, and horn tip 34 is fitted and fixed into this recess 32a. Horn tip 34 has a deformed hexagonal cross section, that is, a deformed hexagonal shape in which two sides of the side corresponding to the top surface are curved.

[0038] The recess 32a has a bottom surface 32a1 and a pair of opposing inner surfaces 32a2, 32a3, one end of which rises from each of the left and right ends of the bottom surface 32a1 toward the other end, and the pair of opposing inner surfaces 32a2, 32a3 are inclined so that the distance between the other ends of the pair of opposing inner surfaces 32a2, 32a3 is greater than the distance between the one ends. Here, the inclination angle of each of the pair of opposing inner surfaces 32a2, 32a3 from one end to the other end is 30 degrees within a range of 20 degrees to 60 degrees.

[0039] The horn tip 34 has an attachment portion 34a and a pressing surface 34b. The attachment portion 34a is fitted into the recess 32a of the horn 32 and then detachably fixed to the horn 32 by a bolt B, which serves as a fixing means. The pressing surface 34b is provided on the attachment portion 34a and presses the workpiece. The attachment portion 34a also has a bottom surface 34a1 that faces the bottom surface 32a1 of the recess 32a, and two side surfaces 34a2 and 34a3 that are continuous with the bottom surface 34a1 and are in surface contact with the pair of opposing inner surfaces 32a2 and 32a3 of the recess 32a, respectively. These two side surfaces 34a2 and 34a3 are inclined at the same inclination angle of 30° as the pair of opposing inner surfaces 32a2 and 32a3. Here, the bottom surface 34a1 and the upper surface facing it are parallel, and this upper surface corresponds to the pressing surface 34b.

[0040] 5 and 6, the horn tip 34 is detachably attached to the horn 32 by two bolts B. Two circular-section through-holes 32b are formed in the surface of the horn 32 opposite the surface on which the recess 32a is formed, aligned in the X-axis direction, and penetrate vertically. Bolts B are inserted into these through-holes 32b, extending in the vertical direction. Each through-hole 32b also has an enlarged-diameter portion 32b1 into which the bolt head fits so that it does not protrude.

[0041] Furthermore, two threaded holes 34c are formed in the bottom surface 34a1 of the horn tip 34, each communicating with the upper end of one of the two insertion holes 32b. These threaded holes 34c communicate with the corresponding insertion holes 32b when the horn tip 34 is fitted into the recess 32a. With the threaded holes 34c and the insertion holes 32b communicating, the tip of a bolt B is threaded into the threaded hole 34c, thereby fixing the horn tip 34 in the recess 32a of the horn 32. Here, the bolt B, the insertion holes 32b, and the threaded hole 34c correspond to the "fixing means" in the present invention. The number of locations where the horn tip 34 is fixed is not limited to two, and it may be fixed by the bolt B at one location or three or more locations.

[0042] Here, the advantages of setting the inclination angle of the pair of opposing inner surfaces 32a2, 32s3 of the recess 32a of the horn 32 and the side surfaces 34a2, 34a3 of the horn tip 34 to 30°, which is the most preferable angle within the range of 20° to 60°, will be described.

[0043] When the inclination angles of the pair of opposing inner surfaces 32a2, 32a3 of the recess 32a of the horn 32 and the side surfaces 34a2, 34a3 of the horn tip 34 were changed to 20°, 30°, 40°, 50°, 60°, and 70°, the lateral amplitude (μm) of the horn tip 34 in the Y-axis direction (see FIGS. 3 and 4), the longitudinal amplitude (μm) of the horn tip 34 in the Z-axis direction (see FIGS. 3 and 4), the load (watts) under no load, and the temperature (°C) of the horn tip 34 were measured. The results are shown in FIG. 7. The temperature was measured using a temperature sensor attached to the horn tip 34.

[0044] First, regarding the lateral amplitude, as shown in Figure 7, the lateral amplitude hardly changes when the tilt angle is changed, but when the tilt angle is between 20° and 30°, the lateral amplitude reaches a minimum of approximately 75 μm, and when the tilt angle is 40° or more, the lateral amplitude gradually increases. This is thought to be an increase in lateral amplitude due to abnormal vibration. Therefore, when the tilt angle is between 20° and 30°, the lateral amplitude is the smallest and most preferable, but from the perspective of the allowable range, it can be said that any tilt angle between 20° and 60° is usable.

[0045] Next, regarding the longitudinal amplitude, as shown in Figure 7, the longitudinal amplitude is smallest at approximately 2.5 μm when the tilt angle is between 30° and 40°, and when the tilt angle is 70°, the longitudinal amplitude increases to approximately 14 μm, almost double the approximately 7 μm at 60°. This is thought to be because when ultrasonic vibrations are applied in the Y-axis direction (see Figures 3 and 4), which are lateral vibrations for bonding, a misalignment occurs between the pair of opposing inner surfaces 32a2, 32s3 of the recess 32a, which should be in surface contact, and the side surfaces 34a2, 34a3 of the horn tip 34, respectively, preventing complete surface contact, and increasing the longitudinal amplitude of the horn tip 34 in the Z-axis direction. Therefore, a tilt angle of 30° to 40° is most preferable because it does not increase the longitudinal amplitude, but from the perspective of the allowable range, a tilt angle in the range of 20° to 60° can be used.

[0046] Furthermore, as shown in Figure 7, the load (watts) in a so-called no-load state, when the workpieces to be bonded are not actually sandwiched between the support 2 and the horn 32, is smallest at about 20 watts when the tilt angle is 20° to 30°, gradually increases when the tilt angle is 40° or more, and reaches about 80 watts when the tilt angle is 70°. This is because it is thought that as the load in the no-load state increases, this amount becomes energy loss and the load (energy) available for bonding decreases. Therefore, if the tilt angle is in the range of 20° to 30°, the load in the no-load state is small and the energy available for bonding can be increased. Therefore, a tilt angle of 20° to 30° is most preferable because it is possible to reduce the load in the no-load state and increase the energy available for bonding, and from the perspective of the allowable range, a tilt angle in the range of 20° to 60° can be said to be usable.

[0047] Furthermore, regarding heat generation at the horn tip 34, it can be seen that the temperature of the horn tip 34 is lowest at approximately 25°C when the tilt angle is in the range of 20° to 30°, and that as the tilt angle becomes 40° or greater, the temperature gradually rises, increasing the heat generation at the horn tip 34. Therefore, a tilt angle of 20° to 30° is most preferable because it keeps the temperature of the horn tip 34 low, but from the perspective of the allowable range, any tilt angle in the range of 20° to 60° can be said to be usable.

[0048] From the data shown in Figure 7, it can be seen that the inclination angles of the pair of opposing inner surfaces 32a2, 32s3 of the recess 32a of the horn 32 and the side surfaces 34a2, 34a3 of the horn tip 34 should be set in the range of 20° to 60°, with the most preferable inclination angle being 30°.

[0049] As shown in Figure 3, the horn tip 34 is attached to the horn 32, which has a length of one wavelength of the ultrasonic vibration, at the position of the maximum amplitude. It has a width W of ¼ to ¼0 wavelength in the Y-axis direction, which is the longitudinal direction of the horn 32, and a length L of ½ to ½4 wavelength in the X-axis direction, which is perpendicular to the longitudinal direction (Y-axis) of the horn 32. Setting the dimensions of the horn tip 34 in this manner eliminates the risk of shifting the resonant frequency of the ultrasonic vibration, as occurs when the width W of the horn tip 34 is greater than ¼ wavelength, and prevents a situation in which the joining width is too small to achieve the desired joining finish, as occurs when the width W is shorter than ¼0 wavelength. Furthermore, if the horn tip has a length L of ½ to ½4 wavelength in the X-axis direction, which is perpendicular to the longitudinal direction of the horn, a sufficiently large horn tip can achieve a good joining finish without affecting the resonant frequency of the ultrasonic vibration.

[0050] For example, when the ultrasonic vibration frequency is 20 kHz and the wavelength determined by the composition of the horn 32 is 240 mm, the width W of the horn tip 34 is 60 mm at 1 / 4 wavelength and 6 mm at 1 / 40 wavelength, and the length L of the horn tip 34 is 120 mm at 1 / 2 wavelength and 10 mm at 1 / 24 wavelength.

[0051] As shown in FIG. 4 , two ventilation holes 36 are formed in the X-axis direction at the upper end of the horn 32, sandwiching the recess 32a. A ventilation hole 37 is also formed in the X-axis direction at approximately the center of the horn tip 34. Cooling air is blown in one direction through these ventilation holes 36, 37 during the joining operation. The cooling air can be blown by a blowing means (not shown). This cools the horn 32 and horn tip 34, which generate heat during joining, thereby enabling stable, continuous joining. Here, the ventilation holes 36, 37 and the blowing means correspond to the "cooling device" in this invention. It is also possible to omit these ventilation holes and instead blow cooling air from the blowing means directly onto the horn 32 and horn tip 34 for cooling.

[0052] 3, 5, and 6, the horn 32 is further provided with a storage means 38 into which usage history data such as the number of times, frequency, and duration of use of the horn tip 34 is written. The data is written readably by the writing function of the control device 4 via communications. The control device 4 reads the usage history data from the storage means 38 via its communications function and determines when it is time to replace the horn tip 34 based on the read data. The control device 4 is also provided with an alarm function that alerts the user to the need to replace the horn tip 34 by sound or by lighting a lamp. Here, the storage means 38 is preferably configured using an IC chip, RFID, or the like with communications capabilities.

[0053] In this way, by providing the memory means 38, the control device 4 determines and notifies the user when it is time to replace the horn tip 34 based on the usage history data read from the memory means 38, so the user can easily know when it is time to replace the horn tip 34, which is very convenient.

[0054] Therefore, according to the first embodiment, the pair of opposing inner surfaces 32a2, 32a3 of the recess of horn 32 are inclined so that the distance between the other ends is greater than the distance between the one ends, the inclination angle of each of the pair of opposing inner surfaces 32a2, 32a3 is 30 degrees within a range of 20 degrees to 60 degrees from one end to the other, and the two side surfaces 34a2, 34a3 that come into surface contact with the pair of opposing inner surfaces 32a2, 32a3 of recess 32a of mounting portion 34a of horn tip 34 are inclined at the same inclination angle as the pair of opposing inner surfaces 32a2, 32a3 of the recess. Therefore, compared to when the inclination angle is less than 20 degrees or more than 60 degrees, the longitudinal vibration component of the ultrasonic vibration of horn tip 34 in a direction perpendicular to the center line of the horn is smaller, and ultrasonic vibration energy loss and heat generation can be reduced, making it possible to obtain a good joint finish without affecting the resonance frequency of the ultrasonic vibration.

[0055] Furthermore, since the bottom surface 34a1 of the mounting portion 34a of the horn tip 34 in the attached state is separated from the bottom surface 32a1 of the recess 32a of the horn 32 with a gap therebetween, the side surfaces 34a2, 34a3 of the horn tip 34 can be in firm surface contact with the opposing inner surfaces 32a2, 32a3 of the recess 32a of the horn 32, and the surface contact state can be firmly maintained, thereby reducing the loss of ultrasonic vibration energy and heat generation.

[0056] Furthermore, if the horn tip 34 has a width of ¼ to 1 / 40 of a wavelength in the longitudinal direction of the horn 32, there is no risk of the resonant frequency due to ultrasonic vibrations being shifted, as occurs when the width W of the horn tip 34 is longer than ¼ of a wavelength, and it is possible to prevent a situation in which the joining width is too small to achieve the desired joining finish, as occurs when the width W is shorter than 1 / 40 of a wavelength. Furthermore, if the horn tip 34 has a length L of ½ to 1 / 24 of a wavelength in the direction perpendicular to the longitudinal direction of the horn 32, a sufficiently large horn tip 34 can achieve a good joining finish without affecting the resonant frequency of the ultrasonic vibrations.

[0057] Furthermore, the cooling device can effectively cool the horn 32 and the horn tip 34, making it possible to stably perform continuous joining.

[0058] In addition, the usage history data of the horn tip 34 is written readably into the memory means 38 provided in the horn 32 by the writing function of the control device 4 via communication, and based on the usage history data read from the memory means 38 by the control device 4, the control device 4 determines when it is time to replace the horn tip 34 and notifies the worker, so that the worker can easily know when it is time to replace the horn tip 34, which is very convenient.

[0059] 8, as a modification of the horn tip 34, a horn tip 341 may be formed having a hexagonal cross section without curved sides, rather than a modified hexagonal cross section as in the first embodiment, and the mounting portion 341a of the horn tip 341 may be fitted into the recess 32a of the horn 32 for detachable attachment. In this case, it is preferable to provide a gap between the bottom surface of the mounting portion 341a of the horn tip 341 and the bottom surface 32a1 of the recess 32a of the horn 32. With this modification, the entire upper surface of the horn tip 341 serves as a pressing surface 341b, making it possible to apply the modification to bonding with a large bonding width (bonding area).

[0060] Second Embodiment A second embodiment of the ultrasonic bonding device of the present invention will be described with reference to Fig. 9. Note that the second embodiment differs from the first embodiment in the shape of the horn tip and the configuration of the fixing means for fixing the horn tip, but the other configurations are the same as those of the first embodiment. Therefore, the following description will mainly focus on the differences from the first embodiment.

[0061] The second embodiment differs from the first embodiment described above in that, as shown in Figure 9, a similar recess 32a is formed on the other side of the horn 32 opposite the side on which the recess 32a is formed, and two horn tips 342 are prepared, each having, for example, a trapezoid mounting portion 342a and a rectangular parallelepiped pressing portion 342b having a pressing surface in the center of one side of the mounting portion 342a, and the mounting portions 342a of the two horn tips 342 are fitted into the two recesses 32a, respectively, and the horn tip 342 is removably fixed to the horn 32 from the pressing portion 342b side of the horn tip 342 by two bolts B on both sides of the pressing portion 342b.

[0062] Here, insertion holes 40 are formed at two positions sandwiching the pressing portion 342b of the horn tip 342, and threaded holes 41 are formed in the bottom surface 32a1 of the recess 32a of the horn 32 so as to communicate with these insertion holes 40. With the horn tip 342 fitted into the recess 32a, bolts B are inserted through both insertion holes 40 and screwed into the threaded holes 41 to secure the horn tip 342 to the horn 32. At this time, the horn tip 342 is secured so that there is a gap between the bottom surface of the horn tip 342 and the bottom surface of the recess 32a of the horn 32.

[0063] According to the second embodiment, it is possible to achieve the same effects as the first embodiment described above, and in addition, even if one horn tip 342 needs to be replaced, the other horn tip 342 can be used for a new joining operation, and when both horn tips 342 need to be replaced, both horn tips 342 can be replaced at the same time, thereby reducing the number of times that the horn tips 342 need to be replaced. In this case, the areas of the pressing surfaces of both horn tips 342 may be different, which makes it easy to join parts with different joining areas.

[0064] The present invention is not limited to the above-described embodiment, and various modifications other than those described above are possible without departing from the spirit of the present invention. For example, in the above-described embodiment, the fixing means is described as a bolt, but the fixing means is not limited to a bolt.

[0065] For example, the first embodiment described above may further include a sensor that detects the bolt B, and an exchange means that detects the bolt B using the sensor, rotates the bolt B in the direction opposite to the threading direction to unscrew it, removes the horn tip 34 from the horn 32, and automatically replaces it with a new horn tip 34. In this case, when the control device 4 notifies that it is time to replace the horn tip, the exchange means can be driven to unscrew the bolt B and automatically replace the horn tip 34, thereby improving the efficiency of the joining work.

[0066] In this case, the replacement means may have a function to determine when it is time to replace the horn tip 34 based on usage history data such as the number of times, frequency, and duration of use of the horn tip 34 stored in the storage means 38, and a function to automatically replace the horn tip 34 when it is determined that it is time to replace it. In this way, it is possible to automatically determine when it is time to replace the horn tip 34, and also to automatically replace the horn tip by the replacement means when it is time to replace it, which is extremely convenient and does not require any manual labor.

[0067] In the above embodiment, the horn 32 and the horn tip 34 are formed from the same material, but the horn 32 and the horn tip 34 may be formed from different materials. In this case, if the horn 32 and the horn tip 34 are formed from different materials, the horn tip 34 can be made from a material stronger than the horn 32, which can extend the replacement interval for the horn tip 34 and reduce costs, compared to when the horn 32 and the horn tip 34 are formed from the same material.

[0068] Furthermore, in the above embodiment, the pressing surface 34b of the horn tip 34 is described as a flat surface, but the pressing surface 34b may be formed with an uneven pattern corresponding to the joining finish of the workpieces, for example, consisting of an arrangement of a large number of quadrangular pyramids.

[0069] The cooling device for cooling the horn tip is not limited to the above-described configuration in which cooling air is blown through the ventilation holes or the configuration in which cooling air is blown directly onto the horn and horn tip. For example, cooling may be performed using a Peltier element.

[0070] Furthermore, when a plurality of (three or more) horn tips are attached to the horn 32, the pressing surface area of ​​each horn tip may be the same or different.

[0071] In the above embodiment, the data stored in the storage means 38 includes usage history data such as the number of uses, frequency of use, and duration of use of the pressing body, but other data such as the pattern of the pressing surface, the limit frequency of use based on the composition of the horn tip, and the bonding area that the pressing surface can bond may also be stored. Note that peak values ​​such as the power and energy of the ultrasonic vibrations and the relative amount of pressing by the pressure means may also be stored in the storage means 38, which makes it possible to achieve bonding under optimal bonding conditions derived using AI (artificial intelligence).

[0072] Furthermore, such storage means is not limited to an IC chip or RFID with communication function provided in the horn 32, but may be provided with a two-dimensional barcode or QR code (registered trademark) on the horn 32 side that makes it possible to identify unique data such as the limit usage frequency of the horn 32 and the pressing surface pattern of the horn 32, and storage means for storing usage history data of the pressing body attached to the horn 32 may be provided on the control device 4 side, and the barcode of the horn 32 may be read by a reading means and the storage data of the corresponding pressing body may be extracted from the storage data of the storage means to manage the usage history.

[0073] The present invention can be applied to an ultrasonic bonding apparatus that bonds objects to be bonded by pressing them while applying ultrasonic vibrations.

[0074] DESCRIPTION OF SYMBOLS 1 ... ultrasonic bonding device 2 ... support 4 ... control device (alert means) 5 ... pressure means 31 ... vibrator (ultrasonic vibration means) 32 ... horn (ultrasonic vibration means) 32a ... recess 32a1 ... bottom surface 32a2, 32a3 ... opposing inner surface 32b ... insertion hole 34, 341, 342 ... horn tip 34a, 341a, 342a ... mounting portion 34b, 341b ... pressing surface 342b ... pressing portion 34a1, 341a1, 342a1 ... bottom surface 34a2, 34a3 ... side surface 34c ... screw hole 36, 37 ... ventilation hole (cooling device) 38 ... memory means B ... bolt (fixing means)

Claims

1. An ultrasonic bonding device for bonding objects by pressing them while applying ultrasonic vibrations, comprising: a support for supporting the objects to be bonded; ultrasonic vibration means having a vibrator and a horn; a horn tip that is detachably attached to the horn and to which ultrasonic vibrations are applied by the ultrasonic vibration means while the objects to be bonded are sandwiched and pressed between the horn tip and the support; and pressure means that presses and applies pressure to the objects to be bonded sandwiched between the ultrasonically vibrating horn tip and the support, the horn tip having an attachment part that is fitted into a recess formed in the shape of a groove in the attachment surface of the horn and is detachably fixed to the horn by fixing means, and a pressure surface that is provided on the attachment part and presses the objects to be bonded, the recess having a bottom surface and a pair of opposing inner surfaces, one end of which rises from each end of the bottom surface toward the other end, an ultrasonic bonding device, characterized in that each of the pair of opposing inner surfaces is inclined so that the distance between the other ends of the pair of opposing inner surfaces is larger than the distance between the one ends thereof, and the inclination angle of each of the pair of opposing inner surfaces is the same angle within a range of 20° to 60° from the one end to the other end; the mounting portion has a bottom surface facing the bottom surface of the recess, and two side surfaces that are continuous with the bottom surface and in surface contact with each of the pair of opposing inner surfaces of the recess; and the two side surfaces of the mounting portion that are in surface contact with each of the pair of opposing inner surfaces are inclined at the same inclination angle as each of the pair of opposing inner surfaces.

2. The ultrasonic bonding device according to claim 1, wherein the horn tip is fixed to the horn with a gap between the bottom surface of the mounting portion and the bottom surface of the recess.

3. The ultrasonic bonding device according to claim 1 or 2, characterized in that the horn is formed to a length of approximately one wavelength of the ultrasonic vibrations produced by the ultrasonic vibration means and has a maximum amplitude point in the center, and the horn tip is attached to the horn at the position of the maximum amplitude point and has a width of 1 / 4 wavelength to 1 / 40 wavelength in the longitudinal direction of the horn.

4. The ultrasonic bonding device according to claim 3, wherein the horn tip has a length of 1 / 2 wavelength to 1 / 24 wavelength in a direction perpendicular to the longitudinal direction of the horn.

5. The ultrasonic bonding apparatus according to claim 1, further comprising a cooling device for cooling the horn tip and the vicinity of the attachment portion of the horn while the horn tip is attached to the horn.

6. The ultrasonic bonding device according to claim 5, characterized in that the cooling device blows cooling air into a ventilation hole provided through the horn tip and a ventilation hole provided near the mounting portion of the horn.

7. The ultrasonic bonding device according to claim 1, characterized in that the fixing means comprises: an insertion hole formed on the side of the horn opposite to the side where the horn tip is attached; a screw hole formed in the horn tip; and a bolt that is inserted into the insertion hole and threaded into the screw hole to fix the horn tip to the horn.

8. The ultrasonic bonding device according to claim 7, further comprising an exchange means for detecting the bolt, rotating the bolt in the opposite direction to the bolt's threading direction to unscrew it, removing the horn tip from the horn, and automatically replacing it with a new horn tip.

9. The ultrasonic bonding device according to claim 1, wherein the horn tips are attached to at least two surfaces of the horn in the longitudinal direction.

10. The ultrasonic bonding apparatus of claim 1, wherein the horn and the horn tip are made of different materials.

11. The ultrasonic bonding device according to claim 1, further comprising: a storage means provided in the horn in which usage history data such as the number of times the horn tip has been used, usage frequency, and usage time is readably written; and a notification means for determining when it is time to replace the horn tip based on the usage history data read from the storage means and notifying the user.

12. The ultrasonic bonding device according to claim 8, characterized in that the replacement means stores usage history data such as the number of times the horn tip has been used, the frequency of use, and the duration of use, determines whether it is time to replace the horn tip based on the stored usage history data, and automatically replaces the horn tip when it determines that it is time to replace it.

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