Ultrasonic cutter online cleaning and peening system and method, and ultrasonic wedge bonder

Abstract

An ultrasonic cutter online cleaning and peening system, an ultrasonic cutter online cleaning and peening method, and an ultrasonic wedge bonder. The system comprises a laser cleaning and peening device and a cutter detection device; the laser cleaning and peening device comprises a laser head (5) that is connected to a laser generator (3) by means of an optical fiber (4), and the laser head (5) irradiates laser light onto an ultrasonic cutter to be cleaned, so as to perform laser cleaning and laser shock peening; the cutter detection device is in signal connection with the laser generator (3), and detects the surface cleanliness condition of a working area of the ultrasonic cutter to be cleaned, and when the surface cleanliness condition exceeds a preset range, the cutter detection device outputs a signal to instruct the laser cleaning and peening device to perform laser cleaning. The ultrasonic cutter online cleaning and peening system can perform online non-contact cleaning and peening on the ultrasonic cutter, thereby improving the production efficiency and quality of ultrasonic processing, and prolonging the service life of the cutter.

Description

An ultrasonic tool on-line cleaning and strengthening system and method, and an ultrasonic wedge bonding machine TECHNICAL FIELD

[0001] The present application belongs to the field of ultrasonic cutting and welding, and particularly relates to an ultrasonic tool on-line cleaning and strengthening system and method, and an ultrasonic wedge bonding machine. BACKGROUND

[0002] After continuous work, the end of an ultrasonic tool will have adhesion residues of the processed metal, such as aluminum accumulation at the end of a wedge bonding machine splitting knife. When the residues accumulate to a certain extent, they are prone to fall off during the continuous work of the ultrasonic splitting knife, which may damage the product and affect the energy transmission efficiency of the ultrasonic splitting knife and the processing quality. Currently, the ultrasonic tool needs to be regularly disassembled for off-line cleaning and then reassembled, which not only causes the production line to stop and affects the production efficiency, but also may introduce assembly errors during the disassembly and assembly of the ultrasonic splitting knife, which is not conducive to production stability. Therefore, providing an ultrasonic tool on-line cleaning and strengthening system has a positive significance for improving the efficiency of ultrasonic processing continuous production and improving production quality.

[0003] SUMMARY

[0004] The present application aims to provide an ultrasonic tool on-line cleaning and strengthening system for cleaning and maintaining the ultrasonic tool on-line. The present application also provides an ultrasonic tool on-line cleaning method and an ultrasonic wedge bonding machine.

[0005] According to an embodiment of one aspect of the present application, an ultrasonic tool on-line cleaning and strengthening system is provided, comprising a laser cleaning and strengthening device and a tool detection device; wherein the laser cleaning and strengthening device comprises a laser generator, an optical fiber, and a laser head, the laser generator generates laser, the optical fiber is connected to the laser generator and guides the laser to one or more laser heads, and the laser head irradiates the laser to the ultrasonic tool to be cleaned; the tool detection device is connected to the laser cleaning and strengthening device, the tool detection device detects the cleaning state of the working area of the ultrasonic tool to be cleaned, and when the cleaning state of the ultrasonic tool to be cleaned exceeds a preset range, the tool detection device sends a signal instruction to the laser cleaning and strengthening device to perform laser cleaning and strengthening.

[0006] The system can use the laser cleaning and strengthening device to perform on-line cleaning of the ultrasonic tool to replace physical grinding or chemical immersion cleaning, without the need to disassemble the ultrasonic tool, thereby avoiding the time consumption caused by off-line cleaning and the assembly errors caused by reassembly after cleaning. The laser pulse can not only vaporize and clean the metal adhesion in the working area, but also strengthen the surface of the working area in the form of laser impact, thereby prolonging the service life of the ultrasonic tool.

[0007] Further, in some embodiments, the laser head outputs laser energy of 5J-9J and pulse width of 10ns-20ns.

[0008] Further, in some embodiments, the tool detection device comprises a visual recognition device configured to capture an image of a working area of the ultrasonic tool to be cleaned, and the cleaning state is configured as an image of the residual metal adhesion state of the working area.

[0009] Further, in some embodiments, the visual recognition device is installed with an ultrasonic tool visual recognition model trained by preset image samples of different residual metal adhesion states of the working area, and is capable of automatically recognizing the residual metal adhesion state of the working area.

[0010] Further, in some embodiments, the tool detection device further comprises an unloaded detection device configured to detect an unloaded working state of the ultrasonic tool to be cleaned, and the detection method of the cleaning state further comprises detecting the change of the unloaded working state caused by the residual metal adhesion of the working area.

[0011] Further, in some embodiments, the unloaded working state comprises one or more of the resonant frequency, resonant current and impedance of the transducer of the ultrasonic tool to be cleaned excited by an unloaded test voltage in the unloaded state.

[0012] Further, in some embodiments, the unloaded test voltage is configured as 10%-30% of the normal working voltage.

[0013] Further, in some embodiments, the tool detection device further comprises a post-visual recognition device configured to visually recognize a product state processed by the ultrasonic tool to be cleaned, and when the product state exceeds a preset range, the tool detection device sends a signal instruction to the laser cleaning and strengthening device to perform laser cleaning and strengthening.

[0014] According to embodiments of another aspect of the present application, there is provided an ultrasonic tool online cleaning method, which uses the ultrasonic tool online cleaning and strengthening system provided in any of the above embodiments, and comprises the following steps:

[0015] Step a) detecting the cleaning state of the working area of the ultrasonic tool to be cleaned by the tool detecting device, when the cleaning state is not beyond the preset range, executing step b); when the cleaning state is beyond the preset range, performing laser cleaning on the working area by the laser cleaning intensifying device until the cleaning state is not beyond the preset range, executing step b);

[0016] Step b) performing ultrasonic working operation and returning to step a) after the working cycle is finished.

[0017] Further, in some embodiments, step a) further comprises a counting step and a counting checking step, when the cleaning state is beyond the preset range, the count is increased by 1, and before performing laser cleaning, checking whether the count is beyond a given threshold, when the count is beyond the given threshold, stopping laser cleaning and replacing the ultrasonic tool to be cleaned and resetting the count.

[0018] Further, in some embodiments, in step a), when performing laser cleaning on the working area, further comprises a step of laser intensifying the working area.

[0019] According to another aspect of the embodiments of the present application, a wedge bonding machine is provided, comprising an ultrasonic assembly and a wedge tool, the ultrasonic assembly drives the wedge tool to perform ultrasonic welding, further comprising an online cleaning system for cleaning the wedge tool, the online cleaning system adopts the ultrasonic tool online cleaning intensifying system provided in any of the preceding embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0020] Fig. 1 is a schematic diagram of the structure of an ultrasonic wedge bonding machine in an embodiment;

[0021] Figs. 2a to 2d are photos of gradually increasing aluminum adhesion in the working area of a wedge tool in an embodiment;

[0022] Fig. 3a is a photo of the working area of a wedge tool with aluminum adhesion in an embodiment;

[0023] Fig. 3b is a photo of the working area of a wedge tool after laser cleaning in an embodiment;

[0024] Fig. 4a is an impedance curve corresponding to Fig. 3a in an empty load test;

[0025] Fig. 4b is an impedance curve corresponding to Fig. 3b in an empty load test;

[0026] Fig. 5 is a photo of a welding sample of a wedge bonding machine in an embodiment.

[0027] Meaning of reference signs: 1-wedge tool; 2-ultrasonic assembly; 3-laser generator; 4-optical fiber; 5-laser head; 6-aluminum adhesion; 7-welding defect.

[0028] The above drawings are intended to provide a detailed description of the present application so that those skilled in the art can understand the technical concept of the present application, and are not intended to limit the present application. In order to express concisely, the above drawings only schematically draw the structures related to the technical features of the present application, and do not strictly draw the complete structures and all details according to the actual proportions. DETAILED DESCRIPTION

[0029] The present application will be further described in detail through specific examples in combination with the drawings.

[0030] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase that the phrase in various places in the specification are not necessarily referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of one another. Those skilled in the art will appreciate from the present description that various embodiments of the application can comprise combinations of features from the described embodiments.

[0031] In the description herein, unless otherwise explicitly specified and limited, the technical terms "mount", "connect", "connection" and the like should be understood in a broad sense, which can be active connection, or fixed connection or integrated. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0032] In the description herein, the terms indicating the orientation or position relationship such as "upper", "lower", "left", "right", "transverse", "longitudinal", "height", "length", "width" and the like are intended to accurately describe the embodiments and simplify the description, and are not intended to limit the parts or structures involved to have a specific orientation, to be installed or operated in a specific orientation, and cannot be understood as limiting the embodiments herein.

[0033] In the description herein, the terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating relative importance or limiting the number, specific order or primary and secondary relationship of the described technical features. In the description herein, the meaning of "a plurality of" is at least two.

[0034] The ultrasonic tool for metal processing such as welding or cutting transmits high-frequency mechanical vibration to the metal to be processed by the ultrasonic tool to achieve welding or cutting. The ultrasonic tool is usually made of high-melting-point metal such as tungsten alloy or tungsten steel, and the metal to be processed is usually low-melting-point alloy such as aluminum. In the processing process, the part of the ultrasonic tool in contact with the metal is easy to adhere, which causes part of the processed metal to adhere to the working area of the ultrasonic tool, which on the one hand affects the efficiency of ultrasonic energy transmission, and on the other hand, the adhered metal accumulated with the working of the ultrasonic tool may fall off at random, which has the risk of damaging the processed parts.

[0035] Currently, for the adhesion of metal, offline cleaning is usually adopted. For example, for the ultrasonic tool accumulation of aluminum caused by aluminum processing, the tool needs to be disassembled and immersed in a 20% concentration of sodium hydroxide solution for ultrasonic cleaning. After cleaning, it is rinsed and dried, and finally the tool is reassembled and calibrated. This process requires a lot of time to disassemble and install, and the production line must be stopped during tool cleaning. Moreover, due to the inevitable installation error during reassembly, offline cleaning of the tool is not conducive to the stability of the production line.

[0036] To solve the above problems, an embodiment of one aspect of the present application provides an ultrasonic tool online cleaning and strengthening system, comprising a laser cleaning and strengthening device and a tool detection device. The laser cleaning and strengthening device comprises a laser generator and a laser head connected by an optical fiber. The laser generator generates laser which is conducted to the laser head by the optical fiber. The laser head irradiates the ultrasonic tool to be cleaned with laser, and the metal adhered to the tool is vaporized by the energy of the laser to achieve laser cleaning. At the same time, the laser pulse can produce a strengthening effect on the working area. In different embodiments, the laser generator can be connected to one or more laser heads through an optical fiber. In a preferred embodiment, the laser head outputs laser energy of 5J-9J, pulse width of 10ns-20ns, and can output at least three consecutive laser pulses.

[0037] In a preferred embodiment, the tool detection device comprises a visual recognition device which can take an image of the working area of the ultrasonic tool to be cleaned and identify the adhesion of residual metal in the working area. According to the adhesion of residual metal, it is determined whether laser cleaning needs to be performed. The visual recognition device can be installed with a visual recognition model which is trained based on a pre-set image sample of the working area residual metal adhesion state, and can automatically identify the working area residual metal adhesion state and determine whether laser cleaning needs to be performed. In a further preferred embodiment, the tool detection device further comprises an empty load detection device which detects the empty load working state of the ultrasonic tool to be cleaned, such as the resonant frequency, resonant current and impedance under the excitation of the empty load test voltage, and determines whether laser cleaning needs to be performed according to the change of the empty load working state caused by the adhesion of residual metal in the working area. In a further preferred embodiment, the empty load test voltage is 10%-30% of the normal working voltage.

[0038] In some embodiments, the ultrasonic tool online cleaning and strengthening system is used for an ultrasonic wedge bonding machine.

[0039] In a preferred embodiment, the structure of the ultrasonic wedge bonding machine is shown in Fig. 1, and in the working state, the ultrasonic assembly 2 drives the cleaver 1 to perform aluminum welding, wherein the cleaver 1 is made of high-melting-point tungsten alloy. As the cleaver 1 continues to work, the aluminum adhesion 6 on the working area of the cleaver 1 gradually increases, which affects the transmission of ultrasonic energy and the welding effect, and excessive aluminum adhesion 6 will also fall off under high-frequency vibration, causing damage to the welded workpiece and causing scrap.

[0040] Therefore, the ultrasonic wedge bonding machine is configured with an ultrasonic online cleaning system, which includes a laser generator 3 and a laser head 5 connected to the laser generator 3 through an optical fiber 4. The laser generator 3 generates laser pulses, which are conducted to the laser head 5 through the optical fiber 4 to irradiate the cleaver 1 for laser cleaning. In a preferred embodiment, the energy of a single laser pulse is 5J-9J, and the pulse width is 10ns-20ns. When the laser spot irradiates the working area of the cleaver 1, the aluminum adhesion 6 will be gasified under the action of high-energy laser pulses, achieving cleaning of the working area of the cleaver 1.

[0041] The ultrasonic online cleaning system also includes a tool detection device (not shown), which includes a visual recognition device including an industrial camera and a processor installed with a tool visual recognition model. During the welding operation, the industrial camera takes an image of the working area of the cleaver 1 after completing a cycle of welding operation, and the image is processed and recognized by the tool visual recognition model to automatically determine whether laser cleaning is needed. In a preferred embodiment, the tool visual recognition model is based on an artificial intelligence algorithm, and is trained using image samples of the working area of the cleaver 1 marked by artificial labels, and the label content is whether the cleaver 1 needs to be laser cleaned. Specifically, when establishing image samples, the cleaver 1 can be continuously welded, and the working area images at different stages can be taken, and the images of the working area can be marked by artificial according to the welding quality. The training work of the tool visual recognition model can be preloaded during the manufacture of the tool detection device, or can be completed using the data accumulated during the production process after the tool detection device is deployed on the production line. In a preferred embodiment, the tool visual recognition model is pre-trained using multiple different models and specifications of the cleaver 1 to improve compatibility. In some embodiments, the image of the working area of the cleaver 1 can also be monitored by artificial recognition to determine whether laser cleaning is needed.

[0042] In the preferred embodiment, the tool detection device further comprises an idle detection device connected to the transducer signal in the ultrasonic assembly 2, which can detect the change of working state of the cleaving knife 1 in the idle state. In the idle test, the transducer is excited at 10%-30% of the normal working excitation voltage to detect the parameters such as resonance frequency, resonance current or impedance, which are compared with the standard data in the aluminum adhesion-free state, and then the parameter changes caused by aluminum adhesion are judged. As shown in FIG. 3a, in the case that there is a large amount of aluminum adhesion 6 in the working area of the cleaving knife 1, the impedance curve in the idle test is shown in FIG. 4a, which is significantly increased at the beginning of the test, and then tends to decrease as the bonding force between the aluminum adhesion and the cleaving knife 1 is weakened after the ultrasonic vibration is excited. After the laser cleaning of the cleaving knife 1 removes the aluminum adhesion 6, as shown in FIG. 3b, the impedance curve obtained by the idle test is shown in FIG. 4b, which shows that the impedance reaches a peak value and basically does not change after the excitation starts. The threshold value of the idle detection device can be set to instruct the laser cleaning when the measured data exceeds the threshold value.

[0043] In the preferred embodiment, the tool detection device further comprises a post-weld detection device as a rear-end visual recognition device, which takes pictures and visually recognizes the product welded by the cleaving knife 1, as shown in FIG. 5, when there is a welding defect 7 (including crushing, roughness, and significant flash) in it, the tool detection device can send a signal to instruct the laser cleaning. The visual recognition process of the post-weld detection device can be assisted by manual intervention, or a trained visual recognition model can be used.

[0044] In different embodiments, the control logic of the idle detection device, the visual recognition device and the post-weld visual recognition device for laser cleaning can be an "and" relationship or an "or" relationship.

[0045] In the preferred embodiment, the ultrasonic wedge bonding machine is provided with a working station and a cleaning station. The cleaving knife 1 performs welding work on the workpiece to be processed on the working station. When the tool detection device detects that the cleaving knife 1 needs to be cleaned, the cleaving knife 1 is transferred to the cleaning station by the driving system. The angle of the laser head 5 on the cleaning station can be preset to irradiate the working area of the cleaving knife 1, and in some embodiments, it can also be swung or scanned to clean the working area of the cleaving knife 1 fully.

[0046] While laser cleaning removes the aluminum adhesion 6, the working area of the wedge knife 1 is laser shock peened using the energy of the laser pulse: the working area absorbs the energy of the laser and forms a violently expanding plasma near the surface layer, when the pressure of the plasma exceeds the elastic limit of the metal material, the metal material undergoes dynamic plastic deformation, causing the grains to be refined, thereby improving the fatigue performance and corrosion resistance. Perform three impacts with an energy of 5J-9J and a pulse width of 10ns-20ns, which can significantly improve the microhardness of the working area of the wedge knife 1 while removing the aluminum adhesion 6. As the service time of the wedge knife 1 increases, the surface hardening layer formed by laser shock peening gradually wears out, and when subsequent laser cleaning is performed again, laser shock peening can be performed again. Since the surface hardening layer has been worn out at this time, re-performing laser shock peening will not cause surface defects such as crack initiation.

[0047] The process of welding and online cleaning using the wedge bonding machine as shown in FIG. 1 is as follows:

[0048] Input the working instructions of the wedge bonding machine, and repeatedly perform multiple cycles of welding operations.

[0049] Before the welding operation cycle starts, first detect the working area of the wedge knife 1 using the tool detection device, use the visual recognition device to take and recognize the surface state of the working area of the wedge knife 1, and load the no-load test voltage to measure the resonant frequency, resonant current and impedance. When the visual recognition model carried by the visual recognition device judges that the aluminum adhesion state of the working area of the wedge knife 1 does not reach the cleaning standard or the parameters measured by the no-load test do not exceed the threshold value, the wedge knife 1 normally performs the welding operation; otherwise, the wedge knife 1 is instructed to move to the cleaning station, and the laser head 5 emits laser to clean and strengthen the working area of the wedge knife 1. After the wedge knife 1 performs the welding operation, the post-weld detection device detects the welding quality, and when the post-weld detection device detects defects caused by aluminum adhesion through visual recognition, the tool detection device also issues an instruction to move the wedge knife 1 to the cleaning station for laser cleaning and strengthening.

[0050] In the preferred embodiment, the tool detection device is built-in with a counting system. Before the wedge knife 1 is laser cleaned, first count up 1 and compare it with the pre-set scrap threshold value. If the count reaches the scrap threshold value, the laser cleaning process will be stopped and an alarm will be issued to indicate that the wedge knife 1 needs to be replaced; if the count does not reach the scrap threshold value, the laser cleaning process will be performed normally. In some embodiments, the scrap threshold value can be set to 6-10. In some embodiments, the visual recognition device can also be used to detect the profile of the wedge knife 1, and when the profile detection exceeds the predetermined limit, an alarm will be issued to indicate that the wedge knife 1 needs to be replaced. The count is reset after the wedge knife 1 is replaced.

[0051] In some preferred embodiments, multiple wedge bonding machines can be connected to the same ultrasonic knife online cleaning and strengthening system, and the bifurcated optical fiber 4 is used to guide the laser generated by the laser generator 3 to different laser heads 5, and each laser head 5 is provided with a control switch to respectively clean and impact the different devices, thereby improving the cleaning efficiency and saving equipment space.

[0052] In preferred embodiments, the welding operation of the wedge bonding machine and the laser cleaning process can be automatically controlled by a preset program, and the online laser cleaning is automatically performed during the welding operation, thereby improving the production efficiency, saving labor costs, and reducing the safety hazards caused by manual operation of the laser.

[0053] The ultrasonic knife online cleaning and strengthening system provided by the above embodiments can use laser cleaning to clean the ultrasonic knife online, and the cleaning process is efficient, accurate, and free of physical contact, thereby not producing toxic and harmful waste, saving energy and protecting the environment, and improving the automatic production level of ultrasonic welding; the surface of the ultrasonic knife can be strengthened while removing the metal adhesion, thereby prolonging the service life.

[0054] The purpose of the above embodiments is to further illustrate the present application in combination with the drawings, so that those skilled in the art can understand the technical concept of the present application. Within the scope of the present application, the structures or methods involved are optimized or equivalently replaced, and the embodiments in different embodiments are combined without structural and principle conflicts, which all fall within the protection scope of the present application.

Claims

1. An ultrasonic tool in-line cleaning enhancement system, comprising: The laser cleaning and strengthening device comprises a laser generator, an optical fiber and a laser head, the laser generator generates laser, the optical fiber is connected to the laser generator and leads the laser to one or more laser heads, and the laser head irradiates the laser to the ultrasonic knife to be cleaned. The tool detection device is connected to the laser cleaning and strengthening device, the tool detection device detects the cleaning state of the working area of the ultrasonic knife to be cleaned, and when the cleaning state of the ultrasonic knife to be cleaned exceeds the preset range, the tool detection device sends a signal to instruct the laser cleaning and strengthening device to perform laser cleaning and strengthening. The laser head outputs laser energy of 5J-9J and pulse width of 10ns-20ns.

2. The ultrasonic tool in-line cleaning enhancement system of claim 1, wherein, The tool detection device comprises a visual recognition device, the visual recognition device takes an image of the working area of the ultrasonic knife to be cleaned, and the cleaning state is configured as an image of the residual metal adhesion state of the working area.

3. The ultrasonic tool in-line cleaning enhancement system of claim 1 or 2, wherein, The visual recognition device is installed with an ultrasonic knife visual recognition model, the ultrasonic knife visual recognition model is trained by using preset image samples of different residual metal adhesion states of the working area, and can automatically identify the residual metal adhesion state of the working area.

4. The ultrasonic tool in-line cleaning enhancement system of claim 3, wherein, The tool detection device further comprises an empty load detection device, the empty load detection device detects the empty load working state of the ultrasonic knife to be cleaned, and the detection method of the cleaning state further comprises detecting the change of the empty load working state caused by the residual metal adhesion of the working area.

5. The ultrasonic tool in-line cleaning enhancement system of claim 3, wherein, The empty load working state comprises one or more of the resonant frequency, resonant current and impedance of the transducer of the ultrasonic knife to be cleaned excited by an empty load test voltage in the empty load state.

6. The ultrasonic tool in-line cleaning enhancement system of claim 5, wherein, The empty load test voltage is configured as 10%-30% of the normal working voltage.

7. The ultrasonic tool in-line cleaning enhancement system of claim 6, wherein, The tool detection device further comprises a post visual recognition device, the post visual recognition device visually recognizes the product state processed by the ultrasonic knife to be cleaned, and when the product state exceeds the preset range, the tool detection device sends a signal to instruct the laser cleaning and strengthening device to perform laser cleaning and strengthening.

8. The ultrasonic tool in-line cleaning enhancement system of claim 3, wherein, The ultrasonic knife on-line cleaning and strengthening system comprises the following steps:

9. An ultrasonic tool on-line cleaning enhancement method, characterized by, Step a): the tool detection device detects the cleaning state of the working area of the ultrasonic knife to be cleaned, when the cleaning state does not exceed the preset range, step b) is performed; when the cleaning state exceeds the preset range, the laser cleaning and strengthening device is used to perform laser cleaning and strengthening on the working area until the cleaning state does not exceed the preset range, and step b) is performed; Step b): ultrasonic working operation is performed, and after the working cycle is completed, the step a) is returned. ​ 10. The ultrasonic tool in-line cleaning enhancement method of claim 9, wherein, The step a) further comprises a counting step and a counting checking step, when the cleaning state exceeds a preset range, the counting increases 1, and before laser cleaning, it is checked whether the counting exceeds a given threshold, when the counting exceeds the given threshold, the laser cleaning is stopped, the ultrasonic tool to be cleaned is replaced, and the counting is restarted.

11. A clincher comprising an ultrasonic assembly and a horn, the ultrasonic assembly driving the horn to perform ultrasonic welding, characterized by, The wedge bonding machine further comprises an online cleaning and strengthening system for cleaning and strengthening the cleaver, the online cleaning system adopts the ultrasonic tool online cleaning and strengthening system according to any one of claims 1 to 8; the wedge bonding machine comprises a working station and a cleaning station, the cleaver can move between the working station and the cleaning station, at the working station, the cleaver is subjected to ultrasonic welding.

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