Ultrasonic welding diagnosis method, manufacturing method for ultrasonically welded member, inspection device, and program

Abstract

To provide an ultrasonic weld diagnosis method, a method for manufacturing ultrasonic weld members, an inspection device, and a program with which it is possible to inspect bonded states with good accuracy in real time in ultrasonic bonding.SOLUTION: An ultrasonic weld diagnosis method includes a computer executing the process of: applying pressure to the object to be bonded, so as to cause surface pressure to occur to the bonding face of the object to be bonded, and inputting an ultrasonic wave to the bonding face; detecting an elastic wave propagating via the object to be bonded, at a plurality of different positions by at least one sensor; and, on the basis of the analysis of the signal detected by the sensor, generating the envelope of the signal; as well as, calculating information relating to the envelope and determining the bonded state at the bonding face on the basis of the calculation result of the information.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to an ultrasonic weld diagnosis method, a manufacturing method of an ultrasonic welded member, an inspection device, and a program. [Background technology]

[0002] There is a known welding method that uses ultrasonic waves to join metal members. Ultrasonic welding is a welding method that utilizes the phenomenon in which ultrasonic vibrations are input to the interface (joint surface) of the members to be joined, such as metals, and the metals at the interface approach each other to the atomic distance due to the frictional force generated at the interface, thereby joining the members by atomic force. In ultrasonic welding, it was sometimes difficult to grasp the welding condition at the joint surface of the members in real time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2010 / 113250 [Patent Document 2] International Publication No. 2018 / 143410 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide an ultrasonic welding diagnosis method, a manufacturing method for ultrasonically welded components, an inspection device, and a program that can accurately inspect the joining condition in real time during ultrasonic joining. [Means for solving the problem]

[0005] In an ultrasonic welding diagnosis method according to an embodiment, a computer executes a process in which a pressure is applied to the objects to be joined so as to generate a surface pressure on the joint surfaces of the objects to be joined, ultrasonic waves are input to the joint surfaces, elastic waves propagating through the objects to be joined are detected by at least one sensor at a plurality of different positions, an envelope of the signal is generated based on an analysis of the signal detected by the sensor, information relating to the envelope is calculated, and a joining condition at the joint surfaces is determined based on the calculation results of the information. [Brief description of the drawings]

[0006] [Figure 1] 1 is a diagram illustrating an outline of the configuration of an ultrasound diagnostic system according to an embodiment. [Diagram 2] 3A to 3C are diagrams for explaining the principle of ultrasonic welding according to the embodiment. [Diagram 3] FIG. 4 is a diagram showing a model of an object to be joined according to the embodiment. [Figure 4] 5 is a diagram showing the relationship between the reflected intensity and transmitted intensity of ultrasonic waves and the porosity according to the embodiment. FIG. [Diagram 5] FIG. 4 is a diagram showing a detected signal waveform according to the embodiment. [Figure 6] 6 is a flowchart showing a process for determining a bonding state of a bonding surface according to an embodiment. [Figure 7] 5A to 5C are diagrams showing examples of signal waveforms indicating various bonding states of bonding surfaces according to an embodiment. [Figure 8] 3 is a flowchart showing a flow of processes executed in a method for manufacturing an ultrasonically welded member according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, an ultrasonic weld diagnosis method, a manufacturing method of an ultrasonic welded member, an inspection device, and a program according to embodiments will be described with reference to the drawings.

[0008] As shown in Fig. 1, an ultrasonic diagnostic system S includes, for example, an ultrasonic welding device 1 that ultrasonically welds objects W to be joined, and an inspection device 10 that inspects the welded state of the objects W to be joined. The objects W to be joined are, for example, two metal members with planar joining surfaces in contact with each other. The objects W to be joined are, for example, a pair of metal plates used for electrodes, etc. The ultrasonic welding device 1 includes, for example, an anvil 2 (first housing) installed on a fixed base E provided on a floor surface, a pressure unit 5 provided above the anvil 2, and an ultrasonic generator 3 that inputs ultrasonic vibrations to the pressure unit 5.

[0009] The anvil 2 is a base on which the workpiece W is placed on the upper surface. The anvil 2 is fixed on a fixed base E via a fixing member B. The fixed base E is provided separately from the anvil 2 that supports the workpiece W, and is in mechanical contact with the anvil 2 via the fixing member B. A pressure unit 5 is provided above the anvil 2. The pressure unit 5 is movable in the vertical direction. The pressure unit 5 is driven by a drive unit 4 (second housing) including a drive source that generates a downward pressing force. The drive unit 4 has a drive source such as a hydraulic jack, for example, and is fixed to the anvil 2. The drive unit 4 may be fixed to another position such as the fixed base E. The drive unit 4 is provided separately from the pressure unit 5. The drive unit 4 holds the pressure unit 5 via a fixing member (not shown) or the like, and is in mechanical contact with the pressure unit 5.

[0010] The pressure applying unit 5 cooperates with the upper surface of the anvil 2 to clamp the objects to be joined W in the vertical direction. The pressure applying unit 5 generates a pressing force in a direction that brings the joining surfaces of the objects to be joined W into contact with each other. The pressure applying unit 5 applies a pressing force to the objects to be joined W so as to generate a surface pressure on the joining surfaces of the objects to be joined W. A horn 3H provided on the ultrasonic generator 3 is connected to the pressure applying unit 5. The horn 3H is a member that transmits ultrasonic vibrations generated by the ultrasonic generator 3 to the pressure applying unit 5. The horn 3H transmits ultrasonic vibrations in the horizontal direction, for example, to the pressure applying unit 5.

[0011] The ultrasonic generator 3 is, for example, a device that inputs an AC voltage having an ultrasonic frequency to a piezoelectric element provided inside to generate ultrasonic vibration. The ultrasonic generator 3 may apply a magnetic field of an ultrasonic frequency to a magnetic material to generate ultrasonic vibration based on the magnetostrictive effect. The ultrasonic generator 3 may generate ultrasonic vibration using a photoelectric element that vibrates based on the photoelectric effect. The ultrasonic generator 3 vibrates the pressure unit 5 in the horizontal direction via the horn 3H, inputs ultrasonic waves to the joining surfaces of the objects to be joined W, and welds the joining surfaces.

[0012] The ultrasonic welding device 1 is provided with at least one sensor that detects elastic waves transmitted through the objects to be joined W. The sensor may be, for example, an acoustic emission (AE) sensor, an acceleration sensor, a vibration sensor, or the like that can detect the movement of members due to elastic waves, and other sensors may also be used. The sensor may be a micro electro mechanical systems (MEMS) acceleration sensor or a MEMS AE sensor. The sensor may be applicable to any vibration generation principle of the ultrasonic generator 3, such as a piezoelectric element, a capacitance type, or an optical type.

[0013] The sensors are provided at a plurality of different positions in the ultrasonic welding device 1. For example, a sensor is provided on the anvil 2 to detect elastic waves transmitted through the workpieces W. A first sensor S1 is provided on one side of the anvil 2. A third sensor S3 is provided on the other side of the anvil 2. A second sensor S2 is provided on the fixed base E near the fixing member B that fixes the anvil 2. The second sensor S2 detects elastic waves propagating from the anvil 2 to the fixed base E. Within the anvil 2, elastic waves may be reflected multiple times, causing a disturbance in the detection signal.

[0014] The second sensor S2 is provided on a fixed base E separate from the anvil 2, and can detect elastic waves propagating through the anvil 2, thereby reducing the effects of elastic waves that are multiple-reflected within the anvil 2. In addition, the driving unit 4 is provided with a fourth sensor S4. The fourth sensor S4 detects reflected waves of elastic waves generated from the workpieces W. The driving unit 4 is provided in a housing provided separately from the pressure unit, and is in mechanical contact with the pressure unit 5 but is not in mechanical contact with the workpieces W.

[0015] The fourth sensor S4 can detect the reflected wave of the elastic wave generated from the joining workpiece W and propagating from the pressure part to the second housing. The fourth sensor S4 can detect the reflected wave of the elastic wave whose signal magnitude relationship is inverted as the welding process progresses, and can detect the welding process in the same way as the other sensors.

[0016] The elastic waves transmitted through the joining workpieces W are analyzed by the inspection device 10. The inspection device 10 is communicatively connected to the ultrasonic welding device 1 by wire or wirelessly. The inspection device 10 may be connected to the ultrasonic welding device 1 through a network.

[0017] The inspection device 10 is configured, for example, by an information processing terminal device such as a personal computer. The inspection device 10 includes, for example, a determination unit 12 that analyzes detection data acquired from a sensor, a storage unit 14 in which data required for the analysis is stored, and a display unit 16 that displays the analysis results. The determination unit 12 acquires detection data from at least one sensor provided in the ultrasonic welding device 1, and determines the bonding state at the bonding surface of the workpieces W based on the analysis of the signal detected by the sensor. The determination unit 12 determines the bonding state at the bonding surface of the workpieces W based on a preset analysis method described later.

[0018] The determination unit 12 determines the bonding state at the bonding surfaces of the objects to be joined W, for example, when ultrasonic waves are input to the bonding surfaces in a state in which pressure is applied to the objects to be joined so as to generate surface pressure on the bonding surfaces of the objects to be joined in the ultrasonic welding device 1. The determination unit 12 analyzes signals of elastic waves propagating through the objects to be joined, which are detected by a plurality of sensors at a plurality of different positions during ultrasonic welding, for example.

[0019] The determination unit 12 generates an envelope of the signal based on an analysis of the signal detected by the sensor, and calculates information about the envelope. The determination unit 12 determines the bonding state of the bonding surface based on the calculation result of the information. The information about the envelope is, for example, a shape of the envelope and a plurality of parameters included in the feature calculated based on the shape. The determination unit 12 outputs at least one of the bonding state of the bonding workpiece W, the bonding strength, and the waveform feature of the envelope based on the signal detected by the sensor.

[0020] The determination unit 12 may, for example, perform machine learning using a neural network in advance based on teacher data related to an envelope corresponding to the bonding state, compare the detection data with the teacher data, and determine the bonding state at the bonding surface. The details of the analysis method will be described later. The determination unit 12 may feedback-control the welding control of the ultrasonic welding device 1 by changing at least one control parameter among the welding time, the output amount, and the adjustment amount of the pressure force in the input of the ultrasonic wave based on the determination result of the bonding state.

[0021] The storage unit 14 stores, for example, an arithmetic expression required for the analysis by the determination unit 12, teacher data required for the analysis, and the like. The storage unit 14 is a storage medium such as a hard disk drive (HDD) or a flash memory. The storage unit 14 may be built into the inspection device 10 or may be connected externally. The storage unit 14 may be a server connected via a network and capable of storing data.

[0022] The display unit 16 is a display device configured by, for example, a liquid crystal display, a touch panel, etc. The display unit 16 displays the display image generated by the determination unit 12.

[0023] Next, the principle of the ultrasonic welding method will be described. Ultrasonic welding systems are generally broadly classified into a Wedge-Reed type and a Lateral Drive type depending on the device configuration. In the Wedge-Reed type, vibration from a piezoelectric element is applied via a wedge arranged perpendicular to the Reed that drives in the vertical direction. This generates vibration in the shear direction in the workpiece, and welding is performed. It consists of a piezoelectric transducer driven by a high-frequency driver, a vibration amplification mechanism (horn), and a pressure cylinder. The ultrasonic welding device 1 of this embodiment is a Wedge-Reed type, which is used for welding relatively thick materials.

[0024] The Lateral Drive type has a structure similar to that of the Wedge-Reed type rotated 90°, and the welding tip has a cantilever structure. Because the clamping pressure is low, it is used for relatively thin samples. The ultrasonic welding device 1 may be configured as a Lateral Drive type.

[0025] The welding conditions for ultrasonic welding are determined by the main parameters: frequency (f), vibration speed (V), clamp pressure (pressing force) (F), power (P), energy (E), and time (T). The relationships between each parameter are shown in the following equations (1) and (2). E = P × T (1) P = F × V (2) Furthermore, the vibration velocity V is determined by the frequency f and the vibration amplitude A. The vibration amplitude range is on the order of 30-60 μm. Frequencies in the range of 15-75 kHz are often used, with 20 kHz being the most commonly used. The energy E required for joining is said to have the relationship shown in the following formula (3) using the Vickers hardness H of the sample, the sheet thickness t, and a constant K based on the material properties. E = K(Ht) 3 / 2 (3) As an example, the configurable parameters are energy (E), power (P), and pressure (F), and when the frequency is fixed (20 kHz), the other associated parameters (vibration amplitude A and time T) are determined based on the above relationship.

[0026] Figure 2 shows a typical joining process for ultrasonic welding. In ultrasonic welding, ultrasonic vibrations are input to the joining surface W1 of objects W, which are made of multiple overlapping metals, while a perpendicular pressure is applied to the joining surface, to join the metals. When opposing joining surfaces W1 of metal objects W to be joined come into contact with a static load P applied, a gap WS exists at the contact surface between the joining surfaces W1 (see Figure 2(A)). When ultrasonic waves are input parallel to the joining surfaces W1, the oxides formed on the metal surfaces are destroyed by friction, and the joining surfaces W1 are mechanically smoothed by friction, reducing the gap WS (see Figure 2(B)).

[0027] In this state, the bonding surface W1 undergoes plastic deformation due to friction, and as the metals at the bonding surface W1 approach each other to the atomic distance (for example, about 0.29 nm for aluminum), an interatomic attractive force acts between the metal atoms at the bonding surface W1, and bonding is achieved in the solid phase (see Figure 2(C)). As shown in the figure, WZ indicates oxides that have been destroyed by friction. Here, in order to consider the characteristics of transmitted elastic waves, we consider the propagation of elastic waves in a gap sandwiched between metals.

[0028] As shown in FIG. 3, to simplify the discussion, a model of a joining object W (e.g., aluminum) consisting of three regions 1, 2, and 3 (with acoustic impedances Z1, Z2, and Z3, respectively, and wave numbers k1, k2, and k3) is considered. In this model, for example, there is a gap (acoustic impedance Z2) with a thickness d between two metals (acoustic impedances Z1 and Z3). When d is sufficiently small, the apparent impedance Z when looking at region 2 from region 1 is q is expressed as the following equation (4) based on the impedance-translation theorem.

[0029]

number

[0030] If the objects to be joined W are a pair of the same kind of metals (Z1=Z3), the reflection coefficient R of the wave input from region 1 to region 2 is given by the following equation (5).

[0031]

number

[0032] By substituting equation (3) into equation (5), we obtain equation (6).

[0033]

number

[0034] If the reflection intensity is |R|, the following equation (7) is obtained.

[0035]

number

[0036] In this case, the transmitted intensity |T| is expressed by the following equation (8).

[0037]

number

[0038] Aluminum is used as the metal to be joined W, and the frequency of the ultrasonic waves to be input is set to 20 kHz, the fundamental frequency used in ultrasonic welding.

[0039] As shown in FIG. 4, the relationship between reflection intensity and transmission intensity, with the horizontal axis representing the gap thickness, reveals that a gap of approximately 0.1 μm to 1 μm is the boundary between reflection and transmission.

[0040] 5 shows waveforms based on transmitted acoustic wave signals measured by sensors (e.g., first sensor S1 to third sensor S3). As shown in the figure, an envelope that envelops the outer diameter of the amplitude is formed based on the signal waveform. The shape of the envelope of the signal waveform is generally classified into a first region I that gradually increases over time from the start of input of ultrasonic waves, and a second region II that is continuous with the first region I and maintains a substantially constant value over time. The first region I shows the process over time in which the gap d existing between the bonding surfaces W1 decreases from the order of microns to about 10 nm (see FIGS. 2 and 3).

[0041] The second region II shows, for example, a state where the gap d reaches a region from 10 nm to the interatomic distance (on the order of sub-nm) required for bonding (see Figs. 2 and 3). That is, the shape of the envelope formed by the signal waveform shows the welding process itself over time based on ultrasonic waves. A number of feature quantities appear in the shape of the envelope. The feature quantities are, for example, the time t I , time t in the second region II II , the amplitude after saturation v II、 Parameters such as the variance σ after removing the increasing trend in the first region I, the variance σ2 of the envelope in the second region II, and the area E of the envelope are extracted.

[0042] The features are the square root of the variance and the mean or amplitude v II Coefficient of variation divided by √(σ2) / v II , √(σ2) / v II The feature amount is not limited to the above, and each parameter may be combined by calculation, or may be arbitrarily scaled. Any parameter may be used as the feature amount as long as it can extract the time-dependent process of ultrasonic welding from the envelope of the signal waveform.

[0043] 6 shows a flow of a process executed in the inspection device 10 to calculate a feature quantity based on the detection value of a signal waveform. The determination unit 12 acquires the waveform of an elastic wave propagating through the workpiece W based on the detection values ​​of each sensor (S1 to S3) (step S100). The determination unit 12 calculates a maximum amplitude V II The determination unit 12, for example, passes the detection value through a bandpass filter with a center frequency set based on the transmission frequency of the ultrasonic waves. The determination unit 12, for example, extracts the positive side of a signal based on the elastic wave that has passed through the bandpass filter, passes the extracted signal through a lowpass filter, and generates an envelope shape (step S102). The determination unit 12 calculates the area of ​​the generated envelope shape, and calculates energy E, which is a feature amount.

[0044] The determination unit 12 passes the generated envelope data through a moving minimum filter to remove noise and smooth the data (step S104). The determination unit 12 performs piecewise linear regression on the smoothed envelope to extract a first region I that gradually increases over time in the shape of the envelope and a second region II that is continuous with the first region and has a substantially constant value over time (step S106). The determination unit 12 extracts the time t I and the time t elapsed in the second region II II The determination unit 12 calculates an increasing trend (slope) in the first region I based on the interval linear regression. The determination unit 12 removes the increasing trend from the envelope data in the first region, and calculates the variance of the welding process, which is a feature, based on the envelope data after the increasing trend has been removed (step S108). The determination unit 12 compares the calculation result with a preset threshold value, and determines whether the joining state of the joining workpieces W is good or bad (step S110). The threshold value is set, for example, based on a feature value database for abnormal mode occurrence conditions acquired in advance.

[0045] As shown in FIG. 7, the waveform shape of the signal waveform changes based on the state of the workpiece W. As shown in FIG. 7(A), when the workpiece W is normal and the joining state is normal, the envelope of the signal waveform data has a characteristic shape that distinguishes the first region from the second region. As shown in FIG. 7(B), when the workpiece W is normal but the joining surface W1 is contaminated with oil or grease, the envelope shape is abnormal. In this case, the joining surface W1 has a slippery interface, which makes it difficult to proceed with welding, and the envelope of the signal waveform has a shape that increases over time, and the first and second region shapes do not appear. As shown in FIG. 7(C), when the workpiece W has an abnormality such as damage, the envelope of the signal waveform has a shape that does not show the normal characteristic amount.

[0046] The threshold value used to determine whether the welding of the joint surface W1 of the workpieces W at the end of welding is normal or abnormal is set based on the feature amount of the signal waveform based on each of the causes of the abnormality described above. The determination unit 12 compares the calculated feature amount with a threshold value of the feature amount previously set for any of the causes such as positional deviation, damage, contamination, etc. of the workpieces W, and determines whether the joint state of the joint surface W1 is good or bad based on the comparison result.

[0047] The determination unit 12 may not only calculate the feature amount but also generate an image of the acquired waveform shape and determine the abnormal mode of the joining object W based on the image. For example, the determination unit 12 may use an image of an envelope corresponding to the joining state as teacher data, perform machine learning using a neural network in advance on the association between the shape of the image and the joining state, and determine the abnormal mode of the joining state of the joining object W based on the image of the waveform shape generated based on the acquired sensor data. The determination unit 12 may perform machine learning in advance based on teacher data related to the envelope corresponding to the joining state, output at least one of the joining state, joining strength, and waveform feature amount of the envelope based on a signal detected by the sensor, and determine the abnormal mode of the joining state of the joining object W.

[0048] In this case, the determination unit 12 may determine the bonding state of the joining objects W based on the signal waveform of the reflected wave of the elastic wave acquired from the fourth sensor S4. The determination unit 12 may determine the bonding state of the joining objects W using the signal waveform data acquired from the fourth sensor S4 alone, or may use it for complementary determination of the bonding state of the joining objects W based on the signal waveform data acquired from the first sensor S3 to the third sensor S3.

[0049] The determination unit 12 may generate a display image including the envelope and display it together with information on the determination result on the display unit 16. The display image may include at least one of information on the first region, the second region, the first time, the second time, the amplitude, the variance, and the area, for example.

[0050] Next, a description will be given of a method for manufacturing an ultrasonically welded member using the ultrasonic welding apparatus 1. The inspection apparatus 10 may be a control device that not only judges the bonding state of the bonding object W (ultrasonic welded member) but also executes the processing of each step of ultrasonic welding in the ultrasonic welding apparatus 1. Furthermore, the inspection apparatus 10 may perform ultrasonic welding in cooperation with a control device (not shown) separately provided in the ultrasonic welding apparatus 1.

[0051] The inspection device 10 controls the drive unit 4 to drive the pressure unit 5, applies pressure to the objects to be joined W, and generates a surface pressure on the joining surface W1 (step S200). The inspection device 10 controls the ultrasonic generator 3 to input ultrasonic waves to the joining surface (step S202). The inspection device 10 detects elastic waves propagating through the objects to be joined W with at least one sensor at different positions (step S204). The inspection device 10 generates an envelope of the signal waveform based on an analysis of the signal detected by the sensor, and calculates information such as a feature amount related to the envelope (step S206). The inspection device 10 analyzes the waveform of the envelope based on the feature amount.

[0052] The inspection device 10 judges the bonding state at the bonding surface based on the calculation result of the information (step S208). The inspection device 10 extracts the bonding objects W after bonding that are in a normal bonding state conforming to a preset threshold based on the judgment result (step S210). When the inspection device 10 extracts an abnormal bonding object W that does not conform to the threshold, it sends it to a line different from the line of normal bonding objects W. The inspection device 10 counts the number of welds and judges whether the planned number has been reached (step S212). If the planned number has not been reached, the process returns to step S200, and if a positive judgment is obtained, the ultrasonic welding is terminated.

[0053] As described above, the inspection device 10 can determine the bonding state of the objects W to be joined that are ultrasonically welded by the ultrasonic welding device 1. The inspection device 10 can determine the bonding state of the objects W to be joined and detect defective products in real time. The inspection device 10 can simplify the device configuration because it is possible to determine the bonding state of the objects W to be joined by attaching a general-purpose product such as an AE sensor to the ultrasonic welding device 1.

[0054] In the above embodiment, the determination unit 12 is a software function unit, but may be a hardware function unit such as an LSI. A part or all of the determination unit 12 is realized, for example, by a processor such as a CPU executing a program (software) stored in the storage unit 14. In addition, a part or all of the functions of these components may be realized by hardware (including circuitry) such as an LSI, ASIC, FPGA, or GPU, or may be realized by cooperation between software and hardware. The program may be stored in a storage device such as an HDD or flash memory in advance, or may be stored in a removable storage medium such as a DVD or CD-ROM, and installed by mounting the storage medium in a drive device.

[0055] According to at least one of the embodiments described above, pressure is applied to the objects to be joined so as to generate a surface pressure on the joining surfaces of the objects to be joined, ultrasonic waves are input to the joining surfaces, elastic waves propagating through the objects to be joined are detected by at least one sensor at a plurality of different positions, an envelope of the signal is generated based on an analysis of the signal detected by the sensor, information relating to the envelope is calculated, and the joining condition at the joining surfaces is judged based on the calculation results, thereby making it possible to accurately inspect the joining condition in real time in ultrasonic joining.

[0056] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope of the invention described in the claims and their equivalents, as well as in the scope and gist of the invention. For example, the inspection device 10 may not only determine the bonding state of the bonding object W of one ultrasonic welding device 1, but also determine the bonding state of the bonding object W of multiple ultrasonic welding devices 1 connected through a network. The inspection device 10 may store the detection data and the judgment results acquired from the multiple ultrasonic welding devices 1, and perform machine learning at a predetermined timing to improve the judgment accuracy. [Explanation of symbols]

[0057] 1...ultrasonic welding device, 5...pressure section, 10...inspection device, 12...determination section, 16...display section, E...fixed base, F...pressure, I...first region, II...second region, S1-S4...sensor, W...joining object, W1...joining surface

Claims

1. applying a pressure to the objects to be joined so as to generate a surface pressure on the joining surfaces of the objects to be joined; Ultrasonic waves are input to the bonding surface, Detecting an elastic wave propagating through the objects to be joined with at least one sensor; generating an envelope of the signal based on an analysis of the signal detected by the sensor; A first region in the shape of the envelope, which gradually increases over time, and a second region that is continuous with the first region and has a substantially constant value over time are extracted; calculating, as information about the envelope, feature amounts including a first time elapsed in the first region, a second time elapsed in the second region, an amplitude of the signal in the second region, a variance after removing an increasing trend in the first region, and an area of ​​the envelope; The ultrasonic welding diagnosis method further comprises a process for determining a bonding condition at the bonding surface based on a calculation result of the information by a computer.

2. the sensor is provided separately from a first housing supporting the object to be joined, and is fixed to a fixed base that is in mechanical contact with the first housing, and detects the elastic wave propagating from the first housing to the fixed base.

2. The ultrasonic weld diagnostic method of claim 1.

3. The sensor is provided separately from a pressure unit that applies pressure to the objects to be joined and generates a surface pressure on the joining surface, and is fixed to a second housing that is in mechanical contact with the pressure unit, and detects the elastic wave propagating from the pressure unit to the second housing.

3. The ultrasonic welding diagnosis method according to claim 1 or 2.

4. The first region and the second region are separated based on a linear regression analysis performed for each section. The ultrasonic welding diagnosis method according to any one of claims 1 to 3.

5. 5. The ultrasonic welding diagnosis method according to claim 1, further comprising the step of: calculating a shape of the envelope based on the signal based on the elastic wave that has passed through a bandpass filter having a center frequency set based on a transmission frequency of the ultrasonic wave.

6. comparing the calculation result with a preset threshold value to determine whether the bonding state is good or bad; The ultrasonic welding diagnosis method according to any one of claims 1 to 5.

7. determining that the bonding state is poor based on any one of the causes of positional deviation, breakage, and contamination of the objects to be bonded; 7. The ultrasonic weld diagnostic method of claim 6.

8. The calculation result is compared with the preset threshold value to determine the bonding strength at the bonding surface.

7. The ultrasonic weld diagnostic method of claim 6.

9. Performing machine learning in advance based on training data regarding the envelope corresponding to the bonding state; outputting at least one of the bonding state, the bonding strength, and a waveform feature amount of the envelope based on the signal detected by the sensor; 9. The ultrasonic weld diagnostic method of claim 8.

10. The ultrasonic welding diagnosis method according to claim 1 , further comprising the steps of: generating a display image including the envelope curve and displaying the display image on a display unit.

11. 11. The ultrasonic weld diagnostic method of claim 10, wherein the displayed image includes at least one of the first region, the second region, the first time, the second time, the amplitude, the variance, and the area.

12. changing at least one of control parameters including a welding time and an output amount in the input of the ultrasonic wave, and an adjustment amount of the pressing force in the input of the surface pressure, based on the judgment result of the joining state; 12. The ultrasonic weld diagnostic method according to any one of claims 1 to 11.

13. applying a pressure to the objects to be joined so as to generate a surface pressure on the joining surfaces of the objects to be joined; Ultrasonic waves are input to the bonding surface, Detecting an elastic wave propagating through the objects to be joined with at least one sensor; generating an envelope of the signal based on an analysis of the signal detected by the sensor; A first region in the shape of the envelope, which gradually increases over time, and a second region that is continuous with the first region and has a substantially constant value over time are extracted; calculating, as information about the envelope, feature amounts including a first time elapsed in the first region, a second time elapsed in the second region, an amplitude of the signal in the second region, a variance after removing an increasing trend in the first region, and an area of ​​the envelope; determining a bonding state at the bonding surface based on a calculation result of the information; The computer executes a process of extracting the joining object after joining, the joining state of which matches a predetermined threshold value based on a result of the determination. A method for joining welding components.

14. In ultrasonic welding, a pressure is applied to objects to be joined so as to generate a surface pressure on a joining surface of the objects to be joined, ultrasonic waves are input to the joining surface, and an elastic wave propagating through the objects to be joined is detected by at least one sensor, an inspection device comprising: a determination unit that generates an envelope of the signal based on an analysis of the signal detected by the sensor; extracts a first region in the shape of the envelope, the first region gradually increasing over time, and a second region that is continuous with the first region and has a substantially constant value over time; calculates feature amounts including a first time elapsed in the first region, a second time elapsed in the second region, an amplitude of the signal in the second region, a variance after removing an increasing trend in the first region, and an area of ​​the envelope as information about the envelope; and determines a bonding condition at the bonding surface based on a calculation result of the information.

15. In ultrasonic welding, a pressure is applied to objects to be joined so as to generate a surface pressure on a joining surface of the objects to be joined, ultrasonic waves are input to the joining surface, and an elastic wave propagating through the objects to be joined is detected by at least one sensor, On the computer, Analyzing the signal detected by the sensor; generating an envelope of the signal based on the analysis results; extracting a first region in the shape of the envelope, the first region gradually increasing over time, and a second region continuous with the first region and having a substantially constant value over time; calculating, as information about the envelope, feature amounts including a first time that elapses in the first region, a second time that elapses in the second region, an amplitude of the signal in the second region, a variance after removing an increasing trend in the first region, and an area of ​​the envelope; A program for determining a bonding state at the bonding surface based on a result of the calculation of the information.

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