Ultrasonic joining device

Abstract

To provide an ultrasonic joining device that accurately and quickly determines whether joining quality is good or bad.SOLUTION: An ultrasonic joining device 1 comprises: a stage 10 on which at least a part of a first component 100a is placed; a horn 11 which joins the first component 100a and a second component 100b by applying ultrasonic vibration while pressing the second component 100b toward the first component 100a placed on the stage 10; a vibrator 14 which is installed on the horn 11, and is a source of ultrasonic vibration; a first probe 20 which is installed on the horn 11, and detects ultrasonic wave propagated to the first component 100a and the second component 100b from the vibrator 14; and a first receiver 21 which receives an electric signal from the first probe 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic bonding device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is an ultrasonic bonding apparatus that bonds a plurality of workpieces to be bonded together by applying ultrasonic vibrations to the horn while the workpieces are sandwiched between a horn and a stage.

[0003] Patent Document 1 discloses a technology relating to an ultrasonic bonding device that detects the temperature of the workpieces being joined by ultrasonic vibrations and controls the drive of the joining tool based on the detected information in order to maintain the joining quality of the materials joined by the ultrasonic bonding device. In this ultrasonic bonding device, the control device changes the control parameters when the temperature of the workpieces is outside the standard range, thereby suppressing a decrease in the joining strength.

[0004] Patent Document 2 discloses a technology relating to an apparatus and method for inspecting in real time the joining quality of all products joined by an ultrasonic joining device. The inspection device determines whether the joining quality is good or bad by comparing parameters obtained by referencing the joining waveform with parameters obtained when joining a product that has been determined to be good with parameters obtained when joining an actual product. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-61156 [Patent Document 2] International Publication No. 2010 / 113250 Summary of the Invention [Problem to be solved by the invention]

[0006] In general, even when the joining of workpieces is repeated under the same conditions in an ultrasonic joining device, variations in the bonding strength of each joining material occur. Therefore, in the ultrasonic joining device disclosed in Patent Document 1, parameter changes based on temperature information depend on thresholds, and taking into account variations in bonding strength, it is difficult to accurately determine the quality of the joining. Furthermore, even with the inspection device disclosed in Patent Document 2, it is difficult to accurately determine the quality of the joining because variations in bonding strength can occur between products.

[0007] On the other hand, in order to more accurately evaluate the bonding quality of a bonding material, it is possible to extract a certain bonding material and perform a tensile test to measure the bonding strength. However, in such a tensile test, it is necessary to destroy the bonding material in advance to extract a sample, which takes time to measure the bonding strength, and therefore it takes time to obtain a result of whether the bonding quality is good or bad.

[0008] The present invention has been made in view of the problems inherent in the prior art, and an object of the present invention is to provide an ultrasonic bonding device that can accurately and quickly determine whether the bonding quality is good or bad. [Means for solving the problem]

[0009] An ultrasonic bonding device according to an embodiment of the present invention includes a stage on which at least a portion of a first member is placed, a horn that bonds the first member and the second member by applying ultrasonic vibrations while pressing the second member against the first member placed on the stage, a vibrator that is installed in the horn and is a source of ultrasonic vibrations, a first probe that is installed in the horn and detects ultrasonic waves propagated from the vibrator to the first member and the second member, and a first receiver that receives an electrical signal from the first probe. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an ultrasonic bonding device that can accurately and quickly determine whether the bonding quality is good or bad. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic view of an ultrasonic bonding device according to a first embodiment. [Figure 2] 3A to 3C are schematic diagrams illustrating the principle of inspection of bonding quality in the first embodiment. [Figure 3] FIG. 10 is a schematic view of an ultrasonic bonding device according to a second embodiment. [Figure 4] 10A and 10B are schematic diagrams illustrating the principle of inspection of bonding quality in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, ultrasonic bonding devices according to the respective embodiments will be described in detail with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the sake of convenience and may differ from the actual proportions.

[0013] (First embodiment) Fig. 1 is a schematic diagram of an ultrasonic bonding apparatus 1 according to a first embodiment. The ultrasonic bonding apparatus 1 overlaps a plurality of workpieces 100 and bonds the workpieces 100 together by applying ultrasonic vibration energy while applying pressure in a direction that brings them closer to each other. Note that Fig. 1 illustrates the ultrasonic bonding apparatus 1 before the bonding operation, in which a bonding tool 12 attached to a horn 11 has not yet come into contact with the workpieces 100.

[0014] In this embodiment, a first member 100a and a second member 100b are assumed as the multiple members to be joined together 100. As an example, the first member 100a and the second member 100b are each a flat plate member made of metal.

[0015] The ultrasonic bonding apparatus 1 includes a stage 10, a horn 11, a bonding tool 12, an ultrasonic oscillator 13, a vibrator 14, a pressure device 15, and a control device 16. The stage 10 and the horn 11 are spaced apart from each other, and during a bonding operation, a first member 100a and a second member 100b are sandwiched between their opposing end faces. In this embodiment, the direction of separation between the stage 10 and the horn 11 is the up-down direction, which corresponds to the Z direction, which is the vertical direction.

[0016] The stage 10 is a block-shaped structure on which at least a portion of the first member 100a is placed. In this embodiment, the second member 100b is ultrasonically bonded to the first member 100a, so that at least a portion of the second member 100b is placed on top of the first member 100a on the stage 10. In other words, the stacking direction of the first member 100a and the second member 100b on the stage 10 also aligns with the Z direction.

[0017] Horn 11 is a block-shaped structure located above stage 10. Horn 11 applies ultrasonic vibrations to second member 100b while pressing it against first member 100a placed on stage 10, thereby joining first member 100a and second member 100b.

[0018] The joining tool 12 is detachably connected to a part of the horn 11 and transmits ultrasonic vibrations by coming into contact with the first component 100a during the joining operation. Note that the joining tool 12 is not an essential component of the ultrasonic joining device 1, and there are cases where a contact surface provided on the horn 11 itself comes into direct contact with the first component 100a during the joining operation.

[0019] The ultrasonic oscillator 13 generates a high-frequency alternating current and supplies it to the vibrator 14 as electrical energy.

[0020] Vibrator 14 is installed on horn 11 and converts electrical energy supplied from ultrasonic oscillator 13 into vibrations. The vibrations emitted from vibrator 14 are transmitted to horn 11. In other words, vibrator 14 is the source of ultrasonic vibrations for horn 11. In this embodiment, the vibration direction VD of horn 11 is along a direction parallel to the horizontal plane, i.e., the X direction perpendicular to the Z direction.

[0021] The pressure device 15 is a driving source for applying a load to the horn 11. During the joining operation, the pressure device 15 presses the welding tool 12 toward the stage 10 in a state in which the stage 10 and the welding tool 12 sandwich the first member 100a and the second member 100b. In this embodiment, the load application direction P is the Z direction.

[0022] The control device 16 controls at least the ultrasonic oscillator 13 and the pressure device 15. The control device 16 may be, for example, a computer including a CPU (Central Processing Unit) and a storage medium such as a memory.

[0023] The ultrasonic bonding device 1 also includes a first probe 20 , a first receiver 21 , and a first oscilloscope 22 .

[0024] The first probe 20 is attached to the horn 11 and detects ultrasonic waves propagated from the oscillator 14 to the first member 100a and the second member 100b via the horn 11 during the joining operation. The first probe 20 may be a so-called single-oscillator type probe that incorporates one oscillator that receives ultrasonic waves.

[0025] The first receiver 21 receives an electrical signal from the first probe 20. Specifically, the received ultrasonic vibration is converted into a high-frequency voltage by a vibrator in the first probe 20, and the first receiver 21 receives the electrical energy supplied from the first probe 20.

[0026] The first oscilloscope 22 visualizes the information obtained from the first receiver 21. Here, the information obtained from the first receiver 21 is information related to the electrical energy supplied from the first probe 20.

[0027] Next, the operation of the ultrasonic bonding device 1 will be described.

[0028] 2 is a schematic diagram illustrating the inspection principle for inspecting the bonding quality of a bonded portion 101 between a first member 100a and a second member 100b during a bonding operation in the ultrasonic bonding apparatus 1. For simplicity of explanation, FIG. 2 only shows the first member 100a and the second member 100b, which are stacked on top of each other, as well as a vibrator 14 as a source of ultrasonic vibrations applied to the second member 100b and a first probe 20. In other words, FIG. 2 does not illustrate components such as the stage 10 in contact with the bottom surface 102 of the first member 100a, the bonding tool 12 in contact with the top surface 103 of the second member 100b, and the horn 11 that holds the vibrator 14 and the first probe 20.

[0029] First, in the ultrasonic bonding apparatus 1, the first member 100a and the second member 100b are sandwiched between the stage 10 and the bonding tool 12 as an initial state of the bonding operation. The control device 16 drives the pressure device 15 from the initial state, causing the horn 11 and the bonding tool 12 to apply a load in the application direction P to the second member 100b. At the same time, the control device 16 operates the ultrasonic oscillator 13 from the initial state, causing the horn 11 and the bonding tool 12 to apply ultrasonic vibrations along the vibration direction VD to the second member 100b. This causes ultrasonic bonding to progress at a bonding portion 101 where the first member 100a and the second member 100b come into contact with each other.

[0030] Furthermore, in the ultrasonic bonding apparatus 1, the control device 16 inspects the bonding quality of the bonded portion 101 in accordance with the bonding operation. Specifically, during the bonding operation, ultrasonic vibrations caused by the vibrator 14 propagate as pulse waves to the second member 100b and the first member 100a. At this time, the pulse waves are reflected by the reflection source, and the first probe 20 receives the reflected waves.

[0031] For example, in a portion of the joint 101 where the defect 110 is not formed, the pulse wave emitted from the transducer 14 passes through the joint 101, reaches the bottom surface 102, is reflected, passes through the joint 101 again, and reaches the first probe 20. In FIG. 2, the trajectory of the pulse wave in this case is shown by a dashed line as a first ultrasonic beam BM1. Furthermore, if the top surface 103 of the second member 100b is defined as the inspection surface that serves as the reference for ultrasonic flaw detection, the distance between the top surface 103 and the bottom surface 102, which is the reflection source in this case, is the first distance W B It is expressed as:

[0032] On the other hand, in the area where the defect 110 is formed in the joint 101, the pulse wave emitted from the transducer 14 reaches the defect 110, is reflected, and then reaches the first probe 20. In FIG. 2, the trajectory of the pulse wave in this case is shown by a dashed line as a second ultrasonic beam BM2. The distance between the upper surface 103 as the inspection surface and the defect 110, which is the reflection source in this case, is a second distance W F The second distance W F is the first distance W B is shorter than.

[0033] In this way, the first distance W B and the second distance W F Since a difference occurs between the reflected and reflected signals, a difference also occurs between the electrical signals received by the first receiver 21 from the first probe 20. Therefore, by visualizing the electrical signals at this time as reflected signals using the first oscilloscope 22, an operator who visually checks the output display can, for example, estimate the size of the defect 110 from the reflected signals and determine whether the joining quality of the joint 101 is good or bad.

[0034] Next, the effects of the ultrasonic bonding device 1 will be described.

[0035] The ultrasonic bonding apparatus 1 includes a stage 10 on which at least a portion of a first member 100a is placed. The ultrasonic bonding apparatus 1 also includes a horn 11 that applies ultrasonic vibrations to the second member 100b while pressing the second member 100b against the first member 100a placed on the stage 10, thereby bonding the first member 100a and the second member 100b together. The ultrasonic bonding apparatus 1 also includes a vibrator 14 that is attached to the horn 11 and serves as a source of ultrasonic vibrations. The ultrasonic bonding apparatus 1 also includes a first probe 20 that is attached to the horn 11 and detects ultrasonic waves propagated from the vibrator 14 to the first member 100a and the second member 100b, and a first receiver 21 that receives an electrical signal from the first probe 20.

[0036] In this ultrasonic bonding device 1, a first probe 20 is installed on the horn 11, and the first receiver 21 uses the electrical signal received from the first probe 20 during the bonding operation to determine whether the bonding quality of the bonded portion 101 is good or bad, as described above.

[0037] In a typical ultrasonic bonding device, even if the bonding of workpieces is repeated under the same conditions, the bonding strength of each bonding material in the bonded product can vary by several hundred N. In contrast, the ultrasonic bonding device 1 according to this embodiment directly detects the formation of defects 110 in the bonded portion 101, making it less susceptible to the influence of variations in bonding strength and allowing for more accurate determination of the quality of the bond.

[0038] Furthermore, with the ultrasonic bonding device 1, the formation of the defect 110 in the bonding portion 101 is detected during the bonding operation, so there is no need to remove a bonding material, destroy it, and then perform a tensile test to measure the adhesive strength, so the quality of the bonding can be determined more quickly.

[0039] As described above, according to this embodiment, it is possible to provide the ultrasonic bonding device 1 that can accurately and quickly determine whether the bonding quality is good or bad.

[0040] The ultrasonic bonding device 1 may also include a first oscilloscope 22 that visualizes the information obtained from the first receiver 21.

[0041] With this ultrasonic bonding device 1, an operator can visually check the output display of the first oscilloscope 22 to estimate the size of the defect 110 formed in the bonded portion 101 from the reflected signal, and can more quickly or more easily determine whether the bonding quality of the bonded portion 101 is good or bad.

[0042] (Second embodiment) In the ultrasonic bonding apparatus 1 according to the first embodiment, the only probe that detects the ultrasonic waves propagating from the vibrator 14 to the first member 100a and the second member 100b is the first probe 20 installed on the horn 11. In contrast, in the ultrasonic bonding apparatus 2 according to the second embodiment, in addition to the first probe 20, a second probe 26 is installed on the stage 10 as a probe that detects the ultrasonic waves propagating from the vibrator 14 to the first member 100a and the second member 100b.

[0043] Fig. 3 is a schematic diagram of the ultrasonic bonding device 2. Here, in the ultrasonic bonding device 2, the same components as those in the ultrasonic bonding device 1 according to the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. For convenience, the first probe 20 and the first receiver 21 are not shown in Fig. 3.

[0044] The ultrasonic bonding device 2 includes a second probe 26, a second receiver 27, and a second oscilloscope .

[0045] The second probe 26 is mounted on the stage 10 and detects ultrasonic waves propagated from the oscillator 14 to the first member 100a and the second member 100b via the horn 11 during the bonding operation. The second probe 26 may be a so-called single oscillator type probe.

[0046] Similar to the first receiver 21 in the first embodiment, the second receiver 27 receives an electrical signal from the second probe 26. In this embodiment, the second receiver 27, similar to the second probe 26, is installed on the stage 10.

[0047] The second oscilloscope 28 visualizes the information obtained from the second receiver 27. Here, the information obtained from the second receiver 27 is information related to the electrical energy supplied from the second probe 26. The second oscilloscope 28 may be shared with the first oscilloscope 22.

[0048] Next, the operation of the ultrasonic bonding device 2 will be described.

[0049] 4 is a schematic diagram for explaining the inspection principle when inspecting the bonding quality of a bonded portion 101 between a first member 100a and a second member 100b during a bonding operation in the ultrasonic bonding apparatus 2. In accordance with FIG. 2 in the first embodiment, FIG. 4 shows only the first member 100a and the second member 100b, as well as the vibrator 14, the first probe 20, the second probe 26, and the second receiver 27. In other words, FIG. 4 also does not show components such as the stage 10 in contact with the bottom surface 102, the bonding tool 12 in contact with the top surface 103, and the horn 11 that holds the vibrator 14 and the first probe 20.

[0050] In the ultrasonic bonding device 2, the control device 16 inspects the bonding quality of the bonded portion 101 in accordance with the bonding operation as follows. Specifically, during the bonding operation, ultrasonic vibrations caused by the vibrator 14 propagate as pulse waves to the second member 100b and the first member 100a, and are directly received by the second probe 26 installed on the stage 10.

[0051] For example, in a portion of the bonded portion 101 where the defect 110 is not formed, the pulse wave emitted from the transducer 14 passes through the bonded portion 101, reaches the bottom surface 102, and then directly reaches the second probe 26. In Fig. 4, the trajectory of the pulse wave in this case is indicated by a dashed line as the third ultrasonic beam BM3.

[0052] On the other hand, at a portion of the bonded portion 101 where a defect 110 is formed, the pulse wave emitted from the transducer 14 reaches the defect 110, but is blocked by the defect 110 and does not reach the second probe 26. In Fig. 4, the trajectory of the pulse wave in this case is indicated by a dashed line as a fourth ultrasonic beam BM4.

[0053] Thus, there is a difference between a portion of the bonded portion 101 where the defect 110 is not formed and a portion where the defect 110 is formed, in terms of whether the second probe 26 detects the pulse wave transmitted from the vibrator 14. Therefore, by using the first probe 20 as exemplified in the first embodiment and visualizing the electrical signal obtained when the second probe 26 is used as a reflected signal by the second oscilloscope 28, it is possible to more accurately determine whether the bonding quality of the bonded portion 101 is good or bad.

[0054] In this way, the ultrasonic bonding device 2 may be provided with a second probe 26 that is installed on the stage 10 and detects ultrasonic waves propagated from the horn 11 to the first member 100a and the second member 100b, and a second receiver 27 that receives an electrical signal from the second probe 26.

[0055] The ultrasonic bonding device 2 uses both a first probe 20 that detects the reflected wave of the pulse wave transmitted from the vibrator 14 and a second probe 26 that directly detects the pulse wave. Therefore, the ultrasonic bonding device 2 can more accurately determine whether the bonding quality of the bonded portion 101 is good or bad than when only the first probe 20 is used.

[0056] In the ultrasonic bonding apparatus 2, the second receiver 27 may be installed on the stage .

[0057] Unlike the horn 11, the stage 10 is not provided with the vibrator 14, the pressure device 15, etc. Therefore, according to this ultrasonic bonding device 2, by providing the second receiver 27 on the stage 10, it is possible to prevent the ultrasonic bonding device 2 from becoming large.

[0058] Furthermore, the ultrasonic bonding device 2 may include a second oscilloscope 28 for visualizing the information obtained from the second receiver 27.

[0059] According to this ultrasonic bonding apparatus 2, as in the first embodiment, the worker can more quickly or more easily determine whether the bonding quality of the bonded portion 101 is good or bad by visually checking the output display of the second oscilloscope 28.

[0060] In the above-described embodiments, the first oscilloscope 22 or the second oscilloscope 28 is used to visualize the information obtained from the first receiver 21 or the second receiver 27. However, visualization using the first oscilloscope 22 or the like is not essential. For example, image processing may be performed based on the information obtained from the first receiver 21 or the second receiver 27, such that the intensity of the pulse wave is displayed as gradations of brightness, and the image may be displayed on a display device (not shown). Such image processing allows the worker to grasp the internal state of the bonding material more specifically, which may result in the condition of the defective portion 110 being more easily identified.

[0061] In the above embodiments, the multiple members to be joined 100 are assumed to be a first member 100a and a second member 100b. However, the multiple members to be joined 100 need only include at least a first member 100a and a second member 100b, and three or more members to be joined, including other members to be joined, may be ultrasonically joined simultaneously. Furthermore, the members to be joined 100 are not limited to flat metal members, but may also be rod-shaped members or the core wires of electric wires, for example.

[0062] Although the embodiments have been described above, the embodiments are not limited to these, and various modifications are possible within the scope of the gist of the embodiments. [Explanation of symbols]

[0063] 1,2 Ultrasonic bonding equipment 10 stages 11 Horn 14 oscillator 20 1st probe 21 First Receiver 22 First Oscilloscope 26 2nd probe 27 Second receiver 28 Second Oscilloscope 100a First member 100b Second member

Claims

1. a stage on which at least a portion of the first member is placed; a horn that applies ultrasonic vibrations to a second member while pressing the second member against the first member placed on the stage, thereby joining the first member and the second member together; a vibrator that is installed on the horn and serves as a source of the ultrasonic vibration; a first probe that is installed on the horn and detects ultrasonic waves propagated from the transducer to the first member and the second member; a first receiver that receives an electrical signal from the first probe; An ultrasonic bonding device comprising:

2. The ultrasonic bonding apparatus of claim 1 , further comprising a first oscilloscope for visualizing information obtained from the first receiver.

3. a second probe that is installed on the stage and detects ultrasonic waves propagated from the transducer to the first member and the second member; a second receiver that receives an electrical signal from the second probe; The ultrasonic bonding device according to claim 1 or 2, comprising:

4. The ultrasonic bonding apparatus according to claim 3 , wherein the second receiver is installed on the stage.

5. 4. The ultrasonic bonding apparatus of claim 3, further comprising a second oscilloscope for visualizing information obtained from the second receiver.

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