Determination device

Abstract

The present disclosure provides a technique for inspecting the strength of a joint portion of a joined body without destroying the joined body.SOLUTION: A determination device comprising: an imaging unit configured to simultaneously image a first member, a second member, and a jig when the first member and the second member are ultrasonically bonded using the jig that pressurizes and vibrates the first member and the second member; and a calculation unit configured to determine a vibration state of each of the first member, the second member, and the jig based on an image captured by the imaging unit, and determine a bonding state of the first member and the second member based on the determined vibration state of each of the first member, the second member, and the jig.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a determination device. [Background technology]

[0002] Patent Document 1 discloses a bonding strength evaluation device that evaluates the bonding strength of a bonded portion where multiple bonding members are overlapped and bonded. Patent Document 1 discloses that the device is provided with a determination means that determines whether the bonding strength of the bonded portion has reached a desired strength based on temperatures measured by temperature sensors at multiple different measurement positions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-008424 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a need to inspect the strength of the bonded portion of a bonded body without destroying the bonded body.

[0005] The present disclosure provides a technique for inspecting the strength of a bonded portion of a bonded body without destroying the bonded body. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided a determination device that includes: an imaging unit that simultaneously images a first member, a second member, and a jig that applies pressure to and vibrates a first member and a second member when ultrasonically bonding the first member and the second member using the jig; and a calculation unit that determines the vibration states of the first member, the second member, and the jig based on the images captured by the imaging unit, and determines the bonding state between the first member and the second member based on the determined vibration states of the first member, the second member, and the jig. [Effects of the Invention]

[0007] According to the determination device of the present disclosure, the strength of the bonded portion of the bonded body can be determined without destroying the bonded body. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an overview of an ultrasonic bonding device in which a determination device according to this embodiment is used. [Figure 2] FIG. 2 is a diagram illustrating an outline of the determination device according to this embodiment. [Figure 3] FIG. 3 is a flowchart illustrating the processing in the calculation unit of the determination device according to this embodiment. [Figure 4] FIG. 4 is a diagram illustrating an operating state immediately after the start of bonding of the ultrasonic bonding apparatus in which the determination device according to this embodiment is used. [Figure 5] FIG. 5 is a diagram illustrating an operating state after bonding of the ultrasonic bonding apparatus in which the determination apparatus according to this embodiment is used. [Figure 6] FIG. 6 is a diagram illustrating an example of the operation of the determination device according to this embodiment. [Figure 7] FIG. 7 is a diagram illustrating an example of the operation of the determination device according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that, in the description of the specification and drawings relating to each embodiment, components having substantially the same or corresponding functional configurations may be designated by the same reference numerals, and redundant description may be omitted. Furthermore, to facilitate understanding, the scale of each part in the drawings may differ from the actual scale.

[0010] In the directions of parallel, right-angle, orthogonal, horizontal, vertical, up-down, left-right, front-back, etc., deviations are permitted to the extent that they do not impair the effects of the embodiments. The shape of the corners is not limited to right angles and may be rounded. Parallel, right-angle, orthogonal, horizontal, and vertical may include approximately parallel, approximately right-angle, approximately orthogonal, approximately horizontal, and approximately vertical, respectively.

[0011] For example, "substantially parallel" means that even if two lines or two surfaces are not completely parallel to each other, they can be treated as parallel as long as it is within the range of manufacturing tolerance. As with "substantially parallel," "substantially right angle," "substantially perpendicular," "substantially horizontal," and "substantially vertical" are also intended to fall under the respective terms as long as the relative position of the two lines or surfaces is within the range of manufacturing tolerance.

[0012] The determination device according to this embodiment will be described. The determination device according to this embodiment includes an imaging unit and a calculation unit. The imaging unit in the determination device according to this embodiment simultaneously images the first member, the second member, and the jig when ultrasonically bonding the first member and the second member using a jig that applies pressure and vibrates. The calculation unit in the determination device according to this embodiment determines the vibration states of the first member, the second member, and the jig based on the images captured by the imaging unit. The calculation unit in the determination device according to this embodiment then determines the bonding state between the first member and the second member based on the determined vibration states of the first member, the second member, and the jig.

[0013] The determination device according to the present embodiment may further include a temperature measurement unit that measures the temperature of at least one of the first member, the second member, and the jig during ultrasonic bonding. The calculation unit in the determination device according to the present embodiment may further determine the bonding state based on the measured temperature.

[0014] The determination device according to the present embodiment will be described in detail with reference to the drawings. Fig. 1 is a diagram illustrating an outline of an ultrasonic bonding device 1, which is an example of an ultrasonic bonding device in which the determination device according to the present embodiment is used.

[0015] For ease of explanation, the drawings include a virtual three-dimensional coordinate system (XYZ Cartesian coordinate system) consisting of mutually orthogonal X, Y, and Z axes (XYZ axes). For coordinate axes perpendicular to the paper surface of the drawings, a cross in a circle indicates that the axis faces the back of the paper. Furthermore, a black circle in a circle indicates that the axis faces the front of the paper.

[0016] However, this coordinate system is defined for the purpose of explanation and does not limit the attitude of the determination device, ultrasonic bonding device, etc. according to this embodiment.

[0017] The ultrasonic bonding apparatus 1 ultrasonically bonds different members together. In the example of Fig. 1, the ultrasonic bonding apparatus 1 bonds a member UTP and a member DTP.

[0018] The ultrasonic bonding device 1 includes an ultrasonic horn 11, a horn tip 12, and an anvil 13. The UTP and DTP members to be bonded are placed between the horn tip 12 and the anvil 13. With the UTP and DTP members to be bonded placed between the horn tip 12 and the anvil 13, the horn tip 12 is ultrasonically vibrated while pressure is applied to it, thereby bonding the UTP and DTP members.

[0019] The UTP member and the DTP member may be made of the same or different metals. Alternatively, the UTP member and the DTP member may be made of a resin material. Furthermore, one of the UTP member and the DTP member may be made of metal, and the other may be made of resin.

[0020] The member UTP and the member DTP may be members that constitute an electromagnetic switch. For example, the member UTP may be a contact in the electromagnetic contactor, and the member DTP may be a base in the electromagnetic contactor.

[0021] The ultrasonic horn 11 generates ultrasonic vibrations. The ultrasonic horn 11 has a horn tip 12 at its tip. The ultrasonic horn 11 vibrates the horn tip 12 in the direction of arrow A. The ultrasonic horn 11 vibrates the horn tip 12 at a frequency of, for example, 10 kilohertz to 100 kilohertz.

[0022] Horn tip 12 vibrates in the direction of arrow A while pressure is changed in the direction of arrow B. To prevent misalignment of the component, in the example of Figure 1, with horn tip 12, knurling or the like is applied to the surface that comes into contact with the component UTP.

[0023] The anvil 13 is where the members to be joined, in the example of Fig. 1, the members UTP and DTP, are placed. The anvil 13 is what is called an anvil. The anvil 13 has knurling or the like applied to the surface that comes into contact with the member DTP so that the members, in the example of Fig. 1, the member DTP, does not shift from the anvil 13 when ultrasonically vibrated.

[0024] The ultrasonic horn 11 and the anvil 13 are each made of, for example, hardened carbon steel.

[0025] When performing bonding using the ultrasonic bonding device 1, parameters include load, amplitude, and vibration time. These parameters are adjusted as desired according to the material and dimensions of the objects to be bonded.

[0026] Next, the determination device according to this embodiment will be described. Fig. 2 is a diagram illustrating an outline of a determination device 2, which is an example of the determination device according to this embodiment.

[0027] The determination device 2 determines the bonding state of the members by the ultrasonic bonding device 1. Explaining this using the example of Fig. 2, the determination device 2 determines the bonding state of the members UTP and DTP when the members UTP and DTP are bonded by the ultrasonic bonding device 1.

[0028] The determination device 2 includes an imaging unit 21, a temperature measurement unit 22, and a calculation unit .

[0029] In the ultrasonic bonding device 1, when ultrasonic bonding is performed using the horn tip 12 that applies pressure to and vibrates the UTP and DTP members, the imaging unit 21 simultaneously captures images of the UTP member, the DTP member, and the horn tip 12. The imaging unit 21 is, for example, a high-speed camera.

[0030] The ultrasonic bonding device 1 vibrates the horn tip 12 at a predetermined frequency. As the horn tip 12 vibrates, the member UTP and the member DTP each enter a vibrating state (vibrating body) or a stationary state (stationary state). To be able to determine whether the horn tip 12, the member UTP, and the member DTP are vibrating, the imaging unit 21 is preferably a high-speed camera capable of capturing images at a frame rate within a range of, for example, 10,000 frames per second to 1,000,000 frames per second.

[0031] In the ultrasonic bonding device 1, when the horn tip 12 that applies pressure to and vibrates the UTP and DTP members is used to ultrasonically bond the UTP and DTP members, the temperature measuring unit 22 measures the temperature of at least one of the UTP member, the DTP member, and the horn tip 12. The temperature measuring unit 22 is, for example, a thermal camera. The temperature measuring unit 22 is a non-contact sensor.

[0032] When imaging is performed by the imaging unit 21, no specific patterns are applied to the UTP material and the DTP material, and no pre-processing is performed. Furthermore, imaging by the imaging unit 21 and temperature measurement by the temperature measurement unit 22 are performed in a non-contact, non-destructive, and non-heating manner.

[0033] The calculation unit 23 determines the vibration states of the member UTP, the member DTP, and the horn tip 12 based on the images captured by the imaging unit 21. Then, the calculation unit 23 determines the bonding state between the member UTP and the member DTP based on the determined vibration states of the member UTP, the member DTP, and the horn tip 12.

[0034] The calculation unit 23 uses digital image correlation (DIC) on the moving image captured by the imaging unit 21 to calculate the vibration modes and deformation amounts of the members UTP, DTP, and horn tip 12 during ultrasonic bonding.

[0035] By using the DIC method, for example, it is possible to process the images in the calculation unit 23 without pre-processing and without providing a unique pattern to each of the members UTP and DTP.

[0036] Using the image analysis results, the calculation unit 23 determines that the bonding is satisfactory if the component UTP and the horn tip 12 vibrate together at first, and then vibrate together after a certain period of time has passed. On the other hand, if the component UTP and the horn tip 12 do not vibrate together at first, the calculation unit 23 determines that the horn tip 12 has not sufficiently fixed the component UTP. Furthermore, even if the component UTP and the component DTP vibrate together at first, the calculation unit 23 determines that the horn tip 12 has not sufficiently fixed the component UTP. Furthermore, if the component UTP and the horn tip 12 vibrate together at first, and then the component UTP and the component DTP do not vibrate together, the calculation unit 23 determines that the bonding is not satisfactory.

[0037] Regarding whether or not the components UTP, DTP, and horn tip 12 are vibrating together, the calculation unit 23 determines that they are vibrating together when, for example, the difference between the movement amounts of the components UTP, DTP, and horn tip 12 falls below a predetermined lower limit value.

[0038] The calculation unit 23 may also make a determination based on temperature measurement using the temperature measurement unit 22. If the bonding is good, heat is actively generated at the bonding interface, so the quality of the bonding can be determined by monitoring the source of heat. For example, the calculation unit 23 may determine the bonding condition by calculating the maximum temperature measured by the temperature measurement unit 22 and the source of the temperature rise.

[0039] It is known that there is a correlation between the temperature during joining and the bond strength in ultrasonic bonding. Therefore, by numerically clarifying the relationship between the temperature during joining and the bond strength for the members to be ultrasonically bonded in advance, if the temperature measured by the temperature measuring unit 22 is equal to or higher than a threshold value, the bond state is determined to be good.

[0040] The processing by the calculation unit 23 will be described in detail. Fig. 3 is a flow chart illustrating processing in the calculation unit 23 of the determination device 2, which is an example of a determination device according to this embodiment. Fig. 3 is a flow chart illustrating processing when joining a member UTP and a member DTP in the determination device 2.

[0041] (Step S10) First, when the ultrasonic bonding device 1 starts operating, the calculation unit 23 determines whether the member UTP is vibrating by processing the video captured by the imaging unit 21. When the ultrasonic bonding device 1 starts operating and the member UTP and the member DTP have not yet been bonded, the member UTP vibrates.

[0042] This section explains the operating states of the horn tip 12, the UTP member, and the DTP member immediately after joining the UTP member and the DTP member by the ultrasonic joining device 1. Fig. 4 is a diagram explaining the operating state immediately after joining starts of the ultrasonic joining device 1 using the determination device 2, which is an example of the determination device according to this embodiment.

[0043] In the ultrasonic bonding device 1, immediately after starting to bond the UTP and DTP components, the horn tip 12 vibrates as shown by arrow A1, causing the UTP component to vibrate as shown by arrow A2. On the other hand, the DTP component does not vibrate much. Therefore, heat is generated at the bonding interface between the UTP and DTP components due to friction between the UTP and DTP components. In Figure 4, range R1 indicates the range where heat is generated. Range R1, which indicates the heat generation range, is the bond between the UTP and DTP components. In other words, if the bond between the UTP and DTP components is good, the bond between the UTP and DTP components will generate heat.

[0044] As described above, when the ultrasonic bonding device 1 starts operating and the member UTP and the member DTP have not yet been bonded, the member UTP vibrates, so the calculation unit 23 determines whether the member UTP is vibrating. If the member UTP is vibrating (YES in step S10), the calculation unit 23 proceeds to step S20. If the member UTP is not vibrating (NO in step S10), the calculation unit 23 proceeds to step S70.

[0045] (Step S20) Next, the calculation unit 23 waits for a certain period of time to pass. For example, the calculation unit 23 waits for about 0.5 to 1.5 seconds. By waiting for the certain period of time to pass, the calculation unit 23 waits for the joining of the member UTP and the member DTP to progress.

[0046] (Step S30) Next, the calculation unit 23 processes the video captured by the imaging unit 21 to determine whether the vibration of the member UTP has decreased. When the ultrasonic bonding device 1 starts operating and the member UTP and the member DTP are bonded, the vibration of the member UTP decreases. Therefore, the calculation unit 23 determines whether the vibration of the member UTP has decreased.

[0047] This section describes the operating states of the horn tip 12, the UTP member, and the DTP member when the UTP member and the DTP member are joined by the ultrasonic joining device 1. Fig. 5 is a diagram for explaining the operating state after joining of the ultrasonic joining device 1 in which the determination device 2, which is an example of the determination device according to this embodiment, is used.

[0048] In the ultrasonic bonding apparatus 1, even if the horn tip 12 vibrates as shown by the arrow A1 after the UTP member and the DTP member are bonded, the movement of the UTP member is inhibited by bonding to the DTP member, and the vibration of the UTP member is reduced as shown by the arrow A21. In Fig. 5, the range R2 indicates the portion (bonded portion) where the UTP member and the DTP member are bonded.

[0049] As described above, after the member UTP and the member DTP are joined, the vibration of the member UTP decreases, so the calculation unit 23 determines whether the vibration of the member UTP has decreased. If the vibration of the member UTP has decreased (YES in step S30), the calculation unit 23 proceeds to step S40. If the vibration of the member UTP has not decreased (NO in step S30), the calculation unit 23 proceeds to step S70.

[0050] (Step S40) Next, the calculation unit 23 determines, based on measurement by the temperature measurement unit 22, whether the location where heat is being generated (heat generating location) is near the joint between the members UTP and DTP. When the ultrasonic bonding device 1 starts operating and the members UTP and DTP are bonded, heat is generated at the joint between the members UTP and DTP. Therefore, the calculation unit 23 determines whether the heat generating location is near the joint between the members UTP and DTP. If the heat generating location is near the joint between the members UTP and DTP (YES in step S40), the calculation unit 23 proceeds to step S50. If the heat generating location is not near the joint between the members UTP and DTP (NO in step S40), the calculation unit 23 proceeds to step S70.

[0051] (Step S50) Next, the calculation unit 23 determines whether the heat-generating location, i.e., the joint between the UTP and DTP members, has reached a predetermined temperature range based on measurements by the temperature measurement unit 22. It is known that when the UTP and DTP members are sufficiently joined, the temperature of the joint between the UTP and DTP members will reach a predetermined temperature or higher. Therefore, the calculation unit 23 determines whether the joint between the UTP and DTP members has reached a predetermined temperature range. If the joint between the UTP and DTP members has reached a predetermined temperature range (YES in step S50), the calculation unit 23 proceeds to step S60. If the joint between the UTP and DTP members has not reached a predetermined temperature range (NO in step S50), the calculation unit 23 proceeds to step S70.

[0052] (Step S60) The calculation unit 23 determines that the joined members UTP and DTP are non-defective. That is, the calculation unit 23 determines that the joining between the members UTP and DTP is good. Then, the calculation unit 23 ends the processing.

[0053] (Step S70) The calculation unit 23 determines that the joined members UTP and DTP are defective. That is, the calculation unit 23 determines that the joining of the members UTP and DTP is defective. Then, the calculation unit 23 ends the process.

[0054] The following describes the results of actual measurements performed using the determination device 2. Figures 6 and 7 are diagrams illustrating an example of the operation of the determination device 2, which is an example of the determination device according to this embodiment.

[0055] Figure 6 shows an example of operation when the contacts of the electromagnetic contactor are joined to the base. The horizontal axis of Figure 6 represents time (unit: seconds), and the vertical axis represents vibration amplitude (unit: micrometers). Line L1 represents the measurement results for the horn tip 12, line L2 represents the measurement results for the contacts corresponding to the UTP member, and line L3 represents the measurement results for the base corresponding to the DTP member.

[0056] 6, it can be seen that the contact point corresponding to the UTP member vibrates together with the horn tip 12, and the vibration decreases in the latter half. It can also be seen that the vibration of the base corresponding to the DTP member increases in the latter half as the contact point joins.

[0057] Fig. 7 is a diagram illustrating the results of measurements made by the temperature measurement unit 22. The horizontal axis of Fig. 6 represents time (unit: seconds), and the vertical axis represents temperature (unit: °C). Line L4 represents the measurement result of the temperature of the joint between the contact point corresponding to the member UTP and the base corresponding to the member DTP.

[0058] From FIG. 7, it can be seen that the temperature rises when the contact point corresponding to the member UTP and the base corresponding to the member DTP are joined.

[0059] The determination device according to the present embodiment can non-destructively determine the bonded state in ultrasonic bonding. The determination device according to the present embodiment can easily determine the bonded state in ultrasonic bonding.

[0060] For example, a compressive shear strength test is commonly used to evaluate the bond strength of bonded joints. The compressive shear strength test requires the creation of a jig that matches the testing machine. Furthermore, the compressive shear strength test may require a test piece to be machined into a specific shape in order to be fixed to the jig. Furthermore, the compressive shear strength test requires, for example, machining into a specific shape after bonding. Therefore, when using the compressive shear strength test, the bond is destroyed to measure the strength, making full inspection impossible. Therefore, when using the compressive shear strength test, sampling inspection is required.

[0061] For example, in the technology disclosed in Patent Document 1, laser light intensity-modulated by a sinusoidal function is focused and irradiated onto ultrasonically bonded components at a measurement position on the upper surface of the bonded components. A technology is presented in which the temperature is measured using a radiation thermometer from the lower surface directly below the irradiated portion, and the bond is evaluated non-destructively based on the phase delay. However, as described in Patent Document 1, irradiating the bonded portion with laser light heats the bonded components, which may cause deterioration of the bond. Furthermore, with the technology disclosed in Patent Document 1, the evaluation is performed using a device separate from the bonding device, making it difficult to evaluate the bond on the spot.

[0062] The determination device according to this embodiment can non-destructively determine the bonded state in ultrasonic bonding, and therefore, the determination device according to this embodiment can inspect all bonded members.

[0063] The member DTP is an example of a first member, the member UTP is an example of a second member, and the horn tip 12 is an example of a jig.

[0064] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0065] 1 Ultrasonic bonding equipment 2 Judgment device 11 Ultrasonic Horn 12 Horn Tip 13 Anvil 21 Imaging unit 22 Temperature measurement section 23 Arithmetic section DTP, UTP materials

Claims

1. an imaging unit that simultaneously images the first member, the second member, and the jig when ultrasonic bonding is performed using a jig that applies pressure and vibrates to the first member and the second member; a calculation unit that determines a vibration state of each of the first member, the second member, and the jig based on the images captured by the imaging unit, and determines a joining state between the first member and the second member based on the determined vibration states of each of the first member, the second member, and the jig; Equipped with Judgment device.

2. a temperature measuring unit that measures a temperature of at least one of the first member, the second member, and the jig during the ultrasonic bonding; The calculation unit further determines the bonding state based on the measured temperature. The determination device according to claim 1 .

3. Each of the first member and the second member is made of a metal. The determination device according to claim 1 or 2.

4. Each of the first member and the second member is made of resin. The determination device according to claim 1 or 2.

5. One of the first member and the second member is made of metal, and the other is made of resin. The determination device according to claim 1 or 2.

6. The temperature measurement unit is a non-contact type. The determination device according to claim 2 .

7. The determination is made without destroying or heating the joined first and second members. The determination device according to claim 1 or 2.

8. The judgment is made without forming any specific pattern on each of the joined first member and the joined second member and without pre-processing. The determination device according to claim 1 or 2.

9. Each of the first member and the second member is a member that constitutes an electromagnetic switch. The determination device according to claim 1 or 2.

10. the calculation unit first vibrates the second member and the jig together, and when the first member and the second member vibrate together after a certain period of time has elapsed, determines that the bonding between the first member and the second member is good; The determination device according to claim 1 or 2.

Images