JP4983236B2 - Ultrasonic bonding inspection apparatus, ultrasonic bonding inspection method, ultrasonic bonding apparatus, and ultrasonic bonding method - Google Patents

Description

  The present invention relates to an ultrasonic bonding inspection apparatus, an ultrasonic bonding inspection method, an ultrasonic bonding apparatus, and an ultrasonic bonding method.

  Secondary batteries such as lithium ion batteries and nickel metal hydride batteries are actively developed as power sources for driving motors of electric vehicles and hybrid electric vehicles. In an assembled battery configured by stacking and electrically connecting a plurality of flat unit cells in which a power generation element is sealed in an exterior member, an electrode tab led out from the exterior member of a plurality of adjacent unit cells, They are joined together by ultrasonic joining.

  As a method for inspecting the bonding state of the ultrasonically bonded electrode tabs, a predetermined force is applied in a direction in which the electrode tabs bonded to each other are peeled off, and it is determined whether or not the electrode tabs are broken. A method for inspecting the bonding strength of a tab is known. However, in the mechanical inspection method for determining whether or not the electrode tab breaks, the electrode tab is joined due to deformation of the electrode tab when a force is applied to the electrode tab and metal fatigue of the electrode tab (load application history). Strength may be deteriorated. Therefore, the electrode tab (single cell) after inspection must be discarded, and the electrode tab is inspected by sampling.

The following Patent Document 1 discloses a method of alternatively detecting the joining state of workpieces by measuring the amplitude of ultrasonic vibration during ultrasonic joining.
Japanese Patent Laid-Open No. 06-099289

  The present invention has been made to solve the above problems. Therefore, an object of the present invention is to provide an ultrasonic bonding inspection apparatus and an ultrasonic bonding inspection method capable of inspecting an ultrasonic bonding state without applying a force to the electrode tab, and an ultrasonic bonding apparatus and an ultrasonic bonding using them. Is to provide a method.

  The above object of the present invention is achieved by the following means.

The ultrasonic bonding inspection apparatus of the present invention uses a temperature measuring means for measuring a temperature distribution of a workpiece that has been ultrasonically bonded, and a temperature difference between an unbonded region and an ultrasonic bonding region of the workpiece on which the temperature distribution is measured. to a calculation means for calculating the ultrasonic bonding area of the work, have a, energizing means for generating Joule heat by the ultrasonic bonding region by energization, said temperature measuring means, in the ultrasonic bonding area The temperature distribution of the workpiece in which the ultrasonic bonding region has a higher temperature than the non-bonding region is measured by the Joule heat .
The ultrasonic bonding inspection apparatus of the present invention uses a temperature measuring means for measuring a temperature distribution of a workpiece that has been ultrasonically bonded, and a temperature difference between an unbonded region and an ultrasonic bonding region of the workpiece on which the temperature distribution is measured. And calculating means for calculating the ultrasonic bonding area of the workpiece, and heating means for heating one member constituting the workpiece by radiant heat, the temperature measuring means from the one member The temperature distribution of the other members of the workpiece in which the ultrasonic bonding region has a higher temperature than the unbonded region is measured by heat conduction.

In the ultrasonic bonding inspection method of the present invention, the step of generating Joule heat in the ultrasonic bonding region of the ultrasonically bonded workpiece by energization, the step of measuring the temperature distribution of the workpiece, and the temperature distribution are measured. that by utilizing a temperature difference between the non-bonded area and the ultrasonic bonding area of the work, possess calculating a ultrasonic bonding region of the workpiece, and in the step of measuring the temperature distribution, the ultrasonic bonding The temperature distribution of the workpiece in which the ultrasonic bonding region has a higher temperature than the unbonded region is measured by Joule heat in the region .
The ultrasonic bonding inspection method of the present invention includes a step of heating one member constituting an ultrasonic bonded workpiece by radiant heat, a step of measuring a temperature distribution of the workpiece, and a workpiece of which the temperature distribution is measured. Calculating the ultrasonic bonding area of the workpiece using a temperature difference between the unbonded area and the ultrasonic bonding area, and in the step of measuring the temperature distribution, heat from the one member The temperature distribution of the other members of the workpiece in which the ultrasonic bonding region has a higher temperature than the unbonded region is measured by conduction.

The ultrasonic bonding apparatus of the present invention is based on ultrasonic bonding means for ultrasonic bonding of workpieces according to bonding conditions, the ultrasonic bonding inspection apparatus, and an ultrasonic bonding area calculated by the ultrasonic bonding inspection apparatus. And a control means for controlling a joining condition when the next workpiece is ultrasonically joined.

Ultrasonic bonding method of the present invention, based on the ultrasonic bonding area which is calculated by the ultrasonic bonding inspection method, characterized that you control the bonding conditions for ultrasonic bonding to the next work.

  According to the ultrasonic bonding inspection apparatus and the ultrasonic bonding inspection method of the present invention, since the ultrasonic bonding region of the workpiece can be calculated from the temperature distribution of the ultrasonic bonded workpiece, the force is not applied to the workpiece. The bonding state can be inspected. Therefore, it is not necessary to discard the workpiece after the inspection, and the joining state of all the workpieces can be inspected.

  In addition, according to the ultrasonic bonding apparatus and the ultrasonic bonding method of the present invention, since the ultrasonic bonding region of the workpiece can be calculated from the temperature distribution of the ultrasonic bonded workpiece, in addition to the above effects, The inspection result of the workpiece can be fed back to the joining condition. Therefore, ultrasonic bonding under optimum bonding conditions can be maintained.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol was used for the same member in the figure.

(First embodiment)
FIG. 1 is a diagram showing a schematic configuration of an ultrasonic bonding inspection apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the ultrasonic bonding inspection apparatus 100 according to the present embodiment includes a thermo camera 200 and a processing unit 300.

  The thermo camera 200 measures the temperature distribution of the electrode tab 900 that is ultrasonically bonded as a temperature measuring means. The thermo camera 200 is disposed so as to face the lower electrode tab 900b of the pair of ultrasonically bonded electrode tabs 900, and images the temperature distribution of the electrode tab 900. Since the thermo camera itself is a general thermo camera, detailed description thereof is omitted. The image information acquired by the thermo camera 200 is transmitted to the processing unit 300.

  The processing unit 300 calculates an ultrasonic bonding region of the electrode tab 900 based on the temperature distribution of the electrode tab 900 to be measured. The processing unit 300 receives the image information transmitted from the thermo camera 200 and calculates the area of the ultrasonic bonding region in the electrode tab 900 by calculating the number of pixels equal to or higher than a predetermined temperature in the image information. The processing unit 300 is, for example, a general computer.

  Next, the processing unit 300 according to the present embodiment will be described in detail with reference to FIG. FIG. 2 is a block diagram showing a schematic configuration of the processing unit 300 in the present embodiment. As illustrated in FIG. 2, the processing unit 300 according to the present embodiment includes a CPU 310, a RAM 320, a ROM 330, a hard disk 340, an input unit 350, a display unit 360, and an interface 370. These units are connected to each other via a bus.

  The CPU 310 performs various calculations on the image information acquired by the thermo camera 200. The CPU 310 functions as a calculation unit (calculation unit), a first determination unit (first determination unit), and a determination unit (determination unit).

  Here, the calculation unit calculates the area of the ultrasonic bonding region by calculating the number of pixels equal to or higher than a predetermined temperature in the image information. The first determination unit determines whether or not the calculated area of the ultrasonic bonding region is less than a lower limit value. The determination unit determines that the electrode tab is poorly bonded when the area of the ultrasonic bonding region is less than the lower limit value. The specific processing contents of each unit will be described later.

  The RAM 320 temporarily stores the above-described image information, and the ROM 330 stores a control program, parameters, and the like in advance.

  The hard disk 340 functions as a storage unit that stores the area of the ultrasonic bonding area calculated for each of the plurality of electrode tabs together with the bonding information of the corresponding electrode tabs. Further, the hard disk 340 calculates the number of pixels equal to or higher than a predetermined temperature in the image information, thereby calculating whether the area of the ultrasonic bonding region is less than a lower limit value. A determination program for determining, and a determination program for determining that the electrode tab is poorly bonded when the area of the ultrasonic bonding region is less than the lower limit value are stored.

  The input unit 350 is a pointing device such as a keyboard, a touch panel, and a mouse, for example. The display unit 360 is a liquid crystal display and a CRT display, for example.

  The interface 370 receives an image signal transmitted from the thermo camera 200.

  As described above, in the ultrasonic bonding inspection apparatus according to the present embodiment configured, the temperature distribution of the electrode tab subjected to ultrasonic bonding is measured, and the ultrasonic distribution of the electrode tab is determined based on the temperature distribution of the electrode tab to be measured. The area of the sonic bonding region is calculated. Then, the quality of the ultrasonic bonding of the electrode tab is determined based on the calculated area of the ultrasonic bonding region. Hereinafter, the ultrasonic bonding inspection method in the present embodiment will be described in detail.

  FIG. 3 is a flowchart showing the ultrasonic bonding inspection method of the present embodiment. In the present embodiment, the temperature distribution of the electrode tab immediately after the ultrasonic bonding that generates heat due to the frictional heat during the ultrasonic bonding is measured, and the quality of the ultrasonic bonding is determined based on the measurement result. More specifically, the ultrasonic bonding region immediately after ultrasonic bonding has a higher temperature than the unbonded region, and the area of the high temperature region corresponding to the ultrasonic bonding region is calculated by the thermo camera, It is determined whether or not the bonding strength of the ultrasonic bonding is sufficient, that is, whether or not the ultrasonic bonding is good.

  As shown in FIG. 3, in the ultrasonic bonding inspection method according to the present embodiment, first, it is determined whether or not the ultrasonic bonding is completed (step S101). When the ultrasonic bonding is not completed (step S101: NO), the process waits until the ultrasonic bonding is completed. On the other hand, when the ultrasonic bonding is completed (step S101: YES), it is determined whether or not a predetermined time has elapsed from the end of the ultrasonic bonding (step S102).

  If the predetermined time has not elapsed (step S102: NO), the process waits until the predetermined time elapses. On the other hand, when the predetermined time has elapsed (step S102: YES), the temperature distribution of the electrode tab is imaged by the thermo camera, and image information is acquired (step S103). As described above, the electrode tab immediately after ultrasonic bonding has a higher temperature in the ultrasonic bonding region than in the non-bonded region due to frictional heat during ultrasonic bonding.

  Here, FIG. 4A is a view for explaining ultrasonic bonding of the electrode tab in the present embodiment. As shown in FIG. 4A, in the present embodiment, a pair of electrode tabs 900 that are overlapped are sandwiched between a horn 710 and an anvil 720, and a predetermined pressure is applied while the horn 710 is ultrasonic. The electrode tab 900 is ultrasonically bonded by reciprocating linear motion by vibration. More specifically, the horn 710 and the anvil 720 of this embodiment each have a plurality of protrusions 711 and 721, and the region of the electrode tab 900 corresponding to the protrusions 711 and 721 is ultrasonically bonded. .

  FIG. 4B is a diagram showing a thermography of the temperature distribution of the electrode tab measured by the thermo camera. As shown in FIG. 4B, in the electrode tab immediately after ultrasonic bonding of the present embodiment, the ultrasonic bonding region (black portion in the drawing) 910 corresponding to the plurality of protrusions is higher than the unbonded region 920. Has temperature. In the case where the electrode tab 900 is not rubbed because oil or the like is interposed between the upper electrode tab 900a and the lower electrode tab 900b to be ultrasonically bonded, unlike the diagram shown in FIG. Therefore, image information having a low temperature can be obtained.

  Next, the number of pixels equal to or higher than a predetermined temperature in the image information is calculated (step S104), and the image information is stored (step S105). In the present embodiment, the predetermined temperature is set so that the area of the ultrasonic bonding region having a temperature higher than that of the unbonded region is calculated, and the number of pixels equal to or higher than the temperature is calculated. The area is calculated. Further, the image information for which the number of pixels is calculated is stored in the hard disk 340 together with joint information input separately. Note that the bonding information includes the surface roughness of the electrode tab from which the image information has been acquired, the bonding conditions during ultrasonic bonding, and the environment (for example, humidity) during ultrasonic bonding.

  Next, it is determined whether or not the calculated number of pixels is less than a lower limit value (step S106). In other words, it is determined whether or not the area of the ultrasonic bonding region of the electrode tab is less than the lower limit area corresponding to the required bonding strength. In the present embodiment, the lower limit is set based on the temperature distribution of the electrode tab that is measured in advance and has good ultrasonic bonding. When the calculated number of pixels is less than the lower limit value (step S106: YES), it is determined that the bonding strength is insufficient, that is, ultrasonic bonding is defective (step S107), and the process is terminated. The determination result is displayed on the display unit 360, for example.

  On the other hand, if the calculated number of pixels is equal to or greater than the lower limit (step S106: NO), it is determined whether or not the number of pixels is equal to or less than the upper limit (step S108). Here, when an excessively large frictional force is applied to the electrode tab, the high temperature region corresponding to the ultrasonic bonding region becomes large, and the electrode tab may be deteriorated. Therefore, in the present embodiment, it is preferable to set an upper limit value (upper limit area) for determining deterioration of the electrode tab in addition to a lower limit value (lower limit area) for determining the bonding strength.

  If the calculated number of pixels is equal to or greater than the upper limit (step S108: YES), it is determined that the ultrasonic bonding is defective (step S107), and the process is terminated. On the other hand, when the calculated number of pixels is less than the upper limit value (step S108: NO), it is determined that the ultrasonic bonding is good (step S109), and the process ends.

  As described above, according to the processing of the flowchart shown in FIG. 3, the area of the ultrasonic bonding region in the electrode tab is determined using the temperature difference between the ultrasonic bonding region and the non-bonded region of the electrode tab immediately after ultrasonic bonding. Calculated. Then, based on the calculated area, the bonding strength of the electrode tab, that is, the quality of ultrasonic bonding is determined. More specifically, when the area of the ultrasonic bonding region is not less than the upper limit value and less than the lower limit value, it is determined that the ultrasonic bonding is defective.

  In the ultrasonic bonding inspection apparatus of the present embodiment, the area of the ultrasonic bonding region in the electrode tab was calculated. However, the distribution shape (distribution status) of the ultrasonic bonding region can also be calculated from the image information. With such a configuration, it is possible to determine not only the bonding strength of ultrasonic bonding but also whether a desired region of the electrode tab is uniformly ultrasonic bonded. As a result, the bonding quality of the electrode tab is further improved.

  In the present embodiment, the area of the ultrasonic bonding region is calculated by calculating the number of pixels equal to or higher than a predetermined temperature. However, it is also possible to calculate the area of the ultrasonic bonding region by calculating the number of pixels below a predetermined temperature to calculate the unbonded region and obtaining the difference from the entire area.

  As described above, the described embodiment has the following effects.

  The ultrasonic bonding inspection apparatus according to the present embodiment includes a thermo camera that measures the temperature distribution of an electrode tab that has been ultrasonically bonded, and a temperature difference between an unbonded region and an ultrasonic bonding region of the electrode tab in which the temperature distribution is measured. And a calculation unit for calculating an ultrasonic bonding region of the electrode tab. Therefore, since the ultrasonic bonding region of the electrode tab can be calculated from the temperature distribution of the electrode tab subjected to ultrasonic bonding, the bonding state can be inspected without applying a force to the electrode tab. As a result, the bonding state of all electrode tabs can be inspected.

  Further, since the area of the ultrasonic bonding region is directly calculated, there are fewer error factors than in an indirect bonding strength determination method of monitoring the vibration state of the horn. Furthermore, the vibration state of the horn is easily corrected to monitor the temperature, compared with the fact that the vibration state easily changes due to frictional heat at the time of joining and heat generation of the device. It is possible.

  The calculation unit calculates image information acquired by the thermo camera and an ultrasonic bonding region of the electrode tab. Therefore, the size and distribution shape of the ultrasonic bonding region in the electrode tab can be calculated from the temperature distribution of the electrode tab.

  The calculation unit calculates the size of the ultrasonic bonding region by calculating the number of pixels equal to or higher than a predetermined temperature in the image information. Therefore, the area of the ultrasonic bonding region can be easily calculated.

  The ultrasonic bonding inspection apparatus according to the present embodiment includes a first determination unit that determines whether or not the area of the ultrasonic bonding region is less than the lower limit value, and the electrode tab when the area of the ultrasonic bonding region is lower than the lower limit value. And a determination unit that determines that the bonding is defective. Therefore, the strength of ultrasonic bonding is determined from the area of the ultrasonic bonding region, and the quality of ultrasonic bonding can be determined.

  The thermo camera measures the temperature distribution of the electrode tab immediately after ultrasonic bonding in which the ultrasonic bonding region has a higher temperature than the unbonded region due to frictional heat during ultrasonic bonding. Therefore, the temperature distribution of the electrode tab can be measured without applying energy from the outside.

  The ultrasonic bonding inspection apparatus according to the present embodiment further includes a storage unit that stores ultrasonic bonding regions calculated for a plurality of electrode tabs together with bonding information of corresponding electrode tabs. Accordingly, the inspection results can be accumulated, and the trend can be grasped by statistically processing the ultrasonic bonding results. In addition, the inspection result can be fed back to the ultrasonic bonding in response to a change in the material rod and other error factors.

  In the ultrasonic bonding inspection method of the present embodiment, a temperature distribution of an ultrasonically bonded electrode tab is measured, and a temperature difference between an unbonded area and an ultrasonic bonded area of the electrode tab where the temperature distribution is measured is calculated. And utilizing the step of calculating an ultrasonic bonding region of the electrode tab. Therefore, since the ultrasonic bonding region of the electrode tab can be calculated from the temperature distribution of the electrode tab subjected to ultrasonic bonding, the bonding state can be inspected without applying a force to the electrode tab. Therefore, the bonding state of all the electrode tabs can be inspected.

(Second Embodiment)
In the first embodiment, the case of measuring the temperature distribution of the electrode tab immediately after ultrasonic bonding that generates heat due to friction during ultrasonic bonding has been described. In the present embodiment, a case where the electrode tab is heated by applying energy from the outside to the electrode tab at room temperature after ultrasonic bonding and the temperature distribution of the heated electrode tab is measured will be described.

  FIG. 5A is a diagram showing a schematic configuration of an ultrasonic bonding inspection apparatus according to the second embodiment of the present invention. As shown in FIG. 5A, the ultrasonic bonding inspection apparatus 100 of the present embodiment includes a thermo camera 200, a processing unit 300, and a power source 400. Except for the power supply 400, the thermo camera 200 and the processing unit 300 are the same as those in the first embodiment, and thus the description thereof is omitted.

  The power supply 400 generates Joule heat in the electrode tab 900 by energization as an energization means. The power source 400 is connected to the upper electrode tab 900a and the lower electrode tab 900b constituting the pair of electrode tabs 900 that are ultrasonically bonded, and applies a voltage to the electrode tab 900. The power source 400 is electrically connected to the processing unit 300 and can apply a voltage in accordance with a command from the processing unit 300.

  According to the ultrasonic bonding inspection apparatus 100 of the present embodiment configured as described above, first, the power supply 400 applies a voltage to the electrode tab 900 based on a command from the processing unit 300, whereby the upper electrode tab 900a. Current flows through the ultrasonic bonding region 910 where the lower electrode tab 900b is solid-phase bonded, and Joule heat is generated in the ultrasonic bonding region 910 (see FIG. 5B). The temperature distribution of the electrode tab 900 in which the ultrasonic bonding region 910 has a temperature higher than that of the non-bonded region due to Joule heat generated in the ultrasonic bonding region 910 is measured by a thermo camera. The quality of joining is judged.

  In addition, when the state which generate | occur | produces a Joule heat in the ultrasonic joining area | region 910 continues for a long time, since the electrode tab 900 whole becomes the substantially same temperature, the ultrasonic joining area | region 910 cannot be calculated. Therefore, the temperature distribution of the electrode tab 900 after the elapse of a predetermined time from energization is measured. Moreover, since it is the same as that of 1st Embodiment except the electrode tab 900 being heated by electricity supply, the detailed description about the ultrasonic bonding method of this Embodiment is abbreviate | omitted.

  As described above, the present embodiment described has the following effects in addition to the effects of the first embodiment.

  The ultrasonic bonding inspection apparatus according to the present embodiment further includes a power source that generates Joule heat in the ultrasonic bonding region by energization, and the thermo camera has not joined the ultrasonic bonding region due to Joule heat in the ultrasonic bonding region. The temperature distribution of the electrode tab having a higher temperature than the region is measured. Therefore, the temperature distribution of the electrode tab is not limited to the electrode tab immediately after ultrasonic bonding, and the temperature distribution of the electrode tab can be measured at any timing, and the ultrasonic bonding region can be calculated.

(Third embodiment)
In the present embodiment, the electrode tab is heated by applying radiant heat to the electrode tab in a room temperature state that has been ultrasonically bonded, and the temperature distribution of the heated electrode tab is measured.

  FIG. 6A is a diagram showing a schematic configuration of an ultrasonic bonding inspection apparatus according to the third embodiment of the present invention. As shown in FIG. 6A, the ultrasonic bonding inspection apparatus 100 according to the present embodiment includes a thermo camera 200, a processing unit 300, and a heater 500. Except for the heater 500, the thermo camera 200 and the processing unit 300 are the same as those in the first embodiment, and thus the description thereof is omitted.

  The heater 500 heats the upper electrode tab 900a of the pair of electrode tabs 900 to be ultrasonically bonded by radiant heat as a heating means. The heater 500 is disposed on the opposite side of the thermo camera 200 with respect to the electrode tab 900, and supplies radiant heat to the upper electrode tab 900a joined to the lower electrode tab 900b facing the thermo camera 200. The heater 500 is electrically connected to the processing unit 300 and can supply radiant heat in response to a command from the processing unit 300.

  According to the ultrasonic bonding inspection apparatus 100 of the present embodiment configured as described above, first, the heater 500 supplies radiant heat to the electrode tab 900 based on a command from the processing unit 300, so that the heater 500 The opposing upper electrode tab 900a is heated. When the upper electrode tab 900a is heated, the ultrasonic bonding region 910 in which the upper electrode tab 900a and the lower electrode tab 900b are solid-phase bonded has air between the upper electrode tab 900a and the lower electrode tab 900b. Heat is transferred in a shorter time than the unbonded region where the layer is interposed. Therefore, when the upper electrode tab 900a is heated, the ultrasonic bonding region 910 of the lower electrode tab 900b has a higher temperature than the unbonded region due to heat conduction from the upper electrode tab 900a (see FIG. 6B). . The temperature distribution of the lower electrode tab 900b in which the ultrasonic bonding region 910 has a higher temperature than the unbonded region is measured by the thermo camera, and the quality of the ultrasonic bonding is determined based on the measurement result.

  Note that, when radiant heat is supplied to the upper electrode tab 900a for a long time, the entire electrode tab 900 is at substantially the same temperature, and the ultrasonic bonding region 910 cannot be calculated. Therefore, the temperature distribution of the electrode tab 900 after the elapse of a predetermined time from the start of radiation is measured. Moreover, since it is the same as that of 1st Embodiment except the electrode tab 900 being heated by radiant heat, the detailed description about the ultrasonic bonding method of this Embodiment is abbreviate | omitted.

  As described above, the present embodiment described has the following effects in addition to the effects of the first and second embodiments.

  The ultrasonic bonding inspection apparatus of the present embodiment further includes a heater that heats the upper electrode tab constituting the electrode tab by radiant heat, and the thermo camera has an ultrasonic bonding region that is not bonded due to heat conduction from the upper electrode tab. The temperature distribution of the lower electrode tab having a higher temperature than the region is measured. Therefore, the temperature distribution of the electrode tab is not limited to the electrode tab immediately after ultrasonic bonding, and the temperature distribution of the electrode tab can be measured at any timing, and the ultrasonic bonding region can be calculated. Furthermore, no large-scale equipment is required.

(Fourth embodiment)
This embodiment is an embodiment of an ultrasonic bonding apparatus in which the ultrasonic bonding inspection apparatus of the first to third embodiments is incorporated.

  FIG. 7 is a diagram showing a schematic configuration of an ultrasonic bonding apparatus according to the fourth embodiment of the present invention. As shown in FIG. 7, the ultrasonic bonding apparatus 600 according to the present embodiment includes a thermo camera 200, a processing unit 300, an ultrasonic bonding unit 700, and a control unit 800. Except for the ultrasonic bonding unit 700 and the control unit 800, the thermo camera 200 and the processing unit 300 are the same as those in the first embodiment, and a description thereof will be omitted.

  The ultrasonic bonding unit 700 is an ultrasonic bonding unit that ultrasonically bonds the electrode tab 900 in accordance with bonding conditions. The ultrasonic bonding unit 700 ultrasonically bonds the electrode tab 900 by applying ultrasonic vibration to the set of electrode tabs 900 that are overlapped. In addition, the ultrasonic bonding unit 700 includes a horn 710 that presses the electrode tab 900 while being reciprocated linearly by ultrasonic vibration, and an anvil 720 that supports the electrode tab pressed by the horn 710. Moreover, in this Embodiment, the horn 710 and the anvil 720 are provided with the some projection part 711,721, respectively.

  The control unit 800 controls the ultrasonic bonding unit 700. In the present embodiment, the control unit 800 controls the bonding conditions for ultrasonic bonding of the next electrode tab based on the ultrasonic bonding region calculated by the processing unit 300.

  According to the ultrasonic bonding apparatus 600 of the present embodiment configured as described above, the temperature distribution of the electrode tab 900 ultrasonically bonded by the ultrasonic bonding portion 700 is measured, and based on the measured temperature distribution, The area of the ultrasonic bonding region is calculated. Based on the calculated area of the ultrasonic bonding region, the bonding condition of the electrode tab to be ultrasonically bonded next is controlled. Hereinafter, the ultrasonic bonding method in the present embodiment will be described in detail.

  FIG. 8 is a flowchart showing the ultrasonic bonding method in the present embodiment. In the ultrasonic bonding method of the present embodiment, first, the electrode tab is ultrasonically bonded (step S201). In the present embodiment, the ultrasonic bonding portion is controlled and the electrode tabs are ultrasonically bonded in accordance with preset bonding conditions.

  Next, it is determined whether or not a predetermined time has elapsed since the end of ultrasonic bonding (step S202). If the predetermined time has not elapsed (step S202: NO), the process waits until the predetermined time elapses. On the other hand, when the predetermined time has elapsed (step S202: YES), the temperature distribution of the electrode tab is measured with a thermo camera, and image information indicating the temperature distribution is acquired (step S203).

  Next, the number of pixels equal to or higher than a predetermined temperature in the image information is calculated (step S204), and the image information is stored (step S205). In the present embodiment, the predetermined temperature is set so that the area of the ultrasonic bonding region having a temperature higher than that of the unbonded region is calculated, and the number of pixels equal to or higher than the temperature is calculated. The area is calculated. The image information for which the number of pixels has been calculated is stored in the hard disk 340 together with the joint information.

  Then, it is determined whether or not the calculated number of pixels is less than a lower limit value (step S206). If the calculated number of pixels is less than the lower limit (step S206: YES), it is determined that the ultrasonic bonding is defective (step S207), and the process is terminated. On the other hand, when the calculated number of pixels is equal to or greater than the lower limit (step S206: NO), it is determined whether the number of pixels is equal to or less than the upper limit (step S208). If the number of pixels is equal to or greater than the upper limit (step S208: YES), it is determined that the ultrasonic bonding is defective (step S207), and the process is terminated. On the other hand, when the calculated number of pixels is less than the upper limit value (step S208: NO), it is determined that the ultrasonic bonding is good (step S209), and the process proceeds to step S210 and subsequent steps.

  In the process shown in step S210, it is determined whether or not the calculated number of pixels is less than the lower limit value of the optimum range indicating the optimum joining state (step S210). In other words, it is determined whether or not the area of the ultrasonic bonding region in the electrode tab is less than the lower limit area of the optimal bonding area. The CPU 310 functions as a second determination unit (second determination unit) that determines whether or not the size of the ultrasonic bonding region is out of the optimum range.

  When the calculated number of pixels is less than the lower limit value of the optimum range (step S210: YES), the joining condition is changed so that the ultrasonic joining region of the electrode tab to be ultrasonically joined next is increased (step S211), and processing Is terminated. More specifically, according to a relational expression set in advance, the joining conditions are adjusted in a direction in which the joining time, vibration amplitude, applied pressure, vibration frequency, and the like in ultrasonic joining increase.

  On the other hand, when the calculated number of pixels is equal to or greater than the lower limit value of the optimum range (step S210: NO), it is determined whether the number of pixels is equal to or greater than the upper limit value of the optimum range (step S212). If the number of pixels is equal to or greater than the upper limit of the optimum range (step S212: YES), the joining conditions are changed so that the ultrasonic joining area of the electrode tab to be ultrasonically joined next is reduced (step S211), and the process is terminated. The More specifically, according to a relational expression set in advance, the joining conditions are adjusted so that the joining time, vibration amplitude, applied pressure, vibration frequency, and the like in ultrasonic joining become smaller. On the other hand, when the calculated number of pixels is less than the upper limit value of the optimum range (step S212: NO), the process is terminated without changing the joining condition.

  As described above, according to the process of the flowchart shown in FIG. 8, when the area of the ultrasonic bonding region is equal to or larger than the upper limit value and smaller than the lower limit value, it is determined that the ultrasonic bonding is defective. Further, when the area of the ultrasonic bonding region deviates from the optimal range, the bonding conditions are controlled and adjusted so that the area of the ultrasonic bonding region of the next electrode tab falls within the optimal range. More specifically, when the area of the ultrasonic bonding area is less than the lower limit of the optimum range, the bonding conditions are controlled so that the ultrasonic bonding area of the next electrode tab becomes large, and the area of the ultrasonic bonding area is optimal. When the upper limit value of the range is exceeded, the bonding conditions are controlled so that the ultrasonic bonding region of the next electrode tab becomes smaller.

  FIG. 9 is a diagram for explaining the area and bonding energy of a plurality of electrode tabs that are continuously ultrasonically bonded by the ultrasonic bonding apparatus of the present embodiment. The vertical axis represents the area of the ultrasonic bonding region, and the horizontal axis represents the number of electrode tabs that are continuously ultrasonically bonded. As shown in FIG. 9, when the calculated area of the ultrasonic bonding region deviates from the optimal range, the bonding condition of the next electrode tab is controlled, and the calculated ultrasonic bonding region area is maintained within the optimal range. The By controlling the bonding conditions, the energy of ultrasonic bonding is controlled.

  In the present embodiment, the temperature distribution of the electrode tab immediately after ultrasonic bonding is measured. However, as described in the second and third embodiments, it is also possible to measure the temperature distribution of the electrode tab that generates heat by applying energy from the outside. In this case, the ultrasonic bonding apparatus 600 further includes a power supply 400 or a heater 500.

  As described above, the present embodiment described has the following effects in addition to the effects of the first to third embodiments.

  The ultrasonic bonding apparatus according to the present embodiment includes an ultrasonic bonding unit that ultrasonically bonds electrode tabs according to bonding conditions, a thermo camera that measures the temperature distribution of the electrode tabs that are ultrasonically bonded, and a temperature distribution that is measured. A calculation unit that calculates the ultrasonic bonding region of the electrode tab using a temperature difference between the unbonded region of the electrode tab and the ultrasonic bonding region, and the next electrode based on the calculated ultrasonic bonding region A control unit that controls bonding conditions when the tab is ultrasonically bonded. Therefore, since the ultrasonic bonding region of the electrode tab can be calculated from the temperature distribution of the electrode tab subjected to ultrasonic bonding, the inspection result of the electrode tab can be fed back to the bonding condition. As a result, it is possible to maintain ultrasonic bonding under optimum bonding conditions.

  The ultrasonic bonding apparatus according to the present embodiment further includes a second determination unit that determines whether or not the size of the ultrasonic bonding region is out of the optimal range, and the size of the ultrasonic bonding region is out of the optimal range. In this case, the control unit adjusts the bonding conditions so that the ultrasonic bonding region of the next electrode tab falls within the optimum range. Therefore, even when there are changes in various conditions (for example, materials, equipment, and environment) related to bonding, and the initially set bonding conditions deviate from the optimum conditions, the optimum bonding state can be maintained following.

  The joining condition is a joining time when the electrode tab is ultrasonically joined. Therefore, the joining conditions can be easily adjusted.

  The joining condition is the vibration amplitude of the horn when the electrode tab is ultrasonically joined. Therefore, the joining conditions can be easily adjusted.

  The ultrasonic bonding method of the present embodiment uses a step of measuring the temperature distribution of the electrode tab subjected to ultrasonic bonding, and a temperature difference between the unbonded region and the ultrasonic bonding region of the electrode tab where the temperature distribution is measured. And the step which calculates the ultrasonic joining area | region of the said electrode tab, and the step which controls the joining conditions at the time of ultrasonically joining the next electrode tab based on the calculated ultrasonic joining area | region are included. Therefore, since the ultrasonic bonding region of the electrode tab can be calculated from the temperature distribution of the electrode tab subjected to ultrasonic bonding, the inspection result of the electrode tab can be fed back to the bonding condition. As a result, it is possible to maintain ultrasonic bonding under optimum bonding conditions.

  As described above, in the present embodiment, the ultrasonic bonding inspection apparatus and the ultrasonic bonding inspection method of the present invention, and the ultrasonic bonding apparatus and the ultrasonic bonding method using these have been described. However, it goes without saying that the present invention can be appropriately added, modified, and omitted by those skilled in the art within the scope of the technical idea.

  For example, in the first to fourth embodiments, the temperature distribution of the electrode tab is measured by a thermo camera. However, it is also possible to discretely measure the temperature distribution of the electrode tab using a general temperature sensor such as a thermocouple. Moreover, the quality of ultrasonic joining can also be easily judged by measuring the temperature of one place of an electrode tab.

1 is a diagram illustrating a schematic configuration of an ultrasonic bonding inspection apparatus according to a first embodiment of the present invention. It is a block diagram which shows schematic structure of the process part 300 of the ultrasonic bonding inspection apparatus shown in FIG. It is a flowchart which shows the ultrasonic bonding inspection method by the ultrasonic bonding inspection apparatus shown in FIG. FIG. 4A is a view for explaining ultrasonic bonding of the electrode tab in the present embodiment, and FIG. 4B is a view showing a thermography of the temperature distribution of the electrode tab measured by the thermo camera. It is. FIG. 5A is a diagram showing a schematic configuration of the ultrasonic bonding inspection apparatus according to the second embodiment of the present invention, and FIG. 5B shows a temperature at which the ultrasonic bonding region is higher than the non-bonding region. It is a schematic diagram which shows the electrode tab which has. FIG. 6A is a diagram showing a schematic configuration of an ultrasonic bonding inspection apparatus according to the third embodiment of the present invention, and FIG. 6B shows a temperature at which the ultrasonic bonding region is higher than the unbonded region. It is a schematic diagram which shows the electrode tab which has. It is a figure which shows schematic structure of the ultrasonic bonding apparatus in the 4th Embodiment of this invention. It is a flowchart which shows the ultrasonic bonding method by the ultrasonic bonding apparatus shown in FIG. It is a figure for demonstrating the area and joining energy of the several electrode tab continuously ultrasonically bonded by the ultrasonic bonding apparatus shown in FIG.

Explanation of symbols

100 ultrasonic bonding inspection equipment,
200 thermo camera,
300 processing unit,
400 power supply,
500 heaters,
600 ultrasonic bonding equipment,
700 ultrasonic bonding part,
800 Control unit.

Claims (13)

Temperature measuring means for measuring the temperature distribution of the ultrasonically bonded workpiece,
Using the temperature difference between the unbonded region of the workpiece and the ultrasonic bonding region where the temperature distribution is measured, calculating means for calculating the ultrasonic bonding region of the workpiece;
Have a, energizing means for generating Joule heat by the ultrasonic bonding region by energization,
The temperature measuring means measures the temperature distribution of a workpiece in which the ultrasonic bonding region has a higher temperature than the non-bonded region due to Joule heat in the ultrasonic bonding region. . Temperature measuring means for measuring the temperature distribution of the ultrasonically bonded workpiece,
Using the temperature difference between the unbonded region of the workpiece and the ultrasonic bonding region where the temperature distribution is measured, calculating means for calculating the ultrasonic bonding region of the workpiece;
Have a, a heating means for heating by radiation heat the one member constituting the workpiece,
The temperature measuring means measures a temperature distribution of another member of the workpiece in which an ultrasonic bonding region has a higher temperature than an unbonded region due to heat conduction from the one member. Sonic bonding inspection device. The temperature measuring means is a thermo camera capable of imaging the temperature distribution of the workpiece,
It said calculation means, wherein the image information acquired by the thermo-camera, ultrasonic bonding inspecting apparatus according to claim 1 or 2, characterized in that to calculate the ultrasonic bonding area of the workpiece. The ultrasonic bonding inspection apparatus according to claim 3 , wherein the calculating unit calculates the size of the ultrasonic bonding region by calculating the number of pixels equal to or higher than a predetermined temperature in the image information. Determining means for determining whether the size of the ultrasonic bonding region is less than a lower limit;
The ultrasonic bonding inspection apparatus according to claim 4 , further comprising a determination unit that determines that the workpiece is defective in bonding when the size of the ultrasonic bonding region is less than a lower limit value. The ultrasonic wave according to any one of claims 1 to 5, further comprising storage means for storing ultrasonic bonding regions respectively calculated for a plurality of workpieces together with bonding information of the corresponding workpieces. Bonding inspection device. Ultrasonic bonding means for ultrasonic bonding of workpieces according to the bonding conditions;
The ultrasonic bonding inspection apparatus according to any one of claims 1 to 6,
An ultrasonic bonding apparatus comprising: control means for controlling a bonding condition when ultrasonically bonding a next workpiece based on an ultrasonic bonding region calculated by the ultrasonic bonding inspection apparatus. A second determination means for determining whether or not the size of the ultrasonic bonding region is out of the optimum range;
When departing from the magnitude optimum range of the ultrasonic bonding area, the control means, according to claim 7, characterized in that ultrasonic bonding area of the next workpiece to adjust the welding conditions to fit optimum range Ultrasonic bonding equipment. The ultrasonic bonding apparatus according to claim 7 or 8 , wherein the bonding condition is a bonding time when the ultrasonic bonding means ultrasonically bonds the workpiece. The ultrasonic bonding apparatus according to claim 7 or 8 , wherein the bonding condition is a vibration amplitude when the ultrasonic bonding means ultrasonically bonds the workpiece. A step of generating Joule heat in the ultrasonic bonding region of the ultrasonically bonded workpiece by energization;
Measuring a temperature distribution of the workpiece,
By utilizing a temperature difference between the non-bonded area and the ultrasonic bonding area of the work which the temperature distribution is measured, possess calculating a ultrasonic bonding region of the workpiece, and
In the step of measuring the temperature distribution, the temperature distribution of a workpiece in which the ultrasonic bonding region has a higher temperature than the unbonded region is measured by Joule heat in the ultrasonic bonding region. Sonic bonding inspection method. Heating one member constituting the ultrasonically bonded workpiece by radiant heat;
Measuring a temperature distribution of the workpiece,
By utilizing a temperature difference between the non-bonded area and the ultrasonic bonding area of the work which the temperature distribution is measured, possess calculating a ultrasonic bonding region of the workpiece, and
In the step of measuring the temperature distribution, the temperature distribution of the other members of the workpiece in which the ultrasonic bonding region has a higher temperature than the unbonded region is measured by heat conduction from the one member. A characteristic ultrasonic inspection method. Based on the ultrasonic bonding area calculated by ultrasonic bonding inspecting method according to claim 11 or 12, ultrasonic bonding wherein that you control the bonding conditions for ultrasonic bonding to the next work .

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