JP2007142049A - Ultrasonic bonding equipment, controller therefor, and ultrasonic bonding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide ultrasonic bonding equipment which allows real time monitoring of the bonding states of all the joints, makes immediate detection of defects upon occurrence thereof, and thereby can be controlled to stop bonding operation or to do other operation when the defects are detected, and which also allows more accurate and surer detection of the ultrasonic vibrating state of a bonding tool, and also to provide a controller for the same. <P>SOLUTION: The ultrasonic bonding equipment 1 comprises the bonding tool 4, an ultrasonic horn 3 which supports one end of the bonding tool 4 and applies ultrasonic vibration to the bonding tool 4, and a vibration measuring means for measuring the vibration of the bonding tool 4 to detect the positions of the nodes of the vibration of the bonding tool 4. The ultrasonic bonding equipment 1 is so controlled to continue or stop the bonding operation depending on the positions of the knots. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultrasonic bonding apparatus that performs bonding using ultrasonic waves together in mounting of a wiring board of a semiconductor device or an electronic component, a control apparatus for the ultrasonic bonding apparatus, and an ultrasonic bonding method.

  A member to be joined such as an electronic component having a gold wire or a bump, such as a wire bonding apparatus or a flip chip bonding apparatus, is pressed against a joining member such as a lead frame or a wiring of a substrate while applying ultrasonic vibration. In addition, an ultrasonic bonding apparatus is known in which the vicinity of the bonded portion is heated as necessary to bond.

  The ultrasonic bonding apparatus is fixed to an ultrasonic generation source that generates ultrasonic vibration, an ultrasonic horn unit that is connected to the ultrasonic generation source and transmits ultrasonic vibration, and a tip of the ultrasonic horn. A bonding tool part, and a bonding member, for example, a metal ball of a wire or an adsorbed semiconductor chip is formed or adsorbed on the tip of the bonding tool part, and is pressed toward the bonding member, for example, a lead frame, Ultrasonic vibration is transmitted from the sound wave generation source to the member to be joined and joined.

  The ultrasonic bonding apparatus is provided on the mounting line of the semiconductor device, and sequentially bonds the members to be bonded to the continuously supplied bonding members. In this semiconductor device mounting line, a regular sampling inspection is usually performed to confirm the bonding state. If a bonding failure is found in this sampling inspection, the mounting line is immediately stopped to investigate the cause of the failure.

  When investigating the cause of defects, in order to investigate the ultrasonic characteristics, which is one of the most important conditions for the quality of the bonded state, it is necessary to measure high-frequency and minute vibrations typified by a laser Doppler meter. Survey using available measuring instruments.

  FIG. 18 is a perspective view showing the positional relationship between the laser Doppler meter used in the conventional investigation and the ultrasonic bonding apparatus. As shown in the figure, an ultrasonic bonding apparatus 101 includes an ultrasonic horn 103 that transmits ultrasonic vibrations from an ultrasonic transducer on a base 102, and a bonding attached to the tip of the ultrasonic horn 103. A tool 104, a support member 105 that supports the ultrasonic horn 103, a frame 106 on which the support member 105 is swingably mounted, and an XY table on which the frame 106 is placed and movable in a horizontal plane 17. Ultrasonic vibration is transmitted to the bonding tool 104 of the ultrasonic bonding apparatus 101 to bond the bonding material and the material 109 to be bonded on the conveying apparatus 108.

  The laser Doppler meter 110 is installed on the same floor as the ultrasonic bonding apparatus 101 and is separated from the ultrasonic bonding apparatus 101 and the conveying apparatus 108, and performs ultrasonic vibrations near a processing point where the bonding tool 104 or the like is bonded. taking measurement. As described above, since the measuring instrument such as the laser Doppler meter 110 is separated from the ultrasonic bonding apparatus 101 and is fixed to the floor surface, the bonding tool 104 that freely moves in the horizontal plane by the XY table 107 is provided. Unable to follow the movement. Therefore, measurement of ultrasonic vibration or the like can be performed only at a minute location for one joining member. Therefore, the measurement of the ultrasonic amplitude and the like was an intermittent measurement.

  If the cause is found as a result of the investigation, measures are taken immediately and the operation of the mounting line is resumed. Conventionally, however, the measurement of the occurrence of a defect and the investigation of the cause can be performed only at the sampling inspection timing. . For this reason, the time from the occurrence of the defect to the sampling inspection is to produce a defective product, and when the discovery is delayed, a large amount of defective products is produced and the yield is lowered. Moreover, since it is a sampling inspection and not a full quantity inspection, there may be a case where a defect cannot be found. Furthermore, even during the investigation stage, since it is an intermittent investigation, it is not always the same as the ultrasonic characteristics during continuous operation, and it is difficult to measure sudden failures. It takes time and effort.

  As described above, the conventional method has a problem that the defect discovery is delayed and the yield is deteriorated, and it takes time to investigate the cause of the defect.

In Patent Document 1, a laser Doppler vibrometer, an optical fiber, and a laser focusing head of a measurement system including a laser focusing head are mounted so as to fix the focal point to the tip of a moving bonding tool. A sonic bonding apparatus is disclosed. This laser focusing head is lightweight and can be attached to a moving joining head.
JP-A-5-206224

  In the ultrasonic bonding apparatus disclosed in Patent Document 1, an optical system that measures vibration using a laser is attached to the tip of a moving bonding tool with a fixed focal position, so that the vibration of the bonding tool is always accurately detected. It is said that it can be measured.

  However, the measurement of ultrasonic vibration is performed on the bonding member and the member to be bonded, and the bonding quality is monitored by reducing these relative vibrations. For this purpose, the amplitude at the tip of the bonding tool is measured. is doing. If the measurement position of the tip is not accurately specified, it is difficult to measure the decrease in relative vibration. Therefore, the laser focusing head is fixedly mounted at a measurement point 1/32 wavelength from the tip of the bonding tool. However, since the laser condensing head and the laser Doppler vibrometer are connected via an optical fiber, the ultrasonic bonding apparatus disclosed in Patent Document 1 Is complicated. Further, the laser Doppler vibrometer itself other than the laser condensing head is as large as the conventional one, and does not contribute to the miniaturization of the ultrasonic bonding apparatus, resulting in no practicality.

  The present invention has been made based on these circumstances, and it is possible to monitor the joining state over the entire number of joints in real time, thereby immediately detecting the occurrence of a defect and controlling the stop of the ultrasonic joining apparatus and the like. Furthermore, it is an object of the present invention to provide an ultrasonic bonding apparatus, an ultrasonic bonding apparatus control apparatus, and an ultrasonic bonding method that can detect an ultrasonic vibration state more accurately and reliably.

  The ultrasonic bonding apparatus of the present invention measures a vibration of the bonding tool part, an ultrasonic horn part that supports one end of the bonding tool part and applies ultrasonic vibration to the bonding tool part, and the bonding tool part. And a vibration measuring means for calculating the position of the vibration node of the bonding tool portion.

  In the ultrasonic bonding apparatus of the present invention, the vibration measuring means includes an amplitude measuring unit that measures amplitude at a plurality of locations at an arbitrary point for any point of the bonding tool unit, and a simultaneous period obtained by the amplitude measuring unit. And a vibration mode calculation unit for calculating the position of the vibration node of the bonding tool unit from the amplitude values of the different parts.

  Further, the vibration measuring means includes an amplitude measuring unit that measures the amplitude at the same time for an arbitrary point of the bonding tool unit and an arbitrary point in the vicinity of the region supporting the bonding tool of the ultrasonic horn unit. A vibration mode calculation unit that calculates the position of the vibration node of the bonding tool unit from the amplitude values at different points in the same period obtained by the amplitude measurement unit may be provided.

  In the ultrasonic bonding apparatus of the present invention, the amplitude measuring unit is reflected by the laser oscillator, the optical member that guides the laser beam emitted from the laser oscillator to be irradiated to the measurement point, and the measurement point. And a light detection unit that receives laser light and outputs an electrical signal.

  Moreover, it is preferable that an amplitude measurement part is fixed with respect to the bracket attached to the ultrasonic horn part, and is relatively fixed with respect to the movement of an ultrasonic horn part.

  Furthermore, the optical member may have a movable part that moves the measurement point in a changeable manner.

  In the ultrasonic bonding apparatus according to the present invention, the vibration mode calculation unit calculates an approximate curve of the vibration of the bonding tool from the amplitude values at different points in the same period obtained by the amplitude measurement unit, and similarly at different times. Measure the amplitude value and calculate the approximate curve at different locations at the same time, and calculate the position of the vibration node of the bonding tool from the resulting approximate curves at different times .

  Further, the ultrasonic bonding apparatus according to the present invention does not satisfy a predetermined necessary condition for the predetermined value by comparing with a predetermined value set in advance based on the value related to the position of the vibration node calculated by the vibration mode calculating unit. In some cases, a control unit that stops the joining operation may be provided.

  The control device for the ultrasonic bonding apparatus of the present invention is connected to a vibration measuring means for measuring the vibration of the bonding tool portion of the ultrasonic bonding apparatus and calculating the position of the node of the vibration, and inputted from the vibration measuring means. A control device for an ultrasonic bonding apparatus that stops the bonding operation of the ultrasonic bonding apparatus based on the value of the vibration node position of the bonding tool section, wherein the vibration level of the bonding tool section calculated by the vibration measuring means is This calculation unit compares the value of the position of the vibration node of the bonding tool unit with the value of the position of the node for the end of bonding set in advance. And a device control unit that stops the bonding operation of the ultrasonic bonding apparatus when the value of the vibration node position of the bonding tool unit does not reach a preset node position. .

  In the control device for an ultrasonic bonding apparatus according to the present invention, the calculation unit determines the value of the position of the vibration node of the bonding tool unit at the time when a predetermined bonding time has elapsed and the position of the node for the end of bonding set in advance. It is preferable to compare with the value of.

  In addition, the control device for the ultrasonic bonding apparatus according to the present invention is configured such that the preset value of the node position for the end of bonding in the arithmetic unit is a correlation between the bonding strength and the vibration node position of the bonding tool unit. It may be determined based on

  Moreover, the value of the position of the node for the end of joining set in advance by the calculation unit may be determined based on statistical data on the quality of joining between the joining member and the joined member.

  In the control apparatus for an ultrasonic bonding apparatus according to the present invention, the calculation unit includes a value of a vibration node position of the bonding tool unit within a predetermined bonding time, and a predetermined node position value for completion of bonding. When the value of the position of the vibration node of the bonding tool compared by the calculation unit reaches the preset node position, the apparatus control unit The joining operation of the ultrasonic joining apparatus can be stopped without waiting for progress.

  Further, in the control device for an ultrasonic bonding apparatus according to the present invention, the calculation unit has a value of the position of the vibration node of the bonding tool unit when a predetermined bonding time has passed, and a preset node for ending the bonding. When the device control unit does not reach the set node position by the set bonding time, the bonding operation is performed up to the maximum allowable bonding time. And the joining operation of the ultrasonic joining device may be stopped when the position of the vibration node of the bonding tool part does not reach the set node position by the maximum allowable joining time. it can.

  In the ultrasonic bonding method of the present invention, when the bonding member and the member to be bonded are ultrasonically bonded, the vibration of the bonding tool portion of the ultrasonic bonding apparatus being bonded is measured in a plurality of regions at the same time, and this bonding is performed. The step of calculating the vibration mode of the tool unit by the vibration mode calculation unit, and the step of continuing or stopping the bonding operation of the ultrasonic bonding apparatus according to the vibration mode of the bonding tool unit calculated by the vibration mode calculation unit. It is characterized by doing.

  According to the ultrasonic bonding apparatus of the present invention, it is possible to accurately measure the state of ultrasonic vibration of the bonding tool in real time over the total number of bondings without stopping the mounting line.

  According to the control device for an ultrasonic bonding apparatus of the present invention, it is possible to detect a bonding failure during bonding by the ultrasonic bonding apparatus and perform control to immediately stop the bonding operation.

  According to the ultrasonic bonding method of the present invention, it is possible to stop the operation of the ultrasonic bonding apparatus based on the vibration mode of the bonding tool during bonding and suppress the generation of defective products.

  Embodiments of an ultrasonic bonding apparatus and an ultrasonic bonding apparatus control apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 shows an example of a wire bonding apparatus and its control apparatus as a diagram showing the configuration of an embodiment of the ultrasonic bonding apparatus and the control apparatus of the ultrasonic bonding apparatus of the present invention. The wire bonding apparatus is an apparatus for electrically bonding, for example, an electrode on a semiconductor element and a lead frame using a wire. In this wire bonding apparatus, an ultrasonic combined thermocompression bonding method in which an electrode and a member to be bonded formed on a wire or a wire tip are bonded by applying ultrasonic vibration, pressure and heat is mainly used.

  An ultrasonic bonding apparatus 1 shown in FIG. 1 includes a piezoelectric element and the like, and an ultrasonic vibrator 2 that generates ultrasonic vibrations, and is connected to the ultrasonic vibrator 2 and extends in the horizontal direction. And a bonding tool 4 attached and fixed to the tip of the ultrasonic horn. The ultrasonic vibration from the ultrasonic vibrator 2 is transmitted to the bonding tool 4 by the ultrasonic horn 3. Is transmitted through.

  The ultrasonic horn 3 is supported and fixed to the support member 5. A rotary shaft 6 is attached to the support member 5 in the horizontal direction, and the rotary shaft 6 is attached to the frame 7 so as to be rotatable. A motor is directly connected to the rotary shaft 6. The support member 5 can swing about the rotary shaft 6 as a rotary shaft. Such means for swinging is a moving means for pressing the joining member and the non-joining member joined by the bonding tool 4 attached to the tip of the ultrasonic horn 3.

  The frame 7 is placed on the XY table 8 and is freely movable in the horizontal plane by the movement of the XY table 8 attached on the base 9. Accordingly, the ultrasonic horn 3 connected to the frame 7 and the bonding tool 4 attached to the tip of the ultrasonic horn 3 can be moved and positioned in the horizontal plane.

  The bonding tool 4 is positioned by the XY table 8 and is swung in the vertical direction around the rotary shaft 6 as a rotary shaft, and joined to a lead frame 32 as a member to be joined placed on the stage 31. An electrode 34 on the semiconductor element 33 as a member is electrically joined using a wire 35. For this electrical bonding, a metal ball 36 formed by melting the wire 35 is formed at the tip of the bonding tool 4, and the metal ball 36 and the electrode 34 or the lead frame are superposed from the ultrasonic transducer 2. While applying ultrasonic vibration transmitted to the bonding tool 4 through the sonic horn 3 and applying pressure by swinging the support member 5 downward, heating is performed as necessary. Such an ultrasonic bonding operation is the same as that of a conventional ultrasonic bonding apparatus.

  The ultrasonic bonding apparatus according to the present embodiment includes vibration measuring means for measuring the vibration of the bonding tool 4 and calculating the position of the vibration node of the bonding tool 4.

  As a result of monitoring the joint state by detecting the displacement of the position of the node instead of the amplitude itself, there is little influence of individual differences of parts and members, and disturbance and noise caused by the installation environment of the ultrasonic joining device It is now possible to obtain measurement results that are not easily affected by. Therefore, when trying to obtain the same quality result, the measurement system can be assembled with a very simple configuration as compared with the conventional measurement environment.

  This vibration measuring means will be described below. On the upper side of the frame 7, a bracket 10 extending in the same direction as the ultrasonic horn 3 is attached and fixed. The bracket 10 fixes an amplitude measuring unit, which is one of the components of the vibration measuring means for measuring the ultrasonic vibration state at a plurality of points of the bonding tool 4, and is relative to the movement of the ultrasonic horn 3. It is for fixing. For this purpose, the bracket 10 shown in FIG. 1 is attached to the upper side of the frame 7 so as to extend in the same direction as the ultrasonic horn 3 and to be connected to the front end of the horizontal portion so as to extend in the vertical direction. And a vertical portion located up to the vicinity of the bonding tool 4.

  The amplitude measurement unit can be configured to measure the amplitude using the laser Doppler effect. Specifically, the measurement point is irradiated with the laser oscillator and the laser beam emitted from the laser oscillator. An optical member that guides light and a light detection unit that receives the laser light reflected at the measurement point and outputs an electrical signal can be used. In the ultrasonic bonding apparatus according to the present embodiment shown in FIG. 1, laser heads 11 </ b> A and 11 </ b> B integrally including a laser oscillator and a light detection unit are attached to a mounting portion that protrudes from a horizontal portion of the bracket 10. The emission direction of the laser light is horizontal and fixed in the vertical direction. As an optical member for guiding laser beams emitted from the laser heads 11A and 11B to measurement points such as a bonding tool and guiding the laser beams reflected at the measurement points to the laser heads 11A and 11B, respectively. The first mirrors 13A and 13B are attached and fixed to the upper end of the vertical portion of the bracket 10 so as to face each other at a predetermined angle with respect to the emission direction of the laser beams emitted from the laser heads 11A and 11B. Further, the second mirrors 14A and 14B are emitted from the laser heads 11A and 11B to the bonding tool 4 at the lower end of the vertical part of the bracket 10, respectively, and reflected by the first mirrors 13A and 13B. Are fixed at an angle so as to form the optical path p.

  The laser heads 11A and 11B are fixed to the bracket 10, and the first mirrors 13A and 13B and the second mirrors 14A and 14B are provided corresponding to the laser heads 11A and 11B. The laser beams emitted separately are irradiated to different points of the bonding tool 4 in a state where the optical axes are present on the same virtual plane. As a result, the amplitude can be measured at the same time at a plurality of locations for any point of the bonding tool 4. By measuring the amplitudes at a plurality of locations at the same time, the position of the vibration node of the bonding tool 4 can be calculated.

  In order to calculate the position of the vibration node of the bonding tool 4, measurement signals from the laser heads 11 </ b> A and 11 </ b> B are input to the amplitude calculation unit 12, and the speed at a specific point of the bonding tool 4 is calculated. The amplitude at a specific point of the bonding tool 4 is calculated from the acceleration data of the bonding tool 4 obtained by differentiating the displacement data or velocity data of the bonding tool 4 obtained by integrating the data or velocity data with time. Therefore, the vibration measuring means is not limited to the one that measures the speed of the bonding tool 4, and any one that measures displacement or that measures acceleration can be used.

  The velocity / speed data and the like at a specific point of the bonding tool 4 calculated by the amplitude calculator 12 are output to the vibration mode calculator 21. The vibration mode calculation unit 21 calculates the position of the vibration node of the bonding tool 4 from the amplitude values at different locations obtained at the same time by the amplitude measurement unit. The vibration mode calculation unit 21 will be described later.

  As the laser heads 11A and 11B shown in FIG. 1, a laser Doppler velocimeter disclosed in Japanese Patent Publication No. 7-69425 can be used. As shown in a schematic diagram of an example of the laser head 11 in FIG. 2, this laser Doppler velocimeter is provided with a lens 111 facing the bonding tool 4 as a measurement object and a laser beam provided facing the lens 111. A laser resonator 112 that emits light, a photodiode 113 provided behind the laser resonator 112, and a lens 111 that accommodates the laser resonator 112 and the photodiode 113 and has a lens 111 attached to the tip so that the focal position can be adjusted. The cylinder 114 is provided, and the optical system is ultra-compact and all of the laser head 11 is provided. In this laser head 11, the laser light oscillated by the laser resonator 112 and the reflected light from the bonding tool 4, which is a measurement object of the laser light, are mixed by the laser resonator 112, and then the vibration speed is increased. A self-mixing type laser Doppler vibration measurement method is employed in which a proportional change in light intensity is output and this change in light intensity is detected by a photodiode 113. By adopting this measurement method, the laser head 11 can be configured with a simple optical system including only the semiconductor laser (laser resonator 112) and the lens 111, and the laser head 11 can be miniaturized. . The downsizing of the laser head 11 enables the speedometer to be integrally mounted on the member of the ultrasonic bonding apparatus on the XY table 8 on which the ultrasonic vibration system is placed. In the illustrated embodiment, the ultrasonic bonding apparatus 1 is integrally mounted on a bracket 10 that is attached and fixed to the upper side of the frame 7.

  Moreover, in the ultrasonic bonding apparatus 1 shown in FIG. 1, the degree of freedom of the position where the laser heads 11A and 11B are installed is increased by refracting the laser light using the mirrors 13A, 13B, 14A and 14B. It is possible to measure the vibration of the ultrasonic vibration system at any time at a position that does not hinder ultrasonic bonding.

  An example of the amplitude calculator 12 to which the signals output from the laser heads 11A and 11B are input will be described with reference to the block diagram shown in FIG. The block diagram shown in FIG. 3 uses the fact that the drive current for driving the laser light source (laser resonator) 112 provided in the laser head 11 varies in proportion to the speed of the measurement object. The vibration speed of the (bonding tool 4) is calculated, and consequently the amplitude is calculated. In FIG. 3, the amplitude calculation unit 12 is detected by a beat detection unit 121 that separates and extracts a Doppler beat signal from a signal from the laser resonator 112, a laser drive circuit 122 that drives the laser resonator 112, and a beat detection unit 121. Speed calculating means 123 for calculating the vibration speed of the bonding tool 4 based on the Doppler beat signal. Further, a direction discriminating means 124 is provided so that the vibration direction of the bonding tool 4 can be discriminated as necessary.

  The laser drive circuit 122 of the amplitude calculator 12 is for driving the laser resonator 112. Laser light is emitted from the laser resonator 112 driven by the laser drive circuit 122 toward the bonding tool 4, and the irradiated laser light is reflected by the bonding tool 4 and subjected to Doppler frequency shift. When the laser beam returns to the laser resonator 112, a self-mixing action is generated in the laser resonator 112 with the laser light not subjected to the Doppler shift, and a Doppler beat is generated. A sawtooth wave signal corresponding to the beat frequency is superimposed on the drive current of the laser resonator 112.

  The beat detector 121 of the amplitude calculator 12 is provided at the output end of the laser drive circuit 122 and outputs a Doppler beat signal that approximates a sawtooth wave superimposed on the drive current from the drive current that drives the laser resonator 112. Extract and output.

  The speed calculation unit 124 converts the Doppler beat signal output from the beat detection unit 121 into a predetermined timing signal, and performs signal processing on the timing signal output from the waveform conversion circuit unit to calculate the speed. A signal processing circuit unit that outputs a signal and an arithmetic circuit unit that calculates the speed of the object to be measured (bonding tool) based on the output of the signal processing circuit unit. Outputs the speed signal of the bonding tool.

  The ultrasonic bonding apparatus of the present embodiment uses the laser heads 11A and 11B and the amplitude calculation unit 12 described above, and a plurality of bonding tools 4 near the ultrasonic vibration system processing point of the ultrasonic bonding apparatus 1 or a bonding tool. Measure vibrations at a plurality of locations in the vicinity including 4. As a result, the vibration mode of the ultrasonic vibration system (hereinafter, also referred to as “vibration mode”) can be derived from the vibration information and associated with the bonding state (bonding strength) at that time. In addition, it is possible to determine the bonding state in real time by nondestructive inspection.

  Further, by measuring the ultrasonic vibration of the bonding tool 4 at a plurality of positions, the vibration mode of the ultrasonic vibration of the bonding tool 4 and the change during bonding of the vibration mode can be accurately measured.

  In the embodiment shown in FIG. 1, as an example of a plurality of measurement positions where the vibration measuring means performs measurement, measurement is performed at two arbitrary points along the longitudinal direction of the bonding tool 4. Further, the present invention is not limited to an example in which two arbitrary points of the bonding tool 4 are measured, and an arbitrary point of the bonding tool 4 and an arbitrary point in the vicinity of the bonding tool 4 in the ultrasonic horn 3 that supports the bonding tool 4 are the same. It is also possible to measure the amplitude at the time.

  A specific example of the measurement point will be described with reference to schematic views of the vicinity of the bonding tool 4 shown in FIGS. FIG. 4A shows an example in which two points at the intermediate part of the bonding tool 4 are measured, FIG. 4B shows an example in which the intermediate part and the tip part of the bonding tool 4 are measured, and FIG. An example of measuring an intermediate portion of the bonding tool 4 and a tip portion of the ultrasonic horn 3 that fixes the bonding tool, FIG. 4D shows the bonding tool 4 from a direction opposite to 180 ° from FIG. It is an example which measures 2 points | pieces of the intermediate part. 5A shows an example of measuring four points along the longitudinal direction of the bonding tool 4, and FIG. 5B shows an ultrasonic horn from two points of the bonding tool 4 and a direction perpendicular to the vibration direction. FIG. 5C shows an example in which two points parallel to the vibration direction of the bonding tool 4 and two points perpendicular to the vibration direction are measured. It is possible to measure the vibration state of the ultrasonic vibration system in any measurement or in a combination of these.

  There are various modes for the position where the laser heads 11A and 11B for measuring the bonding tool 4 or a plurality of points in the vicinity thereof are integrally attached and fixed, and the position of the optical system constituted by the mirror that reflects the laser light. can do. Examples of this position are shown schematically in FIGS. 6 to 8 show an example in which two points in the longitudinal direction of the bonding tool 4 are measured as measurement examples at a plurality of positions.

  In FIG. 6A, laser heads 11A and 11B are mounted and fixed on a bracket 10A provided immediately above the bonding head, and mirrors 13C, 14A and 14b for reflecting laser light from the laser heads 11A and 11B are provided. Attached and fixed to the bracket 10A, these mirrors 13C, 14A and 14b are used to refract the optical path to irradiate the bonding tool 4 with laser light, and to guide the reflected light from the bonding tool 4 to the laser heads 11A and 11B. I am doing so.

  In FIG. 6B, the laser heads 11A and 11B are fixed to a bracket 10B provided immediately above the bonding head so that the laser light irradiation direction is vertically downward, and the laser light from the laser heads 11A and 11B. 14A and 14b are attached to the bracket 10B and fixed, and the optical path is refracted using these mirrors 14A and 14b to irradiate the bonding tool 4 with laser light, and the reflected light from the bonding tool 4 is reflected on the laser head. It leads to 11A and 11B.

  In FIG. 6C, the wiring between the laser heads 11A and 11B and the amplitude calculation unit 12 is extended, and these laser heads 11A and 11B are fixed by another fixing means (not shown). The laser beam is directly irradiated to the bonding tool 4 in parallel with the vibration direction.

  In FIG. 7A, the laser heads 11A and 11B are attached and fixed to the side surface portion of the support member 5, and the mirror 14C is fixed to the end portion extending below the bracket 10 attached to the upper side of the support member 5. The laser beams irradiated from the laser heads 11A and 11B are reflected by the mirror 14C and reach the bonding tool 4.

  In FIG. 7B, the laser heads 11A and 11B are attached and fixed to the front portion of the support member 5, and the laser light is directly irradiated onto the bonding tool 4 from the laser heads 11A and 11B.

  In FIG. 7C, the laser heads 11A and 11B are attached and fixed to the side surface portion of the support member 5, and the laser beam is directly irradiated onto the bonding tool 4 from the laser heads 11A and 11B.

  In the example shown in FIGS. 6 and 7, two laser heads, a laser head 11A and a laser head 11B, are provided, and different points of the bonding tool 4 are measured at the same time by the respective laser heads. The present invention is not limited to this example, and an optical member that arranges a single laser head and guides the laser light emitted from the laser head moves the bonding tool 4 or a measurement point in the vicinity of the bonding tool 4 in a changeable manner. It can also have a movable part. Such an example is shown in FIG.

  In FIG. 8A, the laser head 11A is mounted and fixed on a bracket 10D provided immediately above the bonding head, and a mirror 13D that reflects the laser light from the laser head 11A is attached and fixed to the bracket 10D. The mirror 14D is attached to the bracket 10D so as to be swingable by a driving device such as a piezoelectric element (not shown). By oscillating the mirror 14D, laser light having different optical axes in the same virtual plane in the longitudinal direction of the bonding tool is generated. Thereby, a plurality of measurement points can be obtained with a single optical system. Measurement points can be changed during the measurement operation, and even when one laser head 11A is used, the amplitudes at a plurality of locations can be measured.

  In FIG. 8B, the laser head 11C is attached to the front portion of the support member 5 so as to be swingable by a driving device such as a piezoelectric element (not shown). By oscillating the laser head 11C, the irradiation direction of the laser head 11C can be changed during measurement. Even when one laser head 11A is used, the laser beam is directly applied to the bonding tool 4. The amplitude of a plurality of locations can be measured.

  Any of the modes shown in FIGS. 6 to 8 described above enables real-time measurement of the ultrasonic vibration system during continuous operation of the mounting line.

  As shown in FIG. 1, the vibration information of the bonding tool 4 or the vicinity thereof measured by the laser heads 11 </ b> A and 11 </ b> B and the amplitude calculation unit 12 is input to the vibration mode calculation unit 21.

  In the vibration mode calculation unit 21, the position of the vibration node is calculated from the measurement results at a plurality of points from the amplitude calculation unit 12. The calculation procedure will be described with reference to the schematic diagram of the bonding tool and the corresponding vibration mode shown in FIG. In the figure, an example is shown in which the amplitude is measured at two locations above and below the bonding tool 4.

  As shown in FIG. 9A, based on the amplitude and phase information at each point of the bonding tool 4, the vibration state of the bonding tool 4 can be expressed using an approximate curve. Therefore, with respect to the vibration state of the bonding tool 4 represented by this approximate curve, the intersection of two approximate curves (primary curves) of the approximate curve when the amplitude is positive and the approximate curve when the amplitude is negative is shown. The node position is in vibration mode.

  Then, the measurement of the vibration mode is performed at an arbitrary time during the ultrasonic bonding, and the change of the vibration mode at each measurement time is observed. FIG. 9B shows a comparison of vibration modes and node positions immediately after the start of bonding and before the completion of bonding (the end of the bonding time). As shown in the figure, the vibration mode changes depending on the joining state of the joining member and the member to be joined, and when joining proceeds, the vibration at the lower end of the bonding tool is constrained. It turns out that it is moving away from the direction, that is, upward. In this way, a change in the vibration state at the time of ultrasonic joining accompanying a change in the joining state can be detected by the movement of the node position in the vibration mode.

  Therefore, the vibration mode calculation unit 21 calculates an approximate curve of the vibration of the bonding tool from the amplitude values at different points obtained by the amplitude measurement unit, and similarly, at different times, different points at the same time Are measured and the approximate curve is calculated, and the position of the vibration node of the bonding tool portion is calculated from the resulting approximate curves at different times.

  FIG. 9C shows an example in which the measurement is performed with four measurement points of the bonding tool 4. Even when there are four measurement points, the node position of the vibration mode can be obtained in the same manner as in the case of two points, and the change of the vibration state during ultrasonic bonding can be detected by the movement of this node position. Can do. Further, increasing the number of measurement points has the advantage that the accuracy of the approximate curve is improved and the error from the actual vibration mode is reduced. However, when the number of measurement points is increased, there are disadvantages in that the calculation time and processing time for obtaining the node position become longer, and the space for attaching the measuring instrument and the control device to the ultrasonic bonding apparatus becomes larger. Therefore, the optimum number of measurement points may be selected from the measurement accuracy, the measurement interval, and the like.

  FIG. 10 shows an example of timing for measuring ultrasonic vibration at the time of ultrasonic bonding, the position in the vertical direction of the bonding tool 4 as the ultrasonic application means, the amplitude of the ultrasonic output applied to the bonding tool 4, and the bonding. It is shown in the timing chart figure shown with the applied pressure applied to a member and a to-be-joined member, and the node position of a vibration mode.

  Immediately after the bonding tool 4 is lowered by the operation of the moving means in the ultrasonic bonding apparatus 1 and the bonding member and the member to be bonded are brought into contact, ultrasonic application and pressurization are started as the bonding operation. As a result, the node position moves upward. At the time of such joining, the vibration mode can be measured by a method (timing A in the figure) from the time when the ultrasonic wave is applied (beginning of joining) to the end of the application, or any time, for example, application A method of measuring just before the end (timing B in the figure), a method of measuring at the start and end of application (timing C in the figure), a method of measuring from the middle of the application to the end (timing D in the figure) There are various methods. Any method can be used, and the measurement timing may be measured in advance by confirming the timing at which the change in the bonding state can be detected by experiments or the like, and performing the measurement at the point. In the present embodiment, the case where measurement is performed all within the bonding time (timing A) is described as an example, unless otherwise specified.

  As described above, the vibration mode calculation unit 21 calculates an approximate curve of the amplitude of vibration of the ultrasonic bonding jig from vibration information signals of the bonding tool 4 measured at a plurality of points at the same time, and further at different times. Similarly, the measurement of the amplitude value of the bonding tool 4 measured at a plurality of points at the same time and the calculation of the approximate curve are performed, and the vibration curve of the bonding tool portion is calculated from the resulting approximate curves at different times. The position is calculated, and the vibration mode of the bonding tool 4 during bonding is calculated as the position of the vibration node. As a result, the change in the vibration state of the bonding tool can be easily grasped, and the relevance to the bondability as described below can be obtained, which is useful for further investigation of the cause of the trouble such as a bonding failure. Further, unlike the prior art, it does not monitor the decrease in the amplitude of the tip of the bonding tool, so that it is not necessary to set the measurement point accurately to be within 1/32 wavelength from the tip of the bonding tool.

  The data of the position of the vibration node of the bonding tool calculated by the vibration mode calculation unit 21 is input to the control device 20 of the ultrasonic bonding apparatus. The control device 20 compares the vibration position value with a predetermined value set in advance, and performs control to stop the joining operation when a predetermined necessary condition for the predetermined value is not satisfied.

  The control device 20 shown in FIG. 1 compares the position of the vibration node of the bonding tool calculated from the vibration mode calculation unit 21 with a preset value of the position of the node for the end of joining. 22, the storage unit 22 a connected to the calculation unit and storing the set position of the node for the end of joining, and the value of the vibration node position of the bonding tool unit compared by the calculation unit 22 An apparatus control unit 23 for stopping the joining operation of the ultrasonic bonding apparatus when the set node position is not reached; a display unit 24 connected to the calculation unit 22 and outputting a result of comparison performed by the calculation unit 22; It has.

  The control device 20 is connected to the ultrasonic bonding device controller 15 of the ultrasonic bonding device 1. The ultrasonic bonding apparatus control unit 15 is connected to an ultrasonic oscillator 16 for causing the ultrasonic vibrator 2 to oscillate ultrasonic vibrations, and can control the amplitude amount and the oscillation time of the ultrasonic vibrations. .

  The calculation unit 22 compares the calculated position of the vibration node of the bonding tool with the predetermined position of the node at the end of bonding, which is measured at a predetermined measurement timing. As described above, the vibration mode of the bonding tool 4 is related to the change in the bonding state. Therefore, from the relationship between the calculated position of the vibration node and the joining state, when the position of the vibration node does not reach the predetermined position, it can be considered that the joining state is defective. Therefore, when the position of the vibration node has not reached the predetermined position, the ultrasonic bonding apparatus can be stopped immediately when a product with poor bonding is generated by controlling the bonding.

  The relationship between the position of the vibration node and the joining state will be described with reference to FIG. FIG. 11A illustrates the difference in the vibration mode of the bonding tool 4 with respect to the difference in bonding strength between the bonding member and the member to be bonded. When the bonding strength is low as in the initial stage of bonding, the tip of the bonding tool 4 shows a mode close to the free end. On the other hand, when the bonding strength is high as at the end of the bonding, the vibration at the tip of the bonding tool 4 is restrained, and a fixed end mode is set. Thus, when the state of the tip of the bonding tool 4 changes according to the bonding strength, the tool vibration mode at that time also changes. In the illustrated example, the change in the vibration mode is a change in the position of a node that is easily detected as the change amount. As shown in the figure, the vibration mode changes and the node position moves upward as the joining state changes, that is, the joining strength increases.

  It has become clear from experiments that the relationship between the node position and the bonding strength at the completion of the bonding process is proportional. From this, the bonding strength can be estimated from the node position of the bonding tool 4 when the bonding process is completed. In other words, it is possible to estimate the joint strength by measuring the node position, and to infer whether the joint is good or not based on whether or not the joint strength is equal to or higher than the previously known allowable joint strength. It is.

  The joint quality estimation is conceptually described with reference to FIG. FIG. 11B shows the characteristics of the joint strength and the node position at the end of the joining process of the bonding tool 4. As shown in the figure, there is a correlation between the node position of the bonding tool 4 and the bonding strength, and the correlation can be shown using an approximate curve (primary curve in the figure). That is, if the node position of the bonding tool is known, the bonding strength between the bonding member being bonded and the bonded member can be estimated from this approximate curve. As a result of comparing the estimated bonding strength during bonding with the allowable bonding strength determined by the bonding member and the bonded member, if the bonding strength is equal to or higher than the allowable bonding strength (that is, the threshold value of the required bonding strength) The bonding state can be considered good. Therefore, a node position corresponding to the threshold value is obtained from the allowable joint strength and the approximate curve, and the node position corresponding to the threshold value is stored in, for example, the storage unit 22 a connected to the calculation unit 22. . Then, the joint position can be estimated by comparing the node position serving as the threshold with the actual joint position of the bonding tool obtained from the measurement result.

  From such an idea, the calculation unit of the control device 20 calculates the value of the position of the vibration node of the bonding tool unit input from the vibration mode calculation unit 21, and the value of the node for termination of the joint set in advance and stored. Compare the position value. If the value of the position of the vibration node of the bonding tool input from the vibration mode calculation unit 21 is set in advance and does not satisfy the stored value of the position of the node for the end of bonding, it is estimated that the bonding is defective. Therefore, a signal for stopping the joining operation is output to the apparatus control unit 23.

  By performing such control, it is possible to reliably stop the bonding operation in the case of a bonding failure, using an element that easily captures the change in the vibration state of the bonding tool 4 such as the position of a node.

  In the example shown in FIG. 11, the description has been given using the node position as the change amount of the vibration mode of the bonding tool 4. The effect is obtained. For example, the phase of vibration can be used. An example using the phase change of the vibration mode will be described with reference to FIG.

  FIG. 12 is a diagram for explaining the relationship between the phase difference between a plurality of measurement points of the bonding tool and the bonding strength. As shown in FIG. 2A, with respect to the vibration amplitude of the bonding tool 4, there are vibration phase differences at two different points of the bonding tool 4. FIG. And this phase difference has correlation with the joining strength of a joining member and a to-be-joined member, as shown in the figure (b), and a phase difference becomes small, so that joining strength becomes large. This correlation can be represented by an approximate line. Therefore, the phase difference of the vibration of the bonding tool during bonding calculated by the vibration mode calculation unit by ultrasonic vibration at a plurality of positions measured by the vibration measuring means, and the relationship between the predetermined phase difference and the bonding strength From the approximate line showing, the bonding strength at the time of bonding can be estimated. As a result of comparing the estimated bonding strength during bonding and a predetermined allowable bonding strength, if the bonding strength is equal to or higher than the allowable bonding strength, the bonding state can be considered good. Therefore, a phase difference corresponding to the threshold value is obtained from the allowable bonding strength and the approximate curve, and the phase difference corresponding to the threshold value is stored in, for example, the storage unit 22a connected to the calculation unit 22, for example. deep. Then, the phase difference serving as the threshold value is compared with the phase difference of the vibration of the actual bonding tool obtained from the measurement result, and the value of the phase difference is set in advance and stored for the end of the bonding. If the value of the phase difference is not satisfied, it can be estimated that the bonding is defective, and therefore a signal for stopping the bonding operation is output to the apparatus control unit 23.

  The change in the vibration state during joining is not limited to the position of the node described with reference to FIG. 11 and the phase difference described with reference to FIG. 12, and the vibration frequency can also be used. Furthermore, even when the control is performed based on the position of the node, the control is not limited to the absolute position value of the node position, and the control can be performed based on the value of the change in the position of the node. .

  In the example described with reference to FIGS. 11 and 12, an example in which an approximate curve is obtained in advance for the relationship between the position of the vibration node and the bonding state has been described. However, in the control device for the ultrasonic bonding apparatus of the present invention, The quality of joining can also be estimated using statistically obtained data. An example of this will be described with reference to FIGS. FIG. 13 is a graph of an example in which the node position of vibration of the bonding tool 4 and the frequency of bonding are investigated, and the result is statistically shown. FIG. 14 is a graph of the control method of the control device in the present embodiment. It is a flowchart figure.

  Unlike the above-described method, this embodiment is suitable when already operating in a line or when the joining conditions are optimized. As shown in FIG. 14, for the ultrasonic bonding apparatus 1 in operation, a large number of ultrasonic bonding is performed while measuring the vibration of the bonding tool 4 by the ultrasonic vibration measuring means, and the ultrasonic bonding vibration mode is set as, for example, bonding. The node position at the end is measured (step S1). Next, the measured vibration mode, for example, data on the node position is accumulated (step S2). This accumulation of data is performed, for example, in a storage area provided in the calculation unit 22 or a storage unit 22 a provided connected to the calculation unit 22. As for the data at this node position, data more than the frequency necessary for statistics is accumulated. The accumulated data is, for example, like the graph shown in FIG.

Next, the average, variance, and the like of the accumulated data are calculated (step S3), and a threshold value (for example, average + 3σ _n-1 or average -3σ _n-1 ) is obtained (step S4). If the joining is performed under a predetermined condition, the majority of the parameters obtained are considered to satisfy the allowable joining strength, and only those that greatly deviate from the average and exceed the threshold value. It can be said that it is a bonding failure. Therefore, the measured vibration mode (node position) is compared with the vibration mode (node position) corresponding to the threshold value (step S5). As a result of the comparison, when this vibration mode (node position) is within the threshold value (YES in Step 6), the line operation is continued to continue ultrasonic bonding with respect to other members. The vibration mode of ultrasonic bonding of the bonding member is measured (return to step S1). On the other hand, if the position of the node exceeds the threshold value in step S6 (NO in step 6), a signal for stopping the ultrasonic bonding apparatus is sent to the ultrasonic bonding apparatus control unit 15 and the apparatus control unit. 23, the bonding is stopped, and the display unit 24 reports a failure and logs (step S7).

  According to the present embodiment, by using statistical data on the relationship between the position of the vibration node and the joining state, it is not necessary to set a threshold value by a preliminary experiment. In addition, since the statistical processing of the measurement data can be continued even during operation, further improvement in the accuracy of the relationship between the position of the vibration node and the joint state is expected.

  As described so far, the calculation unit 22 controls the continuation or stop of the bonding operation of the ultrasonic bonding apparatus according to the change of the vibration mode (vibration mode). Since the position of the node of the bonding tool 4 can always be input to the calculation unit in real time, the operation of the ultrasonic bonding apparatus can be stopped immediately when a bonding failure occurs, and the bonding operation can be stopped. The amount of defective products can be minimized.

  Moreover, the calculating part 22 can be used not only for estimation of the joining state at the time of ultrasonic joining, but also for detecting, for example, surface contamination of the joining member. FIG. 15 is a graph showing the temporal characteristics of the change in node position when the surface of the joining member is clean and the joining is good (A) and when the joining surface is contaminated and the joining is poor (B). is there. As shown in the figure, the node position in the vibration mode of the bonding tool 4 moves upward as the bonding time elapses, but the node position change amount per predetermined time (node position change amount / time) A remarkable difference is observed between A, which is an example of good bonding properties, and B, which is an example of poor bonding properties. Since the bonding failure example B is a bonding failure because the bonding surface is contaminated, the amount of change in the node position of the vibration of the bonding tool at a predetermined time is compared, so that the bonding member It is possible to guess that it is contaminated. In addition, in the same manner, it is possible to estimate a change in the state of the holding state of the member and the assembled state of the ultrasonic wave application means. The control device 20 can perform control to continue or stop the joining operation in accordance with the change in the node position that varies depending on these factors.

  Furthermore, the calculation unit 22 can optimize the joining conditions, and can change the joining conditions during operation of the apparatus. This will be described with reference to FIGS. First, FIG. 16 shows temporal changes in the node position of the bonding tool 4 during bonding for four types (joining member A, bonding member B, bonding member C, and bonding member D) having the same bonding member and different bonding properties. Is.

  In FIG. 16, the joining member A and the joining member B reach the threshold value within a specified time for joining the joining members, and it is considered that the joining state is good. On the other hand, in the joining members C and D, the node position does not reach the prescribed value for some reason even when the prescribed time is reached, and when the joining is completed within this prescribed time, a reduction in the joining strength can be expected.

  From these results, two bonding operations can be proposed for the ultrasonic bonding apparatus.

(I) First, regarding the joining of the joining members A and B in the figure, the joining operation is stopped in a joining time shorter than a predetermined time for joining. Thereby, optimization which shortens joining time can be performed, and improvement of productivity can be expected by extension.

  In order to perform this joining method, the control device 20 of the ultrasonic joining apparatus is configured such that the calculation unit 22 calculates the position of the vibration node calculated by the vibration mode calculation unit 21 within the set joining time during joining, Compare with the position of the vibration node corresponding to the threshold value of the state. As a result, if the calculated position of the node has reached the position of the node corresponding to the set threshold value, A signal for stopping the joining operation of the ultrasonic joining apparatus is output to the apparatus control unit 23 without waiting for the passage of time.

(II) The second is to continue bonding until the threshold is reached. For example, in FIG. 16, when the joining member C is mixed in the production line, the joining time is automatically extended until the node position reaches the threshold value. Thereby, insufficient bonding strength can be prevented. In addition, even if it is a joining member that is assumed to be a defective product because the position of the node does not reach the threshold value at the normal setting joining time, the joining time is extended and longer than the set joining time. Since the bonding can be made favorable by performing the bonding, the yield of the product is improved. If the node position does not reach the threshold even when the maximum allowable joining time is reached as in the joining member D, it can be assumed that the joining is poor, and thus joining is stopped.

  In order to perform this bonding method, in the control device 20 of the ultrasonic bonding apparatus, the calculation unit 22 calculates the position value of the vibration node calculated by the vibration mode calculation unit within the set bonding time during bonding, The position of the vibration node corresponding to the state threshold value is compared, and as a result, when the calculated node position has not reached the node position corresponding to the threshold value by the set joining time, The joint operation is continued up to the maximum allowable joining time and the comparison of the node positions is continued, and the calculated node position value is the value of the node whose node position corresponds to the threshold at this maximum allowable joining time. If the position has not been reached, a signal for stopping the joining operation of the ultrasonic joining apparatus is output to the apparatus control unit 23.

  A control sequence of the arithmetic unit 22 that performs these two joining operations will be described with reference to a flowchart shown in FIG.

  When a bonding operation is started by the ultrasonic bonding apparatus 1, the vibration of the bonding tool 4 is continuously measured by the ultrasonic vibration measuring means, and the vibration node position is continuously calculated by the vibration mode calculation unit 21. Thus, the value of the node position is continuously input to the calculation unit 22. Thereby, the movement of the node is monitored (step S11). Then, this node position is compared with the node position corresponding to the threshold value stored in the storage unit 22a or the like (step S12), and when the measured node position reaches the threshold value, Without waiting for the specified joining operation time, a joining stop signal is output to the ultrasonic joining device control unit 15 and the device control unit 23 to finish joining. In step S12, when the measured node position does not reach the threshold value, the joining time measured from the start of the joining work by the timer in the vibration mode calculation unit 21 and the specified joining work time (Step S13), if the joining time has not reached the prescribed joining work time, the joining is continued and the node position is continuously monitored, and the node position is compared with the threshold value. (Return to step S12). Next, in step S13, when the joining time has reached the specified joining work time, joining is performed with the joining time extended (step S14). The joining operation is continued until the extended joining time reaches the maximum joining time (step S15), and the node position is continuously monitored, and the node position and the threshold value are compared (return to step S12). As a result, even if the extended joining time reaches the maximum joining time, if the node position does not reach the threshold value, the result of the joining failure is reported to the display unit 24 and a log is recorded ( Step S16), a joining stop signal is output to the ultrasonic joining device control unit 15 and the device control unit 23, and the joining operation is finished.

  With the above control sequence, it is possible to optimize the joining conditions and improve the product yield.

  The device control unit 23 of the control device 20 continues or stops the bonding operation of the ultrasonic bonding apparatus 1 and transmits information to the ultrasonic bonding device control unit 15 based on the signal output from the calculation unit 22. .

  The display unit 24 displays the result of comparing the positions of the nodes by the calculation unit 22. By displaying the comparison result on the display unit 24, when the control device 20 stops the ultrasonic bonding device 1, information on the situation causing the stop is transmitted to the administrator, so investigation and investigation of the cause Can be useful.

  About the result of the comparison performed in the calculating part 22, it can record sequentially and it can be set as the structure which can statistics this result. This sequential recording can be stored in, for example, a storage area provided in the calculation unit 22 or a storage unit 22 a provided connected to the calculation unit 22. By recording the results, it becomes easy to investigate the history, investigate the cause of defects, etc. at an early stage, shorten the production line stoppage time, and thus improve productivity.

  As described above, the control device of the ultrasonic bonding apparatus according to the present embodiment determines the vibration mode from the amplitude or phase information at a plurality of measurement points of the ultrasonic vibration system, and the vibration mode is Focusing on the change depending on the state, the joint state can be detected in a non-destructive manner in real time by monitoring the movement of the node or the phase change and estimating the joint state. In addition, the result of the detection can be inferred from the correlation data with the joining state obtained in advance through experiments or the like, and in the case of a defect, the device is stopped and a warning is given to the operator. Mass production can be prevented. Furthermore, the state of ultrasonic bonding can be detected in real time, and when a sign of a bonding failure or a change in the bonding state appears, the display unit 24 can warn the operator, investigate the cause, take countermeasures, and change the conditions. Improvements in yield and productivity can be expected.

  As mentioned above, although the Example of the ultrasonic bonding apparatus of this invention and the Example of the control apparatus of the ultrasonic bonding apparatus were described using drawing, the ultrasonic bonding apparatus and ultrasonic bonding apparatus of this invention are limited to an Example. Many variations are possible. For example, although the ultrasonic bonding apparatus shown in FIG. 1 is an apparatus applied to wire bonding, flip-chip bonding or other ultrasonic bonding apparatuses can be used as long as the bonding method uses ultrasonic waves. Similar effects can be expected.

  Moreover, the ultrasonic bonding apparatus of the present invention may be configured to include the configuration of the control apparatus for the ultrasonic bonding apparatus of the present invention.

The figure which shows the structure of one Example of the control apparatus of the ultrasonic bonding apparatus of this invention, and an ultrasonic bonding apparatus. The schematic diagram of the laser head of a laser Doppler velocimeter. The block diagram of a vibration measurement part. The schematic diagram of the bonding tool vicinity. The schematic diagram of the bonding tool vicinity. The schematic diagram which shows the example of the attachment position of a laser head. The schematic diagram which shows the example of the attachment position of a laser head. The schematic diagram which shows the example of the attachment position of a laser head. Schematic diagram of correspondence between bonding tool and vibration mode. The timing chart which shows the example of the timing which measures an ultrasonic vibration. Explanatory drawing of the relationship between the position of a vibration node, and a joining state. Explanatory drawing of the relationship between the phase difference of a vibration, and a joining state. The graph which shows an example of the relationship between the node position of the vibration of a bonding tool, and the frequency of the quality of joining. The flowchart figure of an example of the control method of a control apparatus. The graph which showed the time-dependent characteristic of the node position change about the member from which surface cleanliness differs. The graph which shows the time-dependent change of the node position of the bonding tool at the time of joining about the member from which joining property differs. The flowchart which shows the example of the control sequence of a calculating part. The perspective view which shows the positional relationship of the conventional ultrasonic bonding apparatus and a laser Doppler meter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ultrasonic bonding apparatus, 2 ... Ultrasonic vibrator, 3 ... Ultrasonic horn, 4 ... Bonding tool, 11 ... Laser head, 12 ... Amplitude calculation part, 20 ... Control apparatus, 21 Vibration mode calculation part, 22 ... Calculation Part, 23 ... device control part, 24 ... display part

Claims (15)

Bonding tool part,
Supporting one end of this bonding tool part, an ultrasonic horn part for applying ultrasonic vibration to the bonding tool part,
An ultrasonic bonding apparatus comprising: a vibration measuring unit that measures vibration of the bonding tool part and calculates a position of a vibration node of the bonding tool part. The vibration measuring means includes
An amplitude measurement unit that measures amplitude at the same time at multiple locations for any point on the bonding tool unit;
The vibration mode calculation unit that calculates the position of the vibration node of the bonding tool unit from the amplitude values of different portions obtained at the same time obtained by the amplitude measurement unit. Sonic bonding device. The vibration measuring means includes
An amplitude measurement unit that measures amplitude at the same time for an arbitrary point of the bonding tool unit and an arbitrary point in the vicinity of the region supporting the bonding tool of the ultrasonic horn unit,
The vibration mode calculation unit that calculates the position of the vibration node of the bonding tool unit from the amplitude values of different portions obtained at the same time obtained by the amplitude measurement unit. Sonic bonding device. The amplitude measuring unit receives a laser oscillator, an optical member that guides the laser beam emitted from the laser oscillator so as to irradiate the measurement point, and receives the laser beam reflected by the measurement point to be electrically The ultrasonic bonding apparatus according to claim 2, further comprising: a light detection unit that outputs a signal.   4. The ultrasonic wave according to claim 2, wherein the amplitude measuring unit is fixed to a bracket attached to the ultrasonic horn unit and is relatively fixed to the movement of the ultrasonic horn unit. Sonic bonding device.   The ultrasonic bonding apparatus according to claim 2, wherein the optical member has a movable part that moves a measurement point in a changeable manner.   The vibration mode calculation unit calculates an approximate curve of the vibration of the bonding tool from the amplitude values at different points in the same period obtained by the amplitude measurement unit, and similarly, at different times, different points at the same time 4. The ultrasonic wave according to claim 2, wherein the amplitude value is measured and the approximate curve is calculated, and the position of the vibration node of the bonding tool portion is calculated from the resulting approximate curves at different times. Joining device. A control unit configured to compare with a predetermined value set in advance based on a value related to a position of a vibration node calculated by the vibration mode calculating unit, and to stop the joining operation when a predetermined necessary condition for the predetermined value is not satisfied; The ultrasonic bonding apparatus according to claim 1, wherein the ultrasonic bonding apparatus is provided. It is connected to the vibration measuring means that measures the vibration of the bonding tool part of the ultrasonic bonding apparatus and calculates the position of this vibration node, and the value of the vibration node position of the bonding tool part input from this vibration measuring means A control device for an ultrasonic bonding apparatus for stopping the bonding operation of the ultrasonic bonding apparatus based on
The value of the position of the vibration node of the bonding tool part calculated by the vibration measuring means is input, and the value of the position of the vibration node of the bonding tool part and the preset position of the node for the end of joining An arithmetic unit for comparing the value of
A device control unit that stops the bonding operation of the ultrasonic bonding apparatus when the value of the vibration node position of the bonding tool unit compared in the arithmetic unit does not reach a preset node position; A control apparatus for an ultrasonic bonding apparatus.   The calculation unit compares the value of the position of the vibration node of the bonding tool when the predetermined bonding time has elapsed and the value of the position of the node for the end of bonding set in advance. The control apparatus for an ultrasonic bonding apparatus according to claim 9, wherein:   The value of the position of the node for the end of joining set in advance in the calculation unit is determined based on the correlation between the bonding strength and the position of the vibration node of the bonding tool unit. The control device for an ultrasonic bonding apparatus according to claim 9 or 10.   The predetermined value of the position of the node for the end of joining in the calculation unit is determined based on statistical data on the quality of joining between the joining member and the member to be joined. The control apparatus for an ultrasonic bonding apparatus according to 9 or 10. The calculation unit compares the value of the vibration node position of the bonding tool part within a predetermined bonding time and the preset value of the node position for the end of bonding,
When the value of the position of the vibration node of the bonding tool compared with the calculation unit reaches the preset node position, the apparatus control unit does not wait for the set joining time to elapse. 10. The control apparatus for an ultrasonic bonding apparatus according to claim 9, wherein the bonding operation of the ultrasonic bonding apparatus is stopped. The calculation unit compares the value of the position of the vibration node of the bonding tool when a predetermined bonding time has elapsed, and the value of the position of the node for the end of bonding set in advance,
The apparatus control unit continues the bonding operation until the maximum allowable bonding time when the position of the vibration node of the bonding tool unit does not reach the set node position by the set bonding time; and
10. The bonding operation of the ultrasonic bonding apparatus is stopped when the position of the vibration node of the bonding tool portion does not reach the set node position by the maximum allowable bonding time. The control apparatus of the described ultrasonic bonding apparatus. When ultrasonically joining a joining member and a member to be joined, vibrations of the bonding tool part of the ultrasonic joining device being joined are measured in a plurality of regions at the same time, and the vibration aspect of the bonding tool part is calculated as a vibration aspect. Calculating by the unit,
A step of continuing or stopping the bonding operation of the ultrasonic bonding apparatus according to the vibration mode of the bonding tool unit calculated by the vibration mode calculation unit.

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