JP2003243450A - Ultrasonic bonding device and ultrasonic bonding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic bonding device and an ultrasonic bonding method in which normal bonding operation can be performed without the generation of irregular oscillation when the operation of a vibrator is started. <P>SOLUTION: In an ultrasonic bonding device, an electronic component 3 is pressure-bonded using a ultrasonic wave and a load on a substrate 2 by a bonding tool 7. An operating frequency signal to instruct the operating frequency of a vibrator 6 is outputted depending on different output modes. Moreover, a normal bonding operation can be performed without generating irregular vibration when the operation of the vibrator is started by turning off a frequency tracking function. When the operation of the vibrator 6 is started, the signal of the frequency same as an instruction frequency is outputted as the operation frequency signal, and the frequency tracking function is turned on by outputting, as the operation frequency signal, a compensated frequency signal where compensation is added to the instruction frequency based on the phase comparison result of a current and a voltage. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic bonding apparatus and an ultrasonic bonding method for bonding an object to be bonded, such as an electronic component or an electrode bonding wire, with ultrasonic vibration. .

[0002]

2. Description of the Related Art As a method of bonding an electronic component to a surface to be bonded such as an electrode of a substrate, a method using ultrasonic bonding is known. In this method, ultrasonic vibration is applied to the electronic component while pressing the electronic component against the surfaces to be joined, and the joint surfaces are caused to vibrate slightly to generate friction, thereby bringing the joint surfaces into close contact with each other. In this ultrasonic bonding, a load and ultrasonic vibration are applied to the electronic component by a bonding tool equipped with a vibrator that is a vibration applying unit.

In order to efficiently carry out stable bonding of quality in ultrasonic bonding, strong vibration is generated by matching the drive frequency of the vibrator with the natural vibration frequency of the vibration system of the bonding tool to cause mechanical resonance. It is desirable to let Since this mechanical resonance frequency fluctuates due to the load load and temperature rise during bonding, the oscillator used in the ultrasonic bonding device is equipped with a frequency automatic tracking function that makes the driving frequency of the vibrator follow the fluctuating resonance frequency. There are many cases.
A phase-locked loop oscillator is known as a method for automatically tracking the frequency. This type of oscillator controls the oscillation frequency by automatically detecting the phase difference between the current and the voltage that drives the vibrator, and automatically follows the resonance frequency.

[0004]

However, the conventional ultrasonic bonding apparatus using the above-mentioned phase locked loop type oscillator has the following inconveniences.
As described above, in order for the phase-locked loop oscillator to operate normally, the condition is that the current flowing in the drive circuit of the vibrator is detected. However, immediately after starting the voltage application to the vibrator when starting the bonding operation,
There is an indeterminate time during which no current flows through the oscillator. If the phase-locked loop is closed during this settling time, normal feedback is not performed and the oscillator oscillates irregularly, which causes an operation error and prevents normal bonding operation.

Therefore, an object of the present invention is to provide an ultrasonic bonding apparatus and an ultrasonic bonding method capable of performing a normal bonding operation without causing irregular oscillation at the start of driving a vibrator.

[0006]

An ultrasonic bonding apparatus according to claim 1, wherein the object to be bonded is pressure-bonded to a surface to be bonded while applying load and ultrasonic vibration to the object to be bonded. A bonding tool that comes into contact with an object, a pressing unit that presses the bonding tool against a surface to be bonded via a bonding object, a vibrator that applies ultrasonic vibration to the bonding tool, and drives the vibrator. A drive unit for supplying electric power for driving the drive unit and a drive frequency signal for instructing the drive frequency of the drive unit to the drive unit according to an output mode selected and instructed from a plurality of different output modes. A drive frequency signal output section for outputting, a detection section for detecting a voltage and a current of the vibrator driven by the vibrator drive section, and a detection section A phase comparison unit that compares the phases of the output voltage and current and outputs the comparison result to the drive frequency signal output unit, and a command frequency that outputs a preset command frequency to the drive frequency signal output unit. A signal output unit and a mode instruction unit for instructing the drive frequency signal output unit to perform the output mode, wherein the plurality of output modes outputs a signal having the same frequency as the command frequency as a drive frequency signal. 1 mode and the 2nd mode which outputs the signal of the corrected frequency which added the correction | amendment based on the comparison result of the said phase comparison part to the said command frequency as a drive frequency signal.

The ultrasonic bonding apparatus according to claim 2 is the ultrasonic bonding apparatus according to claim 1,
A bonding control means is provided for controlling the mode instructing section so that the first mode is instructed at the start of driving the vibrator in the bonding operation and then the mode is switched to the second mode.

The ultrasonic bonding apparatus according to claim 3 is the ultrasonic bonding apparatus according to claim 1,
The command frequency signal output unit includes a frequency instructing unit for instructing a frequency and a resonance frequency detecting unit for detecting a resonance frequency of the oscillator, and the frequency instructing unit is a resonance detected by the resonance frequency detecting unit. The frequency is set as the basic frequency of the vibrator and is instructed to the command frequency signal output unit, and the command frequency signal output unit outputs the command frequency signal based on the basic frequency.

The ultrasonic bonding apparatus according to claim 4 is the ultrasonic bonding apparatus according to claim 3,
When the resonance frequency of the vibrator is detected by the resonance frequency detecting means, the drive frequency signal output section outputs the drive frequency signal in the first mode.

An ultrasonic bonding apparatus according to a fifth aspect is the ultrasonic bonding apparatus according to the third or fourth aspect, in which the resonance frequency detecting means drives the vibrator to set a command frequency within a predetermined range. The frequency sweeping means for regularly changing the frequency, the storage means for storing the detection value detected by the detection section during the frequency sweep and the command frequency corresponding to the detection value in association with each other, and the storage means Resonant frequency searching means for searching for a command frequency at which the drive current of the vibrator is approximately maximum or impedance is approximately minimum based on the detected value and set as the resonant frequency.

According to the sixth aspect of the ultrasonic bonding method of the present invention, there is provided a bonding tool that comes into contact with an object to be bonded, a pressing unit that presses the bonding tool against a surface to be bonded via the object to be bonded, and the bonding tool. A vibrator for applying ultrasonic vibration, a vibrator drive unit for supplying electric power for driving the vibrator, and a drive frequency signal for instructing the vibrator drive unit of the drive frequency of the vibrator A drive frequency signal output section for outputting according to an output mode selected and instructed from a plurality of different output modes, and a command frequency signal output section for outputting a preset command frequency to the drive frequency signal output section, An ultrasonic bonder using an ultrasonic bonding apparatus, comprising: a mode instructing unit that instructs the drive frequency signal output unit to perform the output mode. In the method, at the start of driving the vibrator in the bonding operation, a first mode for outputting a signal having the same frequency as the command frequency as a drive frequency signal is instructed, and then the command frequency is compared by the phase comparison unit. The mode is switched to the second mode in which the signal of the corrected frequency added with the correction amount based on is output as the driving frequency signal.

An ultrasonic bonding method according to a seventh aspect of the present invention includes a bonding tool that comes into contact with an object to be bonded, a pressing means that presses the bonding tool against a surface to be bonded via the object to be bonded, and the bonding tool. A vibrator for applying ultrasonic vibration, a vibrator drive unit for supplying electric power for driving the vibrator, and a drive frequency signal for instructing the vibrator drive unit of the drive frequency of the vibrator A drive frequency signal output section for outputting according to an output mode selected and instructed from a plurality of different output modes, and a command frequency signal output section for outputting a preset command frequency to the drive frequency signal output section, A mode instructing unit for instructing the output mode to the drive frequency signal output unit, and a frequency instructing unit for instructing a frequency to the command frequency signal output unit. An ultrasonic bonding method using an ultrasonic bonding apparatus, comprising: a number indicating section; and a resonance frequency detecting means for detecting a resonance frequency of the vibrator, wherein the frequency indicating section is a resonance detected by the resonance frequency detecting means. The frequency is set as the basic frequency of the vibrator and is instructed to the command frequency signal output unit, and the command frequency signal output unit outputs the command frequency signal based on the basic frequency.

The ultrasonic bonding method according to claim 8 is the ultrasonic bonding method according to claim 7,
When the resonance frequency of the vibrator is detected by the resonance frequency detecting means, the drive frequency signal output section outputs the drive frequency signal according to a first mode in which a signal having the same frequency as the command frequency is output as a drive frequency signal. To do.

According to the present invention, the driving frequency signal for instructing the driving frequency of the vibrator is output according to different output modes, and when the driving of the vibrator is started, the signal having the same frequency as the command frequency is used as the driving frequency signal. Output,
After that, the corrected frequency signal, which is the command frequency plus the correction based on the phase comparison result of the current and voltage, is output as the drive frequency signal, so that the normal bonding operation can be performed without generating irregular oscillation at the start of driving the vibrator. It can be performed.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an ultrasonic bonding apparatus according to an embodiment of the present invention, FIG. 2 is a flowchart of drive frequency signal output processing of the ultrasonic bonding apparatus according to an embodiment of the present invention, and FIG. A flowchart of a basic frequency setting process by the ultrasonic bonding apparatus according to the embodiment of the invention, FIG. 4 is a graph showing frequency search data of the bonding apparatus according to the embodiment of the invention, and FIG. 5 is an embodiment of the invention. 5 is a flowchart of a vibrator driving process during a bonding operation by the ultrasonic bonding apparatus of FIG.

First, the structure of the ultrasonic bonding apparatus will be described with reference to FIG. In FIG. 1, a substrate 2 is placed on a bonding stage 1. An electronic component 3, which is an object to be joined, is mounted on the upper surface of the substrate 2, which is the surface to be joined, by ultrasonic bonding. Bonding stage 1
A bonding mechanism 4 is disposed above the. The bonding mechanism 4 has a structure in which a bonding tool 7 is held by an elevating block 8 which is moved up and down by an elevating mechanism section 9 driven by a head driving section 12.

The bonding tool 7 is constructed by mounting a vibrator 6 on the end of a horizontally elongated horn 5, and by driving the vibrator 6, ultrasonic vibration is applied to the bonding tool 7. It The lower part of the central part of the horn 5 is provided with a joining action part 5a projecting downward, and the joining action part 5a is brought into contact with the upper face of the electronic component 3 and vacuum suction is performed from a suction hole (not shown). The electronic component 3 is held on the joining action portion 5a.

The horn 5 is driven by driving the vibrator 6.
A longitudinal vibration of ultrasonic waves is applied to the ultrasonic wave, and the ultrasonic vibration is transmitted to the electronic component 3 via the bonding action portion 5a. Horn 5
Is supported by a holding member 8a at a position corresponding to a node of standing wave vibration generated by the vibrator 6,
The loss caused by the vibration induced in the horn 5 being transmitted to the lifting block 8 is prevented as much as possible.

The bonding tool 7 is lowered by driving the elevating mechanism 9 in a state where the electronic component 3 is adsorbed and held by the joining action portion 5a, and the electronic component 3 is pressed against the substrate 2 with a predetermined load. . By driving the vibrator 6 in this state, the electronic component 3 is pressure-bonded to the substrate 2, which is the surface to be bonded, by the action of the load and ultrasonic vibration. The lifting mechanism 9 serves as a pressing unit that presses the bonding tool 7 against the substrate 2 via the electronic component 3.

Next, a drive circuit for driving the vibrator 6 and a control system for controlling the drive circuit will be described. The ultrasonic bonding apparatus according to the present embodiment has a phase-locked loop type frequency tracking function, and the drive frequency of the vibrator 6 is adjusted so that the phase difference between the voltage and the current of the vibrator 6 becomes a predetermined value. The frequency of ultrasonic vibration generated by the vibrator 6 can be made to follow the resonance frequency of the bonding tool 7 by controlling the.

Even when the frequency tracking function is provided as described above, since it is necessary to instruct the drive frequency for each bonding tool at the start of driving, the drive frequency at the time of starting the drive of the vibrator 6 ( Free-running frequency) is preset. As the free-running frequency, a resonance frequency when the bonding tool is oscillated in an air state where no load is applied is generally used.

The resonance frequency in the unloaded state has a characteristic as a fundamental frequency peculiar to each individual bonding tool, and it is desirable to register it as data for each product type and each solid. For this reason, the ultrasonic bonding apparatus of the present embodiment is provided with a resonance frequency detecting means for automatically detecting the resonance frequency as the fundamental frequency of the vibrator 6 mounted on the bonding tool.

First, the drive circuit for the vibrator 6 will be described. The vibrator driving unit 10 is a driver that causes the vibrator 6 to generate ultrasonic vibrations, and when the drive voltage V and the drive frequency f are commanded, the vibrator 6 is generated according to these commands.
Supply power to drive the. Drive voltage V,
The drive frequency f is a command parameter that determines the power and frequency of the ultrasonic vibration output from the vibrator 6. The drive voltage V is the drive voltage instruction unit 16 f of the control unit 16.
The drive frequency f is instructed from the drive frequency signal output unit 18 to the vibrator drive unit 10 as a drive frequency signal.

The detection unit 13 detects the drive voltage (USV) of the vibrator 6 by detecting the voltage between the two connection terminals of the vibrator 6 driven by the vibrator drive unit 10, and also detects both ends of the resistor. The drive current (USI) of the vibrator 6 is detected by detecting the voltage between them. Phase comparison unit 15
Compares the phases of the voltage and the current detected by the detector 13. The comparison result is output to the drive frequency signal output unit 18 as a voltage value proportional to the phase difference.

When the drive frequency signal output section 18 issues a drive frequency signal to the vibrator drive section 10,
A command frequency signal output from the command frequency signal output unit 17 is commanded to be a drive frequency signal in which a correction amount (correction frequency) corresponding to the above-described comparison result (phase difference between voltage and current) is added. Here, an analog circuit outputs a correction frequency substantially proportional to the phase difference, and this correction frequency is added to the command frequency. With this phase-locked loop circuit, the vibrator driving unit 10 supplies the vibrator 6 with power having a drive frequency that follows the resonance frequency of the bonding tool 7.

Here, the command frequency is reference data for determining the drive frequency, and is preset based on the above-mentioned basic frequency f0. In setting the command frequency, two types of setting patterns can be selected. That is, there are a case where the basic frequency f0 itself is used as the command frequency and a case where a frequency obtained by adding a predetermined offset frequency to the basic frequency f0 is used as the command frequency. In the present embodiment, a setting pattern using the fundamental frequency f0 itself as the command frequency will be described.

The command frequency is instructed by the frequency instructing unit 16e of the control unit 16 reading data such as the basic frequency f0 and the offset frequency from the drive parameter storage unit 23 and instructing the command frequency signal output unit 17. Done. The command frequency signal output unit 17 then
The command frequency signal is output to the drive frequency signal output unit 18 according to the instruction of the frequency instruction unit 16e. Of these data, the fundamental frequency f0 is detected by the resonance frequency detecting means provided in the ultrasonic bonding apparatus as described later and stored in the drive parameter storage unit 23.

That is, the frequency instructing section 16e sets the resonance frequency f0 detected by the resonance frequency detecting means as the fundamental frequency of the vibrator 6 and instructs it to the command frequency signal output section 17. And the command frequency signal output unit 1
7 outputs a command frequency signal based on the fundamental frequency f0 to the drive frequency signal output unit 18.

When the drive frequency signal output unit 18 outputs the drive frequency signal to the vibrator drive unit 10, the drive frequency signal output unit 18 can output the drive frequency signal in accordance with an output mode selected and instructed from a plurality of different output modes. It has become. These output modes include an output mode (first mode) for performing frequency tracking with the phase-locked loop circuit being closed, and a phase-locked loop circuit opened to turn off the frequency tracking function. The output mode (second mode) is included. These output mode instructions are given by the mode instruction unit 16d of the control unit 16.

Now, the relationship between the drive frequency output signal for instructing the drive frequency and the output mode will be described with reference to FIG. FIG. 2 shows a drive frequency signal output process when the drive frequency signal output unit 18 outputs a drive frequency signal to the vibrator drive unit 10.

First, a command frequency signal is read from the command frequency signal output section 17 and an output mode instruction is read from the mode instructing section 16d (ST1). Then, the output mode is determined (ST2). Here, in the first mode, a signal having the same frequency as the command frequency is output to the vibrator driving unit 10 as a drive frequency signal (ST3).

In the second mode, the following processing is performed. First, the comparison result of the phase comparison unit 15 is read (ST
4). Then, the correction frequency is obtained based on the comparison result (ST5). That is, a correction frequency that is substantially proportional to the phase difference between the voltage and the current is output by the analog circuit, and the corrected frequency signal obtained by adding the correction amount to the command frequency is output as the drive frequency signal (ST6). By designating the output mode in this way, it is possible to select ON / OFF of the frequency tracking function.

Next, the control system will be described. The control unit 16 is a bonding control unit that controls the entire bonding operation, and has processing functions described in the following units. The head drive instruction section 16 a controls the head drive section 12 that drives the elevating mechanism section 9. The detection value writing processing unit 16b
A process for writing the detection data of the detection unit 13 in the detection value storage unit 24 is performed. The voltage and current analog data detected by the detection unit 13 is converted into an effective value by the conversion unit 14 and further converted into digital data. The detection value writing processing unit 16b processes the digital data to write the data in the detection value storage unit 24 in a predetermined data format. As a result, frequency search data (see FIG. 4) necessary for the resonance frequency detection process is created.

The calculation unit 16c performs various calculation processes such as a resonance frequency detection calculation for obtaining a resonance frequency based on the frequency search data stored in the detected value storage unit 24. The mode instructing unit 16d instructs the drive frequency signal output unit 18 about the output mode based on the bonding operation program stored in the program storage unit 22 and the basic frequency detection processing program. The frequency instruction unit 16e reads out a frequency parameter from various parameters stored in the drive parameter storage unit 23, and instructs the command frequency signal output unit 17 of a required frequency. The drive voltage instruction unit 16f instructs the drive voltage V to the vibrator drive unit 10. The frequency measuring unit 16g uses the drive voltage USV of the vibrator 6.
By counting the frequencies of the
The fundamental frequency of the vibrator 6 driven by is measured.

The operation / input unit 20 is an input means such as a keyboard and a mouse, and inputs operation commands and data. The display unit 21 is a display panel such as a CRT, and displays a guide screen during data input and operation. The program storage unit 22 stores various operation programs and processing programs such as bonding operation and fundamental frequency detection processing.

The drive parameter storage unit 23 stores the fundamental frequency f0 indicating the resonance frequency when the bonding tool is oscillated in the air, the sweep frequency data for the frequency sweep executed in the fundamental frequency detection processing (the lower limit frequency of the sweep range). fmin.Upper limit frequency fmax. and sweep pitch frequency Δf), drive voltage V, bonding time t, and other various drive parameters used for driving the vibrator 6 to perform bonding operations and various processes are stored. The inspection value storage unit 24 stores the current and voltage detection data detected by the detection unit 13 in the form of frequency search data necessary for the resonance frequency detection process.

Next, the fundamental frequency detecting process will be described with reference to FIG. Here, the resonance frequency in the unloaded state when the vibrator 6 is driven in the air state where the bonding tool 7 is raised is obtained by frequency sweep. The resonance frequency at this time is measured by the frequency measuring unit 16g.
You may confirm by actually measuring using. Then, the obtained resonance frequency is set as a fundamental frequency, and is used as a free-running frequency which is a drive frequency when the drive of the vibrator 6 is started in the bonding operation. Of course, the resonance frequency in the load state in which the bonding tool 7 is pressed against the substrate 2 can be obtained by the same detection process.

First, the first mode is designated as the output mode of the drive frequency signal (ST10). Thus, when the drive frequency signal output unit 18 outputs the drive frequency signal to the vibrator drive unit 10, the drive frequency signal of the same frequency as the command frequency output from the command frequency signal output unit 17 is output according to the first mode. The signal will be output.

Next, the sweep frequency data is read (S
T11). That is, the lower limit frequency fmi of the sweep range
n. Upper limit frequency fmax. And the sweep pitch frequency Δf is read from the drive parameter storage unit 23. Next, the drive voltage V is read from the drive parameter storage unit 23 (ST12). The lower limit frequency fmin. Is designated as the command frequency f (ST13).

After that, the vibrator 6 is driven. That is, the vibrator 6 is driven with the drive current V and the drive frequency f (same as the command frequency) (ST14). In the process of driving the vibrator 6, the detector 13 detects the drive current (USI) of the vibrator 6 (hereinafter, simply referred to as the current I) (ST15), and associates the detected value with the drive frequency f at this time. The detected value is stored in the storage unit 24 (ST16).

Next, the sweep pitch frequency Δf is added to the drive frequency f to increase the drive frequency f (ST1
7). The drive frequency f is the upper limit frequency fmax. Is determined (ST18), and if not reached, the process returns to (ST14) and the subsequent processes are repeatedly executed to detect the current and store the detected value. In the frequency sweep, the order of frequency sweep is set to the upper limit frequency fmax.
To the lower limit frequency fmin. You may make it change toward.

In the above process, the frequency instruction unit 16e
Is a frequency sweep means for regularly changing the command frequency within a predetermined range while driving the vibrator 6. The detection value writing processing unit 16b and the detection value storage unit 24 serve as a storage unit that stores the detection value detected by the detection unit 13 during the frequency sweep and the command frequency corresponding to the detection value in association with each other. There is.

Then, in (ST18), the command frequency f is the upper limit frequency fmax. If, in other words, all the data points shown in the graph of FIG. 4 are obtained,
If it is stored in the detected value storage unit 24 as frequency search data, frequency search processing is performed. That is, the maximum current value Imax. Of the maximum value Imax. The command frequency f (Imax.) Corresponding to is calculated (ST19). This search processing is performed by the calculation unit 16c.

Then, the maximum value Imax. The command frequency f (Imax.) Corresponding to is set as the resonance frequency (fundamental frequency f0) and stored in the drive parameter storage unit 23 (ST20). In the bonding operation, the command frequency at the start of driving the vibrator 6 is set based on this basic frequency f0. In the above process, the calculation unit 16c searches for a command frequency at which the drive current of the vibrator 6 is approximately maximum or impedance is approximately minimum based on the detection value stored in the detection value storage unit 24, and the resonance frequency is set as the resonance frequency. It is a frequency search means. Instead of using the current value as the parameter, the impedance may be used as the parameter, and the minimum impedance value may be searched to obtain the command frequency corresponding to this minimum value. Note that the resonance frequency may be obtained by utilizing the fact that the phase difference between the voltage USV across the vibrator 6 and the current USI flowing through the vibrator 6 is substantially zero in the resonance state.

Next, referring to FIG. 5, the vibrator driving process during the bonding operation will be described. First, the transducer drive parameters are read from the parameter storage unit 23 (ST
21). As a result, the fundamental frequency f0, the drive voltage V, and the vibrator drive time t are read. Next, when driving the vibrator 6, the first mode is designated as the output mode of the driving frequency signal (ST22). Accordingly, when the drive frequency signal output unit 18 outputs the drive frequency signal to the vibrator drive unit 10, according to the first mode,
A signal having the same frequency as the command frequency output from the command frequency signal output unit 17 is output, and the frequency tracking function is turned off.

That is, the drive frequency f is output from the drive frequency signal output unit 18 to the vibrator drive unit 10, and the vibrator 6 is driven at the drive frequency f and the drive voltage V equal to the basic frequency f0 ( ST23). Then, in this driving state, the detection unit 13 detects the current I (ST24), and determines whether or not a current equal to or larger than a predetermined current value set in advance as a threshold current is detected (ST).
25).

If the predetermined current value has not been reached, the process returns to (ST23) to continue driving the vibrator 6 at the drive frequency described above. If the predetermined current value has been reached, the mode is set. The instruction unit 16d instructs the second mode as the output mode of the drive frequency signal (ST26).
Thus, when the drive frequency signal output unit 18 outputs the drive frequency signal to the vibrator drive unit 10, the phase comparison unit compares the command frequency output from the command frequency signal output unit 17 with the second mode. The corrected frequency added with the correction amount based on the comparison result of 15 is output as the drive frequency signal, and the frequency tracking function is turned on.

That is, the vibrator 6 is driven at the drive frequency corrected according to the phase difference between the current and the voltage detected by the detector 13 (ST27). As a result, even if the resonance frequency changes depending on the load condition,
The drive frequency of the vibrator 6 can be made to follow the resonance frequency in the load state. After that, it is determined whether or not the vibrator driving time t has timed up (ST28), and if the time-up is confirmed, the driving of the vibrator 6 is stopped (ST29). This completes the bonding operation.

In the above bonding, the control unit 16
Controls the mode instructing unit 16d in accordance with the bonding operation program so that the first mode is instructed at the start of driving the vibrator 6 in the bonding operation.
After that, the instruction is switched to the second mode.

In the vibrator driving process in the above-described bonding, the vibrator 6 is always driven at the drive frequency according to the command frequency in the first mode during the indefinite time in which no current normally flows in the vibrator 6 immediately after the driving is started. Driven. Therefore, irregular oscillation does not occur due to the phase-locked loop being closed during the irregular settling time during which no current flows through the oscillator 6, and the operation error due to irregular oscillation is eliminated, and normal bonding operation is performed. can do.

[0051]

According to the present invention, the driving frequency signal for instructing the driving frequency of the vibrator is output according to different output modes, and when the driving of the vibrator is started, the signal having the same frequency as the command frequency is output. It outputs as a signal, and after that, it outputs the signal of the corrected frequency, which is the corrected frequency based on the result of the phase comparison of the current and voltage, as the driving frequency signal. A normal bonding operation can be performed without any occurrence.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an ultrasonic bonding apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart of drive frequency signal output processing of the ultrasonic bonding apparatus according to the embodiment of the present invention.

FIG. 3 is a flowchart of a basic frequency setting process by the ultrasonic bonding apparatus according to the embodiment of the present invention.

FIG. 4 is a graph showing frequency search data of the bonding apparatus according to the embodiment of the present invention.

FIG. 5 is a flowchart of a vibrator driving process during a bonding operation by the ultrasonic bonding apparatus according to the embodiment of the present invention.

[Explanation of symbols] 2 substrates 3 electronic components 5 horns 6 oscillators 7 Bonding tool 10 Transducer drive section 13 Detector 15 Phase comparator 16 Control unit 16d mode indicator 17 Command frequency signal output section 18 Drive frequency signal output section 24 Detection value storage

Claims (8)

[Claims] 1. An ultrasonic bonding apparatus for press-bonding to a surface to be bonded while applying load and ultrasonic vibration to the object to be bonded, the bonding tool being in contact with the object to be bonded, and the bonding tool. Pressing means for pressing the bonding surface via the bonding tool, a vibrator for applying ultrasonic vibration to the bonding tool, a vibrator driving unit for supplying electric power for driving the vibrator, and the vibrator. A drive frequency signal output unit that outputs a drive frequency signal for instructing a drive frequency of the vibrator to the drive unit according to an output mode selected and instructed from a plurality of different output modes, and the vibrator drive unit. A detection unit that detects the voltage and current of the driven vibrator,
A phase comparison unit that compares the phase of the voltage and the current detected by this detection unit and outputs the comparison result to the drive frequency signal output unit, and a preset command frequency to the drive frequency signal output unit. Command frequency signal output section to output,
A mode instructing section for instructing the output mode to the drive frequency signal output section, wherein the plurality of output modes include a first mode in which a signal having the same frequency as the command frequency is output as a drive frequency signal; And a second mode for outputting a signal of a corrected frequency obtained by adding a correction amount based on a comparison result of the phase comparison unit to a command frequency as a drive frequency signal. 2. A bonding control means for controlling the mode instructing section so as to instruct the first mode at the start of driving of the vibrator in the bonding operation and then switch to the second mode instruction. The ultrasonic bonding apparatus according to claim 1. 3. A frequency instructing section for instructing a frequency to said command frequency signal output section, and a resonance frequency detecting means for detecting a resonance frequency of said vibrator, said frequency instructing section comprising said resonance frequency detecting means. The resonance frequency detected by the method is set as a fundamental frequency of the vibrator to instruct the command frequency signal output unit, and the command frequency signal output unit outputs a command frequency signal based on the fundamental frequency. The ultrasonic bonding device according to claim 1. 4. The drive frequency signal output section outputs the drive frequency signal in the first mode when the resonance frequency of the vibrator is detected by the resonance frequency detecting means. The ultrasonic bonding apparatus described. 5. The frequency sweeping means, wherein the resonance frequency detecting means regularly changes the command frequency within a predetermined range while driving the vibrator, and the detection value detected by the detecting portion during the frequency sweeping. And a storage unit that stores the command frequency corresponding to the detected value in association with each other, and a command frequency at which the drive current of the vibrator is substantially maximum or the impedance is substantially minimum is searched based on the detection value stored in the storage unit. 5. The ultrasonic bonding apparatus according to claim 3, further comprising a resonance frequency search unit that sets the resonance frequency as a resonance frequency. 6. A bonding tool that contacts an object to be joined, a pressing means that presses the bonding tool against a surface to be joined via the object to be joined, and a vibrator that applies ultrasonic vibration to the bonding tool. , A vibrator driving unit that supplies electric power for driving the vibrator, and a driving frequency signal for instructing the driving frequency of the vibrator to the vibrator driving unit from a plurality of different output modes. With respect to the drive frequency signal output unit that outputs according to the output mode instructed to select, the command frequency signal output unit that outputs a preset command frequency to the drive frequency signal output unit, and the drive frequency signal output unit An ultrasonic bonding method using an ultrasonic bonding apparatus, comprising: a mode instructing unit for instructing the output mode. At the start of driving the oscillator, the first mode for outputting a signal having the same frequency as the command frequency as a drive frequency signal is instructed, and then the command frequency is corrected by adding a correction amount based on the comparison result of the phase comparator. An ultrasonic bonding method characterized by switching to a second mode in which a signal of a rear frequency is output as a drive frequency signal. 7. A bonding tool that contacts an object to be joined, a pressing means that presses the bonding tool against a surface to be joined via the object to be joined, and a vibrator that applies ultrasonic vibration to the bonding tool. , A vibrator driving unit that supplies electric power for driving the vibrator, and a driving frequency signal for instructing the driving frequency of the vibrator to the vibrator driving unit from a plurality of different output modes. With respect to the drive frequency signal output unit that outputs according to the output mode instructed to select, the command frequency signal output unit that outputs a preset command frequency to the drive frequency signal output unit, and the drive frequency signal output unit A mode instructing unit for instructing the output mode, a frequency instructing unit for instructing a frequency to the command frequency signal output unit, and a resonance frequency of the oscillator are detected. An ultrasonic bonding method using an ultrasonic bonding apparatus having a resonance frequency detecting means, wherein the frequency instructing section sets the resonance frequency detected by the resonance frequency detecting means as a fundamental frequency of the vibrator and issues an instruction. An ultrasonic bonding method, wherein an instruction is given to a frequency signal output unit, and the command frequency signal output unit outputs a command frequency signal based on the fundamental frequency. 8. When the resonance frequency of the vibrator is detected by the resonance frequency detecting means, the drive frequency signal output section outputs the signal having the same frequency as the command frequency as a drive frequency signal according to the first mode. 8. The ultrasonic bonding method according to claim 7, wherein a driving frequency signal is output.