JP2003243451A - 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, even when the resonance frequency of a vibrator changes to a large extent due to a load, it is possible to surely follow up the resonance frequency of a predetermined vibration mode to assure a stable bonding process. <P>SOLUTION: In ultrasonic bonding to pressure-bond electronic components to a substrate using a load and vibration, a relation among a basic frequency f0 indicating the resonance frequency under a non-loading condition, a load resonance frequency under the non-loading condition and a pressing load is stored in a storage means. Moreover, a self-running frequency when the operation of the vibrator is started is outputted with an addition of a frequency offset α, to the basic frequency f0, which is set based on the load resonance frequency corresponding to the pressing load during the relevant bonding operation. Accordingly, even when the resonance frequency of the vibrator changes to a large extent to f1 from f0 due to the load, the frequency surely follows the resonance frequency f1. <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 the resonance frequency that causes the mechanical resonance differs for each bonding tool, it is necessary to obtain the resonance frequency for each individual. This resonance frequency detection is generally detected by driving the vibrator in a no-load state where the bonding tool is in the air. Then, when the bonding operation is started, this resonance frequency is set as the free-running frequency of the vibrator.

[0004]

However, the resonance frequency of the vibrating system composed of the vibrator and the bonding tool may fluctuate greatly depending on the load load during bonding, and the pressing load is applied to the bonding tool in the actual bonding process. The resonance frequency in the loaded load state may be significantly different from the resonance frequency in the non-load state described above, and may fall out of the frequency followable range or may erroneously follow a frequency other than the desired vibration mode.

For this reason, the driving frequency of the vibrator cannot be made to follow the resonance frequency that fluctuates after the start of the bonding operation, and bonding cannot be performed, or the frequency other than the desired vibration mode is incorrectly followed, resulting in defective bonding. There was a problem that occurs.

In view of the above, the present invention is an ultrasonic bonding device that can reliably follow the resonance frequency of a desired vibration mode and perform stable bonding even when the resonance frequency of the vibrator changes significantly due to a load. An object of the present invention is to provide an apparatus and an ultrasonic bonding method.

[0007]

An ultrasonic bonding apparatus according to claim 1, which is an electronic component bonding apparatus for press-bonding an object to be 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 the surfaces to be bonded via the object to be bonded, a vibrator that applies ultrasonic vibration to the bonding tool, and a vibrator. A vibrator driving unit that supplies electric power for driving, a drive frequency signal output unit that outputs a drive frequency signal for instructing a vibrator driving frequency to the vibrator driving unit, and the bonding tool are A fundamental frequency indicating a resonance frequency at the time of oscillation in the air that drives the vibrator without a load and a pressing load applied to the bonding tool by the pressing means. Storage means for storing the relationship between the load resonance frequency and the pressing load at the time of load oscillation for driving the vibrator in a loaded state, and the drive frequency signal output section at the start of driving the vibrator in the bonding operation. The drive start frequency setting means sets the frequency of the drive frequency signal based on the basic frequency and the load resonance frequency corresponding to the pressing load in the bonding operation.

According to another aspect of the ultrasonic bonding method of the present invention, there is provided a bonding tool which abuts on the object to be joined, a pressing means which presses the bonding tool against a surface to be joined via the object to be joined, and the bonding tool. A vibrator for applying ultrasonic vibration to the vibrator, a vibrator drive unit for supplying electric power for driving the vibrator, and a drive frequency for instructing the vibrator drive unit of the drive frequency of the vibrator. An ultrasonic bonding method using an ultrasonic bonding device having a drive frequency signal output unit for outputting a signal, wherein the bonding tool has a fundamental frequency indicating a resonance frequency during aerial oscillation in which the vibrator is driven under no load and When the oscillator vibrates under load, the bonding tool is loaded with the pressing load of the pressing means. The relationship between the load resonance frequency and the pressing load is stored in the storage means, and the frequency of the drive frequency signal output from the drive frequency signal output unit at the start of driving the vibrator in the bonding operation is set to the basic frequency. It is set based on the load resonance frequency corresponding to the pressing load in the bonding operation.

According to the present invention, the relationship between the fundamental frequency indicating the resonance frequency in the no-load state and the load resonance frequency at the time of load oscillation in the load state and the pressing load is stored in the storage means, and in the bonding operation. When the drive frequency of the vibrator is started, the frequency of the drive frequency signal output from the drive frequency signal output section is set based on the fundamental frequency and the load resonance frequency corresponding to the pressing load in the bonding operation. Even if the resonance frequency of the child changes significantly, it is possible to reliably follow the resonance frequency of the desired vibration mode and perform stable bonding.

[0010]

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. FIG. 4 is an explanatory diagram of frequency offset data of a bonding apparatus according to one embodiment of the invention, FIG. 4 is a flowchart of a vibrator driving process during a bonding operation by the ultrasonic bonding apparatus according to one embodiment of the invention, and FIG. FIG. 6 is a chart showing the vibrator driving timing in the ultrasonic bonding method of the embodiment, and FIG. 6 is a graph showing the relationship between the driving frequency and the impedance of the ultrasonic bonding apparatus of the embodiment of the invention.

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 while 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, it is necessary to instruct the driving frequency for each bonding tool at the start of driving, so that the driving frequency when driving the vibrator 6 ( Free-running frequency) is preset. As this free-running frequency, a resonance frequency during air oscillation in which a load is not applied to the bonding tool is generally used. This unloaded resonance frequency is
It has a characteristic as a fundamental frequency unique to each individual bonding tool, and is registered as data for each product type and each individual.

In the ultrasonic bonding apparatus according to the present embodiment, the load resonance frequency and the pressing load at the time of load oscillation for driving the vibrator under the load condition in which the pressing load is applied to the bonding tool together with the above-mentioned basic frequency data. The data indicating the relation of is also stored in the storage means,
The drive frequency (free-running frequency) output from the drive frequency signal output unit at the start of driving the vibrator is set based on the basic frequency and the load resonance frequency corresponding to the pressing load in the bonding operation.

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 the 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.

When the drive frequency signal output unit 18 issues a drive frequency signal to the vibrator drive unit 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 cases where the basic frequency f0 itself is used as the command frequency and cases where the frequency obtained by adding a frequency offset to be described later to the basic frequency f0 is used as the command frequency. In the present embodiment, a setting pattern for adding a frequency offset to the fundamental frequency f0 as a command frequency will be described.

The command frequency is instructed by the frequency instructing unit 16e of the control unit 16 by reading data such as the basic frequency f0 and the frequency offset 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. Here, the command frequency signal output unit 17 outputs the frequency obtained by adding the frequency offset to the basic frequency f0 as the command frequency to the drive frequency signal output unit 18 as described above.

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 the 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.

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, the correction frequency corresponding to the phase difference between the voltage and the current is obtained from the correction data for frequency tracking stored in the drive frequency signal output unit 18, and the corrected frequency signal obtained by adding the correction amount to the command frequency is driven. It is output as a 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 analog data of the voltage and current 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.

The calculation unit 16c performs various calculation processes such as a calculation for processing the data stored in the detected value storage unit 24. The mode instruction unit 16d includes a program storage unit 22.
The output mode is instructed to the drive frequency signal output unit 18 based on the bonding operation program stored in. The frequency instruction unit 16e includes a drive parameter storage unit 23.
The frequency parameter is read out from the various parameters stored in, and the required frequency is instructed to the command frequency signal output unit 17. The drive voltage instruction unit 16f instructs the drive voltage V to the vibrator drive unit 10. The frequency measuring unit 16g counts the frequency of the drive voltage USV of the vibrator 6 to measure the fundamental frequency and the load resonance frequency of the vibrator 6 driven by the vibrator driving unit 10.

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 drives the vibrator 6 such as the fundamental frequency f0 indicating the resonance frequency when the bonding tool is oscillated in the air, the frequency offset data described later, the drive voltage V, and the vibrator drive time t. Then, various driving parameters used in executing the bonding operation and various processes are stored. The drive parameter storage unit 23 is a storage unit that stores the relationship between the fundamental frequency f0, the load resonance frequency, and the pressing load. The inspection value storage unit 24 stores the detection data of the current and voltage detected by the detection unit 13.

Next, the frequency offset data will be described with reference to FIG. The frequency offset data is data determined based on the relationship between the load resonance frequency and the pressing load, and is obtained by actual measurement or approximation calculation using empirical values. The actual measurement may be performed by connecting a known frequency counter or the like, but it is more simple and desirable to perform the actual measurement by using the frequency measuring unit 16g. By providing this frequency offset data, the resonance frequency under various bonding conditions can be estimated in advance, and the estimated resonance frequency can be used as the free-running frequency. In this embodiment, the frequency offset data is stored in two types of data formats.

That is, as shown in FIG. 3A, the difference between the actually measured load resonance frequency (f1, f2 ...) And the basic resonance frequency (frequency offset α1, for each bonding load (L1, L2 ...)). α2, ...) may be stored as a pre-stored data table,
Further, as shown in FIG. 3B, within a predetermined load range (L
In (a) to L (b), an approximate expression (f = F (f0, kL), f0: fundamental frequency, which linearly approximates the relationship between the bonding load L and the load resonance frequency f based on empirical values,
k: straight line inclination) is used together with the method of storing.

The data table method has an advantage that the corresponding frequency offset value is immediately obtained when the bonding load is designated. Further, the method using the approximate expression has an advantage that the free-running frequency can be set without actually measuring the resonance frequency within a certain bonding load range.

Next, referring to FIGS. 4 and 5, a vibrator driving process during the bonding operation will be described. First, the vibrator drive parameters are read from the parameter storage unit 23 (ST21). As a result, the basic frequency f0, the frequency offset data, the drive voltage V, and the oscillator drive time t
Is read. Next, when driving the vibrator 6, the first mode is designated as the output mode of the driving frequency signal (ST22). As a result, the drive frequency signal output unit 18
When the drive frequency signal is output to the vibrator drive unit 10, a signal having the same frequency as the command frequency output from the command frequency signal output unit 17 is output according to the first mode.

That is, the drive frequency signal output unit 18 outputs the drive frequency f to the vibrator drive unit 10 by adding the frequency offset α to the basic frequency f0, and the vibrator 6 is driven by the drive frequency f and the drive voltage V. Are driven (ST23). FIG. 5A shows the timing of driving start, and the frequency offset α (see FIG. 3) corresponding to the bonding load L is set at the timing t0 when the pressing load rises and becomes stable at the predetermined bonding load L. The driving is started at the driving frequency f added to the basic frequency f0. Here, the command frequency signal output unit 17 determines the frequency of the drive frequency signal output from the drive frequency signal output unit 18 at the start of driving the vibrator 6 in the bonding operation,
It is a drive start frequency setting means for setting based on the basic frequency f0 and the load resonance frequency corresponding to the pressing load in the bonding operation.

Then, in this driving state, the detection unit 13
Thus, the current I is detected (ST24), and it is determined whether or not a current equal to or larger than a predetermined current value preset as a threshold current is detected (ST25). Here, if the predetermined current value has not been reached, it is determined that the vibrator 6 is not in a stable drive state, and the process returns to (ST23) to continue driving the vibrator 6 at the drive frequency f, and again When the current value is reached, it is determined that the frequency tracking function by the phase locked loop is in a normal operating state, and the mode instructing unit 16d
Instructs the second mode as the output mode of the drive frequency signal (ST26).

As a result, when the drive frequency signal output unit 18 outputs the drive frequency signal to the vibrator drive unit 10, the command frequency output from the command frequency signal output unit 17 is set in accordance with the second mode. The corrected frequency added with the correction amount based on the comparison result of the phase comparison unit 15 is output as the drive frequency signal.

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). After this, it is judged whether or not the vibrator drive time t has expired (S
If the time-up is confirmed in T28), the driving of the vibrator 6 is stopped (ST29). This completes the bonding operation.

FIG. 6 is a graph showing the relationship between the impedance Z obtained based on the voltage and current detected by the detection unit 13 and the drive frequency f when bonding is performed using the same vibrator 6. Is. Here, the frequency that gives the minimum impedance Z indicates the resonance frequency. FIG. 6A shows the variation of the resonance frequency when the pressing load is varied.

That is, the impedance Z in the unloaded state is represented by the graph shown by the broken line, and the resonance frequency at this time is the fundamental frequency f0. When the vibrator 6 is used with a bonding load L, the impedance Z is represented by a graph shown by a solid line, and the load resonance frequency f1 at this time is a value obtained by adding the frequency offset α to the fundamental frequency f0. Has become.

In this way, when the driving of the vibrator 6 is started,
Even if the frequency followable range by the phase locked loop is limited by adding the frequency offset α corresponding to the bonding load L and starting the driving at the free-running frequency corresponding to the load resonance frequency, The drive frequency can accurately follow the resonance frequency of the tracking target. As described above, the transmission loss of the electric power required to drive the vibrator 6 can be minimized.

That is, as shown in FIG. 6A, when the fundamental frequency f0 is the free-running frequency, the load resonance frequency f1 is not included in the followable range [0] so that normal oscillation cannot be performed. Even in such a case, the load resonance frequency f1 is included in the followable range [1] changed by adding the frequency offset α,
Reliable frequency tracking is realized.

Further, depending on the characteristics of the vibration system constituted by the vibrator 6 and the bonding tool 7, as shown in FIG. There may be f'1. In such a case, assuming that the fundamental frequency f0 is the free-running frequency as described above, the secondary resonance frequency f'in the followable range [0].
When 1 is included, the resonance frequency, which is not a tracking target, is followed, and a correct oscillation state cannot be obtained. Even in such a case, the frequency offset α
By adding, the load resonance frequency f1 is included in the followable range [1] that does not include the resonance frequency f ′, and reliable frequency tracking is realized.

Further, during the indefinite time in which the current does not normally flow through the vibrator 6 immediately after the start of the bonding operation, the vibrator 6 is always driven by the drive frequency according to the command frequency in the first mode. 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.

[0045]

According to the present invention, the fundamental frequency indicating the resonance frequency in the unloaded state and the relationship between the load resonance frequency and the pressing load during load oscillation in the loaded state are stored in the storage means, and the bonding is performed. By setting the frequency of the drive frequency signal output from the drive frequency signal output unit at the start of driving the vibrator in the operation based on the fundamental frequency and the load resonance frequency corresponding to the pressing load in the bonding operation, Even if the resonance frequency of the vibrator greatly changes, the resonance frequency of the desired vibration mode can be reliably followed and stable bonding can be performed.

[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 an explanatory diagram of frequency offset data of the bonding apparatus according to the embodiment of the present invention.

FIG. 4 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.

FIG. 5 is a chart diagram showing vibrator driving timing in the ultrasonic bonding method according to the embodiment of the present invention.

FIG. 6 is a graph showing the relationship between drive frequency and impedance of 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 23 Drive Parameter Storage 24 Detection value storage

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Claims (2)

[Claims] 1. A bonding apparatus for an electronic component, wherein a bonding object is pressure-bonded to a surface to be bonded while applying load and ultrasonic vibration to the bonding object, the bonding tool being in contact with the bonding object, and the bonding tool being the bonding tool. A pressing unit that presses a surface to be joined through an object, a vibrator that applies ultrasonic vibration to the bonding tool, a vibrator driving unit that supplies electric power for driving the vibrator, and A drive frequency signal output unit that outputs a drive frequency signal for instructing the drive frequency of the vibrator to the vibrator drive unit, and a resonance frequency during aerial oscillation in which the bonding tool drives the vibrator with no load. At the fundamental frequency and the bonding tool at the time of load oscillation for driving the vibrator under a load state in which the pressing load by the pressing means is applied. Storage means for storing the relationship between the load resonance frequency and the pressing load, and the frequency of the drive frequency signal output from the drive frequency signal output section at the start of driving the vibrator in the bonding operation, the basic frequency and the bonding operation. And a drive-start-time frequency setting means for setting the load resonance frequency corresponding to the pressing load in the above. 2. A bonding tool that comes into contact with an object to be joined, a pressing unit 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. And a vibrator driving unit that supplies electric power for driving the vibrator, and a drive frequency signal output unit that outputs a drive frequency signal for instructing the vibrator driving unit of the driving frequency of the vibrator. An ultrasonic bonding method using an ultrasonic bonding apparatus, comprising: a fundamental frequency indicating a resonance frequency during aerial oscillation in which the bonding tool drives a vibrator in a no-load state; and pressing by the pressing means on the bonding tool. Describes the relationship between the load resonance frequency and the pressing load during load oscillation that drives the vibrator under load. Means for storing the frequency of the drive frequency signal output from the drive frequency signal output unit at the start of driving the vibrator in the bonding operation, the load resonance corresponding to the basic frequency and the pressing load in the bonding operation. An ultrasonic bonding method characterized by setting based on the frequency.