JP2000174068A - Apparatus and method for ultrasonic compression welding electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic compression welding tool having a resonance frequency measuring function. SOLUTION: A first ultrasonic instructor 31 sends an instruction to an ultrasonic controller 11 for controlling the drive of a tool's oscillator, thereby gradually increasing the oscillation frequency of the oscillator, a measuring unit 12 measures the current flowing in the oscillator in this time to detect a resonance frequency from the max. current, the detected resonance frequency is registered in a resonance data memory 14b, and a second ultrasonic instructor 32 calls the resonance frequency of the tool from the resonance data memory 14b and outputs a drive instruction to the ultrasonic controller 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic crimping apparatus and an ultrasonic crimping method for an electronic component which applies ultrasonic vibration to an electronic component and presses the electronic component on a work.

[0002]

2. Description of the Related Art As a method for mounting an electronic component such as a flip chip on a work such as a substrate, a method using an ultrasonic pressure bonding apparatus is known. The ultrasonic crimping apparatus presses a crimping tool against an electronic component, and ultrasonically vibrates the tool, thereby applying ultrasonic vibration to the electronic component and crimping the electronic component on a workpiece. The tool has its dimensions and
It has a unique resonance frequency depending on the shape and the like, and when the tool is pressed against the electronic component to press the electronic component against the work, it is necessary to vibrate the tool strongly at the resonance frequency and a predetermined power.

Tools are exchanged according to the type of electronic component. Therefore, when the tool is replaced, the unique resonance frequency of the new tool and the impedance at that time are measured, and the ultrasonic pressure bonding apparatus is operated based on the measurement result. Therefore, conventionally, when a new tool is set and used in the ultrasonic crimping device,
Prior to this set, the resonance frequency and impedance of this tool were measured by a measuring device, and the ultrasonic component was operated to crimp the electronic component to the work according to the measurement result.

[0004]

However, conventionally,
Equipment costs are high because a measuring device that measures the resonance frequency and impedance is required in addition to the ultrasonic crimping device, and the operator's work load is heavy because the operator must measure the resonance frequency and impedance with the measuring device. there were.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an ultrasonic crimping apparatus and method for electronic components having a function of measuring the resonance frequency and impedance of an ultrasonic crimping tool.

[0006]

SUMMARY OF THE INVENTION The present invention is an ultrasonic crimping apparatus for an electronic component, which presses a replaceable tool against an electronic component and presses the electronic component on a workpiece while ultrasonically oscillating the tool. A vibrator for ultrasonically vibrating the tool, an ultrasonic control unit for controlling the driving of the vibrator, and a first ultrasonic command unit for outputting a drive command for changing the vibration frequency of the tool to the ultrasonic control unit A measuring unit that measures a current and a voltage flowing through the vibrator while changing a vibration frequency of the tool in accordance with a command of the first ultrasonic command unit; and A resonance state detector for detecting the resonance frequency and impedance, a resonance data storage unit for registering the resonance frequency and impedance detected by the resonance state detector, A second ultrasonic command unit that calls out the resonance frequency and impedance of the tool to be used from the resonance frequency and impedance registered in the storage unit and outputs a drive command to the ultrasonic control unit. It is an ultrasonic crimping device for electronic parts to be formed.

According to the present invention, a drive command is output from an ultrasonic command unit to a vibrator which vibrates a tool which is exchangeably mounted on a bonding tool, and a current and a voltage which flow through the vibrator while changing the vibration frequency of the tool. Is measured by the measurement unit, the resonance frequency and impedance of the tool are detected by the resonance state detection unit from the measured data, and the registration operation of registering the resonance frequency and impedance of the tool in the resonance data storage unit is performed. The above-mentioned registration operation is performed on the tool to register the respective resonance frequencies and impedances in the resonance data storage unit, and when the electronic component is crimped to the work, the resonance frequency and the impedance of the tool to be used are called from the resonance data storage unit. An ultrasonic crimping method of an electronic component, wherein

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an ultrasonic bonding apparatus for electronic components according to an embodiment of the present invention, FIG. 2 is a block diagram of the ultrasonic control unit, FIG. 3 is a functional block diagram of FIG.
FIGS. 5, 6, and 7 are screen views of the monitor, FIGS. 8, 9,
FIG. 10 is a flowchart of the operation.

First, an overall configuration of an ultrasonic bonding apparatus for electronic components will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes a bonding unit, below which a tool 2 for ultrasonic pressure bonding is exchangeably mounted. A vibrator 3 for ultrasonically vibrating the tool 2 is mounted on a side portion of the tool 2. The tool 2 is provided with a protrusion 2a. The bumps 5 of the flip chip 4 are pressed against the electrodes of the substrate 6 while pressing the projections 2a against the upper surface of the flip chip 4 and performing ultrasonic vibration. Reference numeral 7 denotes a table for positioning the substrate 6. The work to be subjected to ultrasonic pressure bonding is not limited to a flip chip, but may be, for example, an outer lead of an electronic component.

Next, a control system for ultrasonically oscillating the tool 2 will be described. Reference numeral 10 denotes a bus, which includes an ultrasonic control unit 11, a measurement unit 12, a control unit 13 including a CPU, a storage unit 14, a display unit 15, and a keyboard and mouse.
The input unit 16 and the input / output unit 17 are connected.

The ultrasonic control unit 11 and the measuring unit 12 include the vibrator 3
The ultrasonic controller 11 controls the driving of the vibrator 3. The current I and the current V of the vibrator 3 are fed back to the ultrasonic control unit 11 and the measurement unit 12. Measuring unit 12
Measures the current I flowing through the vibrator 3 and outputs data of the measured current and voltage as measurement data.

The control unit 13 has a program (ultrasonic crimping,
Controls necessary to execute programs such as impedance detection, resonance point detection, and tool settings. The storage unit 14 stores resonance frequency and impedance data for each tool calculated from the measurement data measured by the measurement unit 12. The input / output unit 17 outputs signals for operating actuators such as motors and cylinders, outputs data, and inputs signals and data sent from various sensors. The actuator, various sensors, and the like are incorporated in the ultrasonic pressure bonding apparatus, and these are well-known elements, and thus detailed description thereof is omitted.

FIG. 2 shows a detailed configuration of the ultrasonic controller 11. In FIG. 2, frequency data is sent from the control unit 13 to the frequency setting unit 21. Then, while storing the data of this frequency, a signal (voltage) proportional to the frequency is output. The ultrasonic oscillating unit 22 outputs an ultrasonic signal having a frequency according to the input voltage. An oscillation command signal is sent from the control unit 13 to the ultrasonic oscillation unit 22. The ultrasonic oscillating unit 22 inputs an ultrasonic signal to the amplifier 23 at the timing specified by the oscillation command signal. The amplifier 23 amplifies the ultrasonic signal with an amplification factor according to the gain signal sent from the control unit 13 and
The pressure is increased at 5 and input to the vibrator 3.

The current I and the voltage V of the vibrator 3 are
6 is input. The phase comparator 26 outputs a signal (voltage) proportional to the phase difference between the current I and the voltage V. Here, if the resonance point shifts due to a crimping operation or the like, the phases of the current I and the voltage V also shift. Therefore, the phase comparing section 26 compares the phase shifts, and feeds back a voltage corresponding to the comparison result to an adding section (described later) 28.

A mode setting section 27 is connected to the phase comparison section 26. The mode setting unit 27 includes a changeover switch 27a
Consists of During normal operation (when the tool 2 is ultrasonically vibrated to press the flip chip 4 against the substrate 6), the changeover switch 27a is closed (the automatic resonance frequency tracking function O).
N). When the measurement unit 12 measures the current I or the voltage V, the changeover switch 27a is opened (resonance frequency automatic tracking function is OFF), and the frequency f is changed from fs to f by a command from the control unit 13.
e. This will be described later with reference to FIG.

An adding unit 28 is connected between the frequency setting unit 21 and the mode setting unit 27. The addition unit 28 adds the voltage from the frequency setting unit 21 and the voltage from the phase comparison unit 26 sent through the mode setting unit 27, and inputs the added voltage to the ultrasonic oscillation unit 22. When the crimping operation is performed, the resonance frequency of the tool 2 fluctuates due to a change in the load acting on the tool 2. The change is detected by the phase comparison unit 26, and the addition unit 2
In step 8, the frequency of the ultrasonic signal output from the ultrasonic oscillator 22 is corrected. That is, the phase comparison unit 26 and the addition unit 28
Are the resonance frequency tracking means. Note that the resonance frequency tracking means can track the resonance frequency only within a relatively limited range around the frequency set in the frequency setting unit 21. Therefore, when the resonance frequency greatly changes due to tool exchange or the like, the frequency setting unit It is necessary to change the frequency itself to be set.

Next, a functional block diagram will be described with reference to FIG. A first ultrasonic command unit 31 and a second ultrasonic command unit 32 are connected to the ultrasonic control unit 11. The first ultrasonic instructing unit 31 changes the setting mode switching signal and a frequency signal for detecting the resonance frequency (a signal for gradually changing the frequency, in this embodiment, the frequency gradually from the measurement start frequency fs to the measurement end frequency fe). The signal to be increased is input to the ultrasonic controller 11. The second ultrasonic instructing unit 32 also includes a frequency (resonant frequency) during normal operation (operation in which the tool 2 is ultrasonically vibrated at a resonance frequency to press the flip chip 4 onto the substrate 6) and an ultrasonic signal generated by the amplifier 24. , That is, a gain signal for determining the output (power) of the ultrasonic controller, is input to the ultrasonic controller 11.

The storage section 14 has an impedance waveform data storage section 14a and a resonance data storage section 14b.
The data of the current I and the voltage V sent from the measurement unit 12 are converted into impedance by the impedance calculation unit 34, and then registered in the impedance waveform data storage unit 14a. The resonance state detection unit 33 detects the resonance frequency from the impedance waveform registered in the impedance waveform data storage unit 14a and inputs the resonance frequency to the resonance data storage unit 14b. At the same time, the impedance at the time of resonance is detected and the value is input to the resonance data storage unit 14b.

The second ultrasonic command section 32 selects a predetermined resonance frequency from a plurality of resonance frequencies registered in the resonance data storage section 14b and inputs the selected resonance frequency to the ultrasonic control section 11. Further, an amplification factor that determines the ultrasonic output of the ultrasonic control unit 11 is obtained from the impedance of the resonance data storage unit 14b and the ultrasonic output from the tool 2 that is predetermined, and is output to the ultrasonic control unit 11 as a gain signal. . The first ultrasonic command section 31, the second ultrasonic command section 32, the resonance state detecting section 33, and the impedance calculating section 34 are software executed by the control section 13.

Next, the operation will be described with reference to FIGS. 4 to 7 show screens of the display unit 15 (FIG. 1), and FIGS. 8 to 10 show flowcharts of the operation. FIG. 4 shows a menu screen of the display unit 15. The menus are "Automatic operation" and "Tool setting".
The “automatic operation” is a normal operation operation in which the tool 2 is pressed against the flip chip 4 and the bumps 5 of the flip chip 4 are ultrasonically pressed to the substrate 6. At this time, the changeover switch 27a of the mode setting unit 27 in FIG. 2 is closed, and the signal of the phase comparison unit 26 is fed back to the addition unit 28,
The ultrasonic oscillator 22 outputs a signal to the multiplier 23 so that the tool 2 vibrates at a predetermined resonance frequency. Also, "tool setting" refers to the work of measuring and setting the resonance frequency of a new tool when a tool is replaced due to a change in the type of electronic component such as a flip chip that is the object of ultrasonic crimping. . At this time, the changeover switch 27a is open. The mode switching signal to the mode setting unit 27 is output from the control unit 13. Hereinafter, the tool setting operation will be described.

On the menu screen shown in FIG. 4, when "tool setting" is clicked and selected, a tool setting screen is displayed (step 1 in FIG. 8). FIG. 5 shows a tool setting screen. In the tool setting screen, the tool name (the planar shape of the projection 2a of the tool 2 of the present embodiment is rectangular, and in this example, the length of one side is 1.0 mm, 1.5 mm... 3.0)
The tool name is displayed as mm, the resonance frequency KHz, the impedance Z at the time of resonance, and the work menu (setting, deletion, measurement, cancellation) are displayed.
As the resonance frequency and impedance Z of each tool, existing data stored in the resonance data storage unit 14b (FIG. 3) is displayed.

At steps 2a, 2b and 2c in FIG. 8, one of "setting", "deletion" and "measurement" is clicked and selected. Here, when "setting" is selected, the selected resonance frequency is set to the frequency of the frequency setting unit 21 (FIG. 2), and the amplification factor (gain signal) obtained from the impedance is set to the amplifier 23. The display screen of FIG.
This indicates that a tool of 5 mm is set. When "delete" is selected, the selected resonance frequency and impedance data are deleted. When "measurement" is selected, a measurement process is executed. "Cancel" is the cancellation of an operation.

The present invention relates to the measurement and setting of the resonance frequency and the impedance of the tool. Therefore, "measurement" is selected on the display screen of FIG. 5, and the measurement processing is executed in the steps of FIGS. . That is, step 3 in FIG.
Then, the message screen of FIG. 6 is displayed. This message screen prompts the operator to confirm whether the tool 2 is correctly set in the bonding unit 1. After confirming that the tool is set correctly, the operator presses the confirmation button in FIG. When the confirmation button is pressed in step 4, the process proceeds to the next process.

In step 5, the changeover switch 27a of the mode setting section 27 is opened to switch to the measurement mode. Next, in step 6, the measurement start frequency fs is set.
Next, in step 7, the oscillation command signal is turned ON, and is input to the ultrasonic oscillation unit 22 (FIG. 2). Then, step 8
The current I is measured by the measuring unit 12 (FIG. 2) while gradually increasing the frequency to the measurement end frequency fe at 10 to 10.

When the measurement end frequency fe is reached, the oscillation command signal (see also FIG. 2) is turned off (step 1).
1) The switch 27a of the mode setting unit 27 is closed to switch to the automatic tracking mode (step 12), a resonance frequency detection process is performed (step 13), and a measurement screen is displayed (step 14 in FIG. 10). FIG. 7 shows the measurement screen at this time.

In the measurement screen of FIG. 7, the frequency is changed from fs to fe.
7 shows waveform data of the impedance Z when the impedance Z is gradually increased, and this waveform is registered in the impedance waveform data storage unit 14a (FIG. 3). The frequency at which the impedance Z is minimum (min) is the resonance frequency fa of the tool. This resonance frequency fa is detected by the resonance state detector 33 (FIG. 3). Next, in step 15, "save" is clicked, and the unique resonance frequency fa of the tool and the impedance Zmin at this time are saved (registered in the resonance data storage unit 14b) together with the tool name (step 16). Thus, the measurement mode ends, and the screen returns to the tool setting screen of FIG. 5 (step 17).

The above-described measurement of the resonance frequency and impedance of a tool is performed for a new tool each time the tool is replaced. Then, the resonance frequencies and impedances of various tools are registered in the resonance data storage unit 14b. When the tool is reused, the second ultrasonic command unit 32 calls the resonance frequency registered under the name of the tool from the resonance data storage unit 14b, and instructs the ultrasonic control unit 11 to drive the resonance frequency. A command is output, and the electronic component is ultrasonically crimped to the work while causing the tool to resonate at the resonance frequency.

[0028]

As described above, according to the present invention, since the ultrasonic pressure bonding apparatus for electronic components has a function of measuring the resonance frequency and impedance of the tool, the resonance of the tool can be easily and quickly performed when the tool is replaced. Frequency and impedance can be measured. In addition, by registering the resonance frequency and impedance of each type of tool in the resonance data storage unit, when the tool is reused, the resonance frequency and impedance of the tool are called to improve the setup. Ultrasonic crimping of electronic components to a workpiece can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an ultrasonic pressure bonding apparatus for electronic components according to an embodiment of the present invention.

FIG. 2 is a block diagram of an ultrasonic control unit of the ultrasonic bonding apparatus for electronic components according to one embodiment of the present invention;

FIG. 3 is a functional block diagram of an ultrasonic pressure bonding apparatus for electronic components according to an embodiment of the present invention.

FIG. 4 is a screen view of a monitor of an ultrasonic pressure bonding apparatus for electronic components according to an embodiment of the present invention.

FIG. 5 is a screen view of a monitor of an ultrasonic crimping apparatus for electronic components according to an embodiment of the present invention.

FIG. 6 is a screen view of a monitor of an ultrasonic pressure bonding apparatus for electronic components according to an embodiment of the present invention.

FIG. 7 is a screen view of a monitor of the ultrasonic pressure bonding apparatus for electronic components according to the embodiment of the present invention.

FIG. 8 is a flowchart of the operation of the ultrasonic bonding apparatus for electronic components according to one embodiment of the present invention.

FIG. 9 is a flowchart of the operation of the ultrasonic bonding apparatus for electronic components according to one embodiment of the present invention.

FIG. 10 is a flowchart of the operation of the ultrasonic bonding apparatus for electronic components according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bonding tool 2 Tool 3 Transducer 4 Flip chip 6 Substrate 11 Ultrasonic control unit 12 Measurement unit 13 Control unit 14 Storage unit 14a Impedance waveform data storage unit 14b Resonance data storage unit 21 Frequency setting unit 22 Ultrasonic oscillation unit 26 Phase comparison Unit 27 mode setting unit 31 first ultrasonic command unit 32 second ultrasonic command unit 33 resonance state detecting unit

Claims (2)

[Claims] An ultrasonic crimping apparatus for an electronic component which presses a replaceable tool against an electronic component and presses the electronic component onto a workpiece while ultrasonically oscillating the tool, wherein the vibrator ultrasonically vibrates the tool. An ultrasonic control unit for controlling the driving of the vibrator, a first ultrasonic command unit for outputting a drive command for changing the vibration frequency of the tool to the ultrasonic control unit, and a first ultrasonic wave A measuring unit that measures a current and a voltage flowing through the vibrator while changing a vibration frequency of the tool according to a command from a command unit, and a resonance that detects a resonance frequency and an impedance of the tool from measurement data measured by the measuring unit. A state detection unit, a resonance data storage unit for registering a resonance frequency and an impedance detected by the resonance state detection unit, and a resonance frequency registered in the resonance data storage unit. And a second ultrasonic command unit for calling a resonance frequency and impedance of a tool to be used from among the number and impedance and outputting a drive command to the ultrasonic control unit. apparatus. 2. A measuring unit which outputs a drive command from an ultrasonic command unit to a vibrator which vibrates a tool which is exchangeably mounted on a bonding tool and changes a vibration frequency of the tool while changing a vibration frequency of the tool. , The resonance frequency and impedance of the tool are detected by the resonance state detection unit from the measured data, and the registration operation of registering the resonance frequency and impedance of the tool in the resonance data storage unit is performed. Performing the registration operation and registering each resonance frequency and impedance in the resonance data storage unit, and when crimping an electronic component to a work, calling the resonance frequency and impedance of the tool to be used from the resonance data storage unit, An ultrasonic pressure bonding method for electronic components, characterized by driving a vibrator.