JPH1118480A - Method and apparatus for monitoring characteristics of driving motor - Google Patents

Abstract

(57) Abstract: A mechanism section in which a movable section moves in accordance with a waveform of a current input to a drive motor is detected by the current input to the drive motor and the movable section. Provided is a method and an apparatus for monitoring the characteristics of a driving motor, in which load input / output is analyzed and a load command value given to a movable part and a control command value are made to coincide with each other. SOLUTION: A mechanism section 12 in which a movable section moves in accordance with a waveform of a current input to a driving motor, current detecting means A for detecting the current, and a load for detecting a load applied to the movable section. Detecting means B; transfer function calculating means S5 for analyzing a frequency characteristic of the current detecting means and a frequency characteristic of the load detected by the load detecting means to calculate a transfer function; and a transfer function detected by the transfer function calculating means. And comparison means S7 for comparing the transfer function with a transfer function analyzed in the past.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for monitoring the characteristics of a driving motor for calibrating an applied load at the time of bonding a wire bonder, for example.

[0002]

2. Description of the Related Art Conventionally, in a wire bonder apparatus, the load applied to the tip of a capillary is calibrated by controlling the wire bonder statically using a tension gauge to push the tension gauge onto the tip of the capillary. Then, the actual load was measured, and each measured value was manually input to the device.

On the device side, a correction coefficient is obtained by comparing the input numerical value (actual load) with the currently set load, and calibration is internally performed so that the command load and the actual load are controlled in agreement. ing.

[0004] In addition, monitoring of a change in output such as load at a working point of processing or assembly with the passage of time or an abnormality indicates that when a change occurs, the frequency component also changes. Only output was measured, and its output fluctuation was determined using a frequency (time) analysis method such as FFT (fast Fourier transform) or wavelet.

[0005]

However, conventionally, in the calibration of the load applied to the tip of the capillary in a wire bonder device, since the tension gauge is also read by a person, variations and errors occur in the measured values, and the accuracy and precision are reduced. There is a side lacking.

Further, in order to judge the characteristic fluctuation at the operation point of the apparatus, in the prior art, only the output at the operation point is measured, and a change with time or abnormality is judged from the result of the analysis (frequency analysis or the like). Was.

However, this conventional method has a problem that the cause of variation cannot be specified because the input is not focused on. That is, there is a problem that it is not possible to specify whether the factor is a variation on the input side (variation of the control set value of the device) or a mechanical variation between input and output of the device.

The present invention has been made in view of the above points, and an object of the present invention is to provide a mechanism for moving a movable section in accordance with a waveform of a current inputted to a driving motor, and a driving motor for the mechanism. A method and apparatus for monitoring the characteristics of a driving motor for analyzing the input and output of the current input to the motor and the load detected by the movable part, and matching the load command value given to the movable part with the control command value. Is to provide.

[0009]

According to a first aspect of the present invention, there is provided a driving motor characteristic monitoring apparatus, wherein a movable section moves in accordance with a waveform of a current input to the driving motor; A current detecting means for detecting a current; a load detecting means for detecting a load applied to the movable portion; and a transfer function by analyzing a frequency characteristic of the current detecting means and a frequency characteristic of the load detected by the load detecting means. It is characterized by comprising transfer function calculating means, and comparing means for comparing a transfer function detected by the transfer function calculating means with a transfer function analyzed in the past.

According to a second aspect of the present invention, there is provided a drive motor characteristic monitoring device, wherein a movable portion moves in accordance with a waveform of a current input to the drive motor, and a current detection device detects the current. Means, load detection means for detecting a load applied to the movable portion, a transfer function calculation means for calculating a transfer function by analyzing the frequency characteristics of the current detection means and the frequency characteristics of the load detected by the load detection means, Comparing means for comparing the transfer function detected by the transfer function calculating means with the transfer function analyzed in the past, and judging means for judging the presence or absence of a change using the comparison result obtained by the comparing means. It is characterized by the following.

According to a third aspect of the present invention, there is provided a drive motor characteristic monitoring apparatus, wherein a movable portion moves in accordance with a waveform of a current input to the drive motor, and a current detection device detects the current. Means, load detection means for detecting a load applied to the movable portion, a transfer function calculation means for calculating a transfer function by analyzing the frequency characteristics of the current detection means and the frequency characteristics of the load detected by the load detection means, Comparing means for comparing the transfer function detected by the transfer function calculating means with the transfer function analyzed in the past; and automatically calibrating the current applied to the movable part according to the mechanism according to the comparison result of the comparing means. Automatic calibration means.

According to a fourth aspect of the present invention, there is provided a driving motor characteristic monitoring apparatus, wherein the mechanism of the first to third aspects is a bonding mechanism. According to a fifth aspect of the present invention, there is provided a method for monitoring the characteristics of a driving motor, comprising: A load detecting step of detecting a load applied to the movable portion, a transfer function calculating step of calculating a transfer function by analyzing a frequency characteristic detected by the current detecting step and a frequency characteristic of the load detected by the load detecting step, A comparison step of comparing the transfer function detected in the transfer function calculation step with the transfer function analyzed in the past.

According to a sixth aspect of the present invention, there is provided a method for monitoring the characteristics of a driving motor, comprising: A load detecting step of detecting a load applied to the movable portion, and a transmission for calculating a transfer function by analyzing a frequency characteristic of the current detected in the current detecting step and a frequency characteristic of the load detected in the load detecting step. A function calculating step, a comparing step of comparing a transfer function detected in the transfer function calculating step with a transfer function analyzed in the past, and a determination of determining whether there is a change using the comparison result obtained in the comparing step. And a step.

According to a seventh aspect of the present invention, there is provided a method for monitoring the characteristics of a driving motor, comprising: A load detecting step of detecting a load applied to the movable portion, and a transmission for calculating a transfer function by analyzing a frequency characteristic of the current detected in the current detecting step and a frequency characteristic of the load detected in the load detecting step. A function calculating step, a comparing step of comparing a transfer function detected in the transfer function calculating step with a transfer function analyzed in the past, and a moving part corresponding to the mechanism according to the result of the comparing step. And an automatic calibration step for automatically calibrating the applied current.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention;
An embodiment will be described. FIG. 1 is a diagram showing a schematic configuration of a bonding apparatus. In FIG. 1, A in FIG.
The motor current shown in FIG.
1 is supplied.

The wire bonding apparatus 11 is provided with a bonding head 12. 13 is a capillary. A chip mounting table 15 is provided on the base 14. A load cell 16 is mounted on the chip mounting table 15. The load cell 16 contains the capillary 1
3 is provided with a receiving portion 17 pressed by the distal end portion 13a.

The motor current A is a current for driving a motor (not shown) for driving the bonding head 12. The motor current A controls the movement of the bonding head 12 and the load on the receiving portion 17 of the tip 13a of the capillary 13.

Originally, a semiconductor chip is mounted at a position where the load cell 16 is mounted. Further, the frequency characteristic of the motor current A described above is based on a fast Fourier transform (FFT) 18.
Is analyzed by

Further, the pressure detected by the load cell 16 is amplified by an amplifier (Amp.) 19. The output of the amplifier 19 is a fast Fourier transform (FFT) 20.
Analyzes the frequency characteristics.

That is, each frequency component of the motor current as an input signal is analyzed by the fast Fourier transform 18.
Further, the frequency characteristic of the load signal B indicating the load is analyzed by the fast Fourier transform 20.

A signal i-fft obtained by frequency-analyzing the motor current A analyzed by the fast Fourier transform 18 and a signal f-fft obtained by frequency-analyzing the load signal B analyzed by the fast Fourier transform 20 are: Are respectively sent to the transfer function calculating unit 21, and the transfer function is calculated by the following equation.

That is, the transfer function calculated by the transfer function calculator 21 is as shown in FIG. In FIG. 2, a portion C where the gain is constant in a low frequency portion of the transfer function indicates a low frequency gain.

Further, the high-frequency portion D of the transfer function
Changes the gain. Next, the operation of the first embodiment of the present invention configured as described above will be described with reference to the flowcharts of FIGS.

First, the load cell 16 is mounted on the chip mounting table 15 of the base 14. And the bonding head 1
Motor current A is supplied to the second motor (not shown). When a motor current A flows through the motor, the tip 13a of the capillary 13 presses the receiving portion 17. The load cell 1 is pressed by the tip portion 13a of the capillary 13 against the receiving portion 17.
6 to load output B proportional to the pressure applied to the receiving portion 17
Is output.

Then, high-frequency components of the motor current A are cut by the low-pass filter (step S1). Next, the frequency characteristic of the motor current A is analyzed by the FFT 18 (step S2).

The high-frequency component of the load output B is cut by a low-pass filter (step S3). next,
The frequency characteristics of the load output B are analyzed by the FFT 20 (step S4).

Then, a transfer function is calculated by dividing the frequency characteristic of the load output B calculated in step S4 by the frequency characteristic of the motor current A calculated in step S2 (step S5).

Then, the calculation result is stored in a memory (not shown) (step S6). Then, the transfer function of the previous generation stored in the memory (not shown) is compared with the currently calculated transfer function (step S).
7).

Then, the presence or absence of a change in the two transfer functions is determined by pattern recognition or the like (step S8). Then, by observing the fluctuations of the two transfer functions, it is possible to determine the abnormality of the capillary 13 and its change with time.

For example, when the transfer function of the past (one generation before) shown in FIG. 4A is compared with the current transfer function shown in FIG. Almost no fluctuation was observed, but an increase in gain was observed in the high frequency region Z affecting the impact force. That is, in the high frequency region Z, the gain is 50
The gain has increased from [dB] to 55 [dB].

As a cause of the gain increase in such a high frequency range Z, the rotation of the motor is caught.
This is because the pressure applied to the load cell 16 increases at the moment when the catch is released.

In this manner, by observing a change in the gain in a specific area, an abnormality in the bonding head 12 or the like can be detected. Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a diagram showing a schematic configuration of the bonding apparatus. In FIG. 5, reference numeral 31 denotes a motor control unit. This motor control unit 3
0 supplies the motor current E to the bonding apparatus 31.

The bonding apparatus 31 is provided with a bonding head 32. 33 is a capillary. A chip mounting table 35 is provided on the base 34. A load cell 36 is mounted on the chip mounting table 35. The load cell 36 is provided with a receiving portion 37 which is pressed by the tip portion 33a of the capillary 33.

The motor current E is a current for driving a motor (not shown) for driving the bonding head 32. The motor current E controls the movement of the bonding head 32 and the pressing force of the tip 33a of the capillary 33 against the receiving portion 37.

Originally, a semiconductor chip is mounted at a position where the load cell 36 is mounted. The frequency characteristic of the motor current E described above is based on the fast Fourier transform (FFT) 38.
Is analyzed by

Further, the pressure detected by the load cell 36 is amplified by an amplifier (Amp.) 39. The output of this amplifier 39 is a fast Fourier transform (FFT) 40
Analyzes the frequency characteristics.

That is, each frequency component of the motor current as an input signal is analyzed by the fast Fourier transform 38.
Further, the frequency characteristic of the load signal B indicating the load is analyzed by the fast Fourier transform 40.

The signal i-fft obtained by frequency-analyzing the motor current A analyzed by the fast Fourier transform 38 and the signal f-fft obtained by frequency-analyzing the load signal B analyzed by the fast Fourier transform 40 are Are transmitted to the transfer function calculation unit 41, and the transfer function is calculated by the following equation.

That is, the transfer function calculated by the transfer function calculator 41 is as shown by G. G = (f−fft) / (i−fft) The ratio calculated by the transfer function calculation unit 41 is the input / output ratio for each frequency component.

The calculated ratio of the DC component of the signal (hereinafter, referred to as a correction coefficient) is fed back to the motor control unit 30 so that the load designated by the user and the actual load coincide with each other. The correction coefficient is updated.

Next, the operation of the second embodiment of the present invention configured as described above will be described with reference to the flowchart of FIG. 6 and FIG. First, the load cell 36 is mounted on the chip mounting table 35 of the base 34. Then, a motor current E flows to a motor (not shown) of the bonding head 32 under the control of the motor control unit 30. When a motor current E flows through this motor, the tip 33a of the capillary 33
Presses the receiving portion 37. Tip 33a of capillary 33
, The load output F proportional to the pressure applied to the receiving portion 37 from the load cell 36 is output.

Then, the high-frequency component of the motor current E is cut by the low-pass filter (step S11).
Next, the frequency characteristic of the motor current E is analyzed by the FFT 38 (step S12).

The high-frequency component of the load output F is cut by a low-pass filter (step S13). Next, the frequency characteristic of the load output B is analyzed by the FFT 40 (step S14).

Then, the frequency characteristic of the load output B calculated in step S14 is compared with the frequency characteristic calculated in step S12.
The ratio is calculated by dividing the frequency characteristic of the data current E (step S15).

Then, the calculation result (that is, the ratio) is stored in a memory (not shown) (step S16).
Then, the correction coefficient is updated. That is, the correction coefficient is automatically updated so that the load designated by the user and the actual load match (step S17).

FIG. 7A shows the result of frequency analysis of motor current E by FFT 38, FIG. 7B shows the result of frequency analysis of load output F by FFT 40, and FIG. The result is shown. The DC portion (horizontal axis 0) in FIG.
(Near Hz) is the correction coefficient.

Then, by actually updating the load command of the load control section, the apparatus is calibrated, and the command load value and the actual load value become equal. In the above embodiment, the wire bonding apparatus has been described.
The same can be applied to the B apparatus and the like.

[0048]

According to the first and fifth aspects of the present invention, the transfer function is calculated by analyzing the frequency characteristics of the current input to the driving motor and the frequency characteristics of the load applied to the movable part. Since the transfer function is compared with the transfer function analyzed in the past, it is possible to monitor a change in the characteristic.

According to the second and sixth aspects of the present invention, the transfer function is calculated by analyzing the frequency characteristics of the current input to the driving motor and the frequency characteristics of the load applied to the movable part. Since this transfer function is compared with the transfer function analyzed in the past to determine whether there is a change, it is possible to monitor whether there is a change in the characteristic.

According to the third and seventh aspects of the present invention, the transfer function is calculated by analyzing the frequency characteristics of the current input to the driving motor and the frequency characteristics of the load applied to the movable part. Since the transfer function is compared with the transfer function analyzed in the past and the current applied to the movable portion is automatically calibrated, the load fluctuation can be calibrated automatically.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a bonding apparatus according to a first embodiment of the present invention.

FIG. 2 is a view showing a transfer function according to the embodiment;

FIG. 3 is a flowchart for explaining a method of monitoring the characteristics of a driving motor.

FIG. 4 is a diagram showing a transfer function when an impact force is changed.

FIG. 5 is a diagram showing a schematic configuration of a bonding apparatus according to a second embodiment of the present invention.

FIG. 6 is a flowchart for explaining a method of monitoring the characteristics of a driving motor.

FIG. 7 shows motor current, load output,
The figure showing a ratio.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Bonding apparatus 12 ... Bonding head 13 ... Capillary 14 ... Base 15 ... Chip mounting table 16 ... Load cell 17 ... Receiving part 18, 20 ... High-speed Fourier transform 19 ... Amplifier 21 ... Transfer function calculating part.

Claims (7)

[Claims] 1. A mechanism in which a movable part moves in accordance with a waveform of a current input to a driving motor, current detection means for detecting the current, and load detection for detecting a load applied to the movable part. Means, a transfer function calculating means for analyzing a frequency characteristic of the current detecting means and a frequency characteristic of the load detected by the load detecting means and calculating a transfer function, and a transfer function detected by the transfer function calculating means and A characteristic monitoring device for a driving motor, comprising: a comparison means for comparing the analyzed transfer function with the analyzed transfer function. 2. A mechanism section in which a movable section moves in accordance with a waveform of a current input to a driving motor, current detection means for detecting the current, and load detection for detecting a load applied to the movable section. Means, a transfer function calculating means for analyzing a frequency characteristic of the current detecting means and a frequency characteristic of the load detected by the load detecting means and calculating a transfer function, and a transfer function detected by the transfer function calculating means and A characteristic monitoring device for a driving motor, comprising: comparison means for comparing the analyzed transfer function with the data; and judgment means for judging the presence or absence of a change using the comparison result obtained by the comparison means. . 3. A mechanism section in which a movable section moves in accordance with a waveform of a current input to a driving motor; current detection means for detecting the current; and load detection for detecting a load applied to the movable section. Means, a transfer function calculating means for analyzing a frequency characteristic of the current detecting means and a frequency characteristic of the load detected by the load detecting means and calculating a transfer function, and a transfer function detected by the transfer function calculating means and A drive comprising: a comparison unit for comparing the analyzed transfer function; and an automatic calibration unit for automatically calibrating a current applied to the movable unit according to the mechanism according to a comparison result of the comparison unit. For monitoring motor characteristics. 4. A characteristic monitoring device for a driving motor according to claim 1, wherein said mechanism is a wire bonding mechanism. 5. A current detecting step for detecting the current of a mechanism section in which a movable section moves according to a waveform of a current input to a driving motor, and a load detecting step for detecting a load applied to the movable section. A transfer function calculating step of analyzing a frequency characteristic detected by the current detecting step and a frequency characteristic of the load detected by the load detecting step to calculate a transfer function; and a transfer function detected by the transfer function calculating step. And a comparing step of comparing a transfer function analyzed in the past with a transfer function. 6. A current detecting step for detecting the current of a mechanism section in which a movable section moves according to a waveform of a current input to a driving motor, and a load detecting step for detecting a load applied to the movable section. A transfer function calculating step of analyzing a frequency characteristic of a current detected in the current detecting step and a frequency characteristic of a load detected in the load detecting step to calculate a transfer function; and A driving mode comprising: a comparing step of comparing a transfer function with a transfer function analyzed in the past; and a judging step of judging the presence or absence of a change using the comparison result obtained in the comparing step. Data monitoring method. 7. A current detecting step of detecting a current of a mechanism section in which a movable section moves in accordance with a waveform of a current input to a driving motor, and a load detecting step of detecting a load applied to the movable section. A transfer function calculating step of analyzing a frequency characteristic of a current detected in the current detecting step and a frequency characteristic of a load detected in the load detecting step to calculate a transfer function; and A comparison step of comparing a transfer function with a transfer function analyzed in the past; and an automatic calibration step of automatically calibrating a current applied to the movable section according to the mechanism according to a result of the comparison. A characteristic monitoring method of a driving motor characterized by the above-mentioned.