JPH11194840A - Heater power controller for bonding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make preferable stable power control even for a heater whose resistance value changes due to temperature change by controlling a feeding power source ON/OFF means into OFF state when power integration value that is actually consumed to control a heater temperature becomes equal to a power command value. SOLUTION: An analog multiplier 4 multiplies voltage value that is applied to a heater 3 at the start of one period (half period of an alternating current) of a pulsating current by current value that is detected by resistance 5 for current detection and calculates power value in real time. An integrated circuit 6 accumulates the power that has been applied to the heater 3 within a half period of an alternating current. A control power commanding means 12 and the circuit 6 are connected to a comparator 7 send control power command value and power integration value to the comparator respectively. The comparator 7 resets a set reset flip-flop 8 when th power integration value becomes equal to the power command value. The flip-flop 8 sends a signal which makes a switching element 2 OFF.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater power control device for controlling a heater temperature in a bonding apparatus, and mainly relates to a temperature control of a pulse heating heater of a flip chip bonding apparatus and an outer lead bonding apparatus. It has been developed mainly for the heater power control device for performing the above.

[0002]

2. Description of the Related Art The amount of heat generated by an electric heater is expressed by the following equation. Heat value = k × power × time (k is a constant). Therefore, in order to adjust the temperature of the electric heater, electric power is controlled. Therefore, conventionally, in order to control a high-output heater so that a high-speed response is possible, power control is performed using phase control of an AC power supply.

In the phase control, as shown in FIG. 3, power control is performed by turning on (turning on) an alternating current for a fixed time every half cycle. In this case, the actual power calculation is AC
In the case of 100 v, the ratio is 100 v × 100 v / R (heater resistance value) × control ratio. When the heater resistance value (R) is constant, the control ratio = power ratio, but the heater resistance value (R)
, The power control according to the control ratio cannot be performed.

That is, in the case of the phase control, if the resistance value of the heater has a small change due to the temperature fluctuation of the heater itself, power control almost in proportion to the command value can be performed.
However, power control according to a command value cannot be performed for a heater whose resistance value changes due to temperature fluctuation. In terms of results,
ON / O at the same control ratio even if the resistance value of the heater changes
Since the FF is repeated, the temperature of the heater changes (power fluctuates). Further, when the resistance value becomes extremely low, an overcurrent may flow through the heater and damage the heater. There is also a problem that controllability fluctuates due to fluctuations in the power supply voltage and individual differences in the resistance value of the heater.

[0005]

SUMMARY OF THE INVENTION The present invention provides a heater power control apparatus which is not affected by a change in the resistance value of a heater with temperature, a change in a power supply voltage, an individual difference in a resistance value of a heater, and the like. It is an object of the present invention to provide a heater power control device in a bonding device that enables accurate and stable temperature control.

[0006]

According to the present invention, there is provided a heater power control apparatus for controlling a heater temperature of a bonding apparatus employing the following means to solve the above-mentioned problems. First, a power supply ON / OFF means for turning ON / OFF the power supply to the heater is provided. Second, as the detection means, there are provided voltage detection means for detecting a voltage supplied to the heater, current detection means for detecting a current supplied to the heater, and temperature detection means for detecting a heater temperature.

Third, as control data calculation means, supply power calculation means for calculating a power value to be supplied to the heater based on a value obtained from the voltage detection means and a value obtained from the current detection means, Integrating means and control power command means for giving a power command value from the temperature detecting means based on the temperature value are provided. Fourthly, there is provided means for controlling the power supply ON / OFF means to be OFF when the power integrated value obtained from the means for integrating the supplied power becomes equal to the power command value.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described together with examples. FIG. 2 is a perspective view showing an outline of a bonding head in which a heater is incorporated. The bonding apparatus used in the present invention heats and pressurizes the semiconductor chip 20 and the like to be bonded and joins the semiconductor chip 20 and the like to the circuit board 21 and the like.

The bonding head 22 includes a heater 2
3 and a tool head 24 for holding the semiconductor chip 20 by suction
Is provided. A power cable 25 for supplying power to the heater and a thermocouple 26 for detecting the temperature of the heater 23 are electrically connected to the heater 23.

FIG. 1 is a power control circuit diagram for controlling the temperature of the heater 3 of the bonding apparatus according to one embodiment of the present invention, which will be described below with reference to FIG. 1 in the figure
Is a full-wave rectifier for converting the alternating current input from the input terminals 10 and 11 into a pulsating flow, and the full-wave rectifier 1 uses a bridge diode.

The pulsating current converted by the full-wave rectifier 1 enters the switching element 2. The switching element 2 is a first embodiment.
Means for turning ON / OFF the power supply to the heater 3 referred to above. As the switching element 2, Tr or FET is used. ON / OFF of the switching element 2 is performed in response to a control signal from the set / reset flip-flop 8.

The pulsating flow from the full-wave rectifier 1 is detected by a phase pulse generator 9 at the starting point of an AC half cycle. By this detection, the set / reset flip-flop 8 connected to the phase pulse generator 9 is set. The phase pulse generator 9 clears the integration value of the integration circuit 6 at the same time.

When the set / reset flip-flop 8 is set by the phase pulse generator 9, the signal is received and the switching element 2 is turned on. When the switching element 2 is turned on, the current flows to the heater 3,
The heater 3 consumes electric power and generates heat.

As detecting means for detecting the power consumption and the temperature, voltage detecting means for detecting a voltage supplied to the heater, current detecting means for detecting a current supplied to the heater, and a temperature detecting means for detecting a heater temperature Means. A thermocouple 26 is used as the temperature detecting means.
Incidentally, reference numeral 5 in the drawing denotes a current detecting resistor.

Next, control basic data is calculated from the data detected by the detection means. As calculation means for control basic data, supply power calculation means for calculating a power value to be supplied to the heater based on a value obtained from the voltage detection means and a value obtained from the current detection means, and a means for integrating the supply power, There is control power commanding means 12 for giving a power command value from the temperature detecting means based on the temperature value.

An analog multiplier 4 as a supply power calculating means
, The voltage value applied to the heater 3 from the start of one cycle of the pulsating flow (half cycle of AC) is multiplied by the current value detected by the current detection resistor 5 to calculate a power value in real time. As means for integrating the supplied power, an integrating circuit 6 is used. The integration circuit 6 accumulates the electric power applied to the heater 3 within the half cycle of the alternating current.

The control power command means 12 and the integration circuit 6
It is connected to the comparator 7 and sends the control power command value and the power integrated value to the comparator 7 respectively. When the power integrated value becomes equal to the power command value, the comparator 7 resets the set / reset flip-flop 8.

When the set / reset flip-flop 8 is reset, the set / reset flip-flop 8 becomes
A signal for turning off the switching element 2 is issued. That is, the set / reset flip-flop 8 is used as a means for issuing a control signal for controlling the power supply ON / OFF means to turn OFF when the power integrated value described in claim 1 becomes equal to the power command value.

When the switching element 2 is turned off, no more power is consumed by the heater 3. After that, the set / reset flip-flop 8 is set at the start of the next half cycle of the alternating current, turning on the switching element 2,
The above operation is repeated.

The switching element 2 includes a phase pulse generator 9
Is turned on in advance through the set / reset flip-flop 8 at the beginning of one cycle of the pulsating flow detected by
The integrating circuit 6 is also cleared to zero at the beginning of the cycle by the phase pulse generator.

Therefore, when a heater such as a ceramic heater having a characteristic in which the resistance value gradually decreases as the temperature rises is used, a voltage waveform as shown in FIG. 4 and an electric power as shown in FIG. It becomes a waveform. Both shaded areas are areas where power supply to the heater is ON. When the resistance value of the heater 3 decreases under the condition that the voltage is constant, the peak value of the current increases and the peak value of the supplied power increases accordingly. In order to keep the supply power per one cycle of the pulsating flow constant, the ON time is gradually shortened.

[0022]

First, unlike the conventional phase control, the present invention is different from the conventional phase control in that when the integrated power value actually consumed becomes equal to the power command value for controlling the heater temperature, the power supply is turned ON / OFF.
Since the OFF means is controlled to be OFF, stable power control can be performed even for a heater whose resistance value changes with a temperature change, and as a result, stable heater temperature control can be performed.

Secondly, since the present invention is controlled in accordance with the power consumption value actually consumed, even heaters having the same heater rating can be used without changing parameters even if the heaters have different initial characteristics.

Third, in the present invention, the power consumption is calculated based on the actual voltage detected by the voltage detecting means, so that even if the power supply voltage fluctuates, accurate power control and, consequently, heater temperature Control becomes possible.

[Brief description of the drawings]

FIG. 1 is a power control circuit diagram according to one embodiment of the present invention;

FIG. 2 is a perspective view showing an outline of a bonding head in which a heater is incorporated.

FIG. 3 is a voltage waveform diagram in a conventional phase control.

FIG. 4 is a voltage waveform diagram when the resistance value is reduced in the present invention.

FIG. 5 is a power waveform diagram of the same.

[Explanation of symbols]

1. . . . . . . . . . 1. full-wave rectifier . . . . . . . . . Switching element 3. . . . . . . . . . Heater 4. . . . . . . . . . Analog multiplier 5. . . . . . . . . . Current detection resistor 6. . . . . . . . . . Integration circuit 7. . . . . . . . . . Comparator 8. . . . . . . . . . 8. Set reset flip-flop . . . . . . . . . Phase pulse generator 10,11. . . . . . Input terminal 12. . . . . . . . . Control power command means 20. . . . . . . . . Semiconductor chip 21. . . . . . . . . Circuit board 22. . . . . . . . . Bonding head 23. . . . . . . . . Heater section 24. . . . . . . . . Tool head 25. . . . . . . . . Power cable 26. . . . . . . . . thermocouple

Claims (1)

[Claims] In a device for controlling a heater temperature of a bonding apparatus by a power supply on / off means for turning on / off a power supply to a heater, voltage detecting means for detecting a voltage supplied to the heater is provided as detecting means. A current detecting means for detecting a current supplied to the heater, and a temperature detecting means for detecting a heater temperature, wherein the control data calculating means calculates a value obtained from the voltage detecting means and a value obtained from the current detecting means. A supply power calculating means for calculating a power value to be supplied to the heater based on the temperature, a means for integrating the supplied power, and a control power command means for giving a power command value based on the temperature value from the temperature detecting means. A power supply ON / OFF unit that is controlled to be OFF when a power integrated value obtained from a unit for integrating power becomes equal to a power command value; Grayed apparatus definitive heater power control unit.