JP3381140B2 - Heater power control device in bonding equipment - Google Patents

Description

Description: 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 device, and mainly relates to a flip chip bonding device and an outer lead. The heater power controller for controlling the temperature of the pulse heater of the bonding apparatus has been developed. [0002] 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. SUMMARY OF THE INVENTION The present invention provides a heater power control apparatus which is not affected by changes in the resistance of a heater due to temperature, fluctuations in power supply voltage, individual differences in the resistance of a heater, and the like. Accordingly, 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. SUMMARY OF THE INVENTION The present invention provides a heater power control device for controlling a heater temperature of a bonding apparatus employing the following means to solve the above problems. First , the power supply to the heater is AC, and the AC
A power supply ON / OFF means for turning ON / OFF the power supply to the heater every half cycle 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 , Means for integrating the supply power of
Control power command means for providing a power command value based on the temperature value from the temperature detecting means is provided. Fourth, a power integrated value for each half cycle is obtained from the means for integrating the supplied power, and when the obtained power integrated value becomes equal to the power command value, the power supply ON / OFF is determined.
Means for controlling the OFF means to be OFF is provided. [0008] Embodiments of the present invention will be described below along 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
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. The ON time is gradually shortened in order to keep the supply power per cycle of the pulsation constant. First, the present invention differs from the conventional phase control in that the power supply is turned on when the integrated power actually consumed becomes equal to the power command value for controlling the heater temperature. /
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. Second, 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 incorporating a heater. 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. . . . . . . . . . 1. full-wave rectifier . . . . . . . . . Switching element3. . . . . . . . . . Heater4. . . . . . . . . . Analog multiplier 5. . . . . . . . . . 5. Current detection resistor . . . . . . . . . Integrator 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)

(57) [Claims] [Claim 1] The power supply to the heater is AC, and the AC power is supplied to the heater.
In a device for controlling a heater temperature of a bonding apparatus by a power supply ON / OFF means which is turned on / off every half cycle, a voltage detection means for detecting a voltage supplied to the heater as a detection means, and a current supplied to the heater And a temperature detecting means for detecting a heater temperature. The control data calculating means supplies the heater to the heater based on a value obtained from the voltage detecting means and a value obtained from the current detecting means. Power supply calculating means for calculating a power value, means for integrating the supply power every half cycle, and control power command means for giving a power command value based on the temperature value from the temperature detecting means, and integrating the supply power. Every half cycle
A power integrated value for each bonding device , and when the obtained power integrated value becomes equal to the power command value, the power supply ON / OFF means is controlled to be turned off. Control device.