JP2840924B2 - Power control method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention heats a crucible for melting a material for semiconductor single crystal and independently supplies power from a single power supply to a plurality of heaters for controlling the temperature of the crucible. The present invention relates to a power control method and apparatus which can be performed.

[0002]

2. Description of the Related Art FIG. 4 is an electric circuit diagram showing a heater and its power control device in a conventional single crystal pulling apparatus.
In the figure, 1 is a three-phase AC power supply, 2 is a switch, 3 is a transformer, and H
Indicates a heater. The AC power supply 1 is connected to the primary side of the transformer 3 via a switch 2. Transformer 3-2
The secondary side is connected to an intermediate point between two series-connected switching elements 4a and 4b in each phase. The switching elements 4a and 4b are constituted by thyristors, and the cathode side of the switching element 4a is connected to one terminal of the heater H via the reactor 5a of the smoothing circuit 5,
The anode side of the switching element 4b is connected to another terminal of the heater H. 5b is a capacitor constituting the smoothing circuit 5. A control signal S is input to the gate terminals of the respective switching elements 4a and 4b through the drive circuit 7, and the respective switching elements 4a and 4b correspond to the control signal S.
4b is controlled.

In such a conventional device, the drive circuit 7 is controlled by the control signal S, and the phase control for both the switching elements 4a and 4b is performed.
The secondary voltage E ₀ is rectified, and the control signal S is supplied to one side of the smoothing circuit 5.
To induce a DC voltage E ₁ corresponding to
A DC voltage E ₂ is applied to both terminals of the heater H to allow the DC current I to flow through the heater H.

FIG. 5 is a block diagram showing another conventional power control apparatus in a single crystal pulling apparatus. In this power control apparatus, a three-phase AC power supply 1 has transformers 3a, 3a connected in parallel with a switch 2 interposed therebetween. is connected to each primary side of 3b, each transformer 3a, so that the allowed to induce a respective secondary voltage E ₀ to the secondary side of the 3b. Each transformer 3a, 3b and heater H
_1, connection aspect between of H ₂ is substantially the same as the power supply device shown in FIG. That is, the transformer 3a is composed of switching elements 4a and 4b each formed of a thyristor connected in series.
Of being connected to an intermediate point, the switching elements 4a cathode is connected by interposing a reactor 5a constituting the smoothing circuit 5 to one terminal of the heater H _1, and each anode of the switching element 4b is the other heater H ₁ Connected to terminal. The same applies to the transformer 3b. 7a and 7b are drive circuits for controlling the phases of the switching elements 4a and 4b.

In such a conventional device, the drive circuits 7a and 7b are operated by the control signals S ₁ and S ₂ , and the switching elements 4a and 4b are phase-controlled through the drive circuits 7a and 7b. The secondary voltages E ₀ of the transformers 3 a and 3 b are rectified, and DC voltages E ₁₁ and E ₂₁ corresponding to the control signals S ₁ and S ₂ are induced upstream of the smoothing circuits 5 and 5. DC voltages E ₁₂ and E ₂₂ are applied to the terminals on both sides of the heaters H ₁ and H ₂ at 5 and 5, respectively, so that DC currents I ₁ and I ₂ are passed through the heaters H ₁ and H ₂ , respectively.

[0006]

However, in such a conventional apparatus, the transformer 3 is provided for each of the heaters H ₁ and H _2.
a, 3b and the switching elements 4a, 4b must be provided, which requires a large installation space, and is large and heavy as a whole, and there is a problem that an increase in cost cannot be avoided. The present invention has been made in view of the above circumstances, and has as its object to reduce the number of parts, to be compact and compact, and to generate harmonic distortion on the power supply side because no thyristor is used. There is no power control method and apparatus therefor.

[0007]

According to a first aspect of the present invention, there is provided a power control method for controlling power to each of a plurality of heaters supplied from a single AC power supply. With the rectifier interposed, the heaters are connected in parallel, and switching elements are connected in series to the respective heaters, so that the switching elements are turned on and off , and the ON operation of the switching elements is performed.
It is characterized in that the timing is shifted .

[0008]

A power control device according to a second aspect of the present invention is a device for controlling the power of each of a plurality of heaters supplied from a single AC power supply, comprising a single rectifier supplied from a single AC power supply. , to the rectifier device, comprising a switching element respectively connected in series, each switching element oN, and a drive circuit for turning off operation, the drive circuit
The timing of ON operation for each switching element
It is characterized in that it is configured to cause

[0010]

[0011]

[Action] In the first invention, whereby on switching elements provided corresponding to the people connected single rectifier outputs a plurality of heaters each in a single AC power source off system
Upon your, that on operation to change the time ratio so as not to overlap each other, Ri Do can to each of the plurality of heaters respectively individually perform power supply control, resulting to reduce the load on the power supply side
You.

[0012]

According to the second aspect of the present invention, a single rectifier output supplied from a single AC power supply is turned on or off by a switching element provided for each of a plurality of heaters.
By changing the time ratio using the drive circuit so that the ON operations do not overlap each other during the OFF control, it is possible to perform accurate power control individually for each of the plurality of heaters. Do Ri may reduce the load on the power supply side.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments. FIG. 1 is a circuit diagram of a power control method and a power control device according to the present invention. In FIG. 1, 1 is a three-phase AC power supply, 2 is a switch, 3 is a transformer, and H ₁ and H ₂ are single crystal pulling devices. 2 shows a heater for heating the crucible disposed around the crucible in FIG. An AC power supply 1 is connected to a primary side of a transformer 3 via a switch 2, and is connected to a secondary side of the transformer 3.
A secondary voltage E ₀ is induced. Transformer 3
Of the rectifier 6a, 6b connected in series is connected to an intermediate point between the rectifiers 6a and 6b connected in series. The secondary voltage E ₀ is connected to the cathode of the rectifier 6a and the anode of the rectifier 6b.
DC voltage E ₁ based on is adapted to be induced.

The cathode side of rectifier 6a and the rectifier 6b
The node side is divided into two branches, each branch line is a thyristor
Of each of the switching elements 9a and 9b
And its cathode constitutes a smoothing circuit 5.
Heaters H with the reactors 5a, 5a₁, H_Two
Are connected to one terminal. In addition, the rectifier 6b
Each of the two branched lines on the node side has a heater H₁,
H _TwoIs connected to the other terminal. 5b is a smoothing circuit 5
Is a capacitor.

Gate ends of switching elements 9a and 9b
Drive circuits 7a and 7b are connected to the
A control signal is provided between the eve circuits 7a and 7b through a frequency dividing circuit 8.
No. S ₁, S_TwoIs input.

Thus, in such an embodiment,
Voltage E induced on the secondary side of the heater 3₀Is the rectifier 6a,
6b, the cathode of the rectifier 6a and the rectifier 6b
DC voltage E between the anode₁Is induced. Switch
The switching elements 9a and 9b are controlled by the frequency dividing circuit 8 to divide the frequency.
Control signal S₁, S _TwoDrives the drive circuits 7a and 7b respectively.
To turn on and off switching elements 9a and 9b
I do. On / off control of the switching elements 9a and 9b
Control and the smoothing circuit 5, the heater H₁, H_Two
E on both side terminals_Two, E_ThreeDC voltage of each
Data H₁, H_TwoDC current I₁, I_TwoIs turned on.

FIG. 2 shows each of the switching elements 9a and 9b.
ON / OFF time ratio and heater H₁, H _TwoDC applied to
Voltage E_Two, E_ThreeFIG. 4 is an explanatory diagram showing a relationship with the above. FIG.
(A) is the ON / OFF time ratio α of the switching element 9a.₁
2 (b) shows the DC voltage E_TwoChange
FIG. 2C shows the switching element 9b.
ON / OFF time ratio α_TwoAnd FIG. 2 (d) is based on this.
DC voltage E _ThreeShows the change.

As shown in FIG.
The on / off ratio of a is t_A1: T_B1(T _A1> T_B1From)
t_A2: T_B2(T_A2<T_B2) Is changed to FIG.
DC voltage E as shown in_TwoIs E_{twenty one}To E_{twenty two}(E_{twenty one}> E_{twenty two})
Changes to

On the other hand, as shown in FIG. 2C, the on / off time ratio of the switching element 9b is t _A3 : t _B3 (t _A3 > t _B3 ).
From t _{A4 to} t _B4 (t _A4 <t _B4 ) as shown in FIG.
As shown in (d), the DC voltage E ₃ is changed from E ₃₁ to E ₃₂ (E ₃₁ >
To change to E _32). That is, the on times t _A1 and t _A3 are shortened,
As the off times t _B1 and t _B3 are increased, the DC voltage E
₂ and E _{3 become} smaller. The on and off timings of the switching elements 9a and 9b are set such that the switching element 9b rises in response to the falling of the switching element 9a in order to reduce the load on the primary side of the transformer 3, and both of them are turned on. It is desirable not to make the operation heavy.

The reciprocal of the sum of the ON and OFF times, ie, t
_A1+ T_B1, T_A2+ T_B2Frequency f which is the reciprocal of₁= 1 /
(T_A1+ T_B1), F_Two= 1 / (t_A2+ T_B2) Is heater H
₁, H _TwoWaveform (ripple content) supplied to the
It is determined in consideration of economic efficiency based on the current value. Figure 3 shows the switch
ON / OFF time ratio α of the switching elements 9a and 9b₁, Α
_TwoAnd the control signal S₁, S_TwoIs a graph showing the relationship with
And the control signal S is plotted on the horizontal axis.₁(Or S_Two) And the vertical axis
Off time ratio α₁(Or α_Two).

As apparent from this graph, the voltages E ₂ , E
_The control signals S ₁ and S
_As the value of ₂ increases, the on / off time ratio α ₁ , α
₂ approaches 1.0, so that the voltages E ₂ and E ₃ also increase. Conversely, as the control signals S ₁ and S ₂ decrease, α ₁ and α ₂ approach zero, and accordingly, the voltages E ₂ and E ₃ also decrease. When t _A1 = 0 and t _A3 = 0, the DC voltage E ₂₁ =
0, E ₃₁ = 0. In the above-described embodiment, the case where the single power supply 1 is divided into _two and supplied to the heaters H ₁ and H ₂ has been described. However, the single power supply 1 may be divided into three or more divided parts. Control can be performed. In the above-described embodiment, the heater for heating the crucible has been described. However, the present invention is not limited to this, and it is needless to say that the heater can be applied to power control of various electric devices.

[0023]

As described above, according to the first aspect of the present invention, in a method of controlling power to each of a plurality of heaters supplied from a single AC power supply, a single rectifier is interposed in a single AC power supply. Then, the heaters are connected in parallel, and switching elements are connected in series to the respective heaters .
By shifting the ON timing of the switching element, the operating time ratio can be varied , distribution and power supply control can be performed for each heater, and the load on the power supply side device can be reduced.
Life can be extended.

[0024]

According to a second aspect of the present invention, in a device for controlling the power of each of a plurality of heaters supplied from a single AC power supply, a single rectifier supplied from a single AC power supply and the rectifier The device comprises a switching element connected in series with each other, and a drive circuit for turning on and off each switching element.
When turning off , turn on the timing of each switching element.
Shifting was at different time ratio that the distribution for people each heater respectively, resulting performs power supply control, also the circuit configuration is simplified, it becomes easy to smaller, lighter, cost reduction can be achieved
At the same time, the load on the power supply side device can be reduced and the service life can be extended
You.

[0026]

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram of a heater power control device in a single crystal pulling apparatus according to an embodiment of the present invention.

FIG. 2 is a waveform diagram showing a relationship between an on / off time ratio of a switching element and a DC voltage applied to a heater.

FIG. 3 is an explanatory diagram showing a relationship between an on / off time ratio of a switching element and control signals S ₁ and S ₂ .

FIG. 4 is an electric circuit diagram of a power control device for a heater in a conventional single crystal pulling apparatus.

FIG. 5 is an electric circuit diagram of another power control device of the heater in the conventional single crystal pulling device.

[Explanation of symbols]

1 AC power supply 3a, 3b transformer 5 smoothing circuit 5a reactor 5b capacitors 6a, 6b rectifier 7a, 7b drive circuit 8 frequency divider H _1, H ₂ heater

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // H01L 21/208 H01L 21/208 P (56) References JP-B-63-13312 (JP, B2) (58) Field (Int.Cl. ⁶ , DB name) H05B 3/00 350 H05B 3/00 310 H05B 3/00 370 H01L 21/208

Claims (2)

(57) [Claims] 1. A method for controlling power to each of a plurality of heaters supplied from a single AC power supply, wherein the heaters are connected in parallel with a single rectifier interposed in a single AC power supply. with a switching element to people each heater respectively connected in series on each of the switching elements, together with the turning off operation, on movement of the respective switching elements
A power control method characterized by shifting the timing of operation . 2. A plurality of heat sources supplied from a single AC power supply.
In a device that controls the power of each
A single rectifier powered by a power source and
The switching elements connected in series with each other
And a drive circuit for turning the switching element on and off.
For example, the drive circuit characterized power controller that are configured to shifting the timing of o <br/> down operation of each switching element.