JP2002014734A - Power unit for high-speed current inversion plating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly plate an object body such as a printed wiring board by inverting a power source at a high speed. SOLUTION: A series circuit of a 1st reactor 4A and a 1st main switching element 8A which turns on and off at a high speed is provided between one end of a 1st DC power unit 2A, and the other end of a 2nd DC power unit 2B and one end of a load. A series circuit of a 2nd reactor 4B and a 2nd main switching element 2B which turns on and off when the 1st main switching element turns on and off is provided between one end of the 2nd DC power unit, and the other end of the 1st DC power unit and the other end of the load. A 1st auxiliary switching element 10A which turns on and off when the 1st main switching element turns on and off is provided between the output end of the 1st reactor and the other end of the 1st DC power unit. A 2nd auxiliary switching element 20B which turns on and off when the 1st main switching element turns on and off is provided between the output end of the 2nd reactor and the other end of the 2nd DC power unit. Further, when the voltage applied across the 1st or 2nd auxiliary switching element is detected to be higher than a specific voltage, the 1st or 2nd auxiliary switching element is turned on.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed current reversal plating power supply device for reversing the current at a high speed and uniformly plating an object to be plated such as a printed wiring board.

[0002]

2. Description of the Related Art By reversing the polarity at a high speed, the current is reversed, the plating is interrupted or dissolved by a negative current, and the plating is interrupted or melted by a positive current. .

However, in a printed wiring board of a multi-layer substrate in which components to be plated can be integrated at a high density, it becomes difficult to obtain a uniform plating in the through hole as the plate layer becomes larger. In particular, it has been found that uniform plating cannot be obtained in the through-hole unless the negative current flows for a sufficiently shorter time than the positive current of the plating and a negative current sufficiently larger than the positive current flows in the through-hole. .

Therefore, the applicant proposed in Japanese Patent Application Laid-Open No. 2000-92841 a power supply device which converts the polarity at a high speed and performs uniform plating on an object to be plated such as a multilayer printed circuit board. That is, the power supply device proposed by the applicant is a power supply as shown in FIG. In FIG. 3, DC power supplies 2A and 2B are formed by rectifying a commercial AC power supply. In some cases, the rectified DC is converted to a high frequency by an inverter and then rectified again. 4A,
4B is an output of one of the DC power supplies 2A and 2B,
For example, the first and second terminals connected to the positive outputs 2A1 and 2B1
Reactors, 6A and 6B are backflow prevention diodes whose anodes are connected to the outputs of the first and second reactors 4A and 4B, respectively, and 8A and 8B are main IGBs whose collectors are connected to the cathodes of the respective backflow prevention diodes 6A and 6B.
T, and the respective emitters of the IGBTs 8A and 8B are connected to the other outputs of the respective DC power supplies 2B and 2A, for example, the negative outputs 2B2 and 2A2.

A short-circuit 10A has a collector connected to a connection point C between the first reactor 4A and one backflow prevention diode 6A, and an emitter connected to another output 2A2 of the first DC power supply 2A. One auxiliary IGBT.
A short-circuit second terminal 10B has a collector connected to a connection point D between the second reactor 4B and the other backflow prevention diode 6B, and an emitter connected to another output 2B2 of the second DC power supply 2B. This is an auxiliary IGBT. Reference numeral 12 denotes a load of the object to be plated. 14 is main IGBT, auxiliary IG
The control device outputs a control signal to the BT. Furthermore, snubber circuits 16 are provided between the collectors and emitters of the main IGBTs 8A and 8B and the auxiliary IGBTs 10A and 10B, respectively.
A, 16B and 18A, 18B are connected. These snubber circuits 16A, 16B, 18A, 18B are provided with, for example, a series circuit of a diode and a capacitor, and a resistor in parallel with the capacitor.

FIG. 4 is a waveform diagram of each part. FIG. 4A shows a waveform of a current flowing through the load 12, and FIGS.
Are the first main IGBT 8A and the first auxiliary IGBT 10 respectively.
A, gate signal waveforms of the second main IGBT 8B and the second auxiliary IGBT 10B are shown. Now, before the time t1 shown in FIG. 4, the gate signal shown in FIG. 4D is input to the second main IGBT 8B, and the second DC power supply 2B supplies the second reactor 4B, the second diode 6B, and the second A positive current shown in FIG. 4A flows to the load 12 via the main IGBT 8B. From these, the plating is interrupted or dissolved.

On the other hand, before the time t1, the first auxiliary IG
The gate signal is input to the BT 10A as shown in FIG. 4C, and the first DC power supply 2A, the first reactor 4A,
A current flows through the first auxiliary IGBT 10A and the first DC power supply 2A, and energy is stored in the first reactor 4A.

Then, at time t1, the second main IGB
At T8B, the gate signal of the first auxiliary IGBT 10A is turned off, and the gate signal is input to the first main IGBT 8A as shown in FIG. When a gate signal is input to the first main IGBT 8A, the first DC power supply 2A, first reactor 4A, first diode 6A, first main IGBT 8A, load 12, first DC power supply 2A, and FIG. A negative current flows as shown. At this time, a current obtained by adding the output current of the first DC power supply device 2A and the current flowing by discharging the energy stored in the first reactor 4A flows to the load 12. Therefore, the current flowing through the load 12 rises sharply. Thereby, the object to be plated of the load 12 is plated.

On the other hand, at time t1, the second auxiliary IGBT 10B
Also, a gate signal is input as shown in FIG.
A current flows through the second DC power supply 2B, the second reactor 4B, the second auxiliary IGBT 10B, and the second DC power supply 2B.
Energy is stored in second reactor 4B.

Next, at time t2, the first main IGBT 8
A, the gate signal of the second auxiliary IGBT 10B is turned off, and the gate signal is input to the second main IGBT 8B as shown in FIG. When a gate signal is input to the main IGBT 8B, a positive current flows to the second DC power supply 2B, the reactor 4B, the diode 6B, the second main IGBT 8B, the load 12, and the second DC power supply 2B as shown in FIG. Flows.
At this time, a current obtained by adding the output current of the second DC power supply device 2B and the current flowing by discharging the energy stored in the second reactor 4B flows to the load 12. For this reason,
The current flowing through the load 12 is rapidly discharged. As a result, the plating is interrupted or dissolved.

On the other hand, at time t2, the first auxiliary IGBT 10A
As shown in FIG. 3C, a gate signal is input to the first DC power supply 2A, the first reactor 4A, and the first auxiliary I.
A current flows through the GBT 10A and the first DC power supply 2A, and energy is stored in the reactor 4A.

Hereinafter, the operation is sequentially repeated. First main IGBT8A
By switching between the second main IGBT 8B and the second main IGBT 10B at a high speed, and switching between the second auxiliary IGBT 10B and the first auxiliary IGBT 10A at a high speed, it is possible to obtain a plating power supply device that reverses the current at a high speed.

If the time during which the negative current for plating flows is T1 and the period during which the positive current for interrupting or melting the plating flows is T2, the inversion ratio of T2 / (T1 + T2) controls the controller 14. This is done by: Main IG
This can be performed by changing the periods of the gate signals of the BTs 8A and 8B and the auxiliary IGBTs 10A and 10B.
Further, although not shown, the magnitude of the current flowing through the load 12 can be detected by detecting the current flowing through the load 12 and controlling the control device 14 according to the detection signal.

[0014]

The object to be plated is hung on a hanger in a yard, carried to a plating tank by a transfer device, and put into the plating tank. Then, a current is passed from the power supply device to the object to be plated, and plating is performed. Further, the object to be plated may be moved in the plating tank by the transfer device.

For this reason, the load may not be able to make sufficient contact with the power supply hanger, or may not be able to make contact due to the vibration of the transfer device, or rust may occur due to the atmosphere at the plating site, and the load may not contact the power supply portion. When the load and the power supply unit cannot contact each other as described above, the auxiliary IGBT 1
A high voltage is applied to both ends of 0A and 10B by the energy stored in the reactors 4A and 4B. For this reason, the snubber circuits 18A and 18B connected in parallel to the short-circuit auxiliary IGBTs 10A and 10B cannot operate, and the IGBTs 10A and 10B do not operate.
B may be damaged.

[0016]

According to a first aspect of the present invention, there is provided a power supply apparatus for plating a high-speed current reversal, comprising: a first DC power supply;
Provide a DC power supply. A first reactor connected between one output terminal of the first DC power supply, the other output terminal of the second DC power supply, and one end of a load;
A series circuit with the first main switching element to be turned off is provided. One output terminal of the second DC power supply,
Between the other output terminal of the DC power supply and the other of the load,
A series circuit of a second reactor and a second main switching element that is turned off and on corresponding to the on and off of the first main switching element is provided. The first DC power supply is connected between the output of the first reactor and the other output terminal of the first DC power supply.
A first auxiliary switching element that turns off and on in response to the on and off of the main switching element is provided, and the second main switching element is provided between the output of the second reactor and the other output terminal of the second DC power supply. A second auxiliary switching element that turns off and on corresponding to the on and off of the element is provided. Further, a first or second voltage detector for detecting a voltage between both ends of the first or second auxiliary switching element is provided,
A control device for turning on the first or second auxiliary switching element when a detection signal of the first or second voltage detector is equal to or higher than a predetermined voltage.

When an ON signal is input to the second main switching element and turned on, a current, for example, a positive current, flows to the load via the second DC power supply, the second reactor, and the second main switching element to be melted. . At this time, the ON signal is also input to the first auxiliary switching element, and a current flows through the first reactor and the first auxiliary switching element. This current causes energy to be stored in the first reactor.

Next, when the ON signals of the second main switching element and the first auxiliary switching element are turned off, both of these switching elements are turned off. When an ON signal is input to the first main switching element and turned on, a current flows to the load via the first DC power supply, the first reactor, and the first main switching element. At this time, when the first auxiliary switching element is turned off, a voltage for adding the output of the first DC power supply is generated in the first reactor, and a steep negative current flows through the load. The ON signal is also input to the second auxiliary switching element, and the second DC power supply, the second reactor,
A current flows through the second auxiliary switching element, and energy is stored in the second reactor.

Next, when the ON signals of the first main switching element and the second auxiliary switching element are turned off, both of these switching elements are turned off. Then, when an ON signal is input to the second main switching element and turned on, a positive current flows to the load via the second DC power supply, the second reactor, and the second main switching element. At this time, when the second auxiliary switching element is turned off, a voltage for adding the output of the second DC power supply is generated in the second reactor, and a steep positive current flows through the load. Further, an ON signal is also input to the first auxiliary switching element, a current flows through the first DC power supply, the first reactor, and the first auxiliary switching element, and energy is accumulated in the first reactor. The following is repeated sequentially.

The current flowing through the first or second main switching element rises sharply, and a current that reverses at a high speed can flow through the load by turning on and off the first and second main switching elements at high speed.

When the load is released, a high voltage is generated in the first or second auxiliary switching element which is turned off by the stored energy of the reactor, and this voltage is detected by the first or second voltage detector. When the detected voltage becomes equal to or higher than a predetermined voltage, an ON signal is input to the first or second auxiliary switching element to be turned on, and no high voltage is applied to the first or second auxiliary switching element.

According to a second aspect of the present invention, in the power supply device for high-speed current reversal plating, the control device may be configured such that the first or second auxiliary switching element is provided when a detection signal of the first or second voltage detector is higher than a predetermined voltage. Is turned on and the energy of the first or second reactor is recovered by the first or second DC power supply device via the first or second auxiliary switching element, and then the first and second DC power supplies are turned on. A control device for turning off the device.

When the load is released as described above, the first or second power supply turned off due to the energy stored in the reactor.
A high voltage is going to be generated in the auxiliary switching element,
This voltage is detected by the first or second voltage detector, and when this detected voltage becomes equal to or higher than a predetermined voltage, the first or second auxiliary switching element is turned on, and the first and second DC power supply devices are turned off. High voltage is not applied to the first or second auxiliary switching element

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to FIG. 1 showing an embodiment of the present invention. FIG. 1 is different from FIG. 3 in that a voltage detector is provided at both ends of a short-circuiting auxiliary IGBT, and the auxiliary IGBT is short-circuited when the load is opened, that is, when the voltage detection signal exceeds a predetermined voltage. It is. That is, DC power supplies 2A and 2B are formed by rectifying a commercial AC power supply by a thyristor or the like. In some cases, the rectified DC is converted to a high frequency by a built-in inverter and then rectified again by a diode to form the DC. 4A and 4B are first and second reactors connected to one output of the DC power supply devices 2A and 2B, for example, positive outputs 2A1 and 2B1, respectively, and 6A and 6B are first and second reactors 4A and 4B, respectively.
The first and second backflow prevention diodes 8A and 8B whose anodes are connected to the output of 4B are the first and second backflow prevention diodes whose collectors are connected to the cathodes of the respective backflow prevention diodes 6A and 6B.
Each of the IGBTs 8A and 8B has its emitter connected to the other output of each of the DC power supplies 2B and 2A, for example, the negative outputs 2B2 and 2A2.

10A is the first reactor 4A and one of the first reactors 4A.
The collector is connected to a connection point C with the backflow prevention diode 6A, and the emitter is connected to another output 2A of the first DC power supply 2A.
2 is a first auxiliary IGBT for short-circuiting connected to the second auxiliary IGBT. A short-circuit second terminal 10B has a collector connected to a connection point D between the second reactor 4B and the other second backflow prevention diode 6B, and an emitter connected to another output 2B2 of the second DC power supply 2B. This is an auxiliary IGBT. Reference numeral 12 denotes a load of the object to be plated. A control device 22 outputs control signals to the main IGBTs 8A and 8B and the auxiliary IGBTs 10A and 10B.

Further, the main IGBTs 8A and 8B and the auxiliary I
Snubber circuits 16A, 16B and 18A, 18B are provided between collectors and emitters of GBTs 10A, 10B, respectively.
Is connected. These snubber circuits 16A, 16B,
18A and 18B are, for example, diodes 16Ac and 16B
c, 18Ac, 18Bc and capacitors 16Aa, 16B
a, a series circuit of 18Aa and 18Ba, and a capacitor 1
6Aa, 16Ba, 18Aa, 18Ba
6Ab, 16Bb, 18Ab, and 18Bb are provided.

Further, at both ends of the auxiliary IGBTs 10A and 10B, there are provided first and second voltage detectors 24A and 24B for detecting voltages at both ends, respectively.
The detection signals detected by A and 24B are input to first and second comparators 26A and 26B, respectively. First and second comparators 2
6A and 26B compare the detection signal with a built-in reference value, and output an output signal to the control device 22 when the detection signal becomes higher than the reference value.

FIG. 2 is a waveform diagram of each part. FIG. 2A shows a waveform of a current flowing through the load 12, and FIGS. 2B to 2E.
Are the first main IGBT 8A and the first auxiliary IGBT 10 respectively.
A, gate signal waveforms of the second main IGBT 8B and the second auxiliary IGBT 10B are shown. Now, before the time t1 shown in FIG. 2, the gate signal shown in FIG. 2D is input to the second main IGBT 8B, and the second DC power supply 2B, the second reactor 4B, the second diode 6B, the second main IGBT 8B A current shown in FIG. 2A, for example, a positive current flows through the load via the IGBT 8B and the load 12. From these, the plating is interrupted or dissolved.

Before the time t1, the first auxiliary IG
The gate signal is input to the BT 10A as shown in FIG. 2C, and the first DC power supply 2A, the first reactor 4A,
A current flows through the first auxiliary IGBT 10A and the first DC power supply 2A, and energy is stored in the first reactor 4A.

Then, at time t1, the second main IGB
At T8B, the gate signal of the first auxiliary IGBT 10A is turned off, and the gate signal is input to the first main IGBT 8A as shown in FIG. When a gate signal is input to the first main IGBT 8A, the first DC power supply 2A, the first reactor 4A, the first diode 6A, the first main IGBT 8A, the load 12, and the first DC power supply 2A are transmitted to the first DC power supply 2A as shown in FIG. )). At this time, the first DC power supply 2A
The current obtained by adding the output current of the first reactor 4A and the current flowing from the energy stored in the first reactor 4A is added to the load 12
Flows to Then, the current flowing through the load 12 rises sharply. Thereby, the object to be plated of the load 12 is plated.

On the other hand, at time t1, the second auxiliary IGBT 10B
Also, a gate signal is input as shown in FIG.
A current flows through the second DC power supply 2B, the second reactor 4B, the second auxiliary IGBT 10B, and the second DC power supply 2B.
Energy is stored in second reactor 4B.

Next, at time t2, the first main IGBT 8
A, the gate signal of the second auxiliary IGBT 10B is turned off, and the gate signal is input to the second main IGBT 8B as shown in FIG. When the gate signal is input to the main IGBT 8B, the second DC power supply 2B, the second reactor 4B, the second diode 6B, the second main IGBT 8B, the load 12, and the second DC power supply 2B are shown in FIG. Positive current flows. At this time, a current obtained by adding the output current of the second DC power supply device 2B and the current flowing by discharging the energy stored in the second reactor 4B flows to the load 12. Therefore, the current flowing through the load 12 is rapidly discharged. As a result, the plating is interrupted or dissolved.

On the other hand, at time t2, the first auxiliary IGBT 10A
The gate signal is also input as shown in FIG.
DC power supply 2A, first reactor 4A, first auxiliary IG
A current flows through the BT 10A and the first DC power supply 2A, and energy is stored in the reactor 4A.

The above operation is sequentially repeated. First main IGBT8A
By switching between the second main IGBT 8B and the second auxiliary IGBT 10B at a high speed, and switching between the second auxiliary IGBT 10B and the first auxiliary IGBT 10A at a high speed, it is possible to obtain a plating power supply device capable of reversing the current at a high speed.

If the time during which the negative current for plating flows is T1 and the period during which the positive current for interrupting or melting the plating flows is T2, the inversion ratio of T2 / (T1 + T2) controls the controller 22. This is done by: , Lord I
This can be performed by changing the periods of the gate signals of the GBTs 8A and 8B and the auxiliary IGBTs 10A and 10B. Further, although not shown, the magnitude of the current flowing through the load 12 can be detected by detecting the current flowing through the load 12 and controlling the control device 22 according to the detection signal.

Next, the second DC power supply 2B, the second reactor 4B, the second reactor 6B, the second main IGBT 8B,
At time t5 in FIG. 2 in which current flows through the load 12, when contact between the plating object of the load 12 and a power supply unit such as a hanger becomes impossible, the energy of the second reactor 4B causes the second auxiliary IGBT 10B. High voltage is generated at both ends. This high voltage is supplied to the second voltage detector 24B.
And a comparator 26B compares it with a reference value.
When the detection signal is higher than the reference value, the gate signal of the second main IGBT 8B is turned off as shown in FIG.
The gate signal of the second auxiliary IGBT 10B is turned on as shown in FIG. Thereby, the energy stored in second reactor 4B is recovered to DC power supply device 2B via second auxiliary IGBT 10B. No high voltage is applied to the second auxiliary IGBT 10B, and the second auxiliary IGBT 10B is protected.

FIG. 2 shows the first auxiliary IGBT 10A.
The gate signal is continuously turned on as shown in FIG.
Further, the energy of the second reactor 4B is changed to the second auxiliary IG.
After being recovered by the second DC power supply 2B via the BT 10B, the control device 22 outputs an off command signal to the DC power supplies 2B and 2A, and turns off both the DC power supplies 2B and 2A. Thereby, the first and second reactors 4A,
4B and the first and second auxiliary IGBTs 10A and 10B, no current flows and the first and second auxiliary IGBTs 10A and 10B
0B is protected. Further, the display device 28 is connected to the load 12.
To show the release. As a result, the operator checks the contact state of the load and shifts the load to a normal state. Reference numeral 30 denotes a reset switch which is used at the time of restart.

In the above embodiment, when the load is released, the auxiliary IGBT is turned on, and the energy of the second reactor 4B is transferred to the second DC power supply 2B via the second auxiliary IGBT 10B.
After being recovered at the DC power supply,
After the auxiliary IGBT is short-circuited, the auxiliary IGBT may be opened again after a predetermined time to allow a current to flow through the load. Then, when the load returns from the open state to the short circuit state, the high-speed current reversal plating power supply device can be normally operated. Also, when the voltage detector operates again, a command is issued from the control device 24 to turn on the auxiliary IGBT, so that the DC power supply device can be shut off.

In the above embodiment, the second main IGBT
While the ON operation of the second auxiliary IGBT during the period when is turned on is described, the first auxiliary IGBT can be turned on when the load is released during the period when the first main IGBT is on. Further, another switching element such as an FET or a bipolar transistor can be used instead of the IGBT.

[0040]

According to the present invention, when the load is released, an excessive voltage tends to be generated in the first or second auxiliary switching element which is turned off by the energy stored in the reactor. 2 Detected by voltage detector,
When the detection voltage becomes equal to or higher than the predetermined voltage, the first or second auxiliary switching element is turned on, and no high voltage is applied to the first or second auxiliary switching element. For this reason, it is not necessary to adopt a snubber circuit provided in parallel with the first or second auxiliary switching having a capacity corresponding to a high voltage due to the energy stored in the reactor as in the related art.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a power supply device for high-speed current reversal plating of the present invention.

FIG. 2 is a waveform chart of each unit in FIG. 1;

FIG. 3 is a block diagram of a conventional power supply device for high-speed current reversal plating.

FIG. 4 is a waveform chart of each part in FIG. 3;

[Explanation of symbols]

 2A (first) DC power supply 2B (second) DC power supply 4A (first) reactor 4B (second) reactor 6A, 6B diode 8A (first) main switching element (IGBT) 8B (second) main switching Element (IGBT) 10A (First) Auxiliary switching element (IGBT) 10B (Second) Auxiliary switching element (IGBT) 12 Load (plated object) 16A, 16B, 18A, 18B Snubber circuit 22 Controller 24A, 24B Voltage detection 26A, 26B Comparator 28 Display

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H410 BB05 CC02 DD02 EA10 EA38 EB01 FF03 FF23 LL03 LL19 5H420 BB13 CC02 DD02 EA11 EA39 EA48 EB01 EB12 EB37 FF03 LL02 NB03 NB12 NB18 NB20 NB32 BB37 BB37 BB37 BB37 DD41 FD26 FG01 FG16 XX04 XX12 XX26 XX32

Claims (2)

[Claims] A first DC power supply; a second DC power supply; one output terminal of the first DC power supply;
A first reactor provided between the other output terminal of the DC power supply device and one end of the load;
A series circuit with a main switching element, a second reactor provided between one output terminal of the second DC power supply, the other output terminal of the first DC power supply, and the other end of the load; A series circuit of a second main switching element that turns off and on in response to the on and off of the first main switching element, and a series circuit between the output of the first reactor and the other output terminal of the first DC power supply device A second auxiliary switching element that turns off and on in response to the on and off of the first main switching element; and a second auxiliary switching element between the output of the second reactor and the other output terminal of the second DC power supply. A second auxiliary switching element that turns off and on in response to the on and off of the main switching element, a first or second voltage detector that detects both ends of the first or second auxiliary switching element, respectively, 2 the voltage detector of the detection signal is high-speed current reversal plating power source device configured by a control device for turning on the first or the second auxiliary switching element when less than a predetermined voltage. 2. The control device according to claim 1, wherein the control device turns on the first or second auxiliary switching element when a detection signal of the first or second voltage detector is equal to or higher than a predetermined voltage, and controls the first and second DC. 2. The power supply device for high-speed current reversal plating according to claim 1, wherein the power supply device is a control device that issues an instruction to turn off the power supply device.