JP2694500B2 - Power supply for arc welding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for arc welding, and in particular, rectifies and smoothes a commercial power supply voltage to generate a direct current voltage, and the direct current voltage has a frequency higher than that of the commercial power supply voltage by an inverter. The present invention relates to a converter-type power source for arc welding that converts the voltage into an AC voltage and outputs the AC voltage.

[0002]

2. Description of the Related Art A converter-type power source for arc welding uses a commercial alternating voltage of 60 Hz or 50 Hz for 20 k.
It is converted into an AC voltage having a high frequency of Hz to 50 kHz and outputted, and the transformer and the reactor are remarkably downsized as compared with the case where a commercial AC power supply voltage is used, and the power source apparatus for arc welding is downsized.

For example, FIG. 3 is a schematic circuit diagram of a main part of a conventionally used converter type power source for arc welding, in which a three-phase commercial power source voltage supplied to an input terminal 51 is rectified by a rectifier circuit 52. , And is smoothed by the capacitor 53 to generate a DC voltage. This DC voltage is supplied to the switching type inverter 50 by, for example, 20 kHz to 50 k
Converted to AC voltage of Hz. The output of the inverter 50 is transformed by the transformer 67, rectified by the rectifier 68 after the transformation, and the output is output to the output terminal 69.

The inverter 50 is an IBG connected in series.
A first switching circuit 54 composed of T56 and 57;
Second, which is also composed of IGBTs 58 and 59 connected in series
And the switching circuit 55. A drive signal from the drive device 60 is input to the control terminals of the switching elements 56 to 59, and the switching circuit operates in response to the drive signal.

The switching circuit 54 which constitutes the inverter 50 includes the IGBTs 56,
57 is configured as a first module in a state where it is insulated from the package substrate, and similarly, the switching circuit 55 is configured as a second module in a package in which the IGBTs 58 and 59 are insulated from the package substrate. Has been done.

The drive device 60 includes drive circuits 61 to 64 for outputting drive signals to the IGBTs 56 to 59, and drive circuits 6 respectively.
A control circuit 65 for controlling 1 to 64 is provided. Each drive circuit is composed of an insulating pulse transformer and electronic circuits such as resistors, capacitors, diodes, and ICs. Further, in this drive device, drive circuits 61 to 64 and a control circuit 65 are mounted on one printed circuit board. Although the commercial power source is shown as a three-phase power source in FIG. 3, a single-phase commercial power source may be used. Also,
As the IGBT for the switching circuit which constitutes the inverter, a MOSFET or a bipolar transistor may be used in addition to the illustrated IGBT. Further, in the arc welding power supply device of FIG. 3, a rectifier 68 is provided on the output side to be used as a DC power supply device, but it may be used as an AC power supply device except for the rectifier 68.

[0007]

In the conventional arc welding power source device of FIG. 3, the switching circuits 54 and 55 and the driving device 60 are separately arranged. Therefore, the drive circuit 61
~ 64 and the wiring between the IGBT56 ~ 59,
The high frequency noise is easily received, and the IGBTs 56 to 59 often malfunction. Therefore, the drive device 60 is wired near the switching circuits 54 and 55, and a special electric wire such as a coaxial wire or a twisted wire is used. Further, since the switching circuits 54 and 55 and the driving device 6 are separately arranged,
The space occupied by the power supply is large, and there is a limit to downsizing the power supply.

[0008]

According to the present invention, there is provided a rectifying circuit and a smoothing capacitor for rectifying and smoothing a commercial power supply voltage to generate a DC voltage, and a DC voltage having a frequency higher than the commercial power supply frequency. An inverter that converts to AC voltage,
A power semiconductor chip that comprises the drive circuit that drives the inverter, and control components that form the drive circuit are placed on a copper circuit in which one side of the upper surface of a metal substrate having an insulating layer is laminated. It is fixed, the semiconductor chip and the control component are covered with a resin case, and the inside of the case is sealed with resin.

A rectifying circuit and a smoothing capacitor for rectifying and smoothing a commercial power supply voltage to generate a DC voltage, an inverter for converting the DC voltage into an AC voltage having a frequency higher than the commercial power supply frequency, and the inverter. The power semiconductor chip that constitutes the above inverter is mounted and fixed on the copper circuit laminated on one side of the upper surface of the metal substrate having the insulating layer, and the control components that constitute the above drive circuit are printed. It is fixed to a substrate and arranged on the metal substrate, the semiconductor chip and the control component are covered with a resin case, and the case is sealed with resin.

[0010]

According to the present invention, a power semiconductor chip that constitutes an inverter and a control component that constitutes a drive circuit are mounted and fixed on a copper circuit laminated on one side of an upper surface of a metal substrate having an insulating layer. Therefore, the distance between the switching circuit and the driving circuit can be designed to be short. Further, since it is mounted on one metal substrate, the size can be reduced.

Further, a power semiconductor chip forming an inverter is mounted and fixed on a copper circuit laminated on one side of an upper surface of a metal substrate having an insulating layer, and a control component forming the drive circuit is fixed on a printed circuit board. The semiconductor chip and the control component are covered with a resin case, and the inside of the case is resin-sealed, so that the power semiconductor chip is mounted on the copper circuit. Fixing and control parts can be fixed to the printed circuit board separately.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a converter-type power source for arc welding according to the present invention, which is electrically the same as the conventional power source device shown in FIG. 3 and uses a three-phase commercial power source voltage supplied to an input terminal 1. IGBTs that are rectified by the rectifier circuit 2 and smoothed by the capacitor 3 to generate a DC voltage, and the DC voltage is connected in series.
20 kHz to 50 kHz by an inverter composed of a second switch circuit 5 composed of IGBTs 8 and 9 connected in series with a first switch circuit 4 composed of 6, 7
Convert to a high frequency alternating voltage of kHz. The output of the inverter is transformed by the transformer 17, after being transformed, it is rectified by the rectifier 18, and the output is output to the output terminal 19. The input AC power supply may be a single-phase commercial AC power supply, and the IGBTs forming the switching circuits 4 and 5 are MOSFETs.
Alternatively, a bipolar transistor may be used. Further, when outputting alternating current, the rectifier 18 on the output side may be omitted.

The drive device 10 includes drive circuits 11 to 14 for outputting drive signals to the IGBTs 6 to 9 and drive circuits 11 respectively.
A control circuit 15 is provided to control ~ 14.

Then, the IGBTs 6 to 9 and the drive unit 10
Are placed on a metal substrate having an insulating layer as shown in FIG. That is, 21 is aluminum having an insulating layer,
A metal substrate such as copper or iron, a copper circuit is laminated on one surface of the metal substrate, and power semiconductor chips 22 to 25 such as IGBTs constituting an inverter circuit on the copper circuit;
Pulse transformers 26 to 29 constituting a drive circuit and electronic components 30 such as resistors, capacitors, ICs and diodes 30 to
40 control parts are mounted, surface-mounted and fixed. Then, the resin case 41 is placed on the peripheral edge or in the vicinity thereof, and the protective resin is filled in the case and cured by heating to form the protective resin layer. Note that 42 to 45 are terminals for external connection.

In the present invention, since the switching circuit and the driving circuit are arranged on the same metal substrate, high frequency noise is not received. In addition, since the switching circuit and the driving circuit are mounted on the same metal substrate at the chip and control component level, the switching circuit is modularized and the driving circuit is smaller than the conventional one.

In the above embodiment, the inverter circuit is applied to the full bridge type inverter, but it goes without saying that it can also be applied to the half bridge type inverter and the pro-shupple type inverter.

Further, in the above embodiment, the power semiconductor chip and the control component are directly surface-mounted on the same metal substrate. However, all or part of the control component is arranged on the printed circuit board, and this printed circuit board is used. The protective resin layer may be formed by disposing the resin case 41 on the metal substrate, placing the resin case 41 on the periphery of the metal substrate or in the vicinity thereof, filling the case with the protective resin up to the upper portion of the printed board, and heating and curing. . further,
Although the control components of the drive device are mounted on the metal substrate, the control components required for constant voltage control, constant current control, and other controls can also be mounted on the metal substrate.

[0018]

As described above, according to the present invention,
Since the power semiconductor chips that make up the switching circuit and the control components of the drive circuit are mounted on the same metal substrate, there is no high-frequency noise and the switching circuit does not malfunction and the coaxial line and There is no need to use special electric wires such as twisted wires. Further, the size of the power source device for arc welding can be reduced as compared with the conventional configuration in which the switching circuits are individually modularized and the drive circuits are arranged on the printed circuit board. Furthermore, when mounting control components on the printed circuit board, mounting and fixing the power semiconductor chip on the copper circuit and fixing the control components to the printed circuit board can be performed separately, and the temperature during soldering of the control components can be controlled. Can be lowered, and damage to control parts can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic circuit diagram of a main part showing an embodiment of a power supply device for arc welding of the present invention.

FIG. 2 is a schematic layout view of a module used in the arc welding power supply device of the present invention.

FIG. 3 is a schematic circuit diagram of a main part showing an embodiment of a conventional arc welding power supply device.

[Explanation of symbols]

 2 Rectifier circuit 4,5 Inverter circuit 6-9 IGBT 10 Drive device 11-14 Drive circuit 15 Control circuit 21 Metal substrate 22-25 Power semiconductor chip 26-29 Pulse transformer 30-40 Electronic component 41 Resin case

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toyoji Yasuda 2-14-3 Awaji, Higashiyodogawa-ku, Osaka-shi, Osaka Makoto Yagi, Inspector, Sansha Electric Manufacturing Co., Ltd. (56) Reference JP-A-5-291783 (JP, A) Actually open Sho 63-43494 (JP, U)

Claims (2)

(57) [Claims] 1. A rectifying circuit and a smoothing capacitor for rectifying and smoothing a commercial power supply voltage to generate a DC voltage, and an inverter for converting the DC voltage into an AC voltage having a frequency higher than the commercial power supply frequency. A power semiconductor chip that comprises the drive circuit that drives the inverter, and control components that form the drive circuit are placed on a copper circuit in which one side of the upper surface of a metal substrate having an insulating layer is laminated. An arc welding power supply device which is fixed, covers the semiconductor chip and the control component with a resin case, and seals the inside of the case with a resin. 2. A rectifying circuit and a smoothing capacitor for rectifying and smoothing a commercial power supply voltage to generate a DC voltage, and an inverter for converting the DC voltage into an AC voltage having a frequency higher than the commercial power supply frequency. A control component which comprises a drive circuit which drives the inverter, and which mounts and fixes a power semiconductor chip which constitutes the inverter on a copper circuit laminated on one side of an upper surface of a metal substrate having an insulating layer to constitute the drive circuit. Is fixed to a printed circuit board and is arranged on the upper part of the metal substrate, and further, the semiconductor chip and the control component are covered with a resin case, and the inside of the case is sealed with resin.