JP2001211661A - Automotive inverter gate power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve vibration-resistant properties of a transformer mounted on a board of an automotive inverter gate power supply, and relieve stresses of soldered parts where lead wires are soldered to the board. SOLUTION: A thin-type transformer is used as the transformer of this inverter gate power supply, and the center of gravity of the transformer is lowered to improve vibration-resistant properties. Further, bent parts 11 are formed in lead wires 10 to relieve stresses.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-vehicle inverter for driving and controlling an electric motor, etc.
The present invention relates to a configuration of a gate power supply for driving an inverter switching element such as an OSFET.

[0002]

2. Description of the Related Art In-vehicle inverters have a function of converting DC from a battery into AC for driving a motor. 6 and 7 show a conventional example of an inverter gate power supply mounted on an inverter for a traveling motor of an EV or HEV. The configuration of the inverter gate power supply will be described with reference to FIG. A multi-output RCC converter uses a general-purpose multi-pin transformer from a 12V battery to obtain a total of four power supplies: three power supplies for the U / V / W phase upper arm and a lower arm power supply common to the U / V / W phase. In FIG. 7, the inverter gate power supply includes an input-side smoothing capacitor 1, a switching element 2, a radiating land 3 for radiating heat from the switching element, a control IC 4, a general-purpose transformer 15, a rectifier diode 6, and an output-side smoothing capacitor 7.

The structure of the general-purpose transformer 15 will be described with reference to FIG. A winding 16 such as a polyurethane wire is wound around a bobbin 17, and a pair of cores 9 sandwich the bobbin 17. When mounting the general-purpose transformer 15 on the board 12, the pins (lead wires) 18 are
Getter 19 soldered to 3 and provided on bobbin 17
Alternatively, the core 9 contacts the surface of the substrate 12 and the general-purpose transformer 1
5 is supported.

A vehicle inverter gate power supply having such a structure requires a transformer having a large number of pins because it is a multi-output power supply. However, a general-purpose transformer 15 used in a conventional vehicle inverter gate power supply has the following problems. It was a large, tall transformer, and the location of the center of gravity was high, so if it was installed in a location where severe vibrations were applied, such as in a vehicle environment, the possibility of flying was high.

Further, in the conventional general-purpose transformer 15, the getter 19 or the core 9 provided on the bobbin 17 is in direct contact with the surface of the substrate 2. Due to the different expansion rates, there is a high possibility that solder cracks will occur in the through holes 13 soldered to the pins (lead wires) 18 under an extremely severe temperature cycle environment such as an engine room.

[0006]

In the conventional inverter gate power supply for a vehicle as described above, the general-purpose transformer is a tall and large-sized one, which may be damaged by vibration, and may be installed in direct contact with the substrate. Therefore, there is a problem that cracks occur at the soldered portions of the pins (lead wires) due to the stress due to the difference in the thermal expansion coefficient of the constituent materials.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a first object of the present invention is to adopt a thin transformer having a low center of gravity as a transformer, thereby improving the vibration resistance of a vehicle. It is intended to provide an inverter gate power supply. A second object of the present invention is to provide a bent portion in the lead wire to absorb stress at this location and prevent a crack from occurring at a soldered portion between the substrate and the lead wire.
A third object is to provide a shock absorbing sheet between the thin transformer and the substrate, and to provide a hole in the substrate to partially embed the thin transformer so as to improve stress absorption and vibration resistance. It is to provide an inverter gate power supply.

[0008]

An inverter gate power supply for a vehicle according to the present invention has a thin transformer including a core, a printed coil, and a lead wire installed on a board, and the lead wire is connected to the board. Is what it is.

Further, the lead wire has a bent portion.

[0010] Further, the thin transformer is provided via an impact absorbing sheet provided on the substrate.

Further, the core of the thin transformer is partially buried in an opening provided in the substrate.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, the vehicle inverter gate power supply comprises an input-side smoothing capacitor 1, a switching element 2, a heat-dissipating land 3 for radiating heat from the switching element, a control IC 4, a thin transformer 5, a rectifier diode 6, and an output-side smoothing capacitor 7. ing. FIG. 2 shows a mounting state of the thin transformer 5 on the substrate 12. The core 9 is in direct contact with the substrate 12 to support the thin transformer 5. The lead wire 10 is soldered to a through hole 13 of the substrate 12. Printed coil 8 composed of a multi-layer substrate or a laminated single-layer substrate
Since a structure is employed in which the lead wire 10 is drawn out in multiple directions (in the example of FIG. 1, four directions), the thickness and size of the transformer can be reduced. Therefore, even if it is installed on the substrate 12, the position of the center of gravity is low, and there is no possibility that the transformer will be damaged even in an environment where vibration conditions are extremely severe, such as in a vehicle environment.

Embodiment 2 FIG. FIG. 3 shows the second embodiment. In FIG. 3, a bent portion 11 is provided on a lead wire 10. The lead wire 10 having the bent portion 11 is
And the thermal expansion of the lead wire 10 is different,
And a structure in which stress is not applied to the soldered portion of the through hole 13 of the substrate 12. For this reason, even in an environment where the temperature cycle is severe such as an engine room, there is little possibility that cracks occur in the soldered portion of the through hole 13. Further, vibration can be absorbed by the bent portion 11 and vibration resistance can be improved.

Embodiment 3 FIG. 4 shows the third embodiment. In FIG. 4, the core 9 of the thin transformer 5 is
It is installed via the shock absorbing sheet 14 provided above. The impact absorbing sheet 14 is preferably a heat-dissipating silicon sheet having good thermal conductivity. A vehicle inverter gate power supply employing such a structure is composed of a core and a lead wire 1.
Even if there is a difference in the thermal expansion of 0, the shock absorbing sheet 14 reduces the stress applied to the soldered portion of the through hole 13 and prevents the occurrence of cracks in the soldered portion. Also,
By using a material having good thermal conductivity for the shock absorbing sheet 14, heat generated from the core 9 can be released to the substrate 12 via the shock absorbing sheet 14, and the core 9 can be reduced in size, and furthermore, like an engine room. It can be used without problems even in a high temperature environment. Further, the shock absorbing sheet 14
The core 9 and the substrate 12 are adhered to each other using a double-sided seal, whereby the vibration resistance can be further improved. FIG.
Although the lead wire 10 has no bent portion,
It is needless to say that the provision of the bent portion 11 as shown in FIG. 3 further reduces stress and vibration.

Embodiment 4 FIG. 5 shows the fourth embodiment. In FIG. 5, a core 9 which is a part of the thin transformer 5 is shown.
Are partially submerged in an opening 20 provided in the substrate 12, and the printed coil 8 is in contact with the shock absorbing sheet 14 provided on the substrate 12 to support the thin transformer 5. In a vehicle inverter gate power supply employing such a structure, even if there is a difference in thermal expansion between the printed coil 8 and the lead wire 10, the shock absorbing sheet 14 reduces the stress of the soldered portion of the through hole 13, To prevent the occurrence of cracks. Further, by bonding the core 9 and the substrate 12 to the shock absorbing sheet 14 using a double-sided seal, the vibration resistance can be further improved. In the fourth embodiment, as shown in FIG.
It is needless to say that the stress and the vibration are further alleviated by providing the above. Further, by using a material having good heat conductivity for the shock absorbing sheet 14, heat generated by the printed coil 8 can be released to the substrate 12 through the shock absorbing sheet 14, so that the printed coil 8 can be downsized. Further, since a part of the thin transformer 5 is buried in the opening 20 of the substrate 12, it is possible to reduce the overall height of the inverter gate power supply device for a vehicle, and to make the device compact and vibration resistant. Can be dramatically improved.

[0016]

Since the present invention is configured as described above, it has the following effects.

Since the thin transformer is mounted on the substrate, the position of the center of gravity is low, and the vibration applied to the in-vehicle inverter gate power supply does not cause the thin transformer to fly, thereby improving the vibration resistance.

Further, since the printed coil lead wire has a bent portion, it is possible to alleviate the stress of the soldering portion of the connection portion with the substrate due to a difference in thermal expansion in a severe temperature cycle, thereby preventing the occurrence of cracks. it can.

Furthermore, since the thin transformer is mounted on the substrate via the shock absorbing sheet, even if a difference in thermal expansion occurs between the core and the lead wire, it is possible to prevent the occurrence of cracks in the soldered portion, and furthermore, to generate heat from the core. Is transmitted to the substrate via the shock absorbing sheet, so that the core can be reduced in size, and the vibration resistance is improved.

Further, since the thin transformer is partially buried in the opening of the substrate, there is an effect that the overall height is reduced and the vibration resistance is improved.

[Brief description of the drawings]

FIG. 1 is a layout diagram showing a first embodiment of the present invention.

FIG. 2 is a thin transformer mounting diagram showing the first embodiment of the present invention.

FIG. 3 is a thin transformer mounting diagram showing a second embodiment of the present invention.

FIG. 4 is a thin transformer mounting diagram showing a third embodiment of the present invention.

FIG. 5 is a thin transformer mounting diagram showing a fourth embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of an inverter gate power supply.

FIG. 7 is a layout diagram of a conventional vehicle inverter gate power supply.

FIG. 8 is a structural diagram showing a conventional general-purpose transformer.

[Explanation of symbols]

1 input side smoothing capacitor, 2 switching element, 3
Heat radiation land, 4 control IC, 5 thin transformer, 6
Rectifier diode, 7 output side smoothing capacitor, 8 printed coil, 9 core, 10 lead wire, 11 bent part, 12 board, 13 through hole, 14 shock absorbing sheet, 15 general transformer, 16 winding, 17 bobbin, 18 pin ( Lead wire), 19 getters, 20 holes.

Claims (4)

[Claims] 1. An in-vehicle inverter gate power supply,
A thin-film transformer comprising a core, a print coil, and a lead wire provided on the print coil is mounted on a substrate, and the lead wire is connected to the substrate. Gate power. 2. The in-vehicle inverter gate power supply according to claim 1, wherein the lead wire has a bent portion. 3. The on-vehicle inverter gate power supply according to claim 1, wherein the thin transformer is provided via an impact absorbing sheet provided on the substrate. 4. The in-vehicle inverter gate power supply according to claim 1, wherein the thin transformer is partially buried in an opening formed in the substrate.