JP3544307B2 - Electronic circuit device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electronic circuit device on which a large heat generating component is mounted.
[0002]
[Prior art]
A voltage conversion type power conversion device having a transformer for charging a battery from a commercial AC power supply or the like is used for an electric vehicle or the like.
This voltage conversion type power conversion device includes a transformer for converting an AC voltage into a voltage, one or more semiconductor rectifiers for rectifying the AC voltage converted by the transformer, and a ripple from the DC voltage rectified by the semiconductor rectifier. A smoothing coil and a smoothing capacitor for removing components are provided.
[0003]
[Problems to be solved by the invention]
However, in an electric vehicle, the weight and space must be allocated to the battery, so that the weight and space allowed for the power conversion device with a built-in transformer must be reduced as much as possible.
To reduce the weight and space of a power converter with a built-in transformer, the size and weight of the transformer must be significantly larger than other components, and the transformer can be used up to the allowable temperature of the resin for electrical insulation. Most effective. In particular, the power conversion device used for the DC-DC converter for performing power transmission between the main battery and the auxiliary battery has a short usage time per time of about several minutes, so that the power transmission efficiency is slightly reduced. Since there is no problem, it is possible to reduce the size of the transformer to achieve the required size and weight reduction of the power converter.
[0004]
However, an increase in heat generation due to the downsizing of the transformer causes a problem that a temperature of a rectifier semiconductor rectifier connected to a secondary coil of the transformer is significantly increased. That is, the rectifier semiconductor rectifier is close to the transformer secondary coil in order to reduce the volume of the power converter and reduce the power loss due to the resistance of the wiring between the transformer secondary coil and the rectifier semiconductor rectifier. As a result, in addition to the heat generated by itself, the temperature rises more than expected due to heat transfer from the high-temperature transformer through the wiring, and furthermore, radiation and convection from the outer surface of the transformer. In order to reduce the heat transfer from the outer surface of the transformer to the semiconductor rectifier, it is effective to separate them from each other. However, in this case, there arises a problem that the size of the power converter increases.
[0005]
This type of problem, that is, heat transmitted by radiation from a large heat-generating component such as the above-described transformer, for example, adversely affects low-temperature-use type circuit components such as a diode module, particularly semiconductor components, which are close to the large heat-generating component. The problem is a problem that is inevitably caused in a power electronic circuit device when the density of the electronic circuit device is increased, and this problem has limited the size reduction of the device.
[0006]
On the other hand, if a special cooling method such as a water cooling device is added, the above problem can be solved and the circuit mounting density can be improved, but in this case, the volume and weight of the cooling device such as the water cooling device increase. This leads to a new problem that the device configuration becomes complicated.
In particular, in electronic circuit devices designed for high-density mounting, it is common to stack a plurality of circuit boards in parallel with each other in order to reduce the projection area. The above problem is further exacerbated because the escape of heat in the surrounding area tends to be poor.
[0007]
The present invention has been made in view of the above problems, and has as its object to provide an electronic circuit device capable of high-density mounting without increasing the physical size and weight of the device.
[0012]
[Means for Solving the Problems]
According to the electronic circuit device of the first aspect, the busbar is located between the large heat-generating component and the low-temperature-use type circuit component and is wider than other parts. It is designed to cover low-temperature circuit components from large heat-generating components in order to block the heat radiated from the components from being irradiated to low-temperature circuit components. life is realized is to be a Ku high density mounting reduce reliability. Further, the above-described partial widening of the bus bar does not require additional members, compared with a case where a simple heat shielding member is interposed between the large heat-generating component and the low-temperature-use type circuit component, and the bus bar has a small size. The effect of reducing the electric resistance to reduce the heat generation can also be obtained .
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Preferred embodiments of a charging device for a hybrid vehicle to which the electronic circuit device of the present invention is applied will be described with reference to the following embodiments.
[0014]
Embodiment 1
As shown in FIG. 1, this charging device includes a low-voltage auxiliary battery 2, a DC / DC converter 6, a main battery 7, a control circuit 8, and a current sensor 10.
As shown in FIG. 2, the DC-DC converter 6 includes a pair of power MOSFETs 61 as an inverter circuit for converting input DC power into AC power, a transformer 62 for changing an output voltage of the power MOSFET 61, and a transformer 62. It has a full-wave rectifier circuit 63 for rectifying the output, and an output smoothing circuit 64 for smoothing the output voltage of the full-wave rectifier circuit 63. Further, in order to reduce voltage fluctuations caused by switching of the DC / DC converter 6, an input-side smoothing capacitor 5 connected between a pair of input terminals of the DC / DC converter 6 is provided.
[0015]
The pair of power MOSFETs 61 are composed of power MOS transistors whose diodes are connected in anti-parallel with each other and are alternately turned on and off. The alternating voltage generated on the secondary side of the transformer 62 due to the alternating reverse phase of the power MOS transistors 61 is rectified by the full-wave rectifier circuit 63 and smoothed by the choke coil 65 and the smoothing capacitor 66 constituting the output smoothing circuit 64. Applied to the main battery 7.
[0016]
The full-wave rectifier circuit 63 includes four diode modules D connected in a bridge. The above-described transformer 62, full-wave rectifier circuit 63, choke coil 65, and smoothing capacitor 66 constitute a power conversion device according to the present invention.
(Arrangement of power converter)
An example of the arrangement of the above-described power conversion device, which characterizes this embodiment, will be described below with reference to FIGS. 3 is a perspective view of the charging device shown in FIG. 1, FIG. 4 is a side view, and FIG. 5 is a developed view of the circuit boards 101 and 104.
[0017]
Reference numeral 100 denotes a metal plate, 101 denotes a first circuit board provided in parallel on the upper surface of the metal plate 100 at a predetermined interval and fixed to a plurality of metal protrusions 100a, and includes a transformer 62, a full-wave rectifier circuit 63, and a choke. The coil 65 and the smoothing capacitor 66 are fixed on the circuit board 101. Reference numeral 104 denotes a second circuit board which is fastened to an upper portion of a support wall 100 b erected from one edge of the metal plate 100 and extends in parallel with the circuit board 101.
[0018]
The four diode modules D constituting the full-wave rectifier circuit 63 are mounted on one surface of an upright circuit board 103 erected on the circuit board 101, and this one surface of the upright circuit board 103 is It has a posture perpendicular to the side surface and perpendicular to the circuit board 101. Also, the widest surface of the diode module D is parallel to the one surface of the upright circuit board 103.
[0019]
With this configuration, since the main surface of the upright circuit board 103 and the widest top surface of the diode module D do not face the side surface of the transformer 62, less radiant heat is received from the transformer 62, and the temperature of the diode module D is thereby reduced. Ascent can be prevented.
A pair of power MOSFETs 61 is provided on the surface of the support wall portion 100b facing the transformer 62.
[0020]
The power MOSFET 61 is housed in a metal container, and its gate electrode and drain electrode are individually connected to a plurality of external extraction terminals provided on the surface of the metal container while being electrically insulated. The terminal is connected to a bus bar (not shown). The source electrode of the power MOSFET 61 is grounded to the support wall 100b through the metal container.
[0021]
In this embodiment, in particular, the bus bar B is provided between one side surface of the transformer 62 and the power MOSFET 61 by a length sufficient to cover the power MOSFET 61 in parallel with the support wall 100b and the opposite side surface of the transformer 62. I have. Further, the width (length in the direction perpendicular to the circuit board (mounting board) 101) of the bus bar B is set wider than other bus bars (not shown). Enlarged enough to cover.
[0022]
In this way, (cold-use circuit components referred to in the present invention) is blocked power -MOSFET thermally This bus bar - B emitted from 62 (large heat-generating component in the present invention) transformer a high temperature 61 Is not irradiated. Further, the air heated on the surface of the transformer 62 convectively moves and hardly contacts the surface of the power MOSFET 61.
[0023]
For this reason, even though the power MOSFET 61 is disposed close to the side surface of the high-temperature transformer 62, overheating of the power MOSFETs 42 and 61 can be prevented, and high-density mounting can be realized while ensuring reliability. it can.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a charging device using an electronic circuit device of the present invention used in Embodiment 1.
FIG. 2 is a circuit diagram of a DC-DC converter of the charging device shown in FIG.
FIG. 3 is a perspective view of the charging device shown in FIG.
FIG. 4 is a side view of the charging device shown in FIG.
5 is a development view of a circuit board of the charging device shown in FIG .
[Explanation of symbols]
101, 103 circuit board (mounting substrate), 62 trans (large heat-generating component), 65 choke coil, 5 smoothing capacitor, B is bus bar over, the power matrix memory (cold-use circuit components 42,61 )

Claims (4)

In an electronic circuit device including a low-temperature use type circuit component whose maximum allowable temperature is equal to or lower than a predetermined value, and a large heat generation component having a higher temperature and a larger calorific value than the low-temperature use type circuit component,
It has a bus bar that is interposed between the both components, the bus bars, than said other portions positioned between both parts is wide Habaka, the orientation of the broadening of the bus bar, the large heat generation An electronic circuit device, which is oriented so as to cover the low-temperature-use circuit component from the large heat-generating component so as to block irradiation of heat radiated from the component to the low-temperature-use type circuit component . The electronic circuit device according to claim 1,
The electronic circuit device, wherein the widened portion of the bus bar has a length and a width sufficient to cover the predetermined low-temperature-use type circuit component from the large heat-generating component. The electronic circuit device according to claim 1,
The electronic circuit device, wherein the low-temperature-use circuit component is provided on a surface of the good heat conductive support wall provided in parallel with the bus bar on a side facing the large heat generating component. The electronic circuit device according to claim 1,
  An electronic circuit device, wherein the bus bar is wider than other bus bars and has a width sufficient to cover the low-temperature-use type circuit component from the large heat-generating component.

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