DE202021103259U1 - In-vehicle current transformer - Google Patents

Abstract

In-vehicle current transformer, comprising:
a heat sink;
a circuit board disposed on or above the heat sink;
a power semiconductor device mounted on or above the circuit board,
a control board support base which is disposed on and / or above the circuit board and which supports a control board; and
a heat transfer element that is disposed between the power semiconductor device and the control board support pedestal and provides a thermal connection between the power semiconductor device and the control board support pedestal.

Description

Technical area

The present disclosure relates to an in-vehicle power converter.

Technical background

Current converters (e.g. DC / DC converters, inverters and chargers) that are installed in electric vehicles and / or hybrid vehicles are known (see e.g. PTL 1).

It is known that with current converters of this type (typically inverters) during the acceleration drive and / or the uphill drive of vehicles, the power increases by about twice the power while driving at constant speed for a few dozen seconds and power semiconductor devices that form the current converters, generate heat quickly. Such overheating of power semiconductor devices leads to a deterioration in the properties of the devices and / or to damage to the devices, so that such overheating states of the power semiconductor devices must be avoided.

In order to cope with such instantaneous heat generation of a power semiconductor device, the improvement of the heat dissipation ability of a heat sink itself for absorbing the heat generated in the power semiconductor device has heretofore been discussed. However, in order to improve the heat dissipation ability of the heat sink itself, an enlargement of the heat sink or the use of a cooling medium having a high heat transfer ability is required, and a problem arises that increases the cost or the size of the power converters.

List of citations

Patent literature

Patent specification 1
Japanese Patent Laid-Open No. 2013-031250

Summary of the invention

Solution of the task

The present disclosure has been made in view of the above problem, and therefore aims to provide an in-vehicle power converter which is capable of coping with instantaneous heat generation of a power semiconductor device and which is simple in structure.

The present disclosure, which mainly solves the above problem, is directed to an in-vehicle power converter comprising: a heat sink; a printed circuit board arranged on or above the heat sink; a power semiconductor device mounted on or above the circuit board; a control board support base disposed on and / or above the circuit board and carrying a control board; and a heat transfer element that is disposed between the power semiconductor device and the control board support pedestal and provides a thermal connection between the power semiconductor device and the control board support pedestal.

Advantageous Effects of the Invention

An in-vehicle power converter according to the present disclosure is capable of coping with instantaneous heat generation of a power semiconductor device with a simple structure.

Figure list

• 1 Fig. 13 is a side view showing a structure of a power converter according to an embodiment;
• 2 Fig. 13 is an exploded perspective view showing the structure of the power converter according to the embodiment;
• 3 Fig. 13 is a block diagram of the power converter according to the embodiment; and
• 4th Fig. 13 is a diagram for describing the heat transfer paths in the power converter according to the embodiment.

Description of embodiments

A preferred embodiment of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that in this specification and the drawings, constituent elements having substantially the same function are denoted by the same reference numerals, and redundant descriptions thereof are omitted.

It should be noted that the following description is made by referring to the upward direction in the figures as “upward” and the downward direction in the figures as “downward” in order to clarify a positional relationship of the structural members. However, these directions are not intended to limit the positions of vehicle installed CTs at the time of use.

[Structure of a vehicle-internal current transformer]

The following describes an exemplary structure of an in-vehicle power converter (hereinafter abbreviated as “power converter”) according to the present embodiment. The current transformer 1 According to the present embodiment, for example, it is used in an in-vehicle inverter for outputting AC power to a motor that drives the vehicle.

1 Fig. 13 is a side view showing a structure of the power converter 1 according to the present embodiment. 2 Fig. 13 is an exploded perspective view showing the structure of the power converter 1 according to the present embodiment. It should be noted that in 1 the current transformer for the sake of simplicity 1 through a schematic representation of the actual current transformer 1 in 2 is drawn.

3 is a block diagram of the current transformer 1 according to the present embodiment.

The current transformer 1 includes the heat sink 10 who have favourited Circuit Board 20th , the power semiconductor devices 30th , the control board support base 40 , the control board 50 and the heat transfer elements 60 . It should be noted that the circuit board 20th , the power semiconductor device 30th , the control board support base 40 , the control board 50 and the heat transfer elements 60 housed in a housing (not shown) that is integral with the heat sink 10 is trained.

The heat sink 10 directs the in the circuit board 20th generated heat (ie, that from the power semiconductor devices 30th generated heat) to the outside of the current transformer 1 away. The heat sink 10 includes, for example, a base plate for supporting the circuit board 20th and heat dissipation fins extending downward from the base plate.

It should be noted that the heat sink 10 for example in one piece with a housing (not shown) of the current transformer 1 is formed, and the base plate serves as a wall surface of the housing. The current transformer 1 is then installed in such a position that the heat sink's heat dissipation fins 10 are positioned within a passage of the cooling medium (e.g. air cooling medium).

The circuit board 20th is a board containing a circuit (here an inverter circuit) for realizing the power conversion functions of the current converter 1 contains. With the circuit board 20th For example, it is a metal plate (e.g. aluminum plate), and a plate obtained by applying an insulating film (e.g. epoxy resin) to a base metal plate and then applying a wiring pattern to the insulating film is used will. Metal plates are useful in that they have favorable heat dissipation properties.

The power semiconductor devices 30th are each a semiconductor component for power conversion, which acts as a switching element in the circuit of the current transformer 1 serves. As a power semiconductor device 30th For example, a discrete component in the form of an insulated gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field effect transistor (MOSFET) is used. It should be noted that, despite the use of a discrete component as a power semiconductor device 30th here a module component, in which a large number of IGBTs or MOSFETs are accommodated in a single housing, as a power semiconductor device 30th can be used.

In the present embodiment, a three-phase bridge inverter having the following components is used as the inverter circuit as shown in FIG 3 shown is: smoothing capacitor 32 ; Power semiconductor devices 30th ( 30a and 30b ), which form a U-phase branch; Power semiconductor devices 30th ( 30c and 30d ), which form a V-phase branch; Power semiconductor devices 30th ( 30e and 30f ), which form a W-phase branch; and free wheeling diodes 31a until 31f (in 1 or 2 not shown), each in parallel with these power semiconductor devices 30th ( 30a until 30f ) are provided. More specifically, according to the present embodiment, there are six power semiconductor devices 30th (here MOSFETs) on the circuit board 20th assembled. The smoothing capacitor 32 and the freewheeling diodes 31a until 31f are together with the power semiconductor devices 30th on the circuit board 20th assembled.

It should be noted that the battery B is connected to an input stage of the inverter circuit, while the motor M is connected to an output stage (U-phase branch, V-phase branch and W-phase branch) of the inverter circuit.

The power semiconductor devices 30th are installed, for example, in a lateral (i.e., flat) state so that they are attached to their heat releasing surfaces (lower surfaces in 1 ) with the circuit board 20th are in contact. Those in the power semiconductor devices 30th Heat generated is through the circuit board 20th to the heat sink 10 derived. It should be noted that the tops of the power semiconductor devices 30th in contact with the heat transfer element 60 stand and those in the power semiconductor devices 30th generated heat also via the heat transfer element 60 on the control board support base 40 can be derived.

The control board support base 40 is on and above the circuit board 20th arranged and carries the control board 50 . The control board support base 40 has a tower-shaped structure, for example, and is above the power semiconductor devices 30th arranged while he is from the power semiconductor devices 30th is spaced.

The control board support base 40 typically consists of a metal material so that it can be used by the power semiconductors 30th can absorb heat emitted. It should be noted that the control board support base 40 between the circuit board 20th and the control board 50 is arranged and thus also as electrical shielding between the circuit board 20th and the control board 50 serves.

A microcomputer (equivalent to the “control circuit” of the present invention) for generating a control signal (eg, PWM signal) for controlling switching of power semiconductor devices 30th (e.g. PWM signal) is for example on or above the control board 50 appropriate. The microcomputer on the control board 50 thus controls the switching on and off of the power semiconductor devices 30th with a control signal and performs a power conversion (here DA conversion) of the power semiconductor devices 30th supplied power. It should be noted that sensor signals from a current sensor for detecting a current value that is supplied to the motor M and a sensor signal from a speed sensor and / or the like for detecting a rotational position of a rotor of the motor M, for example, in the control board 50 can be entered.

The heat transfer element 60 is between the power semiconductor devices 30th and the control board support base 40 arranged and couples the power semiconductor devices 30th and the control board support base 40 thermal. When the power semiconductor devices 30th generate heat quickly (typically while accelerating and / or driving the vehicle uphill), conducts the heat transfer element 60 the heat of the power semiconductor devices 30th on the control board support base 40 (details are described below).

It should be noted that the heat transfer element 60 is arranged to be the top of each of the plurality of power semiconductor devices 30th covers that on the circuit board 20th are mounted. Thus, each of the plurality of power semiconductor devices is 30th via the heat transfer element 60 thermal with the control board support base 40 coupled.

The heat transfer element 60 consists for example of a resin material with high thermal conductivity, typically of a gap filler, a potting material or a heat dissipation pad. The heat transfer element 60 is arranged so that there is a gap between the power semiconductor devices 30th and the control board support base 40 fills out and in close contact with the power semiconductor devices 30th and the control board support base 40 stands. It should be noted that in order to provide electrical insulation between the power semiconductor devices 30th and the control board support base 40 to ensure for the heat transfer element 60 preferably a material with insulating properties is used. The material that makes up the heat transfer element 60 however, it can be any material as long as the material is capable of thermal coupling between the power semiconductor devices 30th and the control board support base 40 to manufacture.

4th Fig. 3 is a diagram for describing the heat transfer routes in the power converter 1 according to the present embodiment. The arrows in 4th represent the heat flows from the power semiconductor devices 30th The state in which the power semiconductor devices 30th generate heat quickly during a vehicle's acceleration or incline along with an increase in the power of the inverter.

Those from the power semiconductor devices 30th Generated heat is generated through the lower surfaces (heat releasing surfaces) of the power semiconductor devices 30th to the heat sink 10 transfer. Those from the power semiconductor devices 30th The heat generated is mostly via the heat sink 10 diverted to the outside.

As the vehicle accelerates or goes up a slope, the power from the power semiconductor devices increases 30th However, the amount of heat generated temporarily increases compared to a normal driving condition. For this reason, we assume that in a case where the heat dissipation of the power semiconductor devices 30th solely through the heat sink 10 is performed, the power semiconductor devices 30th go into an overheating state.

In this regard, the current transformer is 1 configured according to the present embodiment so as to be able to absorb the heat of the power semiconductor devices 30th via the heat transfer element 60 on the control board Support base 40 to direct. As the control board support base 40 itself does not have a heat dissipation function, the heat that the control board support socket 40 from the power semiconductor devices 30th received, in the control board support base 40 accumulated. The heat of the power semiconductor devices 30th however, is in addition to the heat sink 10 temporarily to the control board support base 40 derived. This increases the heat dissipation ability of the power semiconductor devices 30th practically increased. Accordingly, the power semiconductor devices may become overheated 30th be avoided.

[Effects]

As described above, the current transformer is 1 according to the present embodiment, capable of being used by the power semiconductor devices 30th Heat generated rapidly while a vehicle is accelerating or climbing a hill is temporarily applied to the control board support pedestals 40 and an overheating condition of these power semiconductor devices 30th to suppress. In particular, the current transformer is 1 according to the present embodiment, useful to prevent an overheating state of the power semiconductor devices 30th to suppress without reducing the size of the heat sink 10 to increase.

In addition, the current transformer is 1 according to the present embodiment capable of providing electrical shielding between the circuit board 20th and the control board 50 by the control board support pedestal (typically formed from a metal material) 40.

Although various examples have been described so far, various changes in forms and details can of course be made without departing from the spirit and scope of the present invention and the invention in the claims described below.

Commercial applicability

The power converter according to the present invention is able to cope with instantaneous heat generation of a power semiconductor device with a simple structure.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• JP 2013031250 [0005]

Claims (7)

In-vehicle current transformer, comprising: a heat sink; a circuit board disposed on or above the heat sink; a power semiconductor device mounted on or above the circuit board, a control board support base which is disposed on and / or above the circuit board and which supports a control board; and a heat transfer element that is disposed between the power semiconductor device and the control board support pedestal and provides a thermal connection between the power semiconductor device and the control board support pedestal. In-vehicle current transformer according to Claim 1 , wherein the heat transfer element is a gap filler, a potting material or a heat dissipation pad. In-vehicle current transformer according to Claim 1 wherein the control board support pedestal is formed from a metal material. In-vehicle current transformer according to Claim 1 wherein a plurality of the power semiconductor devices are mounted on or above the circuit board, and the plurality of the power semiconductor devices are each thermally coupled to the control board support pedestal via the heat transfer element. In-vehicle current transformer according to Claim 1 , wherein the circuit board is a metal plate. In-vehicle current transformer according to Claim 1 wherein the in-vehicle power converter is an inverter that outputs alternating current to a motor that drives a vehicle. In-vehicle current transformer according to Claim 1 further comprising a control circuit mounted on or above the control board and controlling the power semiconductor device.

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