JP2010251551A - Electronic circuit board and power semiconductor module - Google Patents

Abstract

A small and inexpensive electronic circuit board and power semiconductor module capable of passing a large current are provided.
An electronic circuit board according to the present invention includes an insulating substrate and a conductor pattern that is formed so as to connect two points on the insulating substrate, and allows current to flow between the two points. Further, it is characterized in that at least one conductive member (metal wire) 5a is connected to both ends of the conductor pattern 3a and allows a part of the current to flow therethrough.
[Selection] Figure 1

Description

  The present invention relates to an electronic circuit board and a power semiconductor module on which a plurality of conductor patterns having different amounts of current to be passed are formed.

The electronic circuit board included in the power semiconductor module includes a conductor pattern through which a relatively large current flows and a conductor pattern through which little current flows. For example, in an electronic circuit as shown in FIG. 5, a large current flows through the wirings 11 and 12 connected to the collector and emitter of the power semiconductor element 10 (IGBT or the like), but the wiring 13 connected to the base (control). Almost no current flows through the signal line.
Therefore, it is necessary to reduce the impedance of the conductor patterns corresponding to the wirings 11 and 12 by increasing the pattern width or increasing the thickness of the conductor. On the other hand, for the conductor pattern corresponding to the wiring 13, it is preferable to reduce the pattern occupation area by reducing the pattern width as much as possible to reduce the size and cost of the substrate.

  As an electronic circuit board that satisfies the above two requirements at the same time, for example, the one described in Patent Document 1 is known. As shown in FIG. 6, in the electronic circuit board 20, the thickness of each conductor pattern 21, 22 is changed according to the amount of current to be passed. On the other hand, the pattern widths of the conductor patterns 21 and 22 are substantially constant without depending on the amount of current.

JP 2001-7456 A

  However, in this conventional electronic circuit board 20, in order to form the conductor pattern 22 through which a large current flows, it is necessary to repeat the steps of forming a resist mask, etching, etc. many times, which complicates the production process. In addition, an increase in production cost due to a decrease in throughput has been a problem.

  Therefore, an object of the present invention is to provide a small and inexpensive electronic circuit board and power semiconductor module that can pass a large current.

  In order to solve the above-described problems, an electronic circuit board according to the present invention is formed so as to connect an insulating substrate and two points on the insulating substrate, and a conductor pattern that allows current to flow between the two points. And at least one conductive member that is connected to both ends of the conductive pattern and allows a part of the current to flow therethrough.

  In this configuration, a part of the current between two points on the insulating substrate flows through the conductive member instead of the conductive pattern, so even if the width of the conductive pattern is narrow and thin, it is equivalent to the case where the width and thickness of the conductive pattern are wide and thick The large current can be passed through.

  Specifically, the conductive member is preferably a metal wire or a metal plate.

  In the electronic circuit board, a plurality of conductive members may be arranged in parallel and / or in series along the current flow direction.

  If a plurality of conductive members are arranged in parallel, the impedance between two points through which a large current flows can be further reduced, so that the pattern width of the conductor pattern can be further reduced and the substrate can be miniaturized. If a plurality of conductive members are arranged in series, impedance can be reduced over the entire region even when the length of the conductor pattern is long.

  In order to solve the above-described problem, an aspect of a power semiconductor module according to the present invention includes the electronic circuit board according to claim 1 and a power semiconductor element mounted on the electronic circuit board. The circuit board includes a power semiconductor element, a connecting metal wire for electrically connecting the conductor pattern formed separately from the power semiconductor element, and an inflow current flowing into the power semiconductor element at both ends as a conductive member. And a reinforcing metal wire connected to a conductor pattern through which an outflow current flowing out from the power semiconductor element flows, and through which a part of the inflow current or outflow current flows.

  In order to solve the above problems, another aspect of the power semiconductor module according to the present invention includes the electronic circuit board according to claim 1 and a power semiconductor element mounted on the electronic circuit board. The circuit board includes a power semiconductor element, a connection metal wire for electrically connecting the conductor pattern formed separately from the power semiconductor element, and an inflow current or power semiconductor flowing into the power semiconductor element as a conductive member And a metal plate that is disposed on a conductor pattern through which an outflow current flowing out from the element flows, and through which a part of the inflow current or outflow current flows.

  And in order to solve the said subject, in the power semiconductor module which concerns on this invention, said reinforcement metal wire or metal plate can also be arrange | positioned in parallel and / or in series along the said current flow direction. .

  According to the present invention, it is possible to provide a small and inexpensive electronic circuit board and power semiconductor module through which a large current can be passed.

It is a top view of the power semiconductor module concerning a 1st embodiment. It is sectional drawing which looked at the power semiconductor module which concerns on 1st Embodiment from the XX direction of FIG. It is a top view of the power semiconductor module which concerns on 2nd Embodiment. It is sectional drawing which looked at the power semiconductor module which concerns on 2nd Embodiment from the XX direction of FIG. It is a circuit diagram which shows an example of a power semiconductor module. It is sectional drawing of the conventional electronic circuit board. It is a top view of the conventional power semiconductor module.

  Preferred embodiments of an electronic circuit board according to the present invention and a power semiconductor module including the electronic circuit board will be described below with reference to the accompanying drawings.

<First Embodiment>
FIG. 1 shows a power semiconductor module according to the first embodiment of the present invention. The power semiconductor module includes an electronic circuit board 1A, and the electronic circuit board 1A includes an insulating substrate 2 made of glass epoxy or the like, and conductive patterns 3a, 3b, and 3c having conductivity formed on the surface thereof. Among these, the bare chip semiconductor component 4 is disposed on the conductor pattern 3a. The thickness of each conductor pattern 3a, 3b, 3c is substantially constant without depending on the amount of current flowing through each pattern.

  The electronic circuit board 1A constitutes a part of the electronic circuit shown in FIG. That is, the bare chip semiconductor component 4 shown in FIG. 1 corresponds to the power semiconductor element 10 shown in FIG. The conductor patterns 3a, 3b, and 3c correspond to the wiring 11 connected to the collector of the power semiconductor element 10, the wiring 12 connected to the emitter, and the wiring 13 connected to the base, respectively.

  The bare chip semiconductor component 4 has the same back surface as the collector of the power semiconductor element 10 and is connected to the conductor pattern 3a via the solder layer 8 (see FIG. 2). A heat spreader for heat radiation is appropriately disposed between the bare chip semiconductor component 4 and the conductor pattern 3a.

  A pad for extracting the emitter of the power semiconductor element 10 is provided on the surface of the bare chip semiconductor component 4, and the pad is connected to the power semiconductor via the metal wire 5 b (corresponding to the “connection metal wire” of the present invention). It is connected to a conductor pattern 3 b formed separately from the element 10. The number of pads and the diameter of the metal wire 5b are determined according to the amount of current flowing out from the emitter. In the present embodiment, the number of pads is three, and the diameters of the metal wires 5b are 350 μm to 500 μm, respectively (see FIG. 1).

  Further, a pad for pulling out the base of the power semiconductor element 10 is provided on the surface of the bare chip semiconductor component 4, and the pad is connected to the metal wire 6 (“conductive member”, “connecting metal wire” of the present invention). And electrically conductive pattern 3c formed separately from power semiconductor element 10 through a corresponding structure. As described above, since almost no current flows through the base of the power semiconductor element 10, in this embodiment, the number of pads is one and the diameter of the metal wire 6 is 125 μm. As the metal wires 5b and 6, low resistance metal wires such as gold and aluminum are used.

As shown in FIG. 1 and FIG. 2, the electronic circuit board 1A has a metal wire 5a (in this case, both ends are connected to the conductor pattern 3a in order to reduce the impedance between two points through which a large current flows. Equivalent to the “reinforcing metal wire” of the invention. A part of the current flowing toward the collector of the power semiconductor element 10 flows through the metal wire 5a instead of the conductor pattern 3a.
As a result, the impedance between the two points can be reduced to the same extent as when the pattern width of the conductor pattern 3a is increased (for example, see FIG. 7) or when the thickness of the conductor pattern is increased. . Furthermore, there is a limit to increasing the current capacity by changing the width and thickness of the pattern, but according to the present embodiment, even if it is difficult to respond by changing the width and thickness of the pattern, the current capacity Can be improved dramatically.

  Specifically, in this embodiment, at least a part of the surface of the conductor pattern 3a is not covered with a resist, and the uncovered part and each end of the metal wire 5a are bonded and connected. . As shown in FIG. 1, in this embodiment, three sets of two metal wires 5a connected in series are arranged in parallel.

  Moreover, in this embodiment, the diameter of each metal wire 5a was 350 micrometers-500 micrometers similarly to the three metal wires 5b which connect the bare chip semiconductor component 4 and the conductor pattern 3b. As a result, the metal wires 5a can be connected together in the process of connecting the bare chip semiconductor component 4 and the conductor pattern 3b (wire bonding process). Can be minimized.

<Second Embodiment>
FIG. 3 shows a power semiconductor module according to the second embodiment of the present invention. The power semiconductor module includes an electronic circuit board 1B. And in this electronic circuit board 1B, the metal plate 7 is used instead of the metal wire 5a of 1st form, and, thereby, the impedance between two points through which a large current flows is reduced.

  The metal plate 7 is preferably a copper plate having excellent conductivity, and its thickness is determined in consideration of the amount of current flowing into the base of the power semiconductor element 10, the width and thickness of the conductor pattern 3a, and the like. As shown in FIG. 4, the metal plate 7 is connected to the conductor pattern 3 a through the solder layer 9.

  The metal plate 7 can be disposed in an existing process for mounting the bare chip semiconductor component 4 and other electronic components. That is, since it is not necessary to provide a new process for arranging the metal plate 7, an increase in production cost can be minimized.

After all, according to the power semiconductor modules according to the first and second embodiments, the impedance between two points through which a large current flows can be easily reduced, so the pattern width of the conductor pattern according to the amount of current. There is no need to increase the width of the conductor pattern or increase the thickness of the conductor pattern.
Further, according to the power semiconductor module according to the first and second embodiments, the conductive member (metal wire 5a, metal plate 7) can be provided in the existing process, so that the increase in production cost is minimized. Can be suppressed.

<Others>
The preferred embodiments of the electronic circuit board and the power semiconductor module according to the present invention have been described above, but the configuration of the present invention is not limited to these configurations.
For example, in the above-described embodiment, the “conductive member” of the present invention is used for the electronic circuit board included in the power semiconductor module. However, the present invention is not limited to this, and an electronic circuit in which a conductive pattern through which a relatively large current flows is formed. The present invention can be applied to all devices including a substrate.
Moreover, in the said 1st Embodiment, although the metal wire 5a made into parallel was made into 3 sets, according to the amount of electric current, it can also be made into 1 set, 2 sets, or 4 sets or more.
Further, instead of the bare chip semiconductor component 4, a resin-sealed package component can be used. However, in this case, since there is no step of connecting a metal wire, it is preferable to use a metal plate as the conductive member.
In the first and second embodiments, the conductive member (metal wire or metal) is formed on the conductor pattern through which the current (inflow current flowing into the power semiconductor element) flowing toward the collector of the power semiconductor element 10 flows. However, of course, the same effect can be obtained by connecting a conductive member on a conductive pattern through which an outflow current flowing out from the power semiconductor element flows.

DESCRIPTION OF SYMBOLS 1A Electronic circuit board 1B Electronic circuit board 2 Insulation board | substrate 3a-c Conductor pattern 4 Bare chip semiconductor component 5a, b Metal wire 6 Metal wire 7 Metal plate 8, 9 Solder layer

Claims (6)

An insulating substrate;
A conductor pattern formed so as to connect two points on the insulating substrate, and for passing a current between the two points;
At least one conductive member connected at both ends to the conductive pattern, and passing a part of the current;
An electronic circuit board comprising:   The electronic circuit board according to claim 1, wherein the conductive member is a metal wire or a metal plate.   The electronic circuit board according to claim 1, wherein a plurality of conductive members are arranged in parallel and / or in series along the current flow direction. An electronic circuit board according to claim 1,
A power semiconductor element mounted on the electronic circuit board,
The electronic circuit board is
A metal wire for connection for electrically connecting the power semiconductor element and a conductor pattern formed separately from the power semiconductor element;
As the conductive member, both ends are connected to a conductor pattern that allows an inflow current flowing into the power semiconductor element or an outflow current flowing out of the power semiconductor element to flow, and a part of the inflow current or the outflow current flows. A reinforcing metal wire;
A power semiconductor module comprising: An electronic circuit board according to claim 1,
A power semiconductor element mounted on the electronic circuit board,
The electronic circuit board is
A metal wire for connection for electrically connecting the power semiconductor element and a conductor pattern formed separately from the power semiconductor element;
As the conductive member, a metal plate is disposed on a conductor pattern through which an inflow current flowing into the power semiconductor element or an outflow current flowing out of the power semiconductor element flows, and a part of the inflow current or the outflow current flows. When,
A power semiconductor module comprising:   6. The power semiconductor module according to claim 4, wherein the reinforcing metal wires or the metal plates are arranged in parallel and / or in series along a current flow direction. 7.

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