Semiconductor device and manufacturing method of the same

The semiconductor device 1 includes an insulating substrate 2, a conductive part 3 that extends in a first direction, a conductive part 4 that is separated in a second direction and extends in the first direction, conductive parts 5 that are lined along the first direction between the part 3 and the part 4, high-side switches 11, 12 and 13, low-side switches 14, 15 and, signal terminals that are arrayed along the first direction, a power supply terminal 21 that is electrically connected to the part 3, a ground terminal 22 that is electrically connected to the part 4, and output terminals 23, 24 and 25 that are electrically connected respectively to the corresponding parts 5, arrayed along the first direction on the other end side of the substrate 2, and provided over a straight line L that passes through the part 4 and extends in the first direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Stage of International Patent Application No. PCT/JP2015/065519 filed on May 29, 2015, the disclosure of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a semiconductor device and its manufacturing method.

BACKGROUND ART

Conventionally, as one of semiconductor devices, an inverter device that converts DC power inputted from a DC power source to AC power and outputs it is known. The inverter device is used, for instance, to convert a DC voltage to a 3-phase AC voltage and drive a 3-phase motor. For such a semiconductor device, miniaturization and efficiency improvement have been demanded more and more in recent years.

Patent Literature 1 describes an inverter device for a purpose of reducing inductance and miniaturizing a device. In this inverter device, both of power supply terminals (inverter input terminals) and ground terminals (inverter ground terminals) are arrayed in one direction without being bundled into one (see FIG. 20 in Patent Literature 1).

Patent Literature 2 describes an inverter device for a purpose of reducing loss and noise. In this inverter device, a power supply block electrically connected to a power supply terminal and a ground block connected to the ground are adjacently arranged (see FIG. 15 in Patent Literature 2).

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

However, in the inverter device of Patent Literature 1, since the power supply terminals and the ground terminals are not bundled into one, a horizontal width increases and it is difficult to advance miniaturization. Also, in the inverter device of Patent Literature 2, since the power supply block and the ground block are adjacently arranged, a current route becomes long, wiring resistance increases, and there is a problem of efficiency decline.

Therefore, an object of the present invention is to provide a semiconductor device of small wiring resistance and high efficiency, which can be miniaturized.

Solution to Problem

A semiconductor device relating to the present invention is a semiconductor device that converts DC power to AC power, and includes:an insulating substrate;a first conductive part provided on the insulating substrate so as to extend in a first direction;a second conductive part provided on the insulating substrate so as to be separated from the first conductive part in a second direction different from the first direction and to extend in the first direction;a plurality of third conductive parts provided on the insulating substrate so as to be lined along the first direction between the first conductive part and the second conductive part;a plurality of first switches mounted on the first conductive part along the first direction, and each provided with a first main electrode, a second main electrode and a control electrode, the first main electrode being electrically connected to the first conductive part;a plurality of second switches each mounted on the corresponding third conductive part, and each provided with a third main electrode, a fourth main electrode and a control electrode, the third main electrode being electrically connected to the second main electrode of the first switch, the fourth main electrode being electrically connected to the second conductive part;a plurality of signal terminals arrayed along the first direction so that the first conductive part is positioned between the signal terminals and the third conductive parts;a power supply terminal electrically connected to the first conductive part, and arranged on one end side of the insulating substrate where the plurality of signal terminals are provided;a ground terminal electrically connected to the second conductive part, and arranged on the one end side of the insulating substrate; anda plurality of output terminals each electrically connected to the corresponding third conductive part, arrayed along the first direction on the other end side which is an opposite side of the one end side of the insulating substrate, and provided over a straight line that passes through the second conductive part and extends in the first direction.

Also, in the semiconductor device,the fourth main electrode of the second switch and the second conductive part may be electrically connected by a conductive wire, and the conductive wire may have one end connected to the fourth main electrode, and have the other end connected to an area between the output terminals that are adjacent to each other in the second conductive part.

Also, in the semiconductor device,tips of the plurality of signal terminals may be arranged zigzag along the first direction.

Also, in the semiconductor device,tips of the power supply terminal and the ground terminal may be arranged zigzag to the plurality of signal terminals.

Also, in the semiconductor device,at least one of the power supply terminal, the ground terminal and the output terminals may have a planar shape that avoids a conductive part provided on a corner of the insulating substrate.

Also, in the semiconductor device,the planar shape may be an L shape.

A manufacturing method of a semiconductor device relating to the present invention is a manufacturing method of a semiconductor device that converts DC power to AC power, and includes:preparing a wiring board having an insulating substrate, a first conductive part provided on the insulating substrate so as to extend in a first direction, a second conductive part provided on the insulating substrate so as to be separated from the first conductive part in a second direction different from the first direction and to extend in the first direction, and a plurality of third conductive parts provided on the insulating substrate so as to be lined along the first direction between the first conductive part and the second conductive part;preparing a lead frame having a first terminal group including a plurality of signal terminals, a power supply terminal and a ground terminal, and a second terminal group including a plurality of output terminals;mounting a plurality of first switches on the first conductive part along the first direction with cream solder interposed therebetween, and mounting second switches on the individual third conductive parts with cream solder interposed therebetween;positioning the wiring board and the lead frame so that a base of the power supply terminal, a base of the ground terminal, and bases of the output terminals are respectively in contact on the first conductive part, on a fourth conductive part which is connected to the second conductive part and extending in the second direction, and on the third conductive parts with cream solder interposed therebetween;joining the power supply terminal, the ground terminal and the output terminals to the first conductive part, the second conductive part and the third conductive parts respectively, by reflow processing; andbonding the second conductive part and the main electrode of the second switch by a conductive wire.

Also, in the manufacturing method of the semiconductor device,the bonding may include first connection of connecting one end of the conductive wire to the main electrode of the second switch, and second connection of connecting the other end of the conductive wire to an area between the output terminals that are adjacent to each other in the second conductive part, after the first connection.

Advantageous Effects of Invention

The semiconductor device relating to the present invention includes a first conductive part that extends in a first direction, a second conductive part that is separated in a second direction different from the first direction and extends in the first direction, a plurality of third conductive parts that are lined along the first direction between the first conductive part and the second conductive part, a plurality of first switches that are mounted on the first conductive part along the first direction, a plurality of second switches that are mounted respectively on the corresponding third conductive parts, a plurality of signal terminals that are arrayed along the first direction so that the first conductive part is positioned between the signal terminals and the third conductive parts, a power supply terminal that is electrically connected to the first conductive part, a ground terminal that is electrically connected to the second conductive part, and a plurality of output terminals that are electrically connected respectively to the corresponding third conductive parts. Then, the power supply terminal and the ground terminal are arranged on one end side of an insulating substrate where the plurality of signal terminals are provided, and the plurality of output terminals are arrayed along the first direction on the other end side of the insulating substrate. Also, the individual output terminals are provided over a straight line that passes through the second conductive part and extends in the first direction. By such a configuration, according to the present invention, the semiconductor device can be miniaturized, and the semiconductor device of small wiring resistance and high efficiency can be provided.

DESCRIPTION OF EMBODIMENT

Hereinafter, a semiconductor device relating to an embodiment of the present invention and its manufacturing method will be described while referring to the drawings.

A semiconductor device1relating to the embodiment of the present invention will be described with reference toFIG. 1andFIG. 2. The semiconductor device1relating to the embodiment is, as illustrated in a circuit diagram inFIG. 2, a semiconductor device (inverter device) that converts DC power inputted from a DC power source (not shown in the figure) connected to a power supply terminal21and a ground terminal22to 3-phase AC power and outputs it from output terminals23,24and25.

In the semiconductor device1, on an insulating substrate2provided with conductive parts3to7on an upper surface, high-side switches11,12and13and low-side switches14,15and16are mounted, constituting a 3-phase full bridge circuit.

The semiconductor device1includes, as illustrated inFIG. 1, the insulating substrate2such as a ceramic substrate, a conductive part3(first conductive part), a conductive part4(second conductive part), a plurality of conductive parts5(third conductive parts), a conductive part6(fourth conductive part), a conductive part7, high-side switches11,12and13(a plurality of first switches), the low-side switches14,15and16(a plurality of second switches), control terminals31to36, monitor terminals41to45, the power supply terminal21, the ground terminal22, the output terminals23,24and25, a thermistor17, conductive wires51to53such as Al wires, and a sealing part60. Hereinafter, individual components of the semiconductor device1will be described in detail.

The conductive parts3to7are conductive patterns provided on the upper surface of the insulating substrate2. The conductive parts3to7are composed of a metal such as copper or aluminum. Note that, a lower surface of the insulating substrate2may be covered with a metal layer (not shown in the figure) in order to improve a heat radiation property.

The conductive part3is, as illustrated inFIG. 1, provided on the insulating substrate2so as to extend in a first direction. On the conductive part3, the high-side switches11,12and13are mounted.

The conductive part4is, as illustrated inFIG. 1, provided on the insulating substrate2so as to be separated from the conductive part3in a second direction and to extend in the first direction. That is, the conductive part4is provided roughly in parallel with the conductive part3. Here, the second direction is a direction different from the first direction, and is, for example, a direction orthogonal to the first direction.

The conductive part4is electrically connected to the ground terminal22through the conductive part6. The conductive part6is connected to the conductive part4and extends in the second direction. Note that, the conductive part6is not an essential configuration, and the conductive part4may be directly connected to the ground terminal22. For example, a terminal formed longer for a portion corresponding to a length of the conductive part6is used as the ground terminal22, and a terminal in a shape (l shape or the like) that does not interfere with the ground terminal22is used as the output terminal25.

The plurality of conductive parts5are, as illustrated inFIG. 1, provided on the insulating substrate2so as to be lined along the first direction between the conductive part3and the conductive part4. On the individual conductive parts5, the low-side switches14,15and16are mounted one by one.

The conductive part7is, as illustrated inFIG. 1, provided in an island shape on a corner of the insulating substrate2. The conductive part7is part where a mold die is to be in contact when forming the sealing part60in manufacture of the semiconductor device1.

The high-side switches11,12and13have a drain electrode (first main electrode), a source electrode (second main electrode) and a gate electrode (control electrode). The drain electrodes, the source electrodes and the gate electrodes are provided respectively on a lower surface, an upper surface and a side face of the high-side switches11,12and13. Note that, the high-side switches11,12and13and the low-side switches14,15and16are power MOSFETs for example, but may be other semiconductor switching elements such as an IGBT.

The high-side switches11,12and13are mounted on the conductive part3along the first direction. The drain electrodes of the high-side switches11,12and13are electrically connected to the conductive part3through solder (not shown in the figure). Also, the source electrodes of the high-side switches11,12and13are electrically connected respectively to the drain electrodes of the corresponding low-side switches14,15and16through conductive wires such as Al wires and the conductive parts5. The gate electrodes of the high-side switches11,12and13are electrically connected respectively to the control terminals31,33and35through thin metallic wires54such as gold wires.

The low-side switches14,15and16have a drain electrode (third main electrode), a source electrode (fourth main electrode) and a gate electrode (control electrode). The drain electrodes, the source electrodes and the gate electrodes are provided respectively on a lower surface, an upper surface and side face of the low-side switches14,15and16.

The low-side switches14,15and16are mounted respectively on the corresponding conductive parts5. The drain electrodes of the low-side switches14,15and16are electrically connected to the source electrodes of the corresponding high-side switches11,12and13through the conductive parts5and the conductive wires. The source electrodes of the low-side switches14,15and16are electrically connected to the conductive part4through the conductive wires51,52and53. The gate electrodes of the low-side switches14,15and16are electrically connected respectively to the control terminals32,34and36through thin metallic wires.

The semiconductor device1has, as signal terminals, the control terminals31to36and the monitor terminals41to45. The control terminals31,33and35are terminals for controlling ON/OFF of the high-side switches11,12and13, and the control terminals32,34and36are terminals for controlling ON/OFF of the low-side switches14,15and16.

The monitor terminals41,42and43are terminals for monitoring output voltages of the individual phases. The monitor terminal41is electrically connected to the source electrode of the high-side switch11and the drain electrode of the low-side switch14. Similarly, the monitor terminal42is electrically connected to the source electrode of the high-side switch12and the drain electrode of the low-side switch15, and the monitor terminal43is electrically connected to the source electrode of the high-side switch13and the drain electrode of the low-side switch16.

The monitor terminals44and45are terminals for monitoring a voltage of the thermistor17. The thermistor17is provided in order to measure an internal temperature of the semiconductor device1. As the thermistor17, for example, the one of an NTC type in which resistance becomes smaller as the temperature becomes higher is used.

As illustrated inFIG. 1, the control terminals31to36and the monitor terminals41to45are lined along one end of the insulating substrate2and arranged. In other words, the control terminals31to36and the monitor terminals41to45are arrayed along the first direction so that the conductive part3is positioned between the control terminals31to36and the monitor terminals41to45and the plurality of conductive parts5.

Note that, tips of the plurality of signal terminals may be arranged zigzag along the first direction. In the present embodiment, as illustrated inFIG. 1, the tips of the control terminals31to36and the monitor terminals41to45are alternately shifted in the second direction. Thus, a pitch of through-holes of a control board (not shown in the figure) on which the semiconductor device1is mounted can be mitigated.

The power supply terminal21is a terminal for being connected to the DC power source, and the ground terminal22is a terminal for grounding. As illustrated inFIG. 1, tips of the power supply terminal21and the ground terminal22are arranged on one end side of the insulating substrate2where the plurality of signal terminals are provided.

The power supply terminal21is electrically connected to the conductive part3. More specifically, the power supply terminal21is soldered to the conductive part3at the base21a. The ground terminal22is electrically connected to the conductive part4. More specifically, the ground terminal22is soldered to the conductive part6at the base22a. The power supply terminal21and the ground terminal22are, as illustrated inFIG. 1, provided so as to hold the control terminals31to36and the monitor terminals41to45therebetween.

Note that, as illustrated inFIG. 1, tips of the power supply terminal21and the ground terminal22may be arranged zigzag to the control terminals31to36and the monitor terminals41to45(the plurality of signal terminals).

The output terminals23,24and25(the plurality of output terminals) are terminals for outputting 3-phase alternating currents converted by the 3-phase full bridge circuit, and are electrically connected respectively to the corresponding conductive parts5. More specifically, the output terminals23,24and25are soldered to the corresponding conductive parts5at the bases23a,24aand25a.

As illustrated inFIG. 1, the output terminals23,24and25are arranged on an opposite side of the control terminals31to36and the monitor terminals41to45. That is, the output terminals23,24and25are arrayed along the first direction on the other end side which is the opposite side of one end side of the insulating substrate2. Tips of the output terminals23,24and25are arranged on the other end side of the insulating substrate2. Also, the output terminals23,24and25are provided over a straight line L as illustrated inFIG. 1. The straight line L is a straight line that passes through the conductive part4and extends in the first direction.

Also, at least one of the power supply terminal21, the ground terminal22and the output terminals23,24and25may have a planar shape that avoids the conductive parts7provided on four corners of the insulating substrate2. Thus, when the sealing part60is formed, the terminal can be prevented from interfering with a mold die. In the present embodiment, the planar shape of the power supply terminal21, the ground terminal22and the output terminals23and25is an L shape so as to avoid the conductive parts7, as illustrated inFIG. 1. However, the planar shape is not limited to the L shape and may be another shape (an arc shape for example) as long as it is a shape that avoids the conductive part7.

As described above, the source electrode of the low-side switch14and the conductive part4are electrically connected by the conductive wire51. The conductive wire51is, as illustrated inFIG. 1, connected to the source electrode of the low-side switch14at one end, and connected to an area “A” between the output terminal23and the output terminal24that are adjacent to each other in the conductive part4at the other end. Similarly, the conductive wire52that electrically connects the source electrode of the low-side switch15and the conductive part4is connected to the source electrode of the low-side switch15at one end, and connected to the area “A” at the other end. The conductive wire53that electrically connects the source electrode of the low-side switch16and the conductive part4is, as illustrated inFIG. 1, connected to the source electrode of the low-side switch16at one end, and connected to an area “B” between the output terminal24and the output terminal25that are adjacent to each other in the conductive part4at the other end.

The sealing part60seals an upper surface side of the insulating substrate2, the conductive parts3to7, the high-side switches11,12and13, the low-side switches14,15and16, the thermistor17, the conductive wires51,52and53, and some of the various kinds of terminals.

As described above, the semiconductor device1relating to the present embodiment includes the conductive part3that extends in the first direction, the conductive part4that is separated in the second direction different from the first direction and extends in the first direction, the plurality of conductive parts5that are lined along the first direction between the conductive part3and the conductive part4, the high-side switches11,12and13that are mounted on the conductive part3along the first direction, the low-side switches14,15and16that are mounted respectively on the corresponding conductive parts5, the plurality of signal terminals that are arrayed along the first direction so that the conductive part3is positioned between the signal terminals and the conductive parts5, the power supply terminal21that is electrically connected to the conductive part3, the ground terminal22that is electrically connected to the conductive part4, and the plurality of output terminals23,24and25that are electrically connected respectively to the corresponding conductive parts5. Then, the power supply terminal21and the ground terminal22are arranged on one end side of the insulating substrate2where the plurality of signal terminals are provided, and the plurality of output terminals23,24and25are arrayed along the first direction on the other end side of the insulating substrate2. Also, the output terminals23,24and25are provided over the straight line L that passes through the conductive part4and extends in the first direction. By such a configuration, a wiring length can be suppressed, impedance and inductance can be reduced, and a device size can be reduced.

Therefore, according to the present embodiment, the semiconductor device can be miniaturized, and the semiconductor device of the small wiring resistance and the high efficiency can be provided.

(Manufacturing Method of Semiconductor Device)

Next, the manufacturing method of the above-described semiconductor device1will be described.

First, a wiring board (not shown in the figure) having the insulating substrate2and the conductive parts3,4and5provided on the insulating substrate2, and a lead frame70are prepared. The lead frame70has, as illustrated inFIG. 3, a first terminal group including the plurality of signal terminals (the control terminals31to36and the monitor terminals41to45), the power supply terminal21and the ground terminal22, and a second terminal group including the plurality of output terminals23,24and25. The bases of the terminals included in the first terminal group and the bases of the terminals included in the second terminal group are provided so as to face each other.

Next, the high-side switches11,12and13are mounted along the first direction on the conductive part3with cream solder interposed therebetween, and the low-side switches14,15and16are mounted on the individual conductive parts5with cream solder interposed therebetween. In addition, the thermistor17is also mounted on a predetermined location of the wiring board.

Next, the wiring board and the lead frame70are positioned so that the base21aof the power supply terminal21, the base22aof the ground terminal22, and the bases23a,24aand25aof the output terminals23,24and25are respectively in contact on the conductive part3, on the conductive part6, and on the conductive parts5with cream solder interposed therebetween.

Note that, without being limited to the above-described procedure, the high-side switches11,12and13and the low-side switches14,15and16may be mounted on the wiring board after the wiring board and the lead frame70are positioned.

Next, by reflow processing, the power supply terminal21, the ground terminal22and the output terminals23,24and25are joined respectively to the conductive part3, the conductive part4and the conductive parts5. Thereafter, flux residue is washed and removed.

Next, the conductive part4and the source electrodes of the low-side switches14,15and16are connected by the conductive wires51,52and53(bonding). The bonding includes first connection of connecting one end of the conductive wires51,52and53to the source electrodes of the low-side switches14,15and16, and second connection of connecting the other end of the conductive wires51,52and53to the areas “A” and “B” between the output terminals that are adjacent to each other in the conductive part4, after the first connection.

Next, by a transfer molding method, the upper surface side of the insulating substrate2, the high-side switches11,12and13, the low-side switches14,15and16, the conductive wires51,52and53, and some of the various kinds of terminals are sealed, and the sealing part60illustrated inFIG. 1is formed. Thereafter, by cutting off unneeded parts (tie bars or the like) of the lead frame70and forming the various kinds of terminals, the semiconductor device1is obtained. Note that, in forming, the various kinds of terminals may be formed so that the tips of the plurality of signal terminals are arranged zigzag along the first direction.

In the above-described manufacturing method, in the bonding, by connecting the other end of the conductive wires51,52and53to the areas “A” and “B” between the output terminals, a bonding device and the output terminals23,24and25do not interfere, and the bonding device can easily cut the conductive wires on the conductive part4. As a result, according to the present embodiment, manufacturability of the semiconductor device can be improved.

On the basis of the above description, those skilled in the art may conceive additional effects and various modifications of the present invention. However, aspects of the present invention are not limited to the individual embodiments described above. Components over the different embodiments may be appropriately combined. Various additions, modifications and partial deletion are possible without departing from the conceptual spirit and meaning of the present invention derived from contents defined in the scope of claims and the equivalency thereof.

REFERENCE SIGNS LIST

21Power supply terminal

A, B Area

L Straight line