3-Phase Bridge Converting Circuit Module

1. Field of the Invention

This invention relates to a 3-phase bridge converting circuit module sealed in a single in-line package (SIP) type package, and more particularly to a 3-phase bridge converting circuit module which can be mounted on a printed circuit (PC) board with a desired arrangement of outer leads.

2. Description of the related art including information disclosed under section 1.97-1.99.

A 3-phase bridge converting circuit module such as a 3-phase bridge inverter circuit includes six transistors. Any set of two out of the six transistors makes a pair to form three inverter circuits. The six transistors are mounted on a lead frame and sealed in a package. The six transistors mounted on the lead frame are arranged in the order of first, fourth, second, fifth, third and sixth transistors. That is, the outer leads connected to the respective transistors are not arranged to correspond to the order of generation of the output signals or the output stages. The first to sixth transistors are arranged in the order as described above in order to simplify the internal connection in the package. With this construction, the pattern of the lead frame can be simplified and the lead frame can be easily formed, and therefore this type of construction is widely used. In addition to the 3-phase bridge inverter circuit, this also applies to other 3-phase bridging converting circuit modules.

In general use, the SIP type package is often directly soldered on the PC board in order to reduce the number of manufacturing steps thus attaining a low manufacturing cost and reducing the size of the device. For the same reason, the SIP package of the 3-phase bridge inverter circuit is directly soldered on the PC board. However, as described before, the outer leads of the SIP type package are not arranged in the order of generation of the output signals. Therefore, when the SIP package is mounted on the PC board, the circuit pattern on the PC board will be complicated. Further, if the circuit pattern on the PC board cannot satisfy the circuit connection, it becomes necessary to additionally form a wiring connection using jumper lines such as short lead lines in addition to the circuit pattern on the PC board. Thus, the step for mounting the module on the PC board will be complicated.

Further, in the case where the first to sixth transistors (semiconductor elements) are large power elements in which a large current will flow, it will be necessary to use a wide wiring pattern as the circuit pattern on the PC board. However, if the circuit pattern becomes complicated, such a wide wiring pattern cannot be used. Therefore, it is difficult to use this type of 3-phase bridge inverter circuit for the large power elements.

An object of this invention is to provide a 3-phase bridge converting circuit module which can be used for large power elements and in which the circuit pattern on the PC board can be simplified and the mounting process can be simplified by properly modifying the arrangement of the outer leads of the SIP type package.

According to one embodiment of this invention, there is provided a 3-phase bridge converting circuit module which comprises a first lead; a first switching circuit connected at one terminal to the first lead; a second lead BU connected to a control input terminal of the first switching circuit; a third lead U connected to the other terminal of the first switching circuit; a second switching circuit connected at one terminal to the first lead; a fourth lead BV connected to a control input terminal of the second switching circuit; a fifth lead V connected to the other terminal of the second switching circuit; a third switching circuit connected at one terminal to the first lead; a sixth lead BW connected to a control input terminal of the third switching circuit; a seventh lead W connected to the other terminal of the third switching circuit; a fourth switching circuit connected at one terminal to the third lead U; an eighth lead BX connected to a control input terminal of the fourth switching circuit; a fifth switching circuit connected at one terminal to the fifth lead V; a ninth lead BY connected to a control input terminal of the fifth switching circuit; a sixth switching circuit connected at one terminal to the seventh lead W; a tenth lead BZ connected to a control input terminal of the sixth switching circuit; and eleventh lead connected to the other terminals of the fourth to sixth switching circuits; and an SIP type package for sealing the inner lead sections of the first to eleventh leads and the first to sixth switching circuits; wherein the eighth lead BX, a ninth lead BY, tenth lead BZ and eleventh lead are arranged adjacent to one another.

According to another embodiment of this invention, there is provided a 3-phase bridge converting circuit module which comprises a first lead; a first switching circuit connected at one terminal to the first lead; a second lead BU connected to a control input terminal of the first switching circuit; a third lead U connected to the other terminal of the first switching circuit; a second switching circuit connected at one terminal to the first lead; a fourth lead BV connected to a control input terminal of the second switching circuit; a fifth lead V connected to the other terminal of the second switching circuit; a third switching circuit connected at one terminal to the first lead; a sixth lead BW connected to a control input terminal of the third switching circuit; a seventh lead W connected to the other terminal of the third switching circuit; a fourth switching circuit connected at one terminal to the third lead U; an eighth lead BX connected to a control input terminal of the fourth switching circuit; a fifth switching circuit connected at one terminal to the fifth lead V; a ninth lead BY connected to a control input terminal of the fifth switching circuit; a sixth switching circuit connected at one terminal to the seventh lead W; a tenth lead BZ connected to a control input terminal of the sixth switching circuit; an eleventh lead connected to the other terminals of the fourth to sixth switching circuits; and an SIP type package for sealing the inner lead sections of the first to eleventh leads and the first to sixth switching circuits; wherein a pair of the second lead BU and third lead U, a pair of the fourth lead BV and fifth lead V, and a pair of the sixth lead BW and seventh lead W are arranged adjacent to one another.

With this construction, since a complicated wiring of the 3-phase bridge converting circuit module is arranged on the bridge wiring side or in the module, and the outer leads are arranged in the order of generation of output signals, the circuit pattern on the PC board can be simplified. Therefore, it is not necessary to effect the wiring connection using jumper lines or the like and the mounting step can be simplified. Further, the circuit pattern can be made wide due to the simplification of the circuit pattern on the PC board, and therefore the 3-phase bridge converting circuit module can be used for large power elements.

FIG. 1A is a plan view of a semiconductor structure obtained in an assembling step of a 3-phase bridge converting circuit module according to one embodiment of this invention;

FIG. 1B is a side view of the 3-phase bridge converting circuit module shown in FIG. 1A;

FIG. 2 is a circuit diagram of the 3-phase bridge converting circuit module shown in FIGS. 1A and 1B and formed to function as a 3-phase bridge inverting circuit;

FIGS. 3 to 5 are circuit diagrams showing the constructions of switching circuits in the circuit of FIG. 2;

FIG. 6 is a circuit diagram of the 3-phase bridge converting circuit module shown in FIGS. 1A and 1B and formed to function as an AC-DC converting circuit;

FIGS. 7 and 8 are circuit diagrams showing the constructions of switching circuits in the circuit of FIG. 6;

FIG. 9A is a plan view of a semiconductor structure obtained in an assembling step of a 3-phase bridge converting circuit module according to another embodiment of this invention; and

FIG. 9B is a side view of the 3-phase bridge converting circuit module shown in FIG. 9A.

FIG 1A is a plan view of a semiconductor structure obtained in an assembling step of a 3-phase bridge converting circuit module according to one embodiment of this invention; and FIG. 1B is a side view of the 3-phase bridge converting circuit module shown in FIG. 1A. Lead frame 11 is formed of, for example, copper by punching a metal sheet with a thickness of 0.8 mm. The portion of lead frame 11 which is hatched in FIG. 1A is removed at the time of completion of the module. Switching circuits are formed on semiconductor chips Q1 to Q6. Outer lead 11-1 of lead frame 11 has mounting portion 11-1A for the semiconductor chips. Semiconductor chips Q1 to Q3 are mounted on mounting portion 11-1A by solder of Pb-Sb or the like. As a result, the first electrode (one terminal) of each of semiconductor chips Q1 to Q3 is connected to outer lead 11-1. Outer lead BU of lead frame 11 and the second electrode (control input terminal) of semiconductor chip Q1 are connected together by bonding wire 12-1 of Al or the like. The wire bonding is attained by, for example, pressure bonding (US bonding) Outer lead U of lead frame 11 and the third electrode (the other terminal) of semiconductor chip Q1 are connected together by bonding wire 12-2. Outer lead BV of lead frame 11 and the second electrode of semiconductor chip Q2 are connected together by bonding wire 12-3. Outer lead V of lead frame 11 and the third electrode of semiconductor chip Q2 are connected together by bonding wire 12-4. Outer lead BW of lead frame 11 and the second electrode of semiconductor chip Q3 are connected together by bonding wire 12-5. Outer lead W of lead frame 11 and the third electrode of semiconductor chip Q3 are connected together by bonding wire 12-6. Semiconductor chip Q4 is mounted on lead 13-1 which is not externally derived. Lead 13-1 and the third electrode of semiconductor chip Q1 are connected together by bonding wire 12-7. Therefore, the first electrode of semiconductor chip Q4 is connected to outer lead U via lead 13-1, bonding wire 12-7, and bonding wire 12-2. Outer lead BX and the second electrode of semiconductor chip Q4 are connected together by bonding wire 12-8. Outer lead 11-2 and the third electrode of semiconductor chip Q4 are connected together by bonding wire 12-9. Semiconductor chip Q5 is mounted on lead 13-2 which is not externally derived. Lead 13-2 and the third electrode of semiconductor chip Q2 are connected together by bonding wire 12-10. Therefore, the first electrode of semiconductor chip Q5 is connected to outer lead V via lead 13-2, bonding wire 12-10, and bonding wire 12-4. Outer lead BY and the second electrode of semiconductor chip Q5 are connected together by bonding wire 12-11. Outer lead 11-2 and the third electrode of semiconductor chip Q5 are connected together by bonding wire 12-12. Semiconductor chip Q6 is mounted on lead 13-3 which is not externally derived. Lead 13-3 and the third electrode of semiconductor chip Q3 are connected together by bonding wire 12-13. Therefore, the first electrode of semiconductor chip Q6 is connected to outer lead W via lead 13-3, bonding wire 12-13, and bonding wire 12-6. Outer lead BZ and the second electrode of semiconductor chip Q6 are connected together by bonding wire 12-14. Outer lead 11-2 and the third electrode of semiconductor chip Q6 are connected together by bonding wire 12-15.

Semiconductor chips Q1 to Q6 and the inner lead of lead frame 11 are sealed in SIP type package 14 (shown by broken lines).

In FIG. 1A, outer lead 11-3 is cut off inside package 14 and is not used for the circuit operation.

FIG. 2 is a circuit diagram of the module shown in FIGS. 1A and 1B and formed to function as a 3-phase bridge inverting circuit. In FIG. 2, portions corresponding to those in FIGS. 1A and 1B are denoted by the same numerals In the case of a 3-phase bridge inverter circuit, a positive DC power source + is connected to outer lead 11-1 and the ground terminal is connected to outer lead 11-2. Outer leads U, V and W are used as 3-phase output terminals. Outer leads BU, BV, BW, BX, BY and BZ are used as control input terminals. Thus, 3-phase signals are output from outer leads U, V and W according to control signals from outer leads BU, BV, BW, BX, BY and BZ.

FIGS. 3 to 5 shown the construction of switching circuits formed in semiconductor chips Q1 to Q6 shown in FIG. 2. FIG. 3 shows the switching circuit formed of NPN type bipolar transistor 15. In the case where bipolar transistor 15 is used to form each of the switching circuits in semiconductor chips Q1 to Q3, collector terminals (corresponding to the first electrode described above) 16 of transistors 15 are commonly connected to outer lead 11-1, base terminals (corresponding to the second electrode described above) 17 are respectively connected to outer leads BU, BV and BW, and emitter terminals (corresponding to the third electrode described above) 18 are respectively connected to outer leads U, V and W. In the switching circuits of semiconductor chips Q4 to Q6, collector terminals 16 of transistor 15 are respectively connected to outer leads U, V and W, base terminals 17 are respectively connected to outer leads BX, BY and BZ, and emitter terminals 18 are commonly connected to outer lead 11-2.

FIG. 4 shows another construction of the switching circuit described above. In this example, protection diode 19 is connected to NPN type bipolar transistor 15 shown in FIG. 3. The anode of diode 19 is connected to the emitter of transistor 15 and the cathode is connected to the collector. The switching circuit of FIG. 4 is preferably used in the case where the inductance load is driven by 3-phase signals generated from outer leads U, V and W. For example, in the case where the inductance load of a 3-phase AC motor or the like is driven, a counter electromotive force is generated at the time of interruption of current supply. At this time, diode 19 permits the counter electromotive force to be transmitted from the positive terminal + to the ground therethrough, thus protecting transistor 15. Resistor 20 connected between the base and emitter of transistor 15 can be obtained as a parasitic resistance at the time of manufacturing the semiconductor chip. When the switching circuit is used for the circuit of FIG. 2, terminals 16, 17 and 18 are connected in the same manner as described with reference to the circuit of FIG. 3.

In FIG. 5, NPN type bipolar transistor 21 is additionally connected to NPN type bipolar transistor 15 in the circuit of FIG. 4 in a Darlington fashion. Resistor 20A connected between the base and emitter of transistor 15, and resistor 20B connected between the base and emitter of transistor 21 can be obtained as a parasitic resistance at the time of manufacturing the semiconductor chip. In the switching circuit of this construction, even when each control signal supplied via outer leads BU, BV, BW, BX, BY and BZ are at a low level, the control signal is amplified by Darlington connected transistors 21 and 15 so that a sufficiently large driving ability can be attained. When the switching circuit is used for the circuit of FIG. 2, terminals 16, 17 and 18 are connected in the same manner as described with reference to the circuits of FIGS. 3 and 4.

FIG. 6 shows the construction of a circuit obtained in the case where the module shown in FIGS. 1A and 1B is used as a 3-phase bridge converting circuit for AC-DC conversion. In this case, outer leads 11-1 and 11-2 are used as DC output terminals OUTl and OUT2. Outer leads U, V and W are used as input terminals for 3-phase signals. Outer leads BU, BV, BW, BX, BY and BZ are used as control input terminals.

FIGS. 7 and 8 show the construction of switching circuits formed in semiconductor chips of FIG. 6. FIG. 7 shows the switching circuit formed of MOSFET 22. In the switching circuits semiconductor chips Q1 to Q3, source terminals 16 of the MOSFET are commonly connected to outer lead 11-1, gate terminals 17 are respectively connected to outer leads BU, BV and BW, and drain terminals 18 are respectively connected to outer leads U, V and W. In the switching circuits of semiconductor chips Q4 to Q6, drain terminals 18 of MOSFET 22 are respectively connected to outer leads U, V and W, gate terminals 17 are respectively connected to outer leads BX, BY and BZ, and source terminals 16 are commonly connected to outer lead 11-2.

FIG. 8 shows the switching circuits formed to function as thyristor 23. In the switching circuits semiconductor chips Q1 to Q3, cathode terminals 16 of thyristor 23 are commonly connected to outer lead 11-1, gate terminals 17 are respectively connected to outer leads BU, BV and BW, and anode terminals 18 are respectively connected to outer leads U, V and W. In the switching circuits of semiconductor chips Q4 to Q6, cathode terminals 16 of thyristor 23 are respectively connected to outer lead 11-2, gate terminals 17 are respectively connected to outer leads BX, BY and BZ, and anode terminals 18 are commonly connected to outer leads U, V and W.

With this construction, a complicated wiring of the 3-phase bridge converting circuit module is arranged on the bridge wiring side or in the module. This permits pairs of outer leads BU and U; BV and V and BW and W to be arranged together and outer leads BX, BY, BZ and 11-2 to be arranged together. Further, since outer leads U, V and W are arranged in the order of generation of output signals, the circuit pattern on the PC board can be simplified. It is not necessary to additionally provide a wiring using jumper lines or the like and the mounting step can be simplified. Further, the circuit pattern can be made wide due to the simplification of the circuit pattern on the PC board, and therefore the 3-phase bridge converting circuit module can be used for large power elements.

It is not always necessary to arrange outer leads BU, U, BV, V, BW and W in the order described above, and it is only necessary to arrange to make pairs of outer leads BU and U; BV and V; and BW and W. Further, it is not necessary to arrange outer leads BX, BY, BZ and 11-2 in the order described above, but it is necessary to arrange outer leads BX, BY, BW and 11-2 together in one place. Since voltage applied to outer leads BX, BY, BZ and 11-2 is low, the outer leads can be arranged with a small distance from one another in order to reduce the size of the SIP package.

FIGS. 9A and 9B are plan and side views of a semiconductor structure obtained in an assembling step of a 3-phase bridge converting circuit module according to another embodiment of this invention. In FIGS. 9A and 9B, those portions which correspond to portions of FIGS. 1A and 1B are denoted by the same numerals. The semiconductor structure of FIGS. 9A and 9B is simpler than that of FIGS. 1A and 1B except for the form of the pattern of lead frame 11 and the wiring pattern. The arrangement of outer leads 11-1, BU, U, BV, V, BW, W, BX, BY and BZ is the same as in FIGS. 1A and 1B. That is, lead 13-1 and outer lead U are connected together by means of bonding wire 24-1 instead of using lead 13-1 and bonding wire 12-7, 12-2 to connect one terminal of semiconductor chip Q4 and outer lead U together. Lead 13-2 and outer lead V are connected together by means of bonding wire 24-2 instead of using lead 13-2 and bonding wire 12-10, 12-4 to connect one terminal of semiconductor chip Q5 and outer lead V together. Further, lead 13-3 and outer lead W are connected together by means of bonding wire 24-3 instead of using lead 13-3 and bonding wire 12-13, 12-6 to connect one terminal of semiconductor chip Q6 and outer lead W together. Connections between leads 13-1 to 13-3 and outer leads U, V and W are effected inside package 14.

With this construction, since a complicated wiring of the 3-phase bridge converting circuit module is arranged on the bridge wiring side or in the module and outer leads are arranged in the order of generation of output signals, the circuit pattern on the PC board can be simplified. Since it is not necessary to additionally provide a wiring using jumper lines or the like, the mounting step can be simplified. Further, the circuit pattern can be made wide due to the simplification of the circuit pattern on the PC board, and therefore the 3-phase bridge converting circuit module can be used for large power elements.

In the embodiment of FIGS. 9A and 9B, connection is made by means of bonding wires 24-1 to 24-3. However, it is possible to weld a jumper wiring board to attain the same connection.