Mitsubishi Denki Kabushiki Kaisha

Mitusbishi Denki Kabushiki Kaisha

Tooru Iwagami

Sukehisa Noda

Hisashi Kawafuji

Satoshi Mori

Yoshio Takagi

Gourab Majumdar

Gorab Majumdar

Mitsutaka Iwasaki

Khalid Hassan Hussein

Shinji Yamada

Seiki Iwagaki

Kazuaki Hiyama

Hiroshi Sakata

Shinya Shirakawa

An inverter circuit to reduce a resistor for overcurrent detection and decrease the number of filters in an inverter circuit for supply polyphase power. Transistors each having a current detection terminal and a protective diode for regenerative current are adopted as switching elements on an 'L' side and their current detection terminals are connected in common to a resistor. Therefore, a voltage drop caused by a current flowing in the resisytor becomes larger when an overcurrent flows in at least one of the transistors and further when an overcurrent flows in a switching element on an 'H' side even if no overcurrent flows in any one of the transistors.

Inverter circuit

In an interface between a high-active driving circuit for driving a predetermined semiconductor power element and a microcomputer for controlling an output signal of the driving circuit, the microcomputer comprises a transistor, a collector terminal of which is an output side of the microcomputer; and the driving circuit comprises a first resistor, one end of which is directly connected with the output side of the microcomputer; a Schmidt circuit which is connected in series with the other end of the first resistor; a diode, an anode side of which is connected to a path between the first resistor and the Schmidt circuit; a power supply voltage connected with a cathode side of the diode; and a second resistor, one end of which is grounded and the other end of which is connected with a side of the first resistor being an input terminal of the driving circuit.

Interface

An inverter circuit to reduce a resistor for overcurrent detection and decrease the number of filters in an inverter circuit for supplying polyphase power. Transistors each having a current detection terminal and a protective diode for regenerative current are adopted as switching elements on an &ldquo;L&rdquo; side and their current detection terminals are connected in common to a resistor. Therefore, a voltage drop caused by a current flowing in the resistor becomes larger when an overcurrent flows in at least one of the transistors and further when an overcurrent flows in a switching element on an &ldquo;H&rdquo; side even if no overcurrent flows in any one of the transistors.

A capacitive element is charged with no excessive flow of current so that a potential to effect the operation of a switching element can be obtained with stability. A capacitor (30) is charged with a circulating current from a load (40). On the charging path, a resistor (21) is provided in series to prevent an excessive flow of the charging current. Between terminals (V.sub.B, V.sub.S) of an upper-arm driving circuit (25) which receive a voltage to effect the operation of an IGBT (34) of an upper arm, the capacitor (30) and the resistor (21) are provided to suppress a decrease in potential (V.sub.B) at the terminal (V.sub.B).

Switching device

Semiconductor device

A groove (21) is formed on an upper surface of sealing resin (2) in the form of a strip. A device (101) is pressed against a flat surface of a radiating fin (55) by a band plate shaped clamper (61) which is engaged with the groove (21). Due to the engagement of the clamper (61) and the groove (21), movement of the device (101) is limited. Namely, the device (101) is stably fixed to the radiating fin (55). Since the device (101) is fixed to the radiating fin (55) by the clamper (61), no hole for receiving a fastening screw is provided in the sealing resin (2). Therefore, the sealing resin (2) is reduced, whereby miniaturization of the device (101) is implemented. Thus, the device is miniaturized at no sacrifice of radiation efficiency.

Semiconductor device, semiconductor module, and radiating fin

In a device (101) formed as an invertor, terminals connected to floating source pins (VS) which are provided in control circuits (31 to 33) are limited to output terminals (U, V, W). In order to hold voltages across floating source pins (VD, VS), capacitive elements (51 to 53) which are provided around the device (101) are connected to the output terminals (U, V, W). Thus, the terminals which are connected with the floating source pins (VS) are shared by the output terminals (U, V, W), whereby the numbers of the terminals and wiring patterns are reduced. Thus, the device (101) is miniaturized.

Semiconductor device and semiconductor module

It is an object to facilitate assembly of an application device. A device (101) is provided with a heat sink (51) to radiate loss heat of an IGBT element (11) as a power semiconductor element to an external radiation fin. External terminals (5 and 6) connected to an external circuit substrate protrude in the direction in which the exposed surface of the heat sink (51) is directed. Accordingly, when assembling an application device by mounting the device (101) on the external circuit substrate together with other circuit elements, it is possible to mount the device (101) and other circuit elements together on the common main surface of the circuit substrate, i.e., on its main surface on the side opposite to the side where the radiation fin is attached. Accordingly, it is possible to collectively apply solder on the common main surface of the circuit substrate and collectively solder the device (101) and the other circuit elements.

A blanked lead frame serves both as an interconnection pattern for a control circuit and a power circuit and as external terminals. Highly heat conducting resin having an electric insulating property is put between the lead frame and the heat sink arranged to face each other to maintain good thermal conductivity therebetween. The heat sink and the lead frame are coupled easily and fixedly by performing a simple process of sealing with the highly heat conducting resin. Accordingly, no expensive circuit boards are required, which have been necessary in conventional devices, nor a process of patterning the interconnection pattern and a process of connecting the external terminals to the interconnection pattern when manufacturing the device required. That is to say, the manufacturing cost is reduced without deteriorating the heat radiating characteristic.

Semiconductor power module

It is an object to downsize a device while maintaining a high breakdown voltage. An external terminal (7) protrudes to the outside from the side wall of a sealing resin (2) and a heat sink (1) is exposed in the bottom of the sealing resin (2). A step surface (21) retracted from the exposed surface of the heat sink (1) is formed in the part of the sealing resin (2) surrounding the periphery of the heat sink (1). When using this semiconductor device, the exposed surface of the heat sink (1) is brought into surface contact with the flat surface (41a) of the radiation fin (41) and an insulation sheet (31) is interposed between the step surface (21) and the flat surface (41a), and which is pressed therebetween. The insulation sheet (31) is disposed to cover the region facing the external terminal (7) in the flat surface (41a). Accordingly, it is possible to set the height of the external terminal (7) from the exposed surface of the heat sink (1) lower than the spatial distance determined on the basis of the rated voltage while keeping the breakdown voltage between the external terminal (7) and the radiation fin (41) as the rated voltage.

Growing community of inventors

Tokyo, Japan

Tooru Iwagami