Active solid-state devices (e.g. – transistors – solid-state diode – Housing or package – With large area flexible electrodes in press contact with...
Reexamination Certificate
2002-01-22
2003-04-15
Clark, Sheila V. (Department: 2815)
Active solid-state devices (e.g., transistors, solid-state diode
Housing or package
With large area flexible electrodes in press contact with...
C257S726000, C257S727000
Reexamination Certificate
active
06548890
ABSTRACT:
CROSS REFERENCE TO RELATED APPLICATION
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. P2001- 15044, filed on Jan. 23, 2001, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a press-contact type semiconductor device, and particularly to a press-contact type semiconductor device of a multiple chip module structure having a plurality of semiconductor elements. Further, the invention relates to a technique which is applicable to press-contact type semiconductor devices used to control vehicle motors in the traction applications and power sources.
2. Description of the Related Art
Referring to
FIG. 12
of the accompanying drawings, a press-contact type semiconductor device
100
of the related art comprises semiconductor elements
103
A and
103
B which are sandwiched in a pressed state between a common emitter power source plate (a lower electrode post)
101
and a common collector power source plate (a upper electrode post)
105
. The semiconductor elements
103
A and
103
B are power switching elements such as insulated gate bipolar transistors (IGBT). The semiconductor element
103
A has an emitter electrode
131
and a gate electrode
132
on its front surface, and a collector electrode
133
on its rear surface. The same holds true to the semiconductor element
103
B. The semiconductor elements
103
A and
103
B are mounted in the face-down state. In
FIG. 12
, the emitter electrodes
131
and gate electrodes
132
are under the semiconductor elements
103
A and
103
B while the collector electrodes
133
are on the semiconductor elements
103
A and
103
B. In each of the semiconductor elements
103
A and
103
B, the emitter electrode
131
, gate electrode
132
and collector electrode
133
are electrically connected in parallel.
The common emitter power source plate
101
and common collector power source plate
105
are mainly made of copper, a copper alloy or the like which has excellent electric conductivity and thermal conductivity. The semiconductor elements
103
A and
103
B are made of silicon. A thermal buffer
102
is provided between the common emitter power source plate
101
and the semiconductor elements
103
A and
103
B considering a difference of thermal expansion coefficients of these materials. Further, another thermal buffer
104
is provided between the common collector power source plate
105
and the semiconductor elements
103
A and
103
B.
A side cover
106
extends around the common emitter power source plate
101
, semiconductor elements
103
A and
103
B and common collector power source plate
105
, and are ceramics insulators or the like in order to avoid electric short-circuiting between the common emitter power source plate
101
and common collector power source plate
105
.
With this press-contact type semiconductor device
100
, a switching voltage V is supplied to the gate electrodes
132
of the semiconductor elements
103
A and
103
B from an external power source
110
in order to intermittently introduce a current I to the common emitter power source plate
101
from the common collector power source plate
105
.
In the semiconductor device
100
, a reference potential of the switching voltage V is an emitter potential. In other words, an external terminal
101
P of the common emitter power source plate
101
is connected to a reference potential terminal of the external power source
110
, and a circuit operating potential terminal is connected to a gate terminal
132
P for supplying the switching voltage V to the gate electrode
132
. See FIG.
12
. As a result, inductances Ls
1
to Ls
4
and Lg
1
to Lg
3
are generated in circuits between the gate electrodes
132
and emitter electrodes
131
of the semiconductor elements
103
A and
103
B.
The inductances Ls
1
and Ls
2
apply an induction voltage to the switching voltage V in response to a variation dI/dt of the current I, which causes mal-operations (error operations) of the semiconductor elements
103
A and
103
B. Further, the inductance Ls
1
and Ls
2
result in current concentration. The inductances Ls
2
, Ls
3
and Lg
1
delay timings for switching on or off the semiconductor elements
103
A and
103
B, which will lead to power loss. Still further, the semiconductor elements
103
A and
103
B may operate at varying timings. The inductances Lg
2
and Lg
3
may cause oscillations between the semiconductor elements
103
A and
103
B, and vibrate the current I. The inductances Lg
2
and Lg
3
cause current concentration.
BRIEF SUMMARY OF THE INVENTION
According to the embodiment of the invention, there is provided a press-contact type semiconductor device comprising at least: a plurality of semiconductor elements each of which has a first main electrode and a control electrode on a front surface thereof and a second main electrode on a rear surface thereof; a second common main power source plate having the semiconductor elements positioned on a front surface thereof and electrically connected to the second main electrodes; a first common main power source plate arranged on the front surface of the semiconductor elements and electrically connected to the first main electrodes of the semiconductor elements; a common control signal/main current plate arranged between the semiconductor elements and having at least a common control signal wiring layer electrically connected to the control electrodes and a main current wiring layer electrically connected to the first main electrodes; a conductive connector electrically for connecting at least the main current wiring layer and the first common maim power source plate; and a conductive elastic member configured to connect electrically the main current wiring layer or the first common main power source plate to the conductive connector by elasticity.
REFERENCES:
patent: 4996586 (1991-02-01), Matasuda et al.
patent: 5610439 (1997-03-01), Hiyoshi et al.
patent: 5708299 (1998-01-01), Teramae et al.
patent: 6281569 (2001-08-01), Sugiyama
patent: 6297549 (2001-10-01), Hiyoshi
patent: 0 923 127 (1999-06-01), None
patent: 2001-102520 (2001-04-01), None
Omura et al.; “Semiconductor Device, Drive Method, and Drive Apparatus”; U.S. patent application No. 09/312,718, filed May 17, 1999.
Miyake et al.; “Pressure—Contact Type Semiconductor Device”; U.S. patent application No. 09/774,610, filed Feb. 1, 2001.
Domon Tomokazu
Endo Yoshiki
Miyake Eitaro
Omura Ichiro
Clark Sheila V.
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Kabushiki Kaisha Toshiba
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