Miscellaneous active electrical nonlinear devices – circuits – and – Gating – Utilizing three or more electrode solid-state device
Reexamination Certificate
2001-01-23
2003-03-04
Lam, Tuan T. (Department: 2816)
Miscellaneous active electrical nonlinear devices, circuits, and
Gating
Utilizing three or more electrode solid-state device
C327S435000, C327S565000
Reexamination Certificate
active
06529062
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor device including a switching semiconductor element and a controlling IC for controlling the switching semiconductor element, and more specifically concerns a power module.
2. Description of the Related Art
Conventionally, an intelligent power module (IPM) containing a power circuit constituted by a switching semiconductor element and a control circuit for controlling the power circuit has a construction in which the power circuit and the control circuit constituted by an integrated circuit (IC) serving as a controlling IC are formed in a separated manner as two stages (FIG.
7
), or the control circuit and the power circuit are integrally formed on one substrate (FIGS.
6
and
8
).
Moreover, a power module shown in
FIG. 6
has a construction in which an MOSFET (metal oxide semiconductor field effect transistor)
100
is connected to an electrode layer
6
on a heat sink
2
and a controlling IC
12
is bonded thereto by a bonding agent layer
16
through an insulating layer
14
on the MOSFET
100
.
Here, a power module shown in
FIG. 8
has a construction in which a switching semiconductor element
8
, a FWDi
10
, a printed substrate
110
and a case
102
are formed on an insulating substrate
4
on a heat sink
2
. A controlling IC
12
is assembled on the printed substrate
110
. The FWDi
10
is connected to the switching semiconductor element
8
and the printed substrate
110
by bonding wires
20
. The switching semiconductor element
8
and the printed substrate
110
are connected to terminals, not shown, on the case
102
, by respective bonding wires
20
.
A power module, shown in
FIG. 7
, has an arrangement in which a switching semiconductor element
8
and a case
102
are placed on an insulating substrate
4
bonded to a heat sink
2
, and a control substrate
104
, supported by a relay terminal
106
on the case
102
, is installed. Here, the switching semiconductor element
8
is connected to a relay terminal
106
by a bonding wire
20
. The control substrate
104
contains a controlling IC for controlling the switching semiconductor element
8
, etc. The relay terminal
106
is used so as to transmit driving input signals, driving output signals, detection signals for current, voltage and temperature, etc. of the switching semiconductor element between the switching semiconductor element
8
and the controlling IC on the control substrate
104
.
Moreover, with respect to a semiconductor device having a construction in which a control circuit constituted by semiconductor elements, and a power circuit, etc. are integrally formed, Japanese Laid-Open Patent Publications No. 6-181286, No. 63-87758, No. 3-226291, No. 11-163256 and No. 8-167838 have disclosed such a construction.
Japanese Laid-Open Patent Publication No. 6-181286 discloses a semiconductor device having a construction in which a controlling IC chip is bump-connected onto a power IC chip fixed to a heat sink through a thin-film substrate.
Japanese Laid-Open Patent Publication No. 63-87758 discloses a semiconductor device having a construction in which a controlling IC is joined to a power MOSFET fixed to a heat sink.
Japanese Laid-Open Patent Publication No. 3-226291 discloses a semiconductor device having a construction in which an IGBT (insulated gate bipolar transistor), an FWDi (Free Wheeling Diode) and a controlling IC are formed into one chip.
Japanese Laid-Open Patent Publication No. 11-163256 discloses a semiconductor device having a construction in which on a semiconductor chip on a heat radiation plate is superposed another semiconductor chip, that is, a so-called chip-on-chip construction, and Japanese Laid-Open Patent Publication No. 8-167838 discloses a semiconductor device having a construction in which a plurality of power-MOSFETs and a control circuit are integrated as one chip.
SUMMARY OF THE INVENTION
For example, in a structure of a semiconductor device shown in
FIG. 6
, in the case when a controlling IC
12
is attached to an MOSFET
100
(IGBT or power MOSFET) by means of a bump, an insulating layer
14
, a bonding-agent layer
16
or a press-joining, etc., a problem arises in which the controlling IC malfunctions due to heat generated by the switching semiconductor element
8
. Here, MOSFET
100
serves as the switching semiconductor element constituted by a power circuit. Moreover, in the case when the controlling IC
12
is packaged inside the switching semiconductor element
8
also, the same problem arises in which the controlling IC malfunctions due to heat generated by the switching semiconductor element
8
. Therefore, the problem with the semiconductor devices having the constructions disclosed in Japanese Laid-Open Patent Publications No. 6-181286 and No. 63-87758 is that the controlling IC is susceptible to malfunctions due to heat.
Moreover, in the semiconductor device disclosed by Japanese Laid-Open Patent Publication No. 3-226291 also, a problem arises in which the controlling IC malfunctions due to heat generated by the IGBT, depending on the positional relationship between the IGBT and the controlling IC.
Furthermore, as illustrated in
FIG. 7
, in the case when, in a power module, the MOSFET or the IGBT serving as a switching semiconductor elements
8
, the FWDi
10
(Free Wheeling Diode) and the controlling IC
12
, etc. are constructed in a separated manner, the number of parts related to the construction increases and the construction becomes complex, resulting in high costs in the module per unit. Another problem is that the power module as a whole becomes comparatively large.
In the case of the power module shown in
FIG. 8
also, a problem arises in which the power module as a whole becomes comparatively large.
The present invention has been devised to solve the above-mentioned problems, and its objective is to make the power module as a whole compact, and to provide an inexpensive power module which can prevent malfunction of the controlling IC due to heat generated by the switching semiconductor element, while maintaining resistance to switching noise from the switching semiconductor element.
The power module of the first aspect of the present invention, which has been devised to solve the above-mentioned problems, is provided with an insulating substrate having a base plate bonded to one of faces thereof and a circuit pattern formed on the other face as an electrode layer, the circuit pattern including: a switching semiconductor element, a free wheeling diode connected to the switching semiconductor element in anti-parallel therewith, and a controlling IC for controlling the switching semiconductor element, and in this arrangement, the controlling IC is formed on the free wheeling diode.
In accordance with the power module of the first aspect of the invention, since the controlling IC is placed on the FWDi which generates less heat upon operation than the switching semiconductor element it is possible to prevent the controlling IC from malfunctioning due to heat generated by the switching element. Therefore, it becomes possible to improve reliability of the power module.
The power module of the second aspect of the present invention, which relates to the power module of the first aspect, is characterized in that the switching semiconductor element and the free wheeling diode are constructed as a monolithic integrated circuit.
In accordance with the power module of the second aspect of the present invention, the switching semiconductor element and the free wheeling diode are constituted as a monolithic integrated circuit; therefore, it is possible to make the power module compact, and also to simplify the construction thereof. Thus, it becomes possible to increase the productivity in the wafer manufacturing process and the assembling process of the semiconductor, and consequently to reduce the unit price of the power module.
The power module of the third aspect of the present invention is provided with an insulating substrate having a base plate bon
Hatae Shinji
Iwagami Toru
Iwasaki Mitsutaka
Majumdar Gourab
Tametani Fumitaka
Lam Tuan T.
Mitsubishi Denki & Kabushiki Kaisha
Nguyen Hiep
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