U.S. patent application number 10/790705 was filed with the patent office on 2005-03-10 for power semiconductor device.
This patent application is currently assigned to MITSUBISHI DENKI KABUSHIKI KAISHA. Invention is credited to Ushijima, Koichi.
Application Number | 20050051874 10/790705 |
Document ID | / |
Family ID | 34225139 |
Filed Date | 2005-03-10 |
United States Patent
Application |
20050051874 |
Kind Code |
A1 |
Ushijima, Koichi |
March 10, 2005 |
POWER SEMICONDUCTOR DEVICE
Abstract
Emitter electrodes (Es) and collector electrodes (Cs) of
elements (101 to 104) are connected to bus electrodes (361 to 364)
of a bus bar (351), respectively. The bus bar (351) contains seven
layers including four insulating layers (not shown) and three
conductive layers (shown) interposed between the insulating layers.
Namely, each of the bus electrodes (361 to 364) is connected to one
of the conductive layers corresponding to one of a positive
electrode (P), a negative electrode (N) and an intermediate
electrode (L). The collector electrodes (Cs) of the elements (103
and 104) are connected one over the other to the bus electrode
(361). The emitter electrodes (Es) of the elements (103 and 104)
are connected one over the other to the bus electrode (362). The
collector electrodes (Cs) of the elements (101 and 102) are
connected one over the other to the bus electrode (363). The
emitter electrodes (Es) of the elements (101 and 102) are connected
one over the other to the bus electrode (364).
Inventors: |
Ushijima, Koichi; (Hyogo,
JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
MITSUBISHI DENKI KABUSHIKI
KAISHA
TOKYO
JP
RENESAS DEVICE DESIGN CORPORATION
Itami City
JP
|
Family ID: |
34225139 |
Appl. No.: |
10/790705 |
Filed: |
March 3, 2004 |
Current U.S.
Class: |
257/573 ;
257/E25.026 |
Current CPC
Class: |
H01L 2924/0002 20130101;
H01L 2924/0002 20130101; H01L 25/115 20130101; H01L 2924/00
20130101 |
Class at
Publication: |
257/573 |
International
Class: |
H01L 027/082 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 5, 2003 |
JP |
2003-313523 |
Claims
What is claimed is:
1. A power semiconductor device, comprising: a first resin-sealed
switching element including a first gate electrode, a first emitter
electrode and a first collector electrode; a second resin-sealed
switching element including a second gate electrode, a second
emitter electrode and a second collector electrode; a third
resin-sealed switching element including a third gate electrode, a
third emitter electrode and a third collector electrode; a fourth
resin-sealed switching element including a fourth gate electrode, a
fourth emitter electrode and a fourth collector electrode; and a
bus bar having first to fourth bus electrodes provided thereon in
this order, wherein said first resin-sealed switching element and
said second resin-sealed switching element are arranged to face
each other with said bus bar therebetween, and said third
resin-sealed switching element and said fourth resin-sealed
switching element are arranged to face each other with said bus bar
therebetween, said first collector electrode and said second
collector electrode are connected one over the other with said
first bus electrode, said first emitter electrode and said second
emitter electrode are connected one over the other with said second
bus electrode, said third collector electrode and said fourth
collector electrode are connected one over the other with said
third bus electrode, and said third emitter electrode and said
fourth emitter electrode are connected one over the other with said
fourth bus electrode.
2. The power semiconductor device according to claim 1, wherein
said first to fourth resin-sealed switching elements are arranged
on a surface of a single cooling fin, and said first to fourth gate
electrodes stand vertically with respect to said surface of said
cooling fin.
3. The power semiconductor device according to claim 2, wherein
said first to fourth emitter electrodes and said first to fourth
collector electrodes stand vertically with respect to said surface
of said cooling fin.
4. The power semiconductor device according to claim 1, wherein
said second bus electrode is connected to a negative electrode,
said third bus electrode is connected to a positive electrode, and
said first bus electrode and said fourth bus electrode are
connected to an intermediate electrode for inputting or outputting
an intermediate potential between a potential of said negative
electrode and a potential of said positive electrode.
5. The power semiconductor device according to claim 2, wherein
said second bus electrode is connected to a negative electrode,
said third bus electrode is connected to a positive electrode, and
said first bus electrode and said fourth bus electrode are
connected to an intermediate electrode for inputting or outputting
an intermediate potential between a potential of said negative
electrode and a potential of said positive electrode.
6. The power semiconductor device according to claim 3, wherein
said second bus electrode is connected to a negative electrode,
said third bus electrode is connected to a positive electrode, and
said first bus electrode and said fourth bus electrode are
connected to an intermediate electrode for inputting or outputting
an intermediate potential between a potential of said negative
electrode and a potential of said positive electrode.
7. A power semiconductor device, comprising: a first resin-sealed
switching element including a first gate electrode, a first emitter
electrode and a first collector electrode; a second resin-sealed
switching element including a second gate electrode, a second
emitter electrode and a second collector electrode; a third
resin-sealed switching element including a third gate electrode, a
third emitter electrode and a third collector electrode; a fourth
resin-sealed switching element including a fourth gate electrode, a
fourth emitter electrode and a fourth collector electrode; a bus
bar having first to fourth bus electrodes provided thereon in this
order; and a resin for sealing said first to fourth resin-sealed
switching elements and said bus bar together, wherein said first
resin-sealed switching element and said second resin-sealed
switching element are arranged to face each other with said bus bar
therebetween, and said third resin-sealed switching element and
said fourth resin-sealed switching element are arranged to face
each other with said bus bar therebetween, said first collector
electrode and said second collector electrode are connected one
over the other with said first bus electrode, said first emitter
electrode and said second emitter electrode are connected one over
the other with said second bus electrode, said third collector
electrode and said fourth collector electrode are connected one
over the other with said third bus electrode, and said third
emitter electrode and said fourth emitter electrode are connected
one over the other with said fourth bus electrode.
8. The power semiconductor device according to claim 7, wherein
said first to fourth resin-sealed switching elements are arranged
on a surface of a single cooling fin, and said first to fourth gate
electrodes stand vertically with respect to said surface of said
cooling fin.
9. The power semiconductor device according to claim 8, wherein
said first to fourth emitter electrodes and said first to fourth
collector electrodes stand vertically with respect to said surface
of said cooling fin.
10. The power semiconductor device according to claim 7, wherein
said second bus electrode is connected to a negative electrode,
said third bus electrode is connected to a positive electrode, and
said first bus electrode and said fourth bus electrode are
connected to an intermediate electrode for inputting or outputting
an intermediate potential between a potential of said negative
electrode and a potential of said positive electrode.
11. The power semiconductor device according to claim 8, wherein
said second bus electrode is connected to a negative electrode,
said third bus electrode is connected to a positive electrode, and
said first bus electrode and said fourth bus electrode are
connected to an intermediate electrode for inputting or outputting
an intermediate potential between a potential of said negative
electrode and a potential of said positive electrode.
12. The power semiconductor device according to claim 9, wherein
said second bus electrode is connected to a negative electrode,
said third bus electrode is connected to a positive electrode, and
said first bus electrode and said fourth bus electrode are
connected to an intermediate electrode for inputting or outputting
an intermediate potential between a potential of said negative
electrode and a potential of said positive electrode.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a power semiconductor
device, and more particularly to a technique of connecting
switching elements in parallel which are sealed with resin by the
transfer mold process and the like in a power control device and
the like.
[0003] 2. Description of the Background Art
[0004] In general, a power semiconductor element including one
switching element (a MOS-FET, a bipolar transistor, an IGBT and the
like) which is sealed with resin by the transfer mold process and
the like is termed a 1 in 1 type power module. A power conversion
device, typically a conventional inverter or converter having the 1
in 1 type power module and a control circuit thereof within, has
presented the following problem: namely, a semiconductor substrate
and the like included in the control circuit is subjected to strong
noise and electromagnetic waves generated by a wiring inductance at
the time of switching of the switching element, resulting in a
malfunction or a breakdown of the power conversion device.
[0005] Another problem with the conventional power conversion
device is an increase in the overall packaging area because of a
wiring bus bar mounted outside the sealing resin.
[0006] Japanese Patent Application Laid-Open No. 11-299239 (1999),
2000-023462 and 10-209197 (1998) give examples of power conversion
devices so designed in length, shape and the like of a wiring that
they reduce the wiring inductance.
[0007] The structures of the above power conversion devices are not
necessarily premised on the use of the 1 in 1 type power module as
a power module. Those are thus less-than-optimal structures when
they are premised on the use of the 1 in 1 type power module,
leaving problems from the viewpoints of wiring inductance,
packaging area and the like.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide a power
conversion device with a reduced wiring inductance and packaging
area.
[0009] A power semiconductor device according to a first aspect of
the present invention includes a first resin-sealed switching
element, a second resin-sealed switching element, a third
resin-sealed switching element, a fourth resin-sealed switching
element and a bus bar. The first resin-sealed switching element
includes a first gate electrode, a first emitter electrode and a
first collector electrode. The second resin-sealed switching
element includes a second gate electrode, a second emitter
electrode and a second collector electrode. The third resin-sealed
switching element includes a third gate electrode, a third emitter
electrode and a third collector electrode. The fourth resin-sealed
switching element includes a fourth gate electrode, a fourth
emitter electrode and a fourth collector electrode. First to fourth
bus electrodes are provided in this order on the bus bar. The first
resin-sealed switching element and the second resin-sealed
switching element are arranged to face each other with the bus bar
therebetween, and the third resin-sealed switching element and the
fourth resin-sealed switching element are arranged to face each
other with the bus bar therebetween. The first collector electrode
and the second collector electrode are connected one over the other
with the first bus electrode. The first emitter electrode and the
second emitter electrode are connected one over the other with the
second bus electrode. The third collector electrode and the fourth
collector electrode are connected one over the other with the third
bus electrode. The third emitter electrode and the fourth emitter
electrode are connected one over the other with the fourth bus
electrode.
[0010] The number of the bus electrodes becomes fewer and the bus
bar correspondingly gets shorter. Therefore, the wiring length
thereby shortened allows a reduction of the wiring inductance.
Moreover, since the bus bar is arranged between the elements, a
packaging area can be reduced.
[0011] A power semiconductor device according to a second aspect of
the present invention includes a first resin-sealed switching
element, a second resin-sealed switching element, a third
resin-sealed switching element, a fourth resin-sealed switching
element, a bus bar and a resin. The first resin-sealed switching
element includes a first gate electrode, a first emitter electrode
and a first collector electrode. The second resin-sealed switching
element includes a second gate electrode, a second emitter
electrode and a second collector electrode. The third resin-sealed
switching element includes a third gate electrode, a third emitter
electrode and a third collector electrode. The fourth resin-sealed
switching element includes a fourth gate electrode, a fourth
emitter electrode and a fourth collector electrode. First to fourth
bus electrodes are provided in this order on the bus bar. The resin
seals the first to fourth resin-sealed switching elements and the
bus bar together. The first resin-sealed switching element and the
second resin-sealed switching element are arranged to face each
other with the bus bar therebetween, and the third resin-sealed
switching element and the fourth resin-sealed switching element are
arranged to face each other with the bus bar therebetween. The
first collector electrode and the second collector electrode are
connected one over the other with the first bus electrode. The
first emitter electrode and the second emitter electrode are
connected one over the other with the second bus electrode. The
third collector electrode and the fourth collector electrode are
connected one over the other with the third bus electrode. The
third emitter electrode and the fourth emitter electrode are
connected one over the other with the fourth bus electrode.
[0012] The insulating property may be enhanced by sealing the first
to fourth resin-sealed switching elements and the bus bar
together.
[0013] These and other objects, features, aspects and advantages of
the present invention will become more apparent from the following
detailed description of the present invention when taken in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows a circuit configuration of a conventional power
conversion device;
[0015] FIG. 2 shows a structure of an element used in the
conventional power conversion device;
[0016] FIG. 3 is a perspective view showing an element
configuration in the conventional power conversion device;
[0017] FIG. 4 is a perspective view showing a connection
configuration of elements in a power conversion device 1 according
to a first preferred embodiment of the invention;
[0018] FIG. 5 is a perspective view showing a connection
configuration of the elements in the power conversion device 1
according to the first preferred embodiment;
[0019] FIG. 6 shows a structure of an element used in a power
conversion device 2 according to a second preferred embodiment of
the invention;
[0020] FIG. 7 is a perspective view showing a connection
configuration of the elements in the power conversion device 2
according to the second preferred embodiment;
[0021] FIG. 8 shows a structure of an element used in a power
conversion device 3 according to a third preferred embodiment of
the invention;
[0022] FIG. 9 shows a structure of an element used in the power
conversion device 3 according to the third preferred embodiment;
and
[0023] FIG. 10 is a perspective view showing a connection
configuration of the elements in the power conversion device 3
according to the third preferred embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] <First Preferred Embodiment>
[0025] A power semiconductor device (power conversion device)
according to a first preferred embodiment of the present invention
features a reduction in length of a bus bar and packaging area, by
arranging two power module elements each on both sides of the bus
bar rather than arranging four power module elements on one side of
the bus bar. Namely, the elements arranged in twos face each other
with the bus bar between.
[0026] First, as a background to the present preferred embodiment,
a configuration of a conventional power conversion device will now
be described with reference to FIGS. 1 to 3.
[0027] FIG. 1 shows a circuit configuration of the conventional
power conversion device.
[0028] The power conversion device includes elements 101 to 104
each of which is the 1 in 1 type power module element sealed with
resin by the transfer mold process and the like. The elements 101
to 104 have a gate electrode G, an emitter electrode E and a
collector electrode C, respectively. As explained below, the
elements 101 to 104 function as first to fourth resin-sealed
switching elements of the present invention, respectively.
[0029] Collector electrodes Cs of the elements 101 and 102 are
connected to a positive electrode P. Emitter electrodes Es of the
elements 103 and 104 are connected to a negative electrode N.
Emitter electrodes Es of the elements 101 and 102 and collector
electrodes Cs of the elements 103 and 104 are connected to an
intermediate electrode L. The intermediate electrode L inputs or
outputs an intermediate potential between a potential of the
positive electrode P and a potential of the negative electrode N. A
target connection of the gate electrodes Gs is omitted here since
it is barely directly pertinent to the present invention.
[0030] Each of the elements 101 to 104 has the same structure as
shown in FIG. 2 and the same electric characteristics. In FIG. 2,
the thickness direction of an element itself which is a rectangular
parallelepiped is defined as "z", and an x axis and a y axis are
defined to be parallel to each side perpendicular to the z axis. In
FIG. 2, a control pin group PG containing a plurality of control
pins extends in the z direction from one side (x=0) of the element
itself. Additionally, a collector electrode C and an emitter
electrode E both of which are made of conducting board extend in
the x direction from the element itself. In FIG. 2, the y
coordinates of the collector electrode C are greater than the y
coordinates of the emitter electrode E. Here, it is assumed that
one of the control pins of the control pin group PG corresponds to
the gate electrode G in FIG. 1.
[0031] FIG. 3 is a perspective view showing a connection
configuration of the elements which corresponds to the circuit
configuration shown in FIG. 1.
[0032] In FIG. 3, the emitter electrodes Es and the collector
electrodes Cs of the elements 101 to 104 are connected to bus
electrodes 311 to 318 of a bus bar 301, respectively. The bus bar
301 contains seven layers including four insulating layers (not
shown) and three conductive layers (shown) interposed between the
insulating layers. The three conductive layers correspond to the
aforementioned positive electrode P, the negative electrode N and
the intermediate electrode L, respectively. Namely, each of the bus
electrodes 311 to 318 is connected to one of the conductive layers
corresponding to one of the positive electrode P, the negative
electrode N and the intermediate electrode L.
[0033] The collector electrode C of the element 101 is connected to
the bus electrode 311. The emitter electrode E of the element 101
is connected to the bus electrode 312. The collector electrode C of
the element 102 is connected to the bus electrode 313. The emitter
electrode E of the element 102 is connected to the bus electrode
314. The collector electrode C of the element 103 is connected to
the bus electrode 315. The emitter electrode E of the element 103
is connected to the bus electrode 316. The collector electrode C of
the element 104 is connected to the bus electrode 317. The emitter
electrode E of the element 104 is connected to the bus electrode
318.
[0034] As shown in FIG. 3, the above connections to the elements
101 to 104 are established by bringing the electrodes to be
connected into contact with each other, putting bolts 401 to 408
through bolt holes made in the electrodes, and fastening the bolts
with nuts 501 to 508.
[0035] Then, the positive electrode P, the negative electrode N and
the intermediate electrode L are connected to the three conductive
layers of the bus bar 301, respectively, by externally using a bus
bar, lead or the like. Consequently, the circuit configuration
shown in FIG. 1 is realized.
[0036] Further, a surface of a cooling fin 601 comes into contact
with the elements 101 to 104. The cooling fin 601 is arranged on a
side (-z direction in FIG. 2) opposite to the control pin group PG
of the elements 101 to 104 in order to avoid contact with the
control pin group PG. Namely, in FIG. 3, the cooling fin 601 is
arranged on the under side of the elements 101 to 104.
[0037] The conventional power conversion device, which is
configured as discussed above, has presented a problem of an
increase in wiring length in the bus bar and a corresponding
increase in inductance. Another problem is an increase in the
overall packaging area because of the four power module elements
arranged on one side of the bus bar (when the elements 101 to 104
are sealed together with resin, the bus bar 301 is arranged outside
the resin).
[0038] FIG. 4 is a perspective view showing a connection
configuration of elements in a power conversion device 1 as a power
semiconductor device according to the first preferred embodiment.
FIG. 4 differs from FIG. 3 in that a bus bar 351 having four bus
electrodes 361 to 364 is used instead of the bus bar 301 having the
eight bus electrodes 311 to 318. Namely, by arranging two elements
each on both sides of the bus bar (making the elements face each
other in twos with the bus bar between) rather than arranging four
elements on one side of the bus bar, it becomes possible to connect
electrodes of the two elements facing each other per one bus
electrode. As explained below, the bus electrodes 361 to 364
function as first to fourth bus electrodes of the present
invention, respectively.
[0039] In FIG. 4, the emitter electrodes Es and the collector
electrodes Cs of the elements 101 to 104 are connected to the bus
electrodes 361 to 364 of the bus bar 351, respectively. As with the
bus bar 301, the bus bar 351 contains seven layers including four
insulating layers (not shown) and three conductive layers (shown)
interposed between the insulating layers. Namely, each of the bus
electrodes 361 to 364 is connected to one of the conductive layers
corresponding to one of the positive electrode P, the negative
electrode N and the intermediate electrode L.
[0040] In regard to the three conductive layers contained in the
bus bar 351 shown in FIG. 4, the bus electrodes 361 and 364 are
provided on a top layer to be connected to the intermediate
electrode L. The bus electrode 362 is provided on a middle layer to
be connected to the negative electrode N. The bus electrode 363 is
provided on a bottom layer to be connected to the positive
electrode P.
[0041] The collector electrodes Cs of the elements 103 and 104 are
connected to the bus electrode 361. The emitter electrodes Es of
the elements 103 and 104 are connected to the bus electrode 362.
The collector electrodes Cs of the elements 101 and 102 are
connected to the bus electrode 363. The emitter electrodes Es of
the elements 101 and 102 are connected to the bus electrode
364.
[0042] As shown in FIG. 4, the above connections to the elements
101 to 104 are established by bringing the electrodes to be
connected into contact with one another, putting the bolts 401 to
404 through bolt holes made in the electrodes, and fastening the
bolts with the nuts 501 to 504.
[0043] Then, the positive electrode P, the negative electrode N and
the intermediate electrode L are connected to the three conductive
layers of the bus bar 351, respectively, by externally using a bus
bar, lead or the like. Consequently, the circuit configuration
shown in FIG. 1 is realized.
[0044] Further, the surface of the cooling fin 601 and a surface of
a cooling fin 602 come into contact with the elements 101, 103 and
the elements 102, 104, respectively. The cooling fins 601 and 602
are arranged on the side (-z direction in FIG. 2) opposite to the
control pin group PG of the elements 101 to 104 in order to avoid
contact with the control pin group PG. Namely, in FIG. 4, the
cooling fin 601 is arranged on the under side of the elements 101
and 103, and the cooling fin 602 is arranged on the upper side of
the elements 102 and 104.
[0045] In the connection configuration shown in FIG. 4, the number
of the bus electrodes becomes fewer and the bus bar correspondingly
gets shorter. Therefore, the wiring length thereby shortened allows
a reduction in wiring inductance.
[0046] Further, since the number of the positive electrode P and
the electrode N is one, respectively, the number of connection
leads can be fewer with reference to FIG. 3. This allows a
reduction in wiring inductance.
[0047] Still further, since the bus bar is arranged between the
elements, a packaging area can be reduced (when the elements 101 to
104 are sealed together with resin, the bus bar 351 can also be
sealed within the resin).
[0048] Moreover, in FIG. 4, the elements 101 and 102 are arranged
on this side of the elements 103 and 104 so that the intermediate
electrode L, the negative electrode N, the positive electrode P and
the intermediate electrode L are connected in this order to the bus
electrodes 361 to 364. Thus, the bolt 403 to be connected to the
positive electrode P and the bolt 402 to be connected to the
negative electrode N are adjacent to each other. Accordingly, in
the case of connecting an up/down converter circuit or the like as
a control circuit on the periphery of the elements 101 to 104, a
connecting wiring inductance can be reduced (even if the elements
103 and 104 are arranged on this side of the elements 101 and 102,
the circuit configuration shown in FIG. 1 may be realized. In this
case, the positive electrode P, the intermediate electrode L, the
intermediate electrode L and the negative electrode N are connected
in this order to the bus electrodes 361 to 364).
[0049] As discussed above, the power conversion device 1 according
to the present preferred embodiment has the effect of reducing the
wiring inductance and the packaging area.
[0050] While the above explanation refers to a case where the
number of the elements is four, the number of the elements may be
greater than four as long as it is a multiple of four. As shown in
FIG. 5, where the number of the elements is increased to eight, for
example, the bus bar is extended and the additional four elements
are connected to the bus bar in the same manner as above. In this
case, the positive electrode P and the negative electrode N are
commonly used for all the elements, while another intermediate
electrode L' is used for the additional four elements besides the
intermediate electrode L for the original four elements.
[0051] <Second Preferred Embodiment>
[0052] In the power conversion device 1 according to the first
preferred embodiment, which contains the elements 101 to 104 each
of which has the same structure as shown in FIG. 2, the two cooling
fins 601 and 602 are required. However, by replacing each of the
elements 102 and 104 with an element having a structure as shown in
FIG. 6, the number of the cooling fins can be reduced to one. The
structure in FIG. 6 differs from the structure in FIG. 2 in that
the control pin group PG extends in the opposite direction (-z
direction), and has the same electric characteristics as those in
FIG. 2.
[0053] FIG. 7 is a perspective view showing a connection
configuration of elements in a power conversion device 2 as a power
semiconductor device according to a second preferred embodiment.
The power conversion device 2 differs from the power conversion
device 1 in FIG. 4 according to the first preferred embodiment in
that the elements 102 and 104 are replaced with elements 202 and
204, respectively. In the power conversion device 2, the control
pin groups PGs of the elements 101, 202, 103 and 204 extend in the
same direction (upward). Therefore, it is possible to cool the four
elements with one cooling fin 603 while keeping the cooling fin 603
from contact with the control pin groups PGs.
[0054] There are cases where tips of the bolts 401 to 404 and the
nuts 501 to 504 come into contact with the cooling fin 603
depending on the shape of an element packaging. For this reason, as
shown in FIG. 7, an insulating member 701 made of resin which has
holes for storing the tips of the bolts 401 to 404 and the nuts 501
to 504 is used for ensuring insulation.
[0055] As discussed above, the power conversion device 2 according
to the present preferred embodiment uses the one cooling fin 603 to
cool the four elements. Therefore, the power conversion device 2
has the effect of simplifying the structure in addition to the
effect of the first preferred embodiment.
[0056] <Third Preferred Embodiment>
[0057] In the first and second preferred embodiments, the element
having the collector electrode C and the emitter electrode E
extending in the x direction from the element itself as shown FIGS.
2 and 6 is used. Alternatively, elements 101a and 103a each of
which has a structure as shown in FIG. 8 and elements 202a and 204a
each of which has a structure as shown in FIG. 9 may be used
instead. The structure in FIG. 8 differs from the structure in FIG.
2 in that the collector electrode C and the emitter electrode E
extend in the z direction from the element itself, and has the same
electric characteristics as those in FIG. 2. The structure in FIG.
9 differs from the structure in FIG. 6 in that the collector
electrode C and the emitter electrode E extend in the -z direction
from the element itself, and has the same electric characteristics
as those in FIG. 6.
[0058] FIG. 10 is a perspective view showing a connection
configuration of elements in a power conversion device 3 as a power
semiconductor device according to a third preferred embodiment. The
power conversion device 3 differs from the power conversion device
2 in FIG. 7 according to the second preferred embodiment in that
the elements 101, 202, 103 and 204 are replaced with the elements
101a, 202a, 103a and 204a, respectively.
[0059] In the power conversion device 3, the collector electrodes
Cs and the emitter electrodes Es extend in the same direction as
the control pin groups PGs. Therefore, the tips of the bolts 401 to
404 and the nuts 501 to 504 are kept from contact with the cooling
fin 603, thereby eliminating the use of the insulating member 701
made of resin.
[0060] Additionally, the distance between the collectors and the
distance between the emitters of the elements facing each other
with the bus bar 351 between become shorter, respectively (the
electrode length's worth of distance becomes the electrode
thickness' worth of distance). This allows a further reduction in
wiring inductance.
[0061] As discussed above, in the power conversion device 3
according to the present preferred embodiment, the collector
electrodes Cs and the emitter electrodes Es extend in the same
direction as the control pin groups PGs from the elements
themselves, and thus the tips of the bolts 401 to 404 and the nuts
501 to 504 are kept from contact with the cooling fin 603.
Therefore, the power conversion device 3 has the effect of
eliminating the use of the insulating member 701 made of resin.
[0062] Moreover, since the distance between the collector terminals
Cs and the distance between the emitter terminals Es of the
elements facing each other with the bus bar 351 between become
shorter, respectively, the power conversion device 3 has the effect
of further reducing the wiring inductance.
[0063] The power conversion devices 1 to 3 described above may
enhance the insulating property by sealing the elements and the bus
bar together with resin, respectively.
[0064] While the invention has been shown and described in detail,
the foregoing description is in all aspects illustrative and not
restrictive. It is therefore understood that numerous modifications
and variations can be devised without departing from the scope of
the invention.
* * * * *