INVERTER R&D
IPT Electronics : High Power Density Inverter
�
300V)
�
coolant, 450ARMS at 72C coolant
� 22kg => 3000W/kg
bidirectional DC-DC converter)
� Advanced power control circuits
� High accuracy torque control
� Designed for automotive reliability
DC-DC Converter Section
Traction Inverter Section
65kW at 250V (80kW at
500ARMS at 57C
(includes 3/2kW
INVERTER R&D
VD C VA C MM M T
ID C IA C N M N T
Customer Specification
Ansoft/Speed
DyRoBeS
Motor Requirements
Motor Thermal Design
Inverter Requirements
Motor Electromagnetic Design
Cost Evaluation
Transmission Requirements
Preliminary Design
Preliminary Design
Performance Evaluation
System Simulation Framework – E-Drives
Inverter
Controller
M otor Transmission DC Supply Load
Matlab/Simulink
Matlab
MotorCad/Ansoft
Motor Mechanical Design
Transmission Assumptions
INVERTER R&D
Advanced Technology Developments
Power Semiconductor Packaging Design & Manufacturing
INVERTER R&D
• Thermal Stress on wire bonds
•
ECOSTAR POWER MODULE FACILITY
Interconnection
Therm
al&
Induct
ance
PathsReliability
Spatial
Require
men
ts
Inductive effects in Power Module
Silicon Efficiency
INVERTER R&D
Thermal and Mechanical Properties of Each Layers
( 3 ) (W/ (J/ (ppm/
8979 389 381
3100 150 880 227
/ 8470 50
8930 170 431 327
/ 11100 35
2703 796
2760 237 70
2330 oC oC
oC oC
702
Material Density
kg mThermal condutivity
m K) Specific heat
kg K) Young’s modile
(GPa) CTE
K)
Copper 112.9 16.4
AlSiC 6.8
60Sn 40 Pb solder 364.5 29.8 21.1
DBC AIN 2.5
95Pb 5Sn solder 133.7 20.4 25.1
Thermal grease 0.735 0.011 16.4
Aluminum 858.8 23.6
Silicon 153 @ 25 119 @ 77
98.9 @ 127 76.2 @ 227
112.9 2.54
INVERTER R&D
Thermal Resistance Predicted Using Numerical Tools
CAD model
Temperature predicted from CFD simulation
� In developing Ballard Custom Power Module with integrated
fluid dynamics (CFD) was used to simulate fluid flow along fins and heat transfer within solids.
� The predicted maximum junction-to-coolant thermal resistance is 0.09 oC/W per switch, and the average number is about 0.08 oC/W per switch.
pinfin baseplate, computational
INVERTER R&D
Junction Temperature of IGBT and Diode
Temperature predicted from CFD simulation for CPM with pinfin baseplate
Inl
l
� Application condition similar to IPT “Full Torque Stall”.
� Power loss is 350W for IGBT and 105W for Diode per switch.
� Coolant inlet temperature is 85 oC, flow rate is 2 gpm.
i l lSi i i lSi
T (oC) 139 118
T (oC) 127 112
IGBT and Diode Temperature for CPMs with Flat and Pinfin Baseplates
118.2
85.0
88.3
91.6
95.0
98.3
101.6
104.9
108.2
111.6
114.9
et
Out et
CPM w th f at A C baseplate CPM w th pinf n A C baseplate
jIGBT
jDiode
INVERTER R&D
Comparison
� Thermal resistance reduced by 40% for integrated pin-fin power module.
lat in ion
l i
o o 40%
j i97 oC oC 40% *
i105 oC oC 47% *
i ion inl oC i i
Standard fbaseplate
Integrated pin-fbaseplate
Percentage reduct
Average thermaresistance per sw tch
0.12 C/W 0.07 C/W
Average IGBT unct on temperature
81
Max mum measured IGBT temperature
84
* Note: Percentage reduct on refers to temperature difference between junct and coolant that has et temperature of 60 n th s test.
INVERTER R&D
Problem Approach to Inductance Challenge
1.00 Simulation & Modeling of Structure
2.00 Inductance formulae for current paths
3.00 Physical Systems Test
INVERTER R&D
Inductance Analysis
OBJECTIVES
•
�
• Optimize layout for minimum inductance Reduce Parasitics
• Lower switching losses • Minimize effects of body diode recovery • Reduce bond wire stress • Minimize EMI
Alternative Embedded Busbar Structures
INVERTER R&D
�Inductance Analysis of the D.C. Link
ANSOFT Simulation Model
i ls
Ta Tb Tc
Sa Sb Sc
Units = nH
Measured Results
Term nashorted phase
4.5 7.2 9.2 6.0 4.1 6.0 9.2 7.2 4.5
INVERTER R&D
0
1
nH
Physical Testing Formulae Based 15 mil wire
0
1
0
Ind
uct
ance
in n
H
nH
Path Inductance - The Bond Wires
Delta Inductance - 15 mil & 20 mil Wires
0.2
0.4
0.6
0.8
1.2
Wire #'s - (1-2), (2-3), (3-4)
20mil 15 mil
Path Inductance of Bond Wires
0.2
0.4
0.6
0.8
10 20 30
Wire Diameter in mil
INVERTER R&D
Achieved Benefits
� Increased package performance: � Significant reduction in
parasitic inductance � Significant reduction in
thermal resistance � Increased power density
� Increase packaging integration
� Reduced system packaging space
� Reduced system cost � Improved reliability
INVERTER R&D
Transient Thermals
Cu baseplate With Al203 DBC
DBC.
a 10% improvement in thermal resistance Due to the Aln
Comparison
° C/W
1.00 E-05
1.00 E-04
1.00 E-03
1.00 E-02
1.00 E-01
1.00 E +00
1.00 E-05
1.00 E-04
1.00 E-03
1.00 E-02
1.00 E-01
1.00 E+00
1.00 E+01
Cu Junction to Base Cu Substrate to Base - Al203
AlSic : Junction to Base AlSic : Substrate to Base - AlN
100mS - Pulse - 800A Power Module
compared to
AlSic and Aln
AlSic & Aln offers
DBC substrate
INVERTER R&D
Materials Reliability
30
50
70
90
13
0
15
0
lii
lii ing
i lSi ln
i l
Comparison
improvement
1.00 E-03
1.00 E-04
1.00 E+05
1.00 E+06
1.00 E+07
1.00 E +08
110
Temperature Delta in Tj
Wire Bond Capabi ty with coat ng
Wire Bond Capabi ty with NO protect ve coat
Solder fat gue for A c & A
Solder fat gue for Cu & A 203
• Cu with Al203
• AlSic with Aln
• Wire Bond Coating
INVERTER R&D
POWER SILICON
• IGBT Heat Diffusion
.
• Stress in bond wire.
This view is below bond wire
- IGBT Devices evaluated -Eupec, Semikron, ABB, Toshiba, Hitachi, Fuji
INVERTER R&D
TOSHIBA
IGBT Technical Trend for Cross Section (600V – 1700V)
Conventional DesignConventional Design Current DesignCurrent Design Future DesignFuture Design
Collector
P+
N Buffer
N- (Epi)
N+
P- Base P+
Emitter
PT-Trench Thin NPT-Trench Ultra Thin PT-Trench Emitter
P+
Gate
N
N
P+P+
N+ N+
P- Base
N Buffer
P+
Gate
P- Base
Emitter
Collector
Gate
Collector
• Ultra Thin Wafer
• Low Injection Efficiency
Improvement for Trade off of
Eoff-VCE(sat)
Improvement forTrade off of
Eoff-VCE(sat)
Ultra-Thin-PT-TrenchPT-PlanerThin-NPT-Trench
INVERTER R&D
TOSHIBA
600V IGBT Eoff-VCE(sat) Trade-off
Eof
f (m
J/A
)
25
PT-PlanerThin NPT-TrenchUltra Thin PT-Trench
PT-Planer (Conventional)
Thin NPT-Trench (Latest)
Ultra Thin PT-Trench (Future) VS VS
Eoff - VCE(sat) of 600V Type
0.00
0.02
0.04
0.06
0.08
0.10
0.12
1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8
VCE(sat) (V)
Future(Target) Compact MIP
@V C C =300V, IC =Rated-IC , VGE=+-15V
125
INVERTER R&D
Switching Waveforms
-25
-20
-15
-10
-5
0
5
10
15
20
25
0 100 -700
-600
-500
-400
-300
-200
-100
0
0
Clamped inductive load switching at 25C.
diode
current voltage
200 300 400 500
Time (ns)
Id (
A)
100 200 300 400
Time (ns)
Vd
(V
)
Red trace SiC, blue trace 1200V hyperfast Si pin
500
INVERTER R&D
Reverse Recovery Summary
25C
3
37%
Qrr (nC) 446 28 6%
i PJ) 139 9
PJ) 198 149 75%
125C
12.5 3 24%
37 19 51%
Recovered charge 231 28 12%
�PJ) 69 9 13%
�PJ) 173 149 86%
Si PiN SiC SiC vs Si
Peak reverse current Ipr (A) 17.5 17%
Reverse recovery time Trr (ns) 51 19
Recovered charge
Diode loss Eoff D ode ( 6%
IGBT loss Eon IGBT (
Si PiN SiC SiC vs Si
Peak reverse current Ipr (A)
Reverse recovery time Trr (ns)
Qrr (nC)
Diode loss Eoff Diode
IGBT loss Eon IGBT
INVERTER R&D
Hybrid Power Inverter Development
Power Inverter Hardware & Analysis for a Hybrid Vehicle Platform
INVERTER R&D
PM Synchronous Motor Model
INVERTER R&D
l
0
l
PM Synchronous Motor – 15 kW Operation
15 kW Peak Operating Points
0.0
50.0
100.0
150.0
200.0
250.0
300.0
0.0 1000.0 2000.0 3000.0 4000.0 5000.0 6000.0
Motor Speed, RPM
To
rqu
e (N
m)
Cu
rren
t (A
pk)
Vo
ltag
e (V
rms)
0.000
0.200
0.400
0.600
0.800
1.000
1.200
Torque L-N Vo tage, Pk Phase Current, Pk Power Factor
15 kW Continuous Operating Points
0.0
50.0
100.0
150.0
200.0
250.0
1000 2000 3000 4000 5000 6000
Motor Speed, RPM
To
rqu
e (N
m)
Cu
rren
t (A
pk)
Vo
ltag
e (V
rms)
0.000
0.200
0.400
0.600
0.800
1.000
Torque L-N Vo tage, Vpk Phase Current, Pk Power Pactor
INVERTER R&D
0
50
100
150
1 2 3 4
i i i i i i ion
Maximum Coolant Temperature – 15 kW Drive
15 kW Inverter - CPM IGBTs / Switch
-150
-100
-50
Number of IGBT Die Per Switch
Max
imu
m A
llow
able
Co
ola
nt
Tem
per
atu
re, C
8 kHz Sw tch ng 4 kHz Sw tch ng 2 kHz Sw tch ng Phase-Phase Rotat
12 April 2003
INVERTER R&D
0
50
100
150
1 2 3 4
i i i i i i ion
il 2003
Maximum Coolant Temperature – 25 kW Drive
25 kW Inverter - CPM IGBTs / Switch
-150
-100
-50
Number of IGBT Die Per Switch
Max
imu
m A
llow
able
Co
ola
nt
Tem
per
atu
re, C
8 kHz Swtch ng 4 kHz Swtch ng 2 kHz Swtch ng Phase-Phase Rotat
12 Apr
INVERTER R&D
Voltage Overshoot Reduction
Integrated DC-Bus Snubbers
INVERTER R&D
Further Work
•
• Silicon integration of gate drive and sensing circuits.
•EMI containment
Thermistor
Silicon Sensor
Vs
Faster Temperature Sensing of Silicon Junction.
- Turn-on speed and diode recovery. - DC Bus Capacitance integrated with
Busbar in module.
