Silicon Carbide Power Devices Understanding & Application Examples Utilizing the MeritsSilicon Carbide Power Devices Understanding & Application Examples Utilizing
the Merits
SiC Power Devices Understanding & Application Examples Utilizing the Merits
What is SiCSilicon Carbide) ?
SiC-SBDSchottky Barrier Diode
SiC-MOSFET
P. 2 © 2017 ROHM Co.,Ltd.
What is SiCSilicon Carbide ? •Major Semiconductor Materials •Properties: Comparison with Si •Background of Development •Merits of SiC •History of SiC Research •Approaches to SiC Devices of ROHM
SiC-SBDSchottky Barrier Diode
SiC-MOSFET
P. 3 © 2017 ROHM Co.,Ltd.
Bonding strength is extremely high
⇒thermally, chemically, mechanically stable
•Thermal stability: No liquid phase at ordinary temperatures, sublimation at 2000
•Mechanical stability: Mohs hardness (9.3) near that of diamond (10)
•Chemical stability: Inert in the presence of nearly all acids and alkalis
• IV-IV group compound semiconductors in which Si and C bond 1-to-1
• Close-packed structures in which Si-C atom pairs form unit layers
• Various polytypes exist
3” 4H-SiC wafer
SiC: Silicon Carbide
What is SiC? : Major Semiconductor Materials
Properties Si 4H-SiC GaAs GaN Application
Crystal Structure Diamond Hexagonal Zincblende Hexagonal
Energy Gap : EG (eV) 1.12 3.26 3x 1.43 3.5
high temp. operation, emission
High frequency devices
Hole Mobility: μp (cm 2/Vs) 600 100 400 200
Breakdown Field; EB (V/cm) x106 0.3 3 10x 0.4 3 Power devices
Thermal Conductivity (W/cmK) 1.5 4.9 3x 0.5 1.3 High heat dissipation
Saturation Drift Velocity: vS (cm/s) x107 1 2.7 3x 2 2.7
High frequency devices
p, n Control Good Good Good Average
Thermal Oxide Good Good Behind Behind MOS structure
P. 5 © 2017 ROHM Co.,Ltd.
What is SiC? : PropertiesSi vs SiC
SiC has excellent parameters which are important for power devices.
Properties Si 4H-SiC
Band Structure Indirect Indirect
Electron Mobility : μn (cm 2/Vs) 1400 900
Hole Mobility : μp (cm 2/Vs) 600 100
Breakdown Field : EB (V/cm) x106 0.3 3
Thermal Conductivity (W/cmK) 1.5 4.9
Saturation Drift Velocity : vS (cm/s) x107 1 2.7
Relative Dielectric Constant : εS 11.8 9.7
p, n Control Good Good
Thermal Oxide Good Good
Switching
Loss
Si SiC
processes
Power Loss: 5 to 10%
AC 105V
AC 100V
AC 6600V
If SiC
P. 7 © 2017 ROHM Co.,Ltd.
Low Resistance
Fast Operation
heat sink
SiSi SiCSiC
SiSi SiCSiC
GS
P. 8 © 2017 ROHM Co.,Ltd.
What is SiC? : History of SiC Research
Early stage of research, Difficult to control single polytype
1960
1980
1990
2000
Application to semiconductor devices has started in the 1980s
Schottky predicted outstanding properties
<Substrate> Improved Rayleigh method
Blue LED
2 Breakthroughs
P. 9 © 2017 ROHM Co.,Ltd.
Stared mass production of the world’s first trench structure SiC-MOSFET. Released full SiC power module product (Jun 2015
2002
2005
2006
2007
2008
2009
2010
2004
Developed prototype of SiC-MOSFET Dec 2004
Introduced the world smallest Ron: 3.1mΩcm² SiC- MOSFET Mar 2006)
Started mass production of SiC-MOSFET Dec 2010, the first in the world
SiC-MOSFET sample shipment Nov 2005)
Introduced the world smallest Ron: 1.7mΩcm² SiC trench MOSFET Sep 2008)
Merged SiCrystal as SiC wafer manufacture Jul 2009)
Established integrated production system for SiC devices and started mass production of SiC-SBD Apr 2010, the first in Japan
Started mass production of full SiC power module Mar 2012, the first in the world1200V 100A
Introduced the mass production technique of SiC epi by ROHM, Kyoto University and Tokyo Electron Jun 2007
2011
Developed the world smallest Ron: sub- 1mΩcm² ultra low loss SiC trench MOSFET Dec 2011)
2012
2015
P. 10 © 2017 ROHM Co.,Ltd.
What is SiCSilicon Carbide ?
SiC-SBDSchottky barrier diode •Positioning of SiC-SBD •Comparison with Si-SBD •Comparison with Si PN Diode •The 2nd Generation SiC-SBD •Merits Using SiC-SBD •Comparison of Forward Characteristics •Product Line-up of the 2nd Generation SiC-SBD
•Adoption Example
SiC-MOSFET
P. 11 © 2017 ROHM Co.,Ltd.
SiC-SBDSchottky barrier diode

6.5kV
3.3kV
1.7kV
1.2kV
900V
600V
400V
100V

6.5kV
3.3kV
1.7kV
1.2kV
900V
600V
400V
100V
• Downsizing of equipment due to higher
frequency operation
Minority carrier devices Low Ron but slow
Majority carrier devices Fast
SiC Breakdown Field
Si Breakdown Field
Electron
For achieving high voltage Si-SBD, thicker n- layer and low carrier density are needed.
Increase n- layer resistance and loss
SiC-SBD: Comparison with Si-SBD
P. 13 © 2017 ROHM Co.,Ltd.
n- (i layer)
Schottky junction
Ohmic junction
Electron Electron
Constructing PN diode with Si, as holds as minority carrier are injected into n- layer,
n- layer resistance becomes small.
Ohmic junction
P. 14 © 2017 ROHM Co.,Ltd.
n- (i layer)
n- (i layer)
Ohmic junction
Due to sweep out many holes in n- layer to p layer and also sweep out may electrons to n layer, the recovery time is long and the amount of recovery charge is large.
Reverse Biased
SiC-SBD: Comparison with Si PN Diode
P. 15 © 2017 ROHM Co.,Ltd.
n
n
Forward Biased Reverse Biased
Transition to reverse bias
Only sweeping out a few electrons in n layer is enough, the recovery time is short and the amount of recovery charge is small.
* Part of carrier disappears due to the life time.
P. 16 © 2017 ROHM Co.,Ltd.
Si PN diode has to sweep out accumulated carriers in n- layer when bias is reversed, therefore, reverse current flows until they are disappeared.
Loss must occurs
SiC Schottky Barrier DiodeSBD
P. 17 © 2017 ROHM Co.,Ltd.
-30
-20
-10
0
10
20
30
Time (nsec)
Time (nsec)
F o
rw a
rd C
u rr
e n
t: I
f (A
Time (nsec)
Time (nsec)
P. 18 © 2017 ROHM Co.,Ltd.
As Si FRD has minority carrier injection, the diffusion length of minority carrier increases with temperature raise, then recovery time at switching increases.
As SiC-SBD has no minority carrier injection, the recovery time doesn’t increase with temperature raise.
SiC-SBD is majority carrier device, therefore, the reverse current is small and no temperature dependency.
SiC-SBD: Comparison with Si PN Diode
P. 19 © 2017 ROHM Co.,Ltd.
PFC Circuit
Downsizing of peripheral parts can be achieved by higher frequency operation
-6
-4
-2
0
2
4
6
8
10
12
0 20 40 60 80 100 120 140 160 180 200
( nsec )

Vin Vout
SiC-SBD Merits Using SiC-SBD
P. 20 © 2017 ROHM Co.,Ltd.
Due to high temperature, Fermi level moves and then barrier height lowers, therefore VF decreases.
Due to high temperature, lattice vibration increases and mobility decreases, therefore, resistance raises.
Merit Preventing thermal runaway because VF increases with temperature raise in case that SiC-SBD is current controlled. Demerit: As VF increases with temperature raise, so IFSM is less than Si-FRD.
SiC-SBD Si-FRD
SiC-SBD: Comparison with Si PN Diode F o rw
a rd
ROHM’s 2nd Generation SiC-SBD Achieved lower VF
Forward Characteristics at 25
650V 10A
Note: These data are just reference based on ROHM’s evaluation result at the same conditions. The characteristics above are not guaranteed by ROHM
Forward Characteristics at 125
P. 22 © 2017 ROHM Co.,Ltd.
SiC-SBD Comparison of Forward Characteristics
SiC-SBD Forward Characteristics
ROHM’s 2nd Generation SiC-SBD Achieved lower VF
Note: These data are just reference based on ROHM’s evaluation result at the same conditions. The characteristics above are not guaranteed by ROHM
P. 23 © 2017 ROHM Co.,Ltd.
Conduction Loss Reduction
e d
t rr
( n s)
company’s)
Hold promise the lowest loss between power diodes (Si-FRDs and SiC-SBDs)
SiC-SBD: ROHM’s 2nd Generation SiC-SBD
P. 24 © 2017 ROHM Co.,Ltd.
650V 6A20A 6A20A 15A40A 6A20A
1200V 5A20A 10A40A
: Automotive grade available
TO247 TO220AC TO220FM
K
P. 25 © 2017 ROHM Co.,Ltd.
650V 6A20A 6A20A 15A40A 6A20A
1200V 5A20A 10A40A
* Under developing 650V/100A products * Under developing 1200V/50A products * Under developing 1700V/10A to 50A products
TO220AC
P. 26 © 2017 ROHM Co.,Ltd.
SiC-SBD Adoption Example in Automotive
Secondary side rectifying SiC SBD 1200V
PFC boost diode SiC SBD 650V
Automotive grade is available for ROHM’s SiC-SBDs (bare-chip,
TO-220AC and TO-247) and they have been adopted and considered
for on-board charging applications in the world.
P. 27 © 2017 ROHM Co.,Ltd.
SiC-SBD
Fast recovery
Low VF vs Si devices and competitor’s SiC-SBDs
→ Reduce conduction loss
SiC-SBD Summary
What is SiCSilicon Carbide ?
SiC-SBDSchottky barrier diode
SiC-MOSFET •Positioning of SiC-MOSFET •Major Power Devices form 600V to 2000V •Performance Comparison of Power Transistors •Internal Diode Characteristics •Reliability of ROHM’s SiC-MOSFET •Product Line-up •Next Generation SiC-MOSFET •Application Examples Utilizing the Merits •Difference from Si-MOSFET
Full SiC Module
P. 29 © 2017 ROHM Co.,Ltd.
SiC-MOSFET
IG B
• Downsizing of equipment due to higher frequency operation
Producible but few merit for Si
Minority carrier devices Low Ron but slow
Majority carrier devices Fast
• Reduction of chip size
Diode Transistor Features
•High voltage is available •Utilize conductivity modulation to compensate Ron
•Slow trr and tail current due to minority carrier accumulation.
Si Majority carrier device
(MOSFET)
SJ-MOSFET
•Ron is a bit improved on SJ. •Fast but high Ron •Large trr •Withstanding up to 900V
SiC
SBD MOSFET
•High voltage is available •Low Ron of epi layer •Fast switching •High temp operation more than 200
SiC-MOSFET6002000V Power Devices
P. 31 © 2017 ROHM Co.,Ltd.
Hi Temp operation
Si DMOS Si Super-Junction MOS Si IGBT SiC DMOS
Ron of the present SiC is 5 to 10mΩcm2 because of other resistances
Metal Metal Metal
Metal p p
R o n
Ron Speed Ron Speed Ron Speed Ron Speed
Withstand Voltage Withstand Voltage Withstand Voltage
P. 32 © 2017 ROHM Co.,Ltd.
0
5
10
15
20
25
Vds (V)
Vds (V)
Vds-Id Characteristics
SiC-MOSFET Comparison with IGBT
Note: These data are just reference based on ROHM’s evaluation result at the same conditions. The characteristics above are not guaranteed by ROHM
P. 33 © 2017 ROHM Co.,Ltd.
SCH2080KE(SiC-MOS+SBD) IGBT+FRD
Large Loss from tail current Become worth with high temp
With high internal Rg, recommend external Rg 0 to 5Ω for fast operation
Turn-off Loss
SiC-MOSFET Comparison with IGBT
Note: These data are just reference based on ROHM’s evaluation result at the same conditions. The characteristics above are not guaranteed by ROHM
P. 34 © 2017 ROHM Co.,Ltd.
Vdd=400VIc=20A Ta=25Vgs=+18V/0V
SCH2080KE(SiC-MOS+SBD) IGBT+FRD
Ic (5A/div)
Vge (5V/div)
Vce (100V/div)
Id (5A/div)
SiC-MOSFET Comparison with IGBT
Note: These data are just reference based on ROHM’s evaluation result at the same conditions. The characteristics above are not guaranteed by ROHM
*Including diode recovery loss
Large Loss by recovery current Become worth with high temp
With high internal Rg, recommend external Rg 0 to 5Ω for fast operation
P. 35 © 2017 ROHM Co.,Ltd.
-30
-25
-20
-15
-10
-5
0
Vgs=0V
Vgs=2V
Vgs=4V
Vgs=6V
Ta=25ºC
Drain - Source Voltage : VDS [V]
Vd- Id Characteristics (reverse direction)
Because of wide bandgap semiconductor, body diode Vf is high (Vgs=0V. But reverse conducting (Vgs=18V) can reduce the losses.
Source (+)
Drain (-)
P. 36 © 2017 ROHM Co.,Ltd. 36
SCT2080KE
Is(10A/div)
Vds(100V/div)
P. 37 © 2017 ROHM Co.,Ltd.
Stable body diode with bias
(Peculiar to SiC)
100% outgoing tested Burn-in test Tjmax: 175
Cosmic ray exposure test 0.1FIT@960V
Stable Vth (Vth sift ±0.2V@Vgs(DC)max)
Si-MOSFET
SiC-MOSFET
Si-IGBT
-0.5
0.0
0.5
1.0
1.5
Stress time [hrs]
P. 38 © 2017 ROHM Co.,Ltd.
As of Sep 5, 2014
SCH series
1200V SCT2080KEC TO247 80mΩ 40A -
1200V SCH2080KEC TO247 80mΩ 40A
1200V SCT2160KEC TO247 160mΩ 22A -
1200V SCT2280KEC TO247 280mΩ 14A -
1200V SCT2450KEC TO247 450mΩ 10A -
650V SCT2120AFC TO220AB 120mΩ 29A -
SiC-SBD
v e rs
a rd
Existing 2G DMOS
Mass Production: Jun 2015
SiC-MOSFET SiC Trench MOSFET
In Mass Production
P P+
SiC sub
Use trench structure for source
The structure can mitigate electric field at the bottom of gate trench, therefore, it ensures long term reliability and realized mass production.
(MV/cm)
1.5
1.2
0.9
0.6
0.3
0.0
Electric field concentration at the bottom of gate trench
Electric field mitigation at the bottom of gate trench
Mitigating concentration of electric field at the bottom of gate trench and need to ensure device long term reliability.
High
Low
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
Ron@25 (mΩ )
C is
s (p
Ron@25(mΩ)
C is
s (p
Same chip size
Great performance improvement with the same chip size Ciss: 35% reduction Ron: 50% reduction
P. 42 © 2017 ROHM Co.,Ltd.
SiC-MOSFET Next Generation SiC-MOSFET
BVDSS RDSon
1200V 40mΩ
1200V 30mΩ
1200V 22mΩ
650V 30mΩ
DC in 800V
DC out 800V
Resonance Capacitor
Comparison of performance with transistors to construct a full bridge inverter.
Si IGBT SiC 2G DMOSFET SiC 3G Trench MOSFET
DC in 800V
DC out 800V
Phase Shift DC/DC Converter Demonstration circuit)
P. 44 © 2017 ROHM Co.,Ltd.
SiC-MOSFET: Application Example #1
Phase Shift DC/DC Converter Efficiency Comparison
Switching Device Si-IGBT
73A
25kHz 100kHz 100kHz
Total Wattage 3kW 10kW 10kW Unit Size 350 x 300 x 120 (same size)
92%
93%
94%
95%
96%
97%
98%
Ef fi
ci e
n cy
o f
C o
n ve
rt e
r B
o ar
SiC 3G UMOS 30mΩ 4pcs 100kHz10kW
SiC 2G DMOS 80mΩ 8pcs
100kHz10kW
92%
93%
94%
95%
96%
97%
98%
Ef fi
ci e
n cy
o f
C o
n ve
rt e
r B
o ar
SiC 2G DMOS 100kHz10kW
SiC makes higher frequency operation and increases out power
P. 45 © 2017 ROHM Co.,Ltd.
Joint work with
Pulse Power
•Use: System momentarily to provide power with short time •Application Gas laser, accelerator, X-ray and plasma power •Requirements: High voltage and fast switching
High voltage high speed switch by SiC Slow Si switch or vacuum tube
Present Future
Klystron Thyratron
2.4m
Gas laser power supply, radiotherapy equipment, switch applied more than 20kV
S e ri a l c o n n e c ti o n
m a k e s h
ig h
o lt a g e
Ultra High voltage high speed switch SiC’s high voltage and high speed are key IGBT is non-competitive from high speed point of view
SiC-MOSFET: Application Example #2
P. 46 © 2017 ROHM Co.,Ltd.
SiC-MOSFET: Application Example #2
• Features: Ultra high voltage pseudo-Nch SiC MOSFET Low Ronless than 1/100 for existing
High repetition frequency (more than 100x for existing
• Applications Charged particle accelerator, medical power, plasma power
• Part of the result is supported by “Kyoto Super Cluster Program of the Ministry of Education, Culture, Sports, Science and Technology.
32kV 240Apeak
SiC switching PCB
ROHM SiC MOSFET
Ultra High Voltage Pules Power Supply
Joint work with Fukushima SiC Applied Engineering Inc., exhibited to CEATEC 2014
P. 47 © 2017 ROHM Co.,Ltd.
SiC-MOSFET: Application Example #2
8kVDC 240Apeak SiC Switching PCB (7-serial, 3-parallel MOSFET-Array
Isolated transformer
Isolated transformer
Cu Plate
maintenance
P. 48 © 2017 ROHM Co.,Ltd.
SiC-MOSFET: Application Example #2
1.1kV rated SiC switch board
Achieved 13.2kV rated SiC switch using 12 pcs of 1.1kV rated SiC switch board connected serially.
Switching Panel
P. 49 © 2017 ROHM Co.,Ltd.
SiC-MOSFET Difference from Si-MOSFET
Vgs-Rdson Id=10A
Vgs (V)
R ds
• Drift layer resistance of SiC-MOSFET is lower than Si-MOSFET
• On the other hand, Ron is high
• Therefore the higher Vgs, the lower Ron
• Saturation will progress gradually when Vgs is more than 20V.
• General drive voltage, Vgs for IGBT and Si-MOSFET is from 10 to 15V.
• Recommended Vgs for SiC-MOSFET is around 18V to obtain enough low Ron
Difference from Si-MOSFET Vgs
P. 50 © 2017 ROHM Co.,Ltd.
•Internal gate resistance, Rg depends on sheet resistance of gate terminal material and chip size
•With the same design, it’s in inverse to chip size, so the smaller chip, the higher Rg
•Because chip size of SiC-MOSFET is smaller than Si devices, so capacitance is smaller but Rg is larger.
•Rg of 1200V 80mΩ SiC-MOSFET is about 6.3Ω.
•Switching time depends on external gate resistance significantly
•For fast switching, external gate resistance will be a few ohms or as small as possible
•Be careful to surge voltage with smaller external gate resistance
Rg (Ω)
Difference from Si-MOSFET Rg
SiC-MOSFET
Fast switching
Body diode characteristics
Developing next generation devices
• Recommended gate drive: 18V
• External gate resistance must be small, as internal Rg is high
SiC-MOSFET Summary
What is SiCSilicon Carbide ?
SiC-SBDSchottky barrier diode
SiC-MOSFET
Full SiC Module •Structure of 1200V/300A Full SiC Module •Switching Loss •Full SiC Module Using the 2nd Generation SiC-MOSFET
•Utilizing Full SiC Module –Gate Drive –Snubber –Practical Full SiC Module Driving –Design Support Tools
SiC Power Devices Understanding & Application Examples Utilizing the Merits
P. 53 © 2017 ROHM Co.,Ltd.
Full SiC Module
SiC MOSFET SiC SBD
Full SiC Module
2nd
Generation
DMOSFET
Full SiC Module
Simulation Condition
m J
1200V/300A BSM300D12P2E001
Switching Loss
Note: These data are just reference based on ROHM’s evaluation result at the same conditions. The characteristics above are not guaranteed by ROHM
Reduced totally 22%
Reduced totally 60%
at hi freq.
Full SiC Module
1200V 120A RDSON 20mΩ typ.
1200V 180A RDSON 10mΩ typ.
SiC-SBD & SiC Trench MOSFET
SBD inside Lower Ron
C type
C type
C type
Full SiC Module
•77% of switching loss reduction for IGBT Module
•42% of switching loss reduction for full SiC module using ROHM’s 2nd generation SiC planar MOSFETs
Comparison between 1200V 180A Modules
Trench MOS BSM180D12P3C007
g L
Full SiC Module
Utilizing Full SiC Module
• Design Support Tools
-100 0
0 0.2 0.4 0.6 0.8 1
V d s (
G a te
V )
1 8 V
displacement
current
Erroneous on-operation due to gate voltage oscillation (upper arm) and gate voltage step-up (lower arm) is considered.
Ringing
Oscillation
P. 60 © 2017 ROHM Co.,Ltd.
0
5
10
15
20
25
30
35
40
IGBTModule
As SiC MOSFET has no tail current, off-switching speed depends on external Rg setting as same as on-switching.
On-switching speed in direct relation to erroneous on-operation is almost the same for the both and it depends on external Rg setting.
ON OFF
Full SiC Module Utilizing Full SiC Module
P. 61 © 2017 ROHM Co.,Ltd.
Parasitic Capacitance SiC-MOS vs Si- IGBT
1.E-10
1.E-09
1.E-08
1.E-07
Ratio of Cgd / Cgs
Parasitic gate capacitance ratio, Cgd/Cgs, which affects lower arm MOSFET gate voltage step-up, is almost the same for both SiC MOSFET and Si-IGBT.
* Cds also exists between drain and source
Rg
Cgd
Cgs
P. 62 © 2017 ROHM Co.,Ltd.
Conditions that lower arm gate voltage step-up becomes larger:
1. Upper arm switching speed, dVds/dt becomes faster (Rg_H is small)
2. Lower arm external gate resistor, Rg_L is larger
18 V
5 V
V in
0 V
Small

to zero Vgs
P. 64 © 2017 ROHM Co.,Ltd.
Note: Component values are just reference. Adjustment of Rg is needed, checking surge voltages.
Gate Driver IC
Gate resistors
Full SiC Module Utilizing Full SiC Module
P. 65 © 2017 ROHM Co.,Ltd.
3
4
5
6
7
8
9
Δ V
g s
SiC Module 1200V 120A (BSM120D12P2C005) • VPN = 600V • Id= 100A
Note: External resistors for high-side and low-side and capacitance of external capacitor is the same for all (no change).
RG
1.0Ω
2.2Ω
3.9Ω
5.6Ω
P. 66 © 2017 ROHM Co.,Ltd.
3
4
5
6
7
8
9
Δ V
g s
SiC Module 1200V 120A (BSM120D12P2C005) • VPN = 600V • Id= 100A
RG
1.0Ω
2.2Ω
3.9Ω
5.6Ω
Full SiC Module Utilizing Full SiC Module
Note: External resistors for high-side and low-side and capacitance of external capacitor is the same for all (no change).
P. 67 © 2017 ROHM Co.,Ltd.
3
4
5
6
7
8
9
Δ V
g s
SiC Module 1200V 120A (BSM120D12P2C005) • VPN = 600V • Id= 100A
RG
Full SiC Module Utilizing Full SiC Module
Note: External resistors for high-side and low-side and capacitance of external capacitor is the same for all (no change).
P. 68 © 2017 ROHM Co.,Ltd.
0
50
100
150
200
250
V s
u rg
e (V
Δ V
g s
1.0Ω
2.2Ω
3.9Ω
5.6Ω
Adding mirror clamp MOSFET is very effective to control erroneous on-operation
1.0Ω
2.2Ω
3.9Ω
0
50
100
150
200
250
V s
u rg
e (V
Achieved controlling oscillation, ringing and rise characteristics to optimize parameters
-50
0
50
100
150
time (us)
time (us)
V D
S ,V
time (us)
V G
Wave Form of Evaluation Circuit
P. 70 © 2017 ROHM Co.,Ltd.
Snubber Capacitor Line Inductance Reduction
• Utilizing fast switching performance, need to reduce parasitic inductance of electric wiring as small as possible.
• Reducing line inductance, to connect the capacitors closely to the power terminal (red circle on the schematic).
Film Capacitor: 120µF 2-parallel & 2-serial
Aluminum electrolytic capacitor
P. 71 © 2017 ROHM Co.,Ltd.
Examples for Snubber Capacitor
Film Capacitor Ceramic Capacitor
800VDC 120µF 2-serial/2-parallel
Murata Manufacturing Co., Ltd. EVSM1D72J2-145MH14 630VDC 270nF 2-serial/2 to 5 parallel
Connection Example: 2-serial/5 parallel x2
Total: 1.35µF
Note: Snubber module is available (same type as this photo)
Full SiC Module Utilizing Full SiC Module
P. 72 © 2017 ROHM Co.,Ltd.
1No Caps 2 Nippon Chemi-Con 3 Murata Manufacturing
Nippon Chemi-Con FHACD1C2V125JTLJZ0 1250VDC 1.2µF
Soshin Electric LC78P801D127K-AA 800VDC 120µF 2-serial/2-parallel
Murata Manufacturing EVSM1D72J2-145MH14 630VDC 270nF 2-serial/5-parallel
Snubber Capacitor Mounting Examples
P. 73 © 2017 ROHM Co.,Ltd.
1 Soshin Electric LC78P801D127K-AA + Nothing
2 Soshin Electric LC78P801D127K-AA + Nippon Chemi-Con FHACD1C2V125JTLJZ0
3 Soshin Electric LC78P801D127K-AA + Murata Manufacturing EVSM1D72J2-145MH14 2-serial/5-parallel
VDD=600 V ID=300 A
925V
860V
798V
Note: Surge wave form depends on capacitor mount position, and also difference of parasitic inductance from structure.
Surge wave form occurs between drain and source when SiC MOSFET cut off current
Snubber Capacitor Off-Wave Form Comparison
Full SiC Module Utilizing Full SiC Module
P. 74 © 2017 ROHM Co.,Ltd.
t1 t2
After turn-off ringing with 23MHz (t1) can be quickly decreased with lower number of parallel line. ⇒ Number of parallel line will be in inverse to ESR
2MHz ringing (t2) occurs if capacitance is smaller. ⇒ Electric Charge will be filled up through a path with larger inductance.
806V 815V
5-para
2-seri
As for ceramic cap, lower number of parallel line and larger capacitance are effective.
Ex. Condition C
Snubber Capacitor Effect by Ceramic Cap Capacitance
Full SiC Module Utilizing Full SiC Module
P. 75 © 2017 ROHM Co.,Ltd.
Presence Absence
806V 798V
No big difference on surge voltage, but 400kHz ringing occurs if the film cap is not. ⇒ Electric charge will be filed up from distant Al electrolytic cap and power supply
DD=600 V ID=300 A
Large capacitance cap is effective to reduce long period ringing.
Shoshin LC78P801D127K-AA ⇒ Comparison presence with absence
Murata EVSM1D72J2-145MH14 ⇒ 2-serial/5-parallel
Full SiC Module Utilizing Full SiC Module
P. 76 © 2017 ROHM Co.,Ltd.
Countermeasure for erroneous on-operation will be required if dedicated driver is not used. – Add CGSµF order) – Use minus bias for VGS (-5V
temperature ()
25
Turn off current (A)
200 Electrolytic cap2200 µF Film cap 120 µF External Inductor 100 µH
SiC Power Module 1200V300A BSM300D12P2E001
Power Supply 600 V
Full SiC Module Utilizing Full SiC Module
P. 77 © 2017 ROHM Co.,Ltd.
Film Capacitor (1600V / 120µF)
Electrolytic cap (1800V 2200µF)
Full SiC Module: Practical Driving Example
P. 78 © 2017 ROHM Co.,Ltd.
Before
time (us)
C u
time (us)
V o
time (us)
V o
•Oscillation of all wave forms is suppressed
•Achieved breakthrough as same as µF
capacitance.
•Loss, Eon is increased: 4.3 mJ to 5.3 mJ
Note: Eon is larger and Eoff is smaller if inductance becomes small.
Before After
Snubber Module Absence Presence
Full SiC Module Utilizing Full SiC Module
P. 79 © 2017 ROHM Co.,Ltd.
Before
time (us)
C u
time (us)
V o
time (us)
V o
Effect of Gate Driver & Snubber Module Turn-off
Before After
Snubber Module Absence Presence
•Loss, Eoff is decreased: 5.3 mJ to 3.8 mJ
* 0.4 mJ of total loss (Eon+Eoff) is reduced
P. 80 © 2017 ROHM Co.,Ltd.
Note: The SiC Module Evaluation Board is only for evaluation purpose, not to support any mass production use.
Possible to use to put it on the SiC Module
Full SiC Module
Design Support Tolls: SiC Module Evaluation Board
Full SiC Module Utilizing Full SiC Module
P. 81 © 2017 ROHM Co.,Ltd.
Murata Manufacturing Co., Ltd KR355WD72J564MH01 630VDC, 270nF
280nF 560nF (2-parallel)
Full SiC Module Utilizing Full SiC Module
Design Support Tolls: Snubber Capacitor Module
P. 82 © 2017 ROHM Co.,Ltd.
ROHM Web Site Go to Power Devices/SiC Power Devices
Download Loss Simulator !
Design Support Tolls: Loss Simulation
P. 83 © 2017 ROHM Co.,Ltd.
Input Output
• Loss simulations for Full SiC Modules and IPM products is possible. • Useful for initial consideration work.
Full SiC Module Utilizing Full SiC Module
Design Support Tolls: Loss Simulation
P. 84 © 2017 ROHM Co.,Ltd.
Full SiC Module
with IGBT Module
Developing with next generation devices → Faster switching type → Larger current type (under development)
Understanding characteristics for utilizing Gate Drive
→ Mirror Clamp, component value consideration, evaluation with driver board
Snubber →Lowest parasitic inductance and use of effective
components
Date Center
Power Supply
P. 86 © 2017 ROHM Co.,Ltd.
SiC-MOSFET • Positioning of SiC-MOSFET • Major Power Devices form 600V to
2000V • Performance Comparison of Power
Transistors • Internal Diode Characteristics • Reliability of ROHM’s SiC-MOSFET • Product Line-up • Next Generation SiC-MOSFET • Application Examples Utilizing the Merits • Difference from Si-MOSFET
Full SiC Module • Structure of 1200V/300A Full SiC Module • Switching Loss • Full SiC Module Using the 2nd Generation
SiC-MOSFET • Utilizing Full SiC Module
–Gate Drive –Snubber –Practical Full SiC Module Driving –Design Support Tools
What is SiCSilicon Carbide ? • Major Semiconductor Materials • Properties: Comparison with Si • Background of Development • Merits of SiC • History of SiC Research • Approaches to SiC Devices of
ROHM
SiC-SBDSchottky barrier diode • Positioning of SiC-SBD • Comparison with Si-SBD • Comparison with Si PN Diode • The 2nd Generation SiC-SBD • Merits Using SiC-SBD • Comparison of Forward
Characteristics • Product Line-up of the 2nd
Generation SiC-SBD • Adoption Example
© 2017 ROHM Co.,Ltd.