wide band gap - engineering center...gan sic reliable performance at higher voltages high junction...
TRANSCRIPT
1
Wide Band Gap
Applications
2
Wide Band Gap Applications
© 2019 KEMET Corporation
Wide Band Gap Overview
• Types:
– Gallium Nitride (GaN)
• Volume production since the 1990’s
• Primary Applications:
‒ RF
‒ LED
– Silicon Carbide (SiC)
• Commercial production since 2008
• Primary Applications:
‒ Power Inverters
‒ Low Voltage Power Distribution
• Advantages over Silicon
‒ Efficiency
‒ High Frequency
‒ High Temperature
‒ High Voltage
• Withstand 10x Voltage
Remember Carborundum?
Cree SiC MOSFET
Six-Pack Power Module
Especially attractive at 1.2+ kV
© 2019 KEMET Corporation
Wide Bandgap (WBG) Semiconductors
Density of StatesE
lectr
on
En
erg
y
Non-Conductive band
Semiconductor Material Bandgap
Energy (eV)
Germanium (Ge) 0.7
Silicon (Si) 1.1
Silicon Carbide (SiC) 3.3
Gallium Nitride (GaN) 3.4
WBG
ConductorsInsulators Semiconductors
10-20 10810410010-410-810-1210-16
Conductivity (S/cm)
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Wide Bandgap (WBG) Semiconductors
Frequency (Hz)
Pow
er
(W)
100 1k 10k 100k 1M 10M 100M 1G 10G 100G
10
100
1k
10k
100k
1M
10M
100M The BIG 3 for WBG• Higher Voltages
• Higher Frequencies
• Higher Temperatures
Si
SiC
Si
Power Converter
GaN
© 2019 KEMET Corporation
Wide Band Gap Overview
• Lower System Losses– Increased Frequency
– Smaller Size
• Passive Component Impact:– 10x to 100x+ smaller value:
• Inductor
• DC Link capacitor
– Power Inverters:• 150 to 175+ degree C Snubber
• Snubber integrated into IC package (Ceramic)
• Ceramic DC Link‒ Frequency response
‒ Temperature
‒ Smaller capacitance required
‒ Up to 1200V and 1700V
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Power Film Technology (Metallized PP)Effect of Higher Temperature and Frequency
• Higher Temperature
– Shorter Life, Lower Reliability
– Voltage & Current Limitation
• Higher Frequency
– Higher DF
– Voltage & Current Limitation
© 2019 KEMET Corporation
Future Power ElectronicsSemiconductor vs. Power vs. Frequency
Source: P. Friedrichs & M. Buschkuhle, Infineon AG, Energetica India, May/June 2016
© 2019 KEMET Corporation
Power Electronics Benefits
• Compared to Si, Wide Band Gap (WBG) IGBT and Power Modules:
– Are smaller
– Require less cooling
– Are more energy efficient
• Snubber and DC Link capacitors requirements for AC/DC conversions in high power inverters and converters will be reviewed
Conversion Efficiency Si Based WBG Based GaN or SiC
DC to DC 85% 95%
AC to DC 85% 90%
DC to AC 96% 99%
Source: Mouser Electronics, L. Culberson, 2016
© 2019 KEMET Corporation
Power Converter Capacitors
1 AC Harmonic Filter 3Φ 2 Snubber 3 DC Link
Typical Capacitor Types:
0 EMI / RFI
Filter 1Φ
L1
L2
CX
CY
CY
Power lineequipment
L1
L2
CX
CY
CY
Power lineequipment
AC/DCConverter
DC/ACInverter
1 12 2
3
AC ~
Power
Source
AC ~
Power
Load
System Overview:
0
© 2019 KEMET Corporation
WBG Capacitor Requirements
Capacitor RequirementWBG Semiconductor Trend
Smaller, low ESR, low ESL low
loss capacitors with high dV/dt &
current handling capability
Higher Switching Frequencies
20kHz → 100kHz → 100’s MHz
Higher Operation Voltages
400V → 900V →1200V→1700V
GaN SiC
Reliable performance at higher
voltages
High Junction Temperatures
105oC → 125oC → 200oC+
SiC
Reliable performance at elevated
temperatures ≥ 125oC with
robust mechanical performance
• Packaging close to the hot
semiconductor to:
‒ Lower ESL
‒ Minimize cooling costs
© 2019 KEMET Corporation
0.001
0.01
0.1
1
10
10 100 1000 10000
Capacitance (
uF
)
Frequency kHz
DC-LINK Capacitance vs Switching Frequency and Voltage of a 10kW Power Converter
400V 650V 1000V
Wide Bandgap TrendImpact on Capacitors
* Source: Prof. R. Kennel, Technical University Munich, Germany
Higher Voltage = Lower Capacitance
𝐶 =𝑃𝑙𝑜𝑎𝑑
𝑉𝑟𝑖𝑝𝑝𝑙𝑒 𝑉𝑚𝑎𝑥 −𝑉𝑟𝑖𝑝𝑝𝑙𝑒
2 ∗ 2 ∗ 𝜋 ∗ 𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦
© 2019 KEMET Corporation
Capacitance Vs. Switching FrequencyExample: 10% Ripple for different power & voltage
Higher Power
More Cap
Higher Voltage
Less Cap
Frequency 10kW 50kW 100kW Voltage
20 5.24μF 26.19μF 52.38μF
40060 1.75μF 8.73μF 17.46μF
100 1.05μF 5.24μF 10.48μF
140 0.75μF 3.74μF 7.48μF
20 1.98μF 9.92μF 19.84μF
65060 0.66μF 3.31μF 6.61μF
100 0.40μF 1.98μF 3.97μF
140 0.28μF 1.42μF 2.83μF
20 0.84μF 4.19μF 8.38μF
100060 0.28μF 1.40μF 2.79μF
100 0.17μF 0.84μF 1.68μF
140 0.12μF 0.60μF 1.20μF
© 2019 KEMET Corporation
Capacitance vs. Switching FrequencyPolypropylene Film to MLCC
• For DC-Link Capacitors:‒ Lower capacitance required promotes
miniaturization due to:• Increasing switching frequency
• Higher voltages
• Lower capacitance is within the range of MLCC.‒ But these must be:
• Extremely reliable
• Over-temperature capable
• Over-voltage capable
• High current capable
• Mechanically robust
• PRO-TIP: MLCC for effective switching noise suppression when placed close to WBG where cooling is limited.
© 2019 KEMET Corporation
Ceramic Dielectric TypesHigh Energy Storage & MLCC Attributes
Paraelectric Ferroelectric Anti-Ferroelectric
EIA
Types
Dielectric
Class-I
C0G, C0H, U2J
CaZrO3
Class-II
X7R, X5R
BaTiO3
Class-II Similar to Y5V
PbLaZrTiO3
MLCC Attributes Target Paraelectric CaZrO3 Ferroelectric BaTiO3 Anti-Ferroelectric PLZT
Energy Storage High High Low High
Dielectric Constant K High Low High High
Dielectric Loss DF Low Low High Medium
Current Handling High High Low Medium
Mechanical Robustness High High Medium Low
Piezo (Electrostriction) Low Low High High
Voltage Stability High High Low Medium
Temperature Stability High High Medium Low
• C0G Development,
Leadless Stacks
for Higher Cap &
U2J Dielectric with
Higher K
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3640 0.22µF 500V Ni BME C0G for 150oCTemperature Accelerated HALT
• MLCC were HALT tested at 260oC
at 1000, 1100, 1200 & 1300VDC
(n = 40, with Au term.)
• MTTF Vs. Voltage was recorded
• Voltage exponent ~ 19 @ 260°C
• Calc. MTTF @ 500VDC ~ 8500 yearsMTTF = 2934 min.
y = 7.13E+59x-18.6
© 2019 KEMET Corporation
Performance Comparison3640 Ni BME C0G vs. Competitor Cu PLZT
3640 0.23cm3 Vs. Cu PLZT 0.35cm3
– 3640 0.22μF has better accelerated life, stable cap with temperature / voltage & less ripple heating
– > 0.33μF with Leadless Stack Solutions
© 2019 KEMET Corporation
Ni BME C0G MLCC 3640 0.22µF 500V 150oCMechanical & Surface Mounted Performance
• Large Case C0G MLCC have
– High MOR
– Board Flex > 3mm
– Pass AEC Q200 temp. cycle testing
Tested
Pieces to
10mm DID
NOT FAIL
Case Size Cap.
(nF)
Rated
Voltage
(VDC)
1000 Cycles
-55oC to +125oC
50 Cycles
-55oC to +200oC
4540 27 1500 0/231 0/50
3640 15 2000 0/154 0/100
3040 39 1000 0/154 0/100
2824 33 630 0/154 0/100
Flex. Term. Or Lead
No Lead
© 2019 KEMET Corporation
Ni BME C0G MLCC 3640 0.22µF 500V 150oCESR & Current Handling @ 150oC 100kHz
• Lower DF & ESR reduce the power
dissipated
P = power dissipated
i = current
d = dissipation factor
f = frequency
C = capacitance
R = resistance, ESR
Ripple Current Life Testing
• No failures after 1000hrs @150oC
– 15ARMS 100kHz
– 10ARMS 100kHz with 400VDC Bias
ESR < 3 mΩ
© 2019 KEMET Corporation
3640 0.22µF 500V 150oCThermal Resistance & Ripple Current
• Measured Thermal Resistance correlates closely to calculated value of 14.1oC/W
• DC Voltage limits ripple current at lower frequencies ≤ 100kHz
• Maximum ripple currents are based on not exceeding the 150oC temperature or voltage capability
© 2019 KEMET Corporation
Performance
C0G 3640 220nF 500V
• PRO-TIP: Ideal for Resonant Capacitors
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3640 0.22µF 500V 150oCPart Number & Properties
CKC 33 C 224 K C G A C TUCase Size Specification/ Capacitance Capacitance Termination Packaging
(L"x W") Series Code (pF) Tolerance Finish (Suffix / C-Spec)
CKC = KC-LINK 33 = 3640 C = Standard 2 Sig. Digits + K = ±10% C = 500 V G = C0G A = N/A C = 100% Matte Sn TU= 7" Reel, Unmarked
Number of Zeros
SeriesRated Voltage
(V)Dielectric
Subclass
Designation
© 2019 KEMET Corporation
Thermal Modeling & Ranges
Case Size 3640 0.22μF, 500V
• Thermal Resistance RƟ (oC/W) models correlate well with experimental results
Max. Cap. Range
Support customer thermal models for design-in
Cap, uF Cap Code 650 1000 500 650 1000 1200 1700 500 650 1000 1200 1700
0.0047 472
0.0056 562
0.0062 622
0.0068 682
0.01 103
0.012 123
0.015 153
0.018 183
0.022 223
0.033 333
0.039 393
0.047 473
0.056 563
0.068 683
0.082 823
0.1 104
0.15 154
0.18 184
0.22 224
0.47 474
KC-LINK1812 2220 3640
Voltage Rating Voltage Rating
RELEASED
Model
© 2019 KEMET Corporation
U2J MLCC Development
• BME C0G capacitors perform well for WBG applications requiring high bias
voltages such as in DC-Link & snubber applications.
• For lower bias voltages such as 48V DC-DC power supplies U2J MLCC with Ni
BME inner electrodes extend the Class-I capacitance range up to 50V rating.
• U2J MLCC properties are similar to C0G making them suitable for low loss
switching in resonant LLC designs.
• U2J has a small, predictable and linear capacitance change vs temperature.
© 2019 KEMET Corporation
KEMET U2J DielectricRelative Capacitance vs. Temperature
Class-I Dielectrics (Examples C0G: 0±30ppm/°C vs. U2J: -750±120ppm/°C)
© 2019 KEMET Corporation
Temperature Rise vs. Ripple Current
• BME C0G and BME
U2J both show high
current carrying
capability.
• Temperature rise
<14°C up to ripple
current of 10Arms.
© 2019 KEMET Corporation
U2J MLCC Range
Case Size
(Inches)
Case Size
(mm)
Rated
Voltage
(Vdc)
Maximum Available Capacitance CAP Increase
vs. current C0GC0G U2J
0402 1005
10 2.2nF 4.7nF +114%
16 / 25 2.2nF 2.2nF -
50 1.5nF 1.8nF +20%
0603 1608
10 15nF 33nF +120%
16 / 25 15nF 15nF -
50 6.8nF 10nF +47%
0805 2012
10 47nF 100nF +112%
16 / 25 47nF 56nF +19%
50 22nF 47nF +114%
1206 321616 / 25 100nF 220nF +120%
50 82nF 150nF +83%
1210 322516 / 25 220nF 330nF +50%
50 150nF 270nF +80%
1812 4532 50 220nF 470nF +114%
Standard and Flexible TerminationUnder Development
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Leadless StacksIntroduction
• MLCC terminations are bonded together using Transient Liquid Phase Sintering
– Sn, Cu, Ag & Au term. finishes
• The resulting Leadless Stacks can be mounted on a circuit board using the
same assembly processes as an MLCC
• The capacitance in a given circuit board area is increased
US Patents 8,902,565 B2 & 9,472,342 B2
© 2019 KEMET Corporation
Leadless Stacks of 3640 0.22µF 500V MLCCElectrical Performance
• Higher Capacitance to ≈ 1µF
• Increased height of Leadless Stacks increases maximum inductance
• High Insulation Resistance to 200oC
10 mm 4-Chip 2.9 nH
5 mm 2-Chip 1.6 nH
2.5 mm MLCC 0.9 nH
2 µA
0.26 µA
© 2019 KEMET Corporation
What is TLPS?
• Low temperature reaction of low melting point metal or alloy with a high melting point metal or alloy to form a reacted metal matrix or alloy.
• Forms a metallurgical bond between 2 surfaces .
• Has high failure temperatures.
Transient Liquid Phase Sintering (TLPS)Basic Technology
CuSn TLPS
Heat
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CTE Mismatch ComparisonLeadless Stacks vs. Leaded MLCC
Leadless Stack Mounted on
Circuit Board
J-Lead Stack Mounted on
Circuit Board
Mounting
Solder
Circuit Board
Small TLPS joint with low
CTE mismatch
J-lead absorbs
mismatch but
CTE mismatch
must be
minimized
© 2019 KEMET Corporation
Leadless Stacks of 3640 0.22µF 500V MLCCReliability
• Board Flexure is > 3mm
• No Failures 0/50 1000 cycles -55 to +150oC
• Low Shear Stress failure @19.1MPa (27.9kg)
is 15 X above the1.8kg AEC Q200 minimum
© 2019 KEMET Corporation
0.88µF Leadless Stacks (4 X 3640 0.22µF 500V)Orientation: Horizontal (Traditional) Vs. Vertical (Low Power Loss)
Vertical Orientation has:
• Higher SRF
• Lower ESR
Horizontal Vertical
3 MHz5.7 MHz Traditional Low Power
Loss
PN: C3640C884MCGLE
2.9 nH 0.9 nH
© 2019 KEMET Corporation
0.88µF Leadless Stacks (4 X 3640 0.22µF 500V)Ripple Current Heating: Horizontal vs Vertical Mounting
Vertical – Low Power Loss Orientation:
• More even heating
• Lower Temp. @ Steady State ≈ - 5oC
STEADY STATE12ARMS @ 140kHz WARMING UP
Top View
Side View
Horizontal - Traditional
Vertical – Low Loss
Side View
Heat dissipation
in Air above.
Heat dissipation
into Cu board.
Top View
34.9oC
29.2oC
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Thermal Modeling3640 0.22µF 500V; 2 & 4 chip Leadless Stacks
Low Loss Model
Study thermal resistance with other boundary conditions• Forced air cooling or dielectric fluids
• Embedded in package
© 2019 KEMET Corporation
Trends
• Improved power conversion efficiency is driving the development of new systems
and components
• Wide Band Gap (WBG) substitute established Si technology
• Trends in Power Electronics:
‒ Higher switching frequencies
‒ Low loss MLCC with high ripple current capability
‒ High operating voltages 400V ➡800V
‒ Higher temperatures 105°C ➡ 150°C
© 2019 KEMET Corporation
Thank You!