Wide Band Gap

Applications

1 Wide Band Gap Applications

2 Wide Band Gap Overview

• Types: – Gallium Nitride (GaN) • Volume production since the 1990’s • Primary Applications: ‒ RF ‒ LED Remember Carborundum? – Silicon Carbide (SiC) • Commercial production since 2008 • Primary Applications: ‒ Power Inverters Especially attractive at 1.2+ kV ‒ Low Voltage Power Distribution • Advantages over Silicon ‒ Efficiency ‒ High Frequency ‒ High Temperature ‒ High Voltage • Withstand 10x Voltage Cree SiC MOSFET Six-Pack Power Module © 2019 KEMET Corporation Wide Bandgap (WBG) Semiconductors

Semiconductor Material Bandgap Energy (eV) Germanium (Ge) 0.7 Silicon (Si) 1.1 Silicon Carbide (SiC) 3.3 Gallium Nitride (GaN) 3.4

WBG Electron Energy Electron Insulators Semiconductors Conductors Non-Conductive band

100M The BIG 3 for WBG 10M SiC • Higher Voltages Power Converter • Higher Frequencies 1M • Higher Temperatures

100k

10k Si

Power Power (W) 1k Si GaN 100

• 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

• Higher Temperature – Shorter Life, Lower Reliability – Voltage & Current Limitation • Higher Frequency – Higher DF – Voltage & Current Limitation

• Compared to Si, Wide Band Gap (WBG) IGBT and Power Modules: – Are smaller – Require less cooling – Are more energy efficient

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

• Snubber and DC Link capacitors requirements for AC/DC conversions in high power inverters and converters will be reviewed

System Overview:

AC ~ AC ~ AC/DC DC/AC Power 0 Converter Inverter Power Source 2 2 Load 1 3 1

Typical Capacitor Types:

0 EMI / RFI 1 AC Harmonic Filter 3Φ 2 Snubber 3 DC Link Filter 1Φ

CY Power line CX equipment

L2 CY

WBG Semiconductor Trend Capacitor Requirement

Higher Switching Frequencies Smaller, low ESR, low ESL low 20kHz → 100kHz → 100’s MHz loss capacitors with high dV/dt & current handling capability

Higher Operation Voltages Reliable performance at higher 400V → 900V →1200V→1700V voltages GaN SiC

High Junction Temperatures Reliable performance at elevated 105oC → 125oC → 200oC+ temperatures ≥ 125oC with SiC robust mechanical performance • Packaging close to the hot semiconductor to: ‒ Lower ESL ‒ Minimize cooling costs

DC-LINK Capacitance vs Switching Frequency and Voltage of a 10kW Power Converter 400V 650V 1000V 10

) uF

Higher Voltage = Lower Capacitance 0.1

Capacitance ( Capacitance 0.01 푃 퐶 = 푙표푎푑 푉 푉 푉푚푎푥 − 푟푖푝푝푙푒 ∗ 2 ∗ 휋 ∗ 푓푟푒푞푢푒푛푐푦 푟푖푝푝푙푒 2 0.001 10 100 1000 10000 Frequency kHz * Source: Prof. R. Kennel, Technical University Munich, Germany © 2019 KEMET Corporation Capacitance Vs. Switching Frequency Example: 10% Ripple for different power & voltage

Frequency 10kW 50kW 100kW Voltage 20 5.24μF 26.19μF 52.38μF 60 1.75μF 8.73μF 17.46μF 400 100 1.05μF 5.24μF 10.48μF 140 0.75μF 3.74μF 7.48μF 20 1.98μF 9.92μF 19.84μF 60 0.66μF 3.31μF 6.61μF 650 100 0.40μF 1.98μF 3.97μF 140 0.28μF 1.42μF 2.83μF 20 0.84μF 4.19μF 8.38μF 60 0.28μF 1.40μF 2.79μF Higher Voltage 1000 100 0.17μF 0.84μF 1.68μF Less Cap 140 0.12μF 0.60μF 1.20μF Higher Power More Cap © 2019 KEMET Corporation Capacitance vs. Switching Frequency Polypropylene 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.

Paraelectric Ferroelectric Anti-Ferroelectric EIA Class-I Class-II Class-II Types C0G, C0H, U2J X7R, X5R Similar to Y5V PbLaZrTiO Dielectric CaZrO BaTiO3 3 3 • C0G Development, Leadless Stacks for Higher Cap & U2J Dielectric with Higher K

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© 2019 KEMET Corporation Medium Low 3640 0.22µF 500V Ni BME C0G for 150oC Temperature 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 @ 500V ~ 8500 years DC MTTF = 2934 min.

y = 7.13E+59x-18.6

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

• Large Case C0G MLCC have No Lead Flex. Term. Or Lead – High MOR – Board Flex > 3mm – Pass AEC Q200 temp. cycle testing

Case Size Cap. Rated 1000 Cycles 50 Cycles (nF) Voltage -55oC to +125oC -55oC to +200oC

(VDC) Tested 4540 27 1500 0/231 0/50 Pieces to 10mm DID 3640 15 2000 0/154 0/100 NOT FAIL

3040 39 1000 0/154 0/100

2824 33 630 0/154 0/100

• Lower DF & ESR reduce the power dissipated

ESR < 3 mΩ

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

• 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

• PRO-TIP: Ideal for Resonant Capacitors

CKC 33 C 224 K C G A C TU Case Size Specification/ Capacitance Capacitance Rated Voltage Subclass Termination Packaging Series Dielectric (L"x W") Series Code (pF) Tolerance (V) Designation 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

Case Size 3640 0.22μF, 500V o • Thermal Resistance RƟ ( C/W) models Max. Cap. Range correlate well with experimental results 1812 2220 3640 KC-LINK Voltage Rating Voltage Rating 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 Model 0.22 224 0.47 474 Support customer thermal models for design-in RELEASED

• 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.

• BME C0G and BME U2J both show high current carrying capability. • Temperature rise <14°C up to ripple

current of 10Arms.

Rated Case Size Case Size Maximum Available Capacitance CAP Increase Voltage (Inches) (mm) vs. current C0G (Vdc) C0G U2J 10 2.2nF 4.7nF +114% 0402 1005 16 / 25 2.2nF 2.2nF - 50 1.5nF 1.8nF +20% 10 15nF 33nF +120% 0603 1608 16 / 25 15nF 15nF - 50 6.8nF 10nF +47% 10 47nF 100nF +112% 0805 2012 16 / 25 47nF 56nF +19% 50 22nF 47nF +114% 16 / 25 100nF 220nF +120% 1206 3216 50 82nF 150nF +83% 16 / 25 220nF 330nF +50% 1210 3225 50 150nF 270nF +80% 1812 4532 50 220nF 470nF +114%

• 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

10 mm 4-Chip 2.9 nH • Higher Capacitance to ≈ 1µF • Increased height of Leadless Stacks increases maximum 5 mm 2-Chip 1.6 nH inductance

2.5 mm MLCC 0.9 nH • High Insulation Resistance to 200oC

0.26 µA 2 µA

What is TLPS? • Low temperature reaction of low melting point metal or alloy Heat with a high melting point metal or alloy to form a reacted metal matrix or alloy. • Forms a metallurgical bond between 2 surfaces . CuSn TLPS • Has high failure temperatures.

Leadless Stack Mounted on J-Lead Stack Mounted on Circuit Board Circuit Board J-lead absorbs Small TLPS joint with low mismatch but CTE mismatch CTE mismatch must be minimized

Mounting Solder

• 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

Horizontal Vertical

2.9 nH 0.9 nH

Traditional Low Power 5.7 MHz Loss 3 MHz

Vertical Orientation has: • Higher SRF • Lower ESR

Horizontal - Traditional Heat dissipation into Cu board.

34.9oC

Vertical – Low Power Loss Orientation:

Side View Top View • More even STEADY STATE heating 12ARMS @ 140kHz WARMING UP Vertical – Low Loss Heat dissipation • Lower Temp. in Air above. @ Steady State ≈ - 5oC 29.2oC

Low Loss Model Study thermal resistance with other boundary conditions • Forced air cooling or dielectric fluids • Embedded in package

• 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