Double-side Cooled, Wirebond-less 6.5 kV SiC MOSFET

Module with Lateral Spring Terminals

Khai Ngo, Christina DiMarino, Guo-Quan Lu, Louis Guido, Suman Dwari,

Sreekant Narumanchi, Rongming Chu

ARPA-E Energy Innovation Summit 2021

Award: DE-AR0001008

2May 24th 2021

Applications for High-Density Converters

Path to Higher Density MV Converters

Improved Devices• Higher Blocking Voltages• Lower Losses• Higher Operating Temperatures

GaN / SiC

High-Density Converters• Streamlined Integration• Reduced System Complexity

Increasing Need for High-Density MV Conversion

ABB 8 MW 3-Phase Converter Commercial 6.5 kV Si IGBT Package

(195 mm x 140 mm x 30 mm)

• Power Rating: 10 kV / 80 A• Power Density: 18 W/mm3

• Parasitic Inductance: 4 nH

CPES 10 kV SiC Wirebond-less MOSFET Power Module

16 mm

6mm

Renewable Energy Aerospace Power Grids

3May 24th 2021

Comparison to the State of the Art

0

1

2

3

4

5

6

7

8

9

0 2 4 6 8 10 12

Po

wer

Den

sit

y W

/mm

3

Rated Voltage (kV)

SoA MV Half-Bridge Power Modules

0

5

10

15

20

25

0 1 2 3 4 5 6 7

Po

wer

Den

sit

y W

/mm

3

Rated Voltage (kV)

SoA MV Discrete Power Modules

Si IGBT

1000 A – 1500 A

Si IGBT

1000 A – 1200 A

SiC MOSFET

550 A – 800 A

Si IGBT

450 ASi IGBT

500 A

SiC MOSFET

75 A (2018)

SiC MOSFET

80 A

SiC MOSFET

25 A

Proposed 6.5 kV SiC MOSFET

Module with Double Sided Cooling

4May 24th 2021

6.5 kV, 25 A SiC MOSFET Package

• Utilizes 10 kV, 25 A SiC MOSFET from Wolfspeed

• Double-sided cooling for improved heat dissipation

• Lateral spring-pin termination for modular converter integration

Spring-Pin

TerminalsDual Cooling

Surfaces

Device

Kelvin

Drain

Gate

Source

5May 24th 2021

Manufacturing Process Overview

Photolithography Die Re-Patterning

BCB

AgAl

Large-Area Low-Pressure Ag Sintering

Pressure-less Ag Sintering Solder Reflow

Solder ReflowEncapsulation

Double-side Cooled,

6.5 kV, 20 A SiC Discrete Package

6May 24th 2021

Electrical Characterization Results

• Developed 6.5 kV capable PCB busbar and test fixture

• Reverse leakage: < 20 nA at 6.5 kV

• Rds-on: 450 mΩ

Reverse Leakage Characterization Forward CharacteristicsTest Fixture

Rds-on

7May 24th 2021

Thermal Characterization Results

Test Bed θjc Transient Characterization for Bottom/Top Side Cooling Surface

• Measured in JEDEC 51-14 compliant test fixture

• Target Specification: < 30ºC temperature rise at 200 W/cm2 → 0.23 ºC/W

• Simulated Performance: 0.2 ºC/W

• Measured Performance: 0.253 ºC/W Top & 0.573 ºC/W Bottom → 0.17 ºC/W

8May 24th 2021

Future Work – 6.5 kV, 50 A Phase Leg

27 W/mm3

+ DC

+ DC

+ DC

• Utilizes 10 kV, 25 A SiC MOSFET from Wolfspeed

• Double-sided cooling for improved heat dissipation

• Spring-pin termination for modular converter integration

• Four devices in total, two per switch position

Devices