3d wirebondless igbt module for high power...
TRANSCRIPT
ASTRI Proprietary 1
3D Wirebondless IGBT Module for
High Power Applications
Dr. Ziyang GAO
Jun. 20, 2014
1
ASTRI Proprietary
Outline
Background Information
Technology Development Trend
Technical Challenges
ASTRI’s Solutions
Concluding Remarks
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ASTRI Proprietary
Power semiconductors are mainly used in the circuits of inverters/ converters for switching & converting of electricity.
Unique features
of IGBT
modules:
Wide switching
frequency (1KHz
– 100KHz);
High switching
power (1KW –
4MW); and
Low switching
power loss.
IGBT’s Feature & Applications
ASTRI’s focus
10M
1M
100K
10K
1K
100
100 1K 10K 100K 1M
IGBT Module High Power
IGBT Module w/
Medium Power
Transportation
New Energy
New Energy
Motor Control Robotics & EV
Home Appliances
Sw
itch
ab
le P
ow
er
(W)
Switching Frequency (Hz)
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ASTRI Proprietary
IGBT’s Application to EV & HEV
IGBT: Emphasized area in
the Chinese government’s
12th Five-Year Plan on Key
Energy Conservation
Technologies, including
New Energy & New Energy
Vehicles. Bil
lio
n, U
SD
Source: Yole, 2013
EV/HEV is expected to be the key IGBT market driver.
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ASTRI Proprietary
IGBT Packaging & Module
Manufacturing of power module consists of 6 major steps.
Back-end & packaging contribute to ~48% of IGBT module cost.
5
ASTRI Proprietary
Outline
Background Information
Technology Development Trend
Technical Challenges
ASTRI’s Solutions
Concluding Remarks
6
ASTRI Proprietary
0
50
100
150
200
250
0
20
40
60
80
100
120
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180
1990 1995 2000 2007 2012 2017
Wafe
r T
hic
kn
ess (
um
)
Po
we
r D
en
sit
y (
KW
/cm
2)
Evolution of IGBT Technologies (1/2)
IGBT Wafer Development Trend
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ASTRI Proprietary
Evolution of IGBT Technologies (2/2)
High
Power &
Thermal
Classic Design
1990’s
2000’s
2010
2016
Flexible Foil & Sintering Ag (Semikron, 2011)
Plated Cu (Siemens, 2012)
AlN Substrate (Denso, 2010)
Baseplate / Heatsink
(Infineon, 2010) SiN Baseplate (Honda, 2006)
Molded Module (Mitsubishi, 2013)
Leadframe (Denso, 2008)
Cu Lead (Honda, 2010)
Flip Chip (Delphi, 2010)
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ASTRI Proprietary
Outline
Background Information
Technology Development Trend
Technical Challenges
ASTRI’s Solutions
Concluding Remarks
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ASTRI Proprietary
Power Electronics v.s. Microelectronics
Power electronics
Microelectronics
LED
Power Heat Flux Density (W/cm2)
Reliability Product Lifetime
Cooling Approaches
Micro-electronics
100W (Pentium 4)
100 (Pentium 4)
1.1 g-level (30 minutes)
~5 years Forced air
Power electronics
120KW (100A IGBT)
1,200 (100A IGBT)
20 g-level (2 hours)
>10 years Liquid cool 10
ASTRI Proprietary
Super High Heat Dissipation
Potential Solutions Company I
Thermal Resistance
(ºC/KW)
IGBT Chip 0.6
TIM1 0.6
DBC Substrate 4.4
TIM 2 0.6
Base Plate 0.7
Module Thickness 20.55 mm
Input Power 0.68 MW
Junction
Temperature Up to 120ºC
Base plate
TIM 2
Cu pattern
Substrate
Cu pattern
TIM 1
IGBT chip Silicone
Single side cooling only!
New materials (e.g., AIN
substrate, nano-silver die
attach, etc.);
New interconnect and/or
structure (e.g., wirebondless,
combined baseplate &
heatsink, etc.).
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ASTRI Proprietary
Interconnect Long-term Reliability
Wire Lift-off
(10x10mm2)
Die Tilt
Creep & Cracking
Overshoot voltage under different interconnects
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ASTRI Proprietary
Outline
Background Information
Technology Development Trend
Technical Challenges
ASTRI’s Solutions
Concluding Remarks
13
ASTRI Proprietary
Delivering Technologies: 3D Wirebondless Structure
Design Concepts:
3D structure replacing wirebond interconnects
Microstructure design on ceramic substrate for better reliability
Surface treatment for enhancing surface wetting
Advantages:
Controllable solder-based bondline thickness
SMT compatible assembly process to improve throughput
Compatible to DBC substrate fabrication process
Wirebond based IGBT module ASTRI’s 3D wirebondless IGBT
module
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ASTRI Proprietary
Reliability and Electrical Performance
Reduced 70%
voltage overshoot!
Electrical Performance
96% & 72% parasitic resistance &
inductance reduction, respectively;
70% overshoot voltage reduction.
Module for Electrical Test
Wirebond 3D-PEM
Tested at China North Railway Co. Ltd.
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ASTRI Proprietary
Heat Dissipation
50
100
150
200
250
300
50 100 150 200 250 300Power dissipation (W)
Ju
nctio
n te
mp
era
ture
(°C
)
Single side, WB-based
Double side, bumped-based
Comparison of junction temperatures.
>35% thermal enhancement
Simulated flow patterns and temperature distributions of coolant.
Coolant in
Temperature contours of 3D-PEM
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ASTRI Proprietary
HKSTP-ASTRI SiP Line
Stencil Print
+Pick & Place Reflow
Busbar
Welding
Underfill
& Cure
Back-end
Pick
&Place
Wafer
Dicing
Vacuum
Reflow
Front-end
HKSTP-ASTRI SiP Line was ready in Aug 2013.
The line has 24 major equipments to support the process
developments of new packages and small volume production.
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ASTRI Proprietary
HKSTP-ASTRI WLP Line
HKSTP-ASTRI Wafer-Level-Packaging Line is under construction
and will be ready by Q1 2015.
The line has 12 major equipments to support the process
development for TSV and other wafer level packages. 18
ASTRI Proprietary
Example: UBM Fabrication for IGBT Wafers
Post-wafer level processing for incoming IGBT wafers.
1200V/100A IGBT wafer with 5~8um Ni UBM
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ASTRI Proprietary
Concluding Remarks
IGBT has been increasingly applied to many
products, from home appliances, motor control,
robotics, EV, new energy, to transportation.
High-end IGBT module development faces many
technical challenges, such as interconnect long-term
reliability, module harsh environment failure, and
super high heat dissipation.
With the support of HKSTP-ASTRI SiP/WLP lines,
ASTRI can provide one-stop total solution to local
industry, including module design, process recipes,
prototype samples, performance testing, and small
volume pilot run.
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ASTRI Proprietary 21
End of Presentation Thank you.
Suggestions are welcome!
Contact us:
Dr Ziyang Gao
Tel: (852) 3406 2571
Email: [email protected]
Our corporate website: www.astri.org
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