|
||
| Oak Ridge National Laboratory | ||
|
Materials for Electric and Hybrid Drive Systems Reaching the 2015 goal of a compact, light weight traction motor and associated power electronics for $12/kw peak will likely require the use of wide band-gap materials like SiC or GaN and low-cost processing techniques. Current materials used in electronic packages operate to 125°C – the limit for Si components. The operation of more compact electronic packages at higher temperatures will cause steeper gradients, transients, and strains in the brittle SiC and electronic ceramic insulator. High-temperature electronic packages will need to be redesigned with new materials with tailored properties in order to eliminate failure and maintain acceptable reliability. For example, new materials will need to be identified to replace conventional epoxies that degrade at temperatures below 200°C. Eutectic lead-tin solders that melt at 183°C will need to be replaced with higher melting materials. Novel electronic substrates will be required whose coefficient of thermal expansion, thermal conductivity and heat capacity will need to be tailored to manage stresses and sustain electrical function. In addition, substrates with integrated thermal dissipation capabilities will likely be needed to adequately cool the electronics. Milestones: Develop the methodology to examine the interaction of the electrical components with the fluids used in the evaporative cooling systems and compare electrical characteristics of two competing commercial IGBTs through the parametric variation of temperature, humidity, and vibration. (09/09) Identify potential alternate compositions or processes with potential to decrease failure rate and improve reliability of high temperature solders. (9/09). Validate the proposed methodology of power pulsing while immersed in coolant for examining the interaction of the electrical components with evaporative coolant. (09/09) Related Agreements:
Modeling and Testing of Environmental Effects on Automotive PE Devices
Approach: Develop and model new concepts that minimize or avoid any detrimental effects caused by environment in PEDs. Such concepts include the identification of alternative materials or architectures whose introduction or substitution into PEDs would lessen such environmental effects without compromise to electronic function. Evaluate and model performance of PEDs as a function of temperature, humidity, and vibration. Use finite element analysis (FEA) and companion probability design sensitivity (PDS) methods to evaluate and improve thermal management effectiveness, PED reliability, and enable sustained higher-temperature use.
Milestone: Compare cooling efficiencies in a hybrid inverter insulated gate bipolar transistor that contains contemporary and alternative ceramic direct bonded copper substrates. (09/09) Contact: Andrew Wereszczak, Oak Ridge National Laboratory, 865-576-1169, wereszczakaa@ornl.gov Complete Project List | Materials for Electric and Hybrid Drive Systems Materials by Design - Solder Joints of High Performance Power Electronics Objective: Solder joints and wire bonds serve as pathways for electrical connection to and from electronic devices used in hybrid and electric vehicles. Failure of these solder joints and wire bonds will result in catastrophic failures of critical electronic components and hence systems used in these automobiles. Thus, there is a significant need to study the failures of electronic packages induced by metallurgical changes of solder joints and wire bonds. Approach: Analyze simple package designs so that the emphasis is on materials rather than electronic design where complexities of devices may overshadow materials issues. Package designs will be stress tested to see where failures originate. Steady-state exposure at high temperatures, cyclic exposures (thermal fatigue) all affect microstructure of the materials and their properties. IR imaging will be used to show hot spots and perhaps voids. IR imaging will be complemented with radiography and acoustic techniques.
In FY 2008, techniques for such reliability testing were established and work was carried out one solder joint material. Discussions with industrial partners have helped identify two additional solder joint materials that are currently being considered for use in packages for high temperature operation. In FY 2009, reliability testing of simple packages using these solder joints will be completed. This information will be used to identify the key properties controlling the reliability of these solder joints. Milestone: Evaluate microstructural evolution and causes related to the failure of two additional solder joint compositions identified through interactions with industrial partners when subjected to stress testing conditions. (9/09) Contact: Govindarajan Muralidharan, Oak Ridge National Laboratory, 865-574-4281, muralidhargn@ornl.gov Complete Project List | Materials for Electric and Hybrid Drive Systems Power Electronics Materials Compatibility
Approach: Analyze simple package designs so that the emphasis is on materials rather than electronic design where complexities of devices may overshadow materials issues. Package designs will be stress tested to see where failures originate. Steady-state exposure at high temperatures, cyclic exposures (thermal fatigue) all affect microstructure of the materials and their properties. IR imaging will be used to show hot spots and perhaps voids. IR imaging will be complemented with radiography and acoustic techniques. In FY 2008, techniques for such reliability testing were established and work was carried out one solder joint material. Discussions with industrial partners have helped identify two additional solder joint materials that are currently being considered for use in packages for high temperature operation. In FY 2009, reliability testing of simple packages using these solder joints will be completed. This information will be used to identify the key properties controlling the reliability of these solder joints. Milestone: Evaluate microstructural evolution and causes related to the failure of two additional solder joint compositions identified through interactions with industrial partners, when subjected to stress testing conditions. (9/09) Contact: Beth Armstrong, Oak Ridge National Laboratory, 865-241-5862, armstrongbl@ornl.gov Complete Project List | Materials for Electric and Hybrid Drive Systems |
U.S. Department of Energy • Office of Vehicle Technologies Program
|
|
 |
|
Oak Ridge National Laboratory is a national multi-program research and development facility Last modified on
December 12, 2008 12:14 PM
|
Objective: To understand the complex relationship between environment (temperature, humidity, and vibration) and automotive power electronic device (PED) performance. There is significant interest in developing more advanced PEDs and systems for transportation applications (e.g., hybrid electric vehicles, plug-in hybrids) that are capable of sustained operation to 200°C and above. Operation at 200ºC will enable the use of advanced SiC semiconductors and lead to more efficient electric and hybrid drive systems. Advances in packaging materials and technology can achieve this but only after their service limitations are better understood.
I
Objective: Solder joints and wire bonds serve as pathways for electrical connection to and from electronic devices used in hybrid and electric vehicles. Failure of these solder joints and wire bonds will result in catastrophic failures of critical electronic components and hence systems used in these automobiles. Thus, there is a significant need to study the failures of electronic packages induced by metallurgical changes of solder joints and wire bonds.