Thermal Interface material Using Carbon Nanotubes · CARBON NANOTUBES Vahab Hassani National...

THERMAL INTERFACE MATERIAL USING CARBON NANOTUBES

Vahab Hassani National Renewable Energy Laboratory vahab_hassani@nrel.gov Tel: 303-275-4427

FY05 Budget: $0K FY06 Budget: $250K

FreedomCAR APEEM Quarterly Program Review Nov. 1-3, 2005

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Where Does This Project Fit?

• Integrated cooling loop • Inlet coolant at 105 oC for hybrid, 85 oC for FCV • Heat fluxes at the order of up to 250 W/cm2

• Eventually, we would like to do air cooling by FY10 to FY15

Power

Electronics

Electrical

Machines

Thermal

Systems

Wide Band-Gap Mat’ls

High-Temp. Capacitors

Wide Band-Gap Mat’ls

High-Temp.Capacitors

Magnets

Reduce Thermal Resistance

Air Cooling105C and 85C WEG

Increase Heat-Transfer Coefficient

• D

Project Description

evelopment of highly conductive thermal interface materials for

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maintaining an acceptable operating temperature for power electronics l Silicon chip

Solder

Direct Bond Copper Cu,

Thermal Paste

Base plate, heat sink

Pin finsTB

TH

TCQ heat

AlN, Cu

, Base plate Temp.

, IGBT Temp.

, coolant Temp.

Goals

The goals of this project are:

• Increase the thermal conductivity of the existing thermal interface material by a factor of 6

• Grow carbon nano-tubes on Si or copper substrate

• Produce prototype material for testing

• Develop a nano-thermo foil TIM

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Technical Approach

• Develop ultra-thin copper-CNT sheets as thermal interface material by synthesizing carbon nanotubes on copper(one side/both sides) using chemical vapor deposition

• Optimize the growth process for the nanothermofoil

• Measure thermal conductance of the nanothermofoil

• Compare the thermal conductance of the nanothermofoil with commercially available products

• Measure the contact resistance at the joint

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Timeline for FY06

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Develop ultra-thin cop er-CNT psheets

Optimize the growth process

Measure thermal conductance

Analysis

Measure thermal Mile-

Resistance stone

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Barriers and Challenges

• Proper growth of carbon nano-tube/distribution

• Optimize the growth process for the nanothermofoil

• Overcoming the impact of contact resistance

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• University of Colorado, Boulder

• National Institute of Standards and Technology (NIST)

Interactions and Collaborations