1. Two-Phase Microfluidic Cooling of Emerging Electronic Devices
Franklin Robinson/545 Keith Coulson/Missouri S&T
Overview
Background
Approach
Contributions
•Miniaturized electronics demand advanced
thermal management
•Embedded, two-phase microgap coolers meet
this requirement
•180 µm tall microgap tested for performance
•60 W of heat was dissipated by thermal test chip
•Microgap height calculated using differential
pressure and fluid properties
•Two-phase heat transfer utilizes latent heat of
vaporization for high flux heat removal with low
pumping power
•Active cooling required for high heat loads from
miniature devices
•As microgap height decreases, gravity plays a
diminishing role
•Channel heights of 180, 480, and 1000 µm
•Mass fluxes of 400, 700, and 1000 kg/m2s
•Heat input until local dryout produces
temperature spike
•Data sampled at 25 Hz to protect test chip (TTC)
•Developed LabVIEW code that controls
loop, collects data, and protects the TTC
•Modified MATLAB code that calculates
microgap height using an iterative solver
•Ran tests and analyzed results
•Performed calibrations, leak checks,
charging and draining operations
Applications
•3-dimensional integrated circuits
•Laser diode arrays/high flux elements
•High-functioning humanoid robotics
6.2mm
0
10
20
30
40
50
60
-5 5 15 25 35
Heaterpower(W)
Degrees of Superheat (°C)
Boiling Curve at Different Mass Fluxes
Diode 6, 380kg/m2s Diode 6, 760kg/m2s Diode 6, 1130kg/m2s
0
10
20
30
40
50
60
-5 5 15 25 35
Heaterpower(W)
Degrees of Superheat (°C)
Boiling Curve for Leading & Trailing Edge
Diode 7, 380kg/m2s Diode 5, 380kg/m2s
Diode 7, 760kg/m2s Diode 5, 760kg/m2s
Diode 7, 1130kg/m2s Diode 5, 1130kg/m2s
6 5 7
G = 380 kg/m2s
Pchip = 12.6 W
G = 380 kg/m2s
Pchip = 18.9 W
G = 380 kg/m2s
Pchip = 25.2 W
G = 380 kg/m2s
Pchip = 36.2 W
Flow
Engineering
Microgap
Single phase
Two-phase
Single phase
Two-phase
Flow
Flow Boiling of HFE-7100 in 180 µm Microgap Cooler