Transcript Electronics Cooling MEP 635

Electronics Cooling
MPE 635
Mechanical Power Engineering
Dept.
Course Goals
1. To establish fundamental understanding of
heat transfer in electronic equipment.
2. To select a suitable cooling processes for
electronic components and systems.
3. To increase the capabilities of post-graduate
students in design and analysis of cooling of
electronic packages.
4. To analysis the thermal failure for electronic
components and define the solution.
• Part-A
• Main topics
• Introduction to electronics cooling and thermal packaging
• Introduction to basic modes of heat transfer
• Conduction heat transfer and extended surfaces in electronic
devices
• Transient conduction
• Natural convection heat transfer (i.e. PCB cooling)
• Forced convection heat transfer (Internal and External flow )
• Fan performance
• Radiation heat transfer and its applications in electronic devices
• Solving the electronics cooling problems with EES software
• Electronics cooling problems
• Solution of selected electronics cooling problems
2. Packaging Trends and
Thermal Management options in
the Electronic Industry
Electronic Packaging and
Interconnection Technology
• Electronics
• Materials properties and materials
compatibility
• Mechanics
• Chemistry
• Metallurgy
• Production technology
• Heat transfer
• Reliability, etc
Types of Electronics and Demands on
Them
Electronic
product
Production
Volume
Life/
reliability
Weight
and Power
Acceptable
Development cost
Comments
Satellite
electronics
one unit
20 years
low
weight
and power
very high
acceptable
no repair
medical
electronics
medium
20 years
low
weight
and power
very high
acceptable
harsh
environment
Telephone
main
switchboard
low and
high
10 years
Variable
high price
pressure
benign
environment
High
very rough
environment
Military
electronics
Very high
reliability
Computers
low and
high
Very short
product
life
Consumer
products
very big
market
very short
product
life
High
performance
and reliability
low
weight
and power
Extreme
price
pressure
No repair.
Packaging Levels
• Level 0: Bare
semiconductor
(unpackaged).
• Level 1: Packaged
semiconductor or
packaged electronic
functional device.
• Level 2: Printed wiring
assembly (PWA).
• Level 3: Electronic
subassembly.
Packaging Levels
•
•
Level 4: Electronic
assembly.
Level 5: System. This
refers to the
completed product.
Package Function
• Signal distribution
• Power Delivery
• Thermal
management
• Gentle environment
• Minimum signal
delay
• Minimum cost
Stages in the Development of a
Packaging Technology
•
•
•
•
•
•
Environment
Building blocks
Enabling technology
Modeling and simulation
Comparison to specifications
Preparation for manufacturing
Environment
Device and chip technology
System Architecture
System Specifications
Manufacturing and field Support
Building Blocks
Single Chip Package
Chip on Board
Multi-Chip Module
Stages in
the
Develop
ment of a
Packagin
g
Technolo
gy
Enabling Technologies
Package attach "PowerSignal-Mechanical"
Chip attach "Power-SignalMechanical"
Thermal Control Technique
Mechanical Components
Substrate Material and Chip
Protection
Substrate connect "Power-SignalMechanical"
Modeling and Simulation
Simulation Tools
Comparison to
specification
SCP
Performance
COB Performance
MCM Performance
Iteration
≠
=
Preparation for
fabrication
Manufacturing
Drawings
Product Categories
• Commodity <$300; disk drives, displays,
micro-controllers, boom-boxes, VCR’s
• Hand-Held < $1000 ; PDA’s, cellular phones
• Cost/Performance <$3000; PC’s and
Notebooks
• High-Performance > $3000; Workstations,
Servers, Supercomputers
• Harsh Environment; Automotive
• Memory; DRAMs, SRAMs
Thermal Packaging Strategies
• Commodity & Memory:
- Natural Convection
• Hand-Held:
- Natural Convection + Spreaders
Thermal Packaging Strategies
• Cost/Performance:
- PC - Forced-Air Heat Sinks, Fan-Sinks
- Notebooks - Heat Pipe Spreaders, Fans,
Heat Sinks
Thermal Packaging Strategies
• High-Performance:
- Forced-Air Heat Sinks; Water-Cooled Cold
Plates; Refrigeration; Immersion
• Harsh Environment:
- Forced Air Heat Sink
Automotive Electronics
Electronic content in cars and trucks has significantly increased
in the last 30 years. Much of the functional content of these
vehicles is now generated or controlled by electronic systems.
History of typical engine control modules (ECMs)
Examples of thermal requirements
for various products
•
Cost/Performance 2004
Microprocessor Thermal Requirements
-
Power Dissipation - 200W
Temperatures: Junct = 95C; Ambient = 45C
Chip Size - 15mm x 15mm 0.3mm
Thermal “Space Claim” - 100 x 100 x 50mm
Thermal “Mass Claim” - 250gm
Flow Parameters: Pressure Drop = 40Pa
(0.15”H2O), 40cfm
Examples of thermal requirements
for various products
• Cost/Performance 2004 RF Chip
Thermal Requirements
-
Power Dissipation - 100W
Temperatures: Junct = 150C; Ambient = 45C
Chip Size - 3mm x 1mm 0.3mm
Wireless Module = 10 Chips, 1kW
Thermal “Space Claim” - 150 x 150 x 150mm
Thermal Resistances:



Spreading (Chip Level) = 0.6K/W
Internal Convective (Chip Level) = 0.2K/W
External Convective (Module Level) = 0.25K/W
Thermal Packaging, Future
Forecasting
•
Future Thermal Packaging Needs
-
•
Higher Power Dissipation
Higher Volumetric Heat Density
Market-Driven Thermal Solutions
Air as the Ultimate Heat Sink
Environmentally-Friendly Design
Future Thermal Packaging Solutions
-
Thermo-fluid Modeling Tools
Integrated Packaging CAD
Compact Heat Exchanger Technology
Design for Manufacturability/Sustainability
“Commodity” Refrigeration Technology
Thermal Packaging Options and Trends
Aims of thermal control
• PREVENT CATASTROPHIC FAILURE
- Electronic Function
- Structural Integrity
• PROVIDE ACCEPTABLE MICROCLIMATE
- Device Reliability
- Packaging Reliability
- Prevent Fatigue, Plastic Deformation and Creep
• SYSTEM OPTIMIZATION
- Fail Safe or Graceful Degradation
- Multilevel Design
- Reduction of “Cost of Ownership”