1. Electronics Cooling MPE 635 Mechanical Power Engineering Dept.

2. 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. Course Goals

3. 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

4. 2. Packaging Trends and Thermal Management options in the Electronic Industry

5. Electronic Packaging and Interconnection Technology Electronics Materials properties and materials compatibility Mechanics Chemistry Metallurgy Production technology Heat transfer Reliability, etc

6. Types of Electronics and Demands on Them CommentsAcceptable Develop- ment cost Weight and Power Life/ reliability Production Volume Electronic product no repairvery high acceptable low weight and power 20 yearsone unitSatellite electronics harsh environment very high acceptable low weight and power 20 yearsmediummedical electronics benign environment high price pressure Variable10 yearslow and high Telephone main switchboard very rough environment HighVery high reliability Military electronics High performance and reliability Very short product life low and high Computers No repair.Extreme price pressure low weight and power very short product life very big market Consumer products

7. 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.

8. Packaging Levels Level 4: Electronic assembly. Level 5: System. This refers to the completed product.

9. Package Function Signal distribution Power Delivery Thermal management Gentle environment Minimum signal delay Minimum cost

10. Stages in the Development of a Packaging Technology Environment Building blocks Enabling technology Modeling and simulation Comparison to specifications Preparation for manufacturing

11. Stages in the Develop ment of a Packagin g Technolo gy Environment  Device and chip technology  System Architecture  System Specifications  Manufacturing and field Support Building Blocks  Single Chip Package  Chip on Board  Multi-Chip Module Modeling and Simulation Simulation Tools Comparison to specification  SCP Performance  COB Performance  MCM Performance ≠ = Preparation for fabrication Manufacturing Drawings Iteration Enabling Technologies  Package attach "Power- Signal-Mechanical"  Chip attach "Power-Signal- Mechanical"  Thermal Control Technique  Mechanical Components  Substrate Material and Chip Protection  Substrate connect "Power-Signal- Mechanical"

12. 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

13. Thermal Packaging Strategies Commodity & Memory: - Natural Convection Hand-Held: - Natural Convection + Spreaders

14. Thermal Packaging Strategies Cost/Performance: - PC - Forced-Air Heat Sinks, Fan-Sinks - Notebooks - Heat Pipe Spreaders, Fans, Heat Sinks

15. Thermal Packaging Strategies High-Performance: - Forced-Air Heat Sinks; Water-Cooled Cold Plates; Refrigeration; Immersion Harsh Environment: - Forced Air Heat Sink

16. 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)

17. 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

18. 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

19. 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

20. 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”