Why Thermal Management? - PowerPoint PPT Presentation

About This Presentation
Title:

Why Thermal Management?

Description:

Why Thermal Management? References: Sergent, J., ... (non-temp-related) failures Due to mechanical interconnections: poor wire bonds, die bonds, lead frame bonds ... – PowerPoint PPT presentation

Number of Views:104
Avg rating:3.0/5.0
Slides: 11
Provided by: MAE3150
Learn more at: https://www.sjsu.edu
Category:

less

Transcript and Presenter's Notes

Title: Why Thermal Management?


1
Why Thermal Management?
  • References Sergent, J., and Krum, A., Thermal
    Management Handbook for Electronic Assemblies,
    McGraw-Hill, 1998
  • And
  • Yeh, L.T., and Chu, R.C., Thermal Management of
    Microelectronic Equipment Heat Transfer Theory,
    Analysis Methods, and Design Practices, ASME
    Press, New York, 2002.

2
Size and Performance Trends
  • Higher levels of integration in semiconductors
  • More multichip modules
  • Faster speeds, smaller devices
  • Leads to both more heat generation and higher
    heat densities

3
Increase in Circuit Complexity
Yeh and Chu, 2002
4
Major Causes of Electronics Failures
Yeh and Chu, 2002
5
Types of Failures
  • Soft failures Properties change, changing
    performance outside the specs
  • Resistors, capacitors, transistors, leakage
    currents
  • Example bipolar transistor gain can change by
    a factor of 3 over the military temperature range

Sergent and Krum, 1998.
6
Types of Failures, cont.
  • Hard failures component doesnt work at all
  • Corrosion, chemical reactions, intermetallic
    compound formation
  • Cracking caused by different coefficient of
    thermal expansions
  • Breakdown of materials

7
Classification of Temp-Related Failures
  • Sergent and Krum, 1998.

8
Yeh and Chu, 2002
9
Other common (non-temp-related) failures
  • Due to mechanical interconnections poor wire
    bonds, die bonds, lead frame bonds, etc. bonds
    not fully formed or incompatible materials
  • Due to manufacturing defects in active devices
    impurities in semiconductors, pinholes in
    insulating oxide, etc.
  • Due to electrical overstress overstress during
    operation or else exposure to electrostatic
    discharge
  • Due to chemical reactions corrosion or formation
    of intermetallic compounds exacerbated by high
    temperatures

10
Designer Reaction to Thermal Issues
  • Two common reactions
  • Underestimate of component temps, resulting in
    too little cooling, leading to failure
  • Overkill cooling a system much more than
    needed, leading to excessive cost and increased
    size and noise
  • To properly design the system, we need to know
    the following
  • How and where heat is generated
  • How to estimate the temperature
  • How to remove the heat
  • Well focus on these three issues in class!
Write a Comment
User Comments (0)
About PowerShow.com