关于热的高级培训教材.ppt

Advanced Thermal Modeling Course Outline 1. Introduction 简介 2. Printed Circuit Boards (PCB板) 3. IC Packages (IC 封装) 4. Heat Sinks 散热器 5. Interface Resistance 接触热阻 6. Fans, Impellers and Blowers 风扇，叶轮，离心风机 7. Altitude Effects 高度的影响 8. Flow Resistances 气流阻尼 9. Radiation 幅射 10. Heat Pipes 热管 11. Joule Heating 电阻发热 12. Thermoelectric Coolers 热电冷却 Course Outline 13. Cold Plates 冷板 14. Transformers 变压器 15. Flow Baffles 气流挡板 16. Wall Effects 壁的效果 17. External Coolers/Heaters 外部冷却器/加热器 Exercises: 练习： 1. PBGA Model PBGA 模型 2. Selecting a Heat Sink 选择散热器 3. Modeling TEC 热电冷却器模型 4. Selecting a Baffle 选择挡板 5. Modeling External Coolers 外部冷却器建模 Introduction The Case for Thermal Management The heat generated in an electronic circuit is inversely proportional to the efficiency of the circuit 电子线路板产生的热与它的效率成反比 The power that is not converted to perform useful electromagnetic work is lost in the form of heat to the surroundings 没有转换成电磁功率的热耗散到了周围的环境 The power wasted as heat includes: 热耗包括 Joule heating (I2R) loss 电阻损失 Power supply 电能提供 The reliability of a semiconductor device is directly affected by its operating temperature 工作环境的温度直接影响到半导体设备的可靠性 The Case for Thermal Management Virtually all electronic failure mechanisms are enhanced by the increase in package temperature: 实际上，所有电子失效的机理都是由于封装温度升高引起的 Stresses due to TCE (=Total Composite Error 总综合误差）mismatch 不匹配 Corrosion 腐蚀 Electro-migration 电子移动 Oxide breakdown 氧化物崩溃 Current leakage (which doubles with every 10 c in active devices) 电流泄漏 Degradation in electrical performance (due to change in device parameters) 电性能下降 The Case for Thermal Management The rate of failure of electronic packages is directly proportional to heat and increases exponentially with the maximum temperature of the package 电子封装失效的比例直接与热成正比，而且与封装的最高温度成指数增长 The rate of failure can be expressed as: 失效的比例可描述为： F = Ae-E/KT where, F = failure rate, 失效率 A=constant 常数 E = activation energy in electron volts (eV) 激活的电能 K = B