دانلود کتاب PCB Design Guide to Via and Trace Currents and Temperatures

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PCB Design Guide to Via and Trace Currents and Temperatures Contents Preface Technical Note: TRM Acknowledgments Chapter 1 Introduction and Historical Background 1.1 Bottom Line 1.2 Historical Background 1.3 A Note about Consistency End Notes Chapter 2 Materials Used in PCBs 2.1 Bottom Line 2.2 Background 2.3 Copper Used in PCBs 2.3.1 Copper-clad laminates 2.3.2 Copper Plating Manufacturing Step 2.3.3 Copper Resistivity 2.3.4 Summary 2.4 Dielectrics Used in PCBs 2.4.1 Thermal Conductivity (Tcon or k) 2.4.2 Glass Transition Temperature (Tg) 2.4.3 Decomposition Temperature (Td) 2.4.4 Time to Delamination (T260/T288) 2.4.5 Summary End Notes Chapter 3 Resistivity and Resistance 3.1 Bottom Line 3.2 Resistivity 3.3 Resistance 3.4 Thermal Coefficient of Resistivity (a) 3.5 Measuring Resistivity 3.5.1 Resistivity Investigation 3.5.2 Nondestructive Measurements End Notes Chapter 4 Trace Heating and Cooling 4.1 Bottom Line 4.2 Overview 4.3 Trace Heating 4.3.1 Power and Energy 4.3.2 Trace Heating 4.4 Trace Cooling 4.4.1 Conductive Cooling 4.5 Mathematical Model of Trace Heating and Cooling 4.6 Role of Current Density 4.7 Measuring Trace Temperature 4.7.1 IPC Procedure 4.7.2 Infrared Measurement 4.7.3 Thermocouple Measurement 4.7.4 Point versus Average Measurements 4.8 Trace Temperature Curves 4.8.1 Typical Curve 4.8.2 Heavy Overload 4.8.3 Marginal Overload End Notes Chapter 5 IPC Curves 5.1 Bottom Line 5.2 IPC-2152 5.3 Measuring the Temperature 5.4 IPC Curves 5.4.1 External Results 5.4.2 External IPC Data Equations 5.4.3 Internal IPC Data Equations 5.4.4 IPC Vacuum Data End Notes Chapter 6 Thermal Simulations 6.1 Bottom Line 6.2 Background 6.3 Modeling Traces 6.4 The Modeling Process End Notes Chapter 7 Thermal Simulations 7.1 Bottom Line 7.2 Sensitivities: Layout Parameters 7.2.1 Small Trace Widths 7.2.2 Transient Response 7.2.3 Thermal Gradients 7.2.4 Changing Trace Length 7.2.5 Dimensional Uncertainties 7.2.6 Presence of Planes 7.2.7 Adjacent Trace 7.2.8 Adjacent Trace with Underlying Pla 7.2.9 Parallel Power Traces 7.2.10 Stacked Power Traces 7.2.11 Air Flow 7.2.12 Summary 7.3 Sensitivities: Material Parameters 7.3.1 Board Thickness and Planes 7.3.2 Effect of Resistivity 7.3.3 Effect of Heat Transfer Coefficien 7.3.4 Effects of Thermal Conductivity Co 7.3.5 Effect of Trace Thickness 7.3.6 Summary 7.4 Sensitivities: Trace Depth 7.5 Conclusions 7.5.1 Call to Action End Notes Chapter 7 Via Temperatures 8.1 Bottom Line 8.2 Background Information 8.3 Thermal Simulation 8.3.1 Simulation Strategy 8.3.2 Board Model 8.3.3 First Simulation 8.3.4 Additional Simulations 8.3.5 Two Vias 8.3.6 Conclusion 8.4 Experimental Verification 8.4.1 Simulation 8.4.2 Simulation Results 8.5 Experimental Results 8.5.1 Measured Results 8.5.2 Conclusion 8.6 Voltage Drop Across Trace and Via 8.6.1 Summary 8.7 Thermal Vias 8.7.1 Special Via 8.7.2 Conclusion End Notes Chapter 9 Current Densities in Vias 9.1 Bottom Line 9.2 Background 9.3 Single Via 9.4 Multiple Vias 9.5 Multiple Vias and Turn 9.6 Conclusions End Notes Chapter 10 Thinking Outside the Boxes 10.1 Bottom Line 10.2 Start Thinking Outside Our Boxes 10.3 Test Board 10.4 Copper Under the Trace 10.4.1 Discussion 10.5 Adding Additional Copper to Traces 10.5.1 Discussion 10.6 Dealing with Connecting Links 10.6.1 Discussion 10.7 Conclusions End Notes Chapter 11 Fusing Currents: Background 11.1 Bottom Line 11.2 Background 11.3 W. H. Preece 11.4 I. M. Onderdonk 11.4.1 Cautions End Notes Chapter 12 Fusing Currents: Analyses 12.1 Bottom Line 12.2 Background 12.3 Fusing Time and Temperature 12.4 Assumptions and Cautions 12.5 Simulation Models 12.5.1 Simulation Results, TRM Fuse 12.5.2 Simulation Results, TRM Trace 12.5.3 Short-time Effects 12.5.4 Final Conclusions 12.6 Experimental Results: 12.6.1 Heating Uncertainties 12.6.2 Cooling Uncertainties 12.7 The Fusing Process 12.7.1 Strong Overload 12.7.2 Slight Overload 12.8 Experimental Results 12.8.1 Case A: Fast Fusing 12.8.2 Case B: Slow Fusing 12.8.3 Other Cases 12.9 Summary End Notes Chapter 13 Do Traces Heat Uniformly? 13.1 Bottom Line 13.2 Background 13.3 Thermal Gradients on Traces 13.3.1 Thermal Gradients on Narrow Trace 13.3.2 Does Trace Thickness Matter? 13.3.3 Is Trace Thickness Uniform? 13.3.4 What Causes Thermal Nonuniformity 13.3.5 Conclusion 13.4 Thermal Gradients Around Corners 13.4.1 Software Simulation 13.4.2 Experimental Verification 13.4.3 Conclusions End Notes Chapter 14 Stop Thinking about Current Density 14.1 Bottom Line 14.2 Background 14.3 Current Density Is Not an Independe 14.4 IPC Curves 14.5 Copper Type 14.6 Dielectric Type 14.7 Right-Angle Corners 14.8 Trace Form Factor 14.9 Via Current Densities 14.10 Conclusion Chapter 15 AC Currents 15.1 Bottom Line 15.2 Digital Simulation Models 15.2.1 Preliminary Results 15.3 Experimental Verification 15.3.1 Conclusions 15.4 Analog AC Currents 15.4.1 Test Circuit 15.4.2 RMS Signal Levels 15.4.3 Nonlinearities 15.4.4 Results 15.4.5 Conclusion End Notes Chapter 16 Industrial CT (X-Ray) Scanning 16.1 Bottom Line 16.2 Background 16.3 The Promise 16.4 The Microsectioning Process 16.5 Industrial CT Scanning 16.5.1 Results 16.6 Comparison of the Processes 16.7 Conclusion End Notes Appendix A Measuring Thermal Conductivity A.1 Measurement End Notes Appendix B Measuring Resistivity B.1 Resistance versus Resistivity B.2 How to Measure PCB Trace Resistivity B.3 Problem with Ohmmeter Measurement B.4 Sources of Measurement Error B.4.1 Trace Width B.4.2 Trace Length B.4.3 Trace Thickness B.4.4 Roughness B.5 An Experimental Study B.5.1 What Is Expected Resistivity? B.6 Summary End Notes Appendix C IPC Internal and Vacuum Curves Fitted wi Appdendix D Detailed Set of Equations for the Curves Appendix E Current/Temperature Curves, 0.25 to 5.0 Appendix F Current Density in Vias F.1 Interpretations F.1.1 Caution F.1.2 Symmetry F.2 Single Via Model F.3 Single Via Model with Core 1 Broken F.4 Simulation of Four Vias, Proceeding F.5 Simulation of Four Vias, Traces at R Appendix G Derivation of Onderdonk’s Equation G.1 Onderdonk’s Equation G.2 Background G.2.1 Basic Equation G.2.2 Solving the Equation G.3 Proof that α * ρ = ρ * α End Notes Appendix H Results of All Six Fusing Configuration Appendix I Nonuniform Heating Patterns About the Authors Index