PCB Design Guide to Via and Trace Currents and Temperatures
Douglas Brooks, Johannes Adam
A very important part of printed circuit board (PCB) design involves sizing traces and vias to carry the required current. This exciting new book will explore how hot traces and vias should be and what board, circuit, design, and environmental parameters are the most important. PCB materials (copper and dielectrics) and the role they play in the heating and cooling of traces are covered. The IPC curves found in IPC 2152, the equations that fit those curves and computer simulations that fit those curves and equations are detailed.
Sensitivity analyses that show what happens when environments are varied, including adjacent traces and planes, changing trace lengths, and thermal gradients are presented. Via temperatures and what determines them are explored, along with fusing issues and what happens when traces are overloaded. Voltage drops across traces and vias, the thermal effects going around right-angle corners, and frequency effects are covered. Readers learn how to measure the thermal conductivity of dielectrics and how to measure the resistivity of copper traces and why many prior attempts to do so have been doomed to failure. Industrial CT Scanning, and whether or not they might replace microsections for measuring trace parameters are also considered.
Contents
Preface xiii
Technical Note: TRM xvii
Acknowledgments xix
1 Introduction and Historical Background 1
2 Materials Used in PCBs 7
3 Resistivity and Resistance 17
4 Trace Heating and Cooling 27
5 IPC Curves 41
6 Thermal Simulations 51
7 Thermal Simulations 63
8 Via Temperatures 89
9 Current Densities in Vias 109
10 Thinking Outside the Box 117
11 Fusing Currents: Background 125
12 Fusing Currents: Analyses 133
13 Do Traces Heat Uniformly? 153
14 Stop Thinking about Current Density 165
15 AC Currents 171
16 Industrial CT (X-Ray) Scanning 187
Appendix A Measu
Sensitivity analyses that show what happens when environments are varied, including adjacent traces and planes, changing trace lengths, and thermal gradients are presented. Via temperatures and what determines them are explored, along with fusing issues and what happens when traces are overloaded. Voltage drops across traces and vias, the thermal effects going around right-angle corners, and frequency effects are covered. Readers learn how to measure the thermal conductivity of dielectrics and how to measure the resistivity of copper traces and why many prior attempts to do so have been doomed to failure. Industrial CT Scanning, and whether or not they might replace microsections for measuring trace parameters are also considered.
Contents
Preface xiii
Technical Note: TRM xvii
Acknowledgments xix
1 Introduction and Historical Background 1
2 Materials Used in PCBs 7
3 Resistivity and Resistance 17
4 Trace Heating and Cooling 27
5 IPC Curves 41
6 Thermal Simulations 51
7 Thermal Simulations 63
8 Via Temperatures 89
9 Current Densities in Vias 109
10 Thinking Outside the Box 117
11 Fusing Currents: Background 125
12 Fusing Currents: Analyses 133
13 Do Traces Heat Uniformly? 153
14 Stop Thinking about Current Density 165
15 AC Currents 171
16 Industrial CT (X-Ray) Scanning 187
Appendix A Measu
Год:
2021
Издательство:
Artech House
Язык:
english
Страницы:
293
ISBN 10:
1630818607
ISBN 13:
9781630818609
Файл:
PDF, 7.30 MB
IPFS:
,
english, 2021