Brooks has been looking at these relationships since the mid '90s. And he has assembled 20-plus years of knowledge into these pages. Starting with a historical background, this book covers: (a) PCB materials (copper and dielectrics) and the role they play in the heating and cooling of traces; (b) The IPC curves found in IPC 2152; (c) Equations that fit those curves; (d) Computer simulations that fit those curves and equations; (e) Sensitivity analyses showing what happens when we vary the environment (adjacent traces and planes, changing trace lengths, thermal gradients, etc.); (f) Via temperatures and what determines them; (g) Via current densities; and (h) Fusing issues, what happens when traces are overloaded. There are supplemental chapters or appendices on measuring the thermal conductivity of dielectrics and measuring the resistivity of copper traces (and why many prior attempts to do so have been doomed to failure.) And there is even a chapter on whether Industrial CT Scanning might replace microsections for measuring trace parameters. This Second Edition adds two new chapters (on AC currents and on thermal gradients around right-angle corners), a greatly expanded Chapter 6 (Thermal Simulations), and other additional information throughout the text.