Without the math, the PDF is just pictures of pads. With the math, it becomes the difference between a prototype that works on the bench and a million units that survive the shipping truck.
for a certain component type, or do you need help setting up design rules in a CAD tool like Altium or KiCad? IPC Class 3 PCB Design and Manufacturing Standards
: A 109-page draft was submitted in 2015, featuring significant updates like proportional pad stacks and rounded rectangle pads.
It provides more specific guidance for thermal pad via patterns to ensure proper heat dissipation without causing solder wicking issues. IPC-7351 Standard Fundamentals
: Replaces the old 3-tier system (Most, Nominal, Least) with pad sizes that scale proportionally to the component lead dimensions. Rounded Rectangles