IPC-7351 and other PCB Design Standards
I’ve been in the PCB design industry for more than 35 years now. One of the great things about working in a high technology field for so long has been the access to be an early adopter of products and technology. My first PCB’s were designed using rolls of tape, Bishop graphics, ruby lithe, non-photo blue pencils and the tool of choice was a exacto knife with a sharp blade. 
One of my most valuable tools was actually a black 4″ thick 3-ring binder that I collected and filled with all the PCB design reference materials that I regularly referred to during the design process. It included everything from drill hole clearance charts with all the dimensions and tolerances for single and multiple holes, both plated and non-plated. Since surface mount components were just making their debut, through-hole was the dominant component type so I also had pages of component pin diameter PTH values were.. I also had resistor and capacitor color code charts, socket dimensions for IC’s, tolerance formulas, wire gauge diameters, the works.. Well, you get the idea. There were no personal computers on our desks and the internet was in it’s infancy, so, no Googling or saved bookmarks to save design industry sites.
Well, THANK GOODNESS times have changed!
So what are some of the bookmarks you save to aid in PCB design? Here’s a list of links that PCB designers should consider bookmarking.
STANDARDS:
smta.org Knowledge Base
ANSI Standards
TOOLS:
In-Circuit Design Multilayer Impedance Calculator
OTHER:
Electronic Products and Technology
Thanks for reading and feel free to share the PCB design bookmarks you refer to most often.
-John
