Rajeev Ranjan E.C.E

Design
A board designed in 1967; the
sweeping curves in the traces are
evidence of freehand design using
self-adhesive tape.
Printed circuit board artwork generation was
initially a fully manual process done on clear
mylar sheets at a scale of usually 2 or 4
times the desired size. The schematic
diagram was first converted into a layout of
components pin pads, then traces were routed
to provide the required interconnections. Pre-
printed non-reproducing mylar grids assisted
in layout, and rub-on dry transfers of common
arrangements of circuit elements (pads,
contact fingers, integrated circuit profiles, and
so on) helped standardize the layout. Traces
between devices were made with self-
adhesive tape. The finished layout "artwork"
was then photographically reproduced on the
resist layers of the blank coated copper-clad
boards.
Modern practice is less labor-intensive since
computers can automatically perform many of
the layout steps. The general progression for
a commercial printed circuit board design