Commercial prototyping services are not new – they’ve been around pretty much since
PC boards started being used extensively in, what, the 1960s? By and large,
they’ve concentrated on the one-off board as an adjunct to their main game –
commercial PC board manufacture.
A potted PC board history
When PC boards first came out, producing artwork for the
pattern was a labour-intensive and exacting process. First of all, the pattern
had to be worked out by the designer or engineer, then hand-drawn by a skilled
draftsman (yep, very few girls back then) using black ink on either film or
I well remember one such draftsman where I worked who had
all-but finished such a drawing – a rather large one at that – and then knocked
over his bottle of ink (guess where!). A week’s work, literally in the bin . . .
Once the drawing was finished, checked and checked again, a
photographic negative had to be produced, usually involving a trip to a photo
lithographer. Then the board had to be produced using one of several
Later came drafting tapes and pads, which allowed the board
pattern to be laid out on film and used directly with positive photo resists.
However, track widths (or more specifically track gaps) had to be kept quite
wide so that the photo resists (and production processes) of the day could
Another memory from way back then is the late Ron Bell, founder
of RCS Radio (and one of Australia’s early PC board gurus!) complaining bitterly
to the project designers at Electronics Australia when we used "25 thou" tapes
and spacing instead of his minimum of "35 thou"!
"No-one in Australia can produce boards with that spacing," he
said. Imagine how Ron would be today with 5-thou tracks and spacing over
PC board PC software
It must have been the late 1980s or early 1990s when software
for printed circuit board design started appearing (remember Autotrax?)
Since then, there have been lots of board layout packages
brought out – some excellent, some average and some, well . . . Some were so
expensive they were way beyond the home constructor but believe it or not, some
were actually freeware or shareware.
OK, so you’ve designed your masterpiece on the computer and
even had the software check it out to make sure there are no mistakes. Where to
As you might imagine, SILICON CHIP faces
this dilemma with just about every project we design, as the vast majority are
based on PC boards.