How Printed Circuit Boards are Designed (1960 Edition)

We found this gem in A Manual of Engineering Drawing for Students and Draftsmen, 9th Ed., by French & Vierck,1960, p. 487.

Printed Circuits allow miniaturization and the elimination of circuit errors—advantages that cannot be obtained by other methods. Once a pattern or suitable design is established, preparation of a black and white drawing can start. Scales for reduction, for example, 4 to 1, 3 to 1, or 2 to 1, are used. To insure sufficient bonding area of the metal laminate during soldering operations, lines should not be less than 1/32 inch in width when reduced. Line separation should never be closer than 1/32 inch on the final circuit. Figure 19.24 illustrates the drawing of printed circuits.

EmailFacebookTwitterGoogle+tumblrPinterestRedditStumbleUpon

5 thoughts on “How Printed Circuit Boards are Designed (1960 Edition)

    • I think that this may be accurate; most circuit boards that I’ve seen from the era do seem to use minimum track width and spacing of roughly that size

  1. Sadly, I remember this. The tracks were made of a crepe material with an adhesive back, and totally opaque black color. It was supplied as rolls similar to today’s adhesive tape, but the rolls were quite thin. If doing a 4:1 layout, the tapes were 1/8 inch wide. The tape was made by Bishop Graphics. It looks exactly like this: http://www.amazon.com/Graphic-Chart-Crepe-Tape-324/dp/B000CCVDOS/ref=sr_1_1?ie=UTF8&qid=1372577868&sr=8-1&keywords=crepe+tape

    Bishop also had rub-on “decals” for pads, and 14 and 16 pin DIPs. This was similar to Letraset, which was also used for board labels: https://www.google.com/search?q=letraset&tbm=isch&tbo=u&source=univ&sa=X&ei=0OHPUZjVDOfriQKCvoC4Aw&sqi=2&ved=0CFcQsAQ&biw=1756&bih=864

    The base material for the layout is Velum. For a two sided board, you laid two sheets of velum on your light table, and when you wanted to place a track or pad on the bottom layer sheet, you lifted up the top layer sheet.

    Some times you would find a piece of track or a pad on your palm or forearm that had come loose, and you would have to search to find where it had come from.

    Eagle, Kicad, Altium, etc. are all so much better.

  2. This certainly continued for long past 1960. IIRC, it was still the default technique in the early 80s; there were some CAD programs back then, but you pretty much had be be DEC/HP/IBM/etc, or at at significantly sized university, to have access to the sort computing resources that they required.

Comments are closed.