There is much more complete information on making printed circuit boards available on the net. I have thrown in only some basics. If you're completely new to this, count on running down and reading some of these supporting information sites. In addition, GEO now has on line a more complete listing of the various ways to construct effects boards.

Laying out the board

Go to your local used book store and in the technical books section, find a book with a title something like "Printed Circuit Drafting and Layout". Read it, ignoring the things about how to lay pads and tape on mylar film, but paying attention to the sections on how to orient parts and run traces to and between them. You can, of course skip this if your effect is a copy of a magazine article which contains a printed circuit layout.

Lay out your board, keeping the board type you will make in mind. There are some tools which will make this easier. For general layout, get grid-ruled paper and tracing paper to draw sketches of layouts on, and a couple of colors of pencil, red and blue being traditional. In general, make your board from a set of postage-stamp circuit fragments, each of which is a tightly connected lump of stuff, usually about one IC and its immediately connected resistors and stuff. Most circuits are a set of such clumps, with signal and power supply lines going between them. make the fragments, then interconnect them. Make all the wires come off one side of the board, not all around it where you will have to knit the board into the box, and certainly not coming out of the middle of the board. Have the inputs on one side of the board, and let the signal progress through the board like on the schematic, in one direction to avoid having unwanted feedback paths. Do not forget to leave some way to mount the board in the box. Wrapping the whole board in plastic foam and leaving it loose in the box is evidence of such forgetfulness, although that is exactly what MXR did in all its early production.

Perfboard

Perf board and Strip board methods. Hack a chunk of circuit board big enough to implement your layout. Read Penfold for the full description of the stripboard method. For the perfboard method with pad-per-hole board, bend the component leads to insert them into the board, then use the excess lead length below the board to make "circuit traces" by bending them flush with the board and routing them from connection to connection. Use wire wrap wire to connect things that the leads can't easily. Solder the leads where they go through the board, and at connections. Solder as you go along, placing a few parts and soldering them. This method is remarkably easy to do, and is reasonably durable if your soldering technique is good. It is about as fast as doing a board layout, so if you have some experience, you can lay out the circuit from the schematic as you go. I would, however, never, ever make more than one of a kind this way. If I think I might EVER make another I would lay out a printed circuit board.

Stripboard

(under construction; Penfold uses stripboard exclusively)

True Printed Circuit Boards

It is NOT in general a good idea to do double sided boards at home, as this more than doubles your difficulty, and plated through holes are not generally possible at home.

• Photo methods
  You can lay out the circuit patterns in black-on-white and have a commercial graphic arts store make you either positive or negative transparencies from this to use the commercially available photo-resist methods of making boards. This method produces premium results if you have the patience and technical consistency to get it to work. It is tedious, but produces great results when you finally get it down pat. There are commercially available kits to do this in a small-at home way.
• Dry transfers
  There are rub down etch resistant transfers similar to Letraset. Not as easy to do but doesn't require a massive capital outlay. You clean the copper surface, then rub down dry-transfer material in the shape of pads, lines, etc., then etch. This can produce very good results if you are careful. I recommend that you clean the copper surface carefully, then use kitchen plastic film to cover all except the small area that you are working on at the moment. This helps keep the surface from oxidizing quite as much, and lets you rest your hands on the board without leaving skin oils that would foul up your etched patterns.
• Toner transfer
  This is today's winner. There exist plastic film and plastic materials that will accept the black toner from a copier or laser printer and then release it after the pattern has been ironed on to a copper clad board blank. These are sold by the names of TEC-200, Dynart, and Press-N-Peel. You can get -*very*- good results from this technique, lines as small as 0.01" wide, and one wire between IC pads.

  I use the Techniks Press-N-Peel Blue material available from Techniks Inc.
  Press-n-Peel sheets
  PO Box 463
  Ringoes, NJ 08551-0463
  Tel: 1-908-788-8249 (Questions)
  Fax: 1-908-788-8837 (24 hour order line)
  

• Drill-and-draw
  This method is for the artists among us. Lay out your board. It is really better if you can lay it out completely and print some kind of real sized pattern. Using the pattern, either just mark or and drill all of the holes in the board. You now have a copper board with only holes in it. Now, using an etch resist pen or lacquer or some other fluid that dries impervious to ferric chloride, draw in the circuit patterns. This will take some time, but if you are careful, you can do a good job this way. I know a fellow who actually laid out and etched most of the circuitry for an Apple II computer this way, using wire wrap for the parts he could not etch. I recommend using the kitchen plastic film again, being careful to let the resist dry in a given area before placing the film over it to avoid smears.

R.G. Keen keen@eden.com Back to GEO Entry Page