PCB Fabrication Process Details
Here's where most projects end, before they ever get started, as a dry article in a ham magazine. The circuits on some of the more complex ones can be very time consuming to wire by hand. Sometimes the author may sell PCB's to accompany the article, but in my case I rarely want to build it exactly as shown. Making your own PCB's solves a lot of these problems
The first step is to transfer the schematic from the magazine to the schematic capture part of the layout program. I even try to use the same reference designators where possible so that I can reference back to the original article to make post-construction troubleshooting and parts correlation easier, if I have to
After the schematic is entered, the PCB layout program
is used to place the parts on the board and route the copper
traces.
After the first few parts are rounted, the "ratsnest"
begins to clear up. If you're lucky, you get a PCB that
requires no external jumper wires
When the layout is done, the board layers are printed
onto special toner transfer paper with a laser printer.
This board "image" is transferred to the bare copper board
with a laminating machine, or a hot clothes iron
After laminating, the board with the paper stuck to it
is soaked to remove the paper, leaving only the toner behind
Inside the etch tank, two aquarium pumps circulate etchant
(Ammonium Persulfate) over the copper boards while two
aquarium heaters keep the solution at 110F.This process can take
anywhere from 10-30 minutes depending on the freshness of the
solution and thickness of the copper
Above is a photo of the raw copper board with toner
remaining, after the transfer paper has been soaked off
After etching, the toner is removed with solvent and the board is tinned using a soldering iron and a small piece of tinned solderwick. Tinning isn't absolutely necessary but it improves the appearance of the board, and prevents the copper from oxidizing before it's time to solder the parts to the board
At this point, holes are drilled for any leaded components
and mounting holes
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