Ten years ago, I worked at a small engineering department within Philips Semiconductors that prototyped all designs before getting them professionally fabricated outside. The method was pretty standard:
- Print artwork using a cheap laser printer onto semi-transparent film
- Tape down top artwork onto bottom artwork and visually align them.
- Cut a PCB to approx size, drill a hole at edge where a wire can be inserted to hold the PCB between insertions in chemicals.
- Insert PCB between artworks, and expose using a homemade UV light box.
- Hook wire into hole on PCB and dunk in a vertical tank containing Sodium Hydroxide and wait until developed
- Put in spray tank and spray with clean water.
- put in vertical tank containing Ferric Chloride etch and leave until etched.
- put in spray tank and spray with clean water
- put in etch remover until etch removed
- Put in vertical tin tank for tinning.
The results were beautiful looking PCBs that were very easy to solder and professional looking, despite a lack of solder mask and screen.
Is this the standard method still used by professional engineering departments when making prototype PCBs today, or are there other methods that give similar great results?