PCB Manufacturing requires careful handling of chemicals that can hurt you and pollute the environment. It is important to avoid looking at tubes or lamps in operation to protect your eyes. Protective gloves and goggles are mandatory!
How to make your own PCB cheap
Printed circuit board (PCB) is a board composed of three thicknesses: a support (epoxy glass or Bakelite), a layer of copper and finally a resin Photosensitive. There are plates that do not have resin, but for the sake of lightening the tutorial one will pass on this detail.
You need a few tools to make your PCB:
– An insole (see tutorial)
– A few empty ice creams
– A developer
– Iron per chloride
Step 1: The design
Let’s start at the beginning: PCB prototype and design. Personally, I use TIC3 which works very well for the amateur that I am, it allows to leave the typons of quality, and to make its own imprints. After a few headaches, we manage to put everything together and connect everything.
Step 2: The artwork
Not to be confused with the small bridge, it is not football. The artwork is the image of the tracks of the printed circuit, it is also the most delicate part of the operation, your artwork must be as opaque as Possible at the level of black, and the rest as transparent as possible. We will print either on transparent or on layer. The layer with my old laser gives the best result; the transparent paper does not retain the toner enough, which gives a poor quality artwork.
3rd step: The insulation
– Cut a piece of epoxy or bakelite, the size of our artwork.
– Remove the protective film and place the piece of epoxy or bakelite resin on the surface. The typon must be laid in such a way that you see the component side on top; otherwise your circuit will be all reversed!
– It is then allowed to insulate the circuit of 1 to 5 minutes according to your material (it will be necessary to make some tests). Personally I let insolate 2’45sec with a 24W insole and a tracing paper.
4th stage: The revelation
And no I would not tell you whether God exists or not
As soon as the sun is over, take your piece of epoxy and soak it in a little bath of revealer. The resin which has been protected during the exposure by the artwork does not move while that exposed to UV gradually disintegrates and reveals the bare copper. To avoid wasting a lot of product, I use a plastic tray that contained surimi sticks. I pour 1 cm at the bottom and I plunge my plate. After 30 seconds stirring from time to time, the tracks appear and the resin disappears. Take out your plate and rinse it under water abundantly while finishing removing the softened resin.
5th step: engraving
No burn-proof or 52X here. The etching resides in immersing the revealed plate in an acid bath in order to gnaw the exposed copper, the tracks protected by the resin will therefore remain alone as a result of this process. The ideal would be to use an engraver, expensive and imposing apparatus equipped with a bubbler and a heating resistor to speed up the process. Here I use only 2 old ice bins, one for the Bain Marie, the other For perchloride of iron. Indeed, the perchloride of iron rather pleases in the neighborhood of 40 ° C, the more it will be cold and more time will be needed to engrave your plate. The second tank floats on that of the bain marie, allowing me to easily move the tank to accelerate the removal of bare copper.
– As soon as the copper has completely disappeared, remove your plate from the perchloride, with rubber gloves (I remember that the perchloride is an acid, which stain and burns the skin) and rinse there abundantly.
– Brush the acetone on the plate to remove the resin residue, using an old toothbrush, for example.
And here is your Printed circuit board is all clean and ready to be drilled: about here are some diameters of drilling.
– Resistors, Diodes, Integrated Circuits, Transistors, Capacitors … 0,8 mm
– Potentiometers: 1,2 or 1,5 mm
– Wires, terminals , etc: 1,5 or more …
Be careful not to throw iron perchloride into the sewers, it is a toxic product, contact your recycling center for recycling. There are neutralization kits for iron perchloride.
PS: Additional fingerprints for the TCI software can be found on the software website.