This is the developing powder for Photoresist Film Sheets for Photo Etched PE PCB, mixing it with water by 20:2000 ratio, and put into a coca cola bottle (2 Liters) to store. This can store more than 3 months. When you use it, just take a little out of the bottle.
This is the price of one bag, 20g.
Photo sensitive film special – used Developing substance 20G
Use 10g of this developing substance and mix it within 0.9-1L water, you can now deploy as standard developing liquid and store in sealed plastic bottle (not metal bottle) for long term use. It’s not necessary to use purified water, normal tap water is fine to use. The most suitable temperature for this developing substance is 30 degree.
Leave the Photosensitive board in the developing liquid, after developing, brush it a few times, then use clean water to clean it up and use hot gun to dry up.
Deployed developing liquid can store in sealed status in plastic bottle more than one month.
Stored in carefully, it’s corrosive to skin, do not leave it at the place where children can get it, do not eat and put in eyes, if do so use plenty of water to clean and ask for doctors.
Complete Tutorial :
Step by step
The film is folding in between of two cover film, remove one side first
Place the film on your copper board.clean the copper board with sand paper beforehand, so it's easy to stick on it, make sure the film is flat, and without bubble.
Also possible to use an heat transfer machine to place the film like this
Or heat the film up with iron, not too hot, so the film is fixed on top of copper plate.
Print Circuit board with photo film.
Exposure the circuit onto copper board which are already covered by film. Depends what kind of light you use, time is varying from 1 mins to 30 mins.For this UV light, you only need 1-2 mins.
Developing, remove the another layer of film, leave it in developing liquid which is pre-mixed with water by 1:00.
Etch. Etch solution.
Removing the rest film by film remover liquid pre-mixed.