plating, anodizing, & finishing Q&As since 1989
Photo resist for electroplating
I am looking for a photo resist that I can apply on copper clad (printed circuit board material). The idea is to electroplate a tin photo image onto the copper. I already have a successful tin plating setup at home using tin acid electrolyte. I tried using a water based silk screen photo emulsion as the photoresist. The problem being that the emulsion is not designed for total water resistance and will absorb a small amount of water. Its therefore not resistant to electroplating because tin ions can travel through the emulsion coating and deposit onto the copper. In the printed circuit board industry they use a special photo sensitive dry film, but I cannot buy this in less than 1000 ft.sq rolls. I am interested in knowing what industries may use a photo resist in a liquid form. I then may be able to start ringing around for a local supplier. Any help on this will be greatly appreciated as I've already spent weeks looking for a suitable photo resist. AdamAdam Seychell
The problem you'll encounter with the solvent based resists will be that most companies won't want to sell them to an individual. I know here in the states it would be difficult since they are very volatile solvents. I wouldn't recommend using that type at all in a non-industrial setting due to the toxic fumes.
A good alternative is to buy the sheets precoated with the dry film. Several companies offer various materials this way. It would save you several steps in your process and not be much more than the cost of the material. One company that comes to mind is Kepro. They have a web site you can check to see if they would be able to get the material you need. If you really want to laminate your own material they do sell a small laminator and rolls of material in 125' lengths.
Mabank, Texas USA
In Germany or Switzerland you can find photo resists in catalogs for hobby electronic freaks. One product name is Positiv 20, and we used it for partial plating in nickel-baths. Maybe you can find something similar in Australia too.Marcus Hahn
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