开云体育Short wave sensitive.? Unshielded mercury vapor arcs.? Expose through negatives where the trace is transparent, background is opaque.? Develop in the appropriate developer and then put the dye on.? That'll show you where the resist really is.? Cover holes (if any) with something opaque, then etch.? It'll withstand ferric chloride, although I'd recommend CuCl etchant (hydrochloric acid and hydrogen peroxide to start with) because it's FAR cheaper, better behaved, and works as well. Once etched, strip off resist or solder through depending on whether or not you want tin-lead plating.? I never had access to tin lead plating when I was using KPR. All of my boards then were using crepe paper tape, 2x photo masters, an 8x10 view camera shooting on kodalith, (use kodalith developer!? Dektol gives? you gray scale), and then contact printing. Harvey
On 3/14/2021 9:07 PM, Sam Reaves wrote:
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