--- In
Homebrew_PCBs@yahoogroups.com, Athar Kaludi <ceo_premium@...> wrote:
>
> Hi All
>
> I found these links useful for PCB fabrication learning. Very descriptive and explanatory
>
> http://www.siongboon.com/projects/2005-09-07_home_pcb_fabrication/
> http://www.cibs.co.uk/etch/x9.html
>
> In addition the below link is for knowledge on chemicals used in Photo resist - developers - etching
Athar,
I am having a bit of difficulty understanding your objective. If you are researching modern photoresists, you need a PhD in organic chemistry to understand the literature and all of the formulations are highly proprietary, requiring exotic organic chemicals not readily available to the individual. For hobbyist PCB making, dry film for photo imaging is really the only way to proceed. It is comparatively cheap and readily available (MG chemicals, Puretch from Cape Fear Press ...). It just doesn't make too much sense to spend a lot of time on homebrewed photoresist. If you can devise a formulation for a resist that can be used in an inkjet, then that is another story.
If you are simply interested in the historical photo imaging processes, this is great. I find the subject fascinating. You might look at the APUG Forum, for alternative photographic processes.
In my post to you relative to dichromated gelatin, my main intent was to point to a patent which gives a recipe and process for a photo imageable solder mask that is accessable to the hobbyist. Solder mask is not cheap and is not available in small quantities. There seems to be great lament among DIY PCB makers about the lack of solder mask to nicely finish their boards. I suggest that this might be a fruitful area for your research.
N.B. For those frightened by ammonium dichromate, the cited patent uses diazo for the sensitizer.
Baxter