Ok yesterday I bought the mgchemicals photofab kit as it was all on for half price. It gives me a 8w UV light, 500ml devloper, a trey and two foam brushes.
This is what I did:
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Print from eagle as solid black to my 1200dpi laser on no toner save extra dark.
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I have ferric chloride in a small oval container and I place it into a pot with near-boiling water for 30min until the ferric chloride is around 50deg (my mixture is FC 5:1 water)
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Put 1 part developer in 10 parts water and swish it around a bit, I keep it in the garage so its at about 5deg.
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cut pcb to size, peel of cover, lay artwork, lay clear weight and expose for 7min
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Place pcb in developer and lightly brush surface. It usually takes 90seconds even though its 5deg. I found that 1:10 at room temperature by the time the artwork is visible and I nutrilize it they traces have faded.
–I develop it untill the exposed copper is shiny and no longer hazy but stop before the traces start to green.
- put pcb in ferric chloride mixture still at 50deg and giggle it with a string as I dont have the aquarium setup and agitate by hand.
The etching process is where I have problems, using the iron on method took forever for a good transfer but it also only took 5min to etch completely. The pre-sensitized boards take we well over 15min. The pre-sensitized boards seems like the machine sanded them just one direction and theirs thousands of little valleys thay dont fully etch so my traces come out looking like I ran they with plus signs. but even disregarding that I did a comparison with my old method and these boards just dont wanna re leave their copper it seams.
I use mgchemical pcb’s #600 pre-sensitized and whatever their regular type is. (as you can tell mg is the only stuff I can get in my city)
Another downside is the photodevoped boards I solder at 400deg and if i use a desolder wick the second i go back to apply more solder the pads lift, I figured because of the 3x longer etching process its weakening the bond between the copper and insulate.
Can anyone see what im doing wrong or does my batch of boards just suck? sofar its three different sizes and thicknesses that have the same end results.
