Where can I get this alternative photoresist developer?

Whelzorn

I've ordered some pre-sensitized PCB's for my Propeller board project, and I'm reading up on the process of exposing/developing them. It turns out the norm for developing is NaOH (sodium Hydroxide) solution. But after reading all the tutorials, I've come across people saying how bad it is because theres a very, very small margin of error regarding how long you can leave the board in it. Either it removes none of the resist, or all of it unless the temperature/time is just right.
So it turns out that there exists a much better alternative which develops the board in only 30 seconds, and you can leave it in 50x too long and it doesn't harm the remaining resist. The only source I've come across is this place: www.peats.com/cgi-bin/test_new/catalog.cgi?view_product=1&id=3027. But lucky for me [noparse][[/noparse]/sarcasm], it's in Europe. Again I ask you all if theres a US source for this stuff. Different brand is fine, as long as the chemical is the same.

Thank you

Dgswaner

that sounds like the stuff I use, I'll run by the store at lunch and see if it's the same thing and where they get it from.

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A complex design is the sign of an inferior designer. - Jamie Hyneman, Myth Buster

Whelzorn

that would be awesome, thank you

Dgswaner

Nope it's sodium Hydroxide. I can tell you how to avoid over exposure, mix it as instructed, but only put about 1/2 Cup in with the board, with a 3"x6" board that shouldn't be enough to developer the whole board, then just slowly add more developer until it's fully developed, once the developer reacts it stops developing, so by limiting the amount of developer you add you greatly decrease the possibility of over developing a board, the only time I have over developed a board is when I forgot to dilute the concentrate. it developed the board down to bare coper instantly.

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A complex design is the sign of an inferior designer. - Jamie Hyneman, Myth Buster

Whelzorn

Ok, great I'll give this a shot then. I did order some Sodium Hydroxide concentrate, so at least I can try your method. the only difference is that I ordered 3"x4" boards, so maybe I'll only add 1/3 cup? does it give some sign that it's developing/no longer developing? and how long does it take?
Maybe this deserves a separate topic, but how long do I expose the boards to light before they're ready to develop? Sorry, but after failing miserably with the toner transfer method, this looks like a decent alternative so I'm completely new to it.

Thanks again

Dgswaner

each step of the process will vary a little bit. depending on your environment. but ya just go with a little developer, you can always add more. you can tell when it's reached it's peak for developing because the "green cloud" will stop forming over the traces, at that point you can agitate and wait for it to reach it maximum effect, and then add more as needed. when you can clearly see the copper traces your there, as I'm adding fresh developer I pour it on areas that might need a little more than others.

Just to clarify, when I say to add developer I don't mean concentrate, only add properly mix/diluted developer.

you'll love the photo resist method far better than toner xfer. IMHO. the board should come with instructions for exposing the board.
any light source should work it's just a matter of how long it takes, I've found that it's better to over expose than under. but with each board you do I would try and fine tune the process, I made a drawer with a 12" florescent light in side. and I bought a special UV light so most of my boards expose in about 10 minutes regular florescent takes longer. it might give you the option for sunlight, I would not use sunlight, as it will be near impossible to get consistent light levels. I've found that with the whole process Patients is the key, don't cut short the exposure time, development time or the etching time. I'm always worried that I'll etch too long.

I've recently learned that there are lost of other products for making really nice PCB's Tinning solution, soldermask, silkscreen etc. I've yet to try them tho.


This thread talks about other products.... disregard my comment about the lack of products. I get corrected straight away.
http://forums.parallax.com/forums/default.aspx?f=15&m=211451

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A complex design is the sign of an inferior designer. - Jamie Hyneman, Myth Buster

Post Edited (Dgswaner) : 10/3/2007 12:08:27 AM GMT

Twisted Pair

Here's an example of a simple Pushbutton PCB that I made using the Toner method. Ferric Chloride and water were used. The smaller holes are .031" and the larger ones are .140"....This should give you an idea of the size of this board and the fine lines that are possible.

Twisted Pair....


Post Edited (Twisted Pair) : 10/13/2007 2:24:53 PM GMT