Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, Simao Cardoso <simaocardoso@...> wrote:
>
> On Tue, 2009-06-16 at 09:20 -0400, Myc Holmes wrote:
> > It seems a bit expensive for some UV curable paint $15 for 1/3 of an
> > ounce,
> 
> 
> I could not stop thinking about from what is made that soldermask. So i
> asked the seller gently.
> 
> (my question)
> hi, i was looking for soldermask and... found yours! But, sorry for
> asking this, i am not convinced yet, soldermask are normally epoxy, and
> yours seems to behave different. If the powerful lamp heats the board
> all the epoxy will be cured. 
> Are this just part A epoxy (resin) with silkscreen sensiblizer? Or other
> type of ink with sensiblizer? I ask because i have to know how long it
> will last, if i can use it in various boards or if only has few days
> self live. The necessary conditions for storage (light, temp, humidity).
> Etc. Sorry if am asking to much. Very thanks, Simao

I think "sensitizer" is the word you are looking for?

> (answer)
> Hi, Yes you are correct, it is UV epoxy. The lamp is provide light
> energy and it is not advise you to bake or roast the PCB, only provide
> bright light, you also do it under sun light or just leave it for indoor
> lighting for 24hours. 
> This is not A+B epoxy.... so no need other type accelerator....
> No.. It can last for 1year. in provide you are not put it under strong
> light. It is better to put it in the drawer, complete dark storage area.
> Regards, Raymond
> 
> 
> 
> UV ink used in outdoors and plastics is not that thick, and is even more
> expensive. I still believes this is epoxy, but just part A (bisphenol
> resin) it's said can cure alone in UV. I might try it, and might even
> buy this (but epoxy glue is cheaper).

Don't confuse UV -cured- polymer with UV -resistant- outdoor ink. Nothing similar.

I'm sure it is UV cured polymer/acrylic. It has been in use in the electronics industry for a long time, and has been used in the gift industry to make stickers.

And I see now for fingernails and a lot of other things.

Steve Greenfield