Thank you for the link, Volkan.
In my occasional searches over the last few years (mostly for terms like "homemade photoresist") I hadn't found that. Excellent information. I'll also check on the AQ 3000; I've heard it mentioned (probably on this group) recently.
Donald.
----- Original Message -----
From: "Volkan Sahin" <v_sahin@...>
To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, November 13, 2009 1:10:19 AM GMT -05:00 US/Canada Eastern
Subject: Re: [Homebrew_PCBs] Making PCB using these new 405nm LASER Diodes
Hello Donald,
There is no magic for the formula check http://www.holowiki.com/index.php/Dichromated_Gelatin_Chemistry they have detailed information on it. I'm using PVA instead of gelatin. The problem is you need to be careful using dichromate, it is not environmentally safe disposing requires care. I'm always keeping water used for development in separate container for recycling/disposal center.
I've decided to switch another photoresist which is environmentally safe, they're also selling it on e-bay AQ 3000 Waterborne Photoresist, it is easier and much more sensitive than DCG.
Volkan
--- On Thu, 11/12/09, Donald H Locker <dhlocker@...> wrote:
From: Donald H Locker <dhlocker@...>
Subject: Re: [Homebrew_PCBs] Making PCB using these new 405nm LASER Diodes
To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com>
Date: Thursday, November 12, 2009, 6:09 PM
Hello, Volkan.
Looks like you have your fingers in several pots (homebrew pcbs, direct print resist, homemade photo resist). I love it.
Are you willing to tell us more about your formula and processing for the homemade dichromated PVA resist? A friend (30 years ago) did some silkscreen work using (IIRC) Elmer's glue, which is a PVA product. What else is involved? Or a pointer to where you have already told everyone and I wasn't watching. :)
Thanks much,
Donald.
----- Original Message -----
From: "Volkan Sahin" <v_sahin@yahoo. com>
To: "Homebrew PCBs" <Homebrew_PCBs@ yahoogroups. com>
Sent: Thursday, November 12, 2009 5:46:45 PM GMT -05:00 US/Canada Eastern
Subject: Re: [Homebrew_PCBs] Making PCB using these new 405nm LASER Diodes
I've a working prototype. I'm using 150mw 405nm blue ray laser diode. Without complicated optics I can get ~3 mil trace width/space. Currently, I'm using Dichromated PVA based homemade photoresist. The problem is without polygon mirror scanner, it is very slow but result is impressive. The exposure time required for 1.5 mil spot is ~20 microseconds.
Volkan
[snip]