The typical photoresists used for PCB's are sensitive from UV up to ~400nm. A bit too low for an LCD since most of the light used behind the LCD mask will be absorbed by the LCD.
You can use a DLP projector with those photoresists. They work even better with the color wheels removed, but it does shorten the life of the DLP. Another option is using photoresists that cure in the visible spectrum >400nm with an LCD or DLP projector. DLP projectors are even used with inverse microscopes for lithography down to ~1um features. https://gmwgroup.harvard.edu/pubs/pdf/757.pdf -Bari On 07/24/2018 09:25 PM, Przemek Klosowski wrote: > I always wondered if a small LCD projector would be enough to expose a > typical photosensitive PCB--they can be had for not much more than $100, > and are surprisingly bright at small distance (of course they aren't worth > much for what they are solf for, displaying onto large walls:) > If that worked, it would be easy and fast (no scanning, just project your > gerbers) > > On Tue, Jul 24, 2018 at 10:07 PM John Dammeyer <[email protected]> > wrote: > >> I like the idea of using a small laser for exposing the PCB. I already >> have >> a CNC router with roller skate bearings (it doesn't yet use the linear >> bearings and rails I bought to upgrade it). Might be nicer than milling >> the >> PCB although still need to drill holes too. >> >> John >> >> >>> -----Original Message----- >>> From: Dan Bloomquist [mailto:[email protected]] >>> Sent: July-24-18 6:53 PM >>> To: Enhanced Machine Controller (EMC) >>> Subject: [Emc-users] Fwd: Re: CAD for LinuxCNC >>> >>> >>> >>> John Dammeyer wrote: >>>>> I've been using Fusion 360 for a few years now. The license is >>>>> $300/year. They have a post processor for linuxcnc so the CAM directly >>>>> generates g-code that I can take out to the machine. As an example, I >>>>> had to cut a couple of these from 303: >>>>> <http://lakeweb.net/CNC/images/200-024.png> >>>> Hi Dan, >>>> Sweet. Are you running a MAC or PC with windows for Fusion? >>>> John >>> Hi John, >>> Thanks. This is my wife's and my business. >>> <https://reserveanalyst.com/> >>> >>> My desk machine, where Fusion lives, is windows 7. Linux is on my mill >>> and I have a couple of beaglebone blacks. >>> >>> But I have to use windows as it is my day job. As far as Apple goes, I >>> was all about it back in the Apple I and II days. But they prioritized >>> when they went to Mac, so I lost interest in Apple. Now that there is >>> Linux, who needs apple :) >>> >>> Best, Dan. >>> >>> P.S. I like this: >>> <https://github.com/hzeller/ldgraphy> >>> I would build the machine differently. But great thing is, you can use >>> the same machine to do a photo sensitive solder mask as a next step! >>> >>> >>> >> ---------------------------------------------------------------------------- >> -- >>> Check out the vibrant tech community on one of the world's most >>> engaging tech sites, Slashdot.org! http://sdm.link/slashdot >>> _______________________________________________ >>> Emc-users mailing list >>> [email protected] >>> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> >> ------------------------------------------------------------------------------ >> Check out the vibrant tech community on one of the world's most >> engaging tech sites, Slashdot.org! http://sdm.link/slashdot >> _______________________________________________ >> Emc-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
