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Subject: Re: [Homebrew_PCBs] Re: DLP for imaging photoresist

From: Clement Quinson <clement.quinson@...>
Date: 2014-06-19

Hello all,
DLP imageing systems are a reality in the PCB manufacturing industry. Several companies do offer such systems: usually they have one or several heads mounted on a CNC machine, and they synchronize motion control & DLP control to achieve the right insolation of the photoresist. It allows a much higher throughput than LDI systems, even those who use several heads, and is more and more a good option for midvolume production. It also allows an arbitrarily high resolution compared to a static DLP projector, which has a very limited number of pixels, so you have to choose how to use those pixels, and thus between resolution & dimension of your PCB.

I've seen such machines at www.productronica.com in Munich ; I could try to find the references if some of you are interested.

Needless to say, those systems are very expensive, and not so easy to design ;)

I'd rather check the conference http://ehsm.eu/ and the talk about http://pcbwriter.github.io/ to see how well this thing works. There are other OSHW projects intended at PCB fabrication, but I'm quite curious to see if one will end up being really useful and powerful.
C.


On Thu, Jun 19, 2014 at 2:16 AM, stan_katz@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:
 

This technology was reported for student use at Pomona College back in 2005:



The cost of the setup was in excess of $5000 due to the use of a consumer grade DLP projector (which are still pricey) and a lab grade trinocular microscope.  The article claims even an ordinary stereo microscope can be used for less demanding applications. I haven't taken a look, but I'll bet the name(s) of one or more of the principals presenting the above paper are on one or more patents that are held by Maskless Lithography Corporation.

I hope there are talented folks in this group who might start thinking about putting together a DLP system on a hobbyist's budget. Up until now, the only hobby systems, presented in this group, not requiring some sort of mask, e.g led/laser flat or cylinder photoplotters have been built by individuals with machine shops at home.