Homebrew PCBs

It is up to you how much information you want to supply. If I or
someone else were to try and duplicate your work it helps to have as
much information as possible. Whether it is datasheets, schematics,
process, etc. That is why I ask all the questions. You are obviously
under no obligation to answer them.

I think the datasheet for the UV LED is probably the most important part.

Thanks,
Damon


--- In Homebrew_PCBs@yahoogroups.com, Markus Zingg <homebrew-pcb@...>
wrote:
>
> 1. Not sure what you mean. I use overhead foils that I print onto using 
> an Epson Stylus C62. The PCB's are laminated using dryfilm fotoresist 
> (in my case Ordyl Alpha 950)
> 
> 2. The datasheet is now uploaded in the project directory ( 
> Homemade_PCB_equipment -> UV LED exposure unig)
> 
> 3. I could, but it's realy dead simple. Since I use 5 LEDs in series, 
> ~20V are requiered. I used a transformer that I took out of an el
cheapo 
> battery charger (a 4 amp part with a center tab actually rated for 12V 
> but by not using the center I can draw 24V @ 2amps). That goes
through a 
> rectifier and then a traditional LM317T is used to regulate the voltage 
> to 20V. Just downlaod the datasheet from national and look at the 
> standard cirquitry. I think if you build such a unit you may want to 
> change things or use some parts you have laying around. Well, if you 
> really want I can upload the eagle schematics and board layout.
> 
> 4. I so far only did boards with it for customers where I first would 
> have to ask for the Ok to publish their board here. My boards are 
> probably a bit special in that they are mostly 4 layers with solder
stop 
> mask etc. pp. So they look pretty much like any other profesionally
made 
> board you may have laying around anyways. However, what in
particular do 
> you want to see/know? I may can upload a part of a board only?
> 
> Markus
> 
> javaguy11111 schrieb:
> >
> > Very nice. A few questions
> > 1. What are you using for the mask
> > 2. Can you upload the datasheet for the LED's you are using.
> > 3. Can you post parts lists and schematics for the driver board.
> > 4. Do you have any pictures of boards you have done with it.
> >
> > Again very nice. Congratulations.
> >
> > --- In Homebrew_PCBs@yahoogroups.com 
> > <mailto:Homebrew_PCBs%40yahoogroups.com>, Markus Zingg <homebrew-pcb@>
> > wrote:
> > >
> > > Hi group
> > >
> > > Last summer I created a UV LED based exposure unit with which I had
> > IMHO
> > > very good results. I uploaded a description and pictures to the
> > > following place in the files section:
> > >
> > > Files </group/Homebrew_PCBs/files/> > Homemade_PCB_equipment
> > > </group/Homebrew_PCBs/files/Homemade_PCB_equipment/> > UV LED
> > exposure unit
> > >
> > > Below you find the descriptive text for your quick reference -
enjoy!
> > >
> > > Markus
> > >
> > > <------- cut here --------->
> > >
> > > UV LED exposer unit
> > > -------------------
> > >
> > > In this folder you can see pics of my homebrew, UV LED based double
> > side exposure unit. The folowing features are maybe "special" enough
> > to be noted:
> > >
> > > - It generates very PARALELL light. This is important if you want to
> > make small traces. Using this unit, I already sucessfully created
> > boards with 5 mil traces using dry film fotoresist.
> > >
> > > - There are two holes in each glass allowing the positioning shafts
> > I use to allign the films against the PCB to remain. This allows me to
> > leave the protection foil on the dryfilm resist, resulting in almost
> > no wear out on the films.
> > >
> > > - Obviousely this unit allows to expose both sides of a PCB at the
> > same time. To do this, the upper box is simply placed on top of the
> > lower. The glass is intentionally NOT mounted to the boxes. This
> > allows me to fimrly press the two glasses together thereby makeing
> > sure there are no air bubbles.
> > >
> > > - The LED distance is 20mm square, distance from the LEDs to the PCB
> > is ~65mm
> > >
> > > The exposure time is longer than what's normal with tube oriented
> > units. I'm almost exclusively working with dryfilm resist due to it's
> > several advantages. There the time is exactly one minute.
> > >
> > > Feel free to ask questions, otherwiese enjoy :-)
> > >
> > > Markus
> > >
> >
> >
>