Homebrew PCBs

 Subject: RE: Vinyl mask, laser paint removal (was:Re: [Homebrew_PCBs] Plastic Resist From 3D Printer?) [1 Attachment]
 To: Homebrew_PCBs@yahoogroups.com
 Date: Monday, January 25, 2016, 8:48 PM
 
 
  The laser I used was overkill, it was designed to cut metal. It was a frequency doubled Q-switched YAG laser of about 3W average and about 100 KW peak if I remember correctly, and cost around $10K. Paint removal should be fairly easy using anything from CO2 at 10.6 um to UV lasers. I think the simplest would be a diode laser in the blue or near UV. The shorter wavelengths should tend to ablate the paint rather than just burning it. If the laser is pulsed, then pulse rate can become an issue to avoid dotted lines.

Bob
 
 
 
   
 
 
     
       
       
       The unknown question is what type of laser and what
 power.  This gentleman
 
 is using a UV laser and documenting his progress.  
 
 
 
 http://gabuleu.blogspot.com/
 
 
 
 From: Homebrew_PCBs@yahoogroups.com
 [mailto:Homebrew_PCBs@yahoogroups.com] 
 
 Sent: Monday, January 25, 2016 10:40 PM
 
 To: Homebrew_PCBs@yahoogroups.com
 
 Subject: Vinyl mask, laser paint removal (was:Re:
 [Homebrew_PCBs] Plastic
 
 Resist From 3D Printer?)
 
 
 
 On 1/25/2016 2:52 PM, Bob Butcher bbutcher85@...m
 [Homebrew_PCBs] 
 
 wrote:
 
 >
 
 >
 
 > --------------------------------------------
 
 > On Mon, 1/25/16, palciatore@... [Homebrew_PCBs]
 
 
 > <Homebrew_PCBs@yahoogroups.com> wrote:
 
 >
 
 > Subject: [Homebrew_PCBs] Plastic Resist From 3D
 Printer?
 
 > To: Homebrew_PCBs@...m
 
 > Date: Monday, January 25, 2016, 12:32 PM
 
 >
 
 > I think ;this could work if the resolution is good
 enough. I have 
 
 > tried a variety of things for etch resist, from
 electrical tape to 
 
 > spray paint and indelible marker ink. Most of these are
 kind of 
 
 > difficult to apply where you want them, and only the
 spray paint 
 
 > really worked well at preventing etching. One idea
 someone came up 
 
 > with was using a CNC vinyl cutter to produce a pattern
 that could be 
 
 > stuck on. Certainly worth a try!
 
 >
 
 > Bob
 
 >
 
 Hello--
 
 
 
 Not knowing anything about the vinyl mask method of PC board
 
 
 fabrication, I went looking and found an explanation on
 
 Instructables:
 
 
 
 http://www.instructables.com/id/Fast-and-Easy-PCB-Prototyping-with-Vinyl/
 
 
 
 Reading down in the comment stream, I noted this: "...I
 have tried the 
 
 laser ablation method and it works wonders.
 
 I just cover my board with matt spray paint up to 3 coats
 and then laser 
 
 etch away the color that
 
 needs to be exposed as copper.
 
 
 
 The success of this process [vinyl mask] is highly dependant
 on a good 
 
 solid stickiness of vinyl to copper.
 
 on straight planar surfaces, its never a problem, but its
 worthwhile to 
 
 recheck that it has no bubbles.
 
 
 
 vinyl is also stretchy when a little heat is applied, so
 make sure you 
 
 don't squeege it too hard.
 
 as an alternate, can we have the opposite parts weeded so
 that tracks 
 
 are exposed, then spray
 
 paint as a stencil, remove the vinyl and then
 etch?...." (comment by 
 
 rupin.chheda)
 
 
 
 One thing that's unclear (and likely hardware-dependent)
 is the minimum 
 
 trace width and pad spacing
 
 capability of this method for consistent results. Based on
 example 
 
 photos, DIP layouts seem feasible.
 
 
 
 Has anyone in the group tried this method?
 
 
 
 73--
 
 
 
 Brad AA1IP
 
 
 
 
 
     
      
 
     
     
 
 
 
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