Homebrew PCBs

The stress concentration in the glass at the corners of the PCB causes breakage when you attemp to suck it down against a rigid backing. Better to suck a flexible membrain against the glass, rubber or polythene. Greenhouse glass works fine.
Polycarbonate block UV so don't use that. 

Malcolm

I don't suffer from insanity I enjoy it!

--- On Mon, 8/16/10, DJ Delorie <dj@delorie.com> wrote:

From: DJ Delorie <dj@...>
Subject: [Homebrew_PCBs] UV: alternatives to glass?
To: Homebrew_PCBs@yahoogroups.com
Date: Monday, August 16, 2010, 9:54 PM







 



  


    
      
      
      

Ok, shame on me, I broke the glass in my UV box.  Too much vacuum.

We've checked a few local places, the glass they have has UV blockers

on it.  I've got more places to try, but I thought I'd ask...



What else can be used besides glass, which will still pass UV without

bending or blocking it?  Something less brittle, more flexible, but

still stiff enough to mostly hold it's shape (my UV box has a foam

gasket along the outside edge of a piece of plywood, the glass rests

on it and is sucked down onto the board).



Even rubber-like flexibility is OK, I suppose - I can make a wooden

frame to hold the edges and use an even thinner gasket, but that's

more work, and it means I have to cut up my films into individual

sections so I don't bend or crease them from the shrink-wrap effect.



DJ



    
     

    
    


 



  






      

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