Homebrew PCBs

With a negative film, this sounds more like under-exposure.
Have you tried increasing exposure time ?

--- On Mon, 10/20/08, lcdpublishing <lcdpublishing@...> wrote:
From: lcdpublishing <lcdpublishing@...>
Subject: [Homebrew_PCBs] Dry film- negative resist... First attempt failure
To: Homebrew_PCBs@yahoogroups.com
Date: Monday, October 20, 2008, 3:19 PM










    
            Hi guys,



I tried my first photo process board this weekend and the process 

failed completely.  I am using the dry film, negative resist from MG 

chemicals.



The failure was in the developing of the resist.  While developing, 

all the resist washed off.  It was developed as I could see the 

traces in the resist, but faintly.



The developer solution was a best guess on dilution so this is 

probably my main failure point.  



I am wondering what actually holds the resist to the board though.  

Per the instructions, I am suppose to peel off the backing, apply 

resist to the board and then run it through a laminator twice.  Is 

this what causes the dry film to stick to the board or is it the 

exposure process?



I also suspect that using vellum for the artwork is not a good 

thing.  Using some scraps, I noticed that exposure is much different 

using transparncy than vellum.  So my next attempt will be using 

transparencies and to carefully measure the developer.



Chris




      

    
    
	
	 
	
	








	


	
	

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