Homebrew PCBs

Thanks for the excellent answer.  I never even thought of making a
component mask.  That is a great idea.  


On Wed, 2004-12-08 at 16:28 +0000, rustyturley wrote:

> 
> The toner Reactive file merely puts a harder surface in the top of 
> the toner image.  It does not fill in holes in the toner nor does it 
> fill any "jaggies" in trace lines or pads.
> 
> Its main purpose is to provide a harder, more impervious cover for 
> the toner.  This is important if you are using Pulsar's 
> recommended "direct rub" method of FeCl etching (which I use). 
> The "direct rub" method relies on use of a soft sponge or brush to 
> wipe the etchant across the board.  Small amounts of etchant are used 
> at room temp and wiped across the board.  This speeds the etching 
> process by constantly resupplying fresh FeCl to the copper surface 
> while removing the copper-saturated etchant. Without the TRF 
> overcoat, some of the toner will be rubbed off, exposing copper that 
> you do not want removed.
> 
> If you are not using the "direct rub" method but are using an etching 
> tank, I do not believe that the TRF is needed, but may enhance 
> quality of the board. 
> 
> I also use the aluminum colored TRF to do the legend side of the 
> board.  I have no problems getting a good component legend with the 
> toner transfer and finishing it with the aluminum TRF.  I do 
> encounter some minor problems when transferring a legend when a 
> legend item is too close to a track or pad on a double-side board.  
> The difference in the height of the copper and the board will cause a 
> small skip in the toner due to this surface irregularity.  
> 
> The TRF coated legend is surprisingly scratch resistant.  I transfer 
> the legend prior to drilling.  The legend side is face down on my 
> drill press and after all of the positioning, sliding and drilling, 
> the legend appears unaffected.
> 
> I use these techniques to make single/double sided boards from 3"x5" 
> to 9"x6".  I do all thru-hole boards, so I make no representations 
> regarding the efficacy of these techniques for SMD work.
> 
> Hope this helps.
> 
> Regards,
> 
> Rusty Turley
> 
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-- 
Kim Lux (Mr.)  Diesel Research Inc