Homebrew PCBs

Leon Heller
G1HSM
----- Original Message ----- 
From: "blalor76" <blalor@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, December 21, 2009 2:06 PM
Subject: [Homebrew_PCBs] Re: Eagle design rules for Pulsar toner transfer


> --- In Homebrew_PCBs@yahoogroups.com, "leon Heller" <leon355@...> wrote:
>>
>> ----- Original Message ----- 
>> From: "blalor76" <blalor@...>
>> To: <Homebrew_PCBs@yahoogroups.com>
>> Sent: Monday, December 21, 2009 12:31 PM
>> Subject: [Homebrew_PCBs] Eagle design rules for Pulsar toner transfer
>>
>>
>> > Morning, all.  I'm wondering if anyone has a set of design rules I 
>> > could
>> > use with Eagle to help increase the likelihood of creating a layout 
>> > that
>> > will work well with the toner transfer method and Pulsar's
>> > PCB-Fab-in-a-box.  Pulsar's site claims that you can do traces as small 
>> > as
>> > 6mil, which seems much smaller than I need at this time.  For my layout
>> > thus far, I'm using 16mil traces which seem to be able to squeeze 
>> > between
>> > DIP pads without too much difficulty, but I'm not sure how far apart
>> > traces should be from one another and from pads/holes to avoid shorts, 
>> > and
>> > how large the pads/holes should be to avoid tearing them up when 
>> > drilling.
>>
>> You have to suck it and see; there are just too many variables with TT.
>> That's why I prefer photo-etch.
>
> Ok, so taking the etching method out of the equation, I still need to 
> drill out the holes without ripping them up.  Is that just a function of 
> the size of the annular ring?

It's more a function of the drill and the bits you use. I use reduced shank 
tungsten carbide bits at the highest speed my drill will do - 18,000 rpm - 
and don't have any problems with pads lifting, whatever the annular ring. I 
do have it fairly wide, as a rule, to make soldering easier.

Leon