Alt-BEAM Archive

Message #02859



To: Richard Piotter richfile@rconnect.com, beam beam@corp.sgi.com
From: Dennison dennlill@buffnet.net
Date: Sat, 1 May 1999 11:31:27 -0400
Subject: [alt-beam] Re: was PCB, now cheap drills



Ahh, your just not doing it right. After you put the dry transfers onto the
PCB you need to burnish them really really hard onto the board. Using say
the back of a spoon. This is super important, you want to grind those
transfers firmly onto the copper. (Make sure you use the blue wax paper
stuff over the PCB though) Then when you use the etchant (which by the way
is standard strength, you can't really, and nor would you want, stronger)
you need to heat the etchant up. Personally I stick it in the microwave(for
like 30 secs). BUT I"M NOT RECOMENDING THIS TO ANYONE! There are other
better methods, little heaters, etc. Once I etched a board in ten seconds.
You typicaaly want a etch time of five minutes.

Dennison


>Also, beware Radio Shack Etchant and Dry Transfer decals. I could not
>figure out why they kept lifting! I could even scratch them lightly, and
>they wouldn't come up! It turns out, the dry transfers were EXPANDING!!!
>They buckled, and would then lift!!! Anyone know where I can get some
>stronger etchant?
>
>Bruce Robinson wrote:
>>
>> Jacob Booth wrote:
>>
>> > ... If you keep snapping those tiny drill bits ...
>>
>> Or, if you're really desperate and don't have a dremel ... Y'know those
>> sets of small jewellers screwdrivers? Press down on the top and twist
>> the body with the thumb & middle finger? Yep, I used the smallest one
>> once to drill several dozen holes. Yeah, I know, a lot of work, but it
>> was a holiday weekend and I couldn't wait for the stores to re-open.
>>
>> It works, but watch out for blisters.
>>
>> Also, James Niemasik wrote:
>>
>> > ... use Ferric Chloride or Ammonium Persulvate in crystal (dissolve it)
>> > or liquid form. Heat the liquid and put the board in, then agitate it
>> > for 5-25 minutes.
>>
>> I found if you leave the board in the etchant too long, it starts to
>> undercut the masking material or artwork. For fine lines this can be a
>> pain. A stronger etching solution gets the job done faster and minimizes
>> undercutting. Take sensible precautions with the etchants -- most of
>> them are toxic.
>>
>> Regards,
>> Bruce
>
>--
>
>
>Richard Piotter
>richfile@rconnect.com
>
>The Richfiles Robotics & TI web page:
>http://richfiles.calc.org
>
>For the BEAM Robotics list:
>BEAM Robotics Tek FAQ
>http://people.ne.mediaone.net/bushbo/beam/FAQ.html


------------------------------------------------------------------------
eGroup home: http://www.eGroups.com/group/alt-beam
http://www.eGroups.com - Simplifying group communications

Home