Re: Home Grown ActionTec Development Daughterboard

Ross,

> Excellent work, Bruce. Just how hard is it to hand build with the SMT
> parts you spec'ed? I'm pretty handy with a soldering iron, and wold be
> interested in doing this myself.

I use a stereo microscope in the range of 7-30x to build surface mount 
stuff, which makes it really easy.  (My microscope cost ~$600 surplus, and 
is Russian-made.)  With rare exception, I do everything, including all 
prototyping, using surface mount components.

The key is seeing what you are doing!  That's why magnification is 
*required*.  A magnifying hood with at least 7x magnification should 
work...and is a lot cheaper than a 'scope.

You need a good extra fine-tip soldering station with temperature control 
($100-200), very fine rosin-core solder, good tweezers, solder flux, 
alcohol for cleaning, and (most importantly) solder-wick to soak up your 
mistakes (i.e., solder bridges).

Some people use solder paste, as I do sometimes, but I usually mix it with 
solder flux and dab it on with a wooden toothpick.  The biggest mistake 
novices make is using too much solder.  I find that a mix of solder paste 
and solder flux on fine-pitch parts helps control this.

The rest takes practice.  (It's only time and money! :-)  It helps a *lot* 
to watch someone experienced do surface mount assembly...and re-work. 
There are lots of simple "tricks" that make what seems hard really easy.

It's the future...better learn it sometime!

Best regards,

Bruce

P.S.- Make sure you value this advice according to what you paid for it! :-)

-- 
  Bruce D. Lightner
  Lightner Engineering
  La Jolla, California
  Voice: +1-858-551-4011
  FAX: +1-858-551-0777
  Email: lightner-2huV/[email protected]
  URL: http://www.lightner.net/lightner/bruce/

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