[Robotgroup] Hauntlites- Review, thoughts, Lessons learned, and improvements...

[Paul Atkinson]

Think they using fuming nitric acid to dissolve the black epoxy on semiconductor chips. Doesn't sound like fun stuff to work with.

I was thinking that sandblasting the LEDs might work. I wonder if Rick has access to a sand or bead blaster since he had access to the sand for same.

Paul

Def Egge <robodigest at innervate.com> wrote: At 13:30 2006/09/29 -0500, you wrote:
>At 12:22 2006/09/29 -0500, you wrote:
>>Def Egge wrote:
>>> Enlarge the hold in the cardboard LED retainer?  We originally thought
that
>>> the extreme sensitivity was a liability.
>>
>>Yup. Our perceptions had a direct run-in with reality yesterday. Now we
>>know that more sensitive to IR = better. ;)
>>
>>> Sandpaper might be less effective than, say, acetone.  I have some here if
>>> we need it.  The LEDs could be roughened without unsoldering...no risk of
>>> damaged leads as per sandpaper.
>>
>>Would good ol'e nail-polish remover do that? If so, my wife has that
>>stuff somewhere... :)
>
>Apparently, no.  I have just tried acetone, toluene, xylene, plus a mixture
>of the latter two.  No evidence of a surface change, whatsoever.
>
>Ed has informed me that the plastic capsule is an epoxy and difficult to
>chemically re-work.  A hot acid bath may etch the surface but desoldering,
>sanding, and resoldering might be quicker.  If we decide to go that route,
>we should check with him for the acrylic disks - with a hole in the middle
>- to mount the LEDs through (and circuit board to).
>
>
>All the best....
>
>Mike

Dang!  Methyl ethyl ketone is equally ineffective at etching the epoxy
capsule on those LEDs.  Anyone got some Dynasolve handy?  How about
Kryptonite?


All the best....

Mike



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