[TriEmbed] APA102 unsoldering

[Alex Davis]

Adam,
 
ChipQuik works great, but I'm out if it at the moment. I've got a temperature-
controlled soldering station, and I usually park the dial midway in the
'green' soldering zone so I'm not really sure what the temperature is. I
never use lead-free solder, as I'm aware it needs more heat and is prone
to reliability issues.
 
I think the challenge with these is they're leadless and made of a
plastic that's definitely less heat-resistant than the typical black
resin. I'll play around with a test strip using a hot-air rework
station, but I'd be reluctant to use that on my array since it's
mounted to foamcore board which probably wouldn't hold up to any stray
heat well.
 
I'll probably try sticking a piece of strip in the reflow oven and see
if I can get the LED to drop off during a cycle. I'd definitely like to
keep a neat appearance on the array and mounting a replacement to the
original pads would look best.
 
Alex
 
 
On Wed, Jun 22, 2016, at 08:59 AM, Adam Haile wrote:
> Also, what temp is your iron set to? Realizing that the ChipQuik only
> helps in removal, but since those LEDs are designed to be reflowed,
> they should certainly survive solder melting temp. One thing that
> might cause an issue is using lead-free solder, especially of a
> cheaper alloy which has a much higher temp. If you are using lead-
> free, try leaded and keep the iron <= 600.
>
> On Wed, Jun 22, 2016 at 8:43 AM, Alex Davis via TriEmbed
> <triembed at triembed.org> wrote:
>> Anyone have any success with unsoldering APA102 LEDs without ruining
>>  them? It seems they are made of really shitty thermoplastic
>>  which melts
>>  at about the melting point of the solder. I had one go bad in
>>  my 44x8
>>  matrix, and I got it off by using a broad tip to reflow one
>>  side at a
>>  time while lifting with tweezers. I'd say the package has the
>>  thermal
>>  resistance of the sort of plastic cheap header strips are made
>>  of. It
>>  was a ruined plastic blob by time I got it off.
>>
>>  As to the repair, I am thinking I will just cut an LED off a
>>  spare strip
>>  and solder it down on top of the blank spot. It won't look as
>>  nice but
>>  it seems like it will have the highest change of success and of not
>>  ruining the mounting strip.
>>
>>  BTW these APA102 have in and out for both data and clock, and in
>>  my case
>>  an LED stopped outputting anything on data out, causing the
>>  whole rest
>>  of the strip to die. Thankfully it was just one unit, but it
>>  gives me
>>  pause to consider building anything large and expensive out of these
>>  things. My setup was working fine before I peeled off the
>>  backing tape
>>  and glued it on to the enclosure.
>>
>>  Alex
>>
>>  --
>>  "The theater of noise is proof of our potential."
>>  |\ |  (¯  \/ |¯\  |V| |\ ¯|¯ |¯) | \/ | | | |¯\ (¯   /¯  /\ |V| -||_
>>  |(_  /\ |_/ @| | |-| |  | \ | /\ |^| | |_/ (_ . \_  \/ | |
>>
>>  You won't find me on Facebook.
>>
>>  _______________________________________________
>>  Triangle, NC Embedded Computing mailing list TriEmbed at triembed.org
>>  http://mail.triembed.org/mailman/listinfo/triembed_triembed.org
>>  TriEmbed web site: http://TriEmbed.org
 
--
"The theater of noise is proof of our potential."
|\ |  (¯  \/ |¯\  |V| |\ ¯|¯ |¯) | \/ | | | |¯\ (¯   /¯  /\ |V|
|-||_ (_  /\ |_/ @| | |-| |  | \ | /\ |^| | |_/ (_ . \_  \/ | |
 
You won't find me on Facebook.
 
 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.triembed.org/pipermail/triembed_triembed.org/attachments/20160622/217e8aa3/attachment.htm>