<p dir="ltr">Chipquik and flux are my go-to for replacing those kind of LEDs, but i usually regard the removed ones as trash for exactly the reasons you mentioned. I'm trying to think of an alternative method to remove them that, ignoring the LEDs, wouldn't wreck the pads. Hot air might be the best bet, provided it doesn't mess up any nearby LEDs. A little bit of flux would probably help.</p>
<p dir="ltr">-Sent from my phone</p>
<div class="gmail_quote">On Jun 22, 2016 9:18 AM, "Alex Davis via TriEmbed" <<a href="mailto:triembed@triembed.org">triembed@triembed.org</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><u></u>
<div><div style="font-family:Arial">Adam,<br></div>
<div style="font-family:Arial"> </div>
<div style="font-family:Arial">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.<br></div>
<div style="font-family:Arial"> </div>
<div style="font-family:Arial">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.<br></div>
<div style="font-family:Arial"> </div>
<div style="font-family:Arial">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.<br></div>
<div style="font-family:Arial"> </div>
<div style="font-family:Arial">Alex<br></div>
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<div>On Wed, Jun 22, 2016, at 08:59 AM, Adam Haile wrote:<br></div>
<blockquote type="cite"><div dir="ltr">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.<br></div>
<div><div style="font-family:Arial"> </div>
<div><div style="font-family:Arial">On Wed, Jun 22, 2016 at 8:43 AM, Alex Davis via TriEmbed <span dir="ltr"><<a href="mailto:triembed@triembed.org" target="_blank">triembed@triembed.org</a>></span> wrote:<br></div>
<blockquote style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div style="font-family:Arial">Anyone have any success with unsoldering APA102 LEDs without ruining<br></div>
<div style="font-family:Arial"> them? It seems they are made of really shitty thermoplastic which melts<br></div>
<div style="font-family:Arial"> at about the melting point of the solder. I had one go bad in my 44x8<br></div>
<div style="font-family:Arial"> matrix, and I got it off by using a broad tip to reflow one side at a<br></div>
<div style="font-family:Arial"> time while lifting with tweezers. I'd say the package has the thermal<br></div>
<div style="font-family:Arial"> resistance of the sort of plastic cheap header strips are made of. It<br></div>
<div style="font-family:Arial"> was a ruined plastic blob by time I got it off.<br></div>
<div style="font-family:Arial"> </div>
<div style="font-family:Arial"> As to the repair, I am thinking I will just cut an LED off a spare strip<br></div>
<div style="font-family:Arial"> and solder it down on top of the blank spot. It won't look as nice but<br></div>
<div style="font-family:Arial"> it seems like it will have the highest change of success and of not<br></div>
<div style="font-family:Arial"> ruining the mounting strip.<br></div>
<div style="font-family:Arial"> </div>
<div style="font-family:Arial"> BTW these APA102 have in and out for both data and clock, and in my case<br></div>
<div style="font-family:Arial"> an LED stopped outputting anything on data out, causing the whole rest<br></div>
<div style="font-family:Arial"> of the strip to die. Thankfully it was just one unit, but it gives me<br></div>
<div style="font-family:Arial"> pause to consider building anything large and expensive out of these<br></div>
<div style="font-family:Arial"> things. My setup was working fine before I peeled off the backing tape<br></div>
<div style="font-family:Arial"> and glued it on to the enclosure.<br></div>
<div style="font-family:Arial"> <span><span style="color:rgb(136,136,136)"><br> Alex<br> <br> --<br> "The theater of noise is proof of our potential."<br> |\ | (¯ \/ |¯\ |V| |\ ¯|¯ |¯) | \/ | | | |¯\ (¯ /¯ /\ |V|<br> |-||_ (_ /\ |_/ @| | |-| | | \ | /\ |^| | |_/ (_ . \_ \/ | |<br> <br> You won't find me on Facebook.<br> <br> _______________________________________________<br> Triangle, NC Embedded Computing mailing list<br> <a href="mailto:TriEmbed@triembed.org" target="_blank">TriEmbed@triembed.org</a><br> <a href="http://mail.triembed.org/mailman/listinfo/triembed_triembed.org" target="_blank">http://mail.triembed.org/mailman/listinfo/triembed_triembed.org</a><br> TriEmbed web site: <a href="http://TriEmbed.org" target="_blank">http://TriEmbed.org</a></span></span></div>
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</blockquote><div style="font-family:Arial"> </div>
<div><div>--<br></div>
<div>"The theater of noise is proof of our potential."<br></div>
<div>|\ | (¯ \/ |¯\ |V| |\ ¯|¯ |¯) | \/ | | | |¯\ (¯ /¯ /\ |V|<br></div>
<div>|-||_ (_ /\ |_/ @| | |-| | | \ | /\ |^| | |_/ (_ . \_ \/ | |<br></div>
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<div>You won't find me on Facebook.<br></div>
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