Damaged SSC P4 emitter

Looks like I came up with a new creative way of messing up emitters.

While unsoldering a USWOH emitter from the star (something I've done a few times before without any problems), I managed to drop it on the floor while it was still hot, and it landed on ceramic tiles slug down. I'm guessing the shock dislodged the die from the slug or something, because this emitter now will not handle more than 400mA of current before the output starts shifting blue. At anything over 500mA, its color is comparable to that of a blue Luxeon, just not as bright


Just wanted to share.

Soldering these LEDs as a form of attaching them to a heat sink is actually a tricky venture, something that really shouldn't be done with hand tools. Even de-soldering from a heat sink can lead to serious issues. It is nearly impossible to solder a high output Rebel to a heat sink by hand without physically damaging the device.

You more than likely melted the solder holding the die to the submount, or the submount to the heat sink.

There is a specific thermal profile that must be followed to successfully solder the heat sink attachments of these devices. Failure to follow that profile can result in many different issues, including delamination of the die, physical separation, heat stress fractures, damage to the phosphor, etc. etc.

I think you should offer a mod service - "I will transform your light to a new random color - $25 + postage"

Hahah random colors . The die is attached with thermal epoxy from Newbie's findings and I would imagine that it's pretty sensitive to heat from soldering since some of them seem to be sensitive to just the heat from driving them.

Yeah that would be my guess, too. Epoxy might soften at high temperatures, and restore its properties after cooling down - unless it was heated too high.

I don't think I overheated the emitter... Following exactly the same procedure, I successfully removed a few of those from stars with no damage at all, so i'm pretty sure that it was the impact - in combination with temporary softened epoxy - that did the trick.