SMD LED desoldering on heatsink plate?

[Jan Catrysse]

Hi,

I am trying to nicely desolder some SMD LED's and replace them, on an aluminium heatsink PCB. Like those commonly found in garden or work lamps.

But my preheater doesn't seem to heat enough, so I have to raise my hotair temperature way to high and I'm burning my LED's.

Does anyone has a good advice on how to do this the right way?

Does anyone has an advice on a good heating plate for this? I found a Weller WHP 1000 Preheating plate, but it only goes upto 300 degrees Celsius, and I don't know if that's enough?

Thank you

[JustMeHere]

300 C is enough. 

[GoneTomorrow]

In the flashlight modding world most people just go medieval on its ass and use something like an electric frypan to heat the MCPCB to swap LED's, since most people can't justify a proper board heater just for this.

[Jan Catrysse]

Thank you!

[Siwastaja]

My suggestion is to preheat slightly below the melting point of the solder, maybe 150 degC for leaded and maybe 200 degC for lead-free. Then you supply the "last bit" of heat with the hot air gun or soldering iron.

Note that practically all components survive those "just below melting point" temperatures for hours just fine, so you are not in a hurry - preheat slowly, take your time, so the whole piece heats up evenly with no colder areas.

[Jan Catrysse]

Thank you, so if I have a device that would have a max temperature of 300 I would be largely ok.

I will try that.

[Jan Catrysse]

Uyue 946c is the machine I found on Ali Express. I will give it a try.

[MosherIV]

If you do not have electric pan try clothes iron, it even has temperature control but it is not precises.
Should be good enough to preheat the heat sink