Removing led diode from board

[ntec]

I'm trying to replace dead led's from my expensive aquarium lights but I am having a hard time removing the led diodes. I've tried using a hot air station at 500 celcius (932 Fahrenheit) but the led won't budge. I tried blasting hot air from both the bottom and top but it won't budge. I don't have a heating plate so is there a better way? As you can see the bottom of the board is all metal.

[redwire]

Re: Removing led diode from board

It's an MCORE PC board, the LED's are thermally bonded to the aluminum plate. Very difficult to work with I find. Basically, you must heat up the aluminum plate, not the LED's.
Lots of hot air on the top will only melt the LED's lens. You can heat the plate bottom though. This will work but takes a lot of hot air power, so a hot plate is better. They are $10-15 or so on Ali. Problem is cranking up the air temp means it can go too hot and melt things. You have to be able to control the heat.
Another risky way is using a blow torch (on the bottom side) but again it's easy to overheat the board and damage it.
I use a hot plate. Find a cellphone repair shop or something with one.

[ntec]

Re: Removing led diode from board

It's an MCORE PC board, the LED's are thermally bonded to the aluminum plate. Very difficult to work with I find. Basically, you must heat up the aluminum plate, not the LED's.
Lots of hot air on the top will only melt the LED's lens. You can heat the plate bottom though. This will work but takes a lot of hot air power, so a hot plate is better. They are $10-15 or so on Ali. Problem is cranking up the air temp means it can go too hot and melt things. You have to be able to control the heat.
Another risky way is using a blow torch (on the bottom side) but again it's easy to overheat the board and damage it.
I use a hot plate. Find a cellphone repair shop or something with one.

Ok thanks, i'll look into a hot plate.

[redwire]

Re: Removing led diode from board

We discussed hot plates in this thread: https://www.badcaps.net/forum/showthread.php?t=100324

[momaka]

Re: Removing led diode from board

Old toaster = poor man's hot plate.

Though if you want more / better control, just place the board / plate a few inches above one of your kitchen's stovetop burners. I use this method as a bottom heater when I want to reflow large motherboards or remove large BGA chips from them. It works surprisingly well.
Start with burner set to lowest and increase heat only if needed. But like I said, make sure you suspend the plate a few inches above the burner. If you place it directly, you can overheat things very easily.

[diif]

Re: Removing led diode from board

This would go on my Honton 2020 not one of those small cheap hotplates that's set on one temperature.
Whole PCB heated to 170c and hot air to remove the failed LED, then using a quality iron the lead free solder would be replaced with leaded, the temperature can be turned up a little and the new LED should reflow into place without using top hot air.