LED lights yield

[Alondro]

I've been collecting LED's from various electronic circuit boards, and have found that there are silvery looking LED's and others that look golden. The best way to determine the bonding wire used (especially on super small chips) is a simple digital microscope with display you can easily find on Amazon. Any silvery or copper wires I toss.
Looking through the scope I soaked the COB LED in some simple label remover solvent and determined the bond wires used are copper. Christmas light LED's and backlight LEDs are copper as well.

Only OLD LEDs have PMs. Once you get to LEDs used in Christmas lights, they're the incredibly cheap modern forms.

Basically, LEDs beyond the year 2000 can be assumed to have nothing of value. So few will have anything worthwhile, you're not losing anything by trashing them. LEDs on old circuit boards, however, can have those nice gold bond wires that simple pyrolizing and ashing protocols can recover.

 

[anarxi]

you make diodes, then only old Soviet ones.
everything else is work for work's sake....

 

[BShan]

Only OLD LEDs have PMs. Once you get to LEDs used in Christmas lights, they're the incredibly cheap modern forms.

Basically, LEDs beyond the year 2000 can be assumed to have nothing of value. So few will have anything worthwhile, you're not losing anything by trashing them. LEDs on old circuit boards, however, can have those nice gold bond wires that simple pyrolizing and ashing protocols can recover.

High power discreet LEDs often still have gold colored bond wires. Because of what they're usually used for, though, not sure how commonly these'd show up in quantity.

After searching before replying to this post I see that there are companies which offer many different types of bond wires including gold-coated silver and gold coated copper. So for all I know, the newer stuff with gold colored bond wires may very well not be solid gold.

More credence to "all that glitters isn't gold" or whatever the saying is.

 

[Alondro]

High power discreet LEDs often still have gold colored bond wires. Because of what they're usually used for, though, not sure how commonly these'd show up in quantity.

After searching before replying to this post I see that there are companies which offer many different types of bond wires including gold-coated silver and gold coated copper. So for all I know, the newer stuff with gold colored bond wires may very well not be solid gold.

More credence to "all that glitters isn't gold" or whatever the saying is.

It's possibly this reason some scrappers have gotten such low yields of gold from processing LEDs, if they have a mix of LEDs that includes a large number of very modern ones. The bond wires LOOK like gold, but only have a nano-layer coating, meaning the actual amount of gold is immeasurably tiny.

A proper study of the subject should test samples of LEDs ONLY from confirmed eras.

For example, half a kilogram known to originate from the 1980s vs half a kilogram known to originate from the 2000s.

 

[Yggdrasil]

It's possibly this reason some scrappers have gotten such low yields of gold from processing LEDs, if they have a mix of LEDs that includes a large number of very modern ones. The bond wires LOOK like gold, but only have a nano-layer coating, meaning the actual amount of gold is immeasurably tiny.

A proper study of the subject should test samples of LEDs ONLY from confirmed eras.

For example, half a kilogram known to originate from the 1980s vs half a kilogram known to originate from the 2000s.

Not a bad idea.