Bond Wire Identification Help

[Quiklearner]

Good Morning Members!

I have a bunch of these BJT power transistors out of some old commercial audio amps. I cut the cap off of one to investigate if there was any gold present. The bond wires were not gold, but a shiny silvery metal (and quite thick). Being made in Mexico, I immediately thought of silver, but when I removed the 2 wires and added a little dilute nitric to them, there was no reaction. These devices can handle 20A, so in fact, I do not believe that silver would have been used.

My question is: Does anyone have an idea of what metal these bond wires could be? Palladium coated copper perhaps?

 

[MicheleM]

Power transistor...Why not simply Al?

 

[kurtak]

They are aluminum

nitric will not dissolve them --- HCl will dissolve them

Kurt

 

[Quiklearner]

Thanks Kurt. I should have known....

 

[mmzhr]

Good Morning Members!

I have a bunch of these BJT power transistors out of some old commercial audio amps. I cut the cap off of one to investigate if there was any gold present. The bond wires were not gold, but a shiny silvery metal (and quite thick). Being made in Mexico, I immediately thought of silver, but when I removed the 2 wires and added a little dilute nitric to them, there was no reaction. These devices can handle 20A, so in fact, I do not believe that silver would have been used.

My question is: Does anyone have an idea of what metal these bond wires could be? Palladium coated copper perhaps?

aluminium bond wire