Black oxidation on transistor leads 2SC4636LS

Semiconductor Discrete Semiconductor Products
,
1

Is there a method to remove the black corrosion or oxidation from my transistor leads?
Should I be concerned if the contamination is up at the molded body?
Will this affect the function of the part (2SC4636LS)?

2

Welcome to the TechForum! Hello dlangford, could you provide a picture of what you are seeing on the leads? Did they arrive this way or have they been in use for some time?

3

This is something that occured during storage in a vacuum sealed bag, although the parts themselfs are within a tube.

image
image354×382 32.1 KB

4

Hmm, it sort of seems like the tinning process wasn’t done very well. The exposed parts of the copper (or whatever the substrate is) seem to only be affected. Generally speaking, corrosion only affects the exposed areas and doesn’t typically “spread inward” to my knowledge. It might impact performance a tiny bit, but only on the pins. You could always try to re-tin the part with solder to cover up those spots. It’s a minor concern that the tinning is spotty.