I think that we compare with the solderability of the wire whose tin thickness is normal and 1um to judge OK or not.
Then I also understand that the cost is increased by increasing the thickness of tin layer.
If there is another improvement idea, I want to know. But I don't have the idea now.
Do you know it ?
So I try to use the wire whose tin thickness is 1um.
But we need to discuss whether we use the wire or not.