Hello All,
 
I've been asked a stumper (for me anyway).
 
Is there a specification for the co-planarity (?) of HASL across the board? My customer is concerned that thickness variations (80 microinches on one land / 800 microinches on the other land - for the same component) are causing tilting of his components.
 
I know that there are minimum thickness requirements which address solderability, but have not heard of the above.
 
Don Karp
Trace Laboratories - Central