Mike,

This is how I've approached this situation in the past.  I've not had
any major rebuttals to the specification
for either OEM or Fab house.  I don't have the original copy I wrote up,
but here it is:

"The SnPb thickness range shall be between 100 to 1200 microinches
across the entire PCB, front and back.  The SnPb thickness shall not be
greater than 100 microinches from pad to pad, within the same QFP."

Hope this helps.

John Gulley




-----Original Message-----
From: Mike Bailey [mailto:[log in to unmask]]
Sent: Friday, June 18, 1999 1:31 PM
To: [log in to unmask]
Subject: [TN] Solder Thickness


I need some ammunition, please. We have a customer who is demanding 100

microinches minimum of tin/lead thickness everywhere on his SMT features

regardless of size shape and location. Solderability has not been an
issue,

but perceived visual appearance is the driver. How would you respond to

this requirement, and what would you commit to? I have my own set of

numbers to throw out, but would rather here your comments.

Thanks for any information