Hi There,

Are you aware of the artificial ageing solderiability test procedure? This is a machine wich generates a cycle of steam, nitrogen purge and then oxygen. Any HAL solder  coupon that passes that with good wetting should be good enough for your requirements.

Ken McGowan
  ----- Original Message ----- 
  From: Yehuda Weisz 
  To: [log in to unmask] 
  Sent: Tuesday, February 20, 2001 4:27 PM
  Subject: [TN] HASL thickness specification


  Dear Technetters,
  I am trying to write a spec. for solder levelled boards received from an outside vendor. The boards contain SMD (some - 0.019" pitch) and some pressfit connectors.
  What solder thickness should I ask for if I wish the boards to maintain solderability after at least one year of storage (under normal conditions) and 3 reflow assembly cycles (sometimes even more).

  Probably, all of you had seen specs that made no sense, I don't want to write another one.

  I'll appreciate very much your inputs.

  Yours,
  Yehuda Weisz