I don't know the specific designs in questions, so I can only make a "semi-educated" guess. One reason is that boards in cellular phones are usually pure SMT, with no through hole, and are also thin. Running a thin board through an HASL machine tends to potatoe chip it. A gold finish requires no heat excursion to fab the finished bare board. At component assembly you don't have to run a pure SMT board over a wave so there is no worry about gold in the wave machine. Gold is also a great way to get a co-planar surface. Component types such as COB or connectors requiring mechanical (not soldered) connections can also drive this, but again I don't know your designs. [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Why Gold finish on Cell phone Boards Author: [log in to unmask] at Dell_UNIX Date: 7/27/95 10:07 AM I was hoping someone out there could help me out and shed some light on a question that I've been trying to get an answer to for a couple of months now (with limited success). Why do the major cell phone manufacturers use gold as their preferred finish? I would appreciate any information. Regards, Steve Sabourin Hadco Corporation [log in to unmask]