In a message dated 2/6/01 9:02:00 AM Eastern Standard Time, [log in to unmask] writes: << We have a couple assemblies that have solder on the gold fingers. >> Hi Rich, I'm sure you'll get an abundance of excellent references on the How-To's for removing solder from gold (and sources for solder wick, etc.). So I'll instead write to share a proactive idea for future-thinking. Have you considered substituting a polymer thick film coating (PTF) for the gold coating? PTF coatings (think "conductive inks") have the advantage of providing a conductive finish to your card edge connectors without the liabilities of electro-deposited Ni/Au. Points to Ponder (in no particular order): Solder Resistivity PTF coatings are generally as resistant to solder adhesion as the solder mask. Thus there is no taping and, consequently, no opportunity for solder seepage. Electrical Performance Most inks today are available in varying resistance formulas, down to 1-ohm per square. Contact resistivity is typically @ or below 1-ohm. Unless you're running very heavy current there's likely no loading problems to anticipate at the connector. Mechanical Performance PTF coatings are the clear winner over gold. The same ingredient that makes the ink conductive - graphite - also acts as a lubricant, so that there develops a self-lubricating relationship between connector and connector fingers. Shelf Life PTF coatings have virtual unlimited shelf life. Cost A PTF finish on card edge connectors should impart a cost adder slightly higher than an additional silkscreen; likely less than the cost adder for electro-deposited card edge connectors. Solvent Resistivity Expect robust performance comparable to FR-4 resin systems and polymer solder masks. Organic Liability PTF formulas are completely non-nutritional and do not promote organic growth. There's more to be said, but my point is that you may have a viable option that will satisfy the connector function without the liability of solder on gold and, most likely, for less money than your currently paying. In the interim, good luck getting your solder removed. Bob Lazzara Circuit Connect, Inc. Tel: +1 706.245.4232 Fax: +1 706.245.4299 Web: www.CircuitConnectInc.com --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------