Return-path: [log in to unmask] From: [log in to unmask] Full-name: Syrtek Message-ID: <[log in to unmask]> Date: Thu, 27 Jan 2000 16:21:38 EST Subject: TEMPERATURE EFFECTS ON ACID COPPER PLATING To: [log in to unmask] MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: AOL 5.0 for Windows sub 45 Dear Net, We've been having a great deal of trouble with smutting in low Asf areas of our Pcb's since the cold snap. Our acid copper plating bath is LeaRonal's PCM Plus. The bath is room temp.. Last week the bath was at 78 F, this week it is at 74F. The other big factor is the preplate line. The rinses are normally heated to 85-88 F. A malfunction caused the temps to be at 58 F. The acid dip must have been affected by the cold panels because its room temp is now 64 F. We started applying 35-40 Asf initially to avoid low current area smutting. It helps. We just discovered the rinse temp prob. and bath temp variation. Could someone explain cold panel issues and the mechanism of this smutting? The panels entered the tank at 64 F. Why don't they all smut? Only about 20-30% smut. I adjusted the rectifier as I loaded each panel. We use direct metallization-Pd vanillin-. I can't recreate in the hull cell. Test panels look good. Thanks, Julie Dixon