Frank, Two thoughts: 1. Are your NPTHs drilled, run through electroless copper, tented then etched out? If so, check to make sure you etch all of the metal out of these holes before going through 'chemical' Ni/Au (is this electroless nickel, immersion gold?) 2. Are you using a palladium catalyst on your electroless Ni, immersion gold line? Leaving some of this catalyst in the NPTHs will cause plate out in these holes. I've certainly seen plateout on laminate areas with these not-so-stable catalysts even with good rinsing after the catalyst step. When this begins to happen, changing out the catalyst seemed to be the only thing which worked to get rid of this plateout. To check out the second of these ideas, run some NPTH test boards through the electroless nickel, immersion gold line skipping the catalyst and catalyst rinse steps. If the plating in NPTHs goes away, yet returns when you go through the catalyst and rinse, you've come close to pinpointing the source of your plateout. I hope this helps. Regards, Dave Sullivan Rockwell Collins, Inc. [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: chemical Ni/Au in NPTH. Author: [log in to unmask] at ccmgw1 Date: 4/15/97 3:48 AM Hello everybody, Now and than we are seeing that chemical Ni/Au is covering the NPTH wall. We and also the supplier of chemicals doesn't know what is causing this phenomenon. Is there somebody out there who does? Any help would be appreciated. Frank Petit ACB Belgium *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * *************************************************************************** Received: from by ccmgw1.cacd.rockwell.com (SMTPLINK V2.11) ; Tue, 15 Apr 97 03:48:01 cst Return-Path: <[log in to unmask]> Received: from stealth.cacd.rockwell.com (stealth) by mailserv with ESMTP (1.40.112.8/16.2) id AA084394082; Tue, 15 Apr 1997 03:48:02 -0500 Received: by stealth.cacd.rockwell.com; id DAA14113; Tue, 15 Apr 1997 03:45:35 -0500 Received: from unknown(168.113.24.64) by stealth.cacd.rockwell.com via smap (3.2) id xma014110; Tue, 15 Apr 97 03:45:25 -0500 Received: from ipc.org by simon.ipc.org via SMTP (940816.SGI.8.6.9/940406.SGI) id DAA12338; Tue, 15 Apr 1997 03:35:28 -0700 Resent-Date: Tue, 15 Apr 1997 03:35:28 -0700 Received: by ipc.org (Smail3.1.28.1 #2) id m0wH3IQ-000Bj1C; Tue, 15 Apr 97 03:08 CDT Resent-Sender: [log in to unmask] Old-Return-Path: <[log in to unmask]> Message-Id: <[log in to unmask]> From: frp <[log in to unmask]> To: "[log in to unmask]" <[log in to unmask]> Subject: chemical Ni/Au in NPTH. Date: Tue, 15 Apr 1997 10:17:59 +0100 X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.837.3 Encoding: 12 TEXT Resent-Message-Id: <"jdDAa2.0.NgI.LUpKp"@ipc> Resent-From: [log in to unmask] X-Mailing-List: <[log in to unmask]> archive/latest/11949 X-Loop: [log in to unmask] Precedence: list Resent-Sender: [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************