To ALL TECHNETER: I made a mistake in the note below. The SIR readings should have been 10 to the eleventh (and not minus 11th) and 10 to the seventh (and not the minus 7th). Sorry about that. It's been a long day. Harry ______________________________ Reply Separator _________________________________ Subject: Re[2]: Mild humor: RE: Walmart Supplies Author: [log in to unmask] (HOHALLOR) at INET Date: 9/26/96 1:59 PM Paul: You are correct. The wetting agents and the surfactants are non-ionic materials which are not detected by the Omegameter or the Ionigraph which only measures the concentration of the ionic materials which are soluble in the alcohol water solution. However, these non-ionic residues have a tendency to attract and absorb water onto the surface of the PWB. As the water is absorbed it is polarized. When a voltage deferential is applied across two adjacent traces the water ionizes forming a plating situation and dendritic growth occurs and eventually a short will develop. So, even though your PWB appears clean according to the Omegameter or the Ionigraph, it is actually a potential problem when it gets to the field. (The differences I saw between boards cleaned by cascade and those cleaned by other methods ranged from 10 to the minus 11th ohms for others to below 10 to the minus 7th ohms for the cascade cleaned boards. This was at 35 degrees C and 85% RH.) Harry ______________________________ Reply Separator _________________________________ Subject: Re: Mild humor: RE: Walmart Supplies Author: [log in to unmask] at INET Date: 9/26/96 10:55 AM Man, and here I thought I heard some weird ones! Great List - it went into my oddities file. Thanks. << By the way, just what surface insulation resistance would one get on a board which was washed in Cascade after hot air solder level? I've understood it had been tested and found it "passed" the "Omegameter" test. Does that mean better than 60%? >> In almost all cases, the SIR gets shot all to hell. An additional 2-3 decades drop due to the cascade. The cause is surfactant and wetting agents which do not register on an Omegameter. Harry O'Halloran also replied to my comment indicating he had seen drops like this. Doug. *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** Received: from camelot.dsccc.com by inet.dsccc.com with SMTP (IMA Internet Exchange 2.02 Enterprise) id 24AB2DB0; Thu, 26 Sep 96 11:44:11 -0500 Received: from offramp.dsccc.com (onramp.dsccc.com [192.1.1.139]) by camelot.dsccc.com (8.6.11/8.6.10) with SMTP id KAA25228; Thu, 26 Sep 1996 10:10:33 -0500 Received: by offramp.dsccc.com (5.67b/SMI-V1.8) id AA07703; Thu, 26 Sep 1996 10:11:26 -0500 Received: from ipc.org(168.113.24.64) by offramp via smap (V1.3mjr) id sma007642; Thu Sep 26 10:10:49 1996 Received: from ipc.org by simon.ipc.org via SMTP (940816.SGI.8.6.9/940406.SGI) id KAA04506; Thu, 26 Sep 1996 10:01:32 -0700 Resent-Date: Thu, 26 Sep 1996 10:01:32 -0700 Received: by ipc.org (Smail3.1.28.1 #2) id m0v6HiR-0000RdC; Thu, 26 Sep 96 09:47 CDT Resent-Sender: [log in to unmask] Old-Return-Path: <[log in to unmask]> From: [log in to unmask] Date: Thu, 26 Sep 1996 10:55:43 -0400 Message-Id: <[log in to unmask]> To: [log in to unmask] Subject: Re: Mild humor: RE: Walmart Supplies Resent-Message-Id: <"vTqzF2.0.WeJ.bTfIo"@ipc> Resent-From: [log in to unmask] X-Mailing-List: <[log in to unmask]> archive/latest/6484 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 unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** Received: from camelot.dsccc.com by inet.dsccc.com with SMTP (IMA Internet Exchange 2.02 Enterprise) id 24AE87F0; Thu, 26 Sep 96 15:33:04 -0500 Received: from offramp.dsccc.com (onramp.dsccc.com [192.1.1.139]) by camelot.dsccc.com (8.6.11/8.6.10) with SMTP id PAA10767; Thu, 26 Sep 1996 15:23:22 -0500 Received: by offramp.dsccc.com (5.67b/SMI-V1.8) id AA25763; Thu, 26 Sep 1996 15:24:10 -0500 Received: from ipc.org(168.113.24.64) by offramp via smap (V1.3mjr) id sma025658; Thu Sep 26 15:23:26 1996 Received: from ipc.org by simon.ipc.org via SMTP (940816.SGI.8.6.9/940406.SGI) id PAA06198; Thu, 26 Sep 1996 15:13:16 -0700 Resent-Date: Thu, 26 Sep 1996 15:13:16 -0700 Received: by ipc.org (Smail3.1.28.1 #2) id m0v6Lap-0000TYC; Thu, 26 Sep 96 13:55 CDT Resent-Sender: [log in to unmask] Old-Return-Path: <[log in to unmask]> Date: Thu, 26 Sep 1996 13:59:22 -0500 Message-Id: <[log in to unmask]> From: [log in to unmask] (HOHALLOR) To: [log in to unmask], [log in to unmask] Subject: Re[2]: Mild humor: RE: Walmart Supplies Resent-Message-Id: <"DOLN42.0.bhM.T6jIo"@ipc> Resent-From: [log in to unmask] X-Mailing-List: <[log in to unmask]> archive/latest/6499 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 unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************