 
| Subject: | |
| From: | |
| Date: | Tue, 5 Nov 1996 08:58:23 -0600 |
| Content-Type: | text/plain |
| Parts/Attachments: |
|
|
Address,
What you and everyone else are saying makes a lot of sense. However,
how is amount of gold diluted into the SnPb controlled. Reflow and
solder rework dwell time (heat) is obviously a large contributor? The
amount of gold diluted is also dependent on what types of gold are
applied (Immersion Au tends to have a higher porosity than
Electroplated Au, in-turn more diluted gold in the SnPb).
Is the gold being soluable a concern at the Reflow operation or at
rework or both. Could someone please comment on how the amount of
diluted gold can be controlled in PROCESS, without an SEM or other
Quality Control Device.
Regards,
John Gulley
______________________________ Reply Separator _________________________________
Subject: goldfinish on PC boards
Author: [log in to unmask] at Internet
Date: 11/4/96 8:52 PM
De: Coderre - JCCODERR BRMVM1
***************************************************************
CLASSIFICATION NON-CLASSIFIE ( ) CONFIDENTIEL ( )
Objet: goldfinish on PC boards
Gold is highly soluble in solder and should not affect the properties
of the solder joint if the concentration is below 3% (wt). This is
true if the gold is completely dissolved in the solder and one does not
find a rich gold concentration at the interface. THis rich zone may occur
if the temperature cycle is such that the dissolution is not complete.
This should be verified by SEM cross-sectioning
Literature references are available upon request
At higher gold concentrations (either local or bulk), embrittlement
will occur
Merci/Regards
Directeur Ingenierie MLC / MLC ENG. MGR
Dept 881/23 BRMT (tel. 514-534-6591, US tieline 552)
INTERNET ADDRESS [log in to unmask]
*** RŠacheminement de la note de SMTP2 --IINUS1 11/04/96 15:05 ***
=========================================================================
Received: from simon.ipc.org by vnet.IBM.COM (IBM VM SMTP V2R3) with TCP;
Mon, 04 Nov 96 15:02:53 EST
Received: from ipc.org by simon.ipc.org via SMTP (940816.SGI.8.6.9/940406.SGI)
id NAA28418; Mon, 4 Nov 1996 13:55:44 -0800
Resent-Date: Mon, 4 Nov 1996 13:55:44 -0800
Received: by ipc.org (Smail3.1.28.1 #2)
id m0vKUCo-0000WUC; Mon, 4 Nov 96 12:57 CST
Resent-Sender: [log in to unmask]
Old-Return-Path: <[log in to unmask]>
Message-Id: <[log in to unmask]>
X-Mailer: DeskLink [Version B.02 95/10/31]
MIME-Version: 1.0
Date: 4 Nov 96 13:11 +0500
Sender: [log in to unmask] (Wolfgang Erat)
To: [log in to unmask]
Subject: goldfinish on PC boards
X-HPDESK-ID: 5627572 0 0 0 "NTMAIL "
X-HPDESK-PRIORITY: 3
X-HPDESK-SYSTEM: 525
From: [log in to unmask] (Wolfgang ERAT)
X-FROM: "Wolfgang ERAT"@[GBY/QC]
X-HPDESK-TO: "A"@[[log in to unmask]]
Content-Type: text/plain;
Name="/HPOFFICE/NETMAIL/C0947488.txt"
Content-Disposition: inline;
Filename="/HPOFFICE/NETMAIL/C0947488.txt"
X-HPDESK-SUBJECT: Message text
Resent-Message-ID: <"aiyHd.0.fB3.snZVo"@ipc>
Resent-From: [log in to unmask]
X-Mailing-List: <[log in to unmask]> archive/latest/7370
X-Loop: [log in to unmask]
Precedence: list
Resent-Sender: [log in to unmask]
Would appreciate any source for info on effects on solderjoint
reliability when assembling (solderpaste / IR Reflow ) a full gold
(approx 30 microinches thick) finished board. What are the effects of
the gold alloying with the tinlead in the joint ? / Thank you.
***************************************************************************
* 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. *
***************************************************************************
***************************************************************************
* 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. *
***************************************************************************
***************************************************************************
* 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. *
***************************************************************************
|
|
|
