TECHNET Archives

1996

TechNet@IPC.ORG
Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
Re:Re:Re: silver vs. HASL/OSPs
From:
Bill Dieffenbacher <[log in to unmask]>
Date:
Fri, 13 Dec 1996 02:26:20 -0600
Content-Type:
text/plain
Parts/Attachments:
text/plain (51 lines) 
Werner,

I agree with your response to Frank.  But have a question; how do you assure
that you have good wetting to the base metal surface when good wetting is
visually apparent?  Are there any subtle aspects of the appearance we should
be looking for?

Bill Dieffenbacher


At 10:56 AM 12/13/96 -0500, you wrote:
:Frank,
:Please do NOT call silver, or any other surface finish 'highly solderable'.
:Surface finishes are NOT soldered to; they certainly promote the flow of
:solder across the surface that the surface finishes cover, but the surface
:underneath the surface finish need to be solderable and wetted to. These
:highly soluble (in tin) surface finishes (gold, silver, sometimes copper) are
:very thin and go into solution with tin almost instantaneously. These surface
:finishes can be dangerous, because they give the appearance of good wetting
:whether or not good wetting has taken place. You can get good coverage this
:way without good wetting to the base metal underneath.
:
:Werner Engelmaier
:Engelmaier Associates, Inc.
:Electronic Packaging, Interconnection and Reliability Consulting
:23 Gunther Street
:Mendham, NJ  07945  USA
:Phone & Fax: 201-543-2747
:E-mail: [log in to unmask]
:
:
:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Bill Dieffenbacher		   Tel. (607)770-2961
Lockheed Martin Control Systems	   Fax. (607)770-2056
600 Main St.  Room R52F            email [log in to unmask]
Johnson City, NY  13790
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

***************************************************************************
* 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.        *
***************************************************************************
* 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]      *
***************************************************************************

ATOM RSS1 RSS2