Sender: |
|
X-To: |
|
Date: |
Tue, 24 May 2005 15:19:34 -0500 |
Reply-To: |
|
Subject: |
|
MIME-Version: |
1.0 |
Content-Transfer-Encoding: |
quoted-printable |
Content-Type: |
text/plain; charset="us-ascii" |
From: |
|
Parts/Attachments: |
|
|
This appears to be contaminants creating voids inside of the vias. I do
not think it is from outside applications of solder, such as from wave
soldering, as the voids appear to be concentrated within the via and are
not seen in the solder joints on the surface of the board. This appears
to be caused by ablation or plating residues left inside the vias after
fabrication. These contaminants will also cause the blistering seen near
the surface.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Werner Engelmaier
Sent: Tuesday, May 24, 2005 3:08 PM
To: [log in to unmask]
Subject: Re: [TN] Solder Joint Anomaly
Hi All,
This is why people tent or fill their vias with soft polymer. These
voids create stress risers at the Cu barrel walls--not a real problem
for benign operating environments, but the death knell in severe
conditions.
Regards,
Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL 32174 USA
Phone: 386-437-8747, Fax: 386-437-8737, Cell: 386-316-5904
E-mail: [log in to unmask], Website: www.engelmaier.com
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e To
unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or
(re-start) delivery of Technet send e-mail to [log in to unmask]: SET
Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the
posts: send e-mail to [log in to unmask]: SET Technet Digest Search the
archives of previous posts at: http://listserv.ipc.org/archives Please
visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for
additional information, or contact Keach Sasamori at [log in to unmask] or
847-615-7100 ext.2815
-----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------
|
|
|