Hi Pradeep,
Hand soldering has been there for many ages & will be there for selected
devices by selected manufacturers. But high volume manufacturers who can
afford automated systems - IR reflow, wave-soldering, selective
soldering, dip soldering etc., will be used by these manufacturers, all
these are controlled operations in terms of temperature, dwell time,
contact time, soldering technique etc., whereas hand soldering is very
subjective, it depends on the skill of the operator performing the
soldering operation, which point they contact the board or the component
& the effect it would have either on the board or component itself.
On the whole hand soldering especially the SMD's is not advisable & it
is not a reliable & repeatable process, you would tend to have hole wall
pull away, localized delamination, pad lifting etc.,
Thanks & Best Regards,
Krishnan C
SANMINA-SCI
Quality Assurance Manager
E-mail: [log in to unmask]
Phone (Off): (6) - 082-363000 Ext. 1602
Mobile: (6) - 012-8888-379
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Pradeep
Sent: Saturday, March 18, 2006 12:27 PM
To: [log in to unmask]
Subject: [TN]
Importance: High
This is Pradeep from Micropack Limited, India, fabricators of high layer
count MLB's
Few of our customers are following hand soldering of multilayer PCB's
for both through hole components as well as SMD's. Couple of stray cases
of failure of the PTH has been reported and the analysis shows this has
happened only for hand soldered boards.
Few of my queries are
1. The separation is mostly on the adjacent layer to the outer
layers.
2. Why is that it is happening only for hand soldered boards
3. Somebody can help us with some reference articles on the
advantages and disadvantages of both hand soldering as well as machine
soldering.
4. The customer keeps telling that the soldering operator is trained
and with 'years of experience' and can not make a mistake!
He keeps soldering the the pads one by one, evenif the pads are
adjacent ones. We feel by doing so, the area is getting
heated up to higher levels which can be avoided by soldering the pads
which are not close sequentially
Rgds
Pradeep
Micropack Limited
---------------------------------------------------
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
-----------------------------------------------------
________________________________________________________________________
_____
Scanned by Sanmina-SCI eShield
________________________________________________________________________
_____
_____________________________________________________________________________
Scanned by Sanmina-SCI eShield ________________________________
---------------------------------------------------
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
-----------------------------------------------------
_____________________________________________
|
