I suspect a lot since all of the work on solderability/reliability in regard
to wetting angles was done many years ago.
Is Werner on the forum?
John
John Burke
(408) 515 4992
-----Original Message-----
From: Paymon Sani [mailto:[log in to unmask]]
Sent: Friday, March 30, 2007 10:15 AM
To: TechNet E-Mail Forum; John Burke
Subject: RE: [TN] Solder Resist Encroachment onto BGA pads
Thank you John, is there any studies on this?
Paymon
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of John Burke
Sent: March 30, 2007 12:45 PM
To: [log in to unmask]
Subject: Re: [TN] Solder Resist Encroachment onto BGA pads
Actually yes.
If you put solder resist over the lands for the BGA you have by
definition a
joint defined by the resist system.
Effectively this will give you a 90 degree wetting angle which is - you
guessed it a stress riser.
So a joint with solder mask defined joints will be more liable to crack
under stress.
John
John Burke
(408) 515 4992
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Paymon Sani
Sent: Friday, March 30, 2007 9:02 AM
To: [log in to unmask]
Subject: [TN] Solder Resist Encroachment onto BGA pads
Hello All,
Does anybody know why IPC does not allow any solder resist encroachment
onto the BGA copper defined lands for PCBs?
------------------------------------------------------------------------
----
-----------
Confidentiality Notice
This e-mail and any attachment(s) are intended for the individual or
entity
to which this email is addressed and may contain information that is
confidential. If you are not the intended recipient or an employee or
agent
responsible for delivering this e-mail to the intended recipient, please
be
aware that any dissemination, distribution or copying of this
communication
is strictly prohibited. If you have received this in error, please
notify
the sender by telephone at 604.430.4336 or by return e-mail, and please
delete or destroy all copies of this communication. Thank you!
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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 15.0
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
-----------------------------------------------------
----------------------------------------------------------------------------
-----------
Confidentiality Notice
This e-mail and any attachment(s) are intended for the individual or entity
to which this email is addressed and may contain information that is
confidential. If you are not the intended recipient or an employee or agent
responsible for delivering this e-mail to the intended recipient, please be
aware that any dissemination, distribution or copying of this communication
is strictly prohibited. If you have received this in error, please notify
the sender by telephone at 604.430.4336 or by return e-mail, and please
delete or destroy all copies of this communication. Thank you!
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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
-----------------------------------------------------
|