Blowhard, trying to make us believe you went through hail and back to
get these posted. We do appreciate it, but I couldn't open these. It
sent me to create my own web-page. That's just what the world needs; my
own web-page.
Take care.
Dewey
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory
Sent: Friday, June 12, 2009 11:10 AM
To: [log in to unmask]
Subject: Re: [TN] Corner ball pad cratering
Hi again Genny!
Got your pictures posted now. We had quite a severe thunderstorm out
here earlier! Sky looked like it was night with an eery greenish tint to
it, had some 60-mph straight line winds and just to the west of us in a
town called Stillwater they had baseball sized hail! Several hundred
cars were damaged from what I heard on the radio! Thanks goodness the
hail missed us!
What were we talking about? Oh yeah, your pictures ;^) go to:
http://stevezeva.homestead.com/files/Cross-Section_laminate_crack_bright
_100x.jpg
http://stevezeva.homestead.com/files/Cross-Section_laminate_crack_bright
_200x.jpg
Steve
-----Original Message-----
From: Genny Gibbard [mailto:[log in to unmask]]
Sent: Friday, June 12, 2009 11:12 AM
To: Steve Gregory; TechNet E-Mail Forum
Subject: RE: [TN] Corner ball pad cratering
As always, Steve, you are a wealth of information. That article is
perfect, thank you. This seems to mirror what Amol said about doing a
1/4 of the length. This article said to do an L shaped bead 2-6 balls
along each corner side.
Here are some photos to post. Would you oblige?
BGA is 40mm per side. PCB is ~1 ft sq. A little bigger than what is
found in the typical blackberry, I think... Ball pitch is 1.27mm.
We believe the cause is mechanical, not thermal.
Thanks everyone.
Genny
-----Original Message-----
From: Steve Gregory [mailto:[log in to unmask]]
Sent: June 12, 2009 6:35 AM
To: TechNet E-Mail Forum; Genny Gibbard
Subject: RE: [TN] Corner ball pad cratering
Morning Genny,
Since you said you were going to look at corner bonding, here is a
really good article (if you haven't seen it already) that Michael
Kochanowski from Intel and Brian Toleno from Henkel did about it:
http://www.trafalgar2.com/documents/Technical_Articles/6.09-kochanowski.
pdf
Steve
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Genny Gibbard
Sent: Thursday, June 11, 2009 3:10 PM
To: [log in to unmask]
Subject: [TN] Corner ball pad cratering
Hello all,
If you have identified a BGA with corner ball pad cratering, what would
be your suggestions to correct this condition?
Our thoughts:
1. We plan to evaluate our handling processes to reduce/remove
excessive flex/strain occurring around this part 2. We plan to evaluate
corner bonding or underfilling for the BGA.
Which do you feel would be the best direction to go? Do you have other
suggestions?
Thanks in advance for all your help
Genny
---------------------------------------------------
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
-----------------------------------------------------
---------------------------------------------------
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
-----------------------------------------------------
|
