Whachoo talking about Willis?
I'm trying real hard not to take this too personally ;-/
-Chris
Bob Willis
<[log in to unmask]
.UK> To
Sent by: TechNet [log in to unmask]
<[log in to unmask]> cc
Subject
10/28/2009 02:57 Re: [TN] Birth of a Solderball
PM
Please respond to
TechNet E-Mail
Forum
<[log in to unmask]>
; Please respond
to
Bob Willis
<[log in to unmask]
.UK>
Not normally as part of the reason for the fault is the capillary action of
the non metal content of the paste taking metal particles under the chip
body. Different paste react differently.
Hey I don't want to get the reputation of being Mr Balls, people may say I
speak B--------------------
Bob Willis
2 Fourth Ave, Chelmsford, Essex, CM1 4HA England
Tel: (44) 1245 351502
Fax: (44) 1245 496123
Mobile: 07860 775858
www.ASKbobwillis.com
www.SolderingStandards.com
New Package on Package Workshops 24th November
www.ASKbobwillis.com/PoPWorkshops.pdf
PCB Inspection & Quality Control Workshop 3rd November
www.ASKbobwillis.com/faworkshops.pdf
Book Bob's "Step by Step Failure Analysis
Workshop"4th November www.ASKbobwillis.com/faworkshops.pdf
Package on Package Assembly & Inspection Workshops 21th January ITRI
www.ASKbobwillis.com/PoPWorkshops.pdf
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Leland Woodall
Sent: 28 October 2009 14:03
To: [log in to unmask]
Subject: Re: [TN] Birth of a Solderball
Bob,
Wouldn't mid-chip solder balls in SMT display slightly flat bottoms as
well?
Leland
-----Original Message-----
From: Bob Willis [mailto:[log in to unmask]]
Sent: Wednesday, October 28, 2009 8:54 AM
To: 'TechNet E-Mail Forum'; Leland Woodall
Subject: RE: [TN] Birth of a Solderball
You can only really tell from the shape.
Trying to microsection balls is fun, you get a great section then the ball
comes out during polishing. I use these images as how not to do sections in
my microsection class at college. Next time I am doing some sections I have
a board with some nice balls from selective that I have vacuum coated.
In selective and wave if the solder ball is still in a liquid state during
contact with the mask it can have a flat bottom. This is normal in air but
not nitrogen
Bob Willis
2 Fourth Ave, Chelmsford, Essex, CM1 4HA England
Tel: (44) 1245 351502
Fax: (44) 1245 496123
Mobile: 07860 775858
www.ASKbobwillis.com
www.SolderingStandards.com
New Package on Package Workshops 24th November
www.ASKbobwillis.com/PoPWorkshops.pdf
PCB Inspection & Quality Control Workshop 3rd November
www.ASKbobwillis.com/faworkshops.pdf
Book Bob's "Step by Step Failure Analysis
Workshop"4th November www.ASKbobwillis.com/faworkshops.pdf
Package on Package Assembly & Inspection Workshops 21th January ITRI
www.ASKbobwillis.com/PoPWorkshops.pdf
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Leland Woodall
Sent: 28 October 2009 11:54
To: [log in to unmask]
Subject: [TN] Birth of a Solderball
TechNetters,
Is there any possible way to determine the origin of a solder ball?
We've had a failure because of one, and we're trying to determine
whether it came from our SMT or wave soldering process.
We use SAC305 at both, so using the SEM to determine alloy composition
is not really helping.
The ball itself is spherical with no "tails" and quite shiny in
appearance.
If we cross section the ball, will we see a difference in grain
structure due to the differences in cool down rates? Is there anything
else we can use or do?
Thanks in advance for your help!
Leland
---------------------------------------------------
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
-----------------------------------------------------
This e-mail message is intended only for the use of the intended recipient(s).
The information contained therein may be confidential or privileged, and its disclosure or reproduction is strictly prohibited.
If you are not the intended recipient, please return it immediately to its sender at the above address and destroy it.
---------------------------------------------------
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
-----------------------------------------------------
|
