Of course both the X-ray system and man plays a big role (Experience
Operator Count) in determining the process/defect. X-ray provides
data/information, while human analyses the information. 

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Rex Waygood
Sent: Wednesday, 7 October 2009 3:13 PM
To: [log in to unmask]
Subject: Re: [TN] BGA X-Ray Defect Detection Capabilities

I consider that an x-ray machine is at its worst looking for opens. We
use a 2D machine with a good oblique view capability. I don't recall it
ever picking up an open (with the correct ball there!) in routine
inspection. What tends to happen is that the machine gets used in
diagnostics and the test engineers narrow down the area of BGA that
might be a problem and then a couple of our experts go through the
joints one by one at all angles looking for the lack of signs of
wetting. It is all very subjective.
Rex  

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Leland Woodall
Sent: 06 October 2009 16:56
To: [log in to unmask]
Subject: [TN] BGA X-Ray Defect Detection Capabilities

Everyone,

I just came back from an X-ray vendor qualification trip, and of course,
have a few questions for my professional peers.

Both vendors experienced problems reliably detecting opens and non-wets.
I really didn't expect to see this, as I thought these would be two of
the most common defects seen among BGA users.  We had to leave boards at
both facilities so they could further develop their algorithms.

We were not able to create a head-in-pillow defect, and thus, were not
able to check their machines for this.  They also had no sample boards
that carried such an anomaly.  Is this another defect that is difficult
to detect, and must one utilize a 3D machine in order to find it
(assuming the machine is capable of both 2D and 3D inspections, and
there are no components beneath the BGA)?

Are there any other caveats you might be able to provide?  Our list of
questions and qualification efforts were extensive, but I'm certain we
missed something.  I just hope whatever it was fell outside of being a
critical item...

Thanks in advance,

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
-----------------------------------------------------