By specially trained eyes, you can detect HOP.  Of course, after you looked at few dozen of those good and bad side by side.  You do see a shadow for the HOP device.  

You need many cups of coffee to enhance your vision. You basically treat it as a ground hog. 

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

Sent using BlackBerry





----- Original Message -----

From: TechNet <[log in to unmask]>

To: [log in to unmask] <[log in to unmask]>

Sent: Tue Oct 06 14:18:42 2009

Subject: Re: [TN] BGA X-Ray Defect Detection Capabilities



Sounds like I’ve been led down a rosy pathway.  I thought these machines would do everything but serve you a cup of coffee.



 



Both of them were 3D with an option to inspect in 2D (or provide a combination of the two).  If the 3D option is utilized and indeed inspecting every solder joint on one BGA, can the machine be “tweaked” enough to assure we’ll catch all the opens, non-wets, and head-in-pillows?



 



If not, I’ve got to back up and punt, and the defensive line is bearing down quickly!  Are there any other suggested options (other than not building a defect in the first place)?



 



Nothing ever goes as planned…



 



Leland



 



From: [log in to unmask] [mailto:[log in to unmask]] 

Sent: Tuesday, October 06, 2009 1:44 PM

To: [log in to unmask]; Leland Woodall

Subject: Re: [TN] BGA X-Ray Defect Detection Capabilities



 



Hi Leland,

John Burke gave you good advice. Forget 2-D for the defects you are interested in, and 3-D is not much better except for some very specialized machines that look at SJs individually—bad part is of course, not very useful in mass production.

Werner



 



 



-----Original Message-----

From: Leland Woodall <[log in to unmask]>

To: [log in to unmask]

Sent: Tue, Oct 6, 2009 11:55 am

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 fi

nd 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



















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