I concur completely with Dave. I can "prove" it otherwise, by photomicrograph of one at the edge of the device and a CT of another. I'll request Steve G. to post these as well. FYI, what caused these is the devices are custom and aged quite nicely by the previous CM that failed to store them properly. The solution was to "prep" the parts remaining by coating with W/S tacky flux, reflow, wash, then place. Worked great! Ed Popielarski Engineering Manager 970 NE 21st Ct. Oak Harbor, Wa. 98277 Ph: 360-675-1322 Fx: 206-624-0965 Cl: 949-581-6601 https://maps.google.com/maps/myplaces?hl=en&ll=48.315753,-122.643578&spn=0.011188,0.033023&ctz=420&t=m&z=16&iwloc=A -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman Sent: Wednesday, May 01, 2013 6:01 AM To: [log in to unmask] Subject: Re: [TN] Pic of head-in-pillow for the site Hi George - that specific BGA was quite large so optical inspection access to see the outer row was pretty minimal which is why we used Xray assessment. I have had the same success as Ed in finding HOP defects - Xray won't find them all but it can do a fair job most of the time especially if you have any form of CT capability or oblique angle viewing. We used cross sectioning to confirm what we had found using Xray assessment. I'll sent the photo to Steve for posting. And we are in agreement on the inspection methodology - we use xray assessment only when optical inspection isn't value added or we suspect that our BGA process control protocols have been compromised. Dave From: "Wenger, George M. [Contractor]" <[log in to unmask]> To: <[log in to unmask]> Date: 04/30/2013 08:20 PM Subject: Re: [TN] Pic of head-in-pillow for the site Sent by: TechNet <[log in to unmask]> Hi Dave, I'm really not a Doubting Thomas and I do believe you (because I know you) that the x-ray is of a HOP defect but I think it would be helpful to say how you know for sure that the x-ray shows a HOP defect. I assume you know it is a HOP defect because you looked at it optically (i.e., with a mirror or fiber scope) and saw it was a HOP defect or you cross sectioned it an confirmed it was a HOP defect. Do you have an optical image or photomicrograph of a cross section of the defect shown in the x-ray image? The problem we've had with x-raying large high I/O count BGAs is that time consuming to scan all of the balls at a high enough magnification to find the balls that appear different from normal solder joints and once we identify the non-normal looking balls we not sure if the defect is a HOP or a non-soldered interconnection due to a solder paste stencil misprint or insufficient print. When the defects are on outer rows we can usually tell by optical inspection what kind of defect it is. Regards, George George M. Wenger Failure Signature & Characterization Lab LLC 609 Cokesbury Road, High Bridge, NJ 08829 (908) 638-8771 Home (732) 309-8964 Mobile E-mail: [log in to unmask] [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman Sent: Tuesday, April 30, 2013 5:10 PM To: [log in to unmask] Subject: Re: [TN] Pic of head-in-pillow for the site Yes, the corner ball has the HOP. Dave From: "Steve Gregory" <[log in to unmask]> To: <[log in to unmask]> Cc: <[log in to unmask]> Date: 04/30/2013 04:08 PM Subject: RE: [TN] Pic of head-in-pillow for the site Hi Dave! Have your picture posted, it?s here: http://stevezeva.homestead.com/HOP_iso1.jpg It?s the corner ball, right? Steve Gregory From: [log in to unmask] [mailto:[log in to unmask]] Sent: Tuesday, April 30, 2013 12:43 PM To: Steve Gregory Subject: Re: [TN] Pic of head-in-pillow for the site Steve - please post this HOP too - same type of thing as Ed's but another example for everyone benefit: Dave From: Steve Gregory <[log in to unmask]> To: <[log in to unmask]> Date: 04/30/2013 10:56 AM Subject: Re: [TN] Pic of head-in-pillow for the site Sent by: TechNet <[log in to unmask]> Hi Ed! Nice image! Got it posted, it's here: http://stevezeva.homestead.com/Head-in-pillow_X-Ray.JPG What about the void off to the right? Is there any concern about that? Steve Gregory Process Engineer Kimco Design and Manufacturing 652 N. Five Mile Road Boise, ID 83713 (208) 322-0500 Ext. 3133 From: Ed Popielarski [mailto:[log in to unmask]] Sent: Tuesday, April 30, 2013 8:58 AM To: Steve Gregory Subject: Pic of head-in-pillow for the site Hi Steve, I have a good X-Ray picture of a head-in-pillow that Leland would find helpful. If you don't mind posting it for him? Ed Popielarski Engineering Manager 970 NE 21st Ct. Oak Harbor, Wa. 98277 Ph: 360-675-1322 Fx: 206-624-0965 Cl: 949-581-6601 https://maps.google.com/maps/myplaces?hl=en&ll=48.315753,-122.643578&spn =0.011188,0.033023&ctz=420&t=m&z=16&iwloc=A <https://maps.google.com/maps/myplaces?hl=en&ll=48.315753,-122.643578&sp n=0.011188,0.033023&ctz=420&t=m&z=16&iwloc=A> ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. 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