Hi Frank, Thanks for the feedback and kind words. You posed good questions. Unfortunately, I don't have answers to most of them. I don't know the board design details. I think this is a blocking cap on the drain side of a 200W RF transistor. -----Original Message----- From: Frank Kimmey [mailto:[log in to unmask]] Sent: Wednesday, September 06, 2017 12:14 PM To: TechNet E-Mail Forum <[log in to unmask]>; Giamis, Andy <[log in to unmask]> Subject: RE: Crazy Solder Andy, First question is What's a lot of RF power? I've seen where 125+ watts can vaporize solderjoints, copper traces, vias, etc. Even though you only measured 170C, I would not be surprised to find out the joint got much hotter very quickly and failed. Any clue as to where the missing solder went to (I expect not)? What size is the cap? How wide is your trace in and out? What is the finished copper weight? Great pics by the way. Good luck, FNK Frank N Kimmey CID+ Electrical Engineer / PCB Design VeriFone Inc 1400 W Stanford Ranch Road, Suite 200 Rocklin, CA 95765 USA W: 1-916-625-1818 M: 1-916-833-9877 [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Giamis, Andy Sent: Wednesday, September 06, 2017 9:25 AM To: [log in to unmask] Subject: [TN] Crazy Solder Hi TechNetters, Here’s something I have not seen before. I have seven different ‘theories’ for what’s happening here. Three of which do not involve mythical creatures, illegal substances or the alignment of celestial bodies. This capacitor is on a path that sees a lot of RF power. The unit went through 20 cycles of -70C to +115C while at nominal power. Temperature sensing suggests this device could be hitting 170C. No, we normally don’t test to these extremes. The PCB has ENiG finish and the solder is SAC. This is normal SMT, no rework. I think I know in general what happened, but I am surprised. I don’t have an explanation for the formation of the big pocket on the right. Has anyone ever come across any solder joints like this? Thanks Steve for uploading the pictures (links below). http://stevezeva.homestead.com/pockets_25.jpg http://stevezeva.homestead.com/Pockets_CS.jpg http://stevezeva.homestead.com/Pocket-left.jpg http://stevezeva.homestead.com/Pockets-right.jpg Best Regards, Andy Andrew C. Giamis Senior Failure Analysis Engineer CommScope 2601 Telecom Pkwy Richardson, TX, 75082, USA ********************************************************* This electronic message and any attachments are intended only for the use of the addressee. The information in this electronic message is confidential and proprietary, and may include privileged information. If you are not the intended recipient, please delete this electronic message and any attachments and notify the sender of the error. Please be aware that any unauthorized use, dissemination, distribution or copying of this message or any attachments is strictly prohibited.