http://www.circuitrework.com/guides/5-0.shtml from Circuit Technology Center describes some methods.  IPC-7711/7721 has repair and rework methods. IPC-6012 says that any repair is AABUS.  Louis Hart

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

From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Golemme

Sent: Friday, November 11, 2016 2:14 PM

To: [log in to unmask]

Subject: [TN] Fixing Cracked via holes



We have a couple of expensive first time build boards that failed ICT in assembly due to what appears to be cracked vias. Adding solder to the via hole seems to fix the issue.



What are folks thoughts on plugging vias with solder to fix them? What risks are we taking by adding solder vs another technique? Could folks recommend alternate repair techniques that may provide better thermal/vibration?



Also, I'd love to hear up alternate possible root causes? This problem screams insufficient plating during fab or thermal shock during assembly, but I'd like to investigate all possible failure modes. This is a multi-layer double sided SMT + wave rigid-flex PCB and the cracking is on the rigid portion.



Thanks,

Stephen Golemme

Manufacturing Engineer, Makani

650-214-5647

solveforx.com/makani