Question: We did some cross sectioning of solder joints on a PCB assembly and found some air bubbles trapped in the solder joints. Do you know if there is an IPC standard to specify the maximum allowable air bubbles or voids in a solder joint?
Answer: Air bubbles or voids are in all the solder joints ever made, in one form or another. At times they are filled with flux or soldering tinning fluids and other times they are caused by outgassing and they are simply a void with nothing in them.
The only documents that discuss this from an IPC perspective are IPC-A-610 in section 8.3.12 Surface Mount Area Array, IPC-7093 – Design and Assembly Process Implementation for Bottom Termination Components and IPC-7095C – Design and Assembly Process Implementation for BGAs
These are the documents that discusses voids in various types of solder joints regardless of whether they are plated through hole solder joints or surface mount solder joints.