To Technet 

Soldering of mixed technology boards:
   I have a problem in which the SMDs show random opens at the solder joint
after the wave soldering of the components that go into the holes.

   The SMD solder connections that are most likely to have opens are those
which have a short heat path thru the via holes to a land that contacts the
solder wave.

   Suggestions have been:
      (1)  Tent or plug all of the holes that contact the wave except
             those that have lead in the hole.

       (2)  Use a nitrogen blanket during wave soldering

       (3) Flood the top side of the board with flux during wave
                        soldering so that any connection that is reflowed
does              not oxidize and will form a new solder joint.

       (4) After wave soldering, flood the top side of the board with
                    flux and reflow it.

Is there any other solutions,  the nitrogen blanket is a long term fix for
the assembly shop but not a present fix.

Thanking you in advance for any solutions 
Phil Hinton
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