🚀 go-pugleaf

Need some soldering advice....

I have a situation here where we are soldering a solid copper wire
into a nickel-plated cup-pin.  The pin cup is a blind hole, that is
no outlet .
 The way we are doing it is to fill the pin cup with the correct amount of
solder paste then install the copper wire and pass this under a 
propane flame for a specified amount of time ( depends on solder, etc)

This part goes into a microphone assembly and must have continuity, ofcourse.

We are using a 60/40 solder with a AC flux, however the AC flux is
organic ( non rosin ) halide.

 The question is corrosion.  In the past, everything ( literature ) has
said do not use AC flux in a electronic application due to the great
potential for corrosion, however, it appears now there are some guides
saying it's ok to use the "organic" AC fluxes.  

WE are having a problem with these connections coming loose at the
solder joint.  

IS corrosion to blame?

How can we determine it?  It seems to get worse over time but that is
very subjective right now because we can't say if the joint was done 
properly a year ago or not.  IS THERE A WAY TO CHECK THE JOINT FOR
CORROSION??

Thanks for any help you can provide.

Mack
US ARMY
ABERDEEN PROVING GROUND.
mdgoodma@crdec8.apgea.army.mil
.