SPC can be applied to a great many areas of PCB assembly. I have brought in
Process Control on solder temperature of the wave solder as well as Sn/Pb
concentrations of the solder. Temperatures of all cleaning solutions (prozone
etc.). As well as that, I,m currently experimenting with attribute charts for
solderability (defects) of boards and board cleanliness results (using an
ionograph).
I am sure there are even more processes I can introduce the technique to (once
I begin snooping).

Martin Farrell (Chemist)
GEC-Marconi Avionics,
Edinburgh.