" Mr.Gross: I have to disagree with your statements regarding "dip"
processing of OSP's as "NOT good practice" compared to conveyorized
processing. Control of OSP immersion processing is not harder than
conveyorized. Chemical analysis and replenishment is basicaly the same.
Immersion processing can be used with a  timer/control system to obtain
repeatable chemical exposure times. Since chemistry doesn"t know up from down
or left from right full immersion creates a uniform reaction across the face
and top and bottom of the panel. Issues such as clogged nozzles, uneven spray
patterns, top/bottom impingement, chemical carry over, areation of chemistry
etc. are eliminated {flood head technology can help).I believe the big
advantage of conveyorized processing is it's ability to handle smaller routed
out parts.
        Both types of processing work well when setup and controlled
properly. Please don't confuse immersion processing with low tech vs. low
complexity. Poor control and quality are more a function of lack of
commitment than equipment :-)."

As a manufacturer of PCB`s with OSP I agree with what is written above
concerning " good quality " of horizontal processing compared to " bad
quality " of immersion process . I am facing this approach from customers QA
people . From their point of view " horizontal , conveyorized processing "
is synonime for quality . I just can say : if horizontal process is out of
spec , there is high degree of certainity , that the whole batch of PCBs
will out of spec . This is exectly like a spirit of ISO 9000 : if You have
nice written but wrong procedure You have 100% certainity , that all
products will end-up in the scrap basket .


Edward Szpruch
Eltek Ltd - Israel
Tel  972 3 9395050
Fax 972 3 9309581
E-mail :  [log in to unmask]