Our experiences are in line with this. OSPs applied with dip processes
have generally been better than those which were applied with conveyorized
processes. By "better" I mean "more consistent and less prone to having
unsolderable features".
Regards,
Greg Bartlett
Mercury Computer Systems
Chelmsford, MA
[log in to unmask]
----
Michael Barmuta wrote:
> 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 :-).
> Regards
> Michael Barmuta
> Staff Engineer
> Fluke
Electronics
> Everett Wa.
> 425-356-6076
>On Sat, 9 Aug 1997 05:32:45 -0700 [log in to unmask] wrote:
>
>> From: [log in to unmask]> Date: Sat, 9 Aug 1997 05:32:45 -0700
>> Subject: Re: [TECHNET] FAB: OSP COATINGS
>> To: [log in to unmask]
>>
>> I agree with the cost issue..however, to apply an OSP with
>> "dip" tanks and the like is NOT good practice. It's too
>> hard to control the process. A conveyorized timed process
>> will gaurantee coverage, quality, etc. At one time, the
>> supplier of the materials would not sell to anyone who did
>> not have proper controls. I don't know what the situation is
>> today.
>
>
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