-----Original Message-----
From: Fulton Feng <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Tuesday, July 28, 1998 11:38 AM
Subject: [TN] Solder-ball


>
>Hi, TechNetter
>I am wondering anybody out there ever experienced solder ball with
mis-print
>PCB. The scenario is when we have  mis-printed PCB in solder paste printing
>process, we used to wipe off the paste with alcohol from the PCB surface
and
>send them to aqueous cleaner. What happened is when we looked at the PCB
>under microscope, we found all the masking edge and vias  sticked with
>solder-balls(Solder paste). The solder paste we used was no-clean
>water-soluable paste. The questions are:
>*        Is there any difference in between clean and no-clean paste for
>cleaning PCB?
>*        Has anybody used ultra-sonic cleaner for PCB cleaner?
>*       What kind of cleaning agent are your guy using?
>*       Any different approach to take care of this solder-ball issue?
>Any input is appreciated!
>
>Thanks in advance!
>
>Fulton Feng
>Nortel
>MPK
>
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Fulton,

If you're using a water clean paste, wipe off the misprint with water, not
alcohol.

                                                                   Frank
Komitsky, Jr.

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