Marvin, There are a LOT of factors to look at when you are trying to obtain and maintain good plating distribution. Here's a few quick ones to be going on with. I'm sure there'll be more. Solution agitation, espescially if the filtration uses the same pump. Air agitation Board movement Anode:cathode area ratio Anode;cathode distance Acid:copper ratio Anode dimensions relative to the board Connections Cleanliness of dry film developer solution Conductivity of direct metalisation if used. Pulse plating "Baffle plates" between anode & cathode Precleaning chemistry I guess none of the above will give you a big improvement on their own, but by improving and controlling each of them you should see a good overall improvement. Depending on your particular set-up I would go for solution agitation first. Hope this helps Geoff Layhe www.lamar-uk.co.uk > ---------- > From: marvin v. picardal[SMTP:[log in to unmask]] > Reply To: TechNet E-Mail Forum.;marvin v. picardal > Sent: 31 August 1999 22:24 > To: [log in to unmask] > Subject: [TN] how to improve plating distribution > > TECHnet'rs, > Greetings!!! PCB Geniuses > > I want to gather suggestions regarding items to be considered to > maintain even distribution for copper plating. So far I have already > evaluated the effect of board spacing, organic chemical dosage > control, tank design modification. But the result shows only few > developments. > > Other related principles such as that of mass transfer would be of > great help. > > thank you. > > > Marvin > Chemical Engineer > PWB > > ############################################################## > TechNet Mail List provided as a free service by IPC using LISTSERV > 1.8c > ############################################################## > To subscribe/unsubscribe, send a message to [log in to unmask] with > following text in > the body: > To subscribe: SUBSCRIBE TECHNET <your full name> > To unsubscribe: SIGNOFF TECHNET > ############################################################## > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for > additional > information. > If you need assistance - contact Gayatri Sardeshpande at > [log in to unmask] or > 847-509-9700 ext.5365 > ############################################################## > ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################