Marvin, In the past with conventional DC plating, the results of many DOE's and practical experience has lead us to rate many factors with respect to their affect on plating distribution: From our experience (rating the factors on a scale of 1-10, with 10 having the most significant weighting) 1. PWB pattern design 10 2. Rack design 10 3. cathode current density 8 4. Anode Cathode/config 7 5. air agitation/sol. Flow 7 5. board agitation(through hole) 7 6. Sol. Composition 7 7. Organic addition agents 5 8. Solution contaminants 3 You can try installing eductors for instead of air agitation. (object is to get laminar solution flow across the panels) Pulse plating may be an option. Raise the acid to copper metal ratio to between 12 to 15 to 1. Cathode cd not to exceed 15ASF. Reduce anode to cathode area. Try slab anodes instead the nugget type. Good luck, Mike -----Original Message----- From: Geoff Layhe [SMTP:[log in to unmask]] Sent: Tuesday, August 31, 1999 8:04 AM To: [log in to unmask] Subject: Re: [TN] how to improve plating distribution 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 ############################################################## ############################################################## 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 ##############################################################