Whoa, Kelly! Saponifiers and polyimide flex are a big No! No! combination. That is, unless you want to etch holes in the substrate. OK, I may exaggerate, but polyimide is chemically degraded at pHs above about 9,5. My recommendation: water-soluble flux/paste (not too aggressive), hold flexes in fixtures with stainless springs looped in holes for that purpose, so that they remain taut, load fixtures in baskets at c. 20° to the vertical, high-throughput batch washer (not dishwasher, unless you have very low throughput of just a couple of circuits per hour), dry in machine with rotary air knives. This will comfortably meet all specs without damage. Brian "Kelly M. Schriver" wrote: > Hi Nancy - > > To begin with, the cleaning media is driven by the particular flux you are > using. This, in turn, will drive the issue of what equipment you may be > able to use for the process. I have had good success removing RMA residues > from flex circuits with quite a number of blended solvents in vapor > degreasers and conveyorized spray systems. Size of the flex assembly must > obviously be considered - there are a number of suppliers who can provide > cleaning baskets to restrain small flexes for processing thru conveyorized > cleaning systems. Manual cleaning would not be my first choice if I were > dealing with a high reliability article, particularly if it were to be > conformal coated. > > Another possibility might be one of the saponifiers, in either a heated bath > or a "dishwasher" type system. > > If you are not currently using a low residue ("no clean") flux, might that > be a possibility? If this is a consideration, and you plan to conformal > coat or use adhesives on the assembly, be sure to verify full compatibility > of the flux residues and the specific coating material you intend to use > before proceeding. > > Contact me directly if I can be of assistance. > > Regards - Kelly > > -----Original Message----- > From: Nancy M. H. Holloway <[log in to unmask]> > To: [log in to unmask] <[log in to unmask]> > Date: Tuesday, January 04, 2000 10:57 AM > Subject: [TN] cleaning flex circuits > > >TechNet, > > > > What is the best technique to clean flux off of a polyimide flex circuit > >after population? Thus far, we have been cleaning the flex circuits with > >alcohol but it is time consuming and tedious. We use a machine to clean > >rigid boards, but I am hesitant to use it for our flex circuits. How are > >you all cleaning your soldered flexible printed circuit boards. > > > > Thanks, > > Nancy > > > >############################################################## > >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 ##############################################################