>From my understanding the Ohmegameter was design to measure residues left behind from the use of rosin fluxes. The solvent was chosen to dissolve the rosin and measure the change in conductivity of the solution based upon the amount of activators remaining on the product. It was also design to see how clean the board was in relation to its preparation to be conformal coated. It was not originally design to check if any electrical failures would occur if the product was dirty with flux. We did experience your dilema some time ago when we converted from Rosin to water soluble fluxes. Many inconsistent readings and all that stuff. The bottom line was that the residues from the water soluble fluxes were not soluble in the Ohmegameter solution, therefore they did not change the conductivity of the solution. This proved to be a major problem as these residues were susceptible to absorbtion of moisture and could and would cause electical failures of the product. Another issue we found was the ability of the solution to dissolve some of the bromides in the FR-4 material, which also changed the readings. So the bottom line is another method had to be developed or utilized which would in fact check for contaminant which would be detrimental to the electrical functionality of the product. I recommend the use of SIR testing at various humidity and temperature levels to see if the flux residues left behind will be detrimental to your product. IPC has test coupons which could be used for this analysis and I believe ALPHA Metals has a piece of equipment which could be used to measure the results. When you do conduct SIR testing make sure you have a control sample, two samples processed, one which is cleaned and one which is not cleaned to get comparative information. Good luck Leo Lambert EPTAC Corp. At 03:09 PM 2/14/97 -0600, [log in to unmask] wrote: > > > > > >Charles Barker >02/14/97 03:09 PM > >We are investigating switching from RMA and SA based fluxes to WS fluxes. >We notice much higher and inconsistent Ohmegameter readings with the WS >fluxes. Is there a better means of measuring Ionic contaminants when using >WS flux? What are others using to check how "clean" a WS processed assembly >is after wash? > >Thanks in advance. > >Charlie Barker > > >*************************************************************************** >* TechNet mail list is provided as a service by IPC using SmartList v3.05 * >*************************************************************************** >* To unsubscribe from this list at any time, send a message to: * >* [log in to unmask] with <subject: unsubscribe> and no text. * >*************************************************************************** >* If you are having a problem with the IPC TechNet forum please contact * >* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * >*************************************************************************** > > > *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************