Greg : It may cause a problem if you leave part of the resist behind and try to laminate, if enough remains you will experience reduced bond strength, Theoretically if only the adhesion promoter remained it would help with adhesion of the prepreg. There is more than a good chance however that there is some of the resist polymer still on the surface in addition to the adhesion promoter. A test I have seen used is Silver nitrate ( 1 N or less) sprayed on the surface with an atomizer, if there is no color change then the surface has something there . It might be difficult to see with DT , but you could give it a try. Other than that you could try FTIR , (use a Multiple internal reflection plate , allows sampling solid surfaces with low concentrations of samples if you can't get good spectra) . You might also try a NANOSPEC. works with very small samples. A few processing tricks you might try are lower the lamination temperature slightly ,and or Expose to a lower step. To remove the resist if it really locks on , try soaking in 10% H2O2 for a few minutes than run through the stripper . One more thing you might run into is in some resists if you run the concentration of the stripper to high , you can run into stripping problems. ---------- From: triprod.gtriggs To: [log in to unmask] Subject: [TN] Stripping of Photoresist Date: Friday, October 20, 2000 2:22PM All, Any thoughts out there regarding the stripping of a alkaline etch resist from reverse side treated foil. We seem to be leaving some of the adhesion promotion system on the board. Does this cause a problem downstream ? Can it be tested for ? How ? We use a stripper based on MEA and Choline. Would this be the correct call ? Thank you in advance. Greg Triggs Tritek Circuit Products --------------------------------------------------------------------------------- TechNet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF TECHNET Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------