Cleaning flux residue

X****Liu

673 1 Sep 23.2019, 17:54:44

I have been using a "no clean" flux paste for some surface mount work recently and it leaves a horrible sticky residue. I have tried removing it by placing the board in isopropyl alcohol and washing with a stiff conductive brush for several mins. after leaving the board to dry for several mins i am still left with a sticky residue. I read online that increasing the polarity of the solvent by adding some water to the IPA works well so I placed the board in a water/IPA solution and scrubbed again then removed the water with neat IPA. but after this I am still left with the same sticky residue. It will just not come off any ideas for removing this residue?