It the material BT/Epoxy or real "straight stuff" BT (Like Mitsubishi)? They process differently. DHH ______________________________ Reply Separator _________________________________ Subject: BT desmear Author: [log in to unmask] at SMTPLINK-HADCO Date: 2/28/96 6:10 PM Does anyone have information concerning desmear requirements for BT laminate material. Is plasma the only system available ? To what degree does BT smear in the first place, some chemical suppliers have stated that BT does not smear. There seems to be consensus from chemical suppliers that permanganate does not significantly attack BT, but of the many board fabricators poled, most use a modified permanganate cycle for desmear. Any information about this would be appreciated. thank you,