Bill - Electrochemicals has done an extensive desmear and plating study of AlliedSignals Resin Coated Copper products. The RCC material being desmeared was not Polyimide but in the same family and desmears similiarly. Let me know if you would like a copy of this study off line. Kevin R. Thomas MicroVia Materials Manager Ph : 608.791.2288 Fax : 608.791.2428 E-mail : [log in to unmask] ---------- >>>From: Bill Chou >>>To: [log in to unmask] >>>Subject: [TECHNET] FAB- Post plasma Cleaning >>>Date: Tuesday, August 19, 1997 2:17PM >>> >>> >>> >>>I need advice or suggestion on cleaning process after laser drill via. >>> >>>We use YAG (UV range, 355 nm) to drill microvia in flex material >>>(Cu/polyimide/Cu). The Cu thickness is 0.2 um+ and polyimide is 1-2 mil >>>thick. Can anyone share your experience about cleaning (wet, dry,...etc.) >>>after laser drill and before metallization step (via fill)? The criteria >>>are >>>(a) maintain the adhesion between original Cu and polyimide without >>>delamination (b) good adhesion between etch via wall and metallization. >>> >>>Thank in advance. >>> >>>Bill Chou >>>Fujitsu Computer Packaging Technologies >>>(408) 943-7721 >>>Fax: (408)943-7790 >>>[log in to unmask] >>>