Ultrasonic cleaning will not work. You may have some luck with bleach at about 60C but the best way to clean carbonacious debris is with an oxygen plasma. Use an RIE or barel asher. For RIE 200-300 mTorr and 200-300 watts RF works well. You might still have problems with the high aspect ratio holes, i.e. the 20um ones, so you might need to increase the pressure still more for those. -Mike Martin U of Louisville >>> oliver77@ms24.url.com.tw 11/25/2004 11:53:19 AM >>> Hello I am looking for a method to clean the holes' walls of polyimide and Mylar films. The holes was drilled by excimer laser. The diameters of holes are in 20um~125um. PI or Mylar film's thickness is 100um. There are debris , carbine and carbon black sticking on the surface and wall of holes. I have tried to clean them with acetone . But obviously I cannot reach the wall of the holes. Can ultrasonic cleaning work it out? How much should be power and frequency of the ultrasonic cleaner ? Is there any kind of solvent can help to clean them? Thanks in advance Oliver Tseng Project Manager K-Jet Laser Tek. Inc. www.kjet.com.tw Taiwan _______________________________________________ MEMS-talk@memsnet.org mailing list: to unsubscribe or change your list options, visit http://mail.mems-exchange.org/mailman/listinfo/mems-talk Hosted by the MEMS Exchange, providers of MEMS processing services. Visit us at http://www.memsnet.org/