If the Polarity is reversed there will still be current flowing as the ions migrate in the glass but no bonding will occur. Shay -----Original Message----- From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] On Behalf Of Brubaker Chad Sent: Tuesday, March 11, 2008 12:21 AM To: General MEMS discussion Cc: Brubaker Chad Subject: RE: [mems-talk] fialed in borofloat-si bonding? As others have commented, the reason for no bonding is no current. This can be due to three possible causes: 1 - Too much resistance in the stack - thick oxide is the most likely reason. 2 - Open circuit - make sure that your potential source is actually in direct contact with your stack. 3 - proper polarity - make sure that you are net negative potiential to the glass - easiest way is to have the silicon attached to a ground, and apply a negative potential to the glass. What kind of bonding system (if any) are you using? This may be something as simple as an electrode out of position. Best Regards, Chad Brubaker