Vacuum packaging technology using localized aluminum/silicon-to-glass bonding

A vacuum package based on localized aluminum/silicon-to-glass bonding has been successfully demonstrated. With 3.4 watts heating power, /spl sim/0.2 MPa applied contact pressure, and 90 minutes wait time before bonding, vacuum encapsulation at 25 mtorr can be achieved. Folded-beam comb drive /spl mu/-resonators are encapsulated and used as pressure monitors. Long-term testing of un-annealed vacuum-packaged /spl mu/-resonators with a Q of 2500 has demonstrated stable operation after 20 weeks. A /spl mu/-resonator with Q of /spl sim/9600 has been vacuum encapsulated and shown to be stable after 7 weeks.