A fully-packaged electromagnetic microrelay

Fully integrated electromagnetically actuated micromachined relays have been successfully fabricated and have been enclosed in ceramic and plastic packages. A multilayer Cu coil is used to actuate a movable NiFe armature, thereby closing the Au contacts. With the current design, magnetic forces of around 1 mN can be achieved. The fabrication process starts with two chips, which, after processing, are flip-chip bonded together using a low-temperature (<350/spl deg/C) solder joining process. The electrical contacts are housed in a hermetically sealed cavity with a predetermined atmosphere. The relay size is about 5/spl times/4/spl times/1 mm/sup 3/ (excluding the package). Typical performance characteristics of the packaged relay include: ON-resistance of 0.4 /spl Omega/, OFF-resistance greater than 10/sup 13/ /spl Omega/, life under low level load of 10/sup 7/ cycles, operate time of 1 ms, and, actuation voltage, current and power of 2 V, 8 mA and 16 mW, respectively.