Design and development of LTCC based package for 3-axis packaging of MEMS sensors

Abstract

There is a wide range of applications for Micro Electro Mechanical Systems (MEMS) based devices which are used in automotives, aerospace, mobile communication etc. Sensor fabrication and its packaging are very closely connected for reliable functioning of the module. Packaging for MEMS based devices should necessarily provide mechanical support, environmental protection and of course the electrical interconnections to the device. Low temperature co-fired ceramic (LTCC) technology is widely used for packaging of MEMS devices and sensors. Being machinable at green stage LTCC offers the flexibility of structuring for customized package design. This paper attempts to develop LTCC based package for 3-axis packaging of MEMS based sensors. For sensors like accelerometer where 3-axis measurement is required in many applications either the device needs to be fabricated in such a manner that it can detect acceleration in 3-axis or the single axis sensitive device may be packaged in such a way so that the packaged module may detect acceleration in 3-axis. These devices involve the movement of the proof mass, therefore special packages with a built-in cavity are also fabricated. The dedicated cavity provides required space for the movement of the proof mass without any hindrance. Thick film alumina based packages have also been developed.