Holed packaging for mems sensors

MEMS devices in consumer applications have expanded rapidly which is in part due to the use of the LGA package. This package technology gives the advantage of low cost small size and flexibility. The first devices using this type of package were accelerometers and then gyroscopes, this has now been followed by pressure sensors and microphones. These new devices requiring access to the external atmosphere are not full moulded but have a hole in the package for the signal to reach the MEMS device. The various options and design criteria for different types of these holed packages will be discussed taking in account the particular design constraints of these MEMS mechanical structures. The characteristics of the materials required in the assembly processes are discussed in order to optimise performance with the LGA platform. Device characterization results showing the effect of different materials and extensive reliability testing results are presented. The use of FEA simulations will show the influence of various aspects of the design and materials. Manufacturing processes will also be outlined showing how LGA style package can be produced in a high volume environment.