Micro Inertial Device Of Three Dimensional Packaging Design And Implementation

Micro-inertial device is one of MEMS that is produced by micro fabricationtechnology. It is used to measure the carriers’ acceleration and angular velocity by useof the inner sensitive structure and signal conditioning circuit. In order to gettingmultiple directions’ inertial parameters, three-dimensional packaging technology canmeet the needs of the application and make device more smaller，portable and reliable,which integrate several micro-inertial devices in one structure. As the advantages ofLow Temperature Co-fired Ceramic (LTCC) in the integrated package, this thesisintegrates two uniaxial micro accelerometers in one package body by LTCC technology.Meanwhile, we analyze and research the package structure’s reliability and feasibility ofpackage processes. The main contents and conclusion are summarized below:1. Basic principles of micro-inertial devices are briefly introduced. According torequisition of accelerometer package, we design a3-D package structure forMicro-accelerometer. It is formed of the top and bottom ceramic cavities, whichinstalled bare chip in cavity and sealed and interconnected by solder.2. In ANSYS, the3-D package body’s thermal performance is simulated. Theresult shows that the structure is line with the requirement of package design.3. In view of the solder is so important that we have deep analysis by thermalcycling simulation. Many conclusions are listed as following: plastic strain play aleading role in strain and increase with the incrassation of the times of cycles. In solderlife prediction, the life cycle of dangerous solders are got in Darveaux Model. Inadditions, we find the seal failures will occur firstly; and the size of solder may affectthe calculation results. In modal analysis, we get the first to sixth order modal frequencyand the corresponding modes. Lastly, the package body has better dynamic response inhalf-sine dynamic accelerations of2000g.4. According to the LTCC process, we design and produce the ceramic body. Thenthe3-D package body is assembled as7mm×8mm×4.1mm. By experiment, theperformances parameters of device are tested.