A Study on Device Level Vacuum Packaging for Silicon MicroGyroscopes

摘要

The device level vacuum packaging was studied in order to carry out vacuum packaging of silicon microgyroscopes.Specially,the vacuum maintenance of device level vacuum packaging was focused on.The special ceramic packages for silicon microgyroscopes were designed and the soldering sealing technology was adopted.The alloy An/St was adopted to suit with the high temperature in the packaging process.Temperature programmed desorption-mass spectrometry (TPD-MS) was used to measure the contents of gases from silicon microgyroscope chips and ceramic packages.According to the contents of trapped gases,the reasonable getter is chosen to absorb the gases and keep the vacuum level of the cavity.Finally,the device-level vacuum packaging process is established.The experiment results show that the quality factor (Q-factor) of gyroscope packaged with device-level vacuum packaging process is about 160 thousand,and the change of Q-factor is less than 0.05% within one year.