A novel test method of low leakage rate of MEMS vacuum packaging

With the development of MEMS technology, especially the development of packaging technology, more and more MEMS devices require the vacuum packaging to improve their performances. However, MEMS vacuum packaging technology has been a technical problem for many years. Currently, we still can´t truly achieve the low leakage rate vacuum packaging of MEMS devices. Meanwhile, the existing detecting method can´t accurately measure low leakage rate. For these reasons, this paper carried out a novel test method to detect the low leakage rate of MEMS vacuum packaging. The use of a crystal to real-time monitoring the vacuum level inside of the envelope to get indirect leakage rate of the envelope was proposed. Through the work of crystal calibration, data testing, modification and re-testing, finally, we got a MEMS vacuum packaging envelope with the leakage rate of 3.2×10^-11Pa·m³/s by the FC135 Patch crystal.