Effect of moisture swelling on MEMS packaging and integrated sensors

• Published in: Microelectronics and reliability Vol. 53; no. 9-11; pp. 1648 - 1654
• Main Authors: Keller, J., Mrossko, R., Dobrinski, H., Stürmann, J., Döring, R., Dudek, R., Rzepka, S., Michel, B.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier Ltd 01.09.2013; Elsevier
• Subjects: Applied sciences; Computer simulation; Design. Technologies. Operation analysis. Testing; Electronics; Exact sciences and technology; General equipment and techniques; Hygrometers; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Integrated circuits; Mathematical models; Micro- and nanoelectromechanical devices (mems/nems); Moisture; Packages; Packaging; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Sensors; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Swelling; Uptakes; Viscoelasticity; Deformation; Moisture sensor; Measurement sensor; Polymer; Output signal; Micromachine; Pressure sensor; Optimal design; Finite element method; Electronic packaging; Humidity; Stress effects; Reliability; Microelectromechanical device
• ISSN: 0026-2714; 1872-941X
• DOI: 10.1016/j.microrel.2013.07.107

In MEMS packaging moisture uptake of packaging materials may lead to severe changes in sensor behavior and package reliability. Knowledge and understanding of the effect of moisture swelling on the overall package deformation and on the sensor system is therefore inevitable for a successful MEMS design and packaging solution. The paper shows a design optimization of a pressure sensor packaging towards minimization of sensor drift due to stresses induced by moisture uptake. The work was done in a combined experimental and simulative approach. Experimental data clearly shows the sensor sensitivity to moisture uptake of polymer based packaging material. Based on the experimental findings the complete sensor package was modeled by means of finite element analysis. In a second step a new packaging geometry was defined to reduce the effect of moisture swelling to sensor signal. Additionally sensitivity of the sensor output signal to viscoelastic properties of three different moulding compounds was simulated. In the result of the work an optimized package design was achieved.