Generally, the quantitative hermeticity of Wafer level Vacuum Packaging (WLVP) has been evaluated by integration of pirani gauge vacuum senses. But, this requires complex fabrication process and higher chip cost. In this work, hermeticity and inner vacuum value of Au/Sn eutectic bonded 8 inch wafer were calculated by analytical method through micro-membrane test. A distinction of well-sealed MEMS sensor applied WLVP will be evaluated from analytical method through micro-membrane test. The yield of above 80% in 8 inch wafer was obtained by analytical method. The correlation of membrane thickness, membrane deformation and inner vacuum parameter was shown equation 1 and figure 5. All the values of inner vacuum in any membrane thickness were saturated under 200torr. This means that low vacuum level is more accurate than high vacuum level. From the equation 1, we can confirm the inner vacuum value is 635torr at the membrane thickness of 60um, as shown in figure 6. A distinction of well-sealed MEMS sensor applied WLVP will be evaluated from this work. The yield of above 80% in 8 inch wafer was obtained by analytical method.
Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2013: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational (Volume 2)
Published: May 12, 2013
Pages: 162 - 165
Industry sector: Sensors, MEMS, Electronics
Topic: MEMS & NEMS Devices, Modeling & Applications