Localized induction heating solder bonding for wafer level MEMS packaging

Abstract

This paper reports a new solder bonding method for the wafer level packaging of MEMS devices. The electroplated magnetic film was heated up using the induction heating, and leaded to solder reflow. It took only several seconds to complete the solder reflow and bonding process. The measurement results showed that the temperature of device region was only 110/spl deg/C during heating. Due to the solder reflow and electroplating technique, hermetic seal of the packaged device is achieved. The bonding strength is up to 18 MPa. In addition, the electroplated thick film also performed as a spacer. In applications, the integration the MUMPs devices with the proposed packaging techniques were demonstrated.