Alpha and Omega Semiconductor has developed a RigidCSP technology where it is possible can decrease the on-resistance while increasing the mechanical strength to reduce breakage during assembly and stress during the lifetime of the battery MOSFET. The new package technology is suitable for applications such as smartphones, tablets, and ultra-thin notebooks.
As requirements increase for higher charging current, then ultra-low electrical resistance is needed for improved performance. In standard WL- CSP, the substrate can be a significant portion of the total resistance on the back-to-back MOSFETs. A thinner substrate will reduce the overall resistance but also drastically reduce the mechanical strength. This reduction of mechanical strength can lead to more stress during the PCB assembly reflow process, which can lead to die warpage or die crack, which leads to failure in the application.
“Using RigidCSP technology offers performance improvement with high robustness. RigidCSP can be used for high aspect ratio CSP die size, and RigidCSP can enable an overall reduction in warpage/breakage from assembly board manufacturing,” said Peter H. Wilson, Marketing Director of MOSFET product line at AOS.
