2L OMEDFC development for larger package to die size ratio in thinner core

The development of a thinner core (:5100um) laminate array based exposed die fcCSP package with package to die area ratio > 12, package total height maximum 0.77mm that meets the JEDEC < ±100um warpage requirement is discussed. The same approach used for the 150um thick core exposed die fcCSP technology was used for this work, namely finite element modeling to guide the choice of mold compound types and properties, mold chase design, substrate core material & core thickness. The development of the 2-Layer Over-Molded Exposed Die Flip Chip device (2LOMEDFC) involved down selecting from a variety of potential candidate materials and doing some initial builds to verify the finite element molding results. After initial development and full characterization of the optimized substrate core material, core thickness, mold chase design and mold compound, a full qualification of assembled packages was completed. The qualification tests included MSL3 260C × 3 preconditioning followed by TC-B 1000cycles, uHAST 96hrs and bHAST 264hrs. To insure there were no delta function reliability effects, some of the qualification tests were extended beyond JEDEC standard times, TC-B 2000cycles, uHAST 192hrs.