Development of UV-curable molding materials with minimum die-shift for FOWLP/FOPLP

While fan-out techniques on wafer and panel level are constantly developed further, two issues associated with the involved compression molding still remain: warpage and die shift. A new approach to overcome these implications is presented in this work. It is shown that by choosing UV cure over heat cure, CTE mismatch effects are significantly reduced. Consequently, higher CTEs are acceptable for the encapsulation compound which in turn allows to reduce viscosity of the compound. This new approach should simplify tooling, as it allows for roomtemperature imprint technology. Encapsulation is done with moderate pressure at room temperature. It is shown that this combination of material and process can reduce die shift significantly.