Laser Direct Structuring of Semiconductor Liquid Encapsulants for Active Mold Packaging

Abstract

New technology trends in smart electronics are driving advanced semiconductor packaging innovations. Mobile RF and automotive IC designs, as examples, continue to evolve towards architectures requiring greater functionality, better shielding at higher frequencies, miniaturization, higher robustness/ ruggedness, and with lower power consumption. In turn, the architecture enhancements put new demands on semiconductor encapsulant material development and criteria. To meet these challenges, new types of SVHC-free, low warpage, liquid compression molding (LCM) encapsulants were developed with Cu Plating capability by laser direct structuring (LDS). Electroless Cu plating of 25/25 μm L/S lasered tracks and lasered through mold vias (TMVs) down to 50 μm have already been demonstrated during 2021.This presentation will cover further material development on a new LDS encapsulant applied via stencil printing aiming for <50 μm thin dielectric layers with 15/15 μm L/S Cu tracks and <50 μm Cu plated TMVs/ blind vias. These metrics provide opportunity for more functionality with even smaller package footprints vs todays' granular and transfer molding encapsulation methods. Moreover, this liquid LDS technology can improve final device building efficiency by introducing only three backend approved processing steps (encapsulation, lasering and plating) versus a typical less efficient mask and lithography based semi-additive process. In contrast to subtractive and semi-additive technologies, LDS is a truly additive, highly selective, and direct technology which provides additional metal planes directly on the encapsulant. And supporting a more sustainable and natural resources saving backend manufacturing of semiconductor packages.