Supercritical fluid extraction was coupled to comprehensive two-dimensional supercritical fluid chromatography with conventional packed columns. With this system, three modes of operations were feasible, such as SFE-SFC, SFC×SFC, and SFE-SFC×SFC. The operations for valve switching and data acquisition were automated using in-house software. In order to evaluate the present system, SFE-SFC for polymer additives in polypropylene, SFC×SFC for a mixture of benzene derivatives with different polarities, and SFE-SFC×SFC for styrene oligomers in polystyrene were performed. With SFE-SFC×SFC, diastereomers were resolved for linear tetramers and pentamers as well as trimers with the tetraline moiety.

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This paper presents an advanced ultra-thin photosensitive dielectric Film (PDM) newly developed with high resolution, low CTE and low residual stress for next-generation high-density redistribution layer (RDL), 2.5D interposer, and high-density fan-out package applications. For high-density RDL, photosensitive dielectric materials need to have low CTE to achieve high package reliability. The CTE of the material is 30–35ppm/K. While maintaining the low CTE, we successfully demonstrated the minimum micro-via diameter of 3um in the 5um thickness. Curing temperature of the PDM is 180°C × 60 min. which is lower than most of the advanced dielectric materials which currently used in industry. Low-temperature curing process results in low stress. We have calculated residual stress in the cured PDM from a test result of warpage measurement on 4 inch wafer. As another benefit of the PDM material in curing process, the PDM can be cured in air oven. Most of advanced photo dielectric materials need to cure in N2 oven due to prevent an oxidation of the material. We have demonstrated copper traces of 2um lines and spaced on the PDM by using semi-additive process (SAP) with sputtered Ti/Cu seed layer. Thanks to the low CTE and low residual stress due to the low-temperature curing, it passed temperature cycle test (1,000 cycles) with daisy chain structure which has 400 vias in the structure. It can be concluded that the newly developed PDM is a promising dielectric material for highly reliable high-density redistribution layer (RDL) for 2.5D interposers and fan-out wafer level package applications.

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