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Controlling photoimaging of epoxies by blending to a specific molecular weight
Author(s) -
Russell David J.
Publication year - 1990
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1990.070410732
Subject(s) - epoxy , solvent , materials science , fraction (chemistry) , size exclusion chromatography , residual , mass fraction , base (topology) , composite material , polymer chemistry , chemical engineering , polymer science , mathematics , organic chemistry , chemistry , algorithm , mathematical analysis , engineering , enzyme
An epoxy formulation developed for a photoimaging application was found to exhibit poor clean‐out in the developing solvent depending on the lot of one of the base resins. Size exclusion chromatographic (SEC) analysis of the residual material showed it to be a high molecular weight ( M w ) fraction of the base resin EpiRez SU‐8. The resin was fractionated, and it was demonstrated that removing the high M w fraction from the formulation enhanced its developability. Lower M w versions of this resin were evaluated and found to be unsuitable. However, blending one of these resins (EpiRez SU‐6) with the SU‐8 resulted in a formulation that exhibited excellent developability. Mathematical relationships were calculated that enabled blends to be made, resulting in a defined molecular weight regardless of the lots of resins used.