This invention belongs to the field of
printed circuit board manufacturing, specifically relating to a nano-
graphite shadowing
reagent for FPCs and its preparation method. The
reagent is prepared by first synthesizing
cerium-doped
yttrium molybdate complexed
nanocages and
sulfonic acid-functionalized silica-coated
barium zirconate core-shell nanoparticles. The former forms a hollow cage structure via a hydrothermal method guided by
sodium citrate; the latter forms a core-shell structure through co-
precipitation,
calcination, and
sol-gel methods, and is ultimately oxidized and grafted with
sulfonic acid groups. In preparing the shadowing
reagent, a premixed solution containing
barium zirconate core-shell particles is dispersed with nano-
graphite, and then a
yttrium molybdate nanocage suspension is introduced. Under alkaline heating conditions, both particles bind to the
graphite sheets through electrostatic and coordination interactions, constructing a stable three-dimensional inorganic network. This method significantly improves the reagent's
dispersion stability, adhesion to pore walls, and uniform coverage of high
aspect ratio micropores, ultimately forming a high-performance conductive
colloid suitable for high-reliability via metallization processes in flexible circuit boards.