Study Of Aqueous Adhesive In Chip Multilayer Inductor Tape-casting

In recent years, the issue of environmental protection has got a lot of attention. In thefield of multilayer chip inductor (MLCI) production, the research of newenvironment-friendly water-based tape-casting has replaced oil-based tape-casting becomingthe focus of current study. Aqueous adhesives used in water-based tape-casting became animportant research direction. Water-based tape-casting process using water as its solvent hastoo many differences with traditional oil-based tape-casting, including slurry preparation,tape-casting operation, drying, lamination, burnout and other processes. In consideration ofenvironmental protection, waste tape-casting films should be recycled. Therefore, it issignificant that researching and developing aqueous adhesives suitable for tape-casting tomake its dry tape-casting films water-soluble and reusable. In this paper, aqueous acrylicadhesives were synthesized by emulsion polymerization and solution polymerization withmolecular design and the tape-casting films were prepared successfully.The core-shell acrylic latex was synthesized of acrylate monomers by pre-emulsifiedsemi-continuous emulsion polymerization. The effect of reaction conditions on the propertiesof acrylic latex and its tape-casting films was studied. The results showed that the latex hadsmall particles with size of121.1nm and narrow distribution，exhibited excellent stability, andits tape-casting slurry exhibited good dispersion and strippability when the content offunctional monomers and reactive emulsifiers were respectively3wt%and4wt%of totalmonomers, the mass ratio of functional monomers in core and shell was10/90, the content ofEA, BA and MMA were respectively72wt%,20wt%,5wt%, the reactive temperature was80℃. But the tape-casting films could not be dissolved in water. It just could be burned to berecycled.Acrylic adhesive solution was synthesized of acrylate monomers by solutionpolymerization. The effect of the type and dosage of functional monomers, hard/softmonomers ratios, the content of initiator, co-solvent, chain transfer agent, neutralization agentand the reactive temperature on the properties of acrylic resin and tape-casting films wasstudied. The results showed that the acrylic resin met tape-casting requirement because of itshigh transmittance, proper viscosity and glass transition temperature when the content of MMA, BA, MAA and functional monomers were respectively33wt%,50wt%,7wt%and10wt%, the content of initiator, co-solvent, chain transfer agent and neutralization agent wererespectively1.0wt%,40wt%,0.8wt%and5.6wt%of total monomers, and the reactivetemperature was96℃. The tape-casting films had smooth surface, excellent strippability,flexibility and water-solubility in dilute solution of ammonia when the content of adhesiveglue dry was17wt%of ceramic powders.The molecular weight, glass transition temperature and thermo-gravimetric curves ofacrylic resin and the composition, the surface and section morphology of its tape-casting filmswere studied by FT-IR, GPC, DSC, TG/DTG and SEM. The results got from the relationshipbetween the structure and properties provided a theoretical basis for the synthesis of aqueousadhesives and its application in tape-casting.