Polymer-ceramic nanocomposites based on new concepts for embedded capacitor

Polymer-ceramic nanocomposites based on new concepts were developed for embedded capacitor applications. The dielectric constant was above 80 at 1 MHz and the specific capacitance was successfully achieved 8 nF/cm2. By use of this nanocomposites, multilayer printed wiring boards with embedded passive components were fabricated for prototypes. The following technologies would be reported in this conference. Firstly, based on the investigation of barium titanate (BaTiO3) crystallites, various particles with the sizes from 17 to 100 nm were prepared by the two-step thermal decomposition method from barium titanyl oxalate (BaTiO(C2O4)2·4H2O). It was clarified that BaTiO3 particles with a size of around 70 nm exhibited a maximum dielectric constant of over 15,000. Secondary, the BaTiO3 surface modification based on a new concept was applied to improve the affinity between BaTiO3 particles and polymer matrix. Thirdly, the blend polymer of an aromatic polyamide (PA) and an aromatic bismaleimide (BMI) was employed as the matrix from a view-point of both the processability during fabricating the substrates with embedded passive components and the thermal stability during assembling LSI chips. Finally, these technologies were combined and optimized for embedded capacitor materials.