Rao Tummala

TL;DR: In this article, the authors present an approach to address these reliability problems by using novel build-up dielectrics with low Young's Modulus to reduce the strains induced in the solder ball interconnections to the board.

TL;DR: In this paper, a filling encapsulant based on epoxy resin is used to connect the different chip sector macros that make up the system chip, which remains thermally stable through the subsequent processing temperature hierarchies during the system chips fabrication.

TL;DR: In this paper, a combination of Bruggeman's effective medium model and Sihvola and Lindell model is used to find the right mixture of cobalt particles and fluoropolymer material for the effective antenna miniaturization.

Abstract: RF capacitor applications for filtering and signal matching need stringent tolerances in Temperature Coefficient of Capacitance (TCC) and Quality factor (Q). In this paper, the temperature dependence of the dielectric properties of polymer-ceramic composites was discussed, with particular emphasis on high Q polymers and paraelectric ceramic particles. This includes the important role of ceramic paraelectric particles such as A12O3, SiO2, Ta2O5 etc. as ceramic fillers and high Q polymers such as benzocyclobutene (BCB) in the development of high Q and low TCC dielectrics for embedded RF capacitors. High Q polymer by itself showed a negative TCC of about -250 ppm/ degC but the composite approach with A12O3, SiO2 and Ta2O5 fillers improved the TCC to -190, -130, +20 ppm/ degC , respectively, between temperatures ranging from room temperature to 125degC. Liquid coatable high Q polymer-based composites with 3-4X improvement in dielectric constant and nearly-zero TCC of approximately within plusmn30 ppm/degC were developed with Ta2O5 as the inorganic filler. This effect can be ascribed to the TCC compensation between negative TCC of high Q polymer and the positive TCC of paraelectric ceramic particle selected. The distribution of the particles in the polymer matrix is also a crucial aspect of this application.

TL;DR: In this article, a stress relief barrier is proposed to reduce effects of stress caused by different coefficients of thermal expansion, and acts as an adhesion promoter between a metallization and an interposer.