Prashant Kumta Abstract The current and future emphasis in packaging technology are aimed at achieving high device densities. These development place stringent requirements on substrate technology. The substrates need to possess good heat dissipation and signal propagation characteristics. Several compromises seem to be essential to match the device output characteristics with the economics of the process. A composite material with optimum thermal and dielectric properties would offer an ideal solution to this problem. A colloidal processing technique combined with a unique microstructural design is proposed to process a glass-ceramic composite with optimum thermal and electrical properties. Modified metal oxide sol-gel (MOSG) process utilizing inexpensive metal oxide precursors is proposed to synthesize borophosphosilicate glass-ceramics. An in-situ solution coating technique will be used to introduce the thermally conducting second phase. Systematic control of the processing parameters such as temperature, solution viscosity, sintering time, and volume fraction will be initiated to generate a duplex microstructure in the dense composite containing a continuous network of the thermally conducting phase. The three main objectives of the proposed study are: (1) Synthesis of the glass-ceramic composite material using the modified solution approach (2) Systematic study and control of the evolved microstructure of the glass-ceramic composite and (3) To understand the effect of the gel structure and the process variables (volume fraction, coating thickness, gel structure, sintering time, temperature) on the microstructure and its properties, using thermal analyses, X-ray diffraction, scanning and transmission electron microscopy. The effect of the microstructure on the electrical and thermal properties will also be assessed by measuring the dielectric constant, thermal expansion and thermal conductivity of the dense composites. The present approach offers a novel method to process dual phase composites with a contiguous microstructure and can be easily extended to process other glass- ceramic, ceramic-ceramic or metal- ceramic composites for electronic and structural application. ***
