Performance Analysis of Low Stress Ultra-Low Dielectric Coatings for High Density Substrates

A major shortcoming that prevented present-day organic substrates and interposers from achieving high VOs at fine pitch and dimensional stability are thermal expansion mismatches between material layers and requirement of low dielectric constant to improve signal transmission. Low-stress materials with ultra-low dielectric coefficient can be used to improve signal transmission and to relieve stresses in circuits on silicon, glass and polymeric substrates. The electrical performance of metallic circuits on newly developed porous materials is investigated in this study. Experimental results showed that the impedance performance of circuit is significantly improved with the new material. Mechanical testing showed that the elastic modulus of the new material is only 1/5 of the conventional polymer, and stresses can be relieved using the by the low elastic modulus, ultralow dielectric material.