A new organic composite dielectric material for high performance IC packages

A new resin coated copper (RCC) composite dielectric material featuring low dielectric constant (D_k) of 3.2 and ultra low loss factor (D_f) of 0.002 (at 9.2 GHz) has been developed for high performance, yet cost effective, organic chip package substrates. Several properties of this new dielectric material distinguish itself from other high performance substrate dielectrics: toughened, high T_g thermosetting resin, ultra low moisture absorption, low isotropic CTE in a broad temperature range, engineered interfaces at all levels, and excellent manufacturability such as laser ablation characteristic and flow/fill properties. High performance flip chip substrates have been manufactured and qualified using the advanced dielectric material (ADM) and mature manufacturing techniques. Design rules for the qualification parts are: 25 μm lines/30 μm spaces, blind and buried vias with diameters of 40 μm, dielectric thickness of 32 μm, via densities > 2400/cm², full array flip chip pitch of 180 μm, package body sizes up to 55 mm, and ability to add embedded capacitance. The material has been used to fabricate 45 mm × 45 mm test vehicles having die of 19 mm × 19 mm with more than 8000 total I/O and has exhibited promising reliability results.