An organic and ceramic laminated BGA package with high thermal and electrical performance characteristics

A new structural face-up LSI package has been developed. The package shows low thermal resistance without a heatsink and low inductance, capacitance, and resistance values. The package is thin enough for portable multimedia equipment applications, with a thickness of 0.5 mn (not including ball height). The measured thermal resistance was 11°C/W under natural convection without a heatsink. The simulated inductance and capacitance were 6.7 nH and 1.1 pF respectively, and measured resistance was 520 mΩ (line length=14.7 mm, width=60 μm). The package consists of a resin film and a ceramic substrate. The film is a liquid crystal polymer (LCP) and the substrate is aluminum nitride (AlN). LCP is a suitable material for buried-bump interconnection technology (B2it^TM). AlN has high thermal conductivity and its coefficient of thermal expansion (CTE) is close to that of silicon. Both materials were laminated by an adhesive agent. This material combination provides a thin structure, low thermal resistance, and low LCR which are suitable for portable multimedia electrical equipment. This paper reports the configuration and performance characteristics of this newly developed package