Packaging technology for high-speed multichip module using copper-polyimide thin film multilayer substrate [for B-ISDN]

Abstract

The authors describe a multichip module (MCM) having a copper-polyimide thin-film multilayer substrate that overcomes the problems of increased transmission loss at high frequencies maintaining crosstalk noise low, and the increased simultaneous switching noise with a larger number of LSI chips. The conductors are designed to be 10-/spl mu/m thick and 25-/spl mu/m wide to enable the transmission of high speed pulses at several Gb/s without decreasing the interconnection density while maintaining crosstalk noise as low as -30 dB. The dielectric thickness between the power and ground layers making up the current loop in the ceramic substrate is designed to be 50/spl mu/m, which gives rise to a low effective inductance.<>