4-Ch × 10-Gb/s chip-to-chip optical interconnections with optoelectronic packages and optical waveguide separated from PCB

Abstract

We have developed optoelectronic packages for on-board optical interconnections and demonstrated 10-Gb/s and up to 12-Gb/s optical transmissions. In this paper, we describe the structure of the optoelectronic packages and optical interconnect systems that we propose for low-cost chip-to-chip signal transmissions. The optoelectronic package is intended to be pluggable from an LGA socket and an optical connector in order to ease system maintenance. The optical connectors with a polymer optical waveguide are designed to be assembled between the packages and an LGA socket. The polymer optical waveguide is separated from a printed circuit board (PCB) in order to produce the PCB with a mature and low-cost fabrication process. Optical devices flip-chip-mounted on the packages are encapsulated with transparent resin material to enhance their reliability and bonding strength. Signal transmission characteristics and optical interchannel crosstalk are evaluated from a transmitter package (Tx) to a receiver package (Rx).