Development of advanced packaging assembly for integrating high-density electrical and optical interconnects in silicon chips for high-speed communications (Conference Presentation)

In this paper, we showcase the advanced 2.5D hybrid integration of photonic and electronic chips in a single package, enabling 512 Gbps bidirectional DWDM data transmission. A 16-layer Low-temperature co-fired interposer (LTCC) has been designed and fabricated to bridge a silicon photonic chip and four electrical ICs (EIC), providing high-density, 1300 high pin count interconnects. The fanout of all the BGA (Ball Grid Array) pads is connected to a custom designed high-frequency PCB (Printed Circuit Board). The photonics and electronics chips are attached to the ceramic interposer, and the ceramic interposer to the PCB, using solder spheres with two distinct thermal properties. An 8-channel fiber array, with a low coupling loss of approximately 3.7 dB per facet at 1550 nm, is attached to the on-chip edge couplers. The entire assembly is enclosed in the custom-made mechanical casing to improve stability, thermal management, and robustness.