3D integration reshapes CPO
IDTechEx expects 3D heterogeneous integration and hybrid bonding to play a growing role as co-packaged optics scales for AI infrastructure.
The growing bandwidth and power demands of AI infrastructure are accelerating the shift from pluggable optical transceivers towards co-packaged optics (CPO), according to IDTechEx.
The research firm expects CPO to reach a cumulative market value of $20 billion by 2036, as optical engines move closer to network switch ASICs to reduce electrical interconnect distances, latency and power consumption.
Early CPO architectures have placed photonic integrated circuits (PICs) and electronic integrated circuits (EICs) side-by-side in 2D or on an interposer in 2.5D configurations. However, increasing bandwidth requirements are creating greater pressure on package real estate, driving interest in vertical 3D integration.
Monolithic integration of PICs and EICs into a single die could minimise interconnect distances, but differences between photonic and electronic manufacturing requirements create performance trade-offs. IDTechEx therefore expects heterogeneous 3D integration, in which separately optimised photonic and electronic dies are vertically stacked, to gain traction.
Cu-Cu hybrid bonding is emerging as a key technology for this approach, enabling interconnect pitches below 10µm while reducing parasitics compared with conventional microbumps. However, tighter pitches increase alignment, manufacturing yield and cost challenges.
Thermal management also remains a major obstacle, particularly because heat-generating electronics are positioned close to temperature-sensitive photonic components. IDTechEx expects 3D heterogeneous integration using hybrid bonding to account for a significant share of the CPO market as optical and electronic integration continues to evolve.
