A Smart, Sensor-Augmented Probe Card for Wafer-Level Photonic Testing of Co-Packaged Optics Devices

The transition from electrical to optical interconnects, enabled by the adoption of co-packaged optics (CPO) in advanced processors, is accelerating the scale-up to high volumes and redefining wafer-level test requirements. As optical interfaces migrate closer to the compute die, an increasing share of functional characterization must occur at the probe, where stringent sub-micron alignment, the mechanical stability necessary to preserve optical coupling against dynamic disturbances, and opto-electrical co-validation introduce new technical challenges. Ensuring repeatable and precise fiber-array-unit (FAU) engagement at the wafer level is therefore essential to enable scalable manufacturing of photonic-enabled processors. This paper introduces the EclipsePhotonic probe card, which embeds the Eclipse Dynamic piezoelectric positioning mechanism into a standard vertical-needle probe head as a route toward six-degree-of-freedom FAU manipulation with nanometric positioning accuracy. This architecture is designed to support repeatable coupling to on-wafer photonic structures without requiring specialized probe-head designs, thereby reducing integration complexity and addressing alignment-related yield risks. The platform is also intended to support multi-site electrical and optical probing, providing a path toward parallel test execution once the corresponding layout, optical-routing, and validation constraints are satisfied. A core innovation of the platform is its embedded sensor network, which integrates low- and higher-frequency displacement sensors, relative displacement sensors, and temperature sensors around a microcontroller-based supervisor. The vibration sensor fulfills a dual operational role: it detects environmental and test-cell disturbances that may have influenced optical coupling, providing essential context for binning decisions or targeted retest, and it contributes to probe card lifecycle monitoring by ensuring that the mechanical signature of the probe card remains within a validated operational “swim lane” throughout its service life. Recently published characterization of the underlying Eclipse Dynamic alignment engine shows that, in the production-optimized high-speed regime with effective hysteresis compensation, the Fixed Gradient routine provides the best normalized trade-off among the evaluated routines, with a normalized alignment cost of 1.44 a.u., 95.8% convergence reliability, and 99.4% of the global maximum optical coupling. These values should be interpreted as inherited algorithmic benchmarking results rather than as absolute wall-clock performance of the fully integrated sensor-augmented platform.