Enabling Glass-Based AP and CPO

The ongoing transition toward heterogeneous integration and co-packaged optics (CPO) demands manufacturing technologies that combine precision, scalability, and material flexibility. Glass is increasingly adopted as a substrate material in advanced packaging due to its exceptional dimensional stability, electrical insulation, and optical transparency. Laser-based manufacturing processes are emerging as key enablers for critical steps in glass substrate processing, offering high precision and compatibility with panel-level High Volume Manufacturing (HVM).

This paper presents a comprehensive evaluation of several laser technologies applied to glass-based advanced packaging. Laser Induced Deep Etching (LIDE) is explored for the formation of Through Glass Vias (TGVs), recess structures, pre-dicing features, and substrate-integrated functional microstructures, including alignment structures for optical interconnects essential to CPO architectures. In addition, laser welding processes for glass-to-glass and glass-to-silicon bonding are examined to enable multilayer glass substrates. Laser ablation for ABF buildup layer removal and die separation is assessed and compared with laser dicing for die singulation.

All processes are analyzed with respect to their suitability for panel-level HVM, considering key factors influencing manufacturability and industrial implementation. Technology readiness levels (TRLs) are estimated based on the current state of process maturity and integration potential.

The paper combines results from independent development activities and collaborative studies conducted within the GPTG (Glass Panel Technology Group) Consortium. These collective efforts contribute to establishing process benchmarks, validating scalability, and accelerating the adoption of laser-based glass processing technologies for next-generation packaging and optical integration.