Large-Field Projection Lithography: Technical Routes and Industrial Value of Full-Wafer Exposure for Advanced Packaging 

  Dr. Bo-Fang PENG

  Founder & Chief Technology Officer，PureChip Technology Co., Ltd., China

Abstract:

The global advanced packaging market is undergoing a structural leap. According to Yole, the sector reached approximately US$55 billion in 2025 and is projected to exceed US$120 billion by 2031. Driven by AI computing power and HBM, CoWoS, FOPLP and Chiplet packages have systematically exceeded conventional lithographic field limits. TSMC's CoWoS-L interposer has reached approximately 100 mm × 100 mm in 2026. The prevailing multi-field stitching strategy introduces overlay accumulation errors, seam-induced yield loss, and throughput bottlenecks.

Concurrently, advanced packaging is experiencing a profound "front-endization" revolution. RDL line widths are evolving from 4 μm toward 1.6 μm, bump pitches compressing from 100 μm to below 1 μm, and process control intensity climbing from 5.3% to 7.4%. Six inspection scenarios have become production-line necessities.

This presentation proposes a Holistic Lithography paradigm for advanced packaging. It articulates a large-field projection lithography path enabling full-chip, stitching-free lithography within a single field, covering both silicon substrate and panel-level scenarios. The core argument is that competitiveness lies not solely in the lithography tool, but in a closed-loop ecosystem coupling inspection, lithography, bonding, and metrology through cross-equipment data feedback loops, upgrading line management from single-tool optimization to system-level yield management.

Speaker's Biography: 

Dr. Bofang Peng is the founder of PureChip Technology. He held senior R&D positions at Shanghai Micro Electronics Equipment (SMEE) and ASML, where he contributed to the early-stage research of domestic 28 nm lithography alignment systems. He founded PureChip Technology during his tenure at Fudan University. With extensive experience in semiconductor front-end process metrology and lithography equipment R&D, his research covers precision optical systems, overlay metrology, TSV 3D topography measurement, large-field lithography architectures, and process-integration strategies.

He is pioneering a lithography-centric, closed-loop-data-driven holistic manufacturing paradigm for advanced packaging, integrating lithography, inspection, bonding, and metrology into a unified process ecosystem. Dr. Peng has been honored with the Gusu Leading Talent Award, the Jiangsu Dual-Innovation Talent Award, and the Silver Prize at the National Entrepreneurship Competition. His current research focuses on large-field stitching-free projection lithography and the industrialization of holistic lithography manufacturing solutions for CoWoS, FOPLP, and HBM packaging platforms.