Co-Packaged Optics (CPO) is a current hotspot in the semiconductor and optical communication industries, and the topic of CPO was also prominent at the Ansys 2025 Global Simulation Conference. On the morning of the second day of the conference (the 12th), two speeches by Ansys engineers at the forum focused on this topic, demonstrating the powerful capabilities of Ansys' multiphysics simulation.
In the opening speech by Mr. Teongming Cheah, Senior Technical Director of Ansys Semiconductor Products, a figure was mentioned: Ansys has helped customers successfully complete a total of 175 3D IC tape-out projects so far. This figure is neither excessively high nor too low. On one hand, it reflects Ansys' multiphysics engine and multi-stage simulation capabilities from chip to system level, as well as its full-process capabilities from concept and optimization to sign-off. On the other hand, it also indicates that 3D IC is still an emerging technology in the semiconductor field.
The report titled "Silicon Photonics Chip Design and Challenges Under CPO" by Mr. Zhou Zheng, Ansys Optical Application Technical Director, and the report "Multiphysics Challenges and Solutions for Co-Packaged Optics (CPO) in 3D Heterogeneous Integration (3DHI)" by Ms. Zhao Jizhi, Ansys Senior Product Expert, focused on the simulation design of optical, thermal, structural, and electrical multiphysics fields. In particular, Ansys' advanced packaging practices in known CPO cases enabled the editor to gain a better understanding of the current actual development level of CPO.
TSMC's COUPE silicon photonics platform is the most eye-catching CPO practice. Mr. Zhou Zheng pointed out that Ansys products played a key role in the implementation of this framework: Optical I/O was designed using Zemax; photonic chips were designed with Lumerical; RedHawk-SC and Totem were used for power integrity sign-off of multiple dies; RaptorX was applied for high-frequency electromagnetic simulation between dies; and RedHawk-SC Electrothermal was utilized for thermal management of the entire heterogeneous system. Among these products, Mr. Zhou Zheng is most proficient in Lumerical, which includes three important tools: FDTD/MODE/Multiphysics for the design of core photonic chip devices, INTERCONNECT as an IC-level simulator, and CML Compiler as a compact model tool for photonic PDKs. The combination of these products can play a role in almost every link of silicon photonics chip design. For example, in the important edge coupling link of silicon photonics design, Lumerical provides two tools: Finite Difference Eigenmode (FDE) solver and Eigenmode Expansion (EME) solver, which can accurately calculate coupling loss. Similarly, in the vertical fiber-to-chip coupling, the combination of Lumerical and Zemax, through ZBF data exchange, realizes the integration of micro and macro-level optical design. Further integration with optiSLang can also achieve simulation automation and optimization processes. Mr. Zhou Zheng concluded that Ansys provides the best simulation tools for PIC and CPO design, covering the entire CPO/PIC design process except for device-level design.
Ms. Zhao Jizhi has rich experience in collaborating with tape-out factories. She told the audience that the main challenge faced by CPO is the multiphysics coupling between different devices. The 3DHI (3D Heterogeneous Integration) design of CPO itself is a paradigm of multiphysics implementation. The electromagnetic part includes power integrity, ESD analysis, electromagnetic field modeling, and signal integrity; the thermal part involves integrity and boundary condition analysis; and the structural part covers structural integrity analysis. Ansys' Electronics Desktop (AEDT) with HFSS + RaptorX + Q3D Extractor provides comprehensive electromagnetic analysis capabilities. RedHawk-SC, Totem-SC, RedHawk-SC-ET, Icepak, etc., offer multi-scale electrical and thermal analysis capabilities.
The introductions by the two Ansys engineers left a deep impression on the editor regarding Ansys' diverse range of simulation and analysis tools. According to AI tools, Ansys provides a complete multiphysics simulation ecosystem tailored for cutting-edge technologies like CPO, covering "electrical-thermal-mechanical-optical" fields. Its main products include:
For a period of time, the editor had been questioning the feasibility of the actual implementation of CPO. However, after listening to these introductions by Ansys, the editor couldn't help but think that the development of today's design tools may be able to overcome many inherent challenges in the development of CPO. Multiphysics simulation design is expected to bring a bright prospect for the development of CPO.