Principal Package Assembly Engineer

Lightmatter is leading the revolution in AI data center infrastructure, enabling the next giant leaps in human progress. The company invented the world’s first 3D-stacked photonics engine, Passage™, capable of connecting thousands to millions of processors at the speed of light in extreme-scale data centers for the most advanced AI and HPC workloads. Lightmatter raised $400 million in its Series D round, reaching a valuation of $4.4 billion. We will continue to accelerate the development of data center photonics and grow every department at Lightmatter! If you're passionate about tackling complex challenges, making an impact, and being an expert in your craft, join our team of brilliant scientists, engineers, and accomplished industry leaders. Lightmatter is (re)inventing the future of computing with light! In this role, you will work on leading-edge packaging technologies to enable AI architectures that set new industry standards for compute power, performance, and efficiency. As part of the Packaging Technology team, you will serve as the lead assembly process integrator. Your responsibilities will include developing assembly & test process technologies and generating assembly/test design rules for Heterogeneous Integrated co-packaged optics technologies by collaborating with design teams, silicon and photonics foundries, and OSAT partners. You will be responsible for developing test chip strategies, managing test chip design, and appropriately planning and managing design of experiments with partners. Additionally, you will work closely with silicon and system architects to define package architectures by incorporating manufacturability considerations into product definitions. The results of your work will lead to advanced package designs that meet assembly, test and reliability requirements, while delivering leading-edge products for data centers and the high-end compute segment. Responsibilities: Develop end-to-end 3D package assembly, test, and fiber-attach processes for Lightmatter products, ensuring robust high yields while meeting performance and reliability goals by working closely with foundry, OSATs and Test vendors. Develop package architectures that prioritize Design for Test (DFT), Design for Manufacturing (DFM), and Design for Reliability (DFR). This is critical for achieving product landing zones while simultaneously meeting performance and cost targets. Define test chip requirements and manage test chip design required for 3D package assembly and test process development. Develop and validate design rules for a high-yielding assembly process. The scope includes assembly/test, backend/RDL, silicon/package interaction, substrate, thermal/mechanical solutions, fiber attach, system integration, and other related areas. Plan and execute design of experiments, manage data, and perform appropriate analysis to gain insights into assembly process and design interactions. Perform analysis to identify key reliability risks under product use conditions and drive appropriate design and materials solutions to improve product mechanical integrity. Summarize and communicate to key stakeholders across Lightmatter, suppliers and customers as required. Write reports and document methodologies. Required Qualifications: MS or PhD in Mechanical Engineering, Material Science, or related engineering field. Minimum of 10 years' hands-on experience in package assembly and test process development, specifically working with Outsourced Semiconductor Assembly and Test (OSAT) providers. Knowledge of Chip-on-wafer process flow, materials, and equipment requirements. Experience in test chip and assembly test vehicle design. Understanding of photonics packaging requirements including various fiber attach methods. Knowledge of 2D/3D packaging technologies and exposure to thermo-mechanical challenges associated with these technologies. Must be based in Taiwan. Fluent in both English and Mandarin Chinese, with the ability to confidently lead high-stakes meetings in either language. Preferred Qualifications: Excellent communication skills, with the ability to convey complex technical concepts to both technical and non-technical stakeholders. Strong project ownership, with a history of driving results independently and with minimal supervision. Proven track record of developing creative solutions for complex technical challenges. Benefits Comprehensive Health Care Plan (Medical, Dental & Vision) Retirement Savings Matching Program Life Insurance (Basic, Voluntary & AD&D) Generous Time Off (Vacation, Sick & Public Holidays) Paid Family Leave Short Term & Long Term Disability Training & Development Commuter Benefits Flexible, hybrid workplace model Equity grants (applicable to full-time employees) Benefits eligibility may vary depending on your employment status and location. Lightmatter recruits, employs, trains, compensates, and promotes regardless of race, religion, color, national origin, sex, disability, age, veteran status, and other protected status as required by applicable law. Export Control Candidates should have capacity to comply with the federally mandated requirements of U.S. export control laws.