Package Design Engineer

About Celestial AI Celestial AI Inc. is advancing generative AI and data center infrastructure. Celestial AI’s Photonic Fabric™ delivers a tenfold increase in performance and energy efficiency compared to competing solutions. The technology is fully compatible with optical interface chiplets, optical interposers, and Optical Multi-chip Interconnect Bridges (OMIB). It enables high bandwidth, low power, and low latency optical interfaces for AI accelerators and GPUs. The ecosystem includes tier‑1 partnerships for custom silicon, system integrators, high‑bandwidth memory, assembly, and packaging suppliers. About The Role We are seeking an experienced Package Designer with expertise in heterogeneous integration and semiconductor packaging design. The role requires cross‑functional design collaboration with Packaging, ASIC, AMS, Photonics, and external partners to ensure design for manufacturing, assembly, reliability, and cost. Essential Duties And Responsibilities Package Design: Lead Si/package/PCB/system co‑design work with downstream system design teams and upstream ASIC designers to develop packages that meet a wide range of performance points while re‑using designs in other Celestial AI products. Scope all aspects of package design feasibility at silicon interposer and substrate level for multi‑chip SiP packaging. Support pre/post silicon bring‑up, yield improvement activities, qualification, failure analysis, and system implementation. Package Layout Expertise: Lead all aspects of package layout based on I/O, SI‑PI and form factor requirements, including routing, design for reliability, thermal, mechanical, manufacturability, bumping, substrate, material selection, assembly, and testing. Meet specifications for high‑speed interfaces such as HBM, DDR, PCIe and 56G/112G SerDes. 2.5D and 3D Package Design Planning and Execution: Plan and execute silicon interposer and RDL‑based design layout solutions for advanced packaging architectures. Netlist management for heterogeneous chiplet assemblies using latest EDA solutions. Substrate Manufacturing and OSAT Assembly Engagement: Support activities related to production and assembly of IC packages with substrate suppliers and OSATs. Work with cross‑functional teams and support package integration and architecture efforts with vendors. Actively participate in qualification of package and board level assembly with sensitivity to physics of failures for high thermo‑mechanical reliability, driving appropriate test vehicle definition and design. Drive ideation and innovation of advanced package solutions and specifications with vendors to advance productization efforts by Celestial AI. Qualifications Education: BS/MS/PhD in EE/ECE/MSE/ME/ChemE or related disciplines. Experience: 5‑10 years in semiconductor packaging design of heterogeneous architectures, including silicon interposer and RDL designs. Technical Expertise: Extensive experience with advanced packaging design tools such as Cadence APD. Experience with MCAD tools such as SolidWorks, AutoCAD, and interconversion of package design databases to MCAD files. Knowledge of delivering high‑density/high‑performance interconnects in 2.5D/3D packaging technologies including InFO, CoWoS, FoCoS and EMIB. Strong understanding of cross‑functional packaging areas: floor plan, package, board layout, architecture, design rules, BOM, enabling material/process technologies, thermal, mechanical, signal/power integrity, design for manufacturing, assembly, reliability and cost. Familiarity with photonics packaging is a plus but not necessary. Substrate Vendor and OSAT Engagement: Proven track record of working with substrate vendors to meet design for manufacturing, yield, and reliability. Proven track record of engagement with OSATs to meet assembly requirements and drive new developments to meet new product requirements. Industry Knowledge: Experience in high‑speed signaling best practices, signal and power integrity requirements. Soft Skills: Strong analytical, problem‑solving, cross‑functional collaboration, project management, and technical presentation skills. Preferred Qualifications Expertise in heterogeneous integration, fan‑out packaging, chiplet architectures – co‑design, layout, and netlist management. Knowledge of signal and power integrity. Experience in substrate vendor and OSAT assembly engagement to meet manufacturing and assembly requirements. Location Santa Clara, CA Employees are encouraged to apply if they are a candidate who has the ability to contribute to best systems and design outcomes. Celestial AI Inc. is a qualified equal‑opportunity workplace and an affirmative action employer. Celestial AI Inc. is proud to be an equal opportunity workplace and is an affirmative action employer. #J-18808-Ljbffr