Principal Package Thermal & Mechanical Engineer

Astera Labs•San Jose, CA

4d•$185,000 - $230,000

About The Position

Astera Labs (NASDAQ: ALAB) provides rack-scale AI infrastructure through purpose-built connectivity solutions. By collaborating with hyperscalers and ecosystem partners, Astera Labs enables organizations to unlock the full potential of modern AI. Astera Labs’ Intelligent Connectivity Platform integrates CXL®, Ethernet, NVLink, PCIe®, and UALink™ semiconductor-based technologies with the company’s COSMOS software suite to unify diverse components into cohesive, flexible systems that deliver end-to-end scale-up, and scale-out connectivity. The company’s custom connectivity solutions business complements its standards-based portfolio, enabling customers to deploy tailored architectures to meet their unique infrastructure requirements. Discover more at www.asteralabs.com . Role Overview As a Principal Package Thermal & Mechanical Engineer at Astera Labs, you will serve as a technical leader driving the development and modeling of advanced IC packaging solutions that enable next-generation AI and high-performance connectivity systems. In this highly visible role, you will define and execute thermal and mechanical modeling strategies across the chip–package–board system, influencing package architecture, material selection, and reliability design. You will partner closely with package design, SIPI, silicon, system, and manufacturing teams to ensure robust thermal/mechanical performance and first-pass success. You will also drive modeling methodologies, correlation strategies, and best-known methods (BKMs), while engaging directly with customers to translate complex simulation insights into actionable system-level solutions.

Requirements

M.S. or Ph.D. in Mechanical Engineering, Materials Science, Electrical Engineering, or related field
8+ years of experience in semiconductor packaging with strong focus on thermal and mechanical modeling
Deep expertise in thermal modeling and simulation, including steady-state and transient analysis, compact thermal modeling (CTM), DELPHI methodology, and system-level thermal integration using tools such as ANSYS Icepak, Flotherm, or equivalent
Deep expertise in thermo-mechanical modeling and FEA simulation, including stress/strain analysis, warpage prediction, and reliability modeling (BLR/CLR), using tools such as ANSYS Mechanical, or equivalent
Proven ability to correlate simulation results with lab measurements
Experience influencing package design and delivering solutions to production
Strong cross-functional collaboration across package design, SIPI, system, and manufacturing teams

Nice To Haves

Experience with high-power AI / HPC packages and large FCBGA (>50mm)
Familiarity with advanced packaging technologies:2.5D / 3D integration, Chiplet, CPO/CPC
Experience with system-level cooling solutions: Liquid cooling, cold plates, immersion cooling
Knowledge of JEDEC standards and reliability qualification methodologies
Experience working with OSATs and substrate vendors on thermal/mechanical design optimization
Proficiency in scripting (Python, MATLAB) for modeling automation
Exposure to multi-physics coupling (electrical–thermal–mechanical interactions)

Responsibilities

Define and drive thermal and mechanical modeling strategies for advanced packages (FCBGA, FCCSP, multi-die, and chiplet-based architectures)
Perform detailed thermal simulations including steady-state and transient heat transfer (conduction, convection, and interface resistances such as TIM1/TIM2)
Develop and deploy compact thermal models (CTM), reduced-order models (ROM), and DELPHI-based models for system-level integration
Analyze power density, hotspot behavior, and package-to-system thermal interactions across air and liquid cooling environments
Perform thermo-mechanical stress/strain analysis including CTE mismatch, viscoelastic material behavior, and deformation
Predict package warpage across process and use conditions (reflow, underfill cure, board attach, field operation)
Model solder joint reliability and fatigue using industry standard models
Drive package design decisions including material selection (EMC, substrate, TIM, lid/heat spreader), thermal path optimization, and early-stage architecture definition across air and liquid cooling solutions (air, cold plate, CPO/CPC)
Conduct DOE, sensitivity studies, and worst-case analysis to guide tradeoffs across performance, cost, reliability, and manufacturability
Partner cross-functionally to drive chip–package–board co-design and resolve system-level thermal/mechanical challenges, including system integration constraints
Serve as a technical interface for customers and internal teams, translating modeling results into actionable insights and leading design reviews and issue resolution
Develop and scale modeling methodologies, workflows, and BKMs; mentor engineers and improve efficiency through automation and scripting (Python, MATLAB)