
Mixx Technologies, Inc. is a California-based technology company specializing in ultra-efficient silicon photonics connectivity solutions designed to scale AI performance sustainably. Their core…

Mixx Technologies, Inc. is a California-based technology company specializing in ultra-efficient silicon photonics connectivity solutions designed to scale AI performance sustainably. Their core…
About Mixx Technologies
Mixx Technologies is building next-generation optical interconnect solutions that enable true system-level integration for hyperscale data centers. We combine expertise in silicon photonics, packaging, fiber connectivity and system integration to deliver products that set new standards for performance, density, and scalability to drive the next generation of artificial intelligence.
Position Overview
We are seeking a Mechanical Engineer with deep expertise in thermal stress, strain management, and finite element analysis (FEA) for advanced semiconductor packages. In this role, you will model, simulate, and optimize 2.5D/3D/3.5D packaging architectures, including silicon and organic interposers, multi-die systems, and heterogeneous integration structures. You'll collaborate closely with electrical, materials, and reliability engineers to ensure robust mechanical and thermal performance in next-generation high-density interconnect designs.
Key Responsibilities
• Perform detailed finite element analysis (FEA) using ANSYS Mechanical (or equivalent tools) to evaluate thermal stresses, warpage, and mechanical strain in advanced package assemblies.
• Develop mechanical models for 2.5D/3D/3.5D multi-die systems including silicon and organic interposers, TSVs, micro-bumps, and underfill materials.
• Conduct tolerance analysis and design of experiments (DOE) to predict system-level behavior under manufacturing and thermal cycling conditions.
• Identify critical material interactions, manage CTE (Coefficient of Thermal Expansion) mismatches, and mitigate reliability risks (e.g., delamination, cracking, solder fatigue).
• Support package layout optimization, thermal-mechanical co-design, and warpage mitigation strategies in collaboration with optical, packaging and materials teams.
• Present simulation results and design recommendations to cross-functional teams and management.
• Continuously refine and validate FEA methodologies through correlation with experimental and reliability test data.
Key Qualifications
• B.S. or M.S. in Mechanical Engineering, Materials Science, or a related discipline (Ph.D. a plus).
• 7+ years of relevant experience in advanced semiconductor packaging, FEA modeling, or thermo-mechanical reliability analysis.
• Strong proficiency in ANSYS Mechanical, including nonlinear material modeling, contact analysis, and thermal-structural coupling.
• Proven experience in tolerance analysis, strain/stress modeling, and warpage prediction at package and module levels.
• Familiarity with 2.5D/3D IC, silicon/organic interposers, multi-chip modules (MCM), and heterogeneous integration.
• Understanding of package materials and interfaces (solder, underfill, epoxy, molding compounds, substrates).
Preferred Skills
• Experience correlating FEA models with reliability data (thermal cycling, drop, humidity, etc.).
• Knowledge of system-level thermal management and heat dissipation design.
• Familiarity with electro-thermal co-simulation or optical-thermal interactions in highperformance systems.
• Excellent communication and collaboration skills across multi-disciplinary teams.
Why Join Us
At Mixx Technologies, you’ll be part of a fast-moving team rethinking what's possible in AI infrastructure. We offer a collaborative culture, deep technical challenges, and the opportunity to shape the mechanics behind the world's most advanced computing systems.
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