Senior Mechanical Engineer - Vacuum

Commonwealth Fusion Systems•Milpitas, CA

10d•$146,000 - $210,000•Onsite

About The Position

Commonwealth Fusion Systems is seeking a Senior Mechanical Engineer to join its R&D and equipment design team. The role focuses on the end-to-end design, integration, and implementation of advanced thermal vacuum equipment and R&D machinery. The engineer will provide technical leadership, develop innovative system architectures, and apply disciplined engineering practices to high-performance hardware. The position involves solving complex thermal-mechanical problems in vacuum environments and mentoring others in a collaborative, fast-paced setting.

Requirements

Master’s degree in Mechanical Engineering or a related field, or equivalent industrial experience.
At least 7 years of experience designing and implementing complex R&D systems or semiconductor manufacturing equipment.
Practical experience managing vacuum architecture, including pumps, gauges, and leak detection, as well as thermal management systems such as chillers and heat exchangers.
Deep understanding of vacuum architecture, including material outgassing, seal integrity, and pump-down optimization.
Expertise with 3D modeling software such as SolidWorks and/or NX, and FEA/thermal simulation tools such as COMSOL or ANSYS.
Hands-on experience bridging design and shop-floor work, including manual/CNC machining, prototyping, and hardware troubleshooting.
Experience selecting and qualifying global vendors for specialized components or custom subsystems.
Demonstrated ability to lead effectively in direct and matrixed organizational structures.
Ability to lift up to 25 lbs occasionally.
Ability to stoop, climb, and stand or sit for extended periods.
Willingness to travel or work required nights, weekends, or on-call occasionally.
Commitment to safety around potential industrial hazards, including heat, cold, noise, fumes, strong magnets, lead, high voltage, high current, pressure systems, and cryogenics.
Ability to comply with U.S. Export Control Laws concerning controlled or protected technologies or information.

Nice To Haves

Prior success building first-of-kind or experimental tools for semiconductor R&D or thin-film deposition.
Familiarity with SEMI, ASME, ASTM, and other industry-standard mechanical codes.
Experience designing precision motion and motor-controlled systems for challenging environments.

Responsibilities

Own the design, integration, and validation of R&D equipment.
Establish system-level requirements and design concepts that connect mechanical precision to product quality.
Implement and maintain engineering workflows and best practices guided by semiconductor standards.
Conduct reviews of mechanical systems and subsystems, emphasizing design for manufacturability and sound mechanical design practices.
Develop and maintain critical interfaces with scientists, vacuum specialists, electrical engineers, and other cross-functional teams.
Report project milestones to stakeholders and support delivery of on-time, in-spec outcomes.
Drive projects from concept through assembly, testing, and implementation.