Senior Mechanical Engineer - Vacuum

Commonwealth Fusion Systems•Milpitas, CA

8d•Onsite

About The Position

Commonwealth Fusion Systems is seeking a Senior Mechanical Engineer to join its R&D and equipment design team. The role is responsible for the end-to-end design, integration, and implementation of advanced thermal vacuum equipment and R&D machinery. The engineer will provide technical expertise, develop innovative system architectures, and maintain disciplined engineering practices for high-performance hardware. The role 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 with vacuum architecture, including pumps, gauges, and leak detection, and thermal management systems, including chillers and heat exchangers.
Deep understanding of vacuum architecture, including material outgassing, seal integrity, and pump-down optimization.
Expertise in 3D modeling using SolidWorks and/or NX, and FEA or thermal simulation tools such as COMSOL or ANSYS.
Ability to bridge design and shop-floor work, including manual or CNC machining, prototyping, and hardware troubleshooting.
Experience selecting and qualifying global vendors for specialized components or custom subsystems.
Demonstrated ability to lead in direct and matrixed organizational structures.
Ability to lift up to 25 lbs occasionally.
Ability to stoop, climb, stand, and sit for extended periods.
Willingness to travel or work required nights, weekends, or on-call occasionally.
Dedication to safety around hazards that may include heat, cold, noise, fumes, strong magnets, lead, high voltage, high current, pressure systems, and cryogenics.
Compliance with U.S. laws concerning export-controlled or protected technologies and information is required.

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 in 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 design reviews of mechanical systems and subsystems, emphasizing manufacturability and mechanical design best practices.
Develop and maintain interfaces with scientists, vacuum specialists, electrical engineers, and other cross-functional teams.
Report project milestones to stakeholders and ensure timely delivery of in-spec outcomes.
Drive projects from concept through assembly, testing, and implementation.