Staff Mechanical Engineer

Onto Innovation•Milpitas, CA

About The Position

Onto Innovation is seeking a Staff Mechanical Engineer to join their team. This role involves applying the Onto Innovation product development process from concept through manufacturing release, with a strong emphasis on control system architecture, integration, and validation for precision semiconductor capital equipment. The engineer will lead mechanical and mechatronic design, focusing on dynamics-informed design to enable high-performance motion control. This includes developing and supporting motion control systems, performing dynamic system analysis, conducting controls-driven design analysis, and defining/validating control performance requirements. The position also involves participating in system integration and commissioning, supporting system-level characterization and validation, and collaborating cross-functionally with controls, electrical, and software teams. The role requires providing technical support to manufacturing, service, and customers for motion performance issues.

Requirements

BS/MS/PhD in Mechanical Engineering or related field with strong emphasis on dynamics, controls, or mechatronics
7+ years of experience in precision mechanical/mechatronic systems with hands-on motion control and servo tuning experience
Strong fundamentals in: Control systems engineering (feedback control, stability, loop shaping)
Strong fundamentals in: Structural dynamics and vibration analysis
Strong fundamentals in: System identification and frequency-domain analysis
Experience with: Servo tuning tools and motion controllers
Experience with: Multi-axis stage systems and precision motion platforms
Experience with: Sensors and feedback systems (encoders, interferometers, capacitive sensors)
Proficiency in: FEA tools for dynamic and thermal modeling
Proficiency in: Troubleshooting complex system-level performance issues
Familiarity with semiconductor equipment or similar high-precision, high-bandwidth motion systems
Understanding of compliance standards (SEMI, CE, UL) with respect to system performance and safety
Strong ability to: Diagnose and resolve control-performance limitations (mechanical vs control root cause)
Strong ability to: Work at system level across mechanical, electrical, and software domains
Strong ability to: Communicate complex control concepts clearly to cross-functional teams

Nice To Haves

Must be able to travel internationally to customer sites at least 20% of the time, with additional travel as business needs require.

Responsibilities

Apply the Onto Innovation product development process from concept through manufacturing release, with strong emphasis on control system architecture, integration, and validation for precision semiconductor capital equipment.
Lead mechanical and mechatronic design with a focus on dynamics-informed design to enable high-performance motion control (stiffness, damping, eigenfrequency management, thermal stability).
Develop and support motion control systems including: Servo loop design, tuning, and optimization (PID, feedforward, notch filtering), Stage control architectures (single-axis, multi-axis, coordinated motion), Integration of encoders, interferometers, and high-resolution feedback systems.
Perform dynamic system analysis including: Modal analysis and frequency response (Bode/Nyquist), Vibration characterization and mitigation aligned to VC standards, Identification and mitigation of structural resonances impacting control bandwidth and stability.
Conduct controls-driven design analysis, including: Tolerance stack-up with impact on control performance (following error, settling time), FEA with focus on dynamic behavior (mode shapes, compliance paths), Thermal-mechanical interactions affecting control accuracy and drift.
Define and validate control performance requirements, including: Positioning accuracy, repeatability, settling time, and throughput, Stability margins and robustness to disturbances, System-level error budgeting (mechanical + control contributions).
Participate in system integration and commissioning, including: Servo tuning and optimization on hardware, Prototype bring-up, system identification, and parameter extraction, Debugging control instabilities, noise, and cross-axis coupling.
Support system-level characterization and validation: Frequency response measurement (FRF), step response, tracking performance, Vibration sensitivity and environmental coupling, Compliance with SEMI and other performance standards.
Collaborate cross-functionally with controls, electrical, and software teams to: Define control architectures and interfaces, Translate system requirements into control specifications, Ensure alignment between mechanical design and control performance.
Support multiple programs by delivering controls-aware designs that meet schedule, cost, and performance targets.
Provide technical support to manufacturing, service, and customers for motion performance issues, root cause analysis, and field improvements.