Senior / Staff Ingenieur für Schweiß- und Dichttechnik (m/w/d)

Factorial Energy is a pioneering U.S.-based solid-state battery company driving the future of energy storage and electrification. Partnered with global leaders including Mercedes-Benz, Stellantis, Hyundai, and Kia, Factorial is at the forefront of developing next-generation e-mobility platforms for commercial, defense, and consumer applications-spanning electric vehicles (EVs), drones, eVTOL aircraft, power tools, marine systems, robotics, and more. The company has achieved multiple industry firsts, including being the first to power a demonstration vehicle with a global OEM (Mercedes- Benz) which achieved over 1,200 km (749 mi) of range, and the first to earn UN 38.3 certification for automotive-sized lithium-metal solid-state cells, the first to deliver B-samples of automotive-sized solid-state batteries to major OEMs.

The Opportunity

Factorial Energy is seeking a Senior / Staff Welding & Sealing Equipment Engineer to join our Cheonan, South Korea site. This person will own the full-cycle development, commissioning, customization, optimization, and mass production scaling of automatic welding and sealing equipment for our Silicon Power Cell pouch cell line. This person will lead welding & sealing equipment R&D, prototype debugging, pilot verification, and mass production iteration; deliver equipment technical upgrades, OEE and yield improvements, and build standardized equipment management systems.

In this role, you will

• Lead full-lifecycle development, commissioning, and mass-production validation of automatic welding and sealing equipment, iterate core process parameters, and complete equipment adaptation for new product launch.
• Conduct equipment review, FAT/SAT acceptance and IQ/OQ/PQ qualification, and unify precision and quality control standards for welding and sealing processes.
• Upgrade and retrofit mass-production welding and sealing equipment to improve OEE, production yield and line capacity, and reduce manufacturing costs.
• Optimize welding fixtures, sealing structures and core process parameters to stabilize production, eliminate welding spatter, virtual welding, seal leakage and wrinkling issues, and support rapid multi-spec pouch cell changeover.
• Build complete standardized equipment management systems for welding and sealing stations, including SOPs, maintenance schedules, calibration specifications, PFMEA, control plans, and equipment failure databases.
• Collaborate with cross-functional teams (R&D, Process, Quality, Manufacturing, Maintenance) and external vendors to advance new line startup, equipment development and technical renovation projects.
• Optimize laser welding energy control, servo positioning logic, and sealing pressure/temperature closed-loop parameters to adapt silicon anode cell characteristics and eliminate assembly defects.
• Lead equipment technical transfer from lab/pilot EVT/DVT/PVT to mass production, identify equipment bottlenecks and drive sustained yield improvement.
• Adopt 8D, DOE, SPC, and root-cause analysis to resolve typical welding and sealing abnormalities, drive cross-functional troubleshooting, and close CAPA for recurrent equipment failures.

We are looking for people who

• Bachelor's degree or above in mechanical, mechatronics, electrical automation, materials, chemical engineering or related fields.
• 3+ years of experience in pouch cell welding & sealing equipment development, retrofit and production ramp-up.
• 2+ years of professional experience in laser welding and thermal sealing equipment structure and control logic; skilled in welding energy tuning, track precision control, temperature/pressure parameter calibration and sealing uniformity optimization.
• Capable of mechanical/electrical drawing reading and CAD/SolidWorks fixture design; familiar with laser control system, servo motion, constant temperature-pressure control and precision automation systems.
• Proficient in DOE, PFMEA, Control Plan, 8D and root cause analysis; independent in equipment troubleshooting and technical optimization.
• Experienced in pouch cell welding & sealing line NPI and mass production ramp-up projects.
• Equipped with cross-functional coordination, project management and overseas vendor communication abilities; competent in on-site troubleshooting and English technical documentation.
• Proficient in English for technical document reading, global technical meetings and technical report delivery.

Work Location

Cheonan, South Korea

Factorial Energy is an equal opportunity employer that values diversity at all levels. All qualified applicants, regardless of personal characteristics, are encouraged to apply.

To request a reasonable accommodation to complete an application, job interview, and/or to otherwise participate in the hiring process, please contact ([email protected])