Test Engineer

Flex is the diversified manufacturing partner of choice that helps market-leading brands design, build and deliver innovative products that improve the world. 

A career at Flex offers the opportunity to make a difference and invest in your growth in a respectful, inclusive, and collaborative environment. If you are excited about a role but don't meet every bullet point, we encourage you to apply and join us to create the extraordinary.

Job Summary

The Test Engineer is responsible for developing, validating, and sustaining cost effective and robust test methodologies for server Power Supply Units (PSU), Battery Backup Units (BBU), and Battery Management Systems (BMS) across R&D, NPI, and mass production. This role leads test system design, automation development, test coverage definition, and data driven problem solving to ensure product quality, yield improvement, and manufacturing readiness.

This position reports to Director, Test Development.

What a typical day looks like:

1. Test Strategy & Coverage Development

• Define comprehensive test coverage, test jig design and specification, limits, and acceptance criteria for EVT, DVT, PVT, and MP phases.
• Establish methodologies for validating power stages, control function, protection features, balancing algorithms, and BMS interfaces.
• Drive DFx/Testability improvements with hardware, firmware, and system teams.

2. Test System & Automation Development

• Architect, build, and integrate test fixtures, load banks, oscilloscopes, DAQs, communication interfaces, and measurement systems.
• Develop automated test sequences using SCPI, NI VISA, VB/VBScript, and internal ATS platforms.
• Ensure test equipment calibration, traceability, and long-term maintainability.
• Implement robust safety procedures for high voltage validation environments.

3. Power & Communication Performance Validation

• Validate PFC, LLC/DC DC stages, efficiency, transient response, protections, thermal behavior, and derating profiles.
• Characterize BMS functions including SOC/SOH estimation, cell balancing, charge/discharge control, and system alarms.
• Validate digital communication protocols including PMBus, CAN/UDS, and RS 485/Modbus to ensure functional and fault tolerant operation.

4. Data Analytics, Reporting & Quality Management

• Acquire, process, and analyze test data to identify trends, escapes, FPY gaps, and systemic issues.
• Prepare clear and structured reports for engineering reviews, customer discussions, and factory builds.
• Maintain controlled revision histories of test methods, scripts, and documentation.

5. Issue Resolution & Continuous Improvement

• Lead root cause analysis for test failures, escapes, and yield issues.
• Drive containment, corrective actions, and long term preventive measures.
• Collaborate cross functionally with FW, HW, ME, TE, and factory quality teams.

6. Manufacturing & NPI Support

• Transfer developed test solutions to manufacturing sites; ensure alignment with process, capability, and quality requirements.
• Train technicians, operators, and factory test engineers.
• Support pilot builds, ramp readiness, and urgent on site issue containment.

The experience we’re looking to add to our team:

• Bachelor’s degree in Electrical Engineering, Electronics Engineering, or related field.
• 3~7+ years of hands-on experience in power electronics testing for PSU, BBU, BMS, or energy storage systems.
• Strong proficiency in power test instrumentation: AC sources, DC loads, power analyzers, DMMs, oscilloscopes, hipots, Burn-in chambers.
• Experience with Chroma systems (ATE, AC/DC loads, power meters).
• Proficient in test automation using SCPI, NI VISA, VB/VBScript, Python, or similar scripting tools.
• Solid knowledge of communication protocols: PMBus, I²C/SMBus, CAN/UDS, RS 485/Modbus.
• Strong abilities in data analysis, statistical interpretation, and technical reporting.
• Clear, concise technical communication.
• Strong ownership and structured problem solving mindset.
• Effective teamwork across hardware, firmware, validation, test jig vendors and manufacturing teams.

Here are a few of our preferred experiences:

• Experience executing test activities across EVT/DVT/PVT for high volume power products.
• Familiarity with ATS/ATE platforms, fixture DFx, and manufacturing test architecture.
• Hands on experience with troubleshooting (automaton bugs, noise and interference effects, grounding practices).

What you’ll receive for the great work you provide:

• Social Insurance (Labor Insurance, NHI, Labor Pension)
• Group Insurance (Life Insurance)
• PTO

EY02

KL03

Job Category

Design, Process & Technology Engineering

Required Skills:

Optional Skills:

Flex is an Equal Opportunity Employer and employment selection decisions are based on merit, qualifications, and abilities. We do not discriminate based on: age, race, religion, color, sex, national origin, marital status, sexual orientation, gender identity, veteran status, disability, pregnancy status, or any other status protected by law. We're happy to provide reasonable accommodations to those with a disability for assistance in the application process. Please email accessibility@flex.com and we'll discuss your specific situation and next steps (NOTE: this email does not accept or consider resumes or applications. This is only for disability assistance. To be considered for a position at Flex, you must complete the application process first).