Sr Principal Signal Integrity Engineer

Location: Livermore, CA

Time Type: Full time

Job Description

Forming Our Future together

FormFactor, Inc. (NASDAQ: FORM), is a leading provider of essential test and measurement technologies along the full semiconductor product life cycle — from characterization, modeling, reliability, and design de-bug, to qualification and production test. Semiconductor companies rely upon FormFactor’s products and services to accelerate profitability by optimizing device performance and advancing yield knowledge. The company serves customers through its network of facilities in Asia, Europe, and North America.

Rooted in our core values — Focus on the Customer, Ownership & Accountability, Respectfully & Effectively Communicate, and Motivate & Develop People — we foster an environment where diverse perspectives are not only welcomed but celebrated. Everyone can make an impact here. Whether it's improving products, supporting customers, or positively influencing peers and the community, the contributions of our people matter.

Shift:

The regular hours for this position are day shift.

Job Description:

FormFactor’s Probes Product Development team is hiring a Signal Integrity (SI) Engineer to architect, simulate, and validate high-speed interconnect performance across complex, fine pitch probe card assemblies used for advanced wafer test. This role is critical in ensuring high-speed electrical performance and signal integrity for advanced semiconductor test solutions. The ideal candidate will have strong expertise in high-frequency design, simulation, and analysis to support next-generation probe card technologies for leading semiconductor manufacturers.

KEY RESPONSIBILITIES:

Design & Analysis

• Perform signal integrity analysis for high-speed interconnects in probe card assemblies.

• Develop and validate electrical models for transmission lines, connectors, probes, and PCB/MLO structures.

• Define electrical stack-ups and impedance targets.

• Perform what-if studies to optimize high-frequency behavior.

Simulation & Modeling

• Utilize tools such as HFSS, ADS, or equivalent for electromagnetic and circuit simulations.

• Conduct time-domain and frequency-domain analysis to ensure compliance with performance requirements.

• Build IBIS AMI or behavioral channel models and eye diagrams for target data rates (e.g., 16–448 Gbps PAM4/NRZ).

Testing & Validation

• Define and execute test plans for signal integrity validation using high-speed measurement equipment (e.g., VNA, TDR).

• Develop fixtures and golden structures.

• Drive simulation to measurement correlation.

• Analyze test data and correlate with simulation results to refine design.

Continuous Improvement

• Drive innovation in probe card electrical design to support evolving semiconductor technology nodes.

• Stay current with industry trends in high-speed interconnects and signal integrity best practices.

PREFFERED QUALIFICATIONS:

• Strong understanding of signal integrity, including transmission line theory, crosstalk reduction, power integrity, and high‑speed interface performance

• Proficiency in EM & circuit tools: HFSS/CST/SIwave + ADS/Sigrity (or equivalents)

• Hands on VNA/TDR/TDT measurement and de embedding skills

• Scripting experience for data analysis, automation, or workflow optimization

• Familiarity with PCIe/HBM/SerDes channel requirements and PAM4 systems

• Experience with probe cards, interposers, fine pitch interconnects, MEMS probes, or advanced socketing is a plus.

Skills:

ANSYS HFSS, ANSYS SIwave, Autodesk AutoCAD, Cadence Tools, Electromagnetic Simulations, High Frequency Measurements, MATLAB, PathWave Advanced Design System (ADS), Power Integrity, Python (Programming Language), Signal Integrity, SolidWorks, Vector Network Analyzer (VNA)

Education & Experience:

Minimum of 8 years of related experience with a Bachelor’s degree; or 6 years and a Master’s degree; or a PhD with 3 years experience; or equivalent experience | Required

Pay Range:

$136,200.00 - $178,815.00

Pay Range Explained:

This role in Livermore, California pays between $136,200.00 and $178,815.00 per year, depending on your experience, skills, and background. Pay may vary in other locations. We offer a full benefits package, including medical, dental, vision, life insurance, disability coverage, a 401(k) with company match, employee stock purchase plan (ESPP), and paid time off. You’ll also be eligible for quarterly profit-sharing bonuses and flexible spending or savings accounts.

Equal Employment Opportunity Statement

FormFactor is an equal opportunity employer. FormFactor complies with all national, state, and local laws that seek to promote equal opportunities for any applicant or employee without regard to age, race, color, gender, gender identity/expression, national origin, sexual orientation, religion, disability, marital status, pregnancy or related condition, military service, or any other legally protected characteristics. These protections apply to all aspects of employment, including but not limited to, recruitment, hiring, training, promotions, and compensation.

For roles that are designated as remote-eligible, employees cannot be located in: AL, AK, AR, DE, GA, HI, IL, IA, KY, LA, ME, MD, MS, MO, NE, NV, NJ, NM, ND, OK, PA, RI, SC, SD, TN, WV, WI, WY. This list is continuously evolving and being updated, please check back with us if the state you live in is on the exclusion list. A role is remote-eligible only when it is listed as "Remote" in the job location.