SI/PI Engineer

Excelon Solutions; Sunnyvale (CA); On-site; USD 150,000 - 190,000; Full time

Job summary

Excelon Solutions, Sunnyvale, CA, seeks an experienced SI/PI Engineer to advance signal and power integrity analysis for next-generation packaging, including 2.5D/3D architectures and high-bandwidth memory interfaces.

You will develop high-speed channel models, perform full-wave EM simulations, and optimize PDN from die to board, collaborating across IC, substrate, PCB, and thermal teams. Strong Python/MATLAB/Tcl scripting and lab measurement experience are required.

Qualifications

• 5+ years of experience in SI/PI analysis for semiconductor packaging or high-speed PCB design.
• Deep understanding of transmission line theory and S-parameter analysis.
• Experience with high-speed interface protocols (PCIe, UCIe, HBM, DDR, Ethernet SerDes).
• Proficiency in package stackup design, impedance control, and via transition optimization.
• Hands-on measurement correlation (VNA, TDR/TDT, oscilloscope).
• Programming/scripting in Python, MATLAB, Tcl for automation and post-processing.

Responsibilities

• Perform SI/PI analysis and design optimization for advanced silicon packages (CoWoS, EMIB, chiplet architectures).
• Develop and validate high-speed channel models for package interconnects (bumps, microbumps, TSVs, RDL, interposers).
• Run full-wave EM simulations to characterize S-parameters, crosstalk, impedance, and loss.
• Design and optimize PDN including decoupling, IR drop, and AC impedance from die to board.
• Conduct time-domain simulations (eye diagrams, BER) for PCIe Gen5/6, UCIe, HBM3/3E, DDR5, SerDes >112 Gbps.
• Collaborate with IC/package/PCB/thermal teams to co-optimize electrical performance.
• Develop and correlate simulation models with lab measurements (VNA, TDR, oscilloscope).
• Define SI/PI design guidelines for substrate stackup, routing, bumps/via assignments.
• Support DFM reviews with OSAT partners and substrate vendors.
• Investigate and resolve SI/PI-related failures during bring-up and validation.

Skills

SI/PI analysis

EM & circuit theory

Python

MATLAB

Tcl

S-parameter analysis

Transmission line theory

Tools

Ansys HFSS

Ansys SIwave

Cadence Clarity 3D

Keysight ADS Momentum

Synopsys HSPICE

Cadence Spectre

Keysight ADS

Ansys RedHawk

Cadence Voltus

Sigrity PowerDC/PowerSI

Job description

We are seeking an experienced SI/PI Engineer to join our Advanced Silicon Packaging team. In this role, you will be responsible for signal integrity and power integrity analysis, modeling, and design optimization of next-generation multi-die packaging architectures including 2.5D/3D integration, silicon interposers, and high-bandwidth memory (HBM) interfaces.

Team: Hardware Design Engineering — Advanced Packaging

Key Responsibilities

• Perform SI/PI analysis and design optimization for advanced silicon packages (CoWoS, EMIB, chiplet-based architectures, fan-out wafer-level packaging)
• Develop and validate high-speed channel models for package interconnects including bumps, microbumps, TSVs, RDL layers, and silicon/organic interposers
• Conduct full-wave electromagnetic (EM) simulations of package structures to characterize S-parameters, crosstalk, impedance, and insertion/return loss
• Design and optimize Power Distribution Networks (PDN) — including decoupling strategy, IR drop analysis, and AC impedance profiling from die to board
• Perform time-domain simulations (eye diagram, BER analysis) for high-speed serial and parallel interfaces (PCIe Gen5/6, UCIe, HBM3/3E, DDR5, SerDes >112 Gbps)
• Collaborate with IC design, package substrate design, PCB layout, and thermal/mechanical teams to co-optimize package electrical performance
• Develop and correlate simulation models with lab measurements (VNA, TDR, oscilloscope, power noise measurements)
• Define SI/PI design guidelines and constraints for package substrate stackup, routing rules, and bump/via assignments
• Support design-for-manufacturability (DFM) reviews with OSAT partners and substrate vendors
• Investigate and resolve SI/PI-related failures during silicon bring-up and validation phases

Required Qualifications

• 5+ years of experience in SI/PI analysis for semiconductor packaging or high-speed PCB design
• Strong proficiency with industry-standard EM and circuit simulation tools:
  • EM Solvers: Ansys HFSS, Ansys SIwave, Cadence Clarity 3D, Keysight ADS Momentum
  • Circuit Simulation: Synopsys HSPICE, Cadence Spectre, Keysight ADS
  • PDN Analysis: Ansys RedHawk, Cadence Voltus, Sigrity PowerDC/PowerSI
• Deep understanding of transmission line theory, Maxwell's equations, and S-parameter analysis
• Experience with high-speed interface protocols (PCIe, UCIe, HBM, DDR, Ethernet SerDes)
• Proficiency in package stackup design, impedance control, and via transition optimization
• Hands-on experience with measurement correlation (VNA, TDR/TDT, near-field scanning)
• Programming/scripting skills (Python, MATLAB, Tcl) for automation and post-processing

Preferred Qualifications

• Experience with 2.5D/3D advanced packaging technologies (CoWoS, EMIB, Foveros, hybrid bonding)
• Familiarity with chiplet-based disaggregated architectures and die-to-die interconnect standards (UCIe, BoW)
• Knowledge of co-simulation methodologies (chip-package-board co-design)
• Experience with statistical analysis and Monte Carlo methods for manufacturing variation impact
• Understanding of thermal-aware electrical analysis (electro-thermal co-simulation)
• Contributions to IEEE/DesignCon publications or industry standards committees (JEDEC, OIF, UCIe Consortium)
• Experience working with OSATs (ASE, Amkor, TSMC InFO/CoWoS) and substrate vendors