Packaging Engineer- Flip Chip

We're seeking experienced engineers to contribute to flip chip package development and assembly processes for advanced semiconductor devices (2.5D/3D/chiplet/fan-out/flip-chip). This spans bump metallurgy, substrate integration, reflow and underfill processes, reliability, failure analysis, and cross-functional support through package and system productization. Core Responsibilities: • Develop and optimize flip chip attach processes including bump formation, placement, reflow, and underfill for high-performance semiconductor packages. • Define and manage bump metallurgy stacks (e.g., Cu pillar, SnAg, micro-bumps) and substrate pad finishes for robust interconnect performance. • Drive package integration from die to substrate, ensuring alignment, coplanarity, and yield optimization. • Evaluate and mitigate assembly risks including warpage, non-wet opens, voiding, head-in-pillow, and interconnect defects. • Collaborate with substrate vendors, OSATs, and internal teams to define design rules (pad pitch, bump pitch, keep-outs, stack-ups). • Lead process development for reflow profiles, flux selection, cleaning, and underfill dispense/cure. • Perform root cause analysis of assembly and reliability failures using cross- sectioning, SEM, CSAM, and other failure analysis techniques. • Support reliability qualification including thermal cycling, drop, mechanical shock, and power cycling. • Work cross-functionally with design, reliability, thermal, and manufacturing teams to ensure robust package performance from concept through high-volume production. Required Technical Skills: • Strong experience in flip chip packaging and assembly processes for semiconductor devices. • Deep understanding of bumping technologies (solder bumps, Cu pillar, micro- bumps) and UBM/metallization systems. • Experience with underfill materials, dispense techniques, flow behavior, and cure processes. • Understanding of thermo-mechanical behavior in flip chip assemblies (CTE mismatch, warpage, solder fatigue, reliability risks). • Hands-on experience with failure analysis and reliability testing (cross-sections, SEM, CSAM, thermal cycling). • Ability to work with OSATs and suppliers to develop and transfer assembly processes into production. • Strong problem-solving skills with ability to debug yield and reliability issues in manufacturing environments. Preferred / Differentiating Skills: • Experience with III-V packaging, photonics packaging, and precision chip attach. • Experience with advanced packaging technologies including 2.5D interposers, 3D stacking, chiplets, and CoWoS-like architectures. • Familiarity with bill of materials used in photonics packaging such as clear adhesives and underfills as well as mold compounds and underfills for 2.5D advanced packaging. • Familiarity with fine-pitch micro-bump and hybrid bonding approaches. • Experience integrating high-power or high-TDP devices with tight warpage and thermal constraints. • Exposure to thermo-mechanical modeling or collaboration with simulation teams for warpage and reliability prediction. • Understanding of system-level interactions (PCB attach, second-level interconnect reliability).