Packaging Engineer- Flip Chip

Role details

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).