Packaging Engineer- Materials

<p>We’re looking for a hands-on process and materials engineer to own wafer level molding and underfill processes, material qualification, and assembly integration across development and manufacturing.</p> <p>&nbsp;</p> <p><strong>Summary:</strong></p> <p>Seeking an experienced engineer to lead wafer level mold and underfill process development for advanced semiconductor packages (fan-out wafer level packaging, 2.5D/3D, chiplet). This role spans</p> <p>mold compound and underfill material selection and qualification, wafer level molding and encapsulation processes, underfill dispense and cure, reliability, failure analysis, and cross-functional support through package and system productization.</p> <p>&nbsp;</p> <p><strong>Core Responsibilities:</strong></p> <ul> <li>Develop and optimize wafer level molding processes including compression molding, transfer</li> </ul> <p>molding, and mold underfill (MUF) for fan-out and advanced heterogeneous packages.</p> <ul> <li>Own mold compound and underfill material selection and qualification, including evaluation of</li> </ul> <p>filler content, CTE, modulus, Tg, viscosity, and moisture uptake to meet thermo-mechanical and</p> <p>reliability requirements.</p> <ul> <li>Drive underfill process development including capillary underfill (CUF) dispense strategies, flow</li> </ul> <p>and void optimization, and cure profile development for high-density flip chip and chiplet</p> <p>assemblies.</p> <ul> <li>Evaluate and mitigate assembly risks including warpage, delamination, void formation, bleed-out,</li> </ul> <p>mold flash, and filler settling; define process windows and controls to ensure repeatable yield</p> <p>across wafer and panel formats.</p> <ul> <li>Collaborate with OSATs and material suppliers to qualify mold and underfill materials, define</li> </ul> <p>dispense and cure equipment requirements, and manage process transfers into production.</p> <ul> <li>Lead characterization of mold and underfill material properties (viscosity, gel time, cure kinetics,</li> </ul> <p>adhesion, CTE, modulus) and correlate material behavior to process outcomes and package</p> <p>reliability.</p> <ul> <li>Work closely with thermal mechanical modeling teams to model solder joint reliability of bump</li> </ul> <p>interconnects with various underfills and predict warpage with various mold compouds.</p> <ul> <li>Support reliability qualification including thermal cycling, drop, mechanical shock, and power</li> </ul> <p>cycling.</p> <ul> <li>Work cross-functionally with design, reliability, thermal, and manufacturing teams to ensure</li> </ul> <p>robust package performance from concept through high-volume production.</p> <p>&nbsp;</p> <p>&nbsp;</p> <p><strong>Required Technical Skills:</strong></p> <ul> <li>Strong experience in wafer level molding and underfill processes for advanced semiconductor</li> </ul> <p>packages including fan-out wafer level packaging (FOWLP), 2.5D, and chiplet architectures.</p> <ul> <li>Deep understanding of mold compound and underfill material science including epoxy resin</li> </ul> <p>systems, filler particle size and loading, cure chemistry, and how material properties drive</p> <p>thermo-mechanical package behavior.</p> <ul> <li>Experience with underfill dispense techniques (capillary, no-flow, mold underfill), flow and void</li> </ul> <p>characterization, bleed-out control, and cure process optimization including staged and snap</p> <p>cure profiles.</p> <ul> <li>Understanding of thermo-mechanical behavior driven by mold and underfill materials including</li> </ul> <p>CTE mismatch, warpage evolution through cure and reflow, delamination driving forces, and</p> <p>material-induced reliability risks.</p> <ul> <li>Hands-on experience with failure analysis of mold and underfill failures including cross-sections,</li> </ul> <p>SEM/EDS, CSAM, TGA, DSC, and DMA for material characterization and thermal cycling reliability</p> <p>evaluation.</p> <ul> <li>Ability to work with OSATs and material suppliers to develop, qualify, and transfer mold and</li> </ul> <p>underfill processes into production, including equipment setup and process control plans.</p> <ul> <li>Strong problem-solving skills with ability to debug mold and underfill yield and reliability issues in</li> </ul> <p>manufacturing environments, including DOE-driven process optimization.</p> <p>&nbsp;</p> <p>&nbsp;</p> <p><strong>Preferred / Differentiating Skills:</strong></p> <ul> <li>Experience underfill materials for III-V or photonics packaging including optically clear</li> </ul> <p>encapsulants and low-modulus underfills.</p> <ul> <li>Experience with mold and underfill integration in advanced packaging architectures including</li> </ul> <p>2.5D interposers, 3D stacking, chiplet assemblies, and CoWoS-like structures where material</p> <p>interactions and warpage are critical constraints.</p> <ul> <li>Familiarity with a broad bill of materials for advanced packaging encapsulation including clear</li> </ul> <p>adhesives and underfills for photonics, high-filler, low-CTE mold compounds for 2.5D interposer</p> <p>assemblies.</p> <ul> <li>Experience developing mold and underfill solutions for high-power or high-TDP devices where</li> </ul> <p>material thermal conductivity, warpage stability, and coefficient of thermal expansion are tightly</p> <p>constrained.</p> <ul> <li>Exposure to thermo-mechanical modeling or collaboration with simulation teams for warpage</li> </ul> <p>prediction, delamination risk assessment, and material property sensitivity analysis for mold and</p> <p>underfill optimization.</p> <ul> <li>Understanding of system-level interactions (TIM application and cold plate interaction with wafer</li> </ul> <p>level molded wafer).</p>