The Sr. Principal Assembly & Test (A&T) SMT Engineer is responsible for owning, optimizing, and supporting Surface Mount Technology processes used in probe card manufacturing. This role ensures high quality PCB assembly, stable process capability, and predictable output across pickandplace, reflow, inspection, and associated upstream/downstream steps. The engineer provides technical leadership for SMT line performance, defect reduction, equipment improvements, and cross functional integration with plating, lithography, mechanical assembly, and electrical test teams.

Key Responsibilities:

SMT Process Engineering

• Develop, qualify, and maintain SMT processes, solder paste selection, solder paste injection and inspection, reflow profiling, and placement parameters.

• Own recipe creation and optimization for high density advanced probe card PCBs.

• Drive process capability improvements (Cp/Cpk) and ensure stable production performance.

Equipment Ownership

• Provide daily engineering support for SMT equipment such as:

• Stencil printer

• Pickandplace machine

• Reflow oven

• SPI (Solder Paste Inspection)

• Lead troubleshooting and root cause analysis for equipment failures, misplacements, reflow defects, or inspection inaccuracies.

• Define and maintain PM schedules, calibration, and spare parts strategies.

Quality & Yield Improvement

• Monitor and analyze yield, defect Paretos, and SPC trends to identify systemic issues.

• Lead DfX (Design for Assembly, Design for Manufacturability) discussions with design engineering.

• Implement corrective actions and sustainable process controls for solder bridging, opens, voiding, tombstoning, and wetting failures.

Manufacturing Support

• Support production technicians with process deviations, equipment issues, and new product introductions.

• Develop documentation including WI/SOPs, process parameters, machine setup sheets, and inspection criteria.

• Drive cycle time reduction, throughput improvements, and operator training.

Cross Functional Collaboration

• Work closely with:

• Plating & Metallization Engineers

• Photolithography Engineers

• Mechanical/Assembly Engineering

• Electrical Test Engineering (FPT, PRVX4)

• Supply Chain & Quality

• Provide engineering support during prototype builds and customer specific configurations.

Continuous Improvement

• Lead Lean/6σ initiatives to reduce waste, improve flow, and enhance process robustness.

• Evaluate and introduce new materials (solder paste, adhesives, fluxes) and improved stencil/hardware designs.

• Participate in equipment justification and capital project planning.

Preferred Experiences and Backgrounds:

• Bachelor’s degree in Electrical Engineering, Mechanical Engineering, Manufacturing Engineering, Materials Science, or related field.

• 3–7 years of SMT or PCB assembly experience (semiconductor, PCBA, or electronics assembly preferred).

• Strong understanding of solder paste behavior, reflow principles, component placement strategies, and defect mechanisms.

• Handson experience with SMT equipment and inspection systems (SPI, AOI).

• Proficiency with SPC, FMEA, DOE, and root cause problem solving.

• Experience in probe card, semiconductor test hardware, or high precision PCB manufacturing.

• Familiarity with high density BGAs, fine pitch components, and micro assembly.

• Knowledge of CAM/EDA data for stencil/paste aperture optimization.

• Lean/6σ Green Belt or Black Belt certification.

• Experience with MES systems and factory automation.