Project Overview

This project addresses recurring soldering defects including solder balls, open joints and cold solder joints detected from the collector mainboard SMT assembly process.

Root Cause Analysis

Process engineers collect defect distribution data, perform cross-section analysis and trace root causes related to stencil design, solder paste property and thermal profile.

Process Optimization

Multiple adjustment groups are designed iteratively: stencil aperture modification, reflow oven temperature curve tuning, printing pressure adjustment and component placement offset compensation. Small-batch trial production is carried out after each adjustment group is released.

First-pass yield data is collected statistically and tracked continuously with SPC charts. Once the optimal parameter set is confirmed, the parameters are solidified and released as official SOP for the assembly workshop, with operator training and quality patrol checkpoints added.

Results & Control

The improvement effectively reduces rework workload, cuts scrap loss and stabilizes daily output capacity of the mainboard production line.

Long-term yield monitoring is scheduled to prevent defect regression after process lock.