Grounding SMT Setup Delays and Attrition Limits in Assembly Agreements
Assembly agreements define line setup boundaries and package specific attrition limits to prevent unexpected downtime surcharges and inventory deficits.
Tape Leadership Component Loss
Leader Attrition
Component packaging specifications require empty non-component carrier tape lengths at the start of continuous embossed carrier reels to facilitate feeder threading. Quantifying tape leadership component loss accounts for missing or unpickable parts sacrificed when attaching tape leaders to placement machine drive sprockets. Automated feeder mechanisms need clear leader length to engage drive gears before the active component pocket reaches the pick position.
Cut tape strips lacking standardized leader lengths lose initial component pockets during manual feeder loading.
Loading Physics
Feeder loading operators pull leading cover tape back to expose initial carrier pockets while threading sprockets. This mechanical setup process causes tape leadership component loss when leading pocket cover tape peels prematurely or spills loose components. Splicing cover and carrier tape onto existing reels reduces leader loss on partial component reels during high-mix assembly.
Automated tape splicing tools join carrier ends without discarding initial component pockets, preserving expensive or low-volume integrated circuits. Factory bill of materials software incorporates leader loss constants per reel change to prevent inventory discrepancy reports.
Material Boundary
Leader scrap accounting applies strictly during reel loading and feeder sprocket threading operations. Component drops occurring after continuous feeder indexing begins belong to operational pick failure metrics rather than tape leader loss.