SOP: Stick and PCBA to bottom shell (sta:a2)

SYNTHETIC example. Rev C, 2026-10-14.

Operators: 1
Equipment: temperature-controlled soldering iron, 350 C, fume extractor, PCBA nest

Steps

1. Hand-solder stick module to the PCBA (6 pins) (op:stick-solder). Hand solder, no-clean flux core wire. Target 22 s.
2. Snap PCBA into bottom shell (op:pcba-place). Two snaps, then press at four bosses. Target 6 s.

Watch for

• ESD strap on. Iron at 350 C, checked at the start of the shift.
• Dwell at most 2 s per pin. No extra flux.
• Inspect all six joints with a 10x loupe: shiny, concave fillets, no flux on the module body.

Risks at this station (PFMEA)

• Flux residue wicks into stick potentiometer: RPN 245 (fm:stick-flux)
• Cold or cracked solder joint on stick pins: RPN 84 (fm:stick-cold-joint)
• Board pressed onto its ledges cracks a support rib: RPN 60 (fm:pcba-boss-crack)