Quality
Process-attributed defect physics, control charts, and yield drivers
M01M02M03M04M11M28M42M53M54
Window
128
modules
FPY
85.9%
σ-level
0.00
long-term, +1.5σ
DPMO
319,196
7 ops/mod
Cpk (Pmax)
-10.11
µ=458W σ=1.7
Rework Q
18
last 200
Defect Pareto (process-attributed)
101 — Crack cell (middle) · Stringer · Tension × thin wafer60 · cum 21%
lever → stringTensionN, cellThicknessUm
117 — Cell flake · PECVD · RF non-uniformity48 · cum 38%
lever → rfPowerMw, pressure
117 — Cell flake · TCO Sputter · Scan / target erosion drift40 · cum 52%
lever → scanSpeedMmS, target life
106 — Broken finger · Curing · Under-cure → high contact ρ39 · cum 65%
lever → curePeakC, dwellSec
151 — String spacing · Stringer · Alignment offset > 0.15 mm31 · cum 76%
lever → stringTensionN
198 — Bubble (active) · Lamination · EVA outgas / vacuum hold short29 · cum 86%
lever → vacuumMbar, vacuumHoldSec
106 — Broken finger · Stringer · Solder iron T too high25 · cum 95%
lever → solderTempC
115 — Incomplete deposition · PECVD · i-layer too thin / Dit excursion13 · cum 100%
lever → iLayerNm, h2Dilution
906 — Power output low · Multi · Aggregate iVoc/FF shortfall1 · cum 100%
lever → Inspect drift
Loss attribution by station
Stringer116 defects · ~4869 W lost
PECVD61 defects · ~2944 W lost
TCO Sputter40 defects · ~1519 W lost
Curing39 defects · ~1623 W lost
Lamination29 defects · ~1623 W lost
Multi1 defects · ~100 W lost
Cell-level process drivers (mean of window)
| Driver | Station | Value | Nominal | Δ |
|---|---|---|---|---|
| iVoc | PECVD | 740 mV | 745 | -5 |
| J0 | PECVD | 12.2 fA/cm² | 25.0 | -12.8 |
| Dit | Cleaning | 1.00 ×10¹⁰ | 1.00 | +0.00 |
| Rsheet TCO | TCO | 38.5 Ω/□ | 60.0 | -21.5 |
| ρ contact | Curing | 4.00 mΩ·cm² | 1.50 | +2.50 |
| Cell FF | 83.32 % | 80.00 | +3.32 | |
| Cell η | Cell-test | 23.24 % | 25.00 | -1.76 |
Tier mix (binned)
Tier A
0
0.0%
Tier B
0
0.0%
Tier C
0
0.0%
Rej
110
85.9%
A ≥ 555 W · B 535–555 · C 510–535 · Reject < 510
Pmax distribution (5 W bins)
µ=458.4 W · σ=1.70 · Cpu=27.75 · Cpl=-10.11 · n=110
Pmax X̄ control chart (n=5)
R̄ = 0.45 W · UCL_R = 0.95 W · subgroups = 25
FPY trend (rolling 20)
Rework queue (with most-likely root station)
| Module | Pmax | Tier | Root |
|---|---|---|---|
| mod_seed_3d | 456 W | Reject | TCO Sputter |
| mod_seed_33 | 456 W | Reject | Curing |
| mod_seed_2t | 457 W | Reject | PECVD |
| mod_seed_2s | 457 W | Reject | Lamination |
| mod_seed_2j | 458 W | Reject | Stringer |
| mod_seed_29 | 458 W | Reject | Stringer |
| mod_seed_1z | 460 W | Reject | Stringer |
| mod_seed_1w | 460 W | Reject | Multi |
| mod_seed_1p | 460 W | Reject | Stringer |
| mod_seed_1f | 460 W | Reject | Stringer |
| mod_seed_15 | 460 W | Reject | Stringer |
| mod_seed_11 | 460 W | Reject | PECVD |