PiG Phosphor-in-Glass One-Page Defect Rectification SOP (Workstation Post Version)

2026-06-18

Scope of Application: Compressed bulk PiG, printed PiGF ｜ Control Standard: Furnace temperature difference ≤3℃, Sintering oxygen content ≤10ppm, Powder vacuum drying: 150℃ for 6h

Process Red Line: Nitride/KSF phosphor prohibited from high-temperature air sintering; Direct dry mixing & compression molding is forbidden

I. Visual Defects (On-site Inspection & Immediate Rectification)

Defect Phenomenon	Root Cause	On-site Quick Solutions (Parameter Adjustment)
Internal bubbles, surface bulges, foggy & low light transmittance	Moist powder, entrapped air, no exhaust heat preservation	1. Vacuum dry raw materials for 6h; 2. Vacuum defoam slurry for 30min; 3. Keep 500℃ for 30min under slight negative pressure for air exhaust
Finished crack, edge chipping, easy breakage during cutting	Fast heating/cooling rate, uneven green body density, no annealing treatment	Heating rate ≤3℃/min, cooling rate ≤5℃/min; Add 450℃ annealing for 60min; Stage compression with 60s pressure holding
Sheet curling, sintering collapse, undersized dimension	Excessive sintering temperature, long holding time, no supporting fixture	Reduce peak temperature by 10~20℃; Shorten high-temperature holding time; Full coverage support with alumina ceramic plate
Black spots, hard impurities, surface pits	Unsieved powder, zirconia tank debris, binder carbonization from incomplete degreasing	Sift powder via 800-mesh screen; Replace grinding tank liner regularly; Extend degreasing holding time at 350℃
Overall devitrification, crystal ring, striped haze	Glass high-temperature crystallization, phosphor-glass interfacial reaction	Reduce furnace temperature by 20℃; Cut high-temperature holding time by half; Adopt coated phosphor preferentially

II. Optical Defects (Integrating Sphere Test & Batch Parameter Adjustment)

Defect Phenomenon	Root Cause	On-site Quick Solutions (Parameter Adjustment)
Large color difference on single piece/batch, excessive color coordinate drift	Powder segregation, uneven furnace temperature, fluctuating oxygen content	Wet mixing + powder granulation; Install homogenizing plate inside furnace; Stabilize furnace oxygen content ≤10ppm
Low luminous efficiency, missing red light, blackened phosphor	Nitride phosphor oxidation, high-temperature thermal degradation	Full-process sealed nitrogen sintering; Adopt low-temperature glass (sintering below 500℃); Eliminate furnace air leakage
Whitening & severe luminous decay after 85℃/85RH aging test	High alkali metal content of glass, ion migration	Replace low-alkali/alkali-free glass; Apply moisture-proof coating on finished products; Add annealing process
Uneven light spot & partial yellowing under high-power lighting	Phosphor agglomeration, poor thermal conductivity, interfacial scattering	Filter slurry to remove agglomerates; Add BN/alumina thermal conductive filler; Apply surface coating on phosphor

III. Green Body & Powder Defects (Mixing & Pressing Station)

Defect Phenomenon	On-site Quick Solutions
Slurry delamination, up-down color difference, powder sedimentation	Add dispersant; Keep low-speed constant stirring before molding; Granulate powder after wet mixing
Powder falling off green body, low strength & easy damage in handling	Adjust binder dosage; Extend pressure holding time; Adopt quantitative powder feeding

IV. 5 Daily Inspection Items Per Shift

Powder: Qualified vacuum drying, sieved without agglomeration
Mixing: Wet mixing mandatory, slurry finished vacuum defoaming
Molding: Stable press pressure, compliant stage compression & pressure holding
Sintering: Stable furnace temperature, qualified oxygen content, normal degreasing process
Environment: Sealed & moisture-proof workshop for nitride phosphor production

V. Emergency Process Rules (Direct Parameter Adjustment for Defects)

Bubble defect: Add 500℃ exhaust heat preservation, sinter under slight negative pressure
Crystallization & color drift: Reduce sintering temperature by 20℃, shorten high-temperature holding time
Red phosphor failure: Inspect furnace airtightness, increase nitrogen replacement flow
Crack defect: Slow down heating/cooling rate, mandatory low-temperature annealing

Φωσφορική σκόνη LED

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Πράσινη φωσφορική σκόνη LED

Πορτοκαλί φωσφορική σκόνη LED

Ειδικός φωσφόρος LED

Φωσφόρος LED Νιτριδίου Κόκκινο

Φωσφορική σκόνη LED

Κόκκινη σκόνη φωσφόρου LED

Πράσινη φωσφορική σκόνη LED

Πορτοκαλί φωσφορική σκόνη LED

Ειδικός φωσφόρος LED

Φωσφόρος LED Νιτριδίου Κόκκινο

PiG Phosphor-in-Glass One-Page Defect Rectification SOP (Workstation Post Version)

PiG Phosphor-in-Glass One-Page Defect Rectification SOP (Workstation Post Version)