Manufacturing & Quality Control Process — How Kingseng Builds LED Fixtures
Every Kingseng fixture passes through 7 production stages and 12 quality checkpoints — from raw material inspection to final shipping. This page documents our complete manufacturing and quality control process, because transparency about how we build is the strongest signal of reliability we can offer to architects, specifiers, and procurement teams.
Stage 1: Design & Prototyping — 5-10 business days
| Step | What Happens | Output / Deliverable |
|---|---|---|
| 1.1 Requirement Review | Engineering team evaluates your spec sheet, 3D files (STEP/IGES), finish samples, and target certifications. Feasibility report within 48 hours. | Feasibility Report + Gap Analysis |
| 1.2 Industrial Design | Our in-house design team refines the aesthetic: proportions, material transitions, finish sampling. 2-3 concept renderings provided. | 3D Renderings + Material Board |
| 1.3 DFM Review | Design for Manufacturability analysis: can this be injection-molded? Are wall thicknesses uniform? Do tolerances stack up? CAD optimization suggestions. | DFM Report + Optimized CAD |
| 1.4 Rapid Prototyping | 3D-printed or CNC-machined prototype for form/fit validation. Includes finish sample swatches. | Physical Prototype + Finish Swatches |
Stage 2: Tooling & Mold Fabrication — 15-25 business days
Kingseng operates its own tooling workshop with 8 CNC machining centers and 6 EDM (electrical discharge machining) stations. We fabricate injection molds, die-casting molds, and stamping dies in-house — no outsourcing to third-party tooling shops.
| Tooling Type | Material | Typical Cavities | Lifespan |
|---|---|---|---|
| Injection Mold (Plastic) | P20 / 718H tool steel | 1-4 cavities | 300,000-500,000 shots |
| Die-Casting Mold (Aluminum/Zinc) | H13 hot-work steel | 1-2 cavities | 80,000-120,000 shots |
| Stamping Die (Metal Brackets) | SKD11 / Cr12MoV | Progressive die | 1,000,000+ strokes |
Stage 3: Material Sourcing & Incoming Inspection — Ongoing
We maintain an Approved Vendor List (AVL) of 40+ pre-qualified material suppliers. Every incoming batch — whether raw aluminum, steel sheet, LED chips, or driver PCBs — passes through our IQC (Incoming Quality Control) station before entering production.
Incoming Inspection Checklist
| Material | Inspection Method | Acceptance Criteria | Sampling |
|---|---|---|---|
| LED Chips (Epistar, San’an, Bridgelux) | Integrating sphere test | Luminous flux within ±5% of datasheet; CRI ≥ spec | AQL 0.65, Level II |
| LED Drivers (Mean Well, Lifud, Eaglerise) | Load test + ripple measurement | Output current ±3%; ripple ≤ 5%; PF ≥ 0.9 | AQL 0.65, Level II |
| Aluminum (ADC12 / A380 / 6063) | XRF spectrometer | Alloy composition within spec; no recycled-content contamination | 1 sample per heat lot |
| Steel / Brass Sheet | Micrometer + Rockwell hardness | Thickness ±0.05mm; hardness within spec | AQL 1.0, Level II |
| Glass (Mirrors, Diffusers) | Visual + dimensional | No scratches > 0.5mm, no edge chips; flatness ≤ 1mm/m | AQL 1.5, Level II |
| Wood (Walnut, Oak, Maple) | Moisture meter + visual grading | Moisture 6-8%; no knots > 3mm, no cracks or warp | 100% inspection |
Stage 4: Production — 5 Manufacturing Lines
4.1 Injection Molding
12 injection molding machines (90-380 ton clamping force) produce plastic components: diffusers, end caps, junction box housings, backlit mirror frames. Cycle time: 25-45 seconds per shot. In-process check every 2 hours: weight, dimensions, surface defects.
4.2 Die Casting & Metal Fabrication
3 die-casting machines (280-500 ton) for aluminum and zinc alloy parts: pendant canopies, sconce backplates, heat sinks. Post-casting: CNC trimming, deburring, sandblasting. Tolerances held to ±0.1mm on critical mounting surfaces.
4.3 Surface Finishing
In-house powder coating line (3-stage: phosphate pre-treatment → electrostatic spray → 200°C curing oven) and wet painting booth. Finish options: matte black, white, brushed nickel, brass, bronze, chrome. Salt spray testing (ASTM B117) to 96 hours for outdoor-rated fixtures. Wood finishing: UV-cured acrylic lacquer with optional fire-retardant intumescent clear coat.
4.4 SMT & Electronics Assembly
2 SMT (Surface-Mount Technology) lines with automatic pick-and-place, reflow soldering, and AOI (Automated Optical Inspection). We produce LED PCBs in-house — no relying on third-party board houses. Production capacity: 5,000 LED boards per day.
4.5 Final Assembly
6 assembly lines organized by product category: pendant lights (Line A), ceiling fans (Line B), wall sconces & track lights (Line C), LED mirrors & cabinets (Line D), wooden lights (Line E), accessories (Line F). Each station has an in-line QC checkpoint with a go/no-go gauge, electrical safety tester, and visual inspection light box.
Stage 5: Quality Control — 12 Checkpoints, 4 Gates
Our QC system follows a 4-gate model adapted from ISO 9001:2015 and the automotive industry’s APQP (Advanced Product Quality Planning) framework:
| Gate | When | What We Check | Tools & Equipment | Pass Rate Target |
|---|---|---|---|---|
| G1 | Incoming Material |
• LED chip lumens, CRI, CCT • Driver output current, PF, ripple • Metal alloy composition • Glass flatness, edge quality • Wood moisture content, grain grade |
Integrating sphere, XRF spectrometer, digital micrometer, moisture meter, Rockwell hardness tester | ≥ 99.5% |
| G2 | In-Process (IPQC) |
• Molded part weight & dimensions • Weld joint integrity • SMT solder quality (AOI) • Paint/powder thickness & adhesion • Wood finish uniformity |
CMM (Coordinate Measuring Machine), AOI machine, coating thickness gauge, cross-hatch adhesion tester | ≥ 98% |
| G3 | Final Assembly (FQC) |
• Electrical safety: ground continuity, hipot (1500V AC / 1 min) • Functional: on/off, dimming, CCT switching • Photometric: lumen output, CCT, CRI (sampling) • Mechanical: fit, gaps, fastener torque • Visual: surface finish, label placement |
Hipot tester, integrating sphere (Gossen Mavospec), torque screwdriver, light box, go/no-go gauges | ≥ 97% |
| G4 | Pre-Shipment (OQC) |
• AQL sampling per ISO 2859-1 • Packaging drop test (ISTA 1A) • Barcode/label scan verification • Accessories completeness check • Carton sealing integrity |
Drop test rig, barcode scanner, checklist tablet, digital scale | ≥ 99% |
Stage 6: Testing & Certification Laboratory
Kingseng maintains an in-house testing laboratory equipped to perform the majority of certification pre-tests before sending fixtures to third-party labs (UL, ETL, SGS, TÜV) for formal certification. This dramatically reduces certification turnaround time — we catch issues internally instead of waiting for lab rejection reports.
In-House Test Capabilities
| Test Category | Specific Tests | Equipment | Standard Reference |
|---|---|---|---|
| Electrical Safety | Hipot (dielectric withstand), ground continuity, insulation resistance, leakage current | Chroma 19032 hipot tester,精密 LCR meter | UL 1598, IEC 60598-1 |
| Photometric | Total luminous flux, CCT, CRI (Ra + R9), chromaticity coordinates, beam angle | 1.5m integrating sphere, Gossen Mavospec spectroradiometer | IES LM-79-19 |
| Thermal | LED junction temperature, driver case temperature, heat sink thermal resistance | 8-channel thermocouple data logger, thermal imaging camera | IES LM-80, ISTMT |
| Environmental | Temperature cycling (-20°C to +60°C), humidity exposure (95% RH), salt spray (96h) | Programmable thermal chamber, salt spray cabinet | ASTM B117, IEC 60068 |
| Mechanical | Vibration test, drop test, impact resistance, cord strain relief, torque test | Vibration table, drop test rig, torque driver, impact hammer | ISTA 1A, IEC 60068-2 |
| EMC / EMI | Conducted emissions, radiated emissions, harmonic current, flicker (pre-compliance only) | Spectrum analyzer, LISN, near-field probe set | FCC Part 15, EN 55015 |
Certifications We Hold
UL 1598 / CSA C22.2
EN 60598 / LVD + EMC
Lead-free, Hg-free
Certified since 2019
EMC Compliance
Stage 7: Packaging & Shipping
| Packaging Tier | Description | Damage Rate Target |
|---|---|---|
| Standard Export | Individual polybag + molded EPE foam insert + 5-layer corrugated kraft carton. Inner carton, master carton. | < 0.3% |
| White-Label Retail | 4-color printed retail box with foam insert + UPC barcode. Ready for shelf display. Includes multilingual manual. | < 0.2% |
| Palletized Bulk | Master cartons on heat-treated ISPM 15 pallets, stretch-wrapped, edge-protected. 48-60 cartons per standard pallet. | < 0.1% |
All packaging passes ISTA 1A drop testing (10 drops from 30 inches on each face, edge, and corner) before a packaging specification is approved for production.
Shipping Ports: Yantian (Shenzhen), Nansha (Guangzhou) — FOB, CIF, or DDP terms available. Typical transit times: US West Coast 14-18 days, US East Coast 28-32 days, Europe 25-30 days, Middle East 18-22 days.
Ready to Manufacture Your Next Lighting Product?
Send us your spec sheet or concept sketch. Our engineering team will return a feasibility report, tooling estimate, and production timeline within 48 hours — at no cost and with no obligation.
This document is part of the Kingseng technical documentation series. For ISO 9001:2015 certificate copies, ETL listing reports, or factory audit scheduling, contact our quality team. Research support: Compare2Best.