COB LED Strip Lights with Dot-Free, Continuous Light Output

Custom COB LED strips: 320–504 chips/m, CRI 90–95, SDCM ≤3 and no visible dots. 24 V, 8–15 W/m, IP20–IP68, 5–50 m reels, 10–15 day lead times.

Coil of 24 V COB LED strip glowing a continuous dot-free line of white light on a black background
COB strip at 320–608 chips/m on 24 V — the continuous line is the phosphor layer, not individual LEDs.
Short answer

A COB LED strip is a flexible linear light source in which bare LED dies are bonded directly onto the FPC and sealed under one continuous phosphor layer, so the light is dot-free instead of showing individual emitters. HFY LED builds COB strips at 320, 480 and 504 chips per metre on 24 V, delivering 8–15 W/m at CRI 90–95 with SDCM ≤ 3 colour consistency, in reels from 5 m to 50 m and sealing from IP20 to IP68.

Scope: what this product page covers

This page covers constant-voltage COB strips for cove lighting, cabinet lighting, linear profiles and mirror backlighting. High-density strips above 504 chips/m, COB strips with individual address control, and constant-current COB modules belong to a custom programme; CCT-tunable and RGB COB are quoted as separate part numbers because the FPC is a different design.

Specifications

Chip density320 / 480 / 608 chips per metre
Input voltage24 V DC (12 V on request)
Power8 – 15 W/m
Colour renderingCRI 90 standard, CRI 95 on request
Colour consistencySDCM ≤ 3 within a reel and across reels
Cut length25 mm (480 chips/m), 50 mm (320 chips/m)
FPC width8 mm and 10 mm
SealingIP20, IP54, IP65, IP67, IP68
Reel length5 m standard, up to 50 m on one reel at 24 V
Lead time10–15 working days after sample approval

Materials

  • 3 oz copper flexible PCB for 50 m single-feed runs
  • Flip-chip COB dies at 2700 K – 6500 K
  • Silicone encapsulation (IP54 / IP65) or full silicone extrusion (IP67 / IP68)
  • 3M 300LSE or Tesa adhesive backing for IP20 builds
  • Nickel-plated copper end connectors, 22–20 AWG lead wire

Manufacturing process

  1. FPC design and copper sizing Copper weight is set from the run length, not from habit. A 5 m run at 12 W/m draws 2.5 A at 24 V and loses about 1.6 V over a 3 oz FPC; the same run at 1 oz loses 4.8 V and visibly dims at the far end. Runs above 10 m are quoted with a 3 oz FPC and feed from both ends.
  2. Die bonding and phosphor coating Dies are bonded at 480 chips/m pitch and covered in a single phosphor and silicone layer, then cured at 150 °C for 60 minutes. Coating thickness is held to ±5 µm because a 10 µm drift in the phosphor layer shifts chromaticity by roughly 2 SDCM, which is the difference between a matched and a mismatched reel.
  3. Colour binning Each reel is measured on a spectroradiometer and sorted into 3-step MacAdam bins, then reels belonging to the same bin and voltage group are packed together. Bin code, flux and forward voltage are printed on the reel label so a replacement reel matches the installed one two years later.
  4. Sealing and assembly IP20 builds receive adhesive backing and are packed in antistatic bags. IP65 adds a silicone coating; IP67 and IP68 are extruded into a silicone profile with end caps and cable glands potted in neutral silicone. Connectors are soldered and pull-tested at 30 N.
  5. Aging and final test Every reel runs 24 hours at rated current before packing, and 100% of reels are checked for open segments and forward voltage. A 1,000-hour LM-80 test runs continuously on each die type, with TM-21 extrapolation issued on request.
From the shop floor

COB LED Strip in production

Typical applications

  • Architectural cove and soffit lighting in hotels and retail
  • Aluminium profile linear lighting for offices and joinery
  • Cabinet, wardrobe and mirror backlighting
  • Display case and museum lighting where dot visibility is unacceptable
  • Backlighting of translucent stone and glass panels
  • Residential indirect lighting where a seamless line is the design intent

Quality and documentation

  • Spectroradiometer binning with SDCM ≤ 3 reported per reel
  • 24-hour burn-in at rated current on 100% of reels
  • LM-80 data and TM-21 lifetime projection on request
  • Voltage drop check on the first and last metre of every long reel
  • CE and RoHS documentation; UL/cULus via joint OEM application

What we do not do

We do not supply COB strips for constant-current drivers without a matching driver, and we do not recommend COB strip for wet locations where the strip is immersed in chlorinated water — IP68 extrusion resists jets and temporary immersion, not continuous pool chemistry. Strips longer than 50 m on one feed are not offered: the voltage drop makes the far end visibly dimmer and the correct answer is a parallel feed or a 48 V system.

COB LED Strip

Technical questions

What is the difference between COB and SMD LED strip?

A COB strip bonds bare dies under one continuous phosphor layer, so there is no visible dot; an SMD strip places packaged LEDs at 8–16 mm pitch, which shows as individual points in a shallow profile. COB costs roughly 20–30% more per metre at the same flux, and it is the right choice when the strip is visible rather than hidden behind a diffuser.

How long a COB strip can I run from one power feed?

Ten metres at 24 V on a 3 oz FPC, feeding both ends. Beyond that the copper resistance produces a visible brightness gradient: a 20 m single-ended run drops about 11% in flux at the far end, which is above the 5% threshold most lighting designers accept.

Can I cut a COB strip anywhere?

No. COB strips have marked cut points every 25 mm at 480 chips/m and every 50 mm at 320 chips/m. Cutting between marks breaks the series circuit and the segment beyond the cut goes dark — this is the single most common installation error we see.

Do you supply samples before a production order?

Yes. A 500 mm sample of any stocked configuration ships within 3 working days, and custom CCT or CRI builds take 7–10 working days. Sample cost is credited against the first production order above 500 m.

Send a specification, get a quotation in 24 hours

Tell us the product type, run length, wattage, CCT, CRI and IP rating. You will receive a fixed price, a lead time, and the feed and driver arrangement in writing — no obligation, and no sales call unless you ask for one.