COB (Chip-On-Board) LED strips are often referred to as "dotless" or "seamless" due to their unique construction and light output. Traditional (SMD) LED strips have individual LED chips spaced out along the strip, which can lead to visible dots or points of light, especially when used with diffusers or light bars.
COB LED strips, on the other hand, have multiple (up to 840 leds per metre) LED chips packed very close together on the board. This allows the light from the individual chips to blend together before it leaves the strip, creating a more consistent and continuous line of light. Hence, they are often referred to as "dotless" or "seamless" LED strips.
The term "dotless" or "seamless" refers to the visual output of the light, not necessarily to the physical structure of the LED strip. It's important to note that while COB LED strips provide this smooth light output, they still require proper installation and heat management to ensure they operate efficiently and have a long lifespan.
COB Led strip products
We have many led strips with COB led technique, such as single color, CCT, RGBW, RGB+CCT.
Single color dottless COB led strips
Single color led lights with 3000K and 4000K, high CRI up to 98. There is also 5 mm super narrow COB stip for small narrow spaces.
CCT COB led strips
This is most popular COB led strip category. You can adust color temperature freely from 2500K to 6500K. There is IP21 for interior use and IP65 for outdoor use. Multiple power versions from 3,6W to 14,4W per meter.
RGBW COB led strip
Popular with youg people and commercial use. NEON like even light with this RRGB+W COB led strip. White led included is 4000K, so you dont have to try to make white light from RGB dots. 4000K has CRI95 accurate quality.
RGB+CCT COB led strip
You want it all? This is ultimate Led strip. No dots, you can adjust colors AND white color temperare in same COB led strip. Its only 12mm wide, cutmark is 5 cm and CRI for white light is 95! Is better than HUE led strips in any measure.
COB LED RGB+CCT
10W per metre
15W per metre
1000 lumens per metre
1000 lumens per metre
54 LEDs per metre
540 LEDs per metre
Requires led profile
For more detailed comparison between COB RGB+CCT and HUE led strip can be read here.
What is Dotless led strip, or COB?
COB stands for Chip on Board, which means that the LED chip is packaged directly on a printed circuit board (PCB). Flexible strip lighting “Chip on Board”. COB-LEDs are essentially a simplified approach to LED design.
A standard SMD (Surface Mount Device) LED has an LED chip holder (bead) with the actual LED chip inside and is then covered with a phosphor coating.
The COB-LED strip structure removes all excess, leaving behind the LED circuit, the yellow phosphor overlay and the junction.
How is COB LED strip made?
“Printing” of printed circuit boards
Chip printer on PCB
Printing of resistors on PCB
“Reflow”, where at 65 degrees the components are combined
Pouring the fluorescent mass onto the led strip
COB led strip for the oven
Led strip light testing and packaging.
Advantages and disadvantages of COB LED strip
Now that you know something about the technique, let’s go through the pros and cons of both techniques.
Advantages of COB LED strip lighting:
Dotless LED strip, COB led strip.
One of the biggest wishes of traditional LED strips is that there would be no dots on the LED strip. A pointless LED strip light is therefore possible with COB technology, as there are points of light up to 840 metres below a flat mass, so no visible points. The light is softer and calmer when it looks like a steady source of light rather than a pinpoint of illumination.
SMD led strips (cri 90), contain fewer of the larger led diodes. Traditionally, the number of LED light points in the so-called. the marketti led strips have 30-60 pieces per metre, so you can see very clearly each light point. There are SMD led strips with 240 LEDs per metre (LedStore EQUAL), but with these types of strip you have to take care of really good cooling, because SMD diodes produce a lot of heat. So in SMD led strip lights you can always see the dots.
With 840 LEDs per metre of COB strip, it is difficult to see individual LED dots. You can only see a single LED if you dim the strip to about 1-5% and stand next to it. This makes the COB led strip light ideal for applications where
The LED strip itself cannot be hidden from view (the surface of the fixture)
The illuminated surface is less than 60cm from the LED strip (Shelves).
Reflective surfaces, such as stone/glass, are everywhere. (dotted led strip)
Those installations where you want an excellent neon effect (RGB versions).
COB LED strip lights are much more flexible than other traditional LED strip lights due to the small size and even distribution of the diodes. These diodes are so small and close together that no point on the strip is actually aligned, e.g. in a corner. This uniformity makes it easy to place the strips unplanned compared to SMD-LEDs, where the circuit itself hits the exact corner where it should bend. The COB led strip light is therefore more flexible in terms of installation comfort and ease of installation at every bend and angle, and there is no need to worry about breaking the led circuit at a 90 degree angle.
More stable, fewer problems
COB led strip is one long led chip directly attached to the PCB, there is no gold wire in its installation. Many of the problems with traditional SMD LED strip lighting are caused by the gold wire inside the LED “beads”. Because gold thread is thin, it breaks easily, for example from excessive heat.
The circuit design of the COB led strip uses three circuits, first in parallel, as a group, then each group and then in series to form a cut-off distance of 2.5m-10cm. Even if two LED circuits are bad at the intersection, the light will still continue forward. And because a COB led strip light has up to 840 LEDs per metre, even if 1-2 circuits don’t light up, no dark area, you can see and to the eye it’s still a score-free led strip.
In the traditional SMD led strip light, a faulty led circuit turns off the whole cutting pitch and that 5 or 10cm cutting pitch is completely dark.
Wide opening angle
A traditional SMD strip light has a beam angle of 110 degrees, while a COB strip light has a beam angle of 180 degrees. Of course, in both cases, the installation profile will affect the final result.
The weaknesses of COB led
Difficult to maintain colour consistency
As there are no COB-LED strip loading machines on the market, all COB-LED strip manufacturers only take samples to ensure colour uniformity. So for COB LED strips, it is difficult to ensure that 100% is within the 3-phase colour tolerance. This brings us to quality control and its importance. High-quality dot-free led strip is difficult to implement.
Lower light output
The efficiency of COB LED strip lighting is currently only around 120 Lumen/Watt.
If you need higher light output, the SMD led strip light is better, as SMD reaches up to 200 Lumen/Watt. The most common ones, of course, at the 100-150Lumen level.
Lower maximum power
The maximum power of a COB LED strip is recommended to be only 15 W/m. Because the number of chips per meter is too high if the power exceeds 15 W/m. The problem is controlling the heat of the chip. Also, the life of COB LED strip is shortened in too hot conditions.