COB LED strips: when a seamless line of light is the right choice

CHECKPOINT / 01

What COB changes in the visible source

Chip-on-board construction places many small LED chips close together under a continuous phosphor layer. From the viewing side it reads more like a continuous line than a row of individual packages. That is useful in shallow profiles, furniture details and visible linear fixtures, but dotless is not a universal guarantee. A low-density or poorly matched COB strip can still show scalloping, and a diffuser can change both uniformity and output.

• Judge uniformity from the intended viewing distance, not only from a close-up photo.
• Ask for density, watts per metre, color quality and cut interval for the exact variant.
• Do not treat a seamless appearance as proof of high CRI, high efficiency or low temperature.

CHECKPOINT / 02

Choose COB or SMD from the job

COB is a strong candidate when the light source will be visible, the profile is shallow or a continuous line is the priority. Conventional SMD remains useful when a particular package, channel output, connector system or replacement strategy matters. Compare the complete assembly at the target brightness: strip, profile, diffuser, surface finish and viewing angle. The best choice is the one that meets the visual requirement without hiding a thermal or service problem.

• Visible line or shallow profile: start with a high-density COB sample.
• High-output task or architectural run: compare measured output and heat, not only the LED count.
• Addressable COB: verify the IC and controller path separately from the COB construction.

CHECKPOINT / 03

Density, beam shape and diffuser still matter

A continuous phosphor line can soften hotspots, while a narrow-beam construction can reduce spill and direct light toward a wall or work surface. A clear cover preserves more output but may reveal the source; an opal cover hides more detail and usually costs some transmission. Increase the strip-to-cover distance when the profile allows it, then confirm the result in a mock-up. Optical uniformity and useful light are a tradeoff, not a single product attribute.

• Specify beam direction when the light grazes a wall or illuminates a work plane.
• Use the same profile and cover in the sample that will be used in the installation.
• Record whether the visual target is a line, wall wash, accent beam or task surface.

CHECKPOINT / 04

Match voltage and run length to the power plan

COB is available in multiple voltage families, but the exact run length, current and cut spacing depend on the selected product. A 24 V low-voltage configuration is often a practical starting point for architectural work; it still needs voltage-drop, injection and supply calculations. High-voltage AC products are a different safety and maintenance class and should not be mixed into a low-voltage DIY assumption.

strip_voltage = exact_variant_voltage
load_w = watts_per_m * length_m
plan = supply + cable + injection + thermal_path

CHECKPOINT / 05

Treat cut marks and thermal mounting as hard limits

Standard COB strips can be cut only at their printed intervals. Any-cut products are a separate construction and must be identified in the product record before a free-form cut is attempted. The aluminum profile remains valuable even when the COB layer hides hotspots: it spreads heat, protects the board and gives the diffuser a stable position. Seal, bend and mount the selected variant according to its actual IP and mechanical instructions.

• Photograph the cut marks and first segment before trimming.
• Do not bend a strip tighter than its documented radius.
• Keep the power supply, connection and replacement path accessible.

FAILURE MODES

What usually goes wrong

• COB is promised as perfectly dotless without checking density, cover and viewing distance.
• A narrow-beam or dark diffuser is chosen for a task-lighting role where its transmission is too low.
• A high-voltage COB run is treated like a safe low-voltage strip installation.
• An any-cut claim from one variant is applied to a standard strip.
• The aluminum profile is removed because COB hides dots, leaving the strip with no reliable thermal path.

TECHNICAL BASIS / VERSION

Keep the decision current

This guide is maintained as a versioned technical record. Recheck the current protocol documentation and the exact product revision before using it in a production installation.