An analysis of 5,000 LED display installations in 2023 revealed a clear trend: flexible LED modules using surface-mounted device (SMD) technology accounted for 78% of unplanned downtime, with 62% of failures attributed to broken solder joints or uneven brightness. For businesses, this translates to an average replacement cost of $1,500 per module, as well as lost revenue. In contrast, flexible LED modules using chip-on-board (COB) technology address these pain points head-on. Our internal testing reveals that COB technology has a 65% lower failure rate than SMD models over a three-year period, along with 30% higher brightness uniformity.
Design Differences Between Flexible LED Modules Using SMD and COB Technology
Flexible LED modules using SMD (surface-mounted device) technology utilize individual LED chips soldered to a flexible PCB. These modules rely on discrete solder joints to connect each LED to the circuit board and are typically used in basic flexible displays where cost is a primary consideration. In contrast, flexible LED modules using COB technology bond multiple bare LED chips directly to a flexible PCB, which is then encapsulated in a single layer of protective resin. This design eliminates the need for individual LED packages and reduces the number of solder joints by 90%, a key advantage for improved durability. For example, a standard 300mm SMD flexible LED module may have 48 individual LEDs (and 96 solder joints), while a COB module of the same size uses 192 bare chips and only 8 bonding points. This streamlined design directly impacts the resistance of each module to bending, moisture, and long-term use.
Flexible LED modules utilizing COB technology provide superior uniformity and clarity compared to SMDs.
COB technology offers significant advantages over SMDs in terms of the aesthetics of flexible LED displays. First, regarding brightness uniformity, SMD flexible LED modules often exhibit brighter spots around individual LEDs because each chip emits light from its own package. COB flexible LED module, on the other hand, utilizes resin-encapsulated chips that evenly distribute light across the module surface, achieving brightness uniformity exceeding 95% (compared to 80-85% for SMD). This is crucial for applications like curved retail displays, where uneven lighting can cause color distortion.
Second, the COB’s resin layer extends the horizontal viewing angle to 160-170 degrees, compared to 120-140 degrees for SMD. For a concert stage backdrop, this means that audience members in the side halls can see the same clear image as those in the center of the stage. Third, regarding pixel density and clarity, COB bare chips can be packed more densely than SMD packaged LEDs, resulting in a higher pixel pitch. This makes a flexible LED module using COB technology ideal for close-up viewing, such as museum exhibits or small indoor signage, where high detail is crucial.
COB vs. SMD Greater Durability
Durability is a real highlight of COB flexible LED modules, as they address the most common failure point of SMDs. The primary concern with SMDs is solder joint fatigue. Every time you bend a flexible LED module that uses SMD technology, you stress its more than 96 solder points. Over time, this can lead to cracking, resulting in failed pixels or complete module failure. Furthermore, COB flexible LED modules have fewer bonding points, so there’s no stress on the solder points when bent. Our production tests indicate that COB modules can withstand over 10,000 180-degree folds without breaking, whereas SMD modules typically break after 2,000-3,000 folds.
Secondly, COB’s resin encapsulation creates a seamless barrier against moisture and dust, giving most COB flexible LED modules an IP65 rating. SMD modules, due to the gaps between individual LEDs, typically have a maximum IP54 rating, which can be problematic in outdoor or high-humidity environments, such as swimming pools or kitchens. Furthermore, COB offers superior impact resistance. The resin layer in the module protects the exposed chip from minor impacts, whereas the exposed LED package of an SMD is susceptible to cracking.
Advantages of COB Flexible LED Modules in Practical Applications
COB flexible LED modules are not only technologically advanced but also address practical issues across various industries. For example, in standard curved retail signage, clothing stores use 3D curved displays to display their brands. However, SMD modules can easily create noticeable seams and hot spots. COB flexible LED modules can conform to curved surfaces without compromising uniformity, making signage and graphics appear more fluid.
Outdoor events such as music festivals and sporting events require modules that are rainproof, windproof, and shockproof. COB’s IP65 rating and strong adhesive properties are sufficient to withstand these conditions. Last summer, we provided a COB flexible LED module for a three-day music festival, and despite heavy rain and stage shaking, the module remained intact.
How should you choose between the two?
While COB flexible LED modules offer advantages over SMD in terms of durability and quality, SMDs still offer advantages in certain specific use cases. If you require long-term reliability, uniform brightness, outdoor/wet environments, or curved designs, choose COB. The 10-15% higher upfront cost of COB is worth it, as it reduces replacement costs by 65%. If you’re on a tight budget, need a simple, static display (for example, a small “Open” sign), or don’t plan to frequently bend the module, choose a display using SMD technology.
COB technology offers better long-term value.
For buyers who prioritize durability and display quality, COB flexible LED modules are a wise choice. This design overcomes the solder joint fatigue and uneven light distribution associated with SMD technology, while providing brighter, more consistent visuals and resistance to moisture, impact, and bending. While SMDs offer upfront cost savings, they incur higher long-term costs due to frequent replacements and downtime. COB flexible LED modules offer a longer lifespan, a more attractive appearance, and address practical issues that plague SMD designs.
