As LED lighting technology continues to evolve, two of the most common types of LED packaging—SMD (Surface Mounted Device) and COB (Chip on Board)—have become the core light sources used in various lighting products. Understanding the differences between SMD and COB LEDs is crucial for selecting the most suitable lighting solution for your specific application.

What Do SMD and COB Stand For?

Their names offer a clue to their structure:

• SMD stands for Surface Mounted Device,

• COB stands for Chip on Board.

Essentially, the difference between them lies in how the LED chips are packaged.

What Is an SMD LED?

An SMD LED is a surface-mounted LED device in which one or more LED chips are packaged onto a lead frame using wire bonding and encapsulation processes. These devices can then be reflow-soldered onto printed circuit boards (PCBs) by luminaire manufacturers, serving as integrated light sources in various lighting applications. Common models include SMD2835, SMD3030, and SMD5050—the numbers represent the physical dimensions of the LED bead (e.g., SMD2835 = 2.8mm × 3.5mm).

Because of their small size, SMD LEDs typically contain only 1 to 3 chips per unit. This limits their power capacity, with most ranging from 0.2W to 1W. However, by enlarging the chip size, increasing chip quantity, or improving the heat sink material, SMD LEDs can reach up to 5W or more. That said, proper thermal management is essential—without it, SMD LEDs can experience significant light degradation or even burn out.

What Is a COB LED?

COB LEDs (Chip on Board) integrate multiple LED chips directly onto a ceramic or metal substrate. These chips are packed tightly together in series or parallel circuits. When lit, they produce a single, uniform light-emitting surface—visually appearing as one large light source.

Due to their structure, COB LEDs can deliver much higher power than SMD LEDs. For instance, COB solutions from brands like CREE can range from 4W to over 230W. The base materials used (such as ceramics or metal) offer excellent thermal conductivity, but again, thermal design is key: a poorly designed fixture housing can dramatically shorten the lifespan of a COB LED due to overheating or excessive light decay.

SMD vs COB: Technical Considerations

Because COB LEDs pack a high density of chips into a compact area, managing thermal performance and long-term reliability is a serious technical challenge. High-end manufacturers like CREE and OSRAM lead the market by maintaining superior quality across chip design, substrate materials, and packaging techniques.

In the high-power COB segment, CREE is widely regarded as the industry benchmark, offering unmatched performance and reliability. Therefore, for fixtures that depend on COB light sources, CREE LEDs are often the first choice.

On the other hand, SMD LEDs—particularly SMD2835 (0.2–1W) and SMD3030 (1W)—have become highly standardized. Since their power is relatively low and the technology is mature, many Chinese manufacturers produce them in large volumes. In fact, many top-tier lighting brands outsource their SMD LED production to these OEMs.

• Low-power SMD LEDs are widely used in indoor lighting such as tubes, bulbs, strips, and panel lights.

• Medium-power SMD LEDs are found in outdoor lighting like floodlights and streetlights.

Which LED Light Source Should You Choose?

The choice between SMD and COB LED depends entirely on your application:

• ✅ For wide, even illumination—such as offices, commercial spaces, or residential areas—SMD LEDs are ideal.

• ✅ For high-intensity, focused lighting—like spotlights or specialized projectors—COB LEDs are the better option.

LEDTEK: Your Partner in LED Light Source Solutions

At LEDTEK, we specialize in high-performance LED lighting solutions. Whether your project calls for SMD or COB LED technology, we provide expert guidance and customizable options to meet your needs.

👉 Visit our LED Knowledge Center to explore more insights and professional tips on choosing the right LED light source.