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COB LEDs: Everything You Need to Know About Them

We’ve all heard the saying about how two heads are better than one. About COB LEDs,And this is also the same principle that most LED chip packages use. Accordingly, there are a variety of chip packages out there for you to select. Namely, you can get surface-mounted diodes, chip-on-board LEDs, multiple chips onboard LEDs, and multiple chips and cups onboard packages.
Nevertheless, in this guide, we will explore COB LEDs and what they are exactly. You will find that they are quite useful. For instance, you can utilize them in your next DIY LED grow-light project. But first, let us explore what a COB LED is and how it works.

What is COB LED & How COB LED Lights Work? 

COB LED Lights Work

As we described in the introduction, COB stands for chip-on-board. The technology only came to market in the last ten years. Thus, we can consider it to be relatively new when compared to other standards.

COB LEDs consist of multiple LED chips grouped and bonded together to create a single module. There are usually nine chips (or more) in a module. As you can tell, this can amount to more intense lighting that can reach up to 250 lumens (at 20mA) on a large chip. Furthermore, they appear as one single light as opposed to multiple single lights. 

Advantages and Disadvantages of COB LEDs

Advantages and Disadvantages of COB LEDs

In this section, we will cover a few pros and cons of using COB LEDs.

Pros:

  • Greater thermal resistance (especially when paired with a LED heatsink)
  • Compact
  • High light efficiency
  • Better lighting effect
  • Larger cooling area
  • They require one circuit with two contacts for power.
  • Lower rates of failure due to fewer amount of welding points
  • Strong anti-vibration capabilities

Cons:

  • Limited amount of colors
  • Light efficiency decreases with the largeness of the chip.

Applications and Uses of COB LEDs

Applications and Uses of COB LEDs

You might be curious as to how you can use COB LEDs. Maybe this section will offer you a bit of inspiration. In it, we will look at a few uses and applications for COB LEDs.

  • Street lights
  • Home light fixtures
  • High-bay lighting
  • LED Lamps
  • Downlights
  • Simple lighting for passages and hallways
  • Playground lighting
  • Replacement for fluorescent lighting
  • Smartphone camera flash
  • Light strip

COB LED vs. SMD LED

COB LED vs. SMD LED

SMD (surface mounted device) LEDs are currently the most popular LEDs on the market. You can consider them to be the predecessor to COB LEDs. SMDs are quite like COB LEDs in that they do not require direct contact to wires. Instead, they use tiny metallic contacts to function. The LED chip connects to a PCB substrate. 

The PCB is usually in the shape of a square or rectangle. You can identify the LED chip by its position on the SMD. It looks like a small black point in the middle of the PCB. SMDs come in various sizes including:  2835 (2.8 x 3.5mm), 3030 (3.0 x 3.0mm) and 3014 (3.5 x 2.8mm). Additionally, you can find them in 5050 (5.0 x 5.0mm) and 5630 (5.6 x 3.0mm) sizes too.

One of an SMD LED’s greatest features is when it contains an RGB (red, green, and blue) diode, you can output almost any color. That’s why we use SMD LEDs in cell phone devices. Additionally, we also use SMD LEDs in strip light and specialized light bulbs.

However, what is the difference between SMD LEDs and COB LEDs?

Firstly, COB LEDs have nine or more diodes, while SMD LED chips contain up to three diodes with a circuit attached to each. Each SMD LED light circuit has a cathode and anode. Compared to COB LED modules, which have all the diodes connected to a single circuit. Accordingly, light from an SMD LED module looks like it projects from multiple sources. Inversely, light from a COB LED looks like projects from a single unified light source. 

However, this also gives the SMD LED module an advantage. This allows it to contain RGB diodes, which we can use in color-changing bulbs. Additionally, SMD LED modules are exceedingly bright. They can produce up to 100 lumens per watt. COB LEDs are still better at single-color applications. Furthermore, they provide you with better lumen per watt ratios when compared to the SMD LEDs. They also require less energy to do so.

COB vs. CREE LED

COB vs. CREE LED

The industry considers CREE to be one of the biggest manufacturers and innovators in bright LED innovation. Not only does CREE refer to a company, but it also refers to the lighting technology they create. One of the most notable features of the technology is its lack of mercury

You can find them with green and blue LED chips. They are powerful enough to deliver up to 815 lumens of light. This is if they are in shatterproof housing. You can use them in radio frequency applications, backlighting, general illumination, solar inverters, and power suppliers.

When you compare CREE light systems to COB LED lights, the first thing you will notice is that they look different. CREE LED lighting systems are larger and have a wider PCB area. Thanks to larger surface areas, CREE systems can dissipate greater amounts of heat. That is important because it can influence a chip’s lifespan. 

Once again, COB LEDs work as a single unified light source. CREE LED systems work very similarly to SMD LEDs. They consist of a variety of components bound to a PCB substrate. Thanks to their design, COB LEDs can illuminate a large visual angle.  

Additionally, COB LEDs have better lumen/watt ratios than CREE LEDs. It is also more heat efficient.  

Flexible COB LEDs Strip

Flexible COB LED Strips

Earlier, we briefly touched on SMD LEDs and compared them to COB LEDs. Generally, the SMD consists of the LED chip, phosphor encapsulation, L-frame solder points, and a plastic reflector. 

Flexible strip lights use miniaturized versions of COB LED. Hence why they may be a little more simplistic in their design than SMDs. They consist of phosphor film, a chip, and solder points underneath. Hence why we use it in LED light strips.

We compact the flip-chip LEDs down the middle of the strip light. You can find up to 512 LEDs for every meter. The best thing about COB-based LED flex strips is the lack of LED hotspots. A hotspot refers to inconsistently bright areas on the SMD LED flex strip.  

COB Flex strips produce smooth, consistent strip lighting. COB LED flex strips are also brighter than SMD-based strip lights. Because of the smaller diode size, they are a lot more flexible and produce less heat. You can cut and shave them. Additionally, they come in a small variety of colors and sizes.

COB LEDs Light

COB LED Lights

As you can see, COB LEDs are very useful. Once again, you can use them to create various projects, such as a COB LED grow light. If you do not have a green thumb and are not fond of plants, you can always create your own focused COB LED work light. 

You can do this using individualized COB LED strips, single modules, or a COB LED bulb. The technology is quite versatile.  

The fact that you can replace high-intensity discharge with LED corn cob lamps further highlights their usefulness. What are LED corn cob lamps? They are large light bulbs that use rows of individual COB LEDs to emit powerful light. Most people see them as a viable replacement for metal halide bulbs because of their efficiency. 

FAQs

FAQs

Why is COB LEDs better? 

COB LEDs are small, flexible, and power-efficient. They also have great heat dissipation when you pair them with an LED heatsink. Additionally, they deliver great lumen/watts per area. They essentially provide you with greater light density.

How Long Do COB LEDs Last?

The lifespan of a COB LED’ will depend on how you use them and how much heat is around them. The average rated lifespan of a COB LED is 50,000 hours. This is if you use them for an average of 12 hours per day. 

Do COB LEDs Need Drivers?

COB LEDs do not necessarily require drivers to function. They do, however, require consistent and constant power. The best way to maintain a current to a COB LED is through a driver.  

Conclusion

There is strength in numbers, and COB LEDs exemplify this. Furthermore, COB LEDs have a very simple circuit design. They are easy to use and provide you with high light density. After reading the above guide, you may want to incorporate them into your next project. Nevertheless, we hope you have enjoyed reading this guide. Please visit the rest of the site if you are interested in more information about LEDs and PCBs. Thank you for reading. 

Hommer
Hi, I am Hommer, the founder of WellPCB. So far we have more than 4,000 customers worldwide. Any questions you can feel free to contact me. Thanks in advance.

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