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Led Heat Sink: What Is It and Why It’s Important?

If you deal with LED PCB lights, chances are you’ve come across an LED heat sink. But if you haven’t, not to worry this article will help.

For starters, heat sinks are a vital part of LED lighting. And it’s because the heat sinks offer a path for heat to reach the outside elements from the LED light source.

Are you still reading?

Then, it means one thing: you’re keen on getting a full grasp of the topic.

In that case, stick around because we’ll cover things like the importance of a heat sink, how it helps the LED light sink, and much more.

What Is a LED Heat Sink?

LED Heat Sink

When it comes to an LED luminaire, a heat sink is the most crucial part of the thermal track. You can also call it a heat exchanger. And it’s because it absorbs thermal energy that an LED module produces.

Afterward, it distributes the energy into the surrounding ambient air. By doing so, it regulates the temperature of an LED.

Why Do LED Lights Need a Heat Sink?

LED Lights

When you touch an LED, the temperature is cool. But the inner part of the LED has a lot of unwanted heat.

How does an LED produce a lot of unwanted heat internally? Well, this happens because of the inadequacy of semiconductors that produce light. In other words, LED losses about 60 – 95% of its input power.

So, how do you handle this amount of internal heat?

Simple, you can remove the heat with a good LED heat sink thanks to its effective thermal management.

A heat sink can distribute energy in 3 different ways: radiation, conduction, and convection.

Radiation involves transferring heat from two bodies via thermal radiation at different temperatures.

Convection is the movement of heat from solid to moving liquid.

Then, conduction is the movement of heat from one solid to another. In summary, using a heat sink means that your LED lights will perform well for a long time.

Heat Sink Material

Heat Sink Material

Aluminum alloys or copper are the most common materials used to make heat sinks. But aluminum is more common than copper for three major reasons. It has high corrosion resistance, fairly high thermal conductivity, and it’s cost-effective.

Copper alloys apply when there’s a need for high levels of thermal conductivity.  

MCPCBs: How It Helps the LED Heat Sink?

If you take a close look at LEDs, you’ll notice one thing. They possess reels like bare emitters. And the reels are usually enclosed in a see-through resin.

What does this mean?

Simple, the LED is a deficient thermal conductor. So, the best option is to place the LED on the aluminum base.

By doing so, it works like a heat spreader. In other words, the MCPCB is a major piece of the circuit board that enhances thermal conductivity.

LED Heat Sink Calculator

You can use the formula below to calculate for heat sink:

θs = (Tj-Ta)  — θjc — θb

          Pd

θs is the subject you’re trying to calculate. It stands for the thermal resistance of the heat sink.  θjc refers to the LED COB module’s thermal resistance. And you can get this value from the datasheets.θb refers to the thermal resistance between the heat sink and LED case.

The Tj in the equation is the maximum junction temperature. The value is usually on the LED datasheet. So, the value should be below 90%.

Ta refers to the temperature of the ambient air around the LED heat sink. If you’re working with recessed ceiling light, the value may be close to 50 or 550C. but, if you have an open-air mounted spotlight, you should expect 300C.

Pd is the power distributed from the LED module. You can estimate the value as 80%.

So, after the calculation, you’ll get a value for θs . Or you’ll get a range. With the value, you can make a good decision about the ideal heat sink.

LED Heatsink Housing

A LED heatsink housing usually fits LED. It comes in different sizes and designs. Plus, the base piece has a center hole. The hole is for electrical threads and wire leads. Also, the housing allows you to assemble different components.

How Do You Mount a LED Heatsink?

 LED Heatsink

First, you need to thin the pads on the aluminum heatsinks. That way, you can mount the LED. While you’re at it, use a thin gauge solder.

Then, arrange the contacts with the pads and solder them individually. But, before you solder, ensure that the contacts align properly. Afterward, confirm the connections with your Multimeter. With that, you can check for polarity.

FAQs

How to Heat Sink a 30w LED Cob Bulb Chip?

To achieve this, apply the LED Heat Sink formula: 

θs = (Tj-Ta)  — θjc — θb

          Pd

How Many Heatsinks Do I Need?

The number of heatsinks you’ll need solely depends on the size of your project.

Is There an Alternative to Heatsink Cooling?

Another option you can try is toothpaste. But it’s not a good fit for a long-term solution.

Is Heat Bad for Led Lights?

In reality, an LED light output is high in a cool environment. But if the temperature is high, the output gets low. So, it’s ideal to keep LED lights in a cooler temperature or environment.

Closing Words

Hope you enjoyed the read on the LED heat sink. By now, you should be clear about what it is and its importance. While you’re at it, you can make good use of the calculator to know the ideal heat sink to use. What did we miss out on this topic? Do you have any suggestions? Don’t forget to contact us.

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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