SMD LED Considerations for Lighting and Indicator Applications
When developing lighting and indicator devices, surface mounted diode (SMD) LEDs offer a variety of benefits. Learn the options available—including multi-color SMD LEDs—and the advantages they provide.
Surface mount diode (SMD) light emitting diodes (LEDs) are one of many LED options used in modern indication and backlighting applications. As the requirements for lighting and indicator solutions evolve, SMD LEDs are one of the primary tools used by engineers and manufacturers when optimizing:
- Status indication
- Power consumption
- Heat generation
- Illumination control
- Working space
For example, providing effective backlight for the latest wearable tech, such as the smart fitness monitor shown in Figure 1, means there are constraints related to size, power consumption, cost, and more.
Figure 1. Smartwatches and fitness watches are small, portable, lightweight, and must perform for a long time on a single charge. Image used courtesy of Pixabay
However, what features do SMD LEDs possess that help engineers find optimal lighting and indicator solutions? In this article, we’ll answer that question and go over some of the different LED types, the benefits/uses of SMD LEDs, and finally, look at a potential solution/product from VCC.
LED Types: DIP, COB, SMD
There are three basic LED technologies:
- DIP (Dual In-Line Package)
- COB (Chip-On-Board)
- SMD (Surface-Mount Diode)
DIP LEDs are the more traditional approach to LED lighting and are a familiar sight with two parallel wires/leads/pins attached to an enclosed diode. They are less energy efficient than COB and SMD LEDs, and heat generation is an issue, leading to a shorter lifespan than the other options.
While COBs and SMDs are smaller and more energy efficient than DIP LEDs, SMD LEDs, like those in Figure 2, can change color and generate less heat than the other two LED types.
Figure 2. SMD LEDs come in wide varieties. Image used courtesy of VCC
A Sleek Status Indication and Illumination Solution
Engineers must deal with the current demand for sleek status indication and illumination control, which can be achieved through the highly versatile nature of SMDs. SMDs are placed directly on the surface of a circuit board and are not traditional through-hole LEDs that require additional wires to function. They also have a wider angle than DIP and COB LEDs, meaning they work better for backlighting (for example, 120 degrees for SMDs as opposed to 45 degrees and 60 degrees for DIPs). This, in turn, means that fewer LEDs are required, further simplifying the design and costs associated with it.
Minimizing visual clutter, focusing light/indication where needed, simplifying the circuitry involved—all of these issues can be addressed through compact SMD LEDs and their ability to be used on their own or with more advanced solutions such as light pipes.
Cost-effective, Long-life Lighting Products
SMD LEDs provide a long operating life compared to traditional approaches to lighting and illumination. When a diode’s performance has degraded to the point that its brightness has been reduced by 50%, it has reached the end of its life. SMD LEDs are known for their low-power usage and low heat generation, thus extending life.
SMD LEDs can provide greater brightness with less power than traditional diode options, which reduces the heat generation that will eventually degrade performance. SMD LEDs are also packaged to promote the transfer of generated heat away from the LED more effectively than DIP or COB LEDs.
SMD LED for Light Intensity and Color Options
As engineers develop innovative lighting products, they also need color and light intensity options. For example, some SMD LED manufacturers have products that support one, two, or three colors using just one LED or as part of an LED array. Another example would be the need for low-brightness LEDs when the lighting industry often focuses on providing the brightest LEDs possible.
Versatility and Compatibility with Other Optoelectronic Devices
SMD LEDs are known for their versatility since they can act as light sources for other optoelectronic devices, such as light pipes and panel mount indicators. In addition, they can be used as a single or array illumination unit and/or act as lamp/bulb light sources.
Here are some examples of the wide variety of applications where engineers are already using SMD LEDs:
- Lightsource for wearable devices, such as smartwatches or fitness bands
- Status indication for portable devices, such as laptops, headphones, or controllers
- Indoor/Outdoor ambiance, mood/illumination lighting and control.
- Status indication on smart appliances, from smart thermostats to home security lights
- IoT and IIoT (Industrial Internet of Things) devices
- Healthcare applications, such as heart rate monitors and glucose monitors
Benefits of Using LED SMDs for Brightness Control
General backlighting and status indication are areas in which LED SMDs excel. This is partly due to their excellent luminous efficiency (or brightness per Watt of power).
Low-intensity brightness is often chosen for applications such as interior backlighting or smart appliance lighting and indication. They can also be used for indicators in environments with low/dim light settings, such as:
- Aircraft cabins (as illustrated in Figure 3)
- Telecom control rooms
- Movie theaters
- Electric vehicle (EV) stations
As mentioned earlier, low-brightness solutions have become harder to find as many SMD, DIP, and COB LEDs manufacturers have shifted their focus to high-brightness chips.
Figure 3. Aircraft cabins are an example of applications where LED brightness needs to be adjustable from low to high. Image used courtesy of Pixabay
Of course, there is still high demand for high-brightness LED for use in environments such as industrial control rooms or where daylight visibility is critical. Additionally, SMD LEDs can also provide those extremely high brightness levels ranging from 50 to 100 lumens per Watt.
VCC SpectraBright RGB and Bi-color SMD LEDs
After going through the benefits and uses of SMD LEDs, one potential solution is VCC’s SpectraBright RGB and bi-color SMD LEDs. These LED products were specifically engineered to meet various status indicators and illumination needs, from color options to brightness.
In terms of color options, these products are available in 3-color (RGB) and 2-color options (red/green, yellow/green, amber/green). This is an alternative to using single-color LEDs to achieve different status indications.
Additionally, using SMD LEDs saves power and space, not to mention the cost, as illustrated in Figure 4 below.
Figure 4. A multicolor SMD LED replaces the need for multiple LEDs by using a single chip. Image used courtesy of VCC
This is due to the reduced amount of required LEDs to achieve those color options. The 3-color and 2-color capabilities offered by SpectraBright also reduce design complexity for both the engineer and the manufacturer.
These LEDs are available at 120 degree viewing angles, making them easy to see when used as indicator lights, and they can light up a significant space when used as backlights. These are available in both high and low brightness options, as well as dual color and tricolor combinations.
Furthermore, these SMD LEDs are carefully engineered for optimum design space/geometry and packaging. As a result, they can create a minimal footprint while maintaining power efficiency and extremely low heat generation.
Finally, the SpectraBright product line claims to offer a longer expected life of 50k+ hours compared to traditional LED approaches because of VCC’s chip design that conducts heat away from the LED and their efficient use of power, which means less heat is generated.
Solving Pressing Design Challenges
Multi-color SMD LEDs such as the VCC SpectraBright Series were designed to help engineers solve their most pressing challenges while providing long-lasting, reliable, safe indication and illumination control that is more efficient for clients and manufacturers. Contact VCC today to learn more about their SMD LED lighting and status indication solutions.
Industry Articles are a form of content that allows industry partners to share useful news, messages, and technology with All About Circuits readers in a way editorial content is not well suited to. All Industry Articles are subject to strict editorial guidelines with the intention of offering readers useful news, technical expertise, or stories. The viewpoints and opinions expressed in Industry Articles are those of the partner and not necessarily those of All About Circuits or its writers.