Surface Mount Device LED: What Do You Know About SMD LED

Figure: custom SMD LED by PCBONLINE

Surface Mount Devices (SMDs) refer to electronic components mounted directly onto a printed circuit board (PCB) surface. SMDs are well-suited for automated assembly lines as they are placed on PCB using pick-and-place machines and then soldered, making production faster and more efficient.

Examples of SMDs are passive components like resistors and capacitors, active components like transistors and diodes, and Surface Mount LEDs often called SMD LEDs. This blog will teach us about SMD LEDs, including their packages, types, and SMD LED vs COB (chip-on-board) LED.

What are SMD LEDs

An LED or Light-emitting Diode is a semiconductor device, which emits light when electric current is passed through it. They produce light through a process called electroluminescence - when electrons gain energy from the applied voltage, they release that energy as photons (light) when they return to a lower energy state.

A surface mount Device light-emitting diode (SMD LED) is a type of LED that is designed to be mounted directly onto the PCB using SMT assembly.

SMD LEDs are compact, highly efficient, and versatile in design. They are ideal for a variety of lighting applications from household and commercial use to industrial applications.

They allow a variety of colors in output, have a high brightness, and use energy efficiently. Each package is recognized by numbers that represent its physical dimensions in millimeters (mm).

Figure: aluminum PCB mounted with SMD LEDs

Common SMD LED Packages and Specifications

Many SMD LED packages are standardized owing to their usefulness in different applications and scenarios. They vary in size (physical dimensions), power consumption, level of brightness, and how efficiently they use energy. A few common packages are discussed here.

SMD LED 0603

The LED SMD 0603 package has a very low power consumption and is available in colors of red, green, blue, white, etc. It's compact and light, suitable for tight spaces and portable applications. It is used in backlighting, indicator lights in compact devices, and lighting in wearables.

SMD LED 0805

The LED SMD 0805 has a better light output than the 0603 package. It finds applications in indicator lights in consumer electronics, backlighting for buttons and displays, and decorative lighting in automotive and home applications.

SMD LED 1010

The LED SMD 1010 package makes a good balance between size and light output. It's used for general lighting for applications requiring a moderate brightness level.

SMD LED 3528

The LED SMD 3528 package is commonly used in applications that have lower power consumption, such as indicator lights, lighting for ambiance, etc. It is typically used in scenarios where intense brightness is not required. However, energy efficiency is preferred.

SMD LED 5050

SMD LED 5050 is larger in size or dimensions. It can have three diodes, which enables it to produce more light and support variations in RGB color. This package is widely used in applications that require higher brightness. Commonly, we can find 5050 SMD LEDs in LED strips, floodlights, and solutions providing high-output lighting.

SMD LED 2835

SMD LED 2835 is an enhancement of 3528, and is known for providing high brightness and better energy efficiency compared to the latter. This package is suitable for applications that require high output without having a tremendous increase in power consumption. The applications include ceiling lights, panel lights, etc.

SMD 3024

SMD LED 3024's size is smaller than that of 5050 or 2835. It offers an ample amount of brightness with reasonable energy efficiency. It is well-suited for specialized lighting applications such as backlighting and automotive lighting.

SMD 2216

The 2216 package is smaller in size but its lighting is highly efficient. Therefore, it is best suited for applications that require compact designs and structures with high-output light. Often, it is used in architectural lighting and compact lighting solutions.

SMD 2110

SMD 2110 LED is designed for applications where space is very limited, as in slim LED strips, wearables, etc.

SMD LED vs COB LED

SMD LED and COB (Chip-on-Board) LED are two common types of LED technologies used for lighting applications. They differ in various aspects including design, performance, and functionality.

1. Design

An SMD LED consists of separate light-emitting diodes mounted directly onto a PCB, while a COB LED integrates multiple diodes onto a single chip, which is mounted on a board.

SMD LED allows for individual control of color and brightness, while COB LEDs combine all diodes in a large efficient light emitting area, producing a more concentrated and intense light.

2. Heat management

In SMD LEDs, heat dissipation is moderate but must be managed well using cooling mechanisms, specifically in applications where multiple LEDs are grouped, such as LED strips.

In contrast, COB LEDs have extremely good heat dissipation abilities, as the diodes are spread out on a larger area, so heat is evenly distributed and doesn't require much cooling.

3. Efficiency

SMD LEDs are efficient but their efficiency is dependent on the design or structure of the lighting solution, whereas COB LEDs are more efficient owing to their streamlined design.

4. Brightness

SMD LEDs offer high brightness that can be adjusted according to the arrangement and number of diodes they have. On the other hand, COB LEDs produce very bright and focused light owing to that all the diodes are packed into a small chip.

5. Light output and distribution

The SMD LED gives a focus and directional light, for which we use reflectors or lenses to control its beam angle.

On the contrary, COB LEDs offer an evenly distributed broader output providing an intense source of light.

6. Color options

SMD LED can produce different colors. They are available in RGB (Red, Green, Blue) versions, which allow them to mix and match colors for different applications. In contrast, COB LEDs are more limited in terms of color output. Since they integrate all diodes onto a single chip, they typically emit a single color or a fixed range of colors.

Overall, SMD LED is used for basic devices, and COB LED serves more advanced applications, due to its high brightness, uniform light, and excellent thermal dissipation.

Types of SMD LEDs

Here are the three types of SMD LEDs:

1. Chip SMD LEDs

Chip SMD LEDs, the most commonly used SMD LEDs, are flat and compact, often placed directly on a circuit board, allowing for better heat dissipation and easier mass production. They are made up of a small semiconductor die mounted on a lead frame. The lead frame connects to external terminals, which carry the electrical signal to the LED chip.

2. Top SMD LEDs

3. Sideview SMD LEDs

To assemble the SMD components on the PCB, a process called surface mount technology (SMT) is used.

Sideview SMD LEDs are specifically designed to emit light sideways, parallel to the circuit board. They are often used in edge-lighting applications, such as backlit keyboards or displays. The LED is oriented so that the light is emitted from the side of the component, instead of directly upwards. This makes them useful for applications where low-profile lighting or side illumination is needed.

One-Stop PCB Assembly Manufacturer PCBONLINE

PCBONLINE is a one-stop PCBA manufacturer that fabricates PCBs and assembles the boards with components including SMD LEDs. It has two large advanced PCB manufacturing bases, one PCB assembly factory, stable supply chains, and an R&D team.

Whether your project is SMD LED PCBA or COB LED PCBA, you can work with PCBONLINE for R&D and production from prototypes to massive assembly.

Besides SMD LED custom fabrication and PCBA, PCBONLINE can make COB LED PCBA with wire bonding and flip-chip technologies. To get a quote for your project, please contact info@pcbonline.com.

Conclusion

SMD LEDs provide effective lighting with various packages to go with different applications. Each type of SMD provides unique benefits to enhance suitability for different tasks. PCBONLINE's approach to PCB manufacturing and assembly ensures quality services and client satisfaction. If you need SMD LEDs and PCBA manufacturing, chat with PCBONLINE from the online chat window.