The term SMD stands for Surface Mount Device.  It is a type of electronic component package that is made to be directly mounted onto the surface of a Printed Circuit Board (also known as PCB). 

SMD components are generally smaller than previous SMT technology which require leads to be inserted through holes within the PCB.  The shift from SMT to SMDs has been monumental in the miniaturisation of modern electronics which has allowed many devices to become smaller and more portable.

The Evolution of SMDs

SMDs are made in a variety of different ways depending on the component type (e.g., resistors, capacitors, integrated circuits, diodes, and LEDs).

SMDs are significantly smaller and lighter than previous SMT through-hole components and are soldered directly onto the surface pads of a PCB removing the need for the leads to be passed through the circuit board.  They are a great choice for automation and their manufacturing process is highly suited for pick and place machines leading to a more efficient production.

Common SMD LED Packages

In terms of lighting SMD often refers to a type of LED package. These packages can be identified by a four-digit which indicates their physical dimensions in millimetres.

What do LEDs have to do with SMDs?

LEDs are a component that can be found inside of a SMD.  When a LED is packaged using Surface Mount Technology it then becomes a “SMD LED.”

There are two types of terms common when referring to LED strips which are COB LEDs and SMD LEDs.  But which one is better?  It is not so much a case of one being better than the other but rather which one is more suitable for my application.  SMD LEDs are recommended for applications requiring flexibility and COB LEDs are better for high-intensity, focused lighting where a smooth, uniform beam of light is needed.

Which SMD LED is the Brightest?

To determine which SMD LED would be the brightest you will need to take into account the chip size and number of chips and the lumen output.   Lumens measure the amount of light that comes out of the LEDs and a larger chip size or number of chips will be able to hold more light.

The Current Brightness Leaders

As of current manufacturing standards, the following packages are often used for high-brightness applications:

1. 5050 and 5630

• 5050: This measures 5.0mm x 5.0mm and contains three separate LED chips on average inside of the housing. This leads to a very bright design thanks to the multiple chips within it and is often used for RGB (multiple coloured) applications or bright white lighting.
• 5630: This measures 5.6mm x 3.0mm. This is engineered for high brightness and is often cited as one of the brightest single-chip SMDs which offers excellent light output per watt and is a popular choice for general lighting fixtures.  It is not generally used for RGB lighting.

2. High-Efficiency 2835

The 2835 measures 2.8mm x 3.5mm making it smaller than the 5050 but its advanced thermal design allows it to handle higher currents than the older 3528 package. The 2835 design has high-density strips making this package extremely bright and efficient, sometimes surpassing the brightness of 5050 strips in white coloured lighting applications. 

For LED strips the overall brightness is often more dependent on the number of LEDs per meter and the lumens that each LED produces.