An LED pixel basically consists of two parts: an LED element or a light-emitting diode and the control in the form of a circuit board. So-called SMD LEDs are the most widespread and mature LEDs. SMD stands for "surface-mounted-device", ie a component that is attached to a surface. In this case, this concerns the LED, which is soldered with the connection surface directly onto a circuit board. However, this is just one of many LED technologies, each with different advantages and disadvantages.

SMD chip LED : The classic SMD variant. The individual LEDs are mounted directly on the circuit board and are surrounded by a transparent body made of epoxy hard. However, the light emitted by the LED overlaps and is widely scattered. Due to the different wavelengths of the colors, screens with this technology appear slightly reddish when viewed from the side. The pixels are placed individually - which can also be clearly felt when you run your finger over them due to the rough surface - and can easily be repaired or replaced.

SMD top LED : With the SMD top LED, the emerging light is directed towards the front through a funnel-shaped plastic housing that surrounds the light-emitting diode. The case is filled with epoxy resin. Due to the targeted light emission, the picture is brighter when viewed from the front. When looking from the side, however, the image looks much darker and is more difficult to see than with chip LED. Repairing or replacing individual pixels is again quite easy.

Since SMD technology is mounted directly on the circuit board, the construction is quite fragile. However, if a particularly high resolution is to be achieved, the pixel spacing and, accordingly, the components must be very small. For razor-sharp images in the high-resolution range, other technologies must be used to increase stability:

GOB (Glue on Board) : The technology is very similar to the SMD top LED. With GOB, however, a layer of epoxy resin is drawn over the entire LED surface, which envelops and seals the pixels. The LEDs are optimally protected and the stability is very high - ideal for outdoor use and large pixel pitch.

AOB (Admixture On Board) : The AOB technology is also similar in structure to the SMD top LED. This time there is an extra silicone layer between the individual housings of the pixels for stabilization. When you run your finger over it, you can feel the individual pixels like with SMD.

COB (Chip on Board) : For Lang AG, the technology of the future in the LED sector. The light-emitting diodes are unencapsulated and placed directly on the PCB board, the circuit board for controlling the LED. As a result, the LEDs are not wired from above, as usual, but directly from below, which is also known as a "flip chip". The individual pixels can thus move even closer together. The cabling from below does not reduce the light output either. Particularly when small mini or micro LEDs are used, very small pixel pitches can be achieved with COB LEDs.

IMD ( Integrated Mounted / Matrix Devices ): The technology transition between SMD and COB. The designation, whether mounted or matrix, varies depending on the manufacturer. An IMD pixel can best be described as a 4in1 LED. This is because four SMD-LED pixels are combined to form a mechanical unit. This optically enables a very fine pixel pitch, while the actual mechanical distance is within a range that is already known to the industry. The image of the IMD LED, however, sometimes appears coarse and irregular with a larger pixel pitch between the individual IMD units. The reason for this is that with a larger pixel pitch, the distance between the LED within the mechanical 4-unit is smaller than between the respective blocks. With a pixel pitch of 1.5mm and more, a black cross is lasered in the middle of the unit,

MiniLED & microLED: Contrary to what is often heard, this does not refer to a manufacturing process, but only to the chip size, which each manufacturer defines for himself. miniLED and microLED, for example, are combined with previously mentioned production processes such as COB or IMD in order to achieve finer pixel pitches of less than 1mm. With SMD-LED or similar technologies, the housing limits how narrow the pixel pitch can be. This is why these technologies are not suitable for mini or microLEDs.