The technologies used in the manufacturing of LED screens are basically two:
PTH (Plating Through Holes)Technology - Individual LEDs are welded from the front side of the printed circuit board into it. To keep the contact and dissipate heating, two pins are used (anode and cathode) that are clearly visible on the back side of the board. To keep this type of LED waterproof it is necessary to coat its base with silicone resins.
SMD (Surface Mounting Device)Technology - Miniaturized LEDs of one color are placed in a single RGB package, that is welded directly onto the front surface of the printed circuit board, with no visible pins on the other side. These SMDs are not normally waterproof on the top and they can be used outdoor only for temporary events unless special polycarbonate or similar protection films are laid over. The solution provided must be checked very carefully with your provider as only a few SMD products can be really used for permanent outdoor installations.
Most of outdoor LED screens are still built with PTH technology. LED screens for indoor are normally built with SMD technology. Due to the increasing brightness and all the engineering studies to make SMDs really waterproof, very reliable and longest lifetime, this is becoming more and more popular for outdoor use too. The visual impact of an SMD screen is generally much better than a PTH screen. Unlike PTH, SMD can not apply Virtual Pixel Technology.
The benefits of SMD screens
Wider vertical viewing angle
Same vertical and horizontal viewing angle
More natural color reproduction and improved clarity
Sharper and more similar to television pictures
Better color uniformity and adjustment
Reproduction of more defined, readable texts
Lack of "pixelation" also at a short shooting or viewing distance
Perception of pure white, without the presence of RGB individual colors, also closely
Narrower "moiré effect" on TV camera
A more efficient pixel-to-pixel color and brightness calibration process
Reduction of maintenance costs for vandalism (removable front)
Product of the future, for which most of the R & D investments of LED suppliers have now been allocated
Source:
