LED 101 / Hardware
DIP, SMD, and COB
Three ways to package the LEDs on a module. Gym walls are usually SMD. Fine-pitch close-view walls often use COB. DIP still appears on coarse outdoor work.
DIP (dual in-line package) uses separate red, green, and blue lamps that stick up from the board. Pixels cannot sit as close as SMD, so DIP is common on wider outdoor pitches, roughly 10 mm and up. The packages are tough and can be very bright.
SMD (surface-mount device) puts the red, green, and blue dies in one small package soldered to the board. That is the usual build for indoor gyms and many outdoor signs. At larger pitches, SMD with a mask can take a ball hit. At fine pitch the packages sit close, the lamps are small, and the surface is fragile. A fingernail or a wipe in the wrong place can kill pixels. Handling rules matter.
COB (chip-on-board) mounts bare chips on the substrate and covers the array with a resin skin. Pitches are often under about 1.5 mm. For close-view rooms, that sealed face is the durable fine-pitch option. Details are in COB LED.
Do not treat COB and gym impact rating as the same story. A mid-pitch SMD gym wall needs a mask and a module lock built for balls. That is covered in Impact-resistant LED for gymnasiums.