Both are forms of Chip-on-Board (COB) packaging, where LED chips are bonded directly to the circuit board rather than being housed in individual lamp packages as with SMD. The difference lies in how the chip is physically oriented and connected.
In standard (face-up) COB, the LED chip sits upright on the substrate and its electrical connections are made using thin wire bonds — tiny gold wires that link the chip to the circuit. This is a well-established and cost-effective approach.
In Flip Chip COB, the LED chip is inverted so that its electrical contacts face directly downward onto the substrate, making contact via solder bumps rather than wire bonds. This eliminates the wire bonds entirely, which has several significant benefits: there are fewer potential failure points, heat is dissipated more efficiently (the thermal path from chip to substrate is shorter), power consumption is reduced by around 40 to 45% at equivalent brightness, and pixel pitches can be made finer — Flip Chip COB is the enabling technology for sub-1 mm pixel pitches and MicroLED displays. The trade-off is a higher manufacturing cost, though this gap is narrowing rapidly as production volumes increase.