Au stud bump can provide a good heat spreading path for the flip-chip LED due to its high thermal conductivity (300 W/mK) . In this paper, we compared four flip-chip LED devices with four different numbers of Au stud bumps. The thermal imaging analysis indicates that the heat dissipation is proportional to the number of Au stud bump. However, when the number of Au stud bumps was larger than 24, the heat dissipation performance will become deteriorated due to the poor bonding between grain and substrate. Therefore, the number of Au stud bumps was optimized to be 20 to 24, which can be employed to develop flip-chip LEDs with optimum electrical and optical performance.