Why does MELF resistor have much better heat dissipation capability than chip resistor?
After the resistor is mounted on the PCB, the way to dissipate heat is to use convection to remove the heat on the resistor's surface and to use solid-state heat conduction inside the resistor to transfer the heat into the PCB. Therefore, we can understand that the size of the surface area and volume of the resistor directly affects its heat dissipation capability. Although the length of MELF resistors is similar to chip resistors, their volume is three times that of chip resistors. Therefore, MELF resistors are better than chip resistors regarding heat dissipation capability.
Thermal test between Firstohm SFP101V and 2512 CHIP resistors.
Test Voltage : 21.2V (With 0.5x rated power) ; Duration: Add the voltage for 0.5 hours
After the test, the surface temperature of MELF resistors decreased by about 17℃ to 20℃ compared to chip resistors.