Light bulb with upward and downward facing leds having heat dissipation

Abstract

A light bulb includes a lamp base unit including a base, an electrically insulative hollow column fastened to the base, a heat sink surrounding the electrically insulative hollow column, a light-transmissive shade surrounding the upper part of the metal cylindrical heat sink and a power supply module electrically connected to the base, a light source module including a metal holder plate, a first circuit board with upward-facing LEDs, a second circuit board with downward-facing LEDs, a first adapter board, a second adapter board, a positioning block and a heat transfer pad and supported on the heat sink in the light-transmissive shade, and a lamp shell fastened to the metal holder plate and capped on the light-transmissive shade. During operation of the LEDs, waste heat can be quickly dissipated into the outside open air through the mounting lugs of the metal holder plate, the heat transfer pad and the heat sink.