In accordance with the invention, a light emitting diode package assembly is provided to emulate the pattern of light produced by an incandescent filament bulb. The package assembly is composed of a substrate for LEDs comprising a heat-sinking base having a pair of opposing major surfaces. Each major surface has an overlying of thermally conducting ceramic and an outer surface layer of light reflective material. Disposed on each surface layer is a plurality of LEDs. Advantageously, the LEDs are arranged on the surface in a configuration of low mutual obstruction. Advantageously, reflecting elements transverse to each surface layer are positioned and shaped to reflect a substantial portion of the light emitted from the LEDs that would otherwise enter neighboring LEDs. In a preferred embodiment, the LEDs are arranged in the general form of a closed curve, and a transverse reflector is disposed in the interior of the curve. Alternatively, the LEDs can be arranged in a linear array. The assembly can be efficiently fabricated by back-to-back assembly of two similar subassemblies.