Light emitting diode filament including flip chip light emitting diodes to reduce the amount of phosphor that is integrated into the filament

A light emitting filament structure comprising:

• a filament substrate;
• a plurality of flip chip light emitting diode (LED) chips;
• and
• a continuous phosphor layer overlying the plurality of the flip chip light emitting diode (LED) chips, the continuous phosphor layer includes first portions that are in direct contact with at least a light transmission surface on an upper surface of the flip chip light emitting diode (LED) chips, and second portions that bridge across the space separating adjacently positioned light emitting diodes of the plurality of flip chip light emitting diode (LED) chips, the space separating the adjacently positioned light emitting diodes has a width extending between exposed sidewalls of the adjacently positioned light emitting diodes, the exposed sidewalls of the adjacently positioned light emitting diodes are not in contact with the continuous phosphor layer, wherein the space separating the adjacently positioned light emitting diodes has an upper surface defined by a lower surface of the second portions of the continuous phosphor layer.

A method of assembling a filament light emitting diode comprising:

• forming a circuit on a filament stent substrate, wherein the circuit having pads arranged along of length of the filament stent substrate;
• bonding light emitting diode (LED) chips to the circuit, the light emitting diode chips including a light emitting diode (LED) die having contacts on a contact surface side of the LED chips for the bonding to the pads of the circuit;
• and
• forming a continuous phosphor layer on the plurality of light emitting diodes, the phosphor layer includes first portions of the continuous phosphor layer that are in direct contact with at least a light transmission surface of the light emitting diode (LED) chips, and second portions of the continuous phosphor layer that bridge across the space separating adjacently positioned light emitting diodes, the second portions of the continuous phosphor layer encapsulating an air gap between the adjacently positioned light emitting diodes.