A method of making a LED light bulb with the Graphene filament contains steps of: A. providing a flexible substrate, wherein the flexible substrate is flexible printed circuit board (PCB); B. coating graphene-based heat dissipation ink on a back side of the flexible substrate; C. cutting the printed circuit board (PCB) on which a graphene-based heat dissipation film is coated to form plural Graphene filaments; D. fixing the plural Graphene filaments into a light bulb. The flexible substrate has copper lines formed on both sides thereof for electronic circuits and heat conduction, and LED chips are mounted on a front side of the flexible substrate. The graphene-based heat dissipation ink is coated on the back side of the flexible substrate before or after LED chips/phosphor molding and then is dried. In addition, the Graphene filaments are fixed in a bended or arched position.

A method of making a LED light bulb with the Graphene filament contains steps of: A. providing a flexible substrate, wherein the flexible substrate is flexible printed circuit board (PCB); B. coating graphene-based heat dissipation ink on a back side of the flexible substrate; C. cutting the printed circuit board (PCB) on which a graphene-based heat dissipation film is coated to form plural Graphene filaments; D. fixing the plural Graphene filaments into a light bulb. The flexible substrate has copper lines formed on both sides thereof for electronic circuits and heat conduction, and LED chips are mounted on a front side of the flexible substrate. The graphene-based heat dissipation ink is coated on the back side of the flexible substrate before or after LED chips/phosphor molding and then is dried. In addition, the Graphene filaments are fixed in a bended or arched position.

An LED array is mounted on a base that is thermally coupled to a heat spreader. At least one aperture is provided between the support area and an edge of the heat spreader. The heat spreader may be coupled to a thermal pad which has sufficient thermal conductivity and is sufficiently thin to allow the thermal resistivity between the heat spreader and a corresponding heat sink to be below a predetermined value.

An LED array is mounted on a base that is thermally coupled to a heat spreader. At least one aperture is provided between the support area and an edge of the heat spreader. The heat spreader may be coupled to a thermal pad which has sufficient thermal conductivity and is sufficiently thin to allow the thermal resistivity between the heat spreader and a corresponding heat sink to be below a predetermined value.

An illumination device includes a supporting base, and a light-emitting element inserted in the supporting base. The light-emitting element includes a substrate having a supporting surface and a side surface, a light-emitting chip disposed on the supporting surface, and a first wavelength conversion layer covering the light-emitting chip and only a portion of the supporting surface without covering the side surface.

An illumination device includes a supporting base, and a light-emitting element inserted in the supporting base. The light-emitting element includes a substrate having a supporting surface and a side surface, a light-emitting chip disposed on the supporting surface, and a first wavelength conversion layer covering the light-emitting chip and only a portion of the supporting surface without covering the side surface.

A method of manufacturing a hexagonal boron nitride laminate contains steps of: a) Dissolve dielectric polymers in solvent. b) Mixing h-BN powder to form a well-mixed h-BN coating slurry. c) Coating slurry on substrates and dried at 100-150° C. The substrates can directly be etched or processed to form electric circuits. Substrates can also be completely etched or detached to attain a free standing laminate. Thereby, a hexagonal boron nitride laminate exhibit thermal conductivity of 10 to 40 W/m.Math.K, which is significantly larger than that currently used in thermal management. In addition, thermal conductivity of hexagonal boron nitride laminates increases with the increasing mass density, which opens a way of fine tuning of its thermal properties. For heat dissipation application, hexagonal boron nitride laminate coating can significantly enhance the performance of LED light bulb.

A method of manufacturing a hexagonal boron nitride laminate contains steps of: a) Dissolve dielectric polymers in solvent. b) Mixing h-BN powder to form a well-mixed h-BN coating slurry. c) Coating slurry on substrates and dried at 100-150° C. The substrates can directly be etched or processed to form electric circuits. Substrates can also be completely etched or detached to attain a free standing laminate. Thereby, a hexagonal boron nitride laminate exhibit thermal conductivity of 10 to 40 W/m.Math.K, which is significantly larger than that currently used in thermal management. In addition, thermal conductivity of hexagonal boron nitride laminates increases with the increasing mass density, which opens a way of fine tuning of its thermal properties. For heat dissipation application, hexagonal boron nitride laminate coating can significantly enhance the performance of LED light bulb.

The present invention discloses an illumination device (100). The illumination device (100) comprises a light source (110) arranged to generate light, a carrier (120) arranged to support the light source and an envelope (130) enclosing the light source and the carrier. The envelope comprises at least two enveloping parts which, when joined together, form the envelope. Further, the carrier is arranged in thermal contact with at least one of the enveloping parts for dissipating heat out of the illumination device.

An illumination unit includes one or more light sources each including a solid-state light-emitting device configured to emit light from a light emission region including a single or a plurality of light-emitting spots. The solid-state light-emitting device includes a single chip or a plurality of chips each emitting a light beam. Three or more of the light-emitting spots are provided within the whole of one or more light sources, to allow the whole of one or more light sources to emit light beams in two or more wavelength bands different from one another, and the solid-state light emitting device in a first light source which is at least one of the one or more light sources, has a plurality of light-emitting spots which emit light in the same wavelength band.