Agilent Technologies, Inc.

Avago Technologies Ecbu IP Pte. Ltd.

Bee Yin Janet Chua

Christopher J Summers

Hisham Menkara

Boon Chun Tan

A lighting device provides a spectrally-shifted light output from a light source. The lighting device includes a semiconductor light emitting device providing a source light and a first thin-film luminescent material layer coating a surface of the semiconductor light emitting device. The first thin-film luminescent material layer includes a luminescent material that emits an emitted light in response to the source light. The first thin-film luminescent material layer has a specific and consistent thickness and specific and consistent density of luminescent particles. The emitted light includes a first luminescent material emitted light when the luminescent material completely absorbs the source light. The emitted light includes a first composite light when the first luminescent material absorbs less than all of the source light. The device may further include a second thin-film luminescent layer coating the first thin-film luminescent layer.

Apparatus for producing a spectrally-shifted light output from a light emitting device utilizing thin-film luminescent layers

The present invention provides a method and system for selectively depositing light emitting film on a light emitting base layer, such as phosphors in a silicon gel carrier on a light emitting diode (LED). The combination of light emitting film and light emitting base layer are selected to give the desired light color, such as white light. The screen printing method comprises applying a photoresist layer to a base layer, masking the photoresist layer, irradiating the photoresist layer through the mask to make a soluble portion and insoluble portion, dissolving the soluble portion to reveal the base layer, and applying a light emitting film to the base layer where the soluble portion was removed. The base layer is then sawn to form LED chips or LED lamps.

Screen printing process for light emitting base layer

The present invention provides a process and apparatus for selectively depositing materials on a semiconductor device, such as depositing phosphors or other optical materials on a light emitting diode (LED), using an electrophoretic deposition process. The semiconductor device comprises a p-side and an n-side. A first biasing voltage is applied between an anode and the p-side of the semiconductor device. A second biasing voltage is applied between the p-side and the n-side of the semiconductor device. The relative biasing of the p-side and the n-side determines where coating is deposited on the semiconductor device. An optional pre-coating process is used to deposit a high resistivity dielectric material, such as silica, on the semiconductor device. The pre-coating can even the electric field on the surface of the semiconductor device, where local features such as metal connections or passivation layers disturb the electric field during phosphor deposition without pre-coating.

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Penang, Malaysia

Bee Yin Janet Chua