Stanley Electric Co., Ltd

Tsutomu Akagi

Yasuyuki Kawakami

Shuichi Ajiki

Mitsunori Harada

Toshinobu Kashima

A light emitting apparatus with a combination of a plurality of LED chips and a phosphor layer is provided and can be configured to significantly reduce variations in chromaticity and luminance. The plurality of semiconductor light emitting devices (LED chips) are disposed with a gap therebetween, and the phosphor layer is formed on the upper surface thereof to bridge over the gaps between the LED chips. The phosphor layer may be uniform in thickness, but can be less in thickness over the gaps between the LED chips than on the upper surface of the LED chips. The phosphor layer can be continuously formed on the upper surface of the array of the chips with no phosphor layer present in between the chips. This configuration allows for reducing variations in luminance and chromaticity which may result from the gaps or the phosphor layer present in between the gaps.

Semiconductor light emitting apparatus

A color converted light emitting apparatus is provided that has excellent light emission characteristics and can be manufactured while a viscosity suitable for a printing method is maintained. The color converted light emitting apparatus can include a light emitting element and a color conversion layer containing a phosphor that is excited by light emitted from the light emitting element and which emits fluorescent light. The color conversion layer can further contain, as first and second thickeners, two types of particles with different average primary particle diameters. The average primary particle diameter of the second thickener can be less than one half of the average primary particle diameter of the first thickener. By appropriately adjusting the average primary particle diameters and the amounts of the thickeners added, the light emission characteristics and the emission chromaticity can be improved. For example, the first thickener can be adjusted to be present in the amount of at least 30 wt % and less than 100 wt % based on a total weight of the first and second thickeners.

Color converted light emitting apparatus

The disclosed subject matter includes reliable semiconductor light-emitting devices having a favorable light distribution using an LED chip, which can emit light having a different color as compared to that emitted directly by the LED chip. The semiconductor light-emitting device can include an LED chip having an electrode, a phosphor layer located on the LED chip except for the electrode, a bonding wire connected to the electrode, and a light-reflecting resin. The light-reflecting resin can be disposed on a light-emitting surface that is exposed around the electrode and on the electrode including the bonding wire, and can prevent the LED chip from exhibiting a leak of light that is not wavelength-converted via the phosphor layer, while increasing light that passes through the phosphor layer. In addition, the light-reflecting resin can protect the bonding wire from vibration, etc. Thus, the disclosed subject matter can provide reliable semiconductor light-emitting devices having high brightness without substantial color variability and that can emit various colored light(s).

Semiconductor light-emitting device

A method for producing a color-converting light-emitting device is provided that can prevent the deposition of elements caused by ion migration during an electrophoresis process used to deposit a phosphor layer on the light emitting device. An anode and a light-emitting device having a semiconductor light-emitting element are disposed in a solution in which phosphor particles are dispersed. An auxiliary cathode can be disposed between the light-emitting device and the anode. A DC voltage can be applied between one electrode of the light-emitting device and the anode so that the electrical potential of the electrode is lower than that of the anode, thereby moving the particles to a surface of the semiconductor light-emitting element and allowing them to deposit thereon. The electrical potential of the auxiliary cathode is maintained lower than that of the surface of the semiconductor light-emitting element. In this manner, cations dissolved from metallic regions of the light-emitting device can be attracted to the auxiliary cathode and prevented from being deposited on a surface of the light emitting device.

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Tokyo, Japan

Tsutomu Akagi