US 9,868,270 B2Granted

Wavelength converting member

AssigneeCoorsTek, Inc.

InventorMasaki Irie

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Abstract

Provided is a wavelength converting member made of a sintered body which inhibits color unevenness of exit light after wavelength conversion and has excellent light emitting efficiency and inhibited decrease in mechanical strength. The wavelength converting member includes a plate-like sintered body having one principal surface as a light entrance surface and the other principal surface as a light exit surface, and a porosity of 0.1% or less with fluorescent material grains containing an activator and light-transmitting material grains, the entrance surface and the exit surface are sintered surfaces in which the fluorescent material grains and light-transmitting material grains are exposed without processing. The sintered surface has an average roughness Ra of 0.1 μm to 0.5 μm, the fluorescent material grains exposed on a surface have an average roughness Ra1 of 0.2 nm to 0.5 nm, and the light-transmitting material grains exposed on a surface have an average roughness Ra2 of 0.3 nm to 0.7 nm.

Claims9

Dependent claims

A wavelength converting member comprising a plate-like sintered body having one principal surface as a light entrance surface and the other principal surface opposite to the entrance surface as a light exit surface, wherein

the plate-like sintered body has a porosity of 1.0% or less which includes fluorescent material grains containing an activator and light-transmitting material grains,
the fluorescent material containing the activator is a material represented by the general formula A3B5O12:Ce, in the formula, A being at least one selected from the group consisting of Y and Gd, and B being Al,
the light-transmitting material is Al2O3 or a material in which at least Sc2O3 or Ga2O3 is contained in Al2O3,
at least the entrance surface and the exit surface are a non-processed sintered surface on which the fluorescent material grains and the light-transmitting material grains are exposed, and the non-processed sintered surface has a calculated average roughness Ra, as an average of 10 points measured with a measurement length of 4 mm, of 0.1 μm to 0.5 μm,
and the fluorescent material grains exposed on the non-processed sintered surface have a calculated average roughness Ra1, as an average of 20 points measured with a measurement length of 1 μm, of 0.2 nm to 0.5 nm, and the light-transmitting material grains exposed on the non-processed sintered surface have a calculated average roughness Ra2, as an average of 20 points measured with a measurement length of 1 μm, of 0.3 nm to 0.7 nm.

2 more elements

A wavelength converting member comprising:

a first layer which contains a YAG-based fluorescent material containing an activator and Al2O3;
an intermediate layer which is laminated on the first layer and includes Al2O3 in which grains with a diameter of 20 μm to 300 μm include no less than 90% of total grain number;
and
a second layer which is laminated on the intermediate layer and includes a YAG-based material containing an activator in an amount of no more than 10% of an activator content in the first layer and Al2O3, wherein
a connected structure is provided in which Al2O3 grains are connected to each other in each layer and Al2O3 grains are also connected to each other at each layer interface,
all of the first layer, the intermediate layer, and the second layer include a sintered body having a porosity of 1.0% or less, surfaces of the first layer and the second layer being a non-processed sintered surface, the non-processed sintered surface has a calculated average roughness Ra, as an average of 10 points measured with a measurement length of 4 mm, of 0.1 μm to 0.5 μm, and
a calculated average roughness Ra1 of the YAG-based fluorescent material grains exposed on the non-processed sintered surface, which is obtained as an average of 20 points measured with a measurement length of 1 μm, is 0.2 nm to 0.5 nm and a calculated average roughness Ra2 of Al2O3 grains exposed on the non-processed sintered surface, which is obtained as an average of 20 points measured with a measurement length of 1 μm, is 0.3 nm to 0.7 nm.

4 more elements

Dependencies are inferred from the claim text.