Light emitter devices and methods for light emitting diode (led) chips

Abstract

Light emitter devices for light emitting diodes (LED chips) and related methods are disclosed. In one embodiment a light emitter device includes a substrate and a chip on board (COB) array of LED chips disposed over the substrate. A layer having wavelength conversion material provided therein is disposed over the array of LED chips for forming a light emitting surface from which light is emitted upon activation of the LED chips. In some aspects, the wavelength conversion material includes phosphoric or lumiphoric material that is settled and/or more densely concentrated within one or more predetermined portions of the layer. In some aspects, the devices and methods provided herein can comprise a lumen density of approximately 30 lm/mm 2 or greater.

What is claimed is: 
     
         1 . A method of providing a light emitter device, the method comprising:
 providing an array of light emitting diode (LED) chips over a substrate, wherein chip spacing between any two adjacent LED chips in the array of LED chips is at least approximately 50 μm or more;   providing a viscous material over the array of LED chips, wherein at least one wavelength conversion material is dispersed therein; and   causing the wavelength conversion material to settle within a predefined portion of the viscous material over the array of LED chips.   
     
     
         2 . The method of  claim 1 , wherein chip spacing between any two adjacent LED chips in the array of LED chips is at least approximately 200 μm or more. 
     
     
         3 . The method of  claim 1 , wherein the chip spacing between any two adjacent LED chips in the array of LED chips is at least approximately 300 μm or more. 
     
     
         4 . The method of  claim 1 , wherein providing the viscous material over the array of LED chips comprises dispensing silicone encapsulant over the LED chips. 
     
     
         5 . The method of  claim 1 , wherein the wavelength conversion material comprises a phosphor for converting light emitted by at least one LED chip of the array of LED chips to a peak wavelength in a red color, a yellow color, a green color, a blue color, a white color, or combinations thereof. 
     
     
         6 . The method of  claim 1 , wherein the array of LED chips forms a light emission area, and wherein a packing density of the LED chips over a floor of the emission area is between approximately 25% and 50%. 
     
     
         7 . The method of  claim 1 , wherein the array of LED chips forms a light emission area having a diameter of approximately 6 mm or more. 
     
     
         8 . The method of  claim 1 , wherein the array of LED chips forms a light emission area having a diameter of approximately 9 mm or more. 
     
     
         9 . The method of  claim 1 , wherein the array of LED chips forms a light emission area having a diameter of approximately 19 mm or more. 
     
     
         10 . The method of  claim 1 , wherein the wavelength conversion material comprises at least two different types of phosphor. 
     
     
         11 . The method of  claim 1 , wherein the wavelength conversion material comprises at least three different types of phosphor. 
     
     
         12 . The method of  claim 1 , wherein causing the wavelength conversion material to settle within a predefined portion of the viscous material comprises changing a viscosity of the viscous material. 
     
     
         13 . The method of  claim 1 , wherein causing the wavelength conversion material to settle within a predefined portion of the viscous material comprises heating the viscous material. 
     
     
         14 . The method of  claim 1 , wherein causing the wavelength conversion material to settle within a predefined portion of the viscous material comprises centrifuging the viscous material. 
     
     
         15 . The method of  claim 1 , wherein causing the wavelength conversion material to settle within a predefined portion of the viscous material comprises vibrating the viscous material. 
     
     
         16 . The method of  claim 1 , wherein causing the wavelength conversion material to settle within a predefined portion of the viscous material comprises causing a first layer of predominantly red phosphor to settle adjacent a second layer of predominantly yellow phosphor. 
     
     
         17 . A light emitter device comprising:
 a planar substrate;   at least one light emitting diode (LED) chip disposed over the substrate; and   an encapsulant comprising a first encapsulant portion predominantly comprising at least a first wavelength conversion material and also comprising a second wavelength conversion material, and the encapsulant comprising a second encapsulant portion disposed over the first encapsulant portion and comprising the second wavelength conversion material.   
     
     
         18 . The device of  claim 17 , further comprising a raised barrier disposed over the substrate at least partially around the LED chip. 
     
     
         19 . The device of  claim 17 , wherein the first and second encapsulant portions each comprise silicone. 
     
     
         20 . The device of  claim 17 , wherein the second encapsulant portion comprises the second wavelength conversion material as well as some of the first wavelength conversion material, wherein an amount of the second wavelength conversion material is more than an amount of the first wavelength conversion material. 
     
     
         21 . The device of  claim 17 , wherein the first wavelength conversion material comprises yellow phosphor and the second wavelength conversion material comprise a non-yellow phosphor. 
     
     
         22 . The device of  claim 21 , wherein the non-yellow phosphor comprises a red or green phosphor. 
     
     
         23 . The device of  claim 17 , wherein a particle size of the first wavelength conversion material is larger than a particle size of the second wavelength conversion material. 
     
     
         24 . The device of  claim 23 , wherein the first and second wavelength conversion materials comprise a same phosphor color. 
     
     
         25 . The device of  claim 23 , wherein the first and second wavelength conversion materials comprise different phosphor colors. 
     
     
         26 . The device of  claim 17 , wherein the at least one LED chip comprises an array of LED chips. 
     
     
         27 . The device of  claim 17 , wherein the second encapsulant portion comprising the second wavelength conversion material is devoid of the first wavelength conversion material.