Highly reliable and reflective led substrate

Abstract

Aspects include features for improving the reliability of a reflective base structure for light emitting diodes (LED) chip-on-board (COB) array products. The reflective base structure reduces reflective material of a reflective layer (e.g., silver) from migrating into adjacent layers. In one configuration used to reduce the migration of reflective material, a reflective base for a light-emitting diode (LED) may comprise a substrate, a reflective layer, and a diffusion barrier layer between the substrate and the reflective layer. In another configuration used to reduce the migration of reflective material, a reflective base for an LED comprising: a substrate, a reflective layer; and a planarizing layer between the substrate and the reflective layer, a thickness of the planarizing layer between the substrate and the reflective layer being less than 70 nm.

1 - 35 . (canceled) 
     
     
         36 . A reflective base for a light-emitting diode (LED) comprising:
 a substrate;   a reflective layer disposed above the substrate and having first and second opposing sides;   a first diffusion barrier layer disposed between the substrate and the first side of the reflective layer, with the first diffusion barrier layer being structurally configured to reduce migration of reflective material from the reflective layer towards the substrate;   a second diffusion barrier layer disposed on the second side of the reflective layer that is opposite the first side; and   at least one dielectric layer disposed above the second diffusion barrier layer and opposite the reflective layer.   
     
     
         37 . The reflective base of  claim 36 , further comprising a planarized layer between the first diffusion barrier layer and the substrate, such that the first diffusion barrier layer is configured to reduce the migration of the reflective material from the reflective layer toward the planarized layer. 
     
     
         38 . The reflective base of  claim 37 , wherein the at least one dielectric layer comprises first and second dielectric layers that are stacked on the second diffusion barrier. 
     
     
         39 . The reflective base of  claim 37 , wherein the planarized layer comprises anodized aluminum or alumina having a thickness less than 70 nm. 
     
     
         40 . The reflective base of  claim 37 , wherein the planarized layer is anodic. 
     
     
         41 . The reflective base of  claim 36 , wherein the first or second diffusion barrier layers comprise one of nickel-vanadium alloy, tungsten, cobalt, ruthenium, tantalum, tantalum nitride, indium oxide, tungsten nitride, and titanium nitride. 
     
     
         42 . The reflective base of  claim 36 , wherein the reflective layer comprises silver (Ag) or Ag alloyed with at least one of platinum (Pt), palladium (Pd), and germanium (Ge). 
     
     
         43 . A reflective base for a light-emitting diode (LED) comprising:
 a substrate;   a reflective layer; and   a planarized anodic layer disposed on the substrate and between the substrate and the reflective layer, with the planarizing layer having a thickness that is less than 70 nm, such that the planarized anodic layer is configured to reduce migration of reflective material from the reflective layer toward the substrate;   at least one dielectric layer disposed over the reflective layer;   a first diffusion barrier layer interposed between the reflective layer and the first dielectric layer; and   a second diffusion barrier layer interposed between the reflective layer and the planarized anodic layer.   
     
     
         44 . The reflective base of  claim 43 , wherein the planarized anodic layer comprises anodized aluminum or alumina. 
     
     
         45 . The reflective base of  claim 43 , wherein the first diffusion barrier layer comprises one of nickel-vanadium alloy, tungsten, cobalt, ruthenium, tantalum, tantalum nitride, indium oxide, tungsten nitride, and titanium nitride. 
     
     
         46 . The reflective base of  claim 43 , wherein the reflective layer comprises silver (Ag) or Ag alloyed with at least one of platinum (Pt), palladium (Pd), and germanium (Ge). 
     
     
         47 . A light-emitting device (LED), comprising:
 a reflective base comprising:
 a substrate; 
 a reflective layer disposed above the substrate and having first and second opposing sides; 
 a first diffusion barrier layer disposed between the substrate and the first side of the reflective layer, with the first diffusion barrier layer being structurally configured to reduce migration of reflective material from the reflective layer towards the substrate; 
 a second diffusion barrier layer disposed on the second side of the reflective layer that is opposite the first side; and 
 at least one dielectric layer disposed above the second diffusion barrier layer and opposite the reflective layer. 
   
     
     
         48 . The light-emitting device of  claim 47 , further comprising a planarized layer between the first diffusion barrier layer and the substrate. 
     
     
         49 . The light-emitting device of  claim 48 , wherein the planarizing layer comprises anodized aluminum or alumina. 
     
     
         50 . The light-emitting device of  claim 47 , wherein the first and second diffusion barrier layers each comprise one of nickel-vanadium alloy, tungsten, cobalt, ruthenium, tantalum, tantalum nitride, indium oxide, tungsten nitride, and titanium nitride. 
     
     
         51 . The light-emitting device of  claim 47 , wherein the LED comprises a distributed Bragg reflector (DBR) structure. 
     
     
         52 . The light-emitting device of  claim 47 , wherein the LED comprises an omni-directional reflector (ODR) structure. 
     
     
         53 . The light-emitting device of  claim 47 , wherein the first diffusion barrier layer is configured to reduce migration of sulfur to the reflective layer. 
     
     
         54 . The light-emitting device of  claim 48 , wherein the second diffusion barrier layer is configured to limit the migration of the reflective material cooperatively with the thickness of the planarized layer. 
     
     
         55 . The light-emitting device of  claim 47 , wherein the first diffusion barrier layer is disposed directly on the reflective layer.