Phosphor converter structures for thin film packages and method of manufacture

Abstract

Light emitting devices (LEDs) and methods of manufacturing LEDs are described. A method includes providing a layer of a wavelength converting material on a temporary tape. The wavelength converting material includes at least a binder or matrix material, particles of a non-luminescent material, and phosphor particles and has a concentration of 60%-90% by volume particles of the non-luminescent material and phosphor particles. The layer of the wavelength converting material is separated on the temporary tape to form multiple wavelength converting structures, which are provided on an array type frame. Heat and pressure are applied to the wavelength converting structures on the array type frame.

What is claimed is: 
     
         1 . A light emitting device (LED) comprising:
 a light emitting semiconductor structure comprising a light-emitting active layer disposed between an n-layer and a p-layer; and   a wavelength converting structure having a first surface in direct contact with the light emitting semiconductor structure, a second surface opposite the first surface, and a side surface connecting the first and second surfaces, the wavelength converting structure comprising a binder or matrix material, particles of a non-luminescent material, and phosphor particles, the wavelength converting structure having a concentration of greater than 60% by volume of the non-luminescent material and phosphor particles, the side surface of the wavelength converting structure having a roughness of less than 100 nm.   
     
     
         2 . The LED of  claim 1 , wherein the first surface of the wavelength converting structure is in direct contact with the light emitting semiconductor structure without intervening adhesive. 
     
     
         3 . The LED of  claim 1 , comprising a non-metallic, thin-film reflector in direct contact with the side surface of the wavelength converting structure. 
     
     
         4 . The LED of  claim 3 , wherein the light emitting semiconductor structure has a first surface, a second surface opposite the first surface, and a side surface connecting the first and second surfaces of the light emitting semiconductor structure, and the non-metallic, thin-film reflector in direct contact with the side surface of the light emitting semiconductor. 
     
     
         5 . The LED of  claim 3 , wherein the thin film reflector is a Bragg reflector. 
     
     
         6 . The LED of  claim 5 , wherein the Bragg reflector has a thickness of 1-10 microns. 
     
     
         7 . The LED of  claim 3 , wherein both the wavelength converting structure and the thin film reflector have a coefficient of thermal expansion (CTE) of between 6 and 20 ppm/C. 
     
     
         8 . The LED of  claim 1 , wherein the binder or matrix material is silicone. 
     
     
         9 . The LED of  claim 8 , comprising a non-metallic, thin-film reflector in direct contact with the side surface of the wavelength converting structure. 
     
     
         10 . A light emitting device (LED) comprising:
 a light emitting semiconductor structure having a first surface, a second surface opposite the first surface, and a side surface connecting the first and second surfaces, the light emitting semiconductor structure comprising a light-emitting active layer disposed between an n-layer and a p-layer;   a wavelength converting structure having a first surface in direct contact with the second surface of the light emitting semiconductor structure, a second surface opposite the first surface, and a side surface connecting the first and second surfaces, the wavelength converting structure comprising silicone, particles of a non-luminescent material, and phosphor particles, the wavelength converting structure having a concentration of greater than 60% by volume of the non-luminescent material and phosphor particles; and   a non-metallic, thin-film reflector in direct contact with the side surface of the wavelength converting structure.   
     
     
         11 . The LED of  claim 10 , wherein the first surface of the wavelength converting structure is in direct contact with the light emitting semiconductor structure without intervening adhesive. 
     
     
         12 . The LED of  claim 10 , wherein the non-metallic, thin-film reflector is in direct contact with the side surface of the light emitting semiconductor structure. 
     
     
         13 . The LED of  claim 10 , wherein the thin film reflector is a Bragg reflector. 
     
     
         14 . The LED of  claim 13 , wherein the Bragg reflector has a thickness of 1-10 microns. 
     
     
         15 . The LED of  claim 10 , wherein both the wavelength converting structure and the thin film reflector have a coefficient of thermal expansion (CTE) of between 6 and 20 ppm/C. 
     
     
         16 . The LED of  claim 10 , wherein the side surface of the wavelength converting structure has a roughness of less than 100 nm. 
     
     
         17 . The LED of  claim 15 , wherein the thin film reflector is a Bragg reflector. 
     
     
         18 . The LED of  claim 17 , wherein the Bragg reflector has a thickness of 1-10 microns. 
     
     
         19 . A light emitting device (LED) comprising:
 a light emitting semiconductor structure having a first surface, a second surface opposite the first surface, a side surface connecting the first and second surfaces, the light emitting semiconductor structure comprising a light-emitting active layer disposed between an n-layer and a p-layer;   a wavelength converting structure having a first surface in direct contact with the second surface of the light emitting semiconductor structure without intervening adhesive, a second surface opposite the first surface, a side surface connecting the first and second surfaces and a coefficient of thermal expansion (CTE) of between 6 and 20 ppm/C, the wavelength converting structure comprising silicone, particles of a non-luminescent material, and phosphor particles, the wavelength converting structure having a concentration of greater than 60% by volume of the non-luminescent material and phosphor particles; and   a non-metallic, thin-film reflector in direct contact with the side surface of the wavelength converting structure, the non-metallic, thin-film reflector having a coefficient of thermal expansion (CTE) of between 6 and 20 ppm/C.   
     
     
         20 . The LED of  claim 19 , wherein the thin film reflector is a Bragg reflector.