Solid State Light Sheet Having Wide Support Substrate and Narrow Strips Enclosing LED Dies in Series

Abstract

A solid state light sheet and method of fabricating the sheet are disclosed. In one embodiment, bare LED chips have top and bottom electrodes, where the bottom electrode is a large reflective electrode. The bottom electrodes of an array of LEDs (e.g., 500 LEDs) are bonded to an array of electrodes formed on a flexible bottom substrate. Conductive traces are formed on the bottom substrate connected to the electrodes. A transparent top substrate is then formed over the bottom substrate. Various ways to connect the LEDs in series are described along with many embodiments. In one method, the top substrate contains a conductor pattern that connects to LED electrodes and conductors on the bottom substrate.

1 - 20 . (canceled) 
     
     
         21 . A light emitting device, comprising:
 a first layer having a length from a first end to a second end, the first layer having a width and a thickness, the length, the width and the thickness being orthogonal to each other, and the thickness being less than the length;   a non-packaged light emitting diode (LED) die configured to emit light having a first spectral power distribution (SPD), the non-packaged LED die having a first die electrode and a second die electrode, the non-packaged LED die being supported by the first layer;   a solid second layer entirely composed of a first material, the solid second layer having a non-planar interface facing the first layer, the first material comprising a wavelength conversion material for converting the light having the first SPD to light having an SPD different from the first SPD; and   an electrically conducting material on a surface of the first layer, the electrically conducting material arranged in a pattern that operatively connects to the first die electrode and the second die electrode of the non-packaged LED die,   wherein a surface of the solid second layer is an outermost surface of the light emitting device.   
     
     
         22 . The light emitting device of  claim 21 , wherein the first die electrode and second die electrode of the non-packaged LED die face the first layer, and the non-packaged LED die is connected to the pattern. 
     
     
         23 . The light emitting device of  claim 21 , wherein the first material is plastically deformed to encase the non-packaged LED die. 
     
     
         24 . The light emitting device of  claim 21 , wherein the first layer and the second layer are coextensive along a length of the light emitting device. 
     
     
         25 . The light emitting device of  claim 24 , wherein the surface of the first layer is a flat surface. 
     
     
         26 . The light emitting device of  claim 21 , wherein the non-packaged LED die is a blue-light emitting LED die or a UV-light emitting LED die. 
     
     
         27 . The light emitting device of  claim 26 , wherein the light emitting device is a white-light emitting device. 
     
     
         28 . The light emitting device of  claim 21 , wherein the wavelength conversion material comprises a phosphor. 
     
     
         29 . The light emitting device of  claim 21 , wherein the first layer comprises a light-transmissive material. 
     
     
         30 . The light emitting device of  claim 29 , wherein the first layer is transparent. 
     
     
         31 . The light emitting device of  claim 21 , wherein the first layer comprises a metal. 
     
     
         32 . The light emitting device of  claim 21 , further comprising multiple of the non-packaged LED die electrically connected in series. 
     
     
         33 . The light emitting device of  claim 21 , wherein the first die electrode and the second die electrode are located on a first side of the non-packaged LED die. 
     
     
         34 . The light emitting device of  claim 33 , wherein the non-packaged LED die is configured to emit the light having the first SPD through a second side of the non-packaged LED die opposite the first side of the non-packaged LED die. 
     
     
         35 . The light emitting device of  claim 34 , wherein the first side of the non-packaged LED die reflects light from within the non-packaged LED die back into the non-packaged LED die. 
     
     
         36 . The light emitting device of  claim 34 , wherein the first side of the non-packaged LED die faces the first layer. 
     
     
         37 . The light emitting device of  claim 21 , further comprising a third layer, the first layer being arranged between the solid second layer and the third layer. 
     
     
         38 . The light emitting device of  claim 37 , wherein the third layer comprises another wavelength conversion material. 
     
     
         39 . The light emitting device of  claim 21 , wherein the non-packaged LED die is a flip-chip LED die. 
     
     
         40 . The light emitting device of  claim 21 , wherein the light emitting device has a flexible cylinder or half-cylinder shape. 
     
     
         41 . The light emitting device of  claim 21 , wherein the light emitting device has a thickness in a range from 1 mm to 1 cm. 
     
     
         42 . The light emitting device of  claim 21 , wherein the first material comprises a light-transmissive material. 
     
     
         43 . The light emitting device of  claim 21 , wherein the non-planar interface of the solid second layer is a textured interface. 
     
     
         44 . The light emitting device of  claim 21 , wherein a thickness of the solid second layer is greater than a height of the non-packaged LED die.