Patterned downconverter and adhesive film for micro-led, mini-led downconverter mass transfer

Abstract

A downconverter layer transfer device, and methods of making and using the downconverter layer transfer device, are disclosed. A downconverter layer transfer device includes a release liner and a downconverter layer disposed on the release liner, the downconverter layer including a downconverter material dispersed throughout an adhesive, the downconverter layer being solid and non-adhesive at a first temperature, and adhesive at an elevated temperature above the first temperature

What is claimed is: 
     
         1 . A structure for transferring a downconverter layer comprising:
 a release liner; and   a downconverter layer disposed on the release liner, the downconverter layer comprising a first downconverter layer pixel and a separate second downconverter layer pixel; the first and second downconverter layer pixels disposed on different areas of the release liner,   the first and second downconverter layer pixels comprising a downconverter material dispersed throughout an adhesive, each downconverter layer pixel being solid and non-adhesive at a first temperature, and adhesive at an elevated temperature above the first temperature, each downconverter layer pixel having a width less than 100 μm, the downconverter material in the first downconverter layer pixel different from the downconverter material in the second downconverter layer pixel.   
     
     
         2 . The structure of  claim 1 , further comprising a siliconized layer disposed between the release liner and the downconverter layer. 
     
     
         3 . The structure of  claim 1 , wherein the downconverter material comprises at least one of a phosphor, an organic dye, a quantum dot, and a scattering agent. 
     
     
         4 . The structure of  claim 1 , wherein the shear modulus G* (at 1 Hz) of each downconverter layer pixel at the first temperature is greater than 100 KPa, and the shear modulus G* (at 1 Hz) of the downconverter layer at the elevated temperature is between 1 KPa and 100 KPa. 
     
     
         5 . The structure of  claim 1 , wherein the downconverter material in the first downconverter layer pixel is a red phosphor and the downconverter material in the second downconverter layer pixel is a green phosphor. 
     
     
         6 . The structure of  claim 5 , comprising a third downconverter layer pixel disposed on an area of the release liner different from where the first and second downconverter layer pixels are disposed, the third downconverter layer comprising a scattering agent and not comprising a downconverter material. 
     
     
         7 . The structure of  claim 1 , wherein the release liner comprises polyethylene terephthalate. 
     
     
         8 . A method of forming a lighting device, the method comprising:
 providing a microLED array comprising a first and second microLEDs mounted on a substrate, each microLED having a light emitting surface;   providing a downconverter layer transfer device having a downconverter layer disposed on the release liner, the downconverter layer comprising a first downconverter layer pixel and a separate second downconverter layer pixel; the first and second downconverter layer pixels disposed on different areas of the release liner, the first and second downconverter layer pixels comprising a downconverter material dispersed throughout an adhesive;   aligning the first downconverter layer pixel with the light emitting surface of the first microLED while simultaneously aligning the second downconverter layer pixel with the light emitting surface of the second microLED;   bringing the downconverter layer into contact with the light emitting surfaces of the first and second microLEDs at an elevated temperature, the elevated temperature being a temperature at which the adhesive adheres to the light emitting surfaces;   cooling the first and second downconverter layer pixels in contact with the light emitting surfaces of the microLEDs to a temperature below the elevated temperature; and   removing the release liner, leaving the downconverter layer adhered to the light emitting surfaces of the microLEDs.   
     
     
         9 . The method of  claim 8 , further comprising curing the downconverter layer. 
     
     
         10 . The method of  claim 8 , wherein bringing the downconverter layer into contact with the light emitting surfaces at an elevated temperature includes applying a vacuum to the downconverter layer transfer device and the light emitting diodes. 
     
     
         11 . The method of  claim 8 , wherein providing the downconverter layer transfer device comprises:
 providing the release liner;   mixing an adhesive material, a downconverter material, and a solvent to form an adhesive downconverter mixture;   coating the release liner with the adhesive downconverter mixture; and   removing the solvent from the adhesive downconverter mixture to form the first downconverter layer pixel.   
     
     
         12 . The method of  claim 11 , further comprising:
 before coating the release liner with the adhesive downconverter mixture, forming a photoresist pattern on the release liner, the photoresist pattern comprising a well, wherein coating the release liner with adhesive downconverter material includes disposing the adhesive downconverter material into the well; and   removing the photoresist pattern to leave a space between the first and second downconverter layer pixels.   
     
     
         13 . The method of  claim 11 , further comprising coating the release liner with a siliconized coating before coating with the adhesive downconverter mixture. 
     
     
         14 . The method of  claim 8 , wherein the downconverter material in the first downconverter layer pixel is different from the downconverter material in the second downconverter layer pixel. 
     
     
         15 . The method of  claim 14 , wherein the downconverter material in the first downconverter layer pixel is a red phosphor and the downconverter material in the second downconverter layer pixel is a green phosphor. 
     
     
         16 . The device of  claim 15 , comprising a third downconverter layer pixel disposed on an area of the release liner different from where the first and second downconverter layer pixels are disposed, the third downconverter layer comprising a scattering agent and not comprising a downconverter material. 
     
     
         17 . The device of  claim 8 , wherein the downconverter material comprises at least one of a phosphor, an organic dye, a quantum dot, and a scattering agent. 
     
     
         18 . The device of  claim 8 , wherein the shear modulus G* (at 1 Hz) of each downconverter layer pixel at the first temperature is greater than 100 KPa, and the shear modulus G* (at 1 Hz) of the downconverter layer at the elevated temperature is between 1 KPa and 100 KPa. 
     
     
         19 . The method of  claim 14 , wherein providing the downconverter layer transfer device comprises:
 providing a release liner;   mixing an adhesive material, a first downconverter material, and a solvent to form a first adhesive downconverter mixture;   mixing the adhesive material, a second downconverter material, and the solvent to form a second adhesive downconverter mixture;   coating the release liner with the first adhesive downconverter mixture on a first area of the release liner;   coating the release liner with the second adhesive downconverter mixture on a second area of the release liner; and   removing the solvent from the first and second adhesive downconverter mixtures to form the first and second downconverter layer pixels.   
     
     
         20 . The method of  claim 19 , further comprising:
 before coating the release liner with the first adhesive downconverter mixture and second adhesive downconverter mixture, forming a photoresist pattern on the release liner, the photoresist pattern including wells, wherein coating the release liner with the first adhesive downconverter mixture includes disposing the first adhesive downconverter mixture in a first well and coating the release liner with the second adhesive downconverter mixture includes disposing the second downconverter mixture in a second well different from the first well; and   removing the photoresist pattern.