System and Method for Making Micro LED Display

Abstract

By using chip-by-chip, mainly separation technology, micro LED can be made very accurately and efficiently. First, after epitaxial process, the LED epi-wafer is processed into micro LEDs. Second, bonding substrates with driving circuits are provided for the LED epi-wafer. Then, each LED chip is fastened to the substrate chip-by-chip simultaneously or sequentially, and each LED chip may be transferred by using separation technology simultaneously or sequentially. The LED epi-wafer per se can be also provided as LED display substrate.

What is claimed is: 
     
         1 . A display panel, comprising:
 a GaAs substrate with a driving circuit thereon for the display panel and a plurality of paired bonding pads, said GaAs substrate including a plurality of red light emitting diode chips; and   a plurality of GaN light emitting diode chips electrically fastening to the plurality of paired bonding pads.   
     
     
         2 . The display panel according to  claim 1 , wherein the driving circuit is an active circuit or a passive circuit. 
     
     
         3 . The display panel according to  claim 2 , wherein said plurality of GaN light emitting diode chips emits blue and green light 
     
     
         4 . A display panel, comprising:
 a bonding substrate with a driving circuit and a plurality of paired bonding electrodes thereon;   a plurality of GaN light emitting diode chips electrically fastening to the plurality of paired bonding electrodes respectively;   a phosphor layer, patterned as a plurality of regions suitable covering the plurality of GaN light emitting diode chips respectively; and   a transparent substrate with a color filter layer thereon to align the plurality of GaN light emitting diode chips respectively.   
     
     
         5 . The display panel according to  claim 4 , wherein the driving circuit is an active circuit or a passive circuit. 
     
     
         6 . The display panel according to  claim 5 , wherein said bonding substrate is PCB, silicon, silicon carbide, or ceramic. 
     
     
         7 . The display panel according to  claim 6 , wherein said phosphor layer is excited by said plurality of GaN light emitting diode chips and white lights are generated by mixing lights from said phosphor layer and said plurality of GaN light emitting diode chips. 
     
     
         8 . The display panel according to  claim 7 , wherein said plurality of GaN light emitting diode chips emit blue light and said phosphor layer provides yellow light. 
     
     
         9 . The display panel according to  claim 7 , wherein said plurality of GaN light emitting diode chips emit UV light and said phosphor layer provides red, green, and blue light. 
     
     
         10 . The display panel according to  claim 6 , wherein said phosphor layer includes quantum dots. 
     
     
         11 . A display panel, comprising:
 a sapphire substrate with a plurality of GaN light emitting diode chips thereon, wherein each of the plurality of GaN light emitting diode chips has a first electrode and a second electrode;   a first dielectric layer on said sapphire substrate with exposed of the first electrodes and the second electrodes;   a first transparent conductive layer, patterned as a first plurality of signal lines, on the first dielectric layer to electrically connect to a row of the first electrodes of the plurality of the GaN light emitting diode chips;   a second dielectric layer on said first dielectric layer and said first transparent conductive layer with exposed of the second electrode;   a second transparent conductive layer, patterned as a second plurality of signal lines, on the second dielectric layer to electrically connect to a column of the second electrodes of the plurality of the GaN light emitting diodes;   a passivation layer blanket covering said second dielectric layer and said second transparent conductive layer;   a phosphor layer, patterned as a plurality of regions suitable covering the plurality of GaN light emitting diode chips, on the passivation layer; and   a transparent substrate with a color filter layer thereon to cover and align with the plurality of GaN light emitting diode chips.   
     
     
         12 . The display panel according to  claim 11 , wherein said first dielectric layer and said second dielectric layer are silicon oxide, TEOS(tetra-ethyl-ortho-silicate), epoxy or silicone. 
     
     
         13 . The display panel according to  claim 12 , wherein said first transparent conductive layer and said second transparent conductive layer are ITO, IZO, IGO, AZO, or IGZO. 
     
     
         14 . The display panel according to  claim 13 , wherein said phosphor layer is excited by said plurality of GaN light emitting diode chips and white lights are generated by mixing lights from said phosphor layer and said plurality of GaN light emitting diode chips. 
     
     
         15 . The display panel according to  claim 14 , wherein said plurality of GaN light emitting diode chips emit blue light and said phosphor layer provides yellow light. 
     
     
         16 . The display panel according to  claim 14 , wherein said plurality of GaN light emitting diode chips emit UV light and said phosphor layer provides red, green, and blue light. 
     
     
         17 . The display panel according to  claim 13 , wherein said phosphor layer includes quantum dots. 
     
     
         18 . An apparatus, comprising:
 a platform for mounting a first substrate with a plurality of light emitting diode chips thereon;   a first stage for providing a first motion with two horizontal directions orthogonal with each other;   a mounting stage on said first stage for fastening a second substrate with a driving circuit and a plurality of paired bonding pads, wherein the plurality of light emitting diode chips face to the plurality of paired bonding pads;   means for separating the plurality of light emitting diode chips from the first substrate; and   a controller for controlling said platform, said first stage, said mounting stage and said separating means, such that the a display panel is formed.   
     
     
         19 . The apparatus according to  claim 18 , further comprising a second stage between said first stage and said mounting stage for providing a vertical motion. 
     
     
         20 . The apparatus according to  claim 18 , wherein said separating means is an excimer LASER when the first substrate is sapphire or SiC, and said separating means is a pressing device for pressing the plurality of light emitting diode chips to the plurality of paired bonding pads when the first substrate is a tape.