LED display apparatus having active devices and fabrication method thereof
An active matrix LED display apparatus and a fabrication method thereof are provided. The active matrix LED display apparatus enables to miniaturize pixel by a formation of wiring on bottom layer and an assembly of each block through each eutectic layer into each transistor block receptor and/or each LED block receptor formed according to each color element unit, and to be embodied with high luminance, low power consumption, high reliability and superior optical property by assembling a transistor block having high electron mobility. And the fabricating method of the present invention enables to make efficiently an AM-LED display apparatus at room temperature in a short time by using different shapes of receptor and block depending on the function of a transistor and/or on the color of an LED.
1. An LED display apparatus comprising:
a buffer layer formed on a substrate;
a switching transistor active layer and a driving transistor active layer formed separately from each other and having a source and a drain in both sides of the each active layer on the buffer layer in a color element unit;
a first insulating layer formed to cover the switching and the driving transistor active layers on the substrate;
a scan line formed across between the source and the drain of the switching transistor on the first insulating layer;
a cathode line formed parallel to and separately from the scan line on the first insulating layer;
a storage capacitor bottom electrode formed across between the source and the drain of the driving transistor and connected electrically to the drain of the switching transistor on the first insulating layer in a color element unit;
a second insulating layer formed to cover the scan line, the cathode line and the storage capacitor bottom electrode on the first insulating layer;
a data line formed vertically to the scan line and connected electrically to the source of the switching transistor on the second insulating layer;
a power supply line formed parallel to and separately from the data line and connected electrically to the source of the driving transistor on the second insulating layer;
a storage capacitor top electrode formed to overlap the storage capacitor bottom electrode and connected electrically to the power supply line on the second insulating layer in a color element unit;
an anode contact layer formed between the data line and the power supply line and connected electrically to the drain of the driving transistor on the second insulating layer in a color element unit;
an LED block receptor formed with a third insulating layer to cover at least one part of the data line, the power supply line, the storage capacitor top electrode and the anode contact layer on the second insulating layer in a color element unit;
a cathode eutectic layer and an anode eutectic layer formed separately from each other and connected electrically to the cathode line and the anode contract layer, respectively, in the LED block receptor; and
an LED block of the color element unit assembled into the LED block receptor through electrical connections of the cathode eutectic layer and the anode eutectic layer to a cathode electrode and an anode electrode of the LED block, respectively.
2. The LED display apparatus of claim 1 ,
wherein the buffer layer is a silicon oxide layer or a silicon nitride layer,
wherein the switching transistor active layer and the driving transistor active layer are a poly-silicon layer, and
wherein the cathode eutectic layer and the anode eutectic layer are a metal or a metal compound with a melting point lower than those of the scan line, the cathode line, the storage capacitor bottom electrode, the data line, the power supply line, the storage capacitor top electrode and the anode contact layer.
3. The LED display apparatus of claim 1 ,
wherein on the substrate assembled with the LED block, a thin film encapsulation layer is additionally formed.
4. The LED display apparatus of claim 1 ,
wherein the LED block receptor has a recessed region with different plane structure depending on a color element, and
wherein the LED block has an LED substrate with a shape corresponded to the recessed region.
5. The LED display apparatus of claim 2 ,
wherein the LED block receptor has a recessed region with different plane structure depending on a color element, and
wherein the LED block has an LED substrate with a shape corresponded to the recessed region.
6. The LED display apparatus of claim 3 ,
wherein the LED block receptor has a recessed region with different plane structure depending on a color element, and
wherein the LED block has an LED substrate with a shape corresponded to the recessed region.
7. The LED display apparatus of claim 4 ,
wherein the LED block receptor is formed to have a wide opening and a narrow bottom, and
wherein the LED block, for corresponding to the shape of the LED block receptor, has a p-type nitrogen compound semiconductor layer/nitrogen compound activation layer/n-type nitrogen compound semiconductor layer/cathode electrode and a p-type nitrogen compound semiconductor layer/anode electrode formed near by in the same direction of each other on the LED substrate or has an n-type nitrogen compound semiconductor layer/nitrogen compound activation layer/p-type nitrogen compound semiconductor layer/anode electrode and an n-type nitrogen compound semiconductor layer/cathode electrode formed near by in the same direction of each other on the LED substrate.
8. The LED display apparatus of claim 5 ,
wherein the LED block receptor is formed to have a wide opening and a narrow bottom, and
wherein the LED block, for corresponding to the shape of the LED block receptor, has a p-type nitrogen compound semiconductor layer/nitrogen compound activation layer/n-type nitrogen compound semiconductor layer/cathode electrode and a p-type nitrogen compound semiconductor layer/anode electrode formed near by in the same direction of each other on the LED substrate or has an n-type nitrogen compound semiconductor layer/nitrogen compound activation layer/p-type nitrogen compound semiconductor layer/anode electrode and an n-type nitrogen compound semiconductor layer/cathode electrode formed near by in the same direction of each other on the LED substrate.
9. The LED display apparatus of claim 6 ,
wherein the LED block receptor is formed to have a wide opening and a narrow bottom, and
wherein the LED block, for corresponding to the shape of the LED block receptor, has a p-type nitrogen compound semiconductor layer/nitrogen compound activation layer/n-type nitrogen compound semiconductor layer/cathode electrode and a p-type nitrogen compound semiconductor layer/anode electrode formed near by in the same direction of each other on the LED substrate or has an n-type nitrogen compound semiconductor layer/nitrogen compound activation layer/p-type nitrogen compound semiconductor layer/anode electrode and an n-type nitrogen compound semiconductor layer/cathode electrode formed near by in the same direction of each other on the LED substrate.
10. The LED display apparatus of claim 7 ,
wherein the LED substrate is a sapphire,
wherein the nitrogen compound is AIN, GaN, InN, or a compound of nitrogen and two or more elements of Al, Ga and In, and
wherein the anode electrode and the cathode electrode are Ti, W, Cr, Au, Ag, Ni, or a compound comprising one or more elements of Ti, W, Cr, Au, Ag and Ni.
11. The LED display apparatus of claim 8 ,
wherein the LED substrate is a sapphire,
wherein the nitrogen compound is AIN, GaN, InN, or a compound of nitrogen and two or more elements of Al, Ga and In, and
wherein the anode electrode and the cathode electrode are Ti, W, Cr, Au, Ag, Ni, or a compound comprising one or more elements of Ti, W, Cr, Au, Ag and Ni.
12. The LED display apparatus of claim 9 ,
wherein the LED substrate is a sapphire,
wherein the nitrogen compound is AIN, GaN, InN, or a compound of nitrogen and two or more elements of Al, Ga and In, and
wherein the anode electrode and the cathode electrode are Ti, W, Cr, Au, Ag, Ni, or a compound comprising one or more elements of Ti, W, Cr, Au, Ag and Ni.
13. The LED display apparatus of claim 10 ,
wherein the cathode eutectic layer and the anode eutectic layer are Sn, Pb, Bi, In, a compound comprising one or more elements of Sn, Pb, Bi and In, or a compound comprising one element of Sn, Pb, Bi and In and one or more elements of Ag, Sb, Cu, Zn and Mg.
14. The LED display apparatus of claim 11 ,
wherein the cathode eutectic layer and the anode eutectic layer are Sn, Pb, Bi, In, a compound comprising one or more elements of Sn, Pb, Bi and In, or a compound comprising one element of Sn, Pb, Bi and In and one or more elements of Ag, Sb, Cu, Zn and Mg.
15. The LED display apparatus of claim 12 ,
wherein the cathode eutectic layer and the anode eutectic layer are Sn, Pb, Bi, In, a compound comprising one or more elements of Sn, Pb, Bi and In, or a compound comprising one element of Sn, Pb, Bi and In and one or more elements of Ag, Sb, Cu, Zn and Mg.