TW202341527A - Light-emitting substrate with active elements - Google Patents

Abstract

The present invention discloses a light-emitting substrate with active elements, and the light-emitting substrate comprises a carrier, a redistribution layer, a plurality of active elements and an encapsulation layer. The redistribution layer is disposed on the carrier and comprises a plurality of circuits. The plurality of active elements each respectively have a body and a plurality of pins, and the active elements are disposed on the redistribution layer. The plurality of pins of the plurality of active elements are respectively electrically connected to the plurality of circuits of the redistribution layer. The encapsulation layer is disposed on the redistribution layer. The bodies of the plurality of active elements are disposed in the encapsulation layer.

Description

Light-emitting substrate with active components

The invention relates to a light-emitting substrate, in particular to a light-emitting substrate with active components.

The packaging method of displays with active micro-light-emitting diodes (Micro LEDs) is usually to transfer the light-emitting diodes to the thin film transistor (TFT) backplane through mass transfer technology, and then place them on the thin film transistor backplane. Assemble to desired size. However, this transfer packaging method will cause several problems.

Since the electrodes of thin film transistors usually use indium tin oxide (ITO) or oxide films as electrodes, the electrodes of light-emitting diodes are usually formed by plating nickel gold layers or pure gold layers. However, since the thickness of electrodes is usually on the micron level, and the electrodes of thin film transistors are only on the nano level, that is, the thickness of the light-emitting diode electrodes will be thicker than the electrodes of thin film transistors. Therefore, when the two are transferred to the thin film transistor backplane, due to the difference in mechanical bonding force, the electrodes (pins) of the thin film transistor are prone to breakage, which makes the light emitting diode and the thin film transistor The overall bonding yield is reduced.

In addition, since the thin film transistor backplane has a large area, if it has a large area, it not only causes difficulties in subsequent packaging and other processes, but also easily causes warpage problems in the structure.

Furthermore, after the production of the large-size thin film transistor backplane is completed, if there is a problem with the thin film transistor or light-emitting diode and other components in the backplane, the entire large-size backplane must be repaired and inspected. Will increase difficulty. In addition, repairing large-sized backplanes requires further repairing equipment, which not only increases the difficulty of repairing and reduces product yields, but also increases the difficulty of manufacturing displays with large backplane sizes and high unit pixels.

Please refer to FIG. 6 , which is a cross-sectional view of the structure of a conventional active micro-LED display. The current active micro-LED display structure 4 is to transfer the micro-LEDs 41 to the rearrangement circuit layer 42, and the rearrangement circuit layer 42 is connected to the thin film transistor backplane 43, and then the transferred thin film transistor is used The back plate 43 and the carrier plate 44 are spliced to assemble the required display size. However, this splicing method not only requires the production of an additional thin film transistor backplane 43 for bonding, but also increases the manufacturing cost of the display.

Accordingly, how to provide a light-emitting substrate with active components has become an urgent research topic.

In view of the above problems, the present invention discloses a light-emitting substrate with active components, including a carrier board, a re-arrangement circuit layer, a plurality of active components and a packaging layer. The rearrangement circuit layer is arranged on the carrier board and has a plurality of circuits. The plurality of active components respectively have a body and a plurality of pins, which are arranged on the re-arrangement circuit layer, and the plurality of pins are respectively electrically connected to a plurality of lines of the re-arrangement circuit layer. The encapsulation layer is disposed on the re-arrangement circuit layer, and the bodies of a plurality of active components are disposed in the encapsulation layer.

Based on the above, the light-emitting substrate with active components of this invention can make the pins of each active component reach a coplanar state by adjusting the height of the pins of the active components before transferring the active components to the rearrangement circuit layer. characteristics to increase the yield of active components transferred to the rearrangement circuit layer. Furthermore, by rearranging the lines on the circuit layer to directly connect the pins of each active component, it is possible to save process steps such as opening holes and connecting wires on the rearranged circuit layer. In addition, the light-emitting substrate with active components of this invention cuts the active components and micro-light-emitting diodes into small units, and detects them before placing the active components and micro-light-emitting diodes on the rearrangement circuit layer to improve the efficiency of the light-emitting substrate. The yield of active components and micro-LEDs further reduces the difficulty of subsequent repairs on large-area panels and avoids warping problems. The micro-LEDs are joined and rearranged through mass transfer. In the circuit layer, each independent thin film transistor small unit or a complementary metal oxide semi-field effect transistor small unit controls each micro light-emitting diode respectively, thereby achieving the purpose of reducing the need for a thin film transistor backplane, and By reducing the overall thickness, the process of transferring the light-emitting diode to the thin film transistor backplane and then connecting it to the carrier board can be simplified, so that the light-emitting substrate with active components of the present invention can be widely used in the existing mass of micro-light-emitting diodes. Transferring technology.

Please refer to FIGS. 1A to 1G , which are step flow charts for manufacturing a light-emitting substrate with active components according to the first embodiment of the present invention. In the step of FIG. 1A , a plurality of active components 11 are disposed on the first temporary substrate 13 with an adhesive layer 12 , and the adhesive layer 12 is disposed on the first temporary substrate 13 so that the pins 111 of the plurality of active components 11 Adhered to the adhesive layer 12. In the steps of FIG. 1B and FIG. 1C , a second temporary substrate 15 having a molding layer 14 is provided. The molding layer 14 is disposed on the second temporary substrate 15 and connected to the active components on the first temporary substrate 13 . 11 and the adhesive layer 12, so that a plurality of active components 11 are embedded in the packaging layer 14. In the step of FIG. 1D , the first temporary substrate 13 and the adhesive layer 12 are removed, so that the active component 11 is separated from the first temporary substrate 13 and the adhesive layer 12 . In the step of FIG. 1E , the thickness of the packaging layer 14 is reduced to expose the pins 111 of the plurality of active components 11 . In the steps of FIG. 1F and FIG. 1G , a plurality of active components 11 are connected to the carrier board 17 with a rearrangement circuit layer 16 , so that the pins 111 of the plurality of active components 11 are respectively connected to the circuits of the rearrangement circuit layer 16 161, and remove the second temporary substrate 15 to complete the light-emitting substrate 1 with active components.

In the step of FIG. 1A , the active component 11 includes a plurality of active components 11A and a plurality of passive components 11B. The active component 11A is a thin film transistor or a complementary metal-oxide half field effect transistor, and the passive component is a light-emitting diode. In the figure, the active component 11 with three pins 111 is an active component 11A, such as a thin film transistor or a complementary metal oxide semiconductor field effect transistor, and the active component 11 with two pins 111 is a passive component 11B, such as Light-emitting diodes include light-emitting diodes that can emit red light (R), green light (G), and blue light (B). The active components 11 are die cut out from the wafer respectively, and are placed through microelectromechanical (MEMS) array technology or elastic stamp (Elastomer) or other die transfer methods that utilize electrostatic, van der Waals force, or magnetism. Pick and place on the adhesive layer 12 of the first temporary substrate 13 . The adhesive layer 12 is disposed on the surface of the first temporary substrate 13 and has adhesiveness. The pins 111 of the active component 11 can be adhered and fixed to the first temporary substrate 13 through the adhesive layer 12 . In this embodiment, the number of the plurality of active components 11A included in the active component 11 is the same as the number of the plurality of passive components 11B, and they correspond one to one, that is, each active component 11A corresponds to a passive component of the control connection. Element 11B. Furthermore, by inputting high and low voltage level signals to the active element 11A, the opening and closing of the active element 11A can be controlled, and the action of the passive element 11B can be further controlled, that is, whether the light-emitting diode emits light or not.

In the steps of FIG. 1B and FIG. 1C , the first temporary substrate 13 , the adhesive layer 12 and the active component 11 are pressed on the second temporary substrate 15 with the encapsulation layer 14 through a pressurizing method, and are cured by heat. After the encapsulation layer 14 is cured, a plurality of active components 11 are fixed and embedded in the encapsulation layer 14 . In the embodiment of the present invention, the encapsulation layer 14 includes epoxy resin material. In addition, it should be noted that in the steps of FIG. 1B and FIG. 1C , the first temporary substrate 13 , the adhesive layer 12 and the active component 11 are pressed from above the second temporary substrate 15 after being turned over 180 degrees. However, this invention is not limited. That is, the first temporary substrate 13, the adhesive layer 12 and the active component 11 can also be used to make the encapsulation layer 14 and the second temporary substrate 15 without turning over as shown in FIG. 1A. Pressure is applied downward from above the first temporary substrate 13 . In addition, no matter which direction the pressure is applied, since in the step of FIG. 1A , the pins 111 of each active component 11 are jointly disposed on the surface of the adhesive layer 12 , therefore, the active pressure is applied in FIGS. 1B and 1C In the step of moving the active component 11 to the packaging layer 14 , the pins 111 of each active component 11 can be made to have coplanar characteristics.

In the step of FIG. 1D , the adhesive layer 12 on the first temporary substrate 13 and the pins 111 of the plurality of active components 11 can be separated by heating or irradiation, so as to facilitate the removal of the first temporary substrate 13 and the adhesive layer 12 . It should be noted that after the first temporary substrate 13 and the adhesive layer 12 are separated from the packaging layer 14, the pins 111 of the active component 11 are exposed but do not protrude from the surface of the packaging layer 14, and the body 112 of the active component 11 is Completely covered by encapsulation layer 14.

In the step of FIG. 1E , the thickness of the packaging layer 14 is reduced by plasma etching, so that the pins 111 of the active component 11 protrude from the surface of the packaging layer 14 .

In the step of FIG. 1F, a carrier board 17 is provided. A rearrangement circuit layer 16 is provided on the carrier board 17. The rearrangement circuit layer 16 includes a plurality of circuits 161 and a soldering layer 162. The soldering layer 162 is provided on the circuit 161 and corresponds to The pins 111 of the active component 11 are connected to the soldering layer 162 of the rearranged wiring layer 16 . The material of the soldering layer 162 includes silver glue or solder paste. The re-arranged circuit layer 16 can be configured and designed to re-arrange the circuits 161 and soldering layers 162 of the circuit layer 16 according to the positions connected to the plurality of active components 11 . Furthermore, in the step of FIG. 1F , the pins 111 of the plurality of active components 11 are connected in position according to the positions of the circuits 161 and the soldering layer 162 on the surface of the re-arranged circuit layer 16 . Therefore, the need for re-arrangement can be reduced. The circuit layer 16 performs the process of opening holes and connecting circuits. In the embodiment of the present invention, the carrier board 17 includes a circuit board (PCB), a glass board or a flexible board.

In the step of FIG. 1G , the light-emitting substrate 1 with active components further includes a filling layer 18 disposed between the redistribution circuit layer 16 and the encapsulation layer 14 to facilitate the bonding of the circuits 161 of the redistribution circuit layer 16 and the active components. The pin 111 of type component 11. For example, the filling layer 18 is an underfill or anisotropic conductive film (ACF). When the filling layer 18 is made of anisotropic conductive adhesive, the re-arrangement circuit layer 16 and the packaging layer 14 can be connected through the anisotropic conductive adhesive. In this case, the soldering layer 162 on the re-arrangement circuit layer 16 can be omitted. Furthermore, in the step of FIG. 1G , taking the active component 11 of the light-emitting diode as an example, in order to increase the brightness of the light-emitting diode, the thickness of the packaging layer 14 can be further reduced to expose the body of the light-emitting diode. . Methods for cutting the encapsulation layer 14 include plasma surface etching. In addition, it should be noted that in the cross-sectional views of FIG. 1F and FIG. 1G , since the cross-sectional view only captures a cross-sectional position of the overall structure, the positions of the circuits 161 and the welding layer 162 of the circuit layer 16 have to be rearranged. , The connection relationship is only for illustration and does not represent the actual line structure.

Please refer to FIGS. 2A to 2C , which are step flow charts for manufacturing a light-emitting substrate with active components according to a second embodiment of the present invention. In the step of FIG. 2A , a plurality of active components 11 and the packaging layer 14 are disposed on the surface 211 of the first carrier board 21 , where the surfaces 113 of the plurality of active components 11 are flat against the surface of the first carrier board 21 211, and encapsulate and cover the body 112 of the active component 11 with the encapsulation layer 14, and expose the bottom of the pin 111 of the active component 11. In the step of FIG. 2B , a rearrangement circuit layer 16 is provided on the packaging layer 14 . The rearrangement circuit layer 16 includes a circuit 161 and a soldering layer 162 , and the circuit 161 of the rearrangement circuit layer 16 is connected to the pin 111 of the active component 11 . It should be noted that the pins 111 of the active component 11 are still buried in the packaging layer 14 , and only the bottoms of the pins 111 are exposed on the surface of the packaging layer 14 to facilitate alignment and connection of the lines 161 of the rearranged circuit layer 16 . In the step of FIG. 2C , a second carrier board 22 with a circuit layer 221 and a soldering layer 222 is provided, and the first carrier board 21 , the packaging layer 14 , the rearranged circuit layer 16 and the active component 11 are flipped up and down 180 degrees. The rearrangement circuit layer 16 is connected to the surface of the second carrier board 22 through a connection layer 23, and after the first carrier board 21 is removed, the light-emitting substrate 2 with active components is completed.

In the step of Figure 2A, the first carrier plate 21 contains a glass plate. The active device 11 includes a thin film transistor, a complementary metal oxide half field effect transistor and a light emitting diode. In the figure, the active device 11 with three pins 111 is a thin film transistor or a complementary metal oxide half field effect transistor. The transistor, the active component 11 with two pins 111 is a light emitting diode. Light-emitting diodes include light-emitting diodes that can emit red light (R), green light (G), and blue light (B). In addition, the encapsulation layer 14 is cured through a thermal curing reaction, and then a plurality of active components 11 are fixed and embedded in the encapsulation layer 14 .

In the step of FIG. 2B , the circuit layer 16 is rearranged into a build-up structure. In the embodiment of the present invention, the build-up structure is not limited to a single-layer or multi-layer circuit structure. In addition, in the step of FIG. 2B , the lines 161 of the rearrangement circuit layer 16 are protrudingly provided on the surface of the rearrangement circuit layer 16 , but in other embodiments, the lines 161 can also be buried on the surface of the rearrangement circuit layer 16 The following are not limited in the present invention.

In the step of FIG. 2C , the connection layer 23 is disposed on the lower surface of the rearrangement circuit layer 16 and is electrically connected to the soldering layer 222 of the second carrier board 22 and the soldering layer 162 of the rearrangement circuit layer 16 . In one embodiment of the invention, the connection layer 23 is a solder ball. Furthermore, when the connection layer 23 is a solder ball, the light-emitting substrate with active components further includes a filling layer 18 disposed between the lower surface of the rearrangement circuit layer 16 and the second carrier board 22 . In addition, after the first carrier board 21 is removed, the surface 113 of the active component 11 is exposed to the packaging layer 14 , and the body 112 of the active component 11 is covered by the packaging layer 14 .

Please refer to FIG. 3 , which is a cross-sectional view of a third embodiment of a light-emitting substrate with active components of the present invention. In the embodiment of FIG. 3 , the connection layer 23 is an anisotropic conductive adhesive and is disposed between the lower surface of the rearrangement circuit layer 16 and the second carrier plate 22 to facilitate the bonding of the rearrangement circuit layer 16 and the second carrier plate 22 . The carrier board 22 is electrically connected to the circuit 221 of the second carrier board 22 and the circuit 161 of the rearranged circuit layer 16 . In the embodiment of the invention, the second carrier board 22 includes a circuit board, a glass board or a flexible board. In addition, after the first carrier board 21 is removed, the surface 113 of the active component 11 is exposed to the packaging layer 14 , and the body 112 of the active component 11 is covered by the packaging layer 14 .

Please refer to FIG. 4 , which is a cross-sectional view of a fourth embodiment of a light-emitting substrate with active components of the present invention. In this embodiment, the light-emitting substrate 3 with active components includes a plurality of active components 11 , a rearrangement circuit layer 16 and a first carrier board 31 . The rearrangement circuit layer 16 is disposed on the first carrier board 31 and has a plurality of circuits 161 and soldering layers 162 . The soldering layers 162 are respectively connected to the pins 111 of a plurality of active components 11 . The difference from the above embodiment is that the plurality of active components 11 are individually arranged on the re-arrangement circuit layer 16. That is, according to the position configuration of the lines 161 on the re-arrangement circuit layer 16, each active element 11 is separately arranged correspondingly. type element 11.

The first carrier board 31 includes a circuit board (PCB), a glass board or a flexible board. The structures of the active component 11 and the re-arranged circuit layer 16 are as described in the above embodiments and will not be described again here.

Please refer to FIGS. 5A to 5C , which are step flow charts of a light-emitting substrate with active components according to the fifth embodiment of the present invention. In the step of FIG. 5A , the surfaces 113 of a plurality of active components 11 are disposed on the second carrier plate 32 together. In the step of FIG. 5B , the first carrier board 31 with the rearrangement circuit layer 16 is provided. The rearrangement circuit layer 16 is disposed on the first carrier board 31 , and the second carrier board 32 and the active component 11 are flipped up and down 180 degrees. The pins 111 of the active component 11 are connected to the circuits 161 of the rearranged circuit layer 16 . In the step of FIG. 5C , after the second carrier board 32 is removed, the light-emitting substrate 3 with active components is completed.

In the embodiment of the present invention, the second carrying plate 32 includes a glass plate. The structures of the active component 11 , the first carrier board 31 and the re-arranged circuit layer 16 are as described in the above embodiments and will not be described again here.

To sum up, in the light-emitting substrate with active components of this invention, before transferring the active components to the rearrangement circuit layer, by adjusting the pin setting height of the active components, the pins of each active component can be coplanar. characteristics to increase the yield of active components transferred to the rearrangement circuit layer. Furthermore, by rearranging the lines on the circuit layer to directly connect the pins of each active component, it is possible to save process steps such as opening holes and connecting wires on the rearranged circuit layer. In addition, the light-emitting substrate with active components of this invention cuts the active components and micro-light-emitting diodes into small units, and detects them before placing the active components and micro-light-emitting diodes on the rearrangement circuit layer to improve the efficiency of the light-emitting substrate. The yield of active components and micro-LEDs further reduces the difficulty of subsequent repairs on large-area panels and avoids warping problems. The micro-LEDs are joined and rearranged through mass transfer. In the circuit layer, each independent small unit of thin film transistor or small unit of complementary metal oxide semi-field effect transistor controls each micro light-emitting diode respectively, thereby achieving the purpose of reducing the need for a thin film transistor backplane. It can simplify the process of transferring the light-emitting diode to the thin film transistor backplane and then connecting it to the carrier board, and reduce the overall thickness, so that the light-emitting substrate with active components of the present invention can be widely used in the existing huge amount of micro-light-emitting diodes. Transferring technology.

1: Light-emitting substrate with active components 11:Active components 11A:Active components 11B: Passive components 111:pin 112:Ontology 113:Surface 12:Adhesive layer 13: First temporary substrate 14: Encapsulation layer 15:Second temporary substrate 16: Rearrange the line layer 161:Line 162:Welding layer 17: Loading board 18:Filling layer 2: Light-emitting substrate with active components 21:First load-bearing plate 211:Surface 22:Second load-bearing plate 221:Line 222:Welding layer 23: Connection layer 3: Light-emitting substrate with active components 31: First load-bearing plate 32: Second load-bearing plate 4: Active micro light-emitting diode display structure 41:Micro light emitting diodes 42: Rearrange the line layer 43:Thin film transistor backplane 44: Loading board

1A to 1G are flow charts of steps for manufacturing a light-emitting substrate with active components according to the first embodiment of the present invention; 2A to 2C are step flow charts for manufacturing a light-emitting substrate with active components according to a second embodiment of the present invention; Figure 3 is a cross-sectional view of a third embodiment of a light-emitting substrate with active components of the present invention; Figure 4 is a cross-sectional view of a fourth embodiment of a light-emitting substrate with active components of the present invention; 5A to 5C are cross-sectional views of the fifth embodiment of the light-emitting substrate with active components of the present invention; and Figure 6 is a cross-sectional view of the structure of a conventional active micro-light emitting diode display.

1: Light-emitting substrate with active components

11:Active components

111:pin

14: Encapsulation layer

16: Rearrange the line layer

161:Line

162:Welding layer

17: Loading board

18:Filling layer

Claims (19)

A light-emitting substrate with active components, including: a load-bearing plate; A circuit layer is arranged on the carrier board and has a plurality of circuits; A plurality of active components, each having a body and a plurality of pins, are arranged on the re-arrangement circuit layer, and the plurality of pins are respectively electrically connected to the plurality of lines of the re-arrangement circuit layer; and An encapsulation layer is provided on the re-arrangement circuit layer; The active component includes a plurality of active components and a plurality of passive components. The light-emitting substrate with active components as claimed in claim 1, wherein the carrier board is a circuit board, a glass plate or a flexible board. The light-emitting substrate with active components as claimed in claim 1, wherein the plurality of lines are disposed in the rearrangement line layer. The light-emitting substrate with an active component as claimed in claim 1, wherein the active component includes at least one thin film transistor or at least one complementary metal oxide semiconductor field effect transistor, and the passive component includes a light emitting diode. The light-emitting substrate with active components as claimed in claim 4, wherein the plurality of active components and the plurality of passive components are connected in a one-to-one correspondence. The light-emitting substrate with active components as described in claim 3, wherein the plurality of pins of the plurality of active components protrude from a surface of the packaging layer. The light-emitting substrate with active components as described in claim 6 further includes a filling layer disposed between the upper surface of the rearrangement circuit layer and the surface of the encapsulation layer. The light-emitting substrate with active components as claimed in claim 7, wherein the filling layer is anisotropic conductive glue or primer. The light-emitting substrate with active components as claimed in claim 1, wherein the encapsulation layer is epoxy resin. The light-emitting substrate with active components as described in claim 1, wherein the encapsulation layer covers the body of the plurality of active components and exposes one surface of the plurality of active components. The light-emitting substrate with active components as claimed in claim 1, wherein the encapsulation layer exposes the bodies of the plurality of active components. The light-emitting substrate with active components as described in claim 1, wherein the encapsulation layer completely covers the body of the plurality of active components. The light-emitting substrate with active components as described in claim 1 further includes a connection layer disposed on a lower surface of the rearrangement circuit layer to connect the carrier board and the plurality of circuits. The light-emitting substrate with active components as claimed in claim 12, wherein the connection layer is a solder ball or anisotropic conductive glue. The light-emitting substrate with active components as described in claim 13 further includes a filling layer disposed between the lower surface of the rearrangement circuit layer and the carrier board. A light-emitting substrate with active components, including: a load-bearing plate; A circuit layer is arranged on the carrier board and has a plurality of circuits; and A plurality of active components, each having a body and a plurality of pins, are arranged on the re-arrangement circuit layer, and the plurality of pins are respectively electrically connected to the plurality of lines of the re-arrangement circuit layer; The active component includes a plurality of active components and a plurality of passive components. The light-emitting substrate with active components as claimed in claim 16, wherein the carrier board is a circuit board, a glass plate or a flexible board. The light-emitting substrate with an active component as claimed in claim 16, wherein the active component includes at least one thin film transistor or at least one complementary metal oxide semiconductor field effect transistor, and the passive component includes a light emitting diode. The light-emitting substrate with active components as claimed in claim 18, wherein the plurality of active components and the plurality of passive components are connected in a one-to-one correspondence.

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