Method for manufacturing LED display

Abstract

To provide a method for manufacturing an LED display which improves the manufacturing through-put in the equipment of LED chips to a plurality of circuit boards.SOLUTION: A method for manufacturing an LED display includes: a singulation step of singulating a plurality of circuit boards from a panel board in which the plurality of circuit boards are formed in-plane; a first placement step of placing the plurality of circuit boards on a carrier substrate; a second placement step of placing the carrier substrate on a mounting stage; and a mounting step of mounting LED chips on the plurality of circuit boards on the mounting stage.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an LED display in which LED (Light Emitting Diode) chips are mounted on a circuit board. [Background technology]

[0002] In recent years, development of LED displays, which have multiple LED chips mounted on a circuit board, has been progressing as a next-generation display device. LED displays have a structure in which LED chips are mounted on a circuit board called a backplane. For example, a bonding device disclosed in Patent Document 1 is used to mount the LED chips. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-36719 Summary of the Invention [Problem to be solved by the invention]

[0004] The manufacturing method for LED displays involves fabricating multiple LED displays on a large substrate called mother glass, and then dividing the large substrate to separate the LED displays at the final stage of the manufacturing process. Mounting LED chips on a large substrate using this manufacturing method requires a large bonding machine, which also requires high precision positioning. Furthermore, cutting the circuit board can lead to the risk of foreign matter getting in and damaging the LED chips.

[0005] An alternative manufacturing method involves dividing a large substrate, separating the circuit boards that form the LED display, feeding them into a bonding machine, mounting the LED chips, and then removing them from the bonding machine, and repeating this process for each circuit board. However, this manufacturing method requires handling and alignment for each circuit board, which can reduce manufacturing throughput.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for manufacturing an LED display that can improve manufacturing throughput when mounting LED chips on a plurality of circuit boards. [Means for solving the problem]

[0007] A method for manufacturing an LED display according to one embodiment of the present invention includes a singulation step of singulating a plurality of circuit boards from a multi-panel substrate having the plurality of circuit boards formed on its surface into individual circuit boards; a first placement step of placing the plurality of circuit boards on a carrier substrate; a second placement step of placing the carrier substrate on a mounting stage; and a mounting step of mounting LED chips on the plurality of circuit boards on the mounting stage. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a flow diagram showing a method for manufacturing an LED display according to an embodiment of the present invention. [Figure 2] 1 is a plan view showing an outline of a circuit board constituting an LED display according to one embodiment of the present invention. [Figure 3] 1 is a plan view showing an outline of a carrier substrate used in a manufacturing method of an LED display according to an embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] 1 is a cross-sectional view showing an outline of a bonding device used in a manufacturing method of an LED display according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. To clarify the description, the drawings may show the width, thickness, shape, etc. of each part more schematically than the actual embodiment, but these are merely examples and are not intended to limit the interpretation of the present invention. In this specification and each drawing, elements similar to those previously described with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0010] A method for manufacturing an LED display according to one embodiment of the present invention will be described. Fig. 1 is a flow chart showing an outline of the steps after dividing a large multi-panel substrate into individual circuit boards in the manufacturing process of an LED display. As shown in Fig. 1, the manufacturing method (S1) for an LED display includes, in order, a dividing step (S11), a first arrangement step (S12), a second arrangement step (S13), a first alignment step (S14), a second alignment step (S15), a mounting step (S16), and a removal step (S17).

[0011] (Singulation step) The singulation step (S11) is a step of singulating a plurality of circuit boards from a multiple substrate on which a plurality of circuit boards are formed in the surface.

[0012] A multi-panel substrate having multiple circuit boards formed on its surface can be divided into individual circuit boards using a known slicer. The size of the multi-panel substrate can be, but is not limited to, various sizes, such as 1500mm x 1800mm for the sixth generation, 2200mm x 2400mm for the eighth generation, and 2940mm x 3370mm for the 10.5th generation. Examples of materials for the multi-panel substrate include aluminosilicate glass.

[0013] Fig. 2 is a plan view of the individual circuit board 2. As shown in Fig. 2, the circuit board 2 has a circuit board main body 21 including a mounting area 211 where a pixel array is formed and where LED chips are mounted, and a peripheral area 212 surrounding the mounting area 211, and a second alignment mark 22 formed in the peripheral area 212. The size of the circuit board 2 can be, for example, a plate-like shape with a length of 20 mm to 60 mm and a width of 20 mm to 60 mm, but is not limited thereto.

[0014] 2, the circuit board 2 has second alignment marks 22 near each of the opposing vertices on the circuit board main body 21. The number and arrangement of the second alignment marks 22 on the circuit board main body 21 are not limited to this. The shape of the second alignment marks 22 is also not limited, and examples include circles, ellipses, polygons, and crosses. By having the second alignment marks 22 on the circuit board 2, it becomes easier to align the bonding head (LED chip) with the circuit board 2 in a bonding device described below, and manufacturing throughput can be improved.

[0015] (First placement step) The first arrangement step (S12) is a step of arranging the individual circuit boards 2 on a carrier substrate.

[0016] FIG. 3 is a plan view of the carrier substrate 3. FIG. 4 is a cross-sectional view of the carrier substrate 3 taken along line IV-IV in FIG. 3. As shown in FIG. 3, the carrier substrate 3 includes a carrier substrate body 31 and first alignment marks 32 formed on the carrier substrate body 31. The carrier substrate body 31 is smaller in size than the multiple substrate. The shape of the carrier substrate body 31 is rectangular in plan view, and the dimensions of each side can be, for example, a plate-like shape with a length of 50 mm to 130 mm and a width of 140 mm to 280 mm, but is not limited to this as long as it can be inserted into a bonding device. Even if the multiple substrate itself cannot be inserted into a bonding device, the carrier substrate 3, which is smaller in size than the multiple substrate, can be inserted into a bonding device. Examples of materials for the carrier substrate body include metals such as aluminum (Al) and stainless steel (SUS).

[0017] 3, eight circuit boards 2 are arranged in two rows and four columns at regular intervals on the carrier substrate body 31. The number, arrangement, and intervals of the circuit boards 2 on the carrier substrate body 31 are not limited to this. By arranging the circuit boards 2 periodically on the carrier substrate 3, it becomes easier for a bonding device to align the LED chips with the circuit boards 2, and manufacturing throughput can be improved.

[0018] 3, the carrier substrate 3 has first alignment marks 32 near each of the opposing vertices of the carrier substrate body 31. The number and arrangement of the first alignment marks 32 on the carrier substrate body 31 are not limited to those shown above. The shape of the first alignment marks 32 may be, for example, a circle, an ellipse, a polygon, or a cross. The carrier substrate 3 having the first alignment marks 32 facilitates alignment of the LED chip with respect to the carrier substrate 3, and therefore alignment of the LED chip with respect to the circuit board 2, thereby improving manufacturing throughput.

[0019] 4, recesses 311 corresponding to the respective circuit boards 2 are formed in the carrier substrate body 31. Since the circuit boards 2 fit into the recesses 311, it is possible to easily align the circuit boards 2 with respect to the carrier substrate body 31. Furthermore, when the carrier substrate 3 is inserted into a bonding device, it is possible to prevent the aligned circuit boards 2 from shifting. Note that the formation of the recesses 311 may be omitted.

[0020] (Second placement step) The second placement step (S13) is a step of placing the carrier substrate 3 on a mounting stage inside the bonding device while holding multiple circuit boards 2. Since multiple circuit boards can be loaded into the bonding device all at once, manufacturing throughput can be improved.

[0021] (First alignment step) The first alignment step (S14) is a step in which the bonding apparatus uses the first alignment mark 32 on the carrier substrate 3 to align the LED chip with respect to the carrier substrate 3. Inside the bonding apparatus, a camera attached to the bonding head detects the first alignment mark 32, and the mounting stage on which the carrier substrate 3 is placed is adjusted in the X, Y, and θ directions, thereby determining the reference position of the bonding head. The first alignment step (S14) roughly positions the LED chip with respect to the circuit board 2, and corresponds to so-called global alignment.

[0022] (Second alignment step) The second alignment step (S15) is a step in which the bonding apparatus aligns the LED chip with respect to the circuit board 2 using the second alignment mark 22 on the circuit board 2. A camera attached to the bonding head detects the second alignment mark 22, and the mounting stage is adjusted in the X, Y, and θ directions, thereby determining the position of the bonding head. The second alignment step (S15) precisely positions the LED chip with respect to the circuit board 2, and corresponds to so-called local alignment.

[0023] (Implementation steps) The mounting step (S16) is a step in which an LED chip is mounted in the mounting area 211 on the circuit board body 21 of the aligned circuit board 2 on the mounting stage of the bonding device.

[0024] FIG. 5 is a cross-sectional view showing an outline of a bonding apparatus. As shown in FIG. 5, the bonding apparatus 4 includes an apparatus main body 41, a bonding head 42 disposed inside the apparatus main body 41, and a mounting stage 43. The carrier substrate 3 is disposed on the mounting stage 43 inside the bonding apparatus 4. A carrier plate 5 on which multiple LED chips (not shown) are disposed is attached below the bonding head 42. As the bonding head 42 moves from top to bottom, the LED chips disposed on the carrier plate 5 are bonded to the circuit board 2. The LED chips can then be mounted on the circuit board 2 by transferring them from the carrier plate 5 using thermocompression bonding or the like. The inside of the apparatus main body 41 of the bonding apparatus 4 can be under a nitrogen atmosphere. The carrier substrate 3 can be fixed to the mounting stage 43 by forming a weak adhesive layer on the mounting stage 43, or by vacuum adsorption via the mounting stage 43.

[0025] Once the mounting of LED chips on one circuit board 2 is complete, the second alignment step (S15) and mounting step (S16) are performed on the next circuit board 2. The second alignment step (S15) and mounting step (S16) are repeated for each circuit board 2 until the mounting of LEDs is complete on all circuit boards placed on the carrier substrate 3. In the conventional manufacturing method in which each circuit board 2 is fed into a bonding device 4 and LED chips are mounted, global alignment is required for each circuit board 2, but by using the carrier substrate 3, global alignment is only required once, thereby improving manufacturing throughput.

[0026] (Removal step) The removal step (S17) is a step of removing the carrier substrate 3, while holding the plurality of circuit boards 2 on which LED chips are mounted, from the mounting stage 43 of the bonding device 4. Since the plurality of circuit boards 2 on which LED chips are mounted can be removed from the bonding device 4 all at once, it is possible to improve manufacturing throughput.

[0027] Other effects and advantages brought about by the aspects described in this embodiment that are clear from the description in this specification or that can be appropriately thought of by a person skilled in the art are naturally understood to be brought about by the present invention. [Explanation of symbols]

[0028] 2 Circuit Boards 22 Second alignment mark 3 Carrier Board 32 First alignment mark 43 Implementation Stage

Claims

1. a singulation step of singulating a plurality of circuit boards from a multiple substrate having a surface on which the circuit boards are formed; a first placement step of placing the plurality of circuit boards on a carrier substrate; a second placement step of placing the carrier substrate on a mounting stage; a mounting step of mounting LED chips on the plurality of circuit boards at the mounting stage; A method for manufacturing an LED display, comprising:

2. the carrier substrate is smaller than the multiple substrate; The method for manufacturing the LED display according to claim 1 .

3. the first arranging step periodically arranges the plurality of circuit boards on the carrier substrate; The method for manufacturing the LED display according to claim 2 .

4. the carrier substrate has a first alignment mark; and a first alignment step of aligning the LED chip with respect to the carrier substrate using the first alignment mark after the second placement step and before the mounting step. The method for manufacturing the LED display according to claim 3 .

5. each of the plurality of circuit boards has a second alignment mark; a second alignment step of aligning the LED chip with respect to the circuit board using the second alignment mark, which is performed after the first alignment step and before the mounting step; The method for manufacturing an LED display according to claim 4.

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