KR102427474B1 - LED Transfer device and transferring method using the same - Google Patents

Abstract

An LED transfer device and a transfer method capable of manufacturing an LED display substrate with high pixel precision are proposed. In the LED transfer device according to the present invention, a first LED seating portion on which a first LED emitting a first color is seated, a second LED seating portion on which a second LED emitting a second color is seated, and a third LED emitting a third color are seated an LED pickup unit including a third LED mounting unit; a vacuum part connected to the first LED seating part, the second LED seating part, and the third LED seating part by a vacuum application tube to apply a vacuum state; and a switch unit positioned between the vacuum application tube and the vacuum unit to control the application of a vacuum state.

Description

LED Transfer device and transferring method using the same}

The present invention relates to an LED transfer apparatus and a transfer method, and more particularly, to an LED transfer apparatus and a transfer method capable of manufacturing an LED display substrate with high pixel precision.

Currently, the most widely used display is a liquid crystal display (LCD) using liquid crystal. However, LCD based displays only pass less than 5% of the light from the backlight source (eg, LED or CFL, etc.), presenting problems of low power efficiency, insufficient daylight display illumination and poor viewing angles. OLED displays using organic light emitting diodes (OLEDs) have improved display power efficiency compared to LCD displays, but OLED technology has problems in that color fading occurs, display durability is low, and lifespan is short.

A display using an inorganic LED (iLED) is being developed to solve this problem. A lot of research is being conducted on displays using inorganic LEDs because of the advantages of low-power driving, long-term use, and high luminance. Inorganic LED displays (hereinafter referred to as LED displays) use, for example, one LED chip for one picture element, or pixel. The LED chip has a small size of micro size. In order to realize a full color micro LED display, red, green, and blue LEDs with a size of several tens of micrometers must be placed on a substrate, and the size of the LED and spacing depends on resolution and placement method.

1 is a view for explaining a method of manufacturing an LED display substrate according to the prior art. Due to the characteristics of the LED, the red LED 21 , the green LED 22 , and the blue LED 23 cannot be manufactured on the same substrate, and only one color LED can be manufactured on one substrate. Therefore, in order to implement RGB LEDs, it is necessary to separately manufacture red, green, and blue LEDs, and then transfer three chips to one substrate. First, from the red LED substrate 11, the red LED 21 is attached to the elastic rubber transfer device 30 having an adhesive characteristic, and transferred to the transfer substrate 40, and again the green LED 22 from the green LED substrate 12. and the blue LEDs are sequentially attached to the transfer device from the blue LED substrate 13 and transferred to the transfer substrate 40 .

When the LED is transferred in this way, a pickup process and a batch process must be performed for each color, respectively. In addition, the elastic rubber transfer device having an adhesive property has a disadvantage in that the adhesive ability decreases as the number of times of use increases. In addition, when the pitch alignment between the LEDs in the red LED substrate, the green LED substrate, and the blue LED substrate is incorrect, the pitch is inaccurate even in the final LED display substrate because it is picked up at the incorrect pitch, which affects the quality.

In addition, when transferring and disposing the LED on the display substrate, a bonding process for electrically connecting the LED and the wiring of the display substrate is required. In general, after applying liquid solder paste, an LED is placed on it, and then heat is applied to solidify it. In the conventional transfer method, since the red LED, green LED, and blue LED are separately placed, when the green LED is placed after the red LED is placed, the red LED is in a solid state and is not fixed to the solder paste, so the LED is even in a small impact. There is a disadvantage that the arrangement interval may be wrong. In order to compensate for this, red LED, green LED, and blue LED are transferred to an arbitrary adhesive film substrate, respectively, and then the process of bonding to the display substrate is performed. In this case, there is a disadvantage in that the number of processes increases.

The present invention has been devised to solve the above problems, and an object of the present invention is to provide an LED transfer device and a transfer method capable of manufacturing an LED display substrate with high pixel precision.

An LED transfer device according to an embodiment of the present invention for achieving the above object includes a first LED seating part on which a first LED emitting a first color is seated, a second LED seating part on which a second LED emitting a second color is seated, and an LED pickup unit including a third LED mounting unit on which a third LED emitting a third color is mounted; a vacuum part connected to the first LED seating part, the second LED seating part, and the third LED seating part by a vacuum application tube to apply a vacuum state; and a switch unit positioned between the vacuum application tube and the vacuum unit to control the application of a vacuum state.

The LED pickup unit may be transparent.

The first LED mounting unit is connected to the vacuum unit through a first vacuum applying pipe, the second LED mounting unit is connected to the vacuum unit through a second vacuum applying pipe, and the third LED mounting unit is connected to the vacuum unit through a third vacuum applying pipe, and , the height of the first vacuum applied pipe, the second vacuum applied pipe, and the third vacuum applied pipe may be different from each other based on the height of the first LED mounting part.

The distance between the first LED seating portion, the second LED seating portion, and the third LED seating portion may be the same as a pitch between the first LED, the second LED, and the third LED on the transfer substrate.

The LED pickup unit may be formed by a 3D printer.

According to another aspect of the present invention, on a transfer substrate, a first LED seating portion on which the first LED emitting a first color is seated, a second LED seating portion on which a second LED emitting a second color is seated, and a third color are emitted An LED pickup unit including a third LED mounting unit on which a third LED is mounted, a vacuum unit connected to the first LED mounting unit, the second LED mounting unit, and the third LED mounting unit through a vacuum application tube to apply a vacuum state, and a vacuum application tube and vacuum A first step of positioning the LED transfer device including a switch unit for controlling the application of a vacuum state located between the study; a second step of seating the first LED, the second LED and the third LED by applying a vacuum state to the first LED seating part, the second LED seating part, and the third LED seating part; and a third step of placing the LED transfer device on the transfer substrate and transferring the first LED, the second LED and the third LED onto the transfer substrate by removing the vacuum state.

The second step is to apply a vacuum state to the first LED seating portion to seat the first LED on the first LED seating portion; applying a vacuum state to the second LED seating portion to seat the second LED on the second LED seating portion; and applying a vacuum state to the third LED seating portion to seat the third LED on the third LED seating portion; may be sequentially performed.

The transfer substrate includes solder paste at the LED transfer position, and the third step includes: locating the first LED, the second LED and the third LED on the solder paste; heating to solidify the solder paste; and transferring the first LED, the second LED, and the third LED to the transfer substrate by removing the vacuum state.

According to embodiments of the present invention, since a transfer device using a vacuum is used to transfer the LED to the display substrate, it can be used multiple times, thereby reducing the cost associated with the process equipment.

In addition, since the interval between the mounting portions of the LED transfer device is constant, the pitch is corrected during LED transfer, thereby increasing the accuracy of the LED pixel and the safety of the transfer process.

When the transfer device according to the present invention is used, the red LED, the green LED and the blue LED are disposed at once instead of being disposed on the display substrate through different processes, so that when performing step by step, it is possible to prevent the previous LED from falling off. This has the effect of increasing the productivity and product reliability of LED display substrates.

1 is a view for explaining a method of manufacturing an LED display substrate according to the prior art.
2 is a plan view of an LED transfer device according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along line A-A' of FIG. 2 .
4 to 11 are views for explaining an LED transfer method according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiment of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art. Although there may be components shown to have a specific pattern or a predetermined thickness in the accompanying drawings, this is for convenience of explanation or distinction, so even if the present invention has a specific pattern and a predetermined thickness, the characteristics of the components shown It is not limited to only.

2 is a plan view of an LED transfer device according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along line A-A' of FIG. 2 . The LED transfer device 100 according to the present invention includes a first LED seating portion 111 on which a first LED emitting a first color is seated, a second LED seating portion 112 on which a second LED emitting a second color is seated, and a second LED transfer device 100 according to the present invention. an LED pickup unit 110 including a third LED mounting unit 113 on which a third LED emitting 3 colors is mounted; a vacuum unit 120 connected to the first LED mounting unit 111 , the second LED mounting unit 112 , and the third LED mounting unit 113 by vacuum application tubes 121 , 122 and 123 to apply a vacuum state; and a switch unit 130 positioned between the vacuum application tubes 121 , 122 , 123 and the vacuum unit 120 to control the application of a vacuum state.

The LED pickup unit 110 picks up the LED from the substrate and moves it to the substrate to be transferred. The LED can be directly transferred from a manufacturing substrate to a substrate to be transferred (hereinafter referred to as a transfer substrate), and after being first moved from the manufacturing substrate to another substrate, transferred again by the LED transfer device 100 according to the present invention It can be transferred to a substrate. Hereinafter, for convenience, it will be described that the LED is directly transferred from the manufacturing substrate to the transfer substrate, but as described above, LEDs located on a substrate other than the manufacturing substrate may also be transferred to the transfer substrate using the LED transfer device 100 .

The LED pickup unit 110 has a seating portion on which the LED is mounted in order to pick up an LED that emits any one of red, green, and blue, respectively. Although the seating part is not shown in FIG. 2, the seating part is a cavity formed on the surface where the LED pickup part 110 is opposite to the manufacturing substrate and is drawn into the LED pickup part 110 in the same manner as the shape of the LED. Based on , the mounting portion formed on the lower surface of the LED pickup unit 110 is not visible, and the vacuum application tubes 121 , 122 , and 123 on the upper surface are shown. Although the vacuum application tubes 121, 122, and 123 are displayed in red, green, and blue, respectively, since the actual vacuum application tubes 121, 122, and 123 do not need to display a color, any color may be implemented.

The vacuum unit 120 is respectively connected to the seating unit of the LED pickup unit 110 to apply a vacuum state. In this specification, 'vacuum state' does not mean an actual perfect vacuum state, but the vacuum unit 120 reduces the pressure inside the mounting unit formed by using a device such as a vacuum pump, etc. to seat the LED into each mounting unit. It means the level of pressure that can make it happen.

The vacuum unit 120 is connected to the seating units 111 , 112 , 113 and vacuum application tubes 121 , 122 , 123 . The switch unit 130 is positioned between the vacuum application tubes 121 , 122 , 123 and the vacuum unit 120 to control the application of a vacuum state.

Since the LED transfer device 100 has to pick up and transfer the red LED, the green LED and the blue LED from each substrate, it is impossible to simultaneously pick up LEDs of different colors. Therefore, for example, if a red LED is picked up first, the switch unit 130 turns off the vacuum application tube connected to the seating part where the green LED and the blue LED are to be located in order to apply a vacuum state to the seating part where the red LED is to be located. and turn ON only the vacuum application tube connected to the seating part where the red LED will be located. When the switch unit 130 picks up the corresponding LED, only the corresponding vacuum application tube is turned on, so that the LED of another color is not affected. The LED transfer method will be described in more detail below.

A cross-section of the LED pickup unit 110 is shown in FIG. 3 . Referring to the drawings, mounting portions 111 , 112 , 113 on which the LED is to be mounted are formed on the lower surface, and the mounting portions 111 , 112 , 113 are connected to the vacuum application tubes 121 , 122 , 123 , respectively. Since the vacuum application tubes 121 , 122 , and 123 must be connected to the switch unit 130 independently of each other according to the LED of each color, it is preferable that they are formed so as not to physically cross each other.

Accordingly, the first LED mounting unit 111 is connected to the vacuum unit 120 through the first vacuum application pipe 121 , and the second LED mounting unit 112 is connected to the vacuum unit 120 through the second vacuum application pipe 122 . 120), and the third LED seating part 113 is connected to the vacuum part 120 through the third vacuum applying pipe 123, the first vacuum applying pipe 121, the second vacuum applying pipe 122. and the height of the third vacuum application tube may be different from each other based on the height of the first LED seating part 111 . Alternatively, the heights of the first vacuum applied pipe 121 , the second vacuum applied pipe 122 , and the third vacuum applied pipe 123 may be set to be the same. In this case, in the LED pickup unit 110 , the When crossing only in some areas, the height can be adjusted differently so that they do not overlap physically.

In the LED pickup unit 110, the LEDs are seated on each of the mounting units 111, 112, and 113 and transferred to the transfer substrate. can be adjusted to the pitch of

The LED pickup unit 110 may be transparent, because an image can be captured from the upper surface of the LED pickup unit 110 to align and pick up the LED positioned on the substrate and the seating portion. When the LED pickup unit 110 is transparent, it is possible to secure an image from the upper portion, so that the LED pickup can be performed accurately.

The LED pickup unit 110 may be formed by a 3D printer. Since the LED is a micro LED, the size is fine, and precise molding using a mold is impossible to form the seating portions 111 , 112 , 113 and the vacuum application tube 121 , 122 , 123 . In particular, when the heights of the vacuum application tubes 121, 122, and 123 are different from each other, more precise molding is required, so it is preferable to form the LED pickup unit 110 using a 3D printer.

4 to 11 are views for explaining an LED transfer method according to another embodiment of the present invention. According to another aspect of the present invention, on the LED substrates (141, 142, 143), the first LED seating portion 111 on which the first LED 210 emitting a first color is seated, and a second LED emitting a second color. An LED pickup unit 110 including a second LED seat 112 on which 220 is seated, and a third LED seat 113 on which a third LED 230 emitting a third color is seated, a first LED seat ( 111), the second LED seating part 112 and the third LED seating part 113 are connected to the vacuum applying tubes 121, 122, 123 to apply a vacuum state and vacuum applying tubes 121, 122, 123 and a first step of positioning the LED transfer device including a switch unit positioned between the vacuum units to control the application of a vacuum state; The first LED 210, the second LED 220, and the third LED 230 are seated by applying a vacuum state to the first LED seating part 111, the second LED seating part 112, and the third LED seating part 113. Step 2; and a third step of placing the LED transfer device on the transfer substrate 150 and removing the vacuum state to transfer the first LED 210 , the second LED 220 and the third LED 230 onto the transfer substrate 150 . There is provided an LED transfer method including;

The first step is a step of positioning the LED transfer device on the LED substrate (141, 142, 143) in order to move the LED from the LED substrate (141, 142, 143) to the LED transfer device, and the second step is a vacuum This is a step of sequentially applying a vacuum state to the seating units 111 , 112 , and 113 through the additional vacuum application tubes 121 , 122 , and 123 to seat the LEDs on the mounting units 111 , 112 , 113 .

4 shows the first LED substrate 141 on which the first LED 210 is located. When the LED transfer device is aligned on the first LED substrate 141 and a vacuum state is applied through the first vacuum application tube 121, the first LED 210 is seated on the first LED seat 111 (FIG. 5). ).

Thereafter, the LED transfer device is placed again on the second LED substrate 142 on which the second LED 220 is located ( FIG. 6 ), and the second vacuum application tube 122 is turned on in the switch unit. Accordingly, a vacuum state is applied to the second LED mounting unit 112 through the second vacuum application pipe 122 , and the second LED 220 is seated on the second LED mounting unit 112 ( FIG. 7 ).

Finally, the LED transfer device is placed again on the third LED substrate 143 on which the third LED 230 is located (FIG. 8), and the third vacuum application tube 123 is turned on in the switch unit. Accordingly, a vacuum state is applied to the third LED mounting unit 113 through the third vacuum application pipe 123 , and the third LED 230 is seated on the third LED mounting unit 113 ( FIG. 9 ). Accordingly, the first LED 210 , the second LED 220 , and the third LED 230 are all seated in the seating portions 111 , 112 , and 113 of the LED pickup unit 110 , and the LEDs of all colors are transferred at once. can be prepared to do

In the third step, the LED transfer device is placed on the transfer substrate 150 , and the vacuum state is removed to transfer the first LED 210 , the second LED 220 , and the third LED 230 onto the transfer substrate 150 . make it

The transfer substrate 150 may include a solder paste 160 at the LED transfer position (FIG. 10). When the transfer substrate 150 includes the solder paste 160 , the third step may include locating the first LED 210 , the second LED 220 , and the third LED 230 on the solder paste 160 ; heating to solidify the solder paste 160; and transferring the first LED 210 , the second LED 220 , and the third LED 230 to the transfer substrate by removing the vacuum state. That is, when the solder paste 160 for attaching the LED is located on the transfer substrate 150, the LEDs of the LED transfer device 100 are placed on the solder paste 160 at once, and the solder paste 160 is heated. After solidification, the LED transfer device 100 may be removed to complete the LED transfer (FIG. 11).

According to the LED transfer method according to the present invention, since it can be applied to a large-area display due to the ease of the process process, when a direct light emitting LED display device is manufactured using the same, it shows advantages of low power operation, long-term use, and high luminance, while exhibiting the advantages of low price. It is possible to manufacture a large-area, high-quality display.

In the above, although embodiments of the present invention have been described, those of ordinary skill in the art can add, change, delete or add components within the scope that does not depart from the spirit of the present invention described in the claims. The present invention may be variously modified and changed by such as, and it will be said that it is also included within the scope of the present invention.

11, 141: first LED substrate
12, 142: second LED substrate
13, 143: third LED substrate
21, 210: first LED
22, 220: second LED
23, 230: third LED
40, 150: transfer board
100: LED transfer device
110: LED pickup unit
111: first LED seating part
112: second LED seating part
113: third LED seating part
120: vacuum unit
121: first vacuum authorization tube
122: second vacuum authorization tube
123: third vacuum authorization tube
130: switch unit
160: solder paste

Claims (8)

An LED comprising a first LED seating part on which the first LED emitting a first color is seated, a second LED seating part on which a second LED emitting a second color is seated, and a third LED seating part on which the third LED emitting a third color is seated. pickup unit;
a vacuum part connected to the first LED seating part, the second LED seating part, and the third LED seating part by a vacuum application tube to apply a vacuum state; and
An LED transfer device comprising a; a switch unit positioned between the vacuum application tube and the vacuum unit to control the application of a vacuum state,
The first LED seating part, the second LED seating part, and the third LED seating part are cavities formed when the LED pickup part is formed on a surface opposite to the manufacturing substrate and is drawn into the LED pickup part,
The first LED seating unit is connected to the vacuum unit through the first vacuum application pipe, the second LED seating unit is connected to the vacuum unit through the second vacuum application pipe, and the third LED seating unit is connected to the vacuum unit through the third vacuum application pipe. ,
The LED transfer device is an LED transfer device, characterized in that the first LED, the second LED and the third LED can be picked up independently of each other. The method according to claim 1,
LED transfer device, characterized in that the LED pickup unit is transparent. The method according to claim 1,
The height of the first vacuum application tube, the second vacuum application tube, and the third vacuum application tube are different from each other based on the height of the first LED mounting part. The method according to claim 1,
The distance between the first LED seating portion, the second LED seating portion and the third LED seating portion is the same as the pitch between the first LED, the second LED and the third LED on the transfer substrate. The method according to claim 1,
LED transfer device, characterized in that the LED pickup unit is formed by a 3D printer. On the LED substrate, a first LED seating part on which the first LED emitting a first color is seated, a second LED seating part on which a second LED emitting a second color is seated, and a third LED on which a third LED emitting a third color is seated The LED pickup unit including the mounting unit, the first LED mounting unit, the second LED mounting unit, and the third LED mounting unit are connected to the vacuum applying tube and are located between the vacuum unit and the vacuum applying tube and the vacuum unit for applying a vacuum state. A first step of positioning the LED transfer device including a switch for controlling the application;
a second step of seating the first LED, the second LED and the third LED by applying a vacuum state to the first LED seating part, the second LED seating part, and the third LED seating part; and
A third step of transferring the first LED, the second LED and the third LED onto the transfer substrate by placing the LED transfer device on the transfer substrate and removing the vacuum state,
The first LED seating part, the second LED seating part, and the third LED seating part are cavities formed when the LED pickup part is formed on a surface opposite to the manufacturing substrate and is drawn into the LED pickup part,
The first LED seating unit is connected to the vacuum unit through the first vacuum application pipe, the second LED seating unit is connected to the vacuum unit through the second vacuum application pipe, and the third LED seating unit is connected to the vacuum unit through the third vacuum application pipe. , LED transfer method, characterized in that the first LED, the second LED and the third LED can be picked up independently of each other. 7. The method of claim 6,
The second step is to apply a vacuum state to the first LED seating portion to seat the first LED on the first LED seating portion;
applying a vacuum state to the second LED seating portion to seat the second LED on the second LED seating portion; and
The step of applying a vacuum state to the third LED seating portion to seat the third LED on the third LED seating portion; LED transfer method, characterized in that sequentially performed. 8. The method of claim 7,
The transfer substrate contains solder paste at the LED transfer position,
The third step is to place the first LED, the second LED and the third LED on the solder paste;
heating to solidify the solder paste; and
Transferring the first LED, the second LED and the third LED to the transfer substrate by removing the vacuum state; LED transfer method comprising the.

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