KR20240083848A - Micro element structure and display device - Google Patents

Abstract

A microdevice structure is provided that includes a body, two electrodes, two solder patterns, and a confinement structure. Two electrodes are placed on the side of the body. Two solder patterns are each disposed on two electrodes. A confinement structure protrudes relative to the body, wherein the confinement structure surrounds one of the electrodes and a solder pattern thereon, and at least a portion of the confinement structure is separated from the surrounding solder pattern by a gap. A display device is also provided.

Description

Micro element structure and display device {MICRO ELEMENT STRUCTURE AND DISPLAY DEVICE}

This disclosure relates to micro device structures and display devices.

When bonding electronic devices to a circuit board, solder material is essential as a medium. For example, in bonding technology, a reflow process is commonly performed. However, especially for extremely small sized micro device structures, because the solder material can temporarily melt during the process and cause overflow, this has the potential to cause shorts in the electrodes or other circuits. there is.

This disclosure relates to micro device structures and display devices that help alleviate short circuit problems caused by solder material overflow.

One embodiment of the present disclosure provides a micro device structure including a body, two electrodes, two solder patterns, and a confinement structure. Two electrodes are placed on the side of the body. Two solder patterns are each disposed on two electrodes. A confinement structure protrudes relative to the body, wherein the confinement structure surrounds one of the electrodes and a solder pattern thereon, and at least a portion of the confinement structure is separated from the surrounding solder pattern by a gap.

One embodiment of the present disclosure provides a display device including a circuit board and a plurality of micro device structures. Micro device structures are placed on a circuit board and electrically connected to the circuit board. Each of the micro device structures includes a body, two electrodes, two solder patterns, and a confinement structure. Two electrodes are placed on the side of the body facing the circuit board. Two solder patterns are disposed on each of the two electrodes and positioned between the two electrodes and the circuit board. A confinement structure protrudes relative to the body, wherein the confinement structure surrounds one of the electrodes and a solder pattern thereon, and at least a portion of the confinement structure is separated from the surrounding solder pattern by a gap.

In order to make the foregoing more understandable, several embodiments accompanied by drawings are described in detail below.

The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the disclosure and, together with the description, contribute to explaining the principles of the disclosure.
1A, 2A, 3A, and 4 to 12 are schematic partial cross-sectional views of micro device structures according to a plurality of embodiments of the present disclosure, respectively.
1B, 2B, and 3B are schematic partial top views of micro device structures according to multiple embodiments of the present disclosure, respectively, where cutting line II-I', cutting line II-II', and cutting line III- The schematic cross-sectional views of FIGS. 1B, 2B and 3B along III' may refer to FIGS. 1A, 2A and 3A, respectively.
13 is a schematic partial cross-sectional view of a display device according to an embodiment of the present disclosure.

Orientation terms mentioned in the following examples, such as “top,” “bottom,” “front,” “back,” “left,” “right,” etc., refer to the orientation of the drawing(s) being described. used and is not intended to limit the present disclosure. Additionally, a device/film layer disposed on (or above) another device/film layer may be defined as a device/film layer disposed directly on (or above) another device/film layer, where the two device/film layers are directly situation of contact; and situations where a device/film layer is disposed indirectly on (or above) another device/film layer, and one or more devices/film layers are between two device/film layers.

In the drawings, each of the drawings illustrates typical features of methods, structures, and/or materials used in specific example embodiments. However, these drawings should not be construed as limiting or limiting the scope or nature covered by these exemplary embodiments. For example, for clarity, the relative thickness and location of each film layer, region and/or structure may be reduced or enlarged.

1A, 2A, 3A, and 4 to 12 are schematic partial cross-sectional views of micro device structures according to a plurality of embodiments of the present disclosure, respectively. 1B, 2B, and 3B are schematic partial top views of micro device structures according to multiple embodiments of the present disclosure, respectively, where cutting line II-I', cutting line II-II', and cutting line III- The schematic cross-sectional views of FIGS. 1B, 2B and 3B along III' may refer to FIGS. 1A, 2A and 3A, respectively. 13 is a schematic partial cross-sectional view of a display device according to an embodiment of the present disclosure.

In the embodiments shown in FIGS. 1A to 13 , identical or similar components may take on identical or similar reference numerals, and descriptions thereof are not repeated. Additionally, features of different embodiments may be combined in the absence of conflict, and simple equivalent changes and modifications made in accordance with the specification and scope of the patent application will still remain within the scope of the present patent.

1A and 1B, the micro device structure 1 includes a body 10, two electrodes 11 and 12, two solder patterns 13 and 14, and a confinement structure 15. ), but the present disclosure is not limited thereto.

In some embodiments, the micro device structure 1 is a micro light-emitting diode (LED) structure, and the body 10 includes a first type semiconductor layer 100, a light emitting layer 101, and a second type semiconductor layer 101. It may include a semiconductor layer 102, but the present disclosure is not limited thereto. The light emitting layer 101 is located between the first type semiconductor layer 100 and the second type semiconductor layer 102, where the second type semiconductor layer 102 is connected to the light emitting layer 101 and two solder patterns 13. , 14).

One of the first type semiconductor layer 100 and the second type semiconductor layer 102 may be a P-type semiconductor layer, and the other may be an N-type semiconductor layer. The materials of the first type semiconductor layer 100 and the second type semiconductor layer 102 include group III and group V materials, such as nitrides and alloys thereof (e.g. gallium nitride, aluminum nitride, indium nitride, indium gallium nitride, aluminum gallium nitride, aluminum indium gallium nitride, etc.), arsenides and their alloys (e.g. gallium arsenide, aluminum arsenide, indium arsenide, indium gallium arsenide, aluminum gallium arsenide, aluminum indium gallium arsenide, etc.), Phosphides and their alloys (such as gallium phosphide, aluminum phosphide, indium phosphide, indium gallium phosphide, aluminum gallium phosphide, aluminum indium gallium phosphide, etc.) may include, but the present disclosure is not limited thereto. The light emitting layer 101 may be a multiple quantum well (MQW) structure, but the present disclosure is not limited thereto.

In some embodiments, body 10 may optionally further include a current spreading layer 103, with second type semiconductor layer 102 positioned between light emitting layer 101 and current spreading layer 103. do. The material of the current diffusion layer 103 may include a transparent conductive material such as a metal oxide, but the present disclosure is not limited thereto. The metal oxide may include indium tin oxide (ITO), but the present disclosure is not limited thereto.

Two electrodes 11 and 12 are disposed on the side of the body 10 . For example, the electrode 11 is disposed on the current spreading layer 103 and is electrically coupled to the second type semiconductor layer 102 through the current spreading layer 103. The electrode 12 is disposed on the first type semiconductor layer 100 and is electrically connected to the first type semiconductor layer 100 . Materials of electrodes 11 and 12 may include metals, alloys, or combinations thereof, but the present disclosure is not limited thereto.

In some embodiments, the current spreading layer 103, the second type semiconductor layer 102, and the light emitting layer 101 may be etched through a conductive via etch to expose the first type semiconductor layer 100; The second electrode 12 then contacts the first type semiconductor layer 100 through the conductive via. Additionally, the top surface of electrode 11 and the top surface of electrode 12 may be flush with each other based on requirements (eg, direct bonding), although the present disclosure is not limited thereto. In other embodiments, as shown in Figure 12, the first type semiconductor layer 100 is etched by platform etching to electrically connect the first type semiconductor layer 100 and the electrode 12. may be exposed.

Two solder patterns 13 and 14 are disposed on the two electrodes 11 and 12, respectively. The material of solder pattern 13 and solder pattern 14 may include tin or other suitable conductive materials.

A confinement structure 15 protrudes relative to the body 10, and in Figure 1a, the confinement structure 15 surrounds one of the electrodes (electrode 11) and the solder pattern 13 thereon. For example, the orthogonal projection P13 of the enclosed solder pattern 13 on the body 10 is completely defined by the orthogonal projection P15 of the confinement structure 15 on the body 10 (as shown in FIG. 1B). surrounded

Additionally, at least a portion of the confinement structure 15 is separated from the surrounding solder pattern 13 by a gap G. For example, in a schematic cross-sectional view of the micro device structure 1 as shown in FIG. 1 , at least a portion of the inner sidewall of the confinement structure 15 (i.e., the confinement structure (i.e., the confinement structure) facing the enclosed solder pattern 13 The surface of 15) is separated from the surrounding solder pattern 13. 1A schematically shows the inner sidewall of the confinement structure 15 being completely separated from the surrounding solder pattern 13, but the present disclosure is not limited thereto. In other embodiments, as shown in Figure 2A, the interior sidewall of the confinement structure 15 may be partially in contact with and partially separated from the solder pattern 13, for example, the confinement structure on the left side. A lower region of the inner sidewall of structure 15 may be in contact with solder pattern 13, while an upper region of the inner sidewall is separated from solder pattern 13. Meanwhile, at least a portion of the inner sidewall of the confinement structure 15 is separated from the surrounding solder pattern 13. As shown in the schematic top view of FIG. 1B, the inner sidewall of confinement structure 15 is completely separated from the surrounding solder pattern 13. In other embodiments, as shown in FIG. 2B, at least one side of the interior sidewall of confinement structure 15 may be in contact with solder pattern 13 and the other side of the interior sidewall of confinement structure 15 may be in contact with solder pattern 13. can be separated from the solder pattern 13.

By surrounding the electrode 11 and the solder pattern 13 thereon with a confinement structure 15, the overflow range of the solder pattern is limited during the reflow process to prevent the overflow of the solder pattern 13 from overflowing. Contact and short circuit of the solder pattern 14 can be prevented. Additionally, by maintaining the distance (i.e., gap G) between the confinement structure 15 and the solder pattern 13, the area surrounded by the confinement structure to limit the overflowing solder pattern 13 is effectively solidified or Or it can be reduced, which helps further reduce the likelihood of short circuits.

In some embodiments, based on reliability or process considerations, the end portion E15 of the confinement structure 15 is aligned with the top portion T13 of the solder pattern 13 and the bottom portion B13 of the solder pattern 13. ) is designed to be located between. The end portion E15 of the confinement structure 15 refers to the end of the confinement structure 15 away from the body 10 . The upper part (T13) of the solder pattern (13) refers to the surface of the solder pattern (13) furthest from the body (10), and the lower part (B13) of the solder pattern (13) refers to the surface of the solder pattern (13) closest to the body (10). This refers to the surface of the pattern (13). The end portion E15 of the confinement structure 15 is higher than the bottom portion B13 of the solder pattern 13 to reduce the possibility of overflow, and the end portion E15 is such that the micro device structure 1 is connected to the circuit. It is lower than the upper portion (T13) of the solder pattern 13 to prevent compressive deformation or breakage of the confinement structure 15 when bonded to a substrate (not shown).

In some embodiments, the ratio of the width WG of the gap G to the thickness TH13 of the enclosed solder pattern 13 (e.g., the thickness at the protruding portion PP of the solder pattern 13) is 0.25 or greater. am. Here, the width WG and the thickness TH13 may be regarded as factors related to the accommodation space of the gap G and the volume of the solder pattern 13, respectively. In other words, a ratio mentioned above higher than 0.25 indicates, for example, that the gap G has a relatively large space to accommodate the solder pattern 13, which Overflow of the restricted area can be better prevented. Additionally, the protrusion height H15 of the confinement structure 15 relative to the body 10 may be 0.1 μm to 0.5 μm, for example, 0.3 μm or more. However, the protrusion height H15 may vary depending on other design parameters (such as the thickness TH13 of the solder pattern 13, the material or manufacturing method of the confinement structure 15, etc.), and thus the present disclosure. It is not limited.

1A also schematically illustrates a confinement structure 15, which surrounds the electrode 11, the eutectic barrier pattern 16, and the solder pattern 13, and which surrounds the confinement structure 15. ) has a rectangular cross-sectional shape, but it should be understood that design parameters such as the number of confinement structures 15, the configuration position and cross-sectional shape of the confinement structures 15, etc. may be changed according to actual needs. For example, in other embodiments, the number of confinement structures 15 may be plural, and the plurality of confinement structures 15 may each surround a plurality of electrode patterns. For example, confinement structure 15 may also surround electrode 12, eutectic barrier pattern 17, and solder pattern 14. Additionally, the cross-sectional shape of the confinement structure 15 may include a horn shape, a triangular shape, a quadrilateral shape, a convex circular shape, a curved shape, or an irregular shape. Quadrilaterals may include, but are not limited to, rectangles, squares, trapezoids, etc., but the present disclosure is not limited thereto.

Additionally, according to different needs, the micro device structure 1 may optionally include other devices or film layers. For example, in some embodiments, although not shown, the micro device structure 1 may be an epitaxial structure formed on an epitaxial substrate. The material of the substrate may include sapphire, gallium nitride, gallium arsenide, silicon, silicon germanium, glass, ceramic, silicon carbide, aluminum nitride, or other suitable materials. Alternatively, after the above-mentioned elements and film layers have been formed on the substrate, the substrate may be selectively removed, for example, the substrate may be subjected to a laser lift-off (LLO) process. It can be separated from the devices and substrate layers above it.

In some embodiments, microdevice structure 1 may include two eutectic barrier patterns (e.g., eutectic barrier pattern 16 and eutectic barrier pattern 17), which are formed on and above electrode 11, respectively. It is positioned between the positioned solder pattern 13 and between the electrode 12 and the solder pattern 14 positioned thereon. The two electrodes are sealed by two eutectic barrier patterns and separated from the two solder patterns to prevent eutectics generated during the subsequent reflow process, thereby improving the electrical performance and structural reliability of the micro device structure 1. can help improve. Materials of the eutectic barrier pattern 16 and the eutectic barrier pattern 17 may include nickel, platinum, titanium or alloys thereof, or transparent conductive materials, but the present disclosure is not limited thereto.

In some embodiments, two electrodes, two eutectic barrier patterns and two solder patterns may be stacked conformally sequentially on body 10 . Since the electrodes 11 and 12 have a recessed shape by partially etching the micro device structure 1, each solder pattern has a groove GR on the side facing away from the body 10 due to conformal stacking. can be formed, which means that the solder pattern is accommodated in the grooves of the electrodes 11 and 12 to reduce the degree of overflow.

Each solder pattern may further have a protruding portion (PP) surrounding the groove (GR). The gap G at the periphery of the solder pattern 13 is a recessed section compared to the protruding portion PP, and the recessed section accommodates a portion of the solder when the solder pattern overflows and determines the degree of overflow. can be reduced.

In some embodiments, micro device structure 1 may include an insulating layer 18. The insulating layer 18 covers, for example, the body 10 and has two openings A. Two electrodes (eg electrode 11 and electrode 12 ) are disposed on the insulating layer 18 and are each connected to the body 10 through two openings A. In some embodiments, confinement structure 15 is disposed on insulating layer 18, and confinement structure 15 and insulating layer 18 may be made of the same material or different materials. For example, the material of the insulating layer 18 may include silicon oxide (SixOy) or titanium oxide, but the present disclosure is not limited thereto. If the confinement structure 15 and the insulating layer 18 are made of the same material, the confinement structure 15 and the insulating layer 18 may be formed integrally, but the present disclosure is not limited thereto.

2A and 2B, the main differences between the micro device structure 1A and the micro device structure 1 of FIGS. 1 A and 1 B are explained as follows. In the micro device structure 1A, at least one side of the inner sidewall of the confinement structure 15 is in contact with the solder pattern 13 and other sides of the inner sidewall of the confinement structure 15 are separated from the solder pattern 13. do. In any embodiment of the present disclosure, the relative arrangement relationship between the confinement structure and the surrounding solder pattern may all have the same variations, which will not be repeated below.

3A and 3B, the main differences between the micro device structure 1A and the micro device structure 1 of FIGS. 1 A and 1 B are described below. The micro device structure 1B includes two confinement structures 15, which surround the solder pattern 13 and solder pattern 14, respectively. The number of constraint structures 15 can vary depending on different requirements. In any embodiment of the present disclosure, the number of constraint structures 15 may be one or two, which will not be repeated below.

Referring to FIG. 4, key differences between micro device structure 1B and micro device structure 1C of FIG. 3A are described below. In the micro device structure 1B of Figure 3A, the confinement structure 15 is disposed on the insulating layer 18 and maintained at a distance from the surrounding eutectic barrier pattern 16 (or eutectic barrier pattern 17). and; In the micro device structure 1C of FIG. 4, the solder pattern 13 (or solder pattern 14) exposes a peripheral portion of the eutectic barrier pattern 16 (or eutectic barrier pattern 17) located underneath it. and the confinement structure 15 is set on the peripheral portion of the eutectic barrier pattern 16 (or eutectic barrier pattern 17) and protrudes relative to the peripheral portion. For example, in Figure 4, confinement structure 15 and eutectic barrier pattern 16 (or eutectic barrier pattern 17) may be formed integrally, i.e., confinement structure 15 and eutectic barrier pattern 16. ) (or eutectic barrier pattern 17) may have the same material. In other embodiments, confinement structure 15 and eutectic barrier layer 16 (or eutectic barrier layer 17) may have different materials.

Referring to FIG. 5, the main differences between the micro device structure 1C and the micro device structure 1D of FIG. 4 are explained as follows. In the micro device structure 1C of Figure 4, the solder pattern 13 and solder pattern 14 are separated by two confinement structures 15. In the micro device structure 1D of FIG. 5, the solder pattern 13 and the solder pattern 14 are separated by one limiting structure 15, that is, between the solder pattern 13 and the solder pattern 14. There is only one barrier (restriction structure 15).

Referring to FIG. 6, key differences between micro device structure 1C and micro device structure 1E of FIG. 4 are described below. In the micro device structure 1E, the cross-sectional shape of the confinement structure 15 is, for example, horn-shaped.

Referring to FIG. 7, key differences between the micro device structure 1C and 1F of FIG. 4 are described below. In the micro device structure 1F, the cross-sectional shape of the confinement structure 15 is, for example, trapezoid. Additionally, confinement structure 15 and eutectic barrier layer 16 (or eutectic barrier layer 17) have different materials, for example.

Referring to FIG. 8, the main differences between the micro device structure 1B and the micro device structure 1G of FIG. 3A are described below. In the micro device structure 1G, the cross-sectional shape of the confinement structure 15 is, for example, triangular.

Referring to FIG. 9, the main differences between the micro device structure 1G and the micro device structure 1H of FIG. 8 are described below. In the micro device structure 1H, the cross-sectional shape of the confinement structure 15 is, for example, a convex circular shape.

Referring to FIG. 10, the main differences between the micro device structure 1E and the micro device structure 1I of FIG. 6 are described below. In the micro device structure 1I, the cross-sectional shape of the confinement structure 15 is, for example, a curved shape.

Referring to FIG. 11, the main differences between the micro device structure 1F and the micro device structure 1J of FIG. 7 are described below. In the micro device structure 1J, the cross-sectional shape of the confinement structure 15 is, for example, an irregular shape.

Referring to FIG. 12, the main differences between the micro device structure 1C and the micro device structure 1K of FIG. 4 are described below. In the micro device structure 1K, the first type semiconductor layer 100 is exposed by platform etching to realize electrical connection between the first type semiconductor layer 100 and the electrode 12, but the present disclosure is not limited thereto. That is not the case. Any embodiment of the present disclosure may also have the same variations, and details thereof are not repeated.

Referring to FIG. 13, the display device DD may include a circuit board 2 and a micro device structure 1. Circuit board 2 may be a complementary metal-oxide-semiconductor (CMOS) substrate, liquid crystal on silicon (LCOS) substrate, thin film transistor (TFT) substrate, or Other substrates having circuits may be included, and this is not limited by the present disclosure. Additionally, the circuit board 2 may include a pad P1 and a pad P2, but the present disclosure is not limited thereto.

The micro device structures (1) are disposed on the circuit board (2) and are electrically connected to the circuit board (2). For example, the solder pattern 13 and solder pattern 14 in the micro device structure 1 may be soldered together with the pad P1 and the pad P2 in the circuit board 2 through a reflow process, respectively. . Under this framework, two electrodes 11, 12 are placed on the side of the body 10 facing the circuit board 2, and two solder patterns 13, 14 are connected to the two electrodes and the circuit. It is located between the substrates 2.

In other embodiments, although not shown, the micro device structure 1 in the display device DD may be replaced with the micro device structure of any one of the embodiments mentioned above, which is repeated herein. It won't work.

Additionally, although FIG. 13 schematically illustrates one micro device structure, display device DD may include multiple micro device structures, including but not limited to blue, red, or green micro LED structures.

In summary, in embodiments of the present disclosure, by surrounding the electrodes and the solder patterns thereon with a confinement structure, the extent of overflow of the solder patterns during the reflow process is limited, thereby preventing overflowed solder patterns resulting in short circuits. Prevents contact with overflowed solder patterns. Additionally, by maintaining the distance (gap) between the confinement structure and the solder pattern, the area enclosed by the confinement structure to limit the overflowing solder pattern can be effectively solidified or reduced, which further reduces the possibility of short circuiting. It helps to do it.

It will be apparent to those skilled in the art that various modifications and variations may be made to the disclosed embodiments without departing from the spirit or scope of the disclosure. In light of the foregoing, the present disclosure is intended to cover such modifications and variations as are provided to fall within the scope of the following claims and their equivalents.

Claims (17)

As a micro device structure,
body;
two electrodes disposed on the side of the body;
two solder patterns respectively disposed on the two electrodes; and
a confinement structure projecting relative to the body, the confinement structure surrounding one of the electrodes and the solder pattern thereon, wherein at least a portion of the confinement structure is separated from the surrounding solder pattern by a gap. A micro device structure comprising a structure.
In claim 1,
The micro device structure is,
The micro device structure further comprising two eutectic barrier patterns disposed respectively between the solder pattern thereon of one of the electrodes and between the solder pattern thereon and another one of the electrodes.
In claim 2,
wherein one of the solder patterns exposes a peripheral portion of the eutectic barrier pattern located beneath it, and the confinement structure is disposed on and protrudes relative to the peripheral portion of the eutectic barrier pattern. .
In claim 3,
wherein the confinement structure and the eutectic barrier pattern are integrally formed.
In claim 3,
wherein the confinement structure and the eutectic barrier pattern have different materials.
In claim 2,
The micro device structure is,
An insulating layer covering the body and having two openings, wherein the two electrodes are disposed on the insulating layer and connected to the body through the two openings, respectively, and the two electrodes are connected to the insulating layer and the two openings. The micro device structure further comprising the insulating layer each sealed by two eutectic barrier patterns and separated from the two solder patterns.
In claim 1,
The micro device structure is,
an insulating layer covering the body and having two openings, wherein the two electrodes are disposed on the insulating layer and are respectively connected to the body through the two openings, and the confinement structure is disposed on the insulating layer. , a micro device structure further comprising the insulating layer.
In claim 7,
The confinement structure and the insulating layer are formed integrally, or the confinement structure and the insulating layer have different materials.
In claim 1,
The micro device structure is,
an insulating layer covering the body and having two openings, the two electrodes being disposed on the insulating layer and each connected to the body through the two openings; and
Two eutectic barrier patterns, wherein the two electrodes, the two eutectic barrier patterns, and the two solder patterns are sequentially stacked conformally on the body, each of the solder patterns The microdevice structure further comprising the two eutectic barrier patterns having grooves on a side away from the body.
In claim 1,
An end portion of the confinement structure is located between a top portion of the solder pattern and a bottom portion of the solder pattern.
In claim 1,
wherein an orthogonal projection of the surrounded solder pattern on the body is completely surrounded by an orthogonal projection of the confinement structure on the body.
In claim 1,
A micro device structure, wherein the ratio of the width of the gap to the surrounding solder pattern is 0.25 or more.
In claim 1,
A micro device structure wherein the protrusion height of the confinement structure relative to the body is 0.1 μm to 0.5 μm.
In claim 1,
A micro device structure wherein the cross-sectional shape of the confinement structure includes a horn shape, a triangular shape, a quadrilateral shape, a convex circular shape, or a curved shape.
As a display device,
circuit board; and
It is disposed on the circuit board and includes a plurality of micro device structures electrically connected to the circuit board,
Each of the micro device structures,
body;
two electrodes disposed on the side of the body facing the circuit board;
two solder patterns each disposed on the two electrodes and positioned between the two electrodes and the circuit board; and
a confinement structure projecting relative to the body, the confinement structure surrounding one of the electrodes and the solder pattern thereon, wherein at least a portion of the confinement structure is separated from the surrounding solder pattern by a gap. A display device containing a structure.
In claim 15,
wherein the confinement structure has an end portion and the solder pattern has a top portion away from the body and a bottom portion close to the body, the end portion being located between the top portion and the bottom portion.
In claim 15,
A display device, wherein an orthogonal projection of the confinement structure on the body completely covers an orthogonal projection of the enclosed solder pattern on the body.

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