TWI777435B - Micro led carrier board - Google Patents

Abstract

A micro LED carrier board is provided. The micro LED carrier board includes a substrate structure having a first surface and a second surface and having a central region and a peripheral region on the outside of the central region. The micro LED carrier board includes a plurality of micro LED elements forming an array and on the second surface of the substrate structure. The micro LED carrier board includes a patterned structure formed on the first surface and the second surface. The patterned structure has a first pattern density in the central region and a second pattern density in the peripheral region, and the first pattern density is different from the second pattern density.

Description

Miniature Light Emitting Diode Carrier

The present invention relates to a semiconductor device, and in particular to a carrier for a miniature light emitting diode structure.

With the advancement of optoelectronic technology, the volume of many optoelectronic components is gradually developing towards miniaturization. In recent years, due to the breakthrough in the production size of light-emitting diodes (LEDs), micro-LED displays made of arrays of light-emitting diodes have gradually attracted attention in the market. . The miniature light emitting diode display belongs to the active type miniature semiconductor element display. Compared with organic light-emitting diode (organic light-emitting diode, OLED) displays, micro light-emitting diode displays are more power-efficient, have better contrast performance, and can be visible in sunlight. In addition, since the micro light emitting diode display adopts inorganic materials, the micro light emitting diode display has better reliability and longer service life than the organic light emitting diode display.

However, miniature light-emitting diodes still have some disadvantages. For example, when mass transfer of micro LED devices is performed, some of the micro LED devices may be damaged or destroyed. As a result, the reliability, yield and durability of the micro light-emitting diode structure will be reduced. Therefore, how to reduce or avoid the damage of the miniature light-emitting diode element during the process of transferring to the receiving substrate has become one of the issues that the industry attaches great importance to.

An embodiment of the present invention discloses a miniature light-emitting diode carrier, including: a substrate structure having a first surface and a second surface, a central area and a peripheral area located outside the central area; a plurality of miniature light-emitting diode elements , wherein the micro light-emitting diode elements form an array and are located on the second surface of the substrate structure; and a patterned structure is formed on the first surface or the second surface of the substrate structure, wherein the patterned structure has a first The pattern density, the patterned structure has a second pattern density in the peripheral region, and the first pattern density is different from the second pattern density.

Another embodiment of the present invention discloses a micro light emitting diode carrier, comprising: a plurality of micro light emitting diode elements; and a substrate structure having a central area and a peripheral area, wherein the substrate structure includes: a substrate having an upper surface and the lower surface; and a bonding layer formed on the lower surface and having a first thickness in the central region, and a second thickness in the peripheral region of the bonding layer, the first thickness being greater than the second thickness; wherein the micro light-emitting diode element is arranged on the on the bonding layer and forming an array.

In an embodiment of the present invention, a micro light-emitting diode carrier is provided. By forming a patterned structure on the first surface or the second surface of the substrate structure, warpage or bending of the substrate structure can be reduced or avoided, or damage to the micro light emitting diode element during the transfer process can be reduced or avoided. In this way, the reliability, yield and durability of the micro light-emitting diode structure can be greatly improved.

The following describes the display device of the present invention in detail. It should be appreciated that the following description provides many different embodiments or examples for implementing different aspects of the invention. The specific elements and arrangements described below are merely illustrative of the invention. Of course, these are only used as examples rather than limitations of the present invention. Furthermore, repeated reference numbers or designations may be used in different embodiments. These repetitions are for simplicity and clarity of description of the present invention and do not represent any association between the different embodiments and/or structures discussed. Furthermore, when it is mentioned that a first material layer is located on or above a second material layer, the case where the first material layer and the second material layer are in direct contact is included. Alternatively, one or more other material layers may be spaced apart, in which case the first material layer and the second material layer may not be in direct contact.

Here, the terms "about" and "approximately" generally mean within 20% of a given value or range, preferably within 10%, and more preferably within 5%. The quantity given here is an approximate quantity, which means that the meanings of "about" and "approximately" can still be implied without a specific description.

Embodiments of the present invention provide a miniature light emitting diode structure. More specifically, in some embodiments of the present invention, the warpage or bending of the substrate structure can be suppressed by the micro light emitting diode carrier having a specific patterned structure, or the micro light emitting diode can be reduced or avoided. The bulk element is damaged during transfer to the receiving substrate. In this way, the reliability, yield and durability of the micro light-emitting diode structure can be greatly improved.

The term "miniature" light-emitting diode elements in this specification refers to light-emitting diode elements whose length, width, and height are in the range of 1 μm to 100 μm. According to an embodiment of the present invention, the maximum width of the miniature light-emitting diode element may be 20 μm, 10 μm or 5 μm. According to embodiments of the present invention, the maximum height of the miniature light-emitting diode element may be 20 μm, 10 μm or 5 μm. It should be understood, however, that embodiments of the invention are not necessarily so limited, and aspects of certain embodiments may be applied to scales that may be larger or smaller.

FIG. 1A is a schematic cross-sectional view corresponding to the transfer process of the micro LED device according to some embodiments of the present invention. Referring to FIG. 1A, the transfer process of the micro-LED device may include moving the micro-LED carrier plate over the receiving substrate 130 by a transfer holder 102, and transferring the micro-LED device 120 is transferred from the micro light emitting diode carrier to the receiving substrate 130 .

The transport holder 102 can hold and move the micro light emitting diode carrier. The transport holder 102 can hold the micro-LED carrier by a suitable force, such as magnetic adsorption or vacuum adsorption. The transport holder 102 can control the movement of the micro light emitting diode carrier in three dimensions. More specifically, by moving the micro-LED carrier plate along the X-axis or the Y-axis direction, the electrodes of the micro-LED device 120 (for example, the first electrode 140a and the second electrode 140b to be described later) can be ) and the bond pads 132 on the receiving substrate 130 are aligned with each other. Next, by moving the micro-LED carrier plate downward along the Z-axis direction, the micro-LED element 120 can be bonded to the receiving substrate 130 . After that, the micro-LED device 120 can be separated from the substrate 110 of the micro-LED carrier board to complete the transfer process of the micro-LED device.

Referring to FIG. 1A , a plurality of bonding pads 132 are disposed on the upper surface of the receiving substrate 130 . The receiving substrate may be, for example, but not limited to, a display substrate, a light-emitting substrate, a substrate having functional elements such as thin film transistors or integrated circuits (ICs), or other types of circuit substrates. The bonding pads 132 can be melted and brought into contact with the micro LED elements 120 by heating. Next, the bonding pads 132 are cooled to a solid state so that the micro LED elements 120 are firmly bonded to the receiving substrate 130 . The bonding pads 132 can provide physical and electrical connections between the micro LED device 120 and the receiving substrate 130 . The bond pads 132 may comprise suitable metallic materials such as gold, silver, aluminum, tin, indium, alloys of the foregoing, or combinations thereof.

2A and 2B are schematic cross-sectional views of the micro LED device 120 according to some embodiments of the present invention. Referring to FIG. 2A, the micro LED device 120 includes a first semiconductor layer 122, a light emitting layer 124, a second semiconductor layer 126, an insulating layer 128, a first electrode 140a, and a second electrode 140b. In some embodiments, the first semiconductor layer 122 is an n-type semiconductor layer, and the second semiconductor layer 126 is a p-type semiconductor layer. In other embodiments, the first semiconductor layer 122 is a p-type semiconductor layer, and the second semiconductor layer 126 is an n-type semiconductor layer. The light emitting layer 124 is disposed between the first semiconductor layer 122 and the second semiconductor layer 126 . The first electrode 140a and the second electrode 140b are disposed on the second semiconductor layer 126, and the first electrode 140a passes through the second semiconductor layer 126 and the light-emitting layer 124 and extends into the first semiconductor layer 122, and is connected with the first semiconductor layer 122 direct contact. The insulating layer 128 is disposed between the first electrode 140a and the light-emitting layer 124 and between the first electrode 140a and the second semiconductor layer 126 to prevent the first electrode 140a from contacting the light-emitting layer 124 and the second semiconductor layer 126 .

Please refer to FIG. 2B, the micro LED device 120 shown in FIG. 2B is similar to the micro LED device 120 shown in FIG. 2A, the difference is the micro LED shown in FIG. 2B The body element 120 has sloped side walls. In other words, the miniature light-emitting diode element 120 shown in FIG. 2B is a trapezoid with a narrow top and a wide bottom. In FIGS. 2A and 2B, the micro LED element 120 has a lower surface 120a and an upper surface 120b. It should be noted that in Figure 1A, the micro LED elements 120 are upside down. In other words, the lower surface 120 a of the micro LED element 120 faces the substrate 110 , and the upper surface 120 b faces the receiving substrate 130 . If the micro LED device 120 shown in FIG. 2B is used for the transfer process, the micro LED device 120 bonded to the receiving substrate 130 is an inverted trapezoid with a wide upper part and a narrow lower part.

The miniature light-emitting diode device 120 shown in FIGS. 2A and 2B is only an example, and is not intended to be limiting. The cross-sectional profile of the micro LED device 120 can be rectangular, trapezoidal, inverted trapezoidal, other suitable shapes, or a combination thereof. In FIG. 1A , in order to simplify the illustration, the cross-sectional outline of the micro LED element 120 is only represented by a rectangle.

Still referring to FIG. 1A , the micro-LED carrier board includes a substrate structure and a plurality of micro-LED elements 120 . The substrate structure has a first surface (ie, upper surface) 110a and a second surface (ie, lower surface) 110b. The micro LED elements 120 form an array and are disposed on the second surface 110b of the substrate structure. The substrate structure includes a substrate 110 and a bonding layer 150 . The substrate 110 can carry and support the micro LED elements 120 during the transfer process. For example, the substrate 110 may be a plastic substrate, a ceramic substrate, a glass substrate or a sapphire substrate. The bonding layer 150 can temporarily fix the micro light-emitting diode device 120 on the lower surface of the substrate 110 during the transfer process. After the micro light emitting diode element 120 is bonded to the receiving substrate 130 , the bonding layer 150 and the micro light emitting diode element 120 can be separated by a suitable method. For example, the bonding layer 150 may be a photodecomposable or thermally decomposed adhesive material. Therefore, the adhesive force of the bonding layer 150 can be reduced by illuminating or heating, so that the bonding layer 150 and the micro light emitting diode element 120 can be separated from each other.

FIG. 1B is a schematic top view of the micro LED carrier of FIG. 1A, and FIG. 1A is drawn along the section line A-A' in FIG. 1B. 1A and 1B, when the substrate structure is viewed from a direction perpendicular to the substrate 110 (ie, the Z-axis direction), the substrate structure has a central area 10 and a peripheral area 20 outside the central area 10 . In other words, in FIG. 1B , the area surrounded by the dotted box is the central region 10 , and the area between the dotted box and the edge of the substrate 110 is the peripheral region 20 . In order to simplify the illustration, FIG. 1B only shows one row of the micro LED elements 120 , in fact, the micro LED elements 120 are arranged on the micro LED carrier board in an array manner. For example, m×n miniature light-emitting diode elements 120 are arranged in a matrix, and m and n are positive integers greater than 0, generally greater than 10.

The definitions of the central area 10 and the peripheral area 20 are described in detail as follows. When a straight line (eg, section line AA') passes through the center point of the center area 10, the edge of the center area 10, the peripheral area 20, and the edge of the substrate structure in sequence, from the center point of the center area 10 to the edge of the substrate structure has The first straight line distance D1 has a second straight line distance D2 from the center point to the edge of the center area 10 . The second straight-line distance D2 is not greater than 0.8 times the first straight-line distance D1, and is not less than 0.2 times the first straight-line distance D1. In some embodiments, the second linear distance D2 is equal to 0.5 times the first linear distance D1 , as shown in FIG. 1B .

Please refer to FIG. 1A and FIG. 1B at the same time, the substrate structure includes a patterned structure formed on the first surface 110 a of the substrate 110 , and the patterned structure includes a plurality of grooves 115 . The trenches 115 can be formed by a suitable process (eg, an etching process). In some embodiments, the grooves 115 are annular and arranged in a concentric shape when viewed from the Z-axis direction. Referring to FIG. 1B , the substrate 110 is rectangular, and the plurality of grooves 115 are concentric rectangular rings. In this embodiment, all the trenches 115 are formed only in the peripheral region 20 , and each of the trenches 115 is spaced apart from the adjacent trenches 115 by a specific distance. In other words, in this embodiment, the patterned structure has a first pattern density in the central area 10 (the first pattern density is 0), and has a second pattern density in the peripheral area 20 , and the first pattern density is smaller than the second pattern density.

Fig. 1C is an enlarged schematic cross-sectional view of the region R1 in Fig. 1A, and Fig. 1D is an enlarged cross-sectional schematic view of the region R2 in Fig. 1A. Please refer to FIG. 1A and FIG. 1C simultaneously, the trench 115 is not formed in the central region 10 of the substrate 110 . On the other hand, please refer to FIG. 1A and FIG. 1D at the same time, there are a plurality of trenches 115 in the peripheral region 20 of the substrate 110 , and one micro LED element 120 corresponds to at least one trench 115 .

During the transfer process, the micro LED elements 120 are bonded to the receiving substrate 130, typically through a heating process. The high temperature environment easily causes warping or bending of the substrate 110 . For example, the peripheral region 20 (especially, the edge portion) of the substrate 110 may warp toward the receiving substrate 130 . Therefore, the distance between each micro light emitting diode element 120 and the receiving substrate 130 is different. In this case, when the micro LED elements 120 located in the peripheral area 20 contact the receiving substrate 130 , the micro LED elements 120 located in the central area 10 are still separated from the receiving substrate 130 by a distance. In order to make the micro LED elements 120 located in the central area 10 contact the receiving substrate 130, the substrate 110 needs to be pressed by the conveying holder 102, so as to keep the micro LED carrier moving downward. As a result, the micro LED elements 120 located in the peripheral region 20 will be subject to great pressure, and will be damaged or destroyed accordingly.

In this embodiment, a plurality of trenches 115 are formed on the first surface 110 a of the peripheral region 20 of the substrate 110 . The distance between the substrates 110 on both sides of the trench 115 is variable. Therefore, when thermal energy is conducted into the substrate 110, the distance between the substrates 110 on both sides of the trench 115 may become larger or smaller. In this way, the degree of warpage of the substrate 110 can be reduced. Furthermore, when the micro LED elements 120 located in the peripheral region 20 are in contact with the receiving substrate 130 , the micro LED elements can be reduced or alleviated by changing the distance between the substrates 110 on both sides of the trench 115 . 120 under pressure. Therefore, damage or destruction of the micro LED elements 120 can be reduced or avoided. The micro light-emitting diode carrier provided in this embodiment can reduce the degree of warpage of the substrate 110 . Furthermore, even if the substrate 110 is warped or bent, the micro LED carrier provided in this embodiment can reduce or prevent the micro LED element 120 from being damaged or destroyed. In this way, the reliability, yield and durability of the micro light-emitting diode structure can be greatly improved.

If the depth of the trench 115 is too small, the degree of variation in the distance between the substrates 110 on both sides of the trench 115 is too small. Therefore, it is difficult to reduce the degree of warpage of the substrate 110 , and it is also difficult to reduce the pressure on the micro light-emitting diode element 120 . As a result, it is not conducive to improving the reliability, yield and durability of the micro light-emitting diode structure. On the other hand, if the depth of the grooves 115 is too great (eg, close to the thickness of the substrate 110 ), the substrate 110 may be damaged or cracked when the transport holder 102 applies pressure to the substrate 110 . Therefore, the position of the micro LED element 120 may be shifted, and the micro LED element 120 may also be damaged. As a result, it is also unfavorable to improve the yield of the micro light-emitting diode structure. The depth of the trench 115 can be controlled within a specific range. Referring to FIG. 1D, the thickness of the substrate 110 is T1, and each of the trenches 115 has a trench depth T2. In some embodiments, trench depth T2 is 10-70% of thickness T1. In other embodiments, the trench depth T2 is 20-60% of the thickness T1. In yet other embodiments, trench depth T2 is 25-35% of thickness T1.

In Figure 1D, the width of trench 115 is uniform from top to bottom. In some embodiments, the width of the trench 115 is tapered from top to bottom. In this embodiment, the so-called “width of the trench 115 ” refers to the width of the top of the trench 115 . If the width of the trench 115 is too small, the degree of variation in the distance between the substrates 110 on both sides of the trench 115 is too small. Therefore, it is difficult to reduce the degree of warpage of the substrate 110 , and it is also difficult to reduce the pressure on the micro light-emitting diode element 120 . As a result, it is not conducive to improving the reliability, yield and durability of the micro light-emitting diode structure. On the other hand, if the width of the trenches 115 is too large, the trench density decreases. It is also difficult to reduce the degree of warpage of the substrate 110 , and it is also difficult to reduce the pressure on the micro light-emitting diode element 120 . The width of the trench 115 can be controlled within a specific range. Referring to FIG. 1D, the micro LED element 120 has an element width W1, and each of the trenches 115 has a trench width W2. The trench width W2 is smaller than the element width W1. More specifically, in some embodiments, trench width W2 is 5-90% of element width W1. In other embodiments, the trench width W2 is 10-60% of the device width W11. In yet other embodiments, the trench width W2 is 15-30% of the element width W1.

The higher the pattern density of the trenches 115 (ie, the number of trenches 115 per unit area) is, the better the effect of reducing the warpage of the substrate 110 is. However, if the pattern density of the trenches 115 is too high or too low, it is difficult to reduce the degree of warpage of the substrate 110 , and it is difficult to reduce the pressure on the micro LED device 120 . The density of the trenches 115 can be controlled within a specific range. For example, the number of trenches 115 overlapping with one micro light emitting diode element 120 is one or more. In this specification, the so-called "micro-LED elements overlap (or correspond to) the trenches" means that the orthographic projection of the micro-LED elements on the XY plane overlaps with the orthographic projection of the trenches on the XY plane ( or corresponding). In this embodiment, the number of trenches 115 overlapping with one micro light-emitting diode element 120 is two, as shown in FIG. 1D . In other embodiments, the number of trenches 115 overlapping with one micro LED element 120 is three. In still other embodiments, the number of trenches 115 overlapping one micro LED element 120 is four.

FIG. 3A is a schematic cross-sectional view corresponding to the transfer process of the micro LED device according to other embodiments of the present invention. FIG. 3B is a schematic top view of the micro LED carrier of FIG. 3A, and FIG. 3A is drawn along the section line A-A' in FIG. 3B. Fig. 3C is an enlarged schematic cross-sectional view of the region R3 in Fig. 3A. FIG. 3D is an enlarged schematic cross-sectional view of the region R4 in FIG. 3A. Figures 3A to 3D are similar to Figures 1A to 1D, respectively. In FIGS. 3A to 3D, the same elements as those shown in FIGS. 1A to 1D are denoted by the same reference numerals. In order to simplify the description, the same components and their forming process steps shown in FIGS. 1A to 1D will not be described in detail here.

The micro LED carrier shown in FIG. 3A is similar to the micro LED carrier shown in FIG. 1A, except that the substrate 110 shown in FIG. 3A includes a first groove 115a and a second Two trenches 115b. Please refer to FIG. 3A and FIG. 3B at the same time, when viewed from the Z-axis direction, the first trenches 115 a and the second trenches 115 b are both annular and arranged in a concentric shape. The first trench 115 a is formed in the peripheral region 20 , and the second trench 115 b is formed in the central region 10 . In the central area 10, two adjacent second trenches 115b are separated by a first distance S1. In the peripheral region 20, two adjacent first trenches 115a are separated by a second distance S2. The second distance S2 is smaller than the first distance S1. In other words, in this embodiment, the patterned structure has a first pattern density in the central area 10 and a second pattern density in the peripheral area 20 , and the first pattern density is smaller than the second pattern density.

In some cases, the central region 10 of the substrate 110 may also warp. The degree of warpage in the central region 10 may be slightly less than the degree of warpage in the peripheral region 20 . In this embodiment, the first trench 115 a and the second trench 115 b are respectively formed on the peripheral region 20 and the central region 10 of the substrate 110 . As described above, the degree of warpage of the substrate 110 can be reduced, and damage or destruction of the micro LED elements 120 can be reduced or avoided. In this way, the reliability, yield and durability of the micro light-emitting diode structure can be greatly improved. Furthermore, in this embodiment, the pattern density of the patterned structure is adjusted according to the degree of warpage. For example, in regions with a higher degree of warpage, the pattern density of the patterned structure is higher. Therefore, the reliability, yield and durability of the miniature light emitting diode structure can be further improved. In order to significantly reduce the degree of warpage of the substrate 110, the ratio S2/S1 of the second pitch S2 to the first pitch S1 can be controlled within a specific range. In some embodiments, the ratio S2/S1 of the second pitch S2 to the first pitch S1 is 0.1-0.8. In other embodiments, the ratio S2/S1 of the second distance S2 to the first distance S1 is 0.2-0.6. In still other embodiments, the ratio S2/S1 of the second pitch S2 to the first pitch S1 is 0.3-0.4.

In addition, the depth Ta1 of the first trench 115a and the depth Tb1 of the second trench 115b may be the same as or different from each other. In some embodiments, the depth Ta1 of the first trench 115a and the depth Tb1 of the second trench 115b independently fall within the aforementioned ranges of the trench depth T2. The width Wa1 of the first trench 115a and the width Wb1 of the second trench 115b may be the same as or different from each other. In some embodiments, the width Wa1 of the first trench 115a and the width Wb1 of the second trench 115b independently fall within the aforementioned ranges of the trench width W2.

FIG. 4 is a schematic top view of the substrate 110 according to other embodiments of the present invention. The substrate 110 shown in FIG. 4 is similar to the substrate 110 shown in FIG. 1B , and the difference lies in the arrangement of the grooves 115X shown in FIG. 4 . Referring to FIG. 4 , when viewed from the Z-axis direction, a plurality of trenches 115X are spaced apart from each other, and each of the trenches 115X extends from the edge of the substrate 110 to the central region 10 . In this embodiment, all the trenches 115X are formed only in the peripheral region 20 . Therefore, if the warpage degree of the peripheral region 20 is significantly greater than that of the central region 10 , the reliability, yield and durability of the micro LED structure can be greatly improved by using the micro light emitting diode carrier of this embodiment. sex. In some embodiments, the depth of the trench 115X falls within the aforementioned range of the trench depth T2, and the width of the trench 115X falls within the aforementioned range of the trench width W2.

FIG. 5 is a schematic top view of the substrate 110 according to other embodiments of the present invention. The substrate 110 shown in FIG. 5 is similar to the substrate 110 shown in FIG. 4 , except that the substrate 110 shown in FIG. 5 is circular. Referring to FIG. 5 , when viewed from the Z-axis direction, a plurality of trenches 115Y are spaced apart from each other, and each of the trenches 115Y extends from the edge of the substrate 110 to the central region 10 . Furthermore, all the trenches 115Y are formed only in the peripheral region 20 . As described above, if the warpage degree of the peripheral region 20 is significantly greater than that of the central region 10 , the use of the micro-LED substrate of this embodiment can greatly improve the reliability and yield of the micro-LED structure and durability. In some embodiments, the depth of trench 115Y falls within the aforementioned range of trench depth T2, and the width of trench 115Y falls within the aforementioned range of trench width W2.

FIG. 6A is a schematic cross-sectional view corresponding to the transfer process of the miniature light-emitting diode device according to other embodiments of the present invention. FIG. 6B is a schematic top view of the micro LED carrier of FIG. 6A, and FIG. 6A is drawn along the section line A-A' in FIG. 6B. Figures 6A and 6B are similar to Figures 1A and 1B, respectively. In FIGS. 6A and 6B, the same elements as those shown in FIGS. 1A and 1B are denoted by the same reference numerals. In order to simplify the description, the same components and their forming process steps shown in FIGS. 1A to 1D will not be described in detail here.

Referring to FIG. 6A , the patterned structure includes a buffer material 145 formed on the first surface 110 a of the substrate 110 . Referring to FIG. 6B , when viewed from the Z-axis direction, the buffer material 145 is located in the peripheral region 20 and surrounds the central region 10 . In this embodiment, the buffer material 145 is formed on the first surface 110 a of the peripheral region 20 of the substrate 110 . When the conveying holder 102 exerts pressure on the substrate 110 that is bent due to thermal stress (eg, the edge of the substrate 110 approaches the receiving substrate 130 ), the pressure on the central area 10 and the peripheral area 20 can be balanced by the provision of the buffer material 145 . In this way, the reliability, yield and durability of the micro light-emitting diode structure can be greatly improved.

In order to balance the pressure on the micro light-emitting diode elements 120 in the central area 10 and the peripheral area 20 , the position and thickness of the buffer material 145 can be controlled within a specific range. Referring to FIG. 6A, the thickness of the substrate 110 is T1, and the buffer material 145 has a thickness T3. In some embodiments, the thickness T3 of the buffer material 145 is 5-30% of the thickness T1 of the substrate 110 . In some embodiments, in order to further reduce thermal stress build-up, the material of the buffer material 145 may have a high thermal conductivity, eg, a thin metal film. Furthermore, in order to provide better cushioning effect, the material of the cushioning material 145 may have a low Young's modulus. In some embodiments, the material of the buffer material 145 may be an organic material with a Young's coefficient ranging from 2.5 GPa to 10 GPa, for example, benzocyclobutene (BCB), polyimide (PI) or other suitable organic materials Material.

In Fig. 6A, the width of the buffer material 145 is uniform from the top to the bottom. In some embodiments, the width of the buffer material 145 gradually narrows from top to bottom. In this specification, the "width of the buffer material 145" refers to the width of the top portion of the buffer material 145 (that is, the portion in contact with the conveyance holder 102). In order to disperse the pressure more effectively in the entire micro light-emitting diode carrier, the width of the buffer material 145 can be controlled within a specific range. Referring to FIG. 6A, the width of the peripheral region 20 is W4, and the buffer material 145 has a width W3. In some embodiments, the width W3 of the buffer material 145 is 20-90% of the width W4. In other embodiments, the width W3 of the buffer material 145 is 30-70% of the width W4. In still other embodiments, the width W3 of the buffer material 145 is 40-60% of the width W4.

FIG. 7 is a schematic cross-sectional view corresponding to the transfer process of the micro LED device according to other embodiments of the present invention. Figure 7 is similar to Figure 1A. In Fig. 7, the same elements as those shown in Fig. 1A are denoted by the same reference numerals. In order to simplify the description, the same components and their forming process steps shown in FIG. 1A will not be described in detail here.

Referring to FIG. 7 , the patterned structure includes a protruding portion 155 formed on the first surface 110 a of the substrate 110 . The protrusions 155 may be formed by partially etching and removing the peripheral region 20 of the substrate 110 . The protrusion 155 is located in the center region 10 when viewed from the Z-axis direction. In this embodiment, the protruding portion 155 is formed on the first surface 110 a of the central region 10 of the substrate 110 . When the transport holder 102 applies pressure to the substrate 110 , the pressure is concentrated in the central region 10 . Furthermore, the substrate 110 located in the peripheral area 20 does not directly contact the conveying holder 102 , and there is a partial space between the substrate 110 and the conveying holder 102 . When the transport holder 102 applies pressure to the substrate 110 , most of the pressure is applied to the central region 10 , thereby reducing or alleviating the pressure on the micro LED elements 120 located in the peripheral region 20 . Therefore, damage or destruction of the micro LED elements 120 in the peripheral region 20 can be reduced or avoided. In this way, the reliability, yield and durability of the micro light-emitting diode structure can be greatly improved.

In order to significantly reduce the pressure on the micro light-emitting diode elements 120 located in the peripheral region 20, the height of the protruding portion 155 can be controlled within a specific range. Referring to FIG. 7 , the thickness of the central region 10 of the substrate 110 is T1 , and the protruding portion 155 has a protruding portion height T4 . In some embodiments, the protrusion height T4 is 5-50% of the thickness T1. In other embodiments, the protrusion height T4 is 10-30% of the thickness T1. If the height T4 of the protruding portion is too large, the central area 10 will be subjected to a force far more than the peripheral area 20 . This will cause the miniature light-emitting diode elements 120 in the central region 10 to be crushed. On the other hand, if the protrusion height T4 is too small, the pressure on the peripheral region 20 cannot be significantly reduced.

FIG. 8 is a schematic cross-sectional view corresponding to the transfer process of the micro LED device according to other embodiments of the present invention. Figure 8 is similar to Figure 1A. In Fig. 8, the same elements as those shown in Fig. 1A are denoted by the same reference numerals. In order to simplify the description, the same components and their forming process steps shown in FIG. 1A will not be described in detail here.

Referring to FIG. 8 , the patterned film 160 is attached to the first surface 110 a of the substrate 110 . The patterned film 160 includes a flat portion 160a and a protruding portion 160b. In some embodiments, a thin film may be fully formed on the first surface 110 a , and then the thin film in the peripheral region 20 may be partially removed to form the patterned film 160 . In other embodiments, a thin film may be formed entirely on the first surface 110 a, and then the same thin film may be partially formed only in the central region 10 , thereby forming the patterned film 160 . The protrusion 160b is located in the center region 10 when viewed from the Z-axis direction. In this embodiment, the protruding portion 160b is formed on the first surface 110a of the central region 10 of the substrate 110 . As described above, when the conveying holder 102 exerts pressure on the substrate 110 , the pressure is concentrated in the central area 10 , and the pressure on the micro LED elements 120 located in the peripheral area 20 can be reduced or moderated. Therefore, damage or destruction of the micro LED elements 120 can be reduced or avoided. In this way, the reliability, yield and durability of the micro light-emitting diode structure can be greatly improved. In some embodiments, to further reduce thermal stress build-up, the material of the patterned film 160 may have a high thermal conductivity, eg, a thin metal film. Furthermore, in order to provide better buffering effect, the material of the patterned film 160 may have a low Young's modulus. In some embodiments, the material of the patterned film 160 may be an organic material with a Young's coefficient ranging from 2.5 GPa to 10 GPa, for example, benzocyclobutene (BCB), polyimide (PI), or other suitable materials of organic materials.

In order to significantly reduce the pressure on the micro light-emitting diode elements 120 located in the peripheral region 20, the height of the protruding portion 160b can be controlled within a specific range. Referring to FIG. 8, the thickness of the substrate 110 is T1, and the protruding portion 160b has a protruding portion height T5. In some embodiments, the protrusion height T5 is 5-50% of the thickness T1 of the substrate 110 . In other embodiments, the protrusion height T5 is 10-30% of the thickness T1 of the substrate 110 .

In order to concentrate the pressure on the central area 10 more effectively, the width of the protrusion 160b may be controlled within a specific range. Referring to FIG. 8, the width of the substrate 110 is W6, and the protruding portion 160b has a protruding portion width W5. In some embodiments, protrusion width W5 is 5-70% of width W6. In other embodiments, the protrusion width W5 is 10-50% of the width W6. In yet other embodiments, protrusion width W5 is 15-25% of width W6. In this embodiment, the protrusion width W5 is 50% of the width W6.

In addition, if the thermal expansion coefficient of the bonding layer 150 is different from the thermal expansion coefficient of the substrate 110 , the substrate 110 may also be warped or bent. In this case, if the patterned film 160 having the same or similar thermal expansion coefficient as the bonding layer 150 is formed on the first surface 110a, the thermal stress on the upper and lower surfaces of the substrate 110 can cancel each other. In this way, warping or bending of the substrate 110 can also be avoided, thereby greatly improving the reliability, yield and durability of the micro light emitting diode structure. In some embodiments, the thermal expansion coefficient and thickness of the patterned film 160 are the same as or similar to the thermal expansion coefficient and thickness of the bonding layer 150 .

FIG. 9A is a schematic cross-sectional view corresponding to the transfer process of the miniature light-emitting diode device according to other embodiments of the present invention. Fig. 9B is a schematic bottom view of the micro LED carrier of Fig. 9A, and Fig. 9A is drawn along the section line A-A' in Fig. 9B. Fig. 9C is an enlarged schematic cross-sectional view of the region R5 in Fig. 9A. Fig. 9D is an enlarged schematic cross-sectional view of the region R6 in Fig. 9A. Figures 9A to 9D are similar to Figures 1A to 1D, respectively. In FIGS. 9A to 9D, the same elements as those shown in FIGS. 1A to 1D are denoted by the same reference numerals. In order to simplify the description, the same components and their forming process steps shown in FIGS. 1A to 1D will not be described in detail here.

The micro-LED carrier shown in FIG. 9A is similar to the micro-LED carrier shown in FIG. 1A , and the difference lies in the location of the grooves 115 shown in FIG. 9A . Please refer to FIGS. 9A to 9D at the same time, a patterned structure is formed on the second surface 110 b of the substrate 110 , and the patterned structure includes a plurality of grooves 115 . The trenches 115 can be formed by a suitable process (eg, an etching process). In some embodiments, the grooves 115 are annular and arranged in a concentric shape when viewed from the Z-axis direction. The substrate 110 is rectangular, and the plurality of grooves 115 are concentric rectangular rings, as shown in FIG. 9B . In the peripheral region 20 of the substrate 110, one micro LED element 120 corresponds to at least one trench 115, as shown in FIG. 9D. In this embodiment, all the trenches 115 are formed only in the peripheral region 20 , and each of the trenches 115 is spaced apart from the adjacent trenches 115 by a specific distance. In other words, in this embodiment, the patterned structure has a first pattern density in the central area 10 (the first pattern density is 0), and has a second pattern density in the peripheral area 20 , and the first pattern density is smaller than the second pattern density.

As mentioned above, different thermal expansion coefficients among materials or uneven heating process may cause warpage or bending of the substrate 110 . In this embodiment, by forming the grooves 115 on the second surface 110b, the substrate 110 and the bonding layer 150 in the peripheral region 20 can be made discontinuous. In other words, in the peripheral region 20, warpage or bending due to differences in thermal expansion coefficients can be reduced or avoided. In this way, the damage or destruction of the micro light emitting diode element 120 can be reduced or avoided, thereby greatly improving the reliability, yield and durability of the micro light emitting diode structure.

Referring to FIG. 9D, the thickness of the bonding layer 150 is T6, and each of the trenches 115 has a trench depth T7. The trench depth T7 is greater than the thickness T6.

In Figure 9D, the width of trench 115 is uniform from top to bottom. In some embodiments, the width of the trench 115 gradually narrows from the bonding layer 150 to the substrate 110 . In this specification, "the width of the trench 115" refers to the width of the portion of the trench 115 where the bonding layer 150 is in contact with the micro light emitting diode element 120. If the width of the trench 115 is too small, it is difficult to reduce the warpage degree of the substrate 110 . On the other hand, if the width of the trench 115 is too large (eg, larger than the width of the micro LED device 120 ), the bonding layer 150 does not exist at the position of the trench and cannot be bonded to the micro LED device 120 . The width of the trench 115 can be controlled within a specific range. Referring to FIG. 9D, the micro LED element 120 has an element width W1, and each of the trenches 115 has a trench width W2. The trench width W2 is smaller than the element width W1. More specifically, in some embodiments, trench width W2 is 5-50% of element width W1. In other embodiments, the trench width W2 is 10-35% of the element width W11 , and each micro LED element 120 corresponds to a plurality of trenches 115 .

The higher the pattern density of the trenches 115 (ie, the number of trenches 115 per unit area) is, the better the effect of reducing the warpage of the substrate 110 is. However, if the pattern density of the trenches 115 is too high, the adhesion of the bonding layer 150 to the light-emitting diode element 120 is insufficient, which may easily cause the light-emitting diode element 120 to fall off. If the pattern density of the trenches 115 is too low, it is difficult to reduce the degree of warpage of the substrate 110 , and it is also difficult to reduce the pressure on the micro light-emitting diode element 120 . The density of the trenches 115 can be controlled within a specific range. For example, the number of trenches 115 overlapping with one micro light emitting diode element 120 is one or more. In this embodiment, the number of trenches 115 overlapping with one micro light-emitting diode element 120 is two, as shown in FIG. 9D . In other embodiments, the number of trenches 115 overlapping with one micro LED element 120 is three. In still other embodiments, the number of trenches 115 overlapping one micro LED element 120 is four.

FIG. 10A is a schematic cross-sectional view corresponding to the transfer process of the micro light-emitting diode device according to other embodiments of the present invention. FIG. 10B is a schematic bottom view of the micro LED carrier of FIG. 10A, and FIG. 10A is drawn along the section line A-A' in FIG. 10B. Fig. 10C is an enlarged schematic cross-sectional view of the region R7 in Fig. 10A. Fig. 10D is an enlarged schematic cross-sectional view of the region R8 in Fig. 10A. Figures 10A to 10D are similar to Figures 3A to 3D, respectively. In FIGS. 10A to 10D , the same elements as those shown in FIGS. 3A to 3D are denoted by the same reference numerals. In order to simplify the description, the same components and their forming process steps shown in FIGS. 3A to 3D will not be described in detail here.

The micro-LED carrier shown in FIG. 10A is similar to the micro-LED carrier shown in FIG. 3A, and the difference lies in the first groove 115a and the second groove shown in FIG. 10A The location of 115b is different. 10A to 10D, a patterned structure is formed on the second surface 110b of the substrate 110, and the patterned structure includes a plurality of first trenches 115a and a plurality of second trenches 115b. When viewed from the Z-axis direction, the first trenches 115 a and the second trenches 115 b are both annular and arranged in a concentric shape. In this embodiment, the substrate 110 is rectangular, and the plurality of grooves 115 are concentric rectangular rings, as shown in FIG. 10B . The first trench 115 a is formed in the peripheral region 20 , and the second trench 115 b is formed in the central region 10 . In the central area 10, two adjacent second trenches 115b are separated by a first distance S1. In the peripheral region 20, two adjacent first trenches 115a are separated by a second distance S2. The second distance S2 is smaller than the first distance S1. In other words, in this embodiment, the patterned structure has a first pattern density in the central area 10 and a second pattern density in the peripheral area 20 , and the first pattern density is smaller than the second pattern density.

In this embodiment, the first trench 115 a and the second trench 115 b are respectively formed on the peripheral region 20 and the central region 10 of the substrate 110 . As described above, the degree of warpage of the substrate 110 can be reduced, and damage or destruction of the micro LED elements 120 can be reduced or avoided. In this way, the reliability, yield and durability of the micro light-emitting diode structure can be greatly improved. Furthermore, in this embodiment, the pattern density of the patterned structure is adjusted according to the degree of warpage. Therefore, the reliability, yield and durability of the miniature light emitting diode structure can be further improved. The ratio S2/S1 of the second pitch S2 to the first pitch S1 can be controlled within a specific range. In some embodiments, the ratio S2/S1 of the second pitch S2 to the first pitch S1 is 0.1-0.8. In other embodiments, the ratio S2/S1 of the second distance S2 to the first distance S1 is 0.2-0.6. In still other embodiments, the ratio S2/S1 of the second pitch S2 to the first pitch S1 is 0.3-0.4.

In addition, the depth Ta2 of the first trench 115a and the depth Tb2 of the second trench 115b may be the same or different from each other. In some embodiments, the depth Ta2 of the first trench 115a and the depth Tb2 of the second trench 115b are each independently greater than the thickness T6 of the bonding layer 150 . The width Wa2 of the first trench 115a and the width Wb2 of the second trench 115b may be the same as or different from each other. In some embodiments, the width Wa2 of the first trench 115a and the width Wb2 of the second trench 115b independently fall within the aforementioned ranges of the trench width W2.

FIG. 11 is a schematic cross-sectional view corresponding to the transfer process of the micro LED device according to other embodiments of the present invention. Figure 11 is similar to Figure 1A. In Fig. 11, the same elements as those shown in Fig. 1A are denoted by the same reference numerals. In order to simplify the description, the same components and their forming process steps shown in FIG. 1A will not be described in detail here.

Referring to FIG. 11 , in this embodiment, the micro light-emitting diode carrier includes a substrate structure having a central area 10 and a peripheral area 20 . The substrate structure includes a substrate 110 and a bonding layer 150 formed on the lower surface of the substrate 110 . The micro LED carrier board includes a plurality of micro LED elements 120 disposed on the bonding layer 150 to form an array. The bonding layer 150 has a first thickness T8 in the central region 10 and a second thickness T9 in the peripheral region 20 . The first thickness T8 is different from the second thickness T9. In this embodiment, the first thickness T8 is greater than the second thickness T9. In other words, the bonding layer 150 is a patterned bonding layer. The bonding layer 150 may be fully formed on the lower surface of the substrate 110 , and then the bonding layer 150 in the peripheral region 20 may be partially removed, thereby forming the patterned bonding layer 150 as shown in FIG. 11 . In other embodiments, the bonding layer 150 may be fully formed on the second surface 110b, and then the bonding layer 150 may only be partially formed in the central region 10, thereby forming the patterned bonding layer 150 as shown in FIG. 11 . . In this embodiment, the bonding layer 150 is a patterned structure formed on the lower surface of the substrate 110 .

As described above, if the thermal expansion coefficient of the bonding layer 150 is different from the thermal expansion coefficient of the substrate 110 , the substrate 110 may be warped or bent. In this embodiment, the thickness of the patterned bonding layer 150 in the central region 10 is greater than that in the peripheral region 20 . When the micro LED elements 120 located in the central area 10 contact the receiving substrate 130 , thermal energy is conducted into the substrate 110 , and the peripheral area 20 of the substrate 110 is warped toward the receiving substrate 130 . When the substrate 110 is warped, the micro LED elements 120 located in the peripheral region 20 will move downward to contact the receiving substrate 130 . In this embodiment, the transport holder 102 can fix the substrate 110 at this specific height position without applying additional pressure to the substrate 110 . In other words, in this embodiment, all the micro light-emitting diode elements 120 can be bonded to the receiving substrate 130 by warping of the patterned bonding layer 150 and the substrate 110 . In this way, damage to the micro light emitting diode element 120 due to pressure can be avoided, thereby greatly improving the reliability, yield and durability of the micro light emitting diode structure.

In order to make the micro light emitting diode elements 120 located in the peripheral region 20 contact with the receiving substrate 130, the ratio T8/T9 of the first thickness T8 to the second thickness T9 can be controlled within a specific range. In some embodiments, the ratio T8/T9 of the first thickness T8 to the second thickness T9 is 1.1-3.0. In other embodiments, the ratio T8/T9 of the first thickness T8 to the second thickness T9 is 1.3-2.0.

It should be understood that the shapes of the substrate 110 shown in FIG. 1B and FIG. 5 are for illustration only, and are not intended to limit the present invention. For example, when the substrate 110 is viewed from the Z-axis direction, the substrate 110 may be a triangle, a parallelogram, a regular polygon, an irregular polygon, an ellipse, or other suitable shapes. Furthermore, the number of grooves and their arrangement are only used for illustration, and are not used to limit the present invention. In addition, the shape of the bonding layer 150 shown in FIG. 11 is only for illustration, and is not intended to limit the present invention. For example, the cross-sectional profile of the bonding layer 150 may also be a triangle or a trapezoid that gradually becomes thinner from the central area 10 to the peripheral area 20 . Those with ordinary knowledge in the technical field to which the present invention pertains can arbitrarily modify or combine the technical concepts disclosed in the embodiments of the present specification. For example, in FIG. 1B , the substrate 110 can be circular, and the plurality of grooves 115 are concentric circular rings. For example, the trenches 115X of FIG. 4 or the trenches 115Y of FIG. 5 may be formed on the second surface (ie, the lower surface) of the substrate.

To sum up, in the micro light-emitting diode carrier provided by the embodiments of the present invention, a patterned structure is formed on the first surface or the second surface of the substrate structure, thereby reducing or preventing the substrate structure from warping or Bending, or alternatively, can reduce or avoid damage to the micro LED elements during the transfer process. In this way, the reliability, yield and durability of the micro light-emitting diode structure can be greatly improved.

Although the present invention has been disclosed above with several preferred embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make any changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the appended patent application.

10: Central area 20: towards the surrounding area 102: Conveyor holder 110: Substrate 110a: First surface 110b: Second surface 115, 115X, 115Y: Groove 115a: first groove 115b: Second groove 120: Miniature Light Emitting Diode Components 120a: Upper surface 120b: lower surface 122: the first semiconductor layer 124: light-emitting layer 126: second semiconductor layer 128: Insulation layer 130: Receiving substrate 132: Bond pads 140a: first electrode 140b: second electrode 145: Buffer material 150: Bonding layer 155: Protrusion 160: Patterned film 160a: Flat part 160b: Protrusion D1: The first straight-line distance D2: The second straight-line distance R1, R2, R3, R4, R5, R6, R7, R8: Region S1: The first spacing S2: Second spacing T1: substrate thickness T2, T7: groove depth T3: Thickness of buffer material T4, T5: Protrusion height T6: Bonding Layer Thickness T8: first thickness T9: Second thickness Ta1, Ta2, Tb1, Tb2: trench depth W1: Component width W2: groove width W3: Buffer width W4: Peripheral area width W5: Projection width W6: substrate width Wa1, Wa2, Wb1, Wb2: trench width

The content of the embodiments of the present invention can be better understood through the following detailed description in conjunction with the accompanying drawings. It is emphasized that, in accordance with standard industry practice, many features are not drawn to scale. In fact, the dimensions of the various components may be arbitrarily increased or decreased for clarity of discussion. FIG. 1A is a schematic cross-sectional view corresponding to the transfer process of the micro LED device according to some embodiments of the present invention. FIG. 1B is a schematic top view of the micro LED carrier of FIG. 1A . Fig. 1C is an enlarged schematic cross-sectional view of the region R1 in Fig. 1A. Fig. 1D is an enlarged schematic cross-sectional view of the region R2 in Fig. 1A. 2A and 2B are schematic cross-sectional views of micro LED devices according to some embodiments of the present invention. FIG. 3A is a schematic cross-sectional view corresponding to the transfer process of the micro LED device according to other embodiments of the present invention. FIG. 3B is a schematic top view of the micro-LED carrier of FIG. 3A . Fig. 3C is an enlarged schematic cross-sectional view of the region R3 in Fig. 3A. FIG. 3D is an enlarged schematic cross-sectional view of the region R4 in FIG. 3A. FIG. 4 is a schematic top view of a substrate according to other embodiments of the present invention. FIG. 5 is a schematic top view of a substrate according to other embodiments of the present invention. FIG. 6A is a schematic cross-sectional view corresponding to the transfer process of the miniature light-emitting diode device according to other embodiments of the present invention. FIG. 6B is a schematic top view of the micro LED carrier of FIG. 6A . FIG. 7 is a schematic cross-sectional view corresponding to the transfer process of the micro LED device according to other embodiments of the present invention. FIG. 8 is a schematic cross-sectional view corresponding to the transfer process of the micro LED device according to other embodiments of the present invention. FIG. 9A is a schematic cross-sectional view corresponding to the transfer process of the miniature light-emitting diode device according to other embodiments of the present invention. FIG. 9B is a schematic bottom view of the micro LED carrier of FIG. 9A . Fig. 9C is an enlarged schematic cross-sectional view of the region R5 in Fig. 9A. Fig. 9D is an enlarged schematic cross-sectional view of the region R6 in Fig. 9A. FIG. 10A is a schematic cross-sectional view corresponding to the transfer process of the micro light-emitting diode device according to other embodiments of the present invention. FIG. 10B is a schematic bottom view of the micro light-emitting diode carrier of FIG. 10A . Fig. 10C is an enlarged schematic cross-sectional view of the region R7 in Fig. 10A. Fig. 10D is an enlarged schematic cross-sectional view of the region R8 in Fig. 10A. FIG. 11 is a schematic cross-sectional view corresponding to the transfer process of the micro LED device according to other embodiments of the present invention.

10: Central area

20: towards the surrounding area

102: Conveyor holder

110: Substrate

110a: First surface

115: Groove

120: Miniature Light Emitting Diode Components

130: Receiving substrate

132: Bond pads

150: Bonding layer

R1, R2: area

Claims (8)

A miniature light-emitting diode carrier board, comprising: a substrate structure with a first surface and a second surface and a central area and a peripheral area located outside the central area, wherein a straight line passes through the central area in sequence A center point, an edge of the center area, the peripheral area, and an edge of the substrate structure, there is a first linear distance from the center point of the center area to the edge of the substrate structure, from the center point to the center The edge of the area has a second straight-line distance, and the second straight-line distance is greater than 0 and less than the first straight-line distance; a plurality of miniature light-emitting diode elements, wherein the miniature light-emitting diode elements form an array and are located in the on the second surface of the substrate structure; and a patterned structure formed on the first surface or the second surface of the substrate structure, wherein the patterned structure has a first pattern density in the central area, the pattern The chemical structure has a second pattern density in the peripheral area, and the first pattern density is different from the second pattern density, wherein the pattern structure includes: a plurality of grooves formed on the substrate structure, and the grooves The grooves extend from the edge of the substrate structure to the central region and are arranged at intervals. The micro light-emitting diode carrier as claimed in claim 1, wherein the patterned structure comprises: a plurality of grooves formed on the first surface of the substrate structure, wherein in the central area, two adjacent The grooves are separated by a first spacing; in the peripheral region, two adjacent grooves are separated by a second spacing, and the second spacing is smaller than the first spacing. The micro light-emitting diode carrier of claim 1, wherein the grooves are formed only in the peripheral region. The miniature light-emitting diode carrier of claim 1, wherein the substrate structure has a thickness, each of the trenches has a trench depth, and the trench depth is 10-70% of the thickness . The micro LED carrier of claim 1, wherein each of the micro LED elements has an element width, each of the trenches has a trench width, and the trench The slot width is smaller than the element width. The miniature light-emitting diode carrier according to claim 1, wherein the number of grooves overlapping with one miniature light-emitting diode element is more than one. A miniature light-emitting diode carrier board, comprising: a substrate structure with a first surface and a second surface and a central area and a peripheral area located outside the central area, wherein a straight line passes through the central area in sequence A center point, an edge of the center area, the peripheral area, and an edge of the substrate structure, there is a first linear distance from the center point of the center area to the edge of the substrate structure, from the center point to the center The edge of the area has a second straight-line distance, and the second straight-line distance is greater than 0 and less than the first straight-line distance; a plurality of miniature light-emitting diode elements, wherein the miniature light-emitting diode elements form an array and are located in the on the second surface of the substrate structure; and a patterned structure formed on the first surface or the second surface of the substrate structure, wherein the patterned structure has a first pattern density in the central area, the pattern change The structure has a second pattern density in the peripheral area, and the first pattern density is different from the second pattern density, wherein the patterned structure includes: a buffer material formed on the first surface of the substrate structure and located in the peripheral area, wherein the buffer material surrounds the central area. The miniature light-emitting diode carrier as claimed in claim 1, wherein the patterned structure comprises: a protrusion formed on the first surface of the substrate structure and located in the central area.

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