Structure with micro light-emitting device

This application claims the priority benefits of Taiwan application serial no. 106135277, filed on Oct. 16, 2017 and U. S. provisional application Ser. No. 62/607,325, filed on Dec. 19, 2017. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification.

1. Field of the Invention

The invention relates to a semiconductor structure. More specifically, the invention relates to a structure with micro light-emitting device.

2. Description of Related Art

At present, transferring micro light-emitting diodes (LEDs) from a carrier substrate to a receiving substrate is mainly done via forces at distance, such as an electrostatic force or a magnetic force. In general, LEDs are held by a holding structure, so that it is easier to pick up the micro LEDs from the carrier substrate and transport and transfer the micro LEDs to the receiving substrate, and the micro LEDs are secured by the fixing structure, so that the quality of the micro LEDs is not affected by external factors during the transfer. However, because a material of the holding structure is brittle, the holding structure is easily fractured by external forces while the holding structure is holding the micro LEDs during the transportation and transfer, resulting in a decrease in a yield of transporting and transferring the micro LEDs. How to enable the micro holding structure to temporarily hold the micro LEDs and how to transport and transfer the micro LEDs from the carrier substrate to the receiving substrate in an easier and more efficient manner have become an important topic in the industry.

An embodiment of the invention provides a structure with micro light-emitting device, with at least one buffer structure directly contacting a holding structure, so as to effectively enhance a yield of transporting and transferring micro LEDs.

A structure with micro light-emitting device provided in an embodiment of the invention includes a substrate, at least one micro light-emitting device, a holding structure, and at least one buffer structure. The at least one micro light-emitting device is disposed on the substrate, and a vertical distance exists between the at least one micro light-emitting device and the substrate. The holding structure is disposed on the substrate and directly contacts the at least one micro light-emitting device. The at least one buffer structure directly contacts the holding structure, wherein a Young's modulus of the at least one buffer structure is smaller than a Young's modulus of the holding structure.

In an embodiment of the invention, a maximum amount of deformation of the holding structure is less than the vertical distance between the at least one micro light-emitting device and the substrate.

In an embodiment of the invention, the at least one micro light-emitting device has a first surface and a second surface opposite to each other as well as a peripheral surface connecting the first surface and the second surface, the first surface faces the substrate, the second surface is away from the substrate, and the holding structure extends toward the substrate from the peripheral surface and is disposed on the substrate.

In an embodiment of the invention, a gap is between the holding structure and the substrate, the at least one buffer structure includes a plurality of buffer structures located in the gap between the holding structure and the substrate and directly contacting the substrate and the holding structure, and the at least one micro light-emitting device, the buffer structures, and the substrate define an air gap.

In an embodiment of the invention, the buffer structures directly contact at least a portion of the peripheral surface or/and at least a portion of the first surface of the at least one micro light-emitting device.

In an embodiment of the invention, the holding structure directly contacts the substrate, the at least one buffer structure includes a plurality of buffer structures located between the holding structure and the substrate and directly contacting the substrate and the holding structure, and the at least one micro light-emitting device, the buffer structures, and the substrate define an air gap.

In an embodiment of the invention, the buffer structures directly contact at least a portion of the peripheral surface or/and at least a portion of the first surface of the at least one micro light-emitting device.

In an embodiment of the invention, the structure with micro light-emitting device further includes a stress buffer structure disposed between the at least one micro light-emitting device and the substrate and at least directly contacting the at least one micro light-emitting device, the at least one buffer structure, the substrate, or a combination thereof, an orthogonal projection area of the stress buffer structure on the substrate is smaller than an orthogonal projection area of the at least one micro light-emitting device on the substrate.

In an embodiment of the invention, a Young's modulus of the stress buffer structure is less than the Young's modulus of the at least one buffer structure.

In an embodiment of the invention, the at least one buffer structure directly contacts the holding structure, the substrate, and the at least one micro light-emitting device, and the holding structure, the at least one micro light-emitting device, and the substrate define a configuration area filled with the at least one buffer structure.

In an embodiment of the invention, the holding structure further extends onto at least a portion of the second surface of the at least one micro light-emitting device from the peripheral surface.

In an embodiment of the invention, a ratio of a contact area of the holding structure and the second surface to a surface area of the second surface is within a range from 0.05 to 0.5.

In an embodiment of the invention, the holding structure is successively arranged on the second surface of the at least one micro light-emitting device.

In an embodiment of the invention, the holding structure exposes a portion of the second surface of the at least one micro light-emitting device.

In an embodiment of the invention, a ratio of a first width of the holding structure arranged on the second surface of the at least one micro light-emitting device to a second width of the second surface of the at least one micro light-emitting device is within a range from 0.1 to 0.8.

In an embodiment of the invention, the at least one buffer structure includes a plurality of buffer structures disposed between the holding structure, the at least one micro light-emitting device, and the substrate and directly contacting the holding structure, the at least one micro light-emitting device, and the substrate, and a height of each of the at least one buffer structure on a vertical cross-section is equal to a height of the at least one micro light-emitting device on the vertical cross-section from the second surface to the substrate.

In an embodiment of the invention, the at least one buffer structure includes a plurality of buffer structures covering the holding structure and the substrate, the holding structure is located between the at least one micro light-emitting device and the at least one buffer structure, and the holding structure, the at least one micro light-emitting device, and the substrate define an air gap.

In an embodiment of the invention, the holding structure directly contacts at least a portion of the peripheral surface.

In an embodiment of the invention, a ratio of a contact area of the holding structure and the peripheral surface to a surface area of the peripheral surface is within a range from 0.05 to 0.5.

In an embodiment of the invention, a top surface of the holding structure is aligned to the second surface of the at least one micro light-emitting device.

In an embodiment of the invention, the at least one micro light-emitting device includes two micro light-emitting devices, and the holding structure is located between the micro light-emitting devices.

Based on the above, in the structure with micro light-emitting device provided in an embodiment of the invention, the holding structure is disposed on the substrate and directly contacts the at least one micro light-emitting device, and the at least one buffer structure directly contacts the holding structure, wherein the Young's modulus of the at least one buffer structure is smaller than the Young's modulus of the holding structure. Thereby, when the at least one micro light-emitting device is being transported and transferred between different substrates, the holding structure is able to well hold and support the micro light-emitting device, and good buffering effects on the holding structure may be achieved by the at least one buffer structure.

To make the above features and advantages of the invention more comprehensible, several embodiments accompanied with drawings are described in detail as follows.

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

FIG. 1A is a schematic cross-sectional view of a structure with micro light-emitting device according to an embodiment of the invention.

FIG. 1B to FIG. 1H are schematic cross-sectional views of a structure with micro light-emitting device according to several embodiments of the invention.

FIG. 1I is a schematic cross-sectional view of a structure with micro light-emitting device according to another embodiment of the invention.

FIG. 2A is a schematic top view of the structure with micro light-emitting device depicted in FIG. 1A .

FIG. 2B is a schematic top view of the structure with micro light-emitting device depicted in FIG. 1G .

FIG. 2C to FIG. 2H are schematic top views of a structure with micro light-emitting device according to several embodiments of the invention.

FIG. 2I is a schematic top view of a structure with micro light-emitting device according to another embodiment of the invention.

FIG. 1A is a schematic cross-sectional view of a structure with micro light-emitting device according to an embodiment of the invention. FIG. 2A is a schematic top view of the structure with micro light-emitting device depicted in FIG. 1A . The structure with micro light-emitting device 100 a in FIG. 1A is depicted along a sectional line A-A′ of FIG. 2A , and some components are omitted from FIG. 2A for better illustration. Referring to FIG. 1A , the structure with micro light-emitting device 100 a provided in an embodiment of the invention includes a substrate 120 , at least one micro light-emitting device 140 , a holding structure 160 a , and at least one buffer structure 180 a . The micro light-emitting device 140 is disposed on the substrate 120 , and a vertical distance H 1 exists between the micro light-emitting device 140 and the substrate 120 . The holding structure 160 a is disposed on the substrate 120 and directly contacts the micro light-emitting device 140 . The buffer structure 180 a directly contacts the holding structure 160 a , wherein a Young's modulus of the buffer structure 180 a is smaller than a Young's modulus of the holding structure 160 a . Herein, the substrate 120 is a temporary substrate, such as a plastic substrate, a glass substrate, or a sapphire substrate, but the invention is not limited thereto.

In particular, as shown in FIG. 1A , the micro light-emitting device 140 of the embodiment is located on one side of the substrate 120 , and the micro light-emitting device 140 has a first surface 142 and a second surface 144 opposite to each other as well as a peripheral surface 146 connecting the first surface 142 and the second surface 144 , the first surface 142 faces the substrate 120 , and the second surface 144 is away from the substrate 120 . Here, the micro light-emitting device 140 may be a horizontal micro light-emitting device, a flip-chip micro light-emitting device, a vertical micro light-emitting device, or other different types of micro light-emitting devices; the form of the micro light-emitting device 140 is not limited in the invention. That is to say, a light-emitting surface (not shown) of the micro light-emitting device 140 may face the substrate 120 , or the light-emitting surface of the micro light-emitting device 140 disposed on the substrate 120 may face away from the substrate 120 ; the invention is not limited thereto. A cross-sectional shape of the micro light-emitting device 140 of the embodiment is, for example, a trapezoidal shape, but the invention is not limited thereto. Herein, a width of the micro light-emitting device 140 is within a range from 1 μm to 100 μm, and a vertical height H 2 of the micro light-emitting device 140 is within a range from 1 μm to 6 μm, but the invention is not limited thereto. The embodiment schematically illustrates one micro light-emitting device 140 , but the number of the micro light-emitting device 140 disposed on the substrate 120 is not limited in the invention.

Next, referring to both FIG. 1A and FIG. 2A , when viewed from the top of the micro light-emitting device structure 100 a , the second surface 144 of the micro light emitting device 140 has four edges SD 1 , SD 2 , SD 3 , and SD 4 and four corners C 1 , C 2 , C 3 , and C 4 . In particular, the edge SD 1 and the edge SD 2 of the second surface 144 of the micro light-emitting device 140 are disposed opposite each other, the edge SD 3 and the edge SD 4 are disposed opposite each other, and the corner C 1 of the micro light-emitting device 140 is constituted by intersecting the edge SD 1 and the edge SD 4 , the corner C 2 is constituted by intersecting the edge SD 1 and the edge SD 3 , the corner C 3 is constituted by intersecting the edge SD 2 and the edge SD 3 , and the corner C 4 is constituted by intersecting the edge SD 2 and the edge SD 4 . In other words, a line connecting the corner C 1 and the corner C 3 overlaps one diagonal line on the second surface 144 of the micro light-emitting device 140 , and a line connecting the corner C 2 and the corner C 4 overlaps the other diagonal line on the second surface 144 of the micro light-emitting device 140 . The micro light-emitting device 140 of the embodiment has a rectangular outline when viewed from the top, but the invention is not limited thereto. In other embodiments not shown in the drawings, the outline of the micro light-emitting device viewed from the top may be circular, trapezoidal, or in other appropriate shapes.

Referring again to both FIG. 1A and FIG. 2A , the holding structure 160 a of the embodiment extends toward the substrate 120 from the peripheral surface 146 of the micro light-emitting device 140 and is disposed on the substrate 120 , and a gap G exists between the holding structure 160 a and the substrate 120 . Herein, the holding structure 160 a of the embodiment further extends onto the second surface 144 of the micro light-emitting device 140 from the peripheral surface 146 of the micro light-emitting device 140 , and, when viewed from the top, the holding structure 160 a successively crosses over the opposite edges SD 1 and SD 2 of the second surface 144 of the micro light-emitting device 140 . The holding structure 160 a passes through a center of the second surface 144 of the micro light-emitting device 140 and is symmetrically arranged with respect to the center of the micro light-emitting device 140 . However, in other embodiments not shown in the drawings, the holding structure may also be symmetrically arranged with respect to the center of the structure with micro-light emitting device but arranged in a different manner or arranged asymmetrically. As long as the holding structure is able to hold and support the micro light-emitting device in a balanced way and smoothly and efficiently transport and transfer the micro light-emitting device in a subsequent manufacturing process, the holding structure falls within the scope of the invention. Herein, the holding structure 160 a has a rectangular outline when viewed from the top, but in other embodiments not shown in the drawings, depending on an actual design that is needed, the outline of each of the holding structures when viewed from the top may be polygonal, semicircular, semi-elliptical, or in other shapes that are sufficient to hold the micro light-emitting device; the invention is not limited thereto.

Herein, a ratio of a contact area of the holding structure 160 a and the second surface 144 to a surface area of the second surface 144 is within a range from 0.05 to 0.5. In detail, if the ratio is less than 0.05, a supporting capacity of the holding structure 160 a to support the micro light-emitting device 140 may be insufficient, resulting in a decrease in a yield of transporting and transferring the micro light-emitting device 140 ; if the ratio is greater than 0.5, a difficulty of separating the micro light-emitting device 140 from the holding structure 160 a in a subsequent manufacturing process is increased. A vertical height H 3 from a top surface S 1 of the holding structure 160 a to the second surface 144 of the micro light-emitting device 140 is, for example, within a range from 0.1 μm to 2 μm. In an embodiment of the invention, a ratio of the vertical height H 3 that is from the top surface S 1 of the holding structure 160 a to the second surface 144 of the micro light-emitting device 140 to the vertical height H 2 of the micro light-emitting device 140 is less than or equal to 0.3. In detail, if the ratio is greater than 0.3, the difficulty of separating the micro light-emitting device 140 from the holding structure 160 a in the subsequent manufacturing process is increased. The holding structure 160 a provided in the embodiment also directly contacts a portion of the peripheral surface 146 of the micro light-emitting device 140 . In an embodiment of the invention, a ratio of a contact area of the holding structure 160 a and the peripheral surface 146 to a surface area of the peripheral surface 146 is within a range from 0.05 to 0.5. In detail, if the ratio is less than 0.05, the supporting capacity of the holding structure 160 a to support the micro light-emitting device 140 may be insufficient, resulting in the decrease in the yield of transporting and transferring the micro light-emitting device 140 ; if the ratio is greater than 0.5, the difficulty of separating the micro light-emitting device 140 from the holding structure 160 a in the subsequent manufacturing process is increased. In particular, a ratio of a width of the holding structure 160 a at the edge SD 1 (or SD 2 ) of the first surface 142 of the light-emitting device 140 to a width of the edge SD 1 (or SD 2 ) of the first surface 142 of the light-emitting device 140 is within a range from 0.05 to 0.6. In detail, if the ratio is less than 0.05, a supporting capacity of the holding structure 160 a to support the micro light-emitting device 140 may be insufficient, resulting in a decrease in a yield of transporting and transferring the micro light-emitting device 140 ; if the ratio is greater than 0.6, a difficulty of separating the micro light-emitting device 140 from the holding structure 160 a in a subsequent manufacturing process is increased.

Referring to FIG. 1A , in the embodiment, the number of the buffer structure 180 a is embodied as being plural, particularly two buffer structures 182 a and 184 a . The buffer structures 182 a and 184 a are disposed on the substrate 120 , located in the gap G between the holding structure 160 a and the substrate 120 , and directly contacting the holding structure 160 a and the substrate 120 . Particularly, the holding structure 160 a of the embodiment does not directly contact the substrate 120 , and an orthogonal projection of the holding structure 160 a on the substrate 120 overlaps an orthogonal projection of the buffer structures 182 a and 184 a on the substrate 120 , such that the holding structure 160 a , the substrate 120 , the micro light-emitting device 140 , and the buffer structures 182 a and 184 a to define an air gap G 1 . Herein, the orthogonal projection of the buffer structures 182 a and 184 a on the substrate 120 does not overlap at all an orthogonal projection of the micro light-emitting device 140 on the substrate 120 . Particularly, the buffer structures 182 a and 184 a do not directly contact the micro light-emitting device 140 . Therefore, the buffer structures 182 a and 184 a are not only able to absorb external forces exerted on the holding structure 160 a holding the micro light-emitting device 140 during the process of transporting and transferring the micro light-emitting device 140 to increase a yield of transporting and transferring the micro light-emitting device 140 but also able to be of no influence on a yield of picking up the micro light-emitting device 140 .

In addition, it should be noted that a Young's modulus of the micro light-emitting device 140 is greater than the Young's modulus of the holding structure 160 a , and the Young's modulus of the buffer structure 180 a is smaller than the Young's modulus of the holding structure 160 a . Therefore, rigidity of the holding structure 160 a contributes to holding and supporting the micro light-emitting device 140 , and ductility of the buffer structure 180 a may achieve good buffering effects on the holding structure 160 a , so as to prevent the holding structure 160 a from being fractured because of the influence of external forces when the holding structure 160 a holds and supports the micro light-emitting device 140 during the process of transporting and transferring the micro light-emitting device 140 . In short, in the embodiment, the holding structure 160 a is able to provide good holding and support due to the composite structure constituted by the buffer structure 180 a and the holding structure 160 a , so as to facilitate the transportation and transfer of the micro light-emitting device 140 between different substrates.

Herein, a material of the buffer structure 180 a is different from a material of the holding structure 160 a , wherein a material of the buffer structures 182 a and 184 a may be a polymer organic material having better strength to achieve a buffering effect to protect the holding structure 160 a that holds and supports the micro light-emitting device 140 from being affected by external forces during the process of transporting and transferring the micro light-emitting device 140 , thereby preventing the holding structure 160 a from being fractured because of the influence of external factors. The material of the holding structure 160 a may be an inorganic material, such as silicon dioxide or silicon nitride, which can withstand high temperature and high pressure during the manufacturing process, wherein a thickness of the holding structure 160 a on a vertical cross-section is within a range from 0.1 μm to 2 μm, so as to achieve both holding and supporting effects. In addition, a connection force between the holding structure 160 a and the micro light-emitting device 140 is greater than a connection force between the holding structure 160 a and the substrate 120 , and a connection force between the buffer structure 180 a and the holding structure 160 a is greater than a connection force between the buffer structure 180 a and the substrate 120 , so that the micro light emitting device 140 may have good performance when being transported and transferred.

In the embodiment, when the structure with micro light-emitting device 100 a is affected by external forces during its transportation and transfer, an amount of deformation of the buffer structure 180 a is greater than an amount of deformation of the holding structure 160 a , and the amount of deformation of the holding structure 160 a is less than the maximum amount of deformation of the holding structure 160 a , so as to absorb the impact of the external forces on the holding structure 160 a . The maximum amount of deformation of the holding structure 160 a is less than the vertical distance H 1 between the micro light-emitting device 140 and the substrate 120 , so as to facilitate the subsequent pick-up process.

The reference numerals and a part of the contents in the previous embodiment are used in the following embodiments, in which identical reference numerals indicate identical or similar components, and repeated descriptions of the same technical contents are omitted. For a detailed description of the omitted parts, reference can be found in the previous embodiment(s), and no repeated description is provided in the following embodiments.

FIG. 1B is a schematic cross-sectional view of a structure with micro light-emitting device according to another embodiment of the invention. Referring to both FIG. 1A and FIG. 1B , a structure with micro light-emitting device 100 b of the embodiment is similar to the structure with micro light-emitting device 100 a of FIG. 1A , and the difference therebetween is as follows: a buffer structure 180 b of the embodiment further directly contacts the micro light-emitting device 140 . Particularly, buffer structures 182 b and 184 b directly contact a portion of the first surface 142 and a portion of the peripheral surface 146 respectively and are located between the substrate 120 and the micro light-emitting device 140 . Herein, the micro light-emitting device 140 , the buffer structures 182 b and 184 b , and the substrate 120 define an air gap G 2 . It is worth mentioning that in the embodiment, a contact area of the buffer structure 180 b and the holding structure 160 a is greater than a contact area of the buffer structure 180 b and the substrate 120 , and the contact area of the buffer structure 180 b and the holding structure 160 a is also greater than a contact area of the buffer structure 180 b and the micro light-emitting device 140 . That is to say, the contact area of the buffer structure 180 b and the holding structure 160 a is greater than the contact area of the buffer structure 180 b and the substrate 120 greater than the contact area of the buffer structure 180 b and the micro light-emitting device 140 , so that a stress exerted on the holding structure 160 a may be sufficiently buffered by the buffer structure 180 b , and an effect of the stress may be transferred to the buffer structure 180 b.

FIG. 1C is a schematic cross-sectional view of a structure with micro light-emitting device according to another embodiment of the invention. Referring to both FIG. 1B and FIG. 1C , a structure with micro light-emitting device 100 c of the embodiment is similar to the structure with micro light-emitting device 100 b of FIG. 1B , and the difference therebetween is as follows: the structure with micro light-emitting device 100 c of the embodiment further includes a stress buffer structure 150 disposed between the micro light-emitting device 140 and the substrate 120 . Particularly, the stress buffer structure 150 is disposed in an air gap G 3 formed among the substrate 120 , the micro light-emitting device 140 , and the buffer structure 180 b . More specifically, an orthogonal projection area of the stress buffer structure 150 on the substrate 120 is smaller than an orthogonal projection area of the micro light-emitting device 140 on the substrate 120 . Herein, the stress buffer structure 150 at least directly contacts the substrate 120 , the micro light-emitting device 140 , the buffer structure 180 b , or a combination thereof. Herein, the stress buffer structure 150 absorbs a stress generated when the micro light-emitting device 140 is bonded to the substrate 120 , thereby increasing a bonding yield. In other words, the stress buffer structure 150 may provide a stress buffering effect between the micro light-emitting device 140 and the substrate 120 . In an embodiment of the invention, a Young's modulus of the stress buffer structure 150 is less than a Young's modulus of the buffer structure 180 b . Herein, a material of the stress buffer structure 150 includes a foam material or an organic polymer material, causing the stress buffer structure 150 to have a plurality of irregular air holes, wherein a porosity of the stress buffer structure 150 made of the foam material is equal to or greater than 50%, and therefore good buffering effects may be achieved.

FIG. 1D is a schematic cross-sectional view of a structure with micro light-emitting device according to another embodiment of the invention. Referring to both FIG. 1B and FIG. 1D , a structure with micro light-emitting device 100 d of the embodiment is similar to the structure with micro light-emitting device 100 b of FIG. 1B , and the difference therebetween is as follows: a holding structure 160 d of the embodiment directly contacts the substrate 120 . The number of the buffer structure 180 d is two according to the present embodiment, i.e., buffer structures 182 d and 184 d , and the buffer structures 182 d and 184 d directly contact the substrate 120 , the holding structure 160 d , and the micro light-emitting device 140 . The holding structure 160 d , the micro light-emitting device 140 , and the substrate 120 define a configuration area A 1 , and the buffer structures 182 d and 184 d are disposed on the substrate 120 and located within the configuration area A 1 . Here, the buffer structures 182 d and 184 d , the micro light-emitting device 140 , and the substrate 120 define an air gap G 4 .

FIG. 1E is a schematic cross-sectional view of a structure with micro light-emitting device according to another embodiment of the invention. Referring to both FIG. 1D and FIG. 1E , a structure with micro light-emitting device 100 e of the embodiment is similar to the micro light-emitting device structure 100 d of FIG. 1D , and the difference therebetween is as follows: the buffer structure 180 e of the embodiment is disposed on the substrate 120 and fills the configuration area A 1 .

FIG. 1F is a schematic cross-sectional view of a structure with micro light-emitting device according to another embodiment of the invention. Referring to both FIG. 1D and FIG. 1F , a structure with micro light-emitting device 100 f of the embodiment is similar to the structure with micro light-emitting device 100 d of FIG. 1D , and the difference therebetween is as follows: a holding structure 160 f of the embodiment only contacts the second surface 144 of the micro light-emitting device 140 directly. The number of the buffer structure 180 f is embodied as two, i.e., buffer structures 182 f and 184 f , and the buffer structures 182 f and 184 f cover the peripheral surface 146 of the micro light-emitting device 140 . The holding structure 160 f is disposed on the buffer structure 180 f and directly connects the buffer structure 180 f and the substrate 120 , and the buffer structure 180 f , the micro light-emitting device 140 , and the substrate 120 define an air gap G 5 . Particularly, a height of the buffer structures 182 f and 184 f on a vertical cross-section is equal to a height of the micro light-emitting device 140 on the vertical cross-section from the second surface 144 to the substrate 120 . The micro light-emitting device 140 of the embodiment is trapezoidal. Since the buffer structure 180 f is further disposed on the peripheral surface 146 of the micro light-emitting device 140 , an influence resulting from the shape of the micro light-emitting device 140 may be lessened, the holding structure 160 f may be protected from being fractured during the manufacturing process, and the production yield of arranging the holding structure 160 f on the micro light-emitting device 140 may be improved.

FIG. 1G is a schematic cross-sectional view of a structure with micro light-emitting device according to another embodiment of the invention. FIG. 2B is a schematic top view of the structure with micro light-emitting device depicted in FIG. 1G . The structure with micro light-emitting device 100 g of FIG. 1G is depicted along a sectional line B-B′ of FIG. 2B , and some components are omitted from FIG. 2B so as to facilitate explanation. Referring to both FIG. 1F and FIG. 1G , a structure with micro light-emitting device 100 g of the embodiment is similar to the structure with micro light-emitting device 100 f of FIG. 1F , and the difference therebetween is as follows: a holding structure 160 g of the embodiment exposes a portion of the second surface 144 of the micro light-emitting device 140 . The number of the holding structure 160 g is two according to the present embodiment, i.e., sub-holding structures 162 g and 164 g , wherein a first width of the holding structure 160 g on the second surface 144 is a total width of a width W 1 of the sub-holding structure 162 g on the second surface 144 and a width W 2 of the sub-holding structure 164 g on the second surface 144 . A ratio of the first width of the holding structure 160 g on the second surface 144 to a second width W 3 of the second surface 144 is within a range from 0.1 to 0.8. In detail, if the ratio is less than 0.1, a supporting capacity of the holding structure 160 g to support the micro light-emitting device 140 may be insufficient, resulting in a decrease in a yield of transporting and transferring the micro light-emitting device 140 ; if the ratio is greater than 0.8, a difficulty of separating the micro light-emitting device 140 from the holding structure 160 g in a subsequent manufacturing process is increased. In the embodiment, the ratio of the first width of the holding structure 160 g on the second surface 144 to the second width W 3 of the second surface 144 is about 0.5, but the invention is not limited thereto.

Particularly, referring to both FIG. 1G and FIG. 2B , when viewed from the top, the sub-holding structures 162 g and 164 g partially cover and directly contact the opposite edges SD 1 and SD 2 of the second surface 144 of the micro light-emitting device 140 , respectively. A distance from the sub-holding structure 162 g to a center of the second surface 144 of the micro light-emitting device 140 is equal to a distance from the sub-holding structure 164 g to the center of the second surface 144 of the micro light-emitting device 140 . That is to say, the sub-holding structures 162 g and 164 g are symmetrically arranged with respect to the center of the micro light-emitting device 140 . Therefore, the sub-holding structures 162 g and 164 g are able to hold and support the micro light-emitting device in a balanced way and smoothly and efficiently transport and transfer the micro light-emitting device in a subsequent manufacturing process.

FIG. 1H is a schematic cross-sectional view of a structure with micro light-emitting device according to another embodiment of the invention. Referring to both FIG. 1A and FIG. 1H , a structure with micro light-emitting device 100 h of the embodiment is similar to the structure with micro light-emitting device 100 a of FIG. 1A , and the difference therebetween is as follows: the number of the buffer structure 180 h of the embodiment is embodied as being plural, particularly two buffer structures 182 h and 184 h , wherein the buffer structures 182 h and 184 h are disposed on the substrate 120 and cover a holding structure 160 h . In detail, the buffer structures 182 h and 184 h are located between the holding structure 160 h and the substrate 120 and extend over and cover the holding structure 160 h in a direction away from the substrate 120 . Here, the buffer structures 182 h and 184 h directly contact the substrate 120 and the holding structure 160 h . The holding structure 160 h , the micro light-emitting device 140 , the buffer structures 182 h and 184 h , and the substrate 120 define an air gap G 6 , and the top surface S 1 of the holding structure 160 h is aligned to a top surface S 2 of the buffer structure 180 h . In other embodiments not shown, the buffer structure may cover the holding structure and not directly contact the substrate. Here, the holding structure directly contacts the substrate, and the holding structure, the micro light-emitting device, and the substrate define an air gap.

FIG. 1I is a schematic cross-sectional view of a structure with micro light-emitting device according to another embodiment of the invention. Referring to both FIG. 1I and FIG. 1A , a structure with micro light-emitting device 100 i of the embodiment is similar to the structure with micro light-emitting device 100 a of FIG. 1A , and the difference therebetween is as follows: the top surface S 1 of a holding structure 160 i of the embodiment is aligned to the second surface 144 of the micro light-emitting device 140 . In detail, the holding structure 160 i only contacts the peripheral surface 146 of the micro light-emitting device 140 and does not contact the second surface 144 of the micro light-emitting device 140 . Thereby, when the micro light-emitting device is picked up from the second surface via a transfer head (not shown) and transported and transferred to a different substrate, the micro light-emitting device may have a greater pick-up area, and the holding structure may also accomplish good holding and supporting effects.

Some components (i.e. buffer structures) are omitted from FIG. 2C to FIG. 2H and FIG. 2I so as to facilitate explanation. FIG. 2C is a schematic top view of a structure with micro light-emitting device according to another embodiment of the invention. Referring to both FIG. 2A and FIG. 2C , a structure with micro light-emitting device 200 c of the embodiment is similar to the structure with micro light-emitting device 100 a of FIG. 2A , and the difference therebetween is as follows: the number of a holding structure 260 c of the embodiment is embodied as being plural, e.g., two sub-holding structures 262 c and 264 c , wherein the sub-holding structures 262 c and 264 c respectively lie across two diagonal lines of the second surface 144 of the micro light-emitting device 140 when viewed from the top. The sub-holding structure 262 c covers and directly contacts the corner C 2 and the corner C 4 of the second surface 144 of the micro light-emitting device 140 , and the sub-holding structure 264 c covers and directly contacts the corner C 1 and the corner C 3 of the second surface 144 of the micro light-emitting device 140 .

FIG. 2D is a schematic top view of a structure with micro light-emitting device according to another embodiment of the invention. Referring to both FIG. 2C and FIG. 2D , a structure with micro light-emitting device 200 d of the embodiment is similar to the structure with micro light-emitting device 200 c of FIG. 2C , and the difference therebetween is as follows: a holding structure 260 d of the embodiment only lies across one diagonal line of the micro light-emitting device 140 and directly contacts and covers the corners C 1 and C 3 of the second surface 144 of the micro light-emitting device 140 . However, in other embodiments not shown in the drawings, the holding structure 260 d may also lie across the corners C 2 and C 4 of the other diagonal line of the micro light-emitting device 140 , and such holding structure still falls within the scope of the invention.

FIG. 2E is a schematic top view of a structure with micro light-emitting device according to another embodiment of the invention. Referring to both FIG. 2B and FIG. 2E , a structure with micro light-emitting device 200 e of the embodiment is similar to the structure with micro light-emitting device 100 g of FIG. 2B , and the difference therebetween is as follows: a holding structure 260 e of the embodiment includes four sub-holding structures 262 e , 264 e , 266 e , and 268 e ; when viewed from the top, the sub-holding structures 262 e , 264 e , 266 e , and 268 e are separately disposed at the four corners C 1 , C 2 , C 3 , and C 4 of the second surface 144 of the micro light-emitting device 140 . Particularly, the sub-holding structure 262 e covers and directly contacts the corner C 1 , the sub-holding structure 264 e covers and directly contacts the corner C 4 , the sub-holding structure 266 e covers and directly contacts the corner C 2 , and the sub-holding structure 268 e covers and directly contacts the corner C 3 . Here, the sub-holding structures 262 e , 264 e , 266 e , and 268 e are symmetrically and equidistantly arranged with respect to the center of the second surface 144 of the micro light-emitting device 140 .

FIG. 2F is a schematic top view of a structure with micro light-emitting device according to another embodiment of the invention. Referring to both FIG. 2B and FIG. 2F , a structure with micro light-emitting device 200 f of the embodiment is similar to the structure with micro light-emitting device 100 g of FIG. 2B , and the difference therebetween is as follows: a holding structure 260 f of the embodiment includes three sub-holding structures 262 f , 264 f , and 266 f , and, when viewed from the top, the sub-holding structures 262 f and 264 f are disposed at the two corners C 1 and C 4 on the same edge SD 4 of the second surface 144 of the micro light-emitting device 140 , and the sub-holding structure 266 f is disposed on the edge SD 3 opposite to the edge SD 4 of the micro light-emitting device 140 . Here, a line connecting the sub-holding structures 262 f , 264 f , and 266 f may form an isosceles triangle, but the invention is not limited thereto. In other embodiments not shown in the drawings, the line connecting the sub-holding structures may also form other types of triangles, e.g., an acute triangle, which still falls within the scope of the invention.

FIG. 2G is a schematic top view of a structure with micro light-emitting device according to another embodiment of the invention. Referring to both FIG. 2A and FIG. 2G , a structure with micro light-emitting device 200 g of the embodiment is similar to the structure with micro light-emitting device 100 a of FIG. 2A , and the difference therebetween is as follows: the number of a holding structure 260 g of the embodiment is embodied as two, i.e., sub-holding structures 262 g and 264 g , and the sub-holding structures 262 g and 264 g are shaped as a cross when viewed from the top. The sub-holding structures 262 g and 264 g extend from the center of the second surface 144 of the micro light-emitting device 140 toward the four edges SD 1 , SD 2 , SD 3 , and SD 4 . Particularly, the sub-holding structure 262 g extends between the edge SD 1 and the edge SD 2 , and the sub-holding structure 264 g extends between the edge SD 3 and the edge SD 4 ; however, the invention is not limited thereto.

FIG. 2H is a schematic top view of a structure with micro light-emitting device according to another embodiment of the invention. Referring to both FIG. 2B and FIG. 2H , a structure with micro light-emitting device 200 h of the embodiment is similar to the structure with micro light-emitting device 100 g of FIG. 2B , and the difference therebetween is as follows: the number of a holding structure 260 h of the embodiment is embodied as one. When viewed from the top, the holding structure 260 h is disposed on the edge SD 2 of the second surface 144 of the micro light-emitting device 140 , but the invention is not limited thereto. In other embodiments not shown in the drawings, the holding structure may also be disposed on the other edges of the second surface of the micro light-emitting device, and such holding structure still falls within the scope of the invention.

FIG. 2I is a schematic top view of a structure with micro light-emitting device according to another embodiment of the invention. Referring to both FIG. 2B and FIG. 2I , a structure with micro light-emitting device 200 i of the embodiment is similar to the structure with micro light-emitting device 100 g of FIG. 2B , and the difference therebetween is as follows: the micro light-emitting device 140 of the embodiment includes two micro light-emitting devices 140 a 1 and 140 a 2 , and a holding structure 260 i is located between the micro light-emitting devices 140 a 1 and 140 a 2 . The holding structure 260 i extends on the second surfaces 144 of the micro light-emitting devices 140 a 1 and 140 a 2 and directly contacts a portion of the edge SD 2 of the micro light-emitting device 140 a 1 and a portion of the edge SD 1 of the micro light-emitting device 140 a 2 . That is to say, the micro light-emitting devices 140 a 1 and 140 a 2 may share the holding structure 260 i to facilitate a simultaneous transport of the micro light-emitting devices between different temporary substrates and to save costs.

In some of the above-mentioned embodiments, one or two holding structures are schematically depicted as examples, but in other embodiments, the holding structure may include four or three sub-holding structures as depicted in FIG. 2E or FIG. 2F , but the invention is not limited thereto. In other embodiments not shown in the drawings, a shape of the holding structure may change according to an actual shape of the micro light-emitting device, and the holding structure may also include a plurality of holding structures depending on actual product requirements or in response to changes of product design, and the way to arrange the holding structure may also be adjusted based on the actual need, so that the micro light-emitting device supported by the holding structure may be easily transported.

Similarly, in the above-mentioned embodiments, one or two buffer structures are exemplarily depicted as examples, but in other embodiments not shown in the drawings, the buffer structure may include a plurality of buffer structures depending on an actual need, so that the holding structure that directly contacts the buffer structure may be protected by the buffer structure during the transportation of the structure with micro light-emitting device. In addition, in other embodiments not shown in the drawings, the micro light-emitting device 140 , the holding structures 160 a , 160 d , 160 f , 160 g , 160 h , 160 i , 260 c , 260 d , 260 e , 260 f , 260 g , 260 h , and 260 i , and the buffer structures 180 a , 180 b , 180 d , 180 e , 180 f , 180 g , and 180 h in the above-mentioned embodiments may be used; thereby, the micro light-emitting device, the holding structure, and/or the buffer structure may contact with each other in a different manner, the micro light-emitting device may be temporarily fixed and held by more holding structures or less holding structures, or the holding structure(s) may be buffered by more buffer structures or less buffer structures. That is to say, the holding structure and the buffer structure may also be selectively connected to a top surface of the micro light-emitting device, a side surface thereof, a bottom surface thereof, or a combination thereof depending on the actual product requirements. As long as the holding structure directly contacts the buffer structure so as to well hold and support the holding structure when the micro light-emitting device is being transported and transferred, and as long as the buffer structure is able to well buffer the holding structure, the holding structure and buffer structure fall within the scope of the invention.

To sum up, in the structure with micro light-emitting device provided in an embodiment of the invention, the holding structure is disposed on the substrate and directly contacts the micro light-emitting device, and the buffer structure directly contacts the holding structure, wherein the Young's modulus of the buffer structure is smaller than the Young's modulus of the holding structure. Thereby, when the micro light-emitting device is being transported and transferred between different substrates, the holding structure may provide well hold and support the micro light-emitting device, and the buffer structure may well buffer the holding structure.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.