Miniature LED display panel, manufacturing method thereof and display device

Abstract

The invention provides a miniature LED element, a miniature LED display panel and a display device. The micro LED display panel includes: a micro LED chip including a driving layer, a micro LED array disposed on the driving layer, and a transparent protective layer disposed on the micro LED array, the driving layer being configured to receive a signal for driving the micro LED array; a flexible circuit board (FCB) disposed adjacent to the micro LED chip and configured to be coupled to the micro LED chip, and a plurality of LED chips disposed on the flexible circuit board and configured to be coupled to the micro LED chip; and a molding layer disposed to bond the micro LED chip and the FCB together.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to micro display technology, and more particularly, to a micro LED display panel, a method of manufacturing a micro LED display panel, and a display device. BACKGROUND

[0002] Inorganic micro-pixel light emitting diodes, also known as micro light emitting diodes, micro LEDs, or μ-LEDs, are becoming more important for various applications including self-emissive micro displays, visible light communication, and optogenetics. Micro LEDs have better strain relaxation, higher light extraction efficiency, and uniform current spreading, and thus have higher output performance than conventional LEDs. Micro LEDs also show several advantages over conventional LEDs, such as improved thermal effects, faster response rate, larger operating temperature range, higher resolution, wider color gamut, higher contrast, lower power consumption, and operability at higher current density.

[0003] Micro LED display panels are manufactured by integrating an array of thousands or even millions of micro LEDs with an Integrated Circuit (IC) backplane. In conventional techniques, micro LEDs can be packaged on the IC backplane, where the array of micro LEDs forms a light emitting area in a functional area of the front side of the IC backplane. Meanwhile, the non-functional area of the front side of the IC backplane can be used for electrodes, which can result in I / O ports for voltage and signal transmission. This packaging arrangement results in a larger micro LED product, which requires more space and thus hinders its application in space-limited products.

[0004] Therefore, there is a need to improve the packaging of micro LEDs. SUMMARY

[0005] Some embodiments of the present disclosure provide a micro LED display panel. The micro LED display panel includes a micro LED chip including a driving layer, an array of micro LEDs disposed on the driving layer, and a transparent protection layer disposed on the array of micro LEDs, wherein the driving layer is configured to receive a signal for driving the array of micro LEDs; a Flexible Circuit Board (FCB) disposed adjacent to the micro LED chip and configured to be coupled to the micro LED chip; and a molding layer disposed to join the micro LED chip and the FCB together.

[0006] Some embodiments of the present disclosure also provide a method of manufacturing a micro-LED display panel, comprising: coupling a flexible circuit board (FCB) to a micro-LED chip, the micro-LED chip comprising a driving layer, a micro-LED array, and a transparent protection layer, the micro-LED array disposed on the driving layer, the transparent protection layer disposed on the micro-LED array, the driving layer configured to receive a signal for driving the micro-LED array, the FCB configured to be coupled to the micro-LED chip; and forming a molding layer to join the micro-LED chip and the FCB together.

[0007] Some embodiments of the present disclosure provide a display device. The display device comprises any micro-LED display panel described herein. BRIEF DESCRIPTION OF DRAWINGS

[0008] Embodiments and various aspects of the present disclosure are illustrated in the following detailed description and in the accompanying drawings. Various features shown in the figures were not drawn to scale.

[0009] Figure 1A A front view of an exemplary micro-LED display panel is shown according to some embodiments of the present disclosure.

[0010] Figure 1B A back view of an exemplary micro-LED display panel is shown according to some embodiments of the present disclosure. Figure 1A A front view of an exemplary micro-LED display panel is shown according to some embodiments of the present disclosure.

[0011] Figure 2A A back view of an exemplary micro-LED display panel is shown according to some embodiments of the present disclosure. Figure 1A A front view of an exemplary micro-LED display panel is shown according to some embodiments of the present disclosure.

[0012] Figure 2B A back view of an exemplary micro-LED display panel is shown according to some embodiments of the present disclosure. Figure 1A A front view of an exemplary micro-LED display panel is shown according to some embodiments of the present disclosure.

[0013] Figure 2C A cross-sectional view of another exemplary micro-LED display panel is shown according to some embodiments of the present disclosure.

[0014] Figure 3A A cross-sectional view of another exemplary micro-LED display panel is shown according to some embodiments of the present disclosure.

[0015] Figure 3B A cross-sectional view of another exemplary micro-LED display panel is shown according to some embodiments of the present disclosure. Figure 1A 、 2AFIG. 2A shows a structure diagram of a micro LED chip of an exemplary micro LED display panel according to some embodiments of the present disclosure.

[0016] Figure 3C FIG. 2B shows a structure diagram of a micro LED chip of another exemplary micro LED display panel according to some embodiments of the present disclosure.

[0017] Figure 4A FIG. 3A shows a front view structure diagram of another exemplary micro LED display panel according to some embodiments of the present disclosure.

[0018] Figure 4B FIG. 3B shows a back view structure diagram of the exemplary micro LED display panel shown in FIG. 3A according to some embodiments of the present disclosure. Figure 4A

[0019] Figure 5A FIG. 4A shows a front view of an exemplary display device having a plurality of micro LED display panels according to some embodiments of the present disclosure.

[0020] Figure 5B FIG. 4B shows a back view of the exemplary display device shown in FIG. 4A according to some embodiments of the present disclosure. Figure 5A

[0021] Figure 6 FIG. 5A shows a structure diagram of another exemplary display device having a combiner according to some embodiments of the present disclosure.

[0022] Figure 7 FIG. 6 shows a flowchart of an exemplary method of manufacturing a micro LED display panel according to some embodiments of the present disclosure.

[0023] Figure 8 FIG. 7A shows a structure diagram of another exemplary display device according to some embodiments of the present disclosure.

[0024] Figure 9 FIG. 7B shows a structure diagram of another exemplary display device according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0025] ​​Reference will now be made specifically to exemplary embodiments. Examples of these exemplary embodiments are illustrated in the accompanying drawings. The following description refers to the drawings, wherein, unless otherwise stated, the same numbers in different figures denote the same or similar elements. The implementations set forth in the following description of the exemplary embodiments do not represent all implementations consistent with the present invention. Rather, these implementations are merely examples of apparatuses and methods consistent with aspects of the invention recounted in the appended claims. Specific aspects of this disclosure are described below in more detail. If any terminology and definitions provided herein conflict with those incorporated by reference, the terminology and definitions provided herein shall prevail.

[0026] Figure 1A and 1B A structural diagram of an exemplary micro-LED display panel 10 according to some embodiments of the present disclosure is shown. Figure 2A and 2B Some embodiments based on this disclosure are shown. Figure 1A A cross-sectional view of an exemplary micro-LED display panel 10 along section line AA. Figure 1A , 1BAs shown in Figures 2A and 2B, the micro-LED display panel 10 includes a micro-LED chip 110, a flexible circuit board (FCB) 120 (e.g., a flexible printed circuit board), and a molding layer 130. The manufacturing process includes creating the molding layer 130 on a portion of the micro-LED chip 110 and on the FCB 120, thereby bonding the micro-LED chip 110 and the FCB 120 together into a single compact structure. The resulting component is extremely small and can be seamlessly integrated into a display device. For example, in a deposition process, the molding layer 130, which has high-temperature properties, can be applied to the micro-LED chip 110 and the FCB 120. At high temperatures, the molding material exhibits a softer texture, allowing it to encapsulate the micro-LED chip 110 and the FCB 120. After cooling and curing, the molding layer 130 effectively encapsulates and bonds to the micro-LED chip 110 and the FCB 120, integrating the micro-LED chip 110 and the FCB 120 into a single compact structure. In some implementations, the molding process can also be transfer molding, injection molding, compression molding, extrusion molding, blow molding, etc. In some implementations, the molding material of the molding layer 130 can be epoxy molding compound (EMC), acrylic acid (polymethyl methacrylate), acrylonitrile butadiene styrene (ABS), polyamide (PA), polycarbonate (PC), polyethylene (PE), etc.

[0027] like Figure 2A As shown, the microLED chip 110 includes a driving layer 111, a microLED array 112 disposed on the driving layer 111, and a transparent protective layer 113 disposed on the microLED array 112 for protecting the microLED array 112. For example, the transparent protective layer 113 can be disposed on the microLED array 112 via an adhesive layer (not shown). The driving layer 111 may include driving circuitry (not shown) for driving the microLED array 112 with received signals. Specifically, the driving layer 111 may include a signal region 114 for receiving signals for driving the microLED array 112 and for transmitting the signals to the driving circuitry. The microLED array 112 is not disposed on the signal region 114 to provide space for leading out electrodes that can be coupled to electrodes within the FCB 120.

[0028] For compact structure of the micro-LED display panel 10, the FCB 120 can be disposed adjacent to the signal region 114 to shorten the overall length of the micro-LED display panel 10. The distance between the micro-LED chip 110 and the FCB 120 can vary from one millimeter to several millimeters. In some embodiments, the distance between the micro-LED chip 110 and the FCB 120 can be set according to the adhesion of the molding material of the molding layer 130, such that the assembly of the micro-LED chip 110 and the FCB 120 will not be damaged due to the applied force. It should be understood that the micro-LED chip 110 and the FCB 120 can be disposed separately at a farther distance, in which case, when the adhesion of the molding material is relatively low, a thicker molding material can be required for the molding layer 130.

[0029] In some embodiments, the FCB 120 includes a connection region 121 for the lead-out electrodes. The FCB 120 can be coupled to the signal region 114 of the driving layer 111 within the connection region 121 of the FCB 120. It should be understood that the FCB 120 can not generate signals for driving the micro-LED array 112, but it can transmit these signals and thus act as a medium for transmitting signals and power. These signals can be generated by a graphic processing unit (GPU) connected to the FCB 120.

[0030] Further referring to Figure 1A , 1B , 2A and 2B, the molding layer 130 can be disposed to bond to the micro-LED chip 110 and the FCB 120 (e.g., the connection region 121 of the FCB 120) and to join the micro-LED chip 110 and the FCB 120 (e.g., the connection region 121 of the FCB 120) into a single compact structure. As described above, the molding layer 130 can be disposed on a portion of the outer surface of the micro-LED chip 110 and the FCB 120 and to bond the micro-LED chip 110 and the FCB 120 together. More particularly, the molding layer 130 can be formed to fill the gap 150 between the micro-LED chip 110 and the FCB 120 and to form on a portion of the front surface of the driving layer 111 on which the micro-LED chip 110 is formed and on the side surface and on the end portion of the FCB 120. The integrated molding layer 130 joins the micro-LED chip 110 and the FCB 120 into a single compact structure.

[0031] The transparent protective layer 113 can be disposed on the micro-LED array 112 in various ways to cover and protect the top surface of the micro-LED array 112. In some embodiments, as Figure 2A and 2BAs shown, the transparent protective layer 113 can include an adhesive layer (not shown) that can be disposed on the entire bottom surface of the transparent protective layer 113. Thus, the transparent protective layer 113 can be adhered to the top surface of the micro-LED array 112 (e.g., the entire top surface of the micro-LED array 112) via the adhesive layer. In some embodiments, the adhesive layer can be disposed near the edges of the bottom surface of the transparent protective layer 113 instead of the entire bottom surface. Specifically, the transparent protective layer 113 can be adhered to the front surface of the driving layer 111 and around the micro-LED array 112. In some cases, while the adhesive layer can be transparent to light, it can absorb light emitted from the micro-LED array 112 to some extent. By disposing the adhesive layer on the driving layer 111, the transparent protective layer 113 can be secured to the micro-LED chip 110 without affecting the light efficiency of the micro-LED array 112. In some embodiments, the adhesive layer can be formed of an epoxy adhesive, a thermosetting adhesive, or a moisture adhesive, etc.

[0032] In some embodiments, the horizontal cross-section of the transparent protective layer 113 projects within the horizontal cross-section of the driving layer 111 in the vertical direction. As Figure 2A and 2B As shown, the cross-sectional width of the transparent protective layer 113 can be the same as the cross-sectional width of the micro-LED array 112. It should be understood that Figure 2A and 2B is Figure 1A A-A cross-sectional view of the micro-LED display panel 10 shown in FIG. 1 along the A-A cross-sectional line. The width of the transparent protective layer 113 and the width of the micro-LED array 112 can also be the same in other cross-sectional views cut parallel to the A-A line.

[0033] In some embodiments, the side surface of the transparent protective layer 113 abuts the molding layer 130. The friction between the transparent protective layer 113 and the molding layer 130 provides additional protection for the components enclosed under the transparent protective layer 113.

[0034] As Figure 2B shown, in some embodiments, the molding layer 130 includes two continuous side surfaces 130-1 and 130-2 bridged by a flange surface 130-3 therebetween. These surfaces are thickened to clearly illustrate their positional relationship. Among them, the lower continuous side surface 130-1 abuts the side surface of the driving layer 111, the upper continuous side surface 130-2 abuts the side surface of the transparent protective layer 113, and the flange surface 130-3 abuts the front surface of the driving layer 111. As described above, the width of the transparent protective layer 113 can be the same as the width of the micro-LED array 112. Thus, the upper continuous side surface 130-2 can abut the side surface of the micro-LED array 112.

[0035] Referring to Figure 2A In some embodiments, the top surface of the molding layer 130 can be aligned with the top surface of the transparent protective layer 113. Under this arrangement, the height H of the micro-LED display panel 10 can be minimized. In some embodiments, referring to Figure 2B The molding layer 130 is arranged to leave an open area 140 above the transparent protective layer 113. That is, the top surface of the molding layer 130 can be higher than the top surface of the transparent protective layer 113. The protruding molding layer 130 can provide additional scratch protection to the transparent protective layer 113. The micro-LED array 112 can emit light representing an image rendered according to a received signal through the open area 140. Except for the distinguished features described here, Figure 2A and 2B the other aspects are the same.

[0036] In some embodiments, Figure 2B The open area 140 in the transparent protective layer 113 is formed to have a specific shape with a peripheral edge defined by the molding layer 130. For example, the open area 140 can be formed to have a trapezoidal cross-section, and has a widening-out opening structure. Alternatively, the open area 140 can be formed to have a rectangular cross-section. In a deposition process to form the molding layer 130, the open area 140 can be blocked by a mold used to form the molding layer 130. The molding material cannot fill the space occupied by the mold. After the molding layer 130 is hardened, the mold can be removed to expose the open area 140. The widening-out opening structure or the rectangular cross-section structure of the open area 140 defined by the peripheral edge of the molding layer 130 facilitates easier demolding. It should be appreciated that the mold can be removed upward without damaging the already hardened molding layer 130.

[0037] Furthermore, the widening-out opening structure reduces undesirable reflections generated by the inner walls of the open area 140 and between the inner walls. Such internal reflections within the open area 140 can blur the image rendered by the micro-LED array 112, which can degrade the display quality. With the widening-out opening structure, most of the light from the micro-LED array 112 can be emitted through the open area 140 and directly reach the viewer’s eyes. In some embodiments, some light from the micro-LED array 112 can be emitted through the open area 140 with limited reflections. As Figure 1A 、 2A and 2B, the micro-LED array 112 is fully exposed from the open area 140. That is, within a certain viewing angle (e.g., within an angular range of eighty-five degrees from the central normal axis of the micro-LED array 112), the light emitted from the micro-LED array 112 can be seen from above the open area 140.

[0038] Figure 3A and 3B A structural diagram of a micro LED chip 110 of an exemplary micro LED display panel 10 according to some embodiments of the present disclosure is shown. For the sake of clearly illustrating the circuit structure, Figure 3A and 3B Some of the components shown can not be externally visible and are represented in dashed lines. As Figure 3A shown, the molding layer 130 and the transparent protection layer 113 are omitted so as to better understand the layout of the micro LED chip 110. The micro LED array 112 can be formed on a surface of the driving layer 111 and coupled with the driving layer 111 on which the micro LED array 112 is formed. In addition, the driving layer 111 can include metal pads 1111 arranged in a signal region 114 on the same surface of the driving layer 111. Some of the metal pads 1111 can be coupled to corresponding electrodes of the micro LED array 112 to achieve coupling therebetween. Due to the characteristics of metal, the metal pads 1111 can reflect light (indicated as “incident light” in Figure 3A and 3B ) irradiated thereon. Some light emitted by the micro LED array 112, for example, inevitably irradiates on the metal pads 1111 through one or more reflections. Such reflected light (indicated as “reflected light” in Figure 3A ) from the metal pads 1111 can blur and degrade the image rendered by the micro LED array 112.

[0039] To prevent this, as Figure 3B shown, a flange surface 130-3 described above in connection with Figure 2B may be provided on the metal pads 1111 of the driving layer 111. The flange surface 130-3 blocks light irradiated on the metal pads 1111 and thus improves the quality of the image rendered by the micro LED array 112.

[0040] In some embodiments, as Figure 3A shown, at least some of the metal pads 1111 can be formed around the micro LED array 112. Figure 3B The flange surface 130-3 in Figure 3B may also be formed around the micro LED array 112 without leaving a gap between the micro LED array 112 and the molding layer 130 (not shown in ). That is, the flange surface 130-3 is formed to cover all the metal pads 1111.

[0041] Figure 3C A structural diagram of a micro LED chip of another exemplary micro LED display panel according to some embodiments of the present disclosure is shown. As Figure 3C shown, a plurality of electrodes 180 can be used to lead out Figure 2A ,2B And the circuit 124 shown in 2C. It should be understood that electrode 180 is connected to the micro LED array 112.

[0042] Further reference Figure 1B , 2A In addition to 2B, the micro-LED display panel 10 also includes a substrate layer 160, which is disposed in conjunction with the molding layer 130 to bond at least a portion of the FCB 120 to the micro-LED chip 110. For example, a connection region 121 of the molding layer 130, the micro-LED chip 110, and the FCB 120 may be disposed on the front surface of the substrate layer 160. On the one hand, the substrate layer 160 can provide mechanical rigidity for surface components disposed thereon (e.g., micro-LED chip 110, FCB 120, etc.). On the other hand, the substrate layer 160 can be attached to the molding layer 130 when the molding layer 130 cools and hardens. Thus, the molding layer 130, together with the substrate layer 160, can provide a sealed or semi-sealed environment for the surface components. In some embodiments, the substrate layer 160 may be formed of a steel sheet. It should be understood that other materials may also be used to form the substrate layer 160, as long as they can provide similar functionality to the steel sheet. For example, the substrate layer 160 may also be formed of ceramic, hard resin, etc.

[0043] In some implementations, the bottom surface of the micro LED chip 110 can be aligned with the bottom surface of the FCB 120. That is, the height of the bottom surface of the micro LED chip 110 can be the same as the bottom surface of the FCB 120.

[0044] In some implementation schemes, such as Figure 2A As shown, FCB 120 may include an adhesive layer 122 adhered to the front surface of substrate 160. The bottom surface of adhesive layer 122 may be aligned with the bottom surface of microLED chip 110. That is, adhesive layer 122 and microLED chip 110 may be attached to substrate 160, which serves as a planar plate. In some embodiments, the bottom surface of adhesive layer 122 may not be aligned with the bottom surface of microLED chip 110. In some embodiments, adhesive layer 122 may be conductive, and its thickness may be from 5 μm to 50 μm. With this arrangement, FCB 120 may be electrically coupled to substrate 160, which may be a common equipotential element in a display device including microLED display panel 10. For example, FCB 120 may be grounded when substrate 160 is grounded. Although not shown, FCB 120 may include conductive lines that act as ground lines and are coupled to the ground potential of elements connected to FCB 120. In some implementations, the adhesive layer 122 may be electrically insulating, and the FCB 120 may not need to be grounded.

[0045] In some embodiments, the driving layer 111 further includes an adhesive layer 1113 adhered to the front surface of the substrate layer 160. The bottom surface of the adhesive layer 1113 may be aligned with the bottom surface of the FCB 120. Specifically, if present, the bottom surface of the adhesive layer 1113 may be aligned with the bottom surface of the adhesive layer 122. In some embodiments, the adhesive layer 1113 is insulating and electrically isolates the driving layer 111 from the substrate layer 160. Because the driving layer 111 may include several electrodes or solder joints on its bottom surface, the back surface of the driving layer 111 may need to be insulated from the external environment. For example, the adhesive layer 1113 may be formed of die attach (DA) adhesive or die attach film (DAF) adhesive. In some embodiments, the bottom surface of the adhesive layer 1113 may not be aligned with the bottom surface of the FCB 120.

[0046] In some embodiments, the thickness of adhesive layer 122 may be similar to the thickness of adhesive layer 1113. In other embodiments, the thickness of adhesive layer 122 may be less than the thickness of adhesive layer 1113.

[0047] In some embodiments, the adhesive layer 122 is disposed only on the bottom surface of the connection region 121, while the substrate layer 160 may be disposed below the connection region 121 via the adhesive layer 122. In some embodiments, such as Figure 2A As shown, the adhesive layer 122 can be further disposed below the bottom surface of the region 123 adjacent to the connection region 121, while the substrate layer 160 is further disposed below the region 123 adjacent to the connection region 121 via the adhesive layer 122. The boundary between the connection region 121 and the region 123 is... Figure 2A The line shown in the middle is dashed. Since FCB 120 is flexible and can be relatively fragile, providing a longer area of ​​FCB 120 on substrate 160 can enhance its reliability in terms of the package of the connection area 121 created by molding layer 130 and substrate 160.

[0048] In some embodiments, the molding layer 130 may also be formed on the FCB 120 extending a distance L1 from the connection region 121. It should be understood that the longer arrangement of the molding layer 130 on the FCB 120 increases the adhesion between the molding layer 130 and the FCB 120. This can ensure better reliability of the FCB 120 in the package created by the molding layer 130 and the substrate layer 160. In some embodiments, the distance L1 extending from the connection region 121 may be equal to or different from the length L2 of the region 123 adjacent to the connection region 121. For example, as... Figure 2C As shown, distance L1 can be longer than length L2 (for example, distance L1 can be 0.05 mm longer than length L2).

[0049] In some embodiments, FCB 120 includes a conductive line 124 extending from connection area 121. FCB 120 can be coupled to signal area 114 via line 124. In some embodiments, such as Figure 2A As shown, the molding layer 130 can be further configured as an encapsulation trace 124. In some embodiments, such as Figure 2C As shown, line 124 may include a bundle of wires extending from different locations in signal area 114 and connection area 121.

[0050] In some implementations, the height of the molding layer 130 is greater than or equal to the height of the micro-LED array 112. The higher molding layer 130 can provide additional protection for the micro-LED array 112, while the lower molding layer 130 can provide a more compact design for the micro-LED display panel 10.

[0051] In some implementation schemes, such as Figure 1A As shown, the width W of the molding layer 130 corresponds to the width of the connection area 121. That is, ignoring manufacturing tolerances and the thin deposition of the molding layer 130 at the edge of the FCB 120, the width of the molding layer 130 can be substantially equal to the width of the connection area 121. In some embodiments, the width of the molding layer 130 can be greater than all areas of the FCB 120 except for the connection area 121. In other words, the connection area 121 is the widest area within the FCB 120 to ensure the rigidity of the two connected parts.

[0052] In some implementation schemes, such as Figure 1A , 1B As shown in Figures 2A and 2B, the micro LED display panel 10 may include a rigid circuit board 170, which is located at the opposite end of the connection area 121 on the FCB 120 and electrically coupled to the FCB 120. The rigid circuit board 170 may include one or more connectors. In this embodiment, the rigid circuit board 170 includes connectors 1701 and 1702 on one surface and connector 1703 on the opposite surface. Connectors 1701, 1702, and 1703 may be connected in a pin-slot configuration to other processing units or other rigid circuit boards of other micro LED display panels. Here, the connectors are not specified as pin-slot configurations, as long as they can be used for communication with external device I / O.

[0053] Figure 4A A structural view of the front side of another exemplary micro LED display panel 40 according to some embodiments of the present disclosure is shown. Figure 4BA structural diagram of the back surface of an exemplary micro-LED display panel 40 is shown. The micro-LED display panel 40 shows many commonalities with the micro-LED display panel 10 described above. However, the micro-LED display panel 40 includes a hard circuit board 460. In some embodiments, the hard circuit board 460 can have a different shape and function from the hard circuit board 170 of the micro-LED display panel 10. Specifically, the hard circuit board 460 includes a storage chip 4602. In some embodiments, the hard circuit board 460 can also include a cover arranged on or above the storage chip 4602 to protect the storage chip 4602. The hard circuit board 460 also includes a connector 4601 on one surface and the storage chip 4602 on the surface opposite the connector 4601. The connector 4601 and the storage chip 4602 are connected together for storing data into and outputting data from the storage chip 4602 through the connector 4601. For example, the storage chip 4602 can cache or store patterns to be displayed or instructions for displaying patterns for the micro-LED display panel 40, which can reduce the communication cost between the micro-LED display panel 40 and a signal source (e.g., a GPU) and thus improve display efficiency.

[0054] Figure 1A 、 1B The micro-LED display panel 10 shown in FIGS. 2A and 2B having connectors 1701-1703 on both surfaces can be used as a hub connected to the micro-LED display panel 40. Other aspects of the micro-LED display panel 40 can be understood by referring to the description of the micro-LED display panel 10 by reference, which will not be described in detail here. Figure 1B 、 2A The micro-LED display panel 10 shown in FIGS. 2A and 2B can also include a storage chip coupled to one or more of the connectors 1701, 1702, 1703. Figure 1A 、 1B The micro-LED display panel 10 shown in FIGS. 2A and 2B can also include a storage chip coupled to one or more of the connectors 1701, 1702, 1703.

[0055] Figure 5A A front surface of an exemplary display device 50 having micro-LED display panels 501 (e.g., corresponding to the micro-LED display panel 10 in FIGS. 1A and 1B) and micro-LED display panels 502 and 503 (e.g., each corresponding to the micro-LED display panel 40 in FIGS. 3A and 3B) according to some embodiments of the present disclosure is shown. Figure 1B 、 2A A front surface of an exemplary display device 50 having micro-LED display panels 501 (e.g., corresponding to the micro-LED display panel 10 in FIGS. 1A and 1B) and micro-LED display panels 502 and 503 (e.g., each corresponding to the micro-LED display panel 40 in FIGS. 3A and 3B) according to some embodiments of the present disclosure is shown. Figure 4A and 4B A front surface of an exemplary display device 50 having micro-LED display panels 501 (e.g., corresponding to the micro-LED display panel 10 in FIGS. 1A and 1B) and micro-LED display panels 502 and 503 (e.g., each corresponding to the micro-LED display panel 40 in FIGS. 3A and 3B) according to some embodiments of the present disclosure is shown. Figure 5B A back surface of the exemplary display device 50 is shown. For clarity in illustrating the coupling relationship between the connectors, Figure 5A and 5B Some components shown in FIGS. 4A and 4B can not be visible from the outside and are represented in dashed lines.

[0056] like Figure 5A As shown, connectors 4601 of micro LED display panels 502 and 503 are respectively inserted into connectors 1701 and 1702 of micro LED display panel 501, forming an exemplary display device 50 with three cooperating micro LED display panels. More specifically, panels 502 and 503 can be flipped by twisting their respective FCBs, so that connectors 4601 of panels 502 and 503 face connectors 1701 and 1702 of micro LED display panel 501, respectively. These micro LED display panels can be specifically driven via connectors 1703 on the back of micro LED display panel 501 by signals received from micro LED display panel 501, such as... Figure 5B As shown. Connector 1703 can be connected to an external device that generates the signal. It should be understood that the micro LED display panels 501, 502, and 503 can be used to display the red, green, and blue components of the composite image, respectively. That is, micro LED display panel 501 can render a red image, micro LED display panel 502 can render a green image, and micro LED display panel 503 can render a blue image.

[0057] Figure 6 Another exemplary display device 60 with a combiner 600 is shown according to some embodiments of the present disclosure. (Refer to...) Figure 6 The display device 60 (e.g., a color projector) includes Figure 5A and 5B The diagram shows micro-LED display panels 501, 502, and 503, as well as a combiner 600 (e.g., a combining prism). The combiner 600 can be used to combine (also “composite”) images rendered by the micro-LED display panels 501, 502, and 503 into a composite image. It should be understood that the display device 60 may also include other components necessary for operation, which are omitted here.

[0058] As described above, the micro LED display panel 501 can render a red image, the micro LED display panel 502 can render a green image, and the micro LED display panel 503 can render a blue image. These images can be combined into a multicolor image by the combiner 600. The red, green, and blue images can be aligned after being passed through the combiner 600 to form a multicolor image.

[0059] In some implementations, the microLED chip 110 includes an integrated circuit (IC) backplane (e.g., Figure 2A , 2BThe micro-LED array 112 includes a plurality of micro-LEDs (not shown). Each micro-LED can form at least a portion of a pixel cell on the micro-LED chip 110. For example, for monochrome display, a pixel cell can be formed by a single micro-LED; and for color display, a pixel cell can be formed by three micro-LEDs. In some embodiments, each dimension of the micro-LED chip 110 does not exceed 1 centimeter (cm), preferably, does not exceed 20 micrometers (pm). The resolution of the micro-LED array 112 can be 720 x 480, 640 x 480, 1920 x 1080, 1280 x 720, 2K (i.e., 2048 x 1080), or 4K (i.e., 3840 x 2160). The diameter of the micro-LEDs is in nanometer scale, for example, from 20 nm to 100 nm. In some embodiments, the pitch of the micro-LED array 112, i.e., the minimum distance center-to-center between adjacent micro-LEDs, can be in the range of 2 pm to 50 pm. In some embodiments, the number of pixels in the micro-LED chip 110 can vary from several thousands to several millions or more. In some embodiments, the micro-LED array 112 can include blue micro-LEDs, green micro-LEDs, or red micro-LEDs.

[0060] In some embodiments, the IC backplane can be electrically connected to each micro-LED of the micro-LED array 112 through a separate metal interconnect. In some embodiments, each micro-LED can be individually electrically controlled through the IC backplane. In some embodiments, the IC backplane can be electrically connected to the electrodes of the micro-LED chip 110 through metal interconnects. In some embodiments, a dielectric layer can be formed in the gaps between the micro-LEDs. In some embodiments, a dielectric layer can also be formed in the gaps between the metal interconnects.

[0061] In some embodiments, each micro-LED of the micro-LED array 112 can include a micro-mesa structure. In some embodiments, the micro-mesa structure can include, from bottom to top, a first type of epitaxial layer, a light emitting layer, and a second type of epitaxial layer. That is, among the three layers, the first type of epitaxial layer is closest to the IC backplane; the light emitting layer is on top of the first type of epitaxial layer and is farther from the IC backplane; and the second type of epitaxial layer is on top of the light emitting layer and is farthest from the IC backplane. In some embodiments, the light emitting layer is formed of several stacked quantum well layers, particularly superlattice stacked quantum well layers. Preferably, the superlattice stacked quantum well layers include several pairs of quantum well layers stacked with quantum barrier layers. In some embodiments, the first type of epitaxial layer is a semiconductor material with a first conductivity type and includes several semiconductor layers. The bulk material of the first type of epitaxial layer can be, but is not limited to, a base material including one or more of Ga, N, As, P, In, or Al, etc. In addition, the first type of epitaxial layer can include, from top to bottom, but not limited to, a waveguide layer, a confinement layer, a transition layer, and a window layer. In addition, an ohmic contact layer can be formed below the window layer. In some embodiments, the second type of epitaxial layer is a semiconductor material with a second conductivity type and includes several semiconductor layers. The bulk material of the second type of epitaxial layer can be, but is not limited to, a base material including one or more of Ga, N, As, P, In, or Al, etc. In addition, the second type of epitaxial layer can include, from top to bottom, but not limited to, a confinement layer and a waveguide layer. In addition, in some embodiments, an ohmic contact layer can be formed on the confinement layer, but is not limited to.

[0062] In some embodiments, a top conductive layer can be formed on the top surface of the micro-LED array 112. In some embodiments, the top conductive layer can be shared by all micro-LEDs in the micro-LED array 112. In some embodiments, the micro-LED array 112 can include a single layer of micro-LEDs. For example, the micro-LEDs can be arranged on a plane. In some embodiments, the micro-LED array 112 can include multiple layers of micro-LEDs vertically stacked with the electrical connection layer. Each micro-LED in the micro-LED array 112 can be controlled individually by independently controlling the anode and cathode of each micro-LED, or by controlling individual cathodes and a common anode electrode layer of the micro-LEDs, or by controlling individual anodes and cathode electrode layers of the micro-LEDs. For example, the micro-LEDs can be arranged on several planes parallel to each other.

[0063] Figure 7 A flowchart illustrating an exemplary method 70 of manufacturing a micro-LED display panel according to some embodiments of the present disclosure is shown. As Figure 7As shown, the method 70 includes steps 702 and 704, which can be implemented by a manufacturing apparatus (e.g., a manufacturing equipment including a chip mounter, a wire bonding machine, a molding machine, a cutting machine, etc.) for manufacturing a micro LED display panel.

[0064] In step 702, the manufacturing apparatus couples a flexible circuit board (FCB) to the micro LED chip. As described above in connection with the micro LED display panel 10, the micro LED chip includes a driving layer, a micro LED array disposed on the driving layer, and a transparent protection layer disposed on the micro LED array. The driving layer can include a signal region on which the micro LED array is not disposed. The signal region can be used to receive signals for driving the micro LED array. In addition, the manufacturing apparatus can dispose the FCB adjacent to the signal region and couple it to the signal region in a connection region of the FCB. Figures 1A to 6

[0065] In some embodiments, the FCB includes a conductive line leading from the connection region. The FCB can be coupled with the signal region via the line. In step 702, a molding layer is further disposed to encapsulate the line.

[0066] In step 704, the manufacturing apparatus forms the molding layer to combine the micro LED chip and the connection region of the FCB into a single compact structure.

[0067] In some embodiments of the present disclosure, the method 70 can further include a step of disposing a substrate layer in cooperation with the molding layer to engage at least a portion of the FCB with the micro LED chip, which can be implemented by the manufacturing apparatus. This step can be implemented before the molding layer is disposed in step 704. In this step, the molding layer, the micro LED chip, and the connection region of the FCB can be disposed on a front surface of the substrate layer.

[0068] Other aspects of the method 70 can be understood by referring to the above description of the micro LED display panel 10, which will not be elaborated here. Figures 1A to 6

[0069] Some embodiments of the present disclosure also provide a display apparatus. The display apparatus can include any of the micro LED display panels described herein.

[0070] Figure 8 An exemplary display apparatus according to some embodiments of the present disclosure is shown. As Figure 8 ​​As shown, a Near Eye Display (NED) 800, such as AR glasses, includes a pair of color projectors 810 and a frame 820 for fixing the color projectors 810. The NED 800 may also include other components, which are omitted here for clarity of the NED 800 configuration. Each color projector 810 may be disposed at the end of a temple (not shown) of the NED 800. A power supply system and processing system for driving the color projectors 810 may be embedded in the temple. The image rendered by each color projector 810 can be captured by the corresponding eye of an observer (not shown), which can be used to create a virtual or augmented scene for the observer. In some embodiments, the term "rendering" may also be referred to as "display," "shown," or equivalent terms. Each color projector 810 may include three micro-LED panels of different colors (e.g., each corresponding to...). Figure 1B , 2A And the miniature LED display panel 10 in 2B or Figure 4A and 4B The image consists of a miniature LED display panel 40 and a combiner (e.g., a combination prism). The combiner can be used to combine (also called “composite”) images rendered by three miniature LED panels into a composite image.

[0071] Figure 9 Another exemplary display device is shown, illustrating some embodiments according to this disclosure. For example... Figure 9 As shown, the head-mounted virtual reality device 900 includes two micro-LED panels 910 (e.g., each corresponding to...). Figure 1B , 2A And the miniature LED display panel 10 in 2B or Figure 4A and 4B The head-mounted virtual reality device 900 may also include a micro-LED display panel 40 (not shown), although it may also include a central processing unit (CPU), a graphics processing unit (GPU) as a signal source, and other related circuitry. Introducing a micro-LED panel embodying the aforementioned micro-LED elements into the head-mounted virtual reality device 900 can improve its illumination efficiency, thereby reducing energy consumption and improving image quality.

[0072] It should be noted that relational terms such as “first” and “second” in this document are used only to distinguish one entity or operation from another, and do not require or imply any actual relationship or order between these entities or operations. Furthermore, the words “including,” “having,” “containing,” and “comprising,” as well as other similar forms, are intended to be equivalent in meaning and are open-ended; one or more items following any of these words do not imply an exhaustive list of such one or more items, or that they are limited to only one or more listed items.

[0073] The term "or" as used herein, unless otherwise indicated, is inclusive and not exclusive. For example, a database can include A or B, unless otherwise indicated or infeasible, the database can include A, or B, or both. In a second example, if a database is said to include A, B, or C, unless otherwise indicated or infeasible, the database can include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C.

[0074] In the foregoing specification, embodiments have been described with reference to numerous specific details that can vary from implementation to implementation. Certain alterations and modifications can be practiced with certain of the above-described embodiments. Other embodiments can be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and described embodiments be considered as illustrative only with the true scope and spirit of the invention being indicated by the following claims. It is also intended that the order of steps in the steps shown in the figures be for illustrative purposes only and not intended to limit the scope of the invention to any particular order of steps. Accordingly, those skilled in the art will recognize that the steps outlined herein can be modified in different sequences or in different ways without departing from the inventive concept.

[0075] In the drawings and specification, there have been disclosed exemplary embodiments. However, many variations and modifications can be made to these embodiments. Therefore, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, as the scope of the inventive concept is intended to be limited only by the claims.

Claims

1. A miniature LED display panel, characterized in that, include: Miniature LED chips, including: Driver layer; A micro-LED array disposed on the driving layer; and A transparent protective layer is disposed on the micro-LED array, wherein the driving layer is configured to receive signals for driving the micro-LED array; A flexible circuit board (FCB) is disposed adjacent to and configured to be coupled to the microLED chip; and A molding layer configured to bond the microLED chip and the FCB together.

2. The micro LED display panel according to claim 1, characterized in that, The driving layer also includes a signal area, on which the micro LED array is not disposed, and the FCB is disposed adjacent to and coupled to the signal area.

3. The micro LED display panel according to claim 2, characterized in that, The FCB also includes a connection area adjacent to the signal area, and The micro LED display panel also includes conductive lines connecting the connection area and the signal area.

4. The micro LED display panel according to claim 1, characterized in that, The transparent protective layer includes an adhesive layer, which is adhered to the top surface of the micro-LED array via the adhesive layer.

5. The micro LED display panel according to claim 1, characterized in that, The transparent protective layer includes an adhesive layer, which is adhered to the front surface of the driving layer around the micro-LED array via the adhesive layer.

6. The micro LED display panel according to claim 1, characterized in that, The projection of the horizontal cross-section of the transparent protective layer in the vertical direction is within the horizontal cross-section of the driving layer.

7. The micro LED display panel according to claim 1, characterized in that, The side surface of the transparent protective layer is adjacent to the molding layer.

8. The micro LED display panel according to claim 7, characterized in that, The molded layer includes two continuous side surfaces, which are bridged by a flange face therebetween; and The first continuous side surface of the two continuous side surfaces is adjacent to the side surface of the drive layer, the second continuous side surface of the two continuous side surfaces is adjacent to the side surface of the transparent protective layer, and the flange face is adjacent to the front surface of the drive layer.

9. The micro LED display panel according to claim 1, characterized in that, The top surface of the molded layer is aligned with the top surface of the transparent protective layer.

10. The micro LED display panel according to claim 1, characterized in that, The molding layer is configured to leave an opening area above the transparent protective layer.

11. The micro LED display panel according to claim 10, characterized in that, The top surface of the molded layer is higher than the top surface of the transparent protective layer.

12. The micro LED display panel according to claim 1, characterized in that, The bottom surface of the micro LED chip is aligned with the bottom surface of the FCB.

13. The micro LED display panel according to claim 1, characterized in that, The molding layer is formed by filling the gap between the microLED chip and the FCB, and the molding layer is further formed on a portion of the front surface and side surface of the driving layer.

14. The micro LED display panel according to claim 1, characterized in that, Also includes: A substrate layer, disposed in conjunction with the molding layer, is provided to bond the microLED chip to at least a portion of the FCB, wherein the molding layer, the microLED chip, and the FCB are disposed on the front surface of the substrate layer.

15. The micro LED display panel according to claim 14, characterized in that, The substrate layer is formed of a steel plate.

16. The micro LED display panel according to claim 14, characterized in that, The FCB includes an adhesive layer that adheres to the surface of the substrate layer, the bottom surface of which is aligned with the bottom surface of the microLED chip.

17. The micro LED display panel according to claim 16, characterized in that, The adhesive layer is conductive.

18. The micro LED display panel according to claim 16, characterized in that, The adhesive layer is a first adhesive layer, and the driving layer further includes a second adhesive layer adhered to the surface of the substrate layer, the bottom surface of the second adhesive layer being aligned with the bottom surface of the FCB.

19. The micro LED display panel according to claim 18, characterized in that, The second adhesive layer is insulating.

20. The micro LED display panel according to claim 19, characterized in that, The second adhesive layer is formed by die attach (DA) adhesive or die attach film (DAF) adhesive.

21. The micro LED display panel according to claim 18, characterized in that, The thickness of the first adhesive layer is less than the thickness of the second adhesive layer.

22. The micro LED display panel according to claim 16, characterized in that, The FCB is coupled to the signal region within the connection region of the FCB, the adhesive layer is disposed on the bottom surface of the connection region, and the substrate layer is disposed below the connection region via the adhesive layer.

23. The micro LED display panel according to claim 22, characterized in that, The adhesive layer is also disposed below the bottom surface of the region adjacent to the connection area, and the substrate layer is further disposed below the adjacent region via the adhesive layer.

24. The micro LED display panel according to claim 23, characterized in that, The molding layer is also formed on the FCB at a distance extending from the connection area.

25. The micro LED display panel according to claim 24, characterized in that, The distance is equal to or different from the length of the adjacent region.

26. The micro LED display panel according to claim 25, characterized in that, The distance is at least 0.05 mm longer than the length of the adjacent region.

27. The micro LED display panel according to claim 3, characterized in that, The molding layer is also configured to encapsulate the circuitry.

28. The micro LED display panel according to claim 1, characterized in that, The FCB is coupled to the signal area within the connection area of ​​the FCB, the width of the molding layer corresponds to the width of the connection area, and the width of the molding layer is greater than the width of all areas of the FCB except the connection area.

29. The micro LED display panel according to claim 1, characterized in that, It also includes a rigid circuit board disposed on the FCB at the opposite end to the micro LED chip and electrically coupled to the FCB, the rigid circuit board including at least one connector disposed on the surface of the rigid circuit board.

30. The micro LED display panel according to claim 29, characterized in that, The rigid circuit board also includes a memory chip, and the at least one connector is coupled to the memory chip.

31. A method for manufacturing a micro LED display panel, characterized in that, include: A flexible circuit board (FCB) is coupled to a micro LED chip, the micro LED chip including a driving layer, a micro LED array and a transparent protective layer, the micro LED array being disposed on the driving layer, the transparent protective layer being disposed on the micro LED array, the driving layer being configured to receive signals for driving the micro LED array, and the FCB being configured to be coupled to the micro LED chip; as well as A molding layer is formed to encapsulate the microLED chip and the FCB into a single unit.

32. The method according to claim 31, characterized in that, The driving layer further includes a signal area on which the micro LED array is not disposed, and the FCB is disposed adjacent to the signal area and coupled to the signal area.

33. The method according to claim 32, characterized in that, The FCB also includes a connection area adjacent to the signal area, and The micro LED display panel also includes conductive lines connecting the connection area and the signal area.

34. The method according to claim 31, characterized in that, Before forming the molded layer, the method further includes: A substrate layer is provided to cooperate with the molding layer to bond at least a portion of the FCB to the micro LED chip, wherein the molding layer, the micro LED chip and the FCB are disposed on the same surface of the substrate layer.

35. The method according to claim 33, characterized in that, The molding layer is also configured to encapsulate the circuitry.

36. A display device, characterized in that, Includes a micro LED display panel according to any one of claims 1 to 30.

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