Miniature LED display panel, manufacturing method thereof and display device

Abstract

The invention provides a miniature LED display panel, a manufacturing method thereof and a display device. The miniature LED display panel comprises a miniature LED chip, the miniature LED chip comprises a driving layer and a miniature LED array arranged on the driving layer, and the driving layer comprises a signal area used for receiving signals for driving the miniature LED array; the flexible circuit board is arranged at a position adjacent to the signal area and is coupled with the signal area; the molding layer is arranged on the micro LED chips and the flexible circuit board and is used for connecting the micro LED chips with the flexible circuit board, and an opening area is reserved on the molding layer above the micro LED array; the substrate layer is arranged in cooperation with the molding layer so that the micro LED chip and at least part of the flexible circuit board can be combined, the molding layer, the micro LED chip and the flexible circuit board are arranged on the front face of the substrate layer, and the substrate layer comprises an edge where the molding layer is not arranged.

Description

Technical Field

[0001] This disclosure relates to the field of microdisplays, and more particularly to a micro LED display panel and a method for manufacturing the same, as well as a display device. Background Technology

[0002] Inorganic micro-pixel light-emitting diodes, also known as micro LEDs, micro LEDs, or μ-LEDs, are becoming increasingly important due to their applications in various fields such as self-emissive micro-displays, visible light communication, and optogenetics. Compared to conventional LEDs, micro LEDs exhibit better strain relaxation, higher light extraction efficiency, and more uniform current diffusion, resulting in higher output performance. Compared to conventional LEDs, micro LEDs also demonstrate several advantages, such as better thermal performance, faster response time, wider operating temperature range, higher resolution, wider color gamut, higher contrast ratio, lower power consumption, and operability at higher current densities.

[0003] Micro-LED display panels are manufactured by integrating an array of thousands or even millions of micro-LEDs with an IC (integrated circuit) backplane. In conventional technologies, micro-LEDs are packaged onto an IC backplane, with the micro-LED array forming the light-emitting area in the functional region on the front of the IC backplane. Simultaneously, the non-functional region on the front of the IC backplane can be used for electrode placement, forming I / O interfaces for voltage and signal transmission. This packaging approach results in a larger micro-LED product size, occupying more space and limiting its application in space-constrained products.

[0004] Therefore, it is necessary to improve the packaging technology of micro LEDs. Summary of the Invention

[0005] This disclosure provides a micro-LED display panel, comprising: a micro-LED chip, a flexible circuit board, a molding layer, and a substrate layer. The micro-LED chip includes a driving layer and a micro-LED array disposed on the driving layer. The driving layer includes a signal region on which the micro-LED array is not disposed, and the signal region is used to receive signals driving the micro-LED array. The flexible circuit board is disposed adjacent to the signal region and coupled to the signal region of the driving layer. The molding layer is disposed on the micro-LED chip and the flexible circuit board, and is used to bond the micro-LED chip to the flexible circuit board. The molding layer has an opening area above the micro-LED array. The substrate layer is cooperating with the molding layer to bond the micro-LED chip and at least a portion of the flexible circuit board. The molding layer, the micro-LED chip, and the flexible circuit board are disposed on the front side of the substrate layer, and the substrate layer includes an edge on which the molding layer is not disposed.

[0006] This disclosure provides a method for manufacturing a micro LED display panel, comprising: providing a substrate layer; disposing a flexible circuit board and a micro LED chip on the front side of the substrate layer, wherein the flexible circuit board and the micro LED chip are coupled, the micro LED chip includes a driving layer and a micro LED array disposed on the driving layer, the driving layer includes a signal area where the micro LED array is not disposed, the signal area being used to receive signals driving the micro LED array, the flexible circuit board being adjacent to and coupled to the signal area; and forming a molding layer on the front side of the substrate layer to bond the micro LED chip and the flexible circuit board into an integral structure, leaving an opening area above the micro LED array, the substrate layer and the molding layer jointly bonding the micro LED chip and the flexible circuit board; wherein the substrate layer includes an edge where the molding layer is not disposed.

[0007] This disclosure also provides a display device. The display device includes any of the micro LED display panels described in this disclosure. Attached Figure Description

[0008] Embodiments and aspects of this disclosure will be set forth in the following detailed description and accompanying drawings. The various features shown in the figures are not drawn to scale.

[0009] Figure 1A A front structural schematic diagram of an exemplary micro-LED display panel according to an embodiment of the present disclosure is shown.

[0010] Figure 1B An embodiment according to this disclosure is shown. Figure 1A A schematic diagram of the rear structure of an exemplary micro-LED display panel is shown.

[0011] Figure 2A An exemplary micro LED display panel according to an embodiment of the present disclosure is shown along... Figure 1A A schematic diagram of the cross-sectional structure of the AA section line.

[0012] Figure 2B An exemplary micro LED display panel according to an embodiment of the present disclosure is shown along... Figure 1A Another cross-sectional structural diagram of the AA section line.

[0013] Figure 2C Another exemplary micro LED display panel according to an embodiment of this disclosure is shown along... Figure 1A Another cross-sectional structural diagram of the AA section line.

[0014] Figure 3A An embodiment according to this disclosure is shown. Figure 1A, Figure 2A , Figure 2B ,as well as Figure 2C The diagram shows a schematic representation of the structure of the microLED chip in an exemplary microLED display panel.

[0015] Figure 3B Examples of embodiments according to this disclosure are shown. Figure 1A , Figure 2A , Figure 2B ,as well as Figure 2C The diagram shows a schematic representation of the structure of the microLED chip in an exemplary microLED display panel.

[0016] Figure 3C Examples of embodiments according to this disclosure are shown. Figure 1A , Figure 2A , Figure 2B ,as well as Figure 2C The diagram shows a schematic representation of the structure of the microLED chip in an exemplary microLED display panel.

[0017] Figure 4A A front structural schematic diagram of another exemplary micro-LED display panel according to an embodiment of the present disclosure is shown.

[0018] Figure 4B An embodiment according to this disclosure is shown. Figure 4A A schematic diagram of the rear structure of an exemplary micro-LED display panel is shown.

[0019] Figure 5A A front structural schematic diagram of an exemplary display device having a plurality of micro-LED display panels according to an embodiment of the present disclosure is shown.

[0020] Figure 5B An embodiment according to this disclosure is shown. Figure 5A A schematic diagram of the rear structure of an exemplary display device is shown.

[0021] Figure 6 A schematic diagram of the structure of another exemplary display device having a synthesizer according to an embodiment of the present disclosure is shown.

[0022] Figure 7 A flowchart illustrating an exemplary method for manufacturing a micro LED display panel according to an embodiment of the present disclosure is shown.

[0023] Figure 8 A schematic diagram of the structure of another exemplary display device according to an embodiment of the present disclosure is shown.

[0024] Figure 9 A schematic diagram of the structure of another exemplary display device according to an embodiment of the present disclosure is shown. Detailed Implementation

[0025] Reference will now be made specifically to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the drawings, where the same reference numerals in different figures denote the same or similar elements unless otherwise stated. The implementations set forth in the following description of the exemplary embodiments do not represent all implementations consistent with this disclosure. Rather, these implementations are merely examples of apparatuses and methods consistent with aspects of the disclosure recited 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 Figure 1B A schematic diagram of the structure of an exemplary micro LED display panel 10 according to an embodiment of the present disclosure is shown. Figure 2A An exemplary micro LED display panel 10 according to an embodiment of the present disclosure is shown along... Figure 1A A schematic diagram of the cross-sectional structure of the AA section line. Figure 2B An exemplary micro LED display panel 10 according to an embodiment of the present disclosure is shown along... Figure 1A Another cross-sectional structural diagram of the AA section line. (See diagram below.) Figure 1A , Figure 1B , Figure 2A ,as well as Figure 2B As shown, 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 of the micro-LED display panel 10 includes forming the molding layer 130 on a portion of the micro-LED chip 110 and the FCB 120, thereby bonding the micro-LED chip 110 and the FCB 120 into an integrated, compact structure. This assembly is small in size and can be seamlessly integrated into a display device. For example, in a deposition process, a molding layer 130 with high-temperature resistance can be applied over the micro-LED chip 110 and the FCB 120. At high temperatures, the molding material used to form the molding layer 130 exhibits a softer texture, thereby encapsulating the micro-LED chip 110 and the FCB 120. After cooling and curing, the molding layer 130 effectively encapsulates and bonds the micro-LED chip 110 and the FCB 120, bonding them into an integrated, compact structure. In some embodiments, the molding process may also be transfer molding, injection molding, compression molding, extrusion molding, or blow molding. In some embodiments, the molding material of the molding layer 130 may be epoxy molding compound (EMC), acrylic resin (polymethyl methacrylate), acrylonitrile-butadiene-styrene copolymer (ABS), nylon polyamide (PA), polycarbonate (PC), polyethylene (PE), etc.

[0027] like Figure 2A As shown, the micro LED chip 110 includes a driving layer 111 and a micro LED array 112 disposed on the driving layer 111. The driving layer 111 may include a driving circuit (not shown) for driving the micro LED array 112 according to received signals. Specifically, the driving layer 111 may include a signal region 113 for receiving signals for driving the micro LED array 112 and transmitting them to the driving circuit. The micro LED array 112 is not disposed on the signal region 113 to reserve space for leading out electrodes, which can be coupled to electrodes within the FCB 120.

[0028] To achieve a compact structure for the micro-LED display panel 10, the FCB 120 can be positioned adjacent to the signal area 113, thereby reducing the overall length of the micro-LED display panel 10. The distance between the micro-LED chip 110 and the FCB 120 can be from 1 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 adhesiveness of the molding material of the molding layer 130 to ensure that the micro-LED chip 110 and the FCB 120 will not break due to external forces after assembly. It is worth noting that when the distance between the micro-LED chip 110 and the FCB 120 is large, if the adhesiveness of the molding material is low, it may be necessary to use a thicker molding material to form the molding layer 130.

[0029] In some embodiments, FCB120 includes a connection region 121 for leading out electrodes. FCB120 can be coupled to signal region 113 of driver layer 111 via its connection region 121. It is understood that FCB120 may not generate signals to drive the micro-LED array 112, but can transmit these signals, thus serving as a signal and electrical transmission medium. These signals may be generated by a graphics processor (GPU) (not shown) connected to FCB120.

[0030] Further reference Figure 1A , Figure 1B , Figure 2A ,as well as Figure 2BThe molding layer 130 can be used to bond with the micro-LED chip 110 and FCB 120 (e.g., the connection area 121 of FCB 120) to form an integrated compact structure. As described above, the molding layer 130 can be located on a portion of the outer surface of the micro-LED chip 110 and FCB 120, thereby bonding the micro-LED chip 110 and FCB 120. More specifically, the molding layer 130 can be formed and filled in the gap 150 between the micro-LED chip 110 and FCB 120, and can also be formed on the side and part of the front of the driving layer 111 (on which the micro-LED array 112 is formed), and in the end region of the FCB 120. Therefore, the molding layer 130 bonds the micro-LED chip 110 and FCB 120 into an integrated compact structure. Figure 2A As shown, by providing a molding layer 130 to leave an opening area 140 above the micro-LED array 112, the micro-LED array 112 can emit light through the opening area 140, thereby displaying an image generated according to the received signal. Therefore, the micro-LED chip 110 is connected to the FCB 120 through the molding layer 130 without affecting the display effect of the micro-LED array 112.

[0031] In some embodiments, the opening region 140 has a specific shape, the outline of which is defined by the molding layer 130. For example, as Figure 2A As shown, the opening region 140 may have a trapezoidal cross-section and an outwardly widening opening structure. During the deposition process of forming the molding layer 130, the opening region 140 is used to shield the mold from the molding layer 130. The molding material cannot fill the space occupied by the mold. Once the molding layer 130 has cured, the mold can be removed to expose the opening region 140. The opening region 140 is defined by the contour of the molding layer 130, and its outwardly widening opening structure facilitates demolding. It is understood that after the molding material has cured, the mold can be removed upwards without damaging the molding layer 130.

[0032] Furthermore, the outwardly widening opening structure reduces undesirable reflections generated on and between the inner walls of the opening region 140. Internal reflections within the opening region 140 cause blurring of the image presented by the micro-LED array 112, thereby reducing display quality. By employing the outwardly widening opening structure, most of the light emitted by the micro-LED array 112 can directly pass through the opening region 140 and reach the viewer's eye. Figure 1A , Figure 2A ,as well as Figure 2B As shown, the micro-LED array 112 is fully exposed from the opening region 140. That is, the light emitted by the micro-LED array 112 can be seen within a specific viewing angle range above the opening region 140 (e.g., within an 85-degree angle with the central normal axis of the micro-LED array 112).

[0033] Figure 3A and Figure 3B A schematic diagram of the microLED chip 110 of an exemplary microLED display panel 10 according to an embodiment of the present disclosure is shown. To clearly illustrate the circuit structure, Figure 3A and Figure 3B Components that cannot be observed from the outside are represented by dashed lines. For example... Figure 3A As shown, the molding layer 130 is not shown for ease of understanding the layout of the micro-LED chip 110. The micro-LED array 112 can be disposed on the surface of the driving layer 111 and coupled to the driving layer 111. Furthermore, the driving layer 111 may include metal pads 1111 disposed within the signal region 113. The metal pads 1111 and the micro-LED array 112 are both disposed on the same surface of the driving layer 111. That is, the signal region 113 extends to the vicinity of one side of the micro-LED array 112. Some of the metal pads 1111 can be electrically connected to the corresponding electrodes of the micro-LED array 112 to achieve coupling. Due to the properties of metal, the metal pads 1111 can reflect light incident upon them (in...). Figure 3A and 3B (Labeled as "incident light"). A portion of the light emitted by the micro-LED array 112 may strike the metal pads 1111, for example, through single or multiple reflections. This reflected light from the metal pads 1111 (in...) Figure 3A (The light marked as "reflected light") may cause the image presented by the micro-LED array 112 to become blurred and degraded.

[0034] To prevent the above phenomenon, such as Figure 3B As shown, a light-shielding layer 1112 can also be disposed on the metal pads 1111 of the driving layer 111. The light-shielding layer 1112 can absorb incident light, thereby improving the image quality presented by the micro-LED array 112. For example, the light-shielding layer 1112 can be black photoresist with a thickness of up to several micrometers. In some embodiments, the light-shielding layer 1112 can also be a black or dark-colored light-shielding film.

[0035] In some embodiments, such as Figure 3A As shown, at least a portion of the metal pads 1111 may be formed around the micro-LED array 112. Figure 3B The light-shielding layer 1112 can also be formed around the micro-LED array 112, and there is no need for a light-shielding layer 1112 between the micro-LED array 112 and the molding layer 130. Figure 3BA gap is left between (not shown). That is, the formed light-shielding layer 1112 covers all metal pads 1111, and when viewed from above the opening region 140, any area of ​​the opening region 140 exposed except for the micro-LED array 112 is shielded by the light-shielding layer 1112. The height of the light-shielding layer 1112 may be the same as the height of the micro-LED array 112. The object height referred to in this disclosure is the distance from the highest point of the object to a reference surface (e.g., the bottom surface of the substrate layer 160 described below). For example, the height of the light-shielding layer 1112 refers to the distance between the top surface of the light-shielding layer 1112 and the back surface of the substrate layer 160. In this case, the top surface of the light-shielding layer 1112 may be aligned with the top surface of the micro-LED array 112. In some embodiments, such as Figure 2A As shown, the height of the light-shielding layer 1112 may be greater than the height of the micro-LED array 112. In some embodiments, the molding layer 130 may be disposed adjacent to the light-shielding layer 1112, but not on top of the light-shielding layer 1112. In some embodiments, such as Figure 2B As shown, the molding layer 130 can be disposed adjacent to the light-shielding layer 1112 and located on the outer periphery of the light-shielding layer 1112.

[0036] Figure 3C Examples of embodiments according to this disclosure are shown. Figure 1A , Figure 2A , Figure 2B ,as well as Figure 2C The diagram shows a schematic representation of the microLED chip structure in an exemplary microLED display panel. Figure 3C As shown, multiple electrodes can be used to lead out 180 degrees. Figure 2A , Figure 2B ,as well as Figure 2C The conductive trace 124 is shown. It can be understood that the electrode 180 is connected to the micro-LED array 112.

[0037] Combination Figure 1B , Figure 2A ,as well as Figure 2BFurther, the micro-LED display panel 10 also includes a substrate layer 160, which is disposed in cooperation with the molding layer 130 for bonding the micro-LED chip 110 and at least a portion of the FCB 120. For example, the connection area 121 of the molding layer 130, the micro-LED chip 110, and the FCB 120 can be disposed on the front side of the substrate layer 160. On one hand, the substrate layer 160 can provide mechanical rigidity for surface components (such as the micro-LED chip 110, FCB 120, etc.) disposed on its surface. On the other hand, when the molding layer 130 is cooled and hardened, the substrate layer 160 can be bonded to the molding layer 130. Thus, the molding layer 130 and the substrate layer 160 together provide a sealed or semi-sealed environment for the surface components. In some embodiments, the substrate layer 160 can be a planar rectangular steel plate. It is understood that other materials that can provide similar functions to a steel plate can also be used as the substrate layer 160. For example, the substrate layer 160 can also be made of materials such as ceramics or hard resins. Figure 2A As shown, the substrate layer 160 includes edges where the molding layer 130 is not disposed, i.e., edges not covered by the molding layer 130. As shown in the plan view of the substrate layer 160, the substrate layer 160 may have three edges E1, E2, and E3 where the molding layer 130 is not disposed. That is, of the four edges of the substrate layer 160 (i.e., edges E1, E2, E3, and E4), edge E4 adjacent to the signal region 113 can be covered by the molding layer 130. In some embodiments, only a portion of the edges are not covered by the molding layer 130 (e.g., edges E1 and E2). In some embodiments, the distance D between any one of the three edges E1, E2, and E3 of the substrate layer 160 and the molding layer 130 can be in the range of 0.05 mm to 0.10 mm. This avoids excessive deposition of the molding layer 130 and facilitates demolding after the molding layer 130 has cured without affecting its shape.

[0038] In some embodiments, 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 height of the bottom surface of the FCB 120.

[0039] In some embodiments, such as Figure 2AAs shown, FCB120 may include an adhesive layer 122 adhered to the front side of substrate layer 160. The bottom surface of adhesive layer 122 may be aligned with the bottom surface of micro-LED chip 110. That is, adhesive layer 122 and micro-LED chip 110 may be attached to the flat substrate layer 160. In some embodiments, the bottom surface of adhesive layer 122 may not be aligned with the bottom surface of micro-LED chip 110. In some embodiments, adhesive layer 122 may be conductive and have a thickness ranging from 5 μm to 50 μm. With this configuration, FCB120 can be electrically coupled to substrate layer 160, which can serve as a common equipotential component in a display device including micro-LED display panel 10. For example, FCB120 may also be grounded when substrate layer 160 is grounded. Although not shown in the figure, FCB120 may include a conductive wire serving as a ground wire coupled to the ground potential of the component connected to FCB120. In some embodiments, adhesive layer 122 may be electrically insulating, and FCB120 may not need to be grounded.

[0040] In some embodiments, the driving layer 111 further includes an adhesive layer 1113 adhered to the front side of the substrate layer 160. The bottom surface of the adhesive layer 1113 may be aligned with the bottom surface of the FCB 120. Alternatively, the bottom surface of the adhesive layer 1113 may be aligned with the bottom surface of the adhesive layer 122 (if present). In some embodiments, the adhesive layer 1113 is insulating, thereby electrically isolating the driving layer 111 from the substrate layer 160. Since the bottom surface (back side) of the driving layer 111 may contain multiple electrodes or solder joints, the back side 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). In some embodiments, the bottom surface of the adhesive layer 1113 may not be aligned with the bottom surface of the FCB 120.

[0041] 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.

[0042] In some embodiments, the adhesive layer 122 is disposed only on the bottom surface of the connection area 121, thereby allowing the substrate layer 160 to be disposed below the connection area 121 via the adhesive layer 122. In some embodiments, such as Figure 2A As shown, the adhesive layer 122 can also be disposed below the bottom surface of the region 123 adjacent to the connection region 121, and the substrate layer 160 can also be 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 2AThe area is indicated by a dashed line. Since FCB120 is flexible and relatively fragile, providing a longer FCB120 area on the substrate layer 160 can enhance the reliability of the connection area 121 formed by the molding layer 130 and the substrate layer 160 in the package.

[0043] In some embodiments, a molding layer 130 is also formed on the FCB 120, and the molding layer 130 extends a distance L1 from the connection region 121 on the FCB 120. It is understood that the longer the molding layer 130 extends on the FCB 120, the stronger the adhesion between the molding layer 130 and the FCB 120. Therefore, the reliability of the FCB 120 can be enhanced by the encapsulation of the molding layer 130 and the substrate layer 160. In some embodiments, the distance L1 from the connection region 121 on the FCB 120 may be equal to or not equal to the length L2 of the region 123 adjacent to the connection region 121. For example, as... Figure 2C As shown, the distance L1 can be greater than the length L2 (for example, the distance L1 can be 0.05 mm longer than the length L2).

[0044] In some embodiments, the FCB 120 includes a conductive trace 124 extending from the connection region 121. The conductive trace 124 couples the FCB 120 to the signal region 113. In some embodiments, such as Figure 2A As shown, the conductive trace 124 can also be encapsulated by the molding layer 130. In some embodiments, such as Figure 2C As shown, the conductive trace 124 may include multiple wires extending from different locations in the signal area 113 and the connection area 121.

[0045] In some embodiments, the height of the molding layer 130 is greater than or equal to the height of the micro-LED array 112. A higher molding layer 130 can provide more protection for the micro-LED array 112, while a lower molding layer 130 allows for a more compact design of the micro-LED display panel 10.

[0046] In some embodiments, such as Figure 1A As shown, the width W of the molding layer 130 corresponds to the width of the connection region 121. That is, neglecting manufacturing tolerances and the thin-layer deposition of the molding layer 130 at the edge of the FCB 120, the width of the molding layer 130 is substantially equal to the width of the connection region 121. In some embodiments, the width of the molding layer 130 may be greater than the width of all regions on the FCB 120 except for the connection region 121. In other words, the connection region 121 is the widest region within the FCB 120, thereby ensuring the rigidity of the connection between the microLED chip 110 and the FCB 120.

[0047] In some embodiments, such as Figure 1A , Figure 1B , Figure 2A ,as well as Figure 2B As shown, the miniature LED display panel 10 may include a rigid circuit board 170, which is disposed at the end of the FCB 120 away from the connection area 121 and is electrically connected to the FCB 120. The rigid circuit board 170 may include one or more connectors. In this example, connectors 1701 and 1702 are provided on one side of the rigid circuit board 170, and connector 1703 is provided on the other side. Connectors 1701, 1702, and 1703 can be connected to the rigid circuit boards of other miniature LED display panels or other processing units via pin-slot connections. It is not limited to using only pin-slot structures for the connectors; any structure that enables I / O communication with external devices can be used.

[0048] Figure 4A A front structural schematic diagram of another exemplary micro LED display panel 40 according to an embodiment of the present disclosure is shown. Figure 4B A schematic diagram of the rear structure of the exemplary micro-LED display panel 40 is shown. The micro-LED display panel 40 shares many similarities with the micro-LED display panel 10 described above. However, the micro-LED display panel 40 includes a rigid circuit board 460. In some embodiments, the rigid circuit board 460 may differ in shape and function from the rigid circuit board 170 of the micro-LED display panel 10. Specifically, the rigid circuit board 460 includes a memory chip 4602. In some embodiments, the rigid circuit board 460 may also include a cover plate disposed on or above the memory chip 4602 for protecting the memory chip 4602. The rigid circuit board 460 also includes a connector 4601 located on one side of it, and the memory chip 4602 located on the opposite side of the connector 4601. The connector 4601 is interconnected with the memory chip 4602, allowing data to be stored and output to the memory chip 4602 via the connector 4601. For example, the memory chip 4602 can cache or store the pattern to be displayed or the pattern display instructions of the micro-LED display panel 40, thereby reducing the communication cost (such as overhead) between the micro-LED display panel 40 and the signal source (such as the GPU), and thus improving display efficiency.

[0049] like Figure 1A , Figure 1B , Figure 2A ,as well as Figure 2B As shown, the miniature LED display panel 10, with connectors 1701 to 1703 on two sides, can serve as a hub for connection to the miniature LED display panel 40. Other aspects of the miniature LED display panel 40 can be found in [reference needed]. Figure 1A , Figure 1B , Figure 2A ,as well as Figure 2BThe description of the micro LED display panel 10 in the previous text will not be repeated here. (See reference...) Figure 1A , Figure 1B , Figure 2A ,as well as Figure 2B It is understood that the micro LED display panel 10 may also include a memory chip disposed on a rigid circuit board 170, the memory chip being coupled to one or more of connectors 1701, 1702, and 1703.

[0050] Figure 5A The front view of an exemplary display device 50 according to an embodiment of the present disclosure is shown. The display device 50 has a micro LED display panel 501 (e.g., corresponding to...). Figure 1A , Figure 1B , Figure 2A ,as well as Figure 2B The miniature LED display panel 10) and miniature LED display panels 502 and 503 (e.g., each corresponding to a miniature LED display panel 10) and miniature LED display panels 502 and 503 respectively Figure 4A and Figure 4B The miniature LED display panel 40 in the middle. Figure 5B The back of the exemplary display device 50 is shown. To clearly illustrate the coupling relationship between the connectors, Figure 5A and 5B Components that are not directly visible from the outside are represented by dashed lines.

[0051] 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, thereby forming a display device 50 with three cooperating micro LED display panels. Specifically, panels 502 and 503 can be flipped by rotating their respective corresponding FCBs, so that connectors 4601 of panels 502 and 503 face connectors 1701 and 1702 of micro LED display panel 501, respectively. Micro LED display panels 502 and 503 can be driven by receiving signals from micro LED display panel 501, such as... Figure 5B As shown, signals are transmitted specifically through connector 1703 on the back of the micro LED display panel 501. Connector 1703 can be connected to an external device that generates the signal. It can be understood that micro LED display panels 501, 502, and 503 can be used to display the red, green, and blue portions of a composite image, respectively. That is, micro LED display panel 501 can display a red image, micro LED display panel 502 can display a green image, and micro LED display panel 503 can display a blue image.

[0052] Figure 6 Another exemplary display device 60 according to an embodiment of the present disclosure is shown, the display device 60 having a synthesizer 600. Reference Figure 6 The display device 60 (e.g., a multicolor 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 light-combining prism). The combiner 600 is used to combine (also referred to as "compositing") the images presented by the micro-LED display panels 501, 502, and 503 respectively into a composite image emitted from surface 602. It should be noted that the display device 60 may also include other necessary operating components, which will not be described in detail here.

[0053] As described above, the micro LED display panel 501 can display a red image, the micro LED display panel 502 can display a green image, and the micro LED display panel 503 can display a blue image. These images can be combined by the synthesizer 600 to form a multicolor image. The red, green, and blue images can be aligned after passing through the synthesizer 600 to form a multicolor image emitted from the surface 602.

[0054] In some embodiments, the microLED chip 110 includes an integrated circuit (IC) backplane (e.g., Figure 2A , Figure 2B ,as well as Figure 3A The driving layer 111 is shown. The micro-LED array 112 includes a plurality of micro-LEDs (not shown). Each micro-LED may constitute at least a portion of a pixel element on the micro-LED chip 110. For example, a pixel element may be composed of a single micro-LED to achieve a monochrome display, or three micro-LEDs to achieve a color display. In some embodiments, the size of each dimension of the micro-LED chip 110 does not exceed 1 centimeter (cm), preferably not exceeding 20 micrometers (μm). The resolution of the micro-LED array 112 may be 720×480, 640×480, 1920×1080, 1280×720, 2K (i.e., 2048×1080), or 4K (i.e., 3840×2160). The diameter of the micro-LEDs is in the nanometer range, for example, 20 nanometers to 100 nanometers. In some embodiments, the spacing of the micro-LED array 112 (i.e., the minimum center-to-center spacing between adjacent micro-LEDs) may be between 2 μm and 50 μm. In some embodiments, the number of pixels in the micro-LED chip 110 may be thousands to millions or more. In some embodiments, the microLED array 112 may include blue microLEDs, green microLEDs, or red microLEDs.

[0055] In some embodiments, the integrated circuit backplane can be electrically connected to each microLED in the microLED array 112 via a separate metal interconnect structure. In some embodiments, each microLED can be independently electrically controlled via the integrated circuit backplane. In some embodiments, the integrated circuit backplane can be electrically connected to the electrodes of the microLED chip 110 via metal interconnects. In some embodiments, a dielectric layer can be formed at the gaps between the microLEDs. In some embodiments, the dielectric layer can also be formed at the gaps between the metal interconnects.

[0056] In some embodiments, each microLED in the microLED array 112 may include a micromesa structure. In some embodiments, the micromesa structure may include, from bottom to top, a first type epitaxial layer, a light-emitting layer, and a second type epitaxial layer. That is, in the three-layer structure, the first type epitaxial layer is closest to the integrated circuit backplane; the light-emitting layer is located above the first type epitaxial layer and is relatively far from the integrated circuit backplane; the second type epitaxial layer is located above the light-emitting layer and is farthest from the integrated circuit backplane. In some embodiments, the light-emitting layer is composed of multiple stacked quantum well layers, particularly superlattice stacked quantum well layers. Preferably, the superlattice stacked quantum well layers include multiple pairs of stacked structures consisting of quantum well layers and quantum barrier layers. In some embodiments, the first type epitaxial layer is composed of a semiconductor material having a first conductivity type and includes multiple semiconductor layers. The host material of the first type epitaxial layer may be, but is not limited to, a substrate material, including one or more elements such as Ga, N, As, P, In, or Al. Furthermore, the first type epitaxial layer may include, but is not limited to, a waveguide layer, a confinement layer, a transition layer, and a window layer from top to bottom. Additionally, an ohmic contact layer may be formed below the window layer. In some embodiments, the second type of epitaxial layer is composed of a semiconductor material having a second conductivity type and includes multiple semiconductor layers. The host material of the second type of epitaxial layer can be, but is not limited to, a substrate material, including one or more elements such as Ga, N, As, P, In, or Al. Furthermore, the second type of epitaxial layer can include, but is not limited to, a top-down confinement layer and a waveguide layer. In some embodiments, an ohmic contact layer can be, but is not limited to, formed on the confinement layer.

[0057] In some embodiments, a top conductive layer may be formed on the top surface of the microLED array 112. In some embodiments, the top conductive layer may be shared by all the microLEDs in the microLED array 112. In some embodiments, the microLED array 112 may include a single layer of microLEDs. For example, the microLEDs may be arranged in a plane. In some embodiments, the microLED array 112 may include a multilayer of vertically stacked microLEDs and electrical connection layers. Each microLED in the microLED array 112 may be controlled independently and separately by: controlling the anode and cathode of each microLED individually; or controlling the common anode electrode layer with the corresponding cathode of each microLED; or controlling the cathode electrode layer with the corresponding anode of each microLED. For example, the microLEDs may be arranged on multiple mutually parallel planes.

[0058] Figure 7 A flowchart illustrating an exemplary method 70 for manufacturing a micro LED display panel according to an embodiment of the present disclosure is shown. Figure 7 As shown, method 70 includes steps 702-706, and the manufacturing of the micro LED display panel can be carried out by manufacturing equipment (e.g., manufacturing equipment including chip mounters, wire bonders, encapsulators, dicers, etc.).

[0059] In step 702, a substrate layer, such as substrate layer 160, is provided by a manufacturing apparatus.

[0060] In step 704, a flexible circuit board (FCB) (e.g., FCB 120) and a micro LED chip (e.g., micro LED chip 110) are disposed on the front side of a substrate layer using a manufacturing apparatus, wherein the FCB can be coupled to the micro LED chip. Figures 1A to 6 As shown, the micro LED chip includes a driving layer (e.g., driving layer 111) and a micro LED array (e.g., micro LED array 112) disposed on the driving layer. The driving layer may include a signal region (e.g., signal region 113), on which no micro LED array is disposed. The signal region can be used to receive signals driving the micro LED array. Furthermore, the manufacturing equipment may place the FCB near the signal region and couple the connection area of ​​the FCB to the signal region.

[0061] In some embodiments, the FCB includes conductive traces (e.g., conductive trace 124) extending from the connection area. These conductive traces can electrically connect the FCB to the signal area. In step 702, a molding layer (e.g., molding layer 130) may also be provided to encapsulate the conductive traces.

[0062] In step 706, a molding layer is formed on the front side of the substrate layer using a manufacturing apparatus to bond the microLED chip to the FCB into an integrated compact structure, and an opening area is left above the microLED array. The substrate layer and the molding layer can work together to bond the microLED chip to the FCB. In some embodiments, the substrate layer includes an edge without a molding layer.

[0063] In some embodiments of this disclosure, method 70 may further include the step of setting a light-shielding layer (e.g., setting a light-shielding layer 1112 on a metal pad 1111) on a metal pad disposed in the signal area on the front side of the driving layer, which may be implemented by a manufacturing apparatus.

[0064] In some embodiments of this disclosure, method 70 may further include the step of co-arranging a substrate layer and a molding layer to bond the microLED chip and at least a portion of the FCB, a step that can be performed by a manufacturing apparatus. This step may be performed prior to step 704, which forms the molding layer. In this step, the molding layer, the microLED chip, and the connection area of ​​the FCB may be disposed on the top surface of the substrate layer.

[0065] Other aspects of method 70 can be understood by referring to the above in combination. Figures 1A to 6 The description is used for understanding, and will not be repeated here.

[0066] Some embodiments of this disclosure also provide a display device. The display device may include any of the micro LED display panels disclosed herein.

[0067] Figure 8 An exemplary display device according to an embodiment of the present disclosure is shown. For example... Figure 8 As shown, a near-eye display (NED) 800 (e.g., AR glasses) includes a pair of multicolor projectors 810 and a frame 820 for fixing the multicolor projectors 810. Other components included in the NED 800 are not shown in the figure to clearly illustrate the structure of the NED 800. Each multicolor projector 810 may be disposed at the end of the temple (not shown) of the NED 800. A power supply system and processing system for driving the multicolor projectors 810 may be embedded within the temple. The eyes of a viewer (not shown) can respectively capture the images presented by each multicolor projector 810, thereby constructing a virtual scene or augmented reality scene for the viewer. In some embodiments, the term "presentation" may also be referred to as "display," "showcase," or other equivalent expressions. Each multicolor projector 810 may include: three micro-LED panels of different colors (e.g., each micro-LED panel corresponds to...). Figure 1A , Figure 1B , Figure 2A as well as Figure 2B The miniature LED display panel 10, or Figure 4A and Figure 4BThe three micro-LED display panels 40 and a synthesizer (e.g., a light-combining prism) are used to combine (also called “composite”) the images displayed on the three micro-LED panels into a composite image.

[0068] Figure 9 Another exemplary display device according to an embodiment of this disclosure is shown. For example... Figure 9 As shown, the head-mounted virtual reality device 900 includes two micro-LED panels 910 (e.g., each micro-LED panel corresponds to...). Figure 1A , Figure 1B , Figure 2A as well as Figure 2B The miniature LED display panel 10, or Figure 4A and Figure 4B The head-mounted virtual reality device 900 may also include a central processing unit (CPU), a graphics processing unit (GPU) as a signal source, and other related circuitry, although not shown in the figure. Using a micro-LED panel with the aforementioned micro-LED elements in the head-mounted virtual reality device 900 can improve its luminous efficiency, thereby reducing energy consumption and improving image quality.

[0069] 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.

[0070] Unless otherwise specified, the term "or" as used herein includes all possible combinations except where it is impractical. For example, if a database is declared to include A or B, then unless otherwise specified or impractical, the database may include A, or B, or A and B. A second example is if a database is declared to include A, B, or C, then unless otherwise specified or impractical, the database may include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C.

[0071] In the foregoing specification, numerous specific details have been described with reference to embodiments that may vary depending on the implementation. Certain adjustments and modifications may be made to the described embodiments. Other embodiments will be apparent to those skilled in the art in light of the specification and practice of the invention disclosed herein. The specification and embodiments are intended to be illustrative only, and the claims indicate the true scope and spirit of the invention. It is also intended that the order of steps shown in the figures be used for illustrative purposes only and is not intended to limit one to any particular order of steps. Therefore, those skilled in the art will understand that these steps may be performed in a different order when implementing the same method.

[0072] Exemplary embodiments have been disclosed in the accompanying drawings and description. However, many variations and modifications can be made to these embodiments. Therefore, although specific terms are used, they are used in a general and descriptive sense only and not for limiting purposes.

Claims

1. A miniature LED display panel, comprising: A micro LED chip includes: a driving layer and a micro LED array disposed on the driving layer, wherein the driving layer includes a signal region, the micro LED array is not disposed on the signal region, and the signal region is used to receive signals that drive the micro LED array; A flexible circuit board is disposed adjacent to the signal area and coupled to the signal area of ​​the driving layer; A molding layer, disposed on the microLED chip and the flexible circuit board, is used to bond the microLED chip to the flexible circuit board, and the molding layer has an opening area above the microLED array; and A substrate layer is disposed in cooperation with the molding layer to bond the micro LED chip and at least a portion of the flexible circuit board, wherein the molding layer, the micro LED chip, and the flexible circuit board are disposed on the front side of the substrate layer, and the substrate layer includes an edge from which the molding layer is not disposed.

2. The micro LED display panel according to claim 1, wherein, The opening region has an outwardly widening opening structure, the outline of which is defined by the molding layer.

3. The micro LED display panel according to claim 2, wherein, The micro-LED array is fully exposed from the opening region.

4. The micro LED display panel according to claim 1, wherein, The driver layer also includes: Metal pads disposed on the front side of the driving layer; and A light-shielding layer is disposed on the metal pad.

5. The micro LED display panel according to claim 4, wherein, The metal pads and the light-shielding layer are formed around the micro-LED array.

6. The micro LED display panel according to claim 5, wherein, The height of the light-shielding layer is greater than the height of the micro-LED array.

7. The micro LED display panel according to claim 4, wherein, The light-shielding layer fills and forms the gap between the micro-LED array and the wall of the molding layer that forms the opening region.

8. The micro LED display panel according to claim 1, wherein, The molding layer fills and forms the gap between the micro LED chip and the flexible circuit board, and the molding layer is also formed on the side and part of the front of the driving layer.

9. The micro LED display panel according to claim 1, wherein, The distance between the edge of the substrate layer and the molding layer is in the range of 0.05 mm to 0.10 mm.

10. The micro LED display panel according to claim 1, wherein, The substrate layer is made of steel plate.

11. The micro LED display panel according to claim 1, wherein, The flexible circuit board includes an adhesive layer that adheres to the surface of the substrate layer, with the bottom surface of the adhesive layer aligned with the bottom surface of the micro LED chip.

12. The micro LED display panel according to claim 11, wherein, The adhesive layer is conductive.

13. The micro LED display panel according to claim 11, wherein, 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, with the bottom surface of the second adhesive layer aligned with the bottom surface of the flexible circuit board.

14. The micro LED display panel according to claim 13, wherein, The second adhesive layer is insulating.

15. The micro LED display panel according to claim 14, wherein, The second adhesive layer is formed of chip adhesive or chip adhesive film.

16. The micro LED display panel according to claim 13, wherein, The thickness of the first adhesive layer is less than the thickness of the second adhesive layer.

17. The micro LED display panel according to claim 11, wherein, The connection area of ​​the flexible circuit board is coupled to the signal area, the adhesive layer is disposed on the bottom surface of the connection area, and the substrate layer is disposed below the connection area through the adhesive layer.

18. The micro LED display panel according to claim 17, wherein, The adhesive layer is also disposed below the bottom surface of the region adjacent to the connection area, and the substrate layer is disposed below the region adjacent to the connection area through the adhesive layer.

19. The micro LED display panel according to claim 18, wherein, The molding layer is also formed on the flexible circuit board, and the molding layer extends a distance from the connection area.

20. The micro LED display panel according to claim 19, wherein, The distance may or may not be equal to the length of the region adjacent to the connecting area.

21. The micro LED display panel according to claim 20, wherein, The distance is at least 0.05 mm longer than the length of the region adjacent to the connecting area.

22. The micro LED display panel according to claim 1, wherein, The connection area of ​​the flexible circuit board is coupled to the signal area, and the flexible circuit board also includes conductive traces led out from the connection area, and the flexible circuit board is coupled to the signal area through the conductive traces.

23. The micro LED display panel according to claim 22, wherein, The molding layer encapsulates the conductive trace.

24. The micro LED display panel according to claim 1, wherein, The bottom surface of the micro LED chip is aligned with the bottom surface of the flexible circuit board.

25. The micro LED display panel according to claim 1, wherein, The height of the molding layer is greater than or equal to the height of the micro-LED array.

26. The micro LED display panel according to claim 1, wherein, The connection area of ​​the flexible circuit board is coupled to the signal area, 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 flexible circuit board except the connection area.

27. The micro LED display panel according to claim 1, further comprising: A rigid circuit board is disposed on the opposite end of the micro LED chip on the flexible circuit board, the rigid circuit board being electrically connected to the flexible circuit board, and the rigid circuit board including at least one connector disposed on its surface.

28. The micro LED display panel according to claim 27, wherein, The rigid circuit board also includes a memory chip, and the at least one connector is coupled to the memory chip.

29. A method for manufacturing a micro LED display panel, comprising: Provide substrate layer; A flexible circuit board and a micro LED chip are disposed on the front side of the substrate layer, wherein the flexible circuit board and the micro LED chip are coupled, the micro LED chip includes a driving layer and a micro LED array disposed on the driving layer, the driving layer includes a signal area where the micro LED array is not disposed, the signal area being used to receive signals driving the micro LED array, the flexible circuit board being adjacent to and coupled to the signal area; and A molding layer is formed on the front side of the substrate layer to bond the micro LED chip and the flexible circuit board into an integral structure. An opening area is left above the micro LED array. The substrate layer and the molding layer together bond the micro LED chip and the flexible circuit board. The substrate layer includes an edge where the molding layer is not provided.

30. The method of claim 29, further comprising: A light-shielding layer is provided on the metal pads provided on the front side of the driving layer.

31. The method of claim 29, further comprising: The conductive traces drawn from the connection area of ​​the flexible circuit board are coupled to the signal area.

32. The method according to claim 31, wherein, The formed molding layer encapsulates the conductive trace.

33. A display device, comprising: The micro LED display panel according to any one of claims 1 to 28.

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