Circuit board, display module and display device

Abstract

The application provides a circuit board, a display module and a display device. The circuit board comprises a substrate, a device area and at least two non-device functional areas arranged on the substrate. The device area is arranged around the at least two non-device functional areas and encloses a containing area. The at least two non-device functional areas are arranged in the containing area. In the containing area, the side surface of the at least two non-device functional areas away from the substrate forms an assembly surface. The circuit board provided by the application arranges the device area around the non-device functional area and encloses the containing area. The originally scattered non-device functional areas distributed everywhere on the substrate are integrated into the containing area, thereby gathering the originally small and scattered available areas into a large continuous assembly surface, and solving the problem that the assembly firmness and reliability are difficult to guarantee due to insufficient assembly area.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a circuit board, a display module, and a display device. Background Technology

[0002] High-resolution display products, such as near-eye display devices like Virtual Reality (VR), Augmented Reality (AR), Mixed Reality (MR), and Extended Reality (XR), generally employ high-resolution display panels and corresponding driving circuits to achieve excellent near-eye viewing effects. The electronic components in the driving circuits are typically mounted on flexible circuit boards, which are then bent and attached to the back of the display panel after bonding to save overall space. In addition to housing components, the flexible circuit board also needs to accommodate differential signal traces, test points, reserved areas for manufacturing processes, and functional areas for marking and coding. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a circuit board, display module and display device with improved functional area layout.

[0004] To achieve the above objectives, an embodiment of the first aspect of this application provides a circuit board, comprising: Base; The device region is disposed on the substrate; At least two non-device functional regions are disposed on the substrate; The device area is arranged around the at least two non-device functional areas and encloses them to form a receiving area, wherein the at least two non-device functional areas are disposed within the receiving area; within the receiving area, the side surface of the at least two non-device functional areas facing away from the substrate forms an assembly surface.

[0005] According to any embodiment of the first aspect of this application, within the accommodating area, the orthographic projections of the different non-device functional regions on the substrate at least partially overlap.

[0006] According to any of the foregoing embodiments of the first aspect of this application, the at least two non-device functional areas include a differential routing area and a process reservation area, wherein the process reservation area is located between the differential routing area and the device area; or, the orthographic projection of the process reservation area on the substrate at least partially overlaps with the orthographic projection of the differential routing area on the substrate.

[0007] According to any of the foregoing embodiments of the first aspect of this application, the at least two non-device functional areas further include a test point area, the test point area being located between the differential trace area and the device area; and / or, the orthographic projection of the test point area on the substrate is at least partially located within the orthographic projection of the process reserved area on the substrate.

[0008] According to any of the foregoing embodiments of the first aspect of this application, the at least two non-device functional areas further include an identification and coding area, wherein the orthographic projection of the identification and coding area on the substrate at least partially overlaps with the orthographic projection of the differential trace area on the substrate; and / or, the orthographic projection of the identification and coding area on the substrate at least partially overlaps with the orthographic projection of the process reserved area on the substrate.

[0009] According to any of the foregoing embodiments of the first aspect of this application, the maximum height difference between any two points on the assembly surface is less than or equal to 100 μm.

[0010] According to any of the foregoing embodiments of the first aspect of this application, the device region includes a plurality of sub-device regions, each sub-device region includes a plurality of electronic components, and the plurality of electronic components in each sub-device region are arranged along the outer edge of the substrate to form a strip-shaped sub-device region; The at least two non-device functional areas include differential routing areas, and the sub-device areas are provided on at least two opposite sides of the differential routing areas.

[0011] An embodiment of the second aspect of this application provides another display module, the display module including a display panel and a circuit board as described in any of the foregoing embodiments of the first aspect of this application, the circuit board being electrically connected to the display panel and bent to the non-display side of the display panel.

[0012] According to any embodiment of the second aspect of this application, the orthographic projection of the circuit board onto the plane where the display panel is located at least partially extends beyond the outer edge of the display panel, and the device area of ​​the circuit board is at least partially located in the area extending beyond the outer edge of the display panel.

[0013] An embodiment of the third aspect of this application provides a display device, which includes a display module of any of the above embodiments.

[0014] The circuit board provided in this application forms a receiving area by surrounding and enclosing the non-device functional areas with the device area, thus consolidating the non-device functional areas that were originally scattered throughout the substrate into the receiving area. The surfaces of each non-device functional area facing away from the substrate together form an assembly surface. This transforms the originally small and scattered usable area into a large, continuous assembly surface, solving the problem of insufficient assembly area leading to difficulties in ensuring assembly robustness and reliability. As the overall mounting surface for assembly with the outer casing, the assembly surface effectively increases the area of ​​the circuit board available for assembly, ensuring the robustness, impact resistance, and service life of the display module after assembly with the outer casing. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the back of the circuit board layout in the related technology; Figure 2 This is a schematic diagram of the circuit board structure according to an embodiment of this application; Figure 3 This is a schematic diagram of the circuit board structure in a display module according to another embodiment of this application; Figure 4 This is a schematic cross-sectional view of a display module according to another embodiment of this application; Figure 5 This is a schematic diagram of the circuit board structure in a display module according to another embodiment of this application; Figure 6 This is a schematic diagram of the circuit board structure in a display module according to another embodiment of this application; Figure 7 This is a schematic diagram of the circuit board structure in a display module according to another embodiment of this application; Figure 8 This is a schematic diagram of the circuit board structure in a display module according to another embodiment of this application; Figure 9 This is a schematic diagram of the circuit board structure in a display module according to another embodiment of this application; Figure 10 This is a schematic diagram of the structure of a display device according to another embodiment of this application.

[0017] Marker explanation: 1000. Display device; 100. Display module; 10. Circuit board; 101. Substrate; 11. Component area; 111. Sub-component area; 120. Accommodation area; 12. Non-component functional area; 121. Differential routing area; 122. Process reserved area; 123. Test point area; 124. Marking and coding area; 20. Display panel; 200. External casing. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0019] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] Figure 1 This is a rear view of the circuit board layout in related technologies. (Reference) Figure 1 For display modules using high-resolution display panels, the circuit board 10 needs to simultaneously arrange multiple non-device functional areas 12, such as the device area 11, differential trace area 121, process reserved area 122, test point area 123, and marking and coding area 124.

[0021] In the process of realizing this invention, the inventors discovered the following problems in the related technology: In a conventional layout, the differential trace area 121 occupies the central area of ​​the substrate 101, the device area 11 is located on both sides of the differential trace area 121, while functional areas such as the test point area 123, the process reserved area 122, and the marking and coding area 124 occupy their own space and are scattered around the edge of the substrate. The conventional circuit board layout results in a relatively flat surface between the circuit board and the outer casing, and the continuous area available for assembly with the outer casing is small and scattered, leading to insufficient effective assembly area between the display module and the outer casing, making it difficult to guarantee the robustness and reliability after assembly. Therefore, how to optimize the layout of each functional area on the circuit board to obtain the largest possible continuous assembly area within a limited area is a problem that needs to be solved.

[0022] In view of this, an embodiment of the first aspect of this application provides a circuit board. For example... Figure 2 As shown, the circuit board 10 includes a substrate 101, a device region 11 disposed on the substrate 101, and at least two non-device functional regions 12 disposed on the substrate 101. The device region 11 surrounds the at least two non-device functional regions 12, forming a receiving area 120. The non-device functional regions 12 are disposed within the receiving area 120, and the side surface of the at least two non-device functional regions 12 facing away from the substrate 101 forms an assembly surface.

[0023] Specifically, substrate 101 is a flexible substrate, and circuit board 10 is a flexible circuit board. For example, substrate 101 is made of materials such as polyimide, polyester, polyethylene naphthalate, or flexible epoxy resin, which have good heat resistance and mechanical flexibility, and can meet the requirements of subsequent bonding and bending processes. Conductive lines are arranged on substrate 101. The conductive lines can be formed by photolithography and etching of copper foil pressed onto substrate 101, and the thickness of the copper foil is, for example, between 12μm and 35μm. The surface of substrate 101 is also covered with a cover film, which can be made of polyimide material, to protect the conductive lines.

[0024] Device area 11 includes multiple electronic components, which may specifically be capacitors, resistors, inductors, integrated circuit chips, connectors, etc. Each electronic component is fixed to the substrate 101 by surface mounting or wire bonding and is electrically connected to conductive lines. Device area 11 is arranged along the outer edge of the substrate 101, meaning the electronic components are distributed along at least two opposite sides of the four sides of the substrate 101, forming a strip-like distribution in the peripheral area of ​​the substrate 101. The electronic components themselves have a significant protrusion height relative to the surface of the substrate 101; for example, the height of the top of the electronic component relative to the surface of the substrate 101 is typically several hundred micrometers to several millimeters. Therefore, the area occupied by device area 11 cannot be directly used as an assembly surface.

[0025] The non-device functional area 12 is a region disposed on the substrate 101 on the same side as the device area 11. No large-sized electronic components are disposed in this type of area, and each region performs a specific circuit function or process auxiliary function. According to embodiments of this application, the non-device functional area 12 may include at least two of the following: differential trace area 121, process reserved area 122, test point area 123, or marking / coding area 124.

[0026] The device area 11 is arranged around the non-device functional area 12, that is, the device area 11 is located on the periphery and encloses the receiving area 120. Each non-device functional area 12 is concentrated within the receiving area 120. Since the non-device functional areas 12 are surrounded and concentrated by the device area 11, the originally scattered small flat areas within the receiving area 120 are converged and integrated. The surface of each non-device functional area 12 facing away from the substrate 101 can form an assembly surface together with the substrate 101 or the uncovered surface of the covering film on the substrate 101. The assembly surface is configured to be assembled and fixed with the outer shell.

[0027] The circuit board 10 provided in this application embodiment forms a receiving area 120 by surrounding the non-device functional area 12 with the device area 11. Within the receiving area 120, through the centralized integration of the non-device functional area 12, a large-area assembly surface is obtained on the back side away from the substrate 101. This assembly surface can be used as a whole for attachment or adhesive fixation to the outer housing, increasing the area available for assembly on the circuit board 10.

[0028] It should be noted that the "assembly surface" in this application refers to the entire surface area within the accommodating region 120 that faces away from the substrate 101 and can be assembled with the outer housing. Physically, the assembly surface may include: the surface of each non-device functional area 12 facing away from the substrate 101, such as the cover film surface of the differential trace area 121, the pad surface of the test point area 123, and the ink surface of the marking / coding area 124; and the surface of the substrate 101 facing the outer housing at the gaps between these functional areas, or the cover film surface on that surface. Since the height differences of these surfaces are all controlled within a predetermined range, they are functionally considered as a continuous, flat surface.

[0029] like Figure 3 , Figure 4 As shown, the circuit board 10 in this application is used in the display module 100. By bending the circuit board 10 to the back of the display panel 20, the assembly surface on the circuit board 10 provides a large, relatively flat assembly surface for the back of the display module 100. When assembling the display module 100 with the outer housing, a large area can be attached and fixed through the assembly surface. The overall assembly area on the back of the display module 100 is increased, which helps to improve the robustness, reliability, and impact resistance of the display module 100 after it is assembled with the outer housing.

[0030] In some embodiments, such as Figure 2 , Figure 3 , Figure 5 , Figure 6 As shown, the orthographic projections of the different non-device functional areas 12 within the accommodating region 120 onto the substrate 101 at least partially overlap.

[0031] Specifically, the orthographic projections of different non-device functional areas 12 onto the substrate 101 overlap, meaning that multiple non-device functional areas 12 are arranged overlappingly in the same or partially the same physical space. The overlapping areas form at least a portion of the assembly surface. The non-device functional areas 12 within the receiving area 120 are centrally integrated through spatial sharing, and the surface on the side facing away from the substrate 101 is used to form the assembly surface.

[0032] By overlapping the projections of different non-device functional areas 12, multiple functional areas can share space. Functional areas that were originally independent and separated are integrated into the same space, further freeing up usable area within the accommodating area 120 without increasing the overall size of the circuit board 10, making the assembly surface more complete. The surfaces of the non-device functional areas 12 of the circuit board 10, such as the differential wiring area 121, process reserved area 122, test point area 123, and marking and coding area 124, are relatively flat and can be used for assembly and fixation with the outer casing. The large flat area formed by concentrating these areas can increase the assembly and fixation area between the back of the display module and the outer casing.

[0033] In some embodiments, at least two non-device functional areas 12 include a differential routing area 121 and a process reserve area 122, with the process reserve area 122 located between the differential routing area 121 and the device area 11.

[0034] In other embodiments, the orthographic projection of the process reserved area 122 on the substrate 101 at least partially overlaps with the orthographic projection of the differential routing area 121 on the substrate 101.

[0035] Specifically, the differential trace area 121 is used to arrange differential pair traces for transmitting high-speed signals. The differential trace area 121 is located in the central part of the accommodating area 120, specifically in a strip area with a width of about 4 mm to 5 mm in the center of the substrate 101.

[0036] The process reserve area 122 is a reserved area configured for automated process equipment to pick up and handle materials. During the bonding assembly process, automated handling equipment needs to grip or pick up materials from the surface of the circuit board 10; therefore, space needs to be reserved for equipment handling, i.e., the process reserve area 122. The surface of the process reserve area 122 needs to maintain a certain degree of flatness to meet the pick-up requirements.

[0037] In one specific embodiment of this application, the circuit board 10 has two process reservation areas 122, and the diameter of each process reservation area 122 is not less than 6 mm. The positions of the two process reservation areas 122 are arranged according to the weight distribution of the component areas 11 on the circuit board 10 to ensure that the circuit board 10 remains balanced during transportation. In other embodiments, the number of process reservation areas 122 may be more than two.

[0038] As a first optional layout, the process reservation area 122 is located between the differential routing area 121 and the device area 11, i.e., from the outside to the inside, the device area 11, the process reservation area 122, and the differential routing area 121 are arranged sequentially. As a second optional layout, the orthographic projection of the process reservation area 122 on the substrate 101 at least partially overlaps with the orthographic projection of the differential routing area 121 on the substrate 101, and the two occupy the same or partially the same planar space, i.e., the area where the differential routing area 121 is located at least partially also serves as the process reservation area 122. In this case, since the routing height of the differential routing area 121 is very small, the equipment nozzle can directly adsorb above it without damaging the routing or causing adsorption leakage.

[0039] The elongated differential trace area 121, which was originally unusable for assembly with the outer casing, can be grouped together with other non-device functional areas 12 and used for assembly and fixation, increasing the assembly and fixation area between the back of the display module and the outer casing. When an alternating arrangement is used, the functional areas are clearly defined and can be selected according to actual process requirements.

[0040] In some embodiments, at least two non-device functional areas 12 further include test point areas 123, which are located between differential trace areas 121 and device areas 11; and / or, the orthographic projection of the test point areas 123 on the substrate 101 is at least partially located within the orthographic projection of the process reservation area 122 on the substrate 101.

[0041] Specifically, the test point area 123 includes multiple test pads for electrical testing during the manufacturing process. The test point area 123 is located in the transition region between the differential trace area 121 and the device area 11.

[0042] Meanwhile, as an optional or additional layout, the orthographic projection of the test point area 123 on the substrate 101 is at least partially located within the orthographic projection of the process reservation area 122 on the substrate 101, meaning that the test point area 123 is spatially embedded within the area occupied by the process reservation area 122. The test point has a planar pad structure with a small protrusion height, comparable to the trace height, and does not affect the device's adsorption operation on the process reservation area 122.

[0043] The test point area 123 may be located only between the differential trace area 121 and the device area 11, without overlapping with the process reserve area 122 in projection. In this case, the test pads of the test point area 123 are arranged along the inner edge of the device area 11, forming an independent strip-shaped test area. The surface of this test area remains relatively flat, and together with other non-device functional areas 12, it constitutes the assembly surface within the accommodating area 120.

[0044] In other embodiments, such as Figure 5 As shown, the test point area 123 is located between the device area 11 and the differential trace area 121, and at least a portion of the test point area 123 can be placed within the process reserve area 122. In this way, the layout of the test point area 123 will not hinder the selection of the process reserve area 122, which is conducive to placing the process reserve area 122 in the most convenient position.

[0045] Among them, the area of ​​the scattered test point area 123, which could not originally be used for assembly with the outer shell, can be grouped together with other non-device functional areas 12 and used for assembly and fixation, thereby increasing the assembly and fixation area of ​​the back of the display module with the outer shell.

[0046] In some embodiments, such as Figure 3 , Figure 5 As shown, at least two non-device functional areas 12 also include marking and coding areas 124, the orthographic projection of marking and coding areas 124 on substrate 101 and the orthographic projection of differential routing areas 121 on substrate 101 at least partially overlap.

[0047] In some embodiments, such as Figure 6As shown, the orthographic projection of the marking area 124 on the substrate 101 at least partially overlaps with the orthographic projection of the process reserved area 122 on the substrate 101.

[0048] Specifically, the marking and coding area 124 is used to print product identification codes. The orthographic projection of the marking and coding area 124 on the substrate 101 at least partially overlaps with the orthographic projection of the differential wiring area 121 on the substrate 101, that is, the coding is directly printed on the surface of the cover film at the location of the differential wiring area 121. Alternatively, the orthographic projection of the marking and coding area 124 on the substrate 101 at least partially overlaps with the orthographic projection of the process reserved area 122 on the substrate 101, and the coding is printed on the surface of the process reserved area 122. Both of the above methods can also be used simultaneously.

[0049] In some embodiments of this application, such as Figures 7 to 9 As shown, the marking area 124 may not overlap with the differential wiring area 121 or the process reserve area 122, but may be set separately in an unoccupied gap within the accommodating area 120, for example, in a narrow blank strip between the process reserve area 122 and the device area 11. Although this layout does not achieve area sharing, the surface of the marking area 124 is flat and can still be included in the assembly surface.

[0050] When the marking / coding area 124 overlaps with the differential wiring area 121 or the process reserve area 122, the marking / coding area 124 does not occupy a separate area within the accommodating area 120. The process reserve area 122 and the marking / coding area 124 can share the area of ​​the differential wiring area 121, and the process reserve area 122 and the marking / coding area 124 can also share the area with each other, so that the area of ​​the differential wiring area 121 is fully utilized by each functional area, and each functional area can be flexibly arranged in a convenient location within a larger area.

[0051] In some embodiments, the maximum height difference between any two points within the assembly surface is less than or equal to 100 μm.

[0052] To ensure the assembly surface achieves the required flatness, the maximum height difference between any two points on the assembly surface shall not exceed 100μm.

[0053] Specifically, the height difference between the highest point (such as the copper foil trace or test pad) and the lowest point (such as the exposed surface of substrate 101 or the surface of the cover film) within the assembly surface can be controlled to be 100μm, 80μm, 60μm, or less. The height difference on the assembly surface mainly originates from: the thickness deviation of substrate 101 itself (typically ≤5μm), the thickness of the copper foil trace (e.g., 12μm, 18μm, or 35μm), the thickness of the cover film (e.g., 12.5μm or 25μm), and the thickness of the inkjet printing ink (e.g., 2-5μm). By selecting thin copper foil (e.g., 12μm or 18μm) and thin cover film (e.g., 12.5μm), the maximum height difference on the assembly surface can be controlled within 60μm.

[0054] The maximum height difference between any two points within the assembly surface is less than or equal to 100μm, ensuring that the assembly surface appears as a flat surface macroscopically. For the double-sided adhesive or foam tape used for assembly (usually with a thickness of 100μm to 300μm), minor undulations can be absorbed and will not affect the adhesion and fixation effect.

[0055] In some embodiments, device region 11 includes a plurality of sub-device regions 111, each sub-device region 111 including a plurality of electronic components, and the plurality of electronic components in each sub-device region 111 are arranged along the outer edge of the substrate 101 to form a strip-shaped sub-device region 111. At least two non-device functional regions 12 include differential trace regions 121, and sub-device regions 111 are disposed on at least two opposite sides of the differential trace regions 121.

[0056] Specifically, each sub-device area 111 includes multiple electronic components. The electronic components within the sub-device area 111 are arranged in a strip shape along the outer edge of the substrate 101. For example, the sub-device area 111 may be linear or zigzag. For instance, one strip-shaped sub-device area 111 may be provided on each of the left and right sides of the substrate 101, and the differential trace area 121 may be located between the two sub-device areas 111. The two sub-device areas 111 together complete the enclosure of the non-device functional area 12 within the accommodating area 120.

[0057] In other embodiments, there are three sub-device regions 111, which are distributed along the two long sides and one short side of the substrate 101, forming a U-shaped surround. The differential trace region 121 is located within the accommodating area 120 enclosed by the three sub-device regions 111.

[0058] In some other embodiments, there are four sub-device regions 111, which are distributed along the four sides of the substrate 101 to form a surrounding layout.

[0059] At least two opposite sides of the differential trace area 121 are provided with sub-device areas 111, for example, one sub-device area 111 on each side. The two sub-device areas 111 together complete the surrounding of the non-device functional area 12 within the accommodating area 120. Sub-device areas 111 may also be provided on other sides. The sub-device areas 111 are symmetrically distributed in the surrounding area of ​​the substrate 101.

[0060] The device area 11 is divided into multiple strip-shaped sub-device areas 111, which can be adjusted according to the shape of the substrate 101. The devices on the circuit board 10 are arranged along the outer edge of the circuit board 10, forming strip-shaped device areas 11 along the outer edge of the circuit board 10. This distributes the device areas 11, which were originally two adjacent differential trace areas 121, to the strip-shaped device areas on both sides of the outer edge of the circuit board 10. This concentrates all the originally scattered small flat areas on the surface of the circuit board 10 into a large, flat area in the middle of the circuit board 10. The multiple sub-device areas 111 balance device layout density with the area of ​​the assembly surface within the accommodating region 120.

[0061] Combination Figure 1 and Figure 2 In a conventional layout, the device area 11 is distributed on both sides of the differential trace area 121, while the test point area 123, process reserved area 122, and marking and coding area 124 are scattered around the edge of the substrate 101. In this layout, the areas on the back of the substrate 101 that can be assembled with the outer housing are scattered and each area is small, and some of the smaller scattered areas cannot be used for assembly and fixation.

[0062] In this embodiment, the device area 11 is arranged in a strip shape along the outer edge of the substrate 101, and the non-device functional areas 12 are concentrated in the receiving area 120 and formed into a large assembly surface through projection overlap, thereby increasing the assembly and fixing area between the back of the display module and the outer shell. The surfaces of the non-device functional areas 12, such as the differential wiring area 121, process reserved area 122, test point area 123, and marking / coding area 124 of the circuit board 10, are relatively flat and can all be used for assembly and fixing with the outer shell. By concentrating all these areas in the middle area of ​​the flexible circuit board, the previously scattered small flat surface areas are combined into a large flat surface area. This increases the assembly and fixing area between the back of the display module and the outer shell, which is beneficial for improving the robustness, reliability, impact resistance, and service life of the display module after assembly with the outer shell.

[0063] An embodiment of the second aspect of this application provides a display module 100. For example... Figure 3 , Figure 4 As shown, the display module 100 includes a display panel 20 and a circuit board 10 in any embodiment of the first aspect. The circuit board 10 is electrically connected to the display panel 20 and is bent to the non-display side of the display panel 20.

[0064] Specifically, the display panel 20 can be an OLED display panel or an LCD display panel. One end of the circuit board 10 is electrically connected to the bonding area of ​​the display panel 20 via a bonding process, and is used to provide drive signals and operating voltage to the display panel 20. The main body of the circuit board 10 is bent to the non-display side of the display panel 20, i.e., the back of the display panel 20. After bending, the assembly surface of the circuit board 10 faces outward, serving as a mounting surface for assembly with the outer housing.

[0065] The display module 100 provided in this embodiment provides a large, flat assembly surface on the back of the display module 100 by bending the circuit board 10 to the back of the display panel 20. When assembling the display module 100 with the outer housing, this assembly surface allows for large-area attachment and fixation, increasing the overall assembly area on the back of the display module 100 and improving its robustness, reliability, and impact resistance after assembly. Furthermore, since the device area 11 surrounds the non-device functional area 12, its thickness can be flexibly arranged according to the housing space, facilitating a thinner and lighter overall design.

[0066] In some embodiments, such as Figures 6 to 9 As shown, the orthographic projection of the circuit board 10 onto the plane where the display panel 20 is located extends at least partially beyond the outer edge of the display panel 20.

[0067] In some embodiments, such as Figures 7 to 9 As shown, the device area 11 of the circuit board 10 is at least partially located in the area that extends beyond the outer edge of the display panel 20.

[0068] Specifically, the overall planar dimension of the circuit board 10 is larger than the size of the corresponding area of ​​the display panel 20. Within the plane of the display panel 20, the projection of the circuit board 10 extends outward from the outer edge of the display panel 20. Accordingly, the device area 11 on the circuit board 10 is at least partially located in the area extending beyond the outer edge of the display panel 20. The flexible circuit board may extend beyond the outer edge of the display screen, and the device area 11 on the surface of the flexible circuit board may also extend beyond the outer edge of the display screen.

[0069] In this design, the component area 11 of the circuit board 10 is moved outside the projected area of ​​the display panel 20, freeing up some space on the back of the display panel 20. The accommodating area 120 on the back of the display panel 20 is occupied by the non-component functional area 12, resulting in a more complete and larger assembly surface. The absence of large protruding components on the back of the display panel 20 facilitates close fitting and assembly with the outer casing. This structure also eliminates the need for additional space for electronic components between the display panel 20 and the outer casing in the thickness direction, contributing to a reduction in the overall thickness of the display device.

[0070] The display module 100 can be used in near-eye display devices. High-resolution products are mostly near-eye display devices, and in order to ensure a better viewing effect when viewed at close range, they need to be equipped with a high-resolution display screen. By adopting the circuit board 10 of the aforementioned embodiment of this application, the display module 100 increases the assembly and fixing area between the back of the display module and the outer housing while ensuring that the high-resolution display screen is lit up normally and emits light accurately.

[0071] An embodiment of the third aspect of this application provides a display device 1000, which includes an outer housing 200 and a display module 100 as described in any embodiment of the second aspect. The display module 100 is mounted on the outer housing 200 via the assembly surface of the circuit board 10.

[0072] Specifically, the display device 1000 includes, but is not limited to, electronic devices such as VR headsets, AR glasses, MR devices, XR devices, mobile phones, watches, tablets, or laptops.

[0073] The display module 100 is mounted to the outer housing 200 via the assembly surface of its circuit board 10. During the assembly process, double-sided adhesive, pressure-sensitive adhesive, or structural adhesive can be applied between the assembly surface of the circuit board 10 and the outer housing 200, or the display module 100 can be fixed to the outer housing 200 using mechanical means such as clips or screws. The area of ​​the assembly surface is sufficient to ensure adequate fixing strength between the housing and the display module 100, thereby passing reliability tests such as drop tests, temperature cycling tests, and high-temperature and high-humidity tests. The circuit board 10 of this application, while meeting the requirements of high-resolution display driving, does not increase the module size, which is beneficial for the miniaturization and thinning of the display device 1000.

[0074] The display module 100 is mounted and fixed to the outer housing 200 via the assembly surface of the circuit board 10, which has a large area and a flat surface. The non-device functional areas of the flexible circuit board, such as the differential trace area 121, process reserve area 122, test point area 123, and marking / coding area 124, all have relatively flat surfaces and are concentrated to form a large flat surface area, which can be used for assembly and fixation with the outer housing, ensuring a firm fit. This improves the overall assembly robustness and drop impact resistance of the display device. Due to the compact layout and high space utilization of the circuit board 10, the overall size of the display module 100 is not increased while meeting the high-resolution driving requirements, which is beneficial for the compact and thin design of the display device.

[0075] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0076] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A circuit board, characterized in that, include: Base; The device region is disposed on the substrate; At least two non-device functional regions are disposed on the substrate; The device area is arranged around the at least two non-device functional areas and encloses them to form a receiving area, wherein the at least two non-device functional areas are disposed within the receiving area; within the receiving area, the side surface of the at least two non-device functional areas facing away from the substrate forms an assembly surface.

2. The circuit board according to claim 1, characterized in that, Within the accommodating area, the orthographic projections of the different non-device functional regions onto the substrate at least partially overlap.

3. The circuit board according to claim 1, characterized in that, The at least two non-device functional areas include a differential routing area and a process reservation area, wherein the process reservation area is located between the differential routing area and the device area; or, the orthographic projection of the process reservation area on the substrate at least partially overlaps with the orthographic projection of the differential routing area on the substrate.

4. The circuit board according to claim 3, characterized in that, The at least two non-device functional areas further include a test point area, which is located between the differential trace area and the device area; and / or, the orthographic projection of the test point area on the substrate is at least partially located within the orthographic projection of the process reserved area on the substrate.

5. The circuit board according to claim 3, characterized in that, The at least two non-device functional areas also include an identification and coding area, wherein the orthographic projection of the identification and coding area on the substrate at least partially overlaps with the orthographic projection of the differential trace area on the substrate; And / or, the orthographic projection of the marking area on the substrate and the orthographic projection of the process reserved area on the substrate at least partially overlap.

6. The circuit board according to claim 1, characterized in that, The maximum height difference between any two points on the assembly surface is less than or equal to 100 μm.

7. The circuit board according to claim 1, characterized in that, The device area includes multiple sub-device areas, each sub-device area includes multiple electronic components, and the multiple electronic components in each sub-device area are arranged along the outer edge of the substrate to form a strip-shaped sub-device area; The at least two non-device functional areas include differential routing areas, and the sub-device areas are provided on at least two opposite sides of the differential routing areas.

8. A display module, characterized in that, It includes a display panel and a circuit board as described in any one of claims 1 to 7, wherein the circuit board is electrically connected to the display panel and is bent to the non-display side of the display panel.

9. The display module according to claim 8, characterized in that, The orthographic projection of the circuit board onto the plane of the display panel extends at least partially beyond the outer edge of the display panel, and the device area of ​​the circuit board is at least partially located in the area extending beyond the outer edge of the display panel.

10. A display device, characterized in that, It includes an outer housing and a display module as described in claim 8 or 9, wherein the display module is mounted on the outer housing via the assembly surface of the circuit board.

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