LED display module and display device

Abstract

The utility model relates to the technical field of semiconductor lighting and backlight, in particular to an LED (light-emitting diode) display module and a display device, which comprise a substrate and an LED chip electrically connected with the substrate, a conductor layer is arranged on the surface of the substrate, a solder mask is covered on the conductor layer, a window is arranged on the solder mask corresponding to the LED chip, a non-conductor area is arranged on the substrate around the window, and the non-conductor area is arranged on the substrate. The non-conductor area is further covered with the solder mask layer, the thickness of the portion, covering the non-conductor area, of the solder mask layer is larger than that of the portion, covering the conductor layer, of the solder mask layer, the solder mask layer has the performance of reflecting light, the thicker the solder mask layer can improve the reflectivity of the LED, the LED display module is helped to concentrate light better, and the reflection efficiency is improved.

Description

[Technical field]

[0001] The utility model relates to the technical field of semiconductor lighting and backlight, and in particular to an LED display module and a display device. [Background technology]

[0002] In recent years, LED light sources have been increasingly used in the fields of lighting and backlighting. As the basis for manufacturing LED light sources, LED packaging technology has also become increasingly mature. In order to achieve a good consumer experience, the light-emitting units on LED light-emitting panels are getting smaller and smaller, and the backlight modules are increasingly pursuing thinness. Mini LED, which is derived from the traditional LED industry and has better backlight display effects, has emerged; the LED packaging substrate materials used in MiniLED display modules include PCB boards or glass substrates. Among them, PCB boards include FPC substrates, FR4 substrates, and BT substrates, but the smaller the size of the MINI LED display module, the higher the brightness requirements. The white oil solder mask solution based on FPC / BT / FR4 is limited by thickness, and the reflectivity can only reach 90%. Direct use on the backlight module is prone to cause shadow problems, affecting the uniform light effect of the LED panel. The existing LED packaging structure can no longer meet the brightness requirements of the MINI LED display module. [Contents of the utility model]

[0003] In order to solve the problem of low reflectivity of the white oil solder resist solution used in the existing MINI LED display module, the utility model provides an LED display module and a display device.

[0004] The solution to the technical problem of the utility model is to provide an LED display module, including a substrate, an LED chip electrically connected to the substrate, a conductor layer is arranged on the surface of the substrate, the conductor layer is covered with a solder resist layer, the solder resist layer has a window corresponding to the LED chip, a conductor-free area is arranged around the window on the substrate, the solder resist layer also covers the conductor-free area, and the thickness of the solder resist layer covering the conductor-free area is greater than the thickness of the solder resist layer covering the conductor layer.

[0005] Preferably, the solder resist layer forms a concave cup structure around the LED chip.

[0006] Preferably, the LED chips are arranged in an array on the substrate.

[0007] Preferably, there is a gap between the concave cup structure and the LED chip.

[0008] Preferably, the thickness of the solder resist layer at the concave cup structure is greater than 50 um.

[0009] Preferably, the thickness of the solder resist layer on the conductor layer is greater than 10 um.

[0010] Preferably, the height of the solder resist layer at the concave cup structure is greater than the height of the LED chip.

[0011] Preferably, the LED chip is a miniLED chip or a microLED chip.

[0012] Preferably, there is a covering film between the solder resist layer and the conductor layer.

[0013] In order to solve the above technical problems, the present invention provides another technical solution as follows: a display device comprises a carrying device and an LED display module as described above, which is arranged on the carrying device.

[0014] Compared with the prior art, the LED display module and display device provided by the utility model have the following advantages:

[0015] 1. In the LED display module provided in the embodiment of the utility model, during the PCB manufacturing process, the printing ink used in the solder resist layer in the conductor-free area is fluid, and the solder resist ink in the conductor-free area is recessed and thicker than the conductor area. The solder resist layer has the performance of reflecting light. The thicker the solder resist layer, the more it can improve the reflectivity of the LED, helping the LED display module to focus more light. The concentration of the conductor-free area also helps to isolate the circuit around the LED chip, effectively avoiding excessive electrical induction, and preventing current short circuit to optimize the manufacturing process.

[0016] 2. The LED display module provided in the embodiment of the utility model has a concave cup mouth structure that adjusts the divergence angle and direction of the light emitted by the LED chip to limit the propagation direction of the light, optimizes the optical properties of the display module, and makes the light better focused within the observation area of ​​the display screen, thereby improving the brightness and contrast of the display. The concave cup mouth structure improves the heat dissipation performance around the LED chip to a certain extent, increases the surface area, improves the heat dissipation efficiency, helps to keep the LED chip within the normal operating temperature range, provides additional protection for the LED chip, and extends its service life.

[0017] 3. The LED display module provided in the embodiment of the utility model has an array-like arrangement which helps to improve the uniformity of lighting and brightness distribution, achieve higher pixel density clarity and detail display, and thus improve the overall performance of the LED display module. There are certain gaps between components to provide better air circulation and help dissipate heat. There is often electromagnetic interference between LED chips. A neat arrangement can reduce the mutual influence between components, improve the stability of the circuit, and enhance the visual effect and user experience.

[0018] 4. In the LED display module provided in the embodiment of the utility model, when the temperature changes, different materials may expand or contract at different rates. The gap between the LED chip and the concave cup structure can provide space for such changes, reduce thermal stress, and make the LED display module more flexible when the temperature changes. It can also avoid the LED chip and the solder resist layer directly contacting the solder resist layer to cause damage to the LED chip.

[0019] 5. The LED display module provided in the embodiment of the utility model has a thicker solder resist layer that can provide better anti-corrosion and protection performance, preventing the risk of corrosion and mechanical damage to the LED chip by external substances; the thicker solder resist layer can improve the insulation performance and improve the thermal management performance, effectively isolate the LED chip and other circuit components, reduce light leakage, and improve the optical performance of the display.

[0020] 6. In the LED display module provided in the embodiment of the utility model, the height of the solder resist layer is greater than the height of the LED chip, which strengthens the protection of the LED chip, enhances the mechanical stability, provides a larger surface area, and helps to improve the heat dissipation performance.

[0021] 7. In the second embodiment of the present invention, an LED display module is provided, wherein a covering film is provided between the solder resist layer and the conductor layer. In a flexible printed circuit board, the covering film can provide additional protection for the conductor layer, effectively preventing the conductor from being worn, oxidized or otherwise damaged.

[0022] Improve the insulation performance, form a layer of isolation between the solder mask layer and the conductor layer, prevent the solder mask material from accidentally contacting the conductor during the soldering process, and also enhance the overall mechanical strength of the flexible printed circuit board, making it more flexible.

[0023] 8. The utility model also provides a display device, including a carrying device and an LED display module as described above arranged on the carrying device, which has the same beneficial effects as the LED display module and will not be described in detail here.

Brief Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 It is a cross-sectional schematic diagram of an LED display module provided by the first embodiment of the utility model;

[0026] Figure 2It is a schematic diagram of a partial structure of an LED display module provided by the first embodiment of the utility model;

[0027] Figure 3 It is a schematic diagram of the solder resist layer of the LED display module structure provided by the first embodiment of the utility model;

[0028] Figure 4 It is a cross-sectional schematic diagram of an LED display module provided by the second embodiment of the utility model;

[0029] Figure 5 It is a schematic diagram of a display device provided in the third embodiment of the present utility model.

[0030] Description of the accompanying drawings:

[0031] 1. LED display module; 3. Display device;

[0032] 11. substrate; 12. solder mask layer; 13. conductor layer; 14. cover film; 30. carrier device;

[0033] 111. LED chip; 121. window; 122. concave cup structure; 131. conductor-free area. [Specific implementation method]

[0034] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below with reference to the accompanying drawings and implementation examples. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0035] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0036] In the present invention, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0037] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in this utility model can be understood according to specific circumstances.

[0038] In addition, the terms "installed", "set", "provided with", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0039] Please combine Figure 1 and Figure 2 The first embodiment of the utility model provides an LED display module 1, including a substrate 11, an LED chip 111 electrically connected to the substrate 11, a conductor layer 13 is arranged on the surface of the substrate 11, and a solder resist layer 12 is covered on the conductor layer 13. The solder resist layer 12 has a window 121 corresponding to the LED chip 111, and a conductor-free area 131 is arranged around the window 121 on the substrate 11. The solder resist layer 12 also covers the conductor-free area 131, and the thickness of the solder resist layer 12 covering the conductor-free area 131 is greater than the thickness of the solder resist layer 12 covering the conductor layer 13.

[0040] It can be understood that the substrate 11 is the main supporting structure of the LED display module 1, which is usually a thin plate-like object made of glass, metal or other specific materials, on which electronic components are installed. In the LED display module 1, the substrate 11 is used to support and install components such as LED chips 111. The LED chip 111 is the core component of the light-emitting diode. The LED chip 111 is electrically connected to the substrate 11 and emits light when current passes through. The conductor layer 13 is a layer of material used for conducting electricity, and materials with good conductive properties are usually used, such as copper, aluminum and other metals. The conductor layer 13 is arranged on the surface of the substrate 11 to transfer current to the LED chip 111. Through photolithography technology, the solder mask 12 is partially exposed and etched to form a window 121 and a conductor-free area 131. The window 121 exposes the LED chip 111 and is connected to the conductor layer 13 to ensure that the LED chip 111 can normally receive current and emit light. The conductor-free area 131 is on the substrate 11.

[0041] Specifically, the coverage of the solder resist layer 12 in the conductor-free area 131 controls the solder resist thickness near the LED chip 111 to be greater than the thickness on the conductor layer 13. The thickness difference brings higher reflection efficiency. Depending on the selection of different solder resist materials and the processing control method, the improved reflectivity is slightly different. In the utility model, the specific solder resist material of the solder resist layer 12 is not limited, as long as the conditions of high solder resist reflectivity are met.

[0042] Specifically, taking white oil as the material of the solder mask layer 12 and copper as the material of the conductor layer 13 as an example, when the actual white oil thickness in the copper-free area near the LED chip 111 reaches more than 50 um, the ink reflectivity at this position of the LED chip 111 can be increased to more than 92%.

[0043] Copper is the most common material for the conductor layer 13, which is covered with positive and negative wirings connecting various electronic components, but in some special applications, other materials can also be used, such as aluminum, gold plating, nickel plating, etc. The LED display module 1 provided by the utility model can also be applied to applications of other conductor layer 13 materials, and the specific material used for the conductor layer 13 is not limited in the utility model.

[0044] For further information, see Figure 1 and Figure 3 The solder resist layer 12 forms a concave cup structure 122 around the LED chip 111 .

[0045] Specifically, the concave cup structure 122 is formed by the fluidity of the solder resist material, which flows from the conductor-free area 131 to the side of the substrate 11. Through reflection and refraction at more angles, more light can be retained around the LED chip 111, and concentrated, focused, and repeatedly propagated in the target area, thereby reducing light loss, improving light utilization, and making the lighting effect more uniform and stable.

[0046] Furthermore, in order to further improve the reflectivity, a reflective coating or an optical reflective structure may be added to the concave cup structure 122 to guide the light more concentratedly to the target area, thereby improving the utilization rate and uniformity of the light.

[0047] Furthermore, the LED chips 111 are arranged on the substrate 11 in an array.

[0048] It can be understood that the array arrangement makes maximum use of the surface area of ​​the substrate 11 and has a regular layout in both horizontal and vertical directions to achieve uniform light distribution.

[0049] Furthermore, the solder resist layer 12 forms a certain inclination angle between the conductor-free area 131 and the side surface of the LED chip 111 .

[0050] Specifically, the light incident angle obtained by the inclination angle within a reasonable range is more optimal, and the reflection efficiency can be maximized, thereby improving the overall brightness of the LED display module 1 and reducing optical energy loss.

[0051] Furthermore, there is a gap between the concave cup structure 122 and the LED chip 111 .

[0052] Furthermore, the height of the solder resist layer 12 at the concave cup structure 122 is greater than the height of the LED chip 111 .

[0053] It can be understood that the gap can prevent the LED chip 111 from directly contacting the solder resist material in the concave cup structure 122 and causing damage to the LED chip 111 .

[0054] Specifically, the size and shape of the LED chip 111 depend on the purpose and category of the LED display module 1, and may include square, circular or other shapes. The solder resist layer 12 opens a window 121 for the LED chip 111 to expose the LED chip 111, and its size and shape need to be set accordingly. In this embodiment, the size and shape of the concave cup structure 122 formed by the solder resist layer 12 in the conductor-free area 131 are not limited, and the projected shape can be arbitrarily changed, and can be adjusted to a circle, ellipse, square or other irregular shapes as needed. The size and shape of the positive and negative electrode traces in the conductor area are also not limited, and the remaining area of ​​the solder resist layer 12 except the window 121 is covered with solder resist material.

[0055] Furthermore, the thickness of the solder resist layer 12 at the concave cup structure 122 is greater than 50 um.

[0056] It can be understood that the greater thickness of the solder resist layer 12 at the concave cup structure 122 can increase the mechanical stability of the entire display module and reduce the possibility of bending and deformation, especially when facing external pressure or force.

[0057] Furthermore, the thickness of the solder resist layer 12 on the conductor layer 13 is greater than 10 um.

[0058] Specifically, in typical PCB board manufacturing, the thickness of the solder resist layer 12 is usually between 20um and 35um, but due to the limitations of PCB process capabilities and SMT die bonding conditions, the solder resist layer 12 cannot be infinitely thickened. Increasing the thickness of the solder resist layer 12 can improve the environmental resistance of the LED display module 1, but a thicker solder resist layer 12 will block the propagation of light and affect the overall heat dissipation performance, and the reflectivity is also limited by the thickness of the solder resist layer 12.

[0059] It can be understood that in this embodiment, the thickness of the solder resist material near the window 121 of the LED chip 111 is increased without affecting the overall thickness of the LED display module 1, thereby improving the actual reflectivity of the solder resist material near the LED window 121.

[0060] Furthermore, the thickness of the conductor layer 13 is 10-70 um.

[0061] Furthermore, an LED display module 1 in the utility model is applied as a display technology for providing backlighting. In order to control the brightness and color of the LED, the LED display module 1 usually includes a driving circuit, which can adjust the current of the LED lamp beads to achieve different brightness levels and color temperatures. These electronic components are electrically connected to the substrate 11 through the conductor layer 13.

[0062] Furthermore, in order to better diffuse the light and improve the light utilization efficiency, some LED display modules 1 will add a diffusion layer or a diffusion device on the top of the solder resist layer 12 to ensure that the light emitted by the LED chip 111 is uniform.

[0063] Furthermore, the LED chip 111 is a miniLED chip or a microLED chip.

[0064] It can be understood that the LED display module 1 provided by the present invention is suitable for lighter and thinner display device design. Compared with traditional LED chips, miniLED chips are smaller in size, realize local backlighting, and have higher brightness and contrast. MicroLED is a self-luminous chip that does not require a backlight source, improves energy efficiency, and achieves deeper and higher contrast, which is used to create larger, more flexible, and more customized display screens.

[0065] For further information, see Figure 4 In the second embodiment of the utility model, an LED display module 2 is provided, wherein a covering film 14 is provided between the solder resist layer 12 and the conductor layer 13 .

[0066] Specifically, a conductor-free area 131 is provided around the opening 121 on the substrate 11, and the solder resist layer 12 forms a concave cup structure 122 in the conductor-free area 131, which is universal and applicable to both rigid printed circuit boards (PCBs) and flexible printed circuit boards (FPCs).

[0067] Furthermore, when the conductor-free area 131 is arranged on the flexible printed circuit board, there is a covering film 14 between the conductor layers 13 and the conductor layers 13. The flexible characteristics of the FPC require the protection and reinforcement of the covering film 14. A covering film-free area is adaptively arranged on the covering film 14 corresponding to the conductor-free area 131. The size and shape of the covering film-free area are the same as those of the conductor-free area 131. The covering film-free area and the conductor-free area 131 work together so that the solder resist material of the solder resist layer 12 can also form a concave cup structure 122 on the flexible printed circuit board due to its fluidity.

[0068] Specifically, the LED display module 2 provided in the second embodiment of the present invention has the same beneficial effects as the LED display module 1 provided in the first embodiment, which will not be described in detail herein.

[0069] See also Figure 5 The third embodiment of the utility model further provides a display device 3, including a carrying device 30 and an LED display module 1 as in the first embodiment or an LED display module 2 as in the second embodiment arranged on the carrying device 30.

[0070] Optionally, the display device 3 can be applied to 3C electronic products and their accessories such as mobile phones and mobile phone cases, or to the surface of products such as home appliances and automobiles, or to smart pens and smart wearable products; according to different application scenarios, the setting method and setting quantity of the LED display module 1 on the supporting device 30 may not be limited.

[0071] Compared with the prior art, the LED display module and display device provided by the utility model have the following advantages:

[0072] 1. In the LED display module provided in the embodiment of the utility model, during the PCB manufacturing process, the printing ink used in the solder resist layer in the conductor-free area is fluid, and the solder resist ink in the conductor-free area is recessed and thicker than the conductor area. The solder resist layer has the performance of reflecting light. The thicker the solder resist layer, the more it can improve the reflectivity of the LED, helping the LED display module to focus more light. The concentration of the conductor-free area also helps to isolate the circuit around the LED chip, effectively avoiding excessive electrical induction, and preventing current short circuit to optimize the manufacturing process.

[0073] 2. The LED display module provided in the embodiment of the utility model has a concave cup mouth structure that adjusts the divergence angle and direction of the light emitted by the LED chip to limit the propagation direction of the light, optimizes the optical properties of the display module, and makes the light better focused within the observation area of ​​the display screen, thereby improving the brightness and contrast of the display. The concave cup mouth structure improves the heat dissipation performance around the LED chip to a certain extent, increases the surface area, improves the heat dissipation efficiency, helps to keep the LED chip within the normal operating temperature range, provides additional protection for the LED chip, and extends its service life.

[0074] 3. The LED display module provided in the embodiment of the utility model has an array-like arrangement which helps to improve the uniformity of lighting and brightness distribution, achieve higher pixel density clarity and detail display, and thus improve the overall performance of the LED display module. There are certain gaps between components to provide better air circulation and help dissipate heat. There is often electromagnetic interference between LED chips. A neat arrangement can reduce the mutual influence between components, improve the stability of the circuit, and enhance the visual effect and user experience.

[0075] 4. In the LED display module provided in the embodiment of the utility model, when the temperature changes, different materials may expand or contract at different rates. The gap between the LED chip and the concave cup structure can provide space for such changes, reduce thermal stress, and make the LED display module more flexible when the temperature changes. It can also avoid the LED chip and the solder resist layer directly contacting the solder resist layer to cause damage to the LED chip.

[0076] 5. The LED display module provided in the embodiment of the utility model has a thicker solder resist layer that can provide better anti-corrosion and protection performance, preventing the risk of corrosion and mechanical damage to the LED chip by external substances; the thicker solder resist layer can improve the insulation performance and improve the thermal management performance, effectively isolate the LED chip and other circuit components, reduce light leakage, and improve the optical performance of the display.

[0077] 6. In the LED display module provided in the embodiment of the utility model, the height of the solder resist layer is greater than the height of the LED chip, which strengthens the protection of the LED chip, enhances the mechanical stability, provides a larger surface area, and helps to improve the heat dissipation performance.

[0078] 7. In the second embodiment of the utility model, an LED display module is provided, wherein a covering film is provided between the solder resist layer and the conductor layer. In a flexible printed circuit board, the covering film can provide additional protection for the conductor layer, effectively prevent wear, oxidation or other damage to the conductor, improve insulation performance, form a layer of isolation between the solder resist layer and the conductor layer, prevent the solder resist material from accidentally contacting the conductor during welding, and can also enhance the overall mechanical strength of the flexible printed circuit board, making it more flexible.

[0079] 8. The utility model also provides a display device, including a carrying device and an LED display module as described above arranged on the carrying device, which has the same beneficial effects as the LED display module and will not be described in detail here.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An LED display module, characterized in that: It includes a substrate, an LED chip electrically connected to the substrate, a conductor layer is arranged on the surface of the substrate, the conductor layer is covered with a solder resist layer, the solder resist layer has a window corresponding to the LED chip, a conductor-free area is arranged around the window on the substrate, the solder resist layer also covers the conductor-free area, and the thickness of the solder resist layer covering the conductor-free area is greater than the thickness of the solder resist layer covering the conductor layer.

2. The LED display module according to claim 1, characterized in that: The solder resist layer forms a concave cup structure around the LED chip.

3. The LED display module according to claim 1, wherein: The LED chips are arranged on the substrate in an array.

4. The LED display module according to claim 2, characterized in that: There is a gap between the concave cup structure and the LED chip.

5. The LED display module according to claim 2, characterized in that: The thickness of the solder resist layer at the concave cup structure is greater than 50um.

6. The LED display module according to claim 1, characterized in that: The thickness of the solder resist layer on the conductor layer is greater than 10um.

7. The LED display module according to claim 2, characterized in that: The height of the solder resist layer at the concave cup structure is greater than the height of the LED chip.

8. The LED display module according to claim 1, wherein: The LED chip is a miniLED chip or a microLED chip.

9. The LED display module according to claim 1, characterized in that: A covering film is provided between the solder resist layer and the conductor layer.

10. A display device, characterized in that: It comprises a carrying device and an LED display module as claimed in any one of claims 1 to 9 arranged on the carrying device.

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