Display module and manufacturing method thereof

Abstract

The invention provides a display module. The display module comprises a driving substrate, a plurality of pixel structures and a light blocking layer. The pixel structure is arranged on the driving substrate. Each pixel structure comprises a plurality of light emitting diode chips and a protective layer. The light emitting diode chip is arranged on the driving substrate. The protection layer wraps the plurality of light emitting diode chips. The light blocking layer is arranged on the driving substrate and surrounds the pixel structure.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a display module with a light-emitting diode chip and its manufacturing method. Background Technology

[0002] In recent years, direct-view LED (DVLED) displays have been developed, which utilize the light-emitting diodes themselves to create images. Compared to traditional LCD displays, DVLED displays can provide larger, brighter, and higher-contrast images. Generally, a DVLED display consists of multiple small LED boards. Each board may contain hundreds of thousands or even millions of LED chips. The spaces between these LED chips need to be coated with black glue to form a light-blocking layer, achieving both protection of the substrate and LED chips, as well as aesthetics, and improving the display's contrast. If black glue is accidentally applied to some LED chips, it can be removed using methods such as laser or plasma etching. However, if too many chips are covered, the entire LED board must be discarded.

[0003] However, LED chips are extremely small, with a nominal height typically only 80–85 micrometers (μm). Furthermore, even within the same manufacturer and model, LED chips of different colors may have different standard dimensions due to variations in manufacturing processes. Moreover, chip tolerances often range from ±10μm to ±15μm, and sometimes even as high as ±20μm to ±30μm. This means that the actual height of the LED chips placed on the LED board can vary considerably. Under these conditions, the precision requirements for the adhesive coating process are extremely high, misapplication of the adhesive is difficult to avoid, product yield is hard to improve, and production costs are difficult to reduce. Summary of the Invention

[0004] The purpose of this invention is to prevent the above-mentioned problems.

[0005] To achieve the above objectives, the present invention provides a display module comprising: a driving substrate; and a plurality of pixel structures disposed on the driving substrate, each pixel structure comprising:

[0006] Multiple light-emitting diode (LED) chips are disposed on the driving substrate; and a protective layer is applied to the multiple LED chips; and

[0007] A light-blocking layer is disposed on the driving substrate and surrounds the plurality of pixel structures.

[0008] Preferably, the size of each light-emitting diode chip is less than or equal to 250 micrometers (μm).

[0009] Preferably, each pixel structure comprises a plurality of light-emitting diode chips, a red light-emitting diode chip, and a blue light-emitting diode chip; in each pixel structure, the red light-emitting diode chip, the green light-emitting diode chip, and the blue light-emitting diode chip are all wrapped by the same protective layer.

[0010] Preferably, the distance between two adjacent LED chips belonging to the same pixel structure is less than the distance between two adjacent LED chips belonging to different pixel structures.

[0011] Preferably, in each of the pixel structures, the protective layer directly contacts the plurality of light-emitting diode chips.

[0012] Preferably, the protective layer is bell-shaped and is transparent or translucent.

[0013] Preferably, the height of the light-blocking layer is equal to or greater than the standard height of the plurality of light-emitting diode chips and the height of the light-blocking layer is less than the height of the protective layer.

[0014] Preferably, the light-blocking layer is in direct contact with the protective layer, and the light-blocking layer is opaque.

[0015] Based on the above objectives, the present invention also proposes a method for manufacturing a display module, comprising: providing a plurality of light-emitting diode (LED) chips with a plurality of pixel structures onto a driving substrate; forming a plurality of protective layers to enclose the plurality of LED chips, wherein each of the protective layers belongs to one of the plurality of pixel structures and encloses the plurality of LED chips of the pixel structure; and forming a light-blocking layer on the driving substrate and surrounding the plurality of pixel structures.

[0016] Preferably, the step of forming the plurality of protective layers includes: dropping a plurality of protective adhesive liquid onto the plurality of light-emitting diode chips, wherein each of the protective adhesive liquid drops is on one of the plurality of light-emitting diode chips of the pixel structure; and curing the plurality of protective adhesive liquid drops.

[0017] Preferably, the protective adhesive is epoxy resin or silicone.

[0018] Preferably, the cured protective adhesive droplets are bell-shaped.

[0019] Preferably, the step of forming the light-blocking layer includes: applying black adhesive to the driving substrate such that the black adhesive surrounds the plurality of protective layers of the plurality of pixel structures; and curing the black adhesive.

[0020] Preferably, the coating height of the black adhesive is equal to or greater than the standard height of the plurality of light-emitting diode chips and less than the height of the plurality of protective layers.

[0021] By setting a protective layer, the black adhesive used to form the light-blocking layer can be prevented from being accidentally applied to the light-emitting diode chip, thereby improving yield and reducing production costs. Attached Figure Description

[0022] Figure 1 A schematic diagram of a display module according to the present invention is shown.

[0023] Figure 2 A schematic diagram of another display module according to the present invention is shown.

[0024] Figure 3 A flowchart illustrating a method for manufacturing a display module according to the present invention is shown.

[0025] Figures 4A to 4I Schematic diagrams showing different stages of a manufacturing method for a display module according to the present invention. Detailed Implementation

[0026] To provide a further understanding of the purpose, structure, features, and functions of the present invention, detailed descriptions are provided below with reference to specific embodiments.

[0027] Please refer to Figure 1 This illustrates a display module 10 according to the present invention. The display module 10 includes a driving substrate 100, a plurality of pixel structures 200, and a light-blocking layer 300. The pixel structures 200 are disposed on the driving substrate 100. Each pixel structure 200 includes a plurality of light-emitting diode (LED) chips 210 and a protective layer 220. The LED chips 210 are disposed on the driving substrate 100. The protective layer 220 covers the LED chips 210. The light-blocking layer 300 is disposed on the driving substrate 100 and surrounds the pixel structures 200.

[0028] Specifically, the driving substrate 100 can be a printed driving substrate. The driving substrate may have the circuitry and / or other related electronic devices required for the light-emitting diode chip 210. However, it is understood that the present invention is not limited thereto.

[0029] Each of the pixel structures 200 may include a plurality of light-emitting diode (LED) chips 210 of different colors. For example, each of the pixel structures 200 may consist of a red LED chip 210R, a green LED chip 210G, and a blue LED chip 210B. In this case, in each of the pixel structures 200, the red LED chip 210R, the green LED chip 210G, and the blue LED chip 210B are all enclosed by the same protective layer 220. However, it is understood that the plurality of LED chips 210 in each of the pixel structures 200 may also be combinations of other numbers and / or colors of LED chips. In some embodiments, at least two of the plurality of LED chips 210 in at least one of the pixel structures 200 have different heights. For example, in Figure 1 In the diagram, the LED chips 210 of the left pixel structure 200 are all depicted with the same height, while the LED chips 210 of the right pixel structure 200 are depicted with three different heights. According to some embodiments, at least two of the plurality of LED chips 210 in at least one of the pixel structures 200 may have different lateral dimensions, that is, they may have different lengths and / or different widths. According to some embodiments, the size of the LED chip 210 is less than or equal to 250 μm, that is, its length, width, and height are all less than or equal to 250 μm.

[0030] In one example, the dimensions of the red LED chip can be 93 (±15) μm × 150 (±15) μm × 80 (±10) μm, and the dimensions of the green and blue LED chips can be 89 (±15) μm × 150 (±15) μm × 80 (±10) μm. In another example, the dimensions of the red, green, and blue LED chips can all be 100 (±15) μm × 200 (±15) μm × 80 (±10) μm. In yet another example, the dimensions of the red LED chip can be 92 (±25) μm × 185 (±25) μm × 80 (±10) μm, and the dimensions of the green and blue LED chips can be 92 (±25) μm × 187 (±25) μm × 85 (±15) μm. In yet another example, the size of the red LED chip can be 100 (±25) μm × 200 (±25) μm × 85 (±10) μm, and the size of the green and blue LED chips can be 100 (±38) μm × 203 (±38) μm × 85 (±15) μm. However, it is understood that the invention is not limited thereto.

[0031] The LED chip 210 can be configured in pixels. In this case, such as Figure 1 As shown, the distance d1 between two adjacent LED chips 210 belonging to the same pixel structure 200 is smaller than the distance d2 between two adjacent LED chips 210 belonging to different pixel structures 200. That is, the LED chips 210 belonging to the same pixel structure 200 are arranged in a more compact manner. This facilitates the formation of the protective layer 220 on all LED chips 210 belonging to the same pixel structure 200. The LED chips 210 can have a standard height hc. Here, the standard height hc can be a manufacturer-provided calibration height. If the calibration heights of LED chips 210 of different colors are different, an average value can be used; alternatively, the maximum value of the calibration heights of different colored LED chips 210 can be used, which can also be the allowable tolerance for the superposition of calibration heights. However, it is understood that the invention is not limited thereto. For example, the standard height hc can also be determined according to design requirements.

[0032] In each of the pixel structures 200, the protective layer 220 directly contacts the light-emitting diode chip 210. According to some embodiments, the protective layer 220 may be bell-shaped. The height hp of the protective layer 220 may be the maximum height of the bell-shaped structure, which may, for example, be approximately twice the standard height hc of the light-emitting diode chip 210, but is not limited thereto. In some embodiments, the protective layer 220 is transparent. In other embodiments, the protective layer 220 is translucent. The material of the protective layer 220 may be epoxy resin or silicone, but is not limited thereto.

[0033] A light-blocking layer 300 is disposed around the pixel structure 200 to prevent lateral light leakage, thereby improving the contrast of the display. The light-blocking layer 300 can directly contact the protective layer 220. The height hb of the light-blocking layer 300 can be equal to or greater than the standard height hc of the light-emitting diode chip 210 and less than the height hp of the protective layer 220. As long as it falls within the above range, the height hb of the light-blocking layer 300 does not require special limitation. For example, in... Figure 1 In the process, the height hb of the light-blocking layer 300 is slightly larger than the standard height hc of the light-emitting diode chip 210. Figure 2 In the display module 10', the light-blocking layer 300' has a greater height, hb', which is greater than the height of all the light-emitting diode chips 210 and approximately equal to the height of the sidewall of the protective layer 220. The light-blocking layer 300 can be opaque. The material of the light-blocking layer 300 can be epoxy resin, silicone, or acrylic adhesive, but is not limited to these.

[0034] Please refer to Figure 3 and Figures 4A to 4IThe manufacturing method of the display module according to the present invention will now be described. Figure 3 This is a flowchart of a method for manufacturing a display module according to the present invention. Figures 4A to 4I This is a schematic diagram illustrating different stages of the manufacturing method of the display module according to the present invention.

[0035] In step S1, as Figure 4A As shown, multiple light-emitting diode (LED) chips 210 with multiple pixel structures 200 are mounted on a driving substrate 100. Specifically, a chip array containing multiple LED chips 210 can be die-bonded onto the driving substrate 100 using a mass transfer process.

[0036] In step S2, a plurality of protective layers 220 are formed to enclose the plurality of light-emitting diode chips 210. Each of the plurality of protective layers 220 belongs to one of the plurality of pixel structures 200 and encloses the light-emitting diode chip 210 of the pixel structure 200.

[0037] Specifically, please refer to Figure 4B In step S21, as indicated by arrow A1, multiple droplets 22 of a protective adhesive (shown in...) are... Figure 4C The protective adhesive is applied to the LED chip 210. The adhesive can be epoxy resin or silicone, but is not limited to these. The adhesive can be transparent or translucent, and its transparency can be adjusted as needed. The adhesive can be applied using a nozzle, but is not limited to this method. Figure 4C As shown, each of the plurality of droplets 22 is dropped onto the light-emitting diode chip 210 of one of the plurality of pixel structures 200. Preferably, the adhesive droplets are dispensed with specific dispensing parameters so that they are bell-shaped; in other words, the lower half of the adhesive droplet has a steeper outer wall and a more rounded top. Next, please refer to... Figure 4D In step S22, as indicated by arrow A2, the protective adhesive droplets 22 are cured. For example, the protective adhesive is a thermosetting adhesive or a UV-curing adhesive, which can be cured by heating or by ultraviolet light irradiation. In some embodiments, the cured droplets 22 are bell-shaped. Thus, the cured protective adhesive droplets 22 form a protective layer 220, which integrally encapsulates and protects multiple light-emitting diode chips 210 in the same pixel structure 200. In this way, one protective layer 220 is required for each pixel structure 200, and the process size is larger than that of each light-emitting diode chip 210. This reduces the process accuracy requirements and workload, greatly reduces production costs, and improves product yield.

[0038] Then, in step S3, a light-blocking layer 300 is formed on the driving substrate 100 and surrounds the pixel structure 200.

[0039] Specifically, please refer to Figure 4E In step S31, as indicated by arrow A3, a layer of black adhesive 30 is applied (shown in...). Figure 4F On the driving substrate 100, the black adhesive 30 surrounds the protective layer 220 of the pixel structure 200, such as... Figure 4F As shown. The black adhesive 30 can be epoxy resin, silicone, or acrylic adhesive, but is not limited to these. The black adhesive 30 can be applied using a nozzle, but is not limited to these. The application height of the black adhesive 30 can be equal to or greater than the standard height of the LED chip 210 and less than the height of the protective layer 220, thereby preventing lateral light leakage and reducing the likelihood of obstruction due to accidental application of black adhesive. Next, please refer to... Figure 4H In step S32, as indicated by arrow A4, the black adhesive 30 is cured. The black adhesive can be a thermosetting adhesive or a UV-curable adhesive, and can be cured by thermosetting or UV light. The cured black adhesive 30 forms a light-blocking layer 300, which can block the space between the driving substrate 100 of each pixel structure 200, reducing stray light caused by reflection. Since the aforementioned protective layer 220 is bell-shaped, the light-blocking layer 300 also guides the direction of light propagation, that is, it propagates as much as possible towards the normal of the driving substrate 100, thereby improving contrast. The light-blocking layer 300 also strengthens the bonding force between the pixel structure 200 and the driving substrate 100, playing a role in protecting the substrate and the light-emitting diode chip.

[0040] Please refer to Figure 4I After the black adhesive is cured, the display module 10 can be obtained.

[0041] In summary, this invention provides a display module 10 and its manufacturing method that can reduce the impact of misapplied black adhesive. In the display module 10 according to this invention, since a protective layer is used to isolate the light-blocking layer 300 from the light-emitting diode chip 210, the influence of the size of the light-emitting diode chip 210 is reduced. Therefore, additional sorting is unnecessary, reducing both procurement and manufacturing costs. Furthermore, the size selection of the light-emitting diode chip 210 is more flexible, thereby increasing customization flexibility. In addition, there is no need to meticulously control the height of the black adhesive 30 during dispensing, significantly reducing the precision requirements of the dispensing equipment and thus lowering equipment costs. Moreover, the thickness of the black adhesive 30 is easy to control, preventing misapplied adhesive to the top surface of the light-emitting diode chip 210, eliminating the need for subsequent plasma desmearing, significantly improving yield and reducing costs.

[0042] The present invention has been described in the above-described embodiments; however, these embodiments are merely examples for implementing the present invention. It must be noted that the disclosed embodiments do not limit the scope of the present invention. Conversely, any modifications and refinements made without departing from the spirit and scope of the present invention are within the scope of patent protection of the present invention.

Claims

1. A display module, characterized in that, include: Drive substrate; Multiple pixel structures are disposed on the driving substrate, each pixel structure comprising: Multiple light-emitting diode chips are disposed on the driving substrate; and A protective layer surrounds the multiple LED chips; and A light-blocking layer is disposed on the driving substrate and surrounds the plurality of pixel structures.

2. The display module as described in claim 1, characterized in that, Each of these LED chips has a size of less than or equal to 250 micrometers (μm).

3. The display module as described in claim 1, characterized in that, Each pixel structure consists of multiple light-emitting diode chips, including red light-emitting diode chips, green light-emitting diode chips, and blue light-emitting diode chips. In each pixel structure, the red LED chip, the green LED chip, and the blue LED chip are all wrapped in the same protective layer.

4. The display module as described in claim 1, characterized in that, The distance between two adjacent LED chips belonging to the same pixel structure among the plurality of LED chips is less than the distance between two adjacent LED chips belonging to different pixel structures among the plurality of LED chips.

5. The display module as described in claim 1, characterized in that, In each of these pixel structures, the protective layer directly contacts the plurality of light-emitting diode chips.

6. The display module as described in claim 1, characterized in that, The protective layer is bell-shaped and is either transparent or translucent.

7. The display module as described in claim 1, characterized in that, The height of the light-blocking layer is equal to or greater than the standard height of the plurality of light-emitting diode chips, and the height of the light-blocking layer is less than the height of the protective layer.

8. The display module as described in claim 1, characterized in that, The light-blocking layer is in direct contact with the protective layer, and the light-blocking layer is opaque.

9. A method for manufacturing a display module, characterized in that, include: Multiple light-emitting diode chips with multiple pixel structures are provided on the driving substrate; Multiple protective layers are formed to enclose the multiple light-emitting diode chips, wherein each of the protective layers belongs to a pixel structure in the multiple pixel structures and encloses the multiple light-emitting diode chips of the pixel structure; as well as A light-blocking layer is formed on the driving substrate and surrounds the multiple pixel structures.

10. The method for manufacturing a display module as described in claim 9, characterized in that, The steps for forming these multiple protective layers include: Multiple protective adhesive droplets are applied to the plurality of light-emitting diode (LED) chips, wherein each droplet of the protective adhesive is applied to one of the plurality of LED chips in the pixel structure; and The multiple protective adhesive droplets are cured.

11. The method for manufacturing a display module as described in claim 10, characterized in that, The protective adhesive is made of epoxy resin or silicone.

12. The method for manufacturing a display module as described in claim 10, characterized in that, The cured protective adhesive droplets are bell-shaped.

13. The method for manufacturing a display module as described in claim 9, characterized in that, The steps of forming the light-blocking layer include: applying black adhesive to the driving substrate such that the black adhesive surrounds the plurality of protective layers of the plurality of pixel structures; and curing the black adhesive.

14. The method for manufacturing a display module as described in claim 13, characterized in that, The coating height of the black adhesive is equal to or greater than the standard height of the plurality of light-emitting diode chips and less than the height of the plurality of protective layers.

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