Micro oled high-efficiency packaging method

Abstract

This invention discloses a high-efficiency packaging method for Micro OLEDs, comprising the following steps: S1, fabricating a CMOS driving circuit on a silicon substrate to form a CMOS substrate; S2, fabricating an anode and pixel definition layer on the driving circuit; S3, coating a hydrophobic material on the dicing channels around individual cells to form a hydrophobic layer; S4, printing spaced hydrophilic group ink droplets on the hydrophobic material of the dicing channels using inkjet printing; S5, fabricating an OLED layer by vacuum evaporation; S6, fabricating an encapsulation layer, with the hydrophilic group ink droplets on the dicing channels forming a discontinuous film; S7, fabricating an OC layer and a CF color filter layer on the encapsulation layer; S8, attaching a glass cover CG film to the color filter layer; S9, dicing the wafer and then performing PCB bonding or FPC bonding. This method ensures that the encapsulation layer is discontinuously formed on the dicing channels, preventing microcracks from forming during dicing and propagating to the display area, thus avoiding packaging failure. This effectively improves packaging efficiency and quality and is simple to implement.

Description

Technical Field

[0001] This invention relates to the field of Micro OLED display technology, and in particular to a high-efficiency packaging method for Micro OLED. Background Technology

[0002] Micro OLED is a micro-display technology that combines semiconductors and OLEDs. It is considered the third generation of display technology after CRT and LCD. Silicon-based OLED microdisplays are suitable for applications such as helmet displays, 3D displays, and eye-mounted displays. When connected to mobile communication networks, satellite positioning systems, and other systems, accurate image information can be obtained anytime, anywhere.

[0003] Silicon-based OLED microdisplays offer an excellent solution for near-eye display applications (such as helmet displays) in consumer, industrial, and even military fields, and Micro OLED microdisplays are poised for explosive growth. The main manufacturing process for silicon-based OLEDs involves driver ICs, photolithography, evaporation, encapsulation, and module assembly. Encapsulation is an essential process in display production, preventing moisture and oxygen from entering the components and causing accelerated aging and failure.

[0004] Currently, the main packaging equipment used includes plasma-enhanced chemical vapor deposition (PECVD) and atomic layer deposition (ALD), but these types of equipment fabricate the entire packaging layer. During wafer dicing, crack propagation can easily occur, leading to packaging failure. To remove excess packaging layers, either a mask is used on the PECVD equipment, or after the packaging layer is fabricated, excess packaging film is removed using coating, exposure, development, and dry etching. However, using a mask introduces shadows, requires a wider margin, resulting in wider boundaries, and easily introduces particles during mask bonding; using the latter involves multiple water washes during the coating, exposure, development, and dry etching processes, affecting the packaging effect. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a high-efficiency encapsulation method for Micro OLEDs, which allows for discontinuous cutting paths during encapsulation layer film formation, making cutting less likely to cause encapsulation failure.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] This efficient packaging method for Micro OLED includes the following steps:

[0008] S1. Fabricate CMOS driving circuits on a silicon substrate to form a CMOS substrate;

[0009] S2. Fabricate the anode and pixel definition layer on the driving circuit;

[0010] S3. Apply a hydrophobic material to the cut lines around a single unit to form a hydrophobic layer;

[0011] S4. Use inkjet printing to print spaced hydrophilic group ink droplets on the hydrophobic material of the cutting path;

[0012] S5. OLED layer is prepared by vacuum evaporation;

[0013] S6. Prepare the encapsulation layer, and encapsulate the discontinuous ink droplets of the hydrophilic groups on the cutting track into a film.

[0014] S7. Prepare the OC layer and CF color filter layer on the encapsulation layer;

[0015] S8. Apply a CG film to the glass cover plate on the color filter layer;

[0016] S9. After dicing the wafer, perform PCB bonding or FPC bonding.

[0017] in,

[0018] The width of the cutting channel ranges from 500um to 1000um.

[0019] The hydrophobic material is polydimethylsiloxane, organosilicon resin, or polyacrylonitrile.

[0020] In step S3, a hydrophobic layer can be formed by screen printing or coating.

[0021] In step S4, the ink droplets are arranged in a staggered, alternating pattern.

[0022] In step S4, the distance between adjacent ink droplets is greater than 100 μm, and the outer diameter of the ink droplets is less than 100 μm.

[0023] In step S4, the contact angle between the ink droplet and the hydrophobic material is greater than 90°.

[0024] In step S6, the encapsulation film layer includes an encapsulation organic layer and an encapsulation inorganic layer. The encapsulation organic layer is patterned individually for each unit, while the encapsulation inorganic layer is formed as a film over the entire surface.

[0025] In step S6, the boundary of the encapsulated organic layer film does not exceed the boundary of the hydrophobic layer mentioned above.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] This efficient Micro OLED encapsulation method is rationally designed. By coating the cutting path with hydrophobic material and then printing hydrophilic groups, a contact angle greater than 90° is formed. This makes the encapsulation layer discontinuous in the cutting path during film formation, avoiding the formation of microcracks during cutting that extend to the display area and cause encapsulation failure. This effectively improves encapsulation efficiency and quality, and is easy to implement. Attached Figure Description

[0028] The following is a brief explanation of the contents of each of the accompanying drawings and the markings in the drawings:

[0029] Figure 1 This is a schematic diagram illustrating the packaging implementation of the present invention.

[0030] Figure 2 This is a schematic diagram of the cutting path of the present invention.

[0031] Figure 3 For along Figure 2 Schematic diagram of section AA.

[0032] Figure 4 This is a schematic diagram illustrating the encapsulation and film-forming characteristics of the present invention.

[0033] In the picture:

[0034] 1. CMOS substrate, 2. Pixel definition layer, 3. Anode, 4. Encapsulation inorganic layer, 5. Encapsulation organic layer, 6. Hydrophobic layer, 7. Ink droplet. Detailed Implementation

[0035] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and through the description of the examples.

[0036] This efficient packaging method for Micro OLED includes the following steps:

[0037] S1. A CMOS substrate 1 is formed by fabricating a CMOS driving circuit on a silicon substrate.

[0038] S2. Fabricate the anode 3 and pixel definition layer 2 on the driving circuit;

[0039] S3. Apply a hydrophobic material to the cut grooves around a single unit to form a hydrophobic layer 6;

[0040] S4. Use inkjet printing to print spaced hydrophilic group ink droplets 7 on the hydrophobic material of the cutting path;

[0041] S5. OLED layer is prepared by vacuum evaporation;

[0042] S6. Prepare the encapsulation layer, and encapsulate the discontinuous ink droplets of the hydrophilic groups on the cutting track into a film.

[0043] S7. Prepare the OC layer and CF color filter layer on the encapsulation layer;

[0044] S8. Apply a CG film to the glass cover plate on the color filter layer;

[0045] S9. After dicing the wafer, perform PCB bonding or FPC bonding.

[0046] The ink droplets are arranged in a staggered, alternating pattern. When the contact angle between the ink droplets and the hydrophobic material is greater than 60°, the film formation quality deteriorates; when it is greater than 90°, film formation is impossible. Figure 4 As shown.

[0047] This invention involves coating the cutting path with a hydrophobic material and then printing hydrophilic groups to form a contact angle greater than 90°. This results in a discontinuous encapsulation layer during film formation on the cutting path, preventing microcracks from forming during cutting and extending to the display area, thus avoiding encapsulation failure. This effectively improves encapsulation efficiency and quality and is easy to implement.

[0048] like Figures 1 to 3 As shown, a preferred embodiment of the present invention is as follows:

[0049] This efficient packaging method for Micro OLED includes the following steps:

[0050] 1. Fabricating CMOS driving circuits on a silicon substrate to form a CMOS substrate;

[0051] 2. Fabricate the anode and pixel definition layer (PDL) on the driving circuit;

[0052] 3. Coat the cutting grooves around a single unit with a hydrophobic material with a width of 500um-1000um. The hydrophobic material can be selected from, but is not limited to, polydimethylsiloxane, silicone resin, polyacrylonitrile, etc. The preparation method includes, but is not limited to, screen printing, coating, etc.

[0053] 4. Use inkjet printing to print hydrophilic droplets onto the hydrophobic material of the cutting path, such as epoxy resin or acrylic. The spacing between adjacent droplets should be greater than 100µm, the outer diameter of the droplets should be less than 100µm, and the droplets should be arranged in a staggered row pattern. The hydrophilic material should not flow smoothly on the hydrophobic surface, and the contact angle between the droplets and the hydrophobic material should be greater than 90°. Figure 3 As shown;

[0054] 5. OLED layers are prepared by vacuum evaporation.

[0055] 6. Preparation of thin film encapsulation layer: The encapsulation film layer consists of a stack of organic and inorganic layers, preferably inorganic / organic / inorganic, forming an encapsulation inorganic layer 4 and an encapsulation organic layer 5; the organic layer is patterned individually for each unit, and its boundary does not exceed the boundary of the hydrophobic layer mentioned above. The organic layer material includes, but is not limited to, epoxy resin, acrylic materials, etc.; the inorganic layer is formed on the whole surface and is prepared by PECVD. The film layer includes SiN, SiO, SiON, etc. Due to the presence of ink droplets with a contact angle greater than 90° on the dicing track, the inorganic layer is discontinuous on the dicing track.

[0056] 7. Prepare the OC layer and CF color filter layer on the encapsulation layer;

[0057] 8. Apply a CG film to the glass cover plate on the color filter layer;

[0058] 9. After dicing the wafer, perform PCB bonding or FPC bonding.

[0059] This invention involves coating the cutting path with a hydrophobic material and then printing hydrophilic groups to form a contact angle greater than 90°. This results in a discontinuous encapsulation layer during film formation, making cutting less likely to cause encapsulation failure.

[0060] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the concept and technical solution of the present invention, or the direct application of the concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A high-efficiency packaging method for Micro OLEDs, characterized in that: The efficient packaging method for Micro OLED includes the following steps: S1. Fabricate CMOS driving circuits on a silicon substrate to form a CMOS substrate; S2. Fabricate the anode and pixel definition layer on the driving circuit; S3. Apply a hydrophobic material to the cut lines around a single unit to form a hydrophobic layer; S4. Use inkjet printing to print spaced hydrophilic group ink droplets on the hydrophobic material of the cutting track, with the contact angle between the hydrophilic group ink droplets and the hydrophobic material being greater than 90°. S5. OLED layer is prepared by vacuum evaporation; S6. Prepare the encapsulation layer, and encapsulate the discontinuous ink droplets of the hydrophilic groups on the cutting track into a film. S7. Prepare the OC layer and CF color filter layer on the encapsulation layer; S8. Apply a CG film to the glass cover plate on the color filter layer; S9. After dicing the wafer, perform PCB bonding or FPC bonding.

2. The high-efficiency packaging method for Micro OLED as described in claim 1, characterized in that: The width of the cutting channel ranges from 500um to 1000um.

3. The high-efficiency packaging method for Micro OLED as described in claim 1, characterized in that: The hydrophobic material is polydimethylsiloxane, organosilicon resin, or polyacrylonitrile.

4. The high-efficiency packaging method for Micro OLED as described in claim 1, characterized in that: In step S3, a hydrophobic layer is formed by screen printing or coating.

5. The high-efficiency packaging method for Micro OLED as described in claim 1, characterized in that: In step S4, the ink droplets are arranged in a staggered, alternating pattern.

6. The high-efficiency packaging method for Micro OLED as described in claim 1, characterized in that: In step S4, the distance between adjacent ink droplets is greater than 100 μm, and the outer diameter of the ink droplets is less than 100 μm.

7. The high-efficiency packaging method for Micro OLED as described in claim 1, characterized in that: In step S6, the encapsulation film layer includes an encapsulation organic layer and an encapsulation inorganic layer. The encapsulation organic layer is patterned individually for each unit, while the encapsulation inorganic layer is formed as a film over the entire surface.

8. The high-efficiency packaging method for Micro OLED as described in claim 7, characterized in that: In step S6, the boundary of the encapsulated organic layer film does not exceed the boundary of the hydrophobic layer mentioned above.

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