Silicon-based micro display screen packaging structure

Abstract

The utility model discloses a silicon-based micro display screen packaging structure, which belongs to the technical field of silicon-based micro display screens, and comprises a silicon substrate, a glass cover plate and a light-emitting element arranged between the silicon substrate and the glass cover plate, the glass cover plate comprises a cover plate main body and an annular flange integrally arranged on the peripheral side of the lower end of the cover plate main body, the annular flange is hermetically connected with the peripheral edge of the upper end face of the silicon substrate to form a closed space, the upper end face of the cover plate body is in arc transition connection with the peripheral face of the annular flange, and the glass edge is arc-shaped, so that the edge strength of the glass cover plate can be improved, and cracks caused by collision are reduced; and the glass cover plate with the structure can improve the edge packaging effect to a great extent, and the protection effect on internal materials is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of silicon-based micro-display screens, and particularly relates to a packaging structure of a silicon-based micro-display screen. Background Art

[0002] As a new display technology combining semiconductors and OLEDs, silicon-based OLED displays will be the main solution for next-generation intelligent wearable displays such as VR / AR. With the continuous progress of 5G and AI technologies, more and more wearable display products will become more attractive. Silicon-based OLED micro-display devices have advantages such as high resolution, low power consumption, small size, and light weight, and are widely used in high-resolution near-eye display industries such as AR, VR, wearable devices, industrial security, and medical care, gradually becoming an important competitive point in the new display industry with huge market potential. Organic Light Emitting Display (OLED) is a new generation of display, which has many advantages such as self-luminescence, fast response, wide viewing angle, and high color saturation compared with liquid crystal displays. However, OLED devices are sensitive to water and oxygen in the air and are prone to absorb water and oxidize, which can cause the lifespan of OLED devices to decrease or pixel failure. Therefore, effectively packaging OLED devices to fully isolate them from water and oxygen is crucial for extending the service life of OLED devices.

[0003] There are two main parts that actually play a packaging role. One is thin-film packaging, and the other is the glass cover plate after thin-film packaging. Conventional packaging structures in the micro-display industry are as Figure 1 shown. Among them, a laminated thin-film packaging layer 3 using AlO / SiN / AlO or other combinations is used for packaging. However, this laminated thin-film packaging layer 3 is prone to cause optical refraction and optical crosstalk, affecting optical performance. The glass cover plate 1 can not only protect the thin-film packaging film layer 3 from being scratched and affecting product performance, but also play a packaging role in preventing water vapor from invading. Therefore, the process of the glass cover plate 1 has a greater impact on the performance of the product. The current glass cover plate 1 uses an OCR (Optically Clear Adhesive, a special adhesive for bonding transparent optical components) 2 bonding process, and a frame adhesive 4 needs to be made on the outer frame. However, this method has the following disadvantages: First, because the frame adhesive 4 is an organic material, it is prone to absorb water, resulting in a poor packaging effect, and the edges cannot play the role of edge packaging. Moreover, the appearance of the frame adhesive 4 is poor and can be seen through the glass cover plate 1, affecting the overall aesthetics of the product. Second, the edge of the glass cover plate 1 is easily broken by external forces. Summary of the Utility Model

[0004] The technical problem to be solved by the present utility model is: to provide a silicon-based micro-display packaging structure, which can improve the edge strength of the glass cover plate, reduce breakage caused by bumps, and improve the protection effect on internal materials.

[0005] To solve the above technical problem, the technical solution of the present utility model is:

[0006] A silicon-based micro-display packaging structure includes a silicon substrate, a glass cover plate, and a light-emitting element disposed between the silicon substrate and the glass cover plate. The glass cover plate includes a cover plate main body and an annular flange integrally provided on the peripheral side of the lower end of the cover plate main body. The annular flange is hermetically connected to the peripheral edge of the upper end surface of the silicon substrate to form a sealed space, and the upper end surface of the cover plate main body and the outer peripheral surface of the annular flange are connected by an arc transition.

[0007] Further, glass powder paste is coated in the space formed between the inner peripheral surface of the annular flange, the light-emitting element, and the silicon substrate. After laser sintering of the glass powder paste, the glass cover plate and the silicon substrate are hermetically bonded and fixed.

[0008] Further, a retaining wall is provided on the silicon substrate on the peripheral side of the light-emitting element. The annular flange is sleeved on the outside of the retaining wall, and the glass powder paste is coated on the outer peripheral surface and the upper end surface of the retaining wall.

[0009] Further, the retaining wall is an inorganic thin film retaining wall.

[0010] Further, the glass cover plate is a 3D glass cover plate.

[0011] Further, a single-layer inorganic thin film encapsulation layer is provided between the light-emitting element and the cover plate main body.

[0012] Further, the single-layer inorganic thin film encapsulation layer is an alumina thin film encapsulation layer.

[0013] Further, a color filter layer is provided between the single-layer inorganic thin film encapsulation layer and the cover plate main body.

[0014] Further, the light-emitting element includes a CMOS circuit layer, a pixel anode layer, a pixel isolation layer, and an OLED light-emitting layer stacked on the silicon substrate.

[0015] Further, the pixel anode layer and the pixel isolation layer are inorganic thin film layers, and the OLED light-emitting layer is an organic thin film layer.

[0016] After adopting the above technical solution, the beneficial effect of the present utility model is:

[0017] Since the silicon-based micro-display packaging structure of the present utility model includes a silicon substrate, a glass cover plate, and a light-emitting element disposed between the silicon substrate and the glass cover plate, the glass cover plate includes a cover plate body and an annular flange integrally provided on the peripheral side of the lower end of the cover plate body. The annular flange is hermetically connected to the peripheral edge of the upper end surface of the silicon substrate to form a sealed space. The upper end surface of the cover plate body and the outer peripheral surface of the annular flange are connected by an arc transition. The glass edge is arc-shaped, which can improve the edge strength of the glass cover plate and reduce the breakage caused by bumps. Moreover, the glass cover plate with this structure can greatly improve the edge packaging effect and enhance the protection effect on the internal materials. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of a silicon-based micro-display packaging structure in the prior art;

[0019] Figure 2 is a schematic structural diagram of the silicon-based micro-display packaging structure of the present utility model;

[0020] Figure 3 is a schematic top view of the appearance of the silicon-based micro-display packaging structure of the present utility model;

[0021] In the figure, 1 - glass cover plate, 2 - OCR, 3 - thin film encapsulation layer, 4 - frame adhesive, 5 - silicon substrate, 6 - CMOS circuit layer, 7 - pixel anode layer, 8 - pixel isolation layer, 9 - OLED light-emitting layer, 10 - single-layer inorganic thin film encapsulation layer, 11 - color filter layer, 12 - cover plate body, 13 - annular flange, 14 - retaining wall, 15 - glass powder paste. Detailed Embodiments

[0022] The present utility model will be further described below in conjunction with the drawings and embodiments. The preferred embodiments of the present utility model are shown in the drawings. The role of the drawings is to supplement the description of the text part of the specification, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present utility model. However, it should not be construed as a limitation on the protection scope of the present utility model.

[0023] As Figure 2 shown, a silicon-based micro-display packaging structure includes a silicon substrate 5, a glass cover plate 1, and a light-emitting element disposed between the silicon substrate 5 and the glass cover plate 1. The glass cover plate 1 includes a cover plate body 12 and an annular flange 13 integrally provided on the peripheral side of the lower end of the cover plate body 12. The annular flange 13 is hermetically connected to the peripheral edge of the upper end surface of the silicon substrate 5 to form a sealed space. The upper end surface of the cover plate body 12 and the outer peripheral surface of the annular flange 13 are connected by an arc transition. The glass edge is arc-shaped, which can improve the edge strength of the glass cover plate 1 and reduce the breakage caused by bumps. Moreover, the glass cover plate 1 with this structure can greatly improve the edge packaging effect and enhance the protection effect on the internal materials. Specifically, the glass cover plate 1 is a 3D glass cover plate.

[0024] As Figure 2 shown, glass powder paste 15 is coated in the space formed between the inner circumferential surface of the annular flange 13 and the light-emitting element and the silicon substrate 5. After the glass powder paste 15 is laser sintered, the glass cover plate 1 and the silicon substrate 5 are hermetically bonded and fixed. The edge of the product can be greatly improved in edge encapsulation effect through glass powder encapsulation and in cooperation with the glass cover plate 1. Among them, the glass powder paste 15 is formed by dissolving low-temperature glass powder in a solvent.

[0025] Since the silicon substrate 5 is made of silicon material and has poor adhesion to the glass powder paste 15, in order to increase the contact performance between the glass powder paste 15 and the silicon substrate 5, a retaining wall 14 is provided on the silicon substrate 5 on the peripheral side of the light-emitting element. The annular flange 13 is sleeved outside the retaining wall 14, and the glass powder paste 15 is coated on the outer circumferential surface and the upper end surface of the retaining wall 14. In this application, it is preferred that the retaining wall 14 is an inorganic thin film retaining wall, such as a SiN (silicon nitride) retaining wall, a SiO (silicon oxide) retaining wall, a SiON (silicon oxynitride) retaining wall or other inorganic material retaining walls. Here, a SiO retaining wall is selected. Therefore, the retaining wall 14 plays a connecting role between the glass powder paste 15 and the silicon substrate 5. The glass powder paste 15 actually contacts the retaining wall 14, and the adhesion between the two is good, thereby ensuring the sealing performance between the glass cover plate 1 and the silicon substrate 5.

[0026] Figure 3 In the top view of the appearance shown, the glass powder paste 15 can be seen at the edge of the glass cover plate 1, and the appearance of the glass powder paste 15 is better than that of the frame adhesive. Therefore, the encapsulation structure of this application can effectively improve the aesthetic feeling of the product.

[0027] As Figure 2 shown, a single-layer inorganic thin film encapsulation layer 10 is provided between the light-emitting element and the cover plate main body 12. Since the glass cover plate 1 of this application has an excellent encapsulation effect, on the basis of using the glass cover plate 1 with this structure for encapsulation, the single-layer inorganic thin film encapsulation layer 10 can realize the encapsulation of the light-emitting element and effectively prevent the water absorption and oxidation of the light-emitting element. Specifically, the single-layer inorganic thin film encapsulation layer 10 is an aluminum oxide thin film encapsulation layer.

[0028] A color filter layer 11 is provided between the single-layer inorganic thin film encapsulation layer 10 and the cover plate main body 12, which can change the white light emitted by the light-emitting element into colored light. The light-emitting element includes a CMOS circuit layer 6, a pixel anode layer 7, a pixel isolation layer 8 and an OLED light-emitting layer 9 stacked on the silicon substrate 5. The pixel anode layer 7 is used to realize the conduction between the CMOS circuit layer 6 and the OLED light-emitting layer 9, so that the OLED light-emitting layer 9 is energized to emit light. The pixel anode layer 7 includes a plurality of pixel units arranged at intervals, and the pixel isolation layer 8 isolates adjacent pixel units.

[0029] Among them, the pixel anode layer 7 and the pixel isolation layer 8 are inorganic thin film layers, and the OLED light-emitting layer 9 is an organic thin film layer. Specifically, the pixel anode layer 7 can be a Ti (titanium) layer, an Al (aluminum) layer, a TiN (titanium nitride) layer, an ITO (indium tin oxide) layer or other inorganic material layers. Here, a Ti / Al / Ti / ITO stacked structure is selected. Electrons in the CMOS circuit layer 6 reach the OLED layer through the Al layer and the ITO layer. The lower Ti layer can prevent the mutual dissolution of Al and the CMOS circuit layer 6, and the upper Ti layer can prevent the oxidation of the Al layer. The pixel isolation layer 8 can be a SiN (silicon nitride) layer, a SiO (silicon oxide) layer, a SiON (silicon oxynitride) layer or other inorganic material layers. Here, a SiN layer is selected.

[0030] The preparation method of the encapsulation structure of this application specifically includes the following steps:

[0031] 1. Design and complete the CMOS driving circuit.

[0032] 2. The foundry completes the production of the CMOS circuit layer 6 on the silicon substrate 5.

[0033] 3. Fabricate the pixel anode layer 7, which is made of inorganic materials. Here, a Ti / Al / Ti / ITO stacked structure is selected. Among them, the thickness of Ti can be 10 - 30 nm, the thickness of Al can be 5 - 100 nm, the thickness of Ti can be 1 - 5 nm, and the thickness of ITO can be 1 - 100 nm. Here, preferably, the thickness of the first layer of Ti is 15 nm, the thickness of Al is 80 nm, the thickness of the second layer of Ti can be 3 nm, and the thickness of ITO is 60 nm. A physical vapor deposition device is used for film formation.

[0034] 4. Fabricate the pixel isolation layer 8, which can be made of inorganic materials. Here, SiN is selected as the pixel isolation layer 8, and the thickness can be: 100 - 500 nm. Preferably, take 200 nm, and a plasma vapor deposition device is used for coating.

[0035] 5. Fabricate the OLED light-emitting layer 9, which is made of organic light-emitting materials, and a thermal evaporation machine is used for thermal film formation, with a thickness of 260 nm.

[0036] 6. Prepare the thin film encapsulation layer 3, which only uses a single-layer inorganic thin film encapsulation, specifically AlO (aluminum oxide) encapsulation, with a thickness of about 30 nm. An atomic layer deposition device is used for coating, which can improve the problem of optical crosstalk and further enhance the optical display effect.

[0037] 7. Prepare the barrier wall 14 around the light-emitting element, which is made of inorganic materials. Here, SiO is selected, and the thickness can be: 1 - 10 um. Preferably, take 5 um, and the width can be 100 - 1000 um. Here, 800 um is selected, and a plasma vapor deposition device is used for coating preparation.

[0038] 8. Prepare the color filter layer 11.

[0039] 9. Prepare the encapsulation of the glass cover plate 1, where the glass used is 3D glass:

[0040] 1) First, clean the glass cover plate 1 to remove foreign matters on the surface of the glass cover plate 1;

[0041] 2) Bake the glass cover plate 1 to remove the residual water on the glass cover plate 1;

[0042] 3) After dissolving the low-temperature glass powder in a solvent to form the glass powder slurry 15, according to the position of the dam 14, use the glass laminating equipment ODF to coat the glass powder slurry 15 on the outside and the top layer of the dam 14. The approximate width of the coated glass powder slurry 15 is 200um - 900um, and 800um is selected here, and the thickness is 1 - 20um, and 8um is selected here;

[0043] 4) Finally, place the glass cover plate 1 on the surface of the product, and then sinter it with a laser at 100 - 300°C for about 1 - 10s. Here, the temperature is selected as 200°C and the time is selected as 5s to complete the hermetic encapsulation of the glass cover plate 1.

[0044] 10. Complete the subsequent processes of the module to fabricate and form a finished product.

[0045] The silicon-based micro-display encapsulation structure of the present utility model is provided with a glass cover plate including a cover plate main body and an annular flange. The annular flange is integrally arranged on the circumferential side of the lower end of the cover plate main body. The annular flange is hermetically connected to the circumferential side edge of the upper end surface of the silicon substrate to form a sealed space. The upper end surface of the cover plate main body and the outer circumferential surface of the annular flange are connected by an arc transition. The edge of the glass is arc-shaped, which can improve the edge strength of the glass cover plate and reduce the breakage caused by bumping. Moreover, the glass cover plate of this structure can greatly improve the edge encapsulation effect and enhance the protection effect on the internal materials.

[0046] In the description of this specification, unless otherwise clearly defined, words such as "set", "installed", and "connected" should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above words in the present utility model in combination with the specific content of the technical solution.

[0047] Although the specific implementation manners of the present utility model have been described above, those skilled in the art should understand that the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. These are only illustrative examples, and the protection scope of the present utility model is defined by the claims. Without departing from the principles and essence of the present utility model and without any creative work, those skilled in the art can make various changes or modifications to these implementation manners, but these changes and modifications all fall within the protection scope of the present utility model.

Claims

1. A silicon-based micro display screen packaging structure, comprising a silicon substrate, a glass cover plate, and a light-emitting element disposed between the silicon substrate and the glass cover plate, characterized in that: The glass cover plate includes a cover plate body and an annular flange integrally arranged on the circumferential side of the lower end of the cover plate body, the annular flange is sealed and connected to the circumferential edge of the upper end surface of the silicon substrate to form a closed space, and the upper end surface of the cover plate body and the outer circumferential surface of the annular flange are connected by an arc transition.

2. The silicon-based micro display screen packaging structure according to claim 1, characterized in that: Glass powder paste is coated in the space formed between the inner peripheral surface of the annular flange and the light emitting element and the silicon substrate. After laser sintering, the glass cover plate and the silicon substrate are sealed and bonded.

3. The silicon-based micro display screen packaging structure according to claim 2, characterized in that: A retaining wall is arranged on the silicon substrate at the peripheral side of the light emitting element, the annular flange is sleeved on the outer side of the retaining wall, and the glass powder slurry is coated on the outer peripheral surface and upper end surface of the retaining wall.

4. The silicon-based micro display screen packaging structure according to claim 3, characterized in that: The retaining wall is an inorganic thin film retaining wall.

5. The silicon-based micro display screen packaging structure according to claim 1, characterized in that: The glass cover plate is a 3D glass cover plate.

6. The silicon-based micro display screen packaging structure according to claim 1, characterized in that: A single-layer inorganic thin film encapsulation layer is arranged between the light emitting element and the cover plate body.

7. The silicon-based micro display screen packaging structure according to claim 6, characterized in that: The single-layer inorganic thin film encapsulation layer is an aluminum oxide thin film encapsulation layer.

8. The silicon-based micro display screen packaging structure according to claim 6, characterized in that: A color filter layer is arranged between the single-layer inorganic thin film encapsulation layer and the cover plate body.

9. The silicon-based micro display screen packaging structure according to any one of claims 1 to 8, characterized in that: The light emitting element comprises a CMOS circuit layer, a pixel anode layer, a pixel isolation layer and an OLED light emitting layer which are stacked on the silicon substrate.

10. The silicon-based micro display screen packaging structure according to claim 9, characterized in that: The pixel anode layer and the pixel isolation layer are inorganic thin film layers, and the OLED light emitting layer is an organic thin film layer.

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