Silicon-based OLED structure with improved encapsulation effect and preparation method thereof

Abstract

The present application relates to the technical fields of electronic packaging technology, and particularly relates to a silicon-based OLED structure for improving packaging effect and a preparation method thereof, which comprises a silicon wafer substrate, an intermediate interlayer arranged on the upper surface of the silicon wafer substrate, a flat layer arranged on the upper surface of the intermediate interlayer, a color filter layer coated on the upper surface of the flat layer, a protective glass cover plate bonded to the upper surface of the color filter layer, and a knife wheel cutting path arranged on one side surface of the intermediate interlayer. Through the above structure, in the PECVD film coating process, a special mask or process parameter control is used to form an inverted corner structure at the edge of the pixel definition layer. When the knife wheel starts to cut, even if a crack occurs, the crack will not continue to the mechanism itself due to the arrangement of the inverted corner structure, and the rupture of the packaging film layer during cutting will not extend to the OLED display area (i.e. the evaporation light-emitting layer 4 area), so that the packaging failure caused by cutting can be effectively improved, and the display life is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic packaging technology, and in particular to a silicon-based OLED structure for improving packaging effect and a preparation method thereof. BACKGROUND

[0002] In the modern electronic industry, electronic packaging technology plays a crucial role. With the continuous development of electronic products towards miniaturization, high performance and high reliability, the requirements for electronic packaging are becoming increasingly stringent. In the emerging display technology field such as silicon-based OLED, the requirements for packaging effect are more special. Improper packaging will quickly lead to a decline in light-emitting performance and a shortening of service life. In the process of cutting a whole silicon wafer into a single display unit, the packaging film layer is easily broken, which may cause circuit damage and display area packaging failure. Therefore, there is a particular need for a silicon-based OLED structure for improving packaging effect and a preparation method thereof.

[0003] However, the current preparation method of the existing silicon-based OLED is to deposit organic light-emitting materials, a cathode metal, a thin film packaging layer, a color filter, and a protective glass cover plate on a silicon wafer substrate with an IC driving circuit and a pixel definition layer. After completing the above processes, the whole silicon wafer is cut into a single display unit. However, the packaging film layer is formed on the whole surface. Cutting may cause the packaging film layer to break, which may extend to the vicinity of the display area, causing circuit damage and display area packaging failure, and reducing the service life of the display. SUMMARY

[0004] The present application aims to solve the above problems by providing a silicon-based OLED structure for improving packaging effect and a preparation method thereof. The defects of the prior art are overcome, as described in detail below.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0006] The silicon-based OLED structure for improving packaging effect provided by the present application comprises a silicon wafer substrate, characterized in that: an intermediate layer is arranged on the upper surface of the silicon wafer substrate, a flat layer is arranged on the upper surface of the intermediate layer, a color filter layer is coated on the upper surface of the flat layer, a protective glass cover plate is bonded to the upper surface of the color filter layer, and a knife wheel cutting path is arranged on one side surface of the intermediate layer.

[0007] The intermediate interlayer comprises a first pixel definition layer, a second pixel definition layer, an evaporation light-emitting layer, a lower thin film encapsulation layer, a middle thin film encapsulation layer and an upper thin film encapsulation layer, the upper surface of the silicon wafer substrate is deposited with the first pixel definition layer, the upper surface of the first pixel definition layer is deposited with the second pixel definition layer, the upper surface of the second pixel definition layer is deposited with the evaporation light-emitting layer, the upper surface of the evaporation light-emitting layer is deposited with the lower thin film encapsulation layer, the upper surface of the lower thin film encapsulation layer is deposited with the middle thin film encapsulation layer, and the upper surface of the middle thin film encapsulation layer is deposited with the upper thin film encapsulation layer.

[0008] Preferably, the first pixel definition layer and the second pixel definition layer are coated by PECVD, and the two layers generally adopt different film layers in order to form an easy-to-cut inverted corner structure, the first pixel definition layer is generally made of SiNx, and the thickness is about 50-200 nm, and the second pixel definition layer is generally made of SiOx, and the thickness is about 50-200 nm.

[0009] Preferably, the evaporation light-emitting layer is generally composed of an organic light-emitting layer and a cathode metal material, and the thickness is 100-1000 nm, which provides white light.

[0010] Preferably, the lower thin film encapsulation layer, the middle thin film encapsulation layer and the upper thin film encapsulation layer are all inorganic layers, the middle thin film encapsulation layer and the upper thin film encapsulation layer are both coated by ALD, the composition is Al2O3, TiO2 or a laminated structure composed of the two, and the thickness is about 30-100 nm, and the middle thin film encapsulation layer is generally coated by PECVD, the composition is SiNx, and the thickness is about 100 nm-1000 nm.

[0011] Preferably, the planar layer is an organic layer, which is coated on the encapsulation layer by gluing, plays a role of planarization, facilitates the subsequent coating of the color filter layer, and the thickness is about 1 um-10 um; the color filter layer is an organic layer, which is composed of R, G and B single-color filter materials, and plays a role of forming RGB pixels, and the thickness is about 0.5-5 um.

[0012] Preferably, the protective glass cover plate is generally pasted by UV glue, which plays a role of protecting the display device and preventing mechanical damage from the outside world; the entire silicon wafer is cut into a single display device by a knife wheel.

[0013] A silicon-based OLED structure for improving encapsulation effect further comprises the following steps.

[0014] Step 1: providing a silicon wafer substrate with a driving circuit;

[0015] Step 2: depositing a layer of SiNx with a thickness of 50-200 nm and a layer of SiOx with a thickness of 50-200 nm on the silicon substrate by PECVD, and forming pixel holes and edge chamfering angle structures by dry etching;

[0016] Step 3: depositing a light-emitting layer and a cathode metal on the inorganic layer of Step 2 by evaporation, with a thickness of about 100-1000 nm;

[0017] Step 4: depositing an ALD+PECVD+ALD encapsulation film layer on the light-emitting layer and the cathode metal by ALD and PECVD, wherein ALD is Al2O3, TiO2, or a laminated structure composed of the two, with a thickness of 30-100 nm, and PECVD is SiNx, with a thickness of 100-1000 nm;

[0018] Step 5: coating an organic planar layer on the encapsulation film layer by coating, with a thickness of 1-10 um;

[0019] Step 6: coating RGB color filters on the organic planar layer by coating, exposure, and development;

[0020] Step 7: pasting a protective glass cover plate on the color filters by UV glue, thereby protecting all the film layers below

[0021] Step 8: cutting the wafer completed with the above process into individual displays by a knife wheel.

[0022] Preferably, in Step 2, the pixel holes and edge chamfering angle structures are formed by dry etching, and an advanced inductively coupled plasma (ICP) etching device is used to ensure that the radio frequency source, gas supply system, vacuum system, and other components of the device are in normal working condition, and the silicon substrate with deposited SiNx and SiOx layers is carefully loaded onto the sample table of the etching device to ensure stable placement and uniform contact with the etching gas flow.

[0023] Preferably, in Step 3, when the light-emitting layer and the cathode metal are deposited by evaporation, the substrate is placed in the chamber of a high-vacuum evaporation device, and the vacuum is pumped to below 1×10⁻ 4 Pa. The organic material is placed in the evaporation source and heated to 150-350°C to sublimate, and the gaseous molecules diffuse to the substrate surface to condense into a light-emitting layer with a thickness of 100-1000 nm. The thickness is precisely controlled by controlling the evaporation source temperature, evaporation time, and source-substrate distance.

[0024] Preferably, in step 7, when applying the protective glass cover plate to the color filter using UV adhesive, care should be taken to ensure that the adhesive is applied evenly and that the thickness of the UV adhesive is properly controlled. After the adhesive is applied, air bubbles generated during the bonding process should be removed.

[0025] The beneficial effects are:

[0026] Through the above structural setup, from Figure 1 (Silicon-based OLED structure with chamfered corners) and Figure 2 (Comparison of traditional silicon-based OLED structures) It can be seen that the encapsulation film layer of the silicon-based OLED structure with the chamfered corner structure is thinner, and this structure can effectively prevent the encapsulation film layer from cracking and extending to the OLED display area (i.e., the vapor-deposited light-emitting layer 4 area) during cutting. This can effectively improve the encapsulation failure caused by cutting and improve the life of the display. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a side view of the external structure of the present invention;

[0029] Figure 2 This is a schematic diagram of a traditional silicon-based OLED structure.

[0030] Figure 3 This is a schematic diagram of the process of the present invention.

[0031] In the diagram: 1. Silicon wafer substrate; 2. Intermediate layer; 201. First pixel definition layer; 202. Second pixel definition layer; 203. Evaporated light-emitting layer; 204. Lower thin film encapsulation layer; 205. Middle thin film encapsulation layer; 206. Upper thin film encapsulation layer; 3. Planarization layer; 4. Color filter layer; 5. Protective glass cover; 6. Cutting wheel groove. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention. Example

[0033] Please refer to Figures 1-3 The application discloses a silicon-based OLED structure with improved packaging effect, which comprises a silicon wafer substrate 1, characterized in that: an intermediate layer 2 is arranged on the upper surface of the silicon wafer substrate 1, a flat layer 3 is arranged on the upper surface of the intermediate layer 2, a color filter layer 4 is coated on the upper surface of the flat layer 3, a protective glass cover plate 10 is bonded to the upper surface of the color filter layer 4, and a cutter wheel cutting path 6 is arranged on one side surface of the intermediate layer 2.

[0034] The intermediate layer 2 comprises a first pixel definition layer 201, a second pixel definition layer 202, an evaporation light-emitting layer 203, a lower thin-film packaging layer 204, a middle thin-film packaging layer 205 and an upper thin-film packaging layer 206, the first pixel definition layer 201 is deposited on the upper surface of the silicon wafer substrate 1, the second pixel definition layer 202 is deposited on the upper surface of the first pixel definition layer 201, the evaporation light-emitting layer 203 is deposited on the upper surface of the second pixel definition layer 202, the lower thin-film packaging layer 204 is deposited on the upper surface of the evaporation light-emitting layer 203, the middle thin-film packaging layer 205 is deposited on the upper surface of the lower thin-film packaging layer 204, and the upper thin-film packaging layer 206 is deposited on the upper surface of the middle thin-film packaging layer 205, through the arrangement of the first pixel definition layer 201, the second pixel definition layer 202, the evaporation light-emitting layer 203, the lower thin-film packaging layer 204, the middle thin-film packaging layer 205 and the upper thin-film packaging layer 206, in use, the layers are sequentially deposited on the upper surface of the silicon wafer substrate 1 in a specific order, starting from the pixel definition layer, to the light-emitting layer, and then to the multi-layer packaging layer, and the ordered structure enables the layers to be closely connected and work cooperatively. For example, the pixel definition layer provides accurate definition of the action area for the light-emitting layer, and the packaging layer gives full protection on the basis of the light-emitting function of the light-emitting layer, so that the whole structure can realize stable operation for a long time while realizing the display function.

[0035] Further, the first pixel definition layer 201 and the second pixel definition layer 202 are formed by PECVD coating, in order to form an easy-to-cut inverted corner structure, the two layers generally adopt different component film layers, the first pixel definition layer 201 is generally made of SiNx and has a thickness of about 50-200 nm, the second pixel definition layer 202 is generally made of SiOx and has a thickness of about 50-200 nm, through the arrangement of the first pixel definition layer 201 and the second pixel definition layer 202, in use, the first pixel definition layer 201 and the second pixel definition layer 202 formed by PECVD coating can provide better cutting guidance in the cutting process due to the different components (SiNx and SiOx) and the specific thickness (50-200 nm) design.

[0036] Further, the evaporation light-emitting layer 203 is generally composed of an organic light-emitting layer and a cathode metal material, and has a thickness of 100-1000 nm. The evaporation light-emitting layer 203 provides white light, which is essential as a basic light source in use. The white light can be filtered by the color filter layer to obtain different proportions of red, green and blue components, thereby combining various colors to meet diversified display requirements, such as displaying realistic images and videos.

[0037] Further, the lower thin film encapsulation layer 204, the middle thin film encapsulation layer 205 and the upper thin film encapsulation layer 206 are all inorganic layers. The lower thin film encapsulation layer 204 and the upper thin film encapsulation layer 206 are both formed by ALD, and are composed of Al2O3, TiO2 or a laminated structure composed of both, with a thickness of about 30-100 nm. The middle thin film encapsulation layer 205 is generally formed by PECVD, and is composed of SiNx, with a thickness of about 100 nm-1000 nm. The multi-layer encapsulation structure composed of the inorganic material can effectively block water vapor and oxygen in the external environment, which are key factors leading to aging and performance degradation of the organic light-emitting layer. The multi-layer blocking can greatly reduce the corrosion of the evaporation light-emitting layer 203.

[0038] Further, the planar layer 3 is an organic layer coated on the encapsulation layer by gluing, and has a planarizing effect, which facilitates the subsequent coating of the color filter layer. The planar layer 3 has a thickness of about 1-10 um. The color filter layer 4 is an organic layer composed of R, G and B single-color filter materials, and has a thickness of about 0.5-5 um. The planar layer 3 coated on the encapsulation layer by gluing creates good conditions for the subsequent coating of the color filter layer. Without the planar layer 3, the surface of the encapsulation layer may have slight unevenness, which will result in uneven thickness of the color filter layer during coating. The planar layer 3 can fill the small gaps and uneven places, so that the color filter layer can be uniformly coated on the surface, thereby ensuring the uniformity of the optical performance of the color filter layer.

[0039] Further, the protective glass cover plate 5 is generally pasted to the cover plate glass through UV glue, which serves to protect the display device and prevent mechanical damage from the outside world; the entire silicon wafer is cut into a single display by means of cutter wheel cutting, and through the arrangement of the protective glass cover plate 5, the protective glass cover plate 5 is pasted above the device through UV glue in use, which can effectively prevent mechanical damage from the outside world. In daily use, the display may be subjected to various accidental collisions, scratches and the like, and even if a sharp object contacts the display, the protective glass cover plate can be scratched before the internal light-emitting layer and circuit layer, thereby playing a barrier role. Embodiment

[0040] A preparation method of a silicon-based OLED with improved packaging effect, which adopts the silicon-based OLED structure with improved packaging effect in claim 1, further comprising the following steps:

[0041] Step 1: providing a silicon wafer substrate 1 with a driving circuit;

[0042] Step 2: depositing a layer of SiNx with a thickness of 50-200 nm and a layer of SiOx with a thickness of 50-200 nm on the silicon wafer substrate 1 by PECVD deposition, and forming a pixel hole and an edge undercut angle structure by dry etching;

[0043] When forming the pixel hole and the edge undercut angle structure by dry etching, an advanced inductively coupled plasma (ICP) etching device should be selected, and the radio frequency source, gas supply system, vacuum system and other components of the device should be ensured to be in normal working condition. The silicon wafer substrate with deposited SiNx and SiOx layers is carefully loaded onto the sample table of the etching device, and it is ensured that the sample is placed stably and uniformly contacts the etching gas flow;

[0044] Step 3: depositing a light-emitting layer and a cathode metal above the inorganic layer in step 2 by evaporation, with a thickness of about 100-1000 nm;

[0045] When depositing the light-emitting layer and the cathode metal by evaporation, the substrate should be placed in the chamber of a high-vacuum evaporation device, and the vacuum should be extracted to be lower than 1×10⁻ 4 Pa. The organic material is heated to 150-350°C in the evaporation source to sublimate, and the gaseous molecules diffuse to the substrate surface to condense into a 100-1000 nm thick light-emitting layer. The thickness is precisely controlled by controlling the evaporation source temperature, evaporation time and source-substrate distance

[0046] Step 4: depositing an ALD+PECVD+ALD structure encapsulation film layer above the light-emitting layer and the cathode metal by ALD and PECVD, wherein ALD is an Al2O3, TiO2 or a laminated structure composed of the two, with a thickness of 30-100 nm, and PECVD is SiNx, with a thickness of 100-1000 nm;

[0047] Step 5: coat an organic flat layer on the encapsulation film layer by coating, with a thickness of 1-10um;

[0048] Step 6: coat RGB color filters on the organic flat layer by coating, exposure and development respectively;

[0049] Step 7: paste the protective glass cover plate on the color filter by UV glue, so as to protect all the film layers below;

[0050] When pasting the protective glass cover plate on the color filter by UV glue, attention should be paid to ensure uniform glue coating and reasonable control of the thickness of the UV glue. After the glue coating is completed, attention should be paid to eliminate the air bubbles generated in the pasting process;

[0051] Step 8: cut the wafer completed with the above process into a single display by a knife wheel.

[0052] Working principle: in the PECVD film coating process, a special mask or process parameter control is used to form an inverted corner structure at the edge of the pixel definition layer. When the knife wheel starts to cut, since the knife wheel cuts the other end of the inverted corner, even if excessive vertical pressure is applied during cutting, causing cracks, the inverted corner structure prevents the cracks from extending to the mechanism itself, preventing the encapsulation film layer from breaking during cutting and extending to the OLED display area (i.e. the area of the evaporated light-emitting layer 4), which can effectively improve the encapsulation failure caused by cutting and improve the display life.

[0053] Although the embodiments of the present application have been shown and described, it can be understood by those of ordinary skill in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A silicon-based OLED structure with enhanced encapsulation effect, comprising a silicon wafer substrate (1), characterized in that: The upper surface of the silicon wafer substrate (1) is provided with an intermediate interlayer (2), the upper surface of the intermediate interlayer (2) is provided with a flat layer (3), the upper surface of the flat layer (3) is coated with a color filter layer (4), the upper surface of the color filter layer (4) is bonded with a protective glass cover plate (10), and one side surface of the intermediate interlayer (2) is provided with a knife wheel cutting groove (6). The intermediate interlayer (2) includes a first pixel definition layer (201), a second pixel definition layer (202), an evaporation light-emitting layer (203), a lower thin film encapsulation layer (204), a middle thin film encapsulation layer (205) and an upper thin film encapsulation layer (206), the upper surface of the silicon wafer substrate (1) is deposited with the first pixel definition layer (201), the upper surface of the first pixel definition layer (201) is deposited with the second pixel definition layer (202), the upper surface of the second pixel definition layer (202) is deposited with the evaporation light-emitting layer (203), the upper surface of the evaporation light-emitting layer (203) is deposited with the lower thin film encapsulation layer (204), the upper surface of the lower thin film encapsulation layer (204) is deposited with the middle thin film encapsulation layer (205), and the upper surface of the middle thin film encapsulation layer (205) is deposited with the upper thin film encapsulation layer (206), and the encapsulation film layer includes the lower thin film encapsulation layer (204), the middle thin film encapsulation layer (205) and the upper thin film encapsulation layer (206). The first pixel definition layer (201) and the second pixel definition layer (202) are coated by PECVD, the material of the first pixel definition layer (201) is SiN X , and the material of the second pixel definition layer (202) is SiO X . The edge of the first pixel definition layer (201) and the second pixel definition layer (202) close to the cutting path is etched by dry etching to form an inverted corner structure, and the whole silicon wafer is cut into a single display by a cutter wheel. The silicon-based OLED structure with the inverted corner structure is provided with a thin encapsulation film layer, which prevents the encapsulation film layer from being broken during cutting and extending to the OLED display area.

2. The silicon-based OLED structure for enhancing encapsulation effect according to claim 1, characterized in that: The thickness of the first pixel definition layer (201) is 50-200nm, and the thickness of the second pixel definition layer (202) is 50-200nm.

3. The silicon-based OLED structure for enhancing encapsulation effect according to claim 1, characterized in that: The evaporation light-emitting layer (203) is composed of an organic light-emitting layer and a cathode metal material, and has a thickness of 100-1000nm, which provides white light.

4. The silicon-based OLED structure for enhancing encapsulation effect according to claim 1, characterized in that: The lower thin film encapsulation layer (204), the middle thin film encapsulation layer (205) and the upper thin film encapsulation layer (206) are all inorganic layers, wherein the lower thin film encapsulation layer (204) and the upper thin film encapsulation layer (206) are both formed by ALD, and the components are Al2O3, TiO2 or a laminated structure composed of both, and the thickness is 30-100 nm; the middle thin film encapsulation layer (205) is formed by PECVD, and the component is SiN X , and the thickness is 100 nm-1000 nm.

5. The silicon-based OLED structure for enhancing encapsulation effect according to claim 1, characterized in that: The flat layer (3) is an organic layer, which is coated on the encapsulation layer in a glue coating manner, plays a flattening role, facilitates subsequent color filter coating, and has a thickness of 1um-10um; the color filter layer (4) is an organic layer composed of R, G and B single color filter materials, which forms RGB pixels, and has a thickness of 0.5-5um.

6. The silicon-based OLED structure for enhancing encapsulation effect according to claim 1, wherein: The protective glass cover plate (5) is pasted with cover glass by UV glue, which protects the display device and prevents mechanical damage from the outside.

7. A method for fabricating a silicon-based OLED with enhanced encapsulation effect, characterized in that: The silicon-based OLED structure for improving encapsulation effect according to any one of claims 1-6 further includes the following steps: Step 1: providing a silicon wafer substrate (1) with a driving circuit; Step 2: Deposit a SiN layer with a thickness of 50~200nm on the silicon substrate (1) using PECVD deposition. X and a layer of SiO2 with a thickness of 50~200nm X To form a first pixel definition layer (201) and a second pixel definition layer (202), pixel holes and edge chamfering structures are formed by dry etching. The edge chamfering structures are located at the edges of the first pixel definition layer (201) and the second pixel definition layer (202) near the cutting path. Step 3: depositing a light-emitting layer and a cathode metal on the inorganic layer of step 2 by evaporation, with a thickness of 100-1000nm; Step 4: depositing an encapsulation film layer above the light-emitting layer and the cathode metal by ALD and PECVD, the encapsulation film layer comprising a lower thin-film encapsulation layer, a middle thin-film encapsulation layer and an upper thin-film encapsulation layer, all of which are inorganic layers, wherein the lower thin-film encapsulation layer (204) and the upper thin-film encapsulation layer (206) are both formed by ALD, and the composition thereof is Al2O3, TiO2 or a laminated structure composed of the two, and the thickness thereof is 30-100 nm, and the middle thin-film encapsulation layer (205) is formed by PECVD, and the composition thereof is SiNx, and the thickness thereof is 100 nm-1000 nm; Step 5: coating an organic planar layer above the encapsulation film layer by coating, and the thickness thereof is 1-10 um; Step 6: coating RGB color filters above the organic planar layer by coating, exposure and development; Step 7: pasting a protective glass cover plate above the color filters by UV glue, so as to protect all the film layers below; Step 8: cutting the silicon wafer on which the above steps 1-7 are completed into single displays by a knife wheel, and the silicon-based OLED structure with a reverse chamfer structure is thinner at the encapsulation film layer, so as to prevent the rupture of the encapsulation film layer from extending to the OLED display area during cutting. 8.The method of claim 7, wherein the method further comprises: forming a first electrode layer on the substrate; forming a first organic layer on the first electrode layer; forming a second electrode layer on the first organic layer; and forming a second organic layer on the second electrode layer. In the step 2, the pixel hole and the edge reverse chamfer structure are formed by dry etching, and an advanced inductively coupled plasma (ICP) etching device is selected, and the radio frequency source, the gas supply system and the vacuum system of the device are ensured to be in a normal working state, and the silicon wafer substrate on which SiNx and SiOx layers are deposited is loaded onto the sample table of the etching device, and the sample is ensured to be placed stably and to be in uniform contact with the etching gas flow. 9.The method of claim 7, wherein the method further comprises: forming a first electrode layer on the substrate; forming a first organic layer on the first electrode layer; forming a second electrode layer on the first organic layer; and forming a second organic layer on the second electrode layer. In step 3, the deposition of the light-emitting layer and the cathode metal by evaporation, the substrate is placed in the chamber of the high-vacuum evaporation device, which is evacuated to a pressure of less than 1 x 10 -4 Pa; the organic material is placed in the evaporation source and heated to 150-350°C to sublimate it, the gaseous molecules diffuse to the substrate surface and condense to a 100-1000 nm thick light-emitting layer, the thickness being precisely controlled by controlling the evaporation source temperature, the evaporation time and the source-substrate distance.

10. The method of claim 7, wherein the method further comprises: In the step 7, when the protective glass cover plate is pasted above the color filters by UV glue, the glue is coated uniformly and the thickness of the UV glue is controlled reasonably, and the air bubbles generated in the pasting process are removed after the glue coating is completed.

Images