Microdisplay production process

Abstract

The present invention discloses a production process of a micro display, comprising the steps of: S1, preparing a driving circuit on a silicon wafer; S2, preparing an anode layer; S3, preparing a pixel definition layer; S4, evaporating an organic light-emitting layer and a cathode layer; S5, thin film encapsulation; S6, preparing a circle of blocking rings outside a pixel area; S7, coating a color photoresist, wherein the blocking ring prevents the spin-coated color photoresist from being thrown away; S8, exposing and developing the color photoresist, wherein the blocking ring can inhibit excessive flushing of the edge by a developer and water; S9, coating a filter protective layer; S10, exposing and developing the filter protective layer, wherein the blocking ring prevents the color photoresist of the filter protective layer from overflowing, thereby ensuring the film thickness of the protective layer; S11, module dispensing, wherein the blocking ring prevents the glue from flowing away, thereby ensuring the glue thickness at the edge of the pixel area; S12, laminating a glass cover plate. The production process of the micro display of the present invention can reduce the edge difference of the pixel area and improve display abnormality.

Description

Technical Field

[0001] The present invention belongs to the field of microdisplay technology, and in particular, relates to a production process of a microdisplay. Background Art

[0002] Microdisplay technology has been widely used in near-eye display terminal products, including virtual reality (VR), augmented reality (AR), mixed reality (MR), etc. Compared with conventional low-resolution displays such as mobile phones, TVs, and computers, microdisplays are small in size, and display anomalies caused by edge effects are more obvious. Near-eye display systems generally use complex optical systems to magnify images and enhance immersion, which will further amplify display anomalies. For example, VR uses lenses and Fresnel lenses; AR and MR use semi-transparent and semi-reflective projection display technology. The display is transmitted through an optical waveguide and amplified by a magnifying grating, and finally presents graphics to the human eye. Figure 3 As shown in the figure, the differences in line width, film thickness, and interface contact between the edge and the middle of the pixel area will lead to differences in the emitted light. The main reason for this edge difference is the unevenness and height difference between the pixel area and the peripheral drive circuit area. The anode layer, pixel definition layer, organic light-emitting layer, and cathode layer are only made in the pixel area, not in the peripheral drive area, so the pixel area will be 0.5-1um higher than the peripheral drive circuit area. Figure 4 As shown in the figure, this height difference will affect the subsequent process and cause the following defects:

[0003] 1. When the color photoresist of the filter is coated, due to the characteristics of spin coating, the height difference will cause the photoresist at the edge of the pixel area to be thinner. During development, the protrusion at the edge of the pixel area will also block the flow of developer and water, causing the edge of the pixel area to develop faster than the middle, ultimately resulting in a small line width and thin film thickness of the color photoresist at the edge of the pixel area;

[0004] 2. The principle of the filter protection layer is similar to that of color photoresist. Under the combined effect of coating and development, the thickness of the filter protection layer at the edge of the pixel area is thin;

[0005] 3. After the module is glued, the glue flows away quickly because the outer edge of the pixel area is lower, and the glue on the edge is thinner. After the glass cover is attached, the glue is easy to overflow under the action of glass and pressure, and overflow to PAD to affect wiring or affect the appearance of the product. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a production process for a micro display, the purpose of which is to reduce the edge difference of the pixel area and improve the display abnormality.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: a production process of a micro display, comprising the steps of:

[0008] S1, preparing a driving circuit on a silicon wafer;

[0009] S2, preparing an anode layer;

[0010] S3, preparing a pixel definition layer;

[0011] S4, evaporating an organic light-emitting layer and a cathode layer;

[0012] S5, thin film packaging;

[0013] S6, preparing a barrier ring outside the pixel area;

[0014] S7, coating of color photoresist is performed, and a blocking ring prevents the spin-coated color photoresist from being thrown away;

[0015] S8, color photoresist exposure and development, the blocking ring can inhibit the developer and water from over-washing the edge, ensuring that the color photoresist remains at the edge of the pixel area;

[0016] S9, coating the filter protective layer;

[0017] S10, the filter protection layer is exposed and developed, and the blocking ring prevents the color photoresist of the filter protection layer from overflowing, thereby ensuring the film thickness of the protection layer;

[0018] S11, glue the module, and use a blocking ring to prevent the glue from flowing away to ensure the glue thickness at the edge of the pixel area;

[0019] S12, glass cover lamination.

[0020] In the step S6, an inkjet printing process is used to prepare a blocking ring outside the pixel area.

[0021] In the step S6, a blocking ring is prepared outside the pixel area by using a screen printing process.

[0022] In the step S6, a coating, exposure and development process is used to prepare a blocking ring outside the pixel area.

[0023] The production process of the micro display of the present invention achieves the purpose of blocking the overflow of color photoresist, filter protection layer and bonding glue by developing a circle of blocking ring structure outside the pixel area of ​​the micro display, reducing the edge difference of the pixel area and improving display abnormality. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] This specification includes the following drawings, which show the following contents:

[0025] This specification includes the following drawings, which show the following contents:

[0026] Figure 1 is a flow chart of the production process of the microdisplay of the present invention;

[0027] Figure 2 is a schematic diagram of the structure of a microdisplay;

[0028] Figure 3 It is a schematic diagram of the structure of an existing micro display;

[0029] Figure 4 It is a flow chart of the production process of the existing micro display;

[0030] The markings in the figure are:

[0031] 1. Anode layer; 2. Pixel definition layer; 3. Light-emitting layer; 4. Cathode layer; 5. Filter; 6. Filter protection layer; 7. Outgoing light; 8. Glass cover; 9. Transparent glue layer; 10. Blocking ring; 11. Encapsulation layer; 12. Driving circuit; 13. Silicon wafer. DETAILED DESCRIPTION

[0032] The specific implementation methods of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of the present invention and facilitating its implementation.

[0033] like Figure 1 and Figure 2 As shown, the present invention provides a production process of a micro display, comprising the steps of:

[0034] S1, preparing a driving circuit on a silicon wafer;

[0035] S2, preparing an anode layer;

[0036] S3, preparing a pixel definition layer;

[0037] S4, evaporating an organic light-emitting layer and a cathode layer;

[0038] S5, thin film packaging;

[0039] S6, preparing a barrier ring outside the pixel area;

[0040] S7, coating of color photoresist is performed, and a blocking ring prevents the spin-coated color photoresist from being thrown away;

[0041] S8, color photoresist exposure and development, the blocking ring can inhibit the developer and water from over-washing the edge, ensuring that the color photoresist remains at the edge of the pixel area;

[0042] S9, coating the filter protective layer;

[0043] S10, the filter protection layer is exposed and developed, and the blocking ring prevents the color photoresist of the filter protection layer from overflowing, thereby ensuring the film thickness of the protection layer;

[0044] S11, glue the module, and use a blocking ring to prevent the glue from flowing away to ensure the glue thickness at the edge of the pixel area;

[0045] S12, glass cover lamination.

[0046] Specifically, if Figure 1 and Figure 2 As shown, in the above step S1, a silicon wafer is first provided, and then a driving circuit is prepared on the silicon wafer.

[0047] like Figure 1 and Figure 2 As shown, in the above step S2, an anode layer is prepared on the driving circuit.

[0048] like Figure 1 and Figure 2 As shown, in the above step S3, a pixel definition layer is prepared on the driving circuit, and there is a pixel definition layer between every two adjacent anode layers.

[0049] like Figure 1 and Figure 2 As shown, in the above step S4, a light-emitting layer and a cathode layer are sequentially deposited on the surface of the pixel definition layer and the anode layer. The light-emitting layer is an organic light-emitting layer.

[0050] like Figure 1 and Figure 2 As shown, in the above step S5, the device is thin-film packaged to form a packaging layer on the surface of the driving circuit and the cathode layer.

[0051] In the above step S6, a blocking ring is prepared on the encapsulation layer by using processes such as inkjet printing, screen printing, coating exposure and development, and the blocking ring is located outside the pixel area and is a ring structure surrounding the pixel area. The pixel area is composed of an anode layer, a pixel definition layer, a light-emitting layer and a cathode layer.

[0052] like Figure 1 and Figure 2 As shown, in the above step S7, colored photoresist is coated on the surface of the encapsulation layer, and the blocking ring can prevent the spin-coated photoresist from being thrown away, thereby finally forming a photoresist layer covering the encapsulation layer.

[0053] like Figure 1 and Figure 2 As shown, in the above step S8, the photoresist layer is exposed and developed to form a filter on the surface of the encapsulation layer. The blocking ring can inhibit excessive flushing of the edge by the developer and water, ensuring that the photoresist at the edge of the pixel area is retained, ensuring that the photoresist at the edge of the pixel area is as thick as the middle, and ensuring the edge line width and film thickness.

[0054] like Figure 1 and Figure 2As shown, in the above step S9, the filter protection layer coating process is the same as the existing conventional photolithography process, and a transparent resin material (Over Coat, OC) is coated on the filter and the packaging layer to form an OC glue layer, and the OC glue layer covers the blocking ring, the filter and the packaging layer. During the coating process, the film thickness is 2-5um, the rotation speed is 500-3000 rpm, the pre-baking is 60-90°C, the continuous application is 2-10min, the post-baking is 90°C, the continuous application is 2-10min, and the hard baking is 90°C, and the continuous application is 2-10min.

[0055] like Figure 1 and Figure 2 As shown, in the above step S10, the filter protective layer is exposed and developed, and a filter protective layer is prepared on the filter layer. The barrier layer surrounds the filter protective layer. The barrier layer has a similar effect on the filter protective layer as a color photoresist, preventing the protective layer photoresist from overflowing and ensuring the film thickness of the protective layer. When the exposure is performed, the time is 20 to 2000ms. When developing, KOH or TMAH developer is used, the development time is 60-600s, the curing temperature is 90°C, and the curing time is 10-20min.

[0056] like Figure 1 and Figure 2 As shown, in the above step S11, the module dispenses glue, injects glue between the filter protection layer and the blocking ring, and forms a transparent glue layer in the blocking ring. The blocking ring can prevent the glue from flowing away, ensuring the glue thickness at the edge of the pixel area.

[0057] like Figure 1 and Figure 2 As shown, in the above step S12, the glass cover plate is bonded, and the glass cover plate is adhered to the transparent glue layer. Under the pressure of the glass cover plate, the glue is not easy to overflow.

[0058] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A production process for a microdisplay, characterized in that: Includes steps: S1, preparing a driving circuit on a silicon wafer; S2, preparing an anode layer; S3, preparing a pixel definition layer; S4, evaporating an organic light-emitting layer and a cathode layer; S5, thin film packaging; S6, preparing a barrier ring outside the pixel area; S7, coating a color photoresist, wherein a blocking ring prevents the spin-coated color photoresist from being thrown away, thereby forming a photoresist layer covering the encapsulation layer and the blocking ring; S8, exposing and developing the photoresist layer, the blocking ring can inhibit excessive washing of the edge by the developer and water, and ensure that the color photoresist at the edge of the pixel area remains; S9, coating the filter protective layer; S10, exposing and developing the filter protection layer, wherein the blocking ring prevents the color photoresist of the filter protection layer from overflowing, thereby ensuring the film thickness of the filter protection layer; S11, glue the module, and use a blocking ring to prevent the glue from flowing away to ensure the glue thickness at the edge of the pixel area; S12, glass cover lamination; Wherein, in step S2, an anode layer is prepared on the driving circuit; In step S3, a pixel definition layer is prepared on the driving circuit, with one pixel definition layer between every two adjacent anode layers; In step S4, an organic light-emitting layer and a cathode layer are sequentially deposited on the surface of the pixel definition layer and the anode layer; In step S5, the device is thin-film packaged to form a packaging layer on the surface of the driving circuit and the cathode layer.

2. The production process of the microdisplay according to claim 1, characterized in that: In the step S6, an inkjet printing process is used to prepare a barrier ring outside the pixel area.

3. The production process of the microdisplay according to claim 1, characterized in that: In the step S6, a blocking ring is prepared outside the pixel area by using a screen printing process.

4. The production process of the microdisplay according to claim 1, characterized in that: In the step S6, a coating, exposure and development process is used to prepare a blocking ring outside the pixel area.

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