An evaporation mask

Abstract

The utility model belongs to the field of evaporation mask, concretely is a kind of evaporation mask, including mask base body, the non-pattern area of mask base body is embedded with embedded thermal deformation compensation strip, the inner wall of the through-hole of mask base body forms self-cleaning micro-cone hole wall structure, the self-cleaning micro-cone hole wall structure includes the multiple taper angle sections distributed in order from substrate side to evaporation source side;The self-cleaning micro-cone hole wall structure includes first taper angle section and second taper angle section, first taper angle section is located substrate side, and second taper angle section is located evaporation source side;The embedded thermal deformation compensation strip is arranged on mask base body along orthogonal grid direction;Through the embedded thermal deformation compensation strip embedded in the non-pattern area of mask base body arrangement along orthogonal grid direction, directly generate reverse deformation under evaporation high-temperature environment, directly limit the thermal expansion displacement amount of mask base body, overcome the defect that the figure drift is caused by high-temperature local deformation mismatch in prior art.

Description

Technical Field

[0001] This utility model relates to the field of vapor deposition masks, specifically a vapor deposition mask. Background Technology

[0002] Silicon-based OLED-on-Silicon (OLEDoS) microdisplays, based on Organic Light Emitting Diode (OLED) technology, offer advantages such as wide color gamut, high contrast, ultra-thinness, low power consumption, and flexibility. They can provide high-quality video displays for portable devices, gaming platforms, and wearable devices, and are particularly suitable for helmet-mounted displays, 3D displays, and eye-mounted displays, with broad application prospects in civilian, industrial, and military fields. There are two methods for colorizing silicon-based OLED microdisplays: one is using a white OLED with a color filter (WOLED+CF), and the other is direct deposition using a fine metal mask (FMM). Because the color filter has low transmittance (only about 30%–40%), resulting in significant light loss, the white OLED+color filter method struggles to achieve high color gamut and high brightness. The advantage of using FMM direct vapor deposition is that it eliminates the need for color filters, avoids light efficiency loss, and can achieve high color gamut and high brightness. However, since the pixel size of microdisplays is small, typically a few micrometers, and the existing FMM has low precision, it cannot meet the resolution requirements of microdisplays.

[0003] In the prior art, such as in publication number CN210683920U, a mask and a vapor deposition apparatus are disclosed. The mask includes a substrate of semiconductor material and a mask pattern formed on the substrate. The mask pattern includes multiple openings, and the cross-sectional shape of the openings in a plane perpendicular to the mask is trapezoidal. This invention, by setting the cross-sectional shape of the openings in the mask pattern to trapezoidal, eliminates the obstruction of the vapor deposition material by the sidewalls of the openings during vapor deposition. This allows the vapor deposition material to uniformly pass through the openings and adhere to the pixel openings of the display substrate, improving vapor deposition uniformity and quality.

[0004] Although the aforementioned patent eliminates the obstruction of the vapor deposition material by setting the cross-sectional shape of the opening in the mask pattern to a trapezoidal shape, the high temperature during vapor deposition causes local thermal expansion mismatch in the mask. In addition, the vapor deposition material tends to accumulate on the hole wall. Therefore, a vapor deposition mask is proposed to address the above problems. Utility Model Content

[0005] To address the shortcomings of existing technologies, such as the mismatch in thermal expansion of the mask due to high temperatures during vapor deposition, and the problem of vapor deposition material accumulating on the hole walls, this invention proposes a vapor deposition mask.

[0006] The technical solution adopted by this utility model to solve its technical problem is as follows: The vapor deposition mask of this utility model includes a mask substrate, an embedded thermal deformation compensation strip is embedded in the non-pattern area of ​​the mask substrate, and a self-cleaning micro-conical hole wall structure is formed in the inner wall of the through hole of the mask substrate. The self-cleaning micro-conical hole wall structure includes a plurality of conical segments distributed sequentially from the substrate side to the vapor deposition source side.

[0007] Preferably, the embedded thermal deformation compensation strips are arranged on the mask substrate along the orthogonal grid direction.

[0008] Preferably, the self-cleaning micro-conical hole wall structure includes a first conical segment and a second conical segment, wherein the first conical segment is located on the substrate side and the second conical segment is located on the vapor deposition source side.

[0009] Preferably, the embedded thermal deformation compensation strip is fixed to the embedded position of the mask substrate by laser welding.

[0010] Preferably, the surface of the self-cleaning microconical pore wall structure is covered with a hydrophobic nano-coating.

[0011] Preferably, the cone angle transition tolerance between the first cone angle segment and the second cone angle segment is controlled within a predetermined range.

[0012] The advantages of this utility model are: 1. This utility model uses embedded thermal deformation compensation strips arranged along the orthogonal grid direction in the non-pattern area of ​​the mask substrate to directly generate reverse deformation under the high temperature environment of vapor deposition, directly limiting the thermal expansion displacement of the mask substrate, and overcoming the defect of pattern drift caused by high temperature local deformation mismatch in the prior art. 2. Based on the synergistic effect of the continuous cone-shaped segments of the self-cleaning micro-conical hole wall structure and the surface hydrophobic nano-coating, this utility model dynamically eliminates the adhesion force of the vapor deposition material on the inner wall of the through hole, significantly reduces the material accumulation rate, and solves the problem of vapor deposition uniformity deterioration caused by the blockage of the hole wall of traditional mask. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the disassembled structure of this utility model; Figure 3 For the present utility model Figure 2 Enlarged view of the structure at point A; Figure 4 This is a schematic diagram of the embedded thermal deformation compensation strip structure of this utility model.

[0015] In the figure: 1. Mask substrate; 2. Embedded thermal deformation compensation strip; 3. Self-cleaning micro-conical hole wall structure; 31. First cone angle segment; 32. Second cone angle segment. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0017] Please see Figures 1-4 As shown, a vapor deposition mask includes a mask substrate 1, an embedded thermal deformation compensation strip 2 is embedded in the non-pattern area of ​​the mask substrate 1, and a self-cleaning micro-conical hole wall structure 3 is formed in the inner wall of the through hole of the mask substrate 1. The self-cleaning micro-conical hole wall structure 3 includes a plurality of conical segments distributed sequentially from the substrate side to the vapor deposition source side. During operation, the compensation strip material with a negative thermal expansion coefficient is micro-processed into a strip structure and then embedded in the orthogonal grid position of the non-pattern area of ​​the mask substrate 1 through laser welding process to form an embedded thermal deformation compensation strip 2. When the evaporation temperature is increased, the embedded thermal deformation compensation strip 2 generates reverse shrinkage deformation, which offsets the thermal expansion displacement of the mask substrate 1 in real time.

[0018] Furthermore, the self-cleaning micro-conical hole wall structure 3 includes a first conical segment 31 and a second conical segment 32, with the first conical segment 31 located on the substrate side and the second conical segment 32 located on the vapor deposition source side. During operation, a femtosecond laser drilling process is used to etch a double-segment cone angle of 85° on the substrate side and 60° on the vapor deposition source side on the inner wall of the through hole of the mask substrate 1, thereby constructing a self-cleaning micro-conical hole wall structure 3. Then, a hydrophobic nano-coating is applied to the hole wall surface using atomic layer deposition technology, so that the vapor of the vapor deposition material slides off when it flows through the cone angle segment due to the synergistic effect of the geometric configuration and low surface energy.

[0019] Furthermore, the surface of the self-cleaning microconical pore wall structure 3 is covered with a hydrophobic nano-coating; During operation, a hydrophobic nano-coating of fluorocarbon compound is uniformly coated on the entire surface of the self-cleaning micro-conical hole wall structure 3 using an atomic layer deposition process. When the vapor of the evaporating material flows through the double-conical corner section, the low surface energy characteristics of the coating prevent the material molecules from adhering stably, directly eliminating the adhesion and accumulation on the hole wall and significantly extending the service life of the mask.

[0020] Furthermore, the cone angle transition tolerance between the first cone angle segment 31 and the second cone angle segment 32 is controlled within a predetermined range; During operation, femtosecond laser etching and real-time topography feedback control technology are used to precisely control the transition tolerance of the cone angle between the first cone angle segment 31 and the second cone angle segment 32. This geometric precision enables the vapor deposition steam flow to form a laminar flow within the hole wall, fundamentally blocking the eddy current retention of material in the transition zone and ensuring that the cross-sectional area of ​​the through hole remains high after high-frequency vapor deposition.

[0021] Working principle: When high-temperature steam flows onto the mask substrate 1, the embedded thermal deformation compensation strip 2, placed in the non-pattern area, undergoes reverse contraction deformation due to heat, directly offsetting the thermal expansion displacement of the mask substrate 1. At the same time, the steam flows through the through holes of the self-cleaning micro-conical hole wall structure 3. The first cone corner segment 31 on the substrate side guides the steam flow to accelerate axially, while the second cone corner segment 32 on the vapor deposition source side induces eddy current stripping through the acute angle structure. Combined with the surface hydrophobic nano-coating, the material particles continuously slide down along the cone corner wall, ultimately achieving the dual effects of dynamic compensation for thermal deformation of the mask and long-term unobstructed flow of the through holes, significantly improving service life.

[0022] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, or similar improvements made within the theoretical and principle content of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A vapor deposition mask, characterized in that: The mask substrate (1) includes an embedded thermal deformation compensation strip (2) embedded in the non-pattern area of ​​the mask substrate (1), and a self-cleaning micro-conical hole wall structure (3) is formed on the inner wall of the through hole of the mask substrate (1). The self-cleaning micro-conical hole wall structure (3) includes multiple cone segments distributed sequentially from the substrate side to the vapor deposition source side.

2. The vapor deposition mask according to claim 1, characterized in that: The embedded thermal deformation compensation strips (2) are arranged along the orthogonal grid direction on the mask substrate (1).

3. The vapor deposition mask according to claim 1, characterized in that: The self-cleaning micro-conical hole wall structure (3) includes a first cone-angle segment (31) and a second cone-angle segment (32), with the first cone-angle segment (31) located on the substrate side and the second cone-angle segment (32) located on the vapor deposition source side.

4. The vapor deposition mask according to claim 1, characterized in that: The embedded thermal deformation compensation strip (2) is fixed to the embedded position of the mask substrate (1) by laser welding.

5. A vapor deposition mask according to claim 1, characterized in that: The surface of the self-cleaning microconical pore wall structure (3) is covered with a hydrophobic nano-coating.

6. A vapor deposition mask according to claim 1, characterized in that: The cone angle transition tolerance between the first cone angle segment (31) and the second cone angle segment (32) is controlled within a predetermined range.

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