Glass substrate metal mask for OLED production
By employing GS-FMM and GS-OMM structures with glass substrates in OLED display manufacturing, the scalability and mechanical stability issues of masks in large-size and high-resolution displays have been resolved, achieving high-yield and high-precision manufacturing, reducing costs and improving production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENZHEN MAXVISION TECHNOLOGY CO LTD
- Filing Date
- 2025-09-05
- Publication Date
- 2026-05-12
AI Technical Summary
Existing segmented FMM and SS-FSM masking technologies have issues with scalability, mechanical stability, and high precision in the manufacturing of large-size and high-resolution OLED displays, leading to pixel crosstalk, uneven evaporation, and increased production costs.
Employing glass-substrate fine metal mask (GS-FMM) and open metal mask (GS-OMM) structures, a low thermal expansion coefficient metal pattern is formed on the glass substrate, providing a consistent pattern deposition across the entire screen. This avoids splicing and alignment issues of segmented mask sections, improving the durability and manufacturing efficiency of the mask.
It has achieved high yield and high precision manufacturing of large-size and high-resolution OLED displays, reduced production costs and maintenance expenses, is suitable for mass production of large-size displays such as monitors and TVs, and improves the production efficiency and device performance of microOLED displays.
Smart Images
Figure CN122013103A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of organic light-emitting diode (OLED) display manufacturing technology, and more particularly to a glass substrate metal mask structure for OLED display production, including a high-precision patterned vapor deposition mask scheme suitable for active matrix organic light-emitting diodes (AMOLED) and micro OLEDs, and covering mask technologies such as fine metal mask (FMM) and open metal mask (OMM). Background Technology
[0002] Segmented FMMs have long been widely used in small-to-medium-sized AMOLED displays such as smartphones and tablets for the precise evaporation of red, green, and blue organic materials to achieve pixel alignment and color accuracy. However, as display sizes increase, the use of segmented masks becomes more challenging. To accommodate large substrates, multiple small mask segments typically need to be spliced together and aligned with high precision during manufacturing. This process is prone to misalignment between segments, leading to defects such as pixel crosstalk and uneven evaporation, thus affecting yield and increasing production costs.
[0003] While the Invar material used for the aforementioned segmented masks has a low coefficient of thermal expansion, its thin and fragile structure makes it susceptible to damage during alignment and stretching. Particularly in the production of large-size, high-resolution displays (such as monitors and televisions), the mechanical stress issues of these masks have become a significant bottleneck limiting their large-scale application. Multi-segment splicing and welding operations increase the risk of failure, and even slight misalignments can lead to image quality degradation, further impacting manufacturing efficiency.
[0004] Therefore, the mechanical structure of traditional FMMs is insufficient for manufacturing large-size displays (such as televisions and monitors). Currently, the industry generally adopts white OLED as an alternative, using color filters instead of direct red, green, and blue pattern evaporation. Although this method solves the masking problem, it sacrifices current efficiency and color purity. The widespread adoption of white OLED solutions is a stopgap measure adopted out of necessity because Invar materials cannot meet the demands of large-size applications.
[0005] While Invar's low coefficient of thermal expansion helps improve evaporation accuracy, its insufficient mechanical strength limits its application in large-size display production. Multiple attempts have shown that extending its use to large-size masks not only presents technological challenges but also, due to its insufficient material rigidity, makes it highly susceptible to deformation during use, severely impacting product yield. Therefore, the industry urgently needs a mask structure that combines scalability and mechanical stability to replace existing Invar-based FMM solutions.
[0006] On the other hand, microOLED displays place higher demands on mask precision, with resolutions typically exceeding two thousand pixels per inch. Traditional FMM technology can no longer meet the requirements for forming such high-precision patterns. In recent years, the industry has begun to try using silicon-substrate-supported fine silicon nitride masks (SS-FSM) to improve pattern precision. However, such materials are fragile and have a short lifespan in high-turnover manufacturing environments, and their use for mass production has not yet been proven.
[0007] In summary, current mask technologies used in AMOLED and microOLED manufacturing all have significant limitations. Segmented Invar masks are difficult to extend to large-size display production, indirectly leading to the compromise adoption of white light solutions; while SS-FSM, although showing potential in terms of precision, still cannot meet the requirements of high reliability and high-volume manufacturing. Therefore, the OLED industry urgently needs a new, scalable, durable, and high-precision mask structure that can simultaneously meet the needs of different sizes and high resolutions. Summary of the Invention
[0008] This invention proposes a Glass-Substrate-Supported Fine Metal Mask (GS-FMM) and Glass-Substrate-Supported Open Metal Mask (GS-OMM) structure based on a glass substrate, significantly improving upon existing FMM and SS-FSM technologies. This approach aims to address core challenges in AMOLED and microOLED manufacturing, including scalability, precision, durability, and manufacturing efficiency.
[0009] In AMOLED display manufacturing, GS-FMM technology offers a solution to the yield and scalability issues of traditional segmented FMMs. Traditional FMMs are mostly used in small-sized displays such as smartphones and tablets; however, their alignment accuracy decreases as substrate size increases. GS-FMMs, using a monolithic glass substrate, eliminate the need for segmented mask sections, enabling consistent pattern deposition across the entire screen. This improves accuracy and yield, making them suitable for manufacturing large-sized displays such as monitors and televisions, which previously relied heavily on white light solutions due to the limited scalability of FMMs.
[0010] In the manufacturing of microOLED displays, where resolutions typically exceed two thousand pixels per inch, GS-FMM offers a more scalable and structurally robust alternative to SS-FSM. SS-FSM relies on 8-inch or 12-inch silicon wafers and uses silicon nitride as the mask material, resulting in size limitations and fragility, making it difficult to meet the demands of high-volume production. In contrast, GS-FMM can be manufactured in a wider range of sizes and thicknesses while maintaining the required pattern precision, making it suitable for the mass production of high-resolution microOLEDs.
[0011] GS-FMM technology offers several key advantages over traditional FMM and SS-FSM. Its glass substrates (such as borosilicate glass or fused silica) possess superior mechanical stability, enabling the fabrication of large-size masks without segmented alignment operations. Furthermore, this technology uses electroforming to create metallic patterns, such as Invar or other low-thermal-expansion alloys, on the glass substrate, significantly improving mask durability and lifespan, reducing maintenance costs, and enhancing overall manufacturing efficiency. This makes it particularly suitable for the mass production needs of high-performance, large-size displays.
[0012] This invention also includes a GS-OMM structure for uniformly depositing common layers such as hole injection layers, hole transport layers, electron transport layers, electron injection layers, and cathodes. GS-OMM can maintain deposition uniformity across the entire screen, making it suitable for large-size AMOLED and microOLED displays, and is of significant value in improving device performance and lifespan. The combination of GS-FMM and GS-OMM constitutes a complete solution for patterned and common layer deposition.
[0013] Another key advantage of GS-FMM lies in its scalability. In AMOLED manufacturing, GS-FMM is suitable for producing large-size masks while maintaining pattern accuracy, thereby improving the yield of large-size displays such as TVs and monitors. In microOLED manufacturing, GS-FMM can be used on 8-inch or 12-inch wafers, possessing the mechanical strength and pattern accuracy required to meet high-resolution pixel density demands, overcoming the size and fragility limitations of SS-FSM.
[0014] In terms of manufacturing efficiency, GS-FMM can manufacture multiple mask units on a large glass substrate and cut them into wafer size for use in microOLED manufacturing. This not only improves the scalability of production but also effectively reduces costs, making it suitable for the commercial production of high-end AMOLED and microOLED displays.
[0015] Furthermore, GS-OMM provides a uniform solution for common layer evaporation, contributing to improved overall display performance and lifespan. The combination of GS-FMM and GS-OMM offers a key mask technology suitable for next-generation high-performance display manufacturing, simultaneously addressing both technical and economic challenges.
[0016] In summary, this invention provides a scalable, high-yield, and high-precision display manufacturing solution by introducing two novel mask structures based on glass substrates: GS-FMM and GS-OMM. GS-FMM outperforms traditional FMM and SS-FSM in terms of structural stability and pattern accuracy, while GS-OMM exhibits superior performance in uniform deposition of the common layer. The combination of these two structures constitutes a core manufacturing platform suitable for the mass production of AMOLED and microOLED displays. Attached Figure Description
[0017] Figure 1A This is a schematic diagram of a traditional split-type FMM used in the manufacture of small-sized AMOLEDs.
[0018] Figure 1B This is a schematic diagram of the OMM structure currently used in the manufacture of large-size AMOLEDs.
[0019] Figure 2A This is a schematic diagram of the GS-FMM structure.
[0020] Figure 2B This is a cross-sectional schematic diagram of RGB parallel vapor deposition achieved by GS-FMM.
[0021] Figure 3A This is a schematic diagram of the first half of Embodiment 1, illustrating the steps of glass substrate preparation, electrode deposition, pattern photolithography, electroforming, and preliminary photoresist removal.
[0022] Figure 3B This is a schematic diagram of the latter half of Embodiment 1, illustrating the process of forming the front protective layer, coating and patterning the back photoresist, etching, and finally forming the mask structure.
[0023] Figure 4A This is a schematic diagram of the first half of Embodiment 2, illustrating the steps of glass substrate preparation, electrode deposition, and metal pattern formation for large-area mask fabrication.
[0024] Figure 4B This is a schematic diagram of the latter half of Embodiment 2, illustrating the front protection, back patterning, etching, and final release steps of the GS-FMM.
[0025] Figure 5A This is a top view of the split GS-FMM.
[0026] Figure 5B yes Figure 5ACross-sectional view of the structure shown.
[0027] Figure 6 This is a comparison chart of the performance parameters of traditional segmented FMM and GS-FMM.
[0028] Figure 7A This is a top view structural diagram of GS-OMM.
[0029] Figure 7B yes Figure 7A Cross-sectional view of the structure shown.
[0030] Figure 8A This is a top view structural diagram of the SS-FSM.
[0031] Figure 8B This is a schematic diagram of the arrangement of multiple GS-FMMs on a large-area glass substrate.
[0032] Figure 9A This is a top view of the circular GS-FMM structure.
[0033] Figure 9B This is a top view of a rectangular GS-FMM structure.
[0034] Figure 10A This is a top view of the GS-OMM used for microOLED.
[0035] Figure 10B yes Figure 10A Cross-sectional view of the structure shown.
[0036] Figure 10C This is a cross-sectional view of the GS-FMM used for microOLED.
[0037] Figure 11A This is a schematic diagram of the arrangement of multiple GS-OMMs on a large-area glass substrate.
[0038] Figure 11B This is a schematic diagram of the arrangement of multiple GS-FMMs on a large-area glass substrate.
[0039] Figure 12 This is a comparison chart of the process performance of SS-FSM and GS-FMM. Detailed Implementation
[0040] The following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings, which illustrate the processes and advantages of manufacturing FMM and OMM based on glass substrates, particularly for structural designs used in AMOLED manufacturing. The core of the present invention lies in GS-FMM for precise RGB pattern evaporation, and also encompasses GS-OMM for common layer evaporation (e.g., hole injection layer (HIL), hole transport layer (HTL), electron transport layer (ETL), electron injection layer (EIL), and cathode), suitable for the fabrication of large-size AMOLED substrates such as G8+.
[0041] Figure 1A This demonstrates a segmented FMM13, traditionally used in the manufacture of small AMOLED displays (such as smartphones and tablets). In this approach, the overall FMM covering the AMOLED substrate 11 is divided into multiple display areas 14, which must be individually aligned and spliced onto the AMOLED substrate 11 during manufacturing. This segmentation is primarily due to the limitations in precision and maneuverability of large metal masks.
[0042] The need for alignment of multiple small mask segments significantly increases the complexity of the manufacturing process. Even tiny misalignments can lead to defects such as pixel crosstalk and reduced display uniformity.
[0043] Split-type FMM13 displays are typically made from extremely thin Invar sheets, which have a low coefficient of thermal expansion. However, due to the extreme thinness of the sheet, its mechanical stability is poor, making precise alignment and operation increasingly difficult as the display size increases.
[0044] To maintain the structural consistency and stability of the segmented FMM13, it is necessary to fix and align it during the manufacturing process through methods such as stretching and welding. These additional steps not only increase manufacturing costs and complexity, but may also introduce risks of mask segment displacement or damage.
[0045] Invar material is typically manufactured through a rolling process, which inherently limits the achievable thickness. While it remains effective in small-sized display applications, the inherent thinness of Invar masks becomes a reliability obstacle for large-sized panels.
[0046] Figure 1B The monolithic OMM15 currently used in the manufacture of large-size AMOLED displays (such as monitors and TVs) is demonstrated. Since FMM cannot be applied to large-size panels, the aperture metal layer 17 is designed to be fully open for all pixels and is supported and fixed by the metal mask frame 12.
[0047] Figure 2AThis is a top view of the GS-FMM described in this invention. The GS-FMM uses a single, solid glass substrate 16 as the mask substrate, avoiding the multi-segment splicing and alignment problems required by traditional segmented masks, and improving the overall process accuracy and scalability.
[0048] GS-FMM is a one-piece molded structure whose size can cover the entire AMOLED substrate11, or even slightly larger than the substrate boundary to achieve complete edge-to-edge vapor deposition coverage, simplifying the alignment process, reducing errors and improving yield.
[0049] The glass substrate 16 has a thickness between 0.5 and 3.0 mm, providing high mechanical stability, and thickened ribs are provided between each display area to enhance structural strength. An aperture metal layer 17 is formed on the glass substrate 16, possessing high precision and resistance to deformation, contributing to long-term stable operation.
[0050] GS-FMM is a monolithic structure, eliminating the need for stretching and welding like traditional FMM, thus reducing the risk of structural failure and simplifying the manufacturing process.
[0051] Unlike traditional FMMs that use Invar rolled sheets, this invention uses an electroforming process to deposit metals with low thermal expansion coefficients (such as Invar, super Invar, Kovar, Alloy 42, nickel, tungsten, molybdenum, zirconium tungsten oxide, tantalum, rhenium, etc.) onto a glass substrate 16 to form a metal electrode layer 19. The thickness of the metal layer can be controlled within the range of 1 to 30 micrometers to suit different needs.
[0052] Figure 2B This is a cross-sectional schematic diagram of the GS-FMM, illustrating its support structure and pattern aperture. The aperture metal layer 17 forms fine apertures 18 to achieve RGB parallel evaporation. The pattern on it is defined by the metal pattern photoresist 20. The overall structure is supported by the glass substrate 16 and ribs to ensure that the mask maintains flatness and high precision during the evaporation process.
[0053] Figure 3A This is a schematic diagram of the first half of Embodiment 1, illustrating the preparation steps of the glass substrate 16 used for mask fabrication. The substrate can be made of borosilicate glass, fused silica, or display-grade glass used in TFT-LCD and AMOLED production, with a thickness ranging from 0.5 to 3.0 mm. It possesses low thermal expansion, high chemical resistance, and good mechanical strength, making it suitable as a high-stability FMM support substrate. Subsequently, a metal electrode layer 19 is deposited on the glass substrate 16 to apply current and perform an electroforming process. The electrode layer can be made of materials with good conductivity, such as copper, chromium, or aluminum.
[0054] Continue as Figure 3AAs shown, a metal pattern photoresist 20 is coated on the metal electrode layer 19, and an opening pattern is formed by mask exposure and development. Within these patterned areas, a low thermal expansion coefficient metal is deposited into a mask structure using an electroforming process. The materials used are the opening metal layer 17, including Invar, super Invar, Kovar, Alloy 42, nickel, tungsten, molybdenum, zirconium tungsten oxide, tantalum, rhenium, etc., with a thickness controlled between 1 and 30 micrometers. The metal pattern photoresist 20 is then removed to prepare for subsequent processing.
[0055] Figure 3B This is a schematic diagram of the latter half of Embodiment 1, showing that after the metal mask structure is formed, front-side photoresist 21 is coated on the front side of the glass substrate 16 to cover and protect the opening metal layer 17. Then, back-side photoresist 22 is coated on the back side of the glass substrate 16, and the back-side etched window is formed by exposure and development.
[0056] like Figure 3B As shown, hydrofluoric acid (HF) is used to back-etch the glass substrate 16 to expose the metal pattern area and form the mask aperture 18. Nitrogen bubbling or stirring can be used to accelerate the reaction during the etching process. After etching, the metal electrode layer 19, the front photoresist 21, and the back photoresist 22 are removed to obtain a glass substrate metal mask structure with precise aperture 18, which has the stability and repeatability required for mass production.
[0057] Figure 3A The diagram illustrates the preparation process of the glass substrate 16 used for mask fabrication. This substrate can be made of borosilicate glass, fused silica, or display-grade glass used in TFT-LCD and AMOLED production. These materials, ranging in thickness from 0.5 mm to 3.0 mm, are chosen as ideal materials for supporting high-strength FMMs due to their low thermal expansion, high chemical resistance, and good mechanical strength.
[0058] A metal electrode layer 19 is then deposited on the glass substrate 16. This layer is crucial for applying the electric field during subsequent electroforming. Optional materials include copper, chromium, or aluminum, which have good electrical conductivity and are compatible with the electroforming process.
[0059] A metal-patterned photoresist 20 is coated on the electrode layer, and the pattern is defined by photolithography to expose the electroforming area. After exposure to ultraviolet light through a mask and development, the photoresist is partially removed, exposing the glass surface for subsequent metal deposition.
[0060] Electroforming is performed in the exposed area to form an open-cell metal layer 17. This metal can be Invar, or other metals with a low coefficient of thermal expansion, such as super Invar, Kovar, Alloy 42, nickel, tungsten, molybdenum, zirconium tungsten oxide, tantalum, or rhenium. The metal layer thickness is controlled between 1 micrometer and 30 micrometers. After electroforming, the metal pattern photoresist 20 is removed.
[0061] Figure 3B First, a front-side photoresist 21 is coated on the aperture metal layer 17 to provide protection during subsequent back-side processing.
[0062] Next, a back-side photoresist 22 is coated on the back side of the glass substrate 16 and patterned by photolithography to form an opening area for back etching.
[0063] Hydrofluoric acid (HF) is used to etch from the back side of the glass substrate 16 to expose the display area 14. The reaction rate can be accelerated during the etching process by bubbling with nitrogen or by mechanical stirring.
[0064] Finally, the metal electrode layer 19 is removed using a suitable etching solution (such as ammonium persulfate for copper or cerium ammonium nitrate for chromium), and the front photoresist 21 and back photoresist 22 are also removed. This results in a metal mask structure with precise aperture 18 formed on the glass substrate.
[0065] Figure 4A The starting steps of Embodiment 2 are shown, illustrating the preparation process of the glass substrate 16 for mask fabrication. This substrate requires cleaning and surface treatment to ensure its suitability for subsequent processes.
[0066] A metal electrode layer 19 is deposited on the glass substrate 16 to allow the application of the required current during the electroforming process. This electrode layer can be formed from a material with excellent conductivity, such as copper, chromium, or aluminum, and has good compatibility with the electroforming process.
[0067] A metal film is deposited on the metal electrode layer 19 for subsequent formation of the porous metal layer 17. The thickness of this metal film ranges from 1 to 30 micrometers and can be deposited using methods such as electroforming, magnetron sputtering, chemical vapor deposition (CVD), evaporation, or atomic layer deposition (ALD). Suitable materials include metals with low coefficients of thermal expansion, such as Invar, super Invar, Kovar, Alloy 42, nickel, tungsten, molybdenum, zirconium tungsten oxide, tantalum, and rhenium.
[0068] Metal pattern photoresist 20 is coated on the metal film, and a mask pattern is formed by photolithography exposure and development process to define the opening positions of the subsequent metal layer.
[0069] The metal film is patterned and etched using reactive ion etching (RIE), ion beam etching, or wet chemical etching to form an open metal layer 17 with a precision aperture 18.
[0070] After etching, the metal pattern photoresist 20 is removed to expose the patterned open-hole metal layer 17.
[0071] like Figure 4B As shown, front-side photoresist 21 is coated on the aperture metal layer 17 to provide protection during subsequent glass back etching.
[0072] A back-side photoresist 22 is coated on the back side of the glass substrate 16 and patterned by photolithography to form an opening in the back-side etched area.
[0073] The glass substrate 16 is etched from the back side using hydrofluoric acid (HF) until the aperture 18 is exposed. The etching process can be accelerated and made more uniform by using nitrogen bubbling or mechanical stirring.
[0074] After etching, the metal electrode layer 19 is removed using an appropriate etching solution (such as ammonium persulfate or cerium ammonium nitrate), and the front photoresist 21 and the back photoresist 22 are stripped to complete the fabrication of the metal mask.
[0075] It should be noted that the formation of the open metal layer 17 can be accomplished not only by electroforming, but also by other deposition methods such as sputtering, CVD, evaporation or ALD, depending on actual needs, to adapt to different mask structures or production equipment conditions.
[0076] Figure 5A This invention demonstrates the concept of a segmented glass substrate metal mask (GS-FMM). Both the first segmented GS-FMM 23 and the second segmented GS-FMM 24 are smaller than the AMOLED substrate 11, with each mask covering only a portion of the display area. By sequentially using multiple such masks, pattern deposition can be completed on the entire AMOLED substrate 11.
[0077] The first segment of the GS-FMM23 is designed to be smaller than the entire AMOLED substrate 11, which helps improve handling convenience and alignment accuracy. This modular design is particularly suitable for large-size AMOLED substrates such as G8+, and is more practical when handling single large masks is difficult.
[0078] Multiple smaller GS-FMMs can be sequentially aligned to the AMOLED substrate 11 to achieve high-precision manufacturing of large-size displays, while avoiding the complexity and risks associated with manipulating a single large mask.
[0079] like Figure 5B As shown, even in the segmented structure, thickened ribs are provided between the patterned areas of each GS-FMM to ensure that each mask segment maintains good structural strength and flatness during handling and use.
[0080] Figure 6 It presents a comparison between traditional FMM and GS-FMM, highlighting its advantages in cost, scalability, production efficiency, and yield.
[0081] The initial cost of traditional segmented FMMs is high for several reasons. This method requires multiple segmented masks, whose manufacturing and operation are complex. Furthermore, the Invar material used is expensive, especially given the costly rolling process it requires. Because the masks are segmented and require complex alignment, the yield is low, further increasing the overall cost.
[0082] In comparison, GS-FMM significantly reduces initial mask costs. It uses a single, integrated mask instead of multiple smaller masks, simplifying the manufacturing process and making it more cost-effective. GS-FMM is manufactured using electroforming or metal coating processes, which are more efficient and precise, helping to improve yield and reduce overall costs.
[0083] Traditional FMMs suffer from very high maintenance costs due to the fragility of Invar sheets. The masks are prone to deformation or damage during manufacturing, requiring frequent adjustments and replacements. To avoid production interruptions caused by mask failures, manufacturers typically maintain a large stock of spare masks.
[0084] GS-FMM has significantly lower maintenance costs. Its glass support structure around the metal film enhances overall durability and reduces the need for frequent adjustments and replacements. Because GS-FMM is less prone to deformation, the number of spare masks required can also be greatly reduced, thus lowering long-term maintenance costs.
[0085] The scalability of traditional FMMs is limited by the rolling size limit of Invar sheets. Invar sheets are relatively fragile and difficult to align with high precision as the substrate size increases, making them unsuitable for mass production of large-size AMOLEDs.
[0086] In contrast, GS-FMM is suitable for large-size substrates such as those used in TVs and monitors, and offers excellent scalability. Its glass-supported metal film structure provides greater stability, and alignment can be completed with just a single mask, making it ideal for mass production of large-size AMOLED displays.
[0087] Traditional FMMs (Fixed Mask Machines) have low production efficiency due to the need to operate multiple masks and perform stretching and welding fixation. This process is not only time-consuming but also prone to errors. In addition, their short lifespan necessitates frequent replacements, further impacting production efficiency.
[0088] GS-FMM significantly improves production efficiency. Due to the use of a single mask, the entire manufacturing process is simplified, eliminating the need for stretching and welding. Furthermore, its robust structure provides a long service life, and its simple operation significantly reduces labor and time costs.
[0089] The yield rate of traditional FMMs is relatively low, mainly due to frequent alignment errors and the fragility of the mask structure. The mask is prone to deformation during use, leading to display defects and reducing product quality.
[0090] Thanks to its precise alignment and robust structure, GS-FMM boasts higher yield rates. The integrated mask structure eliminates the risk of misalignment between multiple mask segments, while the glass-supported metal sheet prevents deformation during use, thus ensuring consistent and high-quality AMOLED production.
[0091] The scalability of traditional segmented FMMs is limited by the rolling size of Invar sheets. Invar sheets are fragile and difficult to align with high precision, especially as substrate sizes increase, making them unsuitable for large-scale AMOLED production.
[0092] In contrast, GS-FMM can be easily scaled to large-size substrates such as those used in TVs and monitors. Its glass-supported metal thin-film structure offers higher structural integrity. Furthermore, the monolithic mask simplifies the alignment process, making it ideal for manufacturing large-size AMOLED displays.
[0093] Traditional segmented FMMs have low production efficiency because the process of using multiple masks is inherently complex. Each mask requires stretching and welding, a time-consuming and error-prone process. Furthermore, segmented FMMs have short lifespans and require frequent replacements, further reducing production efficiency.
[0094] GS-FMM significantly improves production efficiency. Due to the use of a single mask, the overall manufacturing process is simplified, eliminating the need for stretching and welding. GS-FMM is robust, has a long service life, and is easy to operate, effectively accelerating production speed and reducing labor costs.
[0095] Traditional FMMs have low yield rates, mainly due to frequent alignment errors and the fragility of the mask. Masks often deform during use, leading to display defects and decreased product quality.
[0096] The significantly improved yield of GS-FMM is attributed to its robust structure and precise alignment. The single-piece mask structure avoids alignment errors between multiple mask segments, while the metal sheet supported by the glass frame is not easily deformed during use, thus ensuring high consistency and high-quality AMOLED production.
[0097] Figure 7A This is a top view schematic diagram of the GS-OMM described in this invention. This GS-OMM structure is used to deposit common layers, such as HIL, HTL, ETL, EIL, and a cathode layer, on a large-size AMOLED substrate 11. The aperture metal layer 17 shown in the figure has a large unobstructed display area 14, which helps to achieve uniform deposition across the entire substrate.
[0098] Figure 7B for Figure 7AThe cross-sectional schematic diagram of the GS-OMM shown illustrates the structural configuration of the aperture metal layer 17 deposited on the glass substrate 16. The GS-OMM structure ensures uniform and precise deposition of the common layer, which has a significant impact on the overall performance and lifespan of the AMOLED display.
[0099] The open-hole metal layer 17 in this GS-OMM typically has a thickness of 5 to 200 micrometers, preferably 50 to 100 micrometers, which ensures structural strength while also facilitating the uniform deposition of a common layer over a large area.
[0100] GS-OMM is particularly suitable for large-size AMOLED substrates 11 such as G8+, offering advantages in handling and alignment compared to traditional metal masks. By using a glass substrate 16, GS-OMM enables high-precision common layer deposition, ensuring uniformity of each layer across the entire substrate.
[0101] Compared to traditional metal masks, which are prone to misalignment during alignment, GS-OMM's glass substrate 16 provides a stable and easy-to-align platform, effectively reducing manufacturing complexity, improving yield, and thus reducing costs.
[0102] Figure 7B The cross-sectional view shown also reveals the outline of the aperture metal layer 17, which helps control the thickness and quality of the common layer and ensures consistent vapor deposition across the entire substrate.
[0103] Figure 8A This is a top view of an SS-FSM fabricated using a silicon substrate 25. This method, employed by companies such as eMagin, uses SS-FSM to fabricate patterned metal masks. However, this method has several limitations, such as the limited size of the silicon substrate 25 and its relatively brittle structure. These factors increase manufacturing difficulty and reduce mask durability when scaled up to larger sizes or higher resolution MicroOLED displays 27.
[0104] Figure 8B This is a top view schematic diagram of the simultaneous fabrication of multiple GS-FMMs on a large-size glass substrate 16. The figure shows multiple MicroOLED display substrates 26 uniformly arranged on the glass substrate 16, each with an independent display area 14 structure. This configuration significantly improves manufacturing efficiency and is suitable for mass production.
[0105] Figure 8BThe glass substrate 16 can be made of borosilicate glass, fused silica, or display-grade glass, such as Corning Eagle XG or Asahi Glass AN100, possessing excellent thermal stability and chemical resistance, and is widely used in TFT-LCD and AMOLED manufacturing processes. Its thickness ranges from 0.5 to 3.0 mm, giving GS-FMM good structural strength, making it more suitable for the manufacturing requirements of high-performance MicroOLED displays 27.
[0106] Figure 9A This is a top view schematic diagram of a large-sized circular GS-FMM formed on a glass substrate 16. The glass substrate 16 can be borosilicate glass, fused silica, or display-grade glass. This figure illustrates that the present invention can fabricate mask structures larger than the MicroOLED display substrate 26, thereby providing a larger coverage area, higher structural strength, and better alignment accuracy during manufacturing—factors particularly critical for MicroOLED applications.
[0107] Figure 9B This is a top view of a large rectangular GS-FMM formed on a glass substrate 16. The figure emphasizes the flexibility of the glass substrate 16 in accommodating various GS-FMM shapes and sizes, without the limitations faced by conventional SS-FSMs. This flexibility meets the requirements for high-resolution material patterning in MicroOLED processes, further demonstrating its advantages over silicon substrate structures.
[0108] The fabrication method of GS-FMM for MicroOLED is basically the same as that for AMOLED, both being structures formed on a glass substrate 16, with adjustments only made in design to accommodate the higher resolution and smaller pixel size required for the MicroOLED display 27. Both employ the same basic manufacturing process, including glass substrate 16 preparation, metal deposition, patterning photolithography, and electroforming, which have been detailed in [details omitted]. Figure 3A , Figure 3B , Figure 4A and Figure 4B In both applications, the glass substrate 16 is a key material for achieving mechanical stability, pattern accuracy, and scalability. Using the same process, MicroOLED uses GS-FMM to maintain pixel-level pattern accuracy and meet the specific requirements of MicroOLED displays 27 for tiny subpixels and tight tolerances.
[0109] Figure 10AThis is a top view of the GS-OMM for MicroOLED, showing its structural configuration. This mask structure, built on a glass substrate 16, is used to deposit common layers such as HIL, HTL, ETL, and cathode on the MicroOLED display substrate 26. The display area 14 has multiple openings to achieve uniform material deposition, helping to ensure the consistency of these common layers across the entire MicroOLED display 27. The GS-OMM structure is particularly suitable for small-size, high-resolution processes where extremely high consistency and alignment accuracy are required.
[0110] Figure 10B for Figure 10A The cross-sectional schematic diagram of the GS-OMM shown illustrates the structural configuration of a metal electrode layer 19 deposited on a glass substrate 16. Apertures 18 are formed on the metal electrode layer 19, their positions precisely corresponding to the MicroOLED display substrate 26, allowing material to be deposited only in the target area. The glass substrate 16 has a thickness ranging from 0.5 to 3.0 mm, providing stability and effectively preventing deformation or warping during the evaporation process, making it suitable for high-precision mass production of MicroOLED wafers.
[0111] Figure 10C This is a cross-sectional schematic diagram of a GS-FMM used for MicroOLED, which is used for high-precision pattern deposition of RGB subpixels. The metal electrode layer 19 has apertures 18 to define RGB pattern areas, ensuring accurate pixel alignment and color precision. The GS-FMM is also supported by a glass substrate 16, whose stable structure helps prevent mask deformation during the manufacturing process, improving overall deposition yield.
[0112] Figure 11A This is a top-view schematic diagram showing multiple MicroOLED GS-OMMs arranged on a large-size glass substrate 16. This diagram illustrates the scalability of the MicroOLED GS-OMM manufacturing process. Multiple substrates can be processed simultaneously on the same glass substrate 16, effectively improving mass production efficiency. Using a single large glass substrate 16 to support multiple GS-OMMs allows for scaling up production without sacrificing the precision required for high resolution. This method ensures the consistency of common layers deposited on multiple substrates, thereby improving the consistency of display performance across all panels.
[0113] Figure 11BThis is a top view of multiple MicroOLED GS-FMMs on a single large-size glass substrate 16. Similar to GS-OMMs, this arrangement allows for the simultaneous fabrication of multiple GS-FMMs, thereby increasing throughput and reducing manufacturing costs. Each GS-FMM is designed for a specific MicroOLED display substrate 26 to achieve precise RGB subpixel deposition. This method improves production efficiency while maintaining the high precision required for the MicroOLED display 27. Simultaneous fabrication of multiple GS-FMMs using a single glass substrate 16 is ideal for the mass production of small, high-resolution displays such as AR / VR devices.
[0114] Figure 12 This paper compares the application differences between SS-FSM and GS-FMM in MicroOLED manufacturing. The comparison table highlights key differences between the two masks in terms of structural design, manufacturing materials, scalability, cost efficiency, and durability, emphasizing the advantages of GS-FMM in multiple aspects.
[0115] SS-FSM uses a silicon substrate 25 as a support, which is size-limited and structurally fragile; GS-FMM, on the other hand, uses a glass substrate 16, offering higher mechanical strength and dimensional flexibility. The mask material for SS-FSM is brittle silicon nitride, while GS-FMM uses a metal material with a low coefficient of thermal expansion, which helps improve thermal stability and process durability. SS-FSM is typically limited to 8-inch or 12-inch silicon substrates, while GS-FMM can fabricate structures larger than the MicroOLED display substrate 26, significantly improving stability and operating space during manufacturing.
[0116] In terms of mask production, SS-FSM can only produce one mask per silicon substrate 25, resulting in high manufacturing costs; GS-FMM, on the other hand, can produce multiple masks simultaneously on a single glass substrate 16, offering higher throughput and lower unit costs. Furthermore, SS-FSM is more brittle and easily damaged during use; while GS-FMM is more robust, reusable, and particularly suitable for high-intensity mass production environments.
[0117] In terms of maintenance costs, SS-FSM is fragile and requires frequent replacement, leading to increased maintenance costs; while GS-FMM, due to its high durability, can withstand multiple process cycles, significantly reducing the frequency of maintenance and replacement. Regarding reusability, SS-FSM is easily worn during cleaning, resulting in a low recycling rate; while GS-FMM maintains its functionality even after multiple cleanings, exhibiting high recyclability and further reducing mass production costs.
[0118] The comparison results clearly demonstrate that GS-FMM possesses excellent scalability, durability, cost-effectiveness, and overall performance in MicroOLED manufacturing. Utilizing a glass substrate 16 that can be larger than the MicroOLED display substrate 26, GS-FMM offers superior structural stability and precision control in high-resolution display applications, making it an ideal mask solution for mass production in the MicroOLED field.
Claims
1. A metal mask supported on a glass substrate for OLED display manufacturing, characterized in that, include: A glass substrate, located only outside the display area, is used to provide structural stability; An open-pore metal layer forms pores in the display area for material deposition.
2. The metal mask supported on a glass substrate as described in claim 1, in, The glass substrate is selected from borosilicate glass, fused silica, or display-grade glass used in the manufacture of TFT-LCD or AMOLED. Its thickness ranges from 0.5 mm to 3.0 mm.
3. The metal mask supported on a glass substrate as described in claim 1, in, The perforated metal layer is selected from metals with a low coefficient of thermal expansion, including Invar, super Invar, Kovar alloy, 42 alloy, nickel, tungsten, molybdenum, tantalum or rhenium.
4. The metal mask supported on a glass substrate as described in claim 1, in, The perforated metal layer is formed by electroforming, sputtering, chemical vapor deposition (CVD), evaporation, or atomic layer deposition (ALD) processes, with the specific deposition method selected based on the mask structure or production equipment conditions.
5. The metal mask supported on a glass substrate according to claim 1, Its features are, The glass substrate has an arrangement structure corresponding to multiple microOLED display substrates, so as to batch process multiple microOLED display substrates.
6. The metal mask supported on a glass substrate according to claim 1, Its features are, The glass substrate is sized to completely cover an AMOLED display substrate so that material can be deposited over the entire display area using a single, integrated mask.
7. A method for manufacturing a metal mask supported on a glass substrate, comprising: Provide a glass substrate as structural support; Deposit a metal electrode layer on a glass substrate; Photoresist is patterned on the metal electrode layer to define openings for OLED material deposition; An open-pore metal layer is formed by electroforming process; Furthermore, the glass substrate and metal electrode layer in the display area are removed through a back-side etching process, leaving only the perforated metal layer in the display area.
8. A method for manufacturing a metal mask supported on a glass substrate, comprising: Provide a glass substrate as structural support; An open-hole metal layer is formed on a glass substrate; The aperture metal layer is patterned within the display area to form an opening for OLED material deposition; And the glass substrate in the display area is removed by a back etching process, so that only the open metal layer is left in the display area.
9. The method for manufacturing a metal mask supported on a glass substrate according to claim 7 or 8, Its features are, The glass substrate is selected from borosilicate glass, fused silica, or display-grade glass used in the manufacture of TFT-LCD or AMOLED. Its thickness ranges from 0.5 mm to 3.0 mm. The method for manufacturing a metal mask supported on a glass substrate according to claim 7 or 8, The feature is that the perforated metal layer is composed of a metal with a low coefficient of thermal expansion, including Invar, super Invar, Kovar alloy, 42 alloy, nickel, tungsten, molybdenum, tantalum or rhenium.
10. The method for manufacturing a metal mask supported on a glass substrate according to claim 7 or 8, Its features are, The perforated metal layer is formed by electroforming, sputtering, chemical vapor deposition (CVD), evaporation, or atomic layer deposition (ALD), and the deposition method is selected according to the mask structure or production equipment conditions.
11. The method for manufacturing a metal mask supported on a glass substrate according to claim 7 or 8, Its features are, The glass substrate has an arrangement structure corresponding to multiple microOLED display substrates, so as to batch process multiple microOLED display substrates.
12. The method for manufacturing a metal mask supported on a glass substrate according to claim 7 or 8, Its features are, The glass substrate is sized to completely cover an AMOLED display substrate so that material can be deposited over the entire display area using a single, integrated mask.