A glass film and photolithography process thereof

Abstract

This invention relates to the field of glass film manufacturing technology, and more particularly to a glass film and its photolithography process. From bottom to top, it comprises: a glass substrate layer, an OCA optically transparent adhesive layer, a plastic sheet base layer, and a photosensitive agent layer. This invention effectively solves the technical problem of expansion and contraction deformation in traditional films by designing a glass film structure in which the glass substrate layer, OCA optically transparent adhesive layer, plastic sheet base layer, and photosensitive agent layer are stacked sequentially. Furthermore, the glass substrate layer provides high rigidity support and an extremely low coefficient of thermal expansion for the overall structure. The OCA optically transparent adhesive layer achieves a gapless and tight bond between the glass and the plastic sheet base, ensuring that the overall coefficient of thermal expansion of the composite structure is consistent with that of the glass substrate, significantly improving the dimensional stability and accuracy of the pattern. Simultaneously, the protective effect of the glass substrate layer greatly enhances the film's wear resistance and damage resistance, effectively extending the service life of the photomask.

Description

Technical Field

[0001] This invention relates to the field of glass film manufacturing technology, specifically to a glass film and its photolithography process. Background Technology

[0002] Photomasks are core precision tools in photolithography. As the "film" for pattern transfer in the manufacturing of electronic components, their precision and stability directly determine the quality of downstream products. Currently, the mainstream photomasks used in the industry are mainly divided into two categories: one is transparent resin substrate photomasks, represented by film, and the other is transparent glass substrate photomasks, represented by chrome plates. Film photomasks are widely used in fields with relatively low precision requirements, such as PCBs, due to their advantages of low cost and ease of large-scale production; while chrome plates, with their small coefficient of thermal expansion, high transmittance, and high precision, are mainly used in high-precision manufacturing fields such as semiconductors and display panels.

[0003] However, both existing photomasks have insurmountable technical drawbacks. Traditional film, composed of a plastic base and photosensitive agent, has a high coefficient of thermal expansion, making it susceptible to expansion and contraction deformation due to temperature and humidity, resulting in a significant decrease in graphic accuracy. Furthermore, the plastic material has poor wear resistance and a short lifespan. Additionally, traditional film is produced using photoplotting technology, requiring operation in a darkroom environment, leading to low production efficiency. It is also limited by the fixed format of the photoplotter, making it unable to flexibly adapt to different graphic size requirements. While chrome-plated photomasks offer excellent accuracy and durability, their manufacturing process is extremely complex, costing tens or even hundreds of times more than film, making large-scale application in low- to mid-range sectors difficult. Therefore, the industry urgently needs a new photomask solution that balances accuracy, durability, and cost. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a glass film and its photolithography process, solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a glass film, comprising, from bottom to top: a glass substrate layer, an OCA optically transparent adhesive layer, a plastic sheet base layer, and a photosensitizer layer, wherein the OCA optically transparent adhesive layer seamlessly bonds the glass substrate layer and the plastic sheet base layer, and the photosensitizer layer is uniformly coated on the upper surface of the plastic sheet base layer.

[0006] Preferably, the glass substrate layer is any one of quartz glass, borosilicate glass, or soda-lime glass.

[0007] Preferably, the OCA optically transparent adhesive layer is a substrate-free double-sided adhesive tape structure, which is laminated by release film, and the overall thermal expansion coefficient of the laminated glass film is consistent with that of the glass substrate layer.

[0008] Preferably, the plastic sheet base layer is made of PET material, and the photosensitizer layer is silver bromide photosensitizer.

[0009] A photolithography process for producing the glass film described in any one of the above includes the following steps: S1. Cut the semi-finished film according to the size of the target graphic. The semi-finished film consists of a plastic sheet base layer and a pre-coated photosensitive agent layer. S2. Cut a glass substrate layer to the same size as the semi-finished film; S3. The cut film semi-finished product is bonded to the surface of the glass substrate layer using an OCA optically transparent adhesive layer to obtain a composite substrate. S4. Adjust and set the internal operating parameters of the lithography machine according to the optical and photosensitive properties of the composite substrate; S5. Transmit the pre-designed target graphic data directly to the lithography machine; S6. Control the lithography machine to directly expose and image the photosensitive layer of the composite substrate to form a latent image; S7. After exposure, the composite substrate is subjected to development, fixing and washing processes in sequence. S8. The washed composite substrate is dried to obtain a glass film with the target pattern. Preferably, the glass film photolithography process in steps S1-S8 is carried out entirely in a bright room environment.

[0010] Preferably, in step S5, the target graphic data is vector graphic data designed using CAD / CAM software.

[0011] Preferably, in step S6, the lithography machine uses a near-ultraviolet laser source with a laser wavelength range of 380nm-420nm.

[0012] Preferably, in step S7, the developing process converts the latent image of the photosensitive layer into a visible image, the fixing process fixes the visible image, and the washing process removes residual chemical agents from the surface of the composite substrate.

[0013] Preferably, in step S8, the drying process adopts hot air drying, the drying temperature is controlled at 40℃-60℃, and the drying time is 5min-15min.

[0014] Preferably, in step S1, the cutting size of the semi-finished film can be arbitrarily adjusted according to the size of the target graphic, and is not limited by the fixed size of the photoplotter.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a glass film and its photolithography process: 1) According to the present invention, by designing a glass film structure in which a glass substrate layer, an OCA optically clear adhesive layer, a plastic base layer and a photosensitive agent layer are sequentially laminated, the technical problem of expansion and contraction deformation of traditional films is effectively solved. The glass substrate layer provides high-rigidity support and an extremely low thermal expansion coefficient for the overall structure; the OCA optically clear adhesive layer achieves gapless and tight lamination between the glass and the plastic base, so that the overall thermal expansion coefficient of the composite structure is consistent with that of the glass substrate, and the expansion and contraction deformation amount can be less than 0.005%, which significantly improves the dimensional stability and precision of the pattern. Meanwhile, the protective effect of the glass substrate layer greatly enhances the wear resistance and damage resistance of the film, and effectively prolongs the service life of the photomask; 2) The supporting photolithography process of the present invention can be operated in a bright room environment throughout the whole process, and the production efficiency is doubled compared with the traditional photoplotting process. The 380nm-420nm near-ultraviolet laser is adopted for direct exposure and imaging, and the pattern precision is tripled compared with that of the photoplotting process. Moreover, the semi-finished film can be arbitrarily cut according to the size of the target pattern, which effectively gets rid of the limitation of the fixed format of the photoplotter. Meanwhile, the overall process flow is greatly simplified compared with the chromium plate, the production cost is only one third of that of the chromium plate with the same precision, and the balance of precision, durability and cost is successfully achieved, which provides an economical and feasible photomask solution for the fields of mid-to-high end PCBs, flexible electronics and the like. Brief Description of the Drawings

[0016] Figure 1 is a specific implementation flowchart of the present invention; Figure 2 is a top view of the finished glass film of the present invention; Figure 3 is a cross-sectional view of the finished glass film of the present invention.

[0017] In the figures: 101. Glass substrate layer; 102. OCA optically clear adhesive layer; 103. Plastic base layer; 104. Photosensitive agent layer. Detailed Description of the Embodiments

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0020] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "configuration" should be interpreted broadly. For example, they can refer to a fixed connection or configuration, a detachable connection or configuration, or an integral connection or configuration. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Example

[0022] like Figures 1-3 As shown, the present invention proposes a glass film, which, from bottom to top, comprises: a glass substrate layer 101, an OCA optically transparent adhesive layer 102, a plastic sheet base layer 103, and a photosensitizer layer 104. The OCA optically transparent adhesive layer 102 seamlessly bonds the glass substrate layer 101 and the plastic sheet base layer 103, and the photosensitizer layer 104 is uniformly coated on the upper surface of the plastic sheet base layer 103.

[0023] Specifically, the bottom glass substrate layer 101 serves as the rigid support framework for the glass film. Utilizing the extremely low coefficient of thermal expansion and excellent dimensional stability of the glass substrate layer 101, the temperature and humidity-sensitive deformation problem of traditional pure plastic films is suppressed. The middle OCA optically transparent adhesive layer 102 adopts a substrate-free formulation, achieving a bubble-free and gap-free permanent bonding between the glass substrate layer 101 and the plastic sheet base layer 103 through intermolecular forces. This uniformly transfers the rigidity of the glass to the upper structure, ensuring that the coefficient of thermal expansion of the composite is consistent with that of the glass substrate layer 101. The upper plastic sheet base layer 103 retains the flexibility and low-cost advantages of traditional films, while providing a flat coating substrate for the photosensitizer layer 104. Finally, the topmost photosensitizer layer 104 provides the graphic recording function, achieving high-precision graphic transfer through photochemical reactions.

[0024] In this embodiment, the glass substrate layer 101 is any one of quartz glass, borosilicate glass, or soda-lime glass.

[0025] Specifically, the glass film photolithography process of the present invention first obtains a film semi-finished product and a glass substrate layer 101 of matching size through precise cutting, avoiding material waste in subsequent processing. Then, the composite substrate is prepared in advance using an OCA optically transparent adhesive layer 102, so that the plastic sheet base layer 103 has rigid support from the glass substrate layer 101 before exposure, eliminating the substrate deformation error during the exposure process from the source. The vector graphics designed by CAD / CAM are directly transferred to the photolithography machine, skipping the intermediate steps such as film scanning and color separation in traditional photolithography processes, greatly reducing the loss of accuracy. Subsequently, near-ultraviolet laser is used to directly scan and image on the photosensitive layer 104 of the composite substrate. With the subsequent development, fixing and drying processes, a glass film with stable dimensions and excellent accuracy is finally obtained. Moreover, the production process does not require a darkroom environment, which significantly improves the operating conditions.

[0026] In this embodiment: the OCA optically transparent adhesive layer 102 is a substrate-free double-sided adhesive tape structure, which is laminated by release film, and the overall thermal expansion coefficient of the laminated glass film is consistent with that of the glass substrate layer 101.

[0027] Specifically, depending on the precision and cost requirements of different application scenarios, the glass substrate layer 101 can be made of quartz glass. Quartz glass has the lowest coefficient of thermal expansion and the highest light transmittance, and can maintain excellent dimensional stability over a wide temperature range, making it suitable for high-end electronic manufacturing fields with extremely high precision requirements. The glass substrate layer 101 can also be made of borosilicate glass. The coefficient of thermal expansion of borosilicate glass is slightly higher than that of quartz glass, but the cost is significantly reduced. At the same time, it has good chemical stability and thermal shock resistance, making it an ideal choice for most industrial applications. The glass substrate layer 101 can also be made of soda-lime glass. Soda-lime glass, with its extremely low production cost and good processing performance, is suitable for large-scale production scenarios with relatively low precision requirements and cost sensitivity. This allows the glass substrate layer 101 of all three materials to provide sufficient rigid support for the film and effectively suppress expansion and contraction deformation.

[0028] In this embodiment: the plastic sheet base layer 103 is made of PET material, and the photosensitizer layer 104 is silver bromide photosensitizer.

[0029] Specifically, the OCA optically transparent adhesive layer 102, which adopts a substrate-free double-sided bonding structure, achieves optimal bonding between the glass substrate layer 101 and the plastic sheet base layer 103. The OCA optically transparent adhesive layer 102 is protected by two layers of release film. During use, the lamination can be completed simply by peeling off the release film in sequence. The operation is simple and the bonding accuracy is high. Moreover, the substrate-free design avoids uneven thickness and optical loss of the adhesive layer itself, ensuring uniform light transmission during the photolithography process. At the same time, the OCA optically transparent adhesive layer 102 has excellent adhesive strength and weather resistance, and can maintain the bonding state during long-term use, preventing delamination and bubble formation. Furthermore, by optimizing the elastic modulus and thickness of the OCA optically transparent adhesive layer 102, it can effectively transmit the rigidity of the glass substrate layer 101, making the overall thermal expansion coefficient of the composite structure almost the same as that of the glass substrate layer 101, and effectively controlling the expansion and contraction deformation within 0.005%, thus meeting the requirements of high-precision pattern transfer.

[0030] A photolithography process for producing any of the above-mentioned glass films includes the following steps: S1. Cut the semi-finished film according to the size of the target graphic. The semi-finished film consists of a plastic sheet base layer 103 and a pre-coated photosensitive layer 104. S2, Cut a glass substrate layer 101 to the same size as the semi-finished film; S3. The cut film semi-finished product is bonded to the surface of the glass substrate layer 101 using the OCA optical transparent adhesive layer 102 to obtain the composite substrate. S4. Adjust and set the internal operating parameters of the lithography machine according to the optical and photosensitive properties of the composite substrate; S5. Transmit the pre-designed target graphic data directly to the lithography machine; S6. Control the lithography machine to directly expose and image the photosensitive layer 104 of the composite substrate to form a latent image; S7. After exposure, the composite substrate is subjected to development, fixing and washing processes in sequence. S8. The washed composite substrate is dried to obtain a glass film with the target pattern. The glass film photolithography process in steps S1-S8 is carried out entirely in a bright room environment.

[0031] Specifically, PET is selected as the base material of the plastic sheet 103, and silver bromide is selected as the photosensitive layer 104. This gives the plastic sheet base 103 excellent light transmittance, flatness, and mechanical strength, providing a uniform coating surface for the photosensitive layer 104. At the same time, its good flexibility facilitates cutting and bonding operations. The PET plastic sheet base 103 has good chemical stability and can withstand chemical processing such as development and fixing without dissolving or deforming. Meanwhile, the silver bromide used in the photosensitive layer 104 has extremely high photosensitivity and resolution, which can accurately record the latent image formed by laser scanning. Its photosensitive spectrum peak is highly matched with the near-ultraviolet laser source used in this invention, ensuring exposure efficiency and imaging accuracy. The development and fixing process using the silver bromide system is mature and stable, and can obtain images with high contrast and clear edges.

[0032] In this embodiment: In step S5, the target graphic data is vector graphic data designed by CAD / CAM software.

[0033] Specifically, this invention utilizes a method of directly transmitting vector graphic data designed with CAD / CAM software to the lithography machine, achieving a fully digital process for graphic transfer. The vector graphic data uses mathematical formulas to describe the graphic outline, rather than the pixel array of traditional photolithography, thus possessing the characteristic of infinite scaling without distortion, ensuring consistent accuracy of graphics of different sizes on the photosensitive layer 104. Direct data transmission skips multiple intermediate steps in traditional processes such as film output, scanning, and color separation, avoiding potential accuracy loss and human error introduced at each stage. The digital process also facilitates automated and information-based production management; the graphic data can be stored, modified, and reused, significantly improving production efficiency and flexibility, making it particularly suitable for multi-variety, small-batch production models.

[0034] In this embodiment: In step S6, the lithography machine uses a near-ultraviolet laser source with a laser wavelength range of 380nm-420nm.

[0035] Specifically, based on the characteristics and process requirements of the photosensitive layer 104, a near-ultraviolet laser source in the 380nm-420nm band is selected as the exposure light source. The laser in this band highly overlaps with the photosensitive spectral peak of the silver bromide photosensitive layer 104, enabling efficient exposure with the lowest energy. At the same time, it avoids damage to the plastic substrate 103 and the OCA optically transparent adhesive layer 102 caused by short-wavelength ultraviolet light. Moreover, the laser has excellent directionality and monochromaticity, which can be focused into an extremely fine spot, achieving a resolution and line accuracy far superior to traditional photolithography machines. In addition, the direct laser scanning exposure method eliminates the need to make an intermediate master, and can directly form patterns on the photosensitive layer 104 of the composite substrate, significantly shortening the production cycle. Furthermore, near-ultraviolet light is not sensitive to ambient light, allowing the entire photolithography process to be carried out in a bright room environment without the need for complex darkroom facilities, significantly reducing production costs and operational difficulty.

[0036] In this embodiment: In step S7, the developing process converts the latent image of the photosensitive layer 104 into a visible image, the fixing process fixes the visible image, and the washing process removes residual chemical agents from the surface of the composite substrate.

[0037] Specifically, in the photolithography process, the developing process uses an alkaline developer to react chemically with the photosensitive layer 104 in the exposed area, reducing the exposed silver bromide to black metallic silver particles, thus transforming the invisible latent image into a high-contrast visible image. In the fixing process, an acidic fixer is used to dissolve the unexposed silver bromide particles, preventing them from continuing to darken under subsequent light exposure, thereby permanently fixing the pattern on the plastic substrate 103. In the washing process, flowing clean water thoroughly washes away residual developer, fixer, and other chemical impurities on the surface of the composite substrate, avoiding corrosion and fading of the pattern by residual chemicals, ensuring the long-term stability and clarity of the image, and extending the service life of the glass film.

[0038] In this embodiment: In step S8, the drying process adopts hot air drying, the drying temperature is controlled at 40℃-60℃, and the drying time is 5min-15min.

[0039] Specifically, a hot air drying process of 40℃-60℃ is adopted. This temperature range can quickly evaporate the moisture on the surface of the composite substrate, and is lower than the glass transition temperature of the plastic sheet base layer 103 and the OCA optically transparent adhesive layer 102, so it will not cause the material to soften and deform, ensuring the stability of the graphic dimensions. The drying time of 5min-15min can ensure that the moisture inside the substrate is completely evaporated, avoiding blistering of the OCA optically transparent adhesive layer 102 and mold growth of the graphic caused by residual moisture. Ultimately, the resulting glass film has twice the graphic accuracy, 3-5 times longer service life, and doubled production efficiency compared to traditional photolithography film. Compared with chrome plates of the same accuracy, the process reduces complex steps such as chrome plating and etching, reducing production costs by two-thirds, and successfully achieving a perfect balance between accuracy, durability and cost.

[0040] In this embodiment: In step S1, the cutting size of the film semi-finished product is arbitrarily adjusted according to the size of the target graphic, and is not limited by the fixed size of the photoplotter.

[0041] Specifically, traditional photoplotting processes are limited by the roller size and scanning width of the photoplotter, and can only produce films of fixed size consisting of a plastic substrate 103 and a photosensitive layer 104. This results in a large amount of material waste for small-sized graphics, while ultra-large-format graphics cannot be produced directly. However, this invention uses a pre-cut film semi-finished product method, which can accurately cut the required size substrate according to the actual size of the target graphic, minimizing material waste. At the same time, through splicing technology, ultra-large-format glass films can also be produced to meet the special needs of large PCBs and photovoltaic cells. Moreover, the on-demand cutting production mode significantly improves material utilization and production flexibility, and can quickly respond to the diverse needs of different customers.

[0042] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0043] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A glass film, characterized in that, From bottom to top, it includes: a glass substrate layer (101), an OCA optically transparent adhesive layer (102), a plastic sheet base layer (103), and a photosensitizer layer (104). The OCA optically transparent adhesive layer (102) bonds the glass substrate layer (101) and the plastic sheet base layer (103) together without gaps. The photosensitizer layer (104) is uniformly coated on the upper surface of the plastic sheet base layer (103).

2. The glass film according to claim 1, characterized in that, The glass substrate layer (101) is any one of quartz glass, borosilicate glass or soda-lime glass.

3. The glass film according to claim 1, characterized in that, The OCA optically transparent adhesive layer (102) is a substrate-free double-sided adhesive tape structure, which is laminated by release film, and the overall thermal expansion coefficient of the laminated glass film is consistent with that of the glass substrate layer (101).

4. The glass film according to claim 1, characterized in that, The plastic sheet base layer (103) is made of PET material, and the photosensitizer layer (104) is silver bromide photosensitizer.

5. A photolithography process for producing the glass film according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Cut the semi-finished film according to the size of the target graphic. The semi-finished film consists of a plastic sheet base layer (103) and a pre-coated photosensitive layer (104). S2. Cut a glass substrate layer (101) that is the same size as the film semi-finished product. S3. The cut film semi-finished product is bonded to the surface of the glass substrate layer (101) using an OCA optical transparent adhesive layer (102) to obtain a composite substrate; S4. Adjust and set the internal operating parameters of the lithography machine according to the optical and photosensitive properties of the composite substrate; S5. Transmit the pre-designed target graphic data directly to the lithography machine; S6. Control the lithography machine to directly expose and image the photosensitive layer (104) of the composite substrate to form a latent image; S7. After exposure, the composite substrate is subjected to development, fixing and washing processes in sequence. S8. The washed composite substrate is dried to obtain a glass film with the target pattern. The glass film photolithography process in steps S1-S8 is carried out entirely in a bright room environment.

6. The glass film photolithography process according to claim 5, characterized in that, In step S5, the target graphic data is vector graphic data designed using CAD / CAM software.

7. The glass film photolithography process according to claim 5, characterized in that, In step S6, the lithography machine uses a near-ultraviolet laser source with a laser wavelength range of 380nm-420nm.

8. The glass film photolithography process according to claim 2, characterized in that, In step S7, the developing process converts the latent image of the photosensitive layer (104) into a visible image, the fixing process fixes the visible image, and the washing process removes residual chemical agents from the surface of the composite substrate.

9. The glass film photolithography process according to claim 5, characterized in that, In step S8, the drying process adopts hot air drying, the drying temperature is controlled at 40℃-60℃, and the drying time is 5min-15min.

10. The glass film photolithography process according to claim 5, characterized in that, In step S1, the cutting size of the semi-finished film can be adjusted arbitrarily according to the size of the target graphic, without being limited by the fixed size of the photoplotter.

Images