Photomask and exposure equipment
By introducing dynamic control of the liquid crystal layer and electrode layer into the photomask, the flexibility and cost-effectiveness of the photomask are improved, solving the problems of poor flexibility and high cost of existing photomasks.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-28
- Publication Date
- 2026-03-06
AI Technical Summary
Existing photomasks are inflexible, costly, and unable to adapt to changes in product specifications.
Design a photomask comprising a transparent substrate, a liquid crystal layer, a polarizer, and an electrode layer. By dynamically changing the light transmittance of the liquid crystal layer through switching, the target pattern can be adjusted in real time, reducing the cost of photomask generation and management.
It improves the flexibility of photomasks, reduces the production and management costs of photomasks, and eliminates the need to remake photomasks when product design changes occur.
Smart Images
Figure CN223977494U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of exposure technology, and more specifically, to a photomask and an exposure device. Background Technology
[0002] Once a photomask (also known as a mask) is manufactured, its light-blocking and light-transmitting areas are fixed and can only be used for specific products to be exposed. When the product changes, a new photomask must be made. Therefore, existing photomasks are inflexible and costly. Utility Model Content
[0003] Therefore, it is necessary to provide a photomask and exposure equipment to solve the technical problems of poor flexibility and high cost of existing photomasks.
[0004] This application provides a photomask. The photomask includes a light-transmitting first substrate, a light-transmitting second substrate, a liquid crystal layer, a first polarizer, a second polarizer, a light-transmitting first electrode layer, a light-transmitting second electrode layer, and a switching layer. The second substrate is opposite to the first substrate. The liquid crystal layer is located between the first and second substrates. The first polarizer is located on the side of the first substrate facing away from the liquid crystal layer. The second polarizer is located on the side of the second substrate facing away from the liquid crystal layer. The first electrode layer is located between the first and second substrates and is spaced apart from the first electrode layer. The second electrode layer is located between the second substrate and the liquid crystal layer. The second electrode layer includes a plurality of second electrodes spaced apart. The switching layer includes a plurality of switches. Each switch is electrically connected to at least one second electrode and, when in an on state, applies a driving signal to the corresponding second electrode, thereby changing the light transmittance of the corresponding area in the liquid crystal layer, so that light passes through the photomask to form a target pattern.
[0005] The photomask of this embodiment can dynamically change the voltage of the second electrode by switching it on and off, thereby altering the light transmittance of the corresponding area of the liquid crystal layer and achieving real-time adjustment of the target pattern. Compared to traditional photomasks with fixed patterns, this photomask can be fixed on the exposure equipment. When product design changes, the target pattern can be freely switched and adjusted without remaking the photomask, thus improving the flexibility of the photomask and reducing its production cost. Furthermore, since the photomask can be fixed in the exposure equipment without constantly switching it, the management and replacement costs of the photomask are reduced.
[0006] In some embodiments, the switch includes a thin-film transistor.
[0007] In some embodiments, the photomask further includes a first alignment film and a second alignment film. The first alignment film is located between the liquid crystal layer and the first electrode layer. The second alignment film is located between the liquid crystal layer and the second electrode layer.
[0008] In some embodiments, the liquid crystal layer is a twisted nematic liquid crystal layer, and the first electrode layer is located between the first substrate and the liquid crystal layer.
[0009] In some embodiments, the liquid crystal layer is a planar liquid crystal layer, and the first electrode layer is located between the second substrate and the liquid crystal layer.
[0010] In some embodiments, the liquid crystal layer is a vertically aligned liquid crystal layer, and the first electrode layer is located between the second substrate and the liquid crystal layer.
[0011] In some embodiments, the polarization directions of the first polarizer and the second polarizer are perpendicular to each other.
[0012] In some embodiments, the first substrate is glass or plastic; the second substrate is glass or plastic.
[0013] A second aspect of this application provides an exposure apparatus. The exposure apparatus includes a light source, a photomask as provided in the first aspect of this application, and a graphic data processor. The photomask is located in the light-emitting path of the light source. The graphic data processor is electrically connected to the photomask and is used to provide graphic data to the photomask in real time, so that the light from the light source, after passing through the photomask, forms a preset target pattern.
[0014] The exposure device of the second aspect of this application has at least the same advantages as the photomask of the first aspect of this application, which will not be repeated here.
[0015] In some embodiments, the exposure apparatus further includes an optical module spaced apart from the photomask and used to receive and adjust the light transmitted through the photomask. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the structure of a photomask according to an embodiment of this application.
[0017] Figure 2 for Figure 1 A schematic diagram of the photomask in use.
[0018] Figure 3 This is a schematic diagram of the structure of an exposure device according to an embodiment of this application.
[0019] Explanation of key component symbols:
[0020] Photomask 10
[0021] First substrate 11
[0022] Second substrate 12
[0023] Liquid crystal layer 13
[0024] First polarizer 14a
[0025] Second polarizer 14b
[0026] First electrode layer 15a
[0027] Second electrode layer 15b
[0028] Second electrode 151
[0029] first alignment film 16a
[0030] Second alignment film 16b
[0031] Light L
[0032] Translucent area TA
[0033] Shading area SA
[0034] Substrate 210
[0035] Photosensitive dry film 220
[0036] Light source 20
[0037] Graphics Data Processor 30
[0038] Optical module 40
[0039] Exposure equipment 100
[0040] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation
[0041] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of this application, and should not be construed as limiting this application.
[0042] In the description of the embodiments of this application, the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the implementation of this application 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 application.
[0043] In the description of the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features.
[0044] In the description of the embodiments of this application, unless otherwise stated, "a plurality of" means two or more.
[0045] In the description of the embodiments of this application, unless otherwise stated, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components.
[0046] Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0047] Currently, exposure equipment can be broadly categorized into three types: contact exposure equipment, projection exposure equipment, and direct imaging exposure equipment.
[0048] Contact exposure equipment requires the use of a photomask during the exposure process, and the entire photomask is exposed at once, resulting in high production speed. However, the use of a photomask reduces flexibility (a new photomask must be fabricated when changing it, which is time-consuming and costly). Furthermore, because the photomask is in contact with the substrate, it is prone to wear and tear, substrate wear, and pressure marks, leading to poor exposure quality. In addition, managing the photomask is also a cost in contact exposure equipment.
[0049] The main advantage of projection exposure equipment over contact exposure equipment is that the photomask in projection exposure equipment does not contact the plate surface, resulting in better exposure quality. However, since projection exposure equipment also requires the use of a photomask during the exposure process, it also suffers from problems such as poor photomask flexibility, and inefficient photomask management and production costs.
[0050] Direct imaging exposure equipment does not require a photomask. The industry primarily uses lasers to directly image the substrate, a technique commonly known as laser direct imaging (LDI). The biggest advantage of LDI is that it eliminates the need for a photomask, resulting in better flexibility, production management, and lower costs. However, due to the focused and limited range of the laser, many lenses need to work simultaneously (similar to scanning), preventing the single-pass exposure required by photomask-based equipment, thus leading to lower production speeds. Furthermore, stitching issues frequently occur between laser heads, also affecting exposure quality.
[0051] Figure 1 This is a schematic diagram of the structure of a photomask 10 according to an embodiment of this application. Figure 1 As shown, the photomask 10 includes a first substrate 11, a second substrate 12, a liquid crystal layer 13, a first polarizer 14a, a second polarizer 14b, a first electrode layer 15a, a second electrode layer 15b, and a switching layer (not shown).
[0052] The first substrate 11, the second substrate 12, the first electrode layer 15a, and the second electrode layer 15b are all light-transmitting.
[0053] The second substrate 12 is opposite to the first substrate 11. The liquid crystal layer 13 is located between the first substrate 11 and the second substrate 12.
[0054] The first polarizer 14a is located on the side of the first substrate 11 opposite to the liquid crystal layer 13. The second polarizer 14b is located on the side of the second substrate 12 opposite to the liquid crystal layer 13.
[0055] The first electrode layer 15a is located between the first substrate 11 and the liquid crystal layer 13. The second electrode layer 15b is located between the second substrate 12 and the liquid crystal layer 13, and is spaced apart from the first electrode layer 15a.
[0056] The second electrode layer 15b includes a plurality of second electrodes 151 spaced apart. The switch layer includes a plurality of switches, each switch being electrically connected to at least one second electrode 151, for applying a driving signal to the corresponding second electrode 151 in the on state, thereby changing the light transmittance of the corresponding area in the liquid crystal layer 13, so that light passes through the photomask 10 to form a target pattern.
[0057] The photomask 10 in this embodiment can dynamically change the voltage of the second electrode 151 by switching it on and off, thereby changing whether the corresponding area of the liquid crystal layer 13 is transparent or not, that is, it can be adjusted in real time according to the target pattern.
[0058] Compared to traditional fixed-pattern photomasks, this photomask 10 can be fixed on the exposure equipment. When the product design changes, the target pattern can be switched and adjusted at will without having to remake the photomask 10, thereby improving the flexibility of the photomask 10 and reducing the production cost of the photomask 10.
[0059] Furthermore, since the photomask 10 can be fixed in the exposure equipment, it is not necessary to constantly switch the photomask 10, thus reducing the management and replacement costs of the photomask 10.
[0060] When the photomask 10 of this application embodiment is used in a projection exposure device, it is beneficial to achieve the goals of high production speed, good flexibility, good management, and reduced additional costs of the photomask 10.
[0061] In some embodiments, the first substrate 11 is transparent glass or transparent plastic. For example, the first substrate 11 can be glass, which results in a smaller coefficient of thermal expansion of the photomask 10, thus helping to ensure the dimensional stability of the photomask 10. Alternatively, the first substrate 11 can be plastic, which helps to reduce the cost of the photomask 10.
[0062] In some embodiments, the second substrate 12 is transparent glass or transparent plastic. For example, the second substrate 12 can be glass, which results in a smaller coefficient of thermal expansion of the photomask 10, thus helping to ensure the dimensional stability of the photomask 10. Alternatively, the second substrate 12 can be plastic, which helps to reduce the cost of the photomask 10.
[0063] In some embodiments, the switch includes a thin-film transistor (TFT). Thus, the TFT enables independent control of each second electrode 151, thereby controlling the rotation angle of the liquid crystal, controlling which areas of the photomask 10 need to be transparent and which areas need to be opaque, and thus adjusting the pattern formed after light passes through the photomask 10 in real time.
[0064] In some embodiments, the switch can be a TFT of one of the following types: amorphous silicon TFT, polycrystalline silicon TFT, oxide TFT, etc., to meet different performance requirements.
[0065] In some embodiments, the second substrate 12, the switching layer, the second electrode layer 15b, etc. constitute a TFT array substrate, which drives the photomask 10 in an active matrix addressing manner to optimize control accuracy and response speed.
[0066] In some embodiments, the materials of the first electrode layer 15a and / or the second electrode layer 15b are, for example, transparent conductive materials such as indium tin oxide, but are not limited thereto. For example, the materials of the first electrode layer 15a and / or the second electrode layer 15b can also be transparent conductive materials such as graphene or metal mesh.
[0067] In some embodiments, the polarization directions of the first polarizer 14a and the second polarizer 14b are perpendicular to each other. Specifically, the first polarizer 14a converts incident light into polarized light in a specific direction, thereby controlling the polarization direction of the light entering the liquid crystal layer 13. The second polarizer 14b, in conjunction with the liquid crystal layer 13, controls the polarization direction of the light emitted from the liquid crystal layer 13.
[0068] In some embodiments, the photomask 10 further includes a first alignment film 16a and a second alignment film 16b. The first alignment film 16a is located between the liquid crystal layer 13 and the first electrode layer 15a. The second alignment film 16b is located between the liquid crystal layer 13 and the second electrode layer 15b. Thus, the first alignment film 16a and the second alignment film 16b are used to guide the initial alignment direction of the liquid crystal molecules, ensuring that the liquid crystal molecules can align in a predetermined direction when no voltage is applied, thereby achieving effective control of light.
[0069] In some embodiments, better alignment results can be obtained by using different alignment materials and alignment methods, such as friction alignment, photoalignment, etc.
[0070] In some embodiments, the liquid crystal layer 13 is a twisted nematic (TN) type liquid crystal layer 13. The first alignment film 16a and the second alignment film 16b have mutually perpendicular friction directions (or alignment directions). This causes the liquid crystal molecules in the liquid crystal layer 13 to form a twisted structure between the first substrate 11 and the second substrate 12, typically twisted at 90 degrees.
[0071] Specifically, the alignment direction of the first alignment film 16a is the same as the polarization direction of the first polarizer 14a, and the alignment direction of the second alignment film 16b is the same as the polarization direction of the second polarizer 14b. This ensures that the incident light, after passing through the first polarizer 14a, can propagate along the initial alignment direction of the liquid crystal molecules, thereby achieving effective light control.
[0072] In other embodiments, the relative orientations of the first alignment film 16a, the second alignment film 16b, the first polarizer 14a, and the second polarizer 14b can be adjusted to optimize light transmittance and contrast.
[0073] The following example illustrates the situation: "The first polarizer 14a can pass 0-degree linearly polarized light, the second polarizer 14b can pass 90-degree linearly polarized light, the alignment direction of the first alignment film 16a is the same as the polarization direction of the first polarizer 14a, and the alignment direction of the second alignment film 16b is the same as the polarization direction of the second polarizer."
[0074] like Figure 1 As shown, when no electric field is formed between the first electrode layer 15a and the second electrode layer 15b, light passing through the first polarizer 14a is filtered into 0-degree linearly polarized light. Due to the arrangement of the first alignment film 16a and the second alignment film 16b, the liquid crystal layer 13 naturally changes its orientation from 0 degrees to 90 degrees. The light passing through the first polarizer 14a is also converted into 90-degree linearly polarized light by the liquid crystal layer 13 and exits through the second polarizer 14b.
[0075] Figure 2 for Figure 1 A schematic diagram of the photomask 10 in its operational state. (See attached diagram.) Figure 2 As shown, a voltage is applied to a portion of the second electrode 151 in the second electrode layer 15b (in Figure 2 The second electrode 151 in the second electrode layer 15b, to which a voltage is applied, is shown in the image with a slash " / ". This causes a change in the orientation of the liquid crystal molecules in the corresponding region of the liquid crystal layer 13, preventing light from passing through the second polarizer 14b. As a result, the photomask 10 forms a predetermined light-transmitting region TA and a light-blocking region SA, enabling light L to form the target pattern after passing through the photomask 10.
[0076] In some embodiments, the photomask 10 requires an external graphics data processor 30 (shown in...). Figure 3In the middle, the graphics data processor 30 transmits the image file to the photomask 10 to control the corresponding switch to turn on and off, applies voltage to the corresponding second electrode 151, thereby changing the direction of the liquid crystal in the corresponding area of the liquid crystal layer 13, and adjusting the position of the light-transmitting area TA and the light-blocking area SA in the photomask 10, so that the light L forms a specific pattern after passing through the photomask 10 without having to remake the photomask 10.
[0077] In other embodiments, the liquid crystal layer 13 may be an in-plane switching (IPS) type liquid crystal layer. That is, the first alignment film 16a and the second alignment film 16b have the same or substantially the same friction direction (or alignment direction) and are parallel to the electric field direction. The liquid crystal molecules in the liquid crystal layer 13 are aligned parallel to the first substrate 11 or the second substrate 12 when there is no electric field. In this case, the first electrode layer 15a is located between the second substrate 12 and the liquid crystal layer 13. That is, both the first electrode layer 15a and the second electrode layer 15b are located on the second substrate 12.
[0078] In other embodiments, the liquid crystal layer 13 may be a vertically aligned (VA) type liquid crystal layer. That is, the first alignment film 16a and the second alignment film 16b have the same or substantially the same friction direction (or alignment direction) and are perpendicular to the electric field direction. The liquid crystal molecules in the liquid crystal layer 13 are aligned perpendicular to the first substrate 11 or the second substrate 12 when there is no electric field. In this case, the first electrode layer 15a is located between the second substrate 12 and the liquid crystal layer 13. That is, both the first electrode layer 15a and the second electrode layer 15b are located on the second substrate 12.
[0079] Figure 3 This is a schematic diagram of the structure of an exposure apparatus 100 according to an embodiment of this application. Figure 3 As shown, the exposure device 100 includes a photomask 10, a light source 20, and a graphics data processor 30, as described in any of the above embodiments of this application.
[0080] The photomask 10 is located on the light emission path of the light source 20. The graphics data processor 30 is electrically connected to the photomask 10 and is used to provide graphics data to the photomask 10 in real time, so that the light from the light source 20 forms a preset target pattern after passing through the photomask 10.
[0081] Therefore, the target pattern of the photomask 10 can be dynamically adjusted according to the output of the graphics data processor 30, thereby improving the flexibility of the photomask 10 and reducing the management and production costs of the photomask 10.
[0082] In some embodiments, different light sources 20 can be used, such as ultraviolet light sources, deep ultraviolet light sources, etc., to adapt to different exposure requirements.
[0083] In some embodiments, the exposure apparatus 100 further includes an optical module 40. The optical module 40 is spaced apart from the photomask 10 and is used to receive and adjust the light transmitted through the photomask 10 to guide the light after passing through the photomask 10 onto the workpiece to be exposed. The workpiece to be exposed includes, for example, a substrate 210 and a photosensitive dry film 220 located on the substrate 210.
[0084] In some embodiments, the optical module 40 includes optical elements such as focusing lenses, mirrors, and apertures to achieve different beam shaping and adjustment functions.
[0085] In some embodiments, the exposure device 100 can be used for, but is not limited to, the fabrication of circuit boards, the fabrication of solar cells, and the fabrication of display panels.
[0086] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.
Claims
1. A reticle, characterized by, The photomask comprises: a first substrate which is transparent; a second substrate which is transparent and opposite to the first substrate; a liquid crystal layer between the first substrate and the second substrate; a first polarizer on the side of the first substrate away from the liquid crystal layer; a second polarizer on the side of the second substrate away from the liquid crystal layer; a first electrode layer which is transparent and between the first substrate and the second substrate; a second electrode layer which is transparent and between the second substrate and the liquid crystal layer and spaced apart from the first electrode layer, the second electrode layer comprising a plurality of second electrodes which are spaced apart; and a switch layer comprising a plurality of switches, each of the switches being electrically connected to at least one of the second electrodes, for applying a driving signal to the corresponding second electrode in an on state, thereby changing the light transmittance of the corresponding area in the liquid crystal layer and forming a target pattern after the light passing through the photomask. The switch comprises a thin film transistor.
2. The photomask of claim 1, wherein, The photomask further comprises:
3. The photomask of claim 1, wherein, a first alignment film between the liquid crystal layer and the first electrode layer; and a second alignment film between the liquid crystal layer and the second electrode layer. The liquid crystal layer is a twisted nematic liquid crystal layer, and the first electrode layer is between the first substrate and the liquid crystal layer.
4. The photomask of claim 3, wherein, The liquid crystal layer is a planar alignment liquid crystal layer, and the first electrode layer is between the second substrate and the liquid crystal layer.
5. The reticle of claim 3, wherein, The liquid crystal layer is a vertical alignment liquid crystal layer, and the first electrode layer is between the second substrate and the liquid crystal layer.
6. The reticle of claim 3, wherein, The polarization directions of the first polarizer and the second polarizer are perpendicular to each other.
7. The photomask of any of claims 1 to 6, wherein, The first substrate is glass or plastic, and the second substrate is glass or plastic.
8. The photomask of any of claims 1 to 6, wherein, The photomask comprises:
9. An exposure apparatus characterized by comprising: a light source; the photomask according to any one of claims 1 to 8, located on the light path of the light source; and a graphic data processor electrically connected to the photomask, for providing graphic data to the photomask in real time, so that the light of the light source forms a preset target pattern after passing through the photomask. The exposure device further comprises an optical module which is spaced apart from the photomask and is used for receiving and adjusting the light passing through the photomask. 10. The exposure apparatus according to one of claims 9, wherein