A dual-station exposure machine and working method

Abstract

This invention provides a dual-station exposure machine and its operating method, including a base, a multi-axis motion platform and a gantry mounted on the base. A substrate platform is mounted on the multi-axis motion platform, and a substrate is placed on the substrate platform. The multi-axis motion platform can drive the substrate to move in three-dimensional space. The multi-axis motion platform includes a Y-axis motion component, which is mounted on the base and passes through the gantry. A first worktable and a second worktable are mounted on the Y-axis motion component. The first and second worktables move along the Y-axis motion component. An exposure system is mounted on the gantry. A first alignment system and a second alignment system, corresponding to the first and second worktables, are respectively mounted on the front and rear sides of the exposure system. The structure is simple and reliable, forming an alternating exposure operation, greatly improving production efficiency, reducing manufacturing and usage costs, and significantly improving product cost-effectiveness.

Description

Technical Field

[0001] The present invention belongs to the technical field of light source direct projection exposure machines, and in particular relates to a double-station exposure machine and a working method. Background Art

[0002] Direct light exposure equipment is also called direct image projection equipment, which can be used in the research and development and production of semiconductors, PCBs and flat imaging. Direct projection uses a pattern generator to replace traditional mask technology, directly exposing computer graphic data to the product, saving costs and improving efficiency. The CCD alignment and exposure of traditional exposure machines are at the same station, with alignment first and exposure later.

[0003] The single-table mode production speed of traditional exposure machines has reached its limit, and a double-table design is needed to increase the production speed. The optical engine is expensive, and the double-table design can improve the utilization rate of the optical part, save costs, and improve the cost performance of the equipment. There are currently two types of double-table exposure machines on the market, both of which have unsatisfactory features. One is the upper and lower interactive double-table mode. In this mode, the guide rail is unevenly stressed on one side, and long-term use will lead to a decrease in accuracy. The other is a left and right double-table structure, with the two tables installed on the left and right. The optical system needs to move left and right. Because the optics are very sensitive, the movable optical system reduces the exposure accuracy. In addition, the above two modes both have two sets of Y-guide rail structures, and the installation requirements are very high. Summary of the invention

[0004] In response to the above problems, the present invention provides a dual-station exposure machine and a working method, which have a simple and reliable structure and form an alternating exposure operation, thereby greatly improving production efficiency, reducing manufacturing and use costs, and greatly improving product cost performance.

[0005] The technical solution is as follows:

[0006] A double-station exposure machine includes a base and a multi-axis motion platform and a gantry arranged on the base, wherein a substrate table is installed on the multi-axis motion platform, and a substrate is placed on the substrate table. The multi-axis motion platform can drive the substrate to move in three-dimensional space, and the multi-axis motion platform includes a y-axis motion component, and the y-axis motion component is arranged on the base and passes through the gantry. A first workbench and a second workbench are arranged on the y-axis motion component, and the first workbench and the second workbench move along the y-axis motion component. The gantry is installed with an exposure system, and a first alignment system and a second alignment system corresponding to the first workbench and the second workbench are respectively installed on the front and rear sides of the exposure system.

[0007] Furthermore, the trajectories of the first workbench and the second workbench moving along the y-axis motion component partially overlap.

[0008] Furthermore, there is at least a distance between the scanning center of the exposure system and the alignment center A of the first alignment system to accommodate a substrate table; there is at least a distance between the scanning center of the exposure system and the alignment center B of the second alignment system to accommodate a substrate table.

[0009] Furthermore, at least one substrate can be arranged on the substrate table along the x-axis, and the first alignment system and the second alignment system align the at least one substrate, and the first alignment system and the second alignment system include two movable alignment cameras located at both ends.

[0010] Furthermore, when more than two substrates are placed in the x-axis direction, it also includes at least one mobile alignment camera located in the middle of the mobile alignment cameras at both ends, and the mobile alignment camera located in the middle simultaneously aligns the alignment points on adjacent sides of adjacent substrates.

[0011] Furthermore, two substrates can be arranged side by side along the x-axis on the substrate table, and the first alignment system and the second alignment system align the two substrates simultaneously.

[0012] Furthermore, the first alignment system and the second alignment system include two mobile alignment cameras located at both ends and a mobile alignment camera located in the middle of the mobile alignment cameras at both ends, and the mobile alignment camera located in the middle simultaneously aligns alignment points on adjacent edges of two substrates.

[0013] Furthermore, the mobile alignment camera located in the middle can be moved along the x-axis direction, or fixed at a fixed position.

[0014] Furthermore, the first alignment system and the second alignment system are arranged in independent gantry mechanisms.

[0015] A working method of a dual-station exposure machine, characterized in that:

[0016] The following steps are involved:

[0017] Step 1: Load the first substrate and place it on the first substrate table;

[0018] Step 2: The first substrate is moved along the y-axis to the position of the first alignment system for alignment;

[0019] Step 3: The first substrate is moved along the y-axis to the exposure system position for exposure scanning, and at the same time, the second substrate is loaded and placed on the second substrate table;

[0020] Step 4: After the first substrate completes scanning exposure, it returns along the y-axis to the loading position of the first substrate for unloading, and at the same time, the second substrate moves along the y-axis to the position of the second alignment system for alignment;

[0021] Step 5: The second substrate is moved along the y-axis to the exposure system position for exposure scanning, and at the same time, the first substrate is reloaded and placed on the empty substrate table;

[0022] Step 6: After the second substrate completes scanning exposure, it retreats along the y-axis to the loading position of the second substrate for unloading. At the same time, the first substrate moves along the y-axis to the position of the first alignment system for alignment;

[0023] Step 7: Repeat steps 3 to 6.

[0024] The double-station exposure machine and working method of the present invention have a simple and reliable structure. The double-station separates the alignment system and the exposure system, and sets two sets of tables symmetrically in the front and back to form an alternating exposure operation, which greatly improves the production efficiency. The double-station exposure has a simple and reliable structure, which ensures durable and stable quality. The configuration of a single machine can provide performance close to that of two single-station machines, reduces manufacturing and use costs, and greatly improves the product cost performance. At the same time, there will be no problem that the long-term use of the two existing double-table exposure machines with upper and lower interactive double tables and left and right double tables will lead to a decrease in exposure accuracy. The installation requirements are also lower than the above two double-table exposure machines. In addition, an extra-large table can be set to place a larger area of ​​substrates or multiple substrates at the same time, further improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of a double-station exposure machine in Example 1;

[0026] Figure 2 It is a schematic diagram of a double-station exposure machine in Example 2;

[0027] Figure 3 It is a schematic diagram of a double-station exposure machine in Example 3;

[0028] Figure 4 A schematic diagram of the mobile alignment camera located in the middle;

[0029] Figure 5 Schematic diagram of the working of the alignment system;

[0030] Figure 6 A schematic diagram of exposure of an exposure system of a double-station exposure machine;

[0031] Figure 7 It is a schematic diagram of the exposure operation of a double-station exposure machine;

[0032] Figure 8 It is a schematic diagram of the exposure operation of a double-station exposure machine;

[0033] Fig. 9 This is a schematic diagram of a dual-station exposure machine.

[0034] Fig.10 This is a schematic diagram of the working position of a double-station exposure machine. DETAILED DESCRIPTION

[0035] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner, and the figures only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout type may also be more complicated.

[0036] Define the coordinate system: the x-axis in the embodiment of the present invention is set along the width direction of the device, the y-axis is set along the length direction of the device, which is also the product scanning exposure direction, and the z-axis is set along the height direction of the device.

[0037] Example 1: See Figure 1 A double-station exposure machine of this embodiment includes a base 1 and a multi-axis motion platform arranged on the base 1. The base 1 is a marble base. A substrate table 2 is installed on the multi-axis motion platform. A suction cup is installed on the substrate table 2. A substrate 4 is placed on the substrate table 2. The multi-axis motion platform can drive the substrate 4 to move in a three-dimensional space. The multi-axis motion platform includes a y-axis motion component 5. The y-axis motion component 5 is arranged on the base 1. Two workbenches are arranged on the y-axis motion component, namely a first workbench and a second workbench. The first workbench and the second workbench share the y-axis motion component 5 and can move in the y-axis direction along the y-axis motion component 5. The trajectory of movement along the y-axis motion component partially overlaps. The first workbench and the second workbench both include an x-axis motion component 6 and a z-axis motion component 7, the z-axis motion component 7 is arranged on the x-axis motion component 6, and the z-axis motion component 7 is respectively provided with a substrate table 2, an exposure system 9 is installed on the base 1 through a gantry 8, and a first alignment system 101 and a second alignment system 102 are respectively installed on the front and rear sides of the exposure system 9 corresponding to the first workbench and the second workbench, the x-axis motion component 6 and the y-axis motion component 5 cooperate to enable the substrate table 2 to move in a plane parallel to the base 1, and the z-axis motion component 7 can move the substrate 4 on the substrate table 2 to the focal plane of exposure and alignment.

[0038] In this embodiment, the first alignment system 101 and the second alignment system 102 respectively include a slide rail 104 installed on the gantry 8 and arranged along the gantry 8, and a mobile alignment camera 105 that can move along the slide rail 104 is arranged on the slide rail 104. There are two mobile alignment cameras 105, and the lenses of the mobile alignment cameras 105 are set toward the substrate table 2. The two mobile alignment cameras cooperate to grasp the alignment points on the substrate, and the mobile alignment camera also includes an illumination light source fixed on the gantry.

[0039] In this embodiment, the exposure system 9 includes a laser 91, an exposure lens 92 and a control board 93, and the exposure lenses are arranged side by side.

[0040] Example 2: See Figure 2 In the present embodiment, a double-station exposure machine comprises a base 1 and a multi-axis motion platform arranged on the base 1, the base 1 is a marble base, a substrate table 2 is installed on the multi-axis motion platform, a suction cup is installed on the substrate table 2, a substrate 4 is placed on the substrate table 2, the multi-axis motion platform can drive the substrate 4 to move in three-dimensional space, the multi-axis motion platform comprises a y-axis motion component 5, the y-axis motion component 5 is arranged on the base 1, two x-axis motion components 6 are arranged on the y-axis motion component, the x-axis motion components 6 are respectively provided with z-axis motion components 7, the z-axis motion components 7 are respectively provided with the substrate table 2, an exposure system 9 is installed on the base 1 through a gantry 8, a first alignment system 101 and a second alignment system 102 are respectively installed on the front and rear sides of the exposure system 9, the x-axis motion component 6 and the y-axis motion component 5 cooperate to enable the substrate table 2 to move in a plane parallel to the base 1, and the z-axis motion component 7 can enable the substrate 4 on the substrate table 2 to move to the focal plane of exposure and alignment.

[0041] In this embodiment, the substrate table 2 is an extra-large table, and two substrates 4 can be arranged side by side along the x-axis on the substrate table 2. The first alignment system 101 and the second alignment system 101 respectively include a slide rail 104 installed on the gantry 8 and arranged along the gantry 8. The slide rail 104 is provided with a mobile alignment camera 105 that can move along the slide rail 104. There are three mobile alignment cameras 105. The lens of the mobile alignment camera 105 is set toward the substrate table 2. The two mobile alignment cameras cooperate to grab the alignment points on the substrate.

[0042] In this embodiment, the exposure system 9 includes a laser 91, an exposure lens 92 and a control board 93. The exposure lenses are arranged side by side, and the exposure system can expose two substrates at the same time.

[0043] Example 3: See Figure 3In this embodiment, a double-station exposure machine includes a base 1 and a multi-axis motion platform arranged on the base 1. The base 1 is a marble base. A substrate table 2 is installed on the multi-axis motion platform. A suction cup is installed on the substrate table 2. A substrate 4 is placed on the substrate table 2. The multi-axis motion platform can drive the substrate 4 to move in a three-dimensional space. The multi-axis motion platform includes a y-axis motion component 5. The y-axis motion component 5 is arranged on the base 1. Two workbenches are arranged on the y-axis motion component, namely a first workbench and a second workbench. The first workbench and the second workbench can move in the y-axis direction along the y-axis motion component 5. The first Both the workbench and the second workbench include an x-axis motion component 6 and a z-axis motion component 7. The z-axis motion component 7 is arranged on the x-axis motion component 6. The z-axis motion component 7 is respectively provided with a substrate table 2. An exposure system 9 is installed on the base 1 through a gantry 8. A first alignment system 101 and a second alignment system 102 are respectively installed on the front and rear sides of the exposure system 9 corresponding to the first workbench and the second workbench. The x-axis motion component 6 and the y-axis motion component 5 cooperate to enable the substrate table 2 to move in a plane parallel to the base 1. The z-axis motion component 7 can move the substrate 4 on the substrate table 2 to the focal plane of exposure and alignment.

[0044] In this embodiment, the substrate table 2 is an extra-large table, and two substrates 4 can be arranged side by side along the x-axis on the substrate table 2. The first alignment system 101 and the second alignment system 101 respectively include a fixed alignment component and a mobile alignment component installed on the gantry, the fixed alignment component is located between the two mobile alignment components, the fixed alignment component 103 includes a fixed alignment camera 103 fixed on the gantry 8, the lens of the fixed alignment camera 103 is set toward the substrate table 2, the mobile alignment component includes a slide rail 104 set along the gantry 8, and a mobile alignment camera 105 that can move along the slide rail 104 is set on the slide rail 104, and the lens of the mobile alignment camera 105 is set toward the substrate table 2, the fixed alignment camera 103 cooperates with the mobile alignment camera 105 to grab the alignment point on the substrate, and the fixed alignment component and the mobile alignment component also include an illumination light source.

[0045] In this embodiment, the exposure system 9 includes a laser, an exposure lens and a control panel, and the exposure lenses are arranged side by side.

[0046] The specific alignment methods of the first alignment system 101 and the second alignment system 102 in Example 2 and Example 3 are shown in Figure 5, the camera of the alignment system automatically adjusts the focal length up and down, scans four points P01, P02, P03, and P04 on the product in the x-axis and y-axis directions, and then scans the size values ​​of L1, L2, L3, L4, W1, and W2 of the product as a whole, and calculates the layout of the entire product and the positional relationship relative to the four points. Among them, the fixed alignment component 103 in Example 3 and the mobile alignment camera located in the middle position in Example 2 scan the P04 and P03 alignment points of the left substrate 4 and the P01 and P02 alignment points of the right substrate, the alignment component located on the left side of the fixed rotation component 103 scans the P01 and P02 alignment points of the left substrate, and the alignment component located on the right side of the fixed rotation component 103 scans the P03 and P04 alignment points of the right substrate. The alignment system completes the alignment of two substrates through three cameras. The number of scanning points depends on the product structure and is not limited to four points. The exposure lens quickly adjusts the distances in the three directions of the x-axis, y-axis, and z-axis according to the pre-alignment data, and then the substrate table moves along the Y direction to perform imaging scanning and exposure of the product. The number of substrates in the x-axis direction in the substrate table can also be more than two. When the number of substrates is more than two, the first alignment system and the second alignment system include two mobile alignment cameras located at both ends and at least two mobile alignment cameras located in the middle of the mobile alignment cameras at both ends. The mobile alignment cameras located in the middle simultaneously align the alignment points on adjacent sides of adjacent substrates. When more than n substrates are placed along the x-axis on the substrate table, n is a natural number greater than or equal to 2. The first alignment system and the second alignment system also include n-1 alignment cameras located in the middle of the two mobile alignment cameras. The alignment cameras can simultaneously align the alignment points on adjacent sides of adjacent substrates. The mobile alignment camera in the middle can be used as follows. Figure 4The mechanism shown includes a first alignment member, a second alignment member and a light source. The first alignment member and the second alignment member include a camera 31 and a lens 32 connected to the camera 31. The first alignment member and the second alignment member are arranged side by side and are connected to each other or have a small gap. The light source 32 is adjacent to the lenses of the first alignment member and the second alignment member, covering the contour range of the lenses of the first alignment member and the second alignment member. The first alignment member and the second alignment member are fixed by a mounting member 34. The light source 33 is connected to the lens, which can be fixed to the lens or fixed to the mounting member 34 by a fixing member. The camera and the lens are fixed by the mounting member. Generally, the lateral width of the lens is greater than the lateral width of the camera. The lenses are arranged at the minimum interval, connected to each other or have a small gap between them. The light source 33 is arranged below the two lenses 32, covering the two lenses 32. The light source 33 is a U-shaped light source, and its outline is in the shape of an athletic track, with arcs at both ends and a straight line in the middle. It provides all-round lighting for the two groups of alignment cameras at the same time. The use of a U-shaped light source can achieve a shadow-free environment and improve the lighting effect.

[0047] In embodiments 1-3, the exposure system may adopt a single-row lens method or a double-row lens method. Figure 6 , the exposure lenses 92 are arranged in two rows, and the exposure lenses in different rows are staggered on the x-axis. When the exposure system adopts a single-row exposure lens, the strips to be scanned are different depending on the exposure lenses used. The scanning can be completed by a single strip or multiple strips. When the exposure system adopts a double-row lens method, single-strip scanning is mostly used. When scanning a single strip, the substrate table only needs to move in the y-axis direction without moving in the x-axis direction. The workbench can only be provided with a z-axis motion component without the need to provide an x-axis motion component. The z-axis motion components are respectively provided on the y-axis motion component, and the substrate platform 2 is provided on the z-axis motion component. Two substrates are arranged side by side on the x-axis, and the exposure lens can expose the two substrates at the same time. Figure 7 and Figure 8 The schematic diagrams are for single-strip scanning and double-strip scanning. In single-strip scanning, the area to be exposed is completed once with one strip. The blank area in the middle of the exposure area is a segmented area, which does not need to be exposed. Only one movement in the y-axis direction is required to complete the exposure scan. Similarly, in double-strip scanning, after completing one scan in the y-axis direction, the x-axis direction must be moved to the next scan strip area, and the exposure scan is completed by moving in the y-axis direction.

[0048] See Fig. 9A correction component may be provided on the substrate table 2, and the correction component includes a glass scale 11 and a screw motion module 12 arranged on one side of the substrate table parallel to the x-axis. A reverse camera 13 and an energy probe 3 are installed on the screw motion module 12. The lens of the reverse camera 13 is arranged upward, and the screw motion module 12 can drive the reverse camera 13 and the energy probe 3 to move to the lower end of each exposure lens.

[0049] The correction component is used to support the calibration and correction work, which is carried out independently on two substrate tables. The glass ruler 11 is fixedly installed at the rear end of the substrate table 2, and moves with the substrate table 2 to the bottom of the camera of the alignment system. The camera grabs the reference point array on the ruler and performs calculation and analysis to achieve the position accuracy correction of the camera of the alignment system; the screw motion module 12 with the reverse camera 13 and the energy probe 3 moves to each exposure lens, which can achieve the exposure position consistency and energy consistency measurement and correction of each exposure lens; the camera reads the fixed ruler position on the table, and can obtain the position relationship between the table and the camera. The lens is projected onto the reverse camera, and the position relationship between the lens and the table can be obtained, thereby obtaining the relative position relationship between the camera, the table and the lens, and reaching the conditions for consistent and coordinated work.

[0050] See Fig.10 , the exposure system 9 is located between the first alignment system 101 and the second alignment system 102. The exposure system 9, the first alignment system 101 and the second alignment system 102 are all independent workstations, which are respectively arranged in independent gantry mechanisms. The scanning center of the exposure system and the alignment center A of the first alignment system have a distance of at least one substrate table. Similarly, the scanning center of the exposure system and the alignment center B of the second alignment system have a distance of at least one substrate table. In this way, the substrate table located on the left side starts alignment at position A, starts exposure scanning at position B, and completes exposure scanning at position C. When the substrate on the left substrate table completes the exposure scanning, it will not collide with the right substrate table located at position D waiting for alignment. The alignment operations of the left substrate and the right substrate are relatively independent, and the exposure scanning operation areas overlap. There is no need to move back and forth multiple times along the Y-axis direction between the alignment and exposure scanning operations, thereby improving production efficiency.

[0051] In an embodiment of the present invention, a working method of a dual-station exposure machine is also provided, comprising the following steps:

[0052] Step 1: Load the first substrate and place it on the first substrate table;

[0053] Step 2: The first substrate is moved along the y-axis to the position of the first alignment system for alignment;

[0054] Step 3: The first substrate is moved along the y-axis to the exposure system position for exposure scanning, and at the same time, the second substrate is loaded and placed on the second substrate table;

[0055] Step 4: After the first substrate completes scanning exposure, it returns along the y-axis to the loading position of the first substrate for unloading, and at the same time, the second substrate moves along the y-axis to the position of the second alignment system for alignment;

[0056] Step 5: The second substrate is moved along the y-axis to the exposure system position for exposure scanning, and at the same time, the first substrate is reloaded and placed on the empty substrate table;

[0057] Step 6: After the second substrate completes scanning exposure, it retreats along the y-axis to the loading position of the second substrate for unloading. At the same time, the first substrate moves along the y-axis to the position of the first alignment system for alignment;

[0058] Step 7: Repeat steps 3 to 6.

[0059] The double-station exposure machine and working method of the present invention have a simple and reliable structure. The double-station separates the alignment system and the exposure system, and sets two sets of tables symmetrically in the front and back to form an alternating exposure operation, which greatly improves the production efficiency. The double-station exposure has a simple and reliable structure, which ensures durable and stable quality. The configuration of a single machine can provide performance close to that of two single-station machines, reduce manufacturing and use costs, and greatly improve the product cost performance. At the same time, there will be no problem that the exposure accuracy will decrease after long-term use in the two existing double-table exposure machines with upper and lower interactive double tables and left and right double tables. The installation requirements are also lower than the above two double-table exposure machines. In addition, an extra-large table can be set to place a larger area of ​​substrates or multiple substrates at the same time, further improving production efficiency.

[0060] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0061] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A dual-station exposure machine, comprising a base, a multi-axis motion platform and a gantry arranged on the base, a substrate table mounted on the multi-axis motion platform, a substrate placed on the substrate table, the multi-axis motion platform can drive the substrate to move in three-dimensional space, characterized in that: The multi-axis motion platform comprises a y-axis motion component, the y-axis motion component is arranged on the base and passes through the gantry, a first workbench and a second workbench are arranged on the y-axis motion component, the first workbench and the second workbench move along the y-axis motion component, an exposure system is installed on the gantry, and a first alignment system and a second alignment system corresponding to the first workbench and the second workbench are respectively installed on the front and rear sides of the exposure system; At least one substrate can be arranged along the x-axis on the substrate table, and the first alignment system and the second alignment system align the at least one substrate, and the first alignment system and the second alignment system include two mobile alignment cameras located at two ends and at least one mobile alignment camera located in the middle of the mobile alignment cameras at the two ends, and the middle mobile alignment camera simultaneously aligns the alignment points on adjacent sides of adjacent substrates; the middle mobile alignment camera includes a first alignment member, a second alignment member and a light source, the first alignment member and the second alignment member include a camera and a lens connected to the camera, the first alignment member and the second alignment member are arranged side by side and are connected to each other or have a small gap, the light source is adjacent to the lenses of the first alignment member and the second alignment member, and covers the contour range of the lenses of the first alignment member and the second alignment member, the first alignment member and the second alignment member are fixed by a mounting member, and the light source is a U-shaped light source, and its contour is in the shape of an athletic track, the two ends are arc-shaped, and the middle connecting part is a straight line connection, and provides all-round lighting for the two groups of alignment cameras at the same time.

2. A dual-station exposure machine according to claim 1, characterized in that: The trajectories of the first workbench and the second workbench moving along the y-axis motion component partially overlap.

3. A dual-station exposure machine according to claim 1, characterized in that: There is at least a distance between the scanning center of the exposure system and the alignment center A of the first alignment system to accommodate one substrate table; there is at least a distance between the scanning center of the exposure system and the alignment center B of the second alignment system to accommodate one substrate table.

4. A dual-station exposure machine according to claim 1, characterized in that: The moving aiming camera in the middle moves along the x-axis direction, or is fixed at a fixed position.

5. The double-station exposure machine according to claim 1, characterized in that: The first alignment system and the second alignment system are arranged in independent gantry mechanisms.

6. A working method for a dual-station exposure machine according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Load the first substrate and place it on the first substrate table; Step 2: The first substrate is moved along the y-axis to the position of the first alignment system for alignment; Step 3: The first substrate is moved along the y-axis to the exposure system position for exposure scanning, and at the same time, the second substrate is loaded and placed on the second substrate table; Step 4: After the first substrate completes scanning exposure, it returns along the y-axis to the loading position of the first substrate for unloading, and at the same time, the second substrate moves along the y-axis to the position of the second alignment system for alignment; Step 5: The second substrate is moved along the y-axis to the exposure system position for exposure scanning, and at the same time, the first substrate is reloaded and placed on the empty substrate table; Step 6: After the second substrate completes scanning exposure, it retreats along the y-axis to the loading position of the second substrate for unloading. At the same time, the first substrate moves along the y-axis to the position of the first alignment system for alignment; Step 7: Repeat steps 3 to 6.

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