Rotary table, printing machine and working method of printing machine

Abstract

The invention belongs to the technical field of screen printing equipment, and particularly relates to a rotary table, a printing machine and a working method thereof. The rotary table is applied to silk-screen printing of a whole square silicon wafer and comprises a rotary table body, and at least two sets of stations are arranged in the circumferential direction of the rotary table body. Each group of stations comprises a printing table top and a transition table top, the printing table top is a glass table top and is internally provided with a first air flow channel, and air channels of the first air flow channel are densely distributed and are used for adsorbing and fixing a whole square silicon wafer in the printing process; the transition table top is a plastic table top and is internally provided with second airflow channels, and the second airflow channels are uniformly and sparsely distributed and are used for limiting and fixing the whole square silicon wafer in the rotary transmission process of the silicon wafer; the airflow pressure of the first airflow channel is larger than that of the second airflow channel.

Description

Technical Field

[0001] This invention belongs to the technical field of screen printing equipment, and particularly relates to a turntable, a printing machine, and its working method. Background Technology

[0002] Screen printing is a key process in photovoltaic cell manufacturing, used to precisely print electrode grid lines on the surface of silicon wafers. To improve production efficiency, dual-station synchronous printing technology has emerged, which aims to print on two silicon wafers simultaneously on the same equipment.

[0003] Existing technologies, such as CN118700687A, disclose a synchronous and unidirectional dual-half-wafer precision screen printing machine. This equipment adopts a structure of a single machine integrating a dual-squeegee module, completing the printing of two rectangular half-wafer solar cells at different stations on the same turntable. Its feeding direction is adapted to the length direction of the rectangular silicon wafer, and after a 90-degree rotation, it achieves the printing requirement of the printing direction being perpendicular to the main grid. The above-mentioned existing technical solutions have the following drawbacks: First, the highly integrated dual-squeegee module makes the printing station structure complex and compact. When a single squeegee module needs maintenance, replacement, or cleaning, the operating space is narrow and extremely inconvenient, which may affect the stability of the other module, or even require the entire machine to be shut down, reducing the maintainability and availability of the equipment. Second, it is designed for rectangular half-wafer silicon wafers that require rotation and alignment. The rotation process may introduce alignment errors, and the process flow is designed for half-wafers and is not suitable for efficient printing scenarios of square whole silicon wafers that do not require rotation.

[0004] Furthermore, existing printing presses typically employ a uniform airflow adsorption design on the carrier table (turntable), providing the same adsorption force during both printing and non-printing stages. While this ensures silicon wafer stability, excessive adsorption force is unnecessary in the transitional non-printing stations, resulting in wasted compressed air and increased energy consumption.

[0005] Therefore, there is an urgent need for a dual-station screen printing solution that is designed for square silicon wafers, has a more reasonable structure, is easier to maintain and clean, and can reduce energy consumption.

[0006] It should be noted that the information disclosed in this background section is only for understanding the background technology of this application concept, and therefore, the above description is not considered to constitute information related to the technology. Summary of the Invention

[0007] This disclosure provides at least one rotary table, a printing press, and a method for operating the same.

[0008] In a first aspect, embodiments of this disclosure provide a turntable for screen printing on a square silicon wafer, comprising: The turntable body has at least two sets of workstations arranged circumferentially. Each workstation includes a printing table and a transition table. The printing table is a glass table and has a built-in first airflow channel. The channels of the first airflow channel are densely distributed and used to adsorb and fix the square silicon wafer during the printing process. The transition platform is a plastic platform and has a built-in second airflow channel. The airflow channels of the second airflow channel are sparsely distributed in a uniform manner and are used to limit and fix the square whole silicon wafer during the silicon wafer rotation and transfer process. The airflow pressure in the first airflow channel is greater than the airflow pressure in the second airflow channel.

[0009] In one optional embodiment, the glass material of the printing table is high borosilicate glass, and the first airflow duct includes a main air duct and several branch air ducts that are interconnected. The air outlets of the branch air ducts are evenly distributed on the bearing surface of the printing table, and the air outlets of the branch air ducts cover the entire bearing area of ​​the square silicon wafer.

[0010] In one optional embodiment, the plastic material of the transition platform is antistatic rigid plastic, and the second airflow channel includes several independent micro-channels. The air outlets of the micro-channels are distributed at the edge of the bearing surface of the transition platform, and are used to perform negative pressure adsorption on the edge of the square silicon wafer.

[0011] In one optional embodiment, a rotation drive assembly is provided in the middle of the turntable body to drive the turntable body to rotate around the central axis and realize the connection of circuits and air passages for each station.

[0012] Secondly, embodiments of this disclosure also provide a printing press, including two independent printing main units, a transport system, and a turntable. The two printing main units are arranged in sequence along the silicon wafer transport direction. The transport system includes a feeding module, a discharging module and a unloading module. The feeding module is used to synchronously transport two square whole silicon wafers to the station of the turntable. The discharge module is used to transfer the silicon wafers conveyed by the turntable to the subsequent printing host; The feeding module is used to simultaneously feed the square silicon wafers that have completed dual-wafer printing. Each of the aforementioned printing main units includes a printing module and an independent lifting drive mechanism. The lifting drive mechanism is connected to the printing module and is used to drive the printing module to lift and lower independently to adapt to the printing height of the square silicon wafer.

[0013] In one optional implementation, the printing modules of both printing hosts include a doctor blade and a back-ink blade, and the printing stations of the two printing hosts are independent of each other. Each printing host performs printing operations only on a single square silicon wafer, and the printing direction is perpendicular to the main gate direction of the square silicon wafer.

[0014] In one optional embodiment, the turntable body is provided with four sets of workstations around its circumference. The printing table and transition table of each set of workstations are integrated into one structure. The four sets of workstations are evenly distributed around the central axis of the turntable body, and the rotation angle of the turntable is adapted to the printing position of the two printing main machines.

[0015] In one optional embodiment, the printing host is provided with a vision alignment module, which includes an infeed camera and an outfeed camera. The infeed camera is used to capture and position the silicon wafer and transmit the data to the printing module. The outfeed camera is used to detect the printing quality of the silicon wafer.

[0016] In one optional implementation, both the feeding module and the discharging module are equipped with dual-wafer synchronous transfer tracks. The width of the transfer tracks is adapted to the size of a square silicon wafer, and the transfer tracks are equipped with a snap-fit ​​positioning component for centering the silicon wafer.

[0017] Thirdly, this disclosure also provides a method for operating a printing press, comprising the following steps: S1, Dual-wafer feeding: The feeding module synchronously transfers two square whole silicon wafers to the same set of workstations on the turntable. One silicon wafer is placed on the printing table and the other silicon wafer is placed on the transition table. The printing table and the transition table of the turntable fix the silicon wafers through the first airflow channel and the second airflow channel, respectively. S2, First wafer printing: The turntable rotates to the printing station of the first printing host. The lifting drive mechanism of the first printing host drives the printing module to descend to the preset height. The squeegee and ink return blade of the printing module work together to screen print the first square whole silicon wafer on the printing table. The second silicon wafer on the transition table is in standby mode and is not printed. S3, Dual Wafer Output: After the first silicon wafer is printed, the turntable rotates to the output module position. The output module synchronously transfers the two silicon wafers to the feeding end of the second printing host, and the positions of the two silicon wafers are swapped. The second silicon wafer on the original transition table is placed on the printing table of the corresponding turntable of the second printing host, and the first silicon wafer on the original printing table is placed on the transition table of the corresponding turntable. S4, Second wafer printing: The lifting drive mechanism of the second printing host drives the printing module to descend to the preset height. The squeegee and ink return blade of the printing module work together to screen print the second square whole silicon wafer on the printing table. The first silicon wafer on the transition table is in standby mode and is not printed. S5, Dual Wafer Cutting: After the second silicon wafer is printed, the turntable rotates to the cutting module position. The cutting module simultaneously cuts out the two square silicon wafers that have been printed, completing one dual wafer printing operation.

[0018] The beneficial effects of this invention are that it provides a turntable, a printing machine, and a method for operating the same. The turntable has a printing table and a transition table, employing a differentiated airflow channel design and adsorption pressure configuration. The printing table achieves firm adsorption of the entire silicon wafer area through a densely distributed first airflow channel, meeting the fixation requirements of the printing process. The transition table uses a sparsely distributed second airflow channel to limit adsorption only at the edges of the silicon wafer, and the airflow pressure in the first airflow channel is greater than that in the second airflow channel. This design abandons the uniform airflow adsorption method in existing technologies, significantly reducing compressed air waste and lowering the equipment's energy consumption while ensuring the stability of silicon wafer transport and fixation, aligning with the energy-saving and consumption-reducing development trend of the photovoltaic industry.

[0019] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 A perspective view of a turntable provided in an embodiment of this disclosure; Figure 2 An internal perspective view of the printing table provided in an embodiment of this disclosure; Figure 3 An internal perspective view of the transition platform provided in an embodiment of this disclosure; Figure 4 A top view of the silicon wafer placement turntable body provided in an embodiment of this disclosure; Figure 5 A top view of a printing press provided in an embodiment of this disclosure; Figure 6 A perspective view of a printing press provided in an embodiment of this disclosure.

[0023] In the picture: 1. Turntable body; 10. Rotation drive assembly; 2. Printing table surface; 3. Transition table surface; 4. Primary airway; 41. Main airway; 42. Branch airways; 5. Secondary airway; 50. Micro-airway; 6. Silicon wafers; 7. Printing main unit; 71. Printing module; 72. Lifting drive mechanism; 8. Transmission system; 81. Feeding module; 82. Discharging module; 83. Unloading module. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In this document, when it is mentioned that a first component is located on a second component, this can mean that the first component can be directly formed on the second component, or that a third component can be inserted between the first and second components. Furthermore, in the accompanying drawings, the thickness of the components may be exaggerated or reduced for the purpose of effectively describing the technical content.

[0026] In this document, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as “at least one of…” modify an entire column of elements when following a column of elements. For example, the expression “at least one of a, b, and c” should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0027] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise expressly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.

[0028] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0029] The defects in the above solutions and the reasons for their occurrence are the results of the inventors' practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed in this disclosure should be considered as the inventors' contributions to this disclosure.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0032] like Figures 1 to 4 As shown, at least one embodiment provides a turntable, including: a turntable body 1, which is a circular disc structure with at least two sets of workstations arranged around its circumference, preferably four sets of workstations; four sets are the industry-optimal number of workstations, which can realize continuous feeding, printing and unloading operations. Each set of workstations is integrally formed with a printing table 2 and a transition table 3. The printing table 2 and the transition table 3 have the same area and are both adapted to the size of the square whole silicon wafer 6 to ensure stable support of the silicon wafer.

[0033] like Figure 1 and Figure 2The printing table 2 is a glass tabletop made of high borosilicate glass. This material is characterized by high temperature resistance, high flatness, strong wear resistance, and good chemical stability. It can withstand repeated scraping by the squeegee during screen printing and will not react with the printing paste, ensuring the flatness of the printing surface and the printing quality of the silicon wafer. The printing table 2 has a built-in first airflow channel 4, which includes an interconnected main airflow channel 41 and several branch airflow channels 42. The main airflow channel 41 is set along the length of the printing table 2, and the branch airflow channels 42 extend radially and evenly from the main airflow channel 41. The air outlets of the branch airflow channels 42 are evenly distributed on the bearing surface of the printing table 2, and the air outlets of all branch airflow channels 42 completely cover the entire bearing area of ​​the square silicon wafer 6, achieving uniform adsorption of the silicon wafer over the entire area. The main airflow channel 41 is connected to an external negative pressure fan to provide a firm adsorption and fixing force for the silicon wafer during the printing process, preventing the silicon wafer from shifting during the squeegee scraping and ensuring printing accuracy.

[0034] like Figure 3 The transition platform is a plastic step, made of anti-static rigid plastic, preferably modified polytetrafluoroethylene (PTFE) anti-static material. Its low surface resistivity effectively prevents static electricity from being generated during the rotation and transport of the silicon wafer 6, thus preventing electrostatic breakdown of the PN junction and damage to the wafer. This material also has good self-lubricating properties, reducing frictional wear between the wafer and the platform. The transition platform 3 has a built-in second airflow channel 5, which includes several independent micro-air channels 50. Their outlets are evenly distributed at the edge of the bearing surface of the transition platform 3, 2-3 mm from the edge of the platform. This provides negative pressure adsorption only on the edge of the square silicon wafer 6, achieving wafer positioning and preventing slippage or displacement during transport. The airflow pressure of the first airflow channel 4 is greater than that of the second airflow channel 5. While ensuring wafer positioning and fixation, this minimizes the energy consumption of the negative pressure fan. The micro-air channels 50 are independently connected to the external negative pressure fan, allowing for individual adjustment of the adsorption pressure.

[0035] like Figure 6 A rotary drive assembly 10 is coaxially fixed in the middle of the turntable body 1. This assembly includes a servo motor, a reducer, a rotary bearing, and a pneumatic slip ring. The servo motor is connected to the turntable body 1 through the reducer, driving the turntable body 1 to rotate intermittently around the central axis. The rotation angle is precisely controlled to rotate 90° each time, which is compatible with the distribution of the four workstations. The pneumatic slip ring is integrated inside the rotary drive assembly 10. One end is connected to the first airflow channel 4, the second airflow channel 5, and the circuit inside the turntable body 1, and the other end is connected to the external negative pressure fan and control system, so as to realize the continuous connection of the circuit and air path during the rotation of the turntable body 1, and ensure the adsorption function and signal transmission stability of each workstation.

[0036] At least one embodiment provides a printing machine, including the aforementioned turntable, two independent printing main units 7 and a transmission system 8. The overall layout is adapted to the process flow of a photovoltaic screen printing production line. The machine frame is made of square steel welded together and the surface is powder coated, which has good structural stability and corrosion resistance.

[0037] like Figure 5 The printing host 7 is arranged as follows: two printing hosts 7 are arranged sequentially on the same side of the two turntable bodies along the transmission direction of the silicon wafer 6, and are precisely adapted to the four work positions of the turntable. After the turntable rotates to a specified angle, one of the work positions can be aligned with the printing position of one of the printing hosts 7 to achieve precise printing.

[0038] like Figure 6 Each printing host 7 includes a printing module 71 and an independent lifting drive mechanism 72. The lifting drive mechanism 72 is fixedly connected to the printing module 71 and provides lifting power for the printing module 71. The lifting drive mechanism 72 can drive the printing module 71 to lift independently in the vertical direction. The lifting stroke is 0-120mm, which can accurately adapt to the printing height of the square whole silicon wafer 6. The lifting actions of the two printing hosts do not interfere with each other.

[0039] Printing Module 71: The printing module 71 includes a squeegee, a back-inking blade, a screen frame, and a paste tank. The squeegee and back-inking blade are arranged in parallel and are both made of hard alloy. The scraping surface of the squeegee is polished to ensure uniform coating of the printing paste. A screen printing plate matching the square silicon wafer 6 is fixed in the screen frame. The grid pattern of the printing plate is perpendicular to the main grid direction of the silicon wafer. Each printing host 7 only performs printing operations on a single square silicon wafer 6 to avoid process interference from double-wafer printing.

[0040] Vision alignment module: A vision alignment module is fixed on the printing host 7. This module includes an infeed camera and an outfeed camera, both of which are industrial high-definition CCD cameras with telecentric lenses. The infeed camera is set on the feeding side of the printing host 7 and is used to photograph and position the silicon wafer 6 on the turntable station, obtain the position coordinate data of the silicon wafer, and transmit it to the control system of the printing module 71 in real time. The control system adjusts the position of the printing module according to the data to achieve precise alignment. The outfeed camera is set on the outfeed side of the printing host 7 and is used to inspect the printing quality of the silicon wafer 6 after printing, and to detect indicators such as the width, spacing, and continuity of the grid lines. The detection data is fed back to the production line control system in real time to achieve quality traceability.

[0041] like Figure 6 The transmission system 8 includes a feeding module 81, a discharging module 82, and a unloading module 83, all of which are adapted to the workstation positions of the turntable to realize automated feeding, transfer, and unloading of silicon wafers, replacing manual operation and improving production efficiency.

[0042] Feeding module 81: The feeding module 81 is located on the loading side of the turntable and includes a dual-wafer synchronous transmission track, a snap-fit ​​positioning component, and a feeding cylinder. The width of the transmission track is adapted to the size of the square whole silicon wafer 6 and can be adjusted according to the size of the silicon wafer, accommodating mainstream square silicon wafers such as 182mm, 183.5mm, and 210mm. The track uses an anti-static belt for transmission. The snap-fit ​​positioning component includes two symmetrically arranged snap-fit ​​plates and a drive cylinder, which can center and position the two silicon wafers on the transmission track with a positioning accuracy of ±0.05mm, ensuring that the silicon wafers are accurately delivered to the printing table 2 and the transition table 3 of the same workstation on the turntable.

[0043] The unloading module 82 is located between the two printing main units 7. Its structure is compatible with the feeding module 81. It also includes a dual-wafer synchronous transfer track and a snap-fit ​​positioning component. It is used to synchronously transfer the two silicon wafers printed by the first printing main unit to the feeding end of the second printing main unit 7, and realize the position swap of the two silicon wafers. The unprinted silicon wafers on the original transition table 3 are transferred to the printing table 2 of the corresponding turntable of the second printing main unit, and the printed silicon wafers on the original printing table 2 are transferred to the transition table 3 of the corresponding turntable.

[0044] Unloading module 83: The unloading module 83 is located on the unloading side of the turntable and includes a dual-wafer synchronous transmission track, an unloading robot, and a receiving station. The transmission track synchronously transports the silicon wafers that have completed dual-wafer printing on the turntable to the unloading position. The unloading robot picks up the silicon wafers and places them on the receiving station to realize automated unloading of silicon wafers. The receiving station is equipped with an anti-static silicone pad to prevent scratches on the surface of the silicon wafers.

[0045] At least one embodiment provides a method for operating a printing press. This method, based on the aforementioned turntable and printing press, is suitable for dual-wafer step-by-step screen printing on a square silicon wafer. It operates fully automatically without manual intervention and specifically includes the following steps: Includes the following steps: S1, Dual-wafer feeding: The feeding module 81 synchronously transfers two square whole silicon wafers 6 to the same set of workstations on the turntable. One silicon wafer 6 is placed on the printing table 2, and the other silicon wafer 6 is placed on the transition table 3. The printing table 2 and the transition table 3 of the turntable fix the silicon wafer 6 through the first airflow channel 4 and the second airflow channel 5, respectively. S2, First wafer printing: The turntable rotates to the printing station of the first printing host 7. The lifting drive mechanism 72 of the first printing host 7 drives the printing module 71 to descend to the preset height. The squeegee and ink return blade of the printing module 71 work together to screen print the first square whole silicon wafer 6 on the printing table 2. The second silicon wafer 6 on the transition table 3 is in standby mode and is not printed. S3, Dual wafer output: After the first silicon wafer 6 is printed, the turntable rotates to the output module 82 position. The output module 82 synchronously transfers the two silicon wafers 6 to the feeding end of the second printing host 7, and the positions of the two silicon wafers 6 are interchanged. The second silicon wafer 6 on the original transition table 3 is placed on the printing table 2 of the corresponding turntable of the second printing host 7, and the first silicon wafer 6 on the original printing table 2 is placed on the transition table 3 of the corresponding turntable. S4. Second wafer printing: The lifting drive mechanism 72 of the second printing host 7 drives the printing module 71 to descend to the preset height. The squeegee and ink return blade of the printing module 71 work together to screen print the second square whole silicon wafer 6 on the printing table 2. The first silicon wafer 6 on the transition table 3 is in standby mode and is not printed. S5, Dual Wafer Cutting: After the second silicon wafer 6 is printed, the turntable rotates to the cutting module 83 position. The cutting module 83 simultaneously cuts out the two square silicon wafers 6 that have been printed, completing one dual wafer printing operation.

[0046] The above steps are repeated cyclically. The four workstations of the turntable sequentially complete the feeding, first wafer printing, transfer, second wafer printing, and unloading operations, realizing continuous and automated screen printing of square silicon wafers.

[0047] In this embodiment of the invention, all electrical controls are implemented through a PLC control system. The control system is equipped with a touch screen, which can display information such as equipment operating status, printing parameters, and production data in real time. Operators can adjust parameters such as printing pressure, squeegee speed, and adsorption pressure through the touch screen to adapt to the printing needs of square whole silicon wafers of different specifications, making operation convenient.

[0048] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0050] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0051] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the 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, and therefore should not be construed as a limitation of the invention. Furthermore, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence unless expressly indicated herein. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed above may be referred to as a second element, component, region, layer, or segment.

[0052] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A turntable for screen printing on a square silicon wafer, characterized in that, include: Turntable body (1), the turntable body (1) is provided with at least two sets of workstations in the circumferential direction; Each of the workstations includes a printing table (2) and a transition table (3). The printing table (2) is a glass table and has a built-in first airflow channel (4). The channels of the first airflow channel (4) are densely distributed and used to adsorb and fix the square whole silicon wafer (6) during the printing process. The transition platform (3) is a plastic platform and has a built-in second airflow channel (5). The airflow channel (5) is sparsely distributed in a uniform manner and is used to limit and fix the square whole silicon wafer (6) during the rotation and transfer of the silicon wafer (6). The air pressure of the first airflow channel (4) is greater than the air pressure of the second airflow channel (5).

2. The turntable as described in claim 1, characterized in that, The glass material of the printing table (2) is high borosilicate glass. The first airflow channel (4) includes a main air channel (41) and several branch air channels (42) that are interconnected. The air outlets of the branch air channels (42) are evenly arranged on the bearing surface of the printing table (2), and the air outlets of the branch air channels (42) cover the entire bearing area of ​​the square silicon wafer (6).

3. The turntable as described in claim 1, characterized in that, The plastic material of the transition platform (3) is antistatic hard plastic. The second airflow channel (5) includes several independent micro-channels (50). The air outlet of the micro-channels (50) is distributed at the edge of the bearing surface of the transition platform (3) and is used to perform negative pressure adsorption on the edge of the square whole silicon wafer (6).

4. The turntable as described in claim 1, characterized in that, The turntable body (1) is provided with a rotation drive assembly (10) in the middle, which is used to drive the turntable body (1) to rotate around the central axis and realize the connection of circuits and air passages of each station.

5. A printing press, characterized in that, It includes two independent printing presses (7), a transmission system (8), and a turntable as described in any one of claims 1-4. Two printing hosts (7) are arranged in sequence along the transmission direction of the silicon wafer (6). The transmission system (8) includes a feeding module (81), an output module (82) and a unloading module (83). The feeding module (81) is used to synchronously transmit two square whole silicon wafers (6) to the station of the turntable. The discharge module (82) is used to transfer the silicon wafer (6) conveyed by the turntable to the subsequent printing host (7). The feeding module (83) is used to simultaneously feed the square whole silicon wafer (6) that has completed double-wafer printing; Each of the printing main units (7) includes a printing module (71) and an independent lifting drive mechanism (72). The lifting drive mechanism (72) is connected to the printing module (71) and is used to drive the printing module (71) to lift independently and adapt to the printing height of the square whole silicon wafer (6).

6. The printing press as described in claim 5, characterized in that, The printing modules (71) of both printing hosts (7) include a doctor blade and a back-ink blade, and the printing stations of the two printing hosts (7) are independent of each other. Each printing host (7) only performs printing operations on a single square whole silicon wafer (6), and the printing direction is perpendicular to the main grid direction of the square whole silicon wafer (6).

7. The printing press as described in claim 5, characterized in that, The turntable body (1) has four sets of workstations arranged around its circumference. The printing table surface (2) and transition table surface (3) of each workstation are integrated. The four sets of workstations are evenly distributed around the central axis of the turntable body (1), and the rotation angle of the turntable is adapted to the printing workstation positions of the two printing main machines (7).

8. The printing press as described in claim 5, characterized in that, The printing host (7) is equipped with a vision alignment module, which includes an infeed camera and an outfeed camera. The infeed camera is used to photograph and position the silicon wafer (6) and transmit the data to the printing module (71). The outfeed camera is used to detect the printing quality of the silicon wafer (6).

9. The printing press as described in claim 5, characterized in that, Both the feeding module (81) and the discharging module (82) are equipped with dual-plate synchronous transmission tracks. The width of the transmission track is adapted to the size of the square whole silicon wafer (6), and the transmission track is equipped with a snap-fit ​​positioning component for centering the silicon wafer (6).

10. A method of operating a printing press according to any one of claims 5-9, characterized in that, Includes the following steps: S1, Dual-wafer feeding: The feeding module (81) synchronously transfers two square whole silicon wafers (6) to the same set of workstations on the turntable. One silicon wafer (6) is placed on the printing table (2), and the other silicon wafer (6) is placed on the transition table (3). The printing table (2) and the transition table (3) of the turntable fix the silicon wafer (6) through the first airflow channel (4) and the second airflow channel (5), respectively. S2, First wafer printing: The turntable rotates to the printing station of the first printing host (7). The lifting drive mechanism (72) of the first printing host (7) drives the printing module (71) to descend to the preset height. The squeegee and ink return knife of the printing module (71) work together to screen print the first square whole silicon wafer (6) on the printing table (2). The second silicon wafer (6) on the transition table (3) is in standby mode and is not printed. S3, Dual wafer output: After the first silicon wafer (6) is printed, the turntable rotates to the output module (82) position. The output module (82) synchronously transfers the two silicon wafers (6) to the feeding end of the second printing host (7), and the positions of the two silicon wafers (6) are swapped. The second silicon wafer (6) on the original transition table (3) is placed on the printing table (2) of the corresponding turntable of the second printing host (7), and the first silicon wafer (6) on the original printing table (2) is placed on the transition table (3) of the corresponding turntable. S4, Second wafer printing: The lifting drive mechanism (72) of the second printing host (7) drives the printing module (71) to descend to the preset height. The squeegee and ink return knife of the printing module (71) work together to screen print the second square whole silicon wafer (6) on the printing table (2). The first silicon wafer (6) on the transition table (3) is in standby mode and is not printed. S5, Double wafer unloading: After the second silicon wafer (6) is printed, the turntable rotates to the unloading module (83) position. The unloading module (83) unloads the two square whole silicon wafers (6) that have been printed simultaneously, completing one double wafer printing operation.

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