A fully automatic double-sided exposure device for circuit boards
By using a Mask moving platform driven by a combination of transmission belts, flexible iron sheets, and electromagnets, the problem of decreased positioning accuracy caused by mechanical wear was solved, enabling high-precision exposure of high-density interconnect boards, effectively suppressing alignment errors, and improving production reliability and efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GUILIN DEQUN EXPRESS ELECTRONICS CO LTD
- Filing Date
- 2025-12-17
- Publication Date
- 2026-08-04
AI Technical Summary
In the existing technology, the Mask moving platform driven by mechanical guide rails and lead screws is prone to wear after long-term high-frequency movement, which leads to drift of the positioning origin and a decrease in repeatability accuracy, affecting the alignment accuracy of the circuit board, and may even cause product scrapping, especially in the production of high-density interconnect boards.
The Mask mobile platform uses a drive system that combines a transmission belt, flexible iron sheet, and electromagnetic adsorption to replace the traditional mechanical guide rail and ball screw drive. Combined with a synchronous belt and tensioning pulley set, it achieves high precision, wear resistance, and adaptive adjustment of the platform. Through flexible coupling and magnetic locking, it reduces friction between the mechanical contact surface and the rigid surface, and absorbs minor vibrations and gaps.
It effectively suppresses pattern alignment errors caused by wear, maintains micron-level repeatability positioning accuracy, and is suitable for production scenarios with high alignment accuracy requirements, such as high-density interconnect boards, thereby improving production reliability and efficiency.
Smart Images
Figure CN224594994U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to an exposure machine, specifically a fully automatic double-sided exposure device for circuit boards. Background Technology
[0002] In PCB (Printed Circuit Board) manufacturing, exposure is a crucial step in pattern transfer. Its function is to precisely copy the designed circuit pattern onto a copper-clad substrate coated with a photosensitive material (such as dry or wet film) using a film. For double-sided and multilayer boards, both surfaces of the substrate need to be exposed separately to ensure the alignment accuracy of the interconnections between the circuits on both sides.
[0003] Referring to the Chinese authorized patent, publication number CN219811126U, publication date 2023-10-10, a fully automatic double-sided exposure integrated machine for flexible circuit boards is disclosed.
[0004] The shortcoming of existing technology is that the mask moving platform, which uses mechanical guide rails and lead screws, is prone to wear and tear on its mechanical components after long-term, high-frequency reciprocating motion. This leads to drift of the positioning origin and a decrease in repeatability. This micron-level error is directly transferred to the exposed pattern, affecting the alignment accuracy of the circuit, and may even cause product scrap, especially when manufacturing high-density interconnect boards. Utility Model Content
[0005] The purpose of this invention is to provide a fully automatic double-sided exposure device for circuit boards to address the aforementioned shortcomings in the prior art.
[0006] To achieve the above objectives, this utility model provides the following technical solution: a fully automatic double-sided exposure device for circuit boards, comprising an exposure machine, and further comprising an exposure system symmetrically distributed about the vertical center of the substrate, wherein the exposure system includes:
[0007] A trapezoidal mirror, with one side of its waist facing the substrate;
[0008] A convex lens, which is coaxial with the upper base of the trapezoidal mirror and maintains a predetermined distance;
[0009] A concave mirror, which maintains a predetermined distance from the convex lens and is axially aligned with it;
[0010] A Mask moving platform that is driven to move horizontally and is symmetrically distributed about the center of the trapezoidal mirror and the substrate;
[0011] The arc-shaped slit flux tray is symmetrically distributed about the Mask moving platform and the trapezoidal mirror.
[0012] Preferably, a UV light emitter is also included, the irradiation surface of which faces the arcuate groove of the arcuate slit flux groove plate and is driven to move along the arcuate groove guide.
[0013] Preferably, a guide rail is also included, on which the Mask moving platform is slidably disposed and moves along the upper and lower sides of the trapezoidal mirror.
[0014] Preferably, the direction of movement of the irradiation surface is perpendicular to the direction of movement of the Mask moving platform.
[0015] Preferably, two sets of transmission systems are symmetrically arranged inside the guide rail component. The transmission system includes a driving wheel and a driven wheel, and a transmission belt is sleeved between the two.
[0016] The side of the Mask mobile platform is fixed to the drive belt surface on either side for synchronous movement.
[0017] Preferably, a number of equidistant flexible iron sheets are fixedly arranged on the inner side of the transmission belt.
[0018] The Mask mobile platform has rectangular bores on both sides. Iron plates are slidably disposed in the rectangular bores and connected by elastic telescopic guide posts fixed inside. An electromagnet is fixedly disposed on the back of the iron plate. When energized, the electromagnet magnetically connects the iron plate with any of the adjacent iron plates.
[0019] Preferably, the iron sheet is divided into a rectangular frame structure and a circular structure that is symmetrically distributed in the center within the rectangular frame structure.
[0020] Preferably, the area of the concave mirror is larger than the area of the lower base of the trapezoidal mirror.
[0021] Preferably, the area of the convex lens is larger than the area of the upper base of the trapezoidal mirror and smaller than the area of the lower base of the trapezoidal mirror.
[0022] Preferably, a timing belt is fitted between the two drive wheels, and the system further includes:
[0023] A fixedly installed drive motor, wherein a synchronous pulley that meshes with the synchronous belt is fixedly installed at the output end of the drive motor.
[0024] The tensioning pulley assembly, which is symmetrical about the center of the drive motor and clamps the outer side of the synchronous belt in a rolling connection, is also connected to it.
[0025] In the above technical solution, the fully automatic double-sided exposure device for circuit boards provided by this utility model has the following beneficial effects:
[0026] 1. By employing a mask moving platform drive system connected by a transmission belt, flexible iron sheet, and electromagnetic adsorption, the traditional mechanical guide rail and lead screw drive are replaced, significantly reducing mechanical contact surfaces and rigid friction. The combined use of the flexible iron sheet and electromagnet provides the platform with a certain degree of buffering and adaptive adjustment during movement, effectively absorbing minor vibrations and gaps, thereby suppressing origin drift caused by wear. This design enables the mask moving platform to maintain micron-level repeatability even after long-term, high-frequency operation, fundamentally solving the problem of pattern alignment errors caused by mechanical wear. It is particularly suitable for production scenarios with extremely high alignment accuracy requirements, such as high-density interconnect boards. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.
[0028] Figure 1 This is a schematic diagram of the structure of the exposure machine provided in an embodiment of the present utility model;
[0029] Figure 2 A schematic diagram of the exposure system provided in an embodiment of this utility model;
[0030] Figure 3 This is a schematic diagram of the structure of the Mask mobile platform and guide rail provided in an embodiment of the present utility model;
[0031] Figure 4 A schematic diagram of the structure of the elastic telescopic guide post, electromagnet, and iron plate provided in an embodiment of this utility model;
[0032] Figure 5 This is a schematic diagram of the transmission belt and flexible iron sheet provided in an embodiment of the present utility model.
[0033] Explanation of reference numerals in the attached figures:
[0034] 1. Exposure machine; 2. Trapezoidal mirror; 3. Convex lens; 4. Concave mirror; 5. Mask moving platform; 6. Arc-shaped slit flux channel plate; 7. Guide rail; 80. Drive wheel; 81. Driven wheel; 82. Transmission belt; 821. Flexible iron sheet; 822. Elastic telescopic guide post; 823. Iron plate; 824. Electromagnet; 83. Synchronous belt; 84. Drive motor; 85. Tensioner assembly. Detailed Implementation
[0035] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.
[0036] Please see Figure 1-5 This utility model provides a technical solution:
[0037] Example 1
[0038] This embodiment provides a basic architecture and optical system implementation method for a fully automatic double-sided exposure device for circuit boards, aiming to solve the fundamental problem of uniformity and consistency of double-sided exposure from the perspective of optical path design.
[0039] The apparatus includes an exposure machine body 1 and an XY-axis carrier platform (not shown in the figure) that carries and drives the movement of the circuit board substrate to be exposed. Its core innovation lies in the setting of two exposure systems that are completely mirror-symmetrical about the vertical central symmetry plane of the substrate (i.e., the plane passing through the center of the substrate thickness).
[0040] Each exposure system, along the optical path propagation direction (from the light source side to the substrate side), includes, in sequence: an arc-shaped slit flux tray 6, a mask moving platform 5, a concave mirror 4, a convex lens 3, and a trapezoidal mirror 2. The optical axes of these components are kept consistent.
[0041] One of the waist-side slopes of the trapezoidal mirror 2 faces and is parallel to the substrate surface, and is used to deflect horizontal light rays by 90 degrees and project them vertically onto the substrate.
[0042] The convex lens 3 and the trapezoidal mirror 2 are coaxially arranged with their upper base (smaller bottom surface) maintaining a first predetermined distance between them, for collimating or pre-focusing light.
[0043] The concave mirror 4 is coaxial with the convex lens 3 and maintains a second predetermined distance. Its concave surface faces the convex lens to converge large-angle light rays from the front and improve light energy utilization.
[0044] Mask moving platform 5 is used to install the mask. Its position is symmetrical about the center of trapezoidal mirror 2 and substrate to ensure the correct pattern projection relationship.
[0045] The arc-shaped slit flux tray 6 is located on the side of the Mask moving platform 5 away from the substrate, and an arc-shaped slit is formed on it.
[0046] It also includes a UV light emitter (such as a mercury lamp or LED array) whose light-emitting surface faces the arcuate groove of the arcuate slit flux slot plate 6. The UV light emitter is mounted on a separate drive mechanism that can controllably move its irradiation surface along the trajectory of the arcuate groove (this direction can be defined as the arcuate path in the Y-axis direction).
[0047] The Mask moving platform 5 is mounted on the guide rail 7 and can be driven to move linearly in the horizontal direction (defined as the X-axis direction, parallel to the extension direction of the upper and lower bases of the trapezoidal mirror). The Y-axis arc movement of the UV light source and the X-axis linear movement of the Mask platform are perpendicular to each other, forming a two-dimensional adjustable exposure scanning mechanism.
[0048] The area of the concave mirror 4 is larger than the area of the lower base (larger bottom surface) of the trapezoidal mirror 2, ensuring that light energy can be fully captured and reflected, and reducing edge light loss.
[0049] The area of the convex lens 3 is larger than the area of the upper base of the trapezoidal mirror 2 but smaller than its lower base area. This design allows the light beam emitted from the convex lens to completely cover the upper base entrance of the trapezoidal mirror, and after reflection and beam expansion inside the trapezoidal mirror, it uniformly covers the entire lower base exit area, thereby obtaining a uniformly illuminated exposure field on the substrate surface.
[0050] Work process:
[0051] The UV light beam emitted by the UV emitter is shaped into an arc-shaped light band by the arc-shaped slit flux channel plate 6. It then passes sequentially through the mask pattern on the Mask moving platform 5, converges via the concave mirror 4, is shaped by the convex lens 3, and enters the trapezoidal mirror 2. After total internal reflection or specular reflection on the inclined surface of the trapezoidal mirror, the light is directed perpendicularly to the substrate surface, completing the pattern transfer. By controlling the arc-shaped movement of the UV light source along the Y-axis and the movement of the Mask platform along the X-axis, large-size substrates can be scanned and exposed, with real-time compensation for edge light intensity. The two symmetrical systems simultaneously expose both sides of the substrate synchronously, ensuring interlayer alignment accuracy and process efficiency.
[0052] Example 2
[0053] Based on Embodiment 1, this embodiment discloses a more specific high-precision, wear-resistant drive and positioning mechanism for the Mask mobile platform 5, aiming to solve the core problem of precision degradation of the mechanical guide rail screw system after long-term operation.
[0054] The Mask moving platform 5 is slidably mounted on the guide rail 7 via a slider. Its drive system is integrated inside the guide rail 7, employing two sets of belt drive systems in a symmetrical layout.
[0055] Basic belt drive structure: Each transmission system includes a drive pulley 80, a driven pulley 81, and an annular transmission belt 82 fitted between them. The side of the Mask moving platform 5 is fixedly connected to the outer surface of the transmission belt 82 on one side via a rigid connector. When the drive pulley 80 is driven to rotate by a motor, it pulls the platform along the guide rail to make precise linear reciprocating motion via the transmission belt 82.
[0056] To further eliminate errors in rigid connections and mechanical transmission chains, multiple flexible iron sheets 821 are fixedly installed at equal intervals on the inner surface of the transmission belt 82. These iron sheets have a certain degree of flexibility.
[0057] Corresponding to the position of the transmission belt, a rectangular boring hole is opened on each of the opposite sides of the Mask moving platform 5. Within each boring hole, a metal plate 823 is mounted via one or more built-in elastic telescopic guide posts 822, such as spring plungers. The elastic telescopic guide posts 822 allow the metal plate 823 to float within a small range within the boring hole.
[0058] An electromagnet 824 is fixedly installed on the back of the iron plate 823 (the side facing the inside of the platform).
[0059] Operating Logic: When the system needs to move or position the platform, the electromagnet 824 is energized, generating a strong magnetic force that attracts one or more flexible iron plates 821 closest to it on the transmission belt 82 through the platform housing, forming a "magnetic lock". At this time, the power transmission of the platform changes from a traditional rigid connection to a "flexible coupling" achieved through magnetic force and flexible plates. The drive motor drives the attracted flexible iron plates 821 through the transmission belt 82, thereby pulling the platform to move. After reaching the target position, the motor stops under closed-loop control. During this process, the elastic telescopic guide post 822 and the flexible iron plates 821 together form a multi-dimensional buffer and error absorption interface, which can effectively attenuate the vibration and jumping of the transmission system itself and the effects of uneven stretching of the transmission belt. After long-term operation, even if the transmission wheel or belt experiences minor wear, the final positioning accuracy of the platform depends only on the control accuracy of the servo motor and the attraction stability of the electromagnet, and is indirectly decoupled from the dimensional accuracy of the transmission components, thus completely suppressing the accuracy drift problem inherent in traditional mechanical systems.
[0060] The 823 iron plate can be designed as a rectangular frame structure to reduce weight, or a circular plate structure can be placed in the center of the rectangular frame. The circular structure allows for a more concentrated and uniform distribution of magnetic field lines, improving the stability and reliability of adsorption.
[0061] Example 3
[0062] Based on Embodiment 2, this embodiment further discloses a synchronization guarantee mechanism for the drive transmission system, which is a solution to the problem of platform jamming or skew caused by asynchronous motion that may occur in a dual drive belt system.
[0063] In Embodiment 2, the drive wheels 80 on both sides need to rotate in perfect synchronization to ensure the platform's stable linear motion. This embodiment achieves this goal by adding a mechanical synchronization linkage device.
[0064] A synchronous belt 83 is fitted between the axles of the two drive wheels 80 or between synchronous pulleys mounted coaxially with the wheels. An independent drive motor 84 is fixedly mounted on the frame, and a drive synchronous pulley is fixedly mounted on its output shaft. This drive synchronous pulley meshes with the synchronous belt 83. Therefore, when the drive motor 84 is working, it directly drives the axles of the two drive wheels 80 through the drive synchronous pulley and the synchronous belt 83 to achieve forced synchronous rotation, fundamentally eliminating the speed asynchrony of the two drive wheels caused by electrical control or minor manufacturing differences.
[0065] To ensure smooth and reliable transmission of the synchronous belt 83, a tensioning pulley assembly 85 is provided, symmetrically distributed about the center of the drive motor 84. The two rollers of this tensioning pulley assembly 85 clamp and roll in contact with the straight section of the synchronous belt 83 from the outside. The tensioning pulley assembly 85 is typically mounted on an adjustable bracket; by adjusting its position, appropriate pretension can be applied to the synchronous belt 83. This design offers three advantages:
[0066] The main control system issues a movement command, activating the drive motor 84. The synchronous belt 83 mechanism ensures that the two drive wheels 80 rotate in perfect sync. Simultaneously, the electromagnet 824 on the Mask moving platform 5 is energized, attracting the flexible iron plate 821 on the transmission belt 82. The synchronously rotating drive wheels pull the platform forward via the two transmission belts 82. Upon reaching the target position, the drive motor 84 precisely stops, and the electromagnet 824 remains energized to lock the position (or for fine-tuning if needed). This solution combines active synchronous drive with passive flexible magnetic coupling, creating a high-precision, high-rigidity, highly reliable, and wear-resistant Mask platform drive system.
[0067] The foregoing description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.
Claims
1. A fully automatic double-sided exposure device for circuit boards, comprising an exposure machine (1), characterized in that, It also includes an exposure system that is symmetrically distributed about the substrate along a vertical center, the exposure system comprising: Trapezoidal mirror (2), one side of which faces the substrate; A convex lens (3) is coaxial with the upper base of the trapezoidal mirror (2) and maintains a predetermined distance; A concave mirror (4) is provided, which maintains a predetermined distance from the convex lens (3) and is axially aligned with it. Mask moving platform (5) is driven to move horizontally and is symmetrically distributed about the trapezoidal mirror (2) and the center of the substrate; The arc-shaped slit flux tray (6) is symmetrically distributed about the Mask moving platform (5) and the trapezoidal mirror (2).
2. The fully automatic double-sided exposure device for circuit boards according to claim 1, characterized in that, It also includes a UV light emitter, whose irradiation surface faces the arcuate groove of the arcuate slit flux groove plate (6) and is driven to move along the arcuate groove guide.
3. The fully automatic double-sided exposure device for circuit boards according to claim 2, characterized in that, It also includes a guide rail (7), on which the Mask moving platform (5) is slidably mounted and extends the upper and lower bottom directions of the trapezoidal mirror (2).
4. The fully automatic double-sided exposure device for circuit boards according to claim 3, characterized in that, The direction of movement of the irradiation surface is perpendicular to the direction of movement of the Mask moving platform (5).
5. The fully automatic double-sided exposure device for circuit boards according to claim 3, characterized in that, Two sets of transmission systems are symmetrically arranged inside the guide rail component (7). The transmission system includes a power wheel (80) and a driven wheel (81), and a transmission belt (82) is sleeved between them. The side of the Mask mobile platform (5) is fixed to the belt surface of the transmission belt (82) on either side for synchronous movement.
6. The fully automatic double-sided exposure device for circuit boards according to claim 5, characterized in that, The inner side of the transmission belt (82) is fixedly provided with a number of equidistant flexible iron sheets (821); The Mask mobile platform (5) has rectangular bores on both sides. A metal plate (823) is slidably disposed in the rectangular bore and connected by an elastic telescopic guide post (822) fixedly disposed inside. An electromagnet (824) is fixedly disposed on the back of the metal plate (823). When energized, the electromagnet (824) magnetically connects the metal plate (823) with any of the adjacent metal plates (823).
7. The fully automatic double-sided exposure device for circuit boards according to claim 6, characterized in that, The iron plate (823) is divided into a rectangular frame structure and a circular structure that is symmetrically distributed in the center within the rectangular frame structure.
8. The fully automatic double-sided exposure device for circuit boards according to claim 1, characterized in that, The area of the concave mirror (4) is larger than the area of the bottom of the trapezoidal mirror (2).
9. The fully automatic double-sided exposure device for circuit boards according to claim 1, characterized in that, The area of the convex lens (3) is larger than the area of the upper base of the trapezoidal mirror (2) and smaller than the area of the lower base of the trapezoidal mirror (2).
10. The fully automatic double-sided exposure device for circuit boards according to claim 5, characterized in that, A timing belt (83) is fitted between the two drive wheels (80), and the system also includes: A fixedly installed drive motor (84) has a synchronous pulley fixedly installed at its output end that meshes with the synchronous belt (83). The tensioning pulley assembly (85) is symmetrical about the center of the drive motor (84) and clamps the outside of the synchronous belt (83) and is in a rolling connection.