Parallel light exposure system
By designing a parallel light exposure system and using light modulation components to form a uniform parallel light field from the mercury lamp light source, the problems of insufficient light source intensity and uneven light intensity distribution in the existing technology are solved, and a highly efficient circuit board exposure effect is achieved.
Patent Information
- Application Number
- CN202520449794.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2026-01-13
- Estimated Expiration
- 2035-03-14
AI Technical Summary
In current circuit board production, conventional exposure machines use LDI light sources with limited brightness and long exposure times, while mercury lamp light sources have diffused light and uneven intensity distribution, resulting in poor exposure effects.
A parallel light exposure system is adopted, which forms a uniform parallel light field by combining an elliptical mirror, a first plane mirror, a compound eye homogenizer, a second plane mirror, and a field mirror, thereby enhancing the intensity of the light source and ensuring uniform and stable illumination.
It improves light energy utilization, enhances the exposure effect of circuit boards, improves photochemical reaction efficiency, shortens exposure or curing time, and reduces system size and energy consumption.
Smart Images
Figure CN223796825U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of circuit board manufacturing, and more specifically, to a parallel light exposure system. Background Technology
[0002] Currently, in the circuit board (PCB) manufacturing process, pattern transfer through exposure using an exposure machine is an essential step, directly affecting the accuracy of the circuit pattern and the quality of the solder mask. Conventional exposure machines mostly use LDI (Light Diode) light sources for exposing PCBs. While widely used in exposure processes, LDI light sources have limitations in brightness and require long exposure times. Using higher-intensity light sources, such as mercury lamps, often produces diffused light with uneven intensity distribution, resulting in unsatisfactory performance. Utility Model Content
[0003] In view of this, the present invention provides a parallel light exposure system.
[0004] The objective of this utility model is achieved through the following technical solution:
[0005] A parallel light exposure system includes a mercury lamp light source, a light modulation component, and a light plate arranged sequentially along an optical path. The light modulation component includes: an elliptical mirror sleeved around the mercury lamp light source, a first plane mirror tilted above the elliptical mirror, a compound eye homogenizer disposed in the reflected light path of the first plane mirror, a second plane mirror disposed in the outgoing light path of the compound eye homogenizer, and a field mirror disposed in the reflected light path of the second plane mirror and located above the light plate.
[0006] In the above technical solution, the light from the mercury lamp light source is converged by an elliptical reflector, reflected by a first plane reflector, homogenized by a compound eye homogenizer, deflected by a second plane reflector, and collimated by a field mirror, forming a uniform parallel light field on the surface of the light plate. Specifically, the elliptical reflector, fitted around the mercury lamp light source, uses its geometric characteristics to focus the diverging light into a high-density beam, significantly enhancing the effective radiation power of the light source and reducing energy loss. The first plane reflector is tilted, folding the light path through an asymmetric reflection path, shortening the physical size of the system while reducing stray light interference and ensuring precise and controllable light transmission direction. The compound eye homogenizer divides the incident beam into multiple sub-beams and re-superimposes them, effectively eliminating spatial non-uniformity of light intensity distribution. The second plane reflector and the field mirror constitute a secondary reflection structure, further correcting the beam divergence angle so that the light can illuminate the light plate parallel to the surface.
[0007] Therefore, this utility model improves the light source intensity by using a mercury lamp light source and a light modulation component, while ensuring that the light source can illuminate the light plate in a parallel, uniform and stable manner. The structure is compact and can effectively improve the utilization rate of light energy, thereby improving the exposure effect of the circuit board.
[0008] Alternatively, in one possible implementation, the mirror normal of the first planar reflector forms an angle of 15-45 degrees with the optical axis of the elliptical reflector.
[0009] In the above technical solution, the included angle range of 15-45 degrees provides a reasonable optical path turning angle, which not only ensures that the light can be smoothly reflected by the first plane mirror, but also avoids the spatial limitation or light energy loss that may be caused by the optical path being too steep or too flat. This makes the entire optical path layout more compact and efficient, which is conducive to reducing the system size and improving the light energy utilization rate.
[0010] Alternatively, in one possible implementation, the reflecting surface of the field mirror is a concave arc surface.
[0011] In the above technical solution, the concave arc surface modulates the incident light field a second time through its geometric curvature, which can compensate for the divergence or distortion of the light emitted from the compound eye homogenizer during transmission, further eliminate the edge light intensity attenuation, thereby forming a highly uniform parallel light spot on the light plate surface, improving exposure resolution and edge sharpness.
[0012] Optionally, in one possible implementation, the side of the first planar reflector away from the elliptical reflector is provided with a composite heat dissipation structure, the composite heat dissipation structure comprising alternating layers of copper foil and graphene thermally conductive layer.
[0013] In the above technical solution, the copper foil layer enables the rapid dissipation of heat along the normal direction of the first plane reflective mirror due to its high longitudinal thermal conductivity, while the graphene layer promotes lateral heat diffusion through its ultra-high in-plane thermal conductivity. The two work together to form a three-dimensional heat dissipation network, which effectively suppresses local temperature rise and avoids deformation of the mirror surface due to thermal expansion.
[0014] Optionally, in one possible implementation, a movable baffle is provided between the compound eye homogenizer and the second plane mirror. The baffle can be moved into the outgoing light path of the compound eye homogenizer and has two working positions: complete blockage and complete avoidance.
[0015] In the above technical solution, the baffle can be used to cut off the propagation of light. Since the mercury lamp light source of the equipment is usually in a constant state, and the exposure of the circuit board is not continuous, the baffle can be set to completely avoid the light path when the board is being made, and can also be set to completely block the light when the board is not being made, so as to prevent the light from continuously shining on the light board. This makes it more flexible and convenient to use.
[0016] Alternatively, in one possible implementation, the shielding surface of the baffle is coated with a wavelength-selective reflective coating.
[0017] In the above technical solution, by reflecting radiation energy of unnecessary wavelengths, the heat absorption of the baffle material under the shielding state is significantly reduced. Combined with the composite heat dissipation structure, the thermal deformation of the baffle can be effectively reduced. In addition, reducing the ineffective absorption of ultraviolet bands under the shielding state can delay the photochemical aging rate of the coating material and improve the service life of the baffle.
[0018] Alternatively, in one possible implementation, the emission spectrum of the mercury lamp light source is in the range of 360-420 nm.
[0019] In the above technical solution, the main spectral peak of 365nm is precisely matched with the key absorption bands of materials such as photoresist and UV-curable resin, which can significantly improve the efficiency of photochemical reaction and shorten the exposure or curing time.
[0020] Optionally, in one possible implementation, the elliptical reflector is coaxially fitted around the outer periphery of the mercury lamp light source, and the major axis of the elliptical reflector coincides with the axis of the mercury lamp light source.
[0021] In the above technical solution, the coaxial structure can eliminate the aberrations introduced by asymmetric reflection, make the converging beam highly spatially consistent, provide a uniform incident angle distribution for the subsequent compound eye homogenizer, and reduce the risk of beam distortion.
[0022] Alternatively, in one possible implementation, the compound eye cycloid is composed of an array of any one of the following: regular hexagonal microlenses, square microlenses, circular microlenses, and rectangular microlenses.
[0023] In the above technical solutions, microlens arrays with different geometries can be used to optimize the spatial distribution characteristics of the light beam, thereby meeting the differentiated requirements of light field uniformity in different scenarios. Attached Figure Description
[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 This is a schematic diagram of the overall structure of one embodiment.
[0026] Reference numerals: 1-Mercury lamp light source; 2-Light modulation component; 21-Elliptical reflector; 22-First plane reflector; 23-Compound eye homogenizer; 24-Second plane reflector; 25-Field mirror reflector; 3-Light plate; 4-Baffle; 5-Reflective coating. Detailed Implementation
[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0028] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0029] Please refer to Figure 1 This embodiment provides a parallel light exposure system, including a mercury lamp light source 1, a light modulation component 2, and a light plate 3 arranged sequentially along the light path. The light modulation component 2 includes: an elliptical reflector 21 sleeved on the outer periphery of the mercury lamp light source 1, a first plane reflector 22 tilted above the elliptical reflector 21, a compound eye homogenizer 23 disposed in the reflected light path of the first plane reflector 22, a second plane reflector 24 disposed in the emitted light path of the compound eye homogenizer 23, and a field mirror reflector 25 disposed in the reflected light path of the second plane reflector 24 and located above the light plate 3.
[0030] In this embodiment, the light from the mercury lamp light source 1 is converged by an elliptical reflector 21, reflected by a first plane reflector 22, homogenized by a compound-eye homogenizer 23, deflected by a second plane reflector 24, and collimated by a field mirror 25, forming a uniform parallel light field on the surface of the light plate 3. The elliptical reflector 21, fitted around the mercury lamp light source 1, uses its geometric characteristics to focus the diverging light into a high-density beam, significantly enhancing the effective radiation power of the light source and reducing energy loss. The first plane reflector 22 is tilted, folding the light path through an asymmetric reflection path, shortening the physical size of the system while reducing stray light interference and ensuring precise control of the light transmission direction. The compound-eye homogenizer 23 divides the incident beam into multiple sub-beams and re-superimposes them, effectively eliminating spatial non-uniformity of light intensity distribution. The second plane reflector 24 and the field mirror 25 form a secondary reflection structure, further correcting the beam divergence angle so that the light can illuminate the light plate 3 in parallel.
[0031] Therefore, this embodiment improves the light source intensity by using the mercury lamp light source 1 and the light modulation component 2, while ensuring that the light source can illuminate the light plate 3 in a parallel, uniform and stable manner. The structure is compact and can effectively improve the utilization rate of light energy, thereby improving the exposure effect of the circuit board.
[0032] In this embodiment, the mirror normal of the first planar reflector 22 forms an angle of 15-45 degrees with the optical axis of the elliptical reflector 21, such as the 30-degree angle set in this embodiment.
[0033] The 15-45 degree angle range provides a reasonable optical path turning angle, ensuring that light can be smoothly reflected by the first plane mirror 22 while avoiding spatial limitations or light energy loss that might result from an overly steep or overly gentle optical path. This makes the entire optical path layout more compact and efficient, which is beneficial for reducing system size and improving light energy utilization. Within this angle range, the tilt angle of the first plane mirror 22 can be flexibly adjusted to adapt to different exposure requirements. For example, by fine-tuning the angle, the incident angle of light before passing through the compound eye homogenizer 23 can be changed, thereby optimizing the homogenization effect; or the incident angle of light reaching the light plate 3 can be adjusted to improve exposure uniformity or achieve a specific exposure pattern.
[0034] In this embodiment, the reflecting surface of the field mirror 25 is a concave arc surface. The concave arc surface modulates the incident light field a second time through its geometric curvature, which can compensate for the divergence or distortion of the light emitted from the compound eye homogenizer 23 during transmission, further eliminate edge light intensity attenuation, thereby forming a highly uniform parallel light spot on the surface of the light plate 3, and improving exposure resolution and edge sharpness.
[0035] It should be noted that the side of the first planar reflector 22 away from the elliptical reflector 21 is provided with a composite heat dissipation structure, which includes alternating layers of copper foil and graphene thermally conductive layers. This composite heat dissipation structure is located on the back of the first planar reflector 22 and is used to dissipate heat from the mercury lamp light source 1. It can completely cover the surface of the first planar reflector 22 by adhering to it, thereby maximizing the heat dissipation area. Furthermore, to further improve the overall heat dissipation effect of the system, the composite heat dissipation structure can be simultaneously provided on the elliptical reflector 21, the first planar reflector 22, the second planar reflector 24, and the field mirror reflector 25.
[0036] The copper foil layer, with its high longitudinal thermal conductivity, enables rapid heat dissipation along the normal direction of the first planar reflector (22 surfaces). The graphene layer, with its ultra-high in-plane thermal conductivity, promotes lateral heat diffusion. Together, they form a three-dimensional heat dissipation network, effectively suppressing local temperature rise and preventing deformation of the mirror surface due to thermal expansion. In addition, the alternating layered structure complements the differences in the thermal expansion coefficients of the materials, resulting in a gradient distribution of overall thermal stress along the thickness direction. Compared with a single-material structure, this reduces interfacial shear stress by approximately 30%, significantly improving the geometric stability of the mirror surface under high-temperature conditions.
[0037] In this embodiment, a movable baffle 4 is provided between the compound eye homogenizer 23 and the second plane mirror 24. The baffle 4 can be moved into the outgoing light path of the compound eye homogenizer 23 and has two working positions: complete blocking and complete avoidance.
[0038] The baffle 4 can be used to cut off the propagation of light. Since the mercury lamp light source 1 of the equipment is usually in a constant state, and the exposure of the circuit board is not continuous, the baffle 4 can be in a completely obstructed state during board fabrication to ensure the continuity of the light path, or in a completely blocked state when the board is not being fabricated to prevent continuous light from shining on the light plate 3, making it more flexible and convenient to use. In addition, the baffle 4 can switch between completely blocked and obstructed states to achieve instantaneous adjustment of exposure energy. In the blocked mode, light transmission can be interrupted to avoid stray light interference in non-exposed areas; in the obstructed mode, the complete transmission of the output light field of the compound eye homogenizer 23 is ensured, meeting the requirements of high-precision exposure processes for instantaneous energy start and stop.
[0039] In this embodiment, the shielding surface of the movable baffle 4 is coated with a wavelength selective reflective coating 5. The reflective coating 5 has a reflectivity of ≥95% for light in the 360-420nm wavelength band and an absorption rate of ≥90% for visible light.
[0040] By reflecting radiation energy of unnecessary wavelengths, the thermal absorption of the baffle 4 material under shielding conditions is significantly reduced. Combined with the composite heat dissipation structure, the thermal deformation of the baffle 4 can be effectively reduced. In addition, reducing ineffective absorption of ultraviolet light under shielding conditions can slow down the photochemical aging rate of the coating material and improve the service life of the baffle 4.
[0041] It should be noted that the emission spectrum of the mercury lamp light source 1 in this embodiment is 360-420nm. Its main spectral peak of 365nm precisely matches the key absorption band of materials such as photoresist and UV-curable resin, which can significantly improve the efficiency of photochemical reaction and shorten the exposure or curing time.
[0042] In this embodiment, the elliptical reflector 21 is coaxially sleeved on the outer periphery of the mercury lamp light source 1, and the major axis of the elliptical reflector 21 coincides with the axis of the mercury lamp light source 1. The overall shape of the elliptical reflector 21 is approximately the shape of a rugby ball cut in half, and a through hole is provided at its center, through which the mercury lamp can pass, so that the mercury lamp light source 1 is located at the center of the elliptical reflector 21.
[0043] The coaxial structure can eliminate aberrations introduced by asymmetric reflection, enabling the converging beam to have high spatial consistency, providing a uniform incident angle distribution for the subsequent compound eye homogenizer 23, and reducing the risk of beam distortion.
[0044] In this embodiment, the compound eye homogenizer 23 is composed of an array of any one of the following: regular hexagonal microlenses, square microlenses, circular microlenses, and rectangular microlenses. Taking a regular hexagonal microlens array as an example, the side length of a single microlens unit is L = 2-5 mm, the total number of array units N ≥ 100, and the center-to-center distance tolerance between adjacent microlens units is less than 0.01 mm. Microlens arrays with different geometric shapes can specifically optimize the spatial distribution characteristics of the beam, thereby meeting the differentiated requirements for light field uniformity in different scenarios.
[0045] In the description of this utility model, it should be understood that terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0047] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A parallel light exposure system, characterized in that, The device includes a mercury lamp light source, a light modulation component, and a light plate arranged sequentially along the light path. The light modulation component includes: an elliptical reflector sleeved on the outer periphery of the mercury lamp light source, a first plane reflector tilted above the elliptical reflector, a compound eye homogenizer disposed in the reflected light path of the first plane reflector, a second plane reflector disposed in the outgoing light path of the compound eye homogenizer, and a field mirror reflector disposed in the reflected light path of the second plane reflector and located above the light plate.
2. The parallel light exposure system according to claim 1, characterized in that, The normal to the first planar reflector forms an angle of 15-45 degrees with the optical axis of the elliptical reflector.
3. The parallel light exposure system according to claim 1, characterized in that, The reflecting surface of the field mirror is a concave arc surface.
4. The parallel light exposure system according to claim 1, characterized in that, The side of the first planar reflector away from the elliptical reflector is provided with a composite heat dissipation structure, which includes alternating layers of copper foil and graphene thermal conductive layer.
5. The parallel light exposure system according to claim 1, characterized in that, A movable baffle is provided between the compound eye homogenizer and the second plane mirror. The baffle can be moved into the output light path of the compound eye homogenizer and has two working positions: complete blockage and complete avoidance.
6. The parallel light exposure system according to claim 5, characterized in that, The shielding surface of the baffle is coated with a wavelength-selective reflective coating.
7. The parallel light exposure system according to claim 1, characterized in that, The emission spectrum of the mercury lamp light source is in the range of 360-420 nm.
8. The parallel light exposure system according to claim 1, characterized in that, The elliptical reflector is coaxially fitted around the outer periphery of the mercury lamp light source, and the major axis of the elliptical reflector coincides with the axis of the mercury lamp light source.
9. The parallel light exposure system according to claim 1, characterized in that, The compound eye homogenizer is composed of an array of any one of the following: regular hexagonal microlenses, square microlenses, circular microlenses, and rectangular microlenses.