Adjusting lens group and method for improving illumination uniformity

Abstract

The invention discloses an adjusting lens group and method for improving illumination uniformity, the adjusting lens group for improving illumination uniformity comprises a first lens, a second lens, a lens barrel, an optical fiber fixing seat and a three-dimensional adjusting mechanism, the first lens and the second lens are plano-convex lenses, the first lens and the second lens are respectively arranged in the lens base, the lens base is arranged in the lens barrel, convex surfaces of the two lenses are oppositely arranged, the optical fiber mounting lens barrel is arranged at the upper end of the lens barrel, the optical fiber fixing base is mounted in the optical fiber mounting lens barrel, and the three-dimensional adjusting mechanism is arranged between the optical fiber mounting lens barrel and the optical fiber fixing base. The three-dimensional adjusting mechanism comprises a screwing nut, a fixing nut and a bulb hexagonal adjuster; the adjustment method of the lens group is simple and low in cost, so that the problems of non-uniform exposure light spot energy distribution, low product yield and the like caused by unstable light emission and insufficient adjustment precision of the optical fiber laser in the existing laser direct imaging photoetching system are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of photolithography equipment, and in particular to an adjusting lens assembly and method for improving illumination uniformity. Background Art

[0002] Optical lithography is a technology that uses light to project and replicate mask patterns. With the increasing demand for micro-sensors, micro-nano optoelectronics and other devices in scientific research, compared with traditional lithography machines, digital maskless lithography technology using digital micro-mirror device (DMD) spatial light modulators allows users to design patterns with greater freedom, thereby significantly improving the complexity of lithography patterns.

[0003] At present, UV light laser direct imaging (LDI) lithography technology is widely used in the field of lithography equipment for processing PCB boards. Compared with the traditional film imaging process, maskless lithography can reduce the process flow by as much as 60%. Thanks to the elimination of steps such as making photographic plates in the process, small-batch express board companies have obviously benefited from direct imaging technology.

[0004] In the field of lithography exposure, the energy uniformity of the lens directly affects the actual exposure capability of the lens, especially in large-area exposure and complex graphic generation. The insufficient light intensity in the exposure edge area and the reduced graphic clarity directly affect the product yield and process stability. In the actual production process, due to processing errors and the light output problem of the laser itself, the uniformity of the produced lens is lower than the target requirement. This directly leads to a decrease in production yield and a significant increase in costs. The uniformity problem has become a major problem restricting the performance of lithography exposure lenses; and the existing fiber laser adjustment structure is not reasonably designed, resulting in energy loss and spot distortion problems in the incident beam, and the overall light energy utilization rate is low, which cannot meet the strict requirements of high-precision lithography for uniform energy distribution and beam quality. The existing adjustment mirror group has a complex structure and a large volume, which is difficult to apply to modern miniaturized and integrated laser direct imaging lithography systems, affecting the integration and process accuracy of the whole machine.

[0005] However, the existing uniform illumination technology is mostly applied in the field of LCD display and projection, and it is difficult to meet the high consistency requirements of the laser energy distribution of the lithography exposure system; for example, patent publication number CN222439827U discloses a uniform illumination device for compensating the relative illumination loss of the lens, including a light source, a light distribution lens, an LCD screen, a front Fresnel mirror, a rear Fresnel mirror and a projection lens, which is applied in the field of LCD display and projection. The technical means adopts a light distribution lens, a Fresnel mirror group and the like to improve the energy distribution of the projection system, which is a simple projection imaging, and cannot meet the application in the field of lithography exposure, and cannot solve the uniformity problem in the high-precision laser exposure system in the field of lithography. Similarly, patent publication number CN117440141A also has the above-mentioned problems.

[0006] Patent publication number CN103885297B discloses a method for correcting the illumination uniformity of a photolithography exposure system; this method realizes light intensity adjustment of the center and edge areas of a rectangular illumination spot by moving the last lens of a condenser group along the optical axis direction to correct the illumination uniformity of the exposure spot, but has the following defects: this method only relies on adjusting the position of the condenser group lens in a single-axis (Z-axis) direction, and cannot realize adjustment in the X and Y directions, and the adjustment dimension is limited, and cannot cope with the complex offset problem existing at the light output end of a fiber laser; this solution is mainly used in step-and-scan photolithography system, and for traditional mask pattern exposure, it is difficult to adapt to the requirements of the laser direct imaging (LDI) system for optical fiber light output collimation and NA (numerical aperture) control; only by adjusting the light intensity distribution by moving the position of the condenser group lens, it is impossible to effectively optimize the light output angle and beam shape of the fiber laser itself, and there is still a risk of insufficient light spot uniformity.

[0007] Patent publication number CN116414009A discloses a uniformity correction device for a photolithography machine illumination system. The device includes a correction plate composed of a number of microcrystalline units with independently controllable transmittances. By adjusting the transmittances of the microcrystalline units, the non-uniformity of the light field integral light intensity is dynamically corrected, which simplifies the structure of the traditional "finger array" shielding device and has a real-time adjustment function. However, this technical solution is mainly used in mask projection photolithography machines and belongs to a light field intensity shielding type adjustment method. This solution has the following problems: it is impossible to adjust the NA of the light output end of the fiber laser or the spatial adjustment of the output angle. The electronic control system of the microcrystalline unit used is complex and the hardware integration is high, which leads to increased costs and increased maintenance difficulties. The transmittance adjustment still relies on the light intensity attenuation mode, which is difficult to take into account the high energy utilization requirements. It is difficult to apply to laser direct imaging lithography systems with compact structure and optimized power consumption; Authorization announcement number: CN103809382B discloses a uniform light adjustment device for lithography equipment, which uses optical lenses to form a closed volume, filled with a conductive solution, and adjusts the refractive index of the conductive solution through an electric field control unit to achieve dynamic adjustment of light transmittance. The detector can correct the uniformity of the light field in real time, and is mainly used for mask template conjugate surfaces; there are the following defects: complex structure, high hardware dependence, and difficult integration and maintenance of the control system; the light intensity is weakened, resulting in a decrease in light energy utilization; it does not have the three-dimensional adjustment capability of the optical fiber laser output end, and cannot optimize the laser beam characteristics; it is only applicable to traditional mask lithography systems and is not suitable for laser direct imaging (LDI) applications. Patent publication number CN103488061B, for EUV extreme ultraviolet lithography systems, solves complex system matching problems; uses optical path simulation and complex eye group adjustment; the system is complex, targeting the exposure requirements of high-end chip manufacturing; it cannot meet the needs of solving the above problems.

[0008] In addition, the existing technology relies on manually adjusting the position of the mirror group to improve the uniformity of the light spot, which has problems such as complex adjustment, poor repeatability, and low efficiency, and it is difficult to meet the needs of modern lithography. In response to the above-mentioned problems, an adjustment mirror group and method for improving light uniformity are proposed. Summary of the invention

[0009] The technical problem to be solved by the present invention is to overcome the existing defects and provide an adjustment lens group and method for improving the uniformity of light illumination, so as to solve the problems in the existing laser direct imaging lithography system, such as uneven energy distribution of the exposure spot and reduced product yield due to unstable light output of the fiber laser and insufficient adjustment accuracy. The adjustment method of the lens group is simple and low in cost, and the exposure uniformity of the lens is improved from 85% to 95%, and the uniformity of the lens is improved by 11.7%, which can effectively solve the problems in the background technology.

[0010] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an adjustment lens group and method for improving illumination uniformity, comprising an adjustment lens group for improving illumination uniformity, the lens group comprising a first lens, a second lens, a lens barrel, an optical fiber fixing seat and a three-dimensional adjustment mechanism, the first lens and the second lens are both plano-convex lenses, the first lens and the second lens are respectively arranged in a lens seat, the lens seat is arranged in the lens barrel, and the convex surfaces of the two lenses are arranged oppositely, an optical fiber mounting lens barrel is arranged at the upper end of the lens barrel, the optical fiber fixing seat is installed in the optical fiber mounting lens barrel, the three-dimensional adjustment mechanism is arranged between the optical fiber mounting lens barrel and the optical fiber fixing seat, and the three-dimensional adjustment mechanism is arranged between the optical fiber mounting lens barrel and the optical fiber fixing seat. The optical fiber mounting lens barrel is provided with a threaded bushing in the circumferential direction, the ball head hexagonal adjuster is installed in the threaded bushing, and the ball head end of the ball head hexagonal adjuster corresponds to the fixing nut, the tightening nut is arranged on the optical fiber mounting lens barrel, the tightening nut and the fixing nut constitute a locking mechanism, the tightening nut is provided with a tightening nut adjustment hole, the optical fiber mounting lens barrel is provided with a fixing seat adjustment hole, and a nut is provided above the optical fiber mounting lens barrel. The adjustment method comprises the following specific steps: Step 1: Install the optical lens group, install the first lens and the second lens in the lens holder respectively, so that the first lens and the second lens are assembled in the lens barrel through the lens holder in a manner that the convex surfaces of the first lens and the second lens are opposite to each other, forming a double lens combination system; Step 2: Installation of the three-dimensional adjustment mechanism: insert the threaded bushing into the optical fiber installation barrel, then install the ball head hexagonal adjuster into the threaded bushing, fix the optical fiber installation barrel to the barrel with the connecting screws, install the optical fiber fixing seat on the fixing nut, put the fixing nut into the optical fiber installation barrel, tighten the fixing nut with the ball head hexagonal adjuster, screw the tightening nut into the optical fiber fixing seat, and then tighten the nut; Step 3: Adjust in the X and Y directions. Slightly loosen the hexagonal adjuster in one direction, and then tighten the hexagonal adjuster in the opposite direction to adjust the eccentricity. Step 4: Adjust in the Z direction. First, loosen the tightening nut through the tightening nut adjustment hole with a wrench, and then use the wrench to rotate the optical fiber fixing seat through the fixing seat adjustment hole to adjust the height. Step 5: Locking operation. After completing the three-dimensional adjustment, use the double nut structure to lock the Z-axis adjustment position. You can use a wrench to tighten the tightening nut through the tightening nut adjustment hole, and lock the adjustment position in the X and Y directions through the ball head hexagonal adjuster. After fixing its position, tighten the nut.

[0011] Furthermore, a vertical convex groove is provided in the circumferential direction of the lens holder, a limiting groove is provided at the bottom of the vertical convex groove, a fixing ring is provided in the circumferential direction of the first lens and the second lens, a connecting rib is provided in the circumferential direction of the fixing ring, the first lens and the second lens are respectively clamped in the vertical convex groove of the lens holder through the connecting rib, a rubber block is provided at the outer end of the connecting rib, and the rubber block is rotatably clamped into the limiting groove.

[0012] Furthermore, an annular inner boss is provided in the inner circumferential direction of the lens holder, and the bottom surfaces of the first lens and the second lens are respectively adhered to the annular inner boss of the lens holder.

[0013] Furthermore, a base plate is provided at the lower end of the optical fiber mounting barrel, a fixing nut abuts against the base plate, the base plate is pressed on the lens seat, a center hole is provided at the center of the base plate, an upward protrusion is provided at the edge of the center hole, and the lower end of the optical fiber fixing seat is located in the center hole.

[0014] Furthermore, the side surface of the optical fiber mounting lens barrel is evenly provided with adjustment holes in the circumferential direction, at least four adjustment holes are provided, threaded bushings are provided in the adjustment holes, and the ball head hexagonal adjuster is screwed into the threaded bushings.

[0015] Furthermore, the first lens and the second lens are made of fused quartz material.

[0016] Furthermore, the optical fiber mounting lens barrel has a height of 8.12 mm and a diameter of 32 mm.

[0017] Furthermore, the adjustment accuracy of the ball head hexagonal adjuster is ±5 microns.

[0018] Furthermore, for exposure uniformity detection and correction, after the adjustment is completed, the illumination uniformity of the optical fiber laser output light beam is detected by a detection device. When the uniformity does not meet the set standard, steps three and four are repeated until the exposure uniformity meets the requirements.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. The first lens and the second lens adopt a double plano-convex lens structure, and are combined in a convex surface-to-concave manner to effectively optimize the shaping and collimation effect of the laser fiber output beam; the double lens structure adjusts the numerical aperture of the fiber laser to achieve the control of the divergence angle of the laser beam, making the light energy distribution more uniform; adjusting the mirror group can improve the illumination uniformity of the laser beam by 11.7%, significantly reduce the energy hot spots and dark areas during the exposure process, and improve the consistency and clarity of the edge of the exposure pattern.

[0020] 2. The three-dimensional adjustment mechanism adopts a ball head hexagonal adjuster with a threaded bushing design to achieve high-precision adjustment in the X, Y, and Z directions, compensating for eccentricity and height inconsistency caused by machining errors or assembly errors; through double-nut locking mechanisms such as tightening nuts, fixing nuts, and nuts, ensure that the fiber laser is fixed and stable after adjustment, avoiding displacement or spot offset during operation of the system; after adopting the three-dimensional adjustment structure, the system has enhanced stability during long-term operation, reduced fluctuations in exposure quality, and significantly improved process consistency and product yield of the lithography system.

[0021] 3. The lens holder adopts a vertical convex groove and a limit slot structure design. The first lens and the second lens are mechanically clamped and fixed by connecting ribs and rubber blocks to avoid lens displacement or falling off due to glue aging, moisture or temperature changes. This mechanical fixing method can ensure the high stability and durability of the lens during operation, reduce maintenance frequency, and extend the service life of the optical lens group.

[0022] 4. The mirror group is only 8.12mm high and 32mm in diameter, which is suitable for miniaturized, high-precision laser direct imaging lithography systems, meeting the needs of today's high-end microelectronics manufacturing equipment for miniaturization and integration. The modular design facilitates system installation, debugging and maintenance, reducing production and operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the cross-sectional structure of the present invention; Figure 2 This is an axonometric drawing of the present invention.

[0024] Figure 3 The structure of the lens holder of the present invention is shown in FIG. Figure 1 ; Figure 4 The structure of the lens holder of the present invention is shown in FIG. Figure 2 ; Figure 5 This is a schematic diagram of the enlarged structure of location A of the present invention; Figure 6 It is a schematic diagram of the structure of the fixing ring of the present invention; Figure 7 This is a schematic diagram of the optical fiber installation lens barrel structure of the present invention; Figure 8 Schematic diagram of the optical path of the double lens combination of the present invention.

[0025] In the figure: 1 lens holder, 2 ball head hexagonal adjuster, 3 optical fiber mounting barrel, 4 tightening nut, 5 optical fiber fixing seat, 6 nut, 7 threaded bushing, 8 fixing nut, 9 first lens, 10 second lens, 11 barrel, 12 connecting screw, 13 fixing seat adjustment hole, 14 tightening nut adjustment hole, 15 annular inner boss, 16 vertical convex groove, 17 limit card slot, 18 connecting rib, 19 rubber block, 20 fixing ring, 21 bottom plate, 22 center hole, 23 adjustment hole. DETAILED DESCRIPTION

[0026] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0027] See also Figure 1-8The present invention provides a technical solution: an adjustment lens group and method for improving illumination uniformity, including an adjustment lens group for improving illumination uniformity, the lens group including a first lens 9, a second lens 10, a lens barrel 11, an optical fiber fixing seat 5 and a three-dimensional adjustment mechanism, the first lens 9 and the second lens 10 are both plano-convex lenses, the first lens 9 and the second lens 10 are respectively arranged in a lens holder 1, the lens holder 1 is arranged in the lens barrel 11, and the convex surfaces of the two lenses are arranged oppositely, a brand-new double-lens structure of the first lens 9 and the second lens 10 is adopted to improve illumination uniformity, and the NA of the optical fiber laser is magnified or reduced by adopting a method in which the two convex surfaces are opposite to each other, so as to preliminarily improve the light emission problem of the optical fiber laser; the lens can be directly purchased as a commercial finished lens, and the cost is low, an optical fiber mounting lens barrel 3 is arranged at the upper end of the lens barrel 11, the optical fiber fixing seat 5 is installed in the optical fiber mounting lens barrel 3, and the optical fiber mounting lens barrel 3 is used to fix the optical fiber laser The three-dimensional adjustment mechanism is arranged between the optical fiber installation barrel 3 and the optical fiber fixing seat 5. The three-dimensional adjustment mechanism includes a tightening nut 4, a fixing nut 8 and a ball head hexagonal adjuster 2. The fixing nut 8 is arranged in the optical fiber installation barrel 3, and the optical fiber fixing seat 5 is installed on the fixing nut 8. A threaded bushing 7 is arranged in the circumferential direction of the optical fiber installation barrel 3. The ball head hexagonal adjuster 2 is installed in the threaded bushing 7, and the ball head end of the ball head hexagonal adjuster 2 corresponds to the fixing nut 8. The tightening nut 4 is arranged on the optical fiber fixing seat 5. The tightening nut 4 and the fixing nut 8 constitute a locking mechanism. The tightening nut 4 locks the optical fiber fixing seat 5 to prevent the optical fiber from deviating. The tightening nut 4 is provided with a tightening nut adjustment hole 14, and the optical fiber fixing seat 5 is provided with a fixing seat adjustment hole 13. A nut 6 is arranged above the optical fiber installation barrel 3. The nut 6 is fixed at the uppermost part and cooperates with the tightening nut 4 to complete the final locking operation. The adjustment method includes the following specific steps: Step 1: Install the optical lens group, install the first lens 9 and the second lens 10 in the lens holder 1 respectively, so that the first lens 9 and the second lens 10 are assembled in the lens barrel 11 through the lens holder 1 in a manner that the convex surfaces of the first lens 9 and the second lens 10 face each other, to form a double lens combination system; Step 2: Installation of the three-dimensional adjustment mechanism: install the threaded bushing 7 into the optical fiber installation lens barrel 3, then install the ball head hexagonal adjuster 2 into the threaded bushing 7, fix the optical fiber installation lens barrel 3 on the lens barrel 11 with the connecting screw 12, install the optical fiber fixing seat 5 on the fixing nut 8, put the fixing nut 8 into the optical fiber installation lens barrel 3, tighten the fixing nut 8 with the ball head hexagonal adjuster 2, screw the tightening nut 4 into the optical fiber fixing seat 5, and then tighten the nut 6; Step 3: Adjust in the X and Y directions. Slightly loosen the ball head hexagonal adjuster 2 in one direction, and then tighten the ball head hexagonal adjuster 2 in the opposite direction. Use this method to adjust the eccentricity. Step 4: Adjust in the Z direction. First, loosen the tightening nut 4 through the tightening nut adjustment hole 14 with a wrench, and then use the wrench to rotate and adjust the height of the optical fiber fixing seat 5 through the fixing seat adjustment hole 13; Step 5: Locking operation. After completing the three-dimensional adjustment, use the double nut structure to lock the Z-axis adjustment position. You can use a wrench to tighten the tightening nut 4 through the tightening nut adjustment hole 14, and lock the adjustment position in the X and Y directions through the ball head hexagonal adjuster 2. After fixing its position, tighten the nut 6.

[0028] The present invention utilizes a double plano-convex lens combination system constructed by the first lens 9 and the second lens 10, and realizes the shaping and collimation functions of the incident laser beam by arranging the convex surfaces relative to each other, optimizes the numerical aperture NA and the beam divergence angle of the optical fiber laser output end, and improves the uniformity of illumination; the three-dimensional adjustment mechanism is based on the combination of the ball head hexagonal adjuster 2 and the threaded bushing 7, realizes high-precision fine-tuning in the X, Y, and Z directions, and effectively calibrates the optical axis offset and incident angle problems of the optical fiber laser; the tightening nut 4 and the fixing nut 8 in the adjustment mechanism form a reliable locking system, which ensures that the overall structure is stable and not loose after the adjustment is completed. Through step-by-step adjustment and locking, the laser beam collimation and irradiation uniformity optimization are realized.

[0029] A vertical convex groove 16 is provided in the circumferential direction of the lens holder 1, and a limit clamping groove 17 is provided at the bottom of the vertical convex groove 16. A fixing ring 20 is provided in the circumferential direction of the first lens 9 and the second lens 10, and a connecting rib 18 is provided in the circumferential direction of the fixing ring 20. The first lens 9 and the second lens 10 are respectively clamped in the vertical convex groove 16 of the lens holder 1 through the connecting rib 18. This method reduces unnecessary blocking of the lens and fully utilizes the lens. A rubber block 19 is provided at the outer end of the connecting rib 18, and the rubber block 19 is vulcanized on the connecting rib 18, the rubber block 19 is rotated and inserted into the limiting slot 17. Since the size of the rubber block 19 is larger than that of the limiting slot 17, the rubber block 19 will be deformed when inserted into the limiting slot 17, and then an extrusion force is generated between the rubber block 19 and the limiting slot 17, so that the rubber block 19 will be fixed in the limiting slot 17 without rotation or shaking, which is suitable for lithography systems with high stability and shock resistance requirements. This method does not require glue fixation, but relies entirely on mechanical force for fixation, and will not fall off after fixation, which has a better effect than glue fixation.

[0030] This embodiment provides stable positioning and locking functions by designing a vertical convex groove 16 and a limit groove 17 on the lens holder 1; a fixing ring 20 is added to the first lens 9 and the second lens 10 in the circumferential direction thereof, and a connecting rib 18 extends into the vertical convex groove 16, and preliminary fixation is completed by mechanical plug-in; a rubber block 19 is installed at the outer end of the connecting rib 18, and the rubber block 19 is inserted into the limit groove 17 by rotation; when the rubber block 19 is inserted into the limit groove 17, due to its size being slightly larger than the limit groove 17, it is deformed to form an elastic pressing force, thereby achieving effective mechanical locking and preventing the lens from loosening or shifting due to vibration or temperature change; this structure does not require the use of adhesives, thereby improving assembly efficiency and reliability, and enhancing durability and environmental adaptability.

[0031] The number and spacing of the vertical convex grooves 16 can be optimized and adjusted according to the diameters of the first lens 9 and the second lens 10 to improve the adaptability of the structure to lenses of different specifications.

[0032] The rubber block 19 can be made of different materials, such as silicone, fluororubber, etc., to improve high temperature resistance, corrosion resistance or aging resistance to meet the requirements of different environmental conditions.

[0033] The connecting rib 18 may be designed in different shapes, such as T-shape, L-shape or arc shape, to meet different requirements of mechanical strength and assembly convenience.

[0034] If there is a higher demand for disassembly and assembly efficiency, a quick-release structure or positioning mark can be added to the rubber block 19 to assist in achieving fast and accurate installation.

[0035] An annular inner boss 15 is provided in the inner circumferential direction of the lens holder 1, and the bottom surfaces of the first lens 9 and the second lens 10 are respectively pasted on the annular inner boss 15 of the lens holder 1. This method is simple to install, but it is easy to fall off over time, and the annular inner boss 15 will form a certain obstruction on the circumferential direction of the lens, thereby increasing the size of the lens group. This method is suitable for systems that do not have high requirements on size, but require easy production and cost reduction. This structure is easy to install and low cost, and is suitable for systems that do not have high requirements on size.

[0036] Adhesive Types Adhesives with different properties can be selected according to application requirements, such as epoxy resin, UV curing adhesive or silicone adhesive to improve temperature resistance, UV resistance and moisture resistance.

[0037] In order to improve the bonding firmness and precision, micro positioning bumps or chamfer structures may be added to the annular inner boss 15 of the lens holder 1 to achieve higher precision mechanical limiting.

[0038] A base plate 21 is provided at the lower end of the optical fiber mounting barrel 3, and the fixing nut 8 is in contact with the base plate 21, and the base plate 21 is pressed on the lens holder 1. The base plate not only supports the double nut structure, but also presses the lens holder 1, thereby reducing the size of the lens group from the structural point of view. The overall structure is compact and reasonable, which helps to control the external dimensions of the optical components and meet the integration requirements of the miniaturized lithography system. A center hole 22 is provided at the center of the base plate 21, and an upward protrusion is provided at the edge of the center hole 22. The lower end of the optical fiber fixing seat 5 is located in the center hole 22, which limits the optical fiber fixing seat 5 and prevents the optical fiber fixing seat 5 from being excessively eccentric.

[0039] Adjustment holes 23 are evenly arranged in the circumferential direction of the side surface of the optical fiber installation barrel 3, and at least four adjustment holes 23 are arranged. The threaded bushing 7 is arranged in the adjustment hole 23, and the ball head hexagonal adjuster 2 is screwed into the threaded bushing 7. The outer dimensions of the optical fiber installation barrel 3 are 8.12mm in height and 32mm in diameter. It is suitable for miniaturized laser direct imaging lithography system and realizes high-precision three-dimensional adjustment to compensate for the errors caused by machining. The incident light source is adjusted in three directions of X, Y, and Z, and the utilization rate of light energy is improved by 11.7%.

[0040] The number of adjustment holes 23 can be increased to six or eight according to application requirements to enhance the adjustment flexibility and stability of more complex systems.

[0041] The threaded bushing 7 can be installed in a snap-fit ​​or quick-insert structure to improve maintenance efficiency and facilitate replacement and maintenance of the adjustment mechanism.

[0042] It is also possible to add anti-loosening designs to the adjustment hole 23 and the ball head hexagonal adjuster 2, such as locking nuts or anti-loosening washers, to avoid a decrease in adjustment accuracy due to vibration or thermal expansion and contraction.

[0043] The first lens 9 and the second lens 10 are made of fused quartz material; in this embodiment, the first lens 9 and the second lens 10 are made of fused quartz material to optimize the overall performance of the optical system. Fused quartz has an extremely low thermal expansion coefficient and excellent thermal stability, and can maintain the stability of size and shape under high temperature and high energy density laser irradiation conditions, avoiding optical distortion caused by temperature changes.

[0044] The high transmittance of fused quartz covers the deep ultraviolet to near-infrared band of approximately 180 nm to 2500 nm, ensuring that the laser has a low light absorption rate in different bands and significantly reducing laser energy loss; its high uniformity and low impurity content reduce scattering and absorption in the optical system, improving beam quality and system efficiency.

[0045] In addition, fused quartz has strong corrosion resistance and radiation resistance, and is suitable for use in environments such as lithography equipment that have extremely high requirements for the performance of optical components; by using fused quartz material, the optical performance and service life of the adjustable mirror system can be further improved; compared with traditional optical glass, fused quartz has a higher laser damage threshold and is suitable for high-energy density application scenarios such as laser direct imaging (LDI) systems, improving product process accuracy and production efficiency.

[0046] In addition to fused quartz, the first lens 9 and the second lens 10 can be made of sapphire, barium titanate glass or high refractive index optical glass according to specific application requirements to adapt to different wavelength ranges and optical performance requirements; multiple layers of anti-reflection coating can be added to the surface of the fused quartz lens to further reduce the surface reflectivity and improve the light flux and system energy transmission efficiency; to meet ultra-high precision requirements, the surface of the fused quartz lens can be polished by ion beam polishing or plasma chemical etching process to further reduce the surface roughness and improve the imaging quality of the lens.

[0047] The height of the optical fiber mounting lens barrel 3 is 8.12 mm and the diameter is 32 mm. The height and diameter of the optical fiber mounting lens barrel 3 are precisely designed to meet the requirements of the laser direct imaging LDI lithography system for compact structure and high integration of optical components. The height of the optical fiber mounting lens barrel 3 is set to 8.12 mm, so that the overall lens group has a lower height profile, thereby effectively reducing the overall size of the system and improving the miniaturization level of the lithography equipment.

[0048] The diameter of 32 mm ensures that the optical fiber installation lens barrel 3 has sufficient mechanical strength and stability, and at the same time provides a reasonable installation space for the internal three-dimensional adjustment mechanism such as the ball head hexagonal adjuster 2 and the fixing nut 8, ensuring the normal operation of the adjustment mechanism and high-precision adjustment capability. Through reasonable structural size design, the optical axis alignment accuracy between the fiber laser and the dual-lens combination system is ensured, and the collimation and light energy utilization rate of the laser incident beam are improved.

[0049] The structural design comprehensively considers factors such as mechanical strength, space utilization, adjustment accuracy, and heat dissipation to ensure efficient and stable operation of the optical fiber mounting lens barrel 3 in the laser direct imaging system.

[0050] The size of the optical fiber mounting lens barrel 3 can be adjusted according to the design requirements of optical fiber lasers or lithography systems of different specifications. For example, the height can be changed to 6 mm or 10 mm, and the diameter can be adjusted to 28 mm or 36 mm to adapt to systems with different power levels and focal length requirements. The outer surface of the optical fiber mounting lens barrel 3 can be added with a heat sink or coated with a high-efficiency thermal conductive coating to improve the heat dissipation efficiency of the laser under long-term working conditions and ensure system stability.

[0051] The adjustment accuracy of the ball head hexagonal adjuster 2 is ±5 microns; by adopting the high-precision ball head hexagonal adjuster 2, micron-level adjustment of the optical fiber fixing seat 5 in the three directions of X, Y, and Z is achieved; the adjustment accuracy of the ball head hexagonal adjuster 2 is controlled within the range of ±5 microns, ensuring extremely high resolution and repeatability during the adjustment process.

[0052] The adjuster 2 is manufactured using high-precision machining technology, and the matching clearance between the ball head component and the threaded bushing 7 is extremely small, ensuring stability and sensitivity during the adjustment process; during the adjustment process, the ball head part is driven to slightly displace by rotating the hexagonal adjustment rod to achieve precise push-pull action on the fixing nut 8, thereby controlling the spatial position of the optical fiber fixing seat 5 and ensuring the optical axis alignment accuracy of the laser beam output end.

[0053] The ±5-micron adjustment accuracy meets the stringent requirements of high-precision laser direct imaging lithography systems for spot collimation, energy distribution uniformity, and beam morphology stability, improving the overall exposure consistency and yield of the system.

[0054] The adjustment accuracy can be further optimized according to different system requirements, such as increasing to ±2 microns or higher to meet the application requirements of ultra-high precision laser systems or semiconductor processing.

[0055] Exposure uniformity detection and correction, after the adjustment is completed, the illumination uniformity of the optical fiber laser output beam is detected by the detection device. When the uniformity does not meet the set standard, repeat steps three and four until the exposure uniformity meets the requirements.

[0056] After the installation and three-dimensional adjustment of the fiber laser and the adjustment mirror group are completed, this implementation uses a special detection device to detect the illumination uniformity of the output light beam of the fiber laser; the detection device may include a CCD camera, an optical power meter or a laser intensity analyzer and other equipment to analyze the light intensity distribution and energy uniformity of the laser output light beam in real time.

[0057] When the test results show that the beam uniformity does not meet the set target standard, the operator needs to re-execute step three of the three-dimensional adjustment steps, X and Y direction adjustment, and step four of the Z direction adjustment according to the test feedback; by fine-tuning the ball head hexagonal adjuster 2 and the height adjustment of the optical fiber fixing seat 5, the subtle position correction of the optical fiber laser output end is achieved to optimize the divergence angle and optical axis position of the beam.

[0058] This method ensures that the exposure uniformity is stable within the set standard range through a closed-loop calibration mechanism of cyclic detection and repeated adjustment, thereby improving the exposure quality and pattern consistency of the lithography system.

[0059] The basic principles, main features and advantages of the present invention are shown and described above. Without departing from the spirit and scope of the present invention, the present invention may also be subject to various changes and improvements, which all fall within the scope of the present invention to be protected.

Claims

1. A method for improving illumination uniformity, characterized in that: The invention relates to an adjustment lens group for improving illumination uniformity, the lens group comprising a first lens (9), a second lens (10), a lens barrel (11), an optical fiber fixing seat (5) and a three-dimensional adjustment mechanism, wherein the first lens (9) and the second lens (10) are respectively arranged in a lens seat (1), the lens seat (1) is arranged in the lens barrel (11), and the convex surfaces of the two lenses are arranged opposite to each other, an optical fiber installation lens barrel (3) is arranged at the upper end of the lens barrel (11), the optical fiber fixing seat (5) is installed in the optical fiber installation lens barrel (3), the three-dimensional adjustment mechanism is arranged between the optical fiber installation lens barrel (3) and the optical fiber fixing seat (5), the three-dimensional adjustment mechanism comprises a tightening nut (4), a fixing nut (8) and a ball head hexagonal adjuster (2), the fixing nut (8) is arranged in the optical fiber installation lens barrel (3), and the optical fiber fixing seat (5) is installed on the fixing nut (8), and the adjustment method comprises the following specific steps: Step 1: installing the optical lens assembly, wherein the first lens (9) and the second lens (10) are respectively installed in the lens holder (1), so that the first lens (9) and the second lens (10) are assembled in the lens barrel (11) through the lens holder (1) with their convex surfaces facing each other, thereby forming a double lens combination system; Step 2: Install the three-dimensional adjustment mechanism. Install the threaded bushing (7) into the optical fiber installation lens barrel (3), then install the ball head hexagonal adjuster (2) into the threaded bushing (7), fix the optical fiber installation lens barrel (3) to the lens barrel (11) with the connecting screw (12), install the optical fiber fixing seat (5) on the fixing nut (8), put the fixing nut (8) into the optical fiber installation lens barrel (3), tighten the fixing nut (8) with the ball head hexagonal adjuster (2), screw the tightening nut (4) into the optical fiber fixing seat (5), and then tighten the nut (6); Step 3: Adjust in the X and Y directions. Slightly loosen the ball head hexagonal adjuster (2) in one direction, and then tighten the ball head hexagonal adjuster (2) in the opposite direction. Use this method to adjust the eccentricity. Step 4: Adjustment in the Z direction: first, loosen the tightening nut (4) through the tightening nut adjustment hole (14) with a wrench, and then use the wrench to rotate and adjust the height of the optical fiber fixing seat (5) through the fixing seat adjustment hole (13); Step 5: Locking operation. After completing the three-dimensional adjustment, use the double nut structure to lock the Z-axis adjustment position. Use a wrench to tighten the tightening nut (4) through the tightening nut adjustment hole (14). Use the ball head hexagonal adjuster (2) to lock the adjustment position in the X and Y directions. After fixing its position, tighten the nut (6).

2. The method for improving illumination uniformity according to claim 1, characterized in that: A vertical convex groove (16) is provided in the circumferential direction of the lens holder (1), a limit slot (17) is provided at the bottom of the vertical convex groove (16), a fixing ring (20) is provided in the circumferential direction of the first lens (9) and the second lens (10), a connecting rib (18) is provided in the circumferential direction of the fixing ring (20), the first lens (9) and the second lens (10) are respectively clamped in the vertical convex groove (16) of the lens holder (1) through the connecting rib (18), a rubber block (19) is provided at the outer end of the connecting rib (18), and the rubber block (19) is rotatably clamped into the limit slot (17).

3. The method for improving illumination uniformity according to claim 1, characterized in that: An annular inner boss (15) is provided in the inner circumferential direction of the lens holder (1), and the bottom surfaces of the first lens (9) and the second lens (10) are respectively adhered to the annular inner boss (15) of the lens holder (1), and the first lens (9) and the second lens (10) are both plano-convex lenses.

4. The method for improving illumination uniformity according to claim 1, characterized in that: A bottom plate (21) is provided at the lower end of the optical fiber mounting lens barrel (3), a fixing nut (8) abuts against the bottom plate (21), the bottom plate (21) is pressed against the lens holder (1), a center hole (22) is provided at the center of the bottom plate (21), an upward protrusion is provided at the edge of the center hole (22), and the lower end of the optical fiber fixing seat (5) is located in the center hole (22).

5. The method for improving illumination uniformity according to claim 1, characterized in that: Adjustment holes (23) are evenly arranged in the circumferential direction of the side surface of the optical fiber installation lens barrel (3), at least four adjustment holes (23) are arranged, a threaded bushing (7) is arranged in the adjustment hole (23), and the ball head hexagonal adjuster (2) is screwed into the threaded bushing (7).

6. The method for improving illumination uniformity according to claim 1, characterized in that: The first lens (9) and the second lens (10) are made of fused quartz material.

7. The method for improving illumination uniformity according to claim 1, characterized in that: The fiber mounting barrel (3) has a height of 8.12 mm and a diameter of 32 mm.

8. The method for improving illumination uniformity according to claim 1, characterized in that: The adjustment accuracy of the ball head hexagonal adjuster (2) is ±5 microns.

9. The method for improving illumination uniformity according to claim 1, characterized in that: After the adjustment is completed, the illumination uniformity of the optical fiber laser output light beam is detected by a detection device. When the uniformity does not meet the set standard, steps three and four are repeated until the exposure uniformity meets the requirements.

10. The method for improving illumination uniformity according to claim 1, characterized in that: A threaded bushing (7) is provided in the circumferential direction of the optical fiber installation lens barrel (3), a ball head hexagonal adjuster (2) is installed in the threaded bushing (7), and the ball head end of the ball head hexagonal adjuster (2) corresponds to the fixing nut (8), a tightening nut (4) is provided on the optical fiber fixing seat (5), the tightening nut (4) and the fixing nut (8) constitute a locking mechanism, a tightening nut adjustment hole (14) is provided on the tightening nut (4), a fixing seat adjustment hole (13) is provided on the optical fiber fixing seat (5), and a nut (6) is provided above the optical fiber installation lens barrel (3).

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