Real-time active focusing exposure machine and intelligent double-platform LDI system

Abstract

The invention provides a real-time active focusing exposure machine and an intelligent double-platform LDI system, and belongs to the field of intelligent laser processing. The exposure machine comprises an exposure head and an active focusing module; the exposure head comprises a laser source and an exposure lens module; the active focusing module comprises a focusing displacement sensor, a compensation optical wedge, an optical wedge driving module and a focusing processor; the optical wedge driving module adjusts and compensates the optical wedge based on product surface fluctuation data measured by the focusing displacement sensor to realize real-time focusing adjustment; the exposure machine disclosed by the invention adopts an active focusing scheme and is suitable for high-speed and high-precision exposure imaging; the system adopts front and back double-station alternate exposure, is high in production efficiency, and is convenient to popularize and apply in the fields of IC support plates, soft plates, HDI plates, multi-layer plates, ceramic substrates, alloy plates and the like.

Description

Technical Field

[0001] The present invention belongs to the field of laser processing, and particularly relates to an exposure machine with real-time active focusing and an intelligent dual-platform LDI system. Background Art

[0002] A Laser Direct Imaging (LDI) exposure machine is a device that uses a laser beam to precisely project a circuit pattern onto a photosensitive material, thereby forming a high-precision circuit board pattern. It is mainly used in the field of circuit board manufacturing, especially in the exposure process of the PCB (Printed Circuit Board) process.

[0003] When facing IC substrates, it is found that the unidirectional or single-channel exposure efficiency is low, and for substrates with small height differences or for the exposure processing of different layers of the same substrate, the traditional focusing method has low accuracy and slow response speed. Therefore, there is an urgent need to develop an exposure machine capable of active high-precision focusing in order to improve efficiency and accuracy. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide an exposure machine with real-time active focusing and an intelligent dual-platform LDI system, which can solve the above problems.

[0005] An exposure machine with real-time active focusing, the exposure machine includes an exposure head and an active focusing module; the exposure head includes a laser source and an exposure lens module; the active focusing module includes a focusing displacement sensor, a compensation optical wedge, an optical wedge driving module, and a focusing processor; the optical wedge driving module adjusts the compensation optical wedge based on the surface undulation data of the product measured by the focusing displacement sensor to achieve real-time focusing adjustment.

[0006] Further, the exposure head further includes an exposure rack and an image acquisition component; the image acquisition component is electrically connected to an image processor.

[0007] Further, the image acquisition component uses a Digital Micromirror Device (DMD), and a DMD water cooling unit is connected to the image acquisition component for temperature control.

[0008] Further, the laser source uses a laser in the ultraviolet / deep ultraviolet band, and a light source water cooling unit is connected to the laser source for temperature control.

[0009] Further, two focusing displacement sensors are arranged before and after each compensation optical wedge of the active focusing module along the exposure direction. The focusing processor drives the compensation optical wedge to move by activating the optical wedge driving module after detecting the undulation position and change amount within the depth of focus range. When the position beyond the depth of focus moves to the position of the optical wedge, the focal plane adjustment is in place.

[0010] Furthermore, the exposure head is arranged in multiple groups in an array, and a corresponding number of active focusing modules are arranged below the lens array of the corresponding exposure lens module.

[0011] Furthermore, the exposure machine further includes a positioning module for positioning the workpiece to be processed below.

[0012] The present invention also provides an intelligent dual-platform LDI system, including an exposure station, a stage A, a stage B, an alignment module, and peripheral modules for controlling temperature, humidity, and pressure; the stage A and the stage B are arranged on both sides of the exposure station for alternate loading and unloading; the exposure station adopts the aforementioned exposure machine; two alignment modules are arranged across the corresponding stage above for pre-positioning of the workpiece to be processed.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: The exposure machine of the present application adopts an active focusing scheme, which is suitable for high-speed and high-precision exposure imaging; the system adopts front and rear double-station alternate exposure, with high production efficiency, and is convenient for popularization and application in the fields of IC substrates, flexible boards, HDI boards, multi-layer boards, ceramic substrates, alloy boards, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the principle of active focusing of the present invention; Figure 2 It is a schematic diagram of the exposure machine with real-time active focusing of the present invention; Figure 3 It is a schematic diagram of the exposure machine arranged in an array; Figure 4 It is a schematic diagram of the intelligent dual-platform LDI system.

[0015] In the figure, 100. Exposure station; 110. Exposure head; 111. Laser source; 112. Upper exposure frame; 113. Exposure lens module; 114. Image acquisition component; 115. Image processor; 116. DMD water cooling unit; 117. Light source water cooling unit; 118. Lower exposure frame; 120. Active focusing module; 121. Focus displacement sensor; 122. Compensation optical wedge; 123. Optical wedge drive module; 130. Positioning module; 200. Stage A; 300. Stage B; 400. Alignment module; 500. Exposure calibration module; 600. Temperature control module; 700. Water chiller; 800. Dryer; 900. Gas storage tank; 1000. Blower. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0017] Exposure machine An exposure machine with real-time active focusing, see Figures 1 - 3 , the exposure machine includes an exposure head 110 and an active focusing module 120; the exposure head 110 includes a laser source 111 and an exposure lens module 113; the active focusing module 120 includes a focusing displacement sensor 121, a compensating optical wedge 122, an optical wedge driving module 123 and a focusing processor; the optical wedge driving module 123 adjusts the compensating optical wedge 122 based on the product surface undulation data measured by the focusing displacement sensor 121 to achieve real-time focusing adjustment.

[0018] Furthermore, the exposure head 110 further includes an exposure frame and an image acquisition component 114; the image acquisition component 114 is electrically connected to an image processor 115.

[0019] The laser source 111 uses ultraviolet / deep ultraviolet band laser, and a light source water cooling unit 117 is connected to the laser source 111 for temperature control.

[0020] The exposure lens module 113 uses a hybrid band imaging lens, and the compensating optical wedge 122 of the active focusing module 120 is arranged directly below the objective lens of the exposure lens module 113.

[0021] The image acquisition component 114 uses a digital micromirror device DMD, and a DMD water cooling unit 116 is connected to the image acquisition component 114 for temperature control.

[0022] In a specific example, the exposure frame includes an upper exposure frame 112 and a lower exposure frame 118.

[0023] Among them, two focusing displacement sensors 121 are arranged before and after each compensating optical wedge 122 of the active focusing module 120 along the exposure direction. The focusing processor drives the compensating optical wedge 122 to move by activating the optical wedge driving module 123 after detecting the undulation position and change amount within the hyperfocal depth range by the focusing displacement sensor 121. When the hyperfocal position moves to the position of the optical wedge, the focal plane adjustment is in place.

[0024] The focusing displacement sensor 121 uses a laser displacement sensor, the compensating optical wedge 122 uses a pair of wedge prisms that slide relative to each other with an air gap therebetween, the surfaces of the pair of wedge prisms are provided with anti-reflection film layers, and the driver of the optical wedge driving module 123 uses an actuator.

[0025] In a specific example, the air gap between the wedge surfaces of the pair of wedge prisms is 0.1 mm - 1.0 mm, and the stroke of the actuator is greater than 14 mm.

[0026] The focusing processor uses a vector diagram position compensation algorithm. Based on the real-time workpiece surface height signal of the laser displacement sensor, it corrects the uncertainty of the exposure position accuracy caused by the motion precision error through an algorithm, reducing the hardware cost.

[0027] See Figure 3 , the exposure head 110 is arranged in multiple groups in an array, and a corresponding number of active focusing modules 120 are provided below the lens array of the exposure lens module 113.

[0028] Furthermore, the exposure machine further includes a positioning module 130 for positioning the workpiece to be processed below.

[0029] Intelligent dual-platform LDI system An intelligent dual-platform LDI system, see Figure 4 , includes an exposure station 100, a stage A 200, a stage B 300, a registration module 400, and a peripheral module for controlling temperature, humidity, and pressure; the stage A 200 and the stage B 300 are arranged on both sides of the exposure station 100 for alternating loading and unloading; the exposure station 100 uses the aforementioned exposure machine; the two registration modules 400 straddle above the corresponding stage for pre-positioning the workpiece to be processed.

[0030] The intelligent dual-platform LDI system further includes an exposure calibration module 500, and the exposure calibration module 500 is connected to the carrier plate modules of the stage A 200 and the stage B 300 through a calibration adapter.

[0031] The peripheral module includes a temperature control module 600, a water chiller 700, a dryer 800, an air storage tank 900, and a blower 1000 for regulating the exposure station 100 to be in a constant temperature, constant humidity, and constant pressure working environment.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A real-time active focusing exposure machine, the exposure machine comprising an exposure head (110) and an active focusing module (120); characterized in that: The exposure head (110) comprises a laser source (111) and an exposure lens module (113); the active focus module (120) comprises a focus displacement sensor (121), a compensating optical wedge (122), an optical wedge driving module (123) and a focus adjustment processor; the optical wedge driving module (123) adjusts the compensating optical wedge (122) based on product surface undulation data measured by the focus displacement sensor (121), thereby achieving real-time focus adjustment.

2. The exposure machine according to claim 1, characterized in that: The exposure head (110) further comprises an exposure frame and an image acquisition component (114); the image acquisition component (114) is electrically connected to an image processor (115).

3. The exposure machine according to claim 1, characterized in that: The image acquisition component (114) uses a digital micromirror device (DMD), and a DMD water cooling unit (116) is connected to the image acquisition component (114) for temperature control.

4. The exposure machine according to claim 1, characterized in that: The laser source (111) uses ultraviolet / deep ultraviolet band laser, and a light source water cooling unit (117) is connected to the laser source (111) for temperature control.

5. The exposure machine according to claim 1, characterized in that: The exposure lens module (113) adopts a mixed-band imaging lens, and the compensation light wedge (122) of the active focusing module (120) is arranged directly below the objective lens of the exposure lens module (113).

6. The exposure machine according to claim 1, characterized in that: Each compensation optical wedge (122) of the active focusing module (120) is provided with two focus displacement sensors (121) in front and behind along the exposure direction. The focus adjustment processor, based on the focus displacement sensor (121), detects the fluctuation position and the variation amount of the hyperfocal depth range, and then stimulates the optical wedge driving module (123) to drive the compensation optical wedge (122) to move. When the hyperfocal depth position moves to the optical wedge position, the focal plane is adjusted to the position.

7. The exposure machine according to claim 1 or 6, characterized in that: The focusing displacement sensor (121) adopts a laser displacement sensor, the compensating optical wedge (122) adopts a double wedge prism that slides at a relative interval, the surface of the double wedge prism is provided with an anti-reflection film layer, and the driver of the optical wedge driving module (123) adopts an actuator.

8. The exposure machine according to claim 2, characterized in that: The exposure head (110) is arranged in multiple arrays, and a corresponding number of active focus modules (120) are arranged below the lens array of the corresponding exposure lens module (113).

9. The exposure machine according to claim 8, characterized in that: The exposure machine also includes a positioning module (130) for positioning a workpiece to be processed below.

10. An intelligent dual-platform LDI system, characterized in that: The invention comprises an exposure station (100), a material table A (200), a material table B (300), an alignment module (400) and a peripheral module for controlling temperature, humidity and pressure; the material table A (200) and the material table B (300) are arranged on both sides of the exposure station (100) to alternately load and unload materials; the exposure station (100) adopts the exposure machine according to claim 8 or 9; two alignment modules (400) are arranged astride the material tables on the corresponding sides to be used for front positioning of the workpiece to be processed.

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