A precision alignment device for an LDI solder mask exposure machine

Abstract

The utility model relates to circuit board manufacturing technical field discloses a kind of precision alignment devices of LDI solder mask exposure machine, including the substrate for supporting, recess is set in the middle of substrate upper end, first placement slot and second placement slot for placing workpiece are set in the middle of substrate upper end, and the inner wall of substrate is fixedly connected with supporting plate, positioning assembly for lifting solder mask exposure alignment precision is installed in the four corners of substrate, and adsorption assembly for fixing workpiece is installed in the inside of substrate.The utility model establishes rigid physical reference by positioning assembly, which can be disassembled and accurately reproduced, the built-in clamping assembly ensures that the posture and depth of positioning rod are consistent during each installation and can effectively resist vibration, providing a long-term stable high-precision reference for visual alignment. Meanwhile, the adsorption assembly generates uniform negative adsorption force, realizing non-contact full-area stable clamping of the PCB, ensuring the flatness and stability of the PCB during processing.

Description

Technical Field

[0001] This utility model relates to the field of circuit board manufacturing technology, specifically to a precision alignment device for an LDI solder resist exposure machine. Background Technology

[0002] LDI solder mask exposure machine is a key piece of equipment in PCB manufacturing. During the exposure process, precise alignment is a crucial step. A PCB board needs to go through multiple pattern transfers, and each pattern must be precisely aligned with the previous processing layer or the board's own positioning system. If the alignment is off, it will directly lead to misalignment of the circuits between different layers, causing fatal defects such as short circuits, open circuits, or poor pad coverage, which will seriously affect the product yield and reliability.

[0003] The PCB single-sided substrate solder mask exposure CCD alignment mechanism, with announcement number CN217470401U, includes a fixed plate. The fixed plate has a main positioning groove on its upper surface and a secondary positioning groove at the outer edge of the main positioning groove. A main target hole is formed at a corner of the upper surface of the fixed plate, and a secondary target hole is formed outside the main target hole. A pin is movably inserted into the inner cavity of the main target hole. The pin consists of a limiting pin and a pin head, with the pin head located at the top of the limiting pin. A cross-shaped aiming groove is formed on the surface of the pin head. Adhesive pads are attached to the bottom of the inner cavities of both the main and secondary target holes. This invention addresses the problems of low alignment efficiency and poor alignment accuracy in existing CCD alignment machines, which easily lead to product scrap. Furthermore, the alignment mechanism cannot perform self-inspection, and errors in the alignment mechanism can cause a large number of scrapped products. This device improves the alignment accuracy of the PCB single-sided substrate solder mask exposure CCD by forming a cross-shaped aiming groove on the pin surface, thus reducing the generation of defective products.

[0004] However, the pins in the aforementioned devices achieve rapid fixation by bonding adhesive pads to limiting pins. This fixation method relies entirely on the physical properties of the adhesive pads. The adhesive ages naturally over time, and its adhesion is severely affected by environmental factors and mechanical stresses from repeated insertions and removals, leading to uncontrollable attenuation of the adhesive force. This makes the pins prone to loosening, tilting, or even falling off during long-term use or when subjected to equipment vibration or impact, causing systematic alignment errors and potentially scrapping entire batches of products. Furthermore, in the aforementioned devices, the PCB board is only initially positioned and limited in lateral restraint by the sidewalls of the positioning groove. During dynamic processes such as the movement of the exposure machine's worktable and laser scanning, the PCB board may experience slight sliding or warping within the groove due to inertia or vibration. This causes a relative displacement between the actual and theoretical positions of the board during processing, resulting in quality defects such as circuit misalignment and affecting PCB manufacturing yield. Therefore, those skilled in the art provide a precision alignment device for an LDI solder mask exposure machine to solve the problem of quality defects such as circuit misalignment affecting PCB manufacturing yield in the aforementioned background art. Utility Model Content

[0005] The purpose of this invention is to provide a precision alignment device for an LDI solder resist exposure machine, thereby solving the problems mentioned in the background section of the prior art.

[0006] This utility model provides the following technical solution: a precision alignment device for an LDI solder resist exposure machine, comprising a substrate for support, a groove formed at the middle of the upper end of the substrate, a first placement groove and a second placement groove formed at the middle of the upper end of the substrate for placing workpieces, a support plate fixedly connected to the inner wall of the substrate, positioning components for improving the alignment accuracy of solder resist exposure installed at the four corners of the substrate, and an adsorption component for fixing workpieces installed inside the substrate.

[0007] As a preferred embodiment of the above technical solution, the positioning component includes a first positioning hole, a second positioning hole, and two slots. The first positioning hole and the second positioning hole are both located at one corner of the substrate, and the two slots are located at one upper corner of the tray. The two slots are respectively located directly below the first positioning hole and the second positioning hole. A positioning rod is provided in the first positioning hole, and the positioning rod matches the slot. Two symmetrically arranged snap-fit ​​components are installed in the positioning rod.

[0008] As a preferred embodiment of the above technical solution, a cross-shaped positioning groove is provided at the middle of the upper end of the positioning rod, and a marking rod is fixedly connected to the middle of the bottom inner wall of the cross-shaped positioning groove. Two symmetrically arranged slots are provided on the inner walls of the first positioning hole and the second positioning hole.

[0009] As a preferred embodiment of the above technical solution, the snap-fit ​​assembly includes a sliding cavity, a plurality of springs are fixedly connected to the inner wall of the sliding cavity, a movable plate is slidably connected inside the sliding cavity, the movable plate is fixedly connected to one end of the plurality of springs, and a wedge block is fixedly connected to the lower part of the side of the movable plate away from the springs. The wedge block penetrates the inner wall of one side of the sliding cavity, and the wedge block and the snap-fit ​​groove engage.

[0010] As a preferred embodiment of the above technical solution, an ejector block is fixedly connected to the upper part of the side of the movable plate away from the spring. The ejector block penetrates the inner wall of one side of the sliding cavity, and a pressing block is fixedly connected to the end of the ejector block away from the movable plate.

[0011] As a preferred embodiment of the above technical solution, the adsorption component includes an air intake chamber and an air extraction pipe. The air intake chamber is located in the middle of the substrate, and the air extraction pipe is located inside the substrate. The air extraction pipe penetrates the substrate and is connected to the inner wall of the air intake chamber. The top inner wall of the air intake chamber is provided with a plurality of air exchange holes arranged in an array, and the plurality of air exchange holes are all connected to the interior of the groove.

[0012] As a preferred embodiment of the above technical solution, a plurality of mounting blocks are fixedly connected to the sidewall of the substrate, and each of the plurality of mounting blocks has a mounting hole at its center, and a screw is provided in each of the plurality of mounting holes.

[0013] Compared with the prior art, the beneficial effects of this utility model are: 1. The positioning assembly of this device uses a positioning rod with an internal sliding cavity, spring, and wedge block. The positioning rod is inserted into the first or second positioning hole, thus establishing a reliable and detachable physical reference. The aiming reference of the cross-shaped positioning groove provides stability and high contrast for the CCD vision system. The snap-fit ​​assembly ensures that the positioning rod is installed in the same posture and depth each time, so that the positioning rod can be stably fixed in the designated position on the substrate and can effectively resist vibration and impact during processing. This establishes a long-term stable and accurately reproducible rigid reference for the CCD alignment system, thereby ensuring alignment accuracy and production yield.

[0014] 2. The adsorption component, through the air suction chamber, air extraction pipe and array of ventilation holes integrated inside the substrate, can generate a uniform and stable downward adsorption force on the PCB board placed in the first and second placement slots, achieving non-contact full-area fixation. This avoids the stress or displacement of the board that may be caused by mechanical clamping, and ensures that the PCB board remains absolutely flat and stable during subsequent alignment and exposure processes, providing a foundation for high-precision processing. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the main structure of a precision alignment device for an LDI solder resist exposure machine; Figure 2 Another perspective schematic diagram of the main structure of a precision alignment device for an LDI solder resist exposure machine; Figure 3 This is an exploded view of the precision alignment device of an LDI solder resist exposure machine. Figure 4 A schematic diagram of the positioning component structure of a precision alignment device for an LDI solder resist exposure machine; Figure 5 A schematic diagram of a cross-shaped positioning groove structure for a precision alignment device of an LDI solder resist exposure machine; Figure 6 This is a schematic diagram of the adsorption component structure of a precision alignment device for an LDI solder resist exposure machine.

[0016] 1. Base plate; 2. Groove; 3. First placement groove; 4. Second placement groove; 5. Support plate; 6. Positioning assembly; 601. First positioning hole; 602. Second positioning hole; 603. Slot; 604. Positioning rod; 605. Cross-shaped positioning groove; 606. Marking rod; 607. Slot; 608. Sliding cavity; 609. Spring; 610. Moving plate; 611. Wedge block; 612. Ejection block; 613. Pressing block; 7. Adsorption assembly; 701. Suction chamber; 702. Suction pipe; 703. Ventilation hole; 8. Mounting block; 9. Mounting hole; 10. Screw. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0018] Please see Figures 1-6 As shown, this utility model provides a technical solution: a precision alignment device for an LDI solder resist exposure machine, including a base plate 1 for support, a groove 2 formed at the middle of the upper end of the base plate 1, a first placement groove 3 and a second placement groove 4 formed at the middle of the upper end of the base plate 1 for placing the workpiece, a support plate 5 fixedly connected to the inner wall of the base plate 1, positioning components 6 for improving the alignment accuracy of the solder resist exposure are installed at the four corners of the base plate 1, and an adsorption component 7 for fixing the workpiece is installed inside the base plate 1.

[0019] Furthermore, the substrate 1 serves as the rigid support foundation for the entire device, providing a stable mounting platform for functional components and ensuring the structural stability of the device during operation. This is a physical prerequisite for achieving high-precision alignment. The groove 2 is located at the upper end of the substrate 1, which reduces the weight of the substrate 1 and provides integrated space for the suction of the adsorption component 7, thus helping to optimize the device structure. The first placement groove 3 and the second placement groove 4 are used to accommodate two different sizes of PCB board processing parts. The boundaries of the first placement groove 3 and the second placement groove 4 provide initial physical positioning of the PCB board processing parts, achieving rapid pre-positioning and improving the equipment's compatibility and operational efficiency for workpieces of different specifications. The tray 5 is fixed to the inner wall of the substrate 1. The structure used to support the placement slot area enhances the rigidity of the area and prevents local deformation caused by slotting, thereby ensuring the flatness of the placement surface. The positioning components 6 are distributed at the four corners of the substrate 1. Their core function is to establish a high-precision physical reference coordinate system, providing accurate and repeatable reference points for the subsequent CCD vision alignment system. This directly determines the final accuracy and repeatability of the entire exposure alignment process. The adsorption component 7 is integrated inside the substrate 1. By generating a uniformly distributed negative pressure, it firmly adsorbs the workpiece placed in the slot onto the working plane, realizing non-contact full-area clamping. This effectively avoids board warping or micro-displacement that may be caused by mechanical clamping, providing stable workpiece fixing conditions for high-precision exposure.

[0020] As one implementation method in this embodiment, please refer to Figures 1-5 As shown, the positioning component 6 includes a first positioning hole 601, a second positioning hole 602, and two slots 603. The first positioning hole 601 and the second positioning hole 602 are both opened at one corner of the base plate 1, and the two slots 603 are opened at one corner of the upper end of the support plate 5. The two slots 603 are respectively located directly below the first positioning hole 601 and the second positioning hole 602. A positioning rod 604 is provided in the first positioning hole 601. The positioning rod 604 matches the slot 603. Two symmetrically arranged snap-fit ​​components are installed in the positioning rod 604. A cross-shaped positioning groove 605 is provided at the middle of the upper end of the positioning rod 604. A marking rod 606 is fixedly connected to the middle of the bottom inner wall of the cross-shaped positioning groove 605. Two symmetrically arranged slots 607 are provided on the inner walls of the first positioning hole 601 and the second positioning hole 602.

[0021] Furthermore, the first positioning hole 601 and the second positioning hole 602, as two sets of reference holes opened at the corner of the substrate 1, provide installation position selection to adapt to the alignment requirements of PCB boards of different sizes, enhancing the versatility of the device. The slot 603 is precisely opened on the support plate 5 and aligned with the first positioning hole 601 and the second positioning hole 602 above, used to receive and guide the bottom end of the positioning rod 604, ensuring that the verticality of the positioning rod 604 after insertion is consistent with the installation depth, providing a basic guarantee for high-precision positioning. The positioning rod 604, as an insertable core reference component, has its body precisely matched with the slot 603, forming a stable, reusable rigid reference post. The cross-shaped positioning groove 605 is machined. At the top of the positioning rod 604, its clear crosshairs provide the CCD vision system with a high-contrast target pattern that is easy to accurately identify the center. This is a key feature for achieving alignment accuracy. The marker rod 606 is fixed to the bottom center of the cross-shaped positioning groove 605, further highlighting the center of the visual target and assisting the CCD camera in capturing the center point more quickly and accurately. The slots 607 are symmetrically opened on the inner walls of the first positioning hole 601 and the second positioning hole 602. They cooperate with the snap-fit ​​components inside the positioning rod 604 to automatically lock after the positioning rod 604 is inserted into place, preventing the positioning rod 604 from shifting or loosening due to vibration during processing, and ensuring the long-term stability and reliability of the reference position.

[0022] As one implementation method in this embodiment, please refer to Figures 3-5 As shown, the snap-fit ​​assembly includes a sliding cavity 608, with multiple springs 609 fixedly connected to the inner wall of the sliding cavity 608. A movable plate 610 is slidably connected inside the sliding cavity 608, and the movable plate 610 is fixedly connected to one end of the multiple springs 609. A wedge block 611 is fixedly connected to the lower part of the side of the movable plate 610 away from the springs 609. The wedge block 611 penetrates the inner wall of one side of the sliding cavity 608, and the wedge block 611 and the snap-fit ​​groove 607 engage in a snap-fit ​​connection. An ejector block 612 is fixedly connected to the upper part of the side of the movable plate 610 away from the spring 609. The ejector block 612 penetrates the inner wall of one side of the sliding cavity 608. A pressing block 613 is fixedly connected to the end of the ejector block 612 away from the movable plate 610.

[0023] Furthermore, the sliding cavity 608, as a cavity opened inside the positioning rod 604, provides the entire locking mechanism with a space for accommodation and a movement track, and is the structural basis for the operation of the component. One end of the spring 609 is fixed to the inner wall of the sliding cavity 608, and the other end is connected to the moving plate 610. The pre-compressed elastic force of the spring 609 provides a continuous and stable driving force for the locking action, which is the core of realizing automatic locking. The moving plate 610 is slidably connected in the sliding cavity 608. The moving plate 610 transmits the elastic force of the spring 609 to the wedge block 611 to realize the functions of insertion self-locking and press unlocking. The wedge block 611 is fixed to the lower side of the moving plate 610. The front end of the wedge block 611 is designed as a bevel. When the positioning rod 604 is inserted into the first positioning hole 601 and the second positioning hole 602, the bevel of the wedge block 611 contacts the edge of the hole and can decompose the vertically downward insertion force into pushing the moving plate 610 horizontally. The inward force compresses the spring 609. When the wedge block 611 moves to align with the slot 607, the spring 609 pushes the moving plate 610, causing the wedge block 611 to quickly pop out and lock into the slot 607, achieving a secure mechanical interlock. This effectively prevents the positioning rod 604 from loosening or coming out during processing vibrations. The ejector block 612 is fixed to the upper side of the moving plate 610. Its function is to directly and efficiently transmit force to the moving plate 610 during external operation. The pressing block 613 is connected to the outer end of the ejector block 612 and exposed on the surface of the positioning rod 604, providing the user with a clear and easy-to-apply operating point. When disassembly is required, pressing the pressing blocks 613 on both sides simultaneously will push the moving plate 610 inward through the ejector block 612, compressing the spring 609 and causing the wedge block 611 to exit the slot 607, thereby easily pulling out the positioning rod 604, achieving quick and non-destructive maintenance and replacement.

[0024] As one implementation method in this embodiment, please refer to Figure 6 As shown, the adsorption component 7 includes an air intake chamber 701 and an air extraction pipe 702. The air intake chamber 701 is located in the middle of the interior of the substrate 1. The air extraction pipe 702 is disposed inside the substrate 1, penetrates the substrate 1, and is connected to the inner wall of the air intake chamber 701. The top inner wall of the air intake chamber 701 is provided with a plurality of air exchange holes 703 arranged in an array. All the air exchange holes 703 are connected to the interior of the groove 2.

[0025] Furthermore, the suction chamber 701, as a core cavity inside the substrate 1, constitutes a negative pressure volume, which can collect and evenly distribute the adsorption force generated by the external vacuum system. This is the basis for achieving stable adsorption across the entire area. The suction pipe 702 penetrates the substrate 1 and connects to the suction chamber 701. One end of the suction pipe 702 is connected to the external vacuum system. The suction effect of the external vacuum system can efficiently introduce gas into the suction chamber 701, which is a direct way to generate and maintain the working negative pressure. The ventilation holes 703 are densely arranged in an array on the top of the suction chamber 701 and connect upward to the working plane of the groove 2. These channels directly transmit the uniform negative pressure in the suction chamber 701 to the back of the PCB board placed above the groove 2, thereby generating a widely distributed and uniformly forceful downward adsorption force. This effectively avoids board warping or local stress caused by uneven adsorption force, ensuring that the PCB board maintains absolute flatness and positional stability throughout the entire processing process, providing crucial fixing conditions for subsequent high-precision alignment and exposure.

[0026] As one implementation method in this embodiment, please refer to Figures 1-3 As shown, multiple mounting blocks 8 are fixedly connected to the side wall of the substrate 1. Each mounting block 8 has a mounting hole 9 at its center, and each mounting hole 9 has a screw 10 installed inside it.

[0027] Furthermore, the mounting block 8, as a protruding structure fixedly connected to the side wall of the substrate 1, provides sufficient operating space and a solid point of force. The mounting hole 9 is precisely opened at the center of each mounting block 8, providing a standard through channel and positioning reference for the fastener, ensuring accurate alignment during installation. The screw 10 passes through the mounting hole 9 and is tightened by engaging with the threaded hole on the external equipment workbench, generating a strong axial clamping force, thereby firmly and reliably locking the entire substrate 1 and the precision components it carries in the predetermined working position, effectively resisting the vibration and impact generated during equipment operation.

[0028] The specific working principle of this utility model is as follows: First, the entire substrate 1 is firmly fixed on the worktable of the LDI solder mask exposure machine through the mounting holes 9 and screws 10 on the mounting block 8. Then, the operator selects to place the PCB board to be processed into the first placement slot 3 or the larger second placement slot 4 for initial positioning according to the size of the PCB board to be processed. The external vacuum system draws air through the air extraction pipe 702, so that the air suction chamber 701 and the multiple air exchange holes 703 connected to it generate negative pressure, so that the PCB board is evenly and firmly adsorbed and fixed in the first placement slot 3 or the second placement slot 4. Subsequently, four positioning rods 604 are inserted into the corresponding first positioning hole 601 or second positioning hole 602. When the positioning rod 604 is inserted, its internal locking assembly is activated. The inclined surface of the wedge block 611 is located at the lower end. When the positioning rod 604 is inserted, the inclined surface of the wedge block 611 contacts the upper end of the substrate 1. The inclined surface of the wedge block 611 can decompose the force, causing the spring 609 to contract under force. When the wedge block 611 moves to align with the slot 607 in the hole, under the push of the spring 609, the moving plate 610 drives the wedge block 611 to pop out and lock into the slot 607, thereby ensuring that all positioning rods 604 are installed vertically and at the same height, so that the positioning rods 604 can be stably fixed at the designated position on the substrate 1. It can effectively resist vibration and impact during processing, thus establishing a long-term stable and accurately reproducible rigid reference for the CCD alignment system, thereby ensuring alignment accuracy and production yield. Then, the worktable moves into the device, and the CCD camera of the LDI equipment moves to the working area to accurately capture the center of the cross-shaped positioning groove 605 at the top of each positioning rod 604 as a target, and compares it with the theoretical coordinates preset by the system to calculate the position deviation. Then, a small amount of translation and rotation compensation is performed to make the actual coordinates of the cross-shaped positioning groove 605 of the positioning rod 604 completely coincide with the theoretical coordinates, which means that the PCB board has reached the alignment accuracy required for exposure, and then scanning and exposure can be performed according to the graphic data. After exposure is complete, turn off the vacuum of the adsorption component 7 to release the fixation of the PCB board, and the PCB board can be taken out. When maintenance is required, press the pressing blocks 613 on both sides of the positioning rod 604, and push the moving plate 610 inward through the ejector block 612 to compress the spring 609, so that the wedge block 611 can be removed from the slot 607, and the positioning rod 604 can be easily pulled out to achieve quick replacement and maintenance.

[0029] The above embodiments are only used to illustrate the technical solution of this utility model, and are not intended to limit it.

Claims

1. A precision alignment device for an LDI solder resist exposure machine, comprising a substrate (1) for support, characterized in that: The substrate (1) has a groove (2) at the middle of the upper end, and a first placement groove (3) and a second placement groove (4) for placing the workpiece are provided at the middle of the upper end of the substrate (1). A support plate (5) is fixedly connected to the inner wall of the substrate (1). Positioning components (6) for improving the alignment accuracy of the solder mask exposure are installed at the four corners of the substrate (1). An adsorption component (7) for fixing the workpiece is installed inside the substrate (1).

2. The precision alignment device for an LDI solder resist exposure machine according to claim 1, characterized in that: The positioning component (6) includes a first positioning hole (601), a second positioning hole (602), and two slots (603). The first positioning hole (601) and the second positioning hole (602) are both located at one corner of the base plate (1). The two slots (603) are located at one corner of the upper end of the tray (5). The two slots (603) are located directly below the first positioning hole (601) and the second positioning hole (602), respectively. A positioning rod (604) is provided in the first positioning hole (601). The positioning rod (604) matches the slot (603). Two symmetrically arranged snap-fit ​​components are installed in the positioning rod (604).

3. The precision alignment device for an LDI solder resist exposure machine according to claim 2, characterized in that: A cross-shaped positioning groove (605) is provided at the middle of the upper end of the positioning rod (604). A marking rod (606) is fixedly connected to the middle of the bottom inner wall of the cross-shaped positioning groove (605). Two symmetrically arranged slots (607) are provided on the inner walls of the first positioning hole (601) and the second positioning hole (602).

4. The precision alignment device for an LDI solder resist exposure machine according to claim 2, characterized in that: The snap-fit ​​assembly includes a sliding cavity (608), with multiple springs (609) fixedly connected to the inner wall of the sliding cavity (608). A movable plate (610) is slidably connected inside the sliding cavity (608). The movable plate (610) is fixedly connected to one end of the multiple springs (609). A wedge block (611) is fixedly connected to the lower part of the side of the movable plate (610) away from the springs (609). The wedge block (611) penetrates the inner wall of one side of the sliding cavity (608). The wedge block (611) and the snap-fit ​​groove (607) engage in a snap-fit ​​connection.

5. The precision alignment device for an LDI solder resist exposure machine according to claim 4, characterized in that: A push-out block (612) is fixedly connected to the upper part of the side of the movable plate (610) away from the spring (609). The push-out block (612) penetrates the inner wall of one side of the sliding cavity (608). A pressing block (613) is fixedly connected to the end of the push-out block (612) away from the movable plate (610).

6. The precision alignment device for an LDI solder resist exposure machine according to claim 1, characterized in that: The adsorption assembly (7) includes an air intake chamber (701) and an air extraction pipe (702). The air intake chamber (701) is located in the middle of the substrate (1). The air extraction pipe (702) is located inside the substrate (1). The air extraction pipe (702) penetrates the substrate (1) and is connected to the inner wall of the air intake chamber (701). The top inner wall of the air intake chamber (701) is provided with a plurality of air exchange holes (703) arranged in an array. The plurality of air exchange holes (703) are all connected to the interior of the groove (2).

7. The precision alignment device for an LDI solder resist exposure machine according to claim 1, characterized in that: The substrate (1) has multiple mounting blocks (8) fixedly connected to its sidewall. Each of the mounting blocks (8) has a mounting hole (9) at its center and a screw (10) is provided in each of the mounting holes (9).

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