A dot-jet compensation etching device

Abstract

This invention belongs to the field of circuit board etching technology and discloses a spot spray compensation etching device, including an etching cylinder and a conveying device. The etching cylinder is used to store etching liquid, and the conveying device is used to convey the etched workpiece. It also includes multiple sets of nozzles, each set of nozzles is arranged sequentially along the conveying direction of the etched workpiece, and each set of nozzles includes multiple nozzles arranged sequentially along the direction perpendicular to the conveying direction of the etched workpiece. The etching cylinder is connected to a compensation pump, which is connected to each nozzle through a pipeline. Each nozzle has a spot spray control valve on its liquid inlet side for controlling the opening and closing of the nozzle. It also includes a controller, and a pressure gauge is installed on the spray pipe. The compensation pump, spot spray control valve, liquid inlet control valve, and pressure gauge are all electrically connected to the controller. This invention can automatically control the opening and closing of the corresponding nozzles according to the distribution of residual copper on the etched workpiece, and is suitable for spot spray compensation etching of various types of circuit boards with different residual copper defects.

Description

Technical Field

[0001] This invention belongs to the field of circuit board etching technology, specifically relating to a dot spray compensation etching device. Background Technology

[0002] During the PCB etching process, uneven etching often occurs due to various factors, such as uneven flow of the etching solution, inaccurate etching time control, and differences in the performance of etching equipment, resulting in residual copper on the PCB. This residual copper affects the electrical performance, reliability, and product quality of the PCB, and traditional etching methods struggle to precisely address it. Currently, while some etching compensation methods exist, most involve large-area secondary etching or manual repair, which is not only inefficient but also makes it difficult to precisely control the etching location and amount, easily damaging already etched areas and affecting the overall performance of the PCB.

[0003] To address this, a spot-spraying compensation etching method has been proposed, which compensates for residual copper by spraying etching solution onto specific areas. However, existing compensation etching spray devices can only achieve this by manually blocking individual nozzles, resulting in a lack of flexibility. Furthermore, with the increasing complexity of PCB products and the more frequent occurrence of residual copper, the demand for localized compensation on PCBs is growing. Moreover, the compensation locations vary depending on the PCB product, process conditions, and equipment, necessitating frequent manual nozzle blocking and hindering efficient and effective compensation etching. Summary of the Invention

[0004] The purpose of this invention is to provide a spot spray compensation etching device, which aims to improve the problem that existing compensation etching spray devices are inflexible and inconvenient to use, making it difficult to achieve effective compensation etching efficiently.

[0005] To achieve the above objectives, the present invention provides a point-spraying compensation etching device, comprising an etching cylinder and a conveying device. The etching cylinder is used to store etching solution, and the conveying device is used to convey the etched workpiece. It also includes multiple sets of nozzles and a controller. Each set of nozzles is arranged sequentially along the conveying direction of the etched workpiece, and each set of nozzles includes multiple nozzles arranged sequentially perpendicular to the conveying direction of the etched workpiece. The etching cylinder is connected to a compensation pump, which is connected to each nozzle via a pipeline. Each nozzle has a point-spraying control valve on its liquid inlet side for controlling the opening and closing of the nozzle. The controller is electrically connected to an optical detection mechanism, which includes an illumination device and an image acquisition device. The image acquisition device is used to acquire images of the etched workpiece, and the illumination device provides sufficient light for the image acquisition device to acquire images. The controller includes a storage module and a residual copper identification module. The image acquisition device transmits the acquired images to the residual copper identification module. The storage module stores a residual copper identification algorithm, and the residual copper identification module calls the residual copper identification algorithm in the storage system to process the image and identify the location and range of residual copper.

[0006] Furthermore, it also includes multiple spray pipes, the length direction of each spray pipe is perpendicular to the conveying direction of the etched workpiece, the number of spray pipes is the same as the number of nozzle groups, each spray pipe is equipped with a set of nozzles, each spray pipe is connected to a compensation pump through a connecting pipe, and each spray pipe is equipped with a liquid inlet control valve on the liquid inlet side, the compensation pump delivers the etching liquid in the etching tank to the spray pipe with the corresponding liquid inlet control valve open.

[0007] Furthermore, a filter is provided between the compensation pump and the connecting pipes of each spray pipe, each spray pipe is equidistantly arranged along the conveying direction perpendicular to the etched workpiece, and multiple nozzles installed on each spray pipe are equidistantly arranged.

[0008] Furthermore, a pressure gauge is installed on the spray pipe, and the compensation pump, the spot spray control valve, the liquid inlet control valve, and the pressure gauge are all electrically connected to the controller.

[0009] Furthermore, the controller is electrically connected to an optical inspection mechanism, which includes an illumination device and an image acquisition device. The image acquisition device is used to acquire images of the etched workpiece, and the illumination device provides sufficient light conditions for the image acquisition device to acquire images. The controller includes a storage module and a residual copper identification module. The image acquisition device transmits the acquired images to the residual copper identification module. The storage module stores a residual copper identification algorithm. The residual copper identification module calls the residual copper identification algorithm in the storage system to process the image and identify the location and range of residual copper.

[0010] Furthermore, the controller is also electrically connected to a conveying photoelectric sensor, which is used to detect the position of the etched workpiece and transmit the detection data to the controller. The controller controls the corresponding nozzle to open when the etched workpiece is conveyed to the point where its residual copper is aligned with the nozzle, based on the position of the etched workpiece, the position of each group of nozzles, the conveying speed, and the position of the residual copper on the etched workpiece. The opened nozzle closes when the etched workpiece is conveyed to the point where its residual copper is no longer aligned with the nozzle.

[0011] Furthermore, based on the position and range of residual copper on the etched workpiece and the travel path of the etched workpiece, the controller calculates all nozzles corresponding to the residual copper on the etched workpiece when the etched workpiece is transported to the point spray compensation etching area. The controller then controls the opening of the point spray control valves corresponding to all nozzles corresponding to the residual copper on the etched workpiece, while the remaining point spray control valves are closed.

[0012] Furthermore, the controller is also electrically connected to a conveying photoelectric sensor, which is used to detect the position of the etched workpiece and transmit the detection data to the controller. The controller performs the following control based on the position of the etched workpiece, the position of each group of nozzles, the conveying speed, and the start and end positions of the residual copper on the etched workpiece along the conveying direction of the etched workpiece: when the etched workpiece is conveyed to the starting end of its residual copper and reaches any group of nozzles, the liquid inlet control valve corresponding to the spray pipe where that group of nozzles is located is opened; when the etched workpiece is conveyed to the ending end of its residual copper and reaches any group of nozzles, the liquid inlet control valve corresponding to the spray pipe where that group of nozzles is located is closed.

[0013] Furthermore, the controller is also electrically connected to an optical interferometer, which measures the thickness distribution of residual copper on the etched workpiece and sends the measurement results to the controller. The controller's storage module stores a basic thickness threshold T0. The controller compares the received residual copper thickness T with the basic thickness threshold T0 and adjusts the opening of the corresponding point spray control valve according to the comparison result. The basic opening of the point spray control valve is less than 100%. The specific adjustment method is as follows:

[0014] When the thickness of the residual copper in a certain residual copper area is T≤0.5×T0, the opening degree of the point spray control valve corresponding to the nozzle in that residual copper area decreases.

[0015] When the thickness of residual copper in a certain residual copper area is 0.5×T0<T≤T0, the opening degree of the point spray control valve corresponding to the nozzle of the residual copper area remains unchanged.

[0016] When the thickness of residual copper in a certain residual copper area is T > T0, the opening degree of the point spray control valve corresponding to the nozzle in that residual copper area increases.

[0017] Furthermore, the interferometer includes a laser source, a beam splitter, a mirror, a detector, and a control module. The laser source provides a beam with a stable wavelength and high coherence. The beam splitter divides the beam emitted by the laser source into two parts: one part serves as a reference beam, and the other part serves as a measurement beam. The mirror reflects the reference beam and the measurement beam back. The detector receives interference fringes and converts them into electrical signals, which are then transmitted to the control module. The control module receives and processes the electrical signals output by the detector and calculates the thickness of the residual copper.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. This invention can automatically control the opening and closing of the corresponding nozzles according to the distribution of residual copper on the etched workpiece. It has a high degree of automation, is flexible and convenient to use, and is suitable for spot spraying compensation etching for circuit boards of various types and with different residual copper defects. It can efficiently achieve effective compensation etching.

[0020] 2. The present invention is equipped with an optical interferometer, which can measure the thickness distribution of residual copper on the etched workpiece and automatically adjust the spray volume of the required etching solution according to the different thicknesses of residual copper, so as to remove residual copper on the etched workpiece more effectively. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the dot spray compensation etching device provided by the present invention;

[0022] Figure 2 This is a block diagram of the electrical control structure of the dot spray compensation etching device provided by the present invention;

[0023] Figures 3-9 This is a schematic diagram of the first process of compensation etching using the dot spray compensation etching device provided by the present invention.

[0024] Figures 10-18 This is a schematic diagram of a second process for compensation etching using the dot-jet compensation etching device provided by the present invention.

[0025] In the diagram: 1. Etching cylinder; 2. Etched workpiece; 3. Nozzle; 4. Compensation pump; 5. Spot spray control valve; 6. Spray pipe; 61. First spray pipe; 62. Second spray pipe; 63. Third spray pipe; 64. Fourth spray pipe; 7. Liquid inlet control valve; 8. Pressure gauge; 9. Filter. Detailed Implementation

[0026] The following description, in conjunction with the accompanying drawings and specific embodiments, provides further details:

[0027] A dot-jet compensation etching device, such as Figure 1As shown, the system includes an etching tank 1, a conveying device, multiple spray pipes 6, and multiple sets of nozzles 3. The etching tank 1 stores the etching solution and has a temperature heating structure and a temperature measuring structure to ensure the etching solution is within a suitable process temperature range. The conveying device conveys the workpiece 2 to be etched; the workpiece 2 is a circuit board. The number of spray pipes 6 is the same as the number of sets of nozzles 3. The length direction of each spray pipe 6 is perpendicular to the conveying direction of the workpiece 2. Each spray pipe 6 is equipped with a set of nozzles 3, and each set of nozzles 3 contains multiple nozzles arranged sequentially along the conveying direction perpendicular to the workpiece 2. Each nozzle 3 has a point-spray control valve 5 on its liquid inlet side to control the opening and closing of the nozzle 3. The point-spray control valve 5 is a pneumatic proportional valve with adjustable valve opening, which can proportionally control the flow rate according to the magnitude of the input signal, enabling continuous and precise flow rate adjustment. The spray pipes 6 are equidistantly arranged along the conveying direction perpendicular to the workpiece 2, and the multiple nozzles 3 installed on each spray pipe 6 are also equidistantly arranged. The etching tank 1 is connected to a compensation pump 4, which is connected to each spray pipe 6 via pipes. Each spray pipe 6 has an inlet control valve 7 on its inlet side. The compensation pump 4 can deliver the etching solution in the etching tank 1 to the spray pipe 6 whose corresponding inlet control valve 7 is open. A filter 9 is installed between the compensation pump 4 and each spray pipe 6. The filter 9 is used to filter solid impurities in the etching solution to prevent clogging of the nozzles 3.

[0028] like Figure 1 and Figure 2 As shown, a pressure gauge 8 is installed on the spray pipe 6. This invention also includes a conveying photoelectric sensor, an optical detection mechanism, and a controller. The controller can use a touchscreen with an MCU control module. The conveying device, compensation pump 4, point spray control valve 5, liquid inlet control valve 7, pressure gauge 8, conveying photoelectric sensor, and optical detection mechanism are all electrically connected to the controller. The motor of the compensation pump 4 is a variable frequency motor, which can adjust the flow rate of the supplied etching solution based on the detection result of the pressure gauge 8 or the number of point spray control valves 5 and liquid inlet control valves 7 to be opened, thereby reducing fluctuations and achieving more stable and accurate flow control for each nozzle 3. The controller can control the conveying speed of the conveying device, and can also calculate the time required for the etched workpiece 2 to be conveyed a certain distance based on the conveying speed of the conveying device, or calculate the distance the etched workpiece 2 is conveyed within a certain time. The conveying photoelectric sensor is used to detect the position of the etched workpiece 2 and transmit the detection data to the controller so that the controller knows whether the etched workpiece 2 has reached a certain set reference position. The reference position can be set as the position where the etched workpiece 2 just enters the spray etching area. The controller can accurately calculate the precise position of the etched workpiece 2 in the spray etching area at a certain moment by interacting with the photoelectric sensor and the conveying device.

[0029] The optical inspection mechanism includes an illumination device and an image acquisition device. The image acquisition device is used to acquire images of the etched workpiece 2, and the illumination device provides sufficient light for the image acquisition device to acquire images. The controller has a storage module and a residual copper identification module. The image acquisition device transmits the acquired images to the residual copper identification module. The storage module stores the residual copper identification algorithm. The residual copper identification module calls the residual copper identification algorithm in the storage system to process the image and identify the location and range of residual copper. The residual copper identification algorithm can adopt image processing techniques based on image grayscale, edge detection, texture analysis, etc. For example, by comparing the grayscale values ​​of different areas in the circuit board image, a certain grayscale threshold is set, and areas with actual grayscale values ​​higher than the grayscale threshold are judged as residual copper areas.

[0030] The point spray compensation etching device provided by this invention is used to perform point spray compensation etching on the workpiece 2. It has a variety of operation and control methods, and the following two usage examples are used to illustrate this.

[0031] Example 1:

[0032] The basic principle of operation and control in this embodiment is as follows: the controller controls the corresponding nozzle 3 to open when the workpiece 2 is conveyed to a point where its residual copper is aligned with the nozzle 3, based on the position of the workpiece 2 being etched, the position of each group of nozzles 3, the conveying speed, and the position of the residual copper on the workpiece 2. The opened nozzle 3 closes when the workpiece 2 is conveyed to a point where its residual copper is no longer aligned with the nozzle 3. The opening and closing of the nozzle 3 here refers to the opening and closing of the point spray control valve 5 used to control the opening and closing of the nozzle 3.

[0033] The specific process is as follows: Figures 3-9 As shown, where, Figure 3 This indicates that the distribution of residual copper on the etched workpiece 2 has been determined. The etched workpiece 2 has not yet entered the spot spray compensation etching area, which has a total of four sets of nozzles 3. Figure 4 This indicates that the etched workpiece 2 has entered the spot spray compensation etching area, and the front end of the residual copper on the etched workpiece 2 is directly below the first set of nozzles 3. At this time, all the nozzles 3 that the residual copper is pointing at are turned on. Figure 5 This indicates that the front end of the residual copper on the etched workpiece 2 is directly below the second set of nozzles 3, and at this time all the nozzles 3 that the residual copper is pointing at are turned on. Figure 6 This indicates that the front end of the residual copper on the etched workpiece 2 is directly below the third set of nozzles 3, and at this time all the nozzles 3 that the residual copper is pointing at are turned on. Figure 7 This indicates that the front end of the residual copper on the etched workpiece 2 is directly below the fourth group of nozzles 3, and at this time all the nozzles 3 that the residual copper is pointing at are turned on. Figure 8 This indicates that the tail end of the residual copper on the etched workpiece 2 has moved away from directly below the first group of nozzles 3, at which point all nozzles 3 in the first group are closed. This continues until... Figure 9The tail end of the residual copper on the etched workpiece 2 is removed from directly below the fourth set of nozzles 3, at which point all nozzles 3 are closed.

[0034] Example 2:

[0035] The basic principle of operation and control in this embodiment is as follows: The controller calculates, based on the position and range of residual copper on the etched workpiece 2 and the travel path of the etched workpiece 2, all nozzles 3 corresponding to the residual copper on the etched workpiece 2 when the etched workpiece 2 is conveyed to all the nozzles 3 located in the point spray compensation etching area. The controller controls the opening of the point spray control valves 5 corresponding to all the nozzles 3 corresponding to the residual copper on the etched workpiece 2, and closes the other point spray control valves 5. When the conveying photoelectric sensor detects the position of the etched workpiece 2, it transmits the detection signal data to the controller. The controller executes the following control based on the position of the etched workpiece 2, the position of each group of nozzles 3, the conveying speed, and the start and end positions of the residual copper on the etched workpiece 2 along the conveying direction of the etched workpiece 2: When the etched workpiece 2 is conveyed to the starting end of its residual copper and reaches any group of nozzles 3, the liquid inlet control valve 7 corresponding to the spray pipe 6 where the group of nozzles 3 is located is opened; when the etched workpiece 2 is conveyed to the ending end of its residual copper and reaches any group of nozzles 3, the liquid inlet control valve 7 corresponding to the spray pipe 6 where the group of nozzles 3 is located is closed.

[0036] The specific process is as follows: Figures 10-18 As shown, where, Figure 10 This indicates that the distribution of residual copper on the etched workpiece 2 has been determined. The controller has calculated all nozzles 3 corresponding to the residual copper on the workpiece 2 when it is fully conveyed to the point-spray compensation etching area. The controller has also opened the point-spray control valves 5 corresponding to all nozzles 3 on the workpiece 2 that correspond to the residual copper. The point-spray compensation etching area has four spray pipes 6, arranged sequentially along the conveying direction of the etched workpiece 2: first spray pipe 61, second spray pipe 62, third spray pipe 63, and fourth spray pipe 64. Each spray pipe 6 is equipped with a set of nozzles 3, and each spray pipe 6 has a liquid inlet control valve 7 on its liquid inlet side.

[0037] Figure 11 This indicates that the etched workpiece 2 has entered the spot spray compensation etching area, and the starting end of the residual copper on the etched workpiece 2 is directly below the first spray pipe 61. At this time, the controller controls the opening of the liquid inlet control valve 7 corresponding to the first spray pipe 61. This liquid inlet control valve 7... Figure 11 The above indicates that the area is filled with black. Figure 12 This indicates that the etched workpiece 2 has entered the spot spray compensation etching area, and the starting end of the residual copper on the etched workpiece 2 is located directly below the second spray pipe 62. At this time, the controller controls the opening of the liquid inlet control valve 7 corresponding to the first spray pipe 61 and the second spray pipe 62. Figure 13This indicates that the etched workpiece 2 has entered the spot spray compensation etching area, and the starting end of the residual copper on the etched workpiece 2 is located directly below the third spray pipe 63. At this time, the controller controls the opening of the liquid inlet control valve 7 corresponding to the first spray pipe 61, the second spray pipe 62 and the third spray pipe 63. Figure 14 This indicates that the etched workpiece 2 has entered the spot spray compensation etching area, and the starting end of the residual copper on the etched workpiece 2 is located directly below the fourth spray pipe 64. At this time, the controller controls the opening of the liquid inlet control valve 7 corresponding to the first spray pipe 61, the second spray pipe 62, the third spray pipe 63 and the fourth spray pipe 64. Figure 15 This indicates that the etched workpiece 2 has entered the spot spray compensation etching area, and the termination end of the residual copper on the etched workpiece 2 has reached and is about to exceed the first spray pipe 61. At this time, it is considered that the termination end of the residual copper on the etched workpiece 2 has reached the set of nozzles 3 installed on the first spray pipe 61. At this time, the controller controls the closing of the liquid inlet control valve 7 corresponding to the first spray pipe 61 and opens the liquid inlet control valves 7 corresponding to the second spray pipe 62, the third spray pipe 63 and the fourth spray pipe 64.

[0038] Figure 16 This indicates that the etched workpiece 2 has entered the dot spray compensation etching area, and the termination end of the residual copper on the etched workpiece 2 has reached and is about to exceed the second spray pipe 62. At this time, it is considered that the termination end of the residual copper on the etched workpiece 2 has reached the set of nozzles 3 installed on the second spray pipe 62, and at this time, the starting end of the residual copper on the next etched workpiece 2 has not yet reached directly below the first spray pipe 61. Therefore, the controller controls the closure of the liquid inlet control valve 7 corresponding to the first spray pipe 61 and the second spray pipe 62, and opens the liquid inlet control valve 7 corresponding to the third spray pipe 63 and the fourth spray pipe 64.

[0039] Figure 17 This indicates that the etched workpiece 2 has entered the spot spray compensation etching area, and the termination end of the residual copper on the etched workpiece 2 has reached and is about to exceed the third spray pipe 63. At this time, it is considered that the termination end of the residual copper on the etched workpiece 2 has reached the set of nozzles 3 installed on the third spray pipe 63. However, at this time, the starting end of the residual copper on the next etched workpiece 2 has reached the first spray pipe 61. Therefore, the controller controls the closure of the liquid inlet control valve 7 corresponding to the second spray pipe 62 and the third spray pipe 63, and opens the liquid inlet control valve 7 corresponding to the first spray pipe 61 and the fourth spray pipe 64.

[0040] Figure 18This indicates that the etched workpiece 2 has entered the spot spray compensation etching area, and the termination end of the residual copper on the etched workpiece 2 has reached and is about to exceed the fourth spray pipe 64. At this time, it is considered that the termination end of the residual copper on the etched workpiece 2 has reached the set of nozzles 3 installed on the fourth spray pipe 64. However, at this time, the starting end of the residual copper on the next etched workpiece 2 has reached the second spray pipe 62. Therefore, the controller controls the closure of the liquid inlet control valve 7 corresponding to the third spray pipe 63 and the fourth spray pipe 64, and opens the liquid inlet control valve 7 corresponding to the first spray pipe 61 and the second spray pipe 62.

[0041] In summary, this invention can automatically control the opening and closing of the corresponding nozzles 3 according to the distribution of residual copper on the etched workpiece 2. It has a high degree of automation, is flexible and convenient to use, and is suitable for spot spraying compensation etching for circuit boards of various types and with different residual copper defects. It can efficiently achieve effective compensation etching.

[0042] In addition, such as Figure 2 As shown, the present invention also includes an optical interferometer electrically connected to the controller. The interferometer includes a laser source, a beam splitter, a mirror, a detector, and a control module. The laser source can be a helium-neon laser, capable of providing a beam with a stable wavelength and high coherence to ensure clear and stable interference fringes. The beam splitter divides the beam emitted by the laser source into two parts: one part serves as a reference beam, and the other as a measurement beam. The mirror reflects both the reference beam and the measurement beam back, with the mirror for the measurement beam positioned for easy adjustment to measure the residual copper surface. The detector can use a charge-coupled device to receive the interference fringes and convert them into electrical signals, which are then transmitted to the control module. The control module controls the operation and operation of the entire optical interferometer. It receives and processes the electrical signals output by the detector and calculates the thickness of the residual copper using a built-in algorithm.

[0043] The principle of using an optical interferometer to measure the thickness distribution of residual copper on an etched workpiece 2: When a beam of light is split into two beams by a beam splitter, namely a reference beam and a measurement beam, the reference beam follows a fixed optical path, while the measurement beam illuminates the residual copper surface of the circuit board. When the two beams reunite, interference occurs due to the optical path difference, forming interference fringes. When residual copper is present, the optical path of the measurement beam reflected from the residual copper surface differs from that of the reference beam, and this optical path difference causes the interference fringes to shift or deform.

[0044] The thickness h of the residual copper is calculated as follows: First, the optical path difference d is calculated using the interference formula 2×d=m×λ, where m is the order of the interference fringes and λ is the wavelength of the light. Then, the thickness h of the residual copper is calculated. When the light is incident perpendicularly, d=2×c×h, where c is the refractive index of copper.

[0045] An optical interferometer is used to measure the thickness distribution of residual copper on the etched workpiece 2 and sends the measurement results to the controller. The controller's storage module stores a thickness baseline threshold T0. The controller compares the received residual copper thickness T with the thickness baseline threshold T0 and adjusts the opening of the corresponding spot spray control valve 5 according to the comparison result. The baseline opening or reference opening of the spot spray control valve 5 is less than 100%, such as 50%, 60%, 75%, etc.

[0046] The specific method for adjusting the opening of the injection control valve 5 is as follows:

[0047] When the thickness of the residual copper in a certain residual copper area is T≤0.5×T0, the opening degree of the point spray control valve 5 corresponding to the nozzle 3 of the residual copper area is reduced, such as reducing the opening degree from 50% to 40%.

[0048] When the thickness of residual copper in a certain residual copper area is 0.5×T0<T≤T0, the opening degree of the point spray control valve 5 corresponding to the nozzle 3 corresponding to the residual copper area remains unchanged.

[0049] When the thickness of residual copper in a certain residual copper area is T > T0, the opening degree of the point spray control valve 5 corresponding to the nozzle 3 corresponding to the residual copper area is increased, such as increasing the opening degree from 50% to 75%.

[0050] It should be noted that after the compensation etching of a circuit board is completed, the controller should control the point spray control valve 5 corresponding to nozzle 3 to return to the basic opening.

[0051] Therefore, by setting up an optical interferometer, the present invention can measure the thickness distribution of residual copper on the etched workpiece 2, and automatically adjust the required amount of etching solution spray according to the different thicknesses of residual copper, which can more effectively remove residual copper on the etched workpiece 2 and avoid the problem that thick residual copper on the etched workpiece 2 cannot be effectively removed in one go.

[0052] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A spot-spraying compensation etching apparatus comprising an etching tank for storing an etching solution and a conveying device for conveying an etching workpiece, characterized in that, The application also comprises a plurality of groups of nozzles and a controller, each group of nozzles is arranged in sequence along the conveying direction of the etching workpiece, and each group of nozzles comprises a plurality of nozzles arranged in sequence along a direction perpendicular to the conveying direction of the etching workpiece; the etching tank is connected with a compensation pump, the compensation pump is connected with each nozzle through a pipeline, and the inlet side of each nozzle is provided with a point spray control valve for controlling the opening and closing of the nozzle; the controller is electrically connected with an optical detection mechanism, the optical detection mechanism comprises an illumination device and an image acquisition device, the image acquisition device is used for acquiring the image of the etching workpiece, and the illumination device provides sufficient light conditions for the image acquisition device to acquire the image; the controller comprises a storage module and a residual copper recognition module, the image acquisition device transmits the acquired image to the residual copper recognition module, the residual copper recognition algorithm is stored in the storage module, the residual copper recognition module calls the residual copper recognition algorithm in the storage module, processes the image, and recognizes the position and range of the residual copper; The controller is electrically connected with a conveying electric eye, the conveying electric eye is used for detecting the position of the etching workpiece and transmitting the detection data to the controller, and the controller executes the following control according to the position of the etching workpiece, the position of each group of nozzles, the conveying speed, and the start and end positions of the residual copper on the etching workpiece along the conveying direction of the etching workpiece: when the etching workpiece is conveyed to the starting end of the residual copper and reaches any group of nozzles, the inlet control valve corresponding to the spray pipe where the group of nozzles is located is opened; when the etching workpiece is conveyed to the terminal end of the residual copper and reaches any group of nozzles, the inlet control valve corresponding to the spray pipe where the group of nozzles is located is closed; The controller is electrically connected with an optical interferometer, the optical interferometer is used for measuring the thickness distribution of the residual copper on the etching workpiece and transmitting the measurement result to the controller; the optical interferometer comprises a laser light source, a beam splitter, a mirror, a detector and a control module, the laser light source is used for providing a light beam with stable wavelength and high coherence, the beam splitter divides the light beam emitted by the laser light source into two parts, one part as a reference light beam and the other part as a measurement light beam; the mirror reflects the reference light beam and the measurement light beam back, the detector is used for receiving interference fringes and converting them into electrical signals, and then the electrical signals are transmitted to the control module, the control module is used for receiving and processing the electrical signals output by the detector and calculating the thickness of the residual copper; The storage module of the controller stores a thickness basic threshold T0, the controller compares the received residual copper thickness T with the thickness basic threshold T0, and adjusts the opening degree of the corresponding point spray control valve according to the comparison result, and the basic opening degree of the point spray control valve is less than 100%; the specific adjustment mode is as follows: When the residual copper thickness T of a certain residual copper area is less than or equal to 0.5×T0, the opening degree of the point spray control valve corresponding to the nozzle corresponding to the residual copper area is reduced; When the residual copper thickness T of a certain residual copper area is greater than 0.5×T0 and less than or equal to T0, the opening degree of the point spray control valve corresponding to the nozzle corresponding to the residual copper area is kept unchanged; When the residual copper thickness T of a certain residual copper area is greater than T0, the opening degree of the point spray control valve corresponding to the nozzle corresponding to the residual copper area is increased.

2. The spot-spray compensation etching apparatus of claim 1, wherein The multiple spray pipes are arranged equidistantly along the direction perpendicular to the conveying direction of the etching workpiece, and the multiple spray nozzles arranged on each spray pipe are also arranged equidistantly.

3. The spot-spray compensation etching apparatus of claim 1, wherein The connecting pipes between the compensation pump and the multiple spray pipes are provided with filters.

4. The spot-spray compensation etching apparatus of claim 1, wherein The pressure gauges are arranged on the spray pipes, and the compensation pump, the point spray control valves, the liquid inlet control valves and the pressure gauges are electrically connected with the controller.

5. The spot-spray compensation etching apparatus of claim 1, wherein The controller calculates all the spray nozzles corresponding to the residual copper on the etching workpiece according to the position and range of the residual copper on the etching workpiece and the travel path of the etching workpiece, controls to open the point spray control valves corresponding to all the spray nozzles corresponding to the residual copper on the etching workpiece, and closes the remaining point spray control valves.

Images