Spot spraying compensation etching device

Abstract

The invention belongs to the technical field of circuit board etching treatment, and discloses a spot-spraying compensation etching device which comprises an etching cylinder and a conveying device, the etching cylinder is used for storing etching liquid, the conveying device is used for conveying etching workpieces, the spot-spraying compensation etching device further comprises a plurality of groups of nozzles, and the nozzles are sequentially arranged in the conveying direction of the etching workpieces. Each group of nozzles comprises a plurality of nozzles which are sequentially arranged in the direction perpendicular to the conveying direction of the etched workpieces; the etching cylinder is connected with a compensation pump, the compensation pump is connected with each nozzle through a pipeline, and the liquid inlet side of each nozzle is provided with a spot spraying control valve used for controlling the nozzle to be opened and closed; the device further comprises a controller, a pressure gauge is installed on the spraying pipe, and the compensation pump, the spot spraying control valve, the liquid inlet control valve and the pressure gauge are all electrically connected with the controller. According to the invention, the opening and closing of the corresponding nozzles can be automatically controlled according to the distribution of the residual copper on the etched workpiece, and the device is suitable for spot spraying compensation etching of various circuit boards with different types and different residual copper defects.

Description

Technical Field

[0001] The invention belongs to the technical field of circuit board etching processing, and in particular relates to a dot-spraying compensation etching device. Background Art

[0002] During the etching process of circuit boards, due to the influence of various factors, such as uneven flow of etching solution, inaccurate etching time control, performance differences of etching equipment, etc., uneven etching often occurs, resulting in residual copper on the circuit board. These residual copper will affect the electrical performance, reliability and product quality of the circuit board. Traditional etching methods are difficult to accurately process these residual copper. At present, although there are some etching compensation methods, most of them are through large-area secondary etching or manual repair, which is not only inefficient, but also difficult to accurately control the etching position and etching amount, which is easy to damage the etched parts and affect the overall performance of the circuit board.

[0003] To this end, some people have proposed a point spray compensation etching method, which performs compensation etching by spraying etching liquid on the residual copper position. However, the existing compensation etching spray device can only be realized by manually plugging a single nozzle of the spray pipe, and there is a problem of inflexible adjustment. Moreover, PCB products are becoming more and more complex, and the phenomenon of residual copper on PCB products is becoming more and more frequent. The demand for local compensation of PCB products is also increasing. In addition, the compensation positions caused by different PCB products, different process conditions, different equipment conditions, etc. are also different. Therefore, frequent manual nozzle plugging is required, and it is difficult to efficiently achieve effective compensation etching. Summary of the invention

[0004] The purpose of the present invention is to provide a point spraying compensation etching device, aiming to improve the problem that the existing compensation etching spray device is inflexible and inconvenient to use, resulting in difficulty in efficiently realizing effective compensation etching.

[0005] In order to achieve the above-mentioned object, the present invention provides a point spray compensation etching device, comprising an etching cylinder and a conveying device, wherein the etching cylinder is used to store etching liquid, the conveying device is used to convey the etching workpiece, and also comprises a plurality of groups of nozzles and a controller, wherein each group of nozzles is sequentially arranged along the conveying direction of the etching workpiece, and each group of nozzles comprises a plurality of nozzles sequentially arranged along a direction perpendicular to the conveying direction of the etching workpiece; the etching cylinder is connected to a compensation pump, the compensation pump is connected to each nozzle through a pipeline, and a point spray control valve for controlling the opening and closing of the nozzle is arranged on the liquid inlet side of each nozzle; the controller is electrically connected to an optical detection mechanism, the optical detection mechanism comprises an illumination device and an image acquisition device, the image acquisition device is used to acquire an image of the etching workpiece, and the illumination device provides sufficient light conditions for the image acquisition device to acquire an 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 storage module stores a residual copper recognition algorithm, and the residual copper recognition module calls the residual copper recognition algorithm in the storage system to process the image and recognize the position and range of the 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 the spray pipes is the same as the number of nozzle groups, each spray pipe is equipped with a group of nozzles, each spray pipe is connected to a compensation pump through a connecting pipe, and a liquid inlet control valve is provided on the liquid inlet side of each spray pipe, and the compensation pump transports the etching liquid in the etching cylinder to the spray pipe with the corresponding liquid inlet control valve opened.

[0007] Furthermore, a filter is provided between the connecting pipes between the compensation pump and each spray pipe, each spray pipe is equidistantly arranged along a conveying direction perpendicular to the etched workpiece, and a plurality of 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 detection mechanism, which includes a lighting device and an image acquisition device, wherein the image acquisition device is used to acquire images of the etching workpiece, and the lighting device provides sufficient light conditions for the image acquisition device to acquire images; the controller includes a storage module and a residual copper recognition module, wherein the image acquisition device transmits the acquired image to the residual copper recognition module, wherein the storage module stores a residual copper recognition algorithm, and the residual copper recognition module calls the residual copper recognition algorithm in the storage system to process the image and identify the position and range of the residual copper.

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

[0011] Furthermore, the controller calculates all nozzles corresponding to the residual copper on the etched workpiece when the etched workpiece is transferred to the spot spray compensation etching area according to the position and range of the residual copper on the etched workpiece and the travel path of the etched workpiece. The controller controls the spot spray control valves corresponding to all nozzles corresponding to the residual copper on the etched workpiece to open, and the other spot spray control valves are closed.

[0012] Furthermore, the controller is also electrically connected to a conveying electric eye, which is used to detect the position of the etching workpiece and transmit the detection data to the controller. The controller performs the following control according to the position of the etching workpiece, the position of each group of nozzles, the transmission speed, and the starting and ending positions of the residual copper on the etching workpiece along the transmission direction of the etching workpiece: when the etching 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 the group of nozzles is located is opened; when the etching 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 the group of nozzles is located is closed.

[0013] Furthermore, the controller is also electrically connected to an optical interferometer, which is used to measure the thickness distribution of the residual copper on the etched workpiece and send the measurement result to the controller. The storage module of the controller stores the thickness basic threshold T0. The controller compares the received residual copper thickness T with the thickness basic threshold T0, and adjusts the opening of the corresponding spot spray control valve according to the comparison result. The basic opening of the spot spray control valve is less than 100%. The specific adjustment method 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 of the spot spray control valve corresponding to the nozzle corresponding to the residual copper area is reduced; When the residual copper thickness of a certain residual copper area is 0.5×T0<T≤T0, the opening of the spot spray control valve corresponding to the nozzle corresponding to the residual copper area remains unchanged; When the residual copper thickness T of a certain residual copper area is greater than T0, the opening of the spot spraying control valve corresponding to the nozzle corresponding to the residual copper area increases.

[0014] Furthermore, the interferometer includes a laser light source, a beam splitter, a reflector, a detector and a control module. The laser light source is used to provide a light beam with a stable wavelength and high coherence. The beam splitter divides the light beam emitted by the laser light source into two parts, one part is used as a reference beam, and the other part is used as a measurement beam; the reflector reflects the reference beam and the measurement beam back, the detector is used to receive interference fringes and convert them into electrical signals, and then transmit the electrical signals to the control module, and the control module is used to receive and process the electrical signals output by the detector and calculate the thickness of the residual copper.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention can automatically control the opening and closing of the corresponding nozzle according to the distribution of residual copper on the etching workpiece, has a high degree of automation, is flexible and convenient to use, is suitable for spot spraying compensation etching for circuit boards of various types and with different residual copper defects, and can efficiently realize effective compensation etching.

[0016] 2. The present invention is provided with an optical interferometer, which can measure the thickness distribution of the residual copper on the etched workpiece, and automatically and adaptively adjust the required spraying amount of the etching solution according to the different thicknesses of the residual copper, so as to more effectively remove the residual copper on the etched workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the dot spray compensation etching device provided by the present invention; Figure 2 It is a block diagram of the electric control structure of the spot spray compensation etching device provided by the present invention; Figure 3-Figure 9 This is a schematic diagram of a first process of performing compensation etching using the dot-spray compensation etching device provided by the present invention; Figure 10-Figure 18 This is a schematic diagram of a second process of performing compensatory etching using the spot spraying compensatory etching device provided by the present invention.

[0018] In the figure: 1. Etching cylinder; 2. Etching workpiece; 3. Nozzle; 4. Compensation pump; 5. Point 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 DESCRIPTION

[0019] The following is a further description with reference to the accompanying drawings and specific embodiments: A dot spray compensation etching device, such as Figure 1As shown, it includes an etching cylinder 1, a conveying device, a plurality of spray pipes 6 and a plurality of groups of nozzles 3. The etching cylinder 1 is used to store etching liquid. The etching cylinder 1 has a temperature heating structure and a temperature measuring structure to ensure that the etching liquid in the etching cylinder 1 is within a suitable process temperature range. The conveying device is used to convey the etching workpiece 2, and the etching workpiece 2 is a circuit board. The number of spray pipes 6 is the same as the number of groups of nozzles 3. The length direction of each spray pipe 6 is perpendicular to the conveying direction of the etching workpiece 2. A group of nozzles 3 is installed on each spray pipe 6, and each group of nozzles 3 includes a plurality of nozzles 3 arranged in sequence perpendicular to the conveying direction of the etching workpiece 2. A point spray control valve 5 for controlling the opening and closing of the nozzle 3 is provided on the liquid inlet side of each nozzle 3. The point spray control valve 5 uses a pneumatic proportional valve with adjustable valve opening, which can control the flow rate proportionally according to the size of the input signal, and can realize continuous and precise adjustment of the flow rate. Each spray pipe 6 is equidistantly arranged along the conveying direction perpendicular to the etching workpiece 2, and the plurality of nozzles 3 installed on each spray pipe 6 are equidistantly arranged. The etching cylinder 1 is connected to a compensation pump 4, which is connected to each spray pipe 6 through a pipeline, and a liquid inlet control valve 7 is provided on the liquid inlet side of each spray pipe 6. The compensation pump 4 can transport the etching liquid in the etching cylinder 1 to the spray pipe 6 with the corresponding liquid inlet control valve 7 opened. A filter 9 is provided between the connecting pipes between the compensation pump 4 and each spray pipe 6, and the filter 9 is used to filter solid impurities in the etching liquid to prevent clogging of the nozzle 3.

[0020] like Figure 1 and Figure 2 As shown, a pressure gauge 8 is installed on the spray pipe 6. The present invention also has a conveying electric eye, an optical detection mechanism and a controller. The controller can use a touch screen with an MCU control module. The conveying device, the compensation pump 4, the spot spray control valve 5, the liquid inlet control valve 7, the pressure gauge 8, the conveying electric eye and the optical detection mechanism are all electrically connected to the controller. The motor of the compensation pump 4 uses a variable frequency motor. The flow rate of the supplied etching liquid can be adjusted according to the detection result of the pressure gauge 8 or the number of the spot spray control valve 5 and the liquid inlet control valve 7 to be opened to reduce fluctuations and achieve more stable and accurate flow control of each nozzle 3. The controller can control the conveying speed of the conveying device, and can also calculate the time required for the etching workpiece 2 to be conveyed a certain distance according to the conveying speed of the conveying device. Of course, it can also calculate the distance that the etching workpiece 2 is conveyed within a certain time. The conveying electric eye is used to detect the position of the etching workpiece 2 and transmit the detection data to the controller so that the controller knows whether the etching workpiece 2 has reached a certain set reference position. The reference position can be set to the position where the etching workpiece 2 just enters the spray etching area. The controller can accurately calculate the precise position of the etching workpiece 2 in the spray etching area at a certain moment by exchanging data with the transmission electric eye and the conveying device.

[0021] The optical detection mechanism includes an illumination device and an image acquisition device, the image acquisition device is used to acquire the image of the etching workpiece 2, and the illumination device provides sufficient light conditions for the image acquisition device to acquire the image. The controller has a storage module and a residual copper recognition module, the image acquisition device transmits the acquired image to the residual copper recognition module, the storage module stores the residual copper recognition algorithm, the residual copper recognition module calls the residual copper recognition algorithm in the storage system, processes the image, and identifies the position and range of the residual copper. The residual copper recognition algorithm can adopt image processing technologies 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 the area where the actual grayscale value is higher than the grayscale threshold is judged as the residual copper area.

[0022] There are multiple operation and control methods for performing spot spray compensation etching of the workpiece 2 using the spot spray compensation etching device provided by the present invention, which are described below with two use embodiments.

[0023] Embodiment 1:

[0024] The basic principle of operation and control of this embodiment is: the controller controls the corresponding nozzle 3 to open when the etching workpiece 2 is conveyed to the point where its residual copper is aligned with the nozzle 3 according to the position of the etching workpiece 2, the position of each group of nozzles 3, the conveying speed, and the position of the residual copper on the etching workpiece 2, and the opened nozzle 3 is closed when the etching workpiece 2 is conveyed to the point where its residual copper is no longer aligned with the nozzle 3. The opening and closing of the nozzle 3 refers to the opening and closing of the spot spray control valve 5 used to control the opening and closing of the nozzle 3.

[0025] The specific process is as follows Figure 3-Figure 9 As shown, Figure 3 It indicates that the residual copper distribution on the etching workpiece 2 has been determined, and the etching workpiece 2 has not yet entered the spot spraying compensation etching area. There are four groups of nozzles 3 in the spot spraying compensation etching area. Figure 4 It indicates that the etched workpiece 2 enters the spot spray compensation etching area, and the front end of the residual copper on the etched workpiece 2 is located directly below the first group of nozzles 3. At this time, all the nozzles 3 aimed at by the residual copper are opened. Figure 5 This indicates that the front end of the residual copper on the etched workpiece 2 is located directly below the second group of nozzles 3, and at this time, all the nozzles 3 that the residual copper is aimed at are opened. Figure 6 This indicates that the front end of the residual copper on the etched workpiece 2 is located directly below the third group of nozzles 3, and at this time, all the nozzles 3 that the residual copper is aimed at are opened. Figure 7 This indicates that the front end of the residual copper on the etched workpiece 2 is located directly below the fourth group of nozzles 3, and at this time, all the nozzles 3 that the residual copper is aimed at are opened. Figure 8 This indicates that the tail end of the residual copper on the etched workpiece 2 has left the bottom of the first group of nozzles 3, and all nozzles 3 of the first group are closed. Fig. 9, the tail end of the residual copper on the etched workpiece 2 is separated from the bottom of the fourth group of nozzles 3, and all the nozzles 3 are closed at this time.

[0026] Embodiment 2:

[0027] The basic principle of operation and control of this embodiment is as follows: the controller calculates all nozzles 3 corresponding to the residual copper on the etching workpiece 2 when the etching workpiece 2 is transferred to the spot spray compensation etching area, and controls to open the spot spray control valves 5 corresponding to all nozzles 3 corresponding to the residual copper on the etching workpiece 2, and the remaining spot spray control valves 5 are closed. When the transmission electric eye detects the position of the etching workpiece 2, the detection signal data is transmitted to the controller, and the controller performs the following control according to the position of the etching workpiece 2, the position of each group of nozzles 3, the transmission speed, and the starting and ending positions of the residual copper on the etching workpiece 2 along the transmission direction of the etching workpiece 2: when the etching workpiece 2 is transferred 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 etching workpiece 2 is transferred to the terminal 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.

[0028] The specific process is as follows Figure 10-Figure 18 As shown, Fig.10 It indicates that the distribution of residual copper on the etched workpiece 2 has been determined, and when the etched workpiece 2 is transferred to the spot spray compensation etching area, all nozzles 3 corresponding to the residual copper on the etched workpiece 2 have been calculated, and the controller has controlled to open the spot spray control valves 5 corresponding to all nozzles 3 corresponding to the residual copper on the etched workpiece 2. There are four spray pipes 6 in the spot spray compensation etching area, which are the first spray pipe 61, the second spray pipe 62, the third spray pipe 63 and the fourth spray pipe 64 in the conveying direction of the etched workpiece 2. A group of nozzles 3 are installed on each spray pipe 6, and a liquid inlet control valve 7 is provided on the liquid inlet side of each spray pipe 6.

[0029] Fig.11 It indicates that the etched workpiece 2 enters the spot spray compensation etching area, and the starting end of the residual copper on the etched workpiece 2 is located 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. The liquid inlet control valve 7 is Fig.11 The above is filled with black. Fig.12 It indicates that the etched workpiece 2 enters 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. Fig.13It indicates that the etched workpiece 2 enters the spot spray compensation etching area, and the starting end of the residual copper on the etched workpiece 2 is 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. Fig.14 It indicates that the etched workpiece 2 enters the spot spray compensation etching area, and the starting end of the residual copper on the etched workpiece 2 is 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. Fig.15 It indicates that the etched workpiece 2 enters the spot spray compensation etching area, and the terminal 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 terminal end of the residual copper on the etched workpiece 2 reaches the group 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 valve 7 corresponding to the second spray pipe 62, the third spray pipe 63 and the fourth spray pipe 64.

[0030] Fig.16 It indicates that the etched workpiece 2 enters the spot spray compensation etching area, and the terminal 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 terminal end of the residual copper on the etched workpiece 2 has reached the group 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 reached directly below the first spray pipe 61, so the controller controls the closing 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.

[0031] Fig.17 It indicates that the etched workpiece 2 enters the spot spray compensation etching area, and the terminal 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 terminal end of the residual copper on the etched workpiece 2 has reached the group of nozzles 3 installed on the third spray pipe 63, but at this time, the starting end of the residual copper on the next etched workpiece 2 has reached the first spray pipe 61, so the controller controls the closing 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.

[0032] Fig.18It indicates that the etched workpiece 2 enters the spot spray compensation etching area, and the terminal 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 terminal end of the residual copper on the etched workpiece 2 has reached the group of nozzles 3 installed on the fourth spray pipe 64, but at this time, the starting end of the residual copper on the next etched workpiece 2 has reached the second spray pipe 62, so the controller controls the closing 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.

[0033] In summary, the present invention can automatically control the opening and closing of the corresponding nozzle 3 according to the distribution of residual copper on the etching workpiece 2, has a high degree of automation, is flexible and convenient to use, is suitable for spot spraying compensation etching for circuit boards of various types and with different residual copper defects, and can efficiently realize effective compensation etching.

[0034] In addition, if Figure 2 As shown, the present invention also has an optical interferometer electrically connected to the controller, and the interferometer includes a laser light source, a beam splitter, a reflector, a detector and a control module. The laser light source can use a helium-neon laser, which can provide a light beam with a stable wavelength and high coherence to ensure that the interference fringes are clear and stable. The beam splitter divides the light beam emitted by the laser light source into two parts, one part is used as a reference beam, and the other part is used as a measurement beam. The reflector reflects the reference beam and the measurement beam back, wherein the reflector of the measurement beam is set at a convenient position for adjustment so as 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, and then transmit the electrical signals to the control module. The control module is used to control the operation and control of the entire optical interferometer. The control module receives and processes the electrical signals output by the detector, and calculates the thickness of the residual copper through a built-in algorithm.

[0035] The principle of optical interferometer measuring the residual copper thickness distribution on the etched workpiece 2 is as follows: When a beam of light is divided into two beams of light, namely the reference beam and the measurement beam, through a beam splitter. The reference beam passes through a fixed optical path, and the measurement beam is irradiated onto the residual copper surface of the circuit board. When the two beams of light reunite, interference occurs due to the existence of the optical path difference, forming interference fringes. When there is a residual copper surface, the optical path of the measurement beam reflected on the residual copper surface is different from that of the reference beam, and the resulting optical path difference causes the interference fringes to move or deform.

[0036] The thickness h of the residual copper is calculated as follows: First, the optical path difference d is calculated according to the interference formula 2×d=m×λ, where m is the order of the interference fringes and λ is the wavelength of light. Then the thickness h of the residual copper is calculated. When the light is incident vertically, d=2×c×h, where c is the refractive index of copper.

[0037] The optical interferometer is used to measure the thickness distribution of the residual copper on the etched workpiece 2, and send the measurement results to the controller. The storage module of the controller stores the thickness basic threshold T0. The controller compares the received residual copper thickness T with the thickness basic threshold T0, and adjusts the opening of the corresponding spot spray control valve 5 according to the comparison result. The basic opening or reference opening of the spot spray control valve 5 is less than 100%, such as 50%, 60%, 75%, etc.

[0038] The specific method of adjusting the opening of the spot spray control valve 5 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 of the spot spray control valve 5 corresponding to the nozzle 3 corresponding to the residual copper area is reduced, such as reducing the opening from 50% to 40%.

[0039] When the residual copper thickness of a certain residual copper area is 0.5×T0<T≤T0, the opening degree of the spot spraying control valve 5 corresponding to the nozzle 3 corresponding to the residual copper area remains unchanged.

[0040] When the residual copper thickness T of a certain residual copper area is greater than T0, the opening of the spot spray control valve 5 corresponding to the nozzle 3 corresponding to the residual copper area is increased, such as increasing the opening from 50% to 75%.

[0041] It should be noted that, after the compensation etching of a circuit board is completed, the controller should control the dot spray control valve 5 corresponding to the nozzle 3 to return to the basic opening.

[0042] Therefore, the present invention can measure the thickness distribution of the residual copper on the etched workpiece 2 by setting an optical interferometer, and automatically and adaptively adjust the required spraying amount of the etching solution according to the different thicknesses of the residual copper, so as to more effectively remove the residual copper on the etched workpiece 2 and avoid the problem that the thick residual copper on the etched workpiece 2 cannot be effectively removed at one time.

[0043] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A point spray compensation etching device, comprising an etching cylinder (1) and a conveying device, wherein the etching cylinder (1) is used to store etching liquid, and the conveying device is used to convey the etching workpiece (2), characterized in that: The invention also comprises a plurality of groups of nozzles (3) and a controller, wherein each group of nozzles (3) is arranged in sequence along the conveying direction of the etching workpiece (2), and each group of nozzles (3) comprises a plurality of nozzles (3) arranged in sequence perpendicular to the conveying direction of the etching workpiece (2); the etching cylinder (1) is connected to a compensation pump (4), wherein the compensation pump (4) is connected to each nozzle (3) through a pipeline, and a dot spray control valve (5) for controlling the opening and closing of the nozzle (3) is arranged on the liquid inlet side of each nozzle (3); the controller is electrically connected to an optical detection mechanism, wherein the optical detection mechanism comprises an illumination device and an image acquisition device, wherein the image acquisition device is used to acquire an image of the etching workpiece (2), and wherein the illumination device provides sufficient light conditions for the image acquisition device to acquire an image; the controller comprises a storage module and a residual copper recognition module, wherein the image acquisition device transmits the acquired image to the residual copper recognition module, wherein the storage module stores a residual copper recognition algorithm, and wherein the residual copper recognition module calls the residual copper recognition algorithm in the storage system to process the image and recognize the position and range of the residual copper.

2. A dot spray compensation etching device according to claim 1, characterized in that: It also comprises a plurality of spray pipes (6), the length direction of each spray pipe (6) being perpendicular to the conveying direction of the etching workpiece (2), the number of the spray pipes (6) being the same as the number of groups of nozzles (3), each spray pipe (6) being mounted with a group of nozzles (3), each spray pipe (6) being connected to a compensation pump (4) via a connecting pipe, and a liquid inlet control valve (7) being arranged on the liquid inlet side of each spray pipe (6), the compensation pump (4) conveying the etching liquid in the etching cylinder (1) to the corresponding spray pipe (6) with the liquid inlet control valve (7) opened.

3. A dot spray compensation etching device according to claim 2, characterized in that: A filter (9) is provided between the connecting pipes between the compensation pump (4) and each spray pipe (6), each spray pipe (6) is arranged at equal distances along a direction perpendicular to the conveying direction of the etched workpiece (2), and a plurality of nozzles (3) installed on each spray pipe (6) are arranged at equal distances.

4. A dot spray compensation etching device according to claim 2, characterized in that: A pressure gauge (8) is installed on the spray pipe (6), and the compensation pump (4), the spot spray control valve (5), the liquid inlet control valve (7) and the pressure gauge (8) are all electrically connected to the controller.

5. A dot spray compensation etching device according to claim 4, characterized in that: The controller is also electrically connected to a conveying electric eye, the conveying electric eye being used to detect the position of the etching workpiece (2) and transmit the detection data to the controller. The controller controls the corresponding nozzle (3) to open when the etching workpiece (2) is conveyed to the point where its residual copper is aligned with the nozzle (3) according to the position of the etching workpiece (2), the position of each group of nozzles (3), the conveying speed, and the position of the residual copper on the etching workpiece (2), and the opened nozzle (3) is closed when the etching workpiece (2) is conveyed to the point where its residual copper is no longer aligned with the nozzle (3).

6. A dot spray compensation etching device according to claim 4, characterized in that: The controller calculates, based on the position and range of the residual copper on the etching workpiece (2) and the travel path of the etching workpiece (2), all nozzles (3) corresponding to the residual copper on the etching workpiece (2) when the etching workpiece (2) is transferred to the spot spray compensation etching area, and the controller controls the spot spray control valves (5) corresponding to all nozzles (3) corresponding to the residual copper on the etching workpiece (2) to open, and the remaining spot spray control valves (5) are closed.

7. A dot spray compensation etching device according to claim 6, characterized in that: The controller is also electrically connected to a conveying electric eye, the conveying electric eye being used to detect the position of the etching workpiece (2) and transmit the detection data to the controller. The controller performs the following control according to the position of the etching workpiece (2), the position of each group of nozzles (3), the conveying speed, and the starting and ending positions of the residual copper on the etching workpiece (2) along the conveying direction of the etching workpiece (2): when the etching workpiece (2) is conveyed to the point where the starting end of its residual copper 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 etching workpiece (2) is conveyed to the point where the ending end of its residual copper 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.

8. A dot spraying compensation etching device according to claim 5 or 7, characterized in that: The controller is also electrically connected to an optical interferometer, the optical interferometer is used to measure the thickness distribution of the residual copper on the etching workpiece (2), and send the measurement result to the controller. 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 of the corresponding spot spray control valve (5) according to the comparison result. The basic opening of the spot spray control valve (5) is less than 100%. The specific adjustment method 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 of the spot spray control valve (5) corresponding to the nozzle (3) corresponding to the residual copper area is reduced; When the residual copper thickness of a certain residual copper area is 0.5×T0<T≤T0, the opening degree of the spot spray control valve (5) corresponding to the nozzle (3) corresponding to the residual copper area remains unchanged; When the residual copper thickness T of a certain residual copper area is greater than T0, the opening of the spot spray control valve (5) corresponding to the nozzle (3) corresponding to the residual copper area increases.

9. A dot spray compensation etching device according to claim 8, characterized in that: The interferometer includes a laser light source, a beam splitter, a reflector, a detector and a control module. The laser light source is used to provide a light beam with a stable wavelength and high coherence. The beam splitter divides the light beam emitted by the laser light source into two parts, one part is used as a reference beam, and the other part is used as a measurement beam; the reflector reflects the reference beam and the measurement beam back. The detector is used to receive interference fringes and convert them into electrical signals, and then transmit the electrical signals to the control module. The control module is used to receive and process the electrical signals output by the detector and calculate the thickness of the residual copper.

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