A circuit board etching processing device and method

Abstract

The invention discloses an etching processing device and method for a circuit board. The etching processing device comprises a conveying mechanism, an etching processing chamber, a spray pump and a nozzle. The etching processing chamber has an etching liquid storage chamber located below the conveying mechanism; and also comprises an etching liquid viscosity detection device. The etching liquid viscosity detection device comprises a controller, a detection pump, a conveying pipe, a first pressure detection gauge and a second pressure detection gauge. A detection liquid suction port and a detection liquid discharge port are arranged on the chamber wall of the etching liquid storage chamber. The suction end of the detection pump is connected to the detection liquid suction port of the etching liquid storage chamber, the liquid discharge end of the detection pump is connected to one end of the conveying pipe, and the other end of the conveying pipe is connected to the detection liquid discharge port of the etching liquid storage chamber; the first pressure detection gauge and the second pressure detection gauge are both installed on the conveying pipe and are both electrically connected to the controller; the invention is provided with an etching liquid viscosity detection device, which can detect the viscosity of the etching liquid in time, and can know in time whether the viscosity of the etching liquid meets the use requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of circuit board etching, and in particular relates to an etching processing device and method for a circuit board. Background Art

[0002] Etching of circuit boards requires the use of etching equipment and etching liquid. The etching quality of circuit boards is affected by many factors, such as the structure of the etching equipment, the spraying method of the etching liquid, the chemical composition of the etching liquid, the temperature of the etching liquid, the concentration of the etching liquid, the viscosity of the etching liquid, etc. Among them, the concentration and viscosity of the etching liquid change during the etching process as the copper continues to dissolve. In order to prevent the adverse effects of changes in the concentration and viscosity of the etching liquid on the etching quality, the concentration and viscosity of the etching liquid need to be controlled.

[0003] In the prior art, the utility model patent with patent application number CN202220249279.7 provides a circuit board etching processing device, which has neither a structure that can detect the concentration of the etching solution nor a structure that can detect the viscosity of the etching solution. The invention patent with patent application number CN202311163742.1 discloses an automatic control system for etching solution concentration, which is mainly composed of a concentration sensor, a control unit, an automatic refilling device and a mixing device. The concentration sensor of the system is used to measure the concentration of the etching solution in real time and transmit the real-time concentration to the control unit. The control unit receives the real-time concentration transmitted by the concentration sensor, and compares it with the preset concentration standard and the concentration measurement value, and then decides whether the concentration needs to be adjusted according to the comparison result. After receiving the command from the control unit, the automatic refilling device adds an etchant or a diluent to the etching solution. The mixing device is started after the automatic refilling device is refilled to ensure that the concentration of the etching solution is uniform.

[0004] Although the automatic etching solution concentration control system provided by the above patent can be applied to the existing circuit board etching processing device to realize automatic and precise control of the etching solution concentration, optimize the etching process, and improve the etching efficiency and quality, it still results in the circuit board etching processing device not having a structure that can detect the viscosity of the etching solution, and cannot adjust the viscosity of the etching solution in time, which will affect the fluidity of the etching solution on the surface of the substrate copper foil and directly affect the etching effect. Summary of the invention

[0005] The object of the present invention is to provide an etching processing device and method for a circuit board, aiming to improve the problem that the existing etching processing device has no structure for detecting the viscosity of the etching solution and cannot adjust the viscosity of the etching solution in time, thereby affecting the etching effect.

[0006] In order to achieve the above-mentioned object, according to a first aspect of the present invention, there is provided an etching processing device for a circuit board, comprising a conveying mechanism, an etching treatment chamber, a spray pump and a nozzle, wherein the conveying mechanism passes through the etching treatment chamber, the nozzle is arranged in the etching treatment chamber, the etching treatment chamber has an etching liquid storage chamber located below the conveying mechanism, the spray pump is connected to the nozzle, the nozzle is used to spray etching liquid onto the circuit board conveyed on the conveying mechanism, and also comprises an etching liquid viscosity detection device, the etching liquid viscosity detection device comprises a controller, a detection pump, a delivery pipe, a first pressure detection gauge and a second pressure detection gauge, a chamber wall of the etching liquid storage chamber is provided with a detection suction port and a detection discharge port, the suction end of the detection pump is connected to the detection suction port of the etching liquid storage chamber, the discharge end of the detection pump is connected to one end of the delivery pipe, and the other end of the delivery pipe is connected to the detection discharge port of the etching liquid storage chamber; the first pressure detection gauge and the second pressure detection gauge are both installed on the delivery pipe, and are both electrically connected to the controller.

[0007] Furthermore, it also includes an etching liquid heating device, which includes an electric heating plate and a temperature sensor. An installation groove is provided on the bottom wall of the etching liquid storage chamber, and the electric heating plate is arranged in the installation groove. The temperature sensor is electrically connected to the controller.

[0008] Furthermore, the etching liquid heating device also includes an etching liquid mixing mechanism, which includes a multi-purpose pump, a first mixing tube and a second mixing tube. The suction end of the multi-purpose pump is connected to the etching liquid storage chamber through the first mixing tube, and the discharge end of the multi-purpose pump is connected to the etching liquid storage chamber through the second mixing tube. The position where the first mixing tube is connected to the etching liquid storage chamber is lower than the position where the second mixing tube is connected to the etching liquid storage chamber, and the position where the first mixing tube is connected to the etching liquid storage chamber is close to the inner bottom wall of the etching liquid storage chamber.

[0009] Furthermore, a first electrically-controlled valve is provided on the first mixing tube, a second electrically-controlled valve is provided on the second mixing tube, the second mixing tube is connected to a discharge pipe, the position where the discharge pipe connects with the second mixing tube is located between the second electrically-controlled valve and the discharge end of the multi-purpose pump, a third electrically-controlled valve is provided on the discharge pipe, and the first electrically-controlled valve, the second electrically-controlled valve and the third electrically-controlled valve are all electrically connected to the controller.

[0010] Furthermore, the etching liquid storage chamber is connected to a liquid inlet pipe, a fourth electrically controlled valve is arranged on the liquid inlet pipe, the liquid inlet pipe is connected to a liquid replenishing pump, and the liquid replenishing pump is connected to a storage box storing the etching liquid; the fourth electrically controlled valve and the liquid replenishing pump are also electrically connected to the controller.

[0011] Furthermore, a liquid level sensor is provided on the etching liquid storage chamber, and the liquid level sensor is also electrically connected to the controller; the detection liquid suction port of the etching liquid storage chamber is lower than the detection liquid discharge port of the etching liquid storage chamber, and the detection liquid discharge port of the etching liquid storage chamber is higher than the liquid level of the etching liquid.

[0012] According to a second aspect of the present invention, there is provided a circuit board etching method, using the circuit board etching device, comprising the following steps:

[0013] S1, start the electric heating plate and the multi-purpose pump, open the first electric control valve and the second electric control valve, heat and mix the etching liquid stored in the etching liquid storage chamber, and stop heating when the etching liquid is heated to the etching process temperature;

[0014] S2, placing the circuit board to be etched on the conveying mechanism, starting the conveying mechanism, and the conveying mechanism drives the circuit board to be etched into the etching processing chamber;

[0015] S3, starting the spray pump and the nozzle, the spray pump delivers the etching liquid that reaches the etching process temperature to the nozzle, and the nozzle sprays the etching liquid onto the circuit board to be etched for etching processing.

[0016] Furthermore, the controller includes a control module, a calculation module and a storage module, and the storage module stores a pressure difference threshold value P0; the etching processing method also includes the following steps:

[0017] S4, the control module controls the detection pump to start with the set power, and the first pressure detection meter and the second pressure detection meter transmit the first pressure detection value P1 and the second pressure detection value P2 to the calculation module;

[0018] S5, the calculation module calculates the pressure difference P through a formula, and compares P and P0, a is the temperature adjustment coefficient, b is the liquid level adjustment coefficient; when P>P0, and (P-P0) / P0*100%≥M%, the value of M is: 0≤M≤5; the calculation module transmits a signal to the control module, and after receiving the signal, the control module controls to start the multi-purpose pump, open the first electric control valve and the third electric control valve, close the second electric control valve, and extract part of the etching liquid in the etching liquid storage chamber through the multi-purpose pump;

[0019] S6. The liquid level sensor transmits the liquid level of the etching liquid to the control module in real time. When the liquid level of the etching liquid in the etching liquid storage chamber drops to the first set liquid level threshold, the control module controls the closing of the third electrically controlled valve, opens the second electrically controlled valve and the fourth electrically controlled valve, and starts the liquid replenishing pump. The liquid replenishing pump replenishes the etching liquid stored in the storage box into the etching liquid storage chamber; when the liquid level of the etching liquid in the etching liquid storage chamber rises to the second set liquid level threshold, the control module controls the closing of the fourth electrically controlled valve, the liquid replenishing pump and the multi-purpose pump to complete the replacement of the etching liquid.

[0020] Furthermore, the etching method further comprises the following steps:

[0021] S7, the temperature sensor transmits the temperature of the etching liquid in the etching liquid storage chamber to the control module. If the temperature is lower than the etching process temperature stored in the storage module, the control module controls the start of the electric heating plate and the multi-purpose pump, and opens the first electric control valve and the second electric control valve at the same time to heat and mix the etching liquid in the etching liquid storage chamber, and stops heating when the etching liquid is heated to the etching process temperature.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention is provided with an etching liquid viscosity detection device, which can detect the viscosity of the etching liquid in time, and can timely know whether the viscosity of the etching liquid meets the use requirements, so that the etching liquid can be replaced in time, and the etching effect of the circuit board will not be affected due to the etching liquid viscosity not meeting the use requirements.

[0024] 2. The present invention is provided with a multi-purpose pump and a liquid replenishing pump, which can be used together with a liquid level sensor and an etching liquid viscosity detection device to automatically replace the etching liquid.

[0025] 3. The present invention is provided with an etching liquid heating device, which includes an electric heating plate, a temperature sensor and an etching liquid mixing mechanism, which can heat the etching liquid to meet the etching process requirements and can also mix the etching liquid so that the etching liquid temperature at various locations in the etching liquid storage chamber is uniform.

[0026] 4. When the present invention detects the viscosity of the etching solution, the temperature adjustment coefficient a and the liquid level adjustment coefficient b are introduced to eliminate the influence of the temperature and liquid level changes of the etching solution, so that the detection result is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the etching processing device of the circuit board of the present invention;

[0028] Figure 2 It is a schematic diagram of the internal structure of the etching processing device of the circuit board of the present invention;

[0029] Figure 3 It is a structural schematic diagram of the circuit board etching processing device of the present invention, in which a first pressure detection gauge, a second pressure detection gauge, a detection pump and a delivery pipe are connected;

[0030] Figure 4 The present invention is a block diagram of the electrical control structure of the etching processing device for the circuit board.

[0031] In the figure: 1. conveying mechanism; 2. etching processing chamber; 3. spray pump; 4. nozzle; 5. first pressure detection gauge; 6. second pressure detection gauge; 7. detection pump; 8. conveying pipe; 9. electric heating plate; 10. temperature sensor; 11. multi-purpose pump; 12. first mixing tube; 13. second mixing tube; 14. first electric-controlled valve; 15. second electric-controlled valve; 16. drain pipe; 17. third electric-controlled valve; 18. liquid inlet pipe; 19. fourth electric-controlled valve; 20. liquid replenishing pump; 21. storage box. DETAILED DESCRIPTION

[0032] The following is a further description with reference to the accompanying drawings and specific embodiments:

[0033] Example 1

[0034] This embodiment provides an etching processing device for a circuit board, such as Figure 2 and Figure 3 As shown, it includes a conveying mechanism 1, an etching treatment chamber 2, a spray pump 3, a nozzle 4, an etching liquid viscosity detection device, and an etching liquid heating device. The conveying mechanism 1 passes through the etching treatment chamber 2, and the nozzle 4 is arranged in the etching treatment chamber 2, and is arranged in sequence along the conveying direction of the conveying mechanism 1, and is located directly above the conveying mechanism 1. The etching treatment chamber 2 has an etching liquid storage chamber located below the conveying mechanism 1, the liquid suction end of the spray pump 3 is connected to the etching liquid storage chamber, and the liquid discharge end of the spray pump 3 is connected to the nozzle 4. The spray pump 3 conveys the etching liquid stored in the etching liquid storage chamber to each nozzle 4, and each nozzle 4 sprays the etching liquid onto the circuit board conveyed on the conveying mechanism 1.

[0035] like Figure 1-Figure 4 As shown, an electric control detection box is arranged on the outer wall of the etching treatment chamber 2, and the etching liquid viscosity detection device is arranged in the electric control detection box. The etching liquid viscosity detection device includes a controller, a detection pump 7, a delivery pipe 8, a first pressure detection gauge 5 and a second pressure detection gauge 6. A detection suction port and a detection discharge port are arranged on the wall of the etching liquid storage chamber. The detection suction port of the etching liquid storage chamber is lower than the detection discharge port of the etching liquid storage chamber, and the detection discharge port of the etching liquid storage chamber is higher than the liquid level of the etching liquid. The suction end of the detection pump 7 is connected to the detection suction port of the etching liquid storage chamber, the discharge end of the detection pump 7 is connected to one end of the delivery pipe 8, and the other end of the delivery pipe 8 is connected to the detection discharge port of the etching liquid storage chamber. The first pressure detection gauge 5 and the second pressure detection gauge 6 are both installed on the delivery pipe 8, and are both electrically connected to the controller. The controller includes a control module, a calculation module and a storage module, and the pressure difference threshold value P0 is stored in the storage module.

[0036] like Figure 2-Figure 4As shown, the etching liquid heating device includes an electric heating plate 9, a temperature sensor 10 and an etching liquid mixing mechanism. A mounting groove is provided on the bottom wall of the etching liquid storage chamber, the electric heating plate 9 is arranged in the mounting groove, and the temperature sensor 10 is electrically connected to the controller. The etching liquid mixing mechanism includes a multi-purpose pump 11, a first mixing tube 12 and a second mixing tube 13. The suction end of the multi-purpose pump 11 is connected to the etching liquid storage chamber through the first mixing tube 12, and the discharge end of the multi-purpose pump 11 is connected to the etching liquid storage chamber through the second mixing tube 13. The position where the first mixing tube 12 is connected to the etching liquid storage chamber is lower than the position where the second mixing tube 13 is connected to the etching liquid storage chamber, and the position where the first mixing tube 12 is connected to the etching liquid storage chamber is close to the inner bottom wall of the etching liquid storage chamber. The first mixing tube 12 is provided with a first electrically controlled valve 14, the second mixing tube 13 is provided with a second electrically controlled valve 15, the second mixing tube 13 is connected with a discharge pipe 16, the position where the discharge pipe 16 and the second mixing tube 13 are connected is located between the second electrically controlled valve 15 and the discharge end of the multi-purpose pump 11, the discharge pipe 16 is provided with a third electrically controlled valve 17, the first electrically controlled valve 14, the second electrically controlled valve 15 and the third electrically controlled valve 17 are all electrically connected to the controller. The etching liquid storage chamber is connected with an inlet pipe 18, the inlet pipe 18 is provided with a fourth electrically controlled valve 19, the inlet pipe 18 is connected with a refilling pump 20, and the refilling pump 20 is connected with a storage box 21 storing etching liquid. The fourth electrically controlled valve 19 and the refilling pump 20 are also electrically connected to the controller. In addition, a liquid level sensor is provided on the etching liquid storage chamber, and the liquid level sensor is also electrically connected to the controller.

[0037] The principle of the present invention for detecting the viscosity of the etching liquid is as follows: the controller includes a control module, a calculation module and a storage module. The storage module stores a pressure difference threshold value P0, which is the critical value for the viscosity of the etching liquid to meet the use requirements. When the detection pump 7 is started, the etching liquid in the etching liquid storage chamber is extracted and returned to the etching liquid storage chamber through the delivery pipe 8. During this process, the first pressure detection gauge 5 and the second pressure detection gauge 6 will respectively detect the first pressure detection value P1 and the second pressure detection value P2. When the viscosity of the etching liquid increases, the pressure difference between the first pressure detection value P1 and the second pressure detection value P2 will also increase. The pressure difference between the first pressure detection value P1 and the second pressure detection value P2 is adjusted by comprehensively considering the influence of the etching liquid temperature and liquid level, and then compared with the pressure difference threshold value P0, so that it can be known whether the viscosity of the etching liquid at the current moment can meet the use requirements.

[0038] Example 2

[0039] This embodiment provides an etching method for a circuit board, using the etching device for a circuit board provided in Embodiment 1. The etching method comprises the following steps:

[0040] S1, start the electric heating plate 9 and the multi-purpose pump 11, open the first electric control valve 14 and the second electric control valve 15, heat and mix the etching liquid stored in the etching liquid storage chamber, and stop heating when the etching liquid is heated to the etching process temperature. When the temperature of the etching liquid is lower than the set value, the etching liquid is heated and mixed again, and the cycle continues.

[0041] S2, placing the circuit board to be etched on the conveying mechanism 1, starting the conveying mechanism 1, and the conveying mechanism 1 drives the circuit board to be etched into the etching processing chamber 2.

[0042] S3, start the spray pump 3 and the nozzle 4, the spray pump 3 delivers the etching liquid that reaches the etching process temperature to the nozzle 4, and the nozzle 4 sprays the etching liquid onto the circuit board to be etched to perform etching processing.

[0043] S4, the control module controls the detection pump 7 to start with the set power to ensure that the power of the detection pump 7 is the same each time it is started. The detection pump 7 extracts the etching liquid in the etching liquid storage chamber and returns it to the etching liquid storage chamber through the delivery pipe 8. During this process, the first pressure detection gauge 5 and the second pressure detection gauge 6 will detect the first pressure detection value P1 and the second pressure detection value P2 respectively. The first pressure detection gauge 5 and the second pressure detection gauge 6 transmit the first pressure detection value P1 and the second pressure detection value P2 to the calculation module.

[0044] S5, the calculation module calculates the pressure difference P through the formula P=a*b*|P1-P2|, and compares P and P0, where a is the temperature adjustment coefficient and b is the liquid level adjustment coefficient. The temperature adjustment coefficient a and the liquid level adjustment coefficient b are to eliminate the influence of the temperature and liquid level changes of the etching solution. When P>P0, and (P-P0) / P0*100%≥M%, it can be determined that the viscosity of the etching solution can no longer meet the use requirements. The value of M is: 0≤M≤5, providing an appropriate fluctuation range. When P>P0, and (P-P0) / P0*100%≥M%, the etching solution in the etching solution storage chamber needs to be replaced. At this time, the calculation module transmits a signal to the control module. After receiving the signal, the control module controls to start the multi-purpose pump 11, open the first electric control valve 14 and the third electric control valve 17, close the second electric control valve 15, and extract part of the etching solution in the etching solution storage chamber through the multi-purpose pump 11.

[0045] The storage module stores the minimum detection temperature value Tmin, the maximum detection temperature value Tmax and a temperature adjustment coefficient table. The temperature adjustment coefficient table is as follows:

[0046]

[0047] In the above table, Tmin<T1<T2……<Tn-<Tmax.

[0048] In step S5, the control module controls the multi-purpose pump 11 to start, and the temperature of the etching liquid is within the range of Tmin-Tmax. The lowest detected temperature value Tmin and the highest detected temperature value Tmax are both within the etching process temperature range.

[0049] The storage module also stores the minimum liquid level value Hmin, the maximum liquid level value Hmax and the liquid level adjustment coefficient table. The liquid level adjustment coefficient table is as follows:

[0050]

[0051] In the above table, Hmin

[0052] In step S5, when the control module controls the multi-purpose pump 11 to start, the liquid level of the etching liquid must be within the range of Hmin-Hmax, otherwise it is necessary to drain or replenish the liquid first.

[0053] Each temperature adjustment coefficient a in the temperature adjustment coefficient table and each temperature adjustment coefficient b in the liquid level adjustment coefficient table can be determined in advance through experiments. When the calculation module calculates the pressure difference P through the formula P=a*b*|P1-P2|, the temperature adjustment coefficient a is selected from the temperature adjustment coefficient table according to the temperature value of the etching solution, and the liquid level adjustment coefficient b is selected from the temperature adjustment coefficient table according to the liquid level value of the etching solution.

[0054] S6, the liquid level sensor transmits the liquid level of the etching liquid to the control module in real time. When the liquid level of the etching liquid in the etching liquid storage chamber drops to the first set liquid level threshold, the control module controls the closing of the third electric control valve 17, opens the second electric control valve 15 and the fourth electric control valve 19, and starts the liquid replenishing pump 20. The liquid replenishing pump 20 replenishes the etching liquid stored in the storage box 21 to the etching liquid storage chamber. When the liquid level of the etching liquid in the etching liquid storage chamber rises to the second set liquid level threshold, the control module controls the closing of the fourth electric control valve 19, the liquid replenishing pump 20 and the multi-purpose pump 11 to complete the replacement of the etching liquid.

[0055] S7, when the etching liquid is replaced, the temperature of the etching liquid in the etching liquid storage chamber may be out of the process temperature range. Therefore, when the etching liquid is replaced, the temperature sensor 10 transmits the temperature of the etching liquid in the etching liquid storage chamber to the control module. If it is less than the etching process temperature stored in the storage module, the control module controls the start of the electric heating plate 9 and the multi-purpose pump 11, opens the first electric control valve 14 and the second electric control valve 15, closes the third electric control valve 17, heats and mixes the etching liquid in the etching liquid storage chamber, and stops heating when the etching liquid is heated to the etching process temperature.

[0056] ​In summary, the present invention is provided with an etching liquid viscosity detection device, which can detect the viscosity of the etching liquid in time, and can know whether the viscosity of the etching liquid meets the use requirements in time, so that the etching liquid can be replaced in time, and the etching effect of the circuit board will not be affected by the etching liquid viscosity not meeting the use requirements. The present invention is provided with a multi-purpose pump 11 and a replenishing pump 20, which can automatically replace the etching liquid by cooperating with a liquid level sensor and an etching liquid viscosity detection device. The present invention is provided with an etching liquid heating device, which includes an electric heating plate 9, a temperature sensor 10 and an etching liquid mixing mechanism, which can heat the etching liquid to meet the etching process requirements, and can mix the etching liquid so that the etching liquid temperature is uniform everywhere in the etching liquid storage chamber. When the present invention detects the viscosity of the etching liquid, by introducing the temperature adjustment coefficient a and the liquid level adjustment coefficient b, the influence of the etching liquid temperature and liquid level changes is eliminated, so that the detection result is more accurate.

[0057] 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. An etching processing device for a circuit board, comprising a conveying mechanism (1), an etching treatment chamber (2), a spray pump (3) and a nozzle (4), wherein the conveying mechanism (1) passes through the etching treatment chamber (2), the nozzle (4) is arranged in the etching treatment chamber (2), the etching treatment chamber (2) has an etching liquid storage chamber located below the conveying mechanism (1), the spray pump (3) and the nozzle (4) are connected, and the nozzle (4) is used to spray the etching liquid onto the circuit board conveyed on the conveying mechanism (1), characterized in that: It also comprises an etching liquid viscosity detection device, the etching liquid viscosity detection device comprising a controller, a detection pump (7), a delivery pipe (8), a first pressure detection gauge (5) and a second pressure detection gauge (6); a detection liquid suction port and a detection liquid discharge port are arranged on the wall of the etching liquid storage chamber; the liquid suction end of the detection pump (7) is connected to the detection liquid suction port of the etching liquid storage chamber, the liquid discharge end of the detection pump (7) is connected to one end of the delivery pipe (8), and the other end of the delivery pipe (8) is connected to the detection liquid discharge port of the etching liquid storage chamber; the first pressure detection gauge (5) and the second pressure detection gauge (6) are both installed on the delivery pipe (8) and are both electrically connected to the controller; Furthermore, an etching liquid heating device is included, the etching liquid heating device comprising an electric heating plate (9) and a temperature sensor (10), a mounting groove is provided on the bottom wall of the etching liquid storage chamber, the electric heating plate (9) is arranged in the mounting groove, and the temperature sensor (10) is electrically connected to the controller; The etching liquid heating device further comprises an etching liquid mixing mechanism, the etching liquid mixing mechanism comprising a multi-purpose pump (11), a first mixing tube (12) and a second mixing tube (13), the liquid suction end of the multi-purpose pump (11) is connected to the etching liquid storage chamber via the first mixing tube (12), the liquid discharge end of the multi-purpose pump (11) is connected to the etching liquid storage chamber via the second mixing tube (13), the position where the first mixing tube (12) is connected to the etching liquid storage chamber is lower than the position where the second mixing tube (13) is connected to the etching liquid storage chamber, and the position where the first mixing tube (12) is connected to the etching liquid storage chamber is close to the inner bottom wall of the etching liquid storage chamber; the first mixing tube (12) is provided with a first electrically controlled valve (14), the second mixing tube (13) is provided with a second electrically controlled valve (15), the second mixing tube (13) is connected to a discharge tube (16), the position where the discharge tube (16) and the second mixing tube (13) are connected is located between the second electrically controlled valve (15) and the discharge end of the multi-purpose pump (11), the discharge tube (16) is provided with a third electrically controlled valve (17), and the first electrically controlled valve (14), the second electrically controlled valve (15) and the third electrically controlled valve (17) are all electrically connected to a controller.

2. The etching processing device for a circuit board according to claim 1, characterized in that: The etching liquid storage chamber is connected to a liquid inlet pipe (18), a fourth electrically controlled valve (19) is arranged on the liquid inlet pipe (18), the liquid inlet pipe (18) is connected to a liquid replenishing pump (20), and the liquid replenishing pump (20) is connected to a storage box (21) storing the etching liquid; the fourth electrically controlled valve (19) and the liquid replenishing pump (20) are also electrically connected to the controller.

3. The etching processing device for a circuit board according to claim 2, characterized in that: The etching liquid storage chamber is provided with a liquid level sensor, which is also electrically connected to the controller; the detection liquid suction port of the etching liquid storage chamber is lower than the detection liquid discharge port of the etching liquid storage chamber, and the detection liquid discharge port of the etching liquid storage chamber is higher than the liquid level of the etching liquid.

4. A method for etching a circuit board, using the circuit board etching device according to claim 3, characterized in that: The steps include: S1, starting the electric heating plate (9) and the multi-purpose pump (11), opening the first electric control valve (14) and the second electric control valve (15), heating and mixing the etching liquid stored in the etching liquid storage chamber, and stopping the heating when the etching liquid is heated to the etching process temperature; S2, placing the circuit board to be etched on the conveying mechanism (1), starting the conveying mechanism (1), and the conveying mechanism (1) drives the circuit board to be etched into the etching processing chamber (2); S3, starting the spray pump (3) and the nozzle (4), the spray pump (3) conveying the etching liquid reaching the etching process temperature to the nozzle (4), and the nozzle (4) spraying the etching liquid onto the circuit board to be etched to perform etching processing; The controller includes a control module, a calculation module and a storage module, and the storage module stores a pressure difference threshold value P0; the etching processing method also includes the following steps: S4, the control module controls the detection pump (7) to start at a set power, and the first pressure detection meter (5) and the second pressure detection meter (6) transmit the first pressure detection value P1 and the second pressure detection value P2 to the calculation module; S5, the calculation module calculates the pressure difference P by the formula P=a*b*|P1-P2|, and compares P and P0, where a is the temperature adjustment coefficient and b is the liquid level adjustment coefficient; when P>P0, and (P-P0) / P0*100%≥M%, the value of M is: 0≤M≤5; the calculation module transmits a signal to the control module, and after receiving the signal, the control module controls the multi-purpose pump (11) to start, open the first electric control valve (14) and the third electric control valve (17), close the second electric control valve (15), and extract part of the etching liquid in the etching liquid storage chamber through the multi-purpose pump (11); S6, the liquid level sensor transmits the liquid level of the etching liquid to the control module in real time; when the liquid level of the etching liquid in the etching liquid storage chamber drops to a first set liquid level threshold, the control module controls the closing of the third electrically controlled valve (17), opens the second electrically controlled valve (15) and the fourth electrically controlled valve (19), and starts the liquid replenishing pump (20); the liquid replenishing pump (20) replenishes the etching liquid stored in the storage box (21) into the etching liquid storage chamber; when the liquid level of the etching liquid in the etching liquid storage chamber rises to a second set liquid level threshold, the control module controls the closing of the fourth electrically controlled valve (19), the liquid replenishing pump (20) and the multi-purpose pump (11), and completes the replacement of the etching liquid.

5. The etching method of a circuit board according to claim 4, characterized in that: The etching process further comprises the following steps: S7, the temperature sensor (10) transmits the temperature of the etching liquid in the etching liquid storage chamber to the control module. If the temperature is lower than the etching process temperature stored in the storage module, the control module controls the start-up of the electric heating plate (9) and the multi-purpose pump (11), and simultaneously opens the first electric control valve (14) and the second electric control valve (15), so as to heat the etching liquid in the etching liquid storage chamber.

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