Circuit board line etching method based on novel bank protection agent and novel bank protection agent

Abstract

The invention provides a circuit board circuit etching method based on a novel bank protection agent and the novel bank protection agent. The circuit board line etching method comprises the following steps: obtaining a novel bank protection agent and an acidic copper chloride solution; mixing the novel bank protection agent and the acidic copper chloride solution according to a preset proportion to obtain an acidic copper chloride etching solution; performing vertical spraying operation on the acidic copper chloride etching solution according to a preset pressure value, so that the acidic copper chloride etching solution performs etching operation on a circuit board; wherein polar groups of the novel bank protection agent can be adsorbed on a circuit copper surface of the circuit board, and non-polar groups of the novel bank protection agent are directionally arranged far away from the circuit copper surface of the circuit board to form a hydrophobic membrane. The novel bank protection agent comprises the following components in parts by mass: 1-30 parts of a polar solvent containing lone pair electrons; 1 to 30 parts of a non-polar solvent; and 50 to 70 parts of deionized water.

Description

Technical Field

[0001] The present disclosure relates to the field of circuit board production, and in particular to a circuit board circuit etching method based on a novel revetment agent and the novel revetment agent. Background Art

[0002] Printed circuit boards (PCBs) are a vital component of the modern electronics industry. From small electronic watches to large aircraft and aerospace applications, wherever electronic components such as integrated circuits are present, PCBs are used to achieve electrical interconnection. During the PCB manufacturing process, circuits are the foundation of the PCB.

[0003] As modern electronic products place increasingly stringent demands on circuit boards, printed circuit boards are also developing towards higher density and higher precision, which places even higher demands on the quality of etched circuits. Circuit board etching typically uses an acidic copper chloride etchant, which is typically sprayed vertically, allowing the acidic copper chloride etchant to fall vertically onto the circuit board for etching. However, the acidic copper chloride etchant not only etches vertically but also diffuses etching laterally around the edge of the circuit board as it drips onto it. As etching progresses, the copper on the edge sidewalls of the circuit board's circuits is etched, causing the sidewalls to tilt, resulting in a reduced line width, affecting the circuit board's electrical conductivity, reducing the quality of the circuit board, and resulting in a low yield rate.

[0004] To address this issue, a new type of revetment agent has emerged on the market. By adding this agent to an acidic copper chloride etching solution, the etching solution forms a protective film on the copper sidewalls of the circuit boards when it drips onto them, preventing the copper chloride from coming into contact with them. Existing revetment agents, primarily composed of EDTA and thiourea, can mitigate side etching, but the resulting protective film cannot adhere to the copper sidewalls, resulting in poor corrosion suppression. This results in low yield rates for high-precision circuit boards. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a circuit board circuit etching method and a new revetment agent based on a new revetment agent, which can reduce the side etching phenomenon during the circuit board circuit etching process to improve the yield rate of the circuit board.

[0006] The purpose of this disclosure is achieved through the following technical solutions:

[0007] A circuit board etching method based on a novel revetment agent comprises the following steps:

[0008] obtain new shore protection agents and acidic copper chloride solutions;

[0009] The novel bank protection agent and the acidic copper chloride solution are mixed in a preset ratio to obtain an acidic copper chloride etching solution;

[0010] The acidic copper chloride etching solution is vertically sprayed according to a preset pressure value, so that the acidic copper chloride etching solution etches the circuit board;

[0011] The polar groups of the novel bank protection agent are adsorbed on the copper surface of the circuit board, and the non-polar groups of the novel bank protection agent are arranged in a direction away from the copper surface of the circuit board to form a hydrophobic film.

[0012] In one embodiment, the preset ratio of the novel bank protection agent to the acidic copper chloride solution is 1:(50-100).

[0013] In one embodiment, the preset pressure value is 3.0 kg / cm 3 ~4.0kg / cm 3 .

[0014] In one embodiment, after the step of mixing the novel bank protection agent and the acidic copper chloride solution in a preset ratio, and before the step of vertically spraying the acidic copper chloride etching solution at a preset pressure value, the circuit board etching method further includes the following steps:

[0015] The circuit board is subjected to surface pretreatment.

[0016] In one embodiment, after the step of performing surface pretreatment on the circuit board and before the step of vertically spraying the acidic copper chloride etching solution according to a preset pressure value, the circuit board circuit etching method further includes the following steps:

[0017] A dry film application operation is performed on the circuit board.

[0018] In one embodiment, the copper ion concentration of the acidic copper chloride etching solution is 120 g / L to 170 g / L.

[0019] In one embodiment, the chloride ion concentration of the acidic copper chloride etching solution is 230 g / L to 350 g / L.

[0020] In one embodiment, the acid equivalent of the acidic copper chloride etching solution is 1.0N to 3.5N.

[0021] In one embodiment, the working temperature of the acidic copper chloride etching solution is 45°C to 55°C.

[0022] A novel revetment agent, used for performing the circuit board etching method based on the novel revetment agent described in any of the above embodiments;

[0023] The novel shore protection agent comprises the following components in parts by weight:

[0024] 1-30 parts of a polar solvent containing lone pair electrons;

[0025] 1 to 30 parts of non-polar solvent;

[0026] 50 to 70 parts of deionized water.

[0027] Compared with the prior art, the present disclosure has at least the following advantages:

[0028] After the new bank protection agent and the acidic copper chloride solution are mixed in a preset proportion, the polar groups of the new bank protection agent are adsorbed on the copper surface of the circuit board, and the non-polar groups of the new bank protection agent are directionally arranged away from the copper surface of the circuit board to form a hydrophobic film, so that the acidic copper chloride etching solution can form a hydrophobic film adsorbed on the copper surface of the circuit board when etching the circuit board. Because the acidic copper chloride etching solution is sprayed vertically according to a preset pressure value, that is, the acidic copper chloride etching solution is sprayed vertically toward the area to be etched of the circuit board, under the preset pressure value, the copper chloride can vertically break through the hydrophobic film on the copper surface of the circuit board and etch the area to be etched of the circuit board. At this time, the pressure value of the acidic copper chloride etching solution dripping on the circuit board suddenly drops, so that the pressure value of the acidic copper chloride etching solution diffusing toward the side wall of the circuit board is insufficient to break through the hydrophobic film on the side wall of the copper surface of the circuit board. In this way, the corrosion of the side wall of the copper surface of the circuit board by the acidic copper chloride etching solution can be effectively reduced, the side corrosion of the circuit board circuit can be greatly reduced, and the yield rate of the circuit board under the production requirements of high-precision circuits can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 Flowchart of a circuit board etching method based on a novel revetment agent in one embodiment;

[0031] Figure 2 This is a cross-sectional view of the circuit board of Example 1;

[0032] Figure 3 This is a cross-sectional view of the circuit board of Comparative Example 1;

[0033] Figure 4 This is a cross-sectional view of the circuit board of Comparative Example 3;

[0034] Figure 5 This is a diagram of the film-forming principle of the new bank protection agent;

[0035] Figure 6 This is a schematic diagram of the principle of inhibiting lateral erosion using a new type of bank protection agent. DETAILED DESCRIPTION

[0036] To facilitate understanding of the present disclosure, a more comprehensive description of the present disclosure will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present disclosure. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure.

[0037] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure pertains. The terms used herein in the specification of this disclosure are intended only to describe specific embodiments and are not intended to limit this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0039] The present disclosure provides a circuit board circuit etching method based on a novel bank protection agent, comprising the following steps: obtaining a novel bank protection agent and an acidic copper chloride solution; mixing the novel bank protection agent and the acidic copper chloride solution in a preset ratio to obtain an acidic copper chloride etching solution; vertically spraying the acidic copper chloride etching solution at a preset pressure value to cause the acidic copper chloride etching solution to etch the circuit board; wherein the polar groups of the novel bank protection agent are adsorbed on the copper surface of the circuit board, and the non-polar groups of the novel bank protection agent are directionally arranged away from the copper surface of the circuit board to form a hydrophobic film.

[0040] The above-mentioned circuit board circuit etching method is to mix the new bank protection agent and the acidic copper chloride solution in a preset ratio, and the polar groups of the new bank protection agent will be adsorbed on the copper surface of the circuit board, and the non-polar groups of the new bank protection agent will be oriented away from the copper surface of the circuit board to form a hydrophobic film, so that the acidic copper chloride etching solution can form a hydrophobic film adsorbed on the copper surface of the circuit board when etching the circuit board. Because the acidic copper chloride etching solution is sprayed vertically according to a preset pressure value, that is, the acidic copper chloride etching solution is sprayed vertically toward the area to be etched on the circuit board, Assuming a pressure value at which copper chloride can vertically break through the hydrophobic film on the copper surface of the circuit board and etch the area to be etched, the pressure of the acidic copper chloride etching solution dripping onto the circuit board suddenly drops, causing the pressure at which the acidic copper chloride etching solution diffuses toward the sidewalls of the circuit board to be insufficient to break through the hydrophobic film on the copper sidewalls of the circuit board. This effectively reduces the corrosion of the acidic copper chloride etching solution on the copper sidewalls of the circuit board, greatly reducing the side corrosion of the circuit board, and effectively improving the yield rate of the circuit board under the production requirements of high-precision circuits.

[0041] See also Figure 1 In order to better understand the circuit board etching method based on the novel revetment agent disclosed in the present invention, the following is a further explanation:

[0042] A circuit board etching method based on a novel revetment agent according to one embodiment comprises the following steps:

[0043] S100, obtain new shore protection agent and acidic copper chloride solution.

[0044] In this embodiment, a new revetment agent and an acidic copper chloride solution are obtained to facilitate etching of the circuit board circuits. The new revetment agent can form a hydrophobic film on the copper surface of the circuit board circuits, thereby inhibiting the side corrosion of the circuit board and improving the yield rate of the circuit board.

[0045] S200, mixing the novel bank protection agent and the acidic copper chloride solution in a preset ratio to obtain an acidic copper chloride etching solution.

[0046] In this embodiment, the novel revetment agent and the acidic copper chloride solution are mixed in an etching tank according to a preset ratio to obtain an acidic copper chloride etching solution that can form a hydrophobic film with good adsorption effect on the copper surface of the circuit board.

[0047] S300, performing a vertical spraying operation on the acidic cupric chloride etching solution according to a preset pressure value, so that the acidic cupric chloride etching solution etches the circuit board.

[0048] In this embodiment, a nozzle is used to vertically spray an acidic cupric chloride etching solution onto the circuit board at a preset pressure value. When the acidic cupric chloride etching solution contacts the copper surface of the circuit board, it is adsorbed on the copper surface and forms a hydrophobic film. However, because the acidic cupric chloride is vertically sprayed onto the circuit board under pressure, the cupric chloride can vertically break through the hydrophobic film on the copper surface of the circuit board circuit and etch the area to be etched of the circuit board at this preset pressure value. At this time, the pressure of the acidic cupric chloride etching solution dripping onto the circuit board drops sharply after breaking through the hydrophobic film in the vertical direction. The pressure value at which the acidic cupric chloride etching solution diffuses toward the sidewalls of the circuit board circuit is insufficient to break through the hydrophobic film on the copper surface sidewalls of the circuit board circuit. In this way, the corrosion of the copper surface sidewalls of the circuit board circuit by the acidic cupric chloride etching solution can be effectively reduced, the side corrosion of the circuit board circuit can be greatly reduced, and the yield rate of the circuit board under the production requirements of high-precision circuits can be effectively improved.

[0049] Furthermore, after the acid copper chloride etching solution completes the etching operation on the circuit board, the acid copper chloride etching solution will flow into the recovery tank, and then the acid copper chloride etching solution in the recovery tank will be transported to the etching tank, and the new revetment agent will be added into the etching tank again, so that the acid copper chloride etching solution can be recycled. Furthermore, the amount of the new revetment agent added again is quantitatively added according to the etching area of ​​the circuit board, and the specific addition standard is per 100m 2 Add 0.5L to 2.0L of new shore protection agent to the etching area.

[0050] In one embodiment, after the step of mixing the novel bank protection agent and the acidic copper chloride solution in a preset ratio, and before the step of vertically spraying the acidic copper chloride etching solution at a preset pressure value, the circuit board etching method further includes the following steps:

[0051] The circuit board is pre-etched using the acidic copper chloride etching solution.

[0052] It should be noted that, by pre-etching the circuit board, i.e. spraying the acidic cupric chloride etching solution vertically on the circuit board, a concave etching groove can be formed in the area to be etched of the circuit board, so that when the circuit board performs a vertical spraying operation, the acidic cupric chloride etching solution can quickly drip into the concave etching groove and complete the etching process in the vertical direction, thereby effectively improving the etching factor of the acidic cupric chloride etching solution in the vertical direction, i.e. improving the vertical etching rate of the acidic cupric chloride etching solution. Further, the circuit board is pre-etched, and a hydrophobic film can be formed on the sidewall of the concave etching groove, which can suppress the side etching phenomenon of the acidic cupric chloride etching solution to the greatest extent, thereby effectively improving the yield rate of the circuit board.

[0053] Furthermore, the pressure value of the pre-etching process is 1.5 kg / cm 3~2.0kg / cm 3 It can be understood that under this pressure value, a concave etching groove can be formed in the area to be etched of the circuit board, so that the acidic copper chloride etching solution can quickly drip into the concave etching groove during vertical spraying, thereby improving the vertical etching factor of the circuit board, thereby improving the production efficiency and yield rate of the circuit board.

[0054] In one embodiment, the preset ratio of the novel revetment agent to the acidic copper chloride solution is 1:(50-100). It is understood that at this preset ratio, a hydrophobic film can be uniformly formed on the copper surface of the circuit board, and the formed hydrophobic film can be vertically broken through by the acidic copper chloride etching solution at a preset pressure value, thereby increasing the vertical etching factor of the acidic copper chloride etching solution while reducing the lateral etching factor of the acidic copper chloride etching solution. The increase and decrease can minimize the side etching phenomenon of the circuit board circuit, thereby effectively improving the production efficiency and yield rate of the circuit board.

[0055] In one embodiment, the preset pressure value is 3.0 kg / cm 3 ~4.0kg / cm 3 It can be understood that under this preset pressure value, the acidic copper chloride etching solution can break through the hydrophobic film in the vertical direction to etch the copper surface, effectively improving the vertical etching factor of the acidic copper chloride etching solution. At the same time, the pressure value carried by the acidic copper chloride etching solution decays after undergoing vertical etching, making the acidic copper chloride etching solution insufficient to break through the hydrophobic film on the copper surface of the circuit side wall, thereby reducing the lateral etching factor of the acidic copper chloride etching solution, thereby effectively suppressing the side etching phenomenon of the circuit board circuit, and effectively improving the production efficiency and yield rate of the circuit board.

[0056] In one embodiment, after the step of mixing the novel bank protection agent and the acidic copper chloride solution in a preset ratio, and before the step of vertically spraying the acidic copper chloride etching solution at a preset pressure value, the circuit board etching method further includes the following steps:

[0057] The circuit board is subjected to surface pretreatment.

[0058] It should be noted that by cleaning the surface of the circuit board, specifically, removing dust and oil from the surface of the circuit board, the surface of the circuit board is kept clean, the contact area of ​​the acidic copper chloride etching solution is increased, and the circuit board has a better etching effect.

[0059] In one embodiment, after the step of performing surface pretreatment on the circuit board and before the step of vertically spraying the acidic copper chloride etching solution according to a preset pressure value, the circuit board circuit etching method further includes the following steps:

[0060] A dry film application operation is performed on the circuit board.

[0061] It should be noted that a dry film is applied to the copper surface of the circuit board in the area that does not need to be etched to protect the copper surface of the circuit, leaving only the copper surface of the area to be etched. After etching with acidic copper chloride etching solution, the circuit is formed to complete the production of the circuit board circuit.

[0062] In one embodiment, the copper ion concentration of the acidic copper chloride etching solution is 120g / L to 170g / L. It is understandable that at this copper ion concentration, the copper in the area to be etched on the circuit board can be etched away, while at the same time maximizing the efficiency of the vertical etching of the acidic copper chloride etching solution, thereby effectively improving the vertical etching factor of the acidic copper chloride etching solution, and further effectively improving the production efficiency and yield rate of the circuit board under the production requirements of high-precision circuits. Further, in one embodiment, the copper ion concentration of the acidic copper chloride etching solution is preferably 150g / L.

[0063] In one embodiment, the chloride ion concentration of the acidic copper chloride etching solution is 230g / L to 350g / L. It is understandable that at this chloride ion concentration, chloride ions can form soluble copper chloride complex ions with copper ions. These complex ions have strong oxidizing properties and can accelerate the oxidation and dissolution process of copper foil, thereby accelerating the etching speed. Specifically, during the etching process, the copper ions in copper chloride are oxidizing and can oxidize the copper on the board surface into monovalent copper ions. The formed cuprous chloride is not easily soluble in water. However, in the presence of excessive chloride ions, cuprous chloride can further react with chloride ions to form soluble copper chloride complex ions, allowing the etching reaction to continue. Further, in one embodiment, the chloride ion concentration of the acidic copper chloride etching solution is preferably 250g / L to 350g / L.

[0064] In one embodiment, the acid equivalent of the acidic copper chloride etching solution is 1.0N to 3.5N. It is understandable that an acidic environment can accelerate the oxidation and dissolution process of copper, which is the core of the etching reaction. In the acidic copper chloride etching solution, copper ions have stronger oxidizing properties under acidic conditions and can more effectively oxidize copper foil into monovalent copper ions, thereby forming soluble copper chloride complex ions to etch the copper surface of the circuit board. Furthermore, acidic conditions can increase the etching rate. On the one hand, the acidic environment helps to accelerate the diffusion and migration of ions, allowing the acidic copper chloride etching solution to penetrate the copper surface faster. On the other hand, the acidic conditions can also promote the complex reaction between chloride ions and copper ions, forming more soluble copper chloride complex ions, thereby accelerating the etching speed. Furthermore, the acidic copper chloride etching solution can maintain good stability under acidic conditions. Specifically, the acidic environment can inhibit the occurrence of some unnecessary side reactions, reduce the decomposition and failure of the etching solution, and the acidic conditions can also maintain the appropriate concentration and ratio of copper ions and chloride ions in the etching solution, thereby ensuring the continuous progress of the etching reaction. Furthermore, in one embodiment, the acid equivalent of the acidic copper chloride etching solution is preferably 2N.

[0065] In one embodiment, the working temperature of the acidic copper chloride etching solution is 45° C. to 55° C. It is understood that at this working temperature, the acidic copper chloride etching solution can obtain a better etching reaction rate and achieve a uniform etching effect, while reducing the volatilization of hydrochloric acid in the acidic copper chloride to maintain the stability of the acidic copper chloride etching solution.

[0066] In one embodiment, the ORP value of the acidic copper chloride etching solution is 450mv to 550mv. It is understood that the ORP value refers to the redox potential, and the CAP value also refers to the redox potential. When the ORP value is 450mv to 550mv, the CAP value corresponds to 20 to 30. The redox state of copper ions in the acidic copper chloride etching solution is measured by the ORP value or CAP value, which is an indicator of the activity of the etching solution. At this ORP value, the acidic copper chloride etching solution has a good etching speed, good etching quality, and good stability.

[0067] It is understandable that the production requirements of high-definition circuits require minimizing lateral etching at a higher vertical etching factor. Excessive levels of the hydrophobic film component in the new revetment agent will minimize lateral etching, but will also reduce the vertical etching factor. Excessive levels of the hydrophobic film component in the new revetment agent can increase the vertical etching factor, but will also result in more severe lateral etching, reducing the yield rate of the circuit board. In one embodiment, an acidic copper chloride etching solution is obtained from the concave etching tank and the film component content of the acidic copper chloride etching solution is tested. It should be noted that the specific operating steps for membrane component detection are: extract 1mL of the acidic copper chloride etching solution in the concave etching tank and add it to a 1000mL volumetric flask to 1000mL. After thorough shaking, gradually add zinc reagent and use an AA machine (atomic absorption spectrophotometer) to read the reading to obtain the hydrophobic membrane component content. Specifically, zinc will undergo a disproportionation reaction with the hydrophobic membrane to form a complex. The zinc complex content is measured by the AA machine to reversely infer the hydrophobic membrane component content, so as to obtain the new revetment agent addition amount corresponding to the optimal hydrophobic membrane component content. Furthermore, a database with a one-to-one correspondence between multiple hydrophobic membrane component contents and multiple new revetment agent addition amounts is established. The database can be used to retrieve the new revetment agent addition amount corresponding to the optimal hydrophobic membrane component content while adapting to different circuit board production requirements, improving the applicability of the circuit board circuit etching method. Furthermore, it is recommended that the specific operating steps for the database with a one-to-one correspondence between multiple hydrophobic membrane component contents and multiple new revetment agent addition amounts are: membrane component content detection is performed on multiple groups of different acidic copper chloride etching solutions to obtain multiple hydrophobic membrane component contents. Furthermore, when testing the film component content of a single set of acidic copper chloride etching solutions, multiple replicate groups are set to obtain multiple hydrophobic film component contents within the single set of acidic copper chloride etching solutions. Furthermore, the multiple hydrophobic film component contents within the single set of acidic copper chloride etching solutions are averaged to obtain the average hydrophobic film component content of the single set of acidic copper chloride etching solutions, thereby improving the accuracy of the hydrophobic film component content detection and effectively improving the accuracy of the database. Furthermore, the optimal hydrophobic film component content is retrieved from the database to determine the optimal addition amount of the new revetment agent, enabling the acidic copper chloride etching solution to obtain a better vertical etching factor while minimizing the undercutting of circuit board circuits, thereby effectively improving the production efficiency and yield rate of circuit boards.

[0068] The present disclosure also provides a novel revetment agent for performing the circuit board etching method based on the novel revetment agent described in any of the above embodiments;

[0069] The novel shore protection agent comprises the following components in parts by weight:

[0070] 1-30 parts of a polar solvent containing lone pair electrons;

[0071] 1 to 30 parts of non-polar solvent;

[0072] 50 to 70 parts of deionized water.

[0073] In this embodiment, the groups containing lone pairs of electrons in the polar solvent are adsorbed on the copper surface of the circuit board, while the non-polar groups of the non-polar solvent are directionally arranged away from the copper surface of the circuit board to form a hydrophobic film. Specifically, the lone pairs of electrons can form coordination bonds with the empty orbitals of the metallic copper, thereby changing the double electric layer structure of the copper surface, enabling the hydrophobic film to be adsorbed on the copper surface of the circuit board. At the same time, the activation energy required for etching the metallic copper ions in the acidic copper chloride etching solution is increased, thereby reducing the etching of the copper surface of the circuit board's circuit sidewall by the acidic copper chloride etching solution, thereby effectively improving the yield rate of the circuit board under the production requirements of high-precision circuits.

[0074] It should be noted that, since the acidic cupric chloride etching solution is sprayed vertically at a preset pressure value, and the activation energy required for copper ion etching of the acidic cupric chloride etching solution can be met at the preset pressure value, the cupric chloride can break through the hydrophobic film on the copper surface of the circuit board line in the vertical direction and etch the area required to be etched on the circuit board, that is, the vertical etching is completed. At this time, the pressure value of the acidic cupric chloride etching solution dripping on the circuit board drops sharply, and the activation energy required for copper ion etching of the acidic cupric chloride etching solution cannot be met, nor can it break through the hydrophobic film on the side wall of the copper surface of the circuit board line. In this way, the side etching phenomenon of the circuit board is suppressed, the side etching phenomenon of the circuit board line is greatly reduced, and the yield rate of the circuit board under the production demand of high-precision lines is effectively improved.

[0075] In one embodiment, the polar solvent containing a lone pair of electrons is a carboxyl-containing solvent or an organic coordination solvent containing S atoms. It is understandable that by forming a coordination bond between the lone pair of electrons and the empty orbital of the copper surface of the circuit board, the polar group can be adsorbed on the copper surface of the circuit board circuit, while increasing the activation energy required for copper ion etching in the acidic copper chloride etching solution, and can suppress the side corrosion phenomenon of the circuit board to the greatest extent, thereby effectively improving the yield rate of the circuit board under the production requirements of high-precision circuits. Further, in one embodiment, the carboxyl-containing solvent is a combination of one or more of acetic acid, citric acid, amino acid, benzoic acid and oxalic acid. Further, in one embodiment, the organic coordination solvent containing S atoms is a combination of one or more of thiol, thiophenol, thioether, sulfonic acid, sulfinic acid, sulfonic acid chloride, sulfonic ester and sulfonamide.

[0076] In one embodiment, the non-polar solvent is a fatty acid hydrophobic agent. It is understood that fatty acid hydrophobic agents contain non-polar long-chain alkyl groups that can be oriented away from the copper surface of the circuit board and form a hydrophobic film, thereby effectively inhibiting side corrosion of the circuit board and improving the yield rate of the circuit board. Furthermore, in one embodiment, the fatty hydrophobic agent is a combination of one or more of stearic acid, sodium stearate, oleic acid, potassium oleate, sodium oleate, lauric acid, potassium laurate, sodium laurate, palmitic acid, potassium palmitate, and sodium palmitate.

[0077] In one embodiment, the novel revetment agent also includes a wetting agent, with the amount of the wetting agent being 0.5 to 3 parts by weight. It is understood that the addition of the wetting agent allows the polar and non-polar solvents to be evenly dispersed in the system, thereby improving the protection of the copper surfaces on the sidewalls of the circuit board circuits. Furthermore, the wetting agent can also increase the vertical etching factor of the acidic copper chloride etchant, that is, accelerate the vertical etching rate of the acidic copper chloride etchant. At the same time, at this amount by weight, it can minimize side etching of the circuit board circuits, further improving the yield rate of the circuit board to meet the production requirements of high-precision circuits. Furthermore, in one embodiment, the wetting agent is a polyoxyethylene alkylphenol ether or a polyoxyethylene fatty alcohol ether. It is understood that these wetting agents can accelerate the dispersion and penetration of the acidic copper chloride etchant on the copper surface, thereby increasing the vertical etching factor of the acidic copper chloride etchant, thereby effectively improving the production efficiency and yield rate of the circuit board.

[0078] Examples are listed below, but it should be noted that the following examples do not exhaust all possible situations, and the materials used in the following examples can be obtained from commercial channels unless otherwise specified.

[0079] Example 1

[0080] The formula of the new shore protection agent is 25 parts of amino acid, 25 parts of stearic acid, 50 parts of deionized water, and 0.5 parts of polyoxyethylene alkylphenol ether;

[0081] The ratio of the new bank protection agent and the acidic copper chloride solution in the etching tank is 1:50;

[0082] Parameters of the solution in the etching tank: copper ion concentration is 149g / L, acid equivalent is 2.1N, CAP value is 24, and working temperature is 50℃;

[0083] The linear speed of the etching line is 2.5 m / min and the etching line length is 6 m;

[0084] The target circuit board's line etching requirement is 40 / 40μm line etching;

[0085] Step 1: Pre-etch the circuit board. The nozzle pressure value of the pre-etching operation is 2.0kg / cm 3 ;

[0086] Step 2: Extract 1mL of acidic copper chloride etching solution from the concave etching tank of the circuit board and add it to a 1000mL volumetric flask to make up to 1000mL. After shaking thoroughly, gradually add zinc reagent and use AA machine (atomic absorption spectrophotometer) to read;

[0087] Step 3: Etch the circuit board. The nozzle pressure for the etching operation is 3.5kg / cm 3 ;

[0088] Step 4: Slice and measure the etched circuit board and calculate the etching factor.

[0089] Example 2

[0090] The formula of the new shore protection agent is 25 parts of amino acid, 25 parts of stearic acid, 50 parts of deionized water, and 0.5 parts of polyoxyethylene alkylphenol ether;

[0091] The ratio of the new bank protection agent and the acidic copper chloride solution in the etching tank is 1:75;

[0092] Parameters of the solution in the etching tank: copper ion concentration is 159g / L, acid equivalent is 2.1N, CAP value is 26, and operating temperature is 50℃;

[0093] The linear speed of the etching line is 2.5 m / min and the etching line length is 6 m;

[0094] The target circuit board's line etching requirement is 40 / 40μm line etching;

[0095] Step 1: Pre-etch the circuit board. The nozzle pressure value of the pre-etching operation is 2.0kg / cm 3 ;

[0096] Step 2: Extract 1mL of acidic copper chloride etching solution from the concave etching tank of the circuit board and add it to a 1000mL volumetric flask to make up to 1000mL. After shaking thoroughly, gradually add zinc reagent and use AA machine (atomic absorption spectrophotometer) to read;

[0097] Step 3: Etch the circuit board. The nozzle pressure for the etching operation is 3.5kg / cm 3 ;

[0098] Step 4: Slice and measure the etched circuit board and calculate the etching factor.

[0099] Example 3

[0100] The formula of the new shore protection agent is 25 parts of amino acid, 25 parts of stearic acid, 50 parts of deionized water, and 0.5 parts of polyoxyethylene alkylphenol ether;

[0101] The ratio of the new bank protection agent and the acidic copper chloride solution in the etching tank is 1:100;

[0102] Parameters of the solution in the etching tank: copper ion concentration is 170g / L, acid equivalent is 2.1N, CAP value is 28, and working temperature is 50℃;

[0103] The linear speed of the etching line is 2.5 m / min and the etching line length is 6 m;

[0104] The target circuit board's line etching requirement is 40 / 40μm line etching;

[0105] Step 1: Pre-etch the circuit board. The nozzle pressure value of the pre-etching operation is 2.0kg / cm 3 ;

[0106] Step 2: Extract 1mL of acidic copper chloride etching solution from the concave etching tank of the circuit board and add it to a 1000mL volumetric flask to make up to 1000mL. After shaking thoroughly, gradually add zinc reagent and use AA machine (atomic absorption spectrophotometer) to read;

[0107] Step 3: Etch the circuit board. The nozzle pressure for the etching operation is 3.5kg / cm 3 ;

[0108] Step 4: Slice and measure the etched circuit board and calculate the etching factor.

[0109] Example 4

[0110] The formula of the new revetment agent is 25 parts of chlorinated sulfonate, 25 parts of stearic acid, 50 parts of deionized water, and 0.5 parts of polyoxyethylene alkylphenol ether;

[0111] The ratio of the new bank protection agent and the acidic copper chloride solution in the etching tank is 1:50;

[0112] Parameters of the solution in the etching tank: copper ion concentration is 149g / L, acid equivalent is 2.0N, CAP value is 25, and working temperature is 50℃;

[0113] The linear speed of the etching line is 2.5 m / min and the etching line length is 6 m;

[0114] The target circuit board's line etching requirement is 51 / 56μm line etching;

[0115] Step 1: Pre-etch the circuit board. The nozzle pressure value of the pre-etching operation is 2.0kg / cm 3 ;

[0116] Step 2: Extract 1mL of acidic copper chloride etching solution from the concave etching tank of the circuit board and add it to a 1000mL volumetric flask to make up to 1000mL. After shaking thoroughly, gradually add zinc reagent and use AA machine (atomic absorption spectrophotometer) to read;

[0117] Step 3: Etch the circuit board. The nozzle pressure for the etching operation is 3.5kg / cm 3 ;

[0118] Step 4: Slice and measure the etched circuit board and calculate the etching factor.

[0119] Example 5

[0120] The formula of the new revetment agent is 25 parts of chlorinated sulfonate, 25 parts of stearic acid, 50 parts of deionized water, and 0.5 parts of polyoxyethylene alkylphenol ether;

[0121] The ratio of the new bank protection agent and the acidic copper chloride solution in the etching tank is 1:75;

[0122] Parameters of the solution in the etching tank: copper ion concentration is 159g / L, acid equivalent is 2.0N, CAP value is 26, and working temperature is 50℃;

[0123] The linear speed of the etching line is 2.5 m / min and the etching line length is 6 m;

[0124] The target circuit board's line etching requirement is 51 / 56μm line etching;

[0125] Step 1: Pre-etch the circuit board. The nozzle pressure value of the pre-etching operation is 2.0kg / cm 3 ;

[0126] Step 2: Extract 1mL of acidic copper chloride etching solution from the concave etching tank of the circuit board and add it to a 1000mL volumetric flask to make up to 1000mL. After shaking thoroughly, gradually add zinc reagent and use AA machine (atomic absorption spectrophotometer) to read;

[0127] Step 3: Etch the circuit board. The nozzle pressure for the etching operation is 3.5kg / cm 3 ;

[0128] Step 4: Slice and measure the etched circuit board and calculate the etching factor.

[0129] Example 6

[0130] The formula of the new revetment agent is 25 parts of chlorinated sulfonate, 25 parts of stearic acid, 50 parts of deionized water, and 0.5 parts of polyoxyethylene alkylphenol ether;

[0131] The ratio of the new bank protection agent and the acidic copper chloride solution in the etching tank is 1:100;

[0132] Parameters of the solution in the etching tank: copper ion concentration is 170g / L, acid equivalent is 2.0N, CAP value is 28, and working temperature is 50℃;

[0133] The linear speed of the etching line is 2.5 m / min and the etching line length is 6 m;

[0134] The target circuit board's line etching requirement is 51 / 56μm line etching;

[0135] Step 1: Pre-etch the circuit board. The nozzle pressure value of the pre-etching operation is 2.0kg / cm 3 ;

[0136] Step 2: Extract 1mL of acidic copper chloride etching solution from the concave etching tank of the circuit board and add it to a 1000mL volumetric flask to make up to 1000mL. After shaking thoroughly, gradually add zinc reagent and use AA machine (atomic absorption spectrophotometer) to read;

[0137] Step 3: Etch the circuit board. The nozzle pressure for the etching operation is 3.5kg / cm 3 ;

[0138] Step 4: Slice and measure the etched circuit board and calculate the etching factor.

[0139] Comparative Example 1

[0140] Use traditional bank protection agents;

[0141] The ratio of bank protection agent and acid copper chloride solution in the etching tank is 1:50;

[0142] Parameters of the solution in the etching tank: copper ion concentration is 149g / L, acid equivalent is 2.1N, CAP value is 24, and working temperature is 50℃;

[0143] The linear speed of the etching line is 2.5 m / min and the etching line length is 6 m;

[0144] The target circuit board's line etching requirement is 40 / 40μm line etching;

[0145] Step 1: Pre-etch the circuit board. The nozzle pressure value of the pre-etching operation is 2.0kg / cm 3 ;

[0146] Step 2: Etch the circuit board. The nozzle pressure for the etching operation is 3.5kg / cm 3 ;

[0147] Step 3: Take cut measurements of the etched circuit board and calculate the etching factor.

[0148] Comparative Example 2

[0149] Use traditional bank protection agents;

[0150] The ratio of bank protection agent and acid copper chloride solution in the etching tank is 1:50;

[0151] Parameters of the solution in the etching tank: copper ion concentration is 149g / L, acid equivalent is 2.0N, CAP value is 25, and working temperature is 50℃;

[0152] The linear speed of the etching line is 2.5 m / min and the etching line length is 6 m;

[0153] The target circuit board's line etching requirement is 51 / 56μm line etching;

[0154] Step 1: Pre-etch the circuit board. The nozzle pressure value of the pre-etching operation is 2.0kg / cm 3 ;

[0155] Step 2: Etch the circuit board. The nozzle pressure for the etching operation is 3.5kg / cm 3 ;

[0156] Step 3: Take cut measurements of the etched circuit board and calculate the etching factor.

[0157] Comparative Example 3

[0158] No revetment agent is added;

[0159] Parameters of the solution in the etching tank: copper ion concentration is 149g / L, acid equivalent is 2.1N, CAP value is 24, and working temperature is 50℃;

[0160] The linear speed of the etching line is 2.5 m / min and the etching line length is 6 m;

[0161] The target circuit board's line etching requirement is 40 / 40μm line etching;

[0162] Step 1: Pre-etch the circuit board. The nozzle pressure value of the pre-etching operation is 2.0kg / cm 3 ;

[0163] Step 2: Etch the circuit board. The nozzle pressure for the etching operation is 3.5kg / cm 3 ;

[0164] Step 3: Take cut measurements of the etched circuit board and calculate the etching factor.

[0165] Comparative Example 4

[0166] No revetment agent is added;

[0167] Parameters of the solution in the etching tank: copper ion concentration is 149g / L, acid equivalent is 2.0N, CAP value is 25, and working temperature is 50℃;

[0168] The linear speed of the etching line is 2.5 m / min and the etching line length is 6 m;

[0169] The target circuit board's line etching requirement is 51 / 56μm line etching;

[0170] Step 1: Pre-etch the circuit board. The nozzle pressure value of the pre-etching operation is 2.0kg / cm 3 ;

[0171] Step 2: Etch the circuit board. The nozzle pressure for the etching operation is 3.5kg / cm 3 ;

[0172] Step 3: Take cut measurements of the etched circuit board and calculate the etching factor.

[0173] The slice data after etching of 40 / 40μm line is shown in Table 1;

[0174] Table 1

[0175] Upper width (μm) Lower width (μm) Copper thickness (μm) Etching Factor Zinc complex content (mg / L) Example 1 28.32 34.61 18.28 5.81 202 Example 2 26.01 34.55 18.19 5.24 158 Example 3 25.88 34.45 18.05 4.98 125 Comparative Example 1 25.24 34.61 18.34 3.91 / Comparative Example 3 24.03 34.53 19.06 3.63 /

[0176] The slice data after etching of 51 / 56μm lines are shown in Table 2;

[0177] Table 2

[0178] Upper width (μm) Lower width (μm) Copper thickness (μm) Etching Factor Zinc complex content (mg / L) Example 4 34.26 48.51 38.85 5.45 212 Example 5 33.89 48.43 38.75 5.31 165 Example 6 33.54 48.38 38.74 5.28 139 Comparative Example 2 32.34 49.18 39.95 4.75 / Comparative Example 4 32.03 50.39 40.65 4.43 /

[0179] It should be noted that the upper width refers to the width of the upper part of the circuit board after etching, and the lower width refers to the width of the lower part of the circuit board after etching. The difference between the upper and lower widths can reflect the side etching phenomenon. The smaller the difference, the smaller the side etching phenomenon, and the larger the difference, the more severe the side etching phenomenon. The general formula for calculating the etching factor is E = V / X, where V is the etching depth and X is the side etching depth. The etching factor reflects the side etching phenomenon and etching rate. The zinc complex content reflects the content of the hydrophobic film.

[0180] See also Figures 2 to 4 , Figure 2 This is a circuit board slice diagram of Example 1. Figure 3 This is a circuit board slice diagram of comparative example 1. Figure 4 This is a cross-sectional view of the circuit board of comparative example 3.

[0181] Depend on Figures 2 to 4It can be seen that compared with traditional revetment agents, the new revetment agent and circuit board etching method disclosed in the present invention can significantly reduce the side corrosion phenomenon of the circuit board.

[0182] As shown in Tables 1 and 2, compared to conventional revetment agents, the etching factor and etching depth of the novel revetment agent and circuit board etching method disclosed herein are significantly improved. This means that the novel revetment agent not only inhibits the side etching phenomenon of the acidic copper chloride etching solution, but also improves the etching effect of the acidic copper chloride etching solution, thereby effectively improving the production efficiency and yield rate of the circuit board. Furthermore, under the same etching line and the same line speed, the thinner the copper thickness, the higher the etching depth, which also means a higher etching rate. The novel revetment agent and circuit board etching method disclosed herein can increase the etching rate of the acidic copper chloride etching solution.

[0183] As shown in Table 1, by comparing the data of Examples 1 to 3, the etching factor of Example 1 has the best etching effect at 40 / 40 μm circuit etching, and the zinc complex content (hydrophobic film content) of Example 1 is also the highest; as shown in Table 2, by comparing the data of Examples 4 to 6, the etching factor of Example 4 has the best etching effect at 51 / 56 μm circuit etching, and the zinc complex content (hydrophobic film content) of Example 4 is also the highest. It can be seen that the optimal opening ratio of the new revetment agent and the acidic copper chloride solution is 1:50. At this opening ratio, the vertical etching factor of the acidic copper chloride solution can be improved while minimizing the side etching phenomenon of the circuit board.

[0184] In summary, the novel revetment agent and circuit board etching method disclosed herein can suppress the undercutting phenomenon of the circuit board during the etching process to the greatest extent, while increasing the etching rate of the circuit board, thereby effectively improving the production efficiency and yield rate of the circuit board.

[0185] Compared with the prior art, the present disclosure has at least the following advantages:

[0186] After the new bank protection agent and the acidic copper chloride solution are mixed in a preset proportion, the polar groups of the new bank protection agent are adsorbed on the copper surface of the circuit board, and the non-polar groups of the new bank protection agent are directionally arranged away from the copper surface of the circuit board to form a hydrophobic film, so that the acidic copper chloride etching solution can form a hydrophobic film adsorbed on the copper surface of the circuit board when etching the circuit board. Because the acidic copper chloride etching solution is sprayed vertically according to a preset pressure value, that is, the acidic copper chloride etching solution is sprayed vertically toward the area to be etched of the circuit board, under the preset pressure value, the copper chloride can vertically break through the hydrophobic film on the copper surface of the circuit board and etch the area to be etched of the circuit board. At this time, the pressure value of the acidic copper chloride etching solution dripping on the circuit board suddenly drops, so that the pressure value of the acidic copper chloride etching solution diffusing toward the side wall of the circuit board is insufficient to break through the hydrophobic film on the side wall of the copper surface of the circuit board. In this way, the corrosion of the side wall of the copper surface of the circuit board by the acidic copper chloride etching solution can be effectively reduced, the side corrosion of the circuit board circuit can be greatly reduced, and the yield rate of the circuit board under the production requirements of high-precision circuits can be effectively improved.

[0187] The above-described embodiments merely represent several implementation methods of the present disclosure. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the disclosed patent. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the scope of the present disclosure, all of which fall within the scope of protection of the present disclosure. Therefore, the scope of protection of the disclosed patent shall be determined by the appended claims.

Claims

1. A circuit board circuit etching method based on a new shore protection agent, characterized in that: The steps include: Obtain new shore protection agents and acid copper chloride solutions; The novel shore protection agent and the acidic copper chloride solution are mixed in a preset ratio to obtain an acidic copper chloride etching solution; The acidic cupric chloride etching solution is vertically sprayed according to a preset pressure value, so that the acidic cupric chloride etching solution etches the circuit board; The polar groups of the novel shore protection agent are adsorbed on the copper surface of the circuit board, and the non-polar groups of the novel shore protection agent are arranged in a direction away from the copper surface of the circuit board to form a hydrophobic film.

2. The circuit board circuit etching method based on the novel shore protection agent according to claim 1 is characterized in that: The preset ratio of the novel shore protection agent to the acidic copper chloride solution is 1:(50-100).

3. The circuit board etching method based on the novel shore protection agent according to claim 1 is characterized in that: The preset pressure value is 3.0kg / cm 3 ~4.0kg / cm 3 .

4. The circuit board circuit etching method based on the novel shore protection agent according to claim 1 is characterized in that: After the step of mixing the novel bank protection agent and the acidic copper chloride solution in a preset ratio and before the step of vertically spraying the acidic copper chloride etching solution at a preset pressure value, the following steps are also included: The circuit board is subjected to surface pretreatment.

5. The circuit board etching method based on the novel shore protection agent according to claim 4 is characterized in that: After the step of performing surface pretreatment on the circuit board and before the step of vertically spraying the acidic copper chloride etching solution according to a preset pressure value, the method further includes the following steps: A dry film is applied to the circuit board.

6. The circuit board circuit etching method based on the novel shore protection agent according to claim 1 is characterized in that: The copper ion concentration of the acidic copper chloride etching solution is 120 g / L to 170 g / L.

7. The circuit board etching method based on the novel shore protection agent according to claim 1 is characterized in that: The chloride ion concentration of the acidic cupric chloride etching solution is 230 g / L to 350 g / L.

8. The circuit board etching method based on the novel shore protection agent according to claim 1 is characterized in that: The acid equivalent of the acidic cupric chloride etching solution is 1.0N to 3.5N.

9. The circuit board etching method based on the novel shore protection agent according to claim 1, characterized in that: The working temperature of the acidic cupric chloride etching solution is 45°C to 55°C.

10. A new shore protection agent, characterized in that: Used to perform the circuit board line etching method based on the novel shore protection agent according to any one of claims 1 to 9; The novel shore protection agent comprises the following components in parts by weight: 1-30 parts of a polar solvent containing a lone pair of electrons; 1 to 30 parts of non-polar solvent; 50 to 70 parts of deionized water.

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