Ammonia-alkaline copper tetraammine sulfate etching process and device for circuit board

Abstract

The invention relates to an ammonia-alkaline tetraamminecopper sulfate etching process for a circuit board, which comprises an etching solution used for etching the circuit board coated with a metal anti-corrosion layer, and is characterized in that the etching solution comprises tetraamminecopper sulfate, a complexing ammonia supply source and a formate supply source, and the ammonia-alkaline tetraamminecopper sulfate is used as a copper etching agent for etching the circuit board, and the copper etching agent in the etching liquid is regenerated through the copper etching agent oxidation regeneration reaction supply source so as to maintain the etching rate. The problem of the production process that the etching liquid attacks and corrodes the silver and tin metal anti-corrosion layer in the prior art can be solved.

Description

A circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process and device Technical Field

[0001] The invention belongs to the field of circuit board etching production technology, and particularly relates to a circuit board ammonia-alkaline sulfuric acid tetraammine copper etching process and a device thereof. Background Art

[0002] Commonly used circuit board etching solutions include acidic copper chloride etching solutions and ammoniacal alkaline copper chloride ammonia etching solutions. The main components of these ammoniacal alkaline copper chloride ammonia etching solutions are ammonia water, ammonium chloride, and a copper chloride ammonia complex. Some ammoniacal alkaline copper chloride ammonia etching solutions also contain additives such as ammonium carbonate. These ammoniacal alkaline copper chloride ammonia etching solutions use the copper chloride ammonia complex [Cu(NH3)4]Cl2 as a copper etching agent. During the etching process, [Cu(NH3)4]Cl2 is converted into [Cu(NH3)2]Cl2 due to the copper etching reaction, which lacks etching ability. This is then oxidized by oxygen in the air and regenerated into [Cu(NH3)4]Cl2, which then participates in etching again.

[0003] According to page 403 of the second volume of "Printed Circuit Technology (Fifth Edition)", "For ammonia-alkaline copper chloride ammonia etching solution, when the copper ion concentration is 0-82g / L, the etching time is long; when it is 82-120g / L, the etching rate is low and the solution control is difficult; when it is 135-165g / L, the etching rate is high and the solution is stable."

[0004] In the industry, the etching solution used in etching operations, specifically in etching production lines, is referred to as the etching process solution. During the chemical etching process, to maintain a stable ratio of the components of the etching process solution, a new solution is added, known as the etching solution. Any solution that overflows from the etching system due to the addition of the etching solution, typically outside the etching machine, becomes etching waste.

[0005] There is a type of patterned metal resist-plated circuit board product in the industry, which is plated with gold, silver, tin, etc. as a metal resist pattern and then etched. Among them, the most common process for metal resist-plated circuit boards is:

[0006] ⑴ Paste photosensitive film or apply photosensitive ink on the copper clad circuit board;

[0007] ⑵After exposure and development, a pattern is made and copper plating and thickening circuits are made according to the pattern;

[0008] (3) Then plating the metal anti-corrosion layer on the obtained copper-plated thickened circuit pattern;

[0009] (4) Then the film is stripped to facilitate subsequent etching of the copper clad laminate.

[0010] In the above process, when the circuit board coated with the silver or tin metal corrosion-resistant layer is subsequently etched using the existing ammonia-alkaline copper chloride ammonia etching solution, the silver or tin metal corrosion-resistant layer will be attacked and corroded by the large amount of chloride ions in the etching solution, becoming thinner and narrower. The copper circuits under the metal corrosion-resistant layer are easily exposed to the etching solution, resulting in the circuit being etched and broken, making the product scrapped.

[0011] Although the above problem can be solved by thickening and widening the metal anti-etching layer to enhance the protection of the copper circuit, it will increase production consumables and increase costs, and will make the film stripping process difficult, resulting in unclean film stripping, and even the photosensitive film / ink being sandwiched between the metal anti-etching layer and the copper surface and unable to be stripped.

[0012] In addition, existing ammonia-alkaline copper chloride ammonia etching waste liquid also has process problems for recycling and reuse. In addition to selling this etching waste liquid to environmental protection companies for treatment, some manufacturers currently use equipment to extract copper from it within the factory and recycle the waste liquid. The most common method for regenerating copper from this etching waste liquid within the factory in the prior art is extraction electrolysis. The entire process of extraction electrolysis is complex and tedious. Specifically, the copper in the ammonia-alkaline copper chloride ammonia etching waste liquid is extracted using an extractant, and then copper sulfate solution is obtained by back-extraction using sulfuric acid, followed by electrolysis to extract copper. The extractant forms a chelate with the copper ions in the ammonia-alkaline copper chloride ammonia etching waste liquid and enters the organic phase. At the same time, the hydrogen in the extractant is released into the etching waste liquid, causing its pH value to decrease. Therefore, when using the extractant residue to prepare the regenerated etching sub-liquid, a large amount of ammonia needs to be added. Only by using highly toxic liquid ammonia can the volume expansion of the regenerated etching sub-liquid be avoided. Liquefied ammonia is very easy to gasify, can cause severe frostbite when contacting, when the concentration of ammonia reaches 0.5-0.6% (calculated by volume) in air, people stop therein half an hour and can be poisoned, and concentration may cause fatal accident when surpassing 0.6-1%.Add that the extraction surplus liquid contains the organic extractant that plays corrosion inhibition, it is mixed with the regeneration etching sub-liquid and is reused in the etching production and can affect etching production quality and production efficiency, so direct electrolysis has occurred in recent years and the ammonia alkaline copper chloride ammonia etching waste liquid is done to get copper regeneration.Yet, owing to contain chlorion and ammonia simultaneously in the ammonia alkaline copper chloride ammonia etching waste liquid, can play chemical reaction and consume ammonia because of electrolysis output chlorine and the ammonia in the etching waste liquid when adopting direct electrolysis to reclaim copper, cause consumption and the waste of raw material, and adopt electrolysis to get the surplus liquid after the copper and prepare the regeneration etching sub-liquid and need equally highly toxic liquefied ammonia, cause this technology to be difficult to be promoted.

[0013] The acidic copper chloride etching solution is acidic and attacks and corrodes metal resist layers other than gold more violently. Therefore, the industry currently still uses ammonia-alkaline copper chloride ammonia etching solution to etch circuit boards with widened and thickened silver and tin metal resist layers.

[0014] In the prior art, some people have tried to use tetraamminecopper sulfate [Cu(NH3)4]SO4 as a copper etching agent because tetraamminecopper sulfate [Cu(NH3)4]SO4 can also react with metallic copper and has the advantage of not containing chloride ions that are highly corrosive to metals. However, since the [Cu2(NH3)4]SO4 generated by the etching reacts with oxygen in the air and regenerates into [Cu(NH3)4]SO4 at a slow rate, the etching rate of the [Cu(NH3)4]SO4 solution is very low without other additives or auxiliary means, which cannot meet the needs of large-scale production and has therefore not been used in practice.

[0015] Chinese patent CN85106153A discloses a "Process for Etching Copper Film on Printed Circuit Boards" to address the problems of slow etching rate of [Cu(NH3)4]SO4 solution and the prior art problem of adding vanadium or vanadium compounds as catalysts to the etching solution to promote the copper etching reaction, resulting in the copper electrolytically extracted from the etching solution having no adhesion, easily peeling, and being difficult to remove from the electrode. The disclosed process uses an etching solution containing [Cu(NH3)4]SO4, NH3, (NH4)2SO4, and a bromine-containing catalyst for etching. The bromine-containing catalyst forms an easily removable, adherent, and flexible copper layer on the cathode after electrolysis from the etching solution, and also increases the etching speed. The etching process uses oxygen in air to oxidize and regenerate the copper etchant [Cu(NH3)4]SO4, and uses an electrolytic cell to remove an appropriate amount of copper ions from the etching solution as the etching time increases. Specifically, the etching solution is added to an undivided electrolytic cell, and [Cu(NH3)4]SO4 is electrochemically reduced to copper metal at the cathode to reduce the copper ion concentration in the solution. The process does not utilize electrolytic anodic oxidation to regenerate the copper etchant. The solution obtained after electrolytic copper removal differs from the etching working solution only in the concentration of the components. The former has a lower copper ion concentration and higher concentrations of NH3 and (NH4)2SO4, and is therefore reused as a regenerated etching sub-liquid in the etching operation. However, since bromine compounds have similar properties to chlorine compounds, the etching process disclosed in this patent still has the problem of corrosive attack on silver and tin metal anti-etching layers, and it has not been used in actual etching production.

[0016] In summary, the industry needs a new etching solution that is friendly to silver and tin metal resist layers. It is hoped that a very thin layer of silver and tin resist can be deposited only on the patterned circuits of the copper-clad laminate to meet the requirements of the circuit board etching process. This would not only save precious metal production raw materials, but also, due to the thin metal resist layer, it would help solve the problem of film stripping in the next step. Furthermore, it would be ideal to achieve 100% recycling of etching waste liquid in environmentally friendly recycling, thereby reducing etching production costs and environmental pollution.

[0017] Summary of the Invention

[0018] The present invention aims to improve the production process problem of etching solution attacking and corroding silver and tin metal anti-corrosion layers in the prior art, and manufactures a device suitable for the etching process of the present invention.

[0019] The first object of the present invention is to provide a circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process.

[0020] A second object of the present invention is to provide a device suitable for the above-mentioned circuit board ammonia-alkaline sulfuric acid tetraammine copper etching solution process.

[0021] The first object of the present invention is achieved through the following technical solutions.

[0022] A circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process includes an etching solution used to etch a circuit board covered with a metal anti-corrosion layer. The etching solution contains tetraammine copper sulfate, a complex ammonia supply source, and a formate supply source. The circuit board is etched using ammoniacal alkaline sulfuric acid tetraammine copper as a copper etching agent, and the copper etching agent in the etching solution is regenerated by an oxidation regeneration reaction source of the copper etching agent to maintain the etching rate.

[0023] Through long-term practical experience and experiments, the inventors have confirmed that good etching performance can only be achieved when the concentrations of various ions in the etching solution are coordinated. Specifically, the etching solution has a copper ion concentration of 10-140 g / L, a pH of 7-11.5, a sulfate ion molar concentration of at least 0.01 times the copper ion molar concentration and no more than 4 mol / L, a total molar concentration of ammonia and ammonium ions of at least 1 times the copper ion molar concentration and no more than 18 mol / L, and a formate concentration of 0.0001-8 mol / L. The total molar concentration of ammonia and ammonium ions is the total molar concentration of free ammonia, ammonium ions, and ammonia and ammonium ions in the copper-ammonia complex in the etching solution.

[0024] Preferably, the etching solution has a pH of 7.6-11, a copper ion concentration of 40-130 g / L, a sulfate ion molar concentration of at least 0.05 times the copper ion molar concentration and no more than 3.8 mol / L, and a total molar concentration of ammonia and ammonium ions of at least 1 times the copper ion molar concentration and no more than 17 mol / L. When the copper ion concentration of the etching solution exceeds 130 g / L, copper salts are likely to crystallize and occlude the nozzle and liquid flow pipes when the solution is left standing.

[0025] More preferably, the copper ion concentration of the etching solution is 45-120 g / L, the pH value range is pH 8.0-10.0, the molar concentration of sulfate ions is at least 0.3 times the molar concentration of copper ions and does not exceed 3.5 mol / L, and the total molar concentration of ammonia and ammonium ions is at least 2.0 times the molar concentration of copper ions and does not exceed 16 mol / L.

[0026] Preferably, the molar concentration of copper ions in the etching solution is not higher than the sum of the molar concentration of sulfate ions and half the molar concentration of formate ions.

[0027] The complexing ammonia supply source described in the present invention is a chemical that can provide ammonia and / or ammonium ions to participate in the regeneration chemical reaction of the tetraammine copper sulfate etching agent and generate complexing ammonia, including but not limited to one or more of ammonia water, ammonia, ammonium carbonate, ammonium bicarbonate, ammonium sulfate, ammonium bisulfate, and ammonium formate.

[0028] The formate source described in the present invention is formic acid and / or ammonium formate, which is used to increase the upper limit of copper solubility in the etching solution, thereby improving the copper ion concentration control parameter of the etching working solution and promoting the chemical reaction of copper etching. When ammonium formate is used as the formate source, the ammonium formate serves as both a source of complexing ammonia and a source of formate.

[0029] The present invention uses the formate supply source to:

[0030] ⒈ Stabilize the copper ions or copper ammonia complex ions in the etching solution: Since the solubility of copper sulfate is much lower than that of copper chloride and is significantly affected by temperature, tetraammine copper sulfate is easily converted into copper sulfate crystals when the concentration is high in an ammonia alkaline solution; Therefore, the ammonia alkaline tetraammine copper sulfate etching solution of the present invention contains formic acid and / or ammonium formate, which provides anionic formate groups for the copper ions or copper ammonia complex ions in the etching solution and stabilizes them. On the one hand, the etching solution allows more copper ions to exist in the solution without crystallization, thereby increasing the concentration of the copper etching agent in the etching solution, thereby increasing the etching rate; On the other hand, it can reduce the change in the tolerance of copper ions in the etching solution caused by the temperature. When the etching working solution temperature drops during shutdown and maintenance, it is not easy for copper sulfate crystals to precipitate, thereby improving the situation where crystals block pipes and nozzles. In addition, since most of the components in the etching solution are ionized into cations and anions, when the sulfate concentration in the etching solution is low, the formate group can stably allow more copper ammonia complex ions to exist in the etching solution, thereby increasing the concentration of the copper etching agent in the etching solution.

[0031] ⒉ Formate can also temporarily store ammonia in the ammonia-alkaline sulfuric acid tetraammine copper etching solution: the formate that temporarily stores ammonia will release NH4 in time when the ammonia concentration in the etching solution is low. + Replenish the etching raw materials. At the same pH value of the etching working solution, increase the oxidation regeneration speed of the copper etching agent and ensure the etching rate. See the following chemical formula.

[0032] The copper etching agent oxidation regeneration reaction supply source described in the present invention is an oxidation electrolytic cell for performing an oxidation regeneration reaction on an etching working solution. The oxidation electrolytic cell is provided with an electrolytic cell separator to separate the electrolytic cell into an anode cell area and a cathode cell area. The anode cell area is connected to an etching liquid tank (i.e., an etching machine) filled with etching working solution and performing etching operations through a pipeline, so that the etching working solution can circulate between the two tanks to maintain the copper etching agent concentration therein. The electrolytic cell separator of the oxidation electrolytic cell can effectively prevent the cations in the anode cell area from entering the cathode cell area, and specifically selects one or more of an anion exchange membrane, a bipolar membrane, and a reverse osmosis membrane. The purpose of the present invention can be achieved by using an aqueous solution of an electrolyte as the electrolyte in the cathode cell area of ​​the oxidation electrolytic cell. The reverse osmosis membrane used in the present invention is the membrane itself, which uses its microporous structure and material characteristics to achieve the purpose of the present invention, and is not a reverse osmosis membrane element or reverse osmosis equipment.

[0033] The copper etchant oxidation regeneration reaction supply source of the present invention regenerates the copper etchant in the etching solution based on the following operating principle: Due to the copper etching chemical reaction, the copper etchant in the etching working solution is reduced to a monovalent copper ammonia complex, which then flows into the anode tank of the oxidation electrolytic cell and undergoes an electrochemical oxidation reaction directly at the electrolytic anode, enabling rapid and efficient regeneration of the copper etchant. After the regeneration reaction, the copper etchant is returned to the etching production process to continue etching. The copper etchant in the solution in the anode tank of the oxidation electrolytic cell is produced through an electrochemical oxidation reaction, but the copper ion concentration remains unchanged; that is, when the copper ion concentration of the etching working solution in the etching machine is stable, its copper ion concentration is consistent with that of the anode electrolyte of the oxidation electrolytic cell.

[0034] The chemical reaction principle of the ammoniacal alkaline sulfuric acid tetraammine copper etching solution of the present invention in the etching copper production process is as follows:

[0035] Etching reaction: Cu(NH3)4SO4+Cu→Cu2(NH3)4SO4;

[0036] Oxidation regeneration reaction of copper etching agent in the anode tank area of ​​the oxidation electrolytic cell:

[0037] Among them, when the electrolytic cell separator of the oxidation electrolytic cell is a bipolar membrane, water molecules will undergo water electrolysis in the bipolar membrane during the electrolysis process, and hydroxide ions will be continuously generated and enter the anode tank area of ​​the oxidation electrolytic cell. When the electrolytic cell separator of the oxidation electrolytic cell is a reverse osmosis membrane, the hydroxide ions and hydrogen ions generated by water electrolysis on the electrolytic electrode during the electrolysis process can pass through the reverse osmosis membrane and enter the tank area on the other side of the membrane to continue to promote the water electrolysis reaction. Therefore, the following side reactions will occur in the case of using the above two membranes: 4OH — +4e - →2H2O+O2↑.

[0038] The copper etching agent oxidation regeneration reaction supply source described in the present invention plays a key role in achieving good etching performance in the ammoniacal alkaline sulfuric acid tetraamminecopper etching solution in practical applications. To address the shortcoming of the slow oxidation reaction of [Cu2(NH3)4]SO4 with oxygen, the ammoniacal alkaline sulfuric acid tetraamminecopper etching solution of the present invention uses an oxidation electrolytic cell to directly electrochemically oxidize the etching working solution through an electrolytic anode to regenerate the copper etching agent, thereby solving the copper etching agent regeneration problem. This measure of the present invention solves the following process pain points brought about by the tetraamminecopper sulfate itself:

[0039] First, the regeneration reaction rate of the tetraammine copper sulfate copper etching agent under the conventional copper etching agent oxidation regeneration conditions is low: since the volume of sulfate ions is much larger than that of chloride ions, it has a significant impact on various aspects such as the reaction rate of the molecule, the structure of the complex, the viscosity of the solution and the solubility of the copper salt. As a result, under the conventional copper etching agent oxidation regeneration conditions, the regeneration rate of the tetraammine copper sulfate copper etching agent is much lower than the regeneration rate of the copper chloride ammonia complex copper etching agent, resulting in a low etching rate that cannot meet the requirements of efficient etching production.

[0040] Second, the low solubility of copper sulfate results in a low copper ion concentration in the etching solution of the present invention: the copper ion concentration in the ammonia-alkaline tetraammine copper sulfate etching solution of the present invention is lower than the copper ion concentration in the existing ammonia-alkaline copper chloride etching solution. If it cannot be ensured that most of the copper ions are restored to the form of copper etching agent, the etching solution will not have a sufficient concentration of copper etching agent and will be difficult to meet the etching production needs of thick copper circuit boards.

[0041] In the continuous production process, in order to maintain a stable ratio of the components of the etching working solution, it is necessary to replenish the etching sub-liquid into the etching working solution. The ammoniacal alkaline sulfuric acid tetraammine copper etching sub-liquid used in the present invention contains sulfate and its main component is the complex ammonia supply source, thereby replenishing the complex ammonia supply source and sulfate ions into the etching working solution. Specifically, one etching sub-liquid or a combination of more than one etching sub-liquid is added.

[0042] Since the etching working liquid circulates between the etcher and the anode tank area of ​​the oxidation electrolytic cell, the etching sub-liquid can be added to any one or more of the following places: the etching working liquid of the etcher, or the anode electrolyte of the oxidation electrolytic cell, or a mixture of the two.

[0043] As a preferred embodiment of the present invention, the main components of the ammonia-alkaline sulfuric acid tetraammine copper etching sub-liquid are a combination of a complexing ammonia supply source in group A, a complexing ammonia supply source in group B and a formate supply source; the complexing ammonia supply source in group A is ammonium sulfate and / or ammonium bisulfate, and the complexing ammonia supply source in group B is one or more of ammonia water, ammonia gas, liquid ammonia, ammonium carbonate, ammonium bicarbonate, and ammonium formate; preferably, the main components of the ammonia-alkaline sulfuric acid tetraammine copper etching sub-liquid are ammonium sulfate, ammonia water and a formate supply source.

[0044] The present invention can be improved as follows: during the etching process, ammonia and / or water are added to the etching working solution and / or the anolyte of the oxidation electrolytic cell. The ammonia and ammonia water can replenish the ammonia in the etching working solution to promote the regeneration chemical reaction of the copper etching agent, and the ammonia water and water can provide moisture to improve the fluidity of the etching working solution. This is because during the etching process, the etching working solution circulates between the etcher and the anode tank area of ​​the oxidation electrolytic cell. Although the etching sub-liquid is added to the etching working solution during the etching process, the etching working solution is still prone to ammonia volatilization and water loss due to electrolytic heat, etching reaction heat release, and water electrolysis reaction, resulting in reduced solution fluidity and affecting etching performance.

[0045] As a preferred embodiment of the present invention, during etching production, at least one of a pH meter, a hydrometer, a photoelectric colorimeter, a redox potentiometer, a liquid level gauge, and a thermometer is used to detect parameters of the etching working solution and / or the anolyte of the oxidation electrolytic cell. The redox potential (ORP) value of the solution can be detected during the regenerative oxidation reaction to monitor the regeneration of the copper etching agent.

[0046] Preferably, the operation of adding the etching sub-liquid and / or ammonia water to the etching working solution and / or the anolyte of the oxidation electrolytic cell is controlled according to the detection results of the pH meter and / or the hydrometer, and the working current of the electrolytic power supply is controlled or started or shut down according to the detection results of the oxidation-reduction potentiometer (ORP meter), so that the concentration of the copper etching agent in the etching working solution is stabilized and the various components in the etching working solution reach a balanced and stable state to achieve efficient continuous etching production.

[0047] More preferably, when etching a circuit board covered with a silver metal anti-corrosion layer, the redox potential of the etching working solution is controlled to not more than 350mV by detecting the redox potential value (ORP value) of the solution during the regeneration oxidation reaction to reduce the occurrence of oxidation and dissolution of the silver metal anti-corrosion layer.

[0048] The ammoniacal alkaline sulfuric acid tetraammine copper etching process of the present invention is applicable to etching of various metal anti-corrosion layer circuit boards, including but not limited to gold, silver, tin metal or alloy anti-corrosion layer circuit boards.

[0049] The inventor believes that after multiple tests and comparisons, the main reason why the ammonia-alkaline copper chloride ammonia etching solution of the prior art attacks the silver or tin metal corrosion resistant layer is that a large amount of chloride ions are stored in the etching solution, which reacts with the silver or tin metal surface to generate silver chloride or stannous chloride. Wherein, silver chloride can be dissolved in ammonia, so that the silver metal is further exposed and further corroded by the etching solution. The ammonia-alkaline sulfuric acid tetraammine copper etching solution of the present invention can avoid the above situation, significantly reduce the attack on the silver and tin metal corrosion resistant layer, and solve the environmental protection problem of chloride ions in the etching solution of the prior art at the same time, so that the circuit board product easily meets the environmental protection standard requirement of the new product with few chlorine compounds. It should be noted that the use of tap water or material containing a small amount of chloride ion impurities to prepare the ammonia-alkaline sulfuric acid tetraammine copper etching solution of the present invention all meets the product technology quality requirements of the present invention.

[0050] The inventors have repeatedly verified that the present invention's tetraammine copper sulphate etching process can help remove film residue remaining on circuit boards during the stripping process before etching, reducing poor etching due to unclean stripping and improving etching quality. This is because the large amount of sulfate radicals contained in the present invention's tetraammine copper sulphate etching solution and its high pH value easily react with the photosensitive film and photosensitive ink, removing film residue. Consequently, the use of organic stripping solutions can be reduced in the stripping process, reducing both stripping costs and organic wastewater pollution.

[0051] The etching operating temperature of the present invention is 10-60°C. When etching circuit boards with gold or tin metal resists, the etching temperature is preferably 40-60°C, as the etching rate of the ammoniacal alkaline sulfuric acid tetraammine copper etching solution of the present invention increases with increasing temperature. When etching circuit boards with silver metal resists, the etching operating temperature is preferably 10-40°C, as higher etching temperatures accelerate the oxidation reaction between the silver metal and oxygen dissolved in the etching solution, causing the silver metal to dissolve in the etching solution. Simultaneously adopting a lower etching temperature and reducing the oxygen content in the etching solution can further protect the silver metal resist.

[0052] As a preferred embodiment of the present invention, the etching solution is adjusted in temperature according to the etching process after completing electrolytic oxidation in the anode tank of the oxidation electrolytic cell and before returning to the etching process. To maintain the copper etchant concentration in the etching solution, a high circulation flow rate is required between the etcher and the anode tank of the oxidation electrolytic cell. By controlling the temperature and flow rate of the etching solution returning to the etching process after electrolytic oxidation, the etching solution can be more efficiently utilized.

[0053] Preferably, when the etching working liquid returns to the etcher after completing electrolytic oxidation in the anode tank area of ​​the oxidation electrolytic cell, the temperature difference between the etching working liquid and the etching working liquid in the etcher is no more than 5°C.

[0054] The present invention can be improved as follows: the ammoniacal alkaline sulfuric acid tetraammine copper etching solution of the present invention further includes no more than 5 mol / L of hydroxylamine to promote the regeneration reaction of the etching solution.

[0055] Since hydroxylamine sulfate can react with the alkaline complex ammonia source in the etching solution to generate hydroxylamine in the etching solution, hydroxylamine sulfate can also be used as the raw material of hydroxylamine in the etching solution, and its concentration does not exceed 2.5 mol / L.

[0056] The principle that hydroxylamine plays a role in the ammoniacal alkaline sulfuric acid tetraammine copper etching process of the present invention is as follows:

[0057] (1) Hydroxylamine can gradually decompose to produce ammonia (as shown in the following chemical formula), which increases the ammonia concentration in the etching solution and promotes the regeneration reaction of the ammoniacal sulfuric acid tetraammine copper etching solution. 3NH2OH→NH3+N2+3H2O.

[0058] (2) Since copper ions exist in the ammoniacal alkaline sulfuric acid tetraammine copper etching solution, they can catalyze the reaction of hydroxylamine and oxygen to generate hydroxyl radicals; hydroxyl radicals are more chemically active than oxygen, and their oxidation and regeneration of copper etching agents are faster than oxygen. Cu2(NH3)4SO4+(NH4)2SO4+2NH4OH+2(·OH)→2Cu(NH3)4SO4+4H2O.

[0059] (3) Hydroxylamine has reducing properties and can effectively consume oxygen in the etching solution when the oxygen content in the etching solution is low. When etching a circuit board covered with a silver metal anti-etching layer, it can reduce the silver oxide generated by the oxidation of the silver anti-etching layer by oxygen, helping to more effectively protect the silver metal anti-etching layer.

[0060] Preferably, since hydroxylamine is unstable and easily decomposed under alkaline conditions, the etching sub-liquid containing hydroxylamine and / or hydroxylamine sulfate is prepared and used immediately, or the hydroxylamine and / or hydroxylamine sulfate solution is prepared to a pH value suitable for the etching working solution and then directly added to the etching working solution according to the process requirements, so that the hydroxylamine and / or hydroxylamine sulfate can exert the best chemical effect during the etching process.

[0061] The present invention can be improved as follows: the supply source for the oxidation regeneration reaction of the copper etching agent also includes oxygen. Specifically, the oxygen is introduced into the etching working solution and / or the anode electrolyte of the oxidation electrolytic cell, and the monovalent copper ammonia complex in the oxidation etching working solution is assisted by a chemical reaction to regenerate it into a copper etching agent. The oxygen source includes but is not limited to: (1) commercial oxygen; (2) oxygen prepared by a molecular sieve oxygen generator; (3) oxygen prepared by a chemical reaction of an oxidant; (4) oxygen prepared by an electrolytic method. Among them, the oxygen sources (1) and (4) have high oxygen production efficiency and low cost, and can better meet the needs of industrial large-scale production. The oxygen source (4) can be the oxygen escaped during the operation of the oxidation electrolytic cell, or oxygen can be prepared by an oxygen-generating electrolytic cell. The purpose of the present invention can be achieved when oxygen is generated and precipitated at the anode of the oxygen-generating electrolytic cell during the electrolysis operation. The electrolyte contacted by the electrolytic anode is an electrolyte aqueous solution containing few chloride ions, and the electrolyte contacted by the electrolytic cathode is not limited.

[0062] Chemical oxidation regeneration reaction of copper etching agent and oxygen: 2Cu2(NH3)4SO4+2(NH4)2SO4+4NH4OH+O2→4Cu(NH3)4SO4+6H2O.

[0063] Although the oxidation reaction of [Cu2(NH3)4]SO4 with oxygen is slow, increasing the oxygen concentration in the etching solution, while maintaining the copper etchant concentration in the etching solution through electrochemical oxidation and regeneration, can promote the chemical regeneration of the copper etchant, tetraamminecopper sulfate, and effectively reduce the loss of the complex ammonia source in the etching solution. Furthermore, when the etching solution is rich in oxygen, oxygen directly oxidizes metallic copper to form copper oxide, which helps convert it into soluble copper ammonia complex ions in the etching solution, thereby increasing the etching rate. However, for circuit boards coated with a silver metal resist, the presence of oxygen in the etching solution can oxidize the silver metal resist, forming silver oxide that dissolves in the etching solution, posing a risk of etching damage to the circuit board. Therefore, using oxygen as a source for the copper etchant oxidation and regeneration reaction is not recommended for circuit boards coated with a silver metal resist.

[0064] The oxygen electrolytic cell can use the ammoniacal alkaline sulfuric acid tetraammine copper etching waste liquid of the present invention as the electrolyte. The main difference between the oxygen electrolytic cell and the oxidation electrolytic cell is that the etching working liquid does not circulate between the etching machine and the anode tank area of ​​the oxygen electrolytic cell to oxidize the copper etching agent online. When the monovalent copper ammonia complex in the electrolyte of the oxygen electrolytic cell is mostly oxidized, the anode mainly electrolyzes oxygen during the oxygen production process: 4OH - -4e - →2H2O+O2↑.

[0065] The oxygen-producing electrolytic cell can also be divided into an anode cell area and a cathode cell area by an electrolytic cell separator, and the electrolytic cell separator is one or more of a cation exchange membrane, an anion exchange membrane, a bipolar membrane, a reverse osmosis membrane, a neutral filter membrane, and a filter cloth.

[0066] The present invention can be improved as follows: a mixing exchange tank is set between the etching machine and the anode tank area of ​​the oxidation electrolytic cell, so that the etching working solution of the etching machine and the anode electrolyte of the oxidation electrolytic cell are mixed and exchanged in the mixing exchange tank through liquid circulation respectively, and the process parameters of the mixed solution of the mixing exchange tank are sampled and detected to control the output size of the working current of the electrolysis power supply of the oxidation electrolytic cell or start or shut down, and / or the flow rate of the etching working solution and / or the anode electrolyte of the oxidation electrolytic cell entering or flowing out of the mixing exchange tank, and / or at least one of ammonia water, ammonia, water, and etching sub-liquid is added to the mixed solution of the mixing exchange tank so that the solution generates and maintains the concentration requirement of the tetraammine copper sulfate etching agent in the oxidation regeneration reaction according to the process. The parameters of the mixed solution of the mixing exchange tank for sampling and detection include but are not limited to one or more of redox potential, pH value, specific gravity, temperature, and liquid level.

[0067] Preferably, the mixed solution in the mixed exchange tank has an oxidation-reduction potential value higher than that of the etching working solution, that is, it has a copper etching agent concentration higher than that of the etching working solution. When the oxidation-reduction potential of the etching working solution of the etching machine is detected to be lower than the process setting value, the flow rate of the mixed solution in the mixed exchange tank entering the etching machine is adjusted so that the copper etching agent of the etching working solution is replenished in time. In this way, by pre-preparing a solution with a higher concentration of copper etching agent, the control response in the etching and oxidation regeneration system is made more efficient and safer.

[0068] The present invention can be improved as follows: a metal electrolysis cell is used to electrolyze copper and / or silver from the ammoniacal alkaline sulfuric acid tetraamminecopper etching waste liquid. An electrochemical reaction occurs at the electrolytic cathode of the metal electrolysis cell, in which copper ions are reduced to metallic copper, and / or silver ions are reduced to metallic silver. When the metal electrolysis cell is not provided with an electrolysis cell divider, the electrolyte contains etching waste liquid and / or electrolyzed etching waste liquid. When the metal electrolysis cell is provided with an electrolysis cell divider separating the anode cell area and the cathode cell area, the cathode electrolyte contains etching waste liquid and / or electrolyzed etching waste liquid. The anode electrolyte is a mixture of one or more of the following: etching working solution, etching waste liquid, electrolyzed cathode electrolyte from the current cell, and electrolyzed cathode electrolyte from other metal electrolysis cells. The electrolysis cell divider is one or more of the following: a cation exchange membrane, an anion exchange membrane, a bipolar membrane, a reverse osmosis membrane, a neutral filter membrane, or a filter cloth. Therefore, an oxidation electrolytic cell and / or an oxygen production electrolytic cell can be used as a metal electrolysis cell.

[0069] When the oxidation electrolytic cell is used as a metal electrolysis cell, the main electrochemical reactions occurring in the cathode cell area are as follows:

[0070] (1) When the electrolytic cell separator is an anion exchange membrane, Cu(NH3)4SO4+4H2O+2e - →2NH4OH+(NH4)2SO4+Cu+2OH - ;

[0071] (2) When the electrolytic cell separator is a bipolar membrane and / or reverse osmosis membrane, Cu(NH3)4SO4+2H2O+2H + +2e - →(NH4)2SO4+2NH4OH+Cu.

[0072] The ammoniacal-alkaline sulfuric acid tetraammine copper etching waste liquid can be directly converted into a regeneration etching sub-liquid after being processed by the metal electrolysis tank for copper electrolysis, or can be converted into a regeneration etching sub-liquid after being prepared as one of the raw materials. The function of the regeneration etching sub-liquid is the same as that of the etching sub-liquid in terms of process, so the regeneration etching sub-liquid can be used as part or all of the etching sub-liquid, and the use effect is not affected when copper ions remain in the regeneration etching sub-liquid. When copper is electrolyzed, tetraammine copper sulfate is reduced to copper metal and is accompanied by the generation of ammonia and ammonium sulfate. Therefore, the ammonia concentration and ammonium sulfate concentration in the resulting solution are improved, and it may also contain other complexing ammonia supply sources, additives and copper ammonia complexes that have not undergone electrochemical reaction that were originally present in the etching waste liquid.

[0073] The present invention can be further improved as follows: when two or more metal electrolysis cells with electrolysis cell dividers are used, they can be divided into Class A and Class B metal electrolysis cells, or multiple levels of metal electrolysis cells, for progressive copper electrolysis. This reduces electrolyte back-etching of the copper deposited on the cathode during copper electrolysis, thereby improving copper recovery efficiency. Specifically, the catholyte of the Class A metal electrolysis cell contains etching waste liquid; starting from the Class B metal electrolysis cell, the catholyte of each level of metal electrolysis cell contains the electrolyzed catholyte from the previous level of metal electrolysis cell.

[0074] When etching a circuit board coated with a silver metal resist for a long period of time, a small amount of the silver metal resist may be oxidized by oxygen and dissolved in the etching solution. A metal electrolysis cell can be used to effectively remove silver ions from the etching solution and / or the etching waste liquid. Because silver is preferentially electrochemically reduced over copper, a graded metal electrolysis cell can be used to perform progressive electrolysis to separate the silver and copper metals. Specifically, a metal electrolysis cell is first used to electrolyze the silver ions from the etching waste liquid, and then a lower-level metal electrolysis cell is used to electrolyze the copper.

[0075] The present invention can be improved as follows: the solution (including the anolyte and / or the catholyte) obtained after the copper electrolysis treatment in the metal electrolysis cell is oxidized with oxygen and / or regenerated by electrochemical oxidation reaction using the electrolytic cell, and then directly or as a raw material after being formulated into a regenerated etching sub-liquid for use in the etching process. This is because the ammoniacal alkaline sulfuric acid tetraammine copper etching waste liquid usually still has copper ions after copper electrolysis, most of which exist in the form of monovalent copper ammonia complex ions. After oxidation, the concentration of the copper etching agent in the solution can be increased, and the subsequent use as the regenerated etching sub-liquid for etching can ensure a constant etching rate.

[0076] The present invention can also be improved as follows: adding a step of washing the cathode copper plate to be taken out of the electrolytic cell in the electrolytic cell to reduce the electrolyte and ammonia gas released when the cathode copper plate is taken out to pollute the environment.

[0077] A second object of the present invention is to provide a device suitable for a circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process.

[0078] A device for a circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process includes an etching machine, characterized in that the etching working fluid used in the etching machine is an ammoniacal alkaline sulfuric acid tetraammine copper etching fluid, and an additional copper etching agent oxidation regeneration reaction supply device is provided. The copper etching agent oxidation regeneration reaction supply device is an oxidation electrolytic cell connected to the etching machine through at least two pipelines, so that the etching fluid can circulate between the two cells. When the etching fluid enters the oxidation electrolytic cell, it directly undergoes an electrochemical oxidation reaction with the electrolytic anode, so that the monovalent copper ammonia complex in the etching fluid can be regenerated into the copper etching agent Cu(NH3)4SO4 of the ammoniacal alkaline sulfuric acid tetraammine copper.

[0079] The etching machine is an etching device of the prior art for circuit boards.

[0080] The oxidation electrolytic cell is provided with an electrolytic cell divider to separate the cell into an anode cell area and a cathode cell area. The anode cell area is connected to an etching machine via a pipeline, allowing etching solution to circulate between the two cells to maintain the concentration of the copper etching agent. The electrolytic cell divider of the oxidation electrolytic cell can effectively prevent cations in the anode cell area from entering the cathode cell area, and is specifically selected from one or more of an anion exchange membrane, a bipolar membrane, and a reverse osmosis membrane.

[0081] The present invention can be improved as follows: the copper etching agent oxidation regeneration reaction supply device further includes an oxygen supply device connected to a device containing an etching working solution via a pipeline, or connected to the etching solution via a pipeline, so that the etching working solution is further oxidized by oxygen during the etching process to produce ammoniacal alkaline sulfuric acid tetraammine copper copper etching agent Cu(NH3)4SO4. The oxygen supply device can be a steel cylinder containing oxygen, a molecular sieve oxygen generator, an oxidant reaction oxygen production device, an oxygen production electrolytic cell, or an oxidation electrolytic cell from which oxygen escapes during operation.

[0082] The present invention can be improved as follows: at least one of a pH meter, a hydrometer, a photoelectric colorimeter, a redox potentiometer, a liquid level meter, a thermometer, and a flow meter is installed in the etching machine and / or the oxidation electrolytic cell to detect the process parameters, and the automatic program controller is used to process and control the various working components such as pumps, valves, electrolysis power supplies, hot and cold temperature exchangers, etc.

[0083] The present invention can be improved as follows: a mixing exchange tank is added to the connecting pipe between the etching machine and the anode tank area of ​​the oxidation electrolytic cell, so that the etching working solution and the anode electrolyte of the oxidation electrolytic cell are mixed and exchanged in the mixing exchange tank through their respective liquid circulation pipes. The solution in the mixing exchange tank is controlled by process parameters, and the output size of the working current of the electrolytic power supply of the electrolytic cell or the start and stop are controlled by detecting the parameter values ​​obtained, and / or at least one of ammonia water, ammonia, water, etching sub-liquid, and regeneration etching sub-liquid is added to the mixing exchange tank, so that the solution generates and maintains the concentration requirements of the tetraammine copper sulfate etching agent in the oxidation and regeneration reaction according to the process. The parameters of the solution in the mixing exchange tank include but are not limited to one or more of the following: redox potential, pH value, specific gravity, temperature, and liquid level.

[0084] Preferably, a variable frequency pump and / or a valve with a variable gate valve opening is installed on the pipeline from the mixing exchange tank to the etching machine to control the solution flow rate, and the redox potential value of the solution in the mixing exchange tank is set to be higher than the redox potential value of the etching working solution in the process, that is, the copper etching agent concentration of the solution in the mixing exchange tank is higher than that of the etching working solution. When the redox potential of the etching working solution is detected and its on-site value is lower than the process setting value, the flow rate of the solution in the mixing exchange tank to the etching machine is controlled by adjusting the valve opening and / or pump speed in the solution circulation flow system between the etching machine and the mixing exchange tank, so that the copper etching agent of the etching working solution is replenished in time. The mixing exchange tank is used to pre-produce and store a solution with a higher copper etching agent concentration, so that the control response in the etching and oxidation regeneration system is more efficient and safe.

[0085] The present invention can also be improved as follows: a metal electrolysis cell is added to receive the ammoniacal alkaline sulfuric acid tetraammine copper etching waste liquid from the etching machine, and electrolyzes the copper and / or silver. When the metal electrolysis cell is not provided with an electrolytic cell divider, the electrolyte contains etching waste liquid and / or electrolyzed etching waste liquid. When the metal electrolysis cell is provided with an electrolytic cell divider to separate the anode cell area and the cathode cell area, the cathode electrolyte contains etching waste liquid and / or electrolyzed etching waste liquid, the anode electrolyte is a mixture of one or more of the etching working liquid, etching waste liquid, electrolyzed cathode electrolyte from the present cell, and electrolyzed cathode electrolyte from other metal electrolysis cells, and the electrolytic cell divider is one or more of the following: a cation exchange membrane, an anion exchange membrane, a bipolar membrane, a reverse osmosis membrane, a neutral filter membrane, and a filter cloth.

[0086] The present invention can be further improved as follows: when two or more metal electrolysis cells with electrolysis cell dividers are used, they are divided into Class A metal electrolysis cells and Class B metal electrolysis cells, or more levels of metal electrolysis cells, to perform progressive copper electrolysis to improve the efficiency of copper electrolysis; the catholyte of the Class A metal electrolysis cell contains etching waste liquid; and starting from the Class B metal electrolysis cell, the catholyte of each level of metal electrolysis cell contains the electrolyzed catholyte from the previous level of metal electrolysis cell. This creates a two-stage progressive device structure in which the catholyte of the Class A metal electrolysis cell contains etching waste liquid, and the overflow liquid after the electrochemical reaction is drained to the cathode cell area of ​​the Class B metal electrolysis cell for metal electrolysis. If the catholyte of the Class B metal electrolysis cell, after overflowing from copper extraction, is further drained to the cathode cell area of ​​the Class C metal electrolysis cell for continued electrolytic metal deposition, the device structure becomes a three-stage progressive copper electrolysis device structure.

[0087] The present invention can also be improved as follows: adding a hot and cold temperature exchanger to control the various solutions in the device according to the process temperature requirements, so that the chemical reaction of the solution is safer and more efficient. Specifically, it is installed in the etching machine and / or oxidation electrolytic cell and / or mixed exchange cell and / or oxygen production electrolytic cell and / or metal electrolysis cell.

[0088] The present invention can also be improved as follows: an agitator is added to make the solution concentration and temperature in the device uniform; specifically, it is installed in the etching machine and / or oxidation electrolytic cell and / or mixed exchange cell and / or oxygen electrolytic cell and / or metal electrolysis cell.

[0089] The present invention can also be improved as follows: a gas-liquid mixer is added to guide the gas to promote the reaction with the solution. The gas-liquid mixer can be one or more of a vacuum ejector, a spray tower, and a bubbling gas-liquid mixer.

[0090] The present invention can also be improved by adding an exhaust gas treatment device to absorb and reuse or environmentally treat the ammonia and oxygen generated during the etching or regeneration chemical reaction. The exhaust gas treatment device is connected to the etcher and / or the oxidation electrolytic cell and / or the oxygen electrolytic cell and / or the metal electrolysis cell. The exhaust gas treatment device is a combination of a vacuum jet gas-liquid mixer or a spray tower gas-liquid mixer and a solution tank, and can adopt a multi-stage structure for treatment.

[0091] The present invention can also be improved as follows: a temporary storage tank is added for temporarily storing materials and / or used as a chemical reaction tank, and is connected to the etching machine and / or the oxidation electrolytic cell and / or the mixed exchange cell and / or the metal electrolysis cell.

[0092] The present invention can also be improved as follows: a solid-liquid separator is added, which can be connected to the etching machine, oxidation electrolytic tank, mixed exchange tank and temporary storage tank to perform solid-liquid separation of etching solution, electrolyte and regeneration preparation liquid.

[0093] The present invention can also be improved as follows: additional liquid flow buffer tanks are provided between different reaction tanks to solve the flow of solutions between tanks.

[0094] The present invention can also be improved as follows: a cathode electrolytic copper plate water washing device is added to the metal electrolysis cell. When the cathode copper plate needs to be removed from the electrolytic cell after the electrolytic copper deposition is completed, the cathode copper plate is first washed in the electrolytic cell to reduce ammonia pollution. After washing, the cathode copper plate is taken out of the cell for copper recovery.

[0095] The anode material of the electrolytic cell in the apparatus of the present invention can be selected from gold, platinum, titanium-coated anodes, and conductive graphite. Preferred anode materials are titanium-coated anodes. The cathode material can be selected from copper, iron, titanium, conductive graphite, and stainless steel. Preferred cathode materials are copper or stainless steel.

[0096] Compared with the prior art, the present invention has the following beneficial effects:

[0097] 1. The etching process of the present invention improves the etching rate of using tetraammine copper sulfate as a copper etching agent, thereby ensuring production efficiency.

[0098] 2. The etching process of the present invention has less corrosion on the silver and tin metal anti-corrosion layers and can be applied on a large scale to the etching production of the silver and tin metal anti-corrosion layer circuit boards; it solves the production problem of the etching solution in the prior art corroding the silver and tin anti-corrosion layers, allowing PCB manufacturers to save a large amount of precious metal raw materials, thereby reducing costs.

[0099] 3. The ammoniacal-alkaline sulfuric acid tetraamminecopper etching solution of the present invention does not contain a large amount of chloride ions. Therefore, the etching waste liquid does not generate a nitrogen trichloride hazard source in the electrolytic copper extraction method, and does not electrolyze chlorine to consume a large amount of ammonia in the solution. The ammoniacal-alkaline sulfuric acid tetraamminecopper etching waste liquid after the copper electrolysis treatment can be directly used as a regenerated etching sub-liquid. Even if ammonia needs to be supplemented to prepare the regenerated etching sub-liquid, liquid ammonia does not need to be used.

[0100] 4. The waste liquid obtained after etching by the ammoniacal alkaline sulfuric acid tetraammine copper etching solution of the present invention contains less chloride ions, so the waste liquid recovery process and equipment become simple, and 100% recycling can be easily achieved, thereby improving economic benefits.

[0101] 5. The ammoniacal alkaline sulfuric acid tetraammine copper etching solution of the present invention contains less chloride ions and can meet the new environmental protection product standard requirement of circuit board products with less chlorine-containing compounds during etching processing.

[0102] 6. The ammoniacal alkaline sulfuric acid tetraammine copper etching solution of the present invention can achieve the same etching effect with a thinner resist layer, greatly reducing the difficulty of stripping the film before etching, and helping to remove film residue remaining on the circuit board from the previous stripping process, thereby improving etching quality and reducing the use of organic stripping solutions, thereby reducing production costs and organic pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0103] The present invention will be further described below with reference to the accompanying drawings.

[0104] FIG1 is a schematic diagram of a circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device according to Example 1 of the present invention;

[0105] FIG2 is a schematic diagram of a circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device according to Example 2 of the present invention;

[0106] FIG3 is a schematic diagram of a circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device according to Example 3 of the present invention;

[0107] FIG4 is a schematic diagram of a circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device according to Example 4 of the present invention;

[0108] Figure 4-1 is an enlarged view of 4-A in Figure 4;

[0109] Figure 4-2 is an enlarged view of 4-B in Figure 4;

[0110] FIG5 is a schematic diagram of a circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device according to Example 5 of the present invention;

[0111] Figure 5-1 is an enlarged view of 5-A in Figure 5;

[0112] Figure 5-2 is an enlarged view of 5-B in Figure 5;

[0113] FIG6 is a schematic diagram of a circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device according to Example 6 of the present invention;

[0114] Figure 6-1 is an enlarged view of 6-A in Figure 6;

[0115] Figure 6-2 is an enlarged view of 6-B in Figure 6;

[0116] FIG7 is a schematic diagram of a circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device according to Example 7 of the present invention;

[0117] Figure 7-1 is an enlarged view of 7-A in Figure 7;

[0118] Figure 7-2 is an enlarged view of 7-B in Figure 7;

[0119] Figure 7-3 is an enlarged view of 7-C in Figure 7;

[0120] FIG8 is a schematic diagram of a circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device according to Example 8 of the present invention;

[0121] Figure 8-1 is an enlarged view of 8-A in Figure 8;

[0122] Figure 8-2 is an enlarged view of 8-B in Figure 8;

[0123] Figure 8-3 is an enlarged view of 8-C in Figure 8;

[0124] FIG9 is a schematic diagram of a circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device according to Example 9 of the present invention;

[0125] Figure 9-1 is an enlarged view of 9-A in Figure 9;

[0126] Figure 9-2 is an enlarged view of 9-B in Figure 9;

[0127] FIG10 is a schematic diagram of a circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device according to embodiments 10 to 14 of the present invention;

[0128] Figure 10-1 is an enlarged view of 10-A in Figure 10;

[0129] Figure 10-2 is an enlarged view of 10-B in Figure 10;

[0130] Figure 10-3 is an enlarged view of 10-C in Figure 10;

[0131] FIG11 is a schematic diagram of an etching apparatus of Comparative Example 1.

[0132] Figure numerals: 1-etching machine, 2-oxidation electrolytic cell, 3-oxygen electrolytic cell, 4-electrolytic anode, 5-electrolytic cathode, 6-electrolytic cell partition, 7-electrolytic power supply, 8-oxygen cylinder, 9-liquid ammonia cylinder, 10-temporary storage tank, 11-solid feeder, 12-impeller agitator, 13-liquid flow agitator, 14-exhaust processor, 15-valve, 16-pump, 17-circuit board, 18-tank sealing cover, 19-vacuum ejector, 20-pipeline bubbling gas-liquid mixer, 21-spraying gas-liquid mixer, 22-liquid flow buffer tank, 23-molecular sieve oxygen preparation machine, 24-oxygen cylinder, 25-electric heater, 26-cold and hot temperature exchanger, 27-gas pressurized pump Pump, 28-Sensor, 29-Automatic program controller, 30-Nozzle, 31-Liquid ammonia cylinder, 32-Solution after electrolytic copper treatment, 33-Etching solution additive, 34-Liquid ammonia, 35-Ammonia water, 36-Ammonium carbonate, 37-Ammonium bicarbonate, 38-Ammonia gas, 39-Clean water, 40-Tetraammine copper sulfate, 41-Formic acid, 42-Ammonium formate, 43-Ammonium sulfate, 44-Hydroxyamine sulfate, 45-Hydroxyamine sulfate, 46-Hydroxyamine, 47-Etching working solution (etching solution), 48-Etching waste liquid, 49-Etching sub-liquid, 50-Regenerated etching sub-liquid, 51-Oxidant, 52-Oxygen, 53-Manganese dioxide, 54-Electrolyte solution, 55-Electroplating brightener, 56-Ammonia gas, 57-ammonium bisulfate, 58-oxygen cleaning tank, 59-solid-liquid separator, 60-cathode copper plate washing device, 61-oxygen oxidation reaction tank, 62-metal electrolysis tank. DETAILED DESCRIPTION

[0133] The present invention is further described below with reference to specific examples.

[0134] The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process in each embodiment of the present invention includes the following steps:

[0135] Step 1: Etching the circuit board using an ammoniacal alkaline sulfuric acid tetraammine copper etching solution in an etching machine. The process parameters of the ammoniacal alkaline sulfuric acid tetraammine copper etching solution are shown in Tables 1 and 2, and the parameters of the circuit board resist layer are shown in Table 3;

[0136] Step 2: During the etching process, a supplementary etching sub-liquid and / or a regenerated etching sub-liquid (the components are shown in Table 2) is added to the etching working solution, and the etching working solution is oxidized and regenerated using a copper etching agent oxidation regeneration reaction supply source to maintain the pH value and ORP value of the etching working solution within the range shown in Table 1;

[0137] Step 3: Check the state of the circuit board's resist layer after etching, and record the inspection results and etching rate in Table 3.

[0138] The length and width of the circuit boards used in the following embodiments and comparative examples are both 200*200 mm. The nozzle pressure of the etching production line is 1.3-3.0 kg.

[0139] Example 1

[0140] The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device shown in FIG1 includes: an etching machine 1, an oxidation electrolytic cell 2, an electrolytic power supply 7, valves, and a pump.

[0141] Specifically, the etching machine 1 is a spray etching machine.

[0142] The oxidation electrolytic cell 2 is the supply source for the oxidation regeneration reaction of the copper etching agent. During electrolysis, its anode directly electrochemically oxidizes the monovalent copper ammonia complex in the etching working solution to generate tetraammine copper sulfate.

[0143] An electrolytic cell separator 6 is provided within the oxidation electrolytic cell 2 to separate it into an anode cell area and a cathode cell area. An electrolytic anode 4 and an electrolytic cathode 5 are located in the anode cell area and the cathode cell area, respectively, and are connected to an electrolytic power supply 7. The electrolytic cell separator 6 is an anion exchange membrane, the electrolytic anode 4 is platinum, and the electrolytic cathode 5 is copper.

[0144] The anode tank area of ​​the oxidation electrolytic tank 2 is connected to the etching machine 1 for liquid circulation through a pipeline equipped with valves and pumps, so that the etching working liquid can circulate between the two tanks to maintain its copper etching agent concentration.

[0145] The anolyte in the oxidation electrolytic cell 2 is an etching working solution, and the catholyte is an ammonium sulfate solution.

[0146] The etching machine is provided with a feeding port for feeding the etching sub-liquid 49 therein. The etching sub-liquid 49 is a mixed aqueous solution of ammonia water, ammonium sulfate and ammonium formate.

[0147] Before the etching process begins, the etching solution is added to the etcher 1, pump 16-1 is activated to spray the etching solution, and the conveyor pulley is driven. Following the above steps, multiple circuit boards 17 (with the resist layer shown in Table 3) are sequentially placed into the etcher for etching. During this process, the etcher is replenished with etching solution to maintain a stable concentration of the various components of the etching solution.

[0148] Example 2

[0149] The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device shown in Figure 2 includes: an etching machine 1, an oxidation electrolytic cell 2, an electrolytic power supply 7, four temporary storage tanks, an impeller stirrer 12, a molecular sieve oxygen generator 23, a commercial oxygen cylinder 24, a gas pressurized extraction pump 27, a sensor 28, a liquid ammonia cylinder 37, two pipeline bubbling gas-liquid mixers, valves and pumps.

[0150] Specifically, in this embodiment, the copper etching agent oxidation regeneration reaction is supplied by the oxidation electrolytic cell 2 and oxygen. The oxygen comes from four sources: oxygen in cylinder 24, oxygen produced by molecular sieve oxygen generator 23, oxygen produced by heating potassium permanganate in temporary storage tank 10-1, and oxygen produced by a chemical reaction between hydrogen peroxide and manganese dioxide in temporary storage tank 10-2. These four oxygen sources are all passed through a pipeline bubbling gas-liquid mixer 20-1 to the etching working solution 47 in the etcher 1.

[0151] An electrolytic cell 2 is provided with an electrolytic cell divider 6, which separates it into an anode cell area and a cathode cell area. An electrolytic anode 4 and an electrolytic cathode 5 are located in the anode cell area and the cathode cell area, respectively, and are connected to an electrolytic power supply 7. The electrolytic cell divider 6 is an anion exchange membrane, the electrolytic anode 4 is platinum, and the electrolytic cathode 5 is copper. The anode cell area of ​​the oxidation electrolytic cell 2 is installed with a pipeline connected to the etcher 1 for liquid circulation. The anolyte in the oxidation electrolytic cell 2 is the etching working solution, and the catholyte is the etching waste liquid.

[0152] The etching machine 1 is a spray etching machine, which is provided with a sensor 28, specifically a pH meter. The etching machine 1 is also connected to a temporary storage tank 10-3 to load the etching waste liquid 48.

[0153] The temporary storage tank 10-4 is connected to the feeding port of the etching machine, and the etching sub-liquid 49 is added thereto. The chemical raw materials liquid ammonia (added from the liquid ammonia bottle through the pipeline bubbling gas-liquid mixer 20-2), ammonium sulfate, ammonium bisulfate, ammonium carbonate, ammonium bicarbonate and ammonia water for preparing the etching sub-liquid 49 are added to the temporary storage tank 10-4, and the impeller stirrer 12 therein is started to prepare. After completion, the impeller stirrer is turned off and the liquid ammonia bottle switch is turned off, and the feeding is stopped.

[0154] Before the etching process begins, the etching solution is added to the etcher 1. Pump 16-1 is turned on for etching spraying and the transport wheel is started. Oxygen is introduced into the etcher via a gas pressure pump and a pipeline bubbling gas-liquid mixer 20-1 to cause the etching solution to undergo an oxidative regeneration reaction. Following the above steps, multiple circuit boards 17 (with the resist layer shown in Table 3) are sequentially placed into the etcher for etching. During the etching process, pump 16-2 is controlled to add etching sub-liquid 49 based on the production setpoint and the measurement results of the pH meter to maintain a stable chemical reaction of the etching solution in etching copper.

[0155] Example 3

[0156] The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device shown in Figure 3 includes: an etching machine 1, an oxidation electrolytic cell 2, an oxygen-generating electrolytic cell 3, an electrolytic power supply 7, two temporary storage tanks 10, an impeller stirrer 12, a liquid flow stirrer 13, a pipeline bubbling gas-liquid mixer 20, a spray tower gas-liquid mixer 21, a liquid flow buffer tank 22, valves and pumps, and an oxygen cleaning tank 58.

[0157] Specifically, the etcher 1 is an immersion etcher with two liquid flow agitators, and a bubbling gas-liquid mixer 20 and sensors 28 - 1 and 28 - 2 , specifically a pH meter and an oxidation-reduction potentiometer (ORP meter), are installed in the machine body.

[0158] The supply sources for the copper etching agent oxidation regeneration reaction in this embodiment are the oxidation electrolytic cell 2 and oxygen.

[0159] The oxidation electrolytic cell 2 is provided with an electrolytic cell divider 6, which divides it into an anode cell area and a cathode cell area. The electrolytic anode 4 and electrolytic cathode 5 are located in the anode cell area and the cathode cell area, respectively, and are connected to an electrolytic power supply 7. The electrolytic cell divider 6 is an anion exchange membrane, the electrolytic anode 4 is platinum, and the electrolytic cathode 5 is copper. The anode cell area of ​​the oxidation electrolytic cell 2 is installed with a pipeline connected to the etching machine for liquid circulation. The anolyte in the oxidation electrolytic cell 2 is the etching working solution, and the catholyte is the etching waste liquid.

[0160] In this embodiment, the oxygen source is oxygen produced by electrolysis in an oxygen electrolytic cell 3, where the electrolyte solution 54 is a sodium hydroxide solution. Within the oxygen electrolytic cell 3, the electrolytic anode 4 is gold, and the electrolytic cathode 5 is stainless steel, connected to the positive and negative electrodes of the electrolytic power supply, respectively. A liquid agitator 13-1 is also installed within the oxygen electrolytic cell 3 to stir the electrolyte.

[0161] The oxygen generated by the oxygen electrolytic cell 3 is cleaned with ammonium sulfate solution in the oxygen washing tank 58 and then passed through the pipeline bubbling gas-liquid mixer 20 to the etching working solution 47 of the etcher 1 .

[0162] The temporary storage tank 10-2 is connected to the feeding port of the etching machine, and the etching liquid 49 is added thereto. The temporary storage tank 10-1 is connected to the overflow port of the etching machine via the liquid flow buffer tank 22, and is used to load the etching waste liquid 48.

[0163] Before the etching process begins, the etching liquid is added to the etcher 1, and multiple circuit boards 17 (with the resist layer shown in Table 3) are placed in sequence. Etching is performed according to the above steps. As the etching process progresses, the pump 16-3 is controlled to add the etching liquid according to the production setting value and the measurement results of the pH meter. The operator uses the value detected by the ORP meter on site to adjust the output current of the electrolytic power supply 7 or shut it down.

[0164] Example 4

[0165] The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device shown in Figure 4 includes: an etching machine 1, five temporary storage tanks 10, two liquid flow buffer tanks 22, two spray-type gas-liquid mixers 21, an oxidation electrolytic cell 2, an oxygen-generating electrolytic cell 3, an electrolytic power supply 7, an oxygen cleaning tank 57, valves and pumps, and four sensors 28.

[0166] Specifically, the supply source for the copper etching agent oxidation regeneration reaction in this embodiment is the oxygen produced by the oxidation electrolytic cell 2 and the oxygen production electrolytic cell 3.

[0167] An electrolytic cell 2 is provided with an electrolytic cell divider 6, which separates it into an anode cell area and a cathode cell area. The cathode cell area is provided with a liquid flow agitator 13-2. An electrolytic anode 4 and an electrolytic cathode 5 are located in the anode cell area and the cathode cell area, respectively, and are connected to an electrolytic power supply 7. The electrolytic cell divider 6 is an anion exchange membrane, the electrolytic anode 4 is platinum, and the electrolytic cathode 5 is copper. The anode cell area of ​​the oxidizing electrolytic cell 2 is connected to an etching tank through a pipeline for liquid circulation. The anolyte in the oxidizing electrolytic cell 2 is an etching working solution, and the catholyte is an etching waste solution.

[0168] The oxygen-generating electrolytic cell 3 is equipped with a cation exchange membrane as a cell separator 6, dividing it into an anode cell area and a cathode cell area. The anode cell area is equipped with a liquid flow agitator 13-1 and a sensor 28-5 (specifically, a hydrometer). The electrolytic anode 4 in the oxygen-generating electrolytic cell 3 is made of conductive graphite, and the electrolytic cathode 5 is made of iron metal. These are located in the anode cell area and the cathode cell area, respectively, and are connected to the positive and negative electrodes of the electrolytic power supply. Both the anolyte and catholyte are etching waste liquids. Oxygen released from the anode cell area of ​​the oxygen-generating electrolytic cell 3 is transferred to the etching working fluid of the etching machine through an oxygen cleaning tank 58.

[0169] The etching machine 1 is a spray etching machine, which is provided with sensors 28-1, 28-2 and 28-3, specifically a pH meter, an ORP meter and a hydrometer.

[0170] The electrolytic copper solution 32 obtained by electrolytically treating the etching wastewater in the oxygen-generating electrolytic cell 3 is then transferred to the temporary storage tank 10-4 via the liquid flow buffer tank 22-2 and the temporary storage tank 10-3. The solution is then supplemented with complexing ammonia source materials and additives and then mixed in the temporary storage tank 10-4 to produce the regenerated etching sub-liquid. The regenerated etching sub-liquid is then transferred to the temporary storage tank 10-5 for storage and then, according to the process settings, is delivered to the feed port of the etching machine via a pipeline.

[0171] In order to enable the oxygen electrolytic cell 3 to efficiently electrolyze metallic copper, the dosage of the pump 16-6 is controlled by a hydrometer therein so that the solution 32 after the copper electrolysis treatment overflowing from the anode tank area still contains a certain amount of copper ions, the concentration of which is 30 g / L.

[0172] In addition, this embodiment also includes temporary storage tanks 10-1 and 10-2. Temporary storage tank 10-1 is used to temporarily store ammonia water and add it to the feed port of the etching machine. Temporary storage tank 10-2 is used to temporarily store etching waste liquid, receiving etching waste liquid from the etching machine and adding etching waste liquid to the oxygen electrolytic tank 3.

[0173] Before the etching operation begins, the etching liquid is injected into the etcher 1, and the etching waste liquid is injected into the cathode and anode tank areas of the oxygen electrolytic cell 3 respectively. The etcher and all other equipment are started, and multiple circuit boards 17 (the anti-corrosion layer is shown in Table 3) are placed in sequence and etched according to the above steps.

[0174] During operation, the oxidation reaction of the copper-ammine complex Cu2(NH3)4SO4 occurs in the anode tank of the oxygen-generating electrolytic cell 3, releasing oxygen gas. Copper is then deposited at the cathode. Based on the hydrometer readings and process settings, pump 16-2 is controlled to pump the etching waste liquid into the anode tank of the oxygen-generating electrolytic cell. When the anode tank is full, any overflow is pumped through buffer tank 22-2 to temporary storage tank 10-3.

[0175] Spray-type gas-liquid mixer 21-1 draws oxygen escaping from the oxygen-generating electrolytic cell to mix with the etching solution. During the etching process, pump 16-1 is controlled to add ammonia from tank 10-1 to the etching solution based on the production setpoint and the pH meter's measurement results. The electrolytic power supply's output current is controlled or shut down based on the production setpoint and the ORP meter's measurement results to control oxygen output. Pump 16-9 is controlled to add regenerated etching sub-liquid to the etching solution based on the production setpoint and the hydrometer's measurement results within the etching machine to maintain the balance of the etching solution's components.

[0176] Example 5

[0177] The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device shown in Figure 5 includes: an etching machine 1, six temporary storage tanks 10, a liquid flow agitator 13, two spray-type gas-liquid mixers 21, two liquid flow buffer tanks 22, an oxidation electrolytic cell 2, an electrolytic power supply 7, a solid-liquid separator 59, four sensors 28, valves and a pump.

[0178] The copper etching agent oxidation regeneration reaction supply source of this embodiment is the oxidation electrolytic cell 2. The anolyte in the oxidation electrolytic cell 2 is the etching working solution, and the catholyte is the etching waste liquid. During electrolysis, the anode directly electrochemically oxidizes the monovalent copper ammonia complex in the etching working solution to produce tetraammine copper sulfate.

[0179] The oxidation electrolytic cell 2 is provided with a cell divider 6, dividing it into an anode and cathode compartments. An electrolytic anode 4 and an electrolytic cathode 5 are located in the anode and cathode compartments, respectively, and are connected to an electrolytic power supply 7. The cell divider 6 is an anion exchange membrane, the electrolytic anode 4 is platinum, and the electrolytic cathode 5 is copper. The anode compartment of the oxidation electrolytic cell is connected to an etching machine through piping for fluid circulation, while the cathode compartment is equipped with a fluid agitator 13 and a sensor 28-4.

[0180] The cathode tank area of ​​the oxidation electrolytic cell 2 electrolyzes the etching waste liquid through electrolytic copper extraction to obtain the electrolytic copper-treated solution 32, which is sent to the temporary storage tank 10-5 through the liquid flow buffer tank 22-2 and the temporary storage tank 10-4. The complexing ammonia supply source material and additives are supplemented in the temporary storage tank 10-5 and mixed by the matching gas-liquid mixer 21-2 and impeller agitator 12 to produce the regenerated etching liquid. After being treated in the solid-liquid separator 59, the regenerated etching liquid is sent to the temporary storage tank 10-6 for storage and then sent to the feed port of the etching machine through a pipeline according to the process settings.

[0181] The etching machine 1 is a spray etching machine, which is provided with a sensor 28-1, a sensor 28-2 and a sensor 28-3.

[0182] The sensor 28 - 1 is a pH meter, the sensors 28 - 2 and 28 - 4 are hydrometers, and the sensor 28 - 3 is an ORP meter.

[0183] This embodiment is provided with a temporary storage tank 10 - 3 , which is connected to the etching machine 1 through a liquid flow buffer tank 22 - 1 , and receives the etching waste liquid from the etching machine and adds the etching waste liquid to the oxidation electrolytic tank 2 .

[0184] This embodiment also includes an exhaust gas treatment device comprising a temporary storage tank 10-1, a vacuum ejector 19, a temporary storage tank 10-2, and a spray-type gas-liquid mixer 21-1, which receives the escaped gases from the oxidation electrolysis cell and other temporary storage tanks for environmental treatment. Temporary storage tank 10-1 stores clean water, while temporary storage tank 10-2 stores sulfuric acid.

[0185] Before etching begins, etching solution is added to the anode tank area of ​​the etcher and the electrolytic cell, and etching waste liquid from the temporary storage tank 10-3 is added to the cathode tank area of ​​the oxidation electrolytic cell. Multiple circuit boards 17 (the anti-corrosion layer is shown in Table 3) are placed in sequence. Pump 16-5 is started to spray and circulate the etching working solution, pump 16-6 is started to circulate the etching working solution between the etcher and the electrolytic anode tank area, pump 16-9 is started to operate the gas-liquid mixer 21-2 normally, and electrolysis power supply 7 is started to cause the oxidation electrolytic cell to perform electrolysis.

[0186] During the etching process, a pH meter and a hydrometer monitor the pH and specific gravity of the etching solution, respectively. Based on the test results and the process settings, pump 16-11 is controlled to add regenerated etching sub-liquid, ensuring stable etching of the etching solution. An ORP meter monitors the redox potential of the etching solution and, accordingly, controls the operating current of electrolytic power supply 7 or shuts it down. A hydrometer is installed in the cathode tank of the oxidation electrolytic cell. Based on its test results and the copper ion concentration in the cathode electrolyte set by the process, pump 16-3 is controlled to add etching waste liquid from temporary storage tank 10-3 to the cathode tank of the oxidation electrolytic cell, allowing the electrolytic anode to properly electrochemically oxidize the monovalent copper ammonia complex in the etching solution and electrolytically deposit metallic copper at the electrolytic cathode.

[0187] Example 6

[0188] The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device shown in Figure 6 includes: an etching machine 1, eight temporary storage tanks 10, a liquid flow agitator 13, two spray-type gas-liquid mixers 21, two liquid flow buffer tanks 22, an oxidation electrolytic cell 2, an electrolytic power supply 7, two solid-liquid separators 59, four sensors 28, a cathode copper plate water washing device 60, valves and pumps.

[0189] In this embodiment, the copper etching agent oxidation regeneration reaction source is an oxidation electrolytic cell 2. An electrolytic cell divider 6 is provided within the oxidation electrolytic cell 2, separating it into an anode cell area and a cathode cell area. The cathode cell area is equipped with a liquid flow agitator 13 and a sensor 28-4. An electrolytic anode 4 and an electrolytic cathode 5 are located in the anode cell area and the cathode cell area, respectively, and are connected to an electrolytic power supply 7. The electrolytic cell divider 6 is a reverse osmosis membrane, the electrolytic anode 4 is an insoluble anode with a titanium-based coating, and the electrolytic cathode 5 is titanium metal. The anolyte in the oxidation electrolytic cell 2 is an etching working solution, and the catholyte is etching waste liquid (i.e., the cathode cell area electrolyzes copper, and the oxidation electrolytic cell 2 also serves as a metal electrolysis cell).

[0190] The etching machine 1 is connected to the anode tank area of ​​the oxidation electrolytic cell 2 via a liquid circulation pipeline. During electrolysis, the anode directly oxidizes the monovalent copper ammonia complex in the etching working solution to generate tetraammine copper sulfate.

[0191] The cathode tank area of ​​the oxidation electrolytic cell 2 electrolyzes the etching waste liquid to obtain a copper-treated solution 32, which is then sent to the temporary storage tank 10-7 through the liquid flow buffer tank 22-2 and the temporary storage tank 10-6. The complexing ammonia supply source material and additives are then mixed in the temporary storage tank 10-7 by the matching gas-liquid mixer 21-2 and impeller agitator 12 to produce a regenerated etching sub-liquid. The regenerated etching sub-liquid is treated in the solid-liquid separator 59-2 and sent to the temporary storage tank 10-8 for storage. According to the process settings, it is sent to the feed port of the etching machine through a pipeline.

[0192] The cathode copper plate washing device 60 is composed of a nozzle in the cathode tank area of ​​the oxidation electrolytic cell 2 and a temporary storage tank 10-4 and a temporary storage tank 10-5, wherein the temporary storage tank 10-4 stores clean water 39 and the temporary storage tank 10-5 temporarily stores cathode electrolyte.

[0193] The etching machine 1 is a spray etching machine, which is provided with a sensor 28-1, a sensor 28-2 and a sensor 28-3.

[0194] The sensor 28 - 1 is a pH meter, the sensors 28 - 2 and 28 - 4 are hydrometers, and the sensor 28 - 3 is an ORP meter.

[0195] This embodiment is provided with a temporary storage tank 10 - 3 , which is connected to the etching machine 1 through a liquid flow buffer tank 22 - 1 , and receives the etching waste liquid from the etching machine and adds the etching waste liquid to the oxidation electrolytic tank 2 .

[0196] This embodiment is also provided with an exhaust gas treatment device including a temporary storage tank 10-1, a vacuum ejector 19, a temporary storage tank 10-2 and a spray-type gas-liquid mixer 21-1, which is used to receive the escaped gas from the oxidation electrolytic cell and other temporary storage tanks for environmental treatment, wherein the temporary storage tank 10-1 is filled with clean water and the temporary storage tank 10-2 is filled with formic acid.

[0197] Before etching begins, add etching solution to the anode tank area of ​​the etcher and the oxidation electrolytic cell. Add etching waste liquid from temporary storage tank 10-3 to the cathode tank area of ​​the oxidation electrolytic cell. Multiple circuit boards 17 (the anti-corrosion layer is shown in Table 3) are placed in sequence. Pumps 16-5 are activated to spray and circulate the etching solution. Pump 16-6 is activated to pump the etching solution in the etcher through solid-liquid separator 59-1 to the anode tank area of ​​the electrolytic oxidation cell for circulation. Pump 16-13 is activated to ensure normal operation of gas-liquid mixer 21-2. Electrolysis power supply 7 is activated to allow the oxidation electrolytic cell to perform electrolysis. When copper electrolysis is complete in the cathode tank area, pump 16-7 pumps the cathode electrolyte to tank 10-5 for temporary storage. Pump 16-10 is then activated to spray clean water from temporary storage tank 10-4 onto the cathode copper plate for cleaning. After cleaning, the cathode copper plate is removed. Pump 16-8 pumps the waste cleaning solution from the cathode tank back into tank 10-4. Pump 16-11 is then activated to return the solution from tank 10-5 to the cathode tank. The cathode and tank cover are then replaced and electrolysis continues. This procedure reduces ammonia contamination caused by removing the cathode copper plate directly from the electrolyte.

[0198] During the electrolytic operation, the electrolytic anode of the oxidation electrolytic cell normally electrochemically oxidizes the monovalent copper ammonia complex in the etching working solution and electrolyzes oxygen, and the electrolytic cathode electrolyzes metallic copper.

[0199] During the etching process, a pH meter and a hydrometer monitor the pH and specific gravity of the etching solution, respectively. Based on the test results and the process settings, pump 16-15 is controlled to add regenerated etching sub-liquid, ensuring stable etching of the etching solution. An ORP meter monitors the redox potential of the etching solution and controls or shuts down the operating current of electrolytic power supply 7 accordingly. A hydrometer is installed in the cathode tank of the oxidation electrolytic cell. Based on its test results and the copper ion concentration in the catholyte set by the process, pump 16-3 is controlled to add the etching waste liquid from temporary storage tank 10-3 to the cathode tank of the oxidation electrolytic cell.

[0200] Example 7

[0201] The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching device shown in Figure 7 includes: an etching machine 1, seven temporary storage tanks 10, five liquid flow agitators 13, a vacuum ejector 19, seven liquid flow buffer tanks 22, two oxidation electrolytic cells 2, three electrolysis power supplies 7, two hot and cold temperature exchangers 26, twelve sensors 28, an automatic program controller 29, multiple valves and pumps, and a metal electrolysis cell 62. The temporary storage tank 10-3 is used as a mixing exchange tank.

[0202] The copper etching agent oxidation regeneration reaction supply source in this embodiment is two oxidation electrolytic cells 2-1 and 2-2. Each oxidation electrolytic cell is equipped with an electrolytic cell divider to separate it into an anode cell area and a cathode cell area, wherein the cathode cell area is equipped with a liquid flow agitator and a sensor. The electrolytic anode and electrolytic cathode are respectively located in the anode cell area and the cathode cell area and are connected to the electrolytic power supply. The electrolytic cell divider 6-1 is a reverse osmosis membrane, and the electrolytic cell divider 6-2 is a bipolar membrane. The electrolytic anode is an insoluble anode with a titanium-based coating, and the electrolytic cathode is stainless steel. The anolyte in the oxidation electrolytic cell is an etching working solution, and the catholyte is etching waste liquid.

[0203] The anode tank areas of the oxidation electrolytic cells 2-1 and 2-2 are each connected to the temporary storage tank 10-3 via a liquid circulation pipeline. The etching machine 1 is also connected to the temporary storage tank 10-3 via a circulating liquid flow pipeline, so that the etching working solution and the electrolyte of the two electrolytic anode tank areas are mixed and exchanged in the temporary storage tank 10-3. The electrolytic anodes of the two oxidation electrolytic cells directly electrochemically oxidize the monovalent copper ammonia complex in the etching working solution, thereby replenishing the copper etching agent in the etching working solution.

[0204] The oxygen electrolyzed from the anode tank area of ​​the two oxidation electrolytic cells 2-1 and 2-2 and one metal electrolysis cell 62 is led to the vacuum ejector 19 to undergo oxidation reaction with the solution 32 after copper extraction from electrolysis in the cell 10-4.

[0205] The etching machine 1 is a spray etching machine, which is provided with a sensor 28-1, a sensor 28-2, a sensor 28-3 and a sensor 28-4.

[0206] This embodiment employs a progressive electrolytic copper extraction method, employing two oxidation electrolytic cells and one metal electrolysis cell as the metal electrolysis cells. Oxidation cell 2-1 and metal electrolysis cell 62 are Class A metal electrolysis cells, while oxidation cell 2-2 is a Class B metal electrolysis cell. The cathode region of the Class A metal electrolysis cell is utilized to reduce the concentration of the copper etchant in the waste etching solution. Once the process requirements are met, the overflowing catholyte from the Class A metal electrolysis cell is fed into the cathode region of the Class B metal electrolysis cell for copper electrolysis extraction.

[0207] Metal electrolysis cell 62 is equipped with a cell divider, separating it into an anode and cathode compartments. The cell divider 6-3 is a cation exchange membrane. The electrolytic anode is an insoluble anode with a titanium-based coating, and the electrolytic cathode is stainless steel. ORP meters 28-11 and 28-12 are installed in both the cathode and anode compartments. The anode compartment is used to oxidize the cathode overflow from electrolytic cell 2-2 to prepare the regenerated etching sub-solvent 50.

[0208] Sensors 28-1 and 28-5 are pH meters, sensors 28-2 and 28-10 are hydrometers, sensors 28-3, 28-7, 28-9, 28-11, and 28-12 are ORP meters, sensors 28-4 and 28-8 are thermometers, and sensor 28-6 is a liquid level gauge. All sensor data is transmitted to the automatic program controller 29 for processing, ensuring the equipment operates normally according to the set program.

[0209] Before etching begins, add etching solution to the anode tank area of ​​the etcher, the mixed exchange tank, and the oxidation electrolytic cell. Add etching waste liquid from the temporary storage tank 10-2 to the cathode tank area of ​​the Class A metal electrolytic cell. Add the overflow solution of the catholyte from the Class A metal electrolytic cell to the cathode tank area of ​​the Class B metal electrolytic cell. Place multiple circuit boards 17 (the anti-corrosion layer is shown in Table 3) in sequence, and start pumps 16-5 to spray and circulate the etching solution. Start pumps 16-8 and 16-9 to circulate the solution from the mixed exchange tank between the mixed exchange tank and the anode tank areas of the two oxidation electrolytic cells. Start electrolysis power supplies 7-1 and 7-2 to allow the two oxidation electrolytic cells to perform electrolysis operations.

[0210] The copper etchant concentration in the mixed exchange tank solution is set to be higher than that in the etching working solution. When the ORP meter of the etching machine sensor 28-3 is lower than the process setting value, the speed of the pump 16-7 or the gate valve opening of the valve 15-4 is controlled to control the flow rate of the solution in the mixed exchange tank to the etching machine to maintain normal etching. If the etching machine is full of liquid, it overflows into the liquid flow buffer tank 22-1 and is pumped back to the mixed exchange tank for circulation.

[0211] When the liquid level in the mixing exchange tank reaches the set point of the liquid level meter 28-6, the pump 16-4 is started to pump part of the solution in the temporary storage tank 10-3 to the temporary storage tank 10-2 as temporary storage of etching waste liquid.

[0212] During the etching process, based on the pH meter readings from sensor 28-1 and the process settings, if the on-site readings fall below the set value, the automatic program controller 29 controls pump 16-16 to add ammonia, according to the hydrometer readings from sensor 28-2. The amount of ammonia added is adjustable on metering pump 16-1. Pump 16-16 is controlled to add regenerated etching solution based on the hydrometer readings from sensor 28-2 and the process settings, ensuring stable etching production. Sensor 28-7 (ORP meter) mounted on the mixing exchange tank transmits the mixed solution's redox potential to the automatic program controller 29, which processes the mixed solution to control the operating current of electrolytic power supplies 7-1 and 7-2, or to shut them down.

[0213] Example 8

[0214] The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching apparatus shown in FIG8 includes: an etching machine 1, seven temporary storage tanks 10, five liquid flow agitators 13, a pipeline bubbling gas-liquid mixer 20, seven liquid flow buffer tanks 22, a gas pressure pump 27, two oxidation electrolytic cells 2, three electrolysis power supplies 7, two hot and cold temperature exchangers 26, twelve sensors 28, an automatic program controller 29, an oxygen-generating electrolytic cell 3, and multiple valves and pumps. The temporary storage tank 10-3 serves as a mixing exchange tank.

[0215] The supply sources for the copper etching agent oxidation regeneration reaction in this embodiment are the oxidation electrolytic cells 2-1 and 2-2, and the oxygen produced by each electrolytic cell in the system.

[0216] The oxidation electrolytic cells 2-1, 2-2 and the oxygen production electrolytic cell 3 are all provided with electrolytic cell separators to separate them into anode cell area and cathode cell area. The electrolytic cell separator 6-1 is a reverse osmosis membrane, the electrolytic cell separator 6-2 is a bipolar membrane, and the electrolytic cell separator 6-3 is a cation exchange membrane.

[0217] The anode tank areas of the oxidation electrolytic cells 2-1 and 2-2 are respectively connected to the mixing exchange tank by liquid circulation pipelines, and the etching machine 1 is also connected to the mixing exchange tank by a circulating liquid pipeline, so that the etching working liquid and the electrolyte of the two electrolytic anode tank areas are mixed and exchanged in the mixing exchange tank. The electrolytic anodes of the two oxidation electrolytic cells are used to directly cause an electrochemical oxidation reaction on the monovalent copper ammonia complex in the etching working liquid, so that the copper etching agent in the etching working liquid is replenished.

[0218] This embodiment utilizes a progressive electrolytic copper extraction process, with oxidation cell 2-1 serving as the Class A metal electrolysis cell, oxidation cell 2-2, and oxygen-generating cell 3 serving as the Class B metal electrolysis cell. The cathode region of the Class A metal electrolysis cell is used to reduce the concentration of the copper-electrolyte in the waste etching solution. Once the process requirements are met, the catholyte overflowing from the Class A metal electrolysis cell is fed into the cathode region of the Class B metal electrolysis cell for copper electrolysis extraction. Furthermore, the catholyte overflowing from oxidation cell 2-2 is fed into the anode region of oxidation cell 2-3 for oxidation.

[0219] The temporary storage tank 10 - 6 receives the anolyte and cathode electrolyte from the oxygen-generating electrolytic tank 3 and prepares the regenerated etching sub-liquid therein.

[0220] The oxygen electrolyzed from the anode area of ​​the oxidation electrolytic cell 2-1, the oxidation electrolytic cell 2-2, and the oxygen production electrolytic cell 3 is introduced into the etching machine to enrich the etching working solution with oxygen. The oxygen is used to react with the metallic copper in the solution to accelerate etching, thereby improving etching production efficiency.

[0221] The etching machine 1 is a spray etching machine, which is equipped with sensors 28-1, 28-2, 28-3 and 28-4. The temporary storage tank 10-3 as a mixing exchange tank is equipped with sensors 28-5, 28-6, 28-7 and 28-8.

[0222] Sensors 28-1 and 28-5 are pH meters; sensors 28-2, 28-10, and 28-12 are hydrometers; sensors 28-3, 28-7, 28-9, and 28-11 are ORP meters; sensors 28-4 and 28-8 are thermometers; and sensor 28-6 is a liquid level gauge. All sensor data is transmitted to the automatic program controller 29 for processing, ensuring the equipment operates normally according to the set program.

[0223] Etching solution is added to the anode tanks of the etcher, the mixing exchange tank, and oxidation electrolytic cells 2-1 and 2-2. Waste etching solution is added to the cathode tank of oxidation electrolytic cell 2-1 from temporary storage tank 10-2. Overflowing cathode electrolyte from oxidation electrolytic cell 2-1 is added to the cathode tanks of oxidation electrolytic cell 2-2 and oxygen electrolytic cell 3. Multiple circuit boards 17 (with the anti-corrosion layer shown in Table 3) are placed in sequence. Pumps 16-4 are activated to spray and circulate the etching solution. Pumps 16-7 and 16-8 are activated to circulate the solution from the mixing exchange tank between the mixing exchange tank and the anode tanks of oxidation electrolytic cells 2-1 and 2-2. Electrolysis power supplies 7-1 and 7-2 are activated to cause oxidation electrolytic cells 2-1 and 2-2 to perform electrolysis.

[0224] The cathode electrolyte of the oxidation electrolytic cell 2-1 is detected by the sensor 28-9 (ORP meter) to control the cathode 5-1 to reduce the electrolytic deposition of copper metal.

[0225] The oxygen gas electrolyzed in the anode tank of the oxidation electrolytic cell is introduced into the pipeline bubbling gas-liquid mixer 20 through the gas pressure pump 27 to enrich the etching working solution with oxygen.

[0226] The anode tank area of ​​the oxygen production electrolytic cell 3 is equipped with a sensor 28-11 (ORP meter), and the cathode tank area is equipped with a sensor 28-12 (hydrometer). The anode electrolyte is the cathode electrolyte overflowed from the oxidation electrolytic cell 2-2 after copper extraction.

[0227] The copper etchant concentration in the mixed exchange tank is set higher than that in the etching solution. When the detection result of the sensor 28-3 (ORP meter) of the etcher is lower than the process setting value, the speed of the pump 16-6 is adjusted to control the pumping of the solution in the mixed exchange tank to the etcher to maintain normal etching. If the etcher is full, the solution overflows into the liquid flow buffer tank 22-1 and is pumped back to the mixed exchange tank for circulation.

[0228] When the liquid level in the mixing exchange tank reaches the set point of sensor 28-6 (liquid level gauge), pump 16-3 is started and pump 16-5 is stopped to pump the solution in the liquid flow buffer tank 22-1 into the temporary storage tank 10-2. The start-up operation of pump 16-5 is resumed only when the liquid level gauge is no longer at the set point.

[0229] The sensor 28-7 (ORP meter) installed on the mixing exchange tank controls the working current of the electrolysis power supply 7-1 and the electrolysis power supply 7-2 or shuts it down by transmitting the redox potential value of the mixed liquid to the automatic program controller 29 for processing.

[0230] Example 9

[0231] The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching apparatus shown in FIG9 includes: an etching machine 1, five temporary storage tanks 10, two liquid flow agitators 13, a vacuum ejector 19, a spray-type gas-liquid mixer 21, four liquid flow buffer tanks 22, an oxidation electrolytic cell 2, an oxygen electrolytic cell 3, two electrolysis power supplies 7, two hot and cold temperature exchangers 26, fifteen sensors 28, an automatic program controller 29, valves, and a pump. Temporary storage tank 10-3 is a mixing exchange tank.

[0232] In this embodiment, the copper-etching agent oxidation regeneration reaction is supplied by the oxidation electrolytic cell 2 and oxygen, with the oxygen source being the oxygen-generating electrolytic cell 3. Both the oxidation electrolytic cell 2 and the oxygen-generating electrolytic cell 3 are equipped with a cell divider, separating them into an anode cell area and a cathode cell area. The cell divider 6-1 of the oxidation electrolytic cell 2 is an anion exchange membrane. The cell divider 6-2 of the oxygen-generating electrolytic cell 3 is a filter cloth. The cathode cell areas of both the oxidation electrolytic cell 2 and the oxygen-generating electrolytic cell 3 are equipped with a liquid flow agitator and a sensor.

[0233] In this embodiment, the anode tank area of ​​the etcher 1 and the oxidation electrolytic cell 2 are connected by a mixing exchange tank as liquid circulation pipelines, so that the etching working solution circulates between the etcher, the mixing exchange tank and the anode tank area of ​​the oxidation electrolytic cell 2. The anode of the oxidation electrolytic cell 2 is used to directly electrochemically oxidize the monovalent copper ammonia complex in the etching working solution. At the same time, the oxygen electrolyzed by the oxygen electrolytic cell 3 and the small amount of oxygen electrolyzed by the oxidation electrolytic cell 2 are directly introduced into the solution of the mixing exchange tank through a vacuum ejector 19, so that the etching working solution in the etcher is enriched with oxygen. The two oxidation reactions of oxygen in the etching solution with oxidized metallic copper and direct electrochemical oxidation of the monovalent copper ammonia complex in the etching working solution by the anode of the oxidation electrolytic cell 2 are used to accelerate etching, thereby improving etching production efficiency.

[0234] The etching machine 1 is a spray etching machine, which is equipped with sensors 28-1, 28-2, 28-3 and 28-4. The temporary storage tank 10-3 as a mixing exchange tank is equipped with sensors 28-5, 28-6, 28-7, 28-8 and 28-9.

[0235] Temporary storage tank 10-5 receives the cathode electrolyte overflowing from oxidation electrolytic tank 2 and oxygen electrolytic tank 3 and prepares the regenerated etching liquid therein. Temporary storage tank 10-5 is equipped with sensors 28-12, 28-13, 28-14, and 28-15. Temporary storage tank 10-6 temporarily stores the regenerated etching liquid from temporary storage tank 10-5 and adds the regenerated etching liquid to the mixing exchange tank according to a set program.

[0236] Sensors 28-1 and 28-9 are thermometers; sensors 28-2, 28-7, 28-11, and 28-13 are hydrometers; sensors 28-3, 28-8, 28-10, and 28-12 are ORP meters; sensors 28-4, 28-5, and 28-14 are pH meters; and sensors 28-6 and 28-15 are liquid level gauges. All sensor field data is transmitted to the automatic program controller 29 for processing, enabling the equipment to operate automatically according to the set program.

[0237] Etching fluid is added to the anode tank of the etcher, the mixed exchange tank, and the oxidation electrolytic cell 2. Waste etching fluid is added to the cathode tank of the oxidation electrolytic cell 2-1 and the oxygen electrolytic cell 3 from the temporary storage tank 10-2. Multiple circuit boards 17 (the resist layers are shown in Table 3) are placed in sequence. All other equipment in the etcher is activated, the etching process begins, and the regenerated etching solution is prepared. The copper etchant concentration in the mixed exchange tank solution is set to be higher than the copper etchant concentration in the etching fluid in the etcher, meaning that the value of sensor 28-8 is greater than the value of sensor 28-3. The flow rate of the mixed exchange tank solution into the etcher is controlled by controlling the speed of pump 16-7 and / or the gate valve opening of valve 15-2 to maintain normal etching. If sensor 28-6 (liquid level gauge) in the mixed exchange tank detects full liquid, pump 16-6 is shut down, and pump 16-4 is activated to pump the solution in the flow buffer tank 22-1 to the temporary storage tank 10-2 for temporary storage. The ORP meter installed on the mixing exchange tank controls the working current of the electrolysis power supply 7-1 and the electrolysis power supply 7-2 or shuts it down by detecting the redox potential value of the solution.

[0238] Example 10

[0239] The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching apparatus shown in FIG10 includes an etching machine 1, seven temporary storage tanks 10, six liquid flow agitators, nine liquid flow buffer tanks, three oxidation electrolytic cells 2, one oxygen electrolytic cell 3, four electrolytic power supplies 7, two hot and cold temperature exchangers, thirteen sensors, an automatic program controller 29, valves, and pumps. Temporary storage tank 10-3 serves as a mixing exchange tank.

[0240] This embodiment uses electrolytic progressive copper extraction, with oxidation cell 2-1 serving as a Class A metal electrolysis cell, oxidation cells 2-2 and 2-3 serving as Class B metal electrolysis cells, and oxygen-generating cell 3 serving as a Class C metal electrolysis cell. The cathode cell area of ​​the Class A metal electrolysis cell is used to reduce the concentration of the copper-etching agent in the etching waste liquid. After meeting process requirements, the cathode electrolyte overflowing from the Class A metal electrolysis cell is fed into the cathode cell area of ​​the Class B metal electrolysis cell for electrolytic copper extraction. Subsequently, a portion of the cathode electrolyte overflowing from the Class B metal electrolysis cell is fed into the cathode cell area of ​​the Class C metal electrolysis cell for electrolytic copper extraction. Furthermore, a portion of the cathode electrolyte overflowing from the Class B metal electrolysis cell is fed into the anode cell area of ​​the Class C metal electrolysis cell for oxidation and oxygen production.

[0241] Each of the above-mentioned electrolytic cells is equipped with a cell divider, separating it into an anode cell area and a cathode cell area. The cathode cell area is equipped with a sensor and a liquid flow agitator. The cell divider 6-1 is a reverse osmosis membrane, the cell divider 6-2 is a bipolar membrane, the cell divider 6-3 is an anion exchange membrane, and the cell divider 6-4 is a cation exchange membrane. The electrolytic anode of each electrolytic cell is an insoluble anode with a titanium-based coating, the electrolytic cathode 5-1 is conductive graphite, the electrolytic cathodes 5-2 and 5-3 are copper plates, and the electrolytic cathode 5-4 is stainless steel.

[0242] The regeneration etching sub-liquid is prepared in tank 10-6.

[0243] The copper etching agent oxidation regeneration reaction supply source of this embodiment is the oxidation electrolytic cells 2-1, 2-2 and 2-3.

[0244] In this embodiment, an etching machine is connected to a mixing exchange tank via a circulating liquid flow conduit. The mixing exchange tank is also connected to the anode tank areas of oxidation electrolytic cells 2-1, 2-2, and 2-3 via a circulating liquid flow conduit. This allows the etching solution and the electrolytes of the three anode tank areas to mix within the mixing exchange tank. The electrolytic anodes of the oxidation electrolytic cells directly electrochemically oxidize the monovalent copper ammonia complex in the etching solution. Oxygen generated by the electrolysis of the anode tank areas of the three oxidation electrolytic cells 2-1, 2-2, and 2-3 and the anode tank area of ​​the oxygen-generating electrolytic cell 3 is introduced into cell 10-7 via an ejector 19 to undergo a chemical oxidation reaction with the solution.

[0245] The etching machine 1 is a spray etching machine, which is equipped with sensors 28-1, 28-2, 28-3 and 28-4. The temporary storage tank 10-3 as a mixed exchange tank is equipped with sensors 28-5, 28-6, 28-7 and 28-8.

[0246] Sensors 28-1 and 28-5 are pH meters; sensors 28, 28-10, 28-11, and 28-13 are hydrometers; sensors 28-3, 28-7, 28-9, and 28-12 are ORP meters; sensors 28-4 and 28-8 are thermometers; and sensor 28-6 is a liquid level gauge. All sensor data is transmitted to an automatic program controller 29 for processing, ensuring the equipment operates normally according to the programmed program.

[0247] Etching solution is added to the anode tanks of the etching machine, the hybrid exchange tank, and the three oxidation electrolytic cells. Etching waste liquid stored in temporary storage tank 10-2 is added to the cathode tank of the Class A metal electrolysis cell. Catholyte overflowing from the Class A metal electrolysis cell is added to the cathode tanks of the two Class B metal electrolysis cells. Catholyte overflowing from the Class B metal electrolysis cell after copper electrolysis is added to the anode and cathode tanks of the Class C metal electrolysis cell. Multiple circuit boards 17 (with the anti-corrosion layer shown in Table 3) are placed in sequence. Pumps 16-4 are activated to spray and circulate the etching solution. Pumps 16-7, 16-8, and 16-9 are activated to circulate the solution between the hybrid exchange tank and the anode tank of the oxidation electrolytic cell. Electrolysis power supplies 7-1, 7-2, 7-3, and 7-4 are activated to cause the four electrolytic cells to perform electrolysis operations.

[0248] The copper etching agent concentration of the mixed exchange tank solution is set to be higher than the copper etching agent concentration in the etching working solution in the etcher. When the sensor 28-3 (ORP meter) of the etcher is lower than the process setting value, the flow rate of the solution pumped from the mixed exchange tank to the etcher is controlled by adjusting the gate valve opening of valve 15-5 to maintain normal etching. If the etcher is full of liquid, it overflows into the liquid flow buffer tank 22-1 and is pumped back to the mixed exchange tank for circulation.

[0249] When the liquid level in the mixing exchange tank reaches the set point, the pump 16-3 is started and the pump 16-5 is stopped to pump the solution in the liquid flow buffer tank 22-1 to the tank 10-2 as a temporary storage of the etching waste liquid.

[0250] During the etching process, the sensor 28-1 (pH meter) in the etching machine detects whether the etching solution meets the set value. When the on-site measured value is lower than the set value, the automatic program controller 29 will control the pump 16-19 to add regenerated etching sub-liquid 50 to the etching machine. When the on-site detection value of the sensor 28-5 (pH meter) in the mixing exchange tank is lower than the preset value, the automatic program controller 29 will control the metering pump 16-1 to add ammonia water to the mixing exchange tank for replenishment, so that the etching working solution can be stably produced. The ORP meter installed on the mixing exchange tank controls the operating current of the electrolytic power supplies 7-1, 7-2 and 7-3 or shuts them down by detecting the redox potential value of the solution and transmitting it to the automatic program controller 29 for processing.

[0251] Examples 11-14

[0252] Using the apparatus shown in FIG10 , the procedures of Example 10 were repeated according to the etching solution parameters and complex ammonia source types shown in Tables 1 and 2. The circuit board parameters used in the etching test of this example are shown in Table 3. The circuit boards after copper etching were inspected and the results, including the etching rate and resist conditions, are reported in Table 3.

[0253] Comparative Example 1

[0254] FIG11 is a schematic diagram of the apparatus of Comparative Example 1. The difference from FIG2 is that the apparatus does not include an oxidation electrolytic cell 2 .

[0255] The supply source for the copper etching agent oxidation regeneration reaction in this comparative example is only oxygen, and the source of oxygen is the same as that in Example 2.

[0256] In this comparative example, the same ammoniacal alkaline sulfuric acid tetraammine copper etchant as in Example 2 was used, and the circuit board parameters for the etching test are shown in Table 3. The circuit boards after copper etching were inspected and the results were obtained, and the etching rates and resist conditions were recorded in Table 3.

[0257] Comparative Example 2

[0258] In this comparative example, the etching test was carried out using the same ammoniacal alkaline sulfuric acid tetraammine copper etching solution and conventional alkaline etching process as in Example 2.

[0259] In this comparative example, the same ammoniacal alkaline sulfuric acid tetraammine copper etchant as in Example 2 was used, and the circuit board parameters for the etching test are shown in Table 3. The circuit boards after copper etching were inspected and the results were obtained, and the etching rates and resist conditions were recorded in Table 3.

[0260] Comparative Example 3

[0261] Etching tests were conducted using a [Cu(NH3)4]SO4 solution as the etching solution and a conventional alkaline etching process. The copper ion concentration of the etching solution was 70 g / L.

[0262] The parameters of the circuit board used in the etching test of this comparative example are shown in Table 3. The circuit board after copper etching was completed was inspected and the results were recorded in Table 3, including the etching rate and the condition of the resist layer.

[0263] Comparative Examples 4-6

[0264] Etching tests were conducted using a conventional ammonia-alkaline copper chloride etching solution and a conventional alkaline etching process. The copper ion concentration of the etching solution was 140-150 g / L and the pH was 8.8.

[0265] The parameters of the circuit board used in the etching test of this comparative example are shown in Table 4. The circuit board after copper etching was completed was inspected and the results were recorded in Table 4, including the etching rate and the condition of the resist layer.

[0266] The present invention may be summarized in other specific forms that do not violate the spirit or main features of the present invention. The above embodiments of the present invention are only to be considered as illustrative and not restrictive of the present invention. Therefore, any minor modifications, equivalent variations, and modifications made to the above embodiments based on the essential technology of the present invention are within the scope of the technical solution of the present invention.

[0267] Table 1

[0268] Table 2

[0269] Table 3

[0270] Table 4

Claims

1. A circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process, comprising an etching solution used to etch a circuit board covered with a metal resist layer, characterized in that: The etching solution contains tetraammine copper sulfate, a complex ammonia supply source, and a formate supply source. Ammonia-alkaline tetraammine copper sulfate is used as a copper etching agent to etch the circuit board, and the copper etching agent in the etching solution is regenerated by the copper etching agent oxidation regeneration reaction supply source to maintain the etching rate.

2. The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process according to claim 1, characterized in that: The pH value of the etching solution is 7-11.5, the copper ion concentration is 10-140 g / L, the molar concentration of sulfate ions is at least 0.01 times the molar concentration of copper ions and does not exceed 4 mol / L, the total molar concentration of ammonia and ammonium ions is at least 1 times the molar concentration of copper ions and does not exceed 18 mol / L, and the formate concentration is 0.0001-8 mol / L.

3. The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process according to claim 2, characterized in that: The complex ammonia supply source is a chemical that can provide ammonia and / or ammonium ions, including one or more of ammonia water, ammonia, ammonium carbonate, ammonium bicarbonate, ammonium sulfate, ammonium bisulfate, and ammonium formate; the formate supply source is formic acid and / or ammonium formate.

4. The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process according to claim 3, characterized in that: The copper etching agent oxidation regeneration reaction supply source is an oxidation electrolytic cell for performing oxidation regeneration reaction on the etching working solution; The oxidation electrolytic cell is provided with an electrolytic cell separator to separate the electrolytic cell into an anode cell area and a cathode cell area, wherein the electrolytic cell separator can effectively prevent cations in the anode cell area from entering the cathode cell area; the anode cell area is connected to an etching machine filled with etching working fluid and performing etching operations through a pipeline, so that the etching working fluid can circulate between the two cells to maintain the concentration of the copper etching agent therein.

5. The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process according to claim 4, characterized in that: In the continuous etching production process, in order to maintain the stable ratio of each component of the etching working solution, the etching sub-liquid is added to the etching working solution, which includes a sulfate and complex ammonia supply source; The etching sub-liquid is added into any one or more of the following places: the etching working liquid of the etching machine, or the anode electrolyte of the oxidation electrolytic cell, or the mixture of the above two.

6. The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process according to claim 5, characterized in that: The etching solution also includes no more than 5 mol / L of hydroxylamine to promote the regeneration reaction of the etching solution.

7. The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process according to any one of claims 1 to 6, characterized in that: The supply source for the copper etching agent oxidation regeneration reaction also includes oxygen; specifically, the oxygen is introduced into the etching working solution and / or the anode electrolyte of the oxidation electrolytic cell, and the monovalent copper ammonia complex in the oxidation etching working solution is assisted by a chemical reaction to be regenerated into the copper etching agent; the sources of oxygen include: (1) commercial oxygen, (2) oxygen prepared by a molecular sieve oxygen generator, (3) oxygen prepared by a chemical reaction of an oxidant, and (4) oxygen prepared by an electrolytic method; wherein the oxygen prepared by the electrolytic method comes from the oxygen escaped during the operation of the oxidation electrolytic cell, and / or oxygen prepared by an oxygen-making electrolytic cell.

8. The circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process according to claim 7, characterized in that: The ammoniacal alkaline sulfuric acid tetraammine copper etching waste liquid is subjected to electrolytic copper and / or silver electrolytic treatment in a metal electrolytic tank. After the ammoniacal alkaline sulfuric acid tetraammine copper etching waste liquid is subjected to the copper electrolytic treatment in the metal electrolytic tank, the ammoniacal alkaline sulfuric acid tetraammine copper etching waste liquid is directly converted into a regenerated etching sub-liquid, or is prepared as one of the raw materials to become a regenerated etching sub-liquid, and the regenerated etching sub-liquid is used as part or all of the etching sub-liquid. When the metal electrolysis cell is not provided with an electrolytic cell partition, the electrolyte contains etching waste liquid and / or electrolyzed etching waste liquid; When the metal electrolysis cell is provided with an electrolytic cell separator to separate the anode cell area and the cathode cell area, the cathode electrolyte contains etching waste liquid and / or electrolyzed etching waste liquid, the anode electrolyte is a mixture of one or more of the etching working liquid, etching waste liquid, electrolyzed cathode electrolyte from the current cell, and electrolyzed cathode electrolyte from other metal electrolysis cells, and the electrolytic cell separator is one or more of the following: a cation exchange membrane, an anion exchange membrane, a bipolar membrane, a reverse osmosis membrane, a neutral filter membrane, and a filter cloth.

9. A device suitable for the circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process according to claim 1, comprising an etching machine, characterized in that: The etching working liquid used in the etching machine is an ammoniacal alkaline sulfuric acid tetraammine copper etching liquid, and a copper etching agent oxidation regeneration reaction supply device is additionally provided. The copper etching agent oxidation regeneration reaction supply device is an oxidation electrolytic cell, which is connected to the etching machine through at least two pipes, so that the etching liquid can circulate between the two cells, so that when the etching liquid enters the oxidation electrolytic cell, it directly undergoes an electrochemical oxidation reaction with the electrolytic anode, so that the monovalent copper ammonia complex in the etching liquid can be regenerated into ammoniacal alkaline sulfuric acid tetraammine copper etching agent Cu(NH3)4SO4; The oxidation electrolytic cell is provided with an electrolytic cell separator to separate the electrolytic cell into an anode cell area and a cathode cell area. The anode cell area is connected to the etching machine through a pipeline so that the etching liquid can circulate between the two cells to maintain its copper etching agent concentration; the electrolytic cell separator of the oxidation electrolytic cell can effectively prevent the cations in the anode cell area from entering the cathode cell area, and specifically one or more of an anion exchange membrane, a bipolar membrane, and a reverse osmosis membrane are selected.

10. The device suitable for the circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process according to claim 9, characterized in that: The copper etching agent oxidation regeneration reaction supply device also includes an oxygen supply device, which is connected to a device containing an etching working liquid through a pipeline, or is connected to the etching liquid through a pipeline, so that the etching working liquid is further oxidized by oxygen during the etching process to produce ammoniacal alkaline sulfuric acid tetraammine copper copper etching agent Cu(NH3)4SO4.

11. The device for the circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process according to claim 10, characterized in that: A mixing exchange tank is added to the connecting pipe between the etching machine and the anode tank area of ​​the oxidation electrolytic cell, so that the etching working solution and the anode electrolyte of the oxidation electrolytic cell are mixed and exchanged in the mixing exchange tank through their respective liquid circulation pipes.

12. The device suitable for the circuit board ammoniacal alkaline sulfuric acid tetraammine copper etching process according to claim 11, characterized in that: A metal electrolysis tank is added to receive the ammoniacal alkaline sulfuric acid tetraammine copper etching waste liquid from the etching machine and perform electrolysis to extract copper and / or electrolysis to extract silver.

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