CN116446029A - A method and device for removing tin from PCB in one step and recovering tin at the same time - Google Patents

A method and device for removing tin from PCB in one step and recovering tin at the same time Download PDF

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CN116446029A
CN116446029A CN202310474416.6A CN202310474416A CN116446029A CN 116446029 A CN116446029 A CN 116446029A CN 202310474416 A CN202310474416 A CN 202310474416A CN 116446029 A CN116446029 A CN 116446029A
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tin
solution
stripping
acid
electrolytic
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杨建广
南天翔
苏安邦
朱强
唐施阳
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Central South University
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    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25FPROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F5/00Electrolytic stripping of metallic layers or coatings
    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25CPROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C1/00Electrolytic production, recovery or refining of metals by electrolysis of solutions
    • C25C1/14Electrolytic production, recovery or refining of metals by electrolysis of solutions of tin
    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25CPROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C7/00Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25FPROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F7/00Constructional parts, or assemblies thereof, of cells for electrolytic removal of material from objects; Servicing or operating
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00Technologies related to metal processing
    • Y02P10/20Recycling

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  • Chemical Kinetics & Catalysis (AREA)
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  • Materials Engineering (AREA)
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  • Organic Chemistry (AREA)
  • Electrolytic Production Of Metals (AREA)

Abstract

本发明公开了一种PCB一步退锡同时回收锡的方法和装置;将经过蚀刻后的线路板通过酸性体系溶液连续退锡电解反应装置中,在外场耦合强化和脉冲电场同时作用的条件下进行电解退锡和回收锡;随着反应的进行,线路板上的锡镀层完全溶解进入溶液中,溶液中的锡离子在阴极沉积析出,获得高质量阴极锡。本发明在有效缩短退锡时间、高效回收锡的同时,有效解决了现行硝酸退锡体系氨氮废水产量大难以资源化利用的问题,具有清洁、高效、选择性强的优点。本发明的装置简单实用,配套使用能够取得更佳退锡和回收效果。The invention discloses a method and a device for recovering tin while removing tin from PCB in one step. The etched circuit board is passed through an acidic system solution in an electrolytic reaction device for continuous tin removal, and is carried out under the conditions of external field coupling strengthening and pulse electric field simultaneous action. Electrolytic tin stripping and tin recovery; as the reaction progresses, the tin coating on the circuit board is completely dissolved into the solution, and the tin ions in the solution are deposited and precipitated at the cathode to obtain high-quality cathode tin. While effectively shortening the tin stripping time and efficiently recovering tin, the present invention effectively solves the problem that the current nitric acid tin stripping system has a large output of ammonia nitrogen wastewater and is difficult to utilize as resources, and has the advantages of cleanliness, high efficiency and strong selectivity. The device of the present invention is simple and practical, and can achieve better tin stripping and recovery effects when used as a set.

Description

一种PCB一步退锡同时回收锡的方法和装置A method and device for removing tin from PCB in one step and recovering tin at the same time

技术领域technical field

本发明具体涉及一种PCB一步退锡同时回收锡的方法和装置,属于有色金属冶金领域。The invention specifically relates to a method and a device for removing tin from a PCB in one step and recovering tin at the same time, and belongs to the field of nonferrous metal metallurgy.

背景技术Background technique

印刷电路板(PCB)是电子元件的支撑体,其主要功能是连接各种类型的电子零组件形成特定的电路,是电子产品的关键电子互联件,任何电子产品或设备都需要采用印刷电路板进行配备。印刷电路板对于时代发展意义重大,其下游产业已经涉及覆盖所有的消费性电子产品,包括信息、通讯、医疗,甚至航天科技产品在内的各个领域都离不开印刷电路板。Printed circuit board (PCB) is the support of electronic components. Its main function is to connect various types of electronic components to form specific circuits. It is the key electronic interconnection of electronic products. Any electronic product or equipment needs to use printed circuit boards. To equip. Printed circuit boards are of great significance to the development of the times, and its downstream industries have covered all consumer electronics products, including information, communications, medical care, and even aerospace technology products. Printed circuit boards are inseparable from each other.

PCB的生产包括开料、钻孔、磨板、沉铜、电镀、图形转移、镀铜、退膜、蚀刻等20多道工序,其中为了避免PCB上铜基体图形在蚀刻时出现破蚀、断线等情况导致报废,镀锡工艺必不可少,在完成图形制作后再将锡镀层退除。目前国内PCB生产企业大多采用硝酸或硝酸-烷基磺酸型退锡水进行退锡。The production of PCB includes more than 20 processes such as cutting, drilling, grinding, copper sinking, electroplating, pattern transfer, copper plating, stripping, and etching. Lines and other conditions lead to scrapping, the tin plating process is essential, and the tin plating layer is removed after the graphic production is completed. At present, most domestic PCB manufacturers use nitric acid or nitric acid-alkylsulfonic acid type tin stripping water for tin stripping.

然而,由于硝酸自身的不稳定性和选择性差等特点,退锡水在进行多次退锡后,其性质会发生较大的变化,退锡水中不仅含有较高浓度的锡离子(100~150g/L),还含有一定浓度的铜离子和铁离子(20~30g/L),此外杂环化合物、多环芳香化合物以及其他聚合物也会因为无法开路而逐渐累积。此时,退锡溶液已经无法再继续有效溶解PCB板上的锡镀层,需要进行开路更换。而退役的退锡溶液不仅含有大量的有价金属,也含有较高浓度的硝酸和其他有机成分,属于危险废物。如果不对其进行有效处理,不仅会造成大量资源的浪费,而且带来了巨大的潜在环境污染风险。迄今为止,废退锡水的处理方法主要有:沉淀法、蒸馏法、电解法等。However, due to the instability and poor selectivity of nitric acid itself, the properties of the tin stripping water will change greatly after repeated tin stripping. The tin stripping water not only contains higher concentrations of tin ions (100-150g /L), also contains a certain concentration of copper ions and iron ions (20 ~ 30g/L), in addition, heterocyclic compounds, polycyclic aromatic compounds and other polymers will gradually accumulate because they cannot be opened. At this time, the tin stripping solution can no longer effectively dissolve the tin coating on the PCB, and needs to be replaced with an open circuit. The decommissioned tin stripping solution not only contains a large amount of valuable metals, but also contains a relatively high concentration of nitric acid and other organic components, which is a hazardous waste. If it is not treated effectively, it will not only cause a lot of waste of resources, but also bring a huge potential risk of environmental pollution. So far, the treatment methods of waste tin stripping water mainly include: precipitation method, distillation method, electrolysis method and so on.

总体来看,现行硝酸或硝酸-烷基磺酸体系的退锡水在退锡过程中及退锡废液的处理还存在两大问题:(1)退锡过程主要以硝酸溶解锡、铜为主,存在NOx气体污染重、污泥和残酸量大、成本高昂的问题;(2)以沉淀法、电解法以及蒸馏法处理退锡水的工艺存在试剂消耗量大、金属回收率低、废水量大等严重问题。Generally speaking, there are still two major problems in the tin stripping water of the current nitric acid or nitric acid-alkylsulfonic acid system in the tin stripping process and the treatment of the tin stripping waste liquid: (1) the tin stripping process mainly uses nitric acid to dissolve tin and copper. Mainly, there are problems of heavy NOx gas pollution, large amount of sludge and residual acid, and high cost; (2) the process of treating tin stripping water with precipitation, electrolysis, and distillation has large reagent consumption, low metal recovery, Serious problems such as large amount of waste water.

为解决上述问题,申请人曾开发了“一种基于盐酸-锡盐体系的退锡水及从废退锡水中会后锡的方法(申请号201410011267.0)”提供了一种基于盐酸-锡盐体系的非硝酸型退锡水,以及退锡后从该类废退锡水中回收锡且同时再生退锡水的方法,虽然小型试验结果表明,采用该退锡水能够将镀锡板上的锡有效退除。然而,后续将该方法应用于印刷电路板退锡并回收锡的工业实践中,却遇到了退锡速度慢(大于10分钟)、PCB铜基板腐蚀严重、隔膜电积提取锡时出现“锡晶须”现象,电积效率低等严重问题。其原因在于,相比于现行的硝酸或硝酸-烷基磺酸体系退锡水,盐酸-锡盐体系的退锡水氧化性能相对较弱,对PCB上镀锡的溶解性能更弱,退锡速度也就更慢。而欲采用该退锡水退除PCB上更多的锡,必然要延长退锡时间,然而由于盐酸-锡盐体系退锡水中Cl-对PCB板的腐蚀属于“点蚀”,倾向于在PCB板上形成众多呈点状分布的小孔,导致退锡后的铜基板表面非常不平整,从而影响PCB后续的电子加工性能。In order to solve the above problems, the applicant has developed "a tin stripping water based on hydrochloric acid-tin salt system and a method for removing tin from waste tin stripping water (application number 201410011267.0)" and provided a system based on hydrochloric acid-tin salt The non-nitric acid type tin stripping water, and the method of recovering tin from such waste tin stripping water after stripping tin and regenerating the tin stripping water at the same time, although the small-scale test results show that the use of this tin stripping water can effectively remove the tin on the tinplate Retire. However, in the subsequent application of this method to the industrial practice of stripping tin from printed circuit boards and recycling tin, they encountered slow tin stripping speed (more than 10 minutes), severe corrosion of PCB copper substrates, and "tin crystals" when tin was extracted by diaphragm electrodeposition. Muster phenomenon, low electrowinning efficiency and other serious problems. The reason is that, compared with the current nitric acid or nitric acid-alkyl sulfonic acid system tin stripping water, the tin stripping water of the hydrochloric acid-tin salt system has relatively weak oxidation performance and weaker solubility for tin plating on PCBs. The speed is also slower. If you want to use this tin stripping water to remove more tin on the PCB, you must prolong the tin stripping time. However, because the corrosion of Cl- in the tin stripping water of the hydrochloric acid-tin salt system belongs to "pitting corrosion", it tends to be on the PCB Many small holes distributed in dots are formed on the board, resulting in very uneven surface of the copper substrate after tin stripping, which affects the subsequent electronic processing performance of the PCB.

为了有效提高退锡速度,申请人还曾开发了“一种PCB板两段法退锡的方法(申请号201811126057.0)”提供了一种第一段基于盐酸-锡盐体系,第二段基于硝酸-硝酸盐体系的复合二段退锡水,进一步在线高效回收锡的同时有效减少废退锡水处理时氨氮废水的排放。然而,NOx气体污染、污泥和残酸等突出的环境问题仍不能完全解决。In order to effectively improve the speed of tin stripping, the applicant has also developed "a two-stage method for stripping tin from PCB boards (application number 201811126057.0)", which provides a system based on hydrochloric acid-tin salt in the first stage and nitric acid in the second stage -The compound two-stage tin stripping water with nitrate system further efficiently recovers tin on-line and effectively reduces the discharge of ammonia nitrogen wastewater during the treatment of waste tin stripping water. However, outstanding environmental problems such as NOx gas pollution, sludge and residual acid cannot be completely resolved.

发明内容Contents of the invention

针对上述现有技术存在的问题及不足,本发明所要解决的技术问题是:提供一种PCB一步退锡同时回收锡的方法,本发明所提供的方法可以有效缩短退锡时间、提高退锡效率的同时回收溶液中的锡,另外,还可以有效避免废退锡水处理时氨氮废水的排放。实现PCB退锡清洁、高效生产的目的。Aiming at the problems and deficiencies in the above-mentioned prior art, the technical problem to be solved by the present invention is: to provide a method for recovering tin while removing tin from PCB in one step. The method provided by the present invention can effectively shorten the time for stripping tin and improve the efficiency of stripping tin At the same time, the tin in the solution can be recovered. In addition, it can also effectively avoid the discharge of ammonia nitrogen wastewater during the treatment of waste tin stripping water. Realize the purpose of clean and efficient production of PCB tin stripping.

本发明的另一目的在于提供一种与上述PCB一步退锡同时回收锡方法配套的,简单实用,能够综合获得较好退锡、回收锡效果的装置。Another object of the present invention is to provide a simple and practical device that is compatible with the above-mentioned method for one-step stripping of PCB and simultaneously recovering tin, and can comprehensively obtain better effects of stripping tin and recovering tin.

为了实现上述目的,本发明采用如下技术方案:In order to achieve the above object, the present invention adopts the following technical solutions:

一种PCB一步退锡同时回收锡的方法,将经过蚀刻后的线路板通过酸性体系溶液连续退锡电解反应装置中,在外场耦合强化条件下和电场同时作用下进行电解退锡和回收锡;随着反应的进行,线路板上的锡镀层溶解进入溶液中,溶液中的锡离子在阴极沉积析出。A method for removing tin from PCB in one step and recovering tin at the same time. The etched circuit board is passed through an acidic system solution in an electrolytic reaction device for continuous tin removal, and electrolytic tin removal and tin recovery are carried out under the condition of external field coupling strengthening and the simultaneous action of an electric field; As the reaction proceeds, the tin coating on the circuit board dissolves into the solution, and the tin ions in the solution are deposited and precipitated at the cathode.

所述酸性体系溶液为选自硫酸、甲基磺酸、盐酸的单一酸或混和酸以及退锡促进剂、退锡缓蚀剂、电解稳定剂、溶液分散剂组成的溶液,优选硫酸或甲基磺酸。The acidic system solution is a solution consisting of a single acid or a mixed acid selected from sulfuric acid, methanesulfonic acid, hydrochloric acid, and a tin stripping accelerator, a tin stripping corrosion inhibitor, an electrolytic stabilizer, and a solution dispersant, preferably sulfuric acid or methyl sulfonic acid.

所述退锡促进剂为四乙基溴化铵、甲基磺酸钠、酒石酸、柠檬酸钠、磺基水杨酸中的一种;所述退锡缓蚀剂为苯骈三氮唑、甲基苯并三氮唑、癸二酸或苯甲酸钠中的一种;所述电解稳定剂为动物骨胶、甲酚磺酸、苯酚磺酸、β-萘酚中的一种;溶液分散剂为环氧乙烷、聚乙二醇、烷基酚聚氧乙烯醚中的一种,优选的退锡促进剂为甲基磺酸钠,优选的退锡缓蚀剂为苯骈三氮唑,优选的电解稳定剂为动物骨胶,优选的溶液分散剂为环氧乙烷。The tin stripping accelerator is one of tetraethylammonium bromide, sodium methanesulfonate, tartaric acid, sodium citrate, sulfosalicylic acid; the tin stripping corrosion inhibitor is benzotriazole, One of tolyl benzotriazole, sebacic acid or sodium benzoate; the electrolytic stabilizer is one of animal bone glue, cresol sulfonic acid, phenol sulfonic acid, β-naphthol; the solution dispersant is One of ethylene oxide, polyethylene glycol, alkylphenol polyoxyethylene ether, the preferred tin stripping accelerator is sodium methanesulfonate, the preferred tin stripping corrosion inhibitor is benzotriazole, preferably The preferred electrolytic stabilizer is animal bone glue, and the preferred solution dispersant is ethylene oxide.

所述酸性体系酸度为1mol/L~5mol/L;退锡促进剂浓度为0.1~5g/L;退锡缓蚀剂浓度为0.01~2g/L;电解稳定剂浓度为0.05~20g/L;溶液分散剂浓度为0.01~5g/L,优选的酸度为2~4mol/L,优选的退锡促进剂浓度为0.5~3mol/L,优选的退锡缓蚀剂浓度为0.5~1mol/L,优选的溶液分散剂浓度为0.05~3mol/L。The acidity of the acidic system is 1mol/L-5mol/L; the concentration of the tin-removing accelerator is 0.1-5g/L; the concentration of the tin-removing corrosion inhibitor is 0.01-2g/L; the concentration of the electrolytic stabilizer is 0.05-20g/L; The concentration of the solution dispersant is 0.01-5g/L, the preferred acidity is 2-4mol/L, the preferred concentration of the tin-removing accelerator is 0.5-3mol/L, and the preferred concentration of the tin-removing corrosion inhibitor is 0.5-1mol/L, The preferred concentration of the solution dispersant is 0.05-3 mol/L.

所述外场耦合强化条件为超声耦合强化,超声频率为20~500kHz,超声功率为10~200W,优选的超声频率为40kHz,优选的超声功率为100W。The external field coupling strengthening condition is ultrasonic coupling strengthening, the ultrasonic frequency is 20-500kHz, the ultrasonic power is 10-200W, the preferred ultrasonic frequency is 40kHz, and the preferred ultrasonic power is 100W.

所述电解退锡电场为脉冲电场,脉冲电场的脉冲频率为50~2000Hz,占空比为50%~90%,电解初始脉冲平均电流密度为10~500A/m2,优选的脉冲频率为100~500Hz,优选的占空比为70~80%,优选的平均电流密度为50~150A/m2The electrolytic tin stripping electric field is a pulse electric field, the pulse frequency of the pulse electric field is 50-2000 Hz, the duty ratio is 50%-90%, the average current density of the electrolytic initial pulse is 10-500A/m 2 , and the preferred pulse frequency is 100 ~500 Hz, the preferred duty cycle is 70-80%, and the preferred average current density is 50-150 A/m 2 .

所述经过刻蚀后的线路板经过连续退锡电解反应装置的时间为15s~120s,优选的反应时间为45~90s。The time for the etched circuit board to pass through the continuous tin stripping electrolytic reaction device is 15s-120s, and the preferred reaction time is 45-90s.

一种PCB一步退锡同时回收锡的装置,包括退锡槽、可升降阳极槽、阳极导杆、阴极导杆、石墨阳极、传送装置、超声发生器、阴极片和脉冲电源;所述的退锡槽底部设有可放置阴极的沟槽以及溶液进/出口;阳极导杆一端与石墨阳极相连,另一端通过导线与脉冲电源正极相连,阴极导杆一端与阴极片相连,另一端通过导线与脉冲电源负极相连。A device for removing tin from PCB in one step and recovering tin at the same time, comprising a tin removal tank, a liftable anode tank, an anode guide rod, a cathode guide rod, a graphite anode, a transmission device, an ultrasonic generator, a cathode sheet and a pulse power supply; The bottom of the tin bath is provided with a groove for placing the cathode and solution inlet/outlet; one end of the anode guide rod is connected to the graphite anode, the other end is connected to the positive electrode of the pulse power supply through a wire, one end of the cathode guide rod is connected to the cathode sheet, and the other end is connected to the graphite anode through a wire. The negative pole of the pulse power supply is connected.

所述的装置,阴极导杆和阳极导杆的材质为不锈钢。In the device, the material of the cathode guide rod and the anode guide rod is stainless steel.

所述的装置,阴极片的材质为不锈钢、钛板或精铜。In the said device, the cathode piece is made of stainless steel, titanium plate or refined copper.

原理与优势Principles and advantages

本发明的方法和设备,通过引入脉冲电场取代原有退锡体系中氧化剂的加入,在所述阳极与PCB镀层接触时,形成电路闭合,镀层表面发生氧化反应使锡以锡离子的形式进入溶液(如式1),阴极表面发生还原反应使锡离子以金属锡的形式在阴极析出(如式2),而更意外的是,在加入超声耦合外场后,超声带来的能量进一步加快了锡镀层溶解的同时,减少了溶液中的浓差极化,使溶液中锡离子的分布更加均匀,尤其显著减少了阴极片附近各个离子的浓差极化,使锡能够以更加平整的形式沉积在阴极片上。另外,本发明采用的脉冲电流进行PCB锡镀层溶解,溶液中本身不存在氧化性物质,当控制在特定的电流及电压条件下,可以使锡溶解的同时避免PCB上铜的溶解,能选择性溶解锡,实现了PCB上锡的高效选择性分离。The method and equipment of the present invention replace the addition of the oxidant in the original tin stripping system by introducing a pulsed electric field. When the anode contacts the PCB coating, a closed circuit is formed, and an oxidation reaction occurs on the coating surface so that tin enters the solution in the form of tin ions. (such as formula 1), the reduction reaction on the surface of the cathode causes tin ions to precipitate at the cathode in the form of metal tin (such as formula 2), and more unexpectedly, after adding the ultrasonic coupling external field, the energy brought by the ultrasonic further accelerates the tin ions When the coating is dissolved, the concentration polarization in the solution is reduced, and the distribution of tin ions in the solution is more uniform, especially the concentration polarization of each ion near the cathode sheet is significantly reduced, so that tin can be deposited in a more flat form on the on the cathode sheet. In addition, the pulse current used in the present invention dissolves the PCB tin coating, and there is no oxidizing substance in the solution itself. When controlled under specific current and voltage conditions, it can dissolve the tin while avoiding the dissolution of copper on the PCB, and can selectively Dissolve tin to achieve efficient and selective separation of tin on PCB.

Sn-2e=Sn2+ (1)Sn-2e=Sn 2+ (1)

Sn2++2e=Sn (2)Sn 2+ +2e=Sn (2)

与现行硝酸或硝酸-烷基磺酸体系相比,本发明避免使用硝酸作为溶液和氧化剂,有效避免了NOx气体污染重、污泥和残酸量大、成本高昂等环境问题的同时极大的减少了处理退锡水工艺存在的试剂消耗量大、金属回收率低以及废水量大的工艺问题,实现了一步退锡同时回收锡。本发明对促进我国PCB生产技术进步、节能降耗以及环境保护均具有重要意义。Compared with the current nitric acid or nitric acid-alkane sulfonic acid system, the present invention avoids the use of nitric acid as a solution and an oxidant, effectively avoids environmental problems such as heavy NOx gas pollution, large amount of sludge and residual acid, and high cost. The process problems of large reagent consumption, low metal recovery rate and large amount of waste water in the process of treating tin stripping water are reduced, and tin stripping and tin recovery are realized in one step. The invention has great significance for promoting the technological progress of PCB production in my country, saving energy and reducing consumption, and protecting the environment.

附图说明Description of drawings

图1为本发明的一步退锡同时回收锡装置示意图。Fig. 1 is a schematic diagram of a device for removing tin in one step and recovering tin simultaneously in the present invention.

图中1-阳极导杆,2-石墨阳极,3-可升降阳极槽,4-PCB传动装置,5-超声发生器,6-溶液进/出口,7-阴极片,8-阴极导杆,9-退锡溶液,10-脉冲电源。In the figure 1-anode guide rod, 2-graphite anode, 3-liftable anode tank, 4-PCB transmission device, 5-ultrasonic generator, 6-solution inlet/outlet, 7-cathode sheet, 8-cathode guide rod, 9-Sn stripping solution, 10-Pulse power supply.

具体实施方案specific implementation plan

以下实施例旨在进一步说明本发明,而不会形成对本发明的限定。The following examples are intended to further illustrate the present invention, but not to limit the present invention.

本发明一步退锡同时回收锡的装置,包括退锡槽、可升降阳极槽、阳极导杆、阴极导杆、石墨阳极、传送装置、超声发生器、阴极片和脉冲电源;所述的退锡槽底部设有可放置阴极的沟槽以及溶液进/出口;阳极导杆一端与石墨阳极相连,另一端通过导线与脉冲电源正极相连,阴极导杆一端与阴极片相连,另一端通过导线与脉冲电源负极相连;阴极材质为钛板。The device for removing tin in one step and reclaiming tin simultaneously in the present invention includes a tin removing tank, a liftable anode tank, an anode guide rod, a cathode guide rod, a graphite anode, a transmission device, an ultrasonic generator, a cathode sheet and a pulse power supply; The bottom of the tank is provided with a groove for placing the cathode and solution inlet/outlet; one end of the anode guide rod is connected to the graphite anode, the other end is connected to the positive electrode of the pulse power supply through a wire, one end of the cathode guide rod is connected to the cathode sheet, and the other end is connected to the pulse power supply through a wire. The negative pole of the power supply is connected; the cathode material is a titanium plate.

实施例1Example 1

某公司提供的镀锡PCB,该PCB表面每平方米镀锡30g。For a tinned PCB provided by a company, the surface of the PCB is tinned with 30g per square meter.

配置硫酸溶液于一步退锡同时回收锡装置中,混和溶液硫酸酸度为1.5mol/L,甲基磺酸钠0.5g/L,苯骈三氮唑0.2g/L,动物骨胶0.1g/L,聚乙二醇0.1g/L,在超声频率为100kHz,超声频率为100W,脉冲频率为200Hz,占空比为70%,脉冲平均电流密度为100A/m2的条件下进行反应,调整传送带速率使PCB在溶液中退锡时间为60s后,得到表面平整光滑的PCB,经光学显微镜观察,得到的退锡板表面无锡镀层,且通过基底表面平整、光滑。采用化学分析法分析该退锡后PCB,发现该退锡后PCB表面含锡量为零。经过连续退锡试验后,阴极获得电流效率为90.51%的锡单质,取出阴极板观察后发现得到的阴极表面平整、光滑。采用化学分析法分析获得阴极,发现其含锡量为99.99%。Configure sulfuric acid solution in the one-step tin removal and recovery tin device, the mixed solution sulfuric acid acidity is 1.5mol/L, sodium methanesulfonate 0.5g/L, benzotriazole 0.2g/L, animal bone glue 0.1g/L, Polyethylene glycol 0.1g/L, react under the condition that the ultrasonic frequency is 100kHz, the ultrasonic frequency is 100W, the pulse frequency is 200Hz, the duty cycle is 70%, and the pulse average current density is 100A/ m2 , and the conveyor belt speed is adjusted After the PCB is stripped in the solution for 60s, a PCB with a flat and smooth surface is obtained. Observation by an optical microscope shows that the surface of the stripped tin plate obtained has no tin coating, and the surface of the substrate is flat and smooth. The PCB after stripping tin was analyzed by chemical analysis method, and it was found that the tin content on the surface of the PCB after stripping tin was zero. After the continuous stripping test, the cathode obtained the tin element with a current efficiency of 90.51%. After taking out the cathode plate for observation, it was found that the surface of the cathode obtained was flat and smooth. The obtained cathode was analyzed by chemical analysis and found to contain 99.99% tin.

实施例2Example 2

某公司提供的镀锡PCB,该PCB表面每平方米镀锡32g。For a tinned PCB provided by a company, the surface of the PCB is tinned with 32g per square meter.

配置硫酸溶液于一步退锡同时回收锡装置中,混和溶液甲基磺酸酸度为2mol/L,酒石酸0.5g/L,甲基苯并三氮唑0.2g/L,甲酚磺酸10g/L,环氧乙烷0.1g/L,在超声频率为200kHz,超声频率为200W,脉冲频率为500Hz,占空比为75%,脉冲平均电流密度为50A/m2的条件下进行反应,调整传送带速率使PCB在溶液中退锡时间为40s后,得到表面平整光滑的PCB,经光学显微镜观察,得到的退锡板表面无锡镀层,且通过基底表面平整、光滑。采用化学分析法分析该退锡后PCB,发现该退锡后PCB表面含锡量为零。经过连续退锡试验后,阴极获得电流效率为91.02%的锡单质,取出阴极板观察后发现得到的阴极表面平整、光滑。采用化学分析法分析获得阴极,发现其含锡量为99.98%。Configure sulfuric acid solution in a one-step tin removal and tin recovery device. The acidity of the mixed solution is 2mol/L methanesulfonic acid, 0.5g/L tartaric acid, 0.2g/L tolylbenzotriazole, and 10g/L cresolsulfonic acid. , Ethylene oxide 0.1g/L, react under the conditions of ultrasonic frequency of 200kHz, ultrasonic frequency of 200W, pulse frequency of 500Hz, duty cycle of 75%, pulse average current density of 50A/ m2 , and adjust the conveyor belt After the PCB is stripped at a rate of 40s in the solution, a PCB with a flat and smooth surface is obtained. Observation by an optical microscope shows that the surface of the stripped tin plate obtained has no tin coating, and the surface of the substrate is flat and smooth. The PCB after stripping tin was analyzed by chemical analysis method, and it was found that the tin content on the surface of the PCB after stripping tin was zero. After the continuous stripping test, the cathode obtained tin element with a current efficiency of 91.02%. After taking out the cathode plate for observation, it was found that the surface of the obtained cathode was flat and smooth. The obtained cathode was analyzed by chemical analysis and found to contain 99.98% tin.

实施例3Example 3

某公司提供的镀锡PCB,该PCB表面每平方米镀锡31g。For a tinned PCB provided by a company, the surface of the PCB is tinned with 31g per square meter.

配置硫酸溶液于一步退锡同时回收锡装置中,混和溶液盐酸酸度为5mol/L,磺基水杨酸0.1g/L,苯甲酸钠0.01g/L,β-萘酚0.05g/L,烷基酚聚氧乙烯醚0.01g/L,在超声频率为20kHz,超声频率为10W,脉冲频率为50Hz,占空比为50%,脉冲平均电流密度为50A/m2的条件下进行反应,调整传送带速率使PCB在溶液中退锡时间为120s后,得到表面平整光滑的PCB,经光学显微镜观察,得到的退锡板表面无锡镀层,且通过基底表面平整、光滑。采用化学分析法分析该退锡后PCB,发现该退锡后PCB表面含锡量为零。经过连续退锡试验后,阴极获得电流效率为84.45%的锡单质,取出阴极板观察后发现得到的阴极表面平整、光滑。采用化学分析法分析获得阴极,发现其含锡量为99.95%。Configure sulfuric acid solution in the one-step tin removal and tin recovery device, the acidity of the mixed solution hydrochloric acid is 5mol/L, sulfosalicylic acid 0.1g/L, sodium benzoate 0.01g/L, β-naphthol 0.05g/L, alkyl Phenol polyoxyethylene ether 0.01g/L, react under the condition that the ultrasonic frequency is 20kHz, the ultrasonic frequency is 10W, the pulse frequency is 50Hz, the duty ratio is 50%, and the pulse average current density is 50A/ m2 , and the conveyor belt is adjusted After the PCB is stripped at a rate of 120s in the solution, a PCB with a flat and smooth surface is obtained. Observation by an optical microscope shows that the surface of the stripped tin plate obtained has no tin coating, and the surface of the substrate is flat and smooth. The PCB after stripping tin was analyzed by chemical analysis method, and it was found that the tin content on the surface of the PCB after stripping tin was zero. After the continuous stripping test, the cathode obtained a tin element with a current efficiency of 84.45%. After taking out the cathode plate for observation, it was found that the surface of the cathode obtained was flat and smooth. The obtained cathode was analyzed by chemical analysis and found to contain 99.95% tin.

对比实施例1(配置的非本发明参数条件下退锡水)Comparative Example 1 (solder stripping water under configured non-invention parameter conditions)

配置如实施例1中所述溶液,不同之处在于不加入退锡促进剂、退锡缓蚀剂、电解稳定剂以及溶液分散剂,在如实施例1中所述超声频率、超声功率、脉冲频率、占空比以及脉冲平均电流密度下进行反应,退锡时间为120s,发现PCB上镀锡层难以彻底退除,分析后发现残留19.14%的锡在PCB上。阴极无特定形貌的物质生成。Configure the solution as described in Example 1, the difference is that no tin stripping accelerator, tin stripping corrosion inhibitor, electrolytic stabilizer and solution dispersant are added, ultrasonic frequency, ultrasonic power, pulse as described in Example 1 The reaction was carried out under frequency, duty cycle and pulse average current density, and the tin removal time was 120s. It was found that the tin layer on the PCB was difficult to remove completely. After analysis, it was found that 19.14% of the tin remained on the PCB. The cathode has no specific morphology generated.

对比实施例2(不施加超声外场耦合强化)Comparative Example 2 (without applying ultrasonic external field coupling enhancement)

配置如实施例2中所述溶液,不同之处在于不施加超声外场耦合强化,在如实施例2中所述脉冲频率、占空比以及脉冲平均电流密度下进行反应,退锡时间为120s,发现PCB上镀锡层难以彻底退除,分析后发现残留8%的锡在PCB上。阴极表面锡长出大量“晶须”,阴极气体析出严重,电流效率仅为42.18%。对比实施例3(不采用脉冲电场)Configure the solution as described in Example 2, the difference is that no ultrasonic external field coupling strengthening is applied, and the reaction is carried out under the pulse frequency, duty cycle and pulse average current density as described in Example 2, and the tin stripping time is 120s. It was found that the tin layer on the PCB was difficult to completely remove, and after analysis, it was found that 8% of the tin remained on the PCB. A large number of "whiskers" grow on the tin on the surface of the cathode, the cathode gas is precipitated seriously, and the current efficiency is only 42.18%. Comparative example 3 (do not adopt pulsed electric field)

配置如实施例2中所述溶液,不同之处在于不施加超声外场耦合强化,在如实施例2中所述超声频率和超声功率下进行反应,退锡时间为120s,发现PCB上镀锡层难以彻底退除,分析后发现残留64%的锡在PCB上。阴极无产物生成。Configure the solution as described in Example 2, the difference is that no ultrasonic external field coupling strengthening is applied, and the reaction is carried out at the ultrasonic frequency and ultrasonic power as described in Example 2. The tin stripping time is 120s, and the tinned layer on the PCB is found. It is difficult to remove completely, and after analysis, it is found that 64% of tin remains on the PCB. No product was formed at the cathode.

Claims (7)

1. A method and a device for withdrawing tin and recovering tin of a PCB in one step are characterized in that: in the continuous tin stripping electrolytic reaction device for the etched circuit board through the acid system solution, electrolytic tin stripping and tin recovery are carried out under the simultaneous actions of an external field coupling strengthening condition and an electric field; along with the progress of the reaction, the tin plating layer on the circuit board is dissolved into the solution, and tin ions in the solution are deposited and separated out at the cathode.
2. The method according to claim 1, characterized in that: the acidic system solution is a solution composed of single acid or mixed acid selected from sulfuric acid, methanesulfonic acid and hydrochloric acid, a tin stripping accelerator, a tin stripping corrosion inhibitor, an electrolytic stabilizer and a solution dispersing agent.
3. Acidic system solution according to claims 1 and 2, characterized in that: the tin stripping accelerant is one of tetraethylammonium bromide, sodium methylsulfonate, tartaric acid, sodium citrate and sulfosalicylic acid; the tin stripping corrosion inhibitor is one of benzotriazole, methylbenzotriazole, sebacic acid or sodium benzoate; the electrolytic stabilizer is one of animal bone glue, cresol sulfonic acid, phenol sulfonic acid and beta-naphthol;
the solution dispersing agent is one of ethylene oxide, polyethylene glycol and alkylphenol polyoxyethylene.
4. An acidic system solution according to claims 1-3, characterized in that: the acidity of the acid system is 1 mol/L-5 mol/L; the concentration of the tin stripping accelerator is 0.1-5 g/L; the concentration of the tin stripping corrosion inhibitor is 0.01-2 g/L; the concentration of the electrolytic stabilizer is 0.05-20 g/L; the concentration of the solution dispersing agent is 0.01-5 g/L.
5. The method according to claim 1, characterized in that: the external field coupling strengthening condition is ultrasonic coupling strengthening, the ultrasonic frequency is 20-500 kHz, and the ultrasonic power is 10-200W.
6. The method according to claim 1, characterized in that: the electrolytic tin stripping electric field is a pulse electric field, the pulse frequency of the pulse electric field is 50-2000 Hz, the duty ratio is 50-90%, and the average current density of the initial electrolytic pulse is 10-500A/m 2
7. The method according to claim 1, characterized in that: the time for the etched circuit board to pass through the continuous tin stripping electrolytic reaction device is 15-120 s.
CN202310474416.6A 2023-04-28 2023-04-28 A method and device for removing tin from PCB in one step and recovering tin at the same time Pending CN116446029A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN118531447A (en) * 2024-05-28 2024-08-23 中南大学 Dense and smooth metal tin based on methylsulfonic acid system and preparation method thereof

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN118531447A (en) * 2024-05-28 2024-08-23 中南大学 Dense and smooth metal tin based on methylsulfonic acid system and preparation method thereof

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