浅议印制电路板蚀刻废液实用再生技术

目前印制电路板蚀刻废液的再生及循环利用,已受到工业界的广泛关注。简要介绍、分析了两种蚀刻废液实用的再生技术。酸性蚀刻废液膜电解技术可同时实现酸性蚀刻废液再生和铜回收,节约大量的氧化剂和盐酸;碱性蚀刻废液萃取-电积技术再生的同时,也可以回收铜。蚀刻废液再生可实现资源最高效的循环利用,预计具有较广阔的应用前景。     

碱性蚀刻废液再生方法评述

碱性蚀刻废液是一种铜含量高、废液浓度高的工业废水,将其再生具有较高的经济价值和环境效益。文章综述了碱性蚀刻废液的污染危害,全面介绍了碱性蚀刻废液的再生方法,指出了碱性蚀刻液再生的发展方向。     

印制板蚀刻、微蚀刻废液的再生和铜回收的技术及设备

传统的印制板蚀刻废液处理方法存在着工艺落后、操作不便、二次污染、效益不高等问题,本工艺采用特殊的萃取电解、吸附电解技术,使蚀刻废液得以再生循环利用,铜得以100%回收,低含铜废水铜得到98%回收,整个系统不产生二次污染,获得的铜为高纯度铜板,在实现污染控制的同时,废液废水得到了资源化利用。     

酸性蚀刻废液处理及铜回收系统

我公司经过多年的研究实验,在成功研制出了“氨性蚀袤4液在线循环再生系统”的基础上,又成功研制出了“酸性蚀刻废液处理及铜回收系统”,彻底解决了印制电路板行业的一大难题,废液进入系统后首先用调节剂对酸性蚀刻废液进行组份调节预处理,把酸性蚀刻废液转化成适合萃取的体系,然后采用成熟的多级萃取膜处理技术,选用合适的萃取剂进行萃取-反萃取-电沉积工艺实现铜的回收,产出高附加值标准阴极铜,铜含量99．95％以上,萃余液经膜处理后由使用厂方根据自身条件选择三种处理方法。     

酸性蚀刻废液中铜的回收及废液再生新技术

为了生态环境和人们身体健康,研究和开发酸性蚀刻液再生利用方法及设备,实现清洁生产,已成为印制线路板行业污染防治工作的重点。文章介绍了一种酸性蚀刻液再生利用的新方法：采用膜电解技术,硫酸作为阳极液,蚀刻废液作为阴极液,将蚀刻废液中的铜离子沉积在阴极板上形成致密的铜板,铜离子浓度降低至1g／L,氢离子浓度上升至3．6m01／L,提铜后的蚀刻废液可当盐酸回用于酸性蚀刻液的配制中。实验结果表明：阴极液铜离子浓度为（15～5）g／L,电流密度为4．16A／dm^2为该电解工艺的最佳参数,能得到纯度高于99％的铜板,并达到80％以上的电流效率,而酸度对该电解工艺影响不大。     

印制电路板废液的综合利用研究

印制电路板蚀刻废液含有大量的铜离子,主要包括酸性蚀刻废液（FeCl3型废液和H2O2型废液）和碱性蚀刻废液,可采用置换法、电解法、化学沉淀法、萃取法、离子交换法、吸附法等使废液中的铜离子呈金属或化合物沉淀析出,各种方法均有自己的优、缺点,其中较为常用的是化学沉淀法。酸性废液和碱性废液混合后进行中和处理是一种较新型的工艺路线,该法具有工艺简单、成本低、污染少、可循环利用等特点,可用来生产硫酸铜、碳酸铜等产品,值得大力推广。     

酸性蚀刻液铜回收及废液再生新技术

废蚀刻液中富含金属铜离子,长期以来都采用传统的化学法处理废液来回收铜,其残液的排放会造成严重的二次污染,给周边环境带来极大的影响和压力,同时处理废液浪费大量的碱液,把可回收的酸也浪费,不能做到资源节约、环保、循环经济、清洁生产等。作者通过三年多的研究,开发出利用离子膜结合电解技术来回收废蚀刻液中的铜,同时再生蚀刻液使其继续返回蚀刻生产线使用。其最大的技术特点在于把盐酸中的铜离子,通过膜技术分离到硫酸溶液中,变成传统的硫酸铜溶液电解。这种技术和思路极大地简化了回收和再生工艺,降低了回收能耗,解决了用萃取工艺回收而引起的的许多问题,是一种先进的回收再生技术。此工艺产业化的推广是印制电路板企业废液处理的一次环保革命,前景广阔。     

PCB铜蚀刻废液“零”排放要大力推广应用开来

文章概述了PCB铜蚀刻废液"零"排放的技术已经成熟和推广应用的重要意义。推广应用的阻力主要来自地方政府保护主义。     

电路板绿色制造技术探讨(5)

(接2010年第9期)5.3.5蚀刻液循环再生技术蚀刻液因其铜含量高,较早为业界回收利用,目前已有比较成熟的PCB行业蚀刻废液回收回用装置,该装置安装在线路板厂内,直接与蚀刻机相连,对蚀     

PCB制造新技术使PCB制造成本便宜50％

据《印制电路技术与标准通讯》报道，瑞典Cuptronic公司研制成功的一种新的PCB制造技术，该新技术是使铜牢固的生长到基板上而制成电路板，不再需要应用蚀刻工艺，没有蚀刻废液的产生所以更加环保。另外它减少铜了的使用量，能使用更廉价的基材，简化生产，降低生产成本50％，增加产量。     

HgCdTe外延材料的缺陷腐蚀特性

通过对Schaake和Chen腐蚀剂在HgCdTe外延材料(111)B面腐蚀坑特性的研究,揭示了HgCdTe液相外延材料中的缺陷特征及其密度分布规律.深度腐蚀实验显示外延材料中确实存在着通常认为的具有定向穿越特性的穿越位错.将两种腐蚀剂作用于同一样品后发现,Schaake和Chen腐蚀剂形成的具有穿越特性的腐蚀坑有一一对应的关系.除了穿越位错外,在两种腐蚀方法揭示出的腐蚀坑中都还存在着一种不具备穿越特性的腐蚀坑,两者在密度分布以及界面处密度增值方面具有相同的特性,但前者在宏观缺陷附近密度出现明显的增值,而后者则没有出现类似的现象.     

Comparative Study of HgCdTe Etchants: An Electrical Characterization

A comparative study of wet etchants for both molecular beam epitaxy (MBE) and liquid phase epitaxy (LPE) grown n- and p-type samples was performed using capacitance–voltage (C–V) characteristics and surface recombination velocity (SRV) extracted from photoconductive decay (PCD) measurements. Different wet etchants were divided in two categories, (i) where bromine is a direct reagent in the etching solution and (ii) where bromine is a byproduct after reaction among different reagents. Negative shift of the flat-band voltages were observed for both n- and p-type samples treated with second category of etchants. A decrease in minority carrier lifetimes and an increase in the surface recombination velocities were also observed for the n-type samples treated with second category of etchants.     

Mextral系列金属萃取剂的性能和应用

文章介绍TMextral系列金属萃取剂的萃取机制、性能和在铜湿法治金工艺、线路板氨浸液回收铜、重金属回收等方面的应用。     

Realization of a resonant tunneling permeable base transistor withoptimized overgrown GaAs interfaces

A resonant tunneling permeable base transistor has been realized experimentally by overgrowing a tungsten grating placed in direct vicinity to a double barrier heterostructure. In this way, we can directly modulate the tunneling current via an embedded gate. Since the quality of the overgrown interface is critical, special attention is paid to this issue, and the effect of different wet etchants prior to overgrowth is studied both by electrical measurements and by the use of an atomic force microscope. A clear dependence of the electrical properties and the crystal quality on the etchants used is found. This is a key result for the realization of our resonant tunneling device     

酸性氯化铜液蚀刻化学及蚀刻液再生方法评述

为了清洁生产、生态环境和人们健康，研究和开发酸性氯化铜蚀刻液的再生方法及再生设备，已成为当前印制板制造行业污染防治工作的重点。为此，文章首次论述了印制板酸性氯化铜液蚀刻化学及蚀刻液的再生方法，讨论了各种方法的优缺点，进而指出了酸性蚀刻液再生的发展趋势。     

Effect of Atmosphere on n -Type Hg1– x Cd x Te Surface after Different Wet Etching Treatments: An Electrical and Structural Study

The impact on surface recombination velocity (SRV) and minority carrier lifetime of three wet etchants are examined here. The etchants are 60DI +  10HBr + 1H₂O₂ (by volume), 1% bromine–methanol, and 2% bromine–lactic acid. After initial etching, the HgCdTe surfaces were exposed in specific time steps to the atmosphere. At each step in the process, the effect of each etchant and of exposure to atmosphere was determined by photoconductive decay (PCD) measurements as well as by x-ray photoelectron spectroscopy (XPS). The PCD results showed that the 60DI + 10HBr + 1H₂O₂ etchant, after exposure to atmosphere, led to a relatively small change in SRV compared to the changes that occurred for the two bromine-based etchants. In addition, XPS measurements showed that there were no neutral tellurium inclusions in the case of 60DI + 10HBr + 1H₂O₂ and that TeO₂ formed strictly out of tellurium bonded to HgCdTe. Moreover, TeO₂ formed at a much slower rate on surfaces etched with HBr compared with those etched with the bromine-based etchants. A model is proposed in terms of band alignment at HgCdTe-Te⁰ and HgCdTe-TeO₂ interfaces to explain the different surface recombination mechanisms that are due to different etchants and to atmospheric exposure.     

Impact of Surface Treatment on the Structural and Electronic Properties of Polished CdZnTe Surfaces for Radiation Detectors

We present the effects of surface treatments on the structural and electronic properties of chemomechanically polished Cd_0.9Zn_0.1Te before contact deposition. Specifically, polished CdZnTe (CZT) samples were treated with four distinct chemical etchants: (1) bromine methanol (BM), (2) bromine in lactic acid, (3) bromine in methanol followed by bromine–20% lactic acid in ethylene glycol, and (4) hydrochloric acid (HCl). The surface structure and surface electronic properties were studied with atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). AFM images showed that three of the four etchants significantly altered the surface morphology and structure of CZT. All etchants created smoother surfaces; however, all except HCl also introduced high densities of defects. HCl was found to not affect the surface structure. XPS measurements indicated that a thick, ～3 nm to 4 nm, TeO₂ layer formed about 1 h after etching; hence, it is very important to process devices immediately after etching to prevent oxide formation.     

碲锌镉晶体常用腐蚀剂的坑形特性研究

大面积、高质量碲锌镉单晶是制备碲镉汞红外焦平面器件的理想衬底材料,而腐蚀法是常用的揭示碲锌镉晶体缺陷和评价晶体质量的方法之一。对碲锌镉晶体常用的Nakagawa、Everson、EAg1和EAg2四种腐蚀剂在碲锌镉材料（111）晶面上的腐蚀坑坑形进行了研究,结果发现,EAg2腐蚀剂在（111）B面上的腐蚀坑为平底坑,Everson腐蚀剂在 (111)B面上产生的腐蚀坑包括平底坑和带有不同倾斜方向坑底的三角锥形坑,进一步的研究还表明,三角锥形坑并未沿着坑底的倾斜方向向下延伸。实验中也首次观察到了EAg腐蚀剂的黑白平底坑。对常用腐蚀剂的坑形特性研究,将有助于更好地利用腐蚀剂开展碲锌镉材料缺陷研究和晶体质量评价工作。