新型304不锈钢软钎焊用钎剂的研制

研究制备了以有机金属盐甲基磺酸亚锡为主要活性成分的新型304不锈钢软钎焊用H36钎剂,并配合Sn-Cu-Ni钎料比较了其与传统H3PO4-C2H5OH钎剂、ZnCl2-HCl钎剂和ZnCl2-NH4Cl钎剂在304不锈钢基板上的润湿铺展性能.结果表明,新研制的H36钎剂的铺展性能明显优于其它钎剂,其最大铺展面积达到109.56 mm2,相比H3PO4-C2H5OH钎剂和ZnCl2-NH4Cl钎剂分别提高了249.4％和239.3％；添加乳化剂6500能进一步提高钎剂的润湿铺展性能,最大铺展面积可达到157.49 mm2.对优化后的H36-2钎剂匹配Sn-Cu-Ni钎料钎焊304不锈钢钎焊接头力学性能的结果表明,钎焊接头的抗拉和抗剪强度分别达到22.72 MPa和33.93 MPa,优于现有文献报道的数据.     

铝及其合金软钎焊技术的研究现状

本文综述了铝及铝合金软钎焊近年来的研究动态。指出了钎剂在铝质材料软钎焊中的重要作用,分析了无铅钎料成分的优缺点,并讨论一些新出现的钎料配方和钎焊工艺以及目前的发展趋势。还阐述了一些较新型的钎焊加热工艺,并指出其优点和应用前景。     

铝用氟化物钎剂的配制方法及对钎焊性能的影响

就铝用氟化物钎剂的不同配制方法进行了对比,测定了各种方法配制的钎剂组成,分析了配制机理,并对制取的钎剂进行了钎焊性能的测定.测定结果表明,四种钎剂的钎焊性能无多大差别.认为水调法、水煮法制取针剂方法简单,更适于生产.     

铝铜钎焊用Zn-Al钎料的研究

研究了Al含量对铝铜异种金属钎焊用Zn-Al钎料的铺展性能和铝铜焊接接头强度的影响。结果表明。Al含量在15wt％以上时,钎料在铜上铺展性较好,含Al10wt％左右的钎料所焊铝铜接头的强度最好。采用含Al10wt％的Zn-Al钎料。配合CsF-AlF3无腐蚀中温钎剂,采用高频感应加热钎焊连接铜铝管,能获得高压下不漏气的理想接头。     

钎剂中Cu元素对铝/钛异种金属熔-钎焊接头影响

将Cu元素合金化Nocolok钎剂成功应用于铝/钛异种金属TIG熔-钎焊。与采用纯Nocolok钎剂相比,采用Cu元素合金化钎剂可显著提高钎料润湿性、有效控制界面化合物厚度并提高接头性能,断裂模式由钛侧钎焊界面的韧脆混合型改变为铝侧熔合区的韧性断裂。Cu元素对润湿性的改善与固、液相线的温度降低及钎剂中的金属氧化物有关。界面化合物厚度的减小及接头性能的提高可归因于钎剂中Cu元素的化学阻挡及界面合金化的共同作用。     

Sn2.5Ag0.7CuxRE钎料对表面贴装元件的最佳润湿工艺参数试验研究

采用润湿平衡法研究了新型无铅钎料Sn2.5Ag0.7CuxRE对表面贴装元件的润湿性能。通过正交试验分析表明,钎焊温度对润湿力起显著作用,当采用水基免清洗助焊剂时,Sn2.5Ag0.7CuxRE无铅钎料合金钎焊的最佳工艺参数分别为:预热时间15 s、钎焊温度250℃和钎焊时间3 s。与两种商业应用的无铅钎料的润湿性能的比较表明,在该工艺条件下,Sn2.5Ag0.7CuxRE无铅钎料合金的润湿性能可略优于商用钎料,表明该钎料在选择合适的钎焊参数和钎剂后,可以满足表面组装行业对无铅钎料润湿性能的要求。     

铜-铝异种金属钎焊材料的研究现状

从钎剂和钎料两方面对国内外有关铜-铝异种接头钎焊材料的研究成果进行了综述,重点介绍了铜-铝异种接头钎焊连接过程中无腐蚀性钎剂和钎料成分对钎焊接头结合机理、界面反应、金属间化合物的微观结构及生长规律等的影响。然而,铜-铝异种接头钎焊材料的应用过程中仍存在以下问题:无腐蚀性钎剂熔化温度和价格均较高,适用范围较窄;铝硅系钎料熔化温度较高,铝合金容易过烧熔蚀;钎料洁净度低,钎缝处容易出现氧化夹杂,影响钎焊接头的力学性能。     

无铅钎焊的困惑、出路和前景

从熔融钎料与母材的相关系和相反应(phase relation and phase reaction)出发,讨论了无铅钎料在铜上铺展率和钎焊性低下的原因,认为是其间过度和过于快速的金属间化合物生长所致.分析了提高无铅钎料本身在铜上铺展率的困难,提出解决无铅钎焊的途径主要是开发有效的钎剂和进行基板母材表面的改性.     

自钎剂铝钎料的研制与应用前景

简述了铝及其合金的钎焊工艺方法，分析了各种铝钎焊方法存在的问题，提出了用自钎剂铝钎料钎焊铝及其合金的新方法，介绍了自钎剂铝钎料的几种制造方法。简要讨论了自钎剂铝钎料的钎焊工艺特点：铺展性、填缝性、润湿性。实践证明用自钎剂铝钎料钎焊的接头抗腐蚀性和力学性能均优于钎料－钎剂法。根据工程试用情况预见了自钎剂铝钎料的发展方向和应用前景。     

铜铝异种金属钎焊问题及其对策

铜铝异种金属在钎焊过程中会出现缺陷,如焊缝中生成金属间化合物,母材出现溶蚀以及焊缝的腐蚀等,这与钎焊工艺参数的选择密切相关.钎焊温度过高和保温时间过长都会引起焊缝中生成脆性相(CuAl2),并造成母材溶蚀;钎料和钎剂选择不当则会导致焊缝严重腐蚀,因此,在铜铝异种金属的钎焊过程中,选择合适的钎焊工艺参数对于获得良好的焊缝质量具有重要的作用.概括了铜铝异种金属钎焊过程中可能会出现的缺陷,详细介绍了其形成机理,针对这些缺陷提出了应对措施,并就铜铝异种金属钎焊今后的发展作出了展望.     

BGA封装IC的返修及在无铅钎焊中的可靠性分析

无铅钎焊比有铅钎焊难度大大增加,无铅BGA元件的返修更是难上加难。文中根据返修经验分析了无铅BGA元件可靠返修中的几个问题,提出了对无铅BGA返修钎焊工艺流程中问题的几点改善措施。     

铝的无铅软钎焊试验研究

研究了Sn-0.7cu,Sn-Ag-Cu,Sn-3.5Ag等软钎料合金对1060 Al的润湿性,结果表明钎料中Ag含量在1.5%～2.5%(质量分数)之间润湿性最好.SEM观察发现,钎料合金/Al界面处Ag2 Al金属问化合物并不是从基体AJ向外生长,而是与Al之间隔了一层富Sn相.最后结合Ag-Al扩散模型与键参数函数理论对Ag-Al化合物相的生长过程及润湿性的影响作出了解释.     

Lift-off phenomenon in wave soldering

The mechanism of lift-off, which is the serious defect formation that the solder fillet is peeled off from a Cu land pad on a printed wiring board in wave soldering, has been examined primarily by using basic Sn–Bi alloys (Sn at 2–5 wt%) and solidification simulation. The probability of lift-off increases with increasing Bi content. Lift-off results from the segregation of Bi, which diffuses in a short distance, in the interfacial region between a Sn–Bi alloy and a Cu land pad during dendritic structure formation. A higher fillet results in a more severe lift-off—the top side of a printed wiring board, where the fillet is low, seldom shows lift-off. The solidification simulation indicates that the solidification of the solder fillet rapidly propagates from a lead wire to a fillet edge. A Cu land acts as a heat sink, with heat flowing from the inner through-hole to the land pad. Both rapid cooling and annealing at high temperature can effectively prevent lift-off.     

钎焊材料行业发展与标准化需求

概述了中国钎焊材料行业发展现状,综述了ISO,EN,GB,AWS等标准化组织及其钎焊材料标准化研究现状,并对钎焊材料标准中的关键指标进行了分析。针对自动化、智能化钎焊制造需求,提出了未来国内钎焊材料标准化发展方向。     

Selection of soldering temperature for ultrasonic-assisted soldering of 5056 aluminum alloy using Zn-Al system solders

The conditions for sound butt-joints of 5056 aluminum alloy containing 4.6 mass% Mg using Zn-xAl (x = 5, 13, and 38 mass%) solder at the relevant temperatures were investigated. Each solder foil was inserted between faying surfaces of 5056 aluminum rods. Ultrasonic vibration at a frequency of 19 kHz was applied to the faying surfaces through an aluminum substrate at soldering temperatures for 4 s in air. The strength of obtained solder joints was measured by tensile tests. The microstructure in the solder layer after the soldering process was evaluated with an SEM-EDX. The results of tensile tests revealed that joints soldered under the liquidus temperature of Zn-Al solders showed higher strength than joints soldered over the liquidus temperature. In the joints soldered over the solder liquidus temperature, the joint strength decreased with an increase in soldering temperature. It was caused by the formation of MgZn₂ in the solder layer due to dissolution of 5056-Al into the solder liquid during the soldering process. On the other hand, ultrasonic-assisted soldering under the solder liquidus temperature suppressed dissolution of 5056-Al and improved the joint strength by reducing the formation of MgZn₂.     

A new reduced-oxide soldering activation method

This article describes a new reduced-oxide soldering activation (ROSA?) process that removes oxides from tin, tin-lead, and copper surfaces without the use of a flux. In this process, surface oxides are electrolessly reduced back to the metallic state by a highly reducing vanadous ion solution that is non-corrosive to most metals and is regenerated electrochemically. The electroless reduction and redox regeneration cycles form a closed loop such that oxygen gas is the only effluent. Wetting time and surface analysis data show that a ten-second exposure to the vanadous ROSA solution completely reduces all tin-lead oxides that would normally be encountered on production components. The ROSA treatment has a wide operating window, provides soldering performance comparable to that attainable with a fully-activated rosin flux, and offers the promise of providing low soldering defect rates without the use of CFC solvents.     

波峰焊工艺参数优化

波峰焊主要用于传统通孔插装印制电路板电装工艺以及表面组装与通孔插装元器件的混装工艺。与手工焊接相比较,波峰焊具有生产效率高、焊接质量好、可靠性高等优点。波峰焊接工艺是一个复杂而系统的工程,在实际生产过程中必须严格控制焊剂涂覆量、印制板预热温度、焊接温度和时间、印制板爬坡角度和波峰高度;综合调整其工艺参数,才能获得较好的焊接质量。     

Aluminium and aluminium alloy hard soldering technology

Aluminium joints find wide application in the welded structures of air conditioning systems, aeronautics, electrical engineering, radio engineering, and many other areas of industry. In spite of their unquestionable qualities, aluminium and aluminium alloy soldering brings about considerable setbacks, especially in the case of highly alloyed aluminium compounds. The problems result from the physical and chemical properties of such materials. For instance, highly alloyed aluminium requires specific solders of sufficiently low melting point, as well as special sources of heat in order to ensure even soldering. An additional problem results from the considerable aluminium-to-oxygen chemical affinity that produces the resultant Al₂O₃ layer on the surface as an integral and barely fusible coat. This article presents the problems related to aluminium and aluminium alloy joining as well as basic methods of aluminium soldering.