电真空器件用金银锗钎料研制

研究了Au-Ag-Ge系列合金的熔化特性、加工性能以及钎焊性能。结果表明,在Au-12Ge合金中加入Ag元素,可以提高合金的熔化温度,但是仍不能满足使用要求。Au-52Ag-6Ge合金熔化温度为566～586℃,采用冷轧制+真空退火工艺可将合金加工制备为0. 10 mm厚的带材,清洁性、溅散性和铺展性能良好,可以与AgCu28共晶钎料、Ag Cu In钎料、AgCuInSn钎料形成四级梯度钎料,满足真空电子器件封接需求。     

钎料钎剂复合型绿色钎料研究进展

钎焊是制造业的关键基础技术之一,复合钎料是践行钎焊绿色化、自动化的重要手段,与传统钎料相比,复合钎料可实现钎剂定位—定温—定时—定量精准反应.综述了国内外钎料钎剂复合型钎料的分类和特点,分析了药芯钎料、药皮钎料、粉末合成钎料等的制备技术、成分设计和典型应用,指出了目前研究的不足,并对复合钎料未来的发展方向提出了建议:借...     

碳纳米管增强TiNi复合钎料的制备与表征

针对CNTs增强TiNi复合钎料制备中存在CNTs的均匀分散性差、结构完整性差、碳基团与基体易反应而导致基体材料污染等问题,采用PECVD方法低温原位在Ni-TiH₂基体上制备CNTs/TiNi复合钎料,采用XRD,SEM,Raman,TEM等对制备的复合钎料进行表征与分析.结果表明,该方法不仅保证了复合钎料中CNTs的结构完美和均匀分散性,而且保证了TiH₂不会因温度过高分解,避免了复合钎料体系中钛与碳之间反应,真正意义上实现了CNTs对TiNi复合钎料的强化.通过复合钎料中CNTs的增强效果,缓解钎焊接头的残余应力,提高钎焊接头的力学、热学及高温性能,可实现陶瓷、复合材料与金属复合构件的可靠连接及高温使用.     

低熔点铝基复合钎料的制备及其性能研究

试验采用电镀的方法在Al-Si共晶薄带上分别镀覆Cu层和Ni层,Cu作为降低钎料熔点的主要元素,Ni做为改善钎料性能的主要元素.通过这种新型方法制备的钎料固相线温度、液相线温度分别为504℃和534.7 ℃,大大降低了Al-Si钎料熔点,且钎料具有较窄的结晶区间,有利于避免母材过烧,提高钎焊质量,同时还具有很好的润湿性以及较高的抗拉强度.     

采用复合钎料的铝合金中温真空钎焊技术

为解决铝合金中温钎焊时难以制备出实用的钎料问题,设计制备了厚度0.1～0.2 mm的Al-Si-Cu复合钎料箔带,钎料呈三明治状叠层结构,具有与普通Al-Si钎料同样的塑性,液相线温度541℃.该复合钎料可方便地用于铝合金实际结构的中温真空钎焊.工艺及性能试验结果表明,钎料具有良好的钎焊工艺性,钎焊2A50接头平均剪切强度172 MPa,并成功用于2A50叶轮结构的真空钎焊.     

烧结压力对自钎剂钎料性能的影响

采用热压烧结法制备了Al-12Si自钎剂钎料环,对不同烧结压力下钎料的润湿性、显微硬度和显微组织进行了研究. 结果表明,自钎剂钎料润湿性环随着烧结压力升高呈现上升趋势,在烧结压力为222 MPa时铺展面积达到152 mm2;随着烧结压力的增大,自钎剂钎料密度、显微硬度逐渐增大,但上升趋势变缓;钎料显微组织主要是灰色基体上均匀分布着黑色大块状相和白色小颗粒;XRD结果显示自钎剂钎料只有α-Al固溶体,初晶硅和Nocolok钎剂三种物相,热压烧结法制备自钎剂钎料未发生氧化、水解等反应,加上硅的活化作用保证了钎料高活性.     

高温钎料焊膏研究进展

针对高温钎料使用便利性的需求,综述了高温钎料焊膏的相关研究现状。介绍了焊膏各组分在焊膏制备和钎焊中的作用,阐述了镍基、铜基、银基、钛基和金基五种常用高温钎料及其焊膏的应用与发展趋势,为高性能高温钎料焊膏的开发提供了参考。     

锌铝药芯钎焊丝制备及润湿性研究

设计制备了不同成分的5种锌铝药芯钎焊丝,对锌铝药芯钎焊丝的制备工艺及其在紫铜和6063铝合金上的润湿性能进行了研究.结果表明,锌铝钎料成分对锌铝药芯钎焊丝的制备工艺性有明显影响,Zn80Al15Ag5、Zn92A18和Zn95A15这3种锌铝带状钎料制备的药芯钎焊丝质量较好;5种锌铝药芯钎焊丝在6063铝合金上均具有良好的铺展性;铝元素含量对锌铝药芯钎焊丝在紫铜上的铺展性能影响较大,在该试验范围内,随钎料中铝元素含量的增加,钎料在铜上的铺展面积迅速增大,Zn72Al28药芯钎焊丝在铜上的铺展面积最大,达到86 mm2.     

钎焊材料形态演变及其发展趋势

随着制造业高速发展,钎焊技术应用越来越广,并向绿色化、高效化、自动化和高可靠方向发展。钎焊材料形态对钎焊自动化和可靠性起着至关重要的作用。目前有关钎料的研究主要基于成分、性能、工艺性及应用领域等方面。对于钎料形态方面的系统研究还鲜有报道。在钎焊过程中,采用恰当形状的钎料,可以优化工艺和提高钎焊可靠性。本文以钎料几何形态为主线,系统总结了丝状/条状、棒状、粒状、箔带状、粉末状、膏状、药芯型、非晶态及预制成形等钎料的特点、应用范围、主要代表体系、制备方法及发展现状,重点阐述了粉末、药芯型和非晶态等钎料以及常用钎焊方法所适用的钎料形态。研究认为：未来钎焊材料形态发展方向是绿色、高效、低成本并适应新材料、自动化、数字化及智能化需求。     

Ag颗粒增强Sn-58Bi无铅钎料力学性能研究

在Sn-58Bi钎料中添加Ag颗粒,制备颗粒增强的低温无铅钎料,研究了钎料焊接头力学性能。本文研究结果表明：Sn-58Bi合金中添加少于1wt％的Ag会均匀分布在基体合金中,提高了合金钎料的拉伸强度。钎料在100℃恒温时效试验中,Bi相的粗化趋势明显低于Sn-58Bi共晶钎料,提高了合金钎料的组织稳定性。钎料的拉剪强度则随着钎料中Ag含量的增加而升高,但量超过1wt％时,拉剪强度又会下降。     

新型低温无铅焊料的研究进展

随着人们对铅毒性的认知及世界各国“限铅令”的颁布,因为铅污染问题,研究人员开始着手研究Sn-Pb焊料的代替品,迫切需要探索一种零污染、低成本的新型电子封装焊料。目前研制的新型低温无铅焊料有Sn-Cu、Sn-Ag、Sn-Bi、Sn-Zn、Sn-In二元焊料和Sn-Ag-Cu三元焊料,但由于新型低温无铅焊料存在着熔点高、抗氧化性能差等问题,有人提出通过在这些无铅焊料中加入第三或第四种合金元素改善无铅焊料的组织性能。介绍了新型低温无铅焊料的应用,制备,优缺点及对它的要求,叙述了目前新型低温无铅焊料的研究进展,并提出了新型低温无铅焊料的研究方向。     

Property alterations of Sn-0.6Cu-0.05Ni-Ge lead-free solder by Ag,Bi, In and Sb addition

The Sn-Cu-Ni-Ge solder is a strong challenger to the Sn-Ag-Cu (SAC) solders as a replacement for the Sn-Pb eutectic solder. This research investigated the effects of addition of Ag, Bi, In, and Sb on the physical properties of the Sn-0.6Cu-0.05Ni-Ge (SCNG) lead-free solder and the interfacial reaction with the Cu substrate. The melting behavior, microstructure, tensile strength, and wettability of the SCNG–x (x=Ag, Bi, In, Sb) solders were examined. The findings revealed that the introduction of Ag, Bi, In, and Sb minimally altered the solidus temperature, liquidus temperature, and tensile strength of the solder. However, the cooling behavior and solidified microstructure of the solder were affected by the concentration of the alloying elements. The wettability of the SCNG solder was improved with the doping of the alloying elements except Sb. The thickness of intermetallic layer was increased by the addition of the alloying elements and was related to the cooling behavior of the solder. The morphology of intermetallic layer between the SCNG–x solders and the Cu substrate was different from that of the typical SAC solders. In conclusion, alloying the SCNG solder with Ag, Bi, In or Sb is able to improve particular properties of the solder.     

Environmentally friendly solders 3-4 beyond Pb-based systems

Based on environmental considerations, global economic pressures, enacted by legislations in several countries, have warranted the elimination of lead from solders used in electronic applications.Sn3.5Ag, SnAgCu, and Sn0.7Cu have emerged among various lead-free candidates as the most promising solder alloys to be utilized in microelectronic industries.However, with the vast development and miniaturization of modern electronic packaging, new requirements such as superior service capabilities have been posed on lead-free solders.In order to improve the comprehensive property of the solder alloys, two possible approaches were adopted in the current research and new materials developed were patented.One approach was involved with the addition of alloying elements to make new ternary or quaternary solder alloys.Proper addition of rare earth element such as La and Ce have rendered solder alloys with improved mechanical properties, especially creep rupture lives of their joints.Another approach, the composite approach, was developed mainly to improve the service temperature capability of the solder alloys.Composite solders fabricated by mechanically incorporating various reinforcement particles to the solder paste have again exhibited enhanced properties without altering the existing processing characteristics.The recent progress and research efforts carried out on lead-free solder materials in Beijing University of Technology were reported.The effects of rare earth addition on the microstructure, processing properties, and mechanical properties were presented.The behaviors of various Sn-3.5Ag based composite solders were also explicated in terms of the roles of reinforcement particles on intermetallic growth, steady-state creep rate, the onset of tertiary creep, as well as the overall creep deformation in the solder joints.Thermomechanical fatigue (TMF) behavior of the solder alloys and composite solders were investigated with different parameters such as ramp rate, dwell time, etc.The damage accumulation features and residual mechanical properties of the thermomechanically-fatigued composite solder joints were compared with non-composite solder joints.To match the lead-free alloys, various types of water soluble no-clean soldering flux have also been developed and their properties were presented.     

电子封装用低银含量无铅钎料的研究和应用进展

电子封装用钎科从传统锡铅合金向无铅钎料的转换过程中适逢手持便携式电子器件高速增长期,加之近年来金属价格的持续上涨,因而低银含量无铅钎料合金作为第二代无铅钎料成为关注的焦点.本文阐述了无铅低银钎料的研究与发展现状,同时分析了其应用情况,最后,对谊钎科及其可靠性的发展趋势进行了分析和展望.     

电子组装用低银无铅焊料的研究进展

对目前国内外电子组装用低银无铅焊料最新的研究和应用情况进行了回顾和评述,介绍了低银无铅焊料的现状和其可靠性问题,以及国内外对几种低银无铅焊料进行的研究情况,最后着重分析和展望了低银无铅焊料研究应用的主要发展方向和趋势。     

Sn-Zn系无铅焊料合金的可靠性研究进展

环保要求和微电子器件的高度集成化驱动了高性能无铅焊料的研究和开发,近年来,Sn-Zn基无铅钎料因熔点与SnPb相近,成本低廉和机械性能优良等优点而备受关注,但是焊料的差异和焊接工艺参数的调整给焊点的可靠性带来了新的影响.本文总结了SnZn系焊料的主要失效模式,重点围绕热疲劳与机械疲劳、焊料和基体界面金属间化合物形成致裂、腐蚀等问题,阐述了SnZn系无铅焊料的可靠性,并指出提高其连接可靠性的几个途径.     

增强颗粒对Sn0.7Cu基复合钎料铺展性能的影响

以Sn0.7Cu共晶钎料作为基体钎料,通过添加微细金属颗粒(1μmAg、1μmNi和8μmCu)形成颗粒增强复合钎料。研究了增强颗粒对复合钎料铺展性能的影响,优选出Sn0.7Cu基复合钎料的最佳增强体。研究表明:Ni(3vol%)颗粒增强Sn0.7Cu复合钎料铺展性能差;Cu(3vol%)颗粒增强复合钎料铺展性能不如Ag(3vol%)颗粒增强复合钎料;对于金属颗粒增强Sn0.7Cu基复合钎料,Ag颗粒为最佳增强体。     

Ag,Al,Ga对Sn-9Zn无铅钎料润湿性能的影响

采用润湿平衡法测试了Sn-9Zn-X(X为Ag,Al,Ga)无铅钎料分别配合ZnCl2-NH4Cl钎剂和免清洗助焊剂,在空气和氮气保护的两种条件下的润湿性能,分析研究了合金元素Ag,Al,Ga的添加量对Sn-9Zn-X无铅钎料润湿性的影响规律.结果表明,合金元素Ag,Al,Ga在Sn-9Zn中的最佳添加量(质量分数)分别为0.3%,0.005%～0.02%,0.5%.采用氮气保护可以显著改善Sn-9Zn-X无铅钎料的润湿性,而Sn-9Zn-X无铅钎料配合ZnCl2-NH4Cl钎剂时具有较好的润湿性,甚至优于Sn-3.5Ag-0.5Cu在相同条件下的润湿性.这一研究结果表明,通过研发适合于Sn-Zn系无铅钎料的高性能助焊剂,从而改善Sn-Zn系钎料的润湿性能是完全可行的.     

半导体激光加热时间对焊膏在铜基板上润湿铺展性能的影响

采用半导体激光软钎焊系统对Sn63Pb37和Sn96Ag3.5Cu0.5焊膏在铜基板上的润湿铺展性能进行了试验,研究了不同激光加热时间对钎料润湿铺展性能的影响,采用扫描电镜分析了Sn63Pb37和Sn96Ag3.5Cu0.5钎缝的显微组织和钎缝界面区组织特征.结果表明,在一定的激光输出功率下,随着激光加热时间的增加,两种钎料的润湿性都得到提高.其中Sn-Pb钎料焊膏的加热时间达到1.5 s时,润湿面积和润湿角趋于稳定,而Sn-Ag-Cu钎料焊膏润湿性需要达到2.5 s时润湿面积和润湿角才趋于稳定.