SnAgCu-xPr钎料组织及性能

研究了不同含量Pr元素（质量分数分别为0,0.05%,0.5%）对Sn-3.8Ag-0.7Cu无铅钎料凝固特性、润湿铺展性能以及微观组织的影响.结果表明,SAC,SAC-0.05Pr以及SAC-0.5Pr的凝固所需过冷度分别为20.6,5.0,5.1℃,说明适量Pr元素的加入能够显著降低SnAgCu钎料凝固所需的过冷度;同时,Pr元素的加入细化了钎料组织,降低钎料组织中初晶β-Sn的尺寸,抑制了SnAgCu/Cu焊点内部不同形貌大块化合物Ag3Sn初晶的形成;当Pr元素的添加量为0.05%时,钎料润湿性能最优、组织最佳;0.5%Pr元素的添加会在钎料以及焊点内部形成PrSn3相,对焊点的性能造成不利的影响.     

Sn-0.3Ag-0.7Cu-xSb无铅钎料润湿性

研究了微量Sb元素对Sn-0.3Ag-0.7Cu无铅钎料润湿性的影响,采用润湿平衡法探讨了Sn-0.3Ag-0.7Cu-xSb钎料在不同氛围和不同钎剂条件下的润湿性能.结果表明,微量的Sb元素可以显著提高Sn-0.3Ag-0.7Cu无铅钎料润湿性.在氮气氛围条件下,Sn-0.3Ag-0.7Cu-xSb钎料的润湿性得到显著改善,主要基于氮气氛围减小熔融钎料的氧化.辅助不同的钎剂,钎料的润湿性差异较大,选择合适的钎剂可以明显提高Sn-0.3Ag-0.7Cu-xSb钎料的润湿性.     

Cu基板粗糙度对SnAgCu无铅钎料润湿性的影响

在微电子封装软钎焊领域,钎料的润湿性直接决定焊接接头的性能.文中以不加入外来元素为前提,以SAC305/Cu钎焊体系为研究对象,完成了SAC305钎料在不同粗糙度Cu基板上的润湿铺展试验,研究了Cu基板粗糙度对SnAgCu钎料润湿性及SnAgCu/Cu界面化合物形貌与分布的影响.结果表明,?SnAgCu钎料在Cu基板上...     

激光钎焊AgCu基钎料润湿性理论模型构建

通过向Ag Cu_(28)共晶粉末中添加适量活性元素钛(Ti)、锆(Zr),制备了AgCu_(28)-4.5Ti和AgCu_(28)-4.5Ti-4Zr两种活性复合钎料,研究了脉冲激光作用下两种钎料的润湿性能。通过三维电控超景深显微镜实验及钎料润湿性理论模型两种方法进行了润湿角的测量计算。结果表明,活性元素Zr能够促进Ag Cu基钎料的润湿铺展性能,使钎料润湿角降低约10°,含Zr钎料的钎焊性能良好。当润湿角在40°左右时,该理论模型能够准确求得钎料焊后润湿角;当钎料润湿性能增强时,钎焊层润湿角测量值与计算值间的误差有所增大,钎料润湿角在30°左右时,其相对误差约为10%。     

Sn-9Zn-xAl无铅钎料润湿性能

采用润湿平衡法测试了不同温度下Sn-9Zn-xAl无铅钎料在空气和氮气两种气氛下的润湿性能,研究探索了合金元素Al的添加量、气氛和温度对Sn-9Zn-xAl无铅钎料润湿性能的影响规律.结果表明,添加Al元素以后,Sn-Zn-xAl无铅钎料的润湿性得到明显改善,在使用ZnCl2-NH4Cl助焊剂时,Al的最佳添加量为0.02%(质量分数),在使用免清洗助焊剂时,Al的最佳添加量为0.005%(质量分数);采用氮气保护时,Cu基板表面张力提高,钎料的氧化减少、表面张力降低,明显改善了钎料在Cu基板上的润湿性能;在215～245℃时,温度升高使钎料的表面张力减小,提高了钎料的润湿性能.     

多元铜基活性钎料对c-BN的润湿性与微观组织

采用座滴法试验研究了多元铜基活性钎料中Ti,Zr活性元素对c-BN润湿性的影响,借助于扫描电镜(SEM)、能谱分析仪(EDS)和X射线衍射仪(XRD),结合键参数理论分析探讨了多元铜基活性钎料的微观组织,发现钎料主要由Cu固溶体、富Sn相和少量金属间化合物组成.通过计算元素间化学亲和力大小,进一步阐述了多元铜基活性钎料中Ti,Zr活性元素对c-BN润湿性的影响机制.结果表明,多元铜基活性钎料中,添加Ti活性元素比Zr元素更容易润湿c-BN.     

无铅钎料与非晶态及晶态Co_(73)Si_(10)B_(17)合金的润湿性

采用平衡润湿法在290～310℃条件下研究纯Sn、SAC307、Sn-0.7Cu这3种软钎料分别与Co_(73)Si_(10)B_(17)非晶箔带晶化前后的润湿行为。通过对表面能和润湿力的测量、对合金体系的表面状态和润湿性进行表征。结果表明:Co基合金的表面自由能远小于其本征值,表明其表面存在氧化膜;钎料的润湿性随着Sn含量的增加而升高,表明该体系润湿机理是一系列复杂的氧化膜去除反应且界面处反应润湿较为剧烈;Co_(73)Si_(10)B_(17)合金的润湿性受界面反应产物和材料表面氧化膜的影响较大,但最终的润湿性由表面氧化膜的去除程度决定。     

添加Zn对AgCu钎料在TiC金属陶瓷表面润湿性的影响

分别采用AgCu共晶钎料和AgCu共晶钎料中添加30%(质量分数)Zn的AgCuZn钎料在TiC金属陶瓷表面进行润湿试验.结果表明,Zn元素的添加显著改善了钎料在TiC金属陶瓷表面的润湿性;AgCu钎料润湿TiC金属陶瓷时,从近钎料外表面到钎料/陶瓷界面,组织依次为Ag(s.s)+Cu(s.s)/(Cu,Ni)+Ag(s.s)/TiC金属陶瓷+Ag(s.s)+Cu(s.s)/TiC金属陶瓷;而采用AgCuZn钎料润湿TiC金属陶瓷后,从近钎料外表面到钎料/陶瓷界面,组织依次为Ag(s.s)+Cu(s.s)+(Cu,Ni)/Ag(s.s)+Cu(s.s)/(Cu,Ni)/TiC金属陶瓷+Ag(s.s)+Cu(s.s)/TiC金属陶瓷.Zn元素在真空中挥发促进了界面处Ni原子的溶解和扩散,使钎料在陶瓷表面的润湿角由120.6°减小到33.9°.     

超声振动和直流电耦合作用对润湿行为的影响

采用平衡润湿测试法研究了270 ℃时,施加超声振动和直流电耦合作用对液态Sn钎料在Cu基体上润湿行为的影响。通过对润湿平衡曲线的测量发现：超声和直流电耦合作用能显著改善Sn钎料的润湿性,随着超声功率和电流强度的增加,最大平衡润湿力也随之增加。对润湿过程中界面微观结构的观察结果显示,超声和直流电耦合作用增强了Cu基体在熔融Sn钎料中的溶解,促进了界面金属间化合物的析出。利用有限元软件对液态Sn钎料内部的声压分布进行模拟,发现最大声压发生在超声探头的端部。在超声振动和直流电耦合作用下,界面析出金属间化合物时所产生的化学驱动力以及超声和直流电作用引起钎料内部强烈的对流作用共同促进了三相线的移动,从而改善了钎料润湿性。     

微量RE对Sn-2．5Ag-0．7Cu钎料合金润湿性的影响

采用润湿平衡法,研究了水洗钎剂条件下Sn-2.5Ag-0.7Cu-xRE无铅钎料合金在1206片式元器件和Cu焊盘上的润湿性.结果表明,添加质量分数为0.1%的RE的Sn-2.5Ag-0.7Cu钎料合金在1206表面贴装元器件和Cu焊盘上有最大的润湿力和铺展面积及最小的润湿角,其润湿性最好,润湿力优于Sn-3.8Ag-0.7Cu钎料合金,满足微电子行业对润湿性能的要求.     

Zr41．25Ti13．75Ni10Cu12．5Be22．5熔体与W的润湿及复合

用座滴法研究了高真空下Zr41.25Tin13.75Ni10Cu12.5Be22.5（原子百分数，下同）熔体在W上的润湿行为及界面相互作用，并用浸渗法制备了W丝增强的Zr41．25Ti13．75Ni10Cu12.5Be22.5块状非晶复合材料。结果表明：在1053K～1173K之间，Zr41.25Ti13.75Ni10Cu12.5Be22.5熔体与W具有较好的润湿性。润湿温度升高会显著降低平衡接触角，并加速熔体的铺展，但也会增大W的溶解量。继续升高温度对平衡接触角和达到平衡接触角所需时间的影响很小。好的润湿性和快的铺展速率为制备W丝增强的Zr41.25Ti13.75Ni10Cu12.5Be22.5块状非晶复合材料选择合理的工艺参数提供了较大的自由空间。     

Wetting Behavior of a Novel Al-Si-Ti Active Brazing Filler Metal Foil on Aluminum Matrix Composite

An active ternary brazing filler metal of Al-12Si-1Ti with a melting temperature range of 851-856 K was developed by adding Ti into Al-Si system alloy to improve the wettability of Al-Si system filler metal on pure aluminum matrix composite reinforced with short alumina fiber (Al₂O_3sf/Al). The wetting behavior of the developed Al-12Si-1Ti and conventional Al-12Si foils were compared using sessile drop test at 883 K for 300, 900, and 1800 s in flowing argon atmosphere. After shorter retardation periods, the interfacial gaps between Al-12Si-1Ti foil and matrix (M/M) micro-interfaces could disappear more easily than the case of using conventional Al-12Si foil. Moreover, the thickness of residual Al-12Si-1Ti foil also decreased faster than that of conventional Al-12Si foil. Especially, the interfacial gaps between reinforcement and filler metal (R/M) micro-interfaces could be eliminated for the developed Al-12Si-1Ti foil, while for conventional Al-12Si foil the interfacial gaps at R/M micro-interfaces could not be eliminated, although Si atoms could penetrate into the composite through bonded M/M micro-interfaces. These results showed that the Ti addition could not only accelerate the wetting at M/M micro-interfaces, but also eliminate the interfacial gaps at R/M micro-interfaces.     

CuSn预合金粉芯复合银钎料的润湿铺展机理

研究了添加质量分数为30%～70%CuSn预合金粉复合银钎料在T2紫铜基体上的润湿铺展过程,并讨论了CuSn预合金粉复合银钎料在紫铜基体上的润湿铺展机理.结果表明,在与紫铜基体的润湿铺展过程中,初始接触角由30%CuSn的119°降低到70%CuSn的94°.最终接触角由30%CuSn的15°下降到70%CuSn的7°.当粉芯中CuSn合金粉含量为60%时,钎料在铜板上的润湿面积达到530.04 mm²,相比于未添加CuSn合金粉时提高了约66%.由于低熔点CuSn预合金粉的前驱润湿作用使复合银钎料表面张力降低,初始接触角和最终接触角随着CuSn预合金粉含量的增加而减小. CuSn预合金粉在钎焊过程中先于BAg30CuZnSn钎料外皮熔化,形成熔融的铜锡液态合金薄层,降低了固液界面张力.随后,熔化的BAg30CuZnSn箔带在先期熔化的铜锡液态薄层上铺展,并与其发生溶质原子的扩散反应,最终形成液态复合钎料.低熔点CuSn预合金粉的加入,使复合银钎料在铜上的润湿性能显著改善.添加40%CuSn预合金粉复合银钎料与铜基体的反应润湿界面均匀致密,其中白色富Ag相互连接,...     

Effect of direct electric current on wetting behavior of molten Bi on Cu substrate

The effect of direct electric current on the wetting behavior of molten Bi on Cu substrate at 370°C was investigated by the sessile drop method. The wettability of molten Bi on Cu without an applied current is poor and the spreading time required to form the steady-state contact angle (about 102°) is approximately 30 min. With the increase of the applied electric current, the spreading of molten Bi on Cu is accelerated significantly and the steady-state contact angle decreases considerably. The cross-section SEM micrographs of the solidified Bi droplet on Cu substrate show that the electric current has a marked effect on the convection of melt. Correspondingly, the application of an electric current obviously enhances the dissolution of Cu into Bi melt, which may change the wetting triple line configuration. The improvement of wettability induced by electric current is also related to the additional driving force for wetting provided by the electromagnetic pressure gradient force.     

锡在Cu6Sn5金属间化合物表面的润湿行为

利用改良座滴法研究了高真空条件下熔融纯Sn在350 ~ 450 ℃下分别与Cu₆Sn₅和T2纯铜的润湿行为. 结果表明,表面镀金的金属间化合物基板在各试验温度下的润湿性均优于纯铜基板;金属基板表面氧化膜对润湿性的影响不容忽视;离子溅射后表面形成的金膜可以作为一种改善润湿性及控制界面IMC厚度的有效方法;润湿性改善的机制为Sn与氧化膜的化学反应,界面析出IMC或者IMC的溶解过程并非限制铺展的主要因素;铺展过程表现出线性铺展规律,可用反应产物控制模型对其进行描述,计算得到Sn/Cu₆Sn₅和Sn/Cu两体系的铺展激活能分别为20.469 kJ/mol和22.270 kJ/mol.     

Thermodynamics and kinetics of dissolutive wetting of Si by liquid Cu

Wetting of Si single crystals by pure copper has been studied using the dispensed drop technique under high vacuum at 1100 °C. At this temperature copper dissolved large quantities of Si during spreading. CuSi droplets presaturated in silicon were also used to obtain non-reactive spreading. From the results obtained the different contributions to “dissolutive wetting” were determined. Moreover, a simple analytical model was formulated for analysing the influence on wetting of the interfacial atomic processes and of Si transport in the liquid. It is seen that, under our experimental conditions, solute transport by Marangoni convection controls the spreading kinetics.     

冷金属过渡下熔融铝合金在钢板上润湿铺展的数值模拟

采用Fluent软件对冷金属过渡条件下第一个周期内熔融铝合金在Q235钢板上润湿及凝固进行了分析和研究,得出温度场对金属凝固的影响和两者对熔滴润湿铺展能力的影响,以及不同初始参数对熔融铝合金在Q235钢板表面润湿行为的影响.结果表明,熔融铝合金首先在三相线处开始凝固,这与温度场的分布相一致;已凝固的金属对熔融铝合金的铺展起到一定的阻碍作用;随着初始温度的增加湘线附近局部凝固的固柏体减小,熔融铝合金在Q235钢板上表现出好的润湿性.     

纯铝与石墨、SiC和Al_2O_3的润湿性

纯铝与过滤材料和夹杂物之间的润湿性是影响铝的过滤性能的重要因素。在10-8bar真空条件下于1000~1300°C,研究液态铝与氧化铝、SiC和石墨之间的润湿角。为了描述铝的过滤和浇铸等在低温条件下铝与陶瓷的润湿行为,使用半经验模型进行研究。计算出的700°C的纯铝与氧化铝的润湿角为97°,与玻璃体石墨的为92°,与单晶和多晶石墨的为126°,与单晶的为SiC79°。结果表明：在浇铸温度下铝不能润湿氧化铝和石墨（或者Al4C3）,但可以润湿SiC。因此,为了让铝能够浸润过滤材料,在铝过滤时需要施加一个压力差作为推动力。提高温度也可以改善铝与陶瓷间的润湿性。     

The role of compound formation in reactive wetting: the Cu/SiC system

Wettability and reactivity in the liquid Cu/SiC couple are studied by the sessile drop technique in high vacuum or purified helium using monocrystalline or sintered α-SiC. This couple exhibits a very unusual wetting behaviour. Particularly, during spreading, an amazing drop shape is established and, for specific conditions, “hexagonal wetting” is observed. We show that these observations can be correctly explained using the concepts of reactive wetting developed recently.     

Wetting behavior of Zr55Cu30Al10Ni5 melt on alumina

The wetting behavior of molten Zr55 Cu30 Al10 Ni5 on Al2O3 was studied by the sessile drop method in high vacuum. The results show that wetting kinetic at 1 163 K is composed of three stages., incubation, quasi-steady decrease and trend constant. Precursor film forms surrounding the wetting tip when wetting temperature is above 1 163K. Formation of precursor film is related to the change of triple line configuration and results in good wettability.Chemical reaction dos not occur at the wetting interface. Al2O3 is an excellent reinforcement for Zr55 Cu30 Al10 Ni5 matrix composite in terms of wettability and reactivity. The kinetic relationship of spreading ratio with spreading timewas also investigated.