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颗粒增强Sn-Ag基无铅复合钎料显微组织与性能 总被引:2,自引:0,他引:2
通过外加法向Sn-3.5Ag焊料中加入体积分数为10%的微米级Cu、Ni颗粒制备了无铅复合钎料,对钎料的显微组织、拉剪及润湿性能进行了研究。结果表明,颗粒周围以及基板界面处的显微组织中生成了金属间化合物,其形态及大小因加入颗粒而不同。颗粒的加入提高了钎料钎焊接头的剪切强度,其中Cu颗粒增强的接头的剪切强度提高了33%,Ni颗粒的提高了20%。两种复合钎料的铺展面积均下降了约15%,其中Cu颗粒增强复合钎料润湿角由11°增加到18°。 相似文献
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采用悬滴法测量了3种无铅钎料合金(Sn-3.0Ag-0.5Cu、Sn-0.7Cu与Sn-9.0Zn)在260℃时的表面张力,分别为525.5,534.8和595.4 mN/m;同时采用座滴法测量了其在260℃熔融状态下与Cu基板的接触角,分别为24.5°、28.0°和102.5°,并且与传统Sn-37.0Pb钎料进行了比较研究。结果表明,无铅钎料合金的表面张力与接触角均大于Sn-37.0Pb钎料。结合Young-Dupre公式讨论了钎料合金表面张力与其润湿性能的相关性,认为Sn基钎料合金在Cu基板上的润湿性能主要取决于其表面张力。 相似文献
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Sn-Cu系无松香无卤免清洗助焊剂研制 总被引:1,自引:0,他引:1
将低沸点与高沸点的有机酸进行复配,添加沸点接近波峰焊温度的混合溶剂及其他添加剂,得到了一种用于Sn-Cu系波峰焊无铅焊锡的助焊剂。测试结果表明:当丁二酸、衣康酸、己二酸、三异丙醇胺的质量比为4∶2∶3∶1,有机酸活化剂质量分数为5%,表面活性剂质量分数为0.15%,成膜剂质量分数为0.50%,有机溶剂质量分数为15%,余量为去离子水时,助焊剂溶液的pH值约为4,钎料焊后的铺展率接近于77%,焊点饱满光亮,对铜板腐蚀性小,焊后无残留,绝缘性良好。 相似文献
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文章阐述了钎料润湿的基本原理,分析了关键工艺参数对钎料铺展性能的影响规律。针对温度、时间和表面状态等关键参数/状态,对无铅钎料SAC305在Au/Ni镀层上的铺展性能开展试验研究。结果表明,随着焊接温度和保温时间的增加,无铅钎料SAC305的铺展性能明显改善,铺展系数逐渐趋于100%。同时,通过RF的Ar等离子对钎料进行表面预处理也能够使其铺展性能有所改善。试验结果与理论分析具有较好的一致性。 相似文献
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在BiSbCu钎料中添加Sn,分析Sn对BiSbCu钎料合金钎焊工艺性能的主要指标——钎料熔点和铺展面积的影响。结果表明:在Bi5Sb2Cu钎料合金中加入Sn可以显著降低钎料的熔点和显著增强钎料合金的铺展性能。当Sn的质量分数为10%时,Bi5Sb2Cu钎料的铺展面积为26.22 mm2,钎焊工艺性能最好。 相似文献
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Experimental Wettability Study of Lead-Free Solder on Cu Substrates Using Varying Flux and Temperature 总被引:2,自引:0,他引:2
Dong-Xia Xu Yong-Ping Lei Zhi-Dong Xia Fu Guo Yao-Wu Shi 《Journal of Electronic Materials》2008,37(1):125-133
The selection of soldering flux plays a critical role in promoting wetting and product reliability of printed circuit board
assemblies. In this study, the effects of fluxes on the wetting characteristics of the Sn-3.0Ag-0.5Cu solder alloy on Cu substrates
was researched by using various flux systems at different soldering temperatures. Because of the distinct characteristic of
the lead-free solder—poor wettability—three kinds of fluxes [no-clean flux with high solid content (NCF), rosin mildly activated
flux (RMA) and water-soluble flux (WSF)] were chosen for the wetting experiments. The wetting time and force were the evaluating
indicators. The experimental observations indicated that the wettability clearly depended on the soldering temperature and
flux system when using the same solder. Furthermore, the corrosion potential of flux residues was measured by surface insulation
resistance (SIR) testing. Scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used to determine
the contents of the flux residues and corrosion products. 相似文献
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无铅波峰焊设备的特点 总被引:1,自引:0,他引:1
相对于传统的Sn-Pb焊料,无铅焊料需要较高的焊接温度,而且润湿性差,另外免清洗助焊剂和水溶性助焊剂的固体含量低,活性温度高和活性区间窄。无铅焊料和助焊剂的特性决定了无铅波峰焊设备在结构和材料选用上有很大不同。通过对无铅波峰焊设备的各个部分的特点进行分析,为传统的旧波峰焊设备的改造提供参考。 相似文献
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Flux development for lead-free solders containing zinc 总被引:1,自引:0,他引:1
New lead-free solders containing zinc are promising candidates to replace near-eutectic tin-lead solders because the solders
melt at lower temperatures than Sn-Ag-base solders. They also possess good mechanical and fatigue properties and are less
expensive. However, the contact angle on copper for Sn-Zn solders is high when fluxes used for Sn-Pb solders are utilized.
A novel approach for flux development to improve wetting of copper surfaces by tin-zinc eutectic solder was developed: tin
containing organic compounds, which decomposes at soldering temperatures and produces metallic tin on surfaces to be soldered
was added to several specially formulated fluxes. This process improves wetting of copper surfaces by molten tin-zinc eutectic
solder. Fluxes were developed that give a contact angle as low as 20°. 相似文献
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The effects of two different fluxes (A6 and B6) on the wetting performance of Sn-3.5Ag-0.5Cu lead-free solder balls were investigated
during the reflow process. Solder ball wetting behavior in real time via an optical microscope coupled with a video recorder
during the reflow process was studied. The lead-free solder balls started to melt and wet at 210°C by using A6, which is 8°C
lower than the melting point (218°C) of the solder material used. The wetting performance of the lead-free solder ball was
dramatically enhanced by using A6. The wettability test indicated that the height of the solder ball after the reflow process
with flux A6 was significantly lower than that with B6. It was found that strong fluxing capability caused these phenomena. 相似文献
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无铅焊料的应用使得波峰焊设备问题更加突出,其中主要的问题是设备的腐蚀及材料的寿命.无铅焊料和助焊剂的特性决定了无铅波峰焊设备在结构和材料选用上有很大不同.无铅钎料的成分配比不同于有铅钎料,因此在无铅钎焊时,其工艺流程、工艺参数也有所改变.从焊接温度、波峰高度、浸锡时间、冷却系统、传输系统等方面分析了无铅波峰焊的工艺要求... 相似文献
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In this study, the contact angles of four lead-free solders, namely, Sn-3.5Ag, Sn-3.5Ag-4.8Bi, Sn-3.8Ag-0.7Cu, and Sn-0.7Cu
(wt.%), were measured on copper substrates at different temperatures. Measurements were performed using the sessile-drop method.
Contact angles ranging from 30° to 40° after wetting under vacuum with no fluxes and between 10° and 30° with rosin mildly
activated (RMA) and rosin activated (RA) fluxes were obtained. The Sn-3.5Ag-4.8Bi exhibited the lowest contact angles, indicating
improved wettability with the addition of bismuth. For all soldering alloys, lower contact angles were observed using RMA
flux. Intermetallics formed at the solder/Cu interface were identified as Cu6Sn5 adjacent to the solder and Cu3Sn adjacent to the copper substrate. The Cu3Sn intermetallic phase was generally not observed when RMA flux was used. The effect of temperature on contact angle was dependent
on the type of flux used. 相似文献
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SnAgCu无铅焊膏用活性物质研究 总被引:3,自引:3,他引:0
以SnAgCu无铅焊膏铺展性能为主要指标,通过回流焊接实验,对用于助焊剂的17种有机酸活性物质进行了筛选。选取两种性能较好的有机酸配成复合活性物质,并对该活性物质的组成进行优化。用湿热试验测试焊后残留物的腐蚀性。结果表明:以羧基官能团比例为3:7的丁二酸和一元酸A混合物作为活性物质,并添加质量约0.66%的乙醇胺调整酸度,得到了pH值约为3的助焊剂;此助焊剂性能优良,可使焊点铺展率达到84%。使用含有此助焊剂的焊膏,采用回流焊接工艺在PCB板上贴装片式元件,所得焊点光亮饱满,且焊后残留物无腐蚀性,可以实现免清洗。 相似文献