铝用低温有机软钎剂中活性剂的研究

铝及铝合金广泛应用于电子设备、散热器等领域。文中针对铝合金低温软钎焊中表面氧化膜难去除的问题，对铝用有机钎剂体系进行了深入研究。为提高钎剂的活性及稳定性，同时选取辛酸亚锡及氟硼酸锌作为活性剂成分。通过铺展实验及X射线成像技术研究了两者对钎焊时SnZn钎料铺展率及孔隙率的影响。通过扫描电镜及差热分析手段深入探讨了活性剂在铝表面的作用机理。同时分析气孔产生的原因，解决钎剂活化后反应剧烈带来的气孔等焊接缺陷问题。结果表明，当辛酸亚锡重量百分比为8%，氟硼酸锌重量百分比控制在16%~24%时，可将软钎焊铺展率提高至90%以上，孔隙率控制在0.8%左右。

Study on Active Agent in Organic Flux for Low-temperature Soldering of Aluminum

Aluminum alloy has been wildly used in electronic equipment, heat exchanger, etc. In order to solve the problem of the oxidation film which is difficult to remove during soldering of aluminum, the origin flux system is studied. The stannous octoate and zinc fluoroborate are chose as active agent in the flux in order to increase the stability and activity of the flux. The effect of the stannous octoate and zinc fluoroborate on the spreading performance and porosity of SnZn solder are studied through spreading test and X-ray imaging technology. The reaction mechanism between the active agent and aluminum substrate is researched using scanning electron microscope and differential thermal analysis. The causes of the porosity producing during soldering are analyzed and the problem of porosity forming by the gasification of the organic flux is solved. The results indicate that the spreading ratio can be increased to 90% and the porosity is decreased to 0.8% when adding 8% (percentage by weight) stannous octoate and 16%~24% (percentage by weight) zinc fluoroborate in the flux.