要注意的焊接技巧

如果系统不可靠，再漂亮的焊接连接也没有意义。

外观上可接受的焊点非常重要，但前提是必须以可靠的方式实现。采用更强的助焊剂可以消除润湿问题，但由此产生的离子污染会导致故障。而元件过热则会导致过早失效。离子污染和过热都不可见，但它们可能比不美观的焊料更致命。任何人都可以将焊料熔化到元件上，但很少有人能可靠地做到这一点。

可靠性无法检查。

外观上有缺陷的焊接连接几乎肯定是不可靠的。然而，仅凭外观上的合格并不能证明什么。真正的可靠性要求每次都能在第一时间完成工作。

There’s no point in beautiful solder connections if the system is unreliable.Cosmetically acceptable solder joints are important but only if they are achieved in a reliable fashion. Wetting issues can be eliminated by employing stronger fluxes, but the resulting ionic contamination can cause failures. And overheating components leads to premature failures. Neither ionic contamination nor overheating can be seen but they can be deadlier than unattractive solder. Anyone can melt solder onto components; very few people do it reliably. Reliability can’t be inspected in.A cosmetically defective solder connection is almost certainly unreliable. However, cosmetically acceptable alone proves nothing. True reliability requires doing the job right the first time, every time.

没有所谓的 "冷 "焊料。

还是那句话，用词很重要。针对 "冷焊 "的合乎逻辑的纠正措施是增加热量，这也是业界解决该问题的通常方法。但是，除非焊料在完成流动之前实际上已经冻结（如质量较重的电镀通孔），否则人们所说的 "冷焊 "只是润湿不良而已。IPC-A-610G 1.8.2 将 "冷焊 "定义为 "润湿性差的焊料连接，其特点是外观呈灰色多孔状。(这是由于焊料中杂质过多、焊接前清洁不充分和/或焊接过程中加热不充分造成的）"。英国人有一个更好的术语，即 "干焊料"，它准确地表达了潜在的可焊性问题。

完美焊接很容易，但 98% 完美焊接却很难。

I began this series by telling you that “perfect soldering is simple.” So, it seems appropriate to end with the same theme. Soldering is actually a fairly straightforward science. If we meet a small number of requirements imposed by nature, the solder will do the work and produce perfect connections. But we must comply with all the requirements. A process that violates just one of nature’s requirements produces visually unacceptable connections; it is necessary to set other parameters to sub-optimal levels that compensate for the initial flawed setting. Perfect soldering really is easy, but it doesn’t happen by luck or guesswork. Read our next article in the soldering series making sense of wave soldering.