我的许多帖子都在讨论不同类型的 波峰焊助焊剂它们的功能和缺点。本节内容与此类似，但将讨论预热器 。但首先要做一个简单的介绍。
The definition of preheating is the practice of applying heat to a PCB after flux deposition and immediately before soldering. Wave soldering can be performed without preheating, but the soldering speed will be slow. The age-old saying that “time is money” emphasizes the need for preheating. In The Handbook of Machine Soldering SMT and TH, Woodgate mentions, “During some experimental work with preheating, a board was soldered at 12 ft. per minute with the normal preheat applied. Without preheat it could not be soldered faster than 2.5 ft. per minute.” Just because a joint can be formed without this process doesn’t mean that it should.
预热的理由几乎都是
- 通过加热 "激活 "助焊剂
- 通过干燥助焊剂溶剂来防止焊球，否则助焊剂溶剂在只接触焊波时就会喷溅出来
- To reduce thermal shock to the PCB from the solder wave, thus decreasing warping and other defects associated with an abrupt increase in temperature
The most important reason to use preheat is to “heat the board, components, terminations, and other parts of the joint so that the final heating and soldering can proceed more quickly.” By minimizing the exposure to the molten solder, damage to the components can be minimized as well.
*敬请期待下一期：预热第一部分--预热器的类型。这是第二个迷你系列的开始，它是题为 波峰焊接（分段概述）.
