The correct choice of soldering iron tip and how to perform effective maintenance
(1) Structure of the soldering iron tip
Soldering iron tips are generally made of copper material. In order to protect it from oxidation and rust under the high temperature conditions of welding, the soldering iron tip is often electroplated, usually iron-nickel alloy plated, and the front end of the soldering iron tip is generally iron plated. Some soldering iron tips are also made of alloy materials that are not easily oxidized.
(2) Shape and specifications of soldering iron tip
There are many shapes and specifications of soldering iron tips. The main shapes of soldering iron tips include conical, chisel-shaped (flat shovel-shaped), horseshoe-shaped, double-piece flat-shovel horseshoe-shaped, square, hot chuck, etc.
(3) Correct selection of soldering iron tip
The correct selection of the soldering iron tip can achieve better welding at the lowest temperature and maximize the service life of the soldering iron tip. The main basis for choosing a soldering tip is as follows.
●Select the appropriate shape of the soldering iron tip according to the type of components to be welded. For example: when disassembling SOIC, you should choose a double-piece flat shovel type horseshoe-shaped soldering iron tip, and when disassembling QFP/PLCC, you should choose a square-shaped soldering iron tip.
●Select the appropriate size soldering iron tip according to the size of the solder joints of the components to be welded. For example, a conical soldering iron tip can be used for small solder joints, and a chisel-shaped or cylindrical soldering iron tip can be used for larger solder joints, as shown in Figure 4-58.
(4) Correct use and maintenance of soldering iron tips
① When tin is applied for the first time, the tin wire should start to contact the soldering iron tip from a low temperature (around 183°C), and should not exceed the tinned section of the soldering iron. Avoid using the soldering iron to top or rub the device pins during use to prevent damage to the coating and deformation of the soldering iron.
② It is best not to use a temperature-controlled soldering iron exceeding 350°C. Excessively high setting temperature will accelerate the damage to the coating.
③Clean the soldering iron tip and add tin to the soldering iron tip to facilitate heat conduction. Keep tin on the tip of the soldering iron and clean the tip at all times.
④The acidity of the flux in the solder wire core is high, which will also affect the life of the soldering iron tip. Never use flux to clean the soldering iron tip.
⑤ The foam plastic used for cleaning must have an appropriate viscosity and humidity. The soldering iron tip is easily oxidized when it comes into contact with water.
⑥For iron-plated nickel alloy soldering iron tips, do not use a knife or other things to scrape the oxide layer, and do not use hard objects to hit the tin slag on the soldering iron tip L (except for homemade copper soldering iron tips).
⑦ When the soldering iron is not used for a long time, the power should be turned off in time to avoid accelerated oxidation of the soldering iron core and shortening the service life (currently, some constant temperature soldering stations are designed with automatic sleep function).
⑧Before turning off the soldering iron, the soldering iron tip should be tinned to avoid accelerated oxidation.
