PCB circuit board welding technology Introduction
In the electronic pcb assembly production process, welding is essential. It requires not only the components fixed to the printed circuit boards, and requires solder joints must be firm, smooth, so the welding technology will affect the success of electronic production, so an electronic welding technology is making every fan must master the basic skills will now introduce the main points of welding:
1. The choice of electric iron
Electric iron power should be determined by the size solder, solder the area, spot cooling speed quickly, so use the electric iron power should also be greater. General electric iron power with 20W 25W 30W 35W 50W and more. Used in the pcb assembly production process more appropriate power of about 30W.
After prolonged use of electric iron, the iron head will generate a layer of oxide, then it is not easy to eat the tin, then you can file with a file out of oxide layer, the iron head after power and other micro-hot iron into the rosin , coated with solder can continue to use the new soldering iron must be bought first before you can use on the tin.
2. Solder and flux
Use low melting point solder and flux is not corrosive, such as rosin, solder should not be used industrial welding and corrosive acid oil, preferably in the solder wire containing rosin, very convenient to use.
3. Welding method
Components must be clean and tin, electronic components stored in the air, the oxidation of the component pin with a layer of oxide film, as well as other dirt, scrape a knife before soldering oxide film can be used, and immediately coated with a layer of solder (commonly known as the lining of tin), and then welding. After these treatment components easy to weld, Weld is not prone to the phenomenon.
Welding temperature and welding time
Welding, soldering iron temperature is higher than the temperature of the solder, but not too much to tip for good exposure to rosin just smoke. Welding time is too short, too low temperature solder, insufficient solder melting, likely to cause Weld rough spot, whereas welding time is too long, the solder flow easily, and easily damaged components overheating components.
The number of welding points on the tin
Solder on the number of welding points can not be too little, too little solder is not strong, poor mechanical strength. Too easily lead to the appearance of the lot while the internal is not connected. Solder should be just to weld all the component pins immersion, outline barely visible as well.
Note the location of iron and solder
Beginners in welding, soldering iron will generally move back and forth in the welding or hard squeeze, this approach is wrong. The correct way is the lining of tin electric soldering iron to reach weld surface, so heat transfer area, welding speed.
4. Welding inspection after
There must be checked after welding seamless welding, Weld and solder flow caused by the short circuit components. Weld difficult to find, you can gently pull the pin clamp clamp components, such as welding that shake immediately.