How to use electric soldering iron in electronic practice
As the packaging of electronic components is updated faster and faster, the components on the circuit board are getting fewer and denser, the pins are getting thinner, and the circuit board is getting smaller and smaller. Moreover, a large number of surface mount components, flip chips and other components are used on the circuit board, which without exception shows that the electronic industry has been developing towards miniaturization and miniaturization, and the difficulty of manual soldering has also increased accordingly. Caution will damage the components, or cause poor welding, so the staff must have a certain understanding of the welding principle, welding process, welding method, evaluation of welding quality, and electronic foundation.
1 soldering tool
The electric soldering iron is the most commonly used tool in welding, and a large part of whether the welding is successful depends on how well it is manipulated. Generally speaking, the greater the power of the electric soldering iron, the greater the heat, and the higher the temperature of the soldering iron tip. For example, we use a 20W internal heating type (30~40W external heating type) electric soldering iron for hardware transformation. If the power is too high, it is easy to burn out the components. Generally, the junction temperature of diodes and triodes will be damaged if the temperature exceeds 200°C.
There are two types of electric soldering irons commonly used now: external heating type and internal heating type. The internal heating type electric soldering iron has high thermal efficiency and fast heating speed. The power of the external heat soldering iron is higher, and the method of use is the same, but there are many accessories for the internal heat soldering iron on the market, so it is recommended to use the internal heat soldering iron.
Ordinary electric soldering irons must be coated with a layer of solder on the tip of the soldering iron before use. The specific method is: first file the tip of the soldering iron into the desired shape, then connect the power supply, when the temperature of the tip of the soldering iron rises to the point where the tin can be melted, apply rosin on the tip of the soldering iron, and then apply a layer of solder until the edge of the tip of the soldering iron It can be used by hanging a layer of tin on the face.
2 Welding method
There are two main types of components on current circuit boards, one is in-line pin components, and the other is patch components. The following will specifically talk about the welding method of each type of component according to these two types of components.
3 Soldering time and temperature setting
1) The temperature is determined by the actual use. It is most suitable to solder a solder point for 1~4 seconds, and the maximum is no more than 8 seconds. Usually observe the tip of the soldering iron. When it turns purple, the temperature setting is too high.
2) Generally, for in-line electronic materials, set the actual temperature of the soldering iron tip to (350~370 degrees); for surface mount materials (SMT), set the actual temperature of the soldering iron tip to (330~350 degrees), generally the melting point of the solder Add 100 degrees.
3) For special materials, the temperature of the soldering iron needs to be specially set. LCD connectors, etc. should use silver-containing tin wires, and the temperature is generally between 290 degrees and 310 degrees.
4) Solder large component feet, the temperature should not exceed 380 degrees, but you can increase the power of the soldering iron
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