the experience of using the hot air desoldering unit and soldering station
The hot air desoldering station is suitable for the desoldering of various components, such as: SOIC, Chip, QFP, PLCC, BGA, etc. It is also very convenient for the desoldering of mobile phone cables and cable holders.
During normal use, the temperature is generally adjusted to about 3000C ~ 350C. When the voltage is low or the nozzle with a larger diameter is replaced, the temperature should be slightly increased. Usually, the desoldering temperature can be judged in this way: put a piece of paper at 2cm to 3cm from the tuyere, if the paper turns yellow immediately, it means that the temperature is just right. When blowing and soldering the chip, it must be vertically facing the PCB board, which can prevent the surrounding SMD components (such as resistors, capacitors, etc.) from being blown away. In addition, it should be blown around the chip components (note: even for BGA chips with pins at the bottom, because the heat transferred through the gaps around the chip is much greater than the heat transferred through the chip itself), if it is in the middle Blow "Long" the chip so that it is scrapped. Generally, the chip can be removed by blowing for 10 to 20 seconds. In terms of air volume, on the basis of referring to the 850-type air gun, add a few more gears. For example, if the air volume of the 850 type is 3-4 gears, then the 858 type should be 5-6 gears. The purpose of doing this is because the wind power of the brushless fan is relatively small (of course, this is also the requirement for all brushless fan hot air desoldering stations. common problem). When desoldering multi-layer boards with more than six layers and a relatively large board area such as computer motherboards and graphics cards, the heat transfer is limited due to the strong heat dissipation of the PCB itself; when desoldering components with large heating areas such as large chips , the desoldering efficiency will be relatively low, and the wind power must be adjusted to the maximum. If conditions permit, it is necessary to preheat around the components to be welded or add a preheating platform at the bottom before desoldering. It is recommended that novices find a few waste boards (such as computer motherboards) to do more practice before using them, and then practice.
Precautions for use: Because the power switch on the hot air desoldering station turns off the power of the entire system, when the handle is put back on the handle frame, the switch cannot be turned off immediately like the 850 hot air desoldering station (850 hot air desoldering station When the switching power supply is turned off, the heating wire will be powered off, but the fan is still powered on and the wind speed will automatically enter the maximum gear, and the relay will be disconnected after a certain time delay to turn off the power of the whole machine). The correct way is: wait until the brushless fan stops and the AIR indicator goes out before turning off the power switch.
In addition, in order to stop the fan as soon as possible, the air volume can be adjusted to the maximum when the handle is put back on the handle frame, so as to accelerate the cooling speed of the heating element.
