小元件的焊接（Welding of small components）.doc

小元件的焊接（Welding of small components） Disassembly and welding of small components 1. guidance The small elements in the circuit include resistors, capacitors, inductors, transistors and so on. The mobile phone has the advantages of small volume, powerful function, complex circuit, determines these elements must be used to install the patch (SMD), through hole components of chip components compared with the conventional SMD components installed high density, reduce the distribution of lead, enhance the ability to engage in electromagnetic interference and radio frequency interference. For these small components, generally using a hot-air gun for removing and welding (welding can also use electric iron), in removing and welding must certainly grasp the wind, wind speed and wind direction, improper operation, not only the small element to blow away, and will bring disaster to the fish pond, the small element is blowing around the position or blow away. 2. operation (1) disassembly of small components Before using a hot-air gun removing small components, will spare batteries on the circuit board to remove the mobile phone (especially from the demolition of the standby battery element is close, otherwise, the backup battery) is easy to heat explosion, pose a threat to human body. Fix the circuit board on the mobile phone maintenance platform, turn on the magnifier with the lamp, and observe the position of the small components which want to be removed. Clean the impurities around the small parts with a small brush and add a little loose perfume to the small components. Install the fine nozzle of the hot air gun, turn on the hot blast gun power switch, adjust the hot blast gun temperature switch in the 2 to 3 files, and the wind speed switch is in the 1 to 2 gear. One hand holds the small component with one finger, and the other hand holds the handle of the hot air gun, so that the nozzle is kept vertical from the small component to be removed, the distance is from 2 to 3cm