According to the SMT electronic product production nature, production of pcba batch, equipment conditions, etc., what should be noted when the installation of integrated PCB circuit and SMT welding? The following jing state technical personnel and you talk.
The interpolation and welding methods of integrated circuits and the interpolation and welding methods of discrete SMT components are basically the same, except that the number of pins of integrated circuits is relatively large, so more attention should be paid to the interpolation and welding of integrated circuits. Generally, different PCB printed circuit board integrated circuit has different mounting methods. In order to make the integrated circuit dissipate heat better, an integrated circuit socket is installed at the bottom of the integrated circuit, and the integrated circuit is fixed by the socket of the integrated circuit.
Integrated circuit internal integration of high, by excessive heat is also easy to damage. It is absolutely cannot bear the temperature higher than 200 ℃, so must be very careful when welding. In addition to mastering the basic essentials of tin welding operation, special attention should be paid to the following points.
(1) do not scrape the gold-plated circuit pins with a knife, just wipe them with alcohol or clean them with a drawing eraser.
(2) do not remove the pre-set short circuit for CMOS circuit before welding.
(3) the welding time should be as short as possible, generally no more than 3s.
(4) using the soldering iron is best solder iron temperature 230 ℃.
(5) the table is best to do anti-static electrical treatment.
(6) choose a narrow tip tip, welding will not encounter the adjacent endpoint.
(7) the safety welding sequence of pins is ground end — output end — power end — input end.