Soldering iron-forming, inserting and soldering of components
1. Component pin forming: Shape the components according to installation requirements and tin them.
(1) The component pins must not be bent from the root, and generally should be kept more than 1.5mm.
(2) The lead should generally not be bent into a dead angle, and the arc radius should be greater than 1 to 2 times the lead diameter.
(3) Try to place the surface of the component with characters where it is easy to observe.
(4) For horizontal installation, the left and right bends of the two pins must be symmetrical, the lead wires must be parallel, and the distance between them should be equal to the distance between the two pad holes of the printed circuit board to facilitate installation.
2. Component layout and installation
(1) Properly lay out the components according to the size of the universal board and the number of circuit components, and require appropriate spacing between components.
(2) Try to ensure that component pins do not cross.
(3) When installing components, the polarity of diodes, transistors, and electrolytic capacitors cannot be reversed or wrongly connected.
(4) The insertion of components should follow the principles of small first then large, light first then heavy, low first then high, inside first then outside.
(5) Installation form: Resistors and diodes are generally installed horizontally, that is, the components are placed horizontally close to the printed circuit board. For high-power resistors and other components, they should be 2~3mm away from the board. Components such as transistors and capacitors are installed vertically, that is, the components are inserted vertically into the printed circuit board, generally requiring a distance of 2~3mm from the board surface.
Several issues you should pay attention to when using a soldering iron
(1) Before using a new electric soldering iron, you should first file the soldering iron tip into a certain shape as required, and then turn on the power. When the temperature of the soldering iron tip rises to a temperature that can melt the solder, apply rosin on the soldering iron tip, etc. After the rosin smokes, apply a layer of solder, and repeat this process until the blade surface is completely covered with solder.
(2) How to deal with the problem that the soldering iron head does not "eat tin": Use fine sandpaper or a file to re-grind the soldering iron head or file out new stubble, and re-tinning.
(3) If there is too much solder on the soldering iron tip during welding: wipe it off with a damp cloth and do not swing the soldering iron.
