(HongKong) FEITA INTERNATIONAL LIMITED
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Soldering techniques about soldering IC on the PCB
Now more and more circuit boards using surface mount components, compared with the traditional packaging, which can reduce the circuit board area, easy batch processing large, high density wiring. Chip resistors and capacitors significantly reduce lead inductance in high frequency circuit has a lot of advantages. Surface mount components inconvenience is not easy to manual welding. To this end, Africa and Thailand electronic welding engineers to common PQFP package chips for example, describes the basic soldering surface mount components method. Required tools and materials needed 25W soldering tools small copper head soldering iron, conditional use adjustable temperature and with ESD protection soldering station, soldering iron tip should be fine, the top width can not be greater than 1mm. A pointed tweezers can be used to check the mobile and fixed chips and circuits. Also prepare thin wire and flux, isopropyl alcohol. The main purpose of using flux increase the flow of solder, so you can use the soldering iron to solder traction, and rely on surface tension wrapped in a smooth pin and pad. After soldering flux with alcohol to remove PCB.
1. FEITA electronic soldering engineer reminded readers in on the pad before soldering flux coated with iron handle again, in order to avoid adverse pad or tin oxide, resulting in poor welding, chips are usually without treatment.
2.carefully PQFP chip into the PCB board, be careful not to damage the pin. Alignment with the pad, to ensure that the chips placed in the right direction. The iron temperature to over 300 degrees Celsius, the sharp tip coated with a small amount of solder, tools hold down the aligned position of the chip, the angular position of the two pairs of pins plus a small amount of flux remains to press and hold the chips, soldering two diagonally-position pin, the chip is fixed and can not be moved. After completion of the weld recheck the diagonal position of the chip is aligned. If necessary, adjust or remove and re-aligned position on the PCB.
3. when all the pins start welding, soldering iron tip should be added to the solder, flux coated all the pins so that pin remains moist. Contactless chip with the soldering iron tip end of each pin, until you see the solder into the pin. When soldering iron tip to maintain parallel and welded pin to prevent the occurrence of excessive solder lap.
4. finished welding all the pins after all wet with solder pin for cleaning solder. Where needed siphoning off excess solder, to remove any short-circuit and lap. Finally tweezers check Weld, inspection is completed, removing solder from the circuit board will be a stiff brush moistened with alcohol to wipe carefully in the direction along the pin until the flux disappears.
5. FEITA Electronics remind you of resistive and capacitive components are relatively easy to weld, we can first point at a spot on the tin, then put one component, forceps components, welded on a later, look to see if the place is a; if put positive, and then welded on to another one. To truly master welding techniques require a lot of practice.