BGA repair technology

BGA repair technology

Place of attention

1, the flux can be too little, otherwise it will damage due to "blow dry chip".

2, the hot air gun chip must be heated evenly, otherwise it will make the solder melting inconsistent hold

chip, skid falls on the circuit board welding copper foil inventory, resulting in scrap the whole board.

3, take the chip to pay attention to the surrounding components, in order to prevent shift and increase the

unnecessary trouble.

4, remove the IC before the first record good installation direction, location, etc. in order to prepare the

correct installation and recovery.

Installation method

1, remove the IC BGA welding plate and the circuit board are more than tin. At this time, on the circuit board

and on the adequate amount of flux, with electric iron will in excess of tin removal, and proper tin make circuit

board each solder feet smooth rounded (not the ceiling flat solder joints), then use the days that water wash.

Tin should pay attention to and will not need to paint from the solder pads on the pad, cannot let off.

2, do a good job, for the removal of the IC, it is recommended not to show that the removal of the solder

(only to remove the solder points and the impact of tin plate with tin solder). If a solder is too large, can be

added to the surface flux in iron, and then removed, then wash with water that day.

3, IC BGA fixed. IC and tin plate is firmly attached IC alignment, alignment, and the tin plate by hand or tweezers

firmly do not move, then the other hand scraping on the solder paste.

4, on the tin slurry. With a flat blade knife pick amount of solder paste to planted on a tin plate, forced down

scraping, scraping edge pressure, uniform solder paste filling to tin plate hole.

5, blow into the ball. Remove the hot air gun. The air temperature to 330 DEG C to a minimum, 340 C. The

wind shook his mouth to the graft tin tin slurry is heated slowly, so slowly melting. When saw the planting

of tinplate individual holes have solder ball formation, indicating that the temperature has been put in

place, at this time should be appropriate to raise the wind of the hot blast gun mouth, avoid the rise in

temperature. High temperature can make the tin slurry boiling, resulting in the failure of tin tin. If the ball

welding blowing and found some ball size uneven, not even on the tin, available paper cutting knife will

lead solder balls on the exposed part and leveling, reoccupy scraper will solder balls are too small and

missing foot holes on the slow solder paste, and then using a hot-air gun to blow a until the ideal state.

Replanting, must be clean, dry and clear tin.

6, IC BGA installation. First IC pins coated with flux, the planting good solder IC according to the open

position into the circuit board, the IC around mobile and gently pressed, then you can feel welded on

the two sides of the foot of the contact with tweezers. Because the feet are welded on both sides of the

ball shaped. So move back and forth if the alignment of the IC has a "climbed to the crest" feeling,

alignment, because the sticky flux on the IC, so it won't move, if IC partial to re positioning.

7, IC BGA welding. With the same planting ball, let the wind mouth at IC central location, slow heating.

When IC saw the sinking and surrounded by a flux overflow, solder and solder joint that has fused circuit

board together. At this time, the wind nozzle of the hot air gun to heat evenly, due to the role of surface

tension, IC BGA and circuit board between the solder joints will be automatically aligned positioning

(note in the heating process, do not force IC BGA, otherwise it will cause the solder spill, causing the

feet and short circuit). After the welding is finished to be cooled, the water will be washed with the plate.

The welding technology is a Skill comes. More practice, do, in the process of carefully, I think we should

quickly grasp the.