BGA rework process

BGA rework process

1. Preheat:
PCB and BGA rework before preheating temperature oven temperature is generally set at 80 ℃ ~ 100 ℃,

time 8 to 20 hours to remove the PCB and BGA internal moisture, eliminate rework phenomenon have

burst heating.

2. Remove the following:
The PCB onto the repair station locating bracket, select the appropriate hot air reflow soldering nozzle and

set the appropriate temperature curve, inching start switch, until the end of the program is running,

manually remove the heat of the limelight, and then vacuum suction pen BGA go.

3. cleaning pads:
PCB and BGA pad clean-up, one with suction-line to drag level, the second is a direct drag with a soldering

iron flat; the best BGA removed in a relatively short time to remove solder, then PBA has not yet completely

cooled, temperature butt damage smaller plate; use solder flux removal process, you can improve the solder

activity, facilitate removal of solder. In order to ensure the reliability of BGA soldering, try to use some of the

more volatile solvents in the cleaning pad residual paste, washer water, industrial alcohol.

4, BGA sik Chu:
On the BGA pad evenly coated with an appropriate amount of flux paste with a brush, select the corresponding

sik Chu stencil with BGA sik Chu Taiwan will grow in the BGA solder balls corresponding pad.

5, BGA solder beads welding:
On the bottom of the heating zone tin soldering station or rework station heating, tin solder beads on the

BGA pads.

6, coating help paste:
On the PCB pads with a brush coated with flux paste, such as painted too much can cause a short circuit, on

the contrary, it is easy to empty solder, solder coating must be uniform so appropriate, to remove dust on the

BGA solder ball impurities, enhance welding results.

7, mounting:
The BGA alignment mounted on a PCB; by hand to position, in order to screen border as an auxiliary to the

position, the tin surface with solder ball BGA pads can be confirmed whether the placement by hand, while

the reflow melting tension produce good self-centering effect when the joints between the fruit.

8, welding:
The good placement of BGA PCB bracket onto the positioning, will move to the next hot limelight working

position, select the appropriate nozzle and set the appropriate hot air reflow soldering profile, start adding

the hot switch, run the welding program, to be run program after this time the square cooling fan starts to

cool BGA, the top heat limelight improved, so that the hot air nozzle from the bottom surface of the BGA 8

to 10 mm, and kept cool for 30 to 40 seconds, or until the start switch lights off after removal of the heat

of the limelight, and then from the heating zone PCB positioning stand steady removed.