Quick know about BGA repairing process

A simple article to let you know something about BGA chip repairing,below is the process flow:

1.PCB & Bga chip Preheating  

2. Take off BGA chip from PCBA

3.Clean the PCBA

4. BGA chip reballing    

5. Brush flux paste  

6.Mount BGA chip 

7. Hot air flow solder 

• 1、Preheating：

The PCB and BGA need to be preheated before rework. The temperature of the constant temperature oven is generally set at 80°C to 100°C for 8 to 20 hours to delete the moisture inside of PCB and BGA, which can prevent bursting occurs while heating.

In this step, the tools you need is oven.

• 2、Desolder：

Place the PCB on rework station, select the appropriate hot air reflow nozzle and set the appropriate welding temperature curve. Turn the switch on,after the setting program finishes,just take off the BGA chip.

At this step, the tools you need is hot air gun/BGA rework station

• 3、Clean PCBA：

Clear PCB and BGA pad , remove the solder dregs with soldering wick wire & soldering iron ; better to remove the solder within a short time after BGA removed, at that time PCBA has not been completely cooled, small temperature difference can prevent damage for the pad ; The use of flux in the removal of solder can improve solder activity and facilitate solder removal. For the soldering reliability of the BGA, try to use some volatile solvents such as industrial alcohol for cleaning the pad.

At this step,the tools you need is solder station

• 4、BGA chip reballing and solder：

Brush solder flux paste to the BGA pad evenly with a brush, select the corresponding stencil to reballing solder ball to chip;

Heating on the bottom of the chip to solder the ball to chip.

• 5、Brush flux paste：

Brush appropriate solder flux paste on the PCB pad. Too much solder may cause short circuit . On the contrary, less solder flux paste will cause open phenomenon.

• 6、Mount BGA chip：

The BGA is mounted on the PCB. Optical BGA rework station with CCD camera can help you do alignment work to improve success ratio.

At this step, optical BGA rework station is the best choice.

• 7,Hot air flow solder

Place the mounted BGA on BGA rework station,select the appropriate nozzle and welding temperature curve, turn on the machine and run the setting temperature profile. After setting file is finished , it will cool the BGA automatically with built-in cooling fan . It will be ok after 30-40 seconds.

At this step, the tools you need is BGA rework station,optical BGA rework station is better.