Computer BGA rework station Procedure

Computer BGA rework station Procedure

1. Baking:
PCB and BGA remove moisture, so when heated soldering, lead soldering failure due to moisture vaporization,

or even damage the chip. Specific baking time and the sensitivity level of the chip, generally at 80 ℃, drying

for about 20 hours. Ordinary oven can bake me a lot of self-service by using Xiaoduwangui modification,

can better achieve drying effect,

2, figuring Lead Lead-Free:
Confirmed by observation of the appearance of the solder, the chip identification, uncertainty iron available

direct heating tests to discern. Lead 183 ℃, lead-free 217 ℃, lead mobility, poor lead-free mobility, from the

appearance point of view, there is a consistent lead bright, bright, bright unleaded inconsistent pale.

3, BGA Rework:
Call the appropriate temperature profile in the repairing heating stage, after removing the BGA to melt by

vacuum suction pen.

4, heavy bumping:
Bead tool with replanting replanting ball, with a soldering iron and suck tin line cleared BGA and PCB pad,

such as BGA is not damaged, it can be reused, such as damage to the need to replace good BGA chip.

Note solder balls need storage and clean and dry environment, do not touch it with your hand or other

objects, in order to prevent solder balls deformed or grease contamination. Unopened tin balls stored for

one year, to help paste save six months.

5, heavy bumping welding:
Call the appropriate replanting curve ball in the repair welding table, tin solder balls on BGA pads.

6, BGA placement:
Carefully inspect the solder resist layer (green oil) PCB pad is intact before Mount, then brush lightly with

a layer of flux paste on the PCB pad or screen printing solder paste on the PCB pad, and then using manual

or rework station BGA alignment feature on the bit attached to the PCB, when in manual placement BGA,

such as solder ball pitch is small operations need to have more skilled experience.

7, reflow:
Appropriate choice of hot air nozzle, call the appropriate temperature curve BGA soldered on the PCB.

Use process monitoring cameras can be clearly observed in the secondary sedimentation process solder.

8, the test:
Conditions are available X-ray equipment to detect welding quality, or directly functional testing, qualified

the repair is completed.