How to repair an LGA chip

Here are the key takeaways:

False soldering/false soldering‌: Insufficient amount of solder or insufficient temperature leads to poor contact. It is necessary to

adjust the stencil opening to 90% of the pad size (such as 0.45mm), and extend the reflow constant temperature stage to 55 seconds.
Or reheat after manual repair soldering.

Cavities/Tin Overflow‌: Insufficient solder paste thickness or poor gas escape. It is recommended to increase the solder paste thickness

to more than 0.2mm, adopt a one-shaped bridge steel mesh design, or pre-tin reflow process:

Offset/Short Circuit: Improper pad design or uneven heating. It is necessary to optimize the pad height difference and use BGA machine

to heat evenly to avoid local overheating.

It is recommended to use the BGA rework station DH-A2E (temperature 180~280℃, time 2~4 minutes), avoid using soldering iron and

heat gun:

‌Auxiliary tools‌: microscope (10-20 times), X-Ray detector, solder absorber and anti-static tweezers.