Definition: BGA (Ball Grid Array) is the chip packaging format used for most chips on phone logic boards. Instead of pins around the chip edges, BGA chips have an array of tiny solder balls on their underside. These balls melt and bond to the board during manufacturing. Because all connections are hidden underneath, BGA chips require a hot air rework station and microscope to remove or replace.
Why it matters for phone repair
BGA packaging is why phone board repair is so much more complex than PC motherboard repair. On a desktop PC, many chips have visible pins you can solder by hand. On a phone, the CPU, RAM, storage, Power IC, and nearly every other chip are BGA packages — all connections hidden underneath, invisible once assembled.
When a BGA chip fails — whether from water damage, a drop, or end-of-life — you cannot simply desolder it with a standard iron. You need a hot air station, a microscope, the correct temperature profile for that specific chip, and the skill to align and reflow the replacement. This is why BGA repair is only offered by specialist microsoldering shops.
How it works
BGA chips are manufactured with a precise grid of solder balls on their underside — the ball count can range from a few dozen on small chips to over a thousand on a CPU package. During phone assembly, the chip is placed on the board with solder paste and run through a reflow oven — melting all balls simultaneously and bonding chip to board.
For repair, the board is preheated to reduce thermal shock, then hot air is applied to the chip at a specific temperature until all balls reflow. The chip lifts off cleanly. The board pads are cleaned, new solder paste or reballed chip is placed, and the process is repeated in reverse.
Shareable fact: The Apple A-series CPU packages used in iPhones are PoP (Package on Package) BGA — two chips stacked vertically, with the RAM package sitting directly on top of the CPU package, both connected by BGA balls. This makes CPU-level repair on iPhones exceptionally complex.
Real example
A customer’s iPhone XR shows “No Service” after a drop. The antenna and SIM card test fine. Board diagnosis under the microscope reveals a cold solder joint on the RF (radio frequency) BGA chip — one of several tiny balls has cracked from the impact. Reflowing the chip with a hot air station re-establishes the connection and restores cellular service without replacing the board.
Common mistakes
- Assuming all chip faults require chip replacement. Many BGA failures are cold solder joints that can be fixed by reflowing the existing chip — no new chip needed.
- Applying too much heat. Incorrect temperature profiles when removing BGA chips lift pads from the board — destroying it permanently. This is an irreversible mistake.
- Not checking schematics before repair. Every BGA chip on a phone board has a specific footprint and temperature profile. Repairing without the correct schematic risks bridging contacts.
Related terms
- Microsoldering — the repair technique used to work with BGA chips
- Reballing — the process of replacing all solder balls on a BGA chip
- Logic Board — the board BGA chips are mounted on
- IC — the broader category that BGA chips belong to
Further reading
- Phone Motherboard Repair at BreakFixNow — BGA chip repair and reflowing for all brands
- Phone Repair vs Replacement: Cost Decision Guide — BGA repair cost vs full board replacement
Chip-level fault after a drop or water damage? BreakFixNow specialises in BGA chip repair and reflowing. Free diagnosis, no fix no fee.
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