On the Gerbers it looks like the Following

What a BGA component looks like

A BGA component on a PCB Looks like the following

Not all PCB Assemblers can fit BGAs, over 95% of the solder joints are not visible after assembly, a lot of care must be taken

When fitted to a PCB it looks like the following

When Assembled they are X-Rayed…

What the Assembler is checking is the Solder Connection

Cold Solder Joints

Now the tighter the Pitch of BGA, the thinner the tracks and gaps, usually the higher the layer count

So for a PCB Manufacturer…

BGAs typically mean finer tracking and spacing

Smaller holes and Tighter Layer Alignment Requirements

BGA pads must be free from any contamination..(>95% of solder joints not visible after soldering)

As stated the problems comes as the pitch gets tighter and the BGA gets larger getting the tracks to reach the centre of the Device can only be achieved by finer tracks up to 3 tracks per bga pitch

So think about the panel size that has been selected.

Look at the Customer Carrier Size….

The Difficulty in Manufacturing a Printed Circuit is directly related to the Pitch and No. of BGAs on the Manufacturing Panel…