According to IPC-A-610 revision G, you can have a 30% void in your BGA device. I every pin in the STM32F417IGH6 device was missing 30% of its connection, would the device still work per the datasheet?
IPC-A-610 revision G page 8-93 indicates that you can have a 30% void in your solder ball. We recently had a STM32F417IGH6 device over heat. Upon X-ray, we discovered that about 80% of the solder balls had voids near 30%.