Apple iPad mini 2 logic board view supplied as a 19.4 MB .pcb boardview. The file links each component designator to its location and nets, so a repairer can follow power rails, locate test points and see which parts are tied to a failed line. It is opened with a boardview viewer that supports this .pcb variant, such as OpenBoardView or FlexBV. Ensure the device is the second-generation mini, since the original mini and later models use different boards and layouts.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @boardview. Enginerys does not host this file.
How to open a .pcb file
In repair archives a .pcb is typically an XZZ (XinZhiZao) boardview — popular for phones and recent laptops.