One of the key factors of the success of Apple iOS devices is the proper selection of its hardware components. Just like the iPhone, the iPad is also a collection of modules, chips, and electronic components from different manufacturers. Internal images for all iPads can be found in the teardown section of http://www.ifixit.com/Device/iPad.
The following images show the internals of the iPad Pro. The images were taken after dismantling the iPad Pro cellular model and were obtained from https://www.ifixit.com/Teardown/iPad+Pro+Teardown/52599.