According to ETNews, Samsung will be back inside the iPhone 7 after five years. While many thought that the reason that Apple pulled Samsung out of the iPhone 6s was pettiness over the trademark battle over who invented the rounded rectangle, it turns out that Apple's wanted electromagnetic interference (EMI) shielding requirements or special coatings on the memory packages.
Apple was looking to individually shield more parts inside its devices so it could dispense with discrete metal shielding components, which could ultimately save on logic board space and allow more room. At the time Samsung's use of ball grid array (BGA) packaging put it at a disadvantage to competing products that use land grid array (LGA) package contacts, which allow the package to sit flush with the printed circuit board.
Samsung's existing sputter coat EMI shielding technologies were insufficient for Apple's performance requirements, becuase of the shielding gaps created by the raised BGA contacts. However new, cheaper spray techniques for ultra-thin coats of metal shielding has changed all that. Also Samsungs 3D V-NAND memories offering up to 256 Gb densities on the market currently.
Samsung is also set to start supplying Apple with OLED panels for future iPhones. All up it means that a big chunk of your iPhone is a Samsung. Still you get what you pay for. Anyway, with the acception of Foxconn, being an Apple supplier is a kiss of death in the long term. Maybe Apple thought it was better to score its revenge on Samsung by making it a partner.