Top side, we have the following ICs:

Intel Core i5-6440HQ Processor (6M Cache, up to 3.50 GHz)

Eight Samsung K4A4G085WE-BCPB 512 MB DDR4 RAM (4 GB on this side and another 4 GB on the reverse)

Nvidia GeForce GTX 965M GPU

Intel GL82CM236 Platform Hub Controller

ON Semiconductor NCP81205 3+3+1 Phase Controller

Infineon SLB 9665 TT 2.0 TPM (as seen in the Surface Book) and Infineon 0812ND HBE613 (x14)

Winbond W25Q128FV 128 M Serial Bit Flash Memory