I like the teardown in EETimes: Teardown: HTC One smartphone.
Better yet, you can see a step by step teardown by following the following link: http://www.ifixit.com/Teardown/HTC+One+Teardown/13494/2
All ICs in the motherboard are located on the front side of the motherboard.
All ICs are located on the front side of the motherboard:
Elpida BA164B1PF 2 GB DDR2 RAM + Qualcomm Snapdragon 600 quad-core 1.7 GHz CPU
Samsung KLMBG4GE2A 32 GB NAND flash memory
Qualcomm PM8921 power management IC
Qualcomm MDM9215M 4G GSM/UMTS/LTE modem
TriQuint TQM7M9023 multi-band power amplifier
Broadcom BCM4335 single-chip 5G WiFi™ 802.11ac MAC/baseband/radio with Bluetooth 4.0+HS & FM receiver
- Galaxy S4 teardown performed ahead of the phone’s official launch (androidauthority.com)