The Flip packs a dense, double-stacked motherboard—known in the industry as a substrate-like PCB. We first saw this space-saving technology in the iPhone X, and more recently in the Note10. It makes life harder for board repair experts, but also packs a lot of chips into a tiny space:

Samsung K3UH7H70AM-AGCL 8 GB LPDDR4X RAM layered on top of the Snapdragon 855 CPU

Samsung KLUEG8UHDB-C2D1 UFS 3.1 256 GB NAND Flash

Broadcom AFEM-9106 front-end module

Skyworks SKY78160-51 Low Noise Amplifier

Qualcomm SDR8150 RF transceiver

Qualcomm WCN3998 WiFi + Bluetooth SoC

NXP Semiconductor PN80T NFC controller w/ Secure Element