MB1791 Development Board PCB Layout

[KKan.1]

Beside the MB1791 BOM doubt, there is PCB Layer Stack doubt too.

About MB1791 PCB & Gerber Files, there is no Signal copper layout in the Middle Layer-1 (G1 Layer) & Middle Layer-2 (G2 Layer). Why the setting applied 4-layers PCB instead of 2-layers PCB ?

Info referring

--> STM32WL55CC - Sub-GHz Wireless Microcontrollers. Dual-core Arm Cortex-M4/M0+ @48 MHz with 256 Kbytes of Flash memory, 64 Kbytes of SRAM. LoRa, (G)FSK, (G)MSK, BPSK modulations. AES 256-bit. Multiprotocol System-on-Chip. - STMicroelectronics

Pls advise.

[Sarra.S]

Hello again @KKan.1​ 

I reported your question internally.

Internal ticket number: 149286  (This is an internal tracking number and is not accessible or usable by customers)

Thank you!