Please ask a question about "PCB specification" in "nRF9160HardwareIntegrationGuidev12.pdf".
The board thickness is 1.6 mm.
Adding the thickness of the listed copper and FR-4, it becomes 1.506mm (18um + 100um + 35um + 1200um + 35um + 100um + 18um = 1506um).
What does the difference thickness 0.094mm (1.6mm-1.506mm) indicate?