Product Name: RO4003C+RO4450F Ultra-Thin Four-Layer High-Frequency Board
Material Model: Rogers RO4003C
Material Properties: RO4003C, Dielectric Constant 3.38, 

Dielectric Thickness RO4003C 0.203mm + RO4450F 0.1mm + RO4003C 0.203mm, Total Thickness 0.6mm, 

Surface ENIG, 1-3 Layer Blind Vias, Back-Drilled with Resin Plugged Vias, High-Frequency PCB Board, i.e., High-Frequency Circuit Board.
Definition: High-frequency circuit boards refer to special circuit boards specifically designed for use in electromagnetic frequencies that are relatively high. 

They are primarily applied in high-frequency (frequencies exceeding 300MHz, corresponding to wavelengths less than 1 meter) and microwave (frequencies exceeding 3GHz, 

corresponding to wavelengths less than 0.1 meter) fields.

These PCB boards are manufactured using standard rigid circuit board production processes or special processing techniques on microwave RF-grade copper-clad laminates.

Generally, high-frequency boards can be defined as circuit boards with frequencies reaching or exceeding 1GHz.