FR-4 (Glass fiber epoxy resin)Features:FR-4 is a glass fiber fabric reinforced epoxy resin with a medium dielectric constant (Dk 4.5-5.5), low dielectric loss (Df 0.02-0.03), high mechanical strength (bending strength ≥400 MPa), and UL94 V-0 flame retardancy.Advantages:Low cost: Material cost is 50%

1、 Core process technology1. Precision lamination and interconnection processThe core of multi-layer PCB lies in interlayer alignment and bonding, and key technologies include:Laminated laminateMaterial stacking: The inner core board (copper-clad substrate) and the semi cured sheet (PP sheet) are al

1、 Core process technology1. Standard process (through-hole metallization process)Key technical points of the process, precision requirementsPreparation of FR-4/CEM-3/Aluminum Substrate Cutting → Copper Foil Thickness 1-2oz (35-70 μ m) Size Tolerance ± 0.15mmDrilling CNC mechanical drilling (apertur

Four-Layer Circuit Board (4-Layer)1. Layer StructureTypical stack-up:Layer → Prepreg → GND Layer → Core → PWR Layer → Prepreg → Bottom Layer(Top signal, ground, power, bottom signal). Core AdvantagesCost-effective: Compared to a double-sided board, adding a power/ground layer, the cost is only 50%~6