... :1.Layer: 2-22 layer2.Product type: Rigid PCB,High Density Inverter PCB,thick copper PCB3.Materials: FR-4, CEM-3 ... 0.4mm14.Resistance Tolerance: ±10%15.Minimum Insulation Thickness: 3mil16.Maximum laser blind hole thickness to diameter ratio: 0.8:117.Maximum working ... , Immersion Gold, Immersion Tin, Immersion Silver, OSP, Gold Finger Plating, Carbon Ink Printing, Peelable Blue Mask-We accept build-to ...