... PCB factory price directory; 2.Assembly service; 3.Finish:HASL,ENIG,Pb free,OSP; 4.Finish copper: 35um. 5.Drop Shippin 1.Layer ... counts: Single, double, four layer, and 6-30 layer boards are available; 2.Material: copper. 3.Finished ... silver/gold, OSP; 8.Other Technology: Gold finger, peelable mask, Non-across blind/buried vias, characteristic impedance control, Rigid-flex ...