ENEPIG for RO4350B with blind vias from L1-L2,L3-L4
This is a high speed testing PCB ,designed by University --high-Speed and Mm-wave IC (CoSMIC) Lab.
RF PCB/high frequency ,material RO4350B.
Stackup :RO4350B 6.6mil+PP+RO4350B 6.6mil
Surface:ENEPIG ---Electroless Nickel Electroless Palladium Immersion Gold
Min trace/space : 4/4mil
See the product link here. https://www.stormpcb.com/productinfo/888592.html