what's multilayer printed circuit boards ?MultiLayer pcb board means has more than two copper layers, such as 4L, 6L, 8L, 10L, 12L, etc. As technology improving, people can put more and more copper layers on the same board. Currently, kdpcb can produce 2L-24L FR4 pcb.More layers it means more complex & difficult, the manufacturing cost will be more expensive. The lead time of multi-layer PCB is different from normal one, please contact usfor a exact lead time.PCB board SpecificationsPcb thickness:1.2mmLayer account:4-LayerSurface finished:immersion gold;Line width&space4/3milsFinished copper:1ozSolder mask:blue;Material:FR4.Certificates:CQC,ISO.TS16949,SGS,ISO9001,UL,ISO.14001,ROHSDelivery time:sample 3-5days,mass production:10-14days;Package details:vacuum pcb,inside bubble all inside,cartoon,ties outside strengthening;4 layer pcb circuit boards structureTop silkscreen/LegendTop Surface finishingTop Soldermask (overlay)Top TraceSubstrate/Core materialPrereg (PP)Middle Layers(Inner1, Inner 2)Prepreg (PP)Bottom trace (if any)Bottom soldermask (overlay)Bottom surface finishingBottom silkscreen/legendKDPCB Advantages1--never set any moq for every pcb board order;2--shortest response for all clients need;3--reasonable competitive price with high quality;4--support "one-stop"service for part of clients;5--shortest delivery time on pcb board production;6--"5S"and ISO.TS16949 quality system control manufacture;7--professional,high communication,trustworthy;8--all kinds of pcb board manufacture are acceptable;9--TNT/UPS/DHL/FEDEX/special shipping agency support with lower price;KDPCB pcb manufacturer specialty is in the complex, advanced technology of PCB fabrication,such as HDI(high density technology)pcb board,rigid-flexible pcb,flexible pcb,ultrathin pcb,gold finger pcb,hard gold plating pcb board and others;KDPCB never price oriented,we only quality oriented,details oriented,all our material vendors is only the famous brand manufacturers such as KB group/ITEQ/ROGERS and others;With us, you receive unparalleled technical expertise support for 4 layer pcb manufacture or PCBA;we strive for our customers to feel that our service is so unique and valuable that they would want to work with us forever.We understand that1)you want solutions support not always make trouble to you ,2)you want what you need and not what a boardhouse wants to sell you.application fieldconsumer electronics such as tablet computer,micro computer electronics;telecommunications electronics;computer electronics;diy electronics;others devices electronics;