A common question about prepreg thickness
Today our customer(Poland) told me that he is designing a 8 layer PCB that with 100ohm impedance controlled.
He has calculated the layer stack-up on Polar si9000 for defining the dielectric parameters, he asked me that he want to make sure that if he can define any prepreg thickness to us(PCB houses), or do we have standard thicknesses?
I answered him the prepreg have standard thickness,and you’d better to choose normal prepreg,because we don’t have any special prepreg in stock for niche market.
Anyway,all of our customers could define the prepreg thickness and type in fabrication spec. If we do not have prepreg with required thickness or types, we will make very small change(by Engineering Query) to meet the layer stack-up and impedance requirements.