Abstract: An insulating medium rubber film and a production method thereof, and a multi-layer printed-circuit board. The insulating medium rubber film includes a release film and an insulating medium layer arranged on the surface of the release film, where materials of the insulating medium layer include saturated polyester resin, amino resin or blocked isocyanate, epoxy resin, a curing agent, inorganic filler and a curing accelerator. According to the insulating medium rubber film and the production method thereof and the multi-layer printed-circuit board, by introducing the saturated polyester resin component into an epoxy resin composition, the produced insulating medium rubber film has the advantages that a dielectric constant is low, a dielectric dissipation factor is low, thermal expansion is not liable to happen, and adhesion is good.

Abstract: A PCB backup plate preparation method comprises: lubricating and radiating resin is coated onto both surfaces of the wood fiberboard and a resin layer forms, before it is totally dried out, wood pulp paper is bonded to its surfaces, then, the surface of the wood pulp paper is coated with unsaturated polyester resin and forms a resin layer, and the PCB backup plate is prepared; the lubricating and radiating resin is prepared by a 95 weight portion of principal component, composed by two or more of polyethylene oxide, polyethylene glycol, glycerol, vinyl acetate and polyvinyl alcohol, and a 5 portion of nonionic surfactant. The lubricating and radiating resin brings the PCB good lubricating and radiating capabilities, therefore increases the drilling hole accuracy when starts to drill, improves the hole wall quality and lowers the drill pin temperature.