● Copper Foil
A printed circuit board (PCB) mechanically supports and electrically connects electronic components, laminating conductive tracks and other materials onto non-conductive substrate.And the components including capacitors, resistors or active devices, are generally soldered on the PCB. Indeed, an advanced PCB may contain components embedded in the substrate, while basic one starts with a copper-clad fiberglass material or thin copper sheets adhered to either side of the board, as shown in the following(cross section view of a 2-layer PCB):
From this picture, we can clearly understand the basic composition of a PCB, namely, the basic materials and items that make up a printed circuit board.
Substrate, also named as dielectric sometimes, is one of the important composition of a PCB. It is a sheet of insulation like fiberglass material that has two sheets of copper adhered to either side. Sometimes there may be just one copper sheet on only one side.
Pre-Preg material is made of material similar to the core material, but is in a soft form and comes in standard-sized thin sheets. And Pre-Preg may be used in a multilayer board, placing between these cores to create one solid board with several copper layers. Moreover, these sheets are stacked to create different thickness according to customers’ requirements.
Copper foil is a thin sheet of copper serves as the conductive material in the composition of a PCB, which is placed on or between Pre-Preg materials and bonds to Pre-Preg with the adhesive.