The main material for printed circuit boards (PCBs) in circuit board factories is copper-clad laminate, which is composed of a substrate, copper foil, and adhesive. The substrate is an insulating layer board composed of polymer synthetic resin and reinforcing materials; A layer of pure copper foil with high conductivity and good weldability is covered on the surface of the substrate, commonly with a thickness of 35-50/ma; a copper clad laminate with copper foil covering one side of the substrate is called a single-sided copper clad laminate, and a copper clad laminate with copper foil covering both sides of the substrate is called a double-sided copper clad laminate; Whether the copper foil can be firmly coated on the substrate depends on the adhesive. The commonly used thicknesses of copper-clad laminates are 1.0mm, 1.5mm, and 2.0mm.

There are several commonly used copper-clad laminates:

FR-1- Phenolic cotton paper, commonly known as electric wood board (more economical than FR-2)

FR-2- Phenolic cotton paper,

FR-3- Cotton paper, epoxy resin

FR-4- Glass cloth, epoxy resin (commonly used fiberglass board in Shenzhen Zhongke Circuit)

FR-5- Glass Cloth, Epoxy Resin

FR-6- frosted glass, polyester

CEM-1- Cotton paper, epoxy resin (flame retardant)

CEM-2- Cotton paper, epoxy resin (non flame retardant)

CEM-3- Glass Cloth, Epoxy Resin

CEM-4- Glass Cloth, Epoxy Resin

CEM-5- Glass Cloth, Polyester

AIN - Aluminum Nitride

SIC - Silicon Carbide

G-10- Glass cloth, epoxy resin

There are also many types of copper-clad laminates. According to different insulation materials, it can be divided into paper substrate, glass cloth substrate, and synthetic fiber board; According to the different adhesive resins, they can be divided into phenolic, epoxy, polyester, and polytetrafluoroethylene, etc; It can be divided into general and special types according to its purpose.