1. Introduction to Copper Clad Laminate
The main material of the printed circuit board (PCB) is copper clad laminate, and the copper clad laminate (copper clad laminate) is composed of a substrate, copper foil and adhesive. The substrate is an insulating layer board composed of polymer synthetic resin and reinforced materials; the surface of the substrate is covered with a layer of pure copper foil with high conductivity and good solderability, the usual thickness is 35-50/ma; the copper foil is covered on the substrate The copper clad laminate on one side is called a single-sided copper clad laminate, and the copper clad laminate with copper foil on both sides of the substrate is called a double-sided copper clad laminate; whether the copper foil can be firmly covered on the substrate is completed by an adhesive. Commonly used copper clad laminates have three thicknesses: 1.0 mm, 1.5 mm and 2.0 mm. There are also many types of copper clad laminates. According to different insulating materials, it can be divided into paper substrate, glass cloth substrate and synthetic fiberboard; according to different binder resins, it can be divided into phenolic, epoxy, polyester and polytetrafluoroethylene; it can be divided into general and special .

2. The structure and characteristics of domestic common copper clad laminates
(1) Copper clad phenolic paper laminate
It is a laminated product made of insulating impregnated paper (TFz-62) or cotton fiber impregnated paper (1TZ-63) impregnated with phenolic resin by hot pressing. The adhesive tape on both surfaces can be attached with a single sheet of alkali-free glass impregnated cloth. Cover one side with copper foil. Mainly used as a printed circuit board in radio equipment.
(2) Copper clad phenolic glass cloth laminate
It is a laminate made of alkali-free glass cloth impregnated with epoxy phenolic resin by hot pressing. One or both sides are coated with copper foil. It has the advantages of light weight, good electrical and mechanical properties, and convenient processing. The surface of the board is light yellow. If melamine is used as the curing agent, the surface of the board is light green with good transparency. Mainly used as a printed circuit board in radio equipment with higher operating temperature and operating frequency.
(3) Copper-clad PTFE laminate
It is a kind of copper-clad board made of PTFE board as the substrate, covered with copper foil and hot pressed. Mainly used for printed boards in high frequency and ultra high frequency circuits.
(4) Copper clad epoxy glass cloth laminate
It is a commonly used material for hole metalized printed boards.
(5) Soft polyester copper clad film
It is a ribbon-shaped material made of polyester film and copper by hot pressing. In application, it is rolled into a spiral shape and placed inside the device. In order to strengthen or prevent moisture, it is often poured into a whole with epoxy resin. Mainly used as flexible printed circuit and printed cable, and can be used as a transition line for connectors.