Basic knowledge of CCL

CCL—–Also known as the base material.

CCL (Copper Clad Laminate) consists of wood pulp paper or glass fiber cloth as reinforcing materials with resin, and single or double-sided coated with copper foil, and laminated under high temperature and high pressure. It is also called a core plate when it is used for multilayer board production.

At present, CCL supplied on the market can be divided into the following main categories based on the base materials: paper plate, fiberglass cloth plate, synthetic fiber cloth plate, non-woven plate, composite plate.

The substrate is insulating layer board composed of polymer resin and reinforced material. the surface of the substrate is covered with copper foil with a high conductivity and good weldability. The copper foil’s thickness commonly is 35~50/ma. The single-sided CCL means that the copper foil cover one side of the base plate, and CCL that two sides of the base plate cover copper foil is called double-sided CCL. Whether the copper foil can be firmly attached to the substrate depends on the binder. The thickness of the common CCL is 1.0mm, 1.5mm and 2.0mm.

The Common CCL:
FR-1 ── Phenolic potton paper, the base material commonly known as Bakelite (higher performance-price ratio than FR-2)
FR-2 ── phenolic cotton paper
FR-3 ── cotton paper, Epoxy
FR-4 ──woven glass, epoxy resin
FR-5 ── Glass cloth, Epoxy resin
FR-6 ── glass, polyester
G-10 ── glass cloth, epoxy
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, multi-ester
AIN ── aluminum nitride
SIC ── silicon carbide

There are also more types of CCL. According to different insulating materials, they can be divided into paper plate, glass cloth and synthetic fiber board; According to the binder resin, they can be divided into phenolic, epoxy, polyester and PTFE, etc.; According to the usage, they can be divided into general-purpose and special type.

Structure and characteristics of common CCL

(1) Phenolic paper copper-clad laminate uses insulating impregnated paper (TFZ 162) or cotton impregnated paper (1tz-163) impregnated with phenolic resin, and laminated thermally. Two-side gummed paper can be attached to a single sheet of alkali-free glass dipping tape, the other side attached to copper foil which is mainly used as printed circuit board in radio equipment.

(2) Phenolic glass cloth Copper-clad laminate uses alkali-free glass cloth impregnated with epoxy resin , and laminated thermally. Its single or double-sided coated with copper foil. And it has light weight, good electrical and mechanical properties, convenient processing and other advantages. Its plate is light yellow. If we used cyanuric diamine as a curing agent, the plate is light green, and has good transparency. It is mainly used as printed circuit board in radio equipment that operate frequently in high temperature.

(3) PTFE copper clad laminate is based on PTFE board, attached to copper foil by hot pressing, which is mainly used in high frequency and UHF circuits for printed boards.

(4) Epoxy glass cloth copper clad laminate is a commonly material for perforated metallized printed boards.

(5) Soft polyester copper film is a ribbon material pressed with polyester film and copper thermally. of It curled into a spiral shape placed inside the device in real application. It is often injected into a whole with epoxy resin for reinforcement or moisture resistance. And It is mainly used as flexible printed circuit and printed cable which is the transition line of the connector.

One thing to be aware of is that the power corresponding connection should be thickened: 5.0V, 3.3V and so on before the copper cover, so that multi-variable structure with different shapes can be formed.