What Is a Copper Clad Laminate?
A copper clad laminate, also known as CCL, is made by laminating resin-impregnated sheets onto a base material such as paper or glass, then applying pressure and heat treatment to produce a laminate with copper foil on both sides.
It is used in a wide variety of printed wiring boards and electronic circuit modules. Electronic components such as ICs and chip capacitors are placed by forming patterned circuits on the surface and inner layers and connecting multilayer wiring with vias.
Uses of Copper Clad Laminates
Copper clad laminates are usually standardized in their final form as printed circuit boards, with the most widely known and universally used being FR-4, which is a glass epoxy substrate.
FR-4 substrates have excellent high-frequency characteristics and mechanical strength. They are used in a wide range of applications, including information equipment such as PCs, home appliances, mobile terminals, OA equipment, and industrial machinery.
FR-5 substrates with excellent heat resistance are used for in-vehicle applications that require high reliability.
Principle of Copper Clad Laminates
Copper clad laminates (CCLs) are made by impregnating a cloth made of woven fibers called glass cloth, which has high insulation properties, with resin. Therefore, it can be said that the composition of the copper clad laminates is the most important factor in the characteristics of a printed circuit board.
There are two main types of copper clad laminates: 3-layer CCL and 2-layer CCL.
The 3-layer CCL is the most widely used today because it is inexpensive and has stable characteristics and quality. Epoxy and acrylic adhesives are used as bonding agents. The lamination method is the most common manufacturing method.
Compared to 3-layer CCL, 2-layer CCL has various manufacturing methods other than lamination, such as casting, sputtering, and plating, but the cost tends to be higher.
However, the cost tends to be higher, but the quality and characteristics are superior to the cost. It is generally purchased as a core material (base material) from chemical material manufacturers who are mainly contracted to manufacture copper clad laminates.