What is Copper clad laminate (CCL)?

1. CCL structure

Copper clad laminate (CCL) is the most basic raw material for PCBs. The structure of the CCL is a structure in which copper clad is attached to one or both sides of an insulator such as glass fiber (FR4), paper, in the center.

 

 

CCL (Copper clad lamination) Double side(L), Sing side(R)

2. Classification of CCL
Paper phenol: It's a yellow PCB you can see on black and white TV. It is a material that is not available these days due to the toxicity of phenols even though it is made for low-cost products. All properties, such as strength, moisture resistance, are weak. These days, it's a material that can only be seen for lead education. .

Paper phenol PCB

- CEM1, CEM3 : CEM1 is made of glass fiber and cellulose, and CEM3 is made of glass fiber and epoxy. It is mainly used for mounting parts with large heat generation and surface is white.

CEM1, CEM3 PCB

       

 

- FR1, FR2, FR3: FR1 is basically the same as FR2. For FR2, the TG of FR1 is 130 ℃ higher than 105℃. Some laminate manufacturers that produce FR1 may not produce FR2 because they are similar in cost and usage and are not cost-effective to have both. FR3 is also FR2 by default. However, instead of phenolic resins, an epoxy resin binder is used.

 

- FR4 : Glass fiber epoxy laminate. This is the most used PCB material. FR4 uses 8 layers of glass fiber material. The maximum ambient temperature is between 120℃ and 130℃ depending on the thickness. FR4 is the most widely used PCB raw material, followed by FR1 and FR2. FR1 and FR2 materials are usually used as cross-sectional PCBs due to poor CNC processing.

 

- Teflon : It is used as a PCB for high-frequency communication, and it is expensive and difficult to process.

 

- PI : Internal insulation within flexible applications is polyamide (PI).