What are Composite Epoxy Materials (CEMs)?

Composite epoxy materials (CEMs) are made by combining two or more materials having different chemical and physical properties to achieve the desired substrate material with unique properties and characteristics. Epoxy synthetic resin is used to combine materials. It acts as a binding agent to hold the materials together. It also transfers the thermal stress between the materials and protects them from mechanical and environmental damage. 

CEMs are light in weight and strong at the same time. They are generally used as a substrate material in PCBs. They are classified as CEM-1, CEM-2, CEM-3, CEM-4, and CEM-5.

CEM-1 is low-cost, flame-retardant, cellulose-paper-based laminate with only one layer of woven glass fabric.

CEM-2 has cellulose paper core and woven glass fabric surface.

CEM-3 is white in color with properties are very similar to FR-4. When compared to FR-4 it has better heat resistance and is more cost effective. But its mechanical endurance is not as good as FR-4.

CEM-4 similar to CEM-3 but is not flame-retardant.

CEM-5 (also called CRM-5) has a polyester woven glass core.

Click here to see a list of CEM PCB Manufacturers.