What is Composite Epoxy Material (CEM)
CEM, short for Composite Epoxy Material, is a type of material used in the manufacturing of printed circuit boards. One such material is CEM-1, which is composed of woven glass fabric surfaces and a paper core combined with epoxy resin. CEM-1 offers excellent electrical properties, higher flexural strength compared to paper-based grades, and can be easily punched up to a thickness of .093″. However, due to its paper core, CEM-1 is not suitable for through-plating.
Another material under the CEM category is CEM-3, which is similar to the widely used FR4 material. CEM-3 utilizes a different type of fabric, known as ‘flies’, and is a flame retardant epoxy copper-clad plate glass material. It is commonly used in electronics with double-sided and multilayer PCB boards. CEM-3 has gained popularity in the Asian market and is considered a viable replacement for FR4.