A flex circuit composite based on a fiber blend

A copper clad composite for flexible and multilayer circuitry, having a good combination of electrical, thermal and mechanical properties in an extremely flexible and easily punchable form is described. The material is based on a newly-developed, random nonwoven fabric which is an intimate blend of polyester and glass fibers. The composite which results when this fabric is impregnated with a flexible, flame retardant epoxy resin possesses attributes not available in circuit materials based on polyimide or polyester films, or on resin saturated woven glass or polyester or polyarylamide papers.