The present invention provides a composition comprising: (a) dielectric material; and (b) porogen comprising at least two fused aromatic rings wherein each of the fused aromatic rings has at least one alkyl substituent thereon and a bond exists between at least two of the alkyl substituents on adjacent aromatic rings. Preferably, the dielectric material is a composition comprising (a) thermosetting component comprising (1) optionally monomer of Formula I as set forth below and (2) at least one oligomer or polymer of Formula II as set forth below where Q, G, h, I, I, and w are as set forth below and (b) porogen. Preferably, the porogen is selected from the group consisting of unfunctionalized polyacenaphthylene homopolymer, functionalized polyacenaphthylene homopolymer, polyacenaphthylene copolymer, polynorbornene, polycaprolactone, poly(2-vinylnaphthalene), vinyl anthracene, polystyrene, polystyrene derivatives, polysiloxane, polyester, polyether, polyacrylate, aliphatic polycarbonate, polysulfone, polylactide, and blends thereof. The present compositions are particularly useful as dielectric substrate material in microchips, multichip modules, laminated circuit boards, and printed wiring boards.