Making a nanoporous substrate, such as the matrix in an elec. laminate, occurs by grafting onto an org. resin backbone a thermolabile functionality by reacting H active groups of the org. resin with a compd. contg. thermolabile groups, then thermally degrading the thermolabile groups grafted on the org. resin to form a nanoporous laminate. The nanoporous elec. laminate has a low dielec. const. (Dk) because of the nanopores present in the laminate matri