| abstract |
The composite sheet of the present invention comprises a matrix and a stiffener impregnated in the matrix, and has a tanδ value (tanδ = G"/G'), which is the ratio of the loss modulus (G") and the storage modulus (G'), of about more than 0 and about less than 0.05. The composite sheet has a tanδ value in a certain range, and the rate of defects which can arise during high temperature processing during substrate manufacture can be reduced in order to impart flexibility, thermal resistance, and, especially, good optical qualities. |