The present invention relates to a Cu—Ni—Sn—P-based
copper alloy sheet having a specific composition, where (1) the
copper alloy sheet is set to have an electrical
conductivity of 32% IACS or more, a
stress relaxation ratio in the direction parallel to the rolling direction of 15% or less, a 0.2%-proof stress of 500 MPa or more and an elongation of 10% or more; (2) the X-
ray diffraction intensity ratio I(200) / I(220) in the sheet surface is set to be a given value or less and at the same time,
anisotropy in the
stress relaxation resistance characteristic is reduced by fining the grain size; (3) the texture of the
copper alloy sheet is set to a texture such that the distribution density of B orientation and the sum of distribution densities of B orientation, S orientation and Cu orientation each is set to fall in a specific range and bendability is thereby enhanced; or (4) the
dislocation density measured using the value obtained by dividing the half-value breadth of the X-
ray diffraction intensity peak from {200} plane in the
copper alloy sheet surface by the peak height is set to a given value or more and press punchability is thereby enhanced. The Cu—Ni—Sn—P-based
copper alloy sheet of the present invention is excellent in the properties required for a terminal or connector and further (1) has excellent strength-
ductility balance, (2) satisfies the
stress relaxation resistance characteristic in the direction orthogonal to the rolling direction, (3) has excellent bendability, or (4) has excellent press punchability.