| 摘要 |
PROBLEM TO BE SOLVED: To provide a package substrate in which the occurrence of peeling or cracks of an optical path for optical signal transmission is prevented and which is therefore excellent in reliability. SOLUTION: The package substrate is provided in which a conductor circuit and an insulating layer are layered on both surfaces of the substrate, at least one solder resist layer is formed on the outermost layer, an optical element is packaged and the optical path for optical signal transmission is formed. The package substrate is characterized in that the solder resist layer has a transmissivity of a communication wavelength of≥60% at the thickness of 30μm. COPYRIGHT: (C)2006,JPO&NCIPI |
