| 摘要 |
PURPOSE:To relieve the strain of substrates and to improve reliability by changing the properties of the adhesive agent between the spacers and substrates provided on the inside circumference and outside circumference of the substrates, using the secure adhesive agent for the inside circumference and using the plastic adhesive agent for the outside circumference. CONSTITUTION:Guide grooves for an optical head for information reading and recording grooves 2 for recording information are provided to the substrates 1. The substrates 1 are disposed to face each other by interposing the inside circumferential spacer 3 and the outside circumferential spacer 4 to the regions in the inside circumferential part and outside circumferential part of the substrates 1 where there are no films 2, then the substrates are joined by the adhesive agents 5, 6. The adhesive agent 5 of an epoxy system having high adhesive strength is used for the substrate 1 and the spacer 3 and the adhesive agent 6 of an urethane system or silicone rubber system having plasticity is used for the substrate 1 and the spacer 4. The strain in the substrates and the strain of the deterioration with age by humidity in use environment are relieved in this way and the fluctuation in the light reflectivity is decreased, by which the reliability is improved. |
