Method for fabrication of disc substrate
AssigneeSony Corporation
InventorsJunichiro Kudo, Jun Shimizu
Life of this patent
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Abstract
An improved method for forming a disc substrate having a bottomed centering hole for rotating and driving the disc. The method includes injecting synthetic resin into a mold cavity formed by a first and second metal molds to form the substrate, and punching at least part of the centering hole by a movable member protruded into the mold cavity to form a through-hole. A stamper containing digital information is held in place inside the mold cavity by its inner circumference by means of a vacuum or a magnet.
Claims8
A method for forming in a mold cavity created by a first metal mold and a second metal mold a disc substrate having a bottomed centering hole and a reference loading plane for disc rotating and driving means, the reference loading plane being substantially parallel to a planar region on which a light beam is incident, the reference loading plane being projected from the planar region, comprising the steps of:
- holding a radially outer edge of a stamper in the mold cavity against an outer edge of the first metal mold with a holder attached to the first metal mold;
- holding a radially inner side of the stamper to the first metal mold;
- injecting synthetic resin into the mold cavity for forming the bottomed centering hole, wherein the bottomed centering hole is formed by a stationary member protruding into the mold cavity;
- and
- punching at least a part of the bottomed centering hole by a movable member protruded into the mold cavity for forming a through-hole.
A method for forming in a mold cavity created by a first metal mold and a second metal mold a disc substrate having a bottomed centering aperture and a reference loading plane for disc rotating and driving means, the reference loading plane being substantially parallel to a planar region on which a light beam is incident, the reference loading plane being projected from the planar region, comprising the steps of:
- holding a radially outer edge of a stamper in the mold cavity against an outer edge of the first metal mold with a holder attached to the first metal mold;
- holding a radially inner side of the stamper to the first metal mold;
- injecting synthetic resin through a sprue bushing into the mold cavity for molding the disc substrate, and
- pushing the sprue bushing out of the mold cavity while simultaneously punching through a central region of the molded disc shaped substrate by projecting a movable member through the second metal mold into the mold cavity for forming the bottomed centering hole in the disc shaped substrate.
A method of molding a disc shaped substrate having a projection, the projection being formed in a central portion of the disc shaped substrate and having a through-hole, the method comprising the steps of:
- moving one of a first metal mold and a second metal mold mounted facing the first metal mold toward and away from the other of the first metal mold and the second metal mold, the second metal mold defining a mold cavity between it and the first metal mold;
- holding at an outer edge of the mold cavity a radially outer side of a stamper mounted on the first metal mold and arranged within the mold cavity and being attached to the first metal mold;
- attracting a radially inner side of the stamper to the first metal mold;
- positioning the stamper by engaging a resin injecting sprue bushing with the central aperture in the stamper;
- injecting resin into the mold cavity via the sprue bushing to form the disc shaped substrate;
- and
- pushing the sprue bushing out of the mold cavity while simultaneously punching through a central region of the molded disc shaped substrate by projecting a movable member into the mold cavity for forming the through-hole in the disc shaped substrate.
Dependencies are inferred from the claim text.