Hybrid disc, method and system of forming the disc

1. A data disc, comprising:

a first substrate structure bonded to a second substrate structure, the first substrate structure having a first substrate and at least a first data layer for access from a first side of the disc, the second substrate structure having a second substrate and at least a second data layer for access from a second side of the disc, wherein the first and second data layers have different data formats; and

the second substrate structure further comprising a first curable material layer disposed over a first side of the second substrate, and a second curable material layer disposed over a second side of the second substrate;

wherein the first and second curable materials each has a property that results in shrinkage associated with curing of the material.

2. The data disc of claim 1 , wherein the first and second curable materials are ultra-violet curable acrylic resins.

3. The data disc of claim 1 , further comprising at least a third curable material layer over the second curable material layer, the third curable material having a property that results in shrinkage associated with curing of the material.

4. The data disc of claim 3 , further comprising a layer of material selected from one of a metal and dielectric between the second and the third curable material layers.

5. The data disc of claim 1 , wherein the second substrate is thinner than the first substrate.

6. The data disc of claim 5 , wherein the first substrate has a thickness less than about 0.65 mm, and the second substrate has a thickness less than about 0.55 mm.

7. The data disc of claim 1 , further comprising a third data layer associated with the first substrate and a fourth data layer associated with the second substrate.

8. The data disc of claim 7 , wherein at least one of the first substrate structure and the second substrate structure has at least two data layers with different formats.

9. The data disc of claim 7 , wherein at least one of the first data layer, the second data layer, the third data layer and the fourth data layer is a recordable data layer.

10. The data disc of claim 1 , having only one annular protruded portion.

11. The data disc of claim 1 , wherein the first format is digital versatile disc (DVD) and the second format is Blu-ray disc (BD).

12. The data disc of claim 1 , having at least one of a total height and flatness that conforms to specification standards for DVD-read only memory (DVD-ROM) and BD-ROM discs.

13. A method for forming a data disc, comprising:

forming a first substrate structure having at least a first data layer for access from a first side of the disc;

forming a second substrate structure having at least a second data layer for access from a second side of the disc, wherein the first data layer and the second data layer have different data formats;

depositing at least a first curable material layer over a first side of a second substrate of the second substrate structure and curing the deposited first material; and

depositing at least a second curable material layer over a second side of the second substrate and curing the deposited second material;

wherein the first curable material has a property that results in a first amount of shrinkage associated with curing of the material, and the second curable material has a property that results in a second amount of shrinkage associated with curing of the material; and

bonding the first substrate structure to the second substrate structure.

14. The method of claim 13 , further comprising:

providing a thickness and material for the second curable material layer such that a curvature of the second substrate structure associated with the second amount of shrinkage is substantially equal to a curvature of the second substrate structure associated with the first amount of shrinkage.

15. The method of claim 13 , further comprising:

forming at least a third layer of curable material over the second curable material layer, the third layer of curable material having a property that results in shrinkage associated with curing of the material.

16. The method of claim 13 , further comprising:

forming a layer of material selected from one of a metal and dielectric between the second and the third curable material layers.

17. The method of claim 13 , further comprising, prior to bonding:

molding the first substrate to provide a first curvature; and

forming the second substrate structure with a second curvature, the second curvature including curvature contributions from at least the first and second amounts of shrinkage;

wherein the first curvature and the second curvature are opposite in directions.

18. The method of claim 13 , further comprising:

forming the first substrate structure and the second substrate structure by selecting a combination of materials and thicknesses to produce the disc with at least one of a total thickness and flatness conforming to specification standards for DVD-read only memory (DVD-ROM) and BD-ROM discs.

19. A data disc, comprising:

a first substrate structure bonded to a second substrate structure;

the first substrate structure having a first substrate and at least a first data layer in a first format for access from a first side of the disc;

the second substrate structure having a second substrate and at least a second data layer in a second format for access from a second side of the disc, the second format being different from the first data format;

wherein the disc has a single annular protruded portion formed on a thinner one of the first and second substrates.

20. The data disc of claim 19 , wherein the first substrate has a thickness between about 0.55 mm and about 0.64 mm, and the second substrate has a thickness between about 0.45 mm and about 0.55 mm.

21. The data disc of claim 19 , wherein at least one of the first substrate structure and the second substrate structure includes a recordable data layer.

22. The data disc of claim 19 , further comprising:

a first material layer disposed over a first side of the second substrate;

a second material layer disposed over a second side of the second substrate;

wherein the first material layer and the second material layer each includes a curable material having a property that results in shrinkage associated with curing of the material.

23. The data disc of claim 19 , wherein at least one of the first substrate structure and the second substrate structure has two data layers with different data formats.

24. A method of forming a data disc, comprising:

providing a first substrate structure having a first substrate and at least a first data layer in a first format for access from a first side of the disc;

providing a second substrate structure having a second substrate thinner than the first substrate and at least a second data layer in a second format for access from a second side of the disc, the second format being different from the first format; and

bonding the first substrate structure to the second substrate structure;

wherein a single annular protruded portion is provided on the disc, and is formed by injection molding of the second substrate.

25. The method of claim 24 , wherein the first substrate structure is formed by:

molding the first data layer into the first substrate;

molding a data pattern on a first side of a third substrate and another annular protruded portion on a second side of the third substrate;

forming a spacer layer on the first substrate;

forming a third data layer on the spacer layer by using the third substrate as a stamper for transferring the data pattern to the spacer layer; and

removing the third substrate from the spacer layer.

26. The method of claim 24 , further comprising:

depositing at least a layer of a first curable material over a first side of the second substrate and curing the deposited first material; and

depositing at least a layer of a second curable material over a second side of the second substrate and curing the deposited second material;

wherein the first curable material and the second curable material each has a property that results in shrinkage associated with curing of the material.

27. The method of claim 24 , further comprising:

forming the first substrate structure and the second substrate structure by selecting a combination of materials and thicknesses to produce the disc with at least one of a total thickness and flatness conforming to a specification standard for a hybrid disc with digital versatile disc (DVD) and Blu-ray disc (BD) formats.

28. A system for use in forming a data disc, comprising:

a first sub-system configured for forming a first substrate structure having a first substrate and at least a first data layer having a first data format for access from a first side of the disc, the first sub-system being configured for forming the first substrate structure without any annular protruded portion;

a second sub-system configured for forming a second substrate structure having a second substrate and at least a second data layer having a second data format for access from a second side of the disc, wherein the second data format is different from the first data format; the second sub-system being configured for forming an annular protruded portion by injection molding of the second substrate; and

a third sub-system configured for bonding the first substrate structure to the second substrate structure to form the data disc.

29. The system of claim 28 , wherein the first sub-system is configured for forming the first substrate structure by performing the steps of:

molding the first data layer onto the first substrate;

molding a data pattern on a first side of a third substrate and an annular protruded portion on a second side of the third substrate;

forming a spacer layer on the first substrate;

forming a third data layer on the spacer layer by using the third substrate as a stamper for transferring the data pattern to the spacer layer; and

removing the third substrate from the spacer layer, the third substrate not forming a part of the data disc.

30. The system of claim 29 , wherein the first sub-system includes:

a first molding machine with a first mold for molding the first data layer on the first substrate without forming an annular protruded portion on the first substrate;

a second molding machine with a second mold for molding the annular protruded portion on the third substrate;

wherein the first sub-system is further configurable for use in producing a dual-layer digital versatile disc (DVD) by using the second mold in the first molding machine for forming a first data layer and an annular protruded portion of the double-layer DVD, and using the first mold in the second molding machine for forming a second data layer of the dual-layer DVD.

31. The system of claim 28 , wherein the first sub-system is configured for forming a digital versatile disc (DVD) substrate structure and the second sub-system is configured for forming a Blu-ray disc (BD) substrate structure.