Ultra-Thin Data Carrier and Method of Read-Out

Abstract

The present invention relates to an ultra-thin data carrier for long-term data conservation and to a method of reading out such a data carrier.

Claims

1-24. (canceled)

25. A data carrier comprising a ceramic substrate having first and second opposite surfaces and a thickness of at most 500 m, wherein the first surface of the ceramic substrate comprises a plurality of laser-ablated recesses encoding information, each recess having a depth of at most 1 m.

26. The data carrier of claim 25, wherein the thickness of the data carrier is at most 200 m.

27. The data carrier of claim 25, wherein the second surface of the ceramic substrate comprises a plurality of laser-ablated recesses encoding information, each recess having a depth of at most 1 m.

28. The data carrier of claim 25, wherein each recess has a depth of at most 100 nm and/or wherein the depth of each recess is smaller than 1% of the thickness of the ceramic substrate.

29. The data carrier of claim 25, wherein the ceramic substrate comprises one or a combination of the following materials: silicon oxide, aluminum oxide, boron oxide, sodium oxide, potassium oxide, lithium oxide, zinc oxide, magnesium oxide.

30. The data carrier of claim 25, wherein the data carrier is wound up in a roll.

31. A data carrier comprising a ceramic substrate having first and second opposite surfaces and a thickness of at most 500 m, wherein the first surface of the ceramic substrate is coated with a first coating, the material of the first coating being different from the material of the ceramic substrate, wherein the first coating comprises a plurality of laser-ablated recesses encoding information.

32. The data carrier of claim 31, wherein the thickness of the ceramic substrate is at most 200 m.

33. The data carrier of claim 31, wherein the second surface of the ceramic substrate is coated with a second coating, the material of the second coating being different from the material of the ceramic substrate, wherein the second coating comprises a plurality of laser-ablated recesses encoding information.

34. The data carrier of claim 31, wherein the thickness of the first coating is at most 10 m.

35. The data carrier of claim 31, wherein each recess in the first coating has a depth of at most 1 m.

36. The data carrier of claim 31, wherein each recess in the first coating has a depth which is smaller than the thickness of the respective coating.

37. The data carrier of claim 31, wherein each recess extends into the ceramic substrate with a depth of at most 1 m.

38. The data carrier of claim 31, wherein a sintered interface is present between the ceramic substrate and the first coating.

39. The data carrier of claim 31, wherein the first coating comprises one or a combination of the following materials: a metal; a metal nitride; a metal carbide; a metal oxide; a metal boride; or a metal silicide.

40. A method of manufacturing a data carrier comprising a ceramic substrate having first and second opposite surfaces and a thickness of at most 500 m, the method comprising: providing the ceramic substrate; and generating a plurality of recesses in the first surface of the ceramic substrate by laser ablation to encode information, wherein each recess has a depth of at most 1 m.

41. A method of manufacturing a data carrier comprising a ceramic substrate having first and second opposite surfaces and a thickness of at most 500 m, the method comprising: providing the ceramic substrate; during a coating process, coating either or both surfaces of the ceramic substrate with first and/or second coatings, the material of the first and/or second coatings being different from the material of the ceramic substrate; and generating a plurality of recesses in the first and/or second coatings by laser ablation to encode information.

42. The method of claim 41, further comprising tempering the data carrier during and/or after the coating process.

43. The method of claim 41, wherein the ceramic substrate is treated on either or both of the first and second surfaces of the ceramic substrate with one or more of the following techniques: heating, sputtering, HiPIMS, applying forming gas such as nitrogen and/or hydrogen.

44. The method of any of claim 41, wherein the ceramic substrate is transparent to the wavelength of a laser light used for the laser ablation, wherein laser ablation is performed with the laser light transmitted through the ceramic substrate.

45. A method of reading out information encoded in a data carrier, wherein the data carrier comprises a ceramic substrate having first and second opposite surfaces and a thickness of at most 500 m, wherein the first surface of the ceramic substrate comprises a plurality of laser-ablated recesses encoding information, each recess having a depth of at most 1 m, the method comprising: illuminating the data carrier with light of a first wavelength; detecting light transmitted through the data carrier and/or reflected by the data carrier; and analyzing the detected light to decode the information encoded in the recesses of the ceramic substrate.

46. A method of reading out information encoded in a data carrier, wherein the data carrier comprises a ceramic substrate having first and second opposite surfaces and a thickness of at most 500 m, wherein the first surface of the ceramic substrate is coated with a first coating, the material of the first coating being different from the material of the ceramic substrate, wherein the first coating comprises a plurality of laser-ablated recesses encoding information, the method comprising: illuminating the data carrier with light of a first wavelength; detecting light transmitted through the data carrier and/or reflected by the data carrier; and analyzing the detected light to decode the information encoded in the recesses of the first coating.

47. The method of claim 46, wherein the ceramic substrate is transparent to the first wavelength, and wherein light transmitted through the ceramic substrate is detected.

48. The method of claim 46, wherein the data carrier is illuminated from the second surface.

49. The method of claim 46, wherein light reflected by the data carrier is detected, wherein light reflected by the data carrier is detected from the second surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] An example of the present invention is subsequently described with reference to the Figures, which show:

[0035] FIG. 1 a transmission microscopy image of an exemplary data carrier at a magnification of 5;

[0036] FIG. 2 a transmission microscopy image of the data carrier of FIG. 1 at a magnification of 10;

[0037] FIG. 3 a transmission microscopy image of the data carrier of FIG. 1 at a magnification of 20;

[0038] FIG. 4 a transmission microscopy image of the data carrier of FIG. 1 at a magnification of 50;

[0039] FIG. 5 a transmission microscopy image of the data carrier of FIG. 1 at a magnification of 100;

[0040] FIG. 6 a transmission microscopy image of another exemplary data carrier inscribed with information encoded digitally; and

[0041] FIG. 7 a transmission microscopy image of another exemplary data carrier inscribed with alphabetic characters in single-line font of 2-8 m height.

DETAILED DESCRIPTION

[0042] For the examples, a ceramic substrate having a size of 10 mm10 mm and consisting of 100 m thick sapphire substrate (Al.sub.2O.sub.3) was coated with a coating of CrN having a thickness of 100 nm by means of physical vapor deposition (PVD). Circular recesses having a diameter of about 1 m (Example 1) and approximately 500 nm (Examples 2 and 3) were ablated from the coating using a 200 femtosecond laser at a wavelength of 515 nm.

[0043] The resulting data carrier of Example 1 was imaged with an Olympus BX-51 at various magnifications. The respective transmission microscopy images at magnifications of 5, 10, 20, 50 and 100 are shown in FIGS. 1-5, respectively.

[0044] As is evident from these Figures, it is possible to reliably and irreversibly create recesses in the coating so as to achieve a superb optical contrast between the material of the ceramic substrate (which is transparent) and the material of the coating layer (which is light absorbing). While the recesses of this Example 1 encode analog information, namely the photograph of the zebra, it is similarly possible to use the various recesses to encode digital information (recess present versus recess not present) as depicted in FIG. 6 (Example 2) or alphanumeric characters as displayed in FIG. 7 (Example 3). In Example 2, individual pixels are smaller than 500 nm in width. In Example 3, the line width of the characters is approximately 500 nm.

[0045] The coating and ablation techniques illustrated above with reference to the examples may be analogously employed with a ceramic substrate having a thickness of at most 200 m. For example, the same coating may be applied onto the so-called glass-ribbon (reference number 2010-03E) available from Nippon Electric Glass. Said glass-ribbon is available in thicknesses between 4 m and 50 m and lengths of up to 100 m. Similarly, Alumina Ribbon Ceramic or Ribbon ceramic made from zirconia (both with a thickness as low as 20 m), available from Corning, may be employed. Other suitable and particularly preferred materials are: AGC Spool, AGC Dragontrail, Corning Willow Glass, Corning Standard Glass Carriers SGC 3.4, SGC 7.8 and SGC 9.0, Nippon Electric GlassG-Leaf (Ultra-thin Glass), SCHOTT AS 87 eco, SCHOTT AF 32 Eco, and SCHOTT Xensation Flex.