Lift printing using thin donor foils

Patent metadata

Field	Value
Publication number	US-12162294-B2
Application number	US-202017427372-A
Country	US
Kind code	B2
Filing date	May 4, 2020
Priority date	May 7, 2019
Publication date	Dec 10, 2024
Grant date	Dec 10, 2024

Abstract

Printing apparatus includes a donor supply assembly, which positions a transparent donor substrate having opposing first and second surfaces and a donor film formed on the second surface so that the donor film is in proximity to a target area on an acceptor substrate. An optical assembly directs one or more beams of laser radiation to pass through the first surface of the donor substrate and impinge on the donor film so as to induce ejection of material from the donor film onto the acceptor substrate. Means are provided to mitigate or compensate for the variation in reflection of the laser radiation across an area of the donor substrate, so as to equalize a flux of the laser radiation that is absorbed in the donor film across the area of the donor substrate.

First claim

The invention claimed is:

1. A printing apparatus, comprising:
a donor supply assembly, which is configured to position a transparent donor substrate having opposing first and second surfaces and a donor film formed on the second surface so that the donor film is in proximity to a target area on an acceptor substrate;
an optical assembly, which is configured to direct one or more beams of laser radiation to pass through the first surface of the donor substrate and impinge on the donor film so as to induce ejection of material from the donor film onto the acceptor substrate;
a monitoring assembly, which is configured to measure a variation in reflection of the laser radiation across an area of the donor substrate; and
a controller, which is configured to adjust an intensity of the laser radiation responsively to the measured variation so as to equalize a flux of the laser radiation that is absorbed in the donor film across the area of the donor substrate.

2. The apparatus according to claim 1 , wherein the monitoring assembly is configured to capture an image of an interference pattern formed by the laser radiation, wherein the interference pattern is indicative of the variation in the reflection.

3. The apparatus according to claim 1 , wherein the donor film comprises a metal and the donor substrate has a thickness between the first and second surfaces that is no greater than 200 μm.

4. The apparatus according to claim 1 , wherein the donor substrate is comprised in a continuous flexible foil, and wherein the donor supply assembly comprises feed rollers, which are configured to feed the foil across the target area.

5. The apparatus according to claim 4 , wherein the donor supply assembly is configured to successively position different donor areas of the foil in proximity to the acceptor substrate, and
wherein the monitoring assembly is configured to measure the variation of the reflection respectively in each of the donor areas, and the controller is configured to adjust the intensity of the laser radiation impinging on each of the donor areas responsively to the respectively measured variation.

6. A printing apparatus, comprising:
a donor supply assembly, which is configured to position a transparent donor substrate having opposing first and second surfaces and a thickness between the first and second surfaces no greater than 200 μm, and having a donor film formed on the second surface so that the donor film is in proximity to a target area on an acceptor substrate; and
an optical assembly, which is configured to direct one or more beams of pulsed visible laser radiation, having a bandwidth of at least 0.8 nm, to pass through the first surface of the donor substrate and impinge on the donor film so as to induce ejection of material from the donor film onto the acceptor substrate.

7. The apparatus according to claim 6 , wherein the pulsed laser radiation comprises pulses having a pulse duration of at least 0.5 ns.

8. The apparatus according to claim 6 , wherein the bandwidth of the visible laser radiation directed to pass through the first surface of the donor substrate is no greater than 1.0 nm.

9. The apparatus according to claim 6 , wherein the optical assembly comprises:
a laser, which generates an input beam of the laser radiation having an initial bandwidth less than 0.4 nm; and
a nonlinear optical element, which is configured to receive and broaden the bandwidth of the input beam to at least 0.8 nm.

10. The apparatus according to claim 9 , wherein the nonlinear optical element is configured to broaden the bandwidth using the optical Kerr effect.

11. The apparatus according to claim 6 , wherein the donor film comprises a metal.

12. The apparatus according to claim 6 , wherein the donor substrate is comprised in a continuous flexible foil, and wherein the donor supply assembly comprises feed rollers, which are configured to feed the foil across the target area.

13. A printing apparatus, comprising:
a donor supply assembly, which is configured to position a transparent donor substrate having opposing first and second surfaces and a donor film formed on the second surface so that the donor film is in proximity to a target area on an acceptor substrate; and
an optical assembly, which comprises:
a laser, which generates an input beam of laser radiation having an initial bandwidth;
a nonlinear optical element, which is configured to receive the input beam and generate an output beam having an output bandwidth at least twice the initial bandwidth;
optics configured to direct the output beam to pass through the first surface of the donor substrate and impinge on the donor film so as to induce ejection of material from the donor film onto the acceptor substrate;
a monitoring assembly, which is configured to measure a variation in reflection of the laser radiation across an area of the donor substrate; and
a controller, which is configured to adjust an intensity of the laser radiation responsively to the measured variation so as to equalize a flux of the laser radiation that is absorbed in the donor film across the area of the donor substrate.

14. The apparatus according to claim 13 , wherein the nonlinear optical element is configured to broaden the bandwidth using the optical Kerr effect.

15. The apparatus according to claim 13 , wherein the donor film comprises a metal.

16. The apparatus according to claim 13 , wherein the donor substrate is comprised in a continuous flexible foil, and wherein the donor supply assembly comprises feed rollers, which are configured to feed the foil across the target area.

17. A printing apparatus, comprising:
a donor supply assembly, which is configured to position a transparent donor substrate having opposing, mutually-parallel first and second surfaces and a thickness between the first and second surfaces no greater than 200 μm, and having a donor film formed on the second surface with the donor film in proximity and parallel to a target area on an acceptor substrate; and
an optical assembly, which is configured to direct one or more beams of pulsed visible laser radiation having a bandwidth of at least 0.8 nm to pass through the first surface of the donor substrate at an angle that deviates from a normal to the first surface by at least 1°, and to impinge on the donor film so as to induce ejection of material from the donor film onto the acceptor substrate.

18. The apparatus according to claim 17 , wherein the donor film comprises a metal.

19. The apparatus according to claim 17 , wherein the optical assembly is configured so that the angle at which the one or more beams of laser radiation pass through the first surface of the donor substrate deviates from the normal to the first surface by at least 5°.

20. The apparatus according to claim 19 , wherein the optical assembly is configurable so that the angle at which the one or more beams of laser radiation pass through the first surface of the donor substrate deviates from the normal to the first surface by 10°.

21. The apparatus according to claim 19 , wherein the donor substrate has a thickness between the first and second surfaces that is no greater than 200 μm.

22. The apparatus according to claim 19 , wherein the donor substrate is comprised in a continuous flexible foil, and wherein the donor supply assembly comprises feed rollers, which are configured to feed the foil across the target area.

23. The apparatus according to claim 17 , wherein the optical

Assignees

• Orbotech Ltd

Inventors

• Altman Marc
• Kotler Zvi
• Peled Itay
• Ermak Oleg
• Cohen Sharona

Classifications

• H10P14/00

  Formation of materials, e.g. in the shape of layers or pillars · CPC title

• B41J3/407

  for marking on special material · CPC title

• B41J2/471

  using dot sequential main scanning by means of a light deflector, e.g. a rotating polygonal mirror · CPC title

• H10K71/18 Primary

  using non-liquid printing techniques, e.g. thermal transfer printing from a donor sheet · CPC title

• B41J2/442

  using lasers · CPC title