METHOD FOR PRODUCING A MICRO-LED MATRIX, MICRO-LED MATRIX AND USE OF A MICRO-LED MATRIX

• US 20140094878A1
• Filed: 10/01/2013
• Published: 04/03/2014
• Est. Priority Date: 10/01/2012
• Status: Active Application

• Current Assignee: Albert-Ludwigs-Universitã¤T Freiburg, Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Albert-Ludwigs-Universitã¤T Freiburg, Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Ruther, Patrick, Gossler, Christian, Schwarz, Ulrich
• Granted Patent: US 10,276,631 B2
• Time in Patent Office: Days
• US Class Current: 607/88
• CPC Class Codes: A61N 1/0541 Cochlear electrodes
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 2005/0652 Arrays of diodes
• CPC Class Codes: A61N 5/0601 Apparatus for use inside the body
• CPC Class Codes: A61N 5/0622 Optical stimulation for exciting neural tissue
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A method for producing a micro-LED matrix by (A) depositing an LED layer structure onto a working substrate; (B) singulating a plurality of LED structures from the LED layer structure on the working substrate; (C) applying a first contact-making structure to a carrier substrate; and (D) transferring the plurality of LED structures from the working substrate to the carrier substrate by bonding and laser lift-off. An at least two-layered carrier substrate is used, including a carrier layer and a first flexible polymer layer, in step C the first contact-making structure is applied indirectly or directly to a side of the first polymer layer which faces away from the carrier layer, and in an additional method step D-0 between method steps C and D, a second flexible polymer layer is formed at least between the singulated LED structures. A micro-LED matrix and use are also provided.

Claims

1. A method for producing a micro-LED matrix comprising the following method steps:

A depositing an LED layer structure onto a working substrate (5);

B singulating a plurality of LED structures (6) from the LED layer structure on the working substrate (5);

C applying a first contact-making structure (4) to a carrier substrate (1);

D transferring the plurality of LED structures (6) from the working substrate (5) to the carrier substrate (1) by bonding and laser lift-off; and

an at least two-layered carrier substrate (1) is used, comprising a carrier layer (2) and a first flexible polymer layer (3), in method step C the first contact-making structure (4) is applied indirectly or directly to that side of the first polymer layer (3) which faces away from the carrier layer (2), and in an additional method step D-0 between method steps C and D, a second flexible polymer layer (13) is formed at least between the singulated LED structures (6).

2. The method as claimed in claim 1, wherein

in an additional method step E, a third flexible polymer layer (16) is applied to the second polymer layer (13) and the embedded LED structures (6).

3. The method as claimed in claim 2, wherein

in an additional method step E-0 before method step E a second contact-making structure (15) formed as a metallic contact-making structure, is applied at least to the embedded LED structures (6).

4. The method as claimed in claim 1, wherein

the singulation of the plurality of LED structures (6) in method step B is effected by at least one of laser ablation or etching.

5. The method as claimed in claim 1, wherein

a flexible biocompatible polymer is used for at least one of the first polymer layer (3), the second polymer layer (13), or the third polymer layer (16).

6. The method as claimed in claim 1, wherein

the second polymer layer (13) is introduced into a region between the singulated LED structures (6) in method step D-0 by application of reduced pressure.

7. The method as claimed in claim 1, wherein

the carrier layer (2) of the at least two-layered carrier substrate (1) is removed by a peel-off process in a method step F.

8. A micro-LED matrix, comprising

a first contact-making structure (4), at least two LED structures (6), said LED structures (6) are arranged in a common horizontal plane,

a first flexible polymer layer (3) on which the LED structures (6) are arranged indirectly or directly, the first contact-making structure (4) being applied indirectly or directly on a side of the first polymer layer (3) which faces the LED structures (6), and

at least a region between the LED structures (6) is filled with a second flexible polymer layer (13).

9. The micro-LED matrix as claimed in claim 8, wherein

a carrier layer (2) is arranged indirectly or directly on a side of the first flexible polymer layer (3) which faces away from the LED structure (6).

10. The micro-LED matrix as claimed in claim 9, wherein

the micro-LED matrix has a third flexible polymer layer (16), said third flexible polymer layer (16) is applied indirectly or directly to the second polymer layer (13) and the embedded LED structures (6).

11. The micro-LED matrix as claimed in claim 8, further comprising

a luminescence conversion element which is active in a wavelength range greater than 530 nm.

12. The micro-LED matrix as claimed in claim 8, wherein

the LED structures (6) are individually drivable, in that the LED structures (6) are connected to a number of lines (27, 28), in such a way that each of the lines (27, 28) connects a plurality of LEDs and each combination of two of the lines (27, 28) makes contact with exactly one LED.

13. The micro-LED matrix as claimed in claim 8, wherein

contact is made with the LED structures (6) both on a front side and on a back side, in such a way that during use each of the LED structure (6) has a substantially vertical current flow.

14. The micro-LED matrix as claimed in claim 8, further comprising electrodes for electrically stimulating biological tissue.

15. A method of at least one of optically or electrically stimulating nerve cells, comprising implanting a micro-LED matrix as claimed in claim 8, and applying power to the micro-LED matrix to at least one of optically or electrically stimulating nerve cells.