Method for fabricating ultra-low density three-dimensional thin film structure based on photo-lithography

Patent metadata

Field	Value
Publication number	US-9878472-B2
Application number	US-201314647849-A
Country	US
Kind code	B2
Filing date	Feb 4, 2013
Priority date	Nov 29, 2012
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

A method for forming an ultra-low density three-dimensional thin film structure made of a solid thin film, including: radiating ultraviolet rays of different patterns in respective predetermined directions to a liquid photosensitive resin bulk so as to harden a portion of the resin bulk; removing the liquid photosensitive resin which is not hardened so as to form a solid photosensitive resin structure; coating the surface of the solid photosensitive resin structure with a thin film; removing the thin film from the outermost surface of the resin bulk so as to expose the solid photosensitive resin; and removing the solid photosensitive resin structure.

First claim

What is claimed is:

1. A method for forming an ultra-low density three-dimensional thin film structure made of a solid thin film, the method comprising the steps of:
hardening a portion of a liquid photosensitive resin bulk as a solid photosensitive resin structure using self propagating phenomenon by radiating ultraviolet rays of different patterns in respective predetermined directions to the portion of the liquid photosensitive resin bulk such that the portion of the liquid photosensitive resin bulk are cured as the solid photosensitive resin structure by the radiated ultraviolet rays
removing the liquid photosensitive resin which is not hardened and leaving the solid photosensitive resin structure;
coating a surface of the solid photosensitive resin structure with a thin film;
removing a portion of the thin film coated on a distal end of the solid photosensitive resin structure so as to expose the distal end of the solid photosensitive resin; and
removing the solid photosensitive resin structure through the removed portion of the thin film,
wherein each of the different patterns has a structure in which predetermined polygonal shapes are arranged in the vicinity of and alternately with each other,
wherein the solid photosensitive resin structure has a structure in which a plurality of prisms intersects with each other, and
wherein the ultra-low density three-dimensional thin film structure has a structure in which hollow polyhedron unit cells having surfaces with a flat surface element are interconnected and repeatedly formed, thus enabling the ultra-low density three-dimensional thin film structure to be formed into an engraved structure relative to the solid photosensitive resin structure.

2. The method of claim 1 , wherein the radiating the ultraviolet rays uses one or more masks with different patterns to each other.

3. The method of claim 1 , wherein the radiating the ultraviolet rays uses maskless lithography technique.

4. The method of claim 1 , wherein the radiating the ultraviolet rays is performed only on a specific plane of the liquid photosensitive resin bulk, according to respective patterns and in respective designated directions.

5. The method of claim 1 , wherein the radiating the ultraviolet rays is performed on two or more planes of the liquid photosensitive resin bulk, according to respective patterns and in respective designated directions.

6. The method of claim 1 , wherein the thin film is metal, ceramic or polymer.

7. The method of claim 1 , wherein the step of coating the surface of the solid photosensitive resin structure with the thin film comprises forming a multilayered thin film by repeatedly performing coating a thin film with a homogeneous or heterogeneous material.

8. The method of claim 7 , after the multilayered thin film is formed, further comprising a chemical, physical or thermal post-processing to mitigate interlayer stress or to suppress interlayer separation.

9. The method of claim 1 , wherein either an inner space as occupied by the hollow polyhedron unit cells or an outer space, or both is filled with a porous material.

10. The method of claim 1 , wherein the removing the thin film from the outermost surface of the resin bulk is performed in a mechanical polishing, electrolytic polishing or chemical etching manner.

11. The method of claim 1 , wherein the removing the solid photosensitive resin structure is performed in one of chemical, physical, thermal and optical methods.

12. The method of claim 1 , wherein the unit cells are one of tetrahedron, cube, octahedron, vector equilibrium, rhombic dedecahedron, and Kagome.

Assignees

• Univ Nat Chonnam Ind Found

Inventors

• Kang Ki Ju
• Han Seung Cheul
• Lee Min Geun

Classifications

• H10P76/2041

  Photolithographic processes · CPC title

• B22C9/12

  Treating moulds or cores, e.g. drying, hardening · CPC title

• B28B1/30

  by applying the material on to a core or other moulding surface to form a layer thereon (to form a permanent layer B28B19/00) · CPC title

• B29L2031/772

  Articles characterised by their shape and not otherwise provided for (closed loop B29L2031/709; ring-like B29L2031/7096; corrugated B29L2016/00, flat B29L2007/00; hollow B29L2022/00; screw-threaded B29L2001/00; toothed B29L2031/775; corrugated tubes B29L2023/18) · CPC title

• B29C35/0266 Primary

  Local curing (for repairing B29C73/34) · CPC title