High strength carbon fiber composite wafers for microfabrication

• US 9,174,412 B2
• Filed: 11/02/2012
• Issued: 11/03/2015
• Est. Priority Date: 05/16/2011
• Status: Active Grant

• Current Assignee: Moxtek (Polatechno Co.,Ltd.), Brigham Young University (The Church of Jesus Christ of Latter-Day Saints)
• Original Assignee: Moxtek (Polatechno Co.,Ltd.), Brigham Young University (The Church of Jesus Christ of Latter-Day Saints)
• Inventors: Davis, Robert C., Vanfleet, Richard, Zufeldt, Kyle, Davis, Andrew L., Liddiard, Steven D.
• Primary Examiner(s): Kao, Glen
• Assistant Examiner(s): FOX, DANIELLE A
• Application Number:
  US13/667,273
• Publication Number:
  US 20130315380A1
• Time in Patent Office: 1,096 Days
• US Class Current: 1/1
• CPC Class Codes: B29K 2307/04 Carbon
• CPC Class Codes: B32B 18/00 Layered products essentially comprising ceramics, e.g. refractory products
• CPC Class Codes: B32B 2260/023 Two or more layers
• CPC Class Codes: B32B 2260/04 Impregnation, embedding, or binder material
• CPC Class Codes: B32B 2262/106 Carbon fibres, e.g. graphite fibres
• CPC Class Codes: B32B 2307/40 having particular optical properties light or UV resistant B32B2307/71
• CPC Class Codes: B32B 2307/54 Yield strength; Tensile strength
• CPC Class Codes: B32B 2307/542 Shear strength
• CPC Class Codes: B32B 2313/04 Carbon
• CPC Class Codes: B32B 2377/00 Polyamides
• CPC Class Codes: B32B 2379/08 Polyimides
• CPC Class Codes: B32B 2551/00 Optical elements
• CPC Class Codes: B32B 27/06 as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a layer of a particular substance B32B9/045; next to a bituminous or tarry layer B32B11/046; next to a water setting substance layer B32B13/12; next to a metal layer B32B15/08; next to a glass layer B32B17/10; next to a layer formed of natural mineral fibres or particles B32B19/045; next to a wood layer B32B21/08; next to a cellulosic plastic layer B32B23/08; next to a natural or synthetic rubber layer B32B25/08
• CPC Class Codes: B32B 27/34 comprising polyamides
• CPC Class Codes: B32B 3/266 characterised by an apertured layer, the apertures going through the whole thickness of the layer, e.g. expanded metal, perforated layer, slit layer regular cells B32B3/12
• CPC Class Codes: B32B 37/06 characterised by the heating method
• CPC Class Codes: B32B 37/10 characterised by the pressing technique, e.g. using action of vacuum or fluid pressure
• CPC Class Codes: B32B 37/18 involving the assembly of discrete sheets or panels only
• CPC Class Codes: G21K 1/00 Arrangements for handling particles or ionising radiation, e.g. focusing or moderating production or acceleration of neutrons, electrically-charged particles, neutral molecular beams or neutral atomic beams H05H3/00 - H05H15/00
• CPC Class Codes: H01J 2235/18 Windows, e.g. for X-ray transmission
• CPC Class Codes: H01J 2235/183 : Multi-layer structures
• CPC Class Codes: H01J 5/18 : Windows permeable to X-rays, gamma-rays, or particles
• CPC Class Codes: H01J 9/24 : Manufacture or joining of vessels, leading-in conductors or bases
• CPC Class Codes: Y10T 428/24124 : Fibers

Abstract

A high strength carbon fiber composite (CFC) wafer, and method of making such wafer, with low surface roughness comprising at least one sheet of CFC including carbon fibers embedded in a matrix. The wafer can have a thickness of between 10-500 micrometers. The wafer can have a root mean square surface roughness Rq, on at least one side, of less than 300 nm in an area of 100 micrometers by 100 micrometers and less than 500 nm along a line of 2 millimeter length. The wafer may be cut to form x-ray window support structures, MEMS, or other micrometer sized structures.

Claims

1. A wafer comprising:

a. at least one sheet of carbon fiber composite (CFC) including carbon fibers embedded in a matrix;

b. a wafer thickness of between 10-500 micrometers;

c. at least one side of the wafer having a root mean square surface roughness Rq of less than 300 nm in an area of 100 micrometers by 100 micrometers and less than 500 nm along a line of 2 millimeter length;

d. a yield strength at fracture of greater than 0.5 gigapascals (GPa), wherein yield strength is defined as a force, in a direction parallel with a plane of a side of the wafer, per unit area, to cause the wafer to fracture; and

e. a strain at fracture of more than 0.01, wherein strain is defined as the change in length caused by a force in a direction parallel with a plane of the wafer divided by original length.

2. The wafer of claim 1, wherein the yield strength is between 2 GPa and 3.6 GPa.

3. The wafer of claim 1, wherein the root mean square surface roughness is less than 200 nanometers in an area of 100 micrometers by 100 micrometers.

4. The wafer of claim 1, wherein at least 90% of the carbon fibers have a diameter of between 2 and 10 micrometers.

5. The wafer of claim 1, wherein the matrix comprises a material selected from the group consisting of polyimide, bismaleimide, epoxy, or combinations thereof.

6. The wafer of claim 1, further comprising a polyimide sheet cured together with and abutting the at least one sheet of carbon fiber composite.

7. The wafer of claim 6, wherein the polyimide sheet has a thickness of between 0.1-100 micrometers.

8. The wafer of claim 1 micropatterned by laser ablation, water jet, or combinations thereof to form an x-ray window support structure comprising:

a. a support frame defining a perimeter and an aperture;

b. a plurality of ribs extending across the aperture of the support frame and carried by the support frame;

c. openings between the plurality of ribs; and

d. the support frame and the plurality of ribs comprising a support structure.

9. An x-ray window comprising:

a. a support frame defining a perimeter and an aperture;

b. a plurality of ribs extending across the aperture of the support frame and carried by the support frame;

c. openings between the plurality of ribs;

d. the support frame and the plurality of ribs comprising a support structure;

e. the support structure comprising a carbon fiber composite (CFC) material, the CFC material comprising carbon fibers embedded in a matrix;

f. the support structure having a thickness of between 10-500 micrometers;

g. a film disposed over, carried by, and spanning the plurality of ribs and disposed over and spanning the openings, and configured to pass x-ray radiation therethrough; and

h. a surface of the support structure facing the film having a root mean square surface roughness Rq of less than 500 nm along a line of 2 millimeter length.

10. The x-ray window of claim 9, wherein the support structure further comprises a polyimide layer cured together with the CFC material, cut to form ribs, openings, and support frame together with the CFC material, and disposed between the CFC material and the film.

11. The x-ray window of claim 9, further comprising:

a. a housing to which the x-ray window is hermetically sealed; and

b. an x-ray detector, disposed within the housing, configured to receive x-rays transmitted through the window, and to output a signal based on x-ray energy.

12. The x-ray window of claim 9, wherein the matrix comprises polymide.

13. The x-ray window of claim 9, wherein the matrix comprises bismaleimide.