Carbonized resin coated anode

• US 6,856,080 B2
• Filed: 08/28/2001
• Issued: 02/15/2005
• Est. Priority Date: 08/28/2001
• Status: Expired due to Fees

• Current Assignee: Air Force Government of The United States of America As Represented By The Secretary
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Haworth, Michael D., Shiffler, Donald A. Jr.
• Primary Examiner(s): Patel, Nimeshkumar D.
• Assistant Examiner(s): Roy, Sikha
• Application Number:
  US09/682,388
• Publication Number:
  US 20030042836A1
• Time in Patent Office: 1,267 Days
• Field of Search: 313/355, 313/311, 313/478, 313/479, 313/348, 428/407, 428/408, 445/58, 445/6
• US Class Current: 313/355
• CPC Class Codes: H01J 1/38 characterised by the material
• CPC Class Codes: H01J 23/027 Collectors
• CPC Class Codes: H01J 29/085 Anode plates, e.g. for screens of flat panel displays
• CPC Class Codes: H01J 9/02 Manufacture of electrodes or electrode systems
• CPC Class Codes: H01J 9/14 of non-emitting electrodes
• CPC Class Codes: Y10T 428/2998 including synthetic resin or polymer
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer

Abstract

A vacuum tube having its anode/collector coated with carbonized resin plus pyrocarbon material to reduce out-gassing and secondary electron emission and the method of coating the anode/collector.

Claims

1. A method of coating an electron impact surface of an anode with pyrocarbon, comprising:

coating the electron impact surface with a carbonizable resin;

carbonizing the resin to form a char;

directing a flow of hydrocarbon gas over the electron impact surface after heating the electron impact surface to at least 1000°

C., to form a coating of pyrocarbon on the char; and

removing any residual water from the pyrocarbon coating.

2. A coating method as recited in claim 1 wherein the removing water step includes heating the anode to at least 100°

C. in a vacuum.

3. A coating method as recited in claim 1 wherein:

the carbonizable resin has volatile components; and

carbonizing the resin includes heating the anode to a temperature sufficient to decompose the resin and release the volatile components, whereby

the char is left as a porous residue.

4. A coating method as recited in claim 1 wherein the carbonizing step includes heating the anode to a temperature of at least 7000°

C. in a non-oxidizing atmosphere.

5. A coating method as recited in claim 4 wherein the carbonizable resin is a phenolic.

6. A coating method as recited in claim 3 wherein the heating step includes baking the anode in an oven providing a non-oxidizing atmosphere.