Gas port sealing for CVD/CVI furnace hearth plates

• US 6,846,514 B2
• Filed: 05/19/2004
• Issued: 01/25/2005
• Est. Priority Date: 06/05/2001
• Status: Expired due to Fees

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Jonnalagadda, Rajanikant, Miller, Brian J.
• Primary Examiner(s): Lund, Jeffrie R.
• Application Number:
  US10/849,273
• Publication Number:
  US 20040211364A1
• Time in Patent Office: 251 Days
• Field of Search: 118/715, 118/724, 118/725, 118/728, 427/249.1, 427/249.2, 294/28, 432/3
• US Class Current: 427/249.2
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 16/455 characterised by the method used for introducing gases into reaction chamber or for modifying gas flows in reaction chamber
• CPC Class Codes: C23C 16/45563 Gas nozzles
• CPC Class Codes: C30B 25/14 Feed and outlet means for the gases; Modifying the flow of the reactive gases
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01L 21/67109 mainly by convection
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A method and apparatus for sealing gas ports in CVD/CVI furnaces and processes is disclosed. A fluid direction nozzle (160) is positioned between a top lip (101) of a gas inlet port (100) delivering a reactant gas (G) to a furnace compartment(200) in a CVD/CVI furnace (10) and corresponding holes (151) of a CVD/CVI process apparatus such as a hearth plate (150). The fluid direction nozzle 160 reduces leakage of reactant gases (G) and ensures a smooth transition of gas flow direction between the gas inlet port (100) and the corresponding holes (151). CVD/CVI process times are significantly reduced with the use of the reusable/replaceable flow direction nozzles (160).

Claims

1. A method for sealing gas inlet ports for delivering a process gas in a CVD/CVI furnace, said method comprising:

positioning flow direction nozzles along upper lips of said gas inlet ports;

loading a CVD/CVI process apparatus having a plurality of gas inlet holes into said furnace;

sealingly engaging the flow direction nozzles to said gas inlet holes of said process apparatus to create a gas-path directing, fluid seal.

2. The method according to claim 1, wherein the CVD/CVI process apparatus is a hearth plate having hearth plate holes, and the CVD/CVI process is a densification process for carbon fiber based brakes.

3. The method according to claim 1, further comprising the step of:

replacing the flow direction nozzles with replacement flow direction nozzles as the flow direction nozzles become damaged or worn.

4. The method according to claim 1, wherein the flow direction nozzles are annular shaped collars made of graphite.