Method and apparatus for thin film coating an article

• US 5,620,572 A
• Filed: 06/07/1995
• Issued: 04/15/1997
• Est. Priority Date: 10/25/1993
• Status: Expired due to Term

• Current Assignee: Tru Vue Inc. (Apogee Enterprises Incorporated)
• Original Assignee: Viratec Thin Films, Inc. (Apogee Enterprises Incorporated)
• Inventors: Kurman, Eric W., Steffenhagen, Debra M., Bjornard, Erik J.
• Primary Examiner(s): Breneman, R. Bruce
• Assistant Examiner(s): MCDONALD, RODNEY GLENN
• Application Number:
  US08/476,091
• Time in Patent Office: 678 Days
• Field of Search: 204/192.1, 204/192.12, 204/192.26, 204/298.07, 204/298.25, 204/298.26, 204/298.23, 204/298.24, 427/64, 427/68, 427/69, 427/70, 427/162, 427/163.3, 427/166, 427/248.1, 427/255, 427/255.5, 427/294, 427/251
• US Class Current: 204/192.12
• CPC Class Codes: C23C 14/042 using masks
• CPC Class Codes: C23C 14/50 Substrate holders
• CPC Class Codes: C23C 14/56 Apparatus specially adapted for continuous coating; Arrangements for maintaining the vacuum, e.g. vacuum locks
• CPC Class Codes: C23C 14/566 using a load-lock chamber
• CPC Class Codes: C23C 14/568 Transferring the substrates through a series of coating stations C23C14/562 takes precedence
• CPC Class Codes: H01J 37/34 operating with cathodic sputtering H01J37/36 takes precedence ; methods of cathodic sputtering C23C14/34
• CPC Class Codes: H01J 37/3411 Constructional aspects of the reactor
• CPC Class Codes: H01J 9/20 Manufacture of screens on or from which an image or pattern is formed, picked up, converted or stored; Applying coatings to the vessel

Abstract

A method and apparatus for coating a CRT screen after assembly. The method and apparatus includes isolating a surface portion of the CRT to be coated from the remaining surface to prevent or minimize coating problems resulting from outgassing and to isolate noncompatible components from the deposition environment.

Claims

1. A continuous process for providing a thin film coating to the front surface of an assembled cathode ray tube, wherein said cathode ray tube includes said front surface to be coated and a rearward portion comprising the remaining surface which remains uncoated, said process comprising:

providing a process section with a cathode ray tube inlet, a cathode ray tube outlet and first and second zones extending from said cathode ray tube inlet to said cathode ray tube outlet wherein said first zone is a deposition zone adjacent to said second zone;

providing a thin film deposition device in said deposition zone;

providing a cathode ray tube support moveable through said process section, said cathode ray tube support substantially and continuously separating said first zone from said second zone throughout said process section and having at least one support opening;

supporting said cathode ray tube relative to said support opening such that said support opening surrounds said front surface, whereby said front surface faces said first zone and said rearward portion faces said second zone;

activating said at least one thin film deposition device and moving said cathode ray tube support through said process section, whereby said cathode ray tube enters said inlet end, moves through said process section with said front surface exposed to said thin film deposition device for application of a thin film thereon, and exits said cathode ray tube outlet.

2. The process of claim 1 including a plurality of thin film deposition devices.

3. The process of claim 1 wherein said thin film deposition device is a sputtering device and said activating step includes applying a thin film to said front surface by reactive sputtering.

4. The process of claim 3 including a plurality of thin film deposition devices in said deposition zone.

5. The process of claim 1 wherein said process section includes a pair of opposing walls and, said cathode ray tube support includes a pair of side edges and wherein said side edges are in association with said walls during movement of said cathode ray tube support through said process section to substantially and continuously separate said first and second zones.

6. The process of claim 1 wherein said cathode ray tube support includes a plurality of cathode ray tube carriers, each having a support opening and a leading edge and a trailing edge.

7. The process of claim 6 wherein said moving step including moving said cathode ray tube carriers through said process section with the leading and trailing edges of each carrier being in association with the trailing and leading edges, respectively, of an adjacent carrier during passage through said process section to form a continuous barrier separating said first and second zones throughout said process section.

8. The process of claim 6 wherein each of said carriers includes a horizontal base and a vertical barrier portion comprising said cathode ray tube support and wherein said supporting step includes mounting the cathode ray tube relative to said support opening whereby said front surface is disposed vertically.

9. The process of claim 1 wherein said second zone is an exhaust zone and wherein said process includes maintaining desired deposition vacuum conditions in said deposition zone and desired exhaust vacuum conditions in said exhaust zone.

10. The process of claim 9 including maintaining exhaust vacuum conditions at a pressure lower than the pressure of said deposition vacuum conditions.

11. The process of claim 10 wherein said activating step including applying a thin film to said front surface by reactive sputtering.

12. The process of claim 1 wherein said cathode ray tube support forms a substantially continuous separation barrier between said first and second zones throughout said process section.

13. The process of claim 1 wherein said rearward portion is a rearward funnel portion.