Vacuum package having vacuum-deposited local getter and its preparation

• US 5,921,461 A
• Filed: 06/11/1997
• Issued: 07/13/1999
• Est. Priority Date: 06/11/1997
• Status: Expired due to Fees

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Williams, Ronald L., Sarver, Charles E., Kennedy, Adam M.
• Primary Examiner(s): Ryan, Patrick
• Assistant Examiner(s): Knapp, Jeffrey T.
• Application Number:
  US08/872,978
• Time in Patent Office: 762 Days
• Field of Search: 228/124.6, 228/217, 228/221
• US Class Current: 228/124.6
• CPC Class Codes: G01D 11/245 Housings for sensors
• CPC Class Codes: G01J 5/04 Casings
• CPC Class Codes: G01J 5/045 Sealings; Vacuum enclosures; Encapsulated packages; Wafer bonding structures; Getter arrangements getter arrangements per se H01L23/26 and H01L21/3221
• CPC Class Codes: H01L 23/26 including materials for absorbing or reacting with moisture or other undesired substances , e.g. getters
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A vacuum package (20) is fabricated by providing a package base (22) with a device (32) affixed to the interior of the package base (22), and a package lid (42). An activatable getter material (54) is deposited onto a preselected region of either the interior (48) of the package lid (42) or that portion of the package base (22) which does not have the device (32) affixed thereto. The deposited getter material (54) is deposited at a temperature such that it is activated during deposition. The vacuum package lid (42) is sealed to the vacuum package base (22). The steps of depositing and sealing are conducted in an evacuated vacuum chamber without exposing the interior to atmosphere.

Claims

1. A method for fabricating a vacuum package, comprising the steps of:

providing a package base having a package base interior and a light sensor device affixed to a first portion of the package base interior, wherein there is no device affixed to a second portion of the package base interior

providing a package lid having a package lid interior, a window therethrough transparent to light of a wavelength to which the light sensor device is sensitive, and a second portion of the package lid interior which is not a part of the window;

depositing an activatable getter material onto a preselected region of at least one of the second portion of the package base interior and the second portion of the package lid interior, the deposited getter material being deposited at a temperature such that it is activated during deposition; and

sealing the vacuum package lid to the vacuum package base,

wherein the steps of providing a package base, providing a package lid, depositing, and sealing are performed in an evacuated chamber without exposure to atmosphere.

2. The method of claim 1, wherein the steps of providing a package base and providing a package lid include the step of

providing a vacuum space clearance between the package base interior and the package lid interior of no more than about 0.100 inch.

3. The method of claim 1, wherein the step of depositing includes the step of

depositing the activatable getter material through an open region of a mask.

4. The method of claim 1, wherein the step of depositing includes the step of

depositing the activatable getter material at a deposition rate such that the surface structure of the getter material is nodular.

5. The method of claim 1, wherein the step of depositing includes the step of

depositing the getter material onto a preselected region of the window.

6. The method of claim 1, wherein the step of depositing includes the step of

depositing the getter material onto a preselected region of the second portion of the package base interior laterally adjacent to the light sensor device.

7. A method for fabricating a vacuum package, comprising the steps of:

providing in an evacuated vacuum chamber a package base having a package base interior and a device affixed to a first portion of the package base interior, wherein there is no device affixed to a second portion of the package base interior;

providing in the evacuated vacuum chamber a package lid having a package lid interior, there being a vacuum space clearance between an interior of the package base and an interior of the package lid;

depositing an activatable getter material onto a preselected region of at least one of the second portion of the package base interior and the package lid interior, the deposited getter material being deposited at a temperature such that it is activated during deposition, the step of depositing being conducted in the evacuated vacuum chamber; and

sealing the vacuum package lid to the vacuum package base, the step of sealing being conducted in the evacuated vacuum chamber.

8. The method of claim 7, wherein the step of depositing includes the step of

depositing the activatable getter material on the preselected region of the second portion of the package base interior.

9. The method of claim 7, wherein the step of depositing includes the step of

depositing the activatable getter material on the preselected region of the package lid interior.

10. The method of claim 7, wherein the steps of providing a package base and providing a package lid include the step of

providing a vacuum space clearance of no more than about 0.100 inch.

11. The method of claim 7, wherein the step of depositing includes the step of

depositing the activatable getter material through an open region of a mask.

12. The method of claim 7, wherein the step of depositing includes the step of

depositing the activatable getter material at a deposition rate such that the surface structure of the getter material is nodular.

13. The method of claim 7, wherein the step of providing in an evacuated vacuum chamber a package base includes the step of

providing a light sensor device affixed to the first portion of the package base interior, and

wherein the step of providing in the evacuated vacuum chamber a package lid includes the step of

providing a package lid comprising a window therethrough transparent to light of a wavelength to which the light sensor device is sensitive.

14. The method of claim 13, wherein the step of depositing includes the step of

depositing the getter material on to a preselected region of the window.

15. The method of claim 13, wherein the step of depositing includes the step of

depositing the getter material onto a preselected region of the second portion of the package base interior laterally adjacent to the light sensor device.