Hydrogen and moisture getter and absorber for sealed devices

• US 5,888,925 A
• Filed: 02/20/1998
• Issued: 03/30/1999
• Est. Priority Date: 09/28/1995
• Status: Expired due to Term

• Current Assignee: Honeywell International Inc.
• Original Assignee: Alliedsignal Inc.
• Inventors: Schicker, James R., Smith, Henry M.
• Primary Examiner(s): Caldarola, Glenn A.
• Assistant Examiner(s): Bullock, In Suk
• Application Number:
  US09/026,831
• Time in Patent Office: 403 Days
• Field of Search: 502/400, 502/439, 502/526, 252/181.1, 252/181.6, 252/194
• US Class Current: 502/400
• CPC Class Codes: C01B 2203/0435 Catalytic purification
• CPC Class Codes: C01B 2203/048 the impurity being an organic compound
• CPC Class Codes: C01B 3/58 including a catalytic reaction
• CPC Class Codes: C01B 5/00 Water
• CPC Class Codes: C08K 3/22 of metals
• 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
• CPC Class Codes: H01L 2924/1423 Monolithic Microwave Integrated Circuit [MMIC]
• CPC Class Codes: Y10S 502/526 Sorbent for fluid storage, other than an alloy for hydrogen storage

Abstract

The present invention is a hydrogen getter and method for formulating and using the getter. This getter effectively removes hydrogen gas typically present in many hermetically-sealed electronic applications where the presence of such gas would otherwise be harmful to the electronics. The getter is a non-organic composition, usable in a wide range of temperatures as compared to organic getters. Moreover, the getter is formulated to be used without the need for the presence of oxygen. The getter is comprised of effective amounts of an oxide of a platinum group metal, a desiccant, and a gas permeable binder which preferably is cured after composition in an oxygen-bearing environment at about 150 to about 205 degrees centigrade.

Claims

1. A hydrogen gas absorber comprising effective amounts of oxides of platinum group metals to remove hydrogen from a particular environment, effective amounts of a desiccant to absorb water produced from the reaction of hydrogen with said oxides, effective amounts of a gas permeable binder to satisfactorily hold said oxides and said desiccant in a matrix formed by said binder, and wherein the absorber has been cured in gas with effective amounts of oxygen and at an effective temperature and for an effective time sufficient to stabilize the absorber from self-catalytic degradation.

2. The absorber as claimed in claim 1 wherein the amounts of said oxides are from about 10 to about 30 percent by weight, the amounts of said desiccant are from about 5 to about 35 percent by weight, the amounts of said binder are from about 85 to about 35 percent by weight, and the absorber has been cured in air at a temperature from about 150 degrees centigrade to about 204 degrees centigrade for at least about 24 hours.

3. The absorber as claimed in claim 2 further comprising effective amounts of a radio frequency absorbing substance to absorb unwanted radio frequency waves.

4. The absorber as claimed in claim 2 wherein said oxides are produced by a salt precipitation technique and contains less than about 200 parts per million by weight of chlorine, wherein said desiccant is a molecular sieve desiccant, and wherein said binder is a room temperature vulcanized silicone.

5. The absorber as claimed in claim 4 further comprising effective amounts of a platinum group metal to accelerate reaction of hydrogen gas with unreacted oxygen.

6. A hydrogen gas absorber comprising from about 10 to about 30 percent by weight palladium monoxide, from about 5 to about and 35 percent by weight of a molecular sieve desiccant, and from about 85 to about 35 percent by weight of a gas permeable binder, said palladium monoxide and said desiccant held in a matrix formed by said binder and wherein the absorber has been cured in air at a temperature from about 170 degrees centigrade to about 204 degrees centigrade for at least about 24 hours.

7. The absorber as claimed in claim 6 wherein said oxides are produced by a salt precipitation technique and contains less than about 200 parts per million by weight of chlorine, wherein said desiccant is a molecular sieve desiccant, wherein said binder is a room temperature vulcanized silicone consisting of a resin reacted with a cure agent, and wherein the ratio of said cure agent to said resin is such that the amount of said cure agent that is unreacted residual is minimized.

8. The absorber as claimed in claim 7 further comprising effective amounts of a radio frequency absorbing substance to absorb unwanted radio frequency waves.

9. The absorber as claimed in claim 7 further comprising effective amounts of a platinum group metal to accelerate reaction of hydrogen with unreacted oxygen.

10. A method of manufacturing a hydrogen absorber comprising the step of:

mixing effective amounts of oxides of platinum group metals to remove hydrogen from a particular environment, effective amounts of a desiccant to absorb water produced from the reaction of hydrogen with said oxides, and effective amounts of a gas permeable binder to satisfactorily hold said oxides and said desiccant in a matrix formed by said binder, and

curing said absorber in a gas with effective amounts of oxygen and at an effective temperature and for an effective time sufficient to stabilize the absorber from self-catalytic degradation.

11. The method as claimed in claim 10 wherein the amounts of said oxide of platinum group metals are from about 10 to about 30 percent by weight and the amounts of said desiccant are from about 5 to about and 35 percent by weight and the amount of said gas permeable binder is from about 85 to about 35 percent by weight and wherein the absorber has been cured in air at a temperature from about 150 degrees centigrade to about 204 degrees centigrade for at least about 24 hours.

12. The method as claimed in claim 11 wherein said oxides are produced by a salt precipitation technique and contains less than about 200 parts per million by weight of chlorine, wherein said desiccant is a molecular sieve desiccant, and wherein said binder is a room temperature vulcanized silicone consisting of a resin reacted with a cure agent and wherein the ratio of said cure agent to said resin is such that the amount of said cure agent that is unreacted residual is minimized.