Frank E Guthrie

US Patent:

6352195, Mar 5, 2002

Filed:

Sep 18, 2000

Appl. No.:

09/664198

Inventors:

Frank E. Guthrie - Rockwall TX
Paul O. Johnson - Allen TX

Assignee:

RF Monolithics, Inc. - Dallas TX

International Classification:

B23K 3102

US Classification:

2281231, 2281246, 228 563, 228245, 228214, 228219, 228220, 2282342

Abstract:

A method of attaching a lid with at least a metallic surface thereon to a substrate to enclose a surface acoustic wave electronic circuit using a fluxless solder preform having an undesired oxide surface and associated with the metallic surface on the lid and in superimposed and abutting relationship with a gold seal ring surrounding the electronic circuit to form a unit that is heated in a furnace having a hydrogen atmosphere such that the hydrogen removes any undesired oxide surfaces from the solder preform and the metallic surface on the lid by combining with the oxygen therein to form moisture so as to remove any oxide surfaces from the solder preform and the lid metallic surface and enable a complete bonding of the fluxless solder preform with the gold seal ring and the lid metallic surface thereby forming a hermetically sealed package.

US Patent:

61199206, Sep 19, 2000

Filed:

Dec 20, 1996

Appl. No.:

8/770268

Inventors:

Frank E. Guthrie - Rockwall TX
Paul O. Johnson - Allen TX

Assignee:

RF Monolithics, Inc. - Dallas TX

International Classification:

B23K 100

US Classification:

2281231

Abstract:

A method of attaching a lid with at least a metallic surface thereon to a substrate to enclose a surface acoustic wave electronic circuit using a fluxless solder preform having an undesired oxide surface and associated with the metallic surface on the lid and in superimposed and abutting relationship with a gold seal ring surrounding the electronic circuit to form a unit that is heated in a furnace having a hydrogen atmosphere such that the hydrogen removes any undesired oxide surfaces from the solder preform and the metallic surface on the lid by combining with the oxygen therein to form moisture so as to remove any oxide surfaces from the solder preform and the lid metallic surface and enable a complete bonding of the fluxless solder preform with the gold seal ring and the lid metallic surface thereby forming a hermetically sealed package.