Metallization for hermetic sealing of ceramic modules

Abstract

A superior hermetic seal for ceramic modules is presented. The case base ber is provided with metallization around the periphery of the cavity. The case cover is provided with metallization not only to mate with the metallization of the base, but the cover metallization extends onto the thickness edge. The dimensions of the cover are less than the corresponding metallization dimensions of the base member. In this manner the solder bead formed about the periphery will wet the exposed metallization surfaces and form a visually inspectable bead.

What is claimed is: 
     
       1. A module for hermetically sealing an interior cavity thereof comprising: a casing comprising a base member and a lid member, the base member defining a cavity for receiving within the cavity a hermetically sealable member, the lid member being adapted for covering the open side of the cavity and enclosing the sealable member within the cavity,   the base member having a first metallization portion circumscribed about the opening of the cavity the metallization being adapted for receiving a hermetically sealing material adhereable to the metallization, the metallized portion being adapted for receiving and abuttingly engaging the lid member thereon with the lid member having an engagably compatible surface for engaging the metallization portion, a portion of the compatible surface of the lid surface being circumscribingly second metallized for mating with the first metallized portion and adhering receiving the hermetically sealing material,   the radial outer dimensions of the metallized surface of the lid being smaller than the corresponding radial outer dimensions of the first metallized portion so that portions of the first and second metallization are exposed, the lid member having a peripheral edge thickness, the metallization of the lid member extending over a portion of the edge thickness so that the hermetically sealing material when applied to the first and second metallizations will form a bead of sealing material. about the outside perimeter of the engagement of the base member and the lid member, said bead extending along the exposed portions of the first and second metallizations.   
     
     
       2. The module of claim 1 wherein the hermetically sealing material is solder and the base member and lid member are made of a ceramic material.