Patent ID: 6933537

Claim:
An electrical device comprising: a substrate having an active region and a bonding region surrounding the active region, the active region comprising active components, wherein the active components include electroluminescent components; and a cap having a recess to contain the active region, the cap mounted on the substrate for sealing the active region from the environment, wherein a non-recessed portion of the cap contacts the substrate in the bonding region to form an interface therebetween, wherein the bonding region has a width W, which is defined by the thickness of the cap in the bonding region, wherein: the interface between the cap and the substrate in the bonding region includes at least one geometrically shaped groove to create an effective bonding width EW that is greater than W, wherein the effective bonding width EW is defined by the length of the shortest path along the interface between the cap and the bonding region; the at least one geometrically shaped groove includes a first indentation formed in the cap; the substrate includes a first projection formed in the bonding region, opposite to the first indentation; the first projection has a shape complimentary to the shape of the first indentation to enable a close fit between the first projection and the first indentation; the cap and the substrate are comprised of different materials, one material being more ductile than the other; at least one surface feature is formed from the less ductile material; and the at least one surface feature in the less ductile material deforms the more ductile material and causes the more ductile material to conform to the shape of the at least one surface feature.