Patent ID: 9708181
Date: 2017-07-18
CPC Classifications: B81B,B81C

Claim:
1. A method for preventing cracking in a substrate having a metal seal ring on a surface of the substrate and solder on the a top surface of the metal seal ring, the solder and the metal seal ring having coincident outer edges, the method comprising: providing a metal stress relief layer between a bottom surface of the metal seal ring and the surface of the substrate with an outer edge of the metal stress relief layer extends outward from the coincident outer edges of the solder and the metal seal ring a distance sufficient to prevent the cracking; the metal stress relief layer comprising: an oxidation blocking/bonding material adhesion layer disposed on a top surface of the metal seal ring; and a diffusion barrier layer disposed under the oxidation blocking/bonding material adhesion layer; providing a bonding material on the oxidation blocking/bonding material adhesion layer of the metal seal ring; providing a metal stress relief buffer layer between the metal seal ring and the surface of the substrate; wherein the bonding material has a yield strength in the same order of magnitude as the yield strength of the stress relief buffer layer; bonding the metal seal ring to the lid structure with the bonding material to form the hermetically sealed package; wherein the bonding material and the metal seal ring, absent the metal stress relief layer, cause cracking of the surface of the substrate; and wherein the metal stress relief buffer layer extends laterally beyond the bonding material a length sufficient to prevent the cracking of the substrate when bonding the metal seal ring to the lid structure with the bonding material forming a hermetically sealed package.