HERMETICALLY SEALED PACKAGE HAVING STRESS REDUCING LAYER

摘要

A sealed package having a device disposed on a wafer structure and a lid structure boned to the device wafer. The device wafer includes: a substrate; a metal ring disposed on a surface portion of substrate around the device and a bonding material disposed on the metal ring. The metal ring extends laterally beyond at least one of an inner and outer edge of the bonding material. A first layer of the metal ring includes a stress relief buffer layer having a higher ductility than that of the surface portion of the substrate and a width greater than the width of the bonding material. The metal ring extends laterally beyond at least one of the inner and outer edges of the bonding material. The stress relief buffer layer has a coefficient of thermal expansion greater than the coefficient of expansion of the surface portion of the substrate and less than the coefficient of expansion of the bonding material.

主权项

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 effect of the coincident outer edges of the solder and the metal seal ring causing the cracking, 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.