In the manufacture of microelectronic devices, a die may be created and affixed to a package to form a device. However, the die and the other parts of the package may have differing characteristics. One important difference relates to the coefficient of thermal expansion (CTE), which is a value that expresses how a material expands or contracts as temperatures change.
If a die has a different CTE than the package and therefore expands at a different rate than the package, there is a risk of mechanical failure, including mechanical failure of interconnects between the die and the package. Reliable connection of a die to a package is difficult, and CTE mismatch between the die and package can complicate fabrication of microelectronic devices. With the use of low K (dielectric constant) ILD (inter-layer dielectric) materials on die in device construction, the risk of failure for microelectronic devices may increase.
USPTO Backgrounds
USPTO Backgrounds