CQFP 68 package material

What are the CQFP68 package material characteristics?

1- Heat slug material (if applicable – P/N with FS suffix) is CuW (copper 10% tungsten 90%).
2- Metallization of heatspreader: 3-4 microns of Nickel overcoated by 2.5 microns of Gold
3- CuW material CTE = 6.0 ppm
AlN material CTE = 4.4 ppm
CuW material CTE = 6.0 ppm
Al2O3 CTE = 6.7 ppm
Si CTE = 3.5 ppm
Coefficient of thermal conductivity:
AlN = 170 W/m/K and CuW =230 W/m/K