This proprietary CSP approach to building memory components uses a novel technique of mounting chips on an interposer with carefully controlled thermal coefficient of expansion
, resulting in cost-effective and reliable stacking of two and four high-chip stacks.
Some minor distortion occurs in BGA components and circuit boards when heated, due to the thermal coefficient of expansion
(TCE) of the materials.
Semitron ESd 420 is said to offer just the right combination of properties for the job: static dissipation, low coefficient of expansion
, and high strength and heat resistance.
In the past, the acrylics had a high shrink rate and coefficient of expansion
If it were desirable, ceramic can have a very low coefficient of expansion
(as low as 2.
Both packages utilize a direct copper bonded Aluminum Nitride substrate which has a thermal coefficient of expansion
closely matched to that of the Z-MOS(TM) die resulting in improved reliability and power cycling performance.