Circuit card assembly having controlled expansion properties

摘要

Piezoelectric material is embedded in epoxy layers of circuit cards to control thermal expansion and contraction as a function of temperature changes. A temperature sensor and thermostat generates a controlled voltage as a function of temperature and applies the voltage to piezoelectric blocks within the circuit card. Local areas of the circuit card can have different amounts of piezoelectric material or different thermostats. Piezoelectric blocks can be arranged in regular patterns or can be randomly or pseudo-randomly placed.