| 摘要 |
<p>Piezoelectric material (120) is embedded in epoxy layers (220) of circuit cards (102) to control thermal expansion and contraction as a function of temperature changes. A temperature sensor (212) and thermostat (214) generates a controlled voltage as a function of temperature and applies the voltage to piezoelectric blocks (120) within the circuit card. Local areas of the circuit card can have different amounts of piezoelectric material (120) or different thermostats (214). Piezoelectric blocks (120) can be arranged in regular patterns or can be randomly or pseudorandomly placed.</p> |
