Abstract: A device that reduces the interfacial stress caused by differential thermal expansion in an IC/PC board assembly can be created by attaching an annular part, that has a higher coefficient of thermal expansion, to the IC at an elevated temperature. When the assembly cools the annular part contracts and compresses the IC, increasing the change in size of the IC and reducing the stress in the IC/PC joint.

Abstract: The electrical drive pulse applied to the piezoelectric crystal of an ink jet printer is designed to cause ejection of a single desired ink droplet from the print head and to preclude ejection of unwanted multiple ink droplets. The drive pulse consists of the superposition of two waveforms wherein the first waveform causes ejection of the desired ink droplet and the superimposed second waveform removes energy from the print head so that mechanical ringing of the ink supply within the print head does not cause ejection of unwanted ink droplets.

Abstract: A piezoelectrically driven ink jet printer includes a shock absorbing mechanism positioned in the ink supply tube for minimizing the effects on the ink within the print head of physical shocks to the ink supply tube or ink supply cartridge. The shock absorbing mechanism includes a flow restriction device and a reservoir device arranged such that the physical performance of the shock absorbing mechanism is analogous to the electrical performance of an RC low pass filter.