Texas Instruments Corporation

Luigi Abbondandolo

Amedeo Salvatore

Pietro De Filippis

A keyboard unit is shown having a substrate in which portions of the substrate are physically displaced to provide a cavity, an embossment and a plurality of protuberances for each switching station. The embossment, in registry with a button contact area, projects upwardly from the floor of the cavity a selected distance with a discontinuous annulus contact area extending around its respective cavity in generally the same plane as that in which the top surface of the substrate lies. The cavity includes a channel shaped portion extending through the discontinued portion of the discontinuous annulus. The protuberances project upwardly from the general plane of the substrate's top surface and serve to laterally locate a snap-acting disc over the contact areas. The disc may be selectively coated with highly electrically conductive material to optimize electrical switching. A piece of flexible, electrically insulative sheet may be placed over the unit to seal it from the environment.

A method for making low profile microswitches, particularly useful for

A keyboard unit is shown having a substrate in which portions of the substrate are physically displaced to provide a cavity, an embossment and a plurality of protuberances for each switching station. The embossment, in registry with a button contact area, projects upwardly from the floor of the cavity a selected distance with a discontinuance annulus contact area extending around its respective cavity in generally the same plane as that in which the top surface of the substrate lies. The cavity includes a channel shaped portion extending through the discontinued portion of the discontinuous annulus. The protuberances project upwardly from the general plane of the substrate's top surface and serve to laterally locate a snap-acting disc over the contact areas. The disc may be selectively coated with highly electrically conductive material to optimize electrical switching. A piece of flexible, electrically insulative sheet may be placed over the unit to seal it from the environment.

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Naples, Italy

Luigi Abbondandolo