Abstract: A keyboard-operated electronic apparatus such as an electronic calculator is made by forming a dielectric card with a plurality of recesses in one card side. Preferably the card is formed with a number of apertures extending through the card. Electrically conductive films are deposited in a selected pattern on the recessed card to define first and complementary contacts within each card recess and to define circuit paths which are connected to these contacts in a selected manner. Electrically conductive elements of a dished configuration are disposed in the respective card recesses to be located by the recesses in engagement with the first contacts in the recesses, and key means are mounted on the recessed card side for selectively moving the dished elements with snap action into an inverted dished configuration so that the elements further engage complementary contacts in the recesses to close selected circuits.

Abstract: A keyboard-operated electronic apparatus such as an electronic calculator is made by forming a dielectric card with a plurality of recesses in one card side. Preferably the card is formed with a number of apertures extending through the card. Electrically conductive films are deposited in a selected pattern on the recessed card to define first and complementary contacts within each card recess and to define circuit paths which are connected to these contacts in a selected manner. Electrically conductive elements of a dished configuration are disposed in the respective card recesses to be located by the recesses in engagement with the first contacts in the recesses, and key means are mounted on the recessed card side for selectively moving the dished elements with snap action into an inverted dished configuration so that the elements further engage complementary contacts in the recesses to close selected circuits.