Stmicroelectronics Gmbh

Fred P Lane

Harry Michael Siegel

Giovanni Gozzini

Richard Parker Evans

Hoyoung Chang

A touch-sensitive semiconductor chip having a physical interface to the environment, where the surface of the physical interface is coated with a fluorocarbon polymer. The polymer is highly scratch resistant and has a characteristic low dielectric constant for providing a low attenuation to electric fields. The polymer can be used instead of conventional passivation layers, thereby allowing a thin, low dielectric constant layer between the object touching the physical interface, and the capacitive sensing circuits underlying the polymer.

Fingerprint sensor having a portion of the fluorocarbon polymer physical interface layer amorphized

Method of making a semiconductor device having a planarized fluoropolymer passivating layer with selectively implanted charged particles

Selective ionic implantation of fluoropolymer film to modify the sensitivity of underlying sensing capacitors

A capacitive fingerprint sensor includes a polymeric protective coating defining a sensing surface and having conductive particles suspended therein. The conductive particles act as parallel strings of series capacitors to couple the capacitance the fingerprint-bearing skin of a user's finger applied to the sensing surface to capacitive sensing elements beneath the protective coating. The polymeric material of the coating is durable and scratch resistant. The conductive particles enable use of a protective coating of 10 to 20 microns in thickness while providing a high degree of sensitivity and image resolution.

Capacitive fingerprint sensor with protective coating containing a conductive suspension

Minute surface damage or irregularities on the sensing surface of a capacitive sensor integrated circuit is detected by acquiring a preliminary image of the capacitance readings for the sensor array, coating the sensing surface with an electrolyte solution, then acquiring an additional image while the sensing surface is coated and/or after the electrolyte solution is removed. The electrolyte solution accelerates manifestation of pixel degradation or failure caused by surface damage or irregularities. Defective regions are identified by change of grayscale pixels in the preliminary image while the electrolyte coating is on the sensing surface and then again after the electrolyte coating is removed.

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Highland Village, TX, United States of America

Fred P Lane