Patent ID: 11921958
Assignee: COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
Field: Computer technology (Electrical engineering)
Classification: CPC G  B | IPC G

Claim 12:
13. A method for fabricating matrices of transducers of a piezoelectric micro-machined ultrasound transducer (PMUT) type of a haptic interface of a ‘mid-air’ type, comprising a control circuit, and a plurality of ultrasonic transducers connected to said circuit, which includes a first set of transducers emitting at a first ultrasound carrier frequency and at least a second set of transducers emitting at a second ultrasound carrier frequency different from the first, the first set of transducers and the second set of transducers emitting within a 20 kHz-150 kHz carrier frequency range, wherein the control circuit is configured to modulate signals sent to the transducers to generate, with ultrasound waves emitted by at least a part of the transducers of the first set, an acoustic pressure detectable by touch within at least a first focal region, and generate, with ultrasound waves emitted by at least a part of the transducers of the second set, an acoustic pressure detectable by touch within at least a second focal region, and a size of and/or materials of the second set of transducers differ from a size of and/or materials of the first set of transducers, the method comprising:
depositing at least a first layer of a material for forming membranes of the transducers on an upper face of a substrate;
depositing at least one piezoelectric stack on said at least a first layer for formation of the membranes, based on a succession of deposition and etching of electrode materials and of piezoelectric material;
forming a plurality of transducers on the substrate by masking and etching of the layers previously deposited;
cutting out the substrate by masking and etching in order to expose a lower face of a membrane of each transducer; and
electrically connecting each transducer to the control circuit, notably by virtue of flexible connectors or connectors passing through the substrate.