Method of manufacturing an acoustic wave element

A method of manufacturing an acoustic wave element comprising:

• simultaneously forming a plurality of electrodes on a surface of a piezoelectric substrate, the plurality of electrodes including a first interdigital transducer (IDT) electrode, a second IDT electrode, and a connection electrode;
• forming an insulation on surfaces of the plurality of electrodes and the surface of the piezoelectric substrate;
• processing a first portion of the insulation over a surface of the second IDT electrode to reduce a thickness of the first portion in a direction perpendicular to the surface of the piezoelectric substrate to a first thickness;
• and
• processing a second portion of the insulation over a surface of the connection electrode and a third portion of the insulation over a surface of the first IDT electrode to reduce a thickness of the second and third portions in a direction perpendicular to the surface of the piezoelectric substrate to a second thickness, the second thickness being less than the first thickness.

A method of manufacturing an acoustic wave element comprising:

• patterning at least one mask layer disposed on a surface of a piezoelectric substrate using photolithography;
• depositing, using thin film deposition, a plurality of electrodes on the surface of the piezoelectric substrate at locations corresponding to a pattern of the at least one mask layer, the plurality of electrodes including a first interdigital transducer (IDT) electrode, a second IDT electrode, and a connection electrode;
• depositing an insulation on surfaces of the plurality of electrodes and the surface of the piezoelectric substrate, the insulation being deposited with a first thickness in a direction perpendicular to the surface of the piezoelectric substrate over the second IDT electrode;
• and
• etching a first portion of the insulation over the first IDT electrode and a second portion of the insulation over the connection electrode to reduce a thickness of the first and second portions in the direction perpendicular to the surface of the piezoelectric substrate to a second thickness, the second thickness being less than the first thickness.