Intersecting ultrasonic transducer arrays and methods of manufacturing therefor

A method for manufacturing an ultrasonic intersecting array transducer wherein the transducer has a central region and front and rear faces, and comprises:

• a first linear array extending through the central region of the transducer and including a signal electrode on the front face of the transducer and a ground electrode on the rear face of the transducer;
• a second linear array extending through the central region of the transducer mutually orthogonally to said first linear array, said second linear array including signal electrodes on the rear face of the transducer and ground electrodes on the front face of the transducer;
• said first and second linear arrays intersecting to form a cross shaped configuration including a central area at which said first and second arrays intersect, said central area including a central group of signal electrodes from the first array on the front face of the transducer and a central group of signal electrodes from the second array on the rear face of the transducer;
• a first interconnection means disposed at the first face of the transducer for providing electrical connection of the signal electrodes of the first array without shunting the ground electrodes of the second array;
• a second interconnection means disposed at the rear face of the transducer for providing electrical connection of the signal electrodes of the second array;
• and a switching device, disposed in the vicinity of the first and second arrays between said first and second interconnection means and external coaxial cables, for switching the central groups of signal electrodes of the first and second arrays between ground and excitation circuitry for providing excitation of the respective central groups, said method comprising:
• providing a signal electrode interconnection means for the signal electrodes of the front face of the transducer, wherein the said signal electrode interconnection means includes a contact surface and comprises part of a sandwich of matching layers arranged such as to selectively expose the contact surface of said signal electrode interconnection means at a contact area with the signal electrodes of the front face of the transducer.

A method for manufacturing an ultrasonic intersecting array transducer wherein the transducer has a central region and front and rear faces, and comprises:

• a first linear array extending through the central region of the transducer and including a signal electrode on the front face of the transducer and a ground electrode on the rear face of the transducer;
• a second linear array extending through the central region of the transducer mutually orthogonally to said first linear array, said second linear array including signal electrodes on the rear face of the transducer and ground electrodes on the front face of the transducer;
• said first and second linear arrays intersecting to form a cross shaped configuration including a central area at which said first and second arrays intersect, said central area including a central group of signal electrodes from the first array on the front face of the transducer and a central group of signal electrodes from the second array on the rear face of the transducer;
• a first interconnection means disposed at the first face of the transducer for providing electrical connection of the signal electrodes of the first array without shunting the ground electrodes of the second array;
• a second interconnection means disposed at the rear face of the transducer for providing electrical connection of the signal electrodes of the second array;
• and a switching device, disposed in the vicinity of the first and second arrays between said first and second interconnection means and external coaxial cables, for switching the central groups of signal electrodes of the first and second arrays between ground and excitation circuitry for providing excitation of the respective central groups, said method comprising:
• providing the first interconnection means of the front face of the transducer in a form comprising a double face flexible printed circuit having an external surface covered by a continuous metal layer for electromagnetic protection.

A method of manufacturing an acoustic front matching device for a cross shaped intersecting ultrasonic array transducer including at least one electrode, said method comprising the following steps:

• (a) providing a first, constant thickness matching layer of the matching device;
• (b) laminating part of a second matching layer to the first matching layer on a portion of the matching device at which an interconnection means is to be assembled to the at least one electrode of the array transducer to produce an intermediate matching device;
• (c) laminating an interconnection means comprising a printed flexible circuit on the intermediate matching device;
• and
• (d) completing said matching device with a complementary part of said second matching layer to form a final matching device of a constant thickness.

A method of manufacturing an acoustic front matching device for a cross shaped intersecting ultrasonic array transducer, said method comprising the following steps:

• (a) providing a piezoelectric member of a cross shape;
• and
• (b) assembling portions of an interconnection means to surface electrodes of said piezoelectric member;
• (c) assembling portions of a first matching layer to further surface electrodes of the piezoelectric member;
• (d) laminating remaining portions of said interconnection means on an outer surface of said portions of said first matching layer and
• (e) completing the matching device by laminating a second matching layer on said first matching layer.