Ultrasonic transducer array having laser-drilled vias for electrical connection of electrodes
AssigneeGeneral Electric Company
InventorJonathan E. Snyder
Life of this patent
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Abstract
A system and process for electrically connecting all elements in a transducer array from one side. A flat block of piezoelectric ceramic material is patterned and drilled with a high-powered laser. The drilling is precisely controlled to define a series of vias which penetrate the ceramic block in the thickness direction. These vias facilitate electrical connection from one side of the ceramic block to the other side when the vias are sputtered or plated with electrically conductive material. In this way the electrodes on the front face of the transducer elements can be electrically connected from the rear to common ground or a signal source.
Claims20
An ultrasonic transducer element comprising:
- a block of piezoelectric ceramic material having a rear face and a front face, wherein said block has a via which extends from said rear face to said front face, said via being defined by a via wall;
- a first electrode having at least a portion thereof formed on said rear face;
- and
- a second electrode having a first portion formed on said front face, a second portion formed on said via wall and a third portion formed on said rear face, said first portion being contiguous with said second portion and said second portion being contiguous with said third portion,
- wherein said first electrode portion on said rear face and said second electrode portion on said rear face are electrically isolated from each other by an electrical isolation zone formed therebetween.
An ultrasonic transducer comprising a plurality of ultrasonic transducer elements and means for supporting said plurality of ultrasonic transducer elements in an array, wherein each of said ultrasonic transducer elements comprises:
- a block of piezoelectric ceramic material having a rear face and a front face, wherein said block has a via which extends from said rear face to said front face, said via being defined by a via wall;
- a first electrode having at least a portion thereof formed on said rear face;
- and
- a second electrode having a first portion formed on said front face, a second portion formed on said via wall and a third portion formed on said rear face, said first portion being contiguous with said second portion and said second portion being contiguous with said third portion,
- wherein said first electrode portion on said rear face and said second electrode portion on said rear face are electrically isolated from each other by an electrical isolation zone therebetween.
A method for fabricating an ultrasonic transducer array comprising the steps of:
- forming a plurality of spaced vias in a block of piezoelectric ceramic material, each via having a wall extending from a rear face to a front face of said block;
- forming a plurality of electrical isolation zones on said rear face, each of said electrical isolation zones encircling the intersection of said rear face and said via wall;
- depositing a layer of electrically conductive material on said rear face except at said plurality of electrical isolation zones;
- depositing a layer of electrically conductive material on said front face;
- depositing a layer of electrically conductive material on said via wall which is electrically connected to said layer of electrically conductive material on said rear face and to said layer of electrically conductive material on said front face;
- and
- forming a plurality of kerfs in said block to divide said block into a plurality of electrically and acoustically isolated ultrasonic transducer elements each comprising one via and one electrical isolation zone.
Dependencies are inferred from the claim text.