Signal strength enhancement in a biometric sensor array

A fingerprint imaging sensor comprising:

• a plurality of capacitive gap sensor electrode traces formed on a glass substrate, wherein the plurality of capacitive gap sensor electrode traces form a two-dimensional array of fingerprint imaging pixel locations within a fingerprint sensing area of the fingerprint imaging sensor, wherein a first plurality of the capacitive gap sensor electrode traces comprises a plurality of transmitter electrode traces and a second plurality of the capacitive gap sensor electrode traces comprises a plurality of receiver electrode traces crossing over the plurality of transmitter electrode traces, wherein changes in resulting signals received by the plurality of receiver electrode traces are indicative of fingerprint image characteristics at the array of fingerprint imaging pixel locations;
• a plurality of dielectric islands between the plurality of transmitter electrode traces and the plurality of receiver electrode traces, wherein each dielectric island of the plurality of dielectric islands separates a respective transmitter electrode trace of the plurality of transmitter electrode traces from a respective receiver electrode trace of the plurality of receiver electrode traces at a crossover point therebetween;
• a controller integrated circuit (IC) mounted to the glass substrate, wherein the controller IC is in electrical contact with the plurality of capacitive gap sensor electrode traces, wherein the controller IC is mounted away from the two dimensional array of biometric sensor imaging pixel locations and outside of the biometric sensing area;
• and
• a molding compound encapsulating the controller IC.

A method of making a biometric object imaging sensor, the method comprising:

• providing a glass substrate;
• depositing a first metal layer over the glass substrate, wherein the first metal layer is patterned into a first plurality of capacitive gap sensor electrode traces;
• depositing a first dielectric layer over the first metal layer, wherein the first dielectric layer is patterned into a plurality of isolation islands;
• depositing a second metal layer over the first dielectric layer, wherein the second dielectric layer is patterned into a second plurality of capacitive gap sensor electrode traces;
• depositing a second dielectric layer over the second metal layer;
• planarizing the second dielectric layer;
• and
• bonding a controller integrated circuit (IC) over the glass substrate.