Sensor interposer employing castellated through-vias
An example sensor interposer employing castellated through-vias formed in a PCB includes a planar substrate defining a plurality of castellated through-vias; a first electrical contact formed on the planar substrate and electrically coupled to a first castellated through-via; a second electrical contact formed on the planar substrate and electrically coupled to a second castellated through-via, the second castellated through-via electrically isolated from the first castellated through-via; and a guard trace formed on the planar substrate, the guard trace having a first portion formed on a first surface of the planar substrate and electrically coupling a third castellated through-via to a fourth castellated through-via, the guard trace having a second portion formed on a second surface of the planar substrate and electrically coupling the third castellated through-via to the fourth castellated through-via, the guard trace formed between the first and second electrical contacts to provide electrical isolation between the first and second electrical contacts.
1 . A wearable biosensor comprising:
a sensor interposer comprising:
a planar substrate;
a first electrical contact formed on the planar substrate and electrically coupled to a first castellated through-via formed in the planar substrate;
a second electrical contact formed on the planar substrate and electrically coupled to a second castellated through-via formed in the planar substrate, the second castellated through-via electrically isolated from the first castellated through-via; and
a sensor physically coupled to the planar substrate, the sensor comprising at least two electrodes, a first electrode of the at least two electrodes electrically coupled to the first electrical contact, and a second electrode of the at least two electrodes electrically coupled to the second electrical contact; and
a sensor chemical disposed on a distal end of the sensor;
a printed circuit board (“PCB”) having a plurality of electrical contacts defined on a first surface of the PCB; and
wherein the sensor interposer is physically coupled to the first surface of the PCB, and wherein the first and second castellated through-vias are electrically and physically coupled to a respective first and second electrical contacts of the plurality of electrical contacts defined on the first surface of the PCB.
2 . The wearable biosensor of claim 1 , further comprising a controller in communication with the sensor, the controller to receive sensor signals from the sensor, and determine an analyte concentration based on the sensor signals.
3 . The wearable biosensor of claim 2 , further comprising a guard trace comprising:
a first portion formed on a first surface of the interposer substrate and electrically coupling a third castellated through-via to a fourth castellated through-via, and
a second portion formed on a second surface of the interposer substrate and electrically coupling the third castellated through-via to the fourth castellated through-via,
the guard trace formed between the first and second electrical contacts to provide electrical isolation between the first and second electrical contacts.
4 . The wearable biosensor of claim 2 , wherein the planar substrate defines an opening between the first and second electrical contacts, wherein a third castellated through-via is formed in a perimeter of the planar substrate, a fourth castellated through-via is formed in a perimeter of the opening, and wherein a first guard trace and a second guard trace are formed on the planar substrate,
the second guard trace having a first portion formed on the first surface of the planar substrate and electrically coupling a fifth castellated through-via to a sixth castellated through-via, the second guard trace having a second portion formed on the second surface of the planar substrate and electrically coupling the fifth castellated through-via to the sixth castellated through-via, the second guard trace formed between the first and second electrical contacts to provide electrical isolation between the first and second electrical contacts, and
wherein the fifth castellated through-via is formed in a perimeter of the planar substrate, and the castellated sixth through-via is formed in a perimeter of the opening.
5 . The wearable biosensor of claim 4 , wherein the PCB defines a surface feature, the surface feature configured to engage with the opening defined in the sensor interposer planar substrate, the surface feature enabling alignment between the PCB and the sensor interposer.
6 . The wearable biosensor of claim 2 , wherein the sensor chemical comprises glucose oxidase.
7 . The wearable biosensor of claim 2 , wherein the sensor chemical comprises a chemical configured to react with one or more of glucose, lactate, or cholesterol.
8 . The wearable biosensor of claim 2 , wherein the sensor comprises a first material and a second material, the second material formed coaxially around the first material, a first portion of the first material extending beyond the second wire material at a first end of the sensor,
wherein the first portion of the first material is electrically coupled to the first electrical contact, and the second material is coupled to the second electrical contact.
9 . A method of manufacturing a wearable biosensor, the method comprising:
providing a sensor interposer comprising:
a planar substrate,
a first electrical contact formed on the planar substrate and electrically coupled to a first castellated through-via formed in the planar substrate,
a second electrical contact formed on the planar substrate and electrically coupled to a second castellated through-via formed in the planar substrate, the second castellated through-via electrically isolated from the first castellated through-via, and
a sensor physically coupled to the planar substrate, the sensor comprising at least two electrodes, a first electrode of the at least two electrodes electrically coupled to the first electrical contact, and a second electrode of the at least two electrodes electrically coupled to the second electrical contact, and
a sensor chemical disposed on a distal end of the sensor; and
providing a printed circuit board (“PCB”) having a plurality of electrical contacts defined on a first surface of the PCB; and
wherein the sensor interposer is physically coupled to the first surface of the PCB, and wherein the first and second castellated through-vias are electrically and physically coupled to a respective first and second electrical contacts of the plurality of electrical contacts defined on the first surface of the PCB.
10 . The method of claim 9 , wherein a controller is in communication with the sensor, the controller to receive sensor signals from the sensor, and determine an analyte concentration based on the sensor signals.
11 . The method of claim 10 , wherein the wearable biosensor further comprises a guard trace comprising:
a first portion formed on a first surface of the interposer substrate and electrically coupling a third castellated through-via to a fourth castellated through-via, and
a second portion formed on a second surface of the interposer substrate and electrically coupling the third castellated through-via to the fourth castellated through-via,
the guard trace formed between the first and second electrical contacts to provide electrical isolation between the first and second electrical contacts.
12 . The method of claim 10 , wherein the planar substrate defines an opening between the first and second electrical contacts, wherein a third castellated through-via is formed in a perimeter of the planar substrate, a fourth castellated through-via is formed in a perimeter of the opening, and wherein a first guard trace and a second guard trace are formed on the planar substrate,
the second guard trace having a first portion formed on the first surface of the planar substrate and electrically coupling a fifth castellated through-via to a sixth castellated through-via, the second guard trace having a second portion formed on the second surface of the planar substrate and electrically coupling the fifth castellated through-via to the sixth castellated through-via, the second guard trace formed between the first and second electrical contacts to provide electrical isolation between the first and second electrical contacts, and
wherein the fifth castellated through-via is formed in a perimeter of the planar substrate, and the castellated sixth through-via is formed in a perimeter of the opening.
13 . The method of claim 12 , wherein the PCB defines a surface feature, the surface feature configured to engage with the opening defined in the sensor interposer planar substrate, the surface feature enabling alignment between the PCB and the sensor interposer.
14 . The method of claim 10 , wherein the sensor chemical comprises glucose oxidase.
15 . The method of claim 10 , wherein the sensor chemical comprises a chemical configured to react with one or more of glucose, lactate, or cholesterol.
16 . The method of claim 10 , wherein the sensor comprises a first material and a second material, the second material formed coaxially around the first material, a first portion of the first material extending beyond the second material at a first end of the sensor,
wherein the first portion of the first material is electrically coupled to the first electrical contact, and the second material is coupled to the second electrical contact.