Proximity sensor
View Patent ↗A proximity sensor includes a printed circuit board (PCB); a first cup and a second cup embedded in the PCB; an electromagnetic radiation transmitter operably mounted in the first cup; and an electromagnetic radiation receiver operably mounted in the second cup.
1. A proximity sensor comprising:
a printed circuit board (PCB);
a first cup and a second cup embedded in the PCB, at least one of the first and second cups comprising an annular tapering wall that is coated with a reflective material;
an electromagnetic radiation transmitter operably mounted in the first cup;
an electromagnetic radiation receiver operably mounted in the second cup;
encapsulant, which is transparent to electromagnetic radiation transmitted by the transmitted, encapsulating the transmitter and the receiver, the encapsulant substantially filling the first cup and the second cup, the encapsulant further forming at least one lens above at least one of the first cup and the second cup;
an opaque layer, which attenuates electromagnetic radiation transmitted by the transmitter, positioned in overlying relationship with the PCB and having a first aperture aligned with the first cup and a second aperture aligned with the second cup; and
at least one molding ring positioned in overlying relationship with at least one of the first aperture and second aperture, the at least one molding ring comprising a laterally extending rim portion and an upright rim portion that are used to form the at least one lens above at least one of the first cup and the second cup, wherein the at least one molding ring is situated between the opaque layer and the PCB.
2. The proximity sensor of claim 1 , wherein the at least one lens comprises a first lens formed above the first cup and wherein the first lens is bonded to an inner wall of the first aperture.
3. The proximity sensor of claim 1 , wherein the at least one lens further comprises a second lens formed above the second cup and wherein the second lens is bonded to an inner wall of the second aperture.
4. The proximity sensor of claim 1 ,wherein the opaque layer is bonded with a top surface of the PCB.
5. The proximity sensor of claim 4 , wherein the at least one lens comprises a first lens that extends above the top surface of the PCB into the first aperture as well as a second lens that extends above the top surface of the PCB into the second aperture, wherein the first lens is bonded to an inner wall of the first aperture, and wherein the second lens is bonded to an inner wall of the second aperture.
6. The proximity sensor of claim 1 , wherein both the first and second cups comprise an annular tapering wall that is coated with the reflective material, the first cup comprising a first annular lip that is coated with a conductive material and is insulated from the reflective material of the first cup's annular tapering wall by a first insulating ring, the second cup comprising a second annular lip that is coated with the conductive material and is insulated from the reflective material of the second cup's annular tapering wall by a second insulating ring.
7. The proximity sensor of claim 1 , wherein the at least one lens is bonded to a cylindrical inner wall of the opaque layer.
8. A proximity sensor comprising:
a printed circuit board (PCB) having a top surface and a bottom surface and having a first cavity and a second cavity, the cavities having first and second openings, respectively, in the top surface;
first and second cups provided in the first and second cavities, respectively;
an infrared (IR) transmitter operably mounted in the first cup;
an IR receiver operably mounted in the second cup;
encapsulant substantially transparent to IR radiation substantially filling each of the cups and forming a lens above each of the cups that fills and extends above the top surface of the PCB, wherein the lens above at least one of the first and second cups is formed, at least in part, by a molding ring that rests upon the top surface of the PCB and is configured to shape the lens above the top surface of the PCB; and
a layer of material substantially opaque to IR radiation overlying the top surface of the PCB, the layer having a first aperture aligned with and at least partially surrounding a portion of the lens that extends from the first cup above the top surface and a second aperture aligned with and at least partially surrounding a portion of the lens that extends from the second cup above the top surface, wherein the molding ring is positioned between the layer of material substantially opaque to IR radiation and the PCB.
9. The proximity sensor of claim 8 , comprising contacts on the bottom surface of the PCB configured to connect the PCB to power and control circuitry.
10. The proximity sensor of claim 8 , wherein a first terminal of the IR transmitter is electrically connected to a bottom portion of the first cup and the bottom surface of the PCB through a via, the first cup further comprising:
a contact on a lip of the first cup which is electrically connected to a second terminal of the IR transmitter, the contact on the lip of the first cup being electrically insulated from the first terminal by at least one insulating ring positioned in the first cup.
11. The proximity sensor of claim 8 , the second cup comprising:
a contact at a bottom portion thereof which is electrically connected to a first terminal of the IR receiver; and
a contact on a lip of the second cup which is electrically connected to a second terminal of the IR receiver, the contact on the lip of the second cup being electrically insulated from the second terminal by at least one insulating ring positioned in the second cup.
12. The proximity sensor of claim 8 , wherein at least one of the first and second cups comprise a highly reflective coating on an interior surface thereof and the first cup comprises an insulating ring configured to electrically insulate a bottom portion of the first cup from an annular lip of the first cup that extends transversely with respect to a longitudinal axis of the first cup.
13. The proximity sensor of claim 8 , wherein the PCB and the layer of material substantially opaque to IR radiation each comprise a thickness extending perpendicular to the top surface of the PCB, the thickness of the layer of material being greater than the thickness of the PCB.
14. The proximity sensor of claim 8 , wherein the layer of material opaque to IR radiation is bonded to the top surface of the PCB.
15. A method for making a proximity sensor comprising:
providing a printed circuit board (PCB) with first and second cups embedded therein and having cup openings proximate a top surface of the PCB;
operably mounting an infrared (IR) transmitter in the first cup;
operably mounting an IR receiver in the second cup;
filling the first cup and second cup with an encapsulant;
forming at least one lens with the encapsulant, the at least one lens being formed within and extending above at least one of the first cup and the second cup, wherein the at least one lens is formed with the use of a molding ring which comprises a laterally extending rim portion and an upright rim portion having a diameter substantially equal to a diameter of at least one of the first and second cup openings; and
overlaying the top surface of the PCB with a layer of substantially IR opaque material having a first aperture aligned with the first cup and a second aperture aligned with the second cup, wherein the layer of substantially IR opaque material is overlayed on the PCB without removing the molding ring.
16. The method of claim 15 , wherein operably mounting the IR transmitter in the first cup comprises connecting a terminal on the bottom of the IR transmitter with an electrical contact at the bottom of the first cup and connecting by wire bonding another terminal of the IR transmitter with an electrical contact on a lip of the first cup, wherein the electrical contact on the bottom of the first cup is electrically connected to a bottom surface of the PCB through an electrically-conductive via that extends through the PCB, and wherein the electrical contact at the bottom of the first cup is insulated from the electrical contact on the lip of the first cup by an insulating ring.
17. The method of claim 15 , further comprising covering the IR transmitter and the IR receiver with an encapsulant that is substantially transparent to IR and molding a first lens projecting above the top surface of the PCB from the encapsulant covering the IR transmitter and molding a second lens projecting above the top surface of the PCB from the encapsulant covering the IR receiver.
18. The method of claim 15 , wherein the at least one lens comprises a first lens formed within and extending above the first cup and a second lens formed within and extending above the second cup, wherein the first lens is bonded to an inner cylindrical wall of the first aperture and wherein the second lens is bonded to an inner cylindrical wall of the second aperture.
19. The method of claim 15 , wherein providing a PCB with first and second cups embedded therein and having cup openings proximate a top surface of the printed circuit board comprises providing the first and second cups with gold on interior surfaces thereof and insulating rings on the interior surfaces thereof.
20. The method of claim 15 , wherein providing a PCB comprises providing contacts on a bottom surface of the PCB that are electrically connectable to power and control circuitry.