JP2003521107A - Optocoupler on metallized PCB and method of manufacturing the optocoupler - Google Patents

Abstract

(57) Abstract: An apparatus for communicating a circuit is disclosed. The apparatus includes a substrate having a top surface and a bottom surface. The light emitter and light detector are positioned above the top surface of the substrate. The light transmitting material couples the light emitter and the light detector. A plurality of electrical conductors extend along a top surface of the substrate, and each of the plurality of electrical conductors is coupled to a contact area. At least one of the electrical conductors provides electrical communication between the light emitter and the associated contact area, and at least one other of the electrical conductors provides electrical communication between the photodetector and the associated contact area. Provide communication.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

  The present invention relates to a device which allows communication between circuits operating at different voltage potentials.

[0002]

[Prior art]

Modern techniques often require communication between circuits that require electrical isolation from each other. For example, computer systems often require communication between circuits that operate at different potentials. The potential difference between these circuits is often so large that it is necessary to electrically insulate these circuits from one another. An optocoupler is a device that allows communication between circuits without electrically connecting these circuits.

Optocouplers typically include an emitter and a photodetector connected to different leads of a leadframe. During operation of the optocoupler, the electrical lead coupled to the light emitter is typically connected to a circuit operating at one potential, and the electrical lead coupled to the photodetector is connected to another at a different potential. Connected to the circuit. When the light emitter receives a signal from its associated circuitry, the light emitter produces an optical signal. The optical signal is transmitted to a photodetector, which converts the optical signal into an electrical signal and provides it to circuitry coupled to the photodetector. Therefore, the optocoupler provides communication between the electrically isolated circuits.

A typical optocoupler is formed by attaching a light emitter and a photodetector to different leads of a leadframe. Next, a light transmitting material is formed over the light emitter and the photodetector. The optical transmission medium allows the transmission of optical signals from the light emitter to the photodetector. An opaque epoxy body is then formed around the light transmitting material to mechanically secure the leads of the leadframe. The epoxy body also functions to electrically insulate the leads, protect the device from external forces, and protect the light transmitting material from external light. The epoxy body is typically formed using transfer molding techniques. The leadframe and transfer molding associated with typical optocouplers is known to add considerable expense to the molding of optocouplers.

[0005]

[Problems to be Solved by the Invention]

  There is a need for optocouplers with less expensive fabrication costs.

[0006]

[Means for Solving the Problems]

The present invention relates to a device with which a circuit is in communication. The device includes an insulating substrate having a top surface and a bottom surface. The light emitter and photodetector are positioned above the top surface of the substrate. The light transmissive material couples the light emitter and the photodetector. A plurality of electrical conductors extend along the top surface of the substrate, each of which is coupled to the contact area. At least one electrical conductor provides electrical communication between the light emitter and the associated contact area, and at least one other electrical conductor provides electrical communication between the photodetector and the associated contact area. I will provide a.

Another embodiment of the device includes a first reflective layer formed on the top surface of the substrate. The light emitter and photodetector are positioned above the top surface of the substrate. A light transmissive material is disposed over the first reflective layer and couples the light emitter and the photodetector.

Yet another embodiment of the device includes an emitter and two photodetectors coupled to the top surface of the substrate. The light transmitting material couples the two photodetectors and the light emitter to direct an optical signal from the light emitter to both the first and second photodetectors.

Additional embodiments of the device include a light emitter and two photodetectors coupled to the top surface of the substrate. The light transmitting material directs a first optical signal from the first emitter to the photodetector and a second optical signal from the second emitter to the photodetector. A light emitter and a photodetector are coupled.

The invention also relates to a method for manufacturing a device in circuit communication. The method includes providing a substrate on which the light emitter and photodetector are mounted. The method also includes coupling the mold to the substrate such that the light emitter and the photodetector are partially positioned within the cavity defined by the concave surface of the mold. The molding part has an injection port. The method also includes casting the light transmitting material precursor into the cavity through the injection port and forming the light transmitting material precursor within the light transmitting material.

Another embodiment of the method includes providing a rigid electrically insulating substrate and forming a first reflective layer on a portion of the substrate. The method also includes forming an electrical conductor on the top surface of the substrate to couple the light emitter and photodetector to the electrical conductor. The method further includes forming an optical transmission material on the first reflective layer to couple the light emitter and the photodetector.

Yet another embodiment of the method includes depositing a second reflective layer over the light transmitting material to form a substantially opaque layer over the second reflective layer.

[0013]

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a device with which a circuit is in communication. The device includes a substrate having a top surface and a bottom surface. The light emitter and photodetector are positioned above the top surface of the substrate. The light transmissive material couples the light emitter and the photodetector. The light transmitting material provides channels for transmitting light from the light emitter to the photodetector.

The light emitter and photodetector are coupled to electrical conductors formed on the top surface of the substrate. These electrical conductors can also include contact areas formed on the top and / or bottom surface of the substrate.

The substrate can include plated through holes. When the contact area is on the bottom surface of the substrate, the electrical conductor extends through the plated through hole to allow contact between the contact area on the top surface of the substrate and the light emitter and / or the contact area on the top surface of the substrate and light. Electrical communication can be provided with the detector. As a result, the device establishes communication between two external circuits by attaching the contact areas on the bottom of the device to the contacts of the external circuit.

Locating the contact area on the bottom surface of the substrate facilitates access of the contact area for attachment to external circuitry. As a result, the substrate can be flat without having to bend the substrate. The use of a flat substrate eliminates the need for leadframes. The removal of the leadframe offers significant cost advantages. further,
The flat substrate may be sufficiently rigid to provide the device with additional structural integrity.
The added structural integrity may be sufficient to eliminate the need to encase the light transmitting material in the epoxy body, thus eliminating the need for a transfer molding step.

The first reflective layer can be formed between the optical transmission material and the substrate. The second reflective layer can be formed above the light transmitting material. The first and second reflective layers form a surface adjacent to the light transmitting material that reflects light from the light emitter back into the light transmitting material. Reflecting light back into the light transmitting material increases the intensity of the light received at the photodetector and thus increases the efficiency of the device.

The device can also include a substantially opaque layer formed over the second reflective layer. The substantially opaque layer reduces the amount of light entering the light transmitting material from outside the light transmitting material. As a result, the substantially opaque layer reduces interference from external sources.

The light transmitting material, the first and second reflective layers and the substantially opaque layer can all be formed by glob top encapsulation. Machines for glob top encapsulation are less expensive than those required for transfer molding. As a result, the present invention can reduce manufacturing costs.

FIG. 1 is a side view of a device 10 in circuit communication. The device 10 includes a substrate 12 having a top surface 14 and a bottom surface 16. Suitable materials for substrate 12 include, but are not limited to, printed circuit boards and epoxy glass laminates. The light emitter 18 and the photodetector 20 are positioned above the top surface 14 of the substrate 12. A suitable light emitter 18 is
It includes, but is not limited to, an LED, a laser or a light emitting structure, and may also include circuitry for driving the light emitter. Suitable photodetectors 20 include, but are not limited to, photosensitive diodes, triacs, and transistors that may be connected to other digital and analog output devices.

The light transmitting material 22 covers at least a portion of both the light emitter 18 and the photodetector 20. That is, the light transmissive material couples the light emitter 18 and the photodetector 20. The light transmitting material 22 may be formed from materials such as silicone, epoxy and urethane. The first reflective layer 24 is formed between the light transmission material 22 of the substrate 12 and the top surface 14, and the second reflective layer 26 is formed above the light transmission material 22. The opaque layer 28 is formed above the second reflective layer 26. Suitable materials for the opaque layer 28 include silicone, epoxy, polyurethane, and Indianapolis, Indi.
Thermoset Plastics, Inc. located in ana. The
including, but not limited to, moset 310. The opacity of the opaque layer 28 can be increased by adding a black filler such as carbon black.

During operation of the device 10, the light emitter produces an optical signal that is detected by the photodetector 20.
The light transmission material 22 functions as a channel for transmitting an optical signal between the light emitter 18 and the photodetector 20. Light from the light emitter 18 may be reflected from the first and / or second reflective layers 24, 26 one or more times before being detected by the photodetector 20. Therefore, the first and second reflective layers 24, 26 allow the light from the light emitter 18 to pass through the light transmission material 2.
Increasing the efficiency of the device 10 by reflecting it back in 2.

The opaque layer 28 can prevent stray light from the outside of the device 10 from entering the light transmitting material 22 and also protect it from mechanical stress. As a result, the opaque layer 28 reduces the chances that the photodetector 20 will receive spurious signals from external sources.

FIG. 2 is a top view of device 10. The light emitter 18 is coupled to two electrical conductors 34 that extend along the top surface 14 of the substrate 12. Two of the electrical conductors 34 couple the light emitter 18 and the contact area 36 so as to provide electrical communication between the contact area and the light emitter. Similarly, the other two electrical conductors 34 couple the photodetector 20 and the contact area 36 to provide electrical communication between the contact area and the photodetector. Suitable materials for contact area 36 include, but are not limited to, gold plated copper. The substrate 12 is preferably an insulator that prevents or minimizes electrical communication between the electrical conductors 34 of the substrate 12. Although the electrical conductor 34 is illustrated on the top of the first reflective layer 24, electrical communication is provided between the electrical conductor 34 and the light emitter 18 and the photodetector 2.
0 between the first reflective layer 24 and the substrate 12 if the electrical conductor 3
4 can be positioned. Alternatively, an electrical conductor can be included on the bottom surface for coupling the electrical conductor 34 through the plated through hole to a contact area that is selectively positioned on the bottom surface of the substrate away from the plated through hole.

As illustrated in FIG. 3, the bottom surface of device 10 may optionally include a plurality of contact areas 36. The contact area 36 is formed on the substrate 1 through the metal plated through hole 40.
The second top surface 14 may be in electrical communication with the contact area 36. Therefore, depending on the arrangement of the through hole 40, the contact area 36 of the bottom surface 16 of the substrate 12 and the light emitter 18
Alternatively, electrical communication with the photodetector 20 is allowed. On the bottom of the board,
To bond the plated through hole to the contact area which is remote from the through hole,
Electrical conductors can also be included on the bottom surface of the substrate.

If the device 10 includes a contact area 36 on the bottom surface of the substrate 12, the device 10 can be mounted on the surface of a printed circuit board that includes external circuitry. By aligning the contact area 36 of the bottom surface 16 with the contact area of the printed circuit board, the device 10 is integrated into an external circuit. Moreover, the contact areas 36 of the substrate can be aligned with the contacts of different circuits. For example, the contact area 36 in communication with the light emitter can be aligned with the contact of the first external circuit, while the contact area in communication with the photodetector can be aligned with the contact of the second external circuit. it can. This configuration electrically insulates the first circuit and the second circuit while allowing communication between the two circuits through the device 10.

The plated through holes 40 can be directly coupled to the electrical conductor 34 without the need for the contact area 36 on the top surface 14 of the substrate 12. Therefore, the use of the contact area 36 on the top surface 14 of the substrate 12 is optional. Although the through hole 40 is illustrated at the edge of the device 10, the through hole 40 can be an opening extending through the central portion of the substrate 12.

4A-4E illustrate steps in manufacturing an embodiment of the device 10 according to the present invention. In FIG. 4A, the first reflective layer 24 is formed on the top surface 14 of the substrate 12 including the through holes 40. Electrical conductors 34 and contact areas 36 are then formed over substrate 12 and first reflective layer 24 utilizing conventional techniques for placing metal traces. If device 10 includes through holes, through holes 40 may be plated with electrical conductors 34 and contact areas. In another embodiment of the method,
The electrical conductors and contact areas are independent of each other until each contact area is coupled to an associated electrical conductor.

FIG. 4B illustrates the light emitter 18 and photodetector coupled to the electrical conductor 34. Attachment of light emitter 18 and photodetector 20 to electrical conductor 34 can be accomplished using an automated die bonding machine. A typical automatic die bonding machine is
The light emitter 18 and the photodetector 20 are mounted at positions relative to the substrate 12, a conductive adhesive is applied to the substrate 12, and the light emitter 18 and the photodetector 20 are arranged on the substrate 12. As illustrated, one or more wires 42 can be used to couple the light emitter 18 and the photodetector 20 to the electrical conductor 34. Wire 42 to electrical conductor 3
Suitable techniques for attaching to 4 include, but are not limited to, thermosonic bail bonding and ultrasonic wedge bonding.

FIG. 4C illustrates the optical transmission material 22 formed above the first reflective layer 24 to couple the light emitter and the photodetector. The light transmission material 22 can be formed by techniques such as transfer molding and glob top encapsulation.
Glob top encapsulation consists of flowing a precursor of the light transmitting material 22 over a portion of the first reflective layer 24 on which the light transmitting material 22 is to be formed. Next, the optical transmission material 22
The precursor of is cured to form a solid or semi-solid optical transmission material 22. The precursor may be air cured, ultraviolet light cured, or heat cured. Suitable light transmission material 22 precursors include, but are not limited to, transparent silicone and epoxy in the fluid state.

The method of flowing the precursor of the light transmitting material 22 onto the substrate 12 can be accomplished by a number of different techniques. For example, a precursor charge of light transmitting material 22 can be obtained on the rod or spatula by dipping the rod or spatula in a bath of precursor of the light transmitting material 22. This charge is then used as the light transmission material 2
The part of the device 10 to be formed is contacted. Alternatively, a syringe or other tool with a hollow needle can be used to introduce the precursor charge of light transmitting material 22 onto the substrate 12.

During the encapsulation of the glob top capsule, the viscosity of the precursor of the light transmitting material 22 must be kept low enough so that the precursor of the light transmitting material 22 will flow sufficiently high to assume the desired shape upon curing. I have to. A method for reducing viscosity is described in the light transmission material 22.
The substrate 12 is heated before the precursor of the above is flown onto the substrate 12. Board 12
For preheating, the substrate 12 is preferably heated to about 50 ° C to 200 ° C, more preferably to about 70 ° C to 150 ° C, and most preferably to about 90 ° C to 120 ° C.

FIG. 4D illustrates a second reflective layer 26 and an opaque layer 28 formed above the light transmitting material 22. These layers can be formed by the transfer molding method or glob top encapsulation method described above, or by coating the precursor to the light transmitting material 22. When using glob top encapsulation,
The viscosity of the precursor must be low enough to allow fluid flow over any previously formed structure. For example, if the opaque layer 28 is formed by glob top encapsulation, the precursor of the opaque layer 28 will be the second reflective layer 2 previously formed.
It must have a viscosity low enough to allow the fluid to flow above 6. If two or more layers are formed by glob top encapsulation, the two or more layers can be cured simultaneously. Alternatively, each layer can be cured sequentially after the previous layer is cured. Light transmission material 22, second reflective layer 26 and / or opaque layer 28
Often have different cure schedules and / or condition requirements, so this sequential processing is often necessary. For example, a typical cure schedule for Thermoset 310 is 16-24 hours at 75 ° C, 6-8 hours at 95 ° C, and 1
At 20 ° C for 2-3 hours, a typical cure schedule for Sylgard 527 is 65 ° C for 4 hours, 100 ° C for 1 hour, and 105 ° C for 15 minutes.

Adhesion between the light transmitting material 22 and the first and second reflective layers 24, 26 may include plasma emission or equivalent surface treatment on existing portions of the device 10 prior to forming the next layer. It can be increased by applying. Similar processes can be utilized to increase the adhesion between the second reflective layer 26 and the opaque layer 28 and / or between the substrate 12 and the first reflective layer 24.

FIG. 4E illustrates the completed device 10. To form the dome 62 on the substrate 12, a light transmitting material 22 (not shown), a second reflective layer 26 (not shown) and an opaque layer 28 are formed in the center of the substrate 12. The substrate 12 and the electrical conductor 34 extend outward from the periphery of the light transmission material 22.

FIG. 5 illustrates an embodiment of the invention in which both the light emitter and the photodetector are each coupled to three contact areas 36. Both the light emitter 18 and the photodetector 20 are
It is mounted directly on the centrally located electrical conductor 34 and both are connected together via wires 42 to two additional electrical conductors 34. It can be appreciated that more contact areas 36 allow integration of the illustrated embodiment with more complex electrical systems.

FIG. 6 illustrates another method for forming the light transmitting material 22, the second reflective layer 26 and / or the opaque layer 28. Hollow shell 50 is coupled to substrate 12 such that light emitter 18 and photodetector 20 are at least partially positioned within cavity 52 defined by the concave surface of hollow shell 50. More generally, the structure for defining the cavity 52 may be a formwork. In the illustrated embodiment, the hollow shell 50 includes an injection port 54 and a vent 56. The precursor 58 of the optical transmission material 22 is
It is flushed through the injection port 54 by a hypodermic needle or other fluid supply device 60. Air from within cavity 52 of hollow shell 50 may exit hollow shell 50 through vent 56 while the precursor of light transmitting material 22 is flowed through injection port 54. As soon as the precursor of the light transmission material 22 is in the cavity 52 of the hollow shell 50, the precursor of the light transmission material 22 is cured to give a solid or semi-solid light transmission material 2
Form 2. Hollow shell 50 can be opaque by an internal reflective coating, thus providing a second reflective layer and opaque layer 28. The hollow shell is held in place by the cured light transmitting material.

Other embodiments of device 10 can be formed by the various methods described above. For example, device 10 having six contacts on top surface 14 of substrate 12 can be formed as illustrated in FIG. Although not shown, other embodiments may include six contacts on the bottom surface of substrate 12.

As illustrated in FIG. 7, the shape of the dome is not limited to the round shape. For example, the dome can have a square shape that helps pick up the device 10 from a flat surface. The square shape may be the result of forming any of the light transmitting material 22, the second reflective layer 26 and / or the opaque layer 28 having a square shape. For example, if the light transmitting material 22 is formed in a square shape, the second reflective layer 26 formed by glob top encapsulation will also be in a square shape. Device 10 having a square shape uses glob top encapsulation to form light transmission material 22 and second reflective layer 26, and transfer molding to form opaque layer 28 in a square shape. Therefore, it is preferable to form it.

Referring to FIG. 8A, the device 10 can include a light emitter 18, a first photodetector 20A, and a second photodetector 20B. As a result, the optical signal from the light emitter 18 can be transmitted to both the first and second output circuits. As illustrated in FIG. 8B, the device 10 may include a single photodetector 20 and multiple light emitters 18A, 18B. In yet another embodiment (not shown), the device can include multiple light emitters and multiple photodetectors.

The above-described embodiments of device 10 can be mass-produced as illustrated in FIG. 9A.
The plurality of devices 10 are formed on the enlarged substrate 72. A saw can be used to separate the device 10 along vertical and horizontal saw lines 70. The plurality of through holes 40 of the enlarged substrate 72 can be formed before forming the dome. Through holes 40 may be plated before the device 10 is separated using a saw.

FIG. 9B illustrates an enlarged substrate 72 for making the device 10 without the contact area 36 on the bottom surface 16 of each device 10. It can be seen that there is no through hole shown in FIG. 9B.

In each of the embodiments of the apparatus described above, a contact area may be integrated with an associated electric conductor such that the electric conductor has a contact area and an electric conductor area. In other embodiments of the device, the contact area and the electrical conductor are formed on the substrate independent of each other, or the electrical conductor and the contact area are independent of each other until each contact area is coupled to an associated electrical conductor.
Further, the electrical conductor can act as a contact area and / or the contact area can act as an electrical conductor.

While the present invention has been disclosed with reference to the preferred embodiments and examples detailed above, those modifications and combinations which may be within the spirit of the invention and the scope of the appended claims It is to be understood that the above examples are intended in a sense of illustrative rather than limiting, as combinations of and combinations are readily envisioned by one of ordinary skill in the art.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of the present invention of a device in circuit communication.

FIG. 2 is a top view of an embodiment of the present invention of a device in circuit communication.

FIG. 3 is a bottom view of an embodiment of the present invention of a device in circuit communication.

FIG. 4A is an embodiment of the invention illustrating formation of a first reflective surface and an electrical conductor on a top surface of a substrate.

FIG. 4B is an embodiment of the invention illustrating an electrical conductor coupled to a photodetector and a light emitter.

FIG. 4C is an embodiment of the invention illustrating an optical transmission material formed over a first reflective layer.

FIG. 4D is an embodiment of the invention illustrating a second reflective layer and an opaque layer formed over a light transmitting material.

FIG. 4E is an embodiment of the invention illustrating a completed device.

FIG. 5 is a top view of an embodiment of the present invention of a device having a top surface with six electrical conductors.

FIG. 6 is an embodiment of the invention illustrating a method of incorporating a hollow shell to form a light transmitting material, a second reflective layer and / or an opaque layer.

FIG. 7 is an embodiment of the invention illustrating a device with a dome having a square contour.

FIG. 8A is an embodiment of the invention illustrating a device having multiple output sections.

FIG. 8B is an embodiment of the present invention illustrating a device having multiple light emitters.

9A is a top view of an embodiment of the invention of an enlarged substrate including multiple devices. FIG.

FIG. 9B is a top view of an enlarged substrate including a plurality of devices having contact areas formed on the top surface of the substrate.

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Claims (39)

[Claims] 1. A circuit communicating device, an insulating substrate having a top surface and a bottom surface, a light emitter and a photodetector positioned above the top surface of the substrate, the light emitter and the light. A light-transmissive material coupling a detector, and a plurality of electrical conductors each of which is coupled to a contact region and extends along a top surface of the substrate, the electrical conductor being at least one of the electrical conductors. One provides electrical communication between the light emitter and the associated contact area, and at least another one of the electrical conductors provides electrical communication between the photodetector and the associated contact area. An apparatus comprising the plurality of electrical conductors provided. 2. The apparatus according to claim 1, wherein the substrate is an insulator. 3. The apparatus according to claim 1, wherein the substrate is a printed circuit board. 4. The apparatus of claim 1, wherein the electrical conductor is a metal trace on the top surface of the substrate. 5. The apparatus of claim 1, wherein the contact area is positioned on the top surface of the substrate. 6. The apparatus of claim 1, wherein the contact area is positioned on the bottom surface of the substrate. 7. The apparatus of claim 6, further comprising plated through holes that couple the electrical conductor and the contact area. 8. The apparatus according to claim 7, wherein the plated through hole is an opening extending through the substrate. 9. The apparatus of claim 7, wherein the plated through holes are positioned at the edge of the substrate. 10. The device of claim 1, further comprising a first reflective layer formed between the light transmitting material and the substrate. 11. The apparatus according to claim 10, wherein the first reflective layer is positioned between the light emitter and the substrate and between the photodetector and the substrate. 12. The device of claim 1, further comprising a second reflective layer formed over the light transmitting material. 13. A second reflective layer formed above the optical transmission material,   An opaque layer formed above the second reflective layer, The apparatus of claim 1, further comprising: 14. The substrate is peripheral to the light transmitting material such that the substrate is flat and at least a portion of the electrical conductor is positioned on a portion of the substrate extending beyond the periphery of the substrate. The device of claim 1 extending beyond. 15. The apparatus of claim 1, wherein the substrate is flat. 16. The device of claim 1, wherein the light transmitting material at least partially covers both the light emitter and the photodetector. 17. A circuit communication device, a substrate having a top surface and a bottom surface, a first reflective layer formed on the top surface of the substrate, and a light emitter above the top surface of the substrate. And a photodetector, and a light transmissive material overlying the first reflective layer coupling the light emitter and the photodetector. 18. The apparatus according to claim 17, wherein the first reflective layer is positioned between the light emitter and the substrate and between the photodetector and the substrate. 19. The device of claim 17, further comprising a second reflective layer formed on the light transmitting material. 20. The device of claim 19, further comprising a substantially opaque layer formed over the second reflective layer. 21. The device of claim 17, wherein the substrate is a printed circuit board. 22. The plurality of electrical conductors each of which is coupled to a contact region and extends along a top surface of the substrate, wherein at least one of the electrical conductors is the light emitter. A plurality of electrical conductors that provide electrical communication between the photodetector and the associated contact region, and at least one other of the electrical conductors provides electrical communication between the photodetector and the associated contact region. 18. The device of claim 17, further comprising: 23. A device in circuit communication, comprising a substrate having a top surface and a bottom surface, a light emitter coupled to the top surface of the substrate, and first and second light coupled to the substrate. To direct an optical signal from both the detector and the light emitter to the first and second photodetectors,
An apparatus comprising an optical transmission material coupling the first and second photodetectors and the light emitter. 24. The apparatus of claim 23, further comprising a first reflective layer formed on the top surface of the substrate between the light transmitting material and the top surface of the substrate. 25. The apparatus of claim 24, wherein the light emitter and the first and second photodetectors are positioned on the first reflective layer. 26. The plurality of electrical conductors each of which is coupled to a contact region and extends along a top surface of the substrate, wherein at least one of the electrical conductors is the light emitter. A plurality of electrical conductors that provide electrical communication between the photodetector and the associated contact region, and at least one other of the electrical conductors provides electrical communication between the photodetector and the associated contact region. 24. The device of claim 23, further comprising: 27. A device in circuit communication, comprising a substrate having a top surface and a bottom surface, first and second light emitters coupled to the top surface of the substrate, and coupling to the top surface of the substrate. A photodetector configured to direct a first optical signal from the first light emitter to the photodetector and a second optical signal from the second light emitter to the photodetector, An apparatus comprising an optical transmission material coupling the first and second light emitters and the photodetector. 28. The device of claim 27, further comprising a first reflective layer formed on the substrate between the light transmitting material and a top surface of the substrate. 29. The apparatus of claim 28, wherein the light emitter and the photodetector are positioned on the first reflective layer. 30. The plurality of electrical conductors each of which is coupled to a contact region and extends along a top surface of the substrate, wherein at least one of the electrical conductors is the light emitter. A plurality of electrical conductors that provide electrical communication between the photodetector and the associated contact region, and at least one other of the electrical conductors provides electrical communication between the photodetector and the associated contact region. 28. The device of claim 27, further comprising: 31. A method for manufacturing a device in circuit communication, comprising providing a substrate on which a light emitter and a photodetector are mounted, the light emitter and the photodetector being an injection port. Coupling the formwork to the substrate so that it is at least partially positioned in the cavity defined by the concave surface of the formwork, and introducing a precursor of light transmitting material into the cavity through the injection port. A method comprising casting and forming a precursor of a light transmitting material into the light transmitting material. 32. The mold is a hollow shell, and flowing the precursor of the photoconductive material comprises venting air located in the cavity through vent holes located in the hollow shell. The method of claim 31. 33. The method of claim 31, further comprising forming a reflective layer on the substrate prior to bonding the formwork to the substrate. 34. The formwork is opaque and has a reflective inner surface.
The method according to 1. 35. A method for manufacturing a circuit communicating device, comprising: providing a rigid electrically insulating substrate; forming a first reflective layer on a portion of the substrate; Forming a light-transmitting material on the top surface of the substrate; coupling a light emitter and a photodetector to the electrical conductor; and coupling an optical transmission material to the first conductor so as to couple the light emitter and the photodetector. A method comprising forming a reflective layer. 36. The method of claim 35, further comprising forming a second reflective layer over the light transmitting material. 37. The method of claim 36, further comprising forming a substantially opaque layer above the second reflective layer. 38. The method of claim 35, further comprising forming the contact area on the substrate such that a contact area is coupled to the electrical conductor. 39. The method of claim 36, wherein a contact area is formed on the bottom surface of the substrate.