TWM562984U - Optical communication module - Google Patents

Abstract

An optical communication module comprising a circuit board and a substrate, and a driving chip/transimpedance amplifier and a light source/photodetector respectively supported on the circuit board and the substrate, so that the photoelectric element is easy to dissipate under the separate bearing of the two carrier plates, and at the same time The substrate serves as the base surface of the lens carrier. The lens carrier has the functions of a lens, a mirror surface, and a cable connector. When the lens carrier is aligned with the substrate, the alignment of the former is matched with the positioning portion of the latter, and after the preliminary alignment of the two components is achieved, the overlapping of the concentric circles of the two components is monitored by the CCD camera, and the alignment is performed. Correction until the two-stack pattern is concentric, so that the accuracy of the alignment of the two components can reach nanometer level, so that the optical signal emitted by the light source can be effectively coupled into the optical fiber and emitted from other optical emitters. The optical signal can also be accurately incident on the photodetector.

Description

Optical communication module

The present invention relates to an optical communication module, and more particularly to an optical communication module that converts an electrical signal into an optical signal, transmits an optical signal through the optical fiber, and converts the optical signal back to the electrical signal.

Optical communication is a way to transmit information using light and fiber, and it is a kind of wired communication. Optical communication systems typically include an optical transmitter that converts electrical signals into optical signals and transmits optical signals through the optical fibers. The system also includes several optical amplifiers and an optical receiver that converts the optical signals back to electrical signals. The optical transmitter and the optical receiver are mostly modularized or packaged in the same module. Therefore, in the present description, the optical communication module generally refers to a light emitting module, a light receiving module, and an optical transceiver module, and only Explain the optical transceiver module.

A typical optical communication module includes a light source, a photodetector, a driving circuit, an amplifying circuit, an optical component, a connector, and a housing. Wherein, the photoelectric elements are all independently carried by a circuit board, and are electrically connected to each other by wires on the circuit board, and the photovoltaic elements are concentrated on the circuit board, so that heat is not easily dissipated.

On the other hand, a photovoltaic element used for optical communication needs to be coupled to an optical element in application to perform the function of transmitting/receiving an optical signal. Since the surface of the board is filled with optoelectronic components and circuitry, it is not possible to provide a flat base surface to hold the optics, which affects the efficiency of optical coupling. In particular, a Light Emitting Diode (LED) or a Laser Diode (LD) as a light source, and As a photodetector photodiode, if it can't be accurately aligned with the optical component, it will cause optical energy loss and/or signal error during transmission. Therefore, in the packaging process, the optical communication module should ensure that the optical components and the optoelectronic components are accurately aligned.

The "optical communication module and its coupling method of optical coupling" disclosed in the national invention patent No. I461775 provides an alignment manner of an optical component and a photovoltaic component. The optical communication module comprises a substrate and a lens coupling carrier, the substrate has at least two light-emitting chips, each of the light-emitting chips has a plurality of photoelectric units, and each of the photoelectric units is marked with a positioning feature; the lens-coupled carrier comprises a frame and A lens array, the lens array being composed of a plurality of lens units, each lens unit corresponding to a photovoltaic unit. When the lens coupling light carrier is aligned with the substrate, the positioning feature on each photoelectric unit can be observed by the CCD camera to be projected to the corresponding lens unit, thereby confirming the optical coupling position and coupling the lens to the light carrier. It can be accurately aligned with the substrate to form a precise optical communication path.

Since the prior patent only marks the positioning feature on the photovoltaic unit, when observing whether the positioning feature of the photovoltaic unit is projected to the corresponding lens unit through the CCD camera, the photoelectric unit must be in an operating state, that is, in a current-carrying state. In the state, the coupling effect is actually detected by image processing, and then the feedback control is used to find the relative position between the components with the best coupling. To put it simply, the previously disclosed patent uses an Active Alignment method to align the lens coupling carrier with the substrate. Of course, active alignment is no problem when producing a small number of products, but if the product needs to be mass-produced, each internal component needs to be calibrated and fixed, which is time consuming and labor inefficient. In addition, it is difficult to couple the lens to the light carrier only by whether the positioning feature marked on the photoelectric unit is projected to the corresponding lens unit. The accuracy of the substrate when it is aligned and fixed reaches the level of the nanometer (nm) level.

This creation is to solve the above problems, and its purpose is to provide an optical communication module that is easy to dissipate heat.

The second purpose of this creation is to provide an optical communication module that ensures that the efficiency of optical coupling is not affected.

Another object of the present invention is to provide an optical communication module capable of aligning optical components and photoelectric components with a precision of 100 nm or even nanometer.

The optical communication module specifically implementing the present invention comprises a circuit board, a substrate fixed on the circuit board, a driving chip supported on the circuit board and a transimpedance amplifier, and a light source carried by the substrate and A photodetector is electrically connected to the driving chip by a set of wires, and the photodetector is electrically connected to the photodetector through another set of wires.

In another embodiment, the substrate is a germanium substrate.

In another embodiment, the circuit board may not include the transimpedance amplifier, and the substrate may not be provided with the optical detector, so that the optical communication module only has the function of emitting an optical signal.

In another embodiment, the circuit board may not include the driving chip, and the substrate may not be provided with the light source, so that the optical communication module only has the function of receiving the optical signal.

In another embodiment, the light source is an array of a plurality of surface-emitting laser diodes; the photodetector is an array of light diodes; the lens The carrier includes a first lens array, a second lens array, a receiving socket and a mirror surface. The first and second lens arrays respectively include a plurality of collimating lenses and a plurality of collecting lenses, wherein the receiving sockets are used to connect one a cable connector; the optical signal emitted by the surface-emitting laser diode is incident on the collimating lens of the first lens array, and is concentrated by the mirror surface reflection and the collecting lens of the first lens array, and then introduced into the cable connector The spliced optical fiber is internally transmitted to other optical receivers, and the optical signals emitted from the other optical transmitters are incident on the collimating lens of the second lens array via the optical fiber, and then reflected by the mirror and the second lens array The concentrating lens is concentrated and transmitted to the photodiode.

In another embodiment, the receiving socket is defined by a front end wall, a top wall and two parallel side walls, and the receiving base further comprises two extending rearward from the two sides of the front end wall, and parallel to the side wall Plugin.

In another embodiment, the surface of the lens carrier includes a chuck holder having a bottom surface having a plurality of pads.

In another embodiment, the substrate further includes at least two positioning portions and two positioning points, the at least two positioning portions are spaced apart on a surface of the substrate, and the two positioning points are spaced apart on a surface of the substrate; the lens carrier Further comprising at least two alignment portions and two transparent windows, the at least two alignment portions are formed on a side of the lens carrier, and the two transparent windows are spaced apart from each other on a surface of the lens carrier, and a center of each transparent window is marked with a In the opposite point, the center distance of the two pairs of points is the same as the center distance of the two positioning points; when the lens carrier is aligned with the substrate, each pair of positions is adapted to each positioning portion to achieve preliminary After alignment, a precise alignment of each pair of points with each positioning point is performed through a CCD camera to accurately fix the lens carrier on the substrate.

In another embodiment, the alignment portion is in the shape of a groove, and It is disposed on the left side and the right side of the lens carrier, and each side has two groove-shaped alignment portions, the groove shape includes but is not limited to a triangle; the positioning portion is matched with the groove-shaped alignment portion. A mark or a bump, each mark or bump corresponding to a groove.

In another embodiment, the substrate further has a concentric circle marked with a center of each positioning point; the lens carrier includes a concentric circle centered on each pair of points and marked within the transparent window, The alignment correction is performed by monitoring the superposition of the concentric circles of the lens carrier and the concentric circles of the substrate through the CCD camera.

The effect of this creation against the prior art is that the circuit board and the substrate are used as carrier plates for driving the wafer/amplifier circuit and the light source/photodetector, respectively, so that the photovoltaic element is easy to dissipate heat.

Secondly, the substrate can provide a flat surface compared to the board, as the base surface of the fixed lens carrier, ensuring that the efficiency of optical coupling is not affected.

Furthermore, by using the Passive Alignment method, when the lens carrier and the substrate are aligned and fixed, the alignment portion of the two components is matched with the positioning portion to achieve a preliminary alignment, and then the two components are performed by the CCD camera. The precise alignment of the position and the positioning point enables the accuracy to reach 100 nm.

In addition, when the lens carrier and the substrate are initially aligned, the CCD camera monitors the superimposed state of the concentric circles of the two components, and the alignment is corrected to increase the accuracy to the nanometer level.

The detailed technical contents and other objects and features of the present invention can be fully understood by referring to the following description of embodiments with reference to the accompanying drawings.

10‧‧‧Optical communication module

20‧‧‧ boards

21‧‧‧Drive chip

22‧‧‧Transistor Amplifier

30‧‧‧Light source/VCSEL array

31‧‧‧Surface-emitting laser diode

32‧‧‧Wire

40‧‧‧Photodetector / Photodiode Array

41‧‧‧Light diode

42‧‧‧Wire

50‧‧‧Substrate

51‧‧‧ Positioning Department

52‧‧‧Location points

53‧‧‧Concentric circles

60‧‧‧Lens Carrier

61‧‧‧First lens array

62‧‧‧Second lens array

63‧‧‧Mirror surface

64‧‧‧ socket

65‧‧‧ Collimating lens

66‧‧‧ Concentrating lens

67‧‧‧ front wall

68‧‧‧ top wall

69‧‧‧ side wall

70‧‧‧ plugin

71‧‧‧Parts

72‧‧‧ windows

73‧‧‧ opposite sites

74‧‧‧Concentric circles

75‧‧‧Sucker holder

76‧‧‧foot pads

77‧‧‧ Concentrating lens

78‧‧‧ Collimating lens

79‧‧‧ Groove

The first picture shows the appearance of the optical communication module.

Figure 2 is an exploded view of the creation.

Figure 3 is a top view of the creation.

Fig. 4 is a cross-sectional view taken along line A-A of Fig. 3.

Figure 5 is an external view of the inverted lens carrier.

As shown in the first to fourth embodiments, the optical communication module 10 disclosed in the present application includes a printed circuit board (PCB) 20, a driving chip 21 fixed on the circuit board 20, and a transimpedance amplifier. (Transimpedence Amplifier, TIA) 22 and other necessary electrical components.

The present invention further includes a substrate 50 bonded to the circuit board 20, and a light source 30 and a photodetector 40 supported on the substrate 50. The substrate 50 can be made of different materials, such as germanium, polymer and ceramic materials, wherein the germanium substrate has the advantages of low cost, easy processing, good electrical conductivity, thermal conductivity and thermal stability, and is a better choice. . The carrier substrate using the germanium substrate as the light source 30 and the photodetector 40 has the following advantages: 1. The germanium substrate is flatter than the circuit board. 2. The substrate can be etched to make the placement accuracy reach the hundred nanometer level. 3. The modulation of the thickness of the substrate can effectively control the wiring distance between the driving chip 21/transistor amplifier 22 and the light source 30/photodetector 40, and improve the performance of the high frequency signal. 4. The substrate can be used as the base surface of the optical component. If the thickness of the substrate is uneven during the Die Mounting process, the optical component is still on the same base surface, and the efficiency of optical path coupling is still not affected. influences. 5. Light source 30 has a preferred heat dissipation mechanism.

The semiconductor elements commonly used as light sources in optical communication systems are light-emitting diodes and laser diodes. In the embodiment of the present creation, the light source 30 is plural A VCSEL array consisting of a Vertical Cavity Surface Emitting Laser Diode (hereinafter referred to as VCSEL or a surface-emitting laser diode) 31, each of which is a single-shot 32 The driving chip 21 is electrically connected, and the driving chip 21 is driven to emit an optical signal. Other light-emitting diodes and Edge Emitting Laser Diodes (EELD), which can be used as light sources, can also be used without being limited by VCSELs.

The photodetector 40 converts the incident optical signal into an electrical signal by using a photoelectric effect. In optical communication systems, photodetectors are typically semiconductor-based photodiodes. In the embodiment of the present invention, the photodetector 40 is a photodiode array (Photo Diodes Array), and each photodiode 41 is electrically connected to the transimpedance amplifier 22 by a wire 42. The transimpedance amplifier 22 processes the electrical signal converted back by the optical diode 41 and converts it into a digital signal through the back end circuit.

Another important component of this creation is the lens carrier 60. The lens carrier 60 is a plastic molded part, which has the functions of a lens, a mirror surface and a cable connector. The three-in-one lens carrier 60 has the following advantages: 1. Small size and light weight. 2. The center of gravity can completely fall on the bonded substrate 50 (or VCSEL array 30 / photodiode array 40). 3. It is possible to reduce the probability of the voltage loss of the drive wafer 21 / transimpedance amplifier 22 and the VCSEL array 30 / photodiode array 40 wire bonding (wire bond) gold wire during packaging.

As shown in FIGS. 2 to 5, the lens carrier 60 includes a first lens array 61, a second lens array 62, a mirror surface 63, and a socket 64 for connecting cable connectors (not shown). . The first lens array 61 includes a plurality of collimating lenses 65 and a plurality of collecting lenses 77, which are disposed at intervals of 90 degrees. Each of the collimating lenses 65 corresponds to a one-shot laser diode 31 and a collecting lens 77, respectively. The optical signal emitted by the surface-emitting laser diode 31 is incident on the collimating lens 65 and converted into a via lens 65. The parallel light beam is reflected by the 45-degree mirror surface 63 into a horizontal direction, and then concentrated by the collecting lens 77 to be coupled to the fiber of the cable connector (not shown), and then transmitted through the optical fiber. To other optical receivers (not shown). The second lens array 62 is the same as the first lens array 61, and is also composed of a plurality of collecting lenses 66 and a plurality of collimating lenses 78, which are disposed at intervals of 90 degrees, and each of the collecting lenses 66 corresponds to a photodiode 41 and a The collimator lens 78, the optical signals emitted from other light emitters (not shown) are sequentially passed through the optical fiber → collimating lens 78 → mirror surface 63 → collecting lens 66 → photodiode 41, where the optical signal is photodiode The body 41 converts back to the electrical signal, and then converts it into a smaller amplitude electrical signal by the transimpedance amplifier 22, and then converts it into a digital signal through the circuit at the back end. The socket 64 is used to connect the cable joint, and is defined by a front end wall 67, a top wall 68 and two parallel side walls 69. The condensing lens 77 and the collimating lens 78 are disposed in an elongated groove 79 formed in the front end wall 67. The socket 64 further includes two inserts 70 extending rearwardly from opposite sides of the front end wall 67 and parallel to the side walls 69 for inserting the receptacles of the cable joints, thereby providing reliable reliability of the cable joints and the lens carrier 60. Mechanical connection.

The lens carrier 60 further includes at least two alignment portions 71; in the embodiment of the drawing, the alignment portion 71 is a triangular (V-shaped) groove and is symmetrically disposed on the left and right sides of the lens carrier 60. There are two trough-shaped alignment portions 71 on each side. Other groove shapes of the alignment portion 71, such as rectangular, square, trapezoidal or semi-circular, are also included in the scope of the present patent application. The function of the aligning portion 71 is to cooperate with the positioning portion 51 corresponding to the surface of the substrate 50, and when the lens carrier 60 and the substrate 50 are aligned and fixed, the initial alignment can be achieved by the alignment of the aligning portion 71 and the positioning portion 51. The effect is left to be described later, and is skipped for the time being. The positioning portion 51 is a mark having the same number as the alignment portion 71 and matching in shape, and each positioning portion 51 corresponds to a pair of position portions 71, This positioning portion 51 can be obtained by a known method such as photolithography. The positioning portion 51 can also be a bump protruding from the surface of the substrate 50, and is not limited by the planar mark.

The surface of the lens carrier 60 further includes two spaced apart transparent windows 72 that are circular while the center of each transparent window 72 is marked with a target 73 of about 20 micrometers (μm). The alignment point 73 is used in the matching substrate 52 on the substrate 50, that is, the substrate 50 includes two positioning points 52 spaced apart on the surface of the substrate 50, and the center distance and size are on the lens carrier 60. The two pairs of points 73 are the same, and after the lens carrier 60 and the substrate 50 are initially aligned, the two pairs of points 73 and the second positioning points 52 can be accurately aligned, and the functions are also left to be described later.

Further, the surface of the lens carrier 60 is provided with a chuck holder 75 for gripping the lens carrier 60 above the substrate 50 by a suction cup (not shown) controlled by a robot arm. In addition, the bottom surface of the lens carrier 60 has a foot pad 76. The foot pad 76 helps the lens carrier 60 maintain a good contact relationship with the surface of the substrate 50, so that the lens carrier 60 can be smoothly bonded to the lens carrier 60. On the substrate 50.

When the lens carrier 60 is aligned and fixed to the substrate 50, the lens carrier can be used in a state where the photoelectric element (the surface-emitting type laser diode 31/photodiode 41) is not in current, and the passive alignment method can be used. 60 is precisely fixed to the substrate 50. As shown in FIG. 3, first, each aligning portion (triangular groove) 71 of the lens carrier 60 is engaged with each positioning portion 51 (triangle mark) of the substrate 50 to complete the preliminary alignment of the two components. The accuracy is up to the micron (μm) level. The alignment of each pair of sites 73 on the lens carrier 60 with each of the positioning points 52 on the substrate 50 is then performed through a Charge Coupled Device (CCD) camera (not shown). When the two pairs of points 73 are respectively aligned with the two positioning points 52, it indicates that the lens carrier 60 has been accurately aligned with the substrate 50, that is, The first lens array 61 and the second lens array 62 are respectively aligned with the VCSEL array 30 and the photodiode array 40, so that the optical signals emitted by the surface-emitting laser diode 31 can be effectively coupled into the optical fiber, and other light The optical signal emitted by the transmitter can also be accurately incident on the photodiode 41 via the optical fiber. The precision of attaching the lens carrier 60 to the substrate 50 using the passive alignment described above can be as high as 100 nanometers (nm).

In a preferred embodiment, as shown in Figures 2 and 3, the present application further applies the Moiré Pattern principle for optical alignment to accurately align the lens carrier 60 with the substrate 50. The degree can be increased to the nano level. The Molyl fold is composed of two sets of concentric circles 53 marked on the surface of the substrate 50, and two sets of concentric circles 74 marked on the surface of the lens carrier 60. Wherein, the concentric circles 53 on the substrate 50 are marked with the positioning point 52 as a center; the concentric circles 74 on the lens carrier 60 are marked in the transparent window 72 with the center of the alignment point 73 as the center, and the periods of the four sets of concentric circles are the same. .

When the lens carrier 60 and the substrate 50 are initially aligned according to the passive alignment method, the overlapping of the two sets of concentric circles 74 of the inspection lens carrier 60 and the concentric circles 53 of the substrate 50 can be directly observed by the CCD camera. Perform optical alignment. As shown in Figure 3, when the two components are accurately overlapped, the pattern of the overlay is concentric; if it is biased to the left, it is a counterclockwise spiral pattern, and when it is biased to the right, a clockwise spiral pattern appears. Therefore, the alignment can be corrected by this phenomenon, and the accuracy when the lens carrier 60 and the substrate 50 are aligned and fixed can be greatly improved to the nanometer level.

It should be noted that the optical communication module 10 disclosed in the present disclosure may also omish the transimpedance amplifier 22, the photodiode array 40 and the second lens array 62, and constitute a light emitting module having only the function of emitting an optical signal, and The optical receiving module for receiving the optical signal is docked to realize bidirectional transmission of the optical signal between the optical transmitting module and the other optical receiving module. Similarly, the driving chip 21 in the optical communication module 10 can also be omitted. The VCSEL array 30 and the first lens array 61 constitute a light receiving module that only receives the optical signal function, and is connected to other light emitting modules for emitting optical signals to implement the light receiving module and other light emitting modules. The optical signal is transmitted in both directions.

Of course, the above description is only a preferred embodiment of the present invention, and thus does not limit the scope of the patent of the present invention. Any equivalent structure or equivalent process transformation using the contents of the present specification and the drawings may be directly or indirectly applied to Other related technical fields are included in the scope of patent protection of this creation.

Claims (10)

An optical communication module includes a circuit board, a substrate fixed on the circuit board, a driving chip supported on the circuit board, and a transimpedance amplifier, and a light source and a light detection carried by the substrate The light source is electrically connected to the driving chip by a set of wires, and the photodetector is electrically connected to the photodetector through another set of wires. The optical communication module of claim 1, wherein the substrate is a germanium substrate. The optical communication module of claim 1, wherein the circuit board does not include the transimpedance amplifier, and the optical detector is not provided, so that the optical communication module only has the function of emitting an optical signal. The optical communication module of claim 1, wherein the circuit board does not include the driving chip, and the substrate is not provided with the light source, so that the optical communication module only has the function of receiving the optical signal. The optical communication module of claim 1, wherein the light source is an array of a plurality of surface-emitting laser diodes; the photodetector is an array of a plurality of photodiodes; the lens carrier includes a first a lens array, a second lens array, a receiving socket and a mirror surface, the first and second lens arrays respectively comprise a plurality of collimating lenses and a plurality of collecting lenses, wherein the receiving socket is used for connecting a cable joint; The optical signal emitted by the laser diode is incident on the collimating lens of the first lens array, and is concentrated by the specular reflection and the collecting lens of the first lens array, and then introduced into the optical fiber of the fiber optic cable connector. Transmitted to other optical receivers, and optical signals emitted from other optical transmitters are incident on the collimating lens of the second lens array via the optical fiber, and then reflected by the mirror surface and the collecting lens of the second lens array Transfer to the photodiode. The optical communication module of claim 5, wherein the receiving socket is defined by a front end wall, a top wall and two parallel side walls, and the receiving base further comprises two extending rearward from the two sides of the front end wall, respectively. And an insert parallel to the side wall. The optical communication module of claim 5, wherein the surface of the lens carrier comprises a chuck holder, and the bottom surface of the lens carrier has a plurality of pads. The optical communication module of claim 5, wherein the substrate further comprises at least two positioning portions and two positioning points, the at least two positioning portions are spaced apart on a surface of the substrate, and the two positioning points are spaced apart on the surface of the substrate. The lens carrier further includes at least two alignment portions and two transparent windows. The at least two alignment portions are formed on sides of the lens carrier, and the two transparent windows are spaced apart on the surface of the lens carrier, each transparent The center of the window marks a pair of sites, the center distance of the two pairs of points is the same as the center distance of the two positioning points; when the lens carrier is aligned with the substrate, each pair of positions is adapted to each After the initial alignment, the positioning unit performs precise alignment of each pair of points and each positioning point through a CCD camera to accurately fix the lens carrier on the substrate. The optical communication module of claim 8, wherein the alignment portion is in the shape of a groove, and is symmetrically disposed on a left side and a right side of the lens carrier, each side having a two-slot alignment portion, The groove shape includes, but is not limited to, a triangle; the positioning portion is a mark or a protrusion that coincides with the groove-shaped alignment portion, and each mark or protrusion corresponds to a groove. The optical communication module of claim 8, wherein the substrate further has a concentric circle indicated by a center of each positioning point; the lens carrier includes a center of each pair of points, and is marked in the transparent window The inner concentric circle is used to monitor the superposition of the concentric circle of the lens carrier and the concentric circle of the substrate through the CCD camera, and correct the alignment.