WO2022142171A1

WO2022142171A1 - Mlg2.0 protocol-based single-mode optical module

Info

Publication number: WO2022142171A1
Application number: PCT/CN2021/100471
Authority: WO
Inventors: 李宁; 李林科; 吴天书; 杨现文; 张健
Original assignee: 武汉联特科技股份有限公司
Priority date: 2020-12-31
Filing date: 2021-06-17
Publication date: 2022-07-07
Also published as: CN112764173A

Abstract

An MLG2.0 protocol-based single-mode optical module, comprising a graphic circuit substrate (8), a PCBA (1), an optical module, and a housing. The optical module is fixed on the PCBA, and the PCBA is fixedly mounted in a space defined by a base (19) of the housing and an upper cover (20). The optical module comprises an optical receiving module and an optical emitting module. The optical receiving module comprises an optical receiving assembly and a photodetector chip (21) which are sequentially provided along an incident light path. The optical emitting module comprises a single-mode VCSEL laser array (6), a reflection prism (11), a lens array (14), an isolator (13) and an emitting end sub-assembly (16) which are sequentially provided along an emergent light path. The emitting end sub-assembly (16) comprises a V-shaped limiting groove, an optical fiber array and a cover plate. The optical fiber array is snap-fitted into the V-shaped limiting groove, and the V-shaped limiting groove, the optical fiber array and the cover plate are fixedly connected by means of an adhesive. The optical module can achieve high-density integrated packaging, has low requirements on the positioning precision of the chip, is easy for batch production, reduces the number of optical components to the utmost extent, is easy to couple and brings better optical reliability.

Description

A single-mode optical module based on MLG2.0 protocol

technical field

The invention belongs to the technical field of optical communication, and in particular relates to a single-mode optical module based on the MLG2.0 protocol.

Background technique

With the rapid development of big data, cloud computing and cloud storage, the bandwidth requirements for data centers to process data traffic are getting higher and higher, which prompts data centers to update and upgrade existing equipment systems in a timely manner. Having a system is a step-by-step process, and it is impossible to replace all the existing equipment at once, which requires a lot of financial costs and also causes a waste of resources. Upgrading a part of the existing system will introduce a new problem, how to interconnect the new equipment with the old equipment, so that the potential of the data center can be maximized. The 100G MLG2.0 multi-link optical module provides a good solution. The electrical interface of the module supports 4 channels of 25Gb electrical signals, and the optical port supports 10 channels of 10Gb parallel optical signals, which enables the optical module to connect with 10 channels of 25Gb electrical signals. 10G SFP+ optical module or 1 40G QSFP+ optical module plus 6 10G SFP+ optical modules or 2 40G QSFP+ optical modules plus 2 10G SFP+ optical modules for interconnection, and the optical module can exchange electrical signals with 100G QSFP28 optical modules. , which finally enables 10G SFP+ optical module, 40G QSFP+ optical module and 100G QSFP28 optical module for data exchange, which greatly improves the interconnection ability between new and old equipment in the data center, and maximizes the efficiency of the data center. realistic meaning.

The difficulty of QSFP28 MLG optical module packaging lies in the high-density integration of optical packaging. However, due to the need to integrate multiple chips and multiple optical components in a QSFP28-sized package, this poses a high challenge to optical packaging technology. In particular, the high-density integrated optical packaging of optical modules and the single-mode multi-channel parallel coupling that is easy to achieve mass production are troubled.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a single-mode optical module with a high-density optical packaging structure based on the MLG2.0 protocol, which solves the single-mode multi-channel parallel coupling problems of high-density integrated optical packaging of optical modules and easy mass production. .

To this end, the present invention provides a single-mode optical module based on the MLG2.0 protocol, comprising a PCBA, an optical module, a graphic circuit substrate, a housing and an upper cover, the graphic circuit substrate is embedded on the PCBA, and the optical The module is fixed on the PCBA and the graphic circuit substrate, and the PCBA is fixedly installed in the space enclosed by the casing and the upper cover. The optical module includes a light receiving module and a light transmitting module. The light-receiving module includes a light-receiving assembly and a photodetector chip array arranged in sequence along the incident optical path, and the light-emitting module includes a single-mode VCSEL laser array, a reflecting prism, a lens array, a single-mode VCSEL laser array, a reflecting prism, a lens array, Isolators and transmitter sub-assemblies;

The isolator is an integral strip isolator, and the integral strip isolator covers multiple beams;

The transmitting end sub-assembly includes a V-shaped limit slot, an optical fiber array and a cover plate, the optical fiber array is clamped with the V-shaped limit slot, and the V-shaped limit slot, the optical fiber array and the cover plate all pass through. Glue fixed.

Preferably, it also includes a heat sink, the PCBA is provided with a square through hole for embedding the heat sink, and the heat sink and the PCBA are bonded by glue.

Preferably, the graphic circuit substrate is buckled downward, embedded in a square through hole on the PCB and closely attached to the heat sink already assembled thereon, and the graphic circuit substrate and the heat sink are bonded by glue.

Preferably, the material of the graphic circuit substrate is aluminum nitride.

Preferably, the pattern array substrate is provided with a support block for supporting the lens array and/or the vertical cavity surface emitting laser chip array and/or the reflective prism.

Preferably, the integral strip isolator is an isolator covering ten parallel beams at the same time.

Preferably, the distance between two adjacent vertical cavity surface emitting laser chip arrays is 750 micrometers, and the distance between two adjacent channels in the vertical cavity surface emitting laser chip array is 250 micrometers.

Preferably, the transmitting end further includes an MT ferrule, and the other end of the optical fiber array is plugged with the MT ferrule.

Beneficial effects of the present invention: The single-mode optical module based on the MLG2.0 protocol provided by the present invention includes a PCBA, a heat sink, a graphic circuit substrate, an optical module, a housing and an upper cover. The heat sink is fixed on the PCBA, and the graphics The circuit substrate is fixed on the heat sink, the optical module receiving module is assembled on the PCBA, the optical module transmitting module is assembled on the graphic circuit substrate, and the PCBA is fixedly installed in the space enclosed by the casing and the upper cover. A receiving module and a light-emitting module, the light-receiving module includes a light-receiving component and a photodetector chip arranged in sequence along the incident optical path, and the light-emitting module includes a vertical cavity surface-emitting laser chip array arranged in sequence along the outgoing optical path , reflective prism, lens array, isolator and transmitting end sub-assembly; the isolator is an integral strip isolator, the overall strip isolator covers multiple beams; the transmitting end sub-assembly includes V-shaped limit groove, fiber array and cover plate , the optical fiber array is clamped with the V-shaped limit slot, and the V-shaped limit slot, the optical fiber array and the cover plate are all fixed by glue. The invention realizes an optical packaging solution of a single-mode optical module conforming to the MLG2.0 protocol, realizes the requirements of high-density integrated optical packaging of optical modules, and solves the problem of high-density integrated optical packaging of optical modules and single-mode optical packaging that is easy to realize mass production. For the problem of the mode multi-channel parallel coupling process, the solution is simple and easy to implement, the positioning accuracy of the chip is low, and it is easy to mass-produce. sex.

The present invention will be further described in detail below with reference to the accompanying drawings.

Description of drawings

1 is a schematic diagram of the overall structure of a single-mode optical module based on the MLG2.0 protocol of the present invention;

2 is a schematic structural diagram of an optical emission module of a single-mode optical module based on the MLG2.0 protocol of the present invention;

FIG. 3 is a schematic diagram of the structure of the optical transmitting end of the single-mode optical module based on the MLG2.0 protocol of the present invention;

4 is a schematic diagram of the lens array installation structure of the single-mode optical module based on the MLG2.0 protocol of the present invention;

5 is a schematic diagram of the installation of the heat sink structure of the single-mode optical module based on the MLG2.0 protocol of the present invention;

6 is a schematic diagram of the housing installation structure of the single-mode optical module based on the MLG2.0 protocol of the present invention;

7 is a schematic diagram of chip mounting of a single-mode optical module based on the MLG2.0 protocol of the present invention;

FIG. 8 is a structural principle block diagram of a single-mode optical module based on the MLG2.0 protocol of the present invention.

DESCRIPTION OF REFERENCE NUMERALS: PCBA1, golden finger 2, signal rate shifter chip 3, laser driver chip 4, transimpedance limiting amplifier chip 5, vertical cavity surface emitting laser chip array 6, graphic circuit substrate 8, optical jumper 9, optical Port 10, reflective prism 11, support block 12, isolator 13, first lens array 14, second lens array 15, emitting end sub-assembly 16, heat sink 17, dust cover 18, base 19, upper cover 20, light Detector chip 21 .

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", The orientation or positional relationship indicated by "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying The device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention.

The terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined with "first" and "second" may expressly or implicitly include one or more of the features; in the description of the present invention, unless otherwise specified, the meaning of "multiple" is two or more.

An embodiment of the present invention provides a single-mode optical module based on the MLG2.0 protocol, as shown in FIG. 1 to FIG. 8 , including a PCBA, an optical module, a heat sink, a graphic circuit substrate, a housing and an upper cover. The circuit substrate is embedded on the PCBA, the optical module is fixed on the PCBA and the graphic circuit substrate, the PCBA1 is fixedly installed in the space enclosed by the casing and the upper cover 20, the optical module It includes a light-receiving module and a light-emitting module. The light-receiving module includes a light-receiving module and a photodetector chip 21 arranged in sequence along the incident optical path. Single-mode VCSEL laser array, reflective prism 11, lens array, isolator 13 and transmitter subassembly 16;

The isolator 13 is an integral strip isolator, and the integral strip isolator covers multiple beams;

The transmitting end subassembly 16 includes a V-shaped limit slot, an optical fiber array and a cover plate, the optical fiber array is clamped with the V-shaped limit slot, and the V-shaped limit slot, the optical fiber array and the cover plate are all between them. Fastened by glue.

The housing includes a base 19 and an upper cover 20 . The dust cover 18 encapsulates each chip, and then encapsulates all the components through the base 19 and the upper cover 20 . That is, a large-sized GearBox (signal rate changer) chip, 10 channels of light-emitting chips and 10 channels of light-receiving chips are integrated in a QSFP28 package.

The single-mode optical module based on the MLG2.0 protocol is mainly composed of the following core components, namely PCBA1 (printed circuit board), GearBox (signal rate transmission chip 3), DRIVER (laser driver chip 4), TIA (transimpedance limiting amplifier) Chip 5), VCSEL (vertical cavity surface emitting laser chip array 6), PD (photodetector chip 21), Substrate1 (heat sink 17), Substrate2 (graphic circuit), (support block 12 includes three) first support block , the second support block, the reflective prism 11, the third support block, the first lens array 14, the second lens array 15, the isolator 13, the optical jumper 9, the dust cover 18 and the housing, the optical module (including the above-mentioned Multiple chip circuits) provide an optical interface through the MT ferrule end of the optical jumper 9, and the gold finger 2 end of the PCBA1 provides an electrical interface for connecting with the system.

Among them, the Gearbox is attached to the PCB by SMT, and the alignment marks of the TIA and PD patches are reserved on the PCB for the patches of TIA and PD; at the same time, a square through hole is opened on the PCBA1, and the square through hole can be used for Effectively prevent rotation loosening, it is used to embed the heat sink 17 and the graphic circuit substrate 8. The heat sink 17 is in a "convex" shape, embedded in the square through holes of the PCBA1 from bottom to top, and bonded together with the PCB by glue. The graphic circuit substrate 8 is buckled down, embedded in the square through holes on the PCB and closely attached to the heat sink 17 that has been assembled on it. The graphic circuit substrate 8 and the heat sink 17 are pasted together by glue, which is used as an example here. The conductive silver paste with good thermal conductivity is, but not limited to, the conductive silver paste; the graphic circuit substrate 8 uses a material with high thermal conductivity, and the example here uses aluminum nitride, but it is not limited to aluminum nitride. The TIA and PD ARRAY are pasted on the PCB by the placement machine, and the DRIVER and two VCSEL ARRAYs are pasted on the graphics circuit substrate 8 by the placement machine.

Among them, the optical module includes two parts, the light emitting module and the light receiving part. The light emitting module consists of a first support block, a second support block, a reflecting prism 11, a third support block, a first lens array 14, a second lens array 15, an isolator 13, a transmitting end subassembly 16, an optical fiber array and an optical port 10 compositions. In the light emission module, the first support block and the second support block are used to support the reflective prism 11, which is fixed on the graphic circuit substrate 8 by glue, and the graphic circuit substrate 8 has reserved identification points for positional alignment for use. The positioning of the first support block and the second support block, this example uses glass material, but is not limited to glass; the reflective prism 11 is placed on the support block through a specific passive alignment platform, and is fixed with the support block by glue, The angle of the reflection prism 11 is 45° in this example, but is not limited to 45°. The function of the reflection prism 11 is to convert the light perpendicular to the PCB board surface emitted by the VCSEL array into light parallel to the PCB board surface; the third support block For supporting the lens array, the position alignment point of the third support block is reserved on the graphic circuit substrate 8, which is fixed on the graphic circuit substrate 8 by glue; the first lens array 14 and the second lens array 15 are respectively used for shaping The array beams emitted by the two VCSEL arrays (ie, the vertical cavity surface emitting laser chip array 6 ), respectively couple the light of their corresponding channels into the corresponding fiber channels in the subsequent transmitting end subassembly 16; The function is to allow the light to pass in one direction and isolate the possible influence of the reflected light in the link on the laser. The position alignment point of the isolator 13 is reserved on the graphic circuit substrate 8 for passive alignment placement. The isolator 13 is fixed on the graphic circuit substrate 8 by glue. In this embodiment, the isolator 13 adopts an integral strip isolator, which covers 10 beams at the same time, which can reduce the precision requirement when the isolator 13 is assembled; The component 16 is composed of a V-shaped limit groove, an optical fiber array, a cover plate, and an MT ferrule. The V-shaped limit groove is used to limit the relative position of the fiber array, so that the fiber array channel spacing is consistent with the VCSEL array channel spacing. It is used to transmit the light coupled in by the VCSEL array; the cover plate is used to further limit the position of the optical fiber, so that the optical fiber is close to the two side walls of the V-shaped limit groove, so that the positioning of the fiber position is more accurate. , the optical fiber array and the cover plate are fixed together by glue, and the transmitting end sub-assembly 16 is fixed on the graphic circuit substrate 8 through glue through the other side of the cover plate. In this embodiment, the distance between two adjacent channels of the VCSEL array is 250 microns, the spacing between the two VCSEL arrays is 750 microns, the adjacent spacing of the V-shaped positioning grooves corresponding to the two VCSEL arrays is 250 microns, and the spacing between the two sets of V-shaped positioning grooves is 750 microns , the other end of the fiber array is inserted into the MT ferrule assembly. In this example, a 24MT ferrule assembly is used, which is divided into upper and lower rows. Each row contains 12 channels. The transmitting end fiber array uses a 10-channel ferrule in the middle of the lower row. The angle on the V-groove side is 0°, but not limited to 0°, and the angle at the MT ferrule is 8°, but not limited to 8°. The light receiving part consists of a V-shaped limit slot, a cover plate, an optical fiber array, and an optical port 10 shared with the light emitting module. The V-shaped limit slot and the cover plate are used to limit the position of the optical fiber, and the optical fiber array is used to transmit the light The light input from port 10 is also used as a component directly coupled to the PD array. The optical port 10 and the optical transmitter module share a 24-channel MT ferrule. In this example, the end of the optical fiber array close to the optical port 10 occupies the upper row of the MT ferrule. There are 10 channels in the middle. The fiber array on the V-groove side adopts an angle of 42.5°, but is not limited to 42.5°. In this example, the PD array adopts 10-channel PD ARRAY, and the interval between adjacent channels is 250 microns. The receiving part of the V-shaped The adjacent spacing of the limit grooves is 250 microns, and the number of channels is 10 channels.

In a preferred solution, the PCBA 1 includes a graphic circuit substrate 8 and a gold finger 2 for providing an electrical interface, and the optical module is mounted on the graphic circuit substrate 8 . The left end is the gold finger 2 , and the right end is the graphic circuit substrate 8 . The transmitting end sub-assembly 16 is fixed on the graphic circuit substrate 8 by glue through the other side of the cover plate.

A preferred solution further includes a heat sink 17, the PCBA1 is provided with a square through hole for embedding the heat sink 17, and the heat sink 17 and the PCBA1 are bonded by glue. The heat sink 17 functions to dissipate heat.

In a preferred solution, the graphic circuit substrate 8 is buckled downward, embedded in a square through hole on the PCB and closely attached to the heat sink 17 that has been assembled on it, and the graphic circuit substrate 8 and the heat sink 17 are bonded by glue . In this way, the installation structure is compact, and the heat dissipation of the circuit board and the chip can be maximized.

In a preferred solution, the material of the graphic circuit substrate 8 is aluminum nitride. A material with high thermal conductivity is used for the graphic circuit substrate 8, and aluminum nitride is used as an example here, but it is not limited to aluminum nitride.

In a preferred solution, the graphic array substrate is provided with a support block for supporting the lens array and/or the vertical cavity surface emitting laser chip array 6 and/or the reflection prism 11 . The supporting block includes a plurality of supporting blocks, which play the role of fixing the corresponding component chips or parts, preventing movement, and simultaneously playing the role of curing the light path.

In a preferred solution, the integral strip isolator is a parallel isolator 13 covering ten beams at the same time. The isolator 13 adopts an integral strip isolator, which covers 10 parallel beams at the same time, which can reduce the precision requirement when the isolator 13 is assembled.

In a preferred solution, the spacing between two adjacent vertical cavity surface emitting laser chip arrays 6 is 750 μm, and the spacing between two adjacent channels in the vertical cavity surface emitting laser chip array 6 is 250 μm . The spacing between two adjacent channels of the VCSEL array is 250 microns, and the spacing between the two groups of VCSEL arrays is 750 microns. The spacing between sets of V-shaped positioning grooves is 750 microns. This arrangement saves space on the one hand, and ensures that each optical path can travel independently without interference. Since two groups of VCSEL arrays and two groups of lens arrays are used for coupling, it can ensure that each group of arrays is coupled to the optimal value during coupling, which is easy to couple, which not only ensures the reliability of the optical path, but also ensures the reliability of the optical path between the two groups of VCSEL arrays. The relative patch position accuracy requirements are low, and it is suitable for low-cost and large-scale production.

In a preferred solution, the transmitting end further includes an MT ferrule, and the other end of the optical fiber array is plugged into the MT ferrule. 24MT ferrule components are used, which are divided into upper and lower rows. Each row contains 12 channels. The fiber array at the transmitting end uses a 10-channel ferrule in the middle of the lower row. The angle of the V-groove side of the fiber array is 0°, but not limited to 0°. , the angle at the MT ferrule is 8°, but not limited to 8°.

Beneficial effects of the present invention: The single-mode optical module based on the MLG2.0 protocol provided by the present invention includes a PCBA, a heat sink, a graphic circuit substrate, an optical module, a housing and an upper cover. The heat sink is fixed on the PCBA, and the graphics The circuit substrate is fixed on the heat sink, the optical module receiving module is assembled on the PCBA, the optical module transmitting module is assembled on the graphic circuit substrate, and the PCBA is fixedly installed in the space enclosed by the casing and the upper cover. A receiving module and a light-emitting module, the light-receiving module includes a light-receiving component and a photodetector chip arranged in sequence along the incident optical path, and the light-emitting module includes a vertical cavity surface-emitting laser chip array arranged in sequence along the outgoing optical path , reflective prism, lens array, isolator and transmitting end sub-assembly; the isolator is an integral strip isolator, the overall strip isolator covers multiple beams; the transmitting end sub-assembly includes V-shaped limit groove, fiber array and cover plate , the optical fiber array is clamped with the V-shaped limit slot, and the V-shaped limit slot, the optical fiber array and the cover plate are all fixed by glue. To achieve the high-density integrated packaging requirements of optical modules, it solves the high-density integrated packaging of optical modules and the single-mode multi-channel parallel coupling problem that is easy to achieve mass production. The solution is simple and easy to implement, and the positioning accuracy of the chip is low. , while minimizing the number of optical components, easy coupling and better optical reliability.

The above examples are only examples of the present invention, and do not constitute a limitation on the protection scope of the present invention, and all designs that are identical or similar to the present invention belong to the protection scope of the present invention.

Claims

A single-mode optical module based on the MLG2.0 protocol, comprising a PCBA, an optical module, a graphic circuit substrate, a casing and an upper cover, the graphic circuit substrate is embedded on the PCBA, and the optical module is fixed on the PCBA and On the graphic circuit substrate, the PCBA is fixedly installed in the space enclosed by the casing and the upper cover, and it is characterized in that: the optical module includes a light receiving module and a light transmitting module, and the light receiving module The module includes a light receiving component and a photodetector chip array arranged in sequence along the incident light path, and the light emission module includes a single-mode VCSEL laser array, a reflective prism, a lens array, an isolator and Transmitter secondary components;

The isolator is an integral strip isolator, and the integral strip isolator covers multiple beams;

The transmitting end sub-assembly includes a V-shaped limit slot, an optical fiber array and a cover plate, the optical fiber array is clamped with the V-shaped limit slot, and the V-shaped limit slot, the optical fiber array and the cover plate all pass through. Glue fixed.
The single-mode optical module based on the MLG2.0 protocol according to claim 1, further comprising a heat sink, the PCBA is provided with a square through hole for embedding the heat sink, and the heat sink is connected to the heat sink. The PCBAs are bonded by glue.
The single-mode optical module based on the MLG2.0 protocol according to claim 2, wherein the graphic circuit substrate is buckled downward, embedded in a square through hole on the PCB and closely attached to the heat sink that has been assembled on it In combination, the graphic circuit substrate and the heat sink are bonded by glue.
The single-mode optical module based on the MLG2.0 protocol according to claim 1, wherein the material of the graphics circuit substrate is aluminum nitride.
The single-mode optical module based on the MLG2.0 protocol according to claim 1, wherein the pattern array substrate is provided with a lens array and/or a vertical cavity surface emitting laser chip array and/or a reflection prism on the substrate. support block.
The single-mode optical module based on the MLG2.0 protocol according to claim 1, wherein the integral strip isolator is an isolator that simultaneously covers ten parallel beams.
The single-mode optical module based on the MLG2.0 protocol according to claim 1, wherein the distance between two adjacent vertical cavity surface emitting laser chip arrays is 750 microns, and the vertical cavity surface emitting laser chip array is 750 microns. The spacing between two adjacent channels within the chip array was 250 microns.
The single-mode optical module based on the MLG2.0 protocol according to claim 1, wherein the transmitting end further comprises an MT ferrule, and the other end of the optical fiber array is plugged with the MT ferrule.