WO2022083366A1

WO2022083366A1 - Optical module

Info

Publication number: WO2022083366A1
Application number: PCT/CN2021/118603
Authority: WO
Inventors: 张加傲; 王欣南; 慕建伟
Original assignee: 青岛海信宽带多媒体技术有限公司
Priority date: 2020-10-20
Filing date: 2021-09-15
Publication date: 2022-04-28

Abstract

An optical module (200), comprising: a circuit board (300); an optical sub-module for generating a signal light and receiving a signal light from the outside of the optical module (200); a first flexible circuit board (310) laid with a high-speed signal line, one end of which is electrically connected to the optical sub-module and the other end is electrically connected to the circuit board (300); a second flexible circuit board (320) laid with a low-speed signal line, one end of which is electrically connected to the optical sub-module and the other end is electrically connected to the circuit board (300); and a third flexible circuit board (330) laid with a high-speed signal line, one end of which is electrically connected to the optical sub-module and the other end is electrically connected to the circuit board (300). The first flexible circuit board (310) and the third flexible circuit board (330) are used for separating bidirectional transmission of high-speed signals between the optical sub-module and the circuit board (300), and the second flexible circuit board (320) is arranged between the first flexible circuit board (310) and the third flexible circuit board (330). In the optical module (200), the second flexible circuit board (320) is used to shield the radiation crosstalk generated by high-speed signals on the first flexible circuit board (310) to the third flexible circuit board (330), so as to reduce the bit error rate caused by the radiation crosstalk generated by the high-speed signals to optical receiving signals.

Description

an optical module

This disclosure requires that it be submitted to the China Patent Office on October 20, 2020, with the application number of 202011124481.9 and the patent name of "An Optical Module", and submitted to the China Patent Office on November 26, 2020, with the application number of 202011354825.5 and the patent name of Priority for "an optical module," which is incorporated by reference in this disclosure in its entirety.

technical field

The present disclosure relates to the technical field of optical communication, and in particular, to an optical module.

Background technique

With the development of new business and application models such as cloud computing, mobile Internet, and video, the development and progress of optical communication technology has become more and more important. In the optical communication technology, the optical module is a tool for realizing the mutual conversion of photoelectric signals, and it is one of the key components in the optical communication equipment. With the development of the optical communication technology, the transmission rate of the optical module continues to increase.

To improve the transmission rate of the optical module, it is usually possible to increase the transmission channel in the optical module, that is, to increase the transmission capacity through multi-channel design in the optical module, thereby achieving the purpose of improving the transmission rate of the optical module. Multi-channel optical modules such as channels. With the increase of optical module transmission channels, in order to complete the encapsulation of the optical module, the optical emitting sub-module and the optical receiving sub-module in the optical module are usually physically separated from the circuit board and electrically connected to the circuit board through the flexible circuit board respectively.

SUMMARY OF THE INVENTION

On the one hand, an optical module provided by the present application includes: a circuit board; an optical sub-module for generating signal light and receiving signal light from outside the optical module; The optical sub-module is electrically connected to the circuit board at the other end; the second flexible circuit board is provided with low-speed signal lines, one end is electrically connected to the optical sub-module, and the other end is electrically connected to the circuit board; the third flexible circuit board, A high-speed signal line is arranged, one end is electrically connected to the optical sub-module, and the other end is electrically connected to the circuit board; wherein, the first flexible circuit board and the third flexible circuit board are used to connect the optical sub-module and the circuit board. Separation of bidirectional transmission of high-speed signals between the circuit boards, the second flexible circuit board is arranged between the first flexible circuit board and the third flexible circuit board.

On the other hand, an embodiment of the present application discloses an optical module, comprising: a circuit board on which an optoelectronic chip, a first high-speed FPC pad, a first low-speed FPC pad and a second high-speed FPC pad are arranged; a first an optical sub-module, electrically connected to the circuit board, electrically connected to the first high-speed FPC pad through the first high-speed flexible circuit board, and electrically connected to the first low-speed FPC pad through the first low-speed flexible circuit board a second optical sub-module, electrically connected to the circuit board, and electrically connected to the second high-speed FPC pad through a second high-speed flexible circuit board; wherein, the first high-speed FPC pad, the first high-speed FPC pad, the first The low-speed FPC pad and the second high-speed FPC pad are located on the same side of the circuit board, and the first high-speed FPC pad and the first low-speed FPC pad are arranged left and right along the length direction of the circuit board , the first low-speed FPC pad and the second high-speed FPC pad are arranged back and forth along the width direction of the circuit board; the first high-speed FPC pad is connected to the optoelectronic chip through the first high-speed differential pair wiring The first low-speed FPC pad is electrically connected to the signal pad of the optoelectronic chip through the low-speed signal wiring, and the second high-speed FPC pad is electrically connected to the signal pad of the optoelectronic chip through the second high-speed differential pair wiring. The signal pads of the optoelectronic chip are electrically connected.

Description of drawings

In order to illustrate the technical solutions of the present disclosure more clearly, the accompanying drawings that need to be used in the embodiments will be briefly introduced below. Other drawings can also be obtained from these drawings.

FIG. 1 is a connection diagram of an optical communication system according to some embodiments;

2 is a structural diagram of an optical network terminal according to some embodiments;

3 is a structural diagram of an optical module according to some embodiments;

4 is an exploded structural diagram of an optical module according to some embodiments;

5 is a cross-sectional view of an optical module structure according to some embodiments;

FIG. 6 is a schematic structural diagram of a circuit board that is electrically connected to a light-emitting sub-module and a light-receiving sub-module according to some embodiments;

7 is an exploded schematic view of a light emitting sub-module and a flexible circuit board according to some embodiments;

8 is a schematic structural diagram of a circuit board according to some embodiments;

9 is an assembly schematic diagram of a circuit board, a light emitting sub-module, and an optical receiving sub-module in an optical module according to some embodiments;

10 is a schematic diagram illustrating the assembly of a light emitting sub-module and a circuit board in an optical module according to some embodiments;

11 is a partially exploded schematic diagram of a light emitting sub-module in an optical module according to some embodiments;

12 is a schematic structural diagram of a light emitting device in a light emitting sub-module in an optical module according to some embodiments;

13 is a schematic structural diagram of a first high-speed flexible circuit board in an optical module according to some embodiments;

14 is a schematic structural diagram of a first low-speed flexible circuit in an optical module according to some embodiments;

15 is a schematic structural diagram of a circuit board in an optical module according to some embodiments;

16 is a schematic diagram illustrating the assembly of a light receiving sub-module and a circuit board in an optical module according to some embodiments;

FIG. 17 is a partial structural diagram of a light receiving sub-module in an optical module according to some embodiments.

Detailed ways

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

In optical communication technology, light is used to carry the information to be transmitted, and the optical signal carrying the information is transmitted to information processing equipment such as computers through information transmission equipment such as optical fibers or optical waveguides to complete the transmission of information. Since optical signals have passive transmission characteristics when transmitted through optical fibers or optical waveguides, low-cost and low-loss information transmission can be achieved. In addition, the signals transmitted by information transmission equipment such as optical fibers or optical waveguides are optical signals, while the signals that can be recognized and processed by information processing equipment such as computers are electrical signals. To establish an information connection between them, it is necessary to realize the mutual conversion of electrical signals and optical signals.

The optical module realizes the mutual conversion function of the above-mentioned optical signal and electrical signal in the technical field of optical fiber communication. The optical module includes an optical port and an electrical port. The optical module realizes optical communication with information transmission equipment such as optical fibers or optical waveguides through the optical port, and realizes electrical connection with an optical network terminal (for example, an optical cat) through the electrical port. It is mainly used to realize power supply, I2C signal transmission, data signal transmission and grounding; optical network terminals transmit electrical signals to information processing equipment such as computers through network cables or wireless fidelity technology (Wi-Fi).

FIG. 1 is a connection diagram of an optical communication system according to some embodiments. As shown in FIG. 1 , the optical communication system mainly includes a remote server 1000, a local information processing device 2000, an optical network terminal 100, an optical module 200, an optical fiber 101 and a network cable 103;

One end of the optical fiber 101 is connected to the remote server 1000 , and the other end is connected to the optical network terminal 100 through the optical module 200 . The optical fiber itself can support long-distance signal transmission, such as signal transmission of several kilometers (6 kilometers to 8 kilometers). On this basis, if repeaters are used, ultra-long distance transmission can theoretically be achieved. Therefore, in a common optical communication system, the distance between the remote server 1000 and the optical network terminal 100 can usually reach several kilometers, tens of kilometers or hundreds of kilometers.

One end of the network cable 103 is connected to the local information processing device 2000 , and the other end is connected to the optical network terminal 100 . The local information processing device 2000 may be any one or more of the following devices: a router, a switch, a computer, a mobile phone, a tablet computer, a television, and the like.

The physical distance between the remote server 1000 and the optical network terminal 100 is greater than the physical distance between the local information processing device 2000 and the optical network terminal 100 . The connection between the local information processing device 2000 and the remote server 1000 is completed by the optical fiber 101 and the network cable 103 ; and the connection between the optical fiber 101 and the network cable 103 is completed by the optical module 200 and the optical network terminal 100 .

The optical module 200 includes an optical port and an electrical port. The optical port is configured to be connected to the optical fiber 101, so that the optical module 200 and the optical fiber 101 can establish a two-way optical signal connection; electrical signal connection. The optical module 200 realizes the mutual conversion of optical signals and electrical signals, so as to establish a connection between the optical fiber 101 and the optical network terminal 100 . For example, the optical signal from the optical fiber 101 is converted into an electrical signal by the optical module 200 and then input into the optical network terminal 100 , and the electrical signal from the optical network terminal 100 is converted into an optical signal by the optical module 200 and input into the optical fiber 101 .

The optical network terminal 100 includes a substantially rectangular housing, and an optical module interface 102 and a network cable interface 104 disposed on the housing. The optical module interface 102 is configured to access the optical module 200, so that the optical network terminal 100 and the optical module 200 can establish a bidirectional electrical signal connection; the network cable interface 104 is configured to access the network cable 103, so that the optical network terminal 100 and the network cable 103 are connected. Establish a two-way electrical signal connection. A connection is established between the optical module 200 and the network cable 103 through the optical network terminal 100 . For example, the optical network terminal 100 transmits the electrical signal from the optical module 200 to the network cable 103, and transmits the signal from the network cable 103 to the optical module 200. Therefore, the optical network terminal 100, as the host computer of the optical module 200, can monitor the optical module 200. work. In addition to the optical network terminal 100, the host computer of the optical module 200 may also include an optical line terminal (Optical Line Terminal, OLT) and the like.

A bidirectional signal transmission channel is established between the remote server 1000 and the local information processing device 2000 through the optical fiber 101 , the optical module 200 , the optical network terminal 100 and the network cable 103 .

FIG. 2 is a structural diagram of an optical network terminal according to some embodiments. In order to clearly show the connection relationship between the optical module 200 and the optical network terminal 100, FIG. 2 only shows the structure of the optical network terminal 100 related to the optical module 200. As shown in FIG. 2 , the optical network terminal 100 further includes a PCB circuit board 105 disposed in the housing, a cage 106 disposed on the surface of the PCB circuit board 105 , and an electrical connector disposed inside the cage 106 . The electrical connector is configured to be connected to the electrical port of the optical module 200 ; the heat sink 107 has protrusions such as fins that increase the heat dissipation area.

The optical module 200 is inserted into the cage 106 of the optical network terminal 100 , and the optical module 200 is fixed by the cage 106 . After the optical module 200 is inserted into the cage 106 , the electrical port of the optical module 200 is connected to the electrical connector inside the cage 106 , so that the optical module 200 and the optical network terminal 100 establish a bidirectional electrical signal connection. In addition, the optical port of the optical module 200 is connected to the optical fiber 101 , so that the optical module 200 and the optical fiber 100 establish a bidirectional electrical signal connection.

FIG. 3 is a structural diagram of an optical module according to some embodiments, and FIG. 4 is an exploded structural diagram of an optical module according to some embodiments. As shown in FIG. 3 and FIG. 4 , the optical module 200 includes a casing, a circuit board 300 disposed in the casing, and an optical transceiver;

The casing includes an upper casing 201 and a lower casing 202. The upper casing 201 is covered on the lower casing 202 to form the above casing with two

openings

204 and 205; the outer contour of the casing generally presents a square body.

In some embodiments, the lower casing 202 includes a bottom plate and two lower side plates located on both sides of the bottom plate and perpendicular to the bottom plate; the upper casing 201 includes a cover plate, and two side plates located on both sides of the cover plate and perpendicular to the cover plate. An upper side plate is combined with the two side plates by two side walls, so as to realize that the upper casing 201 is covered on the lower casing 202 .

The direction of the connection between the two

openings

204 and 205 may be consistent with the length direction of the optical module 200 , or may be inconsistent with the length direction of the optical module 200 . Illustratively, the opening 204 is located at the end of the light module 200 (the left end of FIG. 3 ), and the opening 205 is also located at the end of the light module 200 (the right end of FIG. 3 ). Alternatively, the opening 204 is located at the end of the optical module 200 , and the opening 205 is located at the side of the optical module 200 . The opening 204 is an electrical port, and the golden fingers of the circuit board 300 protrude from the electrical port 204 and are inserted into the host computer (such as the optical network terminal 100 ); The optical fiber 101 is connected to the optical transceiver device inside the optical module 200 .

The combination of the upper case 201 and the lower case 202 is used to facilitate the installation of the circuit board 300, optical transceivers and other devices into the case, and the upper case 201 and the lower case 202 can form encapsulation protection for these devices. In addition, when assembling components such as the circuit board 300, it is convenient to deploy the positioning components, heat dissipation components and electromagnetic shielding components of these components, which is conducive to the implementation of automated production.

In some embodiments, the upper casing 201 and the lower casing 202 are generally made of metal material, which is beneficial to achieve electromagnetic shielding and heat dissipation.

In some embodiments, the optical module 200 further includes an unlocking component 203 located on the outer wall of the housing thereof, and the unlocking component 203 is configured to realize a fixed connection between the optical module 200 and the upper computer, or release the connection between the optical module 200 and the upper computer fixed connection.

For example, the unlocking components 203 are located on the outer walls of the two lower side panels 2022 of the lower casing 202, and include engaging components matching with the cage of the upper computer (eg, the cage 106 of the optical network terminal 100). When the optical module 200 is inserted into the cage of the upper computer, the optical module 200 is fixed in the cage of the upper computer by the engaging part of the unlocking part 203; when the unlocking part 203 is pulled, the engaging part of the unlocking part 203 moves accordingly, thereby changing the The connection relationship between the engaging member and the host computer is used to release the engaging relationship between the optical module 200 and the host computer, so that the optical module 200 can be pulled out from the cage of the host computer.

The circuit board 300 includes circuit traces, electronic components (such as capacitors, resistors, triodes, MOS tubes) and chips (such as MCU, laser driver chip, limiter amplifier chip, clock data recovery CDR, power management chip, data processing chip DSP) Wait.

The circuit board 300 connects the above-mentioned devices in the optical module 200 together according to the circuit design through circuit traces, so as to realize functions such as power supply, electrical signal transmission, and grounding.

The circuit board 300 is generally a rigid circuit board. Due to its relatively hard material, the rigid circuit board can also realize the bearing function. For example, the rigid circuit board can carry chips smoothly; the rigid circuit board can also be inserted into the electrical connector in the upper computer cage. , in some embodiments disclosed in the present application, metal pins/gold fingers are formed on one end surface of the rigid circuit board for connecting with the electrical connector; these are inconvenient to be realized by the flexible circuit board.

Flexible circuit boards are also used in some optical modules; flexible circuit boards are generally used in conjunction with rigid circuit boards. For example, flexible circuit boards can be used to connect the rigid circuit boards and optical transceivers as a supplement to the rigid circuit boards.

The optical transceiver device includes an optical transmitting sub-module and an optical receiving sub-module. As shown in FIG. 4 , the optical module provided by the embodiment of the present application includes an optical transmitting sub-module 400 and an optical receiving sub-module 500 . The optical transmitting sub-module 400 and the optical receiving sub-module 500 are located on the edge of the circuit board 300 , and the optical transmitting sub-module 500 is located at the edge of the circuit board 300 . 400 and the light receiving sub-module 500 are arranged on top of each other. In some embodiments of the present application, the light-emitting sub-module 400 is closer to the upper casing 201 than the light-receiving sub-module 500 , but it is not limited to this, and the light-receiving sub-module 500 may be closer to the upper than the light-emitting sub-module 400 housing 201 . Of course, the optical sub-module in the embodiment of the present application is an integrated transceiver structure. In some embodiments of the present application, the optical sub-module is located at the end of the circuit board 300 , and the optical sub-module is physically separated from the circuit board 300 . The optical sub-module is connected to the circuit board 300 through a flexible circuit board.

In some embodiments of the present application, the light-emitting sub-module 400 and the light-receiving sub-module 500 are physically separated from the circuit board 300, respectively, and are connected to the circuit board 300 through a flexible circuit board or an electrical connector, respectively.

When the light-emitting sub-module 400 is closer to the upper casing 201 than the light-receiving sub-module 500 , the light-emitting sub-module 400 and the light-receiving sub-module 500 are disposed in a wrapping cavity formed by the upper and lower casings. The lower case 202 can support the light receiving sub-module 500 ; in some embodiments of the present application, the lower case 202 supports the light receiving sub-module 500 through a spacer, and the light receiving sub-module 500 supports the light emitting sub-module 400 .

FIG. 5 is a cross-sectional view of an optical module structure according to some embodiments. As shown in FIG. 5 , the optical module provided by the embodiment of the present application includes a lower casing 202 , a circuit board 300 , a light emitting sub-module 400 and an optical receiving sub-module 500 . The end of the light emitting sub-module 400 away from the circuit board 300 is provided with a first optical fiber adapter 410, and the first optical fiber adapter 410 is used to transmit the signal light generated by the light emitting sub-module 400 to the outside of the optical module. The end of the light receiving sub-module 500 away from the circuit board 300 is provided with a second optical fiber adapter 510 .

In some embodiments of the present application, because the overall size of the optical module must conform to the interface size of the host computer, which is limited by industry standards, the optical transmitting sub-module 400 and the optical receiving sub-module 500 are relatively large in size and cannot be installed on the circuit board. Therefore, it is set apart from the circuit board, and the electrical connection and transfer are realized through the flexible circuit board. As shown in FIG. 5 , the first optical fiber adapter 410 and the second optical fiber adapter 510 are located at the same height compared to the bottom surface of the lower housing 202 . The first optical fiber adapter 410 and the second optical fiber adapter 510 are respectively used to connect with the optical fiber connector outside the optical module; and the optical fiber connector outside the optical module is a standard part commonly used in the industry, and the shape and size of the external optical fiber connector limit the optical fiber connector. The positions of the two fiber optic adapters inside the module, so the first fiber optic adapter 410 and the second fiber optic adapter 510 are set at the same height in the product.

The circuit board 300 is electrically connected to the light-emitting sub-module 400 and the light-receiving sub-module 500 through corresponding flexible circuit boards, respectively. As shown in FIG. 5 , in the embodiment of the present application, the flexible circuit board includes a first flexible circuit board 310 , a second flexible circuit board 320 and a third flexible circuit board 330 , and the light emitting sub-module 400 passes through the first flexible circuit board 310 and the third flexible circuit board 330 . The second flexible circuit board 320 is electrically connected to the circuit board 300 , the light receiving sub-module 500 is electrically connected to the circuit board 300 through the third flexible circuit board 330 , and the second flexible circuit board 320 is arranged between the first flexible circuit board 310 and the third flexible circuit between plates 330 . Wherein: high-speed signal lines are arranged on the first flexible circuit board 310 for high-speed signal transmission between the circuit board 300 and the light emitting sub-module 400, and the first flexible circuit board 310 transmits high-speed signals to the light emitting sub-module 400; the second Low-speed signal lines such as power lines are arranged on the flexible circuit board 320 for the circuit board 300 to supply power to the electrical devices in the light-emitting sub-module 400 ; high-speed signal lines are arranged on the third flexible circuit board 330 for connecting the light-receiving sub-module 500 The converted high-speed current signal is transmitted to the circuit board 300 , and the light receiving sub-module 500 transmits the high-speed signal to the circuit board 300 through the third flexible circuit board 330 . Therefore, the separation of the high-speed signal transmission between the light-emitting sub-module 400, the light-receiving sub-module 500 and the circuit board is achieved through the first flexible circuit board 310 and the third flexible circuit board 330. In addition, some power lines can also be arranged on the third flexible circuit board 330 as required, so that the circuit board 300 can supply power to the electrical devices in the light receiving sub-module 500; Low-speed signal lines such as power lines of the sub-module 500 , and the flexible circuit board may be disposed between the second flexible circuit board 320 and the third flexible circuit board 330 .

In the traditional optical module, the optical emitting sub-module and the optical receiving sub-module usually use a flexible circuit board to connect the circuit board (for the convenience of description, the flexible circuit board used to connect the optical emitting sub-module and the circuit board is recorded as flexible circuit board 1, The flexible circuit board used to connect the light receiving sub-module and the circuit board is denoted as flexible circuit board 2), and when the light-emitting sub-module 400 and the light-receiving sub-module 500 are placed on top of each other, the flexible circuit board 1 and the flexible circuit board 2. The distance is relatively close (close to side-by-side); usually the flexible circuit board has a two-layer structure, one is the high-speed wiring and power wiring layer, and the other is the ground layer, and even if the flexible circuit board 1 is far away from the flexible circuit board 2 The high-speed signal lines corresponding to the optical emission sub-modules are uniformly laid on one side of the optical emitting sub-module, and the ground layer is uniformly laid on the other side of the flexible circuit board 1. The receiving signal lines laid on the flexible circuit board 2 are connected with the high-speed wiring and the power wiring layer of the flexible circuit board 1. It is only separated by one layer, and it is difficult to have a good isolation effect on the radiation generated by multi-channel high-speed signals.

Compared with the arrangement of the flexible circuit board in the traditional optical module, the optical module provided by the embodiment of the present application is disposed between the first flexible circuit board 310 and the third flexible circuit board 330 through the second flexible circuit board 320 , and the second flexible circuit board 320 is arranged between the first flexible circuit board 310 and the third flexible circuit board. The flexible circuit board 320 at least includes a power line and a ground layer, and the first flexible circuit board 310 and the third flexible circuit board 330 are isolated by the second flexible circuit board 320 , thereby realizing the shielding of the first flexible circuit board 310 through the second flexible circuit board 320 The radiation crosstalk generated by the upper high-speed signal to the third flexible circuit board 330 helps to reduce the bit error rate caused by the radiation crosstalk generated by the high-speed signal to the light receiving signal. In the embodiment of the present application, the second flexible circuit board 320 may also be a flexible circuit board for connecting the light receiving sub-module 500 and the circuit board 300 .

At the same time, when the optical emission sub-module is only connected to the circuit board through the flexible circuit board 1, if the optical emission sub-module includes multiple channels, such as 4, 8, etc., the number of high-speed signal lines, power lines, etc. will reach dozens of However, if dozens of wires are arranged side by side on the flexible circuit board 1, a relatively wide flexible circuit board 1 may be required, which will lead to a tight circuit board layout. However, in the optical module provided by the embodiment of the present application, the layout requirements of the flexible circuit board 1 are shared by the first flexible circuit board 310 and the second flexible circuit board 320, which is beneficial to relieve the tense layout of the connection between the optical emission sub-module and the circuit board. To a certain extent, it is convenient to promote the development of multi-channel optical modules.

FIG. 6 is a schematic structural diagram of a circuit board electrically connecting a light emitting sub-module and a light receiving sub-module according to some embodiments. As shown in FIG. 6 , the light-emitting sub-module 400 is stacked and disposed above the light-receiving sub-module 500; one end of the first flexible circuit board 310 is electrically connected to the light-emitting sub-module 400, the other end is electrically connected to the circuit board 300, and the second flexible circuit board 310 is electrically connected to the light-emitting sub-module 400. One end of the circuit board 320 is electrically connected to the light emission sub-module 400, and the other end is electrically connected to the circuit board 300, and then the light emission sub-module 400 is electrically connected to the circuit board 300 through the first flexible circuit board 310 and the second flexible circuit board 320, and the first flexible circuit board 310 and the first flexible circuit board 320 are electrically connected. The flexible circuit board 310 is arranged above the second flexible circuit board 320 ; one end of the third flexible circuit board 330 is electrically connected to the light-emitting and receiving module 500 , and the other end is electrically connected to the circuit board 300 and the light-receiving sub-module 500 passes through the third flexible circuit board 330 The circuit board 300 is electrically connected, and the third flexible circuit board 330 is disposed under the second flexible circuit board 320 , and the second flexible circuit board 320 is further disposed between the first flexible circuit board 310 and the third flexible circuit board 330 at intervals. If the light receiving sub-module 500 is stacked on the light emitting sub-module 400, the third flexible circuit board 330 will be disposed above the second flexible circuit board 320 and the first flexible circuit board 310 will be disposed on the second flexible circuit board Below the circuit board 320, the second flexible circuit board 320 is disposed between the first flexible circuit board 310 and the third flexible circuit board 330 at intervals.

7 is an exploded schematic view of a light emitting sub-module and a flexible circuit board according to some embodiments. As shown in FIG. 7 , in the optical module provided by the embodiment of the present application, the optical emitting sub-module 400 includes an electrical connector 420 , and the optical emitting sub-module 400 is connected to the first flexible circuit board 310 and the second flexible circuit through the electrical connector 420 The board 320 and the electrical connector 420 facilitate the electrical connection with the first flexible circuit board 310 and the second flexible circuit board 320 . In some embodiments of the present application, a boss 421 is provided at one end of the electrical connector 420 for connecting the first flexible circuit board 310 and the second flexible circuit board 320 , and the boss 421 includes a first connection surface 4211 and a second connection. Surface 4212, the first connection surface 4211 and the second connection surface 4212 are respectively provided with pads; one end of the first flexible circuit board 310 is welded to the first connection surface 4211, and one end of the second flexible circuit board 320 is welded to the second connection surface 4212 . By arranging the boss 421 on the electrical connector 420, the first connecting surface 4211 and the second connecting surface 4212 respectively form steps with the top surface and the bottom surface of the electrical connector 420, and the steps can be used for the first flexible circuit board 310 and the second connecting surface 4212. The position of the end of the flexible circuit board 320 is more convenient for the first flexible circuit board 310 and the second flexible circuit board 320 to be welded and connected to the electrical connector 420 .

In the embodiment of the present application, the first flexible circuit board 310 includes a first insulating dielectric layer 311 ; high-speed signal lines are arranged on the top surface of the first insulating dielectric layer 311 , that is, high-speed wirings are formed on the top surface of the first insulating dielectric layer 311 The bottom surface of the first insulating medium layer 311 is arranged with an emission ground, that is, a ground layer is formed on the bottom surface of the first insulating medium layer 311 . In some embodiments of the present application, the second flexible circuit board includes a second insulating medium layer 321 ; power lines are arranged on the top surface of the second insulating medium layer 321 , that is, power lines are formed on the top surface of the second insulating medium layer 321 The power ground is arranged on the bottom surface of the second insulating dielectric layer 321 , that is, a ground layer is formed on the bottom surface of the second insulating dielectric layer 321 . In this way, at least the ground layer of the first insulating medium layer 311 , the power wiring layer of the second insulating medium layer 321 and the second insulating medium layer 321 are spaced between the receiving signal line of the third flexible circuit board 330 and the high-speed signal line of light emission. Therefore, the radiation on the transmitting high-speed signal line of the optical emission sub-module 400 needs to pass through the ground layer of the first insulating medium layer 311, the power wiring layer of the second insulating medium layer 321 and the ground layer three of the second insulating medium layer 321 at least. The layer shielding reaches the light-receiving signal line, which helps to shield the radiation crosstalk generated by the radiation on the transmitting high-speed signal line of the light-emitting sub-module 400 to the third flexible circuit board.

In the embodiment of the present application, the third flexible circuit board 330 includes a third insulating dielectric layer 331 ; the top surface of the third insulating dielectric layer 331 is arranged with receiving signal lines, that is, the top surface of the third insulating dielectric layer 331 forms the receiving signal lines The power ground is arranged on the bottom surface of the third insulating dielectric layer 331 , that is, a ground layer is formed on the bottom surface of the third insulating dielectric layer 331 . In this way, the ground layer of the third insulating medium layer 331 is used to conveniently shield the radiation crosstalk from under the third insulating medium layer 331 , which helps to reduce the radiation crosstalk to the receiving signal line outside the third flexible circuit board 330 .

Therefore, in the embodiment of the present application, the radiation crosstalk from the high-speed signal line on the first flexible circuit board 310 to the signal wiring layer on the third flexible circuit board 330 passes through the ground layer on the first insulating medium layer 311 and the second insulating medium layer 321 The power trace layer above and the ground layer on the second insulating dielectric layer 321 are shielded in three layers, and the radiation crosstalk under the signal trace layer on the third flexible circuit board 330 is shielded by the ground layer on the third insulating dielectric layer 331, which is fully shielded. The electromagnetic isolation effect of the receiving signal wiring on the third flexible circuit board 330 is ensured, thereby increasing the sensitivity of the light receiving sub-module 500 .

The top surface and bottom surface of the insulating medium layer are the main wiring surfaces of the circuit board. In the orientation shown in FIG. 7 in the embodiment of the present application, the upward facing surface of the insulating medium layer is the top surface of the insulating medium layer, and the insulating medium layer faces downward. The surface is the bottom surface of the insulating dielectric layer.

In some embodiments of the present application, the light receiving sub-module 500 is provided with an opening 520 , that is, an opening 520 is provided in the cavity of the light receiving sub-module 500 , and one end of the third flexible circuit board 330 is passed through the opening 520 . One end of the third flexible circuit board 330 is inserted into and fixed in the cavity of the light receiving sub-module 500 to be electrically connected to the light receiving chip, transimpedance amplifier and other electrical devices, and the other end of the third flexible circuit 330 is used for electrical connection with the circuit board 300 .

FIG. 8 is a schematic structural diagram of a circuit board according to some embodiments. As shown in FIG. 8 , the top surface of the circuit board 300 is provided with a first soldering area 312 , a second soldering area 322 and a third soldering area 332 , and the first soldering area 312 , the second soldering area 322 and the third soldering area 332 are in sequence. Arranged at the end of the circuit board 300 , and the third bonding pad 332 is located at the leftmost end of the end of the circuit board 300 . The first welding area 312 is used for welding the other end of the first flexible circuit board 310, the second welding area 322 is used for welding and connecting the other end of the second flexible circuit board 320, and the third welding area 332 is used for welding and connecting the first flexible circuit board 320. The other end of the three flexible circuit boards 330 . Disposing the first welding area 312 , the second welding area 322 and the third welding area 332 on the same side of the circuit board 300 and at the end of the circuit board 300 is beneficial to improve the utilization of the layout on the circuit board 300 and improve the circuit Space utilization of the board 300 . In the embodiment of the present application, the first soldering area 312 , the second soldering area 322 and the third soldering area 332 are not limited to be disposed at the end of the top surface of the circuit board 300 , but may also be disposed at the end of the bottom surface of the circuit board 300 . The first soldering area 312 , the second soldering area 322 and the third soldering area 332 are arranged on the same side of the circuit board 300 , which also facilitates soldering of the first flexible circuit board 310 , the second flexible circuit board 320 and the third flexible circuit board 330 .

In some embodiments of the present application, high-speed signal lines are respectively arranged on the top surface and bottom surface of the circuit board 300 , that is, the high-speed signal lines directly electrically connected to the first bonding pad 312 and the bottom surface of the circuit board 300 are arranged on the top surface of the circuit board 300 . The high-speed signal lines electrically connected to the third pads 332 are laid out, and then the high-speed signal lines laid on the bottom surface of the circuit board 300 are electrically connected to the third pads 332 through vias. Of course, in the present application, the third welding area 332 may also be disposed on the bottom surface of the circuit board 300 , and the second welding area 322 may also be disposed on the bottom surface of the circuit board 300 . Furthermore, in the present application, the first soldering area 312 and the third soldering area 332 may be located on different surfaces of the circuit board 300, and the second soldering area 322 and the first soldering area 312 may be located on the same side of the circuit board 300, or may be located on the same surface as the first soldering area 312. The three bonding pads 332 are located on the same side of the circuit board 300 .

FIG. 9 is an assembly schematic diagram of a circuit board, a light emitting sub-module and a light receiving sub-module in an optical module according to some embodiments. As shown in FIG. 5 , the first optical sub-module and the second optical sub-module in the optical module are placed in the same row on the circuit board 300 , and one end of the first high-speed flexible circuit board 410 and the first low-speed flexible circuit board 420 are respectively connected to the first The optical sub-module is electrically connected, and the other end is electrically connected to the circuit board 300, respectively, for realizing high-speed and low-speed signal transmission between the first optical sub-module and the circuit board 300; one end of the second high-speed flexible circuit board 510 is inserted into the second optical sub-module 510. The other end of the sub-module is electrically connected to the circuit board 300 for realizing high-speed signal transmission between the second optical sub-module and the circuit board 300 .

In some embodiments of the present application, the circuit board 300 is provided with an optoelectronic chip 310A, a first high-speed FPC pad, a first low-speed FPC pad, and a second high-speed FPC pad. One end is connected to the first optical sub-module, the other end is electrically connected to the first high-speed FPC pad, and the first high-speed FPC pad is electrically connected to the signal pad of the optoelectronic chip 310A through the first high-speed differential pair wiring to realize the first High-speed signal transmission between the optical sub-module and the circuit board 300; one end of the first low-speed flexible circuit board 420 is connected to the first optical sub-module, and the other end is electrically connected to the first low-speed FPC pad, and the first low-speed FPC pad passes the low-speed signal The traces are electrically connected to the signal pads of the optoelectronic chip 310A to realize low-speed signal transmission between the first optical sub-module and the circuit board 300 . One end of the second high-speed flexible circuit board 510 is inserted into the second optical sub-module, and the other end is electrically connected to the second high-speed FPC pad, and the second high-speed FPC pad is soldered to the signal of the optoelectronic chip 310A through the second high-speed differential pair wiring. The disks are electrically connected to realize high-speed signal transmission between the second optical sub-module and the circuit board 300 .

When the first optical sub-module and the second optical sub-module are arranged in the same row, due to the dense layout of circuit traces, electronic components, chips, etc. on the circuit board 300, there is no space on the lower side of the circuit board 300 to place more flexible circuit boards connection pads, so the first high-speed FPC pads, the first low-speed FPC pads and the second high-speed FPC pads connected to the second high-speed flexible circuit board 510 can be connected The FPC pads are all placed on the upper side of the circuit board 300 .

In addition, the width of the circuit board 300 is limited by the QSFP-DD interface package. After the space for the whole machine is reserved, only 14.75mm of width is left for the receiving and transmitting flexible circuit boards to be connected to the circuit board 300, and the receiving end flexible circuit is reserved. After the width of the interface pad of the board, the width of the transmitting end is only 7.37mm. Therefore, the first high-speed FPC pad and the first low-speed FPC pad located on the same side of the circuit board 300 cannot be arranged on the circuit board 300 side by side. The first high-speed FPC pads and the first low-speed FPC pads are arranged in double rows on the circuit board 300 , that is, the first high-speed FPC pads and the first low-speed FPC pads are arranged left and right along the length direction of the circuit board 300 . Since the first optical sub-module and the second optical sub-module are arranged side by side on the circuit board 300 , the first low-speed FPC pads and the second high-speed FPC pads are arranged back and forth along the width direction of the circuit board 300 .

The first high-speed FPC pad and the first low-speed FPC pad are disposed between one end of the circuit board 300 and the optoelectronic chip 310A, the first high-speed FPC pad is close to the optoelectronic chip 310A, and the first low-speed FPC pad is close to the circuit board 300 end of . In some embodiments of the present application, the left-right direction is the length direction of the circuit board 300, and the front-rear direction is the width direction of the circuit board 300. Therefore, the first low-speed FPC pad is close to the left end of the circuit board 300, and the first high-speed FPC solder pad The pad is located to the right of the first low-speed FPC pad, the second high-speed FPC pad is close to the left end of the circuit board 300, and the second high-speed FPC pad is located behind the first low-speed FPC pad.

In the embodiment of the present application, the first optical sub-module may be the light-emitting sub-module 400 , the second optical sub-module may be the light-receiving sub-module 500 , and the first high-speed flexible circuit board is the first high-speed flexible circuit board connected to the light-emitting sub-module 400 . In the flexible circuit board 410 , the first low-speed flexible circuit board is the first low-speed flexible circuit board 420 connected to the light-emitting sub-module 400 , and the second high-speed flexible circuit board is the second high-speed flexible circuit board 510 connected to the light-receiving sub-module 500 . Since the light receiving sub-module 500 is electrically connected to the circuit board 300 through the double flexible circuit board, the circuit board 300 is also provided with a second low-speed FPC pad, and one end of the second low-speed flexible circuit board 520 is inserted into the light receiving sub-module 500 , the other end is electrically connected to the second low-speed FPC pad, and the second low-speed FPC pad is electrically connected to the receiving signal pad of the optoelectronic chip 310A through the low-speed signal wiring, so as to realize the low-speed signal of the light receiving sub-module 500 and the circuit board 300 transmission.

The first optical sub-module can also be the light-receiving sub-module 500, the second optical sub-module can also be the light-emitting sub-module 400, and the first high-speed flexible circuit board is the second high-speed flexible circuit board 510 connected to the light-receiving sub-module 500, The first low-speed flexible circuit board is the second low-speed flexible circuit board 520 connected to the light-receiving sub-module 500 , and the second high-speed flexible circuit board is the first high-speed flexible circuit board 410 connected to the light-emitting sub-module 400 . Since the light emitting sub-module 400 is electrically connected to the circuit board 300 through the dual flexible circuit board, the circuit board 300 is further provided with a second low-speed FPC pad, and the low-speed flexible circuit board connected to the second low-speed FPC pad is used for connecting light The first low-speed flexible circuit board 420 and the second low-speed FPC pads of the transmission sub-module 400 are electrically connected to the transmission signal pads of the optoelectronic chip 310A through low-speed signal traces, so as to realize the low-speed signal transmission between the optical transmission sub-module 400 and the circuit board 300 transmission.

The lower side of the circuit board 300 can leave a space for placing a flexible circuit board connection pad, so the second low-speed FPC pad and the second high-speed FPC pad can be placed on different sides of the circuit board 300, that is, the first high-speed FPC pad. The FPC pad, the first low-speed FPC pad and the second high-speed FPC pad are located on the upper side of the circuit board 300, and the second low-speed FPC pad is located on the lower side of the circuit board 300; the second high-speed FPC pad, The second low-speed FPC pads are all placed on the upper side of the circuit board 300 , that is, the first high-speed FPC pads, the first low-speed FPC pads, the second high-speed FPC pads and the second low-speed FPC pads are all located on the circuit board 300 . On the upper side, the space on the lower side of the circuit board 300 can be saved.

FIG. 10 is a schematic diagram illustrating the assembly of a light emitting sub-module and a circuit board in an optical module according to some embodiments, FIG. 11 is a partial exploded schematic diagram of a light emitting sub-module in an optical module according to some embodiments, and FIG. 12 is a schematic diagram according to some embodiments. Schematic diagram of the structure of the light emitting device in the light emitting sub-module of the optical module. As shown in FIG. 10 , FIG. 11 , and FIG. 12 , the light emitting sub-module 400 includes a emitting housing 430 and a ceramic adapter block 440 inserted into the emitting housing 430 . The device 450 is electrically connected to the ceramic adapter block through a signal line, one end of the first high-speed flexible circuit board 410 is electrically connected to one side of the ceramic adapter block 440, and the other end is electrically connected to the first high-speed FPC pad. One end of the circuit board 420 is electrically connected to the opposite side of the ceramic adapter block 440, and the other end is electrically connected to the first low-speed FPC pad.

The light emitting device 450 in the light emitting sub-module 400 includes a plurality of laser assemblies, a plurality of collimating lenses, an optical multiplexer and an optical prism. The direction of the outgoing light of the multiple laser components is to convert multiple beams of different wavelengths into multiple collimated beams; the optical multiplexer is arranged in the light outgoing direction of the multiple collimating lenses, and the multiple collimated beams enter the optical complex. In the device, the multiple collimated beams entering the optical multiplexer can be reflected in the optical multiplexer, and finally multiplexed into a composite beam; the composite beam is input to the optical fiber adapter through the optical prism to realize the emission of signal light.

The light emitting device 450 further includes a laser driver, the plurality of laser assemblies are respectively connected to the laser driver through gold wires, and the laser driver drives the laser assemblies through the gold wires, so that the laser assemblies emit light beams. A plurality of laser components, laser drivers, etc. are respectively connected to the ceramic transition block 440 through gold wires. The side of the ceramic adapter block 440 facing the circuit board 300 is provided with a boss, the upper side of the boss is electrically connected with the first high-speed flexible circuit board 410, and the lower side is electrically connected with the first low-speed flexible circuit board 420, so as to pass through the first high-speed flexible circuit board 410. A high-speed flexible circuit board 410 and a first low-speed flexible circuit board 420 realize the transmission of high-speed signals and low-speed signals between the light emitting sub-module 400 and the circuit board 300 .

In the embodiment of the present application, the side of the ceramic adapter block 440 close to the laser component is provided with multi-layer grooves, and the laser components, laser drivers, etc. are respectively connected to the grooves of different layers of the ceramic adapter block 440 through gold wires, such as The high-speed signal is connected to the groove of the ceramic adapter block 440 near the upper side of the ceramic adapter block 440 through gold wires, and the low-speed signal is connected to the groove of the ceramic adapter block 440 near the lower side of the ceramic adapter block 440 through the gold wire. In this way, high-speed signals are transmitted to the circuit board 300 through the first high-speed flexible circuit board 410 connected to the upper side of the boss, and low-speed signals are transmitted to the circuit board 300 through the first low-speed flexible circuit board 420 connected to the lower side of the boss.

13 is a schematic structural diagram of a first high-speed flexible circuit board in an optical module according to some embodiments. As shown in FIG. 13 , one end of the first high-speed flexible circuit board 410 is provided with a plurality of pairs of high-speed signal pair pads 412 , a plurality of isolation pads 413 and a high-speed positioning pad 411 , and a high-speed signal pair pad 412 and an isolation pad 413 Set along the width direction of the first high-speed flexible circuit board 410, the adjacent high-speed signal pair pads 412 are separated by isolation pads 413; the high-speed positioning pads 411 and the high-speed signal pair pads 412 are arranged along the first high-speed flexible The length directions of the circuit boards 410 are arranged in sequence, and the first high-speed flexible circuit board 410 is positioned and connected to the first high-speed FPC pads through the high-speed positioning pads 411 .

In some embodiments of the present application, one end of the first high-speed flexible circuit board 410 is provided with four pairs of high-speed signal pair pads 412 and five isolation pads 413 , and the two isolation pads 413 are respectively located on the first high-speed flexible circuit At the edge of the board 410 in the width direction, that is, one isolation pad 413 is located on the upper edge of the first high-speed flexible circuit board 410 , and the other isolation pad 413 is located at the lower edge of the first high-speed flexible circuit board 410 . The other three isolation pads 413 are respectively located between the four pairs of high-speed signal pair pads 412 , that is, the four pairs of high-speed signal pair pads 412 are respectively separated by three isolation pads 413 to avoid adjacent high-speed signal pair pads 412 interference between them.

The first high-speed FPC pads on the circuit board 300 are FPC pads corresponding to the four pairs of high-speed signal pair pads 412 and the five isolation pads 413 on the first high-speed flexible circuit board 410 , and the first high-speed flexible circuit board 410 The four pairs of high-speed signal pair pads 412 and the five isolation pads 413 are respectively connected to the first high-speed FPC pads in a one-to-one correspondence.

The high-speed positioning pads 411 and the high-speed signal pair pads 412 are sequentially arranged along the length direction of the first high-speed flexible circuit board 410 , that is, the high-speed signal pair pads 412 and the isolation pads 413 are both arranged on the right side of the first high-speed flexible circuit board 410 . At the side end, the high-speed positioning pad 411 is provided on the left side of the high-speed signal pair pad 412 . The high-speed positioning pad 411 is an arc-shaped pad, and the first high-speed FPC pad includes an arc-shaped FPC pad corresponding to the high-speed positioning pad 411 , and the high-speed positioning pad 411 corresponds to the arc-shaped FPC pad one-to-one. connection, so as to realize the positioning connection between the first high-speed flexible circuit board 410 and the circuit board 300 . In the embodiment of the present application, the arc-shaped pad may be a semi-circular pad or a semi-elliptical pad.

14 is a schematic structural diagram of a first low-speed flexible circuit in an optical module according to some embodiments. As shown in FIG. 14 , one end of the first low-speed flexible circuit board 420 is provided with a first group of low-speed signal pads 421A and a second group of low-speed signal pads 422 , and the first group of low-speed signal pads 421A along the first low-speed flexible circuit The board 420 is arranged in the width direction, the first group of low-speed signal pads 421A and the second group of low-speed signal pads 422 are arranged in sequence along the length direction of the first low-speed flexible circuit board 420, and the first group of low-speed signal pads 421A are arranged in the first group. The right end of a low-speed flexible circuit board 420 . The second group of low-speed signal pads 422 may be positioning pads, and the first low-speed flexible circuit board 420 is positioned and connected to the first low-speed FPC pads through the second group of low-speed signal pads 422 .

The second group of low-speed signal pads 422 can also be low-speed signal pads, that is, the second group of low-speed signal pads 422 can not only implement positioning functions, but also transmit low-speed signals. The first low-speed FPC pads include a first group of low-speed FPC pads and a second group of low-speed FPC pads that are sequentially arranged along the length direction of the circuit board 300 , and the first group of low-speed signal pads 421A are electrically connected to the first group of low-speed FPC pads , the second group of low-speed signal pads 422 are electrically connected to the second group of low-speed FPC pads.

In the 200G LMQ3618-PC optical module, the low-speed signal of the light emitting sub-module 400 plus the GND signal has a total of 16 signals. Therefore, the first group of low-speed signal pads 421A can include 16 low-speed signal pads for transmitting low-speed signals. and GND signal; the second group of low-speed signal pads 422 are low-speed positioning pads, and the first low-speed flexible circuit board 420 is positioned and connected to the circuit board 300 through the second group of low-speed signal pads 422 . The first group of low-speed signal pads 421A may also include 14 low-speed signal pads, and the second group of low-speed signal pads 422 may include 2 low-speed signal pads for transmitting low-speed signals and GND signals respectively.

FIG. 15 is a schematic structural diagram of a circuit board in an optical module according to some embodiments. As shown in FIG. 15 , the first high-speed FPC pad 320A, the first low-speed FPC pad 330A and the second high-speed FPC pad 340A are located on the same side of the circuit board 300 , and the second high-speed FPC pad 340A and the second low-speed FPC pad 340A are located on the same side of the circuit board 300 . The pads are respectively located on opposite sides of the circuit board 300 ; the first high-speed FPC pads 320A and the first low-speed FPC pads 330A are arranged left and right along the length direction of the circuit board 300 , and the first low-speed FPC pads 330A are located on the circuit board 300 . On the left side, the first high-speed FPC pad 320A is located to the right of the first low-speed FPC pad 330A. The first low-speed FPC pad 330A and the second high-speed FPC pad 340A are disposed forward and backward along the width direction of the circuit board 300 , that is, the second high-speed FPC pad 340A is located behind the first low-speed FPC pad 330A.

In the embodiment of the present application, the end of the circuit board 300 away from the light emitting sub-module 400 is provided with a gold finger, that is, a gold finger is provided on the right side of the circuit board 300, and the optoelectronic chip 310A is provided on the first high-speed FPC pad 320A and the gold finger In between, the side of the optoelectronic chip 310A facing the gold finger is provided with a first signal pad, and the first signal pad is electrically connected to the gold finger through signal traces; the two sides of the optoelectronic chip 310A adjacent to the first signal pad A second signal pad and a third signal pad are respectively arranged on the upper side, that is, the first signal pad is arranged on the right side of the optoelectronic chip 310A, the second signal pad is arranged on the upper side of the optoelectronic chip 310A, and the third signal pad is arranged on the upper side of the optoelectronic chip 310A. The pads are disposed on the lower side of the optoelectronic chip 310A.

The second signal pad includes a first high-speed signal pad and a first low-speed signal pad, the first high-speed FPC pad is electrically connected to the first high-speed signal pad through the first high-speed differential pair wiring, and the first low-speed FPC pad It is electrically connected to the first low-speed signal pad through a low-speed signal trace. In this way, the electrical connection between the optoelectronic chip 310A and the first high-speed FPC pad 320A and the first low-speed FPC pad 330A is realized, and then one end of the first high-speed flexible circuit board 410 is connected to the first high-speed FPC pad 320A, and the first high-speed FPC pad 320A is connected. One end of a low-speed flexible circuit board 420 is connected to the first low-speed FPC pad 330A, thereby realizing the electrical connection between the optoelectronic chip 310A and the light emitting sub-module 400 .

FIG. 16 is a schematic diagram of an assembly of a light receiving sub-module and a circuit board in an optical module according to some embodiments, and FIG. 17 is a schematic diagram of a partial structure of a light receiving sub-module in an optical module according to some embodiments. As shown in FIG. 16 and FIG. 17 , the light receiving sub-module 500 includes a receiving casing 530 , a light receiving device is arranged in the receiving casing 530 , and one end of the second high-speed flexible circuit board 510 and the second low-speed flexible circuit board 520 are inserted into the receiving casing 530 . inside the casing 530 and are respectively electrically connected with the light receiving devices through signal wires. In this embodiment of the present application, the light receiving device may include an optical prism, an optical demultiplexer, a photodetector, a transimpedance amplifier, etc., and the signal light is transmitted to the light receiving sub-module 500 via an optical fiber adapter, and the signal light passes through the optical prism. It is injected into the optical demultiplexer, and a composite beam is demultiplexed into multiple signal lights of different wavelengths by the optical demultiplexer, and the multiple signal lights of different wavelengths enter the photodetector and the transimpedance amplifier in turn. Convert optical signals to electrical signals. The transimpedance amplifier is electrically connected to the second high-speed flexible circuit board 510 and the second low-speed flexible circuit board 520 respectively through gold wires, the high-speed signal is electrically connected to one end of the second high-speed flexible circuit board 510 through the gold wire, and the low-speed signal is electrically connected through the gold wire It is electrically connected to one end of the second low-speed flexible circuit board 520 . The other end of the second high-speed flexible circuit board 510 is electrically connected to the second high-speed FPC pad 340A on the circuit board 300 , and the other end of the second low-speed flexible circuit board 520 is electrically connected to the second low-speed FPC pad on the circuit board 300 .

The second high-speed FPC pad 340A and the second low-speed FPC pad on the circuit board 300 can be electrically connected to the third signal pad on the optoelectronic chip 310A through signal traces. In some embodiments of the present application, the third signal The pads include a second high-speed signal pad and a second low-speed signal pad, the second high-speed FPC pad 340A is electrically connected to the second high-speed signal pad through the second high-speed differential pair wiring, and the second low-speed FPC pad passes through the low-speed differential pair. The signal trace is electrically connected to the second low-speed signal pad; then one end of the second high-speed flexible circuit board 510 is connected to the second high-speed FPC pad 340A, and one end of the second low-speed flexible circuit board 520 is connected to the second low-speed FPC pads, thereby realizing the electrical connection between the optoelectronic chip 310A and the light receiving sub-module 500 .

The optical module provided by this application includes a circuit board, a light-emitting sub-module and a light-receiving sub-module, and the circuit board is provided with an optoelectronic chip, a first high-speed FPC pad, a first low-speed FPC pad, a second high-speed FPC pad and a third high-speed FPC pad. Two low-speed FPC pads, the light emission sub-module is electrically connected to the first high-speed FPC pad through the first high-speed flexible circuit board, and is electrically connected to the first low-speed FPC pad through the first low-speed flexible circuit board; used for emitting signal light; The light receiving sub-module is electrically connected to the second high-speed FPC pad through the second high-speed flexible circuit board, and is electrically connected to the second low-speed FPC pad through the second low-speed flexible circuit board; used for receiving signal light; the first high-speed FPC pad , The first low-speed FPC pad and the second high-speed FPC pad are located on the same side of the circuit board, and the second high-speed FPC pad and the second low-speed FPC pad are located on opposite sides of the circuit board respectively; The disk and the first low-speed FPC pads are arranged left and right along the length direction of the circuit board, and the first low-speed FPC pads and the second high-speed FPC pads are arranged forward and backward along the width direction of the circuit board; the first high-speed FPC pads pass through the high-speed differential pair. The wire is electrically connected to the emission signal pad of the optoelectronic chip, the first low-speed FPC pad is electrically connected to the emission signal pad of the optoelectronic chip through the low-speed signal routing, and the second high-speed FPC pad is connected to the optoelectronic chip through the high-speed differential pair routing. The receiving signal pad is electrically connected, and the second low-speed FPC pad is electrically connected to the receiving signal pad of the optoelectronic chip through the low-speed signal wiring. In this application, the light emitting sub-module is welded to the circuit board through the double-row pads of the double flexible circuit board, and the light-receiving sub-module is welded to the circuit board through the double flexible circuit board. The disks are arranged left and right along the length direction of the circuit board. The high-speed FPC pads and low-speed FPC pads of the receiving end are located on different sides of the circuit board, respectively. The FPC pads of the transmitting end and the FPC pads of the receiving end are arranged forward and backward along the width direction of the circuit board, so The 200G rate laser covers too many signals and the structural limitation of the QSFP-DD interface package effectively saves the space of the circuit board and satisfies the limitation of the structural width of the miniaturized optical module, which is conducive to the miniaturization of the optical module. development. In addition, the high-speed signal and the low-speed signal are respectively transmitted through the dual flexible circuit boards, which can meet the 200G rate of lasers covering too many signals, which improves the signal transmission quality.

The flexible circuit board provided by the embodiment of the present application adopts a double-row pad design, which is not limited to the flexible circuit board connected with the light receiving sub-module, but also applicable to the flexible circuit board connected with the light emitting sub-module, which not only satisfies the requirements of light The transmission integrity of the multi-type signals of the module also satisfies the limitation of the structural width of the optical module, which is beneficial to the miniaturization development of the optical module.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, but not to limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

An optical module, characterized in that it includes:

circuit board;

an optical sub-module for generating signal light and receiving signal light from outside the optical module;

a first flexible circuit board, on which a high-speed signal line is arranged, one end is electrically connected to the optical sub-module, and the other end is electrically connected to the circuit board;

The second flexible circuit board is provided with a low-speed signal line, one end is electrically connected to the optical sub-module, and the other end is electrically connected to the circuit board;

The third flexible circuit board is provided with high-speed signal lines, one end is electrically connected to the optical sub-module, and the other end is electrically connected to the circuit board;

Wherein, the first flexible circuit board and the third flexible circuit board are used to separate high-speed signals for bidirectional transmission between the optical sub-module and the circuit board, and the second flexible circuit board is arranged on the first flexible circuit board. between a flexible circuit board and the third flexible circuit board.
The optical module according to claim 1, wherein the optical sub-module comprises:

Light emission sub-module for generating signal light;

a light-receiving sub-module for converting the received signal light into a current signal, and the light-emitting sub-module and the light-receiving sub-module are arranged on top of each other;

One end of the first flexible circuit board is electrically connected to the light-emitting sub-module, and one end of the third flexible circuit board is electrically connected to the light-receiving sub-module.
The optical module according to claim 2, wherein the first flexible circuit board comprises a first insulating medium layer, the high-speed signal line is arranged on the top surface of the first insulating medium layer, and the first insulating medium The emission ground is arranged on the bottom surface of the layer, and the top surface of the first insulating medium layer is away from the second flexible circuit board.
The optical module according to claim 2, wherein the second flexible circuit board comprises a second insulating medium layer, the power lines are arranged on the top surface of the second insulating medium layer, and the bottom surface of the second insulating medium layer is arranged Lay out the power ground.
The optical module according to claim 2, wherein the third flexible circuit board comprises a third insulating medium layer, the receiving signal line is arranged on the top surface of the third insulating medium layer, and the third insulating medium The power ground is arranged on the bottom surface of the layer.
The optical module according to claim 1, wherein the first flexible circuit board is electrically connected to the top surface of the circuit board, and the second flexible circuit board is electrically connected to the first surface or the second surface of the circuit board. The second flexible circuit board is electrically connected to the bottom surface of the circuit board.
The optical module according to claim 6, wherein a high-speed signal line is arranged on the top surface of the circuit board and is electrically connected to the high-speed signal line on the first flexible circuit board;

High-speed signal lines are arranged on the bottom surface of the circuit board and are electrically connected to the high-speed signal lines on the third flexible circuit board.
The optical module according to claim 2, wherein the light emitting sub-module includes an electrical connector, a boss is provided on the electrical connector, and the boss includes a first connection surface and a second connection surface , the first flexible circuit board is electrically connected to the first connection surface, and the second flexible circuit board is electrically connected to the second connection surface.
The optical module according to claim 1, wherein the end of the top surface of the circuit board is provided with a first welding area, a second welding area and a third welding area arranged in sequence, and the third welding area is relatively the second welding area is closer to the optical port of the optical module;

The other end of the first flexible circuit board is connected to the first welding area by welding, the other end of the second flexible circuit board is connected to the first welding area by welding, and the other end of the third flexible circuit board is connected by welding the third welding zone.
The optical module according to claim 2, wherein an opening is provided on the light receiving sub-module, and one end of the third flexible circuit board is penetrated in the opening.
An optical module, characterized in that it includes:

a circuit board, which is provided with an optoelectronic chip, a first high-speed FPC pad, a first low-speed FPC pad and a second high-speed FPC pad;

a first optical sub-module, electrically connected to the circuit board, electrically connected to the first high-speed FPC pad through a first high-speed flexible circuit board, and electrically connected to the first low-speed FPC pad through the first low-speed flexible circuit board electrical connection;

a second optical sub-module, electrically connected to the circuit board, and electrically connected to the second high-speed FPC pad through a second high-speed flexible circuit board;

Wherein, the first high-speed FPC pad, the first low-speed FPC pad and the second high-speed FPC pad are located on the same side of the circuit board, and the first high-speed FPC pad and the second high-speed FPC pad are located on the same side of the circuit board. A low-speed FPC pad is arranged left and right along the length direction of the circuit board, and the first low-speed FPC pad and the second high-speed FPC pad are arranged forward and backward along the width direction of the circuit board;

The first high-speed FPC pad is electrically connected to the signal pad of the optoelectronic chip through the first high-speed differential pair wiring, and the first low-speed FPC pad is connected to the signal pad of the optoelectronic chip through the low-speed signal wiring. Electrical connection, the second high-speed FPC pad is electrically connected to the signal pad of the optoelectronic chip through a second high-speed differential pair wiring.
The optical module according to claim 11, wherein the first optical sub-module is a light-emitting sub-module, the second optical sub-module is a light-receiving sub-module, and a second optical sub-module is further provided on the circuit board. A low-speed FPC pad, the second optical sub-module is electrically connected to the second low-speed FPC pad through a second low-speed flexible circuit board; the second high-speed FPC pad and the second low-speed FPC pad are located at the different sides of the circuit board, and the second low-speed FPC pads are electrically connected to the receiving signal pads of the optoelectronic chip through low-speed signal traces.
The optical module according to claim 11, wherein the first optical sub-module is a light receiving sub-module, the second optical sub-module is a light-emitting sub-module, and the circuit board is further provided with a second optical sub-module. A low-speed FPC pad, the second optical sub-module is electrically connected to the second low-speed FPC pad through a second low-speed flexible circuit board; the second high-speed FPC pad and the second low-speed FPC pad are located at the different sides of the circuit board, and the second low-speed FPC pads are electrically connected to the emission signal pads of the optoelectronic chip through low-speed signal traces.
The optical module according to claim 12 or 13, wherein a gold finger is provided at one end of the circuit board away from the light emitting sub-module, and a first side of the optoelectronic chip facing the gold finger is provided with a first a signal pad, the first signal pad is electrically connected to the gold finger through a signal trace;

A second signal pad and a third signal pad are respectively provided on the two sides of the optoelectronic chip adjacent to the first signal pad, and the second signal pad includes a first high-speed signal pad and a third signal pad. A low-speed signal pad, the first high-speed FPC pad is electrically connected to the first high-speed signal pad through the first high-speed differential pair wiring, and the first low-speed FPC pad is routed through the low-speed signal The wire is electrically connected to the first low-speed signal pad; the third signal pad includes a second high-speed signal pad and a second low-speed signal pad, and the second high-speed FPC pad passes through the second high-speed differential The pair of wirings are electrically connected to the second high-speed signal pads, and the second low-speed FPC pads are electrically connected to the second low-speed signal pads through the low-speed signal wirings.
The optical module according to claim 11, wherein the first high-speed FPC pad and the first low-speed FPC pad are arranged between an end of one end of the circuit board and the optoelectronic chip, so The first high-speed FPC pad is close to the optoelectronic chip, and the first low-speed FPC pad is close to the end of the circuit board.
The optical module according to claim 15, wherein one end of the first high-speed flexible circuit board is provided with a plurality of pairs of high-speed signal pair pads, a plurality of isolation pads and high-speed positioning pads, and adjacent high-speed signal The isolation pads are spaced between the pads; the high-speed positioning pads and the high-speed signal pair pads are arranged in sequence along the length direction of the first high-speed flexible circuit board, and the first high-speed flexible circuit The board is positioned and connected to the first high-speed FPC pad through the high-speed positioning pad.
The optical module according to claim 16, wherein one end of the first high-speed flexible circuit board is provided with four pairs of high-speed signal pair pads and five isolation pads, and the two isolation pads are respectively located at the At the edge in the width direction of the first high-speed flexible circuit board, the other three isolation pads are respectively located between the four pairs of the high-speed signal pair pads for separating the four pairs of the high-speed signal pair pads.
The optical module according to claim 11, wherein one end of the first low-speed flexible circuit board is provided with a first group of low-speed signal pads and a second group of low-speed signal pads, the first group of low-speed signal solder pads The pad and the second group of low-speed signal pads are arranged in sequence along the length direction of the first low-speed flexible circuit board, and the first group of low-speed signal pads are close to the end of the circuit board; the second group The low-speed signal pads are positioning pads, and the first low-speed flexible circuit board is positioned and connected to the first low-speed FPC pads through the second group of low-speed signal pads.
The optical module according to claim 18, wherein the second group of low-speed signal pads are low-speed signal pads, and the first low-speed FPC pads comprise first low-speed FPC pads arranged in sequence along the length direction of the circuit board A set of low-speed FPC pads and a second set of low-speed FPC pads, the first set of low-speed signal pads and the first set of low-speed FPC pads are electrically connected, and the second set of low-speed signal pads and the second set of low-speed signal pads A group of low-speed FPC pads are electrically connected.
The optical module according to claim 19, wherein the first group of low-speed signal pads includes 14 low-speed signal pads, and the second group of low-speed signal pads includes 2 signal pads.