CN113721330B

CN113721330B - High-speed laser assembly and optical module

Info

Publication number: CN113721330B
Application number: CN202111013601.2A
Authority: CN
Inventors: 陈骁; 赵昀松; 刘志程; 李静思; 李召松
Original assignee: Hisense Broadband Multimedia Technology Co Ltd
Current assignee: Hisense Broadband Multimedia Technology Co Ltd
Priority date: 2021-08-31
Filing date: 2021-08-31
Publication date: 2023-01-24
Anticipated expiration: 2041-08-31
Also published as: CN113721330A

Abstract

The application provides a high-speed laser subassembly and optical module includes: a socket provided with a pin for receiving a high frequency signal; the laser chip is arranged on one side of the tube seat and electrically connected with the high-frequency signal pin; a flexible circuit board disposed at the other side of the socket; the flexible circuit board includes: an insulating medium; the high-frequency signal wire is arranged on the first surface of the insulating medium and is electrically connected with the high-frequency signal pin; the ground layer is arranged on the second surface of the insulating medium and electrically connected with the grounding pin; and the ground through hole is arranged on the insulating medium and is positioned around the high-frequency signal wire connected with the high-frequency signal pin, the ground through hole is filled with a metal material, and the bottom surface of the pipe seat and the ground layer are electrically connected through the metal material. Through the ground through holes arranged around the connection positions of the high-frequency signal lines and the high-frequency signal pins and the metal materials filled in the ground through holes, the TO encapsulation form can be used for high-frequency and ultrahigh-frequency optical modules.

Description

High-speed laser assembly and optical module

Technical Field

The application relates to the technical field of optical fiber communication, in particular to a high-speed laser assembly and an optical module.

Background

With the development of new services and application modes such as cloud computing, mobile internet, video and the like, the development and progress of the optical communication technology become increasingly important. In the optical communication technology, an optical module is a tool for realizing the interconversion of optical signals and is one of key devices in optical communication equipment, and the transmission rate of the optical module is continuously increased along with the development requirement of the optical communication technology.

Generally, a core device in an optical module includes a semiconductor laser chip, the semiconductor laser chip is a device that generates laser light by using a semiconductor material as a working substance, and with the continuous increase of the requirement on the transmission rate of the optical module, the requirement on the high-frequency modulation performance of the semiconductor laser is also increasing. The high-frequency modulation performance of the semiconductor laser in the optical module is determined by the active region (intrinsic laser) of the semiconductor laser and the high-frequency response of the high-speed transmission structure. The high-speed transmission structure is crucial to the performance of high bandwidth and ultra-high bandwidth, and has become an important technical barrier affecting the performance of high-speed optical communication. The design of an optical module/optical device with excellent high-speed performance can obviously improve the key performance index and competitiveness of the product. Any impedance mismatch or resonance effects can seriously degrade the performance of the whole product, and the device cannot realize high-speed application.

The coaxial TO package is a packaging use form of a semiconductor laser chip in an optical module, has the characteristics of simple manufacturing process, low cost and flexible and convenient use, and is widely applied TO low-speed laser packaging. In the current optical module, the TO is electrically connected with a circuit board inside the optical module through a flexible circuit board, but in the high-speed semiconductor laser chip packaging, impedance mismatch and resonance effect are easily caused at the connection position between the TO and the flexible circuit board, which is a risk point of high-frequency transmission, and the high-frequency performance of the semiconductor laser chip is greatly reduced. Specifically, the transmission mode of electromagnetic waves at the connecting position between the TO and the flexible circuit board changes suddenly, and the low-loss impedance transition effect is difficult TO realize, and more importantly, the backflow ground plane design of the flexible circuit board and the backflow ground of the TO tube seat generate strong resonance at the high-frequency 15-20GHz position, which affects the performance and reliability of the high-speed optical module, and directly causes that the TO packaging form is difficult TO be used in high-frequency and ultrahigh-frequency optical modules.

Disclosure of Invention

The embodiment of the application provides a high-speed laser assembly and an optical module, so that a TO packaging form can be used for high-frequency and ultrahigh-frequency optical modules.

In a first aspect, the present application provides a high-speed laser assembly comprising:

a tube seat provided with a pin and a high-frequency signal pin;

the laser chip is arranged on one side of the tube seat and is electrically connected with the high-frequency signal pin;

a flexible circuit board disposed at the other side of the socket;

wherein, the flexible circuit board includes:

an insulating medium;

a high-frequency signal line disposed on the first surface of the insulating medium, the high-frequency signal line being electrically connected to the high-frequency signal pin;

the ground layer is arranged on the second surface of the insulating medium and is electrically connected with the grounding pin;

and the ground through hole is arranged on the insulating medium and is positioned around the high-frequency signal pin connected with the high-frequency signal wire, a metal material is filled in the ground through hole, and the bottom surface of the tube seat and the ground layer are electrically connected through the metal material.

In a second aspect, the present application provides an optical module, including a high-speed laser module, where the high-speed laser module is the high-speed laser module according to the first aspect.

In the high-speed laser assembly and the optical module, the laser chip is arranged on one side of the tube seat, the flexible circuit board is arranged on the other side of the tube seat, and the laser chip is electrically connected with the flexible circuit board through the tube seat and the pin and the high-frequency signal pin which are arranged on the tube seat; meanwhile, a high-frequency signal wire is arranged on the flexible circuit board, a ground through hole is arranged around the connection position of the high-frequency signal wire and the high-frequency signal pin, a metal material is filled in the ground through hole, and the ground through hole is electrically connected with the bottom surface of the tube seat through the metal material. When a high-frequency signal is transmitted TO the laser chip through a high-frequency signal line on the flexible circuit board, the transmission mode of a high-frequency electromagnetic wave from the flexible circuit board TO the TO is changed, and the ground through hole which are arranged around the connection position of the high-frequency signal line and the high-frequency signal pin are filled with metal materials and are used for electromagnetic wave transmission matching TO compensate the loss of the high-frequency signal, so that the reflection of the high-frequency electromagnetic wave from the flexible circuit board TO the TO and the electromagnetic wave loss can be effectively reduced, and the TO packaging form can be used in high-frequency and ultrahigh-frequency optical modules.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic diagram of connection relationship of an optical communication terminal;

FIG. 2 is a schematic diagram of an optical network unit;

fig. 3 is a schematic structural diagram of an optical module according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of an exploded structure of an optical module according to an embodiment of the present application;

fig. 5 is a schematic diagram of an internal structure of an optical module according to an embodiment of the present application;

fig. 6 is a schematic view illustrating an assembly structure of a high-speed laser module and a circular-square tube according to an embodiment of the present disclosure;

FIG. 7 is a schematic structural diagram of a socket according to an embodiment of the present disclosure;

fig. 8 is a partial schematic diagram of a high speed laser module according to the present disclosure;

fig. 9 is a schematic structural diagram of a second side of a flexible circuit board according to an embodiment of the present disclosure;

fig. 10 is a cross-sectional view of a flexible circuit board provided in an embodiment of the present application;

FIG. 11 is a schematic illustration of a portion of another high speed laser assembly provided herein;

fig. 12 is a schematic structural diagram of a second side of another flexible circuit board according to an embodiment of the present application.

Detailed Description

In order to facilitate the technical solution of the present application, some concepts related to the present application will be described below.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.

One of the core links of optical fiber communication is the interconversion of optical and electrical signals. The optical fiber communication uses optical signals carrying information to transmit in information transmission equipment such as optical fibers/optical waveguides and the like, and the information transmission with low cost and low loss can be realized by using the passive transmission characteristic of the light in the optical fibers/optical waveguides; meanwhile, the information processing device such as a computer uses an electric signal, and in order to establish information connection between the information transmission device such as an optical fiber or an optical waveguide and the information processing device such as a computer, it is necessary to perform interconversion between the electric signal and the optical signal.

The optical module realizes the function of interconversion of optical signals and electrical signals in the technical field of optical fiber communication, and the interconversion of the optical signals and the electrical signals is the core function of the optical module. The optical module is electrically connected with an external upper computer through a golden finger on an internal circuit board of the optical module, and the main electrical connection comprises power supply, I2C signals, data signals, grounding and the like; the electrical connection mode realized by the gold finger has become the mainstream connection mode in the optical module industry, and on the basis of the mainstream connection mode, the definition of the pins on the gold finger forms various industry protocols/specifications.

Fig. 1 is a schematic diagram of connection relationship of an optical communication terminal. As shown in fig. 1, the connection of the optical communication terminal mainly includes the interconnection among the optical network terminal 100, the optical module 200, the optical fiber 101 and the network cable 103;

one end of the optical fiber 101 is connected with a far-end server, one end of the network cable 103 is connected with local information processing equipment, and the connection between the local information processing equipment and the far-end server is completed by the connection between the optical fiber 101 and the network cable 103; and the connection between the optical fiber 101 and the network cable 103 is made by the optical network terminal 100 having the optical module 200.

An optical port of the optical module 200 is externally connected to the optical fiber 101, and establishes bidirectional optical signal connection with the optical fiber 101; an electrical port of the optical module 200 is externally connected to the optical network terminal 100, and establishes bidirectional electrical signal connection with the optical network terminal 100; the optical module realizes the interconversion of optical signals and electric signals, thereby realizing the establishment of information connection between the optical fiber and the optical network terminal; specifically, the optical signal from the optical fiber is converted into an electrical signal by the optical module and then input to 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 and input to the optical fiber.

The optical network terminal is provided with an optical module interface 102, which is used for accessing the optical module 200 and establishing bidirectional electric signal connection with the optical module 200; the optical network terminal is provided with a network cable interface 104, which is used for accessing the network cable 103 and establishing bidirectional electric signal connection with the network cable 103; the optical module 200 is connected to the network cable 103 through the optical network terminal 100, specifically, the optical network terminal transmits a signal from the optical module to the network cable and transmits the signal from the network cable to the optical module, and the optical network terminal serves as an upper computer of the optical module to monitor the operation of the optical module.

At this point, a bidirectional signal transmission channel is established between the remote server and the local information processing device through the optical fiber, the optical module, the optical network terminal and the network cable.

Common information processing apparatuses include routers, switches, electronic computers, and the like; the optical network terminal is an upper computer of the optical module, provides data signals for the optical module, and receives the data signals from the optical module, and the common upper computer of the optical module also comprises an optical line terminal and the like.

Fig. 2 is a schematic diagram of an optical network terminal structure. As shown in fig. 2, the optical network terminal 100 has a circuit board 105, and a cage 106 is disposed on a surface of the circuit board 105; an electric connector is arranged in the cage 106 and used for connecting an electric port of an optical module such as a golden finger; the cage 106 is provided with a heat sink 107, and the heat sink 107 has a projection such as a fin for increasing a heat radiation area.

The optical module 200 is inserted into the optical network terminal, specifically, the electrical port of the optical module is inserted into the electrical connector inside the cage 106, and the optical port of the optical module is connected to the optical fiber 101.

The cage 106 is positioned on the circuit board, and the electrical connector on the circuit board is wrapped in the cage, so that the electrical connector is arranged in the cage; the optical module is inserted into the cage, held by the cage, and the heat generated by the optical module is conducted to the cage 106 and then diffused by the heat sink 107 on the cage.

The fifth generation mobile communication technology (5G) currently meets the increasing demand for high-speed wireless transmission. The frequency spectrum adopted by the 5G communication is much higher than that adopted by the 4G communication, which brings a greatly improved communication rate for the 5G communication, but the transmission attenuation of the signal is relatively obviously increased.

The new service characteristics and higher index requirements of 5G provide new challenges for the bearer network architecture and each layer of technical solutions, wherein the optical module serving as a basic constituent unit of the physical layer of the 5G network also faces technical innovation and upgrade, which is reflected in that the optical module applied to 5G transmission needs to have two basic technical characteristics of high-speed transmission and low return loss. In order to meet the requirement of an optical module in a 5G communication network, an embodiment of the present application provides an optical module. Fig. 3 is a schematic view of an optical module according to an embodiment of the present disclosure, and fig. 4 is a schematic view of an exploded structure of an optical module according to an embodiment of the present disclosure. As shown in fig. 3 and 4, an optical module 200 provided in the embodiment of the present application includes an upper housing 201, a lower housing 202, a circuit board 203, and a transceiver sub-assembly 300.

The upper shell 201 is covered on the lower shell 202 to form a wrapping cavity with two openings; the outer contour of the wrapping cavity is generally a square body, and specifically, the lower shell comprises a main plate and two side plates which are positioned at two sides of the main plate and are perpendicular to the main plate; the upper shell comprises a cover plate, and the cover plate covers two side plates of the upper shell to form a wrapping cavity; the upper shell can also comprise two side walls which are positioned at two sides of the cover plate and are perpendicular to the cover plate, and the two side walls are combined with the two side plates to realize that the upper shell covers the lower shell.

The two openings can be two ends (204, 205) in the same direction, or two openings in different directions; one opening is an electric port 204, and a gold finger of the circuit board extends out of the electric port 204 and is inserted into an upper computer such as an optical network terminal; the other opening is an optical port 205 for external optical fiber access; the photoelectric devices such as the circuit board 203 and the optical transceiver sub-assembly 300 are positioned in the packaging cavity formed by the upper shell and the lower shell.

The upper shell 201 and the lower shell 202 are combined in an assembling mode, so that the optical transceiver sub-module 300 and other devices can be conveniently installed in the shells, and the upper shell 201 and the lower shell 202 form an outermost packaging protection shell of the optical module; the upper shell 201 and the lower shell 202 are generally made of metal materials, which is beneficial to realizing electromagnetic shielding and heat dissipation; generally, the housing of the optical module is not made into an integrated component, so that when devices such as a circuit board and the like are assembled, the positioning component, the heat dissipation component and the electromagnetic shielding component cannot be installed, and the production automation is not facilitated.

Typically, the optical module 200 further includes an unlocking component located on an outer wall of the package cavity/lower housing 202 for implementing a fixed connection between the optical module and the upper computer or releasing the fixed connection between the optical module and the upper computer.

The unlocking component is provided with a clamping component matched with the upper computer cage; the end of the unlocking component can be pulled to enable the unlocking component to move relatively on the surface of the outer wall; the optical module is inserted into a cage of the upper computer, and the optical module is fixed in the cage of the upper computer by a clamping component of the unlocking component; by pulling the unlocking component, the clamping component of the unlocking component moves along with the unlocking component, so that the connection relation between the clamping component and the upper computer is changed, the clamping relation between the optical module and the upper computer is released, and the optical module can be drawn out from the cage of the upper computer.

The circuit board 203 is provided with circuit traces, electronic components (such as capacitors, resistors, triodes, and MOS transistors), and chips (such as an MCU, a clock data recovery CDR, a power management chip, and a data processing chip DSP).

The circuit board 203 connects the electrical appliances in the optical module together according to the circuit design through circuit wiring to realize the electrical functions of power supply, electrical signal transmission, grounding and the like.

The circuit board 203 is generally a rigid circuit board, which can also realize a bearing effect due to its relatively hard material, for example, the rigid circuit board can stably bear a chip; when the optical transceiver is positioned on the circuit board, the rigid circuit board can also provide stable bearing; the hard circuit board can also be inserted into an electric connector in the upper computer cage, and specifically, a metal pin/gold finger is formed on the surface of the tail end of one side of the hard circuit board and is used for being connected with the electric connector; these are not easily implemented with flexible circuit boards.

A flexible circuit board is also used in a part of the optical module to supplement a rigid circuit board; the flexible circuit board is generally used in combination with a rigid circuit board, for example, the rigid circuit board may be connected to the optical transceiver device through the flexible circuit board.

Fig. 5 is a schematic view of an internal structure of an optical module according to an embodiment of the present application. As shown in fig. 5, in the optical module provided in this embodiment, the rosa 300 includes a circular-square tube 310, and the circular-square tube 310 is embedded with the high-speed laser module 400 and the optical receiving module 500 disposed on the circular-square tube 310; the high-speed laser assembly 400 and the light receiving assembly 500 are respectively electrically connected with the circuit board 203, so that the high-speed laser assembly 400 is used for outputting signal light and the light receiving assembly 500 is used for receiving the signal light from the outside of the optical module, and the electro-optic and photoelectric conversion of the optical module is realized; the round and square tube 310 is usually provided with a lens assembly for changing the propagation direction of the output signal light of the high-speed laser assembly 400 or the input signal light of the external optical fiber.

In some embodiments of the present application, the high-speed laser assembly 400 and the light receiving assembly 500 each include a flexible circuit board, and the flexible circuit boards are electrically connected to the circuit board 203, so that the electrical connection between the electrical devices in the high-speed laser assembly 400 and the light receiving assembly 500 and the circuit board 203 is realized through the corresponding flexible circuit boards.

Fig. 6 is a schematic view of an assembly structure of a high-speed laser module and a circular-square tube according to an embodiment of the present disclosure. As shown in fig. 6, the high-speed laser module 400 includes a stem 410 and a flexible circuit board 420, and one end of the flexible circuit board 420 is electrically connected to one side of the stem 410 and the other end is used for electrically connecting the circuit board 203. In the embodiment of the present application, pins, such as a ground pin and a high-frequency signal pin, are provided on the header 410, and one end of the flexible circuit board 420 is electrically connected to the pins on the header 410.

Fig. 7 is a schematic structural diagram of a socket according to an embodiment of the present application. As shown in fig. 7, the other side of the stem 410 is provided with a laser chip 430; the pins arranged on the tube seat 410 penetrate from one side of the tube seat 410 to the other side of the tube seat 410; the laser chip 430 can be connected with a corresponding pin through routing, then the circuit board is electrically connected through the flexible circuit board 420 electrically connected with the pin, the flexible circuit board 420 is provided with metal routing, and then power supply or signal transmission and the like are realized for electric devices such as the laser chip 430 in the high-speed laser assembly 400 through the flexible circuit board 420.

In the embodiment of the present application, a high frequency signal line is provided on the flexible circuit board 420 for transmitting a high frequency signal to the laser chip 430. However, in the specific working process, the high-frequency signal is transmitted from the flexible circuit board 420 TO the tube seat 410 and then transmitted TO the laser chip 430 through the tube seat 410, and since the high-speed signal is transmitted from the flexible circuit board 420 TO the tube seat 410, the transmission mode of the high-frequency electromagnetic wave from the flexible circuit board 420 TO the tube seat 410 changes suddenly, which causes great loss of reflection and electromagnetic wave, so that the TO packaging form is difficult TO be used in high-frequency and ultrahigh-frequency optical modules. In the embodiment of the present application, a ground via is provided at the connection point of the flexible circuit board 420 and the socket 410, the ground via is filled with a metal material, such as solder, copper, etc., and the metal material in the ground via electrically connects the socket 410 and the ground layer of the flexible circuit board 420. The ground through hole filled with the metal material is used for electromagnetic wave transmission matching so as TO compensate the loss of high-frequency signals, and further, the reflection of the high-frequency electromagnetic waves from the flexible circuit board TO the TO and the electromagnetic wave loss can be effectively reduced. In the embodiment of the application, the metal material filled in the ground through hole is filled in or slightly overflows the ground through hole, so that the performance of electromagnetic wave transmission matching is conveniently exerted.

In the embodiment of the present application, the flexible circuit board 420 includes an insulating medium, and the ground layer of the flexible circuit board 420 electrically connected to the metal material in the ground via may be disposed on a surface of the insulating medium different from the high-frequency signal line of the flexible circuit board 420, so as to facilitate the electrical connection between the metal material in the ground via and the ground layer of the flexible circuit board 420, but the embodiment of the present application is not limited to that the ground layer of the flexible circuit board 420 electrically connected to the metal material in the ground via may be disposed on the same surface of the insulating medium as the high-frequency signal line of the flexible circuit board 420.

In the embodiment of the application, the ground through hole is arranged around the high-frequency signal pin connected with the high-frequency signal wire, and the ground through hole is close to the connection part of the high-frequency signal wire and the high-frequency signal pin; and a metal layer is arranged in the ground through hole and is connected with the ground layer. Optionally, a plurality of ground vias are arranged around the high-frequency signal pin connected with the high-frequency signal line, and each ground via is filled with a metal material, for example, 2 or 3 ground vias are arranged around the connection position of the high-frequency signal line and the high-frequency signal pin. In order to ensure the electromagnetic wave transmission matching effect of the ground through holes, the ground through holes are uniformly arranged around the high-frequency signal pins connected with the high-frequency signal lines; if two ground through holes are respectively arranged around the connection part of each high-frequency signal wire and each high-frequency signal pin, the two ground through holes are symmetrically arranged at the connection part of the high-frequency signal wire and each high-frequency signal pin. Optionally, the two ground vias are symmetrically disposed at the connection between the high-frequency signal line and the high-frequency signal pin along the length direction of the flexible circuit board 420.

In some embodiments of the present application, in order to ensure the electromagnetic wave transmission matching effect of the ground via, the ground via is a round or oval ground via with smooth edges. Furthermore, in order to ensure the electromagnetic wave transmission matching effect of the ground through hole, the size of the ground through hole is 0.5mm-1.5mm; if the ground through hole is circular, the diameter of the ground through hole is 0.5mm-1.5mm; if the ground through hole is oval, the minor axis dimension of the ground through hole is 0.5mm-1.5mm.

In some embodiments of the present application, in order to ensure the electromagnetic wave transmission matching effect of the ground through hole, the distance between the center of the connection between the high-frequency signal line and the high-frequency signal pin and the circle center or focus of the ground through hole is 1mm-3mm, which will also facilitate the arrangement of the ground through hole. In some embodiments of the present application, in order to facilitate connection between the high-frequency signal line and the high-frequency signal pin, the flexible circuit board 420 is provided with a high-speed signal line hole, and the high-frequency signal pin is electrically connected to the high-frequency signal line through the high-speed signal line hole; therefore, the distance between the circle center of the high-speed signal line hole and the circle center or focus of the ground through hole is 1mm-3mm.

In the high-speed laser module 400 provided in the embodiment of the present application, the flexible circuit board 420 is provided with a high-frequency signal line, a ground through hole is provided around a connection portion between the high-frequency signal line and a high-frequency signal pin, the ground through hole is filled with a metal material, and the ground through hole is electrically connected to the bottom surface of the tube seat through the metal material. When a high-frequency signal line is transmitted TO the laser chip 430 through a high-frequency signal line on the flexible circuit board 420, the transmission mode of high-frequency electromagnetic waves from the flexible circuit board TO the TO changes, and the ground through holes which are arranged around the connection position of the high-frequency signal line and the high-frequency signal pin are filled with metal materials and used for electromagnetic wave transmission matching so as TO compensate the loss of the high-frequency signal, so that the reflection and the electromagnetic wave loss caused by the high-frequency electromagnetic waves from the flexible circuit board 420 TO the TO can be effectively reduced, and the TO packaging form can be used for high-frequency and ultrahigh-frequency optical modules.

Fig. 8 is a partial structural diagram of a high-speed laser module according to the present application, and fig. 8 shows a partial structure of a flexible printed circuit 420, where a second side of the flexible printed circuit contacts a bottom surface of a header in fig. 8. As shown in fig. 8, the high-speed laser module 400 includes a first high-frequency signal pin 411 on the header, the flexible printed circuit 420 includes an insulating medium 421, a first high-frequency signal line 422 is disposed on a first surface of the insulating medium 421, and an end of the first high-frequency signal line 422 is electrically connected to the first high-frequency signal pin 411; a first ground via 423 and a second ground via 424 are provided on the flexible wiring board 420 near the connection of the first high-frequency signal line 422 and the first high-frequency signal pin 411.

As shown in fig. 8, the first ground via hole 423 and the second ground via hole 424 are provided on both sides of the first high-frequency signal line 422, near the connection of the first high-frequency signal line 422 and the first high-frequency signal pin 411. In some embodiments of the present application, the first ground via 423 and the second ground via 424 are symmetrically disposed at both sides of the first high-frequency signal line 422; for example, the first ground via 423 and the second ground via 424 are symmetrically disposed on both sides of the first high-frequency signal line 422 along the length direction of the flexible wiring board 420, and are close to the connection of the first high-frequency signal line 422 and the first high-frequency signal pin 411.

In some embodiments, the first ground via 423 and the second ground via 424 are filled with solder, and the bottom surface of the socket and the ground layer on the flexible circuit board 420 are electrically connected through the solder in the first ground via 423 and the second ground via 424. As shown in fig. 8, the ground layer on the flexible circuit board 420 is disposed on the second side of the insulating medium 421 and is shielded, and in the embodiment of the present application, the structure of the ground layer on the flexible circuit board 420 is not particularly limited, and may be selected according to the shape of the flexible circuit board 420 and the requirements of the ground layer. Of course, if the size of the flexible circuit board 420 is sufficient, the ground layer of the embodiment of the present application may also be disposed on the first side of the insulating medium 421, and is located on the same side of the insulating medium 421 as the first high-frequency signal line 422.

In some embodiments of the present application, as shown in fig. 8, the first ground through hole 423 and the second ground through hole 424 are circular ground through holes, and the size of the first ground through hole 423 and the second ground through hole 424 is greater than 0.5mm and less than 1.5mm. Of course, in the embodiment of the present application, the shapes of the first ground through hole 423 and the second ground through hole 424 are not limited to the circular shape, and may be elliptical shapes, etc.

In some embodiments of the present application, as shown in fig. 8, a first high-frequency signal line hole 422-1 is provided at an end of the first high-frequency signal line 422, and the first high-frequency signal line 422 is electrically connected to the first high-frequency signal pin 411 through the first high-speed signal line hole 422-1. Optionally, the distance between the center of the first high-speed signal line hole 422-1 and the center of the first ground through hole 423 is greater than 1mm and less than 3mm, and the distance between the center of the first high-speed signal line hole 422-1 and the center of the second ground through hole 424 is greater than 1mm and less than 3mm.

In some embodiments of the present application, the ground pin on the header may be electrically connected to the ground layer through the first ground via 423 or the second ground via 424; of course, the flexible circuit board 420 may also be provided with a via hole for connecting the ground pin of the socket to the ground layer, and the ground pin is electrically connected to the ground layer through the via hole.

Fig. 9 is a schematic structural diagram of a second side of a flexible circuit board according to an embodiment of the present disclosure, and fig. 9 shows a schematic structural diagram of a via hole on the flexible circuit board in fig. 8 filled with a metal material. As shown in fig. 9, a ground layer 427 is disposed on the second side of the flexible circuit 420, the ground layer 427 surrounding the first ground via 423 and the second ground via 424. In the present embodiment, the ground layer 427 at the flex circuit 420 for electrical connection to the header 410 may be exposed by opening a window, i.e., where the surface of the ground layer 427 is not covered with insulation. In some embodiments of the present application, no insulating material is disposed on the surface of formation layer 427 between insulating medium 421 and the bottom surface of header 410, and no insulating material is disposed on the surface of formation layer 427 between insulating medium 421 and the bottom surface of header 410; in the orientation shown in FIG. 9, an upper window of formation 427 is exposed and an insulating material is disposed on a lower surface of formation 427.

Fig. 10 is a cross-sectional view of a flexible circuit board according to an embodiment of the present invention, and fig. 10 shows a partial cross-sectional view of the first ground via 423 in fig. 8, and the first ground via 423 is filled with a metal material. As shown in fig. 10, in the embodiment of the present invention, a metal layer is disposed on the hole wall of the first ground via 423, the metal layer on the hole wall of the first ground via 423 is electrically connected to the ground layer 427, and the first ground via 423 is filled with a metal material, which is electrically connected to the metal layer on the hole wall of the first ground via 423 and the bottom surface of the socket 410. In some embodiments of the present application, the metal layer on the walls of the first ground vias 423 may be an integral metal layer with the ground layer.

Fig. 11 is a partial structural schematic diagram of another high-speed laser module provided in the present application, and fig. 9 shows a partial structure of another flexible wiring board 420. As shown in fig. 9, the high-speed laser module 400 includes a first high-frequency signal pin 411 and a second high-frequency signal pin 412 on a stem, the flexible wiring board 420 includes an insulating medium 421, a first high-frequency signal line 422 and a second high-frequency signal line 425 are provided on a first surface of the insulating medium 421, an end of the first high-frequency signal line 422 is electrically connected to the first high-frequency signal pin 411, and an end of the second high-frequency signal line 425 is electrically connected to the second high-frequency signal pin 412.

The second high-frequency signal line 425 is provided on one side of the first high-frequency signal line 422 in the direction shown in fig. 11, and the second high-frequency signal line 425 is provided on the right side of the first high-frequency signal line 422. A first ground via 423 and a second ground via 424 are provided on the flexible wiring board 420 near the connection of the first high-frequency signal line 422 and the first high-frequency signal pin 411, the second ground via 424 is located between the first high-frequency signal line 422 and the second high-frequency signal line 425 and the second ground via 424 is near the connection of the second high-frequency signal line 425 and the second high-frequency signal pin 412; a third ground via 426 is also provided on the side of the second high-frequency signal line 425 remote from the first high-frequency signal line 422, the third ground via 426 being close to the junction of the second high-frequency signal line 425 and the second high-frequency signal pin 412.

In some embodiments of the present application, the first ground via 423 and the second ground via 424 are symmetrically disposed on both sides of the first high-frequency signal line 422 along the length direction of the flexible wiring board 420 and near the connection of the first high-frequency signal line 422 and the first high-frequency signal pin 411, and the second ground via 424 and the third ground via 426 are symmetrically disposed on both sides of the second high-frequency signal line 425 along the length direction of the flexible wiring board 420 and near the connection of the second high-frequency signal line 425 and the second high-frequency signal pin 412.

In some embodiments of the present application, the first ground via 423, the second ground via 424, and the third ground via 426 are filled with solder, and the solder that passes through the first ground via 423, the second ground via 424, and the third ground via 426 electrically connects the bottom surface of the socket to ground layers on the flexible circuit board 420. As shown in fig. 9, the ground layer on the flexible circuit board 420 is disposed on the second surface of the insulating medium 421 and is shielded, in the embodiment of the present invention, the ground layer structure on the flexible circuit board 420 is not particularly limited, and may be selected according to the shape of the flexible circuit board 420 and the requirement of the ground layer. Of course, if the size of the flexible circuit board 420 is sufficient, the ground layer of the embodiment of the present invention may also be disposed on the first side of the insulating medium 421, and the first high-frequency signal line 422 and the second high-frequency signal line 425 are located on the same side of the insulating medium 421.

In some embodiments of the present application, as shown in fig. 11, the first ground through hole 423, the second ground through hole 424, and the third ground through hole 426 are elliptical ground through holes, and the minor axis dimension of the first ground through hole 423, the second ground through hole 424, and the third ground through hole 426 is greater than 0.5mm and less than 1.5mm. Of course, in the embodiment of the present application, the shapes of the first ground through hole 423, the second ground through hole 424, and the third ground through hole 426 are not limited to the oval shape, and may be circular, and the like. Of course, the first ground through hole 423, the second ground through hole 424 and the third ground through hole 426 may have different shapes.

In some embodiments of the present application, as shown in fig. 9, a first high-frequency signal line hole 422-1 is provided at an end of the first high-frequency signal line 422, a second high-frequency signal line hole 425-1 is provided at an end of the second high-frequency signal line 425, the first high-frequency signal line 422 is electrically connected to the first high-frequency signal pin 411 through the first high-speed signal line hole 422-1, and the second high-frequency signal line 425 is electrically connected to the second high-frequency signal pin 412 through the second high-speed signal line hole 425-1. The distance between the circle center of the first high-speed signal line hole 422-1 and the center axis of the first ground through hole 423 is more than 1mm and less than 3mm, the distance between the circle center of the first high-speed signal line hole 422-1 and the center axis of the second ground through hole 424 is more than 1mm and less than 3mm, the distance between the circle center of the second high-speed signal line hole 425-1 and the center axis of the second ground through hole 424 is more than 1mm and less than 3mm, and the distance between the circle center of the second high-speed signal line hole 425-1 and the center axis of the third ground through hole 426 is more than 1mm and less than 3mm.

In some embodiments of the present application, the ground pins on the header are electrically connected to the ground layer through the second ground vias 424; of course, in the embodiment of the present application, the ground pin on the socket may be electrically connected to the ground layer through the first ground via 423 or the third ground via 426; alternatively, the flexible circuit board 420 may further be provided with a via hole for connecting the ground pin on the socket to the ground layer, and the ground pin is electrically connected to the ground layer through the via hole.

Fig. 12 is a schematic structural diagram of a second side of a flexible circuit board according to an embodiment of the present application, and fig. 12 shows a schematic structural diagram of fig. 11 in which a via hole is filled with a metal material. As shown in fig. 12, a ground layer 427 is provided on the second face of the flexible circuit 420, the ground layer 427 surrounding the first ground via 423, the second ground via 424, and the third ground via 426. In the present embodiment, the ground layer 427 at the flexible circuit 420 for electrical connection to the header 410 may be exposed through a window, i.e., where the surface of the ground layer 427 is not covered with insulation. In some embodiments of the present application, no insulating material is disposed on the surface of formation layer 427 between insulating medium 421 and the bottom surface of header 410, and no insulating material is disposed on the surface of formation layer 427 between insulating medium 421 and the bottom surface of header 410; in the orientation shown in FIG. 9, the upper window of formation 427 is exposed and the lower surface of formation 427 is provided with insulation.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims

1. A high speed laser assembly for an optical module, comprising:

a tube base provided with a ground pin and a high-frequency signal pin;

a flexible circuit board disposed at the other side of the socket;

wherein the flexible circuit board includes:

the second surface of the insulating medium is closer to the bottom surface of the tube seat than the first surface;

the high-frequency signal wire is arranged on the first surface of the insulating medium and is electrically connected with the high-frequency signal pin;

at least two ground through holes are arranged on the insulating medium, penetrate through the insulating medium and the ground layer and are positioned on two sides of the high-frequency signal pin connected with the high-frequency signal line; filling a metal material in the through hole, and electrically connecting the bottom surface of the tube seat and the stratum through the metal material; the ground via is not present for passing the ground pin.

2. A high speed laser assembly according to claim 1, wherein the high frequency signal line comprises a first high frequency signal line, the ground via comprises a first ground via and a second ground via, and the high frequency signal pin comprises a first high frequency signal pin;

the first ground through hole and the second ground through hole are symmetrically arranged at the connection position of the first high-frequency signal wire and the first high-frequency signal pin along the length direction of the flexible circuit board.

3. A high-speed laser module according to claim 2, wherein the high-frequency signal line further comprises a second high-frequency signal line provided on one side of the first high-frequency signal line;

and a third ground through hole is formed in one side, far away from the first high-frequency signal, of the second high-frequency signal line, the second ground through hole is located between the first high-frequency signal line and the second high-frequency signal line, and the third ground through hole and the second ground through hole are symmetrically formed in the connection position of the first high-frequency signal line and the high-frequency signal pin along the length direction of the flexible circuit board.

4. A high speed laser assembly according to claim 1, wherein the second surface of the insulating medium contacts the bottom surface of the stem; and no insulating substance is arranged on the surface of the stratum between the insulating medium and the bottom surface of the pipe seat, and no insulating substance is arranged on the surface of the stratum between the insulating medium and the bottom surface of the pipe seat.

5. A high-speed laser module according to claim 1, wherein a high-speed signal line hole is provided in the flexible circuit board where the high-frequency signal line is connected to the high-frequency signal pin, and the high-frequency signal pin passes through the high-speed signal line hole and is electrically connected to the high-speed signal line;

the ground through holes are symmetrically arranged on two sides of the high-speed signal line hole.

6. A high speed laser assembly according to claim 1, wherein a metal layer is provided within the ground via, the metal layer electrically connecting the ground layer; the ground through hole is a circular or oval ground through hole; the size of the ground through hole is 0.5mm-1.5mm.

7. A high speed laser assembly according to claim 1, wherein the side of the metallic material remote from the base surface of the stem is higher than the first surface of the insulating medium.

8. A high speed laser assembly according to claim 5, wherein the spacing between the center of the high speed signal line hole and the center of the ground via is 1mm to 3mm.

9. An optical module comprising a high speed laser assembly, said high speed laser assembly being the high speed laser assembly of claim 1.