CN214540157U

CN214540157U - Optical module

Info

Publication number: CN214540157U
Application number: CN202121078919.4U
Authority: CN
Inventors: 王欣南; 张加傲; 慕建伟
Original assignee: Hisense Broadband Multimedia Technology Co Ltd
Current assignee: Hisense Broadband Multimedia Technology Co Ltd
Priority date: 2021-05-18
Filing date: 2021-05-18
Publication date: 2021-10-29
Anticipated expiration: 2031-05-18

Abstract

The application provides an optical module, which comprises a circuit board, a ceramic substrate and a shielding case, wherein the circuit board is provided with a first high-speed signal wire, a first grounding wire and a second grounding wire, and the first grounding wire and the second grounding wire are arranged on two sides of the circuit board; the ceramic substrate is positioned on one side of the circuit board and is provided with a second high-speed signal wire, a third grounding wire and a fourth grounding wire which are arranged on two sides of the ceramic substrate, the first high-speed signal wire and the second high-speed signal wire are connected through a first gold wire, the first grounding wire and the third grounding wire are connected through a second gold wire, and the second grounding wire and the fourth grounding wire are connected through a third gold wire; one end of the shielding cover is connected with the circuit board, the other end of the shielding cover is connected with the ceramic substrate, and the shielding cover is pressed on the second gold wire and the third gold wire; be provided with the through-hole on the shield cover, first gold thread is located the through-hole. This application shield cover's mode is connected, is shielded the unable shield cover of punching the position of ground hole on the earth connection, has not only reduced the length of the backward flow route of high-speed signal effectively, has still played the effect that the shielding prevented crosstalk to signal integrality has been promoted effectively.

Description

Optical module

Technical Field

The application relates to the technical field of optical fiber communication, in particular to 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.

Various electronic components used by the optical module can adopt a Chip On Carrier (COC) to package a Chip so as to improve the integration level of the optical module. The COC and the circuit board are mostly connected by wire bonding, because the positions GND on the circuit board and the COC, which are close to the bonding pad, are very narrow and bottom holes cannot be punched, the return path of the signal line is enlarged at the position close to the bonding pad, the mode is also changed, the floor is incomplete, and the crosstalk among channels is increased.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides an optical module, which aims to solve the problems that when the COC in the existing optical module is connected with a circuit board, the backflow path of a signal wire is large, mode conversion is caused, floor laying is incomplete, and crosstalk among channels is increased.

The application provides an optical module, includes:

the circuit board is provided with a first high-speed signal wire, a first grounding wire and a second grounding wire, wherein the first grounding wire and the second grounding wire are arranged on two sides of the first high-speed signal wire;

the ceramic substrate is positioned on one side of the circuit board, and is provided with a second high-speed signal wire, a third grounding wire and a fourth grounding wire which are arranged on two sides of the second high-speed signal wire, wherein the first high-speed signal wire is connected with the second high-speed signal wire through a first gold wire, the first grounding wire is connected with the third grounding wire through a second gold wire, and the second grounding wire is connected with the fourth grounding wire through a third gold wire;

one end of the shielding cover is connected with the circuit board, the other end of the shielding cover is connected with the ceramic substrate, and the shielding cover is pressed on the second gold wire and the third gold wire; a through hole is formed in the first gold thread, and the first gold thread is located in the through hole.

The optical module comprises a circuit board, a ceramic substrate and a shielding case, wherein a first high-speed signal wire, a first grounding wire and a second grounding wire are arranged on the circuit board; the ceramic substrate is positioned on one side of the circuit board, and is provided with a second high-speed signal wire, a third grounding wire and a fourth grounding wire which are arranged on two sides of the second high-speed signal wire; one end of the shielding cover is connected with the circuit board, the other end of the shielding cover is connected with the ceramic substrate, and the shielding cover is pressed on the second gold wire and the third gold wire to communicate the second gold wire and the third gold wire, so that the ceramic substrate and a grounding wire on the circuit board are communicated, and the length of a backflow path of a high-speed signal can be effectively reduced; the shielding cover is provided with a through hole, and the first gold wire is positioned in the through hole and is not contacted with the shielding cover, so that the influence on the signal transmission of the high-speed signal wire can be avoided. This application shield cover's form is done positive GND, the mode of shield cover is used to the position that can't beat the ground hole on the earth connection to circuit board and ceramic substrate is connected, is shielded, so both can effectually reduce the ground backward flow route of signal, can keep apart crosstalking between passageway and passageway again, can also get up the effectual shielding of signal line on the ceramic substrate connecting circuit board in the space, play the effect that the shielding prevented crosstalk, thereby can effectual promotion signal integrality.

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 a 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 an exploded structural diagram of an optical module according to an embodiment of the present disclosure;

fig. 5 is a schematic view illustrating an assembly of an optical sub-assembly and a circuit board in an optical module according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of signal connections of an exemplary circuit board to a ceramic substrate;

FIG. 7 is a partial schematic view of an exemplary circuit board with partial signal connections to a ceramic substrate;

fig. 8 is an assembly diagram of a circuit board, a ceramic substrate, and a shielding case in an optical module according to an embodiment of the present disclosure;

fig. 9 is a partial schematic view illustrating an assembly of a circuit board, a ceramic substrate, and a shielding can in an optical module according to an embodiment of the present disclosure;

fig. 10 is an exploded view illustrating an assembly of a circuit board, a ceramic substrate and a shielding case in an optical module according to an embodiment of the present disclosure;

fig. 11 is a schematic structural diagram of a shield case in an optical module according to an embodiment of the present disclosure;

fig. 12 is a schematic view of another angular structure of a shielding can in an optical module according to an embodiment of the present disclosure;

fig. 13 is an assembly cross-sectional view of a circuit board, a ceramic substrate, and a shield case in an optical module according to an embodiment of the present application.

Detailed Description

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, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within 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 information transmission with low cost and low loss can be realized by using the passive transmission characteristic of 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 of the optical module industry, and on the basis of the mainstream connection mode, the definition of the pin 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 accessed 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 an 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 that increases 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.

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, an unlocking component 203, a circuit board 300, a tosa 400, a tosa 500, a first fiber adapter 600, and a second fiber adapter 700.

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 third shell, and the third shell covers the two side plates of the upper shell to form a wrapping cavity; the upper shell can also comprise two side walls which are positioned on two sides of the third shell and are perpendicular to the third shell, and the two side walls are combined with the two side plates to cover the upper shell on the lower shell.

The two openings may 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 to connect the optical transmitter sub-module 400 and the optical receiver sub-module 500 inside the optical module; the optoelectronic devices such as the circuit board 300, the tosa 400, the rosa 500, the first fiber adapter 600, and the second fiber adapter 700 are located in the package cavity.

The assembly mode of combining the upper shell and the lower shell is adopted, so that the circuit board 300, the transmitter optical subassembly 400, the receiver optical subassembly 500, the first optical fiber adapter 600, the second optical fiber adapter 700 and other devices can be conveniently installed in the shells, and the outermost packaging protection shell of the optical module is formed by the upper shell and the lower shell; the upper shell and the lower shell are made of metal materials generally, so that electromagnetic shielding and heat dissipation are facilitated; 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.

The unlocking component 203 is located on the outer wall of the wrapping cavity/lower shell 202, and is used for realizing the 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 203 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 300 is provided with circuit traces, electronic components (such as capacitors, resistors, triodes, and MOS transistors), and chips (such as an MCU, a laser driver chip, a limiting amplifier chip, a clock data recovery CDR, a power management chip, and a data processing chip DSP).

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

The chip on the circuit board 300 may be a multifunctional integrated chip, for example, a laser driver chip and an MCU chip are integrated into one chip, or a laser driver chip, a limiting amplifier chip and an MCU chip are integrated into one chip, and the chip is an integrated circuit, but the functions of the circuits do not disappear due to the integration, and only the circuit appears and changes, and the chip still has the circuit form. Therefore, when the circuit board is provided with three independent chips, namely, the MCU, the laser driver chip and the limiting amplifier chip, the scheme is equivalent to that when the circuit board 300 is provided with a single chip with three functions in one.

The circuit board is generally a hard circuit board, and the hard circuit board can also realize a bearing effect due to the relatively hard material of the hard circuit board, for example, the hard 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/golden 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.

Generally, the carrier of the optical module is a circuit board, all high-frequency Signal lines are laid on the circuit board, the mode of the high-speed Signal lines is a GSG mode (GND-Signal-GND), the GSG model cannot be converted, the more ground holes are required on the positions of the ground not only for covering the ground but also for covering the ground on the two sides of the Signal lines uniformly, the shorter the return path of the Signal is, the better the ground holes are required to be covered by copper sheets for shielding and isolating. Particularly, all the 100G/200G/400G/800G optical modules are in a multi-channel layout, and if the inter-channel isolation is not performed, the performance of the optical module is greatly influenced due to poor signal quality.

Fig. 5 is an assembly diagram of an optical sub-assembly and a circuit board 300 in an optical module according to an embodiment of the present disclosure. As shown in fig. 5, when the tosa 400 and the rosa 500 in the optical module are packaged, COC may be used to package the light emitting chip and the light receiving chip, that is, the light emitting chip or the light receiving chip is disposed on the ceramic substrate, so as to improve the integration level of the optical module.

The tosa 400 includes optical devices such as a light emitting chip (e.g., a laser) and a lens, where the laser is a common light emitting chip of an optical module, and the laser is used to emit laser light waves, and the laser becomes a preferred light source for the optical module and even optical fiber transmission with better single wavelength characteristics and better wavelength tuning characteristics. The laser is generally disposed on the ceramic substrate 410, and the driving chip on the circuit board 300 is electrically connected to the ceramic substrate 410 by gold wires, so as to reduce signal loss between the driving chip and the ceramic substrate 410, the distance between the ceramic substrate 410 and the driving chip on the circuit board 300 needs to be shortened as much as possible. In the present application, the upper surface of the ceramic substrate 410 is flush with the upper surface of the circuit board 300, so as to shorten the distance between the ceramic substrate 410 and the driving chip on the circuit board 300, thereby reducing the length of the gold wire connecting the ceramic substrate 410 and the driving chip.

Specifically, a circuit trace is disposed on the ceramic substrate 410, and the laser is disposed on the ceramic substrate 410 and connected to the circuit trace on the ceramic substrate 410; the circuit traces on the ceramic substrate 410 are connected to the circuit board 300 by gold wires. Thus, the circuit board 300 transmits the driving signal to the corresponding circuit trace of the ceramic substrate 410 through the gold wire, and the circuit trace of the ceramic substrate 410 transmits the driving signal to the laser to drive the laser to emit the laser beam.

Fig. 6 is a schematic diagram of signal connection between the circuit board 300 and the ceramic substrate 410 in the exemplary optical module, and fig. 7 is a partial schematic diagram of signal connection between the circuit board 300 and the ceramic substrate 410 in the exemplary optical module. As shown in fig. 6 and 7, in the conventional optical module, most of the connection methods of the ceramic substrate 410 and the circuit board 300 are that the signal lines on the ceramic substrate 410 and the circuit board 300 are connected by gold wires, and the ceramic substrate 410 and the GND on the circuit board 300 are connected by gold wires, so that the copper skin is very narrow at the position close to the pad position, and the ground hole cannot be drilled at the position and the reference surface below the ground hole cannot be connected together.

Specifically, the circuit board 300 is provided with a first high-speed signal line 310, and a first ground line 320 and a second ground line 330 disposed on two sides of the first high-speed signal line 310; the ceramic substrate 410 is disposed on one side of the circuit board 300, and is provided with a second high-speed signal line 4110, and a third ground line 4120 and a fourth ground line 4130 disposed on two sides of the second high-speed signal line 4110, wherein the first high-speed signal line 310 on the circuit board 300 is connected to the second high-speed signal line 4110 on the ceramic substrate 410 via a first gold wire 910, the first ground line 320 on the circuit board 300 is connected to the third ground line 4120 on the ceramic substrate 410 via a second gold wire 920, and the second ground line 330 on the circuit board 300 is connected to the fourth ground line 4130 on the ceramic substrate 410 via a third gold wire 930, thereby achieving signal connection between the ceramic substrate 410 and the circuit board 300.

However, since the positions GND near the pads on the circuit board 300 and the ceramic substrate 410 are extremely narrow and cannot be used for ground drilling, the return paths of the signal lines become large at the positions near the pads, and the GSG mode is also converted, so that the ground coverage is incomplete, and the crosstalk between channels increases.

In order to solve the above problems, the present application provides an optical module, in which a metal bridge shield is designed on a ceramic substrate 410 and a circuit board, and a positive GND is used to improve signal integrity as much as possible, reduce crosstalk between channels, and improve crosstalk resistance.

Fig. 8 is an assembly schematic diagram of a circuit board 300, a ceramic substrate 410, and a shield cover 800 in an optical module according to an embodiment of the present disclosure, fig. 9 is a side view of a partial assembly of the circuit board 300, the ceramic substrate 410, and the shield cover 800 in the optical module according to the embodiment of the present disclosure, and fig. 10 is an exploded schematic diagram of the circuit board 300, the ceramic substrate 410, and the shield cover 800 in the optical module according to the embodiment of the present disclosure. As shown in fig. 8, 9, and 10, the optical module according to the embodiment of the present invention further includes a shield cover 800, one end of the shield cover 800 is connected to the circuit board 300, and the other end is connected to the ceramic substrate 410, specifically, the left side of the shield cover 800 is attached to the first ground line 320 on the circuit board 300 and the third ground line 4120 on the ceramic substrate 410, and the right side of the shield cover 800 is attached to the second ground line 330 on the circuit board 300 and the fourth ground line 4130 on the ceramic substrate 410, so as to fix the shield cover 800 above the connection point between the circuit board 300 and the ceramic substrate 410.

When the shielding case 800 is covered above the connection position of the circuit board 300 and the ceramic substrate 410, the second gold wire 920 connecting the first ground line 320 and the third ground line 4120 is connected to the left side of the shielding case 800, and the third gold wire 930 connecting the second ground line 330 and the fourth ground line 4130 is connected to the right side of the shielding case 800, so that the second gold wire 920 is connected to the third gold wire 930 through the shielding case 800, and the high-speed signal has a return path of the second gold wire 920-the shielding case 800-the third gold wire 930, which can reduce the length of the return path of the high-speed signal without punching a ground hole.

When the shielding case 800 is used to connect the second gold wire 920 and the third gold wire 930 to reduce the length of the reflow path of the high-speed signal, the shielding case 800 should be made of metal, so that the second gold wire 920 and the third gold wire 930 can be connected to realize signal reflow.

Fig. 11 is a schematic structural diagram of a shield can 800 in an optical module according to an embodiment of the present disclosure, and fig. 12 is a schematic structural diagram of the shield can 800 in an optical module according to another angle according to the embodiment of the present disclosure. As shown in fig. 11 and 12, in order to cover the shielding cover 800 above the connection position between the circuit board 300 and the ceramic substrate 410, the shielding cover 800 includes a first supporting plate 830, a second supporting plate 840, and a connecting plate 820 connecting the first supporting plate 830 and the second supporting plate 840, the first supporting plate 830 is fixedly connected to the left side of the connecting plate 820, and the second supporting plate 840 is fixedly connected to the right side of the connecting plate 820. The connecting plate 820, the first supporting plate 830 and the second supporting plate 840 may be an integral structure or a separate structure, that is, the first supporting plate 830 and the second supporting plate 840 are respectively connected to the connecting plate 820.

The first support plate 830 is disposed on the first ground line 320 on the circuit board 300 and the third ground line 4120 on the ceramic substrate 410 in the front-rear direction, and the front side portion of the first support plate 830 is in contact with the third ground line 4120 on the ceramic substrate 410 and the rear side portion is in contact with the first ground line 320 on the circuit board 300. Similarly, the second support plate 840 is disposed on the second ground line 330 on the circuit board 300 and the fourth ground line 4130 on the ceramic substrate 410 in the front-rear direction, and the front side portion of the second support plate 840 is in contact with the fourth ground line 4130 on the ceramic substrate and the rear side portion is in contact with the second ground line 330 on the circuit board 300.

In the embodiment of the present application, the first support plate 830 of the shielding cover 800 is pressed on the first ground line 320 on the circuit board 300 and the third ground line 4120 on the ceramic substrate 410, and the second support plate 840 of the shielding cover 800 is pressed on the second ground line 330 on the circuit board 300 and the fourth ground line 4130 on the ceramic substrate 410, so as to fix the shielding cover 800 above the connection between the circuit board 300 and the ceramic substrate 410.

The shielding case 800 is provided with a through hole 810, the through hole 810 extends from the front side to the rear side of the connecting plate 820, the central axis of the through hole 810 is parallel to the first supporting plate 830 and the second supporting plate 840, that is, the size of the through hole 810 in the front-rear direction is consistent with the size of the connecting plate 820 in the front-rear direction, the upper side of the through hole 810 can be the lower side of the connecting plate 820, the lower side of the through hole 810 is open, the left side of the through hole 810 can be the right side of the first supporting plate 830, the right side of the through hole 810 can be the left side of the second supporting plate 840, so that the through hole opened towards the circuit board 300 is formed on the shielding case 800, and the structure of the shielding case 800 is a bridge type shielding case. In the embodiment of the present application, the through hole 810 of the shield can 800 is a square through hole.

In the embodiment of the present application, in order to prevent the first high speed signal line 310 on the circuit board 300, the second high speed signal line 4110 on the ceramic substrate 410, and the first gold wire 910 connecting the first high speed signal line 310 and the second high speed signal line 4110 from contacting the shielding case 800, the dimension of the through hole 810 in the left-right direction on the shielding case 800 is larger than the dimension of the first high speed signal line 310 on the circuit board 300 and the second high speed signal line 4110 on the ceramic substrate 410 in the left-right direction, and the dimension of the through hole 810 in the up-down direction is larger than the dimension of the first gold wire 910 connecting the first high speed signal line 310 and the second high speed signal line 4110 in the up-down direction.

After the through hole 810 is formed in the shielding cover 800, when the first support plate 830 of the shielding cover 800 is attached to the first ground line 320 on the circuit board 300 and the third ground line 4120 on the ceramic substrate 410, and the second support plate 840 of the shielding cover 800 is attached to the second ground line 330 on the circuit board 300 and the fourth ground line 4130 on the ceramic substrate 410, the first high-speed signal line 310 on the circuit board 300, the second high-speed signal line 4110 on the ceramic substrate 410, and the first gold wire 910 connecting the first high-speed signal line 310 and the second high-speed signal line 4110 are all located in the through hole 810, and the first high-speed signal line 310, the second high-speed signal line 4110, and the first gold wire 910 are not in contact with the shielding cover 800, so as to prevent the high-speed signal line from being connected to the ground line.

When the first support plate 830 of the shield cover 800 is adhered to the first ground wire 320 on the circuit board 300 and the third ground wire 4120 on the ceramic substrate 410, and the second support plate 840 of the shield cover 800 is adhered to the second ground wire 330 on the circuit board 300 and the fourth ground wire 4130 on the ceramic substrate 410, in order to facilitate the contact of the second gold wire 920 for connecting the first ground wire 320 and the third ground wire 4120 with the first support plate 830, the lower side (the side facing the surface of the circuit board 300) of the first support plate 830 is provided with a first contact groove 8310, the first contact groove 8310 corresponds to the second gold wire 920, after the first ground wire 320 and the third ground wire 4120 are connected through the second support plate 920, when the first support plate 830 of the shield cover 800 is adhered to the first ground wire 320 on the circuit board 300 and the third ground wire 4120 on the ceramic substrate 410, the second contact groove 920 is embedded in the first contact groove 8310 on the first support plate 830, so as to connect the second gold wire 920 with the shield can 800.

Similarly, in order to facilitate the contact between the third gold wire 930 connected to the second ground line 330 and the fourth ground line 4130 and the second support plate 840, a second contact groove 8410 is formed on the lower side (the side facing the surface of the circuit board 300) of the second support plate 840, the second contact groove 8410 corresponds to the third gold wire 930, and after the third gold wire 930 is connected to the second ground line 330 and the fourth ground line 4130, when the second support plate 840 of the shielding case 800 is adhered to the second ground line 330 on the circuit board 300 and the fourth ground line 4130 on the ceramic substrate 410, the third gold wire 930 is embedded in the second contact groove 8410 of the second support plate 840 to connect the third gold wire 930 and the shielding case 800. In the present embodiment, the through hole 810 is recessed in the first contact groove 8310 and the second contact groove 8410.

Fig. 13 is an assembly cross-sectional view of a circuit board 300, a ceramic substrate 410, and a shield can 800 in an optical module according to an embodiment of the present disclosure. As shown in fig. 13, all of the 100G/200G/400G/800G optical modules are multi-channel layouts, and need to be isolated among channels to avoid the performance of the optical modules from being affected by poor signal quality, and in order to increase isolation and shielding effects among the channels, it is necessary to place the first gold wire 910 connecting the first high-speed signal line 310 and the second high-speed signal line 4110, the second gold wire 920 connecting the first ground line 320 and the third ground line 4120, and the third gold wire 930 connecting the second ground line 330 and the fourth ground line 4130 inside the shielding can 800, so as to place the signal pad of the first high-speed signal line 310 on the circuit board 300, the signal pad of the first ground line 320, the signal pad of the second ground line 330, and the signal pad of the second high-speed signal line 4110 on the ceramic substrate 410, the signal pad of the third ground line 4120, and the signal pad of the fourth ground line 4130 inside the shielding can 800, thereby effectively shielding the signal lines on the ceramic substrate 410 connected to the circuit board 300 to prevent external signals from interfering with signal transmission between the circuit board 300 and the ceramic substrate 410.

The optical module provided by the embodiment of the application comprises a circuit board, a ceramic substrate and a shielding case, wherein the circuit board is provided with a first high-speed signal wire, a first grounding wire and a second grounding wire, and the first grounding wire and the second grounding wire are arranged on two sides of the first high-speed signal wire; the ceramic substrate 410 is located on one side of the circuit board 300, and is provided with a second high-speed signal line, a third ground line and a fourth ground line which are arranged on two sides of the second high-speed signal line, wherein the first high-speed signal line is connected with the second high-speed signal line through a first gold wire, the first ground line is connected with the third ground line through a second gold wire, and the second ground line is connected with the fourth ground line through a third gold wire; one end of the shielding cover is connected with the circuit board, the other end of the shielding cover is connected with the ceramic substrate, and the shielding cover is pressed on the second gold wire and the third gold wire; a first contact groove is formed in a first supporting plate of the shielding cover and corresponds to a second gold wire for connecting a first grounding wire and a third grounding wire; a second contact groove is formed in a second supporting plate of the shielding cover, and corresponds to a third gold wire for connecting a second grounding wire and a fourth grounding wire; thus, when the first support plate of the shielding cover is pasted on the first grounding wire on the circuit board and the third grounding wire on the ceramic substrate, and the second support plate is pasted on the second grounding wire on the circuit board and the fourth grounding wire on the ceramic substrate, the second gold wire for connecting the first grounding wire and the third grounding wire is embedded in the first contact groove, and the third gold wire for connecting the second grounding wire and the fourth grounding wire is embedded in the second contact groove, so that the connection of the second gold wire and the third gold wire with the shielding cover is realized, the ceramic substrate is communicated with the grounding wire on the circuit board, and the length of a backflow path of a high-speed signal is effectively reduced; be equipped with the through-hole on the shield cover, this through-hole extends to the trailing flank by the leading flank of shield cover, and first high-speed signal line on the circuit board, the second high-speed signal line on the ceramic substrate, the first gold thread of connecting first high-speed signal line and second high-speed signal line all are located this through-hole, and just first high-speed signal line, second high-speed signal line, first gold thread all are not connected with the shield cover, have avoided influencing the signal transmission of high-speed signal line. This application shield cover's form is done positive GND, the mode of shield cover is used to the position that can't beat the ground hole on the earth connection to circuit board and ceramic substrate shield, so both can effectually reduce the backward flow route of signal, can keep apart the crosstalking between passageway and passageway again, can also get up the effectual shielding of signal line on the ceramic substrate connecting circuit board in the space, play the effect that the shielding prevented crosstalking to promote signal integrality effectively.

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 light module, comprising:

2. The optical module of claim 1, wherein the shield cover comprises a first support plate, a second support plate, and a connection plate connecting the first support plate and the second support plate, the first support plate is press-fit on the first ground wire, the third ground wire, and the second gold wire, and the second support plate is press-fit on the second ground wire, the fourth ground wire, and the third gold wire.

3. The optical module according to claim 2, wherein the first support plate has a first contact groove, the second support plate has a second contact groove, the second gold wire is embedded in the first contact groove, and the third gold wire is embedded in the second contact groove.

4. The optical module of claim 3, wherein the through hole penetrates through the connecting plate, and the through hole is recessed in the first contact groove and the second contact groove.

5. The optical module according to claim 4, wherein the through hole is a through hole opened toward the circuit board, and the first gold wire is not in contact with the shield case.

6. The optical module according to claim 5, wherein neither the first high-speed signal line nor the second high-speed signal line is in contact with the shield case.

7. The optical module of claim 1, wherein the first gold wire, the second gold wire and the third gold wire are all located in the shielding case.

8. The optical module of claim 1, wherein the shield is a metal bridge shield.

9. The optical module of claim 1, wherein the through-hole is a square through-hole.