CN218037453U - Optical module - Google Patents

Abstract

The application discloses optical module includes: the lower shell and the upper shell cover a wrapping cavity formed by covering, and the circuit board is arranged in the wrapping cavity. The circuit board includes: a data processing chip and a light emitting device; the first signal wire is positioned on the upper surface of the circuit board, one end of the first signal wire is connected with the data processing chip, and the other end of the first signal wire is connected with the light emitting device; a first grounding wire and a second grounding wire are respectively arranged on two sides of the first signal wire. The circuit board top is provided with the shield cover, includes: the first support arm is arranged above the first grounding wire; the second support arm is arranged above the second grounding wire; the top plate is positioned above the first support arm and the second support arm; the projection of the shield case on the circuit board covers the first signal line. The shielding cover is arranged above the circuit board, encloses and is grounded to the first signal line, provides a backflow path for electromagnetic radiation generated by the first signal line, reduces dissipation of the electromagnetic radiation, and improves the electromagnetic shielding effect of the optical module.

Description

Optical module

Technical Field

The application relates to the technical field of 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 becomes more and more 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.

With the gradual increase of the speed, the frequency of the signal inside the optical module is gradually increased, the generated electromagnetic radiation is more and more, and the interference to the surrounding circuit is stronger.

SUMMERY OF THE UTILITY MODEL

The application provides an optical module to improve the electromagnetic shielding effect of the optical module.

In order to solve the technical problem, the embodiment of the application discloses the following technical scheme:

the embodiment of the application discloses an optical module, includes: an upper housing;

the lower shell is covered with the upper shell to form a wrapping cavity;

the circuit board set up in the parcel cavity, include:

the data processing chip is positioned on the surface of the circuit board;

a light emitting device;

the first signal wire is positioned on the upper surface of the circuit board, one end of the first signal wire is connected with the data processing chip, and the other end of the first signal wire is connected with the light emitting device;

the first grounding wire is positioned on the upper surface of the circuit board and positioned on one side of the first signal wire;

the second grounding wire is positioned on the upper surface of the circuit board and positioned on the other side of the first signal wire;

the shield cover, set up in the circuit board top for electromagnetic shield component, includes:

the first support arm is arranged above the first grounding wire;

the second support arm is arranged above the second grounding wire;

the top plate is positioned above the first support arm and the second support arm;

the projection of the shielding case on the circuit board covers the first signal line.

The beneficial effect of this application:

the application discloses optical module includes: the lower shell and the upper shell cover a package cavity formed, and a circuit board arranged in the package cavity. The circuit board includes: a data processing chip and a light emitting device; the first signal wire is positioned on the upper surface of the circuit board, one end of the first signal wire is connected with the data processing chip, and the other end of the first signal wire is connected with the light emitting device; a first grounding wire and a second grounding wire are respectively arranged on two sides of the first signal wire. The circuit board top is provided with the shield cover, includes: the first support arm is arranged above the first grounding wire; the second support arm is arranged above the second grounding wire; the top plate is positioned above the first support arm and the second support arm; the projection of the shielding case on the circuit board covers the first signal line. The shielding case is arranged above the circuit board, encloses and is grounded to the first signal wire, provides a backflow path for electromagnetic radiation generated by the first signal wire, reduces dissipation of the electromagnetic radiation, and improves the electromagnetic shielding effect of the optical module.

Drawings

In order to more clearly illustrate the technical solutions of the present disclosure, the drawings required to be used in some embodiments of the present disclosure will be briefly described below, and it is apparent that the drawings in the following description are only drawings of some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art according to these drawings. Furthermore, the drawings in the following description may be regarded as schematic diagrams, and do not limit the actual size of products, the actual flow of methods, the actual timing of signals, and the like, involved in the embodiments of the present disclosure.

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

FIG. 2 is a block diagram of an optical network terminal according to some embodiments;

FIG. 3 is a block diagram of a light module according to some embodiments;

FIG. 4 is an exploded view of a light module according to some embodiments;

fig. 5 is an exploded schematic view of a light emitting device according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of a circuit board structure according to an example;

FIG. 7 is a schematic partial cross-sectional view of a signal line according to an example of the present application;

FIG. 8 is a schematic diagram of electromagnetic radiation from a first signal line of a circuit board according to an example of the present application;

fig. 9 is a schematic circuit structure diagram of a circuit board according to an example of the present application;

fig. 10 is a schematic circuit cross-sectional view of a portion of an optical module according to an example of the present application;

fig. 11 is a second schematic circuit cross-sectional view of a part of an optical module according to an example of the present application;

fig. 12 is a schematic diagram of a second upper surface structure of a circuit board according to an example of the present application;

fig. 13 is a schematic diagram of near-end signal crosstalk of a signal line under different conditions of an example of the present application;

fig. 14 is a near-end signal crosstalk diagram of a signal line under different conditions of an example of the present application.

Detailed Description

Technical solutions in some embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present disclosure, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments provided in the present disclosure are within the scope of protection of the present disclosure.

In an optical communication system, an optical signal is used to carry information to be transmitted, and the optical signal carrying the information is transmitted to information processing equipment such as a computer through information transmission equipment such as an optical fiber or an optical waveguide, so as to complete information transmission. Since light has a passive transmission characteristic when transmitted through an optical fiber or an optical waveguide, low-cost and low-loss information transmission can be realized. Further, since a signal transmitted by an information transmission device such as an optical fiber or an optical waveguide is an optical signal and a signal that can be recognized and processed by an information processing device such as a computer is an electrical signal, it is necessary to perform interconversion between the electrical signal and the optical signal in order to establish an 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.

The optical module realizes the function of interconversion between the optical signal and the electrical signal in the technical field of optical communication. The optical module comprises an optical port and an electric port, the optical module realizes optical communication with information transmission equipment such as optical fibers or optical waveguides and the like through the optical port, realizes electric connection with an optical network terminal (such as an optical modem) through the electric port, and the electric connection is mainly used for power supply, I2C signal transmission, data information transmission, grounding and the like; the optical network terminal transmits the electric signal to the computer and other information processing equipment through a network cable or a wireless fidelity (Wi-Fi).

Fig. 1 is a connection diagram of an optical communication system. As shown in fig. 1, the optical communication system includes a remote server 1000, a local information processing device 2000, an optical network terminal 100, an optical module 200, an optical fiber 101, and a network cable 103.

One end of the optical fiber 101 is connected to the remote server 1000, and the other end is connected to the optical network terminal 100 through the optical module 200. The optical fiber itself can support long-distance signal transmission, for example, signal transmission of several kilometers (6 kilometers to 8 kilometers), on the basis of which if a repeater is used, theoretically, infinite distance transmission can be realized. Therefore, in a typical optical communication system, the distance between the remote server 1000 and the optical network terminal 100 may be several kilometers, tens of kilometers, or hundreds of kilometers.

One end of the network cable 103 is connected to the local information processing device 2000, and the other end is connected to the optical network terminal 100. The local information processing apparatus 2000 may be any one or several of the following apparatuses: router, switch, computer, cell-phone, panel computer, TV set etc..

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

The optical module 200 includes an optical port configured to access the optical fiber 101 and an electrical port, so that the optical module 200 establishes a bidirectional optical signal connection with the optical fiber 101; the electrical port is configured to be accessed into the optical network terminal 100, so that the optical module 200 establishes a bidirectional electrical signal connection with the optical network terminal 100. The optical module 200 converts an optical signal and an electrical signal to each other, so that an information connection is established between the optical fiber 101 and the optical network terminal 100. For example, an optical signal from the optical fiber 101 is converted into an electrical signal by the optical module 200 and then input to the optical network terminal 100, and an electrical signal from the optical network terminal 100 is converted into an optical signal by the optical module 200 and input to the optical fiber 101. Since the optical module 200 is a tool for implementing the interconversion between the optical signal and the electrical signal, and has no function of processing data, information is not changed in the above-mentioned photoelectric conversion process.

The optical network terminal 100 includes a housing (housing) having a substantially rectangular parallelepiped shape, and an optical module interface 102 and a network cable interface 104 provided on the housing. The optical module interface 102 is configured to access the optical module 200, so that the optical network terminal 100 establishes a bidirectional electrical signal connection with the optical module 200; the network cable interface 104 is configured to access the network cable 103 such that the optical network terminal 100 establishes a bi-directional electrical signal connection with the network cable 103. The optical module 200 is connected to the network cable 103 via the optical network terminal 100. For example, the onu 100 transmits the electrical signal from the optical module 200 to the network cable 103, and transmits the electrical signal from the network cable 103 to the optical module 200, so that the onu 100 can monitor the operation of the optical module 200 as an upper computer of the optical module 200. The upper computer of the Optical module 200 may include an Optical Line Terminal (OLT) in addition to the Optical network Terminal 100.

The remote server 1000 establishes a bidirectional signal transmission channel with the local information processing device 2000 through the optical fiber 101, the optical module 200, the optical network terminal 100, and the network cable 103.

Fig. 2 is a configuration diagram of the optical network terminal, and fig. 2 only shows a configuration of the optical module 200 of the optical network terminal 100 in order to clearly show a connection relationship between the optical module 200 and the optical network terminal 100. As shown in fig. 2, the optical network terminal 100 further includes a circuit board 105 disposed within the housing, a cage 106 disposed on a surface of the circuit board 105, a heat sink 107 disposed on the cage 106, and an electrical connector disposed inside the cage 106. The electrical connector is configured to access an electrical port of the optical module 200; the heat sink 107 has a projection such as a fin that increases a heat radiation area.

The optical module 200 is inserted into a cage 106 of the onu 100, the cage 106 holds the optical module 200, and heat generated by the optical module 200 is conducted to the cage 106 and then diffused by a heat sink 107. After the optical module 200 is inserted into the cage 106, the electrical port of the optical module 200 is connected to the electrical connector inside the cage 106, so that the optical module 200 is connected to the optical network terminal 100 by a bidirectional electrical signal. Further, an optical port of the optical module 200 is connected to the optical fiber 101, and the optical module 200 establishes bidirectional optical signal connection with the optical fiber 101.

FIG. 3 is a block diagram of a light module according to some embodiments. As shown in fig. 3, the optical module 200 includes a housing (shell), a circuit board 300 disposed in the housing, and an optical transceiver module 400.

The shell comprises an upper shell 201 and a lower shell 202, wherein the upper shell 201 is covered on the lower shell 202 to form the shell with two openings; the outer contour of the housing generally appears square.

In some embodiments of the present disclosure, the lower housing 202 includes a bottom plate 2021 and two lower side plates 2022 located at both sides of the bottom plate 2021 and disposed perpendicular to the bottom plate 2021; the upper case 201 includes a cover 2011, and the cover 2011 covers the two lower side plates 2022 of the lower case 202 to form the above case.

In some embodiments, the lower housing 202 includes a bottom plate 2021 and two lower side plates 2022 located at two sides of the bottom plate 2021 and disposed perpendicular to the bottom plate 2021; the upper case 201 includes a cover plate 2011 and two upper side plates which are located on two sides of the cover plate 2011 and are perpendicular to the cover plate 2011, and the two upper side plates and the two lower side plates 2022 are combined to cover the upper case 201 on the lower case 202.

The direction of the connecting line of the two openings 204 and 205 may be the same as the length direction of the optical module 200, or may not be the same as the length direction of the optical module 200. For example, the opening 204 is located at an end portion (right end in fig. 3) of the optical module 200, and the opening 205 is also located at an end portion (left end in fig. 3) of the optical module 200. Alternatively, the opening 204 is located at an end of the optical module 200, and the opening 205 is located at a side of the optical module 200. The opening 204 is an electrical port, and a gold finger of the circuit board 300 extends out of the electrical port 204 and is inserted into an upper computer (for example, the optical network terminal 100); the opening 205 is an optical port configured to access the external optical fiber 101, so that the external optical fiber 101 is connected to the optical transceiver module 400 inside the optical module 200.

The upper shell 201 and the lower shell 202 are combined in an assembly mode, so that the circuit board 300, the optical transceiver module 400 and other devices can be conveniently installed in the shells, and the upper shell 201 and the lower shell 202 form encapsulation protection for the devices. In addition, when the devices such as the circuit board 300 and the optical transceiver module 400 are assembled, the positioning components, the heat dissipation components and the electromagnetic shielding components of the devices are convenient to arrange, and the automatic production is facilitated.

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

In some embodiments, the optical module 200 further includes an unlocking component located outside its housing, and the unlocking component is configured to realize a fixed connection between the optical module 200 and the upper computer or release the fixed connection between the optical module 200 and the upper computer.

Illustratively, the unlocking member is located on the outer walls of the two lower side plates of the lower housing 202, and has a snap-fit member that mates with a host cage (e.g., the cage 106 of the optical network terminal 100). When the optical module 200 is inserted into the cage of the upper computer, the optical module 200 is fixed in the cage of the upper computer by the engaging member of the unlocking member; when the unlocking member is pulled, the engaging member of the unlocking member moves along with the unlocking member, and further the connection relationship between the engaging member and the upper computer is changed, so that the engagement relationship between the optical module 200 and the upper computer is released, and the optical module 200 can be drawn out from the cage of the upper computer.

The circuit board 300 includes circuit traces, electronic components, and chips, and the electronic components and the chips are connected together by the circuit traces according to a circuit design to implement functions of power supply, electrical signal transmission, grounding, and the like. Examples of the electronic components include capacitors, resistors, transistors, and Metal-Oxide-Semiconductor Field-Effect transistors (MOSFETs). The chip includes, for example, a Micro Controller Unit (MCU), a laser driver chip, a limiting amplifier (limiting amplifier), a Clock and Data Recovery (CDR) chip, a power management chip, and a Digital Signal Processing (DSP) chip.

The circuit board 300 is generally a rigid circuit board, which can also perform a bearing function due to its relatively rigid material, for example, the rigid circuit board can stably bear the electronic components and chips; when the optical transceiver component is positioned on the circuit board, the rigid circuit board can also provide smooth bearing; the rigid circuit board can also be inserted into an electric connector in the cage of the upper computer.

The circuit board 300 further includes a gold finger formed on an end surface thereof, the gold finger being composed of a plurality of pins independent of each other. The circuit board 300 is inserted into the cage 106 and electrically connected to the electrical connector in the cage 106 by gold fingers. The gold fingers may be disposed on only one side of the circuit board 300 (e.g., the upper surface shown in fig. 4), or may be disposed on both upper and lower sides of the circuit board 300, so as to adapt to the situation where the requirement of the number of pins is large. The golden finger is configured to establish an electrical connection with the upper computer to realize power supply, grounding, I2C signal transmission, data signal transmission and the like.

Of course, a flexible circuit board is also used in some optical modules. Flexible circuit boards are generally used in conjunction with rigid circuit boards to supplement the rigid circuit boards. For example, a flexible circuit board may be used to connect the rigid circuit board and the optical transceiver module.

The optical transceiving component comprises an optical transmitting device and an optical receiving device, wherein the optical transmitting device is configured to transmit optical signals, and the optical receiving device is configured to receive the optical signals. Illustratively, the light emitting device and the light receiving device are combined together to form an integrated light transceiving component.

Fig. 5 is an exploded schematic view of a light emitting device according to an embodiment of the present disclosure; the overall structure of the light emitting section of the optical module of the present application is explained below with reference to fig. 5. As shown in fig. 5, the light emitting device 400 includes a cover plate 401 and a housing 402, the cover plate 401 and the housing 402 are coupled to each other in a covering manner, and specifically, the cover plate 401 covers the housing 402 from above, one side wall of the housing 402 has an opening 404 for insertion of the circuit board 300, and the other side wall of the housing 402 has a through hole for insertion of the fiber optic adapter 403.

Specifically, the circuit board 300 extends into the housing 402 through the opening 404, and the circuit board 300 is fixed to the lower case 202; the circuit board 300 is plated with metal traces, and the optical device can be electrically connected to the corresponding metal traces by wire bonding, so as to electrically connect the optical device in the housing 402 to the circuit board 300.

The signal light emitted by the light emitting device is emitted into the through hole, the optical fiber adapter 403 extends into the through hole 405 to be coupled and receive the signal light, the assembling structure design can enable the optical fiber adapter 403 to move back and forth in the through hole 405, the required size of the optical fiber between the light emitting device and the optical fiber plug can be adjusted, and when the optical fiber is short, the optical fiber adapter can move back (towards the outer direction of the cavity) in the through hole to meet the requirement of the connecting size; when the optical fiber is longer, the optical fiber adapter can be moved forwards (towards the inner direction of the cavity) in the through hole so as to straighten the optical fiber and avoid bending the optical fiber. The fiber adapter 403 is inserted into the through hole to achieve fixation with the light emitting device 400; during assembly, the fiber optic adapters 403 may be moved within the through-holes to select a fixed position.

One side wall of the housing 402 has an opening 404 for insertion of the circuit board 300 and the other side wall of the housing 402 has a through hole for insertion of the fiber optic adapter 403.

In the signal transmission process, after receiving the electrical signal transmitted by the circuit board 300, the optical transmitter inside the housing 402 converts the electrical signal into an optical signal, and then the optical signal enters the fiber adapter 403 and is transmitted to the outside of the optical module.

One end of the circuit board 300 extends into the opening 404 and is electrically connected to the light emitting device by wire bonding.

In the embodiment of the present application, ten board layers are taken as an example, and the circuit board 300 includes: the laminated plate comprises a first plate layer, a second plate layer, a third plate layer, a fourth plate layer, a fifth plate layer, a sixth plate layer, a seventh plate layer, an eighth plate layer, a ninth plate layer and a tenth plate layer which are sequentially stacked, wherein a dielectric layer is filled between every two adjacent plate layers, and the dielectric layer is made of an insulating material, and is filled with glass fiber or epoxy resin and other media. For convenience, the second, third, fourth, fifth, sixth, seventh, eighth, and ninth plies may also be referred to as the middle ply in this application. The DSP chip is arranged on the upper surface of the circuit board, namely, above the first board layer, and the light emitting device is connected with a circuit routing on the upper surface of the circuit board. Or the light emitting device is connected with the circuit on the upper surface of the circuit board by wire bonding.

For convenience of description, the plies on the lower surface and the lower surface, i.e., the first ply and the tenth ply, are referred to as skin layers, and the plies between the first ply and the tenth ply are referred to as intermediate plies. In order to reduce the dielectric loss of the electric signals in the transmission process, the electric signal lines are laid on the surface layer of the circuit board. For the signal wire on the surface layer, the metal layer is only arranged on the middle layer close to one side of the signal wire on the surface layer and used for shielding the electromagnetic radiation of the signal wire, and the other side of the signal wire is exposed on the surface of the circuit board and is not covered by the metal layer, so that the other side of the signal wire cannot provide an electromagnetic reflux path, and the electromagnetic radiation has great influence on the periphery. As shown in the figure, the first signal line is disposed on the upper surface of the circuit board, and a first ground layer is disposed at a corresponding position of the second board layer below the first signal line, the first ground layer is grounded and connected to the first signal line, and the first ground layer is a metal conductive layer. An insulating layer is arranged between the upper surface and the second plate layer.

Fig. 6 is a schematic circuit diagram of a circuit board according to an example of the present application. Fig. 7 is a schematic cross-sectional view of a circuit board according to an example of the present application. As shown in the drawing, the upper surface of the circuit board is provided with a plurality of signal lines including: the first signal line, the second signal line, the third signal line, wherein there is the interval between first signal line and the second signal line, and there is the interval between second signal line and the third signal line.

A first grounding wire is arranged on one side of the first signal wire, and a second grounding wire is arranged on the other side of the first signal wire. One side of the second signal wire is a second grounding wire, and the other side of the second signal wire is provided with a third grounding wire. One side of the third signal wire is a third grounding wire, and the other side of the third signal wire is provided with a fourth grounding wire.

One end of the first signal wire is positioned at the end part of the circuit board and is connected with the light emitting device through a routing. One end of the second signal wire is positioned at the end part of the circuit board and is connected with the light emitting device through a routing.

Fig. 8 is a schematic diagram of electromagnetic radiation of a first signal line of a circuit board according to an example of the present application. As shown in the figure, radiation generated by the first signal line 3011 surrounds the first signal line, and when the electromagnetic radiation generated by the first signal line 3011 covers the adjacent second signal line 3012, the electromagnetic radiation of the first signal line generates crosstalk to the electrical signal of the second signal line, which affects the photoelectric communication efficiency.

Similarly, when the radiation generated by the second signal line 3012 surrounds the second signal line, and the electromagnetic radiation range generated by the second signal line covers the adjacent first signal line, the electromagnetic radiation of the second signal line generates crosstalk to the electrical signal of the first signal line, which affects the photoelectric communication efficiency.

When the electromagnetic radiation range generated by the first signal line 3011 covers the adjacent second signal line 3012 and the electromagnetic radiation range generated by the second signal line 3012 covers the adjacent first signal line 3011, the electrical signal of the first signal line and the electrical signal of the second signal line are mutually interfered, which affects the photoelectric communication efficiency.

Fig. 9 is a schematic circuit structure diagram of a circuit board according to an example of the present application. Fig. 10 is a schematic circuit cross-sectional view of a part of an optical module according to an example of the present application.

As shown in fig. 9 and 10, the upper surface of the circuit board is provided with a plurality of signal lines, including: the signal line driver includes a first signal line 3011 and a second signal line 3012, where one side of the first signal line 3011 is provided with a first ground line 3013, and the other side of the first signal line 3011 is provided with a second ground line 3014. One side of the second signal line 3012 is a second ground line 3014, and the other side is provided with a third ground line 3015. The second board layer is provided with a first grounding area 311, and the projection of the first grounding area 311 on the first board layer covers the first signal line. The circuit board is also provided with a shielding cover used for shielding the electromagnetic radiation generated by the first signal wire positioned above the circuit board. The shield case includes: a plurality of support arms connected with the grounding wire and a top plate arranged on the upper surface of the support arms. Wherein the lower surface of roof is connected with a plurality of support arms, and the upper surface supports and leans on in the inner wall of lower casing.

The shield case includes: the first arm 501 is located above the circuit board, and has one end connected to the first ground line 3013 and the other end connected to the top plate. The width of the first arm 501 is less than or equal to the width of the first ground line 3013. The second arm 502 is located above the circuit board, and has one end connected to the second ground line 3014 and the other end connected to the top plate. The width of the second arm 502 is less than or equal to the width of the second ground line 3014. The base plate is disposed on the upper surfaces of the first arm 501 and the second arm 502. Therefore, the first signal line is located in a wrapping ring formed by the first grounding line 3013, the first arm 501, the top plate 504, the second arm 502, the second grounding line 3014 and the first grounding region, and shields electromagnetic radiation generated by the first signal line from multiple directions. Meanwhile, the interference of external electromagnetic radiation to the first signal line in the wrapping ring can be reduced, and the anti-interference capability of the optical module is improved.

The first signal line is disposed between the first ground line 3013 and the second ground line 3014, electromagnetic radiation generated by the first signal line surrounds the first signal line, and electromagnetic radiation generated by the first signal line 3011 in the plane of the circuit board is reflowed by the first ground line 3013 and the second ground line 3014 on both sides of the first signal line 3011 to shield the electromagnetic radiation generated by the first signal line 3011. The first grounding area is located in an area below the first signal line 3011 and shields electromagnetic radiation generated by the first signal line 3011, so that electromagnetic leakage is reduced, and crosstalk to adjacent signals is reduced. The first arm 501 shields electromagnetic radiation generated by the first signal line 3011 and located on one side of the first ground line 3013, and the second arm 502 shields electromagnetic radiation generated by the first signal line 3011 and located on one side of the second ground line 3014, so that electromagnetic leakage is reduced, and crosstalk to adjacent signals is reduced. The top plate 504 shields electromagnetic radiation generated by the first signal line 3011 and located above the circuit board, so as to reduce electromagnetic leakage and reduce crosstalk to adjacent signals.

Usually, the surface of the circuit board is provided with a solder resist layer, which is located between the circuit board and the shield can, not shown in this figure.

The shield case further includes: the third arm 503 is located above the circuit board, and has one end connected to the third ground line 3015 and the other end connected to the top plate 504. The width of the third arm 503 is less than or equal to the width of the third ground line 3015. Therefore, the second signal line is located in a wrapping ring formed by the second grounding line 3014, the second arm 502, the top plate 504, the third arm 503, the third grounding line 3015 and the first grounding area, and shields electromagnetic radiation generated by the second signal line from multiple directions. The projection of the first grounding area covers the shielding case to shield the electromagnetic radiation generated by the first signal wire and the second signal wire.

The second signal line 3012 is disposed between the second ground line 3014 and the third ground line 3015, electromagnetic radiation generated by the second signal line 3012 surrounds the second signal line 3012, and electromagnetic radiation generated by the second signal line 3012 in the plane of the circuit board is reflowed by the third ground line 3015 and the second ground line 3014 on both sides of the second signal line 3012 to shield the electromagnetic radiation generated by the second signal line 3012. The area of the first grounding area below the second signal line 3012 shields electromagnetic radiation generated by the second signal line 3012, reduces electromagnetic leakage, and reduces crosstalk to adjacent signals. The second arm 502 shields electromagnetic radiation generated by the second signal line 3012 and located on one side of the second ground line 3014, and the third arm 503 shields electromagnetic radiation generated by the second signal line 3012 and located on one side of the third ground line 3015, so as to reduce electromagnetic leakage and reduce crosstalk to adjacent signals. The top plate 504 shields electromagnetic radiation generated by the second signal line 3012 and located above the circuit board, so as to reduce electromagnetic leakage and reduce crosstalk to adjacent signals.

The first signal line 3011 is further connected to the DSP chip and carries a high-frequency signal, and one end of the first signal line 3011 is connected to the light emitting device through a first wire. One end of the first wire is connected to the first signal line 3011, and the other end is connected to the light emitting device. In order to facilitate the arrangement of the first wire, the first wire is prevented from being in contact connection with the shielding case during the installation process to cause a signal short circuit, and a portion of the first signal line 3011 is exposed outside the coverage range of the shielding case. As shown in the figure, the first signal line 3011 includes: a first signal wiring region 30111 and a first signal extension region 30112, wherein the first signal wiring region 30111 is near the end of the circuit board and is connected to a first wire; the first signal extension area is located between the first signal wiring area and the DSP chip. The second signal line 3012 includes: a second signal wiring region 30121 and a second signal extension region 301222, where the second signal wiring region is near the end of the circuit board and is connected to a second wire; the second signal extension area is located between the second signal wiring area and the DSP chip.

Fig. 11 is a second schematic circuit cross-sectional view of a part of an optical module according to an example of the present application. In some embodiments of the present application, the shield case and the upper housing are an integral structure, and when the upper housing is closed, the circuit board is in contact connection with the shield case. In order to ensure the stability of the contact between the shield and the circuit board and avoid the component between the shield and the circuit board caused by the dimensional tolerance, a first gasket is disposed below the first support arm 501, and the first gasket is made of a flexible conductive material and is used for absorbing the stress between the first support arm and the circuit board. The first gasket can be tin foil, conductive cloth, conductive adhesive tape or the like. Similarly, a second gasket is disposed below the second arm 502, and the second gasket is made of a flexible conductive material and is used for absorbing stress between the second arm and the circuit board. A third gasket is disposed below the third support arm 503, and the third gasket is made of a flexible conductive material and is used for absorbing stress between the third support arm and the circuit board.

In order to avoid short circuit between the first signal wire and the grounding wire, the width of the bottom surface of the second support arm is smaller than the spacing distance between the first signal wire and the second signal wire. To further reduce the risk of short circuits, the width of the bottom surface of the second arm is not greater than the width of the second ground line. The width of the bottom surface of the first support arm is not larger than that of the first grounding wire. The width of the bottom surface of the third support arm is not greater than the width of the third ground wire.

In order to reduce electromagnetic leakage, the length of the first arm 501 is equal to that of the first signal line 3011. The extending direction of the first arm 501 coincides with the wiring of the first signal line 3011. The length of the second arm 502 is equal to the longer of the first signal line 3011 and the second signal line 3012 adjacent thereto. The length of the third arm 503 is equal to the length of the second signal line 3012.

For the case of multiple sets of signal lines, the principle of the arrangement of the support arms in the shielding case is the same as that of the first support arm 501, the second support arm 502, and the third support arm 503, and therefore, the description thereof is omitted.

Fig. 12 is a schematic diagram of a top surface structure of a circuit board according to an example of the present application. In order to facilitate the connection with the light emitting device, the signal lines at the connection part of the light emitting component and the circuit board are orderly arranged, the distances among the signal lines are the same, and the distance among the signal extension areas is larger than the distance among the signal wiring areas. The projection of the shielding case on the circuit board does not cover the first signal wiring area and the second signal wiring area, so that the first lead and the second lead are conveniently connected, and the first lead, the second lead and the shielding case are prevented from being in contact connection in the installation process to cause signal short circuit.

The first signal wiring region and the second signal wiring region are arranged in parallel, and the distance between the first signal wiring region and the second signal wiring region is smaller than the distance between the first signal extension region and the second signal extension region.

Fig. 13 is a schematic diagram of near-end signal crosstalk of a signal line under different conditions of an example of the present application. Fig. 14 is a schematic diagram of near-end signal crosstalk of a signal line under different conditions of an example of the present application. As shown in the figure, the ordinate is the electromagnetic decibel value, and the abscissa is the frequency of the signal carried in the signal line. In fig. 13 and 14, line 1 of the three lines represents the electromagnetic radiation when there is no shield in the vicinity of the signal line, line 2 represents the electromagnetic radiation when the shield covers four fifths of the length of the signal line, and line 3 represents the electromagnetic radiation when the shield completely covers the length of the signal line. It is illustrated that the closer the length of the spacer is to the length of the electrical signal line, the better the isolation effect.

The shielding case is an electromagnetic shielding component, and can be made of copper, kovar alloy and other materials.

In the present application, a shield case includes: the first arm 501 is located above the circuit board, and has one end connected to the first ground line 3013 and the other end connected to the top plate 504. The width of the first arm 501 is less than or equal to the width of the first ground line 3013. The second arm 502 is located above the circuit board, and has one end connected to the second ground line 3014 and the other end connected to the top plate 504. The width of the second arm 502 is less than or equal to the width of the second ground line 3014. The base plate is disposed on the upper surfaces of the first arm 501 and the second arm 502. Therefore, the first signal line 3011 is located in a wrapping ring surrounded by the first ground line 3013, the first arm 501, the top plate 504, the second arm 502, the second ground line 3014, and the first ground region, and shields electromagnetic radiation generated by the first signal line 3011 from multiple directions. The upper surface of the top plate 504 is connected with the inner wall of the upper shell, so that heat dissipation of the circuit board is facilitated.

Since the above embodiments are all described by referring to and combining with other embodiments, the same portions are provided between different embodiments, and the same and similar portions between the various embodiments in this specification may be referred to each other. And will not be described in detail herein.

It is noted that, in this specification, relational terms such as "first" and "second," and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a circuit structure, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such circuit structure, article, or apparatus. Without further limitation, the phrases "comprising a" \8230; "defining an element do not exclude the presence of additional like elements in a circuit structure, article, or device comprising the element.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the present disclosure. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

The above-described embodiments of the present application do not limit the scope of the present application.

Claims (10)

1. A light module, comprising: an upper housing;

the lower shell is covered with the upper shell to form a wrapping cavity;

the circuit board set up in the parcel cavity, include:

the data processing chip is positioned on the surface of the circuit board;

a light emitting device;

the first signal wire is positioned on the upper surface of the circuit board, one end of the first signal wire is connected with the data processing chip, and the other end of the first signal wire is connected with the light emitting device;

the first grounding wire is positioned on the upper surface of the circuit board and positioned on one side of the first signal wire;

the second grounding wire is positioned on the upper surface of the circuit board and positioned on the other side of the first signal wire;

the shield cover set up in circuit board top is electromagnetic shield component, includes:

the first support arm is arranged above the first grounding wire;

the second support arm is arranged above the second grounding wire;

the first signal line is positioned between the first support arm and the second support arm;

the top plate is positioned above the first support arm and the second support arm;

the projection of the shielding case on the circuit board covers the first signal line.

2. The optical module of claim 1, wherein a width of the first arm is less than or equal to a width of the first ground line.

3. The optical module of claim 1, wherein a width of the second arm is less than or equal to a width of the second ground line.

4. The optical module according to claim 1, wherein a lower surface of the top plate is connected to an upper surface of the first arm, and an upper surface of the top plate is connected to an inner wall of the upper housing in contact therewith.

5. The light module of claim 1, wherein the circuit board further comprises: the second plate layer is arranged below the upper surface of the circuit board and is provided with a first grounding area, and the projection of the upper surface of the circuit board covers the first signal line.

6. The light module of claim 1, wherein the circuit board further comprises: the second signal wire is positioned on the upper surface of the circuit board, one end of the second signal wire is connected with the data processing chip, and the other end of the second signal wire is connected with the light emitting device;

and the second signal wire is positioned between the second grounding wire and the third grounding wire.

7. The optical module of claim 6, wherein the shield further comprises: the third support arm is positioned above the third grounding wire and connected with the top plate; the projection of the shielding case on the circuit board covers the second signal line.

8. The optical module of claim 1, wherein the shield is integrally formed with the upper housing.

9. The light module of claim 6, wherein the circuit board further comprises: and the second board layer is arranged below the upper surface of the circuit board and is provided with a first grounding area, and the projection of the first grounding area on the upper surface of the circuit board covers the second signal line and the first signal line.

10. The optical module of claim 9, wherein a projection of the shield on the circuit board covers the first signal line and the second signal line, and a projection of the first ground area covers the shield.

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