CN216411656U - Optical module - Google Patents

Abstract

The optical module comprises a circuit board and an optical transmitter sub-module, wherein a first differential signal wiring and a second differential signal wiring are arranged on the surface of the circuit board, a convex hull structure is arranged on the first differential signal wiring, the second differential signal wiring is provided with a bending structure, the bending structure is positioned in a projection area of the convex hull structure, and the length of the convex hull structure is greater than that of the bending structure, so that the lengths of the two wirings tend to be equal, the differential signal is prevented from being converted into a common-mode signal, common-mode noise is further inhibited, and the integrity of the signal is ensured; meanwhile, the two signal wires can be in a bent state, so that the wire trend difference of the two signal wires is reduced as much as possible, and the continuity of impedance is ensured; meanwhile, the change of the distance between the two signal wires can be reduced as much as possible, the continuity of impedance is further ensured, the reflection of signals is reduced, and the integrity of the signals is further ensured.

Description

Optical module

Technical Field

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

Background

The optical module comprises a circuit board, wherein various circuit wires such as differential signal wires are arranged on the surface of the circuit board, and the differential signals have strong anti-interference capability.

When high-speed PCB wiring is carried out, due to factors such as device distribution, pin distribution and via holes in the PCB, two differential signal lines cannot meet the design requirements of equal length, the lengths of the two signal lines are different, signal transmission delay and phase inconsistency can be caused, then the differential signals are converted into common-mode signals, common-mode noise is caused, and the signal quality is influenced due to the fact that the signals are incomplete due to overlarge common-mode noise.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides an optical module, which is used for length compensation of two differential signal wires with length difference so as to ensure the integrity of signals.

An embodiment of the present application provides an optical module, including:

the optical transmitter sub-module is electrically connected with the circuit board and receives high-speed signals from the first differential signal wiring and the second differential signal wiring;

a first distance of the first differential signal trace is not equal to a second distance of the second differential signal trace, wherein the first distance is a linear distance between a starting point and an end point of the first differential signal trace, and the second distance is a linear distance between a starting point and an end point of the second differential signal trace;

the first differential signal routing has a convex hull structure;

the second differential signal routing has a bending structure, and the bending structure is located in a projection area of the convex hull structure;

the length of the convex hull structure is greater than that of the bending structure.

The optical module provided by the embodiment of the application comprises a circuit board and a light emission sub-module, wherein a first differential signal wiring and a second differential signal wiring are arranged on the surface of the circuit board, the linear distance between the starting point and the end point of the first differential signal wiring is unequal to the linear distance between the starting point and the terminal of the second differential signal wiring, a convex hull structure is arranged on the first differential signal wiring, the second differential signal wiring is provided with a bending structure, the bending structure is positioned in the projection area of the convex hull structure, and the length of the convex hull structure is greater than that of the bending structure, so that the lengths of the two wirings tend to be equal, the differential signal is prevented from being converted into a common mode signal, common mode noise is inhibited, and the integrity of the signal is ensured; meanwhile, the two signal wires can be in a bent state, so that the wire trend difference of the two signal wires is reduced as much as possible, and the continuity of impedance is ensured; meanwhile, the change of the distance between the two signal wires can be reduced as much as possible, the continuity of impedance is further ensured, the reflection of signals is reduced, and the integrity of the signals is further ensured.

Drawings

In order to more clearly illustrate the technical solutions in the present disclosure, the drawings needed 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 the 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 illustrates a differential signal routing design for an optical module according to some embodiments;

FIG. 6 is another differential signal trace design pattern for an optical module according to some embodiments;

FIG. 7 illustrates another differential signal trace design for an optical module according to some embodiments.

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 by the present disclosure belong to the protection scope of the present disclosure.

Unless the context requires otherwise, throughout the description and the claims, the term "comprise" and its other forms, such as the third person's singular form "comprising" and the present participle form "comprising" are to be interpreted in an open, inclusive sense, i.e. as "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" and the like are intended to indicate that a particular feature, structure, material, or characteristic associated with the embodiment or example is included in at least one embodiment or example of the present disclosure. The schematic representations of the above terms are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be included in any suitable manner in any one or more embodiments or examples.

In the following, the terms "first", "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of the present disclosure, "a plurality" means two or more unless otherwise specified.

In describing some embodiments, expressions of "coupled" and "connected," along with their derivatives, may be used. For example, the term "connected" may be used in describing some embodiments to indicate that two or more elements are in direct physical or electrical contact with each other. As another example, some embodiments may be described using the term "coupled" to indicate that two or more elements are in direct physical or electrical contact. However, the terms "coupled" or "communicatively coupled" may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents herein.

"at least one of A, B and C" has the same meaning as "A, B or at least one of C," each including the following combination of A, B and C: a alone, B alone, C alone, a and B in combination, a and C in combination, B and C in combination, and A, B and C in combination.

"A and/or B" includes the following three combinations: a alone, B alone, and a combination of A and B.

The use of "adapted to" or "configured to" herein is meant to be an open and inclusive language that does not exclude devices adapted to or configured to perform additional tasks or steps.

As used herein, "about," "approximately," or "approximately" includes the stated values as well as average values that are within an acceptable range of deviation for the particular value, as determined by one of ordinary skill in the art in view of the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system).

In the optical communication technology, light is used to carry information to be transmitted, and an 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. Because the optical signal has the passive transmission characteristic when being transmitted through the optical fiber or the optical waveguide, the information transmission with low cost and low loss 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 fiber communication. The optical module comprises an optical port and an electrical 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 electrical connection with an optical network terminal (such as an optical modem) through the electrical port, and the electrical connection is mainly used for realizing power supply, I2C signal transmission, data signal 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 according to some embodiments. As shown in fig. 1, the optical communication system mainly includes a remote server 1000, a local information processing device 2000, an optical network terminal 100, an optical module 200, an optical fiber 101, and a network cable 103;

one end of the optical fiber 101 is connected to the remote server 1000, and the other end is connected to the optical network terminal 100 through the optical module 200. The optical fiber itself can support long-distance signal transmission, for example, signal transmission of several kilometers (6 kilometers to 8 kilometers), on the basis of which if a repeater is used, ultra-long-distance transmission can be theoretically achieved. 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 device 2000 and the remote server 1000 is completed by the optical fiber 101 and the network cable 103; and the connection between the optical fiber 101 and the network cable 103 is completed by the optical module 200 and the optical network terminal 100.

The optical module 200 includes an optical port and an electrical port. The optical port is configured to connect with the optical fiber 101, 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 a 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.

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 optical network terminal 100 transmits an electrical signal from the optical module 200 to the network cable 103, and transmits a signal from the network cable 103 to the optical module 200, so that the optical network terminal 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) and the like 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 structural diagram of an optical network terminal according to some embodiments, and fig. 2 only shows a structure of the optical module 100 related to the optical module 200 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 PCB circuit board 105 disposed in the housing, a cage 106 disposed on a surface of the PCB circuit board 105, 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 optical network terminal 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, an electrical port of the optical module 200 is connected to an electrical connector inside the cage 106, and thus the optical module 200 establishes a bidirectional electrical signal connection with the optical network terminal 100. Further, the optical port of the optical module 200 is connected to the optical fiber 101, and the optical module 200 establishes bidirectional electrical signal connection with the optical fiber 101.

Fig. 3 is a block diagram of a light module according to some embodiments, and fig. 4 is an exploded view of a light module according to some embodiments. As shown in fig. 3 and 4, the optical module 200 includes a housing, a circuit board 105 disposed in the housing, and an optical transceiver;

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 204 and 205; the outer contour of the housing generally appears square.

In some embodiments of the present disclosure, the lower housing 202 includes a bottom plate and two lower side plates located at two sides of the bottom plate and disposed perpendicular to the bottom plate; the upper housing 201 includes a cover plate, and two upper side plates disposed on two sides of the cover plate and perpendicular to the cover plate, and is combined with the two side plates by two side walls to cover the upper housing 201 on the lower housing 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 (left end in fig. 3) of the optical module 200, and the opening 205 is also located at an end (right 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. Wherein, the opening 204 is an electrical port, and the gold finger of the circuit board 105 extends out of the opening 204 and is inserted into an upper computer (such as the optical network terminal 100); the opening 205 is an optical port configured to receive the external optical fiber 101, so that the optical fiber 101 is connected to an optical transceiver inside the optical module 200.

The upper shell 201 and the lower shell 202 are combined in an assembly mode, so that devices such as the circuit board 105 and the optical transceiver device can be conveniently installed in the shells, and the upper shell 201 and the lower shell 202 can form packaging protection for the devices. In addition, when the devices such as the circuit board 105 and the like are assembled, the positioning components, the heat dissipation components and the electromagnetic shielding components of the devices are convenient to arrange, and the automatic implementation 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 203 located on an outer wall of a housing thereof, and the unlocking component 203 is configured to realize a fixed connection between the optical module 200 and an upper computer or release the fixed connection between the optical module 200 and the upper computer.

Illustratively, the unlocking members 203 are located on the outer walls of the two lower side plates of the lower housing 202, and include snap-fit members that mate with a cage of an upper computer (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 203; when the unlocking member 203 is pulled, the engaging member of the unlocking member 203 moves along with the unlocking member, and 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 105 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. The electronic components may include, for example, capacitors, resistors, transistors, Metal-Oxide-Semiconductor Field-Effect transistors (MOSFETs). The chip may include, for example, a Micro Controller Unit (MCU), 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 105 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 a chip; the rigid circuit board can also be inserted into an electric connector in the cage of the upper computer.

The circuit board 105 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 105 is inserted into the cage 106 and electrically connected to an electrical connector in the cage 106 by gold fingers. The gold fingers may be disposed on only one side of the circuit board 105 (e.g., the upper surface shown in fig. 4), or may be disposed on both the upper and lower sides of the circuit board 105, 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 achieve 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 commonly used in conjunction with rigid circuit boards to supplement the rigid circuit boards.

The optical module further includes a transmitter optical subassembly and a receiver optical subassembly, which may be collectively referred to as an optical subassembly. As shown in fig. 4, the optical module provided in the embodiment of the present application includes a tosa 400 and a rosa 500, the tosa 400 is located at an edge of the circuit board 105, and the tosa 400 and the rosa 500 are arranged on a surface of the circuit board 105 in a staggered manner, which is beneficial to achieving a better electromagnetic shielding effect. The tosa 400 includes:

the light emission submodule cavity;

the light emitting chip is arranged in the light emission submodule cavity and used for generating signal light;

the lens is arranged in the light emission submodule cavity, arranged on a transmission light path of the signal light and used for converging the signal light to the optical fiber coupler;

the optical receive sub-module 500 includes: light receiving sub-module cavity

And the photoelectric detector is arranged in the light receiving submodule cavity and used for converting the received signal light into an electric signal.

The tosa 400 is disposed on a surface of the circuit board 105. in another conventional package, the tosa is physically separated from the circuit board and electrically connected to the pcb through a flexible board for outputting signal light.

The tosa 400 is located in a package cavity formed by upper and lower shells. As shown in fig. 4, the circuit board 105 is provided with a notch for placing the tosa; the notch can be arranged in the middle of the circuit board and also can be arranged at the edge of the circuit board; the transmitter optical subassembly is arranged in the gap of the circuit board in an embedding mode, so that the circuit board can conveniently extend into the transmitter optical subassembly, and the transmitter optical subassembly and the circuit board can be conveniently fixed together. Alternatively, the tosa 400 may be fixedly supported by the lower housing 202.

The rosa 500 is disposed on the surface of the circuit board 105. in another conventional packaging method, the rosa is physically separated from the circuit board and electrically connected to the circuit board through a flexible board for receiving optical signals from the outside of the optical module.

Further, the rosa 500 includes an optical device and an optoelectric conversion device. Among them, optical devices such as fiber optic adapters, arrayed waveguide gratings, lenses, etc. The optical fiber transmits the signal light to the optical device, then the optical device carries out conversion of a signal light beam transmission path, and finally the signal light beam is transmitted to the photoelectric conversion device.

As the clock rate of signals increases, differential interconnects are increasingly used in high-speed transmission circuits, where differential signals are transmitted, each differential interconnect is mainly composed of a pair of copper wires, which we may refer to as a differential pair. The transmitting end driver of the differential pair has two output ends for outputting two mirror image signals, and the signals received by the receiving end are differential signals. The differential signals are transmitted through the differential pair, and the output end of the differential pair is respectively driven by two drivers to drive two transmission signal lines in the differential pair and simultaneously output two signals with opposite directions, equal amplitude and the same side. After receiving the two signals, the receiving end obtains information by reading the voltage difference of the two signals.

The output signals of the differential signal driver have two opposite polarities, the voltage of the positive output signal is V1, the voltage of the negative output signal is V2, and the differential signal is the difference between V1 and V2.

The laser chip of the transmitter optical subassembly is electrically connected with the first differential signal wiring and the second differential signal wiring respectively; the voltage of the output signal of the first differential signal wire is V1, the voltage of the output signal of the second differential signal wire is V2, the signal received by the laser chip is the difference value between V1 and V2, and the laser chip extracts the information in the difference value signal between V1 and V2 to be used for transmitting the optical signal.

The laser driving chip of the transmitter optical subassembly is electrically connected with the first differential signal wiring and the second differential signal wiring respectively; the voltage of the output signal of the first differential signal wire is V1, the voltage of the output signal of the second differential signal wire is V2, the signal received by the laser chip is the difference value between V1 and V2, and the information in the difference value signal between V1 and V2 is extracted by the laser driving chip and used for driving the laser to emit a light signal.

The DSP chip of the transmitter optical subassembly is electrically connected with the first differential signal wiring and the second differential signal wiring respectively; the voltage of the output signal of the first differential signal wire is V1, the voltage of the output signal of the second differential signal wire is V2, the signal received by the laser chip is the difference value between V1 and V2, and the DSP chip extracts and processes the information in the difference value signal between V1 and V2.

When high-speed PCB wiring is carried out, due to factors such as device distribution, pin distribution and via holes in the PCB, two differential signal lines cannot meet the design requirement of equal length.

Due to the fact that the differential signals are converted into the common mode signals due to some factors of the differential signal lines, such as the difference of the routing lengths, optical mode noise is caused, and the signals are incomplete due to excessive common mode noise, so that signal quality is affected. The magnitude of the common mode noise is related to whether the differential signal lines are ideally symmetrical, and the more the differential signal lines tend to be ideally symmetrical, the smaller the common mode noise is; accordingly, the more asymmetrical the differential signal lines, the greater the common mode noise.

Therefore, a certain compensation means is needed to realize that the two differential signal wires in the differential pair are equal in length.

In the conventional technology, a relatively short signal wire is usually provided with a bent structure, and a relatively long signal wire is kept unchanged, so that the two signal wires are bent differently, and the distance between the two signal wires in the vertical direction is changed greatly, so that impedance discontinuity occurs, impedance discontinuity is caused, and signal reflection is caused, and the integrity of the signal is influenced; the signal integrity refers to whether the receiving end can correctly identify the signal when the signal enters the transmission path through the sending end and reaches the receiving end through the transmission path, and the signal cannot be lost in the transmission process.

The large variation of the line width can cause the impedance of the signal line to be discontinuous, so that a part of the signal can be reflected back to the driving end, and the signal is reflected. In designing a high-speed PCB differential signal line, the equidistant design of the differential signal line is important as equal-length windings in order to ensure the continuity of transmission line impedance and reduce signal reflection. The design rules for the differential signal lines are therefore: the distance between the two signal lines cannot be changed too much.

In summary, when designing differential signal traces on a PCB, it is required to ensure that two differential signal traces are equal in length and the variation of the pitch is as small as possible.

In fig. 5-7, the P line length of the differential routing is relatively short, and the N line length of the differential routing is relatively long, for example, in the two P lines and the two N lines of the differential routing. The straight line distance between the starting point and the end point of the differential trace P is not equal to the straight line distance between the starting point and the end point of the differential trace N.

In the embodiment of the present application, fig. 5 provides a differential signal trace design mode; FIG. 6 provides another differential signal trace design; fig. 7 provides another differential signal trace design.

As can be seen from fig. 5 to 7, in the embodiment of the present application, the two differential signal traces are both provided with the bending structures, and both are in a bending state, which is different from the traditional design concept of bending only on the relatively short differential signal trace.

In fig. 5-7, the included angle between the line segment L1 and the horizontal line and the included angle between the line segment L3 and the horizontal line are designed to be 45-50 degrees, preferably 45 degrees; the common mode noise is small at the corner of 45 degrees, which is beneficial to signal transmission; it should be noted that the included angle between the line segment L1 and the horizontal line and the included angle between the line segment L3 and the horizontal line may be designed to be other degrees, and is not limited to 45 °.

FIG. 5 shows a differential signal trace design provided in an embodiment of the present application; as shown in fig. 5, the drawing includes two differential signal traces, which are a differential signal trace P and a differential signal trace N, respectively, and the differential trace P has a relatively short length and the differential trace N has a relatively long length, for example, a relatively large convex-packet structure is disposed on the differential trace P, a relatively small convex-packet structure is disposed on the differential trace N, and the relatively large convex-packet structure on the differential signal trace P has a length greater than the relatively small convex-packet structure on the differential signal trace N, so that the lengths of the two differential signal traces tend to be equal, thereby preventing the differential signal from being converted into a common-mode signal, further suppressing the common-mode noise, and ensuring the integrity of the signal.

The convex hull structure on the differential trace P comprises a line segment L1, a line segment L2 and a line segment L3; the starting point of the line segment L1 is the end of the normal P line, the end point of the line segment LI is connected to the starting point of the line segment L2, the end point of the line segment L2 is connected to the starting point of the line segment L3, the line segment L1 is inclined upward, the line segment L2 is inclined horizontally, and the line segment L3 is inclined downward, so that the line segment L1, the line segment L2 and the line segment L3 are sequentially connected end to form a convex hull structure in a trapezoidal state.

Under the projection of the relatively large convex hull structure of the P line, a relatively small convex hull structure is arranged on the response area of the N line, the shape of the relatively small convex hull structure is the same as that of the relatively large convex hull structure on the P line, the relatively small convex hull structure on the N line also comprises a line segment M1, a line segment M2 and a line segment M3, and the line segment M1, the line segment M2 and the line segment M3 are connected end to end in sequence to form the convex hull structure in a trapezoidal state.

In some embodiments, the parameters of the convex hull structure on the P-line and the parameters and number of the convex hull structure on the N-line may be designed according to the length difference between the differential signal line P and the differential signal line N.

In the embodiment of the present application, the number of the relatively large bump structures provided on the differential signal line P may be 1.

In the embodiment of the present application, the starting points of the line segment L1 and the line segment M1 are on the same vertical line, and the end points of the line segment L3 and the last corresponding line of the last small bump structure on the N line are on the same vertical line, so that the two signal traces can be kept as much as possible to have the same trace bending trend, the trace trend difference of the two signal traces is reduced as much as possible, and the continuity of the impedance is ensured. Wherein the same vertical line refers to the vertical dashed line in the drawings.

It should be noted that the starting points of the line segment L1 and the line segment M1 in the embodiment of the present application may not be on the same vertical line; it is within the scope of the embodiments of the present application that the starting points are not on the same vertical line.

In the embodiment of the present application, the line segment L1 is parallel to the line segment M1, and the line segment L3 is parallel to the last corresponding line segment of the last small bump structure on the N line, so that the distance between the two signal traces can be maintained as much as possible, the change in the distance between the two signal traces can be reduced as much as possible, the continuity of impedance is further ensured, the reflection of signals is reduced, and the integrity of signals is further ensured.

Fig. 6 is another differential signal trace design mode according to an embodiment of the present disclosure; as shown in fig. 6, the drawing includes two differential signal traces, which are a differential signal trace P and a differential signal trace N, respectively, and taking the case that the length of the differential trace P is relatively short and the length of the differential trace N is relatively long, a relatively large bump structure is disposed on the differential trace P, and a bending structure is disposed on the differential trace N, where the bending structure includes a first step-like structure and a second step-like structure that are symmetrical to each other, and the first step-like structure and the second step-like structure are connected by a horizontal line segment. The length of the convex package structure on the differential signal wiring P is larger than that of the bending structure on the differential signal wiring N, so that the lengths of the two differential signal wirings tend to be equal, the differential signal is prevented from being converted into a common-mode signal, common-mode noise is further inhibited, and the integrity of the signal is ensured.

As shown in fig. 6, the first stepped structure includes a line segment O1, a line segment O2, and a line segment O3 arranged in steps, and the second stepped structure includes a line segment O5, a line segment O6, and a line segment O7 arranged in steps.

The first stepped structure and the second stepped structure are connected by a line segment O4.

In some embodiments, parameters of the convex hull structure on the P line, and parameters and the number of the first stepped structure and the second stepped structure which are symmetrical to each other on the N line may be designed according to the length difference between the differential signal line P and the differential signal line N; and the number of broken line segments in the first stepped structure and the second stepped structure, that is, the number of steps, can be designed according to the length difference between the differential signal line P and the differential signal line N.

In the embodiment of the present application, the number of the convex hull structures provided on the differential signal line P may be 1.

In the embodiment of the present application, the starting points of the line segment L1 on the P line and the line segment O1 on the N line are on the same vertical line, and the end points of the line segment L3 on the P line and the line segment O7 on the N line are on the same vertical line, so that the two signal traces can be kept to have the same trace bending tendency as much as possible, the trace trend difference of the two signal traces is reduced as much as possible, and the continuity of the impedance is ensured.

It should be noted that the starting points of the line segment L3 on the P line and the line segment O7 on the N line in the present embodiment may not be on the same vertical line, and the end points of the line segment L3 on the P line and the line segment O7 on the N line in the present embodiment may not be on the same vertical line; the situation where the two lines are not on the same vertical line is also within the scope of the embodiments of the present application.

In the embodiment of the present application, the line segment L1 is parallel to the line segment O1, and the line segment L3 is parallel to the line segment O7, so that the distance between two signal traces can be kept as much as possible, the change in the distance between two signal traces can be reduced as much as possible, the continuity of impedance is further ensured, the reflection of signals is reduced, and the integrity of signals is further ensured.

Fig. 7 is another differential signal trace design mode provided in the present embodiment; as shown in fig. 7, the drawing includes two differential signal traces, which are a differential signal trace P and a differential signal trace N respectively, and the length of the differential trace P is relatively short, and the length of the differential trace N is relatively long, for example, a relatively large bump structure is disposed on the differential trace P, a bending structure is disposed on the differential trace N, the bending structure includes a line segment K1, a line segment K2, and a line segment K3, and the line segment K1, the line segment K2, and the line segment K3 are sequentially connected end to end and are in a trapezoid configuration.

In some embodiments, the convex hull structure parameter on P and the bending structure parameter on N may be designed according to the specific length difference of the two signal traces.

The starting point of the line segment K1 is on the same vertical line as the starting point of the line segment L1, and the end point of the line segment K3 is on the same vertical line as the end point of the line segment L3; therefore, the two signal wires can be kept to have the same wire bending trend as much as possible, the difference of the wire trend of the two signal wires is reduced as much as possible, and the continuity of impedance is ensured.

It should be noted that the starting point of the line segment K1 and the starting point of the line segment L1 in the embodiment of the present application may not be on the same vertical line; it is within the scope of the embodiments of the present application that the starting points are not on the same vertical line.

The line segment K1 is parallel to the line segment L1, the line segment K2 is parallel to the line segment L2, and the line segment K3 is parallel to the line segment L3, so that the distance between the two signal wires can be kept as far as possible, the change of the distance between the two signal wires can be reduced as far as possible, the continuity of impedance is further ensured, the reflection of signals is reduced, and the integrity of the signals is further ensured.

From the foregoing, fig. 5 provides a differential signal trace design; FIG. 6 provides another differential signal trace design; FIG. 7 illustrates another differential signal trace design; in addition, in the embodiment of the application, the two differential signal wires are respectively provided with a bending structure, and are both in a bending state, so that the design concept that the bending structure is only arranged on the relatively short differential signal wire in the traditional design method is different from the traditional design concept that the bending structure is only arranged on the relatively short differential signal wire in the traditional design method.

In the embodiment of the application, the convex hull structure is arranged on the signal running line with shorter straight-line distance between the starting point and the terminal of the running line, the bending structure is arranged on the longer signal running line, the arrangement forms are respectively shown in fig. 5, 6 and 7, and the length of the convex hull structure is greater than that of the bending structure; the two signal wires are provided with corresponding length compensation structures, and the compensation length of the shorter wire is greater than that of the bending structure, so that the lengths of the two wires tend to be equal, the differential signal is prevented from being converted into a common-mode signal, common-mode noise is further inhibited, and the integrity of the signal is ensured; meanwhile, the two signal wires can be in a bent state, so that the wire trend difference of the two signal wires is reduced as much as possible, and the continuity of impedance is ensured; meanwhile, the change of the distance between the two signal wires can be reduced as much as possible, the continuity of impedance is further ensured, the reflection of signals is reduced, and the integrity of the signals is further ensured.

The above description is only for the specific embodiments of the present disclosure, but the scope of the present disclosure is not limited thereto, and any person skilled in the art will appreciate that changes or substitutions within the technical scope of the present disclosure are included in the scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims (9)

1. A light module, comprising:

the surface of the circuit board is provided with a first differential signal wire and a second differential signal wire;

the optical transmitter sub-module is electrically connected with the circuit board and receives high-speed signals from the first differential signal wiring and the second differential signal wiring;

a first distance of the first differential signal trace is not equal to a second distance of the second differential signal trace, wherein the first distance is a linear distance between a starting point and an end point of the first differential signal trace, and the second distance is a linear distance between a starting point and an end point of the second differential signal trace;

the first differential signal routing has a convex hull structure;

the second differential signal routing has a bending structure, and the bending structure is located in a projection area of the convex hull structure;

the length of the convex hull structure is greater than that of the bending structure.

2. The optical module of claim 1, wherein the convex hull structure comprises a first line segment, a second line segment, and a third line segment, and the first line segment, the second line segment, and the third line segment are sequentially connected end to end and are in a trapezoidal arrangement.

3. The optical module according to claim 2, wherein the bending structure comprises a plurality of small convex hull structures, the small convex hull structures are the same as the convex hull structures in shape, and the area of the small convex hull structures is smaller than that of the convex hull structures;

the starting point of the convex hull structure and the starting point of the small convex hull structure are on the same vertical line, and the end point of the convex hull structure and the end point of the small convex hull structure are on the same vertical line;

the first line segment of the first small convex hull structure in the bending structure is parallel to the first line segment, and the last line segment of the last small convex hull structure in the bending structure is parallel to the third line segment.

4. The optical module according to claim 2, wherein the bending structure comprises a first step-like structure and a second step-like structure which are symmetrically arranged, and the first step-like structure and the second step-like structure are connected by a horizontal line segment;

the first step-shaped structure and the second step-shaped structure comprise steps formed by connecting a plurality of line segments end to end;

the starting point of the convex hull structure and the starting point of the first stepped structure are on the same vertical line, and the key point of the convex hull structure and the end point of the second stepped rotating structure are on the same vertical line;

the first line segment of the first stepped structure is parallel to the first line segment, and the last line of the second stepped structure is parallel to the third line segment.

5. The optical module according to claim 2, wherein the bending structure comprises a fourth line segment, a fifth line segment and a sixth line segment, and the fourth line segment, the fifth line segment and the sixth line segment are sequentially connected end to end and are arranged in a trapezoid shape;

the starting point of the fourth line segment and the starting point of the first line segment are on the same vertical line, and the end point of the sixth line segment and the end point of the third line segment are on the same vertical line;

the fourth line segment is parallel to the first line segment, the fifth line segment is parallel to the second line segment, and the sixth line segment is parallel to the third line segment.

6. The optical module according to claim 2, wherein the first line segment forms an angle of 45 ° to 50 ° with the horizontal line, and the third line segment forms an angle of 45 ° to 50 ° with the horizontal line.

7. The optical module of claim 1, wherein a laser chip of the tosa is electrically connected to the first differential signal trace and the second differential signal trace, respectively.

8. The optical module of claim 1, wherein a laser driver chip of the tosa is electrically connected to the first differential signal trace and the second differential signal trace, respectively.

9. The optical module of claim 1, wherein the DSP chip of the tosa is electrically connected to the first differential signal trace and the second differential signal trace, respectively.

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