CN111511097A - High-speed transmission optical module circuit board structure and manufacturing method thereof and crosstalk prevention method - Google Patents

High-speed transmission optical module circuit board structure and manufacturing method thereof and crosstalk prevention method Download PDF

Info

Publication number
CN111511097A
CN111511097A CN202010339662.7A CN202010339662A CN111511097A CN 111511097 A CN111511097 A CN 111511097A CN 202010339662 A CN202010339662 A CN 202010339662A CN 111511097 A CN111511097 A CN 111511097A
Authority
CN
China
Prior art keywords
layer
differential signal
speed transmission
crosstalk
circuit board
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202010339662.7A
Other languages
Chinese (zh)
Other versions
CN111511097B (en
Inventor
刘萍
刘平
周俊文
彭彦辉
刘斌
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shenzhen Optic King Technology Co ltd
Original Assignee
Shenzhen Optic King Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shenzhen Optic King Technology Co ltd filed Critical Shenzhen Optic King Technology Co ltd
Priority to CN202011409623.6A priority Critical patent/CN112437537B/en
Priority to CN202010339662.7A priority patent/CN111511097B/en
Publication of CN111511097A publication Critical patent/CN111511097A/en
Application granted granted Critical
Publication of CN111511097B publication Critical patent/CN111511097B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/0213—Electrical arrangements not otherwise provided for
    • H05K1/0216—Reduction of cross-talk, noise or electromagnetic interference
    • H05K1/0228—Compensation of cross-talk by a mutually correlated lay-out of printed circuit traces, e.g. for compensation of cross-talk in mounted connectors
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/42—Coupling light guides with opto-electronic elements
    • G02B6/4201—Packages, e.g. shape, construction, internal or external details
    • G02B6/4274—Electrical aspects
    • G02B6/428—Electrical aspects containing printed circuit boards [PCB]
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/0201—Thermal arrangements, e.g. for cooling, heating or preventing overheating
    • H05K1/0203—Cooling of mounted components
    • H05K1/0209—External configuration of printed circuit board adapted for heat dissipation, e.g. lay-out of conductors, coatings
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/0213—Electrical arrangements not otherwise provided for
    • H05K1/0237—High frequency adaptations
    • H05K1/0245—Lay-out of balanced signal pairs, e.g. differential lines or twisted lines
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/0271—Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion

Abstract

In order to effectively integrate and isolate differential signal lines in a high-speed transmission optical module, the circuit board structure comprises a multilayer circuit lamination body and rows of contact fingers arranged on two sides of a plugging side, the multilayer circuit lamination body comprises a transmission signal layer, a control signal layer, a power signal layer and an integrated circuit layer managed in a partition mode, the first sections of paired first differential signal lines and paired second differential signal lines are located on the transmission signal layer, the first differential signal lines are connected to the first rows of contact fingers, the second sections of the second differential signal lines are located in the first regions of the integrated circuit layer and connected to the corresponding second rows of contact fingers, the first sections and the second sections of the second differential signal lines are electrically connected through long connecting through holes, the rest second rows of contact fingers are electrically connected through short connecting through holes to the corresponding control signal layer, and the first sections and the second sections of the second differential signal lines are electrically connected through the short connecting holes, The integrated circuit layer also comprises a power line connecting section, a control line connecting section and a grounding heat dissipation island which are positioned in the second area.

Description

High-speed transmission optical module circuit board structure and manufacturing method thereof and crosstalk prevention method
Technical Field
The invention relates to the technical field of internal devices of a high-speed transmission optical module, in particular to a circuit board structure of the high-speed transmission optical module, a manufacturing method of the circuit board structure and an anti-crosstalk method of the circuit board structure.
Background
High-speed transmission optical module, such as single/double fiber pluggable optical module (SFP), is a small pluggable transceiver device containing a source chip and a light receiving transmitter, and is applied to high-speed telecommunication and data communication, the data volume required to be transmitted for matching the lower limit time of 5G, 6G or more advanced communication protocols is also increasing, the transmission rate is increased to 100 Gb/s or more, and in order to correct/correct the distortion or delay of data at high transmission rate, a differential signal line is adopted in the circuit board structure as high-speed data transmission. However, there are no signal lines for data transmission, the optical module circuit board itself needs to be configured with control signal lines, power lines and clock signals, the differential signal lines are easily interfered by other lines, and in pin design, the contact fingers connected to the differential signal lines are usually configured in pairs at corresponding positions of the individual row contact fingers on both sides of the plugging side, and the differential signal lines on the top and bottom surfaces are also easily interfered by overlapping of extending positions of the lines, which will impair the transmission speed and accuracy of the optical module data in the differential signal lines. In addition, the double-sided arrangement of the differential signal lines may also result in the displacement of layout space of other lines.
Regarding some high-speed transmission optical modules in the prior art, patent publication No. CN104467972A discloses a 100GQSFP28SR4 parallel optical transceiver module, which performs data recovery processing on a 100G electrical signal through a first clock data recovery module, so that an array driving module can drive a laser emission module to convert the electrical signal into an optical signal after the electrical signal after the data recovery processing is continuously modulated and demodulated, and then couples the optical signal to an optical fiber to be transmitted to a photoelectric conversion module, the photoelectric conversion module converts the received optical signal into an electrical signal, and a main control end outputs a 4-channel 25G electrical signal which is converted into a 4-channel 25G parallel optical signal through the photoelectric conversion module.
The utility model discloses a 100GQSFP28SR4 optical transceiver module assembly based on COB technology, which comprises a metal shell, an optical fiber interface, a PCB circuit, an MCU controller and COB packaging; the COB package is integrated with a driving chip, an amplitude limiting amplifier, a light emitting assembly and a light receiving assembly; one end of the light emitting component is connected with the light receiving component, the other end of the light emitting component is connected with the driving chip, the other end of the light receiving component is connected with the limiting amplifier, one end of the MCU controller is connected with the driving chip, and the other end of the MCU controller is connected with the limiting amplifier.
Utility model patent publication No. CN207732769U discloses a QSFP28SR4 short-distance photovoltaic module, include: go up casing, electric interface's circuit board, engine connector, optic fibre, MPO connecting portion, light mouth, lower casing, engine connector, optic fibre, MPO connecting portion, light mouth set up after linking gradually in last casing and between the casing down, the circuit board of electric interface have a plurality of perforation, the engine have a plurality of pins, the pin pass through one by one the perforation form the solder joint and connect in the circuit board of electric interface on.
None of the above prior art patents disclose how to integrate the printed circuit board of the optical module into the specific circuit structure of the differential signal line.
Patent publication No. CN107896418A discloses an optical module for reducing crosstalk between differential signal lines. The optical module comprises a printed circuit board, wherein the printed circuit board comprises a top layer, a first intermediate signal transmission layer, a second intermediate signal transmission layer and a bottom layer; the signal transmission layer is provided with a grounding layer which is arranged adjacent to the signal transmission layer in a laminated mode, and a differential signal line pair is arranged on the signal transmission layer; the first intermediate signal transmission layer is positioned between the top layer and the second intermediate signal transmission layer, and the second intermediate signal transmission layer is positioned between the first intermediate signal transmission layer and the bottom layer; the top layer and the bottom layer are provided with golden fingers, and the top layer comprises a laser driving chip; one end of the first intermediate signal transmission layer and one end of the second intermediate signal transmission layer are respectively connected with the laser driving chip through blind holes, and the other end of the first intermediate signal transmission layer and the second intermediate signal transmission layer are connected with the golden finger on the top layer through the blind holes; the other end of the second intermediate signal transmission layer is connected with the golden finger at the bottom layer through a blind hole; the bottom layer is connected with the laser driving chip through the via hole. In a limited space, the golden fingers are arranged on the same side of the board surface in a multi-section breaking mode. Furthermore, the intermediate signal transmission layer is connected with the golden finger, the intermediate signal transmission layer is connected with the laser driving chip through blind holes, and the blind holes are used for dispersing differential signal line pairs of three wiring designs, so that crosstalk between the differential signal lines can be reduced. Except for the differential signal line pairs connected with the blind holes in an embedded mode, the first signal transmission layer (the top surface differential signal line) is connected with the golden finger on the top layer, and the second signal transmission layer (the bottom surface differential signal line) is connected with the golden finger on the bottom layer, so that the concentrated crosstalk of the differential signal line on the first signal transmission layer to the differential signal line on the second signal transmission layer can be avoided; the differential signal lines on the surface are positioned in the hollow-out patterns of the ground plane on the same layer, which cannot obtain enough mechanical strength for a small-sized printed circuit board applied by the optical module, and the problem of layer peeling caused by heating when the high-transmission optical module operates is easy to occur. With the trend of multi-layer and miniaturized circuit board structure of optical module, how to reasonably allocate the device mounting position in a small-sized circuit board without the problem of signal crosstalk in high-speed transmission needs to be continuously researched and improved.
Disclosure of Invention
The present invention provides a circuit board structure of a high-speed transmission optical module, which effectively integrates differential signal lines for high-speed transmission of data, improves the phenomenon of insufficient mechanical strength of a multi-layer circuit board structure applied to an optical module under the design of size miniaturization and ground surface maximization, and solves the problem of layer peeling caused by heat generation during the operation of the high-speed transmission optical module.
The invention also provides a method for manufacturing the circuit board structure of the high-speed transmission optical module, which can be used for manufacturing the circuit board structure which can consolidate the insulating materials at two sides of the differential signal wire and integrate the crosstalk prevention mechanism, so that the bonding strength between adjacent layers is stronger, the peeling between the circuit board layers is not easy to generate, and the thermal stress concentration on the differential signal wire or the long-connection through hole can be reduced.
The third objective of the present invention is to provide a crosstalk prevention method for differential signal lines, which achieves the crosstalk prevention effect of the differential signal lines and enhances the structural positioning of the differential signal lines in the circuit board.
The main purpose of the invention is realized by the following technical scheme:
the circuit board structure of the high-speed transmission optical module comprises a multilayer circuit laminated body, a first row of contact fingers, a second row of contact fingers, a long-connection through hole and a short-connection through hole;
the multilayer circuit laminated body comprises a transmission signal layer, a control signal layer, a power signal layer and an integrated circuit layer which are separated by an isolation layer, wherein at least one isolation layer is arranged between the signal layers, the isolation layer comprises a ground plane structure, the transmission signal layer comprises a plurality of paired first differential signal lines and a plurality of paired first sections of second differential signal lines, the integrated circuit layer is divided into a high-speed transmission area and a low-speed transmission area, and the integrated circuit layer comprises a second section of the second differential signal line positioned in the high-speed transmission area, a power line connecting section positioned in the low-speed transmission area, a control line connecting section and a grounding heat dissipation island;
the second row of contact fingers correspond to the first row of contact fingers and are arranged at the plugging side of the integrated circuit layer, and the second section of the second differential signal line is connected to the second row of contact fingers corresponding to the high-speed transmission pins;
the short-circuit via hole is electrically connected with other part of pins of the second row of contact fingers except for the high-speed transmission pins to the corresponding control signal layer and the power signal layer, and the distance from the short-circuit via hole to the correspondingly connected second row of contact fingers is less than the distance from the long-circuit via hole to the correspondingly connected second row of contact fingers;
in the observation direction facing the board surface, the extension of the second section of the second differential signal line to the device region is staggered with the first differential signal line, so that the long-contact via holes are regularly distributed in gaps or side edges between the first differential signal lines;
the transmission signal layer further comprises a plurality of first crosstalk-proof guard posts and a plurality of second crosstalk-proof guard posts, the first crosstalk-proof guard posts are arranged in a line along the line extending direction at gaps or side edges between the first differential signal lines which are adjacent in pairs, the second crosstalk-proof guard posts are arranged in a line along the line extending direction at gaps or side edges between first sections of the first differential signal lines and the second differential signal lines, the integrated circuit layer further comprises a plurality of third crosstalk-proof guard posts which are arranged in a line along the line extending direction at gaps or side edges of second sections of the second differential signal lines, and the first crosstalk-proof guard posts, the second crosstalk-proof guard posts and the third crosstalk-proof guard posts are respectively and convexly combined to ground planes in adjacent isolation layers.
By adopting the basic technical scheme, the transmission signal layer is used as a main wiring area of the differential signal line, the high-speed transmission area of the integrated circuit layer is used as a secondary wiring area of the differential signal line segment, the adjacent isolation layers of the transmission signal layer and the integrated circuit layer are both provided with ground plane structures, a plurality of anti-crosstalk guard posts which are arranged in a row along the extending direction of the circuit are arranged at the gap or the side edge between the differential signal lines, and the anti-crosstalk guard posts are respectively combined on the ground planes in the adjacent isolation layers in an outwards protruding mode. Under the structural design, the differential signal wire can obtain the effect of preventing signal crosstalk in the optical module circuit board, the bonding strength between inner layers of the circuit board is higher, and the stress protection effect on the differential signal wire is also realized.
The present invention in a preferred example may be further configured to: the connection of the first differential signal line and the corresponding first row of contact fingers or/and the connection of the second section of the second differential signal line and the corresponding second row of contact fingers form symmetrically converging oblique edges, preferably with a pair of concave bends.
The preferred technical scheme utilizes the symmetrical convergent bevel edge shape of the connection part of the differential signal line and the corresponding contact finger to avoid the discontinuity of the width of the transmission signal line and cause the discontinuity of impedance, and preferably, the paired concave bending can reduce the signal reflection phenomenon when the connection part of the contact finger outputs and inputs data under high-speed transmission.
The present invention in a preferred example may be further configured to: the ground heat dissipation island is provided with a solderless cover exposed opening which is opposite to the optical communication chip, and preferably, the transmission signal layer is provided with a plurality of heat conduction through holes which are thermally coupled to the ground heat dissipation island.
By adopting the preferred technical scheme, the grounding heat dissipation island of the integrated circuit layer is utilized to provide the solderless cover exposed opening which reversely corresponds to the optical communication chip, the reverse side convection heat dissipation of the optical communication chip arranged on the front side on the back side of the circuit board is accelerated, and when the multilayer circuit board structure has mutually close temperatures on the front side and the bottom side, the warping deformation of the multilayer circuit laminated body can be avoided due to the reduction of the temperature difference of the two sides when the circuit board operates.
The present invention in a preferred example may be further configured to: the multilayer circuit laminated body is provided with positioning groove holes on two sides, and the high-speed transmission area of the integrated circuit layer is positioned between the splicing side and the connecting lines of the positioning groove holes on the two sides.
By adopting the preferable technical scheme, the multilayer circuit laminated body can be positioned in the upper shell and the lower shell of the optical module by utilizing the positioning slotted hole. The connecting lines of the positioning slot holes on the two sides can also be used for planning the maximum boundary position of the high-speed transmission area of the integrated circuit layer, namely, the wiring area of the second section of the second differential signal line can be limited between the contact finger and the connecting lines of the positioning slot holes on the two sides, and the partition management of the second differential signal line is achieved.
The present invention in a preferred example may be further configured to: the device district includes optical communication chip installing zone, little control chip installing zone, power MOS pipe installing zone, power chip installing zone, optical communication chip installing zone is located in the transmission signal layer, little control chip installing zone power MOS pipe installing zone with power chip installing zone is located integrate the circuit layer in the low-speed transmission district.
By adopting the preferred technical scheme, the preferred configuration of the positions of the optical communication chip mounting area, the micro control chip mounting area, the power MOS tube mounting area and the power supply chip mounting area is utilized to achieve the facet management of the mounting of the double-sided device of the circuit board structure based on the high-low speed signal separation design.
The present invention in a preferred example may be further configured to: the isolation layer comprises a ground reference layer positioned between the transmission signal layer and the control signal layer, a first ground plane layer positioned between the control signal layer and the power supply signal layer, and a second ground plane layer positioned between the power supply signal layer and the integrated circuit layer, and preferably, the multilayer circuit laminated body further comprises an I2C signal layer positioned between the first ground plane layer and the power supply signal layer.
By adopting the preferred technical scheme, the first crosstalk prevention guard post and the second crosstalk prevention guard post can be combined to the grounding reference layer in a short path and the third crosstalk prevention guard post can be combined to the second grounding layer in a short path by utilizing the specific structure of the isolation layer between the signal layers, the distribution of the upper guard post and the lower guard post can not interfere with each other, and compared with the grounding pattern of a wrapping line, the wiring design of other signal layers can not be disturbed too much.
The present invention in a preferred example may be further configured to: and a plurality of fourth crosstalk-proof guard columns which extend in parallel with the holes are arranged around the long through hole and are penetratingly combined to the ground plane in the isolation layer for consolidating the peripheral insulating material.
By adopting the preferred technical scheme, the fourth crosstalk-proof guard post arranged around the long-joint conducting hole is utilized to increase the crosstalk-proof effect of the conducting hole connected between the segmented differential signal lines, and meanwhile, the breakage of the long-joint conducting hole under thermal stress is avoided.
The present invention in a preferred example may be further configured to: the transmission signal layer comprises a plurality of first protection element regions and a plurality of second protection element regions, the first protection element regions divide the first differential signal lines into contact finger connecting sections and first device connecting sections, the second protection element divides the first section of the second differential signal line into an intermediate section and a second device connecting section; preferably, the first and second electrodes are formed of a metal, the long connection through hole, the second protection element area and the first protection element area are arranged in a zigzag staggered manner, the first protective element region is closer to the first row of contact fingers than the second protective element region, the first protection element area is approximately positioned in the middle of the Z-shaped inclined rod, and the long connection through hole and the second protection element area are arranged at two ends of the Z-shaped cross rod; more preferably still, the first and second liquid crystal compositions are, the fourth crosstalk prevention guard post is correspondingly overlapped and integrated with part of the first crosstalk prevention guard post or/and the second crosstalk prevention guard post.
By adopting the preferable technical scheme, the arrangement of the long-connection through hole, the second protection element area and the first protection element area is utilized, so that the middle section of the first section of the second differential signal line still has certain extension length, for example, the protection element of the capacitor can be jointed with the first protection element area and the second protection element area at a distance enough for surface mounting, and the patterning welding cover covering of the top surface of the circuit board is facilitated.
The main purpose of the invention is realized by the following technical scheme:
the method for manufacturing the high-speed transmission optical module circuit board structure comprises a lamination method or a layer adding method, preferably, the lamination method comprises the steps of laminating the transmission signal layer and a plurality of adjacent layers on the top surface of the PCB to form an upper half lamination of the multilayer circuit lamination, laminating the integrated circuit layer and the adjacent layers on the bottom surface of the PCB to form a lower half lamination of the multilayer circuit lamination, laminating the upper half lamination and the half lamination to form the multilayer circuit lamination, and more preferably, after laminating the multilayer circuit lamination, performing welding cover painting treatment and not exposing welding covers to the grounding heat dissipation islands.
By adopting the technical scheme, the pre-lamination with the upper part and the lower part separated by the multi-layer circuit lamination body is preferably utilized, the alignment mark of the transmission signal layer and the integrated circuit layer can be kept to the lamination of the upper half lamination body and the lower half lamination body, the alignment degree of the circuit pattern lamination can be improved, and the process yield can be effectively improved.
The main purpose of the invention is realized by the following technical scheme:
the method for preventing the crosstalk of the differential signal wire comprises the steps of arranging first crosstalk-preventing guard columns among a plurality of groups of paired differential signal wires, enabling the first crosstalk-preventing guard columns to be arranged in a row along the extending direction of the wire and to be combined on ground planes in adjacent isolation layers in an outward protruding mode respectively, enabling a through hole to penetrate through the isolation layers of the circuit board and to electrically connect a first section and a second section of the differential signal wire when the differential signal wire is formed in different layers of the circuit board in a segmented mode, enabling a plurality of second crosstalk-preventing guard columns extending in a hole parallel direction to the through hole to be arranged around the through hole and to be combined on the ground planes in the isolation layers in a penetrating mode to be used for consolidating peripheral insulating materials, and preferably further comprising a welding cover covering the differential signal wire and the first and second crosstalk-preventing guard columns.
By adopting the technical scheme, the crosstalk prevention effect of the differential signal wire is enhanced by utilizing the position configuration and combination relationship of the crosstalk prevention guard posts.
The invention also provides an optical module, a circuit board structure of a high-speed transmission optical module according to any of the above technical solutions, which has a reasonable device distribution design, so that the size of the circuit board can be further reduced, and no signal crosstalk problem occurs during high-speed transmission. More preferably, the transmission signal layer provides a COB surface of the multi-layer circuit stack for direct chip mounting on a top surface of the multi-layer circuit stack, and the integrated circuit layer provides an SMT surface of the multi-layer circuit stack for device mounting on a bottom surface of the multi-layer circuit stack.
In summary, the invention includes at least one of the following beneficial technical effects:
1. the circuit board structure of the high-speed transmission optical module is capable of preventing crosstalk and layer peeling;
2. differential signal lines are connected in double-sided multi-row contact fingers, and the differential signal lines designed in a segmented mode are protected from being influenced by thermal stress fracture;
3. the back heat dissipation of the optical communication chip arranged on the top surface of the circuit board is facilitated, and the warping of the multilayer circuit laminated body is reduced;
4. the reasonable and efficient configuration of the devices mounted on the two sides of the circuit board structure of the high-speed transmission optical module is realized, for example, the top surface of the circuit board can be a COB surface, the bottom surface can be an SMT surface, and the structural form of the differential signal line by dividing the surface into sections and partitioning the surface into sections isolates a circuit pattern area which is not used for high-speed data transmission, an intermediate signal layer arranged between the inner surface of the transmission signal layer and the inner surface isolation layer of the integrated circuit layer and a low-speed transmission area arranged on the integrated circuit layer, so that the signal crosstalk phenomenon of the low-speed transmission signal line to the differential signal.
Drawings
FIG. 1 is an exploded perspective view of a high speed transmission optical module with a circuit board structure according to a first preferred embodiment of the present invention;
FIG. 2 is a schematic top view of the high speed transmission optical module on a circuit board structure;
FIG. 3 is a schematic diagram of a transmission signal layer of the high speed transmission optical module circuit board structure from the top surface to the first layer;
FIG. 4 is a schematic diagram of a second layer of the high speed transmission optical module circuit board structure from the top (first isolation layer);
FIG. 5 is a schematic diagram of the third control signal layer from the top of the high speed transmission optical module circuit board structure;
fig. 6 is a schematic diagram illustrating a first groundplane layer (a second isolation layer) of the high speed transmission optical module circuit board structure from the top surface to the fourth layer;
fig. 7 is a schematic diagram of the I2C signal layer of the fifth layer of the high speed transmission optical module circuit board structure from the top;
FIG. 8 is a schematic diagram of a sixth power signal layer (third isolation layer) from the top of the high speed transmission optical module circuit board structure;
fig. 9 is a schematic diagram illustrating a second groundplane layer (a fourth isolation layer) of the high speed transmission optical module circuit board structure from the top surface to the seventh layer;
FIG. 10 is a schematic diagram of an eighth integrated circuit layer from the top of the high speed transmission optical module circuit board structure;
fig. 11 and 12 are schematic diagrams respectively illustrating pin definitions of the high-speed transmission optical module circuit board structure on two sides of the plugging side;
FIG. 13 is a bottom view of the high speed transmission optical module circuit board structure;
FIG. 14 is a block flow diagram illustrating an exemplary method for manufacturing a high speed transmission optical module circuit board structure according to a second preferred embodiment of the present invention;
fig. 15 is a block flow diagram illustrating a method for preventing crosstalk between differential signal lines according to a third preferred embodiment of the present invention.
The reference numeral 1 denotes a multilayer circuit laminated body, 1A denotes a plug side, 1B denotes a positioning slot, 10 denotes a transmission signal layer, 11 denotes a first differential signal line, 12 denotes a first segment of a second differential signal line, 13 denotes a first crosstalk-proof guard post, 14 denotes a second crosstalk-proof guard post, 15 denotes a concave bend, 16 denotes a first thermal via, 17 denotes a second ground heat dissipation island, 10A denotes an optical communication chip mounting region, 10B denotes a first protective element region, 10C denotes a second protective element region, 20 denotes a ground reference layer, 21 denotes a ground plane, 30 denotes a control signal layer, 31 denotes a ground pattern, 32 denotes a control signal line, 40 denotes a first ground plane layer, 41 denotes a ground plane, 50 denotes an I2C signal layer, 51 denotes a ground pattern, 52 denotes an I2C signal line, 60 denotes a power signal layer, 61 denotes a ground pattern, 62 denotes a first ground layer, a second ground pattern, and a third ground pattern, 63. Power supply pattern, 70, a second grounding layer, 71, a grounding surface, 80, an integrated circuit layer, 81, a high-speed transmission area, 82, a low-speed transmission area, 83, a second section of a second differential signal line, 84, a power supply line connecting section, 85, a control line connecting section, 86, a first grounding heat dissipation island, 87, a third anti-crosstalk guard post, 88, a solderless cover exposed opening, 89, a second heat conduction through hole, 82A, a micro-control chip mounting area, 82B, a power MOS tube mounting area, 82C, a power supply chip mounting area, 91, a first row of contact fingers, 92, a second row of contact fingers, 93, a long-connection through hole, 94, a short-connection through hole, 95, a fourth anti-crosstalk guard post, 111, an optical communication chip, 112, an optical signal transceiver, 121, a micro-control chip, 122, a power MOS tube, 123, a power supply chip, 131, a short-circuit protection post, a, The optical fiber connector comprises an upper shell, a lower shell, a pull ring, an optical fiber interface, an upper shell, a pull ring, an optical signal transmission line, a pull ring, an optical fiber connector, a pull ring, an optical signal transmission line and a pull ring, wherein the pull ring.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of embodiments for understanding the inventive concept of the present invention, and do not represent all embodiments, nor do they explain only embodiments. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention under the understanding of the inventive concept of the present invention are within the protection scope of the present invention.
It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indications are changed accordingly.
In order to facilitate understanding of the technical solution of the present invention, the circuit board structure of the high-speed transmission optical module, the manufacturing method thereof, and the crosstalk prevention method of the present invention will be described and explained in further detail below, but are not to be construed as the scope of protection defined by the present invention.
In the first explanation, the row direction is the same direction as the side edge of the optical module insertion/extraction side in the horizontal plane of the board surface, and the row direction is the row direction perpendicular to or close to the vertical direction, and is usually the same as the optical module insertion/extraction direction or slightly inclined (deflected to a curved section with a slope of not more than 45 degrees). The optical module is generally in the shape of a long bar, and one end of the optical module is an optical fiber interface, and the other end of the optical module is a plug interface combined with communication equipment. The term "long" refers to a long distance from the linker, and the term "short" refers to a short distance from the linker. The line gap refers to a space between lines without wiring, and the line side refers to a space without wiring on one or both outer sides of the aggregate after all lines are regarded as one aggregate. "regular assignment" refers to a regular distribution, such as a single linear arrangement or multiple linear arrangements, rather than a random, chaotic assignment of positions. The arrangement along the line extending direction means that the arrangement path of the specified objects is consistent with the line extending path of the adjacent line, for example, a certain line is linear, a plurality of the adjacent objects (specifically, the anti-crosstalk pillars) are also arranged according to the adjacent parallel virtual lines of the certain line, when the certain line is bent, a plurality of the adjacent objects (specifically, the anti-crosstalk pillars) are also arranged in a bent manner, and the shortest allowable distance from the distance between the adjacent objects and the target line segment for compliant arrangement is controlled within a tolerable target value range. The relationship "corresponding" includes one or more of signal correspondence, position correspondence, quantity correspondence and size correspondence, and should be interpreted reasonably in light of the objective technical conditions of the two correspondences (or groups of objects). The "high-speed transmission area" generally refers to a concentrated area of the circuit layer of the circuit board where the differential signal lines for transmitting data at high speed are required to be disposed, and the "low-speed transmission area" generally refers to another concentrated area of the circuit layer of the circuit board where the differential signal lines for transmitting data at high speed are not required to be disposed, and the high-speed transmission area and the low-speed transmission area do not overlap on the same plane. "bollard" refers to a rigid body of stud fixed to either side of a line segment and protruding from the bonded or penetrated substrate (specifically, the ground plane), typically harder than the surrounding dielectric material, for mitigating or sharing the deleterious effects of external signals and stresses on the protected line segment, and is typically made of a metallic material or a rigid composite material including a conductive material.
The circuit board structure exemplified in the following examples of the present invention is suitable for high speed transmission optical modules, such as 100GQSFP28SR4 optical modules, but is not limited thereto and can be applied to other types of optical modules under the same inventive concept.
FIG. 1 is an exploded perspective view of a high speed transmission optical module with a circuit board structure according to a first preferred embodiment of the present invention; fig. 2 is a schematic top view of the high speed transmission optical module on a circuit board structure. The main body of the circuit board structure of the high-speed transmission optical module according to an example of the present invention includes a multi-layer circuit laminated body 1, which is installed in an upper housing 131 and a lower housing 132 of the optical module. The multilayer circuit laminated body 1 has a plugging side 1A on one short side for plugging and electrically connecting to a communication device having a plugging and mounting hole, and positioning slot holes 1B on two long sides, the plugging side 1A is provided with a first row of contact fingers 91 on the top surface and a row of contact fingers (detailed later) on the bottom surface, and the positioning slot holes 1B are used for positioning the multilayer circuit laminated body 1 in an upper shell 131 and a lower shell 132. The top surface of the multi-layer circuit laminated body 1 is provided with an optical communication chip 111, the top surface of the multi-layer circuit laminated body 1 is provided with an optical signal transceiver 112 at the other shorter side relatively far away from the plugging side 1A, and the optical signal transceiver 112 is used for transmitting the received high-speed signal to the optical communication chip 111. The optical signal transmission line 142 is connected to the optical signal transceiver 112 and the optical fiber interface 141 at one end of the optical module. The optical fiber interface 141 is provided with a pull ring 133 to facilitate the plugging and unplugging of the optical module by the communication device. The optical module may specifically be a 100G QSFP28SR4 optical module.
In this embodiment, but not limited to, the multi-layer circuit laminate 1 may have an eight-layer circuit structure, and the circuit layer structures from the top surface to the bottom surface are shown in fig. 3 to 10, respectively. FIG. 3 is a schematic diagram of a first layer of transmission signal layers from the top; FIG. 4 is a schematic diagram of a ground reference layer (first isolation layer) of the second layer; FIG. 5 is a schematic diagram of a control signal layer of the third layer; FIG. 6 is a schematic diagram of a fourth layer of a first groundplane layer (second isolation layer); FIG. 7 is a schematic diagram of the I2C signal layer of the fifth layer, FIG. 8 is a schematic diagram of the power signal layer (the third isolation layer) of the sixth layer, and FIG. 9 is a schematic diagram of the second ground plane layer (the fourth isolation layer) of the seventh layer; fig. 10 is a schematic diagram of an integrated circuit layer of the eighth layer.
The circuit board structure of the high-speed transmission optical module provided by this example includes a multi-layer circuit lamination body 1, a first row of contact fingers 91 (shown in fig. 3) located on one side of the top surface, a second row of contact fingers 92 (shown in fig. 10) located on one side of the bottom surface and corresponding to the first row of contact fingers 91, a long via hole 93 penetrating through the multi-layer circuit lamination body 1, and a short via hole 94 (shown in fig. 3 and 10) adjacent to the contact fingers.
The multilayer circuit laminated body 1 comprises a transmission signal layer 10, a control signal layer 30, a power signal layer 60 and an integrated circuit layer 80 which are separated by isolation layers, wherein at least one isolation layer is arranged between the signal layers, and the isolation layers comprise ground plane structures. As shown in fig. 3, the transmission signal layer 10 includes a plurality of pairs of first differential signal lines 11 and a plurality of pairs of first segments 12 of second differential signal lines. As shown in fig. 10, the integrated circuit layer 80 is divided into a high speed transmission region 81 and a low speed transmission region 82, and the integrated circuit layer 80 includes a second segment 83 of the second differential signal line located in the high speed transmission region 81, and a power line connection segment 84, a control line connection segment 85 and a first ground heat dissipation island 86 located in the low speed transmission region 82.
As shown in fig. 3, the first row of contact fingers 91 is disposed on the plugging side 1A of the transmission signal layer 10, and the first differential signal line 11 is connected to the first row of contact fingers 91 corresponding to the pins, as shown in fig. 10, the second row of contact fingers 92 is disposed on the plugging side 1A of the integrated circuit layer 80 corresponding to the first row of contact fingers 91, and the second segment 83 of the second differential signal line is connected to the second row of contact fingers 92 corresponding to the high-speed transmission pins.
Observing the position of the long via hole 93 from fig. 3 and 10 and comparing fig. 5 and 7, the long via hole 93 passes through the control signal layer 30, the power signal layer 60 and the isolation layer and electrically connects the first segment 12 and the second segment 83 of the second differential signal line. Referring to fig. 10, the short via hole 94 electrically connects the pins of the second row of contact fingers 92 except the high speed transmission pins to the corresponding control signal layer 30 and the power signal layer 60, and the distance from the short via hole 94 to the correspondingly connected second row of contact fingers 92 is smaller than the distance from the long via hole 93 to the correspondingly connected second row of contact fingers 92.
In the observation direction toward the board surface, the extension of the second segment 83 of the second differential signal line toward the device region is offset from the first differential signal line 11, so that the long via hole 93 is regularly distributed in the gap or the side between the first differential signal lines 11.
And, as shown in fig. 3, the transmission signal layer 10 further includes a plurality of first crosstalk prevention guard posts 13 and a plurality of second crosstalk prevention guard posts 14, the first crosstalk prevention guard posts 13 are arranged in a row along the line extending direction at the gaps or sides between the pairs of adjacent first differential signal lines 11, the second crosstalk prevention guard posts 14 are arranged in a line along the line extending direction at the gap or side between the first differential signal line 11 and the first section 12 of the second differential signal line; as shown in figure 10 of the drawings, the integrated circuit layer 80 further includes a plurality of third crosstalk prevention posts 87 arranged in a row in the line extending direction at the gaps or sides of the second section 83 of the second differential signal line, the first, second and third crosstalk prevention posts 13,14 and 87 are respectively protrusively bonded to the ground plane in the adjacent isolation layer. Specifically, the first and second anti-crosstalk protection posts 13 and 14 are coupled to the ground reference plane 21 of the ground reference layer 20 shown in fig. 4, and the third anti-crosstalk protection post 87 is coupled to the ground plane 71 of the second ground layer 70 shown in fig. 9.
The basic principle of the present invention is that the transmission signal layer 10 is used as the main wiring area of the differential signal line, the high-speed transmission area 81 of the integrated circuit layer 80 is used as the secondary wiring area of the differential signal line segment, the adjacent isolation layers of the transmission signal layer 10 and the integrated circuit layer 80 have ground plane structures, and a plurality of anti-crosstalk protection posts 13,14,87 arranged in a row along the line extending direction are arranged at the gaps or sides between the differential signal lines 11,12,83, and the anti-crosstalk protection posts 13,14,87 are respectively and externally protruded and combined on the ground planes 21,71 in the adjacent isolation layers. Under the structural design, the differential signal lines 11,12 and 83 can obtain the effect of preventing signal crosstalk in the optical module circuit board, and the bonding strength between the inner layers of the circuit board is higher, so that the differential signal lines also have the stress protection effect.
Referring to fig. 3, in a preferred example, the transmission signal layer 10 can be used as a circuit board structure on a top circuit layer on which an optical communication chip is mounted, and the transmission signal layer 10 mainly runs 4 × 25G high-speed signal lines by using differential signal lines, and in an actual product, eight pairs of differential signal lines are specifically provided, so that the differential impedance of the signal lines for high-speed data transmission is accurately controlled to 100 ohms; meanwhile, the first crosstalk prevention guard post 13 and the second crosstalk prevention guard post 14 disposed along the side of the differential signal line are preferably ground planes connected in series by two layers, but do not penetrate through the entire multilayer circuit laminated body 1, so as to reduce the reflow area.
Referring to fig. 3 and 10, in a preferred example, the junction of the first differential signal line 11 and the corresponding first row of contact fingers 91 or/and the junction of the second segment 83 of the second differential signal line and the corresponding second row of contact fingers 92 form symmetrically converging oblique edges, preferably having a pair of concave bends 15. Therefore, the symmetrical convergent bevel shape of the connection between the differential signal line and the corresponding contact finger can prevent the discontinuity of impedance caused by the abrupt change of the width of the transmission signal line, and preferably, the signal reflection phenomenon at the time of outputting and inputting data under high-speed transmission at the connection between the contact fingers can be reduced by using the paired concave bends 15.
Referring to fig. 10 and 13, which respectively show the integrated circuit layer 80 (corresponding to the bottom surface of the circuit board) before and after mounting the device, in a preferred example, the first ground heat-dissipation island 86 has a solderless exposed opening 88 opposite to the optical communication chip, and preferably, in conjunction with fig. 3, the signal transmission layer 10 is provided with a plurality of first thermal vias 16 thermally coupled to the first ground heat-dissipation island 86. Therefore, the first grounding heat-dissipation island 86 of the integrated circuit layer 80 is used to provide the solderless-cover-exposed opening 88 corresponding to the optical communication chip in the reverse direction, so as to accelerate the reverse-side convection heat dissipation of the optical communication chip mounted on the front side on the back side of the circuit board, and when the temperatures of the front side and the bottom side of the multilayer circuit board structure are close to each other, the reduction of the temperature difference between the two sides of the circuit board structure during operation can prevent the multilayer circuit laminated body 1 from warping and deforming.
Referring to fig. 3, in addition to the transmission signal layer 10 being configured with a plurality of first thermal vias 16 in the optical communication chip mounting area 10A, the transmission signal layer 10 may further include a second ground heat-dissipation island 17 corresponding to the micro-control chip mounting area 82A of the integrated circuit layer 80, and referring to fig. 10, the integrated circuit layer 80 is configured with a plurality of second thermal vias 89 thermally coupled to the second ground heat-dissipation island 17, so as to form a bidirectional and double-sided thermal conduction and dissipation effect. The second ground heat-dissipation island 17 is aligned with the mounting position of the optical transceiver, and is preferably covered without a solder mask, so as to facilitate the mounting of the optical transceiver 112.
Referring to fig. 10, in a preferred example, the high speed transmission region 81 of the integrated circuit layer 80 is located between the plugging side and the connection lines of the two side positioning slots 1B. Therefore, the multilayer circuit laminated body 1 can be positioned in the upper and lower housings of the optical module by the positioning groove hole 1B. The connecting lines of the two side positioning slots 1B can also be used to plan the maximum boundary position of the high-speed transmission region 81 of the integrated circuit layer 80, i.e. the wiring area of the second section 83 of the second differential signal line can be limited between the contact finger and the connecting line of the two side positioning slots 1B, so as to achieve the partition management of the second differential signal line.
Referring to fig. 3 and 10, in a preferred example, the device region includes an optical communication chip mounting region 10A, a micro control chip mounting region 82A, a power MOS transistor mounting region 82B, and a power chip mounting region 82C, the optical communication chip mounting region 10A is located in the transmission signal layer 10, and the micro control chip mounting region 82A, the power MOS transistor mounting region 82B, and the power chip mounting region 82C are located in the low speed transmission region 82 of the integrated circuit layer 80. Therefore, the optimal configuration of the positions of the optical communication chip mounting area 10A, the micro-control chip mounting area 82A, the power MOS transistor mounting area 82B and the power chip mounting area 82C is utilized to achieve the facet management of the circuit board structure double-sided device mounting based on the high-low speed signal separation design.
In the sequence of stacking of fig. 3-10, in a preferred example, the isolation layers include a ground reference layer 20 between the transmission signal layer 10 and the control signal layer 30, a first groundplane layer 40 between the control signal layer 30 and the power signal layer 60, and a second groundplane layer 70 between the power signal layer 60 and the integrated circuit layer 80, and preferably, the multilayer circuit stack 1 further includes an I2C signal layer 50 between the first groundplane layer 40 and the power signal layer 60. Therefore, with the specific structure of the isolation layer between the signal layers, the first crosstalk prevention post 13 and the second crosstalk prevention post 14 can be coupled to the ground reference layer 20 in a short path, the third crosstalk prevention post 87 can be coupled to the second ground plane layer 70 in a short path, the upper and lower posts can be distributed without interfering with each other, and the wiring design of other signal layers can be not disturbed much compared to the ground pattern of the wrapping line.
Referring to fig. 4, in an embodiment of the ground reference layer 20, the ground reference layer 20 includes a large-area ground plane 21, in order to ensure high-quality transmission of high-speed transmission signals, the ground plane 21 is a monolithic ground plane, preferably without routing other power signal lines or data transmission signal lines, in order to reduce crosstalk between transmission and reception caused by top-layer signals, between two corresponding ground planes of the two sets of signal lines, the ground plane 21 is formed with a cut-slit (e.g., a longitudinal slit in the lower half of fig. 3) in an arrangement region of the differential signal lines, referring to fig. 6 and 9, the first and second ground planes 40 and 70 each include a large-area ground 41,71, the first ground plane 40 is used to isolate high-speed transmission signals from the power structure, to reduce noise interference of power sources to high-speed transmission signals, the second ground plane 70 is used to isolate non-high-speed signal layers from the power structure, referring to fig. 5, the control signal layer 30 specifically includes a longer routing wire extending control signal line 32 and a ground pattern 31 wrapping the control signal line 32 with a cut-out area, the routing layer is used to isolate the power source signal layers 70 from the power source structure, the power source layer 20 includes a power source signal routing pattern 62, a more detailed routing pattern 62, the power source pattern 26 is used to reduce noise of the serial routing pattern 62, the serial routing pattern 54, the serial routing pattern of the serial routing layer 18, the serial routing pattern of the serial routing layer 18, the serial routing layer 54, the serial routing pattern of the serial routing.
Looking at the arrangement positions of the long via holes 93 in fig. 3 to 10, in a preferred example, a plurality of fourth crosstalk-proof pillars 95 extending parallel to the holes are disposed around the long via holes 93, and are penetratingly coupled to the ground planes 21 and 71 in the isolation layer for consolidating the peripheral insulating material. Therefore, the fourth crosstalk prevention guard post 95 provided around the long via hole 93 increases the crosstalk prevention effect of the via hole connected between the segmented differential signal lines while preventing the long via hole 93 from being broken under thermal stress. The via hole 93 is formed with a large-sized avoiding hole in the peripheral area of the via hole 93 at other layers except the signal transmission layer 10 and the integrated circuit layer 80, thereby preventing the via hole from being connected in series with a control line, a power line and an inner-layer grounding structure. And the fourth crosstalk prevention guard post 95 may be disposed at a corner of the avoidance hole.
Referring to fig. 3, in a preferred example, the signal transmission layer 10 includes a plurality of first protection element regions 10B and a plurality of second protection element regions 10C, the first protection element regions 10B divide the first differential signal lines 11 into contact finger connecting sections and first device connecting sections, the second protection element regions 10C divide the first differential signal lines 12 into intermediate sections and second device connecting sections, the long contact via holes 93, the second protection element regions 10C and the first protection element regions 10B are preferably arranged in a zigzag manner, the first protection element regions 10B are closer to the first row of contact fingers 91 than the second protection element regions 10C, the first protection element regions 10B are substantially located at the middle positions of zigzag diagonal bars, the long contact via holes 93 and the second protection element regions 10C are disposed at both ends of the zigzag diagonal bars, and more preferably, the fourth crosstalk prevention guard post 95 is overlapped with a part of the first crosstalk prevention guard post 13 or/and the second crosstalk prevention guard post 14 in a corresponding position. Therefore, by the arrangement of the long via hole 93, the second protection device region 10C and the first protection device region 10B, the middle section of the first section 12 of the second differential signal line still has a certain extension length, so that the protection device, such as a capacitor, can be bonded to the first protection device region 10B and the second protection device region 10C at a distance sufficient for surface mounting, and facilitates the patterned solder mask coverage of the top surface of the circuit board. In addition, the solder mask can prevent the short circuit of the signal caused by the long-joint via hole 93 and the neighboring fourth crosstalk-proof guard post 95 falling to the board surface due to the pollution dust particles, and also prevent the short circuit of the crosstalk- proof guard posts 13,14,87 and the signal of the neighboring differential signal line.
Fig. 11 and 12 respectively illustrate pin definitions of the high-speed transmission optical module circuit board structure on both sides of the plugging side 1A. In fig. 11, the longer line connected with the capacitor in the first row of contact fingers 91 is a data high-speed transmission pin, which includes 4 pairs of TX2N _ D, TX2P _ D, TX4 _ 4N _ D, TX4P _ D, RX3P _ D, RX3 _ 3N _ D, RX1P _ D, RX1 _ 1N _ D, the corresponding pin numbers are 2 and 3, 5 and 6, 14 and 15, and 17 and 18, and the transmission signal layer 10 has 4 pairs of first differential signal lines 11 in common. In fig. 12, the longer line connected with the capacitor in the second row of contact fingers 92 is also a data high-speed transmission pin, and includes 4 pairs of TX1N _ D, TX1 _ 1P _ D, TX3 _ 3N _ D, TX3P _ D, RX4 _ 4P _ D, RX4 _ 4N _ D, RX2 _ 2P _ D, RX2 _ 2N _ D, the corresponding pin numbers are 37 and 36, 34 and 33, 25 and 24, 22 and 21, and the integrated circuit layer 80 has a second segment 83 of 4 pairs of second differential signal lines. Wherein the pin marks 2 and 3 of the first row of contact fingers 91 are longitudinally corresponding to the pin marks 37 and 36 of the second row of contact fingers 92, respectively, in terms of positional relationship.
Fig. 13 is a bottom view of the high speed transmission optical module circuit board structure after mounting devices thereon. Other embodiments of the present invention further provide an optical module, such as a circuit board structure of a high-speed transmission optical module according to any of the above-mentioned technical solutions, which has a reasonable device distribution design, so that the size of the circuit board can be further reduced without causing signal crosstalk problem under high-speed transmission, and preferably, the optical module is mounted on the top surface of the multi-layer circuit stacked body 1 and includes an optical communication chip 111 and an optical signal transceiver 112, and the micro-control chip 121, the power MOS 122 and the power supply chip 123 are mounted on the bottom surface of the multi-layer circuit stacked body 1. More preferably, the transmission signal layer 10 provides a COB surface of the multi-layer circuit stack 1 for direct chip mounting on the top surface of the multi-layer circuit stack 1, and the integrated circuit layer 80 provides an SMT surface of the multi-layer circuit stack 1 for device mounting on the bottom surface of the multi-layer circuit stack 1. COB is short for Chip-On-Board and shows that the Chip can be directly mounted On the circuit Board, and SMT is short for Surface Mounting Technology and shows a Technology for Mounting a device by using welding, wherein the device is usually a packaged Chip and has a packaging structure with welding terminals. The optical communication chip 111 is specifically a 100G optical chip, because the optical communication chip 111 is preferably directly mounted on the circuit board, a bonding area for electrically connecting with the driving power chip is arranged at the side of the optical communication chip mounting area 10A, and a chip bonding and wire bonding technology (die bond and wire bond) is adopted, so that the optical-electrical chip is directly attached to the circuit board (direct binding of the optical-electrical chip on the PCB is completed), which is different from the traditional BOX (BOX) packaging, thereby reducing the device cost, reducing the production process, saving the significant layout space, and being beneficial to radiating to the back of the circuit board. In the installation area of the optical transceiver 112, since the lens is required to be placed, it is preferable that the layout of components is not performed, and the copper sheet is mainly laid, not covered with the green oil, and sufficiently contacted with the air, which is beneficial to the heat dissipation of the PCBA and the stable operation of the optical chip, that is, the second grounding heat dissipation island 17 is exposed without a solder mask.
A second embodiment of the present invention proposes a method for manufacturing a high-speed transmission optical module circuit board structure according to any one of the above examples, wherein the manufacturing step of the multilayer circuit laminated body 1 comprises a lamination method or a layer-adding method. The preferred process steps can be seen in fig. 14, where the layer lamination process includes:
s1, laminating the transmission signal layer 10 on the top surface of the PCB with a plurality of adjacent layers (such as the ground reference layer 20, the control signal layer 30 and the first ground plane layer 40) to form a top half laminate of the multilayer circuit laminate 1;
s2, laminating the integrated circuit layer 80 on the bottom surface of the PCB and a plurality of adjacent layers (such as a second grounding layer 70, a power signal layer 60 and an I2C signal layer 50) to form a lower half laminated body of the multilayer circuit laminated body 1;
s3, laminating the upper half laminated body and the half laminated body into the multilayer circuit laminated body 1;
s4, as a preferred embodiment, the top and bottom surfaces of the circuit board may then be painted with solder mask, and the solder mask is patterned to expose the center portion of the first ground heat island 86 without solder mask, and preferably also to include the center portion of the second ground heat island 17.
Therefore, it is preferable to divide the multi-layer circuit lamination body 1 into pre-lamination with upper and lower portions separated, so that the alignment marks of the transmission signal layer 10 and the integrated circuit layer 80 can be retained to the lamination of the upper and lower half lamination bodies, thereby improving the alignment of the circuit pattern lamination and effectively improving the process yield.
Referring to fig. 15, a third embodiment of the present invention provides a method for preventing crosstalk between differential signal lines, including the following steps:
s11, arranging first anti-crosstalk guard posts 13,14 between the differential signal lines 11 in pairs, wherein the first anti-crosstalk guard posts 13,14 are arranged in a line along the line extending direction and are respectively combined to the grounding surfaces 21 in the adjacent isolation layers in an outwards protruding mode;
s12, when the differential signal line is sectionally formed in different layers of the circuit board, a via hole 93 penetrates through the isolation layer of the circuit board and electrically connects the first section 12 and the second section 83 of the differential signal line;
s13, a plurality of second anti-crosstalk protection posts 95 extending parallel to the holes are additionally arranged around the via hole 93, and are penetratingly combined with the ground planes 21 and 71 in the isolation layer for consolidating the peripheral insulating materials, so that the anti-crosstalk effect of the differential signal wire is enhanced by utilizing the position configuration and combination relationship of the anti-crosstalk protection posts;
s14, as a preferred specific step, the solder mask covers the differential signal line and the first and second anti-crosstalk pillars 13,14 and 95, so that the anti-crosstalk pillars are embedded without changing the appearance and color of the circuit board structure.
The first crosstalk- proof guard posts 13 and 14 can also play a role in high-speed signal backflow, wherein one main role is to increase an anti-reflection backflow path; the second crosstalk prevention guard post 95 has a backflow effect around the high-speed differential signal layer changing hole, and plays a role in maintaining impedance continuity except for increasing a backflow path, and the diameters of the two and the size of a fixed joint surface need to be adapted after simulation. Specifically, the crosstalk prevention guard posts 13,14, and 95 are substantially cylindrical in shape, and have a diameter about 1 to 3 times the diameter of the adjacent differential signal lines, and a gap between adjacent crosstalk prevention guard posts is about 0.5 to 5 times the diameter of the crosstalk prevention guard posts, and the crosstalk prevention guard posts extend along the lines to form virtual guard lines that protect both side edges of the differential signal lines.
The embodiments of the present invention are merely preferred embodiments for easy understanding or implementing of the technical solutions of the present invention, and not intended to limit the scope of the present invention, and all equivalent changes in structure, shape and principle of the present invention should be covered by the claims of the present invention.

Claims (10)

1. A circuit board structure of a high-speed transmission optical module is characterized by comprising:
a multilayer circuit laminate (1) comprising a transmission signal layer (10), a control signal layer (30), a power signal layer (60) and an integrated circuit layer (80) separated by isolation layers, each signal layer being separated by at least one of said isolation layers (20,40,70), the isolation layer (20,40,70) comprises a ground plane structure, the transmission signal layer (10) comprises a plurality of pairs of first differential signal lines (11) and a plurality of pairs of first segments (12) of second differential signal lines, the integrated circuit layer (80) is divided into a high-speed transmission region (81) and a low-speed transmission region (82), the integrated circuit layer (80) comprises a second section (83) of the second differential signal line positioned in the high-speed transmission area (81), a power line connecting section (84) positioned in the low-speed transmission area (82), a control line connecting section (85) and a grounding heat dissipation island (86);
the first row of contact fingers (91) are arranged on the plugging side (1A) of the transmission signal layer (10), and the first differential signal line (11) is connected to the first row of contact fingers (91) of the corresponding pin position;
a second row of contact fingers (92) corresponding to the first row of contact fingers (91) and arranged on the plug side (1A) of the integrated circuit layer (80), wherein a second section (83) of the second differential signal line is connected to the second row of contact fingers (92) corresponding to the high-speed transmission pins;
a long via hole (93) passing through the control signal layer (30), the power signal layer (60) and the isolation layer (20,40,70) and electrically connecting the first segment (12) and the second segment (83) of the second differential signal line;
the short-circuit through hole (94) is used for electrically connecting other part of pins of the second row of contact fingers (92) except for high-speed transmission pins to the corresponding control signal layer (30) and the power signal layer (60), and the distance from the short-circuit through hole (94) to the correspondingly connected second row of contact fingers (92) is smaller than the distance from the long-circuit through hole (93) to the correspondingly connected second row of contact fingers (92);
in the observation direction towards the board surface, the extension of the second section (83) of the second differential signal line to the device area is staggered with the first differential signal line (11), so that the long connecting via hole (93) is regularly distributed in the gap or the side edge between the first differential signal lines (11);
and the transmission signal layer (10) further comprises a plurality of first crosstalk prevention guard columns (13) and a plurality of second crosstalk prevention guard columns (14), the first crosstalk prevention guard columns (13) are arranged in a line along the line extending direction at the gaps or the sides between the pairs of adjacent first differential signal lines (11), the second crosstalk prevention guard columns (14) are arranged in a line along the line extending direction at the gaps or the sides between the first differential signal lines (11) and the first sections (12) of the second differential signal lines, the integrated line layer (80) further comprises a plurality of third crosstalk prevention guard columns (87) arranged in a line along the line extending direction at the gaps or the sides of the second sections (83) of the second differential signal lines, and the first crosstalk prevention guard columns (13), the second crosstalk prevention guard columns (14) and the third crosstalk prevention guard columns (87) are respectively and convexly combined to the adjacent isolation layers (20), 70) on the ground plane (21, 71).
2. High speed transmission light module circuit board structure according to claim 1, characterized in that the connection of the first differential signal line (11) to the corresponding first row of contact fingers (91) or/and the connection of the second section (83) of the second differential signal line to the corresponding second row of contact fingers (92) form symmetrically converging oblique edges, preferably with a pair of concave bends (15).
3. The high-speed transmission optical module circuit board structure of claim 1, wherein the ground heat-dissipation island (86) has a solderless exposed opening (88) corresponding to the optical communication chip, preferably the transmission signal layer (10) is provided with a plurality of heat-conducting through holes (16) thermally coupled to the ground heat-dissipation island (86), or/and the multi-layer circuit laminated body (1) has two-sided positioning slots (1B), and the high-speed transmission region (81) of the integrated circuit layer (80) is located between the plugging side and the connection line of the two-sided positioning slots (1B).
4. The high-speed transmission optical module circuit board structure according to claim 1, wherein the device region comprises an optical communication chip mounting region (10A), a micro control chip mounting region (82A), a power MOS transistor mounting region (82B), and a power chip mounting region (82C), the optical communication chip mounting region (10A) is located in the transmission signal layer (10), and the micro control chip mounting region (82A), the power MOS transistor mounting region (82B), and the power chip mounting region (82C) are located in the low-speed transmission region (82) of the integrated circuit layer (80).
5. The high speed transmission optical module circuit board structure according to claim 1, wherein the isolation layer (20,40,70) comprises a ground reference layer (20) between the transmission signal layer (10) and the control signal layer (30), a first ground plane layer (40) between the control signal layer (30) and the power signal layer (60), and a second ground plane layer (70) between the power signal layer (60) and the integrated circuit layer (80), preferably the multilayer circuit laminate (1) further comprises an I2C signal layer (50) between the first ground plane layer (40) and the power signal layer (60).
6. The high speed transmission optical module circuit board structure according to any one of claims 1-5, wherein a plurality of fourth crosstalk-proof guard posts (95) extending parallel to the holes are arranged around the long via holes (93), penetratingly bonded to the ground plane (21,41,71) in the isolation layer (20,40,70), for consolidating the peripheral insulating material.
7. The high speed transmission optical module circuit board structure of claim 6, wherein the transmission signal layer (10) comprises a plurality of first protection element regions (10B) and a plurality of second protection element regions (10C), the first protection element regions (10B) divide the first differential signal lines (11) into contact finger connecting sections and first device connecting sections, the second protection element regions (10C) divide the first sections (12) of the second differential signal lines into intermediate section and second device connecting sections, preferably the long connection via holes (93), the second protection element regions (10C) and the first protection element regions (10B) are arranged in a zigzag staggered manner, the first protection element regions (10B) are closer to the first row of contact fingers (91) than the second protection element regions (10C), and the first protection element regions (10B) are located approximately in the middle of a zigzag diagonal, more preferably, the fourth crosstalk prevention guard post (95) is overlapped and integrated with a part of the first crosstalk prevention guard post (13) or/and the second crosstalk prevention guard post (14) in a corresponding position.
8. A method for manufacturing a circuit board structure of a high-speed transmission optical module according to any one of claims 1-7, wherein the step of forming the multi-layer circuit laminate (1) comprises a lamination method or a layer-adding method, preferably the lamination method comprises laminating the transmission signal layer (10) on the top surface of the PCB and a plurality of adjacent layers to form an upper half laminate of the multi-layer circuit laminate (1), laminating the integrated circuit layer (80) on the bottom surface of the PCB and a plurality of adjacent layers to form a lower half laminate of the multi-layer circuit laminate (1), then laminating the upper half laminate and the half laminate to form the multi-layer circuit laminate (1), and more preferably, after laminating the multi-layer circuit laminate, further comprising a solder mask painting treatment and no solder mask grounding heat dissipation island exposure.
9. A method for preventing crosstalk in differential signal lines, comprising providing first crosstalk-preventing guard columns (13,14,15) between a plurality of pairs of differential signal lines (11,12,83), the first crosstalk-preventing guard columns (13) being arranged in a line extending direction and being respectively protrudingly bonded to ground planes (21,71) in adjacent isolation layers (20,70), and when the differential signal lines are sectionally formed in different layers of a circuit board, passing a via hole (93) through the isolation layers (20,70) of the circuit board and electrically connecting a first section (12) and a second section (83) of the differential signal lines, while a plurality of second crosstalk-preventing guard columns (95) extending in parallel with the hole are additionally provided around the via hole (93), penetratingly bonded to the ground planes (21,71) in the isolation layers (20,70), for reinforcing a peripheral insulating material, preferably, the differential signal wire and the first and second crosstalk-proof guard columns (13,14,15,95) are covered by the welding cover.
10. An optical module, comprising a circuit board structure of a high-speed transmission optical module according to any one of claims 1 to 7, preferably, an optical communication chip (111) and an optical signal transceiver (112) are mounted on the top surface of the multi-layer circuit stack (1), a micro-control chip (121), a power MOS (122) and a power supply chip (123) are mounted on the bottom surface of the multi-layer circuit stack (1), more preferably, the transmission signal layer (10) provides a COB surface of the multi-layer circuit stack (1) for direct chip mounting on the top surface of the multi-layer circuit stack (1), and the integrated circuit layer (80) provides an SMT surface of the multi-layer circuit stack (1) for device mounting on the bottom surface of the multi-layer circuit stack (1).
CN202010339662.7A 2020-06-18 2020-06-18 High-speed transmission optical module circuit board structure and manufacturing method thereof and crosstalk prevention method Active CN111511097B (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN202011409623.6A CN112437537B (en) 2020-06-18 2020-06-18 High-speed transmission optical module and manufacturing method thereof
CN202010339662.7A CN111511097B (en) 2020-06-18 2020-06-18 High-speed transmission optical module circuit board structure and manufacturing method thereof and crosstalk prevention method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010339662.7A CN111511097B (en) 2020-06-18 2020-06-18 High-speed transmission optical module circuit board structure and manufacturing method thereof and crosstalk prevention method

Related Child Applications (1)

Application Number Title Priority Date Filing Date
CN202011409623.6A Division CN112437537B (en) 2020-06-18 2020-06-18 High-speed transmission optical module and manufacturing method thereof

Publications (2)

Publication Number Publication Date
CN111511097A true CN111511097A (en) 2020-08-07
CN111511097B CN111511097B (en) 2020-12-29

Family

ID=71874704

Family Applications (2)

Application Number Title Priority Date Filing Date
CN202010339662.7A Active CN111511097B (en) 2020-06-18 2020-06-18 High-speed transmission optical module circuit board structure and manufacturing method thereof and crosstalk prevention method
CN202011409623.6A Active CN112437537B (en) 2020-06-18 2020-06-18 High-speed transmission optical module and manufacturing method thereof

Family Applications After (1)

Application Number Title Priority Date Filing Date
CN202011409623.6A Active CN112437537B (en) 2020-06-18 2020-06-18 High-speed transmission optical module and manufacturing method thereof

Country Status (1)

Country Link
CN (2) CN111511097B (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113281859A (en) * 2021-05-18 2021-08-20 青岛海信宽带多媒体技术有限公司 Optical module
CN114384648A (en) * 2020-10-20 2022-04-22 青岛海信宽带多媒体技术有限公司 Optical module
TWI769063B (en) * 2021-03-25 2022-06-21 嘉雨思科技股份有限公司 Signal transmission circuit packaging structure
TWI777570B (en) * 2021-05-21 2022-09-11 嘉雨思科技股份有限公司 Signal transmission circuit packaging structure
TWI828130B (en) * 2022-04-29 2024-01-01 國立臺北科技大學 A connector structure and a method to increase data transmission rate

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114217390B (en) * 2021-12-24 2024-02-23 苏州浪潮智能科技有限公司 Optical switch design method, optical switch, electronic device, and storage medium

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050245103A1 (en) * 2004-04-30 2005-11-03 Ellison Thomas L Transceiver module having a flexible circuit
CN101277593A (en) * 2008-04-16 2008-10-01 北京星网锐捷网络技术有限公司 Light communication apparatus
US20090263140A1 (en) * 2008-04-22 2009-10-22 Osamu Kagaya Optical communication module and flexible printed circuit board
CN103163603A (en) * 2011-12-16 2013-06-19 富士通光器件株式会社 Optical transceiver and production method thereof
CN104996001A (en) * 2012-11-28 2015-10-21 泰科电子瑞典控股有限责任公司 Electrical connection interface for connecting electrical leads for high speed data transmission

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4036008B2 (en) * 2002-02-13 2008-01-23 住友電気工業株式会社 Parallel transceiver module
JP4566089B2 (en) * 2005-08-08 2010-10-20 日本電信電話株式会社 Bidirectional optical transceiver using flexible substrate
TWI384268B (en) * 2008-12-01 2013-02-01 Ho Ming Feng Small form-factor pluggable transceiver module
US8267718B2 (en) * 2010-04-07 2012-09-18 Panduit Corp. High data rate electrical connector and cable assembly
JP5919873B2 (en) * 2012-02-21 2016-05-18 富士通株式会社 Multilayer wiring board and electronic device
US9300092B1 (en) * 2014-09-30 2016-03-29 Optical Cable Corporation High frequency RJ45 plug with non-continuous ground planes for cross talk control
CN107896418B (en) * 2017-10-10 2020-11-06 青岛海信宽带多媒体技术有限公司 Optical module
US11589458B2 (en) * 2018-10-17 2023-02-21 Hisense Broadband Multimedia Technologies Co., Ltd. Circuit board and optical module
CN110596829B (en) * 2019-09-16 2022-01-07 青岛海信宽带多媒体技术有限公司 Optical module with OTDR function
CN110780397B (en) * 2019-11-08 2021-07-27 青岛海信宽带多媒体技术有限公司 Optical module

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050245103A1 (en) * 2004-04-30 2005-11-03 Ellison Thomas L Transceiver module having a flexible circuit
CN101277593A (en) * 2008-04-16 2008-10-01 北京星网锐捷网络技术有限公司 Light communication apparatus
US20090263140A1 (en) * 2008-04-22 2009-10-22 Osamu Kagaya Optical communication module and flexible printed circuit board
CN103163603A (en) * 2011-12-16 2013-06-19 富士通光器件株式会社 Optical transceiver and production method thereof
CN104996001A (en) * 2012-11-28 2015-10-21 泰科电子瑞典控股有限责任公司 Electrical connection interface for connecting electrical leads for high speed data transmission

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114384648A (en) * 2020-10-20 2022-04-22 青岛海信宽带多媒体技术有限公司 Optical module
CN114384648B (en) * 2020-10-20 2023-04-14 青岛海信宽带多媒体技术有限公司 Optical module
TWI769063B (en) * 2021-03-25 2022-06-21 嘉雨思科技股份有限公司 Signal transmission circuit packaging structure
CN113281859A (en) * 2021-05-18 2021-08-20 青岛海信宽带多媒体技术有限公司 Optical module
TWI777570B (en) * 2021-05-21 2022-09-11 嘉雨思科技股份有限公司 Signal transmission circuit packaging structure
TWI828130B (en) * 2022-04-29 2024-01-01 國立臺北科技大學 A connector structure and a method to increase data transmission rate

Also Published As

Publication number Publication date
CN112437537A (en) 2021-03-02
CN111511097B (en) 2020-12-29
CN112437537B (en) 2021-10-15

Similar Documents

Publication Publication Date Title
CN111511097B (en) High-speed transmission optical module circuit board structure and manufacturing method thereof and crosstalk prevention method
US7275937B2 (en) Optoelectronic module with components mounted on a flexible circuit
CN102081205B (en) Combined optical and electrical interconnection module and method for producing same
US7306377B2 (en) Integrated optical sub-assembly having epoxy chip package
JP6890966B2 (en) Optical module and optical transmission device
JP4852442B2 (en) Optical transmission module
CN101498819B (en) Optical-electrical transmission connector, optical-electrical transmission device and electronic device
JP2007071980A (en) Optical module
CN111308620B (en) Optical module
US9270041B2 (en) Stacked connector component in which high-speed signal pins are routed to different side than low-speed signal pins, and circuit board therefor
CN106646778B (en) Optical module
EP2643725A1 (en) Optical circuit board
TW201401304A (en) Composite flexible circuit cable
JP2008015336A (en) Circuit board and semiconductor device optical coupling method
WO2022083366A1 (en) Optical module
CN102736195A (en) Optical module, manufacturing method of optical module and optical communication device
KR20180103108A (en) Rigid-flex assembly for high-speed sensor module
JP4852979B2 (en) Flex-rigid board, optical transceiver module and optical transceiver
CN105339820A (en) Optical-module member, optical module, and electronic device
US20090026565A1 (en) Optical Module
US20100172037A1 (en) Optical module
CN112993058B (en) Photoelectric microsystem packaging structure based on hybrid integration process
US20220304149A1 (en) Multilayer circuit board
WO2024001684A1 (en) Multi-channel light receiving/transmitting assembly and optical module
WO2023185194A1 (en) Photoelectric co-packaging structure and communication device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant