Optical module gold finger structure and optical module for improving crosstalk performance

Abstract

This application provides an optical module gold finger structure and optical module with improved crosstalk performance. It relates to the field of communication technology. It includes: a target differential signal transmission layer comprising a first balanced reference ground and a first ground copper layer; a first target ground layer comprising a second ground copper layer, a first ground laser aperture, a first balanced reference ground laser aperture, and a balanced reference ground pad, wherein the first ground copper layer and the second ground copper layer are interconnected through the first ground laser aperture, and the balanced reference ground pad is coplanar with the second ground copper layer; a target reference layer comprising a third ground copper layer, a second ground laser aperture, and a second balanced reference ground laser aperture, wherein the second ground copper layer and the third ground copper layer are interconnected through the second ground laser aperture, and the second balanced reference ground laser aperture is interconnected with the third ground copper layer. This improves near-end crosstalk, far-end crosstalk, and electromagnetic interference between the differential signal gold fingers, thereby further improving the near-end crosstalk, far-end crosstalk, and electromagnetic interference performance of the entire differential signal of the optical module.

Description

Technical Field

[0001] This application relates to the field of communication technology, and more specifically, to an optical module gold finger structure and an optical module for improving crosstalk performance. Background Technology

[0002] Optical modules are primarily used in data communication, where their function is to convert photoelectric signals into each other. The rise of big data, blockchain, cloud computing, the Internet of Things, artificial intelligence, and 5G has led to a rapid increase in data traffic, making optical interconnects in data centers and mobile communications a research hotspot in the optical communication industry. With the development of electronic technology, the printed circuit boards (PCBs) of optical modules, especially high-density interconnect (HDI) PCBs, have increasingly higher wiring densities and greater complexity. High-density wiring often causes crosstalk between differential signals during signal transmission.

[0003] The differential signal amplitude of the received signal traces in an optical module is very small, while the signal amplitude of the adjacent transmitted differential signal traces is very large. This leads to greater crosstalk between the differential signals of the optical module, resulting in a high bit error rate in data transmission. It also causes poor eye diagrams and excessive electromagnetic interference (EMI). The signal integrity design of the differential signal gold fingers of the optical module is particularly important, as they serve as high-speed external signal interfaces.

[0004] Invention patent application publication number CN 112996286 A discloses an optical module in which differential signal traces are grounded to reduce crosstalk between differential signal lines. Invention patent authorization publication number CN107896418B discloses an optical module that, on the one hand, uses blind vias to reduce crosstalk between differential signal lines of signal layers, and on the other hand, uses a ground layer to provide shielding for the signal transmission layer to avoid crosstalk caused by two signal layers being directly adjacent. Invention patent application publication number CN 113946019 A proposes a method for solving crosstalk between differential signal lines of an optical module using a board-edge reference ground structure. Invention patent application publication number CN 111511097 A mentions an anti-crosstalk method for optical modules including: each signal layer is separated by at least one ground isolation layer, and the transmission signal layer contains multiple anti-crosstalk pillars and solder masks covering the differential signal traces and their anti-crosstalk pillars.

[0005] The above methods have all improved the problem of crosstalk between differential signal traces on optical module printed circuit boards to some extent under the trend of multi-layering and miniaturization, but they all neglect the treatment of this crosstalk source, the gold fingers of differential signals. Summary of the Invention

[0006] The purpose of this application is to provide an optical module gold finger structure and optical module with improved crosstalk performance, so as to improve the crosstalk of differential signal gold fingers.

[0007] In a first aspect, this application provides a gold finger structure for an optical module to improve crosstalk performance, comprising:

[0008] The target differential signal transmission layer includes a first balanced reference ground and a first ground copper layer;

[0009] The first target ground layer includes a second ground copper layer, a first ground laser hole, a first balanced reference ground laser hole, and a balanced reference ground pad. The first ground copper layer and the second ground copper layer are interconnected through the first ground laser hole, and the balanced reference ground pad is coplanar with the second ground copper layer.

[0010] The target reference layer includes a third ground copper layer, a second ground laser aperture, and a second balanced reference ground laser aperture. The second ground copper layer and the third ground copper layer are interconnected through the second ground laser aperture, and the second balanced reference ground laser aperture is interconnected with the third ground copper layer.

[0011] In an optional implementation, it further includes:

[0012] The first differential signal layer also includes a first ground gold finger, a differential signal gold finger, a second ground gold finger, and differential signal traces;

[0013] The target power layer includes a fourth ground copper layer and a first ground mechanical via; the third ground copper layer and the fourth ground copper layer are interconnected through the first ground mechanical via;

[0014] The second target grounding layer includes a fifth ground copper layer and a second ground mechanical via; the fourth ground copper layer and the fifth ground copper layer are interconnected through the second ground mechanical via;

[0015] The first ground mechanical hole and the second ground mechanical hole are located on the edge of the gold finger side of the optical module gold finger structure, and together with the second ground laser hole located directly above the first ground mechanical hole, they form a row of buried holes. The row of buried holes enables the interconnection of the second ground copper foil, the third ground copper foil, the fourth ground copper foil and the fifth ground copper foil.

[0016] In an optional implementation, it further includes:

[0017] The differential signal trace is grounded, and the grounding vias are a first ground laser via and a second ground laser via located on both sides of the differential signal trace.

[0018] In an optional embodiment, the first ground laser aperture and the second ground laser aperture form a U-shaped ground wrapping for the differential signal gold finger, wherein the second ground gold finger is interconnected with the third ground copper foil through the first ground laser aperture and the second ground laser aperture formed by the U-shaped ground wrapping; the first ground laser aperture, the second ground laser aperture formed by the U-shaped ground wrapping of the second ground gold finger, and the second ground laser aperture located between the end of the differential signal gold finger and the first ground mechanical hole at the edge of the optical module gold finger structure board for improving crosstalk performance, together form the U-shaped ground wrapping of the differential signal gold finger.

[0019] In an optional implementation, it further includes:

[0020] The differential signal gold finger is excavated using a full-dig method, hollowing out the second, third, and fourth layers of ground below the differential signal gold finger, so that the differential signal gold finger is referenced to the fifth layer of ground every other layer. The excavation size of the second layer of ground is designed to be an outward expansion of the outer contour of the differential signal gold finger by a first value, and the excavation sizes of the third and fourth layers of ground are designed to be a horizontal inward contraction of the outer contour of the differential signal gold finger by a second value and a vertical outward expansion of the outer contour of the differential signal gold finger by a first value.

[0021] In an optional implementation, the first value is 4mil and the second value is 2mil.

[0022] In an optional embodiment, the aperture of the first ground laser aperture is 60 μm, the aperture of the first balanced reference ground laser aperture is 60 μm, the diameter of the balanced reference ground pad is 250 μm, the aperture of the first ground laser aperture is 60 μm, and the aperture of the first ground mechanical aperture is 150 μm.

[0023] In an optional embodiment, the optical module includes: a first differential signal transmission layer, a first ground layer, a first reference layer, a first power layer, a second ground layer, a second power layer, a third ground layer, a second reference layer, a fourth ground layer, and a second differential signal transmission layer.

[0024] The target differential signal transmission layer is the first differential signal transmission layer; the first target ground layer is the first ground layer; the target reference layer is the first reference layer; the target power layer is the first power layer;

[0025] Alternatively, the target differential signal transmission layer may be the second differential signal transmission layer; the first target ground layer may be the fourth ground layer; the target reference layer may be the second reference layer; and the target power layer may be the second power layer.

[0026] In an optional implementation, the differential signal gold fingers located in the first differential signal transmission layer and the differential gold fingers located in the second differential transmission layer are electromagnetically isolated from each other through a second ground layer.

[0027] Secondly, this application provides an optical module, including the optical module gold finger structure as described in any of the foregoing embodiments.

[0028] This application provides an optical module gold finger structure and optical module with improved crosstalk performance. It includes: a target differential signal transmission layer, comprising a first balanced reference ground and a first ground copper layer; a first target ground layer, comprising a second ground copper layer, a first ground laser via, a first balanced reference ground laser via, and a balanced reference ground pad, wherein the first ground copper layer and the second ground copper layer are interconnected through the first ground laser via, and the balanced reference ground pad is coplanar with the second ground copper layer; and a target reference layer, comprising a third ground copper layer, a second ground laser via, and a second balanced reference ground laser via, wherein the second ground copper layer and the third ground copper layer are interconnected through the second ground laser via, and the second balanced reference ground laser via is interconnected with the third ground copper layer. This improves near-end crosstalk (NEXT), far-end crosstalk (FEXT), and electromagnetic interference (EMI) between the differential signal gold fingers, thereby further improving the overall NEXT, FEXT, and EMI performance of the optical module. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 A schematic diagram of the structure of a 3+4+3 high-density interconnect (HDI) printed circuit board for a QSFP-DD (Quad Small Form Factor Pluggable-Double Density) packaged 400G FR4 optical module provided for embodiments of this application;

[0031] Figure 2 A schematic diagram of a gold finger structure for improving crosstalk performance provided in this application embodiment;

[0032] Figure 3 This is a schematic diagram of the first signal transmission layer of an optical module gold finger structure for improving crosstalk performance, provided in an embodiment of this application.

[0033] Figure 4 This application provides a schematic diagram of the first ground layer of an optical module gold finger structure for improving crosstalk performance, as shown in the embodiments of this application.

[0034] Figure 5 This application provides a schematic diagram of the first reference layer of an optical module gold finger structure for improving crosstalk performance, as shown in the embodiments of this application.

[0035] Figure 6 This application provides a schematic diagram of the first power layer of an optical module gold finger structure for improving crosstalk performance, as shown in an embodiment of the present application.

[0036] Figure 7 This is a schematic diagram of the second grounding layer of an optical module gold finger structure for improving crosstalk performance, provided in an embodiment of this application. Detailed Implementation

[0037] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0038] like Figure 1 As shown, the optical module involved in this application can be a 3+4+3 high-density interconnect (HDI) printed circuit board structure of a QSFP-DD (Quad Small Form Factor Pluggable-Double Density) packaged 400G FR4 optical module, which can adopt a ten-layer stack-up design and the board thickness can be 1mm. As an example, it can include the following structure:

[0039] First differential signal transmission layer, first ground layer, first reference layer, first power layer, second ground layer, second power layer, third ground layer, second reference layer, fourth ground layer, and second differential signal transmission layer.

[0040] Wherein, the target differential signal transmission layer is the first differential signal transmission layer; the first target ground layer is the first ground layer; the target reference layer is the first reference layer; and the target power layer is the first power layer.

[0041] Alternatively, the target differential signal transmission layer is the second differential signal transmission layer; the first target ground layer is the fourth ground layer; the target reference layer is the second reference layer; and the target power layer is the second power layer.

[0042] Figure 2 The structure of the optical module gold finger structure for improving crosstalk performance shown can be located in the first differential signal transmission layer 100, the first ground layer 200, the first reference layer 300, the first power layer 400, and the second ground layer 500.

[0043] Alternatively, the optical module's gold finger structure for improving crosstalk performance can be located on the second differential signal transmission layer, the fourth ground layer, the second reference layer, the third ground layer, the second power layer, and the second ground layer. The differential signal gold fingers located on the first differential signal transmission layer and the differential gold fingers located on the second differential transmission layer achieve electromagnetic isolation from each other through the second ground layer, thereby reducing electromagnetic interference (EMI).

[0044] In other words, the optical module gold finger structure for improving crosstalk performance may include a target differential signal transmission layer, a first target ground layer, a target reference layer, and a target power layer.

[0045] As an example, the target differential signal transmission layer is the first differential signal transmission layer 100; the first target ground layer is the first ground layer 200; the target reference layer is the first reference layer 300; and the target power layer is the first power layer 400.

[0046] As another example, the target differential signal transmission layer is the second differential signal transmission layer; the first target ground layer is the fourth ground layer; the target reference layer is the second reference layer; and the target power layer is the second power layer.

[0047] Figure 3 The target differential signal transmission layer of the optical module gold finger structure for improving crosstalk performance shown may include a first ground gold finger 11, a differential signal gold finger 12, a second ground gold finger 13, a first balanced reference ground 14, a differential signal trace 15, and a first ground copper foil 16.

[0048] Figure 4 The first target ground layer of the optical module gold finger structure shown for improving crosstalk performance may include a second ground copper foil 27, a first ground laser hole 28, a first balanced reference ground laser hole 281, and a balanced reference ground pad 282.

[0049] The first ground copper foil 16 and the second ground copper foil 27 are interconnected through the first ground laser hole 28.

[0050] The aperture of the first laser aperture 28 is 50um-70um, preferably 60um.

[0051] The aperture of the laser aperture 281 of the first balancing reference ground is 50um-70um, preferably 60um.

[0052] The balanced reference ground pad 282 is coplanar with the second ground copper pad 27, and its pad diameter is 240um-260um, preferably 250um.

[0053] In some embodiments, the balanced reference ground pad 282 may be circular, square, or other shapes.

[0054] Figure 5The target reference layer of the optical module gold finger structure for improving crosstalk performance shown may include a third ground copper foil 39, a second ground laser aperture 310, and a second balanced reference ground laser aperture 3101.

[0055] The second ground copper foil 27 and the third ground copper foil 39 are interconnected through the second ground laser hole 310.

[0056] Differential signal trace 15, layer 15, references third ground copper foil 39.

[0057] Interconnection refers to the physical connection between components. There must be at least one physical connection line between two components. It provides the material basis and conditions for the exchange of signals, energy and other signals between the two components, but it does not guarantee that the two components can exchange signals, energy and other signals.

[0058] Alternatively, differential signal trace 15 can also refer to the second ground copper trace 27.

[0059] The aperture of the first laser aperture 28 is 50um-70um, preferably 60um.

[0060] Figure 6 The target power layer of the optical module gold finger structure shown for improving crosstalk performance may include a fourth ground copper foil 411 and a first ground mechanical hole 412.

[0061] The third copper foil 39 and the fourth copper foil 411 are interconnected through the first mechanical hole 412.

[0062] The diameter of the first mechanical hole 412 is 140um-160um, preferably 150um.

[0063] Figure 7 The second target ground layer of the optical module gold finger structure shown for improving crosstalk performance may include a fifth ground copper foil 513 and a second ground mechanical hole 514.

[0064] The fourth copper foil 411 and the fifth copper foil 513 are interconnected through the second mechanical hole 514.

[0065] The diameter of the second mechanical hole 412 is 140um-160um, preferably 150um.

[0066] The first ground mechanical hole 412 and the second ground mechanical hole 514 are located on the edge of the gold finger side of the optical module gold finger structure to improve crosstalk performance, and together with the second ground laser hole 310 located directly above the first ground mechanical hole 412, they form a row of buried holes. This row of buried holes can realize the interconnection of the second ground copper foil 27, the third ground copper foil 39, the fourth ground copper foil 411 and the fifth ground copper foil 513, and destroy the propagation of electromagnetic radiation generated by the differential signal gold finger 12, thereby reducing the external electromagnetic interference (EMI) of the differential signal on the differential signal gold finger 12.

[0067] Furthermore, if space permits, underground boreholes can be arranged in multiple rows.

[0068] In some embodiments, the balanced reference ground structure between the conversion portions of the differential signal trace 15 and the differential signal gold finger 12 may include a first balanced reference ground 14, a first balanced reference ground laser hole 281, a balanced reference ground pad 282, and a second balanced reference ground laser hole 3101.

[0069] The balanced reference ground structure is interconnected with the third ground copper foil 39 through the second balanced reference ground laser hole 3101, which improves the symmetry of the electromagnetic field of the differential signal trace, thereby suppressing the mode conversion from differential mode to common mode, and thus reducing the external electromagnetic interference (EMI) of the differential signal on the differential signal gold finger 12.

[0070] In some embodiments, the differential signal trace 15 can also be grounded, with the grounding vias being a first ground laser via 28 and a second ground laser via 310 located on both sides of the differential signal trace. Grounding can reduce crosstalk and electromagnetic interference (EMI) and ensure the quality of the differential signal.

[0071] Furthermore, if the layout space allows, the vias can also be arranged in multiple rows.

[0072] In addition to the first ground laser aperture 28 and the second ground laser aperture 310 mentioned above, the remaining first ground laser apertures 28 and second ground laser apertures 310 can form a U-shaped ground wrapping for the differential signal gold finger 12. The first ground gold finger 11 and the second ground gold finger 13 are interconnected with the third ground copper foil 39 through the U-shaped ground wrapping first ground laser apertures 28 and 310. The U-shaped ground wrapping first ground laser apertures 28 and 310 of the first ground gold finger 11 and the second ground laser aperture 310, together with the second ground laser aperture 310 located between the end of the differential signal gold finger 12 and the edge of the optical module gold finger structure board for improving crosstalk performance, together form the U-shaped ground wrapping of the differential signal gold finger 12.

[0073] The U-shaped ground plane of the differential signal gold finger 12 disrupts the propagation of electromagnetic radiation generated by the differential signal gold finger 12, improves the near-end crosstalk (NEXT), far-end crosstalk (FEXT) and electromagnetic interference (EMI) between the differential signal gold fingers 12, and thus further improves the overall differential signal performance of the optical module.

[0074] Furthermore, where layout space permits, add as many U-shaped ground-enclosing first ground laser apertures 28 and second ground laser apertures 310 as possible to improve the suppression of near-end crosstalk (NEXT), far-end crosstalk (FEXT), and electromagnetic interference (EMI).

[0075] In some embodiments, the differential signal gold finger 12 can be completely excavated to hollow out the ground of the second, third, and fourth layers below the differential signal gold finger 12, so that the differential signal gold finger 12 is referenced to the fifth layer of ground every other layer. The excavation size of the second layer of ground is designed to be 4mil outward from the outer contour of the differential signal gold finger 12, and the excavation size of the third and fourth layers of ground is designed to be 2mil inward in the horizontal direction and 4mil outward in the vertical direction from the outer contour of the differential signal gold finger 12.

[0076] The impedance of the differential signal gold finger 12 is compensated by the ground excavation design, thereby compensating for the impedance discontinuity of the differential signal gold finger 12.

[0077] Optionally, the excavated layer can be the second layer, or the second and third layers.

[0078] Furthermore, Figure 2 The optical module gold finger structure shown for improving crosstalk performance, which is used to improve crosstalk between differential signal gold fingers, is also applicable to the differential signal gold fingers of other boards, such as the differential signal gold fingers of 56G optical modules and the differential signal gold fingers of PCIe 6.0 boards.

[0079] In this embodiment, the inner reference ground layer on the edge of the gold finger side of the optical module printed circuit board is interconnected by one or more rows of buried vias; this disrupts the propagation of electromagnetic radiation generated by the differential signal gold finger, thereby reducing the external electromagnetic interference (EMI) of the differential signal on the differential signal gold finger.

[0080] A balanced reference ground structure is introduced between the differential signal traces and the differential signal gold finger conversion section. This improves the symmetry of the electromagnetic field of the differential signal traces, thereby suppressing mode conversion from differential mode to common mode, and thus reducing electromagnetic interference (EMI) from high-speed signals on the differential gold finger.

[0081] By drilling grounding holes on the grounding gold fingers, a U-shaped grounding treatment is achieved for the differential signal gold fingers; this disrupts the propagation of electromagnetic radiation generated by the differential signal gold fingers, thereby suppressing near-end crosstalk (NEXT), far-end crosstalk (FEXT), and electromagnetic interference (EMI) between the differential signal gold fingers.

[0082] The reference ground layer or reference power layer below the differential signal gold finger is hollowed out; this compensates for the impedance of the differential signal gold finger, thereby compensating for the impedance discontinuity of the differential signal gold finger.

[0083] This application provides a gold finger structure for an optical module, which improves the near-end crosstalk (NEXT), far-end crosstalk (FEXT), and electromagnetic interference (EMI) between differential signal gold fingers, thereby further improving the overall NEXT, FEXT, and EMI performance of the optical module.

[0084] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0085] In the various embodiments of this application, the functional modules can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0086] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0087] The above are merely embodiments of this application and are not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A gold finger structure for an optical module to improve crosstalk performance, characterized in that, include: The target differential signal transmission layer includes a first balanced reference ground and a first ground copper layer; The first target ground layer includes a second ground copper layer, a first ground laser hole, a first balanced reference ground laser hole, and a balanced reference ground pad. The first ground copper layer and the second ground copper layer are interconnected through the first ground laser hole, and the balanced reference ground pad is coplanar with the second ground copper layer. The target reference layer includes a third ground copper layer, a second ground laser aperture, and a second balanced reference ground laser aperture. The second ground copper layer and the third ground copper layer are interconnected through the second ground laser aperture, and the second balanced reference ground laser aperture is interconnected with the third copper layer. Also includes: The target differential signal transmission layer also includes a first ground gold finger, a differential signal gold finger, a second ground gold finger, and differential signal traces; The target power layer includes a fourth ground copper layer and a first ground mechanical via; the third ground copper layer and the fourth ground copper layer are interconnected through the first ground mechanical via; The second target grounding layer includes a fifth ground copper layer and a second ground mechanical via; the fourth ground copper layer and the fifth ground copper layer are interconnected through the second ground mechanical via; The first ground mechanical hole and the second ground mechanical hole are located on the edge of the gold finger side of the gold finger structure of the optical module, and together with the second ground laser hole located directly above the first ground mechanical hole, they form a row or multiple rows of buried holes. The rows of buried holes realize the interconnection of the second ground copper foil, the third ground copper foil, the fourth ground copper foil and the fifth ground copper foil. The differential signal trace is grounded, and the grounding vias are a first ground laser via and a second ground laser via located on both sides of the differential signal trace. in, The first ground laser aperture and the second ground laser aperture form a U-shaped ground wrapping for the differential signal gold finger, wherein the first ground gold finger and the second ground gold finger are interconnected with the third ground copper foil through the first ground laser aperture and the second ground laser aperture formed by the U-shaped ground wrapping; the first ground laser aperture, the second ground laser aperture formed by the U-shaped ground wrapping of the first ground gold finger and the second ground laser aperture located between the end of the differential signal gold finger and the edge of the optical module gold finger structure board for improving crosstalk performance, together form the U-shaped ground wrapping of the differential signal gold finger.

2. The optical module gold finger structure according to claim 1, characterized in that, Also includes: The differential signal gold finger is excavated using a full-dig method, hollowing out the second, third, and fourth layers of ground below the differential signal gold finger, so that the differential signal gold finger is referenced to the fifth layer of ground every other layer. The excavation size of the second layer of ground is designed to be an outward expansion of the outer contour of the differential signal gold finger by a first value, and the excavation sizes of the third and fourth layers of ground are designed to be a horizontal inward contraction of the outer contour of the differential signal gold finger by a second value and a vertical outward expansion of the outer contour of the differential signal gold finger by a first value.

3. The optical module gold finger structure according to claim 2, characterized in that, The first value is 4mil, and the second value is 2mil.

4. The optical module gold finger structure according to claim 1, characterized in that, The diameter of the first ground laser aperture is 60 μm, the diameter of the first balanced reference ground laser aperture is 60 μm, the diameter of the balanced reference ground pad is 250 μm, the diameter of the first ground laser aperture is 60 μm, and the diameter of the first ground mechanical aperture is 150 μm.

5. The optical module gold finger structure according to claim 1, characterized in that, The optical module includes: a first differential signal transmission layer, a first ground layer, a first reference layer, a first power layer, a second ground layer, a second power layer, a third ground layer, a second reference layer, a fourth ground layer, and a second differential signal transmission layer; The target differential signal transmission layer is the first differential signal transmission layer; the first target ground layer is the first ground layer; the target reference layer is the first reference layer; the target power layer is the first power layer; Alternatively, the target differential signal transmission layer may be the second differential signal transmission layer; the first target ground layer may be the fourth ground layer; the target reference layer may be the second reference layer; and the target power layer may be the second power layer.

6. The optical module gold finger structure according to claim 5, characterized in that, The differential signal gold fingers located in the first differential signal transmission layer and the differential gold fingers located in the second differential transmission layer are electromagnetically isolated from each other through the second ground layer.

7. An optical module, characterized in that, Includes the optical module gold finger structure as described in any one of claims 1-6.

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