A method and system for designing high-speed signals for the gold fingers of an optical module.

Abstract

This invention belongs to the field of optical module gold finger design technology, specifically providing a high-speed signal design method and system for optical module gold fingers. The method includes: designing layers 1, 3, 8, and 10 as differential signal routing layers according to a 10-layer, 2-order stacked OSFP gold finger structure; performing SI simulation analysis on the gold fingers to obtain the OSFP gold finger outgoing differential lines with optimal impedance; determining the center-to-center spacing of the differential line GND vias based on SI simulation analysis; designing the differential line layer-switching vias outside the AC pads; and handling impedance discontinuities in the optical module's gold fingers. By optimizing the via and pad spacing, flatness within the 40G band is ensured, reducing high-frequency bandwidth; and after reflection optimization at 40G, the performance is close to -15dB. Furthermore, this scheme significantly reduces insertion loss and common-mode return loss, improving the overall differential signal transmission capability.

Description

Technical Field

[0001] This invention relates to the field of optical module gold finger design technology, and more specifically, to a high-speed signal design method and system for optical module gold fingers. Background Technology

[0002] With the development of society and technology, data transmission speeds are increasing. To meet the market demand for higher transmission rate optical module connectors, eight-channel signal transmission optical module connectors have emerged. Some applications require splitting the optical channel into two, for example, splitting the output of an optical module transceiver (comprising a set of 16 fibers, 8 for Tx and 8 for Rx) into two groups of 8 fibers (4 for Tx and 4 for Rx). Each group is compatible with the optical ports of a four-channel small form factor pluggable (QSFP) transceiver or a disassembled QSFP-DD or OSFP transceiver. OSFP is an 8-channel connector, slightly larger than QSFP-DD, but relatively hotter, with higher wattage optical engines and transceivers, and slightly better heat dissipation. The OSFP form factor does not offer backward compatibility with existing specifications, but its design provides maximum thermal and electrical performance. The "O" stands for "octal," and it is designed to use 8 electrical channels to achieve 400GbE.

[0003] Optical module gold fingers offer higher speed and density than four-channel connectors. However, the increased data transmission volume of eight-channel connectors makes them more prone to causing overall system and connector temperature rise. This is especially true in terms of insertion loss control (e.g., resonance control), in-band flatness, high-frequency bandwidth, and in-band reflections (e.g., signal noise and electromagnetic interference, EMI) immunity, which place higher demands on these aspects. Currently, the gold fingers of connectors on the market only offer simple soldering and circuit connection functions, resulting in relatively poor overall signal transmission performance, particularly regarding the transmission of differential signals within the optical module's gold fingers. Summary of the Invention

[0004] This invention addresses the technical problem of poor signal transmission capability of the gold fingers of optical modules in existing technologies.

[0005] This invention provides a high-speed signal design method for the gold finger of an optical module, comprising the following steps:

[0006] S1, based on the OSFP gold finger with a 10-layer 2-level stack-up structure, layers 1, 3, 8 and 10 are designed as differential signal routing layers;

[0007] S2, perform SI simulation analysis on the gold finger to obtain the OSFP gold finger outgoing differential line with the optimal impedance;

[0008] S3, the center-to-center spacing of the differential line GND vias is obtained based on SI simulation analysis;

[0009] S4 places the differential line layer-swapping vias outside the AC pads;

[0010] S5 handles impedance discontinuities on the gold fingers of the optical module.

[0011] Preferably, S1 specifically includes: designing the 2nd, 4th, 7th and 9th layers as complete planar layers;

[0012] Layers 5 and 6 are designed as power and other signal layers.

[0013] Preferably, S2 specifically includes: obtaining the optimal line-out impedance of the optical module's gold finger according to SI and actual measurement verification as 95 ohms.

[0014] Preferably, S3 specifically includes: the center-to-center spacing of the differential line GND vias is optimally 0.4mm.

[0015] Preferably, S4 specifically includes:

[0016] The distance from the center of the via to the center of the AC pad is 0.45mm;

[0017] When changing layers, the vias are all compensated by expanding outward by 0.2mm on one side at the layer to which the via is located;

[0018] The AC capacitor is extended outward by 0.15mm on one side.

[0019] Preferably, S4 further includes:

[0020] Referring to the 7th layer GND, the vias in layers 8 to 10 are expanded outwards for clearance compensation;

[0021] Referring to the L4 layer GND, the vias of layers 1 to 3 are expanded outwards for clearance compensation.

[0022] Preferably, S5 specifically includes:

[0023] The golden finger is used to draw a teardrop, with the teardrop being the same width as the finger.

[0024] The GND network design on the gold finger is a through-hole ground;

[0025] The second to fourth layers below the top layer of the finger should be completely hollowed out, 0.2mm from the base of the finger. Refer to the fifth layer, but do not hollow out the fifth layer.

[0026] The 7th to 9th layers below the BOT layer of the gold finger are completely hollowed out, 0.2mm away from the base of the finger, as in the 6th layer, but the 6th layer is not hollowed out.

[0027] This invention also provides a high-speed signal design system for the gold fingers of an optical module. The system is used to implement a high-speed signal design method for the gold fingers of an optical module, comprising:

[0028] The modeling module is used to design layers 1, 3, 8, and 10 as differential signal routing layers according to the OSFP gold fingers of a 10-layer 2-level stack-up structure.

[0029] Impedance design module, used to perform SI simulation analysis on the gold fingers to obtain the OSFP gold finger outgoing differential line with the optimal impedance;

[0030] The GND via spacing design module is used to obtain the center spacing of differential line GND vias based on SI simulation analysis.

[0031] The layer-change via design module is used to design differential line layer-change vias outside the AC pads;

[0032] The discontinuity processing module is used to process impedance discontinuities on the gold fingers of optical modules.

[0033] This invention also provides an electronic device, including a memory and a processor, wherein the processor is used to execute a computer management program stored in the memory to implement the steps of a high-speed signal design method for the gold finger of an optical module.

[0034] This invention also provides a computer-readable storage medium storing a computer management program thereon, which, when executed by a processor, implements the steps of a high-speed signal design method for the gold fingers of an optical module.

[0035] Beneficial Effects: This invention provides a high-speed signal design method and system for the gold fingers of an optical module. The method includes: designing layers 1, 3, 8, and 10 as differential signal routing layers according to a 10-layer, 2-order stacked OSFP gold finger structure; performing SI simulation analysis on the gold fingers to obtain the OSFP gold finger outgoing differential lines with optimal impedance; obtaining the center-to-center spacing of the differential line GND vias based on SI simulation analysis; designing the differential line layer-switching vias outside the AC pads; and handling impedance discontinuities of the optical module's gold fingers. By optimizing the via and pad spacing, flatness within the 40G band is ensured, reducing high-frequency bandwidth; and after reflection optimization at 40G, the performance is close to -15dB. Furthermore, this scheme significantly reduces insertion loss and common-mode return loss, improving the overall differential signal transmission capability. Attached Figure Description

[0036] Figure 1 A schematic diagram of a high-speed signal design method for the gold finger of an optical module provided by the present invention;

[0037] Figure 2The present invention provides an optimal design diagram for the impedance of differential lines.

[0038] Figure 3 The via center distance design drawing provided for this invention;

[0039] Figure 4 This is a via design diagram for the line-changing layer provided by the present invention;

[0040] Figure 5 A schematic diagram of the hardware structure of a possible electronic device provided by the present invention;

[0041] Figure 6 This is a schematic diagram of the hardware structure of a possible computer-readable storage medium provided by the present invention. Detailed Implementation

[0042] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0043] Figure 1 The present invention provides a high-speed signal design method for the gold finger of an optical module, comprising the following steps:

[0044] S1, according to the OSFP gold finger with a 10-layer 2-level stack-up structure, layers 1, 3, 8 and 10 are designed as differential signal routing layers; according to the 10-layer 2-level stack-up, differential lines are routed to L1 / L3 / L8 / L10, and L2&L4, L7&L9 are complete ground planes.

[0045] S2, perform SI simulation analysis on the gold finger to obtain the OSFP gold finger outgoing differential line with the optimal impedance;

[0046] S3, the center-to-center spacing of the differential line GND vias is obtained based on SI simulation analysis;

[0047] S4 places the differential line layer-swapping vias outside the AC pads;

[0048] S5 handles impedance discontinuities on the gold fingers of the optical module.

[0049] Layers 2, 4, 7, and 9 are designed as complete ground plane layers; layers 5 and 6 are designed as power and other signal layers.

[0050] The preferred solution, S2, specifically includes: Based on SI and actual measurement verification, the optimal outgoing impedance of the optical module's gold finger is determined to be 95 ohms. The OSFP gold finger outgoing differential line is designed with an impedance controlled at 95 ohms; based on SI and actual measurement verification, controlling the outgoing impedance of the optical module's gold finger at 95 ohms is optimal. Figure 2 As shown.

[0051] In the preferred embodiment, S3 specifically includes: the optimal center-to-center spacing of the differential line GND vias is 0.4mm. The impedance line grounding design, based on SI simulation, optimizes the center-to-center spacing of the differential line GND vias to 0.4mm. Figure 3 As shown.

[0052] The preferred design, based on SI simulation, places the differential line layer-swapping vias outside the AC pads. For example... Figure 4 As shown, S4 specifically includes:

[0053] The distance from the center of the via to the center of the AC pad is 0.45mm;

[0054] When changing layers, the vias are all compensated by expanding outward by 0.2mm on one side at the layer to which the via is located;

[0055] The AC capacitor is extended outward by 0.15mm on one side.

[0056] A further proposed solution is to use vias V8-10, avoiding L8-L10 with compensation for deviation, referring to the L7 layer GND. Similarly, vias V1-3 should avoid L1-L3 with compensation for deviation, referring to the L4 layer GND.

[0057] The preferred solution, S5, specifically includes:

[0058] The golden finger is used to draw a teardrop, with the teardrop being the same width as the finger.

[0059] The GND network design on the gold finger is a through-hole ground;

[0060] The second to fourth layers below the top layer of the finger should be completely hollowed out, 0.2mm from the base of the finger. Refer to the fifth layer, but do not hollow out the fifth layer.

[0061] The 7th to 9th layers below the BOT layer of the gold finger are completely hollowed out, 0.2mm away from the base of the finger, as in the 6th layer, but the 6th layer is not hollowed out.

[0062] Beneficial effects:

[0063] By optimizing the spacing between holes and pads, flatness within the 40G band is ensured, reducing the high-frequency bandwidth. Furthermore, after optimization of reflection at 40G, the performance is close to -15dB. In addition, this solution greatly reduces insertion loss and common-mode return loss, thereby improving the overall differential signal transmission capability.

[0064] This invention also provides a high-speed signal design system for the gold fingers of an optical module. The system is used to implement the high-speed signal design method for the gold fingers of an optical module as described above, including:

[0065] The modeling module is used to design layers 1, 3, 8, and 10 as differential signal routing layers according to the OSFP gold fingers of a 10-layer 2-level stack-up structure.

[0066] Impedance design module, used to perform SI simulation analysis on the gold fingers to obtain the OSFP gold finger outgoing differential line with the optimal impedance;

[0067] The GND via spacing design module is used to obtain the center spacing of differential line GND vias based on SI simulation analysis.

[0068] The layer-change via design module is used to design differential line layer-change vias outside the AC pads;

[0069] The discontinuity processing module is used to process impedance discontinuities on the gold fingers of optical modules.

[0070] Please see Figure 5 This is a schematic diagram illustrating an embodiment of the electronic device provided in this invention. For example... Figure 5 As shown, an embodiment of the present invention provides an electronic device, including a memory 1310, a processor 1320, and a computer program 1311 stored in the memory 1310 and executable on the processor 1320. When the processor 1320 executes the computer program 1311, it performs the following steps: S1, according to the OSFP gold fingers of a 10-layer 2-level stack-up structure, the first layer, the third layer, the eighth layer, and the tenth layer are designed as differential signal routing layers;

[0071] S2, perform SI simulation analysis on the gold finger to obtain the OSFP gold finger outgoing differential line with the optimal impedance;

[0072] S3, the center-to-center spacing of the differential line GND vias is obtained based on SI simulation analysis;

[0073] S4 places the differential line layer-swapping vias outside the AC pads;

[0074] S5 handles impedance discontinuities on the gold fingers of the optical module.

[0075] Please see Figure 6 This is a schematic diagram illustrating an embodiment of a computer-readable storage medium provided by the present invention. (See diagram below.) Figure 6 As shown, this embodiment provides a computer-readable storage medium 1400, on which a computer program 1411 is stored. When the computer program 1411 is executed by a processor, it performs the following steps: S1, according to the OSFP gold fingers of a 10-layer 2-level stack-up structure, the 1st layer, the 3rd layer, the 8th layer and the 10th layer are designed as differential signal routing layers.

[0076] S2, perform SI simulation analysis on the gold finger to obtain the OSFP gold finger outgoing differential line with the optimal impedance;

[0077] S3, the center-to-center spacing of the differential line GND vias is obtained based on SI simulation analysis;

[0078] S4 places the differential line layer-swapping vias outside the AC pads;

[0079] S5 handles impedance discontinuities on the gold fingers of the optical module.

[0080] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0081] Although preferred embodiments of the invention 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 both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0082] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for designing a high-speed signal of a gold finger of an optical module, characterized in that, It comprises the following steps: S1, according to the OSFP gold finger of 10 layers 2 order laminated structure, the first layer, the third layer, the eighth layer and the tenth layer are designed as differential signal trace layer; S2, the SI simulation analysis of the gold finger is carried out to obtain the best impedance of the OSFP gold finger out line differential line; S3, the differential line GND via hole center spacing is obtained according to SI simulation analysis; S4, the differential line layer via hole is designed outside the AC pad; S5, the impedance discontinuity point of the gold finger of the optical module is processed; S1 specifically comprises: the second layer, the fourth layer, the seventh layer and the ninth layer are designed as complete ground plane layer; The fifth layer and the sixth layer are designed as power supply and other signal layer; S2 specifically comprises: according to SI and actual measurement verification, the best impedance of the gold finger out line of the optical module is 95 ohm; S3 specifically comprises: the differential line GND via hole center spacing is best 0.4mm.

2. The method of claim 1, wherein the method is characterized by: S4 specifically comprises: The spacing between the via hole center and the AC pad center is 0.45mm; The layer via hole is expanded by 0.2mm on one side to avoid; The AC capacitor is expanded by 0.15mm on one side.

3. The method of claim 2, wherein the method further comprises: S4 also comprises: Referring to the GND of the seventh layer, the via holes of the eighth layer to the tenth layer are expanded to avoid compensation; Referring to the GND of L4 layer, the via holes of the first layer to the third layer are expanded to avoid compensation.

4. The method of claim 1, wherein the method is characterized by: S5 specifically comprises: The gold finger out line is supplemented with tear drop, and the tear drop is equal in width to the finger; The GND network on the gold finger is designed as a through hole ground; The second layer to the fourth layer below the TOP layer of the gold finger are fully dug away from the root of the finger by 0.2mm, and the fifth layer is not dug; The seventh layer to the ninth layer below the BOT layer of the gold finger are fully dug away from the root of the finger by 0.2mm, and the sixth layer is not dug.

5. A system for designing a high-speed signal of a gold finger of an optical module, the system comprising: The system is used to realize the gold finger high-speed signal design method of the optical module as claimed in any one of claims 1-4, comprising: A modeling module is used to design the first layer, the third layer, the eighth layer and the tenth layer as differential signal trace layer according to the OSFP gold finger of 10 layers 2 order laminated structure; An impedance design module is used to obtain the best impedance of the OSFP gold finger out line differential line by SI simulation analysis of the gold finger; A GND via hole spacing design module is used to obtain the differential line GND via hole center spacing according to SI simulation analysis; A layer via hole design module is used to design the differential line layer via hole outside the AC pad; A discontinuity point processing module is used to process the impedance discontinuity point of the gold finger of the optical module.

6. An electronic device, comprising: It comprises memory and processor, and the processor is used to execute the computer management type program stored in the memory to realize the steps of the gold finger high-speed signal design method of the optical module as claimed in any one of claims 1-4.

7. A computer-readable storage medium, characterized in that, A computer management type program is stored thereon, and the steps of the gold finger high-speed signal design method of the optical module as claimed in any one of claims 1-4 are realized when the computer management type program is executed by the processor.

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