Optical transceiver with ground via
By introducing grounding through holes in the optical transceiver and optimizing the arrangement of the RF signal line, the impact of electromagnetic interference on the optical transceiver is solved, and more stable optical transmission is achieved.
Patent Information
- Application Number
- CN202410176509.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-12-28
- Filing Date
- 2024-02-08
- Publication Date
- 2025-07-01
AI Technical Summary
Existing optical transmission technologies are susceptible to electromagnetic interference, especially optical transceiver packages that operate at high frequencies, resulting in electromagnetic interference radiation affecting its normal operation.
An optical transceiver design with grounding through holes is adopted, including a substrate, a filter capacitor, a radio frequency signal line and a plurality of grounding through holes. The first and second conductive parts are connected through the conductive through holes, and grounding through holes are provided on multiple side edges and distal edges of the substrate to ensure that the shortest distance between each radio frequency signal line and the side edge is greater than 0.95 mm, and the leakage of electromagnetic interference is reduced.
It effectively reduces the impact of electromagnetic interference on optical transceivers and improves its operation stability and efficiency.
Smart Images
Figure CN120233498A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an optical transceiver, and particularly to an optical transceiver having a ground via. Background Art
[0002] Optical fibers are widely used for transmitting audio and data signals. As a transmission medium, optical technology has more advantages than traditional electronic communication methods. For example, optical signals allow extremely high transmission rates and very high bandwidth capacities. In addition, optical components also provide more secure signal transmission because it does not allow part of the signal to escape from the fiber optic cable, which may occur in a wire system. Optical transmission can also cover longer distances without the signal loss typically associated with copper wires carrying telecommunications signals.
[0003] However, there are still many challenges to overcome in existing optical transmission technologies. Summary of the Invention
[0004] In view of the above, the present invention provides an optical transceiver with a ground via to solve the problems of existing optical transmission technologies.
[0005] An optical transceiver according to an embodiment of the present invention includes: a substrate, a plurality of filter capacitors, a plurality of RF signal lines, and a plurality of ground vias. The substrate has opposite side edges and a distal edge between the side edges, and the substrate has a main region and a gold finger region closer to the distal edge than the main region. The plurality of filter capacitors are disposed in the main region of the substrate. The plurality of RF signal lines are connected to the plurality of filter capacitors, and each RF signal line includes: a first conductive portion, a second conductive portion, and a conductive via. The first conductive portion is disposed in the substrate and extends from the main region to the gold finger region. The second conductive portion is disposed on the substrate and is located in the gold finger region. The conductive via conductively connects the first conductive portion and the second conductive portion and does not extend beyond three layers of the substrate. The plurality of ground vias are located at the side edges and the distal edge, and the plurality of ground vias are distributed from the main region to the gold finger region. The shortest distance between each RF signal line and the side edges is greater than 0.95 mm.
[0006] In summary, the electromagnetic interference of the optical transceiver according to one or more embodiments of the present disclosure can be reduced, thereby reducing the impact of electromagnetic interference on the operation of the optical transceiver.
[0007] The above description of the content of the present invention and the following description of the embodiments are used to illustrate and explain the spirit and principle of the present invention, and provide a further explanation of the protection scope of the present invention. Brief Description of the Drawings
[0008] Figure 1It is a schematic diagram of an optical transceiver according to an embodiment of the present disclosure.
[0009] Figure 2 It is a schematic diagram of the arrangement of radio frequency signal lines on a substrate according to an embodiment of the present disclosure.
[0010] Figure 3 It shows Figure 1 the positions of a plurality of ground vias of the optical transceiver shown in
[0011] Figure 4 It is a schematic diagram of the arrangement of ground vias according to an embodiment of the present disclosure.
[0012] Figure 5 It is a schematic diagram of a ground via penetrating through a substrate according to an embodiment of the present disclosure.
[0013] Figure 6 It is a schematic diagram of an optical transceiver having a housing according to an embodiment of the present disclosure.
[0014] Figure 7 It is an enlarged view of a pair of differential signal lines of a radio frequency signal line according to an embodiment of the present disclosure.
[0015] Figure 8 It is a schematic diagram of an optical transceiver according to another embodiment of the present disclosure.
[0016] Figure 9 It shows Figure 8 the positions of a plurality of ground vias of the optical transceiver shown in
[0017] Figure 10 It shows the experimental results of the electromagnetic interference (EMI) level when conductive vias extend to different layers of the substrate.
[0018] Figure 11 It shows the experimental results of the electromagnetic interference level between a pair of differential signal lines at different distances.
[0019]
Description of Reference Numerals
[0020] 1, 2: Optical transceiver
[0021] 10, 20: Substrate
[0022] 11: Filter capacitor
[0023] 12, 22: Radio frequency signal line
[0024] 121, 221: First conductive part
[0025] 122,222: The second conductive part
[0026] 123,223: Conductive vias
[0027] 12a, 12b: Differential signal lines
[0028] 13, 23: Ground vias
[0029] A1, A1’: Main regions
[0030] A2, A2’: Gold finger regions
[0031] E1, E2, E1’, E2’: Side edges
[0032] E3, E3’: Distal edges
[0033] d1, d2: Shortest distances
[0034] d3, d4, X, S: Distances
[0035] W: Width
[0036] P1: Point
[0037] L1 to L12, Lt, Lm1 to Lm n , Lb: Layers
[0038] C1: The first curve
[0039] C2: The second curve
[0040] C3: The third curve Detailed implementation manners
[0041] The detailed features and advantages of the present invention are described in detail in the following implementation manners. The content is sufficient for those of ordinary skill in the art to understand the technical content of the present invention and implement it accordingly. According to the content disclosed in this specification, the scope of protection, and the drawings, those of ordinary skill in the art can easily understand the related purposes and advantages of the present invention. The following embodiments further illustrate the viewpoints of the present invention in detail, but do not limit the scope of the present invention in any way.
[0042] With the increase in the optical transmission speed provided by electronic modules, additional problems have emerged. For example, electronic devices and components operating at high frequencies typically emit signals called electromagnetic interference (EMI). This form of electronic noise is undesirable because electromagnetic interference can disrupt the normal operation of other electronic components. Optical transceiver packages, especially those operating at high transmission speeds, are particularly vulnerable to electromagnetic interference radiation.
[0043] An optical transceiver according to an embodiment of the present disclosure includes conductive vias located on a substrate. The conductive vias conductively connect a first conductive portion and a second conductive portion and do not extend beyond three layers of the substrate. Thereby, electromagnetic interference can be reduced, and further the influence of electromagnetic interference on the operation of the optical transceiver can be reduced.
[0044] An optical transceiver according to an embodiment of the present disclosure includes a plurality of ground vias located on a substrate. The ground vias can be distributed from the main area of the substrate to the gold finger area of the substrate. Thereby, the electromagnetic interference leakage through multiple sides of the substrate can be reduced.
[0045] An optical transceiver according to an embodiment of the present disclosure includes a pair of differential signal lines located on a substrate. The distance between the pair of differential signal lines is less than three times the width of each of the pair of differential signal lines. Through the above arrangement, the degree of electromagnetic interference can be reduced.
[0046] Please refer to Figure 1 , wherein Figure 1 is a schematic diagram of an optical transceiver according to an embodiment of the present disclosure. Figure 1 shows a way to implement the optical transceiver 1 with an octal small form factor pluggable (OSFP) transceiver. As Figure 1 shown, the optical transceiver 1 includes a substrate 10, a plurality of filter capacitors 11, a plurality of radio-frequency (RF) signal lines 12, and a plurality of ground vias 13.
[0047] The substrate 10 has two side edges E1 and E2 and a distal edge E3. The two side edges E1 and E2 are opposite to each other. The two side edges E1 and E2 are connected to each other and are defined to have the same or different distances from the nearest RF signal line 12. The distal edge E3 is located between the side edge E1 and the side edge E2. And, the substrate 10 has a main area A1 and a gold finger area A2. The gold finger area A2 is closer to the distal edge E3 than the main area A1.
[0048] The filtering capacitor 11 is disposed in the main area A1 on the substrate 10 and connected to the plurality of radio frequency signal lines 12. The filtering capacitor 11 may also correspond to the radio frequency signal lines 12 in a one-to-one relationship. The shortest distance d1 between the radio frequency signal lines 12 and the side edges E1 and E2 is greater than 0.95 millimeters (mm). And, the shortest distance d2 between one of the radio frequency signal lines 12 and each of the two side edges E1 and E2 is greater than 1.3 mm. In one embodiment, the shortest distance d2 between a portion of each of the radio frequency signal lines 12 and each of the two side edges E1 and E2 may be greater than 1.3 mm, and there may be a distance d3 of 8 mm between a portion of each of the radio frequency signal lines 12 and the distal edge E3.
[0049] Each of the radio frequency signal lines 12 includes a first conductive portion 121, a second conductive portion 122, and a conductive via 123. The first conductive portion 121 extends from the main area A1 to the gold finger area A2. The second conductive portion 122 is located in the gold finger area A2. A portion of each of the radio frequency signal lines 12 may be a point P1 where each first conductive portion 121 is connected to a corresponding second conductive portion 122.
[0050] Please refer to Figure 1 and Figure 2 , wherein Figure 2 is a schematic diagram of the configuration of the radio frequency signal lines on the substrate shown according to an embodiment of the present disclosure. The substrate 10 is formed into multiple layers, and Figure 2 shows that the substrate 10 has 12 layers. As Figure 2 shown, the first conductive portion 121 is located within the substrate 10, and at least a portion of the second conductive portion 122 is located on the outer surface of the substrate 10. The conductive via 123 conductively connects the first conductive portion 121 and the second conductive portion 122. Figure 2 Exemplarily, it shows that the conductive via 123 extends from the top layer L1 to the middle layer L3. In other words, the conductive via 123 does not extend beyond three layers of the substrate 10, thereby reducing electromagnetic interference (EMI) radiation. Figure 2 Exemplarily, it shows two radio frequency signal lines 12, one of the radio frequency signal lines 12 is disposed in the upper half of the substrate 10, and the other radio frequency signal line 12 is disposed in the lower half of the substrate 10. In another embodiment, the radio frequency signal lines 12 may be disposed only in the upper half of the substrate 10 or the upper half of the substrate 10. It should be noted that Figure 2 the number of layers of the substrate 10 shown in
[0051] Combined with Figure 1 , Figure 3 is a schematic diagram showing the positions of the plurality of ground vias of the optical transceiver shown in Figure 1 Figure 4 is a schematic diagram of the arrangement of ground vias illustrated according to an embodiment of the present disclosure, and Figure 5 is a schematic diagram of the ground vias penetrating through the substrate illustrated according to an embodiment of the present disclosure. The ground vias 13 are located at the two side edges E1 and E2 and the distal edge E3. A part of the ground vias 13 may be located in the main area A1, and another part of the ground vias 13 may be located in the finger area A2. In other words, the ground vias 13 may be distributed from the main area A1 to the finger area A2. By providing the ground vias 13 at the two side edges E1 and E2 and the distal edge E3, the electromagnetic interference leakage through multiple sides of the substrate 10 can be reduced.
[0052] As Figure 4 shown, the projections of the ground vias 13 on the substrate 10 are staggered with each other. In other words, the ground vias 13 can define a fence structure. In the fence structure, there may be a distance X / 2 between the center points of one ground via 13 on one line and another ground via 13 on an adjacent line. And, a distance X may exist between two ground vias provided on the same line.
[0053] As Figure 5 shown, the substrate 10 may have a top layer Lt, a plurality of intermediate layers Lm1 to Lm n and a bottom layer Lb, where n is a positive integer greater than 3. Each ground via 13 may penetrate through the substrate 10 from the top layer Lt to the intermediate layer Lm n . It should be noted that Figure 5 the number of layers of the substrate 10 shown in
[0054] Combined with Figure 1 , Figure 6 is a schematic diagram of an optical transceiver having a housing illustrated according to an embodiment of the present disclosure. The optical transceiver 1 further includes a housing 14. The housing 14 can be used to define a virtual boundary that divides the main area A1 from the finger area A2. The filtering capacitor 11 may be located within the main area A1, and both the main area A1 and the finger area A2 have their respective RF signal lines 12 and ground vias 13. In addition, the distance d4 between each filtering capacitor 11 and the edge of the housing 14 closest to the distal edge E3 is greater than 2.3 mm. Accordingly, the electromagnetic interference leakage caused by the gap of the housing can be effectively suppressed.
[0055] Please refer to Figure 1 and Figure 7 , where Figure 7It is an enlarged view of a pair of differential signal lines of a radio frequency signal line shown according to an embodiment of the present disclosure. Each radio frequency signal line may include a pair of differential signal lines 12a and 12b. The distance S between the pair of differential signal lines 12a and 12b is less than three times the width W of each of the pair of differential signal lines 12a and 12b. In one embodiment, the distance S between the differential signal lines 12a and 12b in the main region may be the same as the distance S between the differential signal lines 12a and 12b in the gold finger region. The widths of the differential signal lines 12a and 12b may be maintained consistent throughout the main region and the entire gold finger region. Through the above arrangement, the degree of electromagnetic interference can be effectively reduced.
[0056] Please refer to Table 1 below, which shows the test results of electromagnetic interference leakage on an optical transceiver (Condition 1) without the structure described above Figures 1 to 7 and the test results of electromagnetic interference leakage on an optical transceiver (Condition 2) with the structure described above Figures 1 to 7 described.
[0057] Table 1
[0058]
[0059]
[0060] Table 1 shows the test parameters of carrier frequency, field strength level, field strength limit, and test distance. The average margin of Condition 2 is 8.58 higher than that of Condition 1, which shows that Condition 2 has improved in reducing electromagnetic interference.
[0061] Please refer to Figure 8 , where Figure 8 is a schematic diagram of an optical transceiver shown according to another embodiment of the present disclosure. Figure 8 shows the way to implement the optical transceiver 2 with a quad small form factor pluggable double density (QSFP-DD) transceiver. As Figure 8 shown, the optical transceiver 2 includes a substrate 20, a plurality of filter capacitors, a plurality of radio frequency signal lines 22, and a plurality of ground vias 23.
[0062] The substrate 20 has two side edges E1' and E2' and a distal edge E3'. The two side edges E1' and E2' are opposite to each other. The distal edge E3' is located between the side edge E1' and the side edge E2'. And, the substrate 20 has a main region A1' and a gold finger region A2'. The gold finger region A2' is closer to the distal edge E3' than the main region A1'.
[0063] Each radio frequency signal line 22 includes a first conductive portion 221, a second conductive portion 222, and a conductive via 223. The first conductive portion 221 is disposed in the substrate 20 and extends from the main region A1' to the boundary that virtually divides the gold finger region A2' from the main region A1'. The second conductive portion 222 is disposed on the substrate 20 and is located in the gold finger region A2'. The conductive via 223 electrically connects the first conductive portion 221 and the second conductive portion 222. As Figure 5 in the embodiment of, the conductive via 223 can extend from the surface of the substrate and only reach the third layer of the substrate.
[0064] Combined with Figure 8 , Figure 9 is a schematic diagram showing the positions of a plurality of ground vias of the optical transceiver shown in Figure 8 . The ground vias 23 are located at the two side edges E1' and E2' and the distal edge E3'. A part of the ground vias 23 can be located in the main region A1', and another part of the ground vias 23 can be located in the gold finger region A2'. The ground vias 23 are distributed from the main region A1' to the gold finger region A2'.
[0065] Referring to Figures 1 to 7 the structure of the optical transceiver described can be applied to Figure 8 and Figure 9 the optical transceiver 2 shown in, the details of which will not be elaborated here.
[0066] Please refer to Figure 10 where Figure 10 shows the experimental results of the electromagnetic interference level when the conductive via extends to different layers of the substrate. Figure 10 The unit of the horizontal axis of the chart in Figure 10 is frequency (gigahertz, GHz), and Figure 10 the unit of the vertical axis of the chart in Figure 10 is decibel (dB).
[0067] Please refer to Figure 11 ,in Figure 11 Experimental results showing the electromagnetic interference levels at different distances between a pair of differential signal lines. Figure 11 The horizontal axis of the graph is in frequency (gigahertz, GHz), and Figure 11 The unit of the vertical axis of the graph is decibel (dB). The first curve C1 is the result when the distance between a pair of differential signal lines is greater than three times the width of each differential signal line. The second curve C2 is the result when the distance between a pair of differential signal lines is 72.5 mils and the width of each differential signal line is 26.5 mils. Meanwhile, the third curve C3 is the result when the distance between a pair of differential signal lines is 74 mils and the width of each differential signal line is 25 mils.
[0068] The absolute value of the electromagnetic interference of the first curve C1 is 79.6618dB, the absolute value of the electromagnetic interference of the second curve C2 is 77.5921dB, and the absolute value of the electromagnetic interference of the third curve C3 is 77.8267dB. The electromagnetic interference of the second curve C2 is 2.1dB lower than that of the first curve C1, and the electromagnetic interference of the third curve C3 is 1.8dB lower than that of the first curve C1, and the electromagnetic interference of the second curve C2 is lower than that of the third curve C3. Accordingly, from the above content, it can be known that when the distance between a pair of differential signal lines becomes shorter (that is, the width of the pair of differential signal lines becomes wider), the degree of electromagnetic interference can be effectively reduced.
[0069] In summary, the electromagnetic interference of the optical transceiver according to one or more embodiments of the present disclosure can be reduced, thereby reducing the impact of the electromagnetic interference on the operation of the optical transceiver.
Claims
1. An optical transceiver, characterized in that: Include: A substrate having two side edges opposite to each other and a distal edge between the two side edges, and the substrate having a main area and a gold finger area closer to the distal edge than the main area; A plurality of filter capacitors are disposed in the main region on the substrate; as well as A plurality of radio frequency signal lines are connected to the plurality of filter capacitors, and each of the plurality of radio frequency signal lines comprises: A first conductive portion is disposed in the substrate and extends from the main area to the gold finger area; A second conductive portion is disposed on the substrate and located in the gold finger region; as well as a conductive via conductively connecting the first conductive portion and the second conductive portion and not extending beyond the three layers of the substrate; as well as A plurality of grounding through holes are located at the two side edges and the distal edge, and the plurality of grounding through holes are distributed from the main area to the gold finger area, The shortest distance between each of the plurality of radio frequency signal lines and the two side edges is greater than 0.95 mm.
2. The optical transceiver according to claim 1, wherein: A shortest distance between a portion of each of the plurality of RF signal lines and each of the two side edges is greater than 1.3 mm, wherein a distance between the portion of each of the plurality of RF signal lines and the distal edge is 8 mm.
3. The optical transceiver according to claim 1, wherein: A shortest distance between each of the plurality of radio frequency signal lines and each of the two side edges is greater than 1.3 mm.
4. The optical transceiver according to claim 1, wherein: It further comprises a shell, wherein the main area and the gold finger area are divided by the shell.
5. The optical transceiver according to claim 4, characterized in that A distance between each of the plurality of filter capacitors and an edge of the housing closest to the distal edge is greater than 2.3 mm.
6. The optical transceiver according to claim 1, wherein: Each of the plurality of ground vias passes through the substrate.
7. The optical transceiver according to claim 1, wherein: The projections of the ground vias on the substrate are staggered with each other.
8. The optical transceiver according to claim 1, wherein: A portion of the plurality of ground vias is located in the main region.
9. The optical transceiver according to claim 1, wherein: Each of the plurality of RF signal lines further includes a pair of differential signal lines, and a distance between the pair of differential signal lines is less than three times the width of each of the pair of differential signal lines.