CN218634665U

CN218634665U - Electromagnetic shield for optical module

Info

Publication number: CN218634665U
Application number: CN202221331937.3U
Authority: CN
Inventors: 王苗庆; 沈胤帆; 程茂康
Original assignee: Shaoxing Zktel Equipment Co ltd
Current assignee: Shaoxing Zktel Equipment Co ltd
Priority date: 2022-05-25
Filing date: 2022-05-25
Publication date: 2023-03-14
Anticipated expiration: 2032-05-25

Abstract

The utility model relates to an electromagnetic shield cover for optical module, including upper cover support and upper cover, the upper cover support encloses to close the structure for four sides, is equipped with the first breach of laminating with three-dimensional device base on the first face of upper cover support, and the video receiving pin of three-dimensional device gets into in the electromagnetic shield cover through first breach, is equipped with the second breach of laminating with the copper spindle nose on the second face of upper cover support, and the overhead signal line of copper spindle gets into in the electromagnetic shield cover through the second breach, the lower part laminating of upper cover support is on PCBA board, and upper portion adopts the upper cover to close and seals; has the advantages that: through setting up the electromagnetic shield cover to cooperation three-dimensional device and copper axle head form an enclosure space on PCBA board upper surface, put the video signal transport part of module in this space, avoid signal interference.

Description

Electromagnetic shield for optical module

Technical Field

The utility model relates to an optical communication field especially relates to an electromagnetic shield cover for optical module.

Background

As shown in fig. 1, currently, radio frequency transmission schemes based on GPON (gigabit passive optical network) transmission systems are mainly adopted in the market: an OLT (optical line terminal) optical module is adopted at the upper end, a wavelength division multiplexer (WDM 1 r) is used for combining a video signal and a GPON signal and then transmitting the signals through an optical fiber, a GPON ONU Treplexer module (GPON ONU three-way module, the structure is shown as a part in a dotted line frame in figure 1) is adopted at the lower end, and the video signal and the GPON signal are separated and applied in the module. The GPON ONU Treplexer module can realize 1.25G1310nm optical signal transmission, 2.5G 1490nm optical signal reception and 1555nm video optical signal reception.

However, the above scheme has the following defects: with the increasing load of customers and the demand of customers for higher speed, the transmission rate of passive optical networks has been greatly increased: the transition from GPON to XGPON (asymmetric 10G PON, downstream 10G/upstream 2.5G) to XGSPON (symmetric 10GPON, downstream 10G/upstream 10G) is still based on GPON systems, but the customers cannot enjoy both higher network speed and high definition cable television.

In view of the above defects, the inventors intend to develop an optical module based on the XGSPON system for transmitting XGSPON signals and video signals, but firstly, the problem of signal interference caused by XGSPON transmission to video reception needs to be solved.

Based on this, the present disclosure is thus directed.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an electromagnetic shield cover for optical module to solve the signal interference problem that XGSPON transmission brought to video reception.

In order to achieve the above purpose, the technical solution of the present invention is as follows:

the utility model provides an electromagnetic shield cover for optical module, electromagnetic shield cover install on the PCBA board, and install three-dimensional device and copper axle head on the PCBA board, electromagnetic shield cover includes upper cover support and upper cover, the upper cover support encloses for the four sides and closes the structure, is equipped with the first breach with three-dimensional device base laminating on the first face of upper cover support, and in the video receiving pin of three-dimensional device got into electromagnetic shield cover through first breach, be equipped with the second breach with the laminating of copper axle head on the second face of upper cover support, in the overhead signal line of copper axle got into electromagnetic shield cover through the second breach, the lower part laminating of upper cover support was on the PCBA board, and upper portion adopts the upper cover lid to close and seals.

The three-way device support comprises a support plate, the three-way device is arranged above the support plate, a sealing piece is arranged on the support plate, and the first notch is sealed by the sealing piece and a base of the three-way device.

Furthermore, a base limiting piece is arranged on the support plate.

Furthermore, the three-way device comprises a pin shielding cover, one side of the pin shielding cover is provided with an opening, the opening is attached to the PCBA, and a welding point of the video receiving pin of the three-way device and the PCBA is positioned in the pin shielding cover.

Further, the first notch is of a U-shaped groove structure, and the opening faces the PCBA.

The heat radiator comprises a heat guiding plate, a heat outlet plate and a heat transfer plate connected with the heat guiding plate and the heat outlet plate, wherein the heat guiding plate is attached to a heating device on the PCBA board and used for introducing heat, and the heat transfer plate is used for radiating the heat outwards.

Furthermore, a heat conducting pad is arranged on the heat guiding plate and/or the heat outlet plate.

Further, the radiator is Z-shaped.

The utility model has the advantages of:

1. an electromagnetic shielding cover is arranged, and a three-way device and a copper shaft head are matched to form a closed space on the upper surface of the PCBA board, and a video signal transmission part of the module is placed in the space, so that external signal interference is avoided; because the video receiving pin of the three-way device needs to penetrate through the PCBA board to be welded to the lower surface of the PCBA board, the risk of signal interference introduced from the pin exists, and the video receiving pin is shielded by adding the pin shielding cover, so that the external signal interference is further avoided;

2. when the distance between the heating device and the module shell is large, the Z-shaped heat dissipation device is arranged, low-cost heat dissipation can be achieved, and the Z-shaped heat dissipation device is simple in structure, convenient to manufacture, low in cost and good in heat dissipation performance.

Drawings

Fig. 1 is a radio frequency transmission scheme based on a GPON transmission system in a conventional scheme;

FIG. 2 is a schematic block diagram of a Triplexer module of an XGSON ONU in an embodiment;

FIG. 3 is a schematic diagram of a three-dimensional structure of a Triplexer module of an XGSON ONU in an embodiment;

FIG. 4 is a schematic three-dimensional structure of FIG. 3 from another perspective;

FIG. 5 is a schematic bottom view of FIG. 3;

fig. 6 is a schematic diagram of a three-dimensional structure of the XGSPON ONU Triplexer module in the embodiment with the upper cover removed;

FIG. 7 isbase:Sub>A schematic sectional view A-A of FIG. 5;

FIG. 8 is an exploded view of the upper cover, the upper cover bracket and the three-way device bracket of the embodiment;

FIG. 9 is a schematic diagram of a three-dimensional structure of the XGSON ONU Triplexer module in the embodiment without a three-way device;

FIG. 10 is a schematic three-dimensional configuration of a three-way device holder according to an embodiment;

FIG. 11 is a schematic view showing the construction of a Z-shaped heat sink in the embodiment;

FIG. 12 is a schematic view showing the structure of a pin shield case in the embodiment;

FIG. 13 is a diagram illustrating pin definitions of gold fingers according to an embodiment;

FIG. 14 is a schematic diagram of an exemplary embodiment of an XGPON-based RF transmission scheme;

fig. 15 is a schematic block diagram of the Triplexer module of the XGSPON ONU after the LDD/LA two-in-one chip is used.

Description of the reference symbols

PCBA board 1;

three-way device 2, video receiving pin 21, base 22;

the upper cover holder 3, the first surface 31, the first notch 311, the second surface 32, the second notch 321, the third surface 33, and the fourth surface 34;

an upper cover 4; a copper shaft head 5;

the three-way support 6, the carrier plate 61, the sealing piece 62 and the base limiting piece 63;

a pin shield case 7; a heat sink 8; a heat generating device 9; a heat conductive pad 10;

english interpretation in figure 1

TX: an optical transmitter; RX: an optical receiver; V-TX: a video transmitter; V-RX: a video receiver;

WBF: a filter for blocking interference signals to RX; WBF-V: a filter for blocking an interference signal to the V-RX;

IF _GPON : an uplink optical signal and a downlink optical signal of the GPON system; IF (intermediate frequency) circuit _video : a downlink video signal;

WDM-G: the wavelength division multiplexing filter in the GPON ONU is used for multiplexing/demultiplexing an uplink optical signal and a downlink optical signal of the G-PON system;

WDM-G': the wavelength division multiplexing filter in the G-PON ONU Triplexer is used for multiplexing/demultiplexing an uplink optical signal, a downlink optical signal and a downlink video signal of the G-PON system;

a wavelength division multiplexing filter in the WDM-G-L G-PON OLT, which is used for multiplexing/demultiplexing the uplink optical signal and the downlink optical signal of the G-PON system;

WDM1r: the wavelength division multiplexing filter is positioned in the service center and is used for multiplexing an uplink optical signal and a downlink video signal of the G-PON system;

splitter: a wavelength splitter for separating the light of different wavelengths mixed together;

english interpretation in figure 14

IF _XGSPON : an uplink optical signal and a downlink optical signal of the XGSPON system; IF (intermediate frequency) circuit _video : a downlink video signal;

WDM-X: the wavelength division multiplexing filter in the XGSPON ONU is used for multiplexing/demultiplexing the uplink optical signal and the downlink optical signal of the XGS-PON system;

WDM-X': the wavelength division multiplexing filter in the XGSON ONU Triplexer is used for multiplexing/demultiplexing an uplink optical signal, a downlink optical signal and a downlink video signal of the XGSON system;

WDM-X-L: the wavelength division multiplexing filter in the XGSPON OLT is used for multiplexing/demultiplexing the uplink optical signal and the downlink optical signal of the XGSPON system;

WDM1r: and the wavelength division multiplexing filter is positioned in the service center and is used for multiplexing the uplink optical signal and the downlink video signal of the XGSPON system.

Detailed Description

The present invention will be described in further detail with reference to examples.

English notation:

LA: a limiting amplifier; LDD: a laser driving chip; AGC: automatic gain control; TO-CAN: a packaging technology of an optical device is TO-CAN coaxial packaging.

In this embodiment, an anti-interference XGSPON ONU Triplexer module is provided, as shown in fig. 1, the electrical components mounted on the PCBA board 1 include a gold finger, a copper spindle 5, an MCU, a DC/DC voltage regulator circuit, an APD booster circuit, an LA chip, an LDD chip, a radio frequency amplifier chip, an AGC circuit, and a three-way optical sub-integrated component. The input end of the DC/DC voltage stabilizing circuit is connected with the power output end of the golden finger and provides 12V/3.3V stable voltage for the XGSON ONU Triplexer module. The MCU is respectively in bidirectional communication connection with the golden finger, the LA chip and the LDD chip, and also receives a level feedback signal output from the radio frequency amplification chip and outputs a level control signal to the AGC circuit. The LA chip is used for receiving the downlink electric signals output by the three-way optical subset assembly, carrying out amplitude limiting amplification on the downlink electric signals and then transmitting the downlink electric signals to the golden finger. The APD booster circuit is in bidirectional electric connection with the LA chip to achieve level control and feedback, and the APD booster circuit is in bidirectional electric connection with the three-way optical subset assembly to achieve level gain. The LDD chip is used for receiving the uplink electric signal output by the golden finger and transmitting the uplink electric signal to the three-way optical sub-integrated component to modulate and drive the DFB laser. The radio frequency amplification chip is used for receiving the video electrical signals output by the three-way optical subset assembly and transmitting the video electrical signals to the copper shaft head 5; the radio frequency amplification chip is in bidirectional electric connection with the AGC circuit and used for realizing level gain. The three-way optical subset assembly is used for receiving a downlink optical signal and a video optical signal input from the optical fiber, converting the downlink optical signal into a downlink electric signal and converting the video optical signal into a video electric signal; the three-way optical sub-assembly is used for converting an input uplink electric signal into an uplink optical signal and outputting the uplink optical signal to an optical fiber.

As shown in fig. 15, in order to improve the circuit layout, reduce the module volume, and reduce the module cost, the present embodiment selects an LDD/LA (Laser Diode Driver/Limiting Amplifier) two-in-one chip, which adopts a GN28L96 chip of Semtech corporation and includes an LDD chip and an LA chip. Preferably, the MCU in this embodiment adopts GD32E232K8Q7 chip of GigaDevice corporation; the radio frequency amplification chip adopts a TAT6254C chip of Qorvo company; the AGC circuit adopts an RFSA3043TR7 chip of Qorvo company.

As shown in fig. 1, the three-way optical subassembly of the present embodiment includes a wavelength division multiplexer WDM, an APD receiver, a DFB laser, and a PIN receiver, all of which adopt TO-CAN coaxial packages. The wavelength division multiplexer is used for receiving and separating a downlink optical signal and a video optical signal input from an optical fiber, transmitting the downlink optical signal to an APD receiver and transmitting the video optical signal to a PIN receiver; the DFB laser receives an uplink electric signal output from the LDD chip and converts the uplink electric signal into an uplink optical signal, and the wavelength division multiplexer receives the uplink optical signal output from the DFB laser and transmits the uplink optical signal to the optical fiber; the APD receiver converts the downlink optical signal into a downlink electric signal and outputs the downlink electric signal to the LA chip; the PIN receiver converts the video optical signal into a video electric signal and outputs the video electric signal to the radio frequency amplification chip; the APD receiver is in bidirectional electrical connection with the APD boost circuit.

In this embodiment, a hot plug can be supported by using a golden finger electrical connection scheme, which uses a golden finger specification compatible with SFF-INF-8074, and the pin definitions are shown in fig. 15, where pin 1 is defined as VeeT, pin 2 is defined as TXFAULT, pin 3 is defined as TXBURST, pin 4 is defined as SDA, pin 5 is defined as SCL, pin 6 is defined as MOD-ABS, pin 7 is defined as Vcc12, pin 8 is defined as RXLOS, pin 9 is defined as TXDIS, pin 10 is defined as VeeR, pin 11 is defined as VeeR, pin 12 is defined as xd-, pin 13 is defined as RXD +, pin 14 is defined as VeeR, pin 15 is defined as VccR, pin 16 is defined as VccT, pin 17 is defined as VeeT, pin 18 is defined as TXD +, pin 19 is defined as TXD-, and pin 20 is defined as VeeT.

After the scheme is adopted, the module is based on the XGSPON system and realizes XGSPON signal transmission and video signal transmission as shown in FIG. 14. The working principle of the XGSON ONU Triplexer module is as follows, the whole XGSON ONU Triplexer module is composed of an XGSON ONU part and a radio frequency receiving part, and a transmission route comprises:

a. the 10Gb/s uplink electric signals from the golden fingers are driven by an LDD chip to a 1270nm DFB laser, and are electro-optically converted into 10Gb/s 1270nm uplink optical signals which are transmitted upwards through optical fibers;

b. the 10Gb/s 1577nm downlink optical signal from the optical fiber is photoelectrically converted into a 10Gb/s downlink electrical signal by an APD receiver, and then is output by a golden finger after a TIA (preamplifier) and an LA (amplifier) chip integrated in an APD TO-CAN (avalanche photo diode-amplifier-CAN) are used;

c. the 1555nm downlink video optical signal from the optical fiber is photoelectrically converted into a downlink video electrical signal by a PIN receiver, and is output through a copper shaft head 5 after radio frequency amplification and radio frequency attenuation (namely, an AGC circuit).

The module of the embodiment is also provided with an electromagnetic shielding cover on the PCBA board 1, and the video signal transmission part is arranged in the electromagnetic shielding cover, so that signal interference is avoided, and the problem of signal interference caused by XGSPON transmission to video reception is solved.

As shown in fig. 3 to 12, the electromagnetic shield includes an upper cover bracket 3 and an upper cover 4, the upper cover bracket 3 is of a four-sided enclosure structure, and four sides of the upper cover bracket 3 are respectively defined as a first side 31, a second side 32, a third side 33, and a fourth side 34. Wherein, be equipped with on the first face 31 of upper cover support 3 with the first breach 311 of the laminating of 2 bases 22 of three-dimensional device, the video receiving pin 21 of three-dimensional device 2 gets into the electromagnetic shield cover through first breach 311 in, be equipped with on the second face 32 of upper cover support 3 with the second breach 321 of the laminating of copper axle head 5, signal line on the copper axle head 5 gets into the electromagnetic shield cover through second breach 321 in, the lower part laminating of upper cover support 3 is fixed on PCBA board 1, and upper portion adopts upper cover 4 lid to close the closure. Thereby achieving that the video signal transmission section is disposed inside the electromagnetic shield.

First breach 311 can set up to the shape with three-way device 2 video reception pin 21 assorted, directly open on first face 31 with nearly big hole of pin diameter, can with the pin insert downthehole during the installation, but such scheme can increase the degree of difficulty of installation (still need the welding between three-way device 2 and PCBA board 1, adopts this scheme, just need to fix upper cover support 3 installation before the welding, causes the welded inconvenience). In order to improve the convenience of installation, the first notch 311 of this embodiment adopts a U-shaped groove structure as shown in fig. 8, and the opening surface of the U-shaped groove is a groove of the PCBA board 1, so that during installation, the three-way component 2 can be fixed first, and then the upper cover bracket 3 can be installed. As shown in fig. 7, after the U-shaped groove gap solution is adopted, the base 22 of the three-way device 2 cannot completely close the first gap 311, which may affect the shielding effect, so the electromagnetic shielding case of this embodiment further includes a bracket for the three-way device 2. The three-way device 2 support comprises a carrier plate 61, the three-way device 2 is arranged above the carrier plate 61, a base limiting piece 63 is arranged on the circumferential direction of the carrier plate 61 to fix the base 22 of the three-way device 2, and meanwhile, a sealing piece 62 is arranged on the carrier plate 61, so that the first notch 311 is sealed by the sealing piece 62 and the base 22 of the three-way device 2. Therefore, the three-way support 6, the upper cover support 3 and the upper cover 4 are matched with the three-way device 2 and the copper shaft head 5, and a closed space is formed on the upper surface of the PCBA board 1.

Since the video receiving pin 21 of the three-way device 2 needs to be soldered through the PCBA board 1 to the lower surface of the PCBA board 1, there is a risk of introducing signal interference from this pin, so that the video receiving pin 21 needs to be shielded. As shown in fig. 4 and 12, the electromagnetic shield case includes a pin shield case 7, one surface of the pin shield case 7 is open and the open surface is attached to the PCBA board 1, and the solder joints between the video receiving pins 21 of the three-way device 2 and the PCBA board 1 are located in the pin shield case 7.

When the distance from the heating device 9 to the module housing (the module is also provided with a housing which wraps the PCBA board 1 and the shielding case) or the electromagnetic shielding case is large, the cost of the scheme of directly placing the heat conducting pad is too high, the heat radiating effect of the module is not ideal, and preferably, the heat radiating module further comprises a heat radiator 8 which is used for guiding heat generated by the heating device 9 on the PCBA board 1 to the outside of the module. The heat radiator 8 comprises a heat guiding plate, a heat outlet plate and a heat transfer plate for connecting the heat guiding plate and the heat outlet plate, the heat guiding plate is attached to a heating device 9 of the XGSPON ONU Triplexer module and used for guiding heat, the heat transfer plate is in contact with an electromagnetic shielding cover or a shell and used for radiating heat outwards, and heat conducting pads 10 (such as heat conducting silica gel) can be arranged on the heat guiding plate and the heat outlet plate to accelerate heat radiation. The radiator 8 can adopt an I shape or a Z shape, but the I shape is inconvenient to process and needs to be welded during manufacturing, and the Z shape can be directly formed by adopting a stamping and bending mode, so the radiator 8 is preferably in the Z shape.

As shown in fig. 7, in the present embodiment, a Z-shaped heat sink 8 is disposed in the electromagnetic shield, a heat conducting pad 10 is disposed at a heat conducting plate at a lower portion of the heat sink 8 for contacting with the heat generating device 9, and a heat discharging plate at an upper portion of the heat sink 8 for discharging heat is in contact with the upper cover 4. The Z-shaped radiator 8 has the advantages of simple structure, convenience in manufacturing, lower cost, good heat dissipation performance and the like.

The above-mentioned embodiments are merely illustrative of the inventive concept and are not intended to limit the scope of the invention, which is defined by the claims and the insubstantial modifications of the inventive concept can be made without departing from the scope of the invention.

Claims

1. The utility model provides an electromagnetic shield cover for optical module, electromagnetic shield cover installs on the PCBA board, and installs three-dimensional device and copper axle head on the PCBA board, its characterized in that, electromagnetic shield cover includes upper cover support and upper cover, the upper cover support encloses for the four sides and closes the structure, is equipped with the first breach with three-dimensional device base laminating on the first face of upper cover support, and in the video receiving pin of three-dimensional device got into electromagnetic shield cover through first breach, be equipped with the second breach with the laminating of copper axle head on the second face of upper cover support, in the overhead signal line of copper axle got into electromagnetic shield cover through the second breach, the lower part laminating of upper cover support was on the PCBA board, and upper portion adopts the upper cover lid to close and seals.

2. The EMI shield for optical modules as set forth in claim 1, including a three-way device holder, said three-way device holder including a carrier plate, said three-way device being disposed above said carrier plate, said carrier plate having a closure tab thereon, said first notch being closed by said closure tab and a base of said three-way device.

3. The electromagnetic shielding case for optical module of claim 2, wherein the carrier board has a base limiting plate.

4. The electromagnetic shield for the optical module of claim 1, comprising a pin shield, wherein one side of the pin shield is open and the open side is attached to the PCBA board, and the solder joint between the video receiving pin of the three-way device and the PCBA board is located in the pin shield.

5. The electromagnetic shield for a light module of claim 1, wherein the first notch is a U-shaped slot configuration and opens toward the PCBA board.

6. The electromagnetic shield for the optical module as set forth in claim 1, comprising a heat spreader, wherein the heat spreader comprises a heat-guiding plate, a heat-discharging plate and a heat-transfer plate connecting the heat-guiding plate and the heat-discharging plate, the heat-guiding plate is attached to a heat-generating device on the PCBA board for guiding heat, and the heat-transfer plate is used for dissipating heat outwards.

7. The electromagnetic shield for an optical module of claim 6, wherein the heat-directing plate and/or the heat-extracting plate is provided with a thermal pad.

8. An electromagnetic shield for an optical module according to claim 6, wherein the heat sink is Z-shaped.