A receiver TO packaging structure and a Combo PON optical module

Abstract

This utility model belongs to the field of optical communication technology, specifically providing a receiver TO packaging structure, including a TO base, a TO cap, a detector, a bracket, and a converging lens. The TO cap is fastened to the TO base, forming a cavity with the TO base. The top of the TO cap has an optical window and an optical window plate for isolating the optical window from the cavity. The bracket is mounted on the cap. The converging lens is mounted on the bracket. The detector is mounted inside the cavity and is located on the converging optical path of the converging lens. This receiver TO packaging structure, without affecting the hermeticity of the TO package, designs a large-curvature lens outside the cap, shortening the optical path working distance, reducing the light spot size, ensuring effective light source input, significantly improving sensitivity performance, effectively extending the lifespan of the existing network, and allowing for a smooth upgrade to the next generation of PON.

Description

Technical Field

[0001] This utility model belongs to the field of optical communication technology, specifically relating to a receiver TO packaging structure and a Combo PON optical module. Background Technology

[0002] Combo PON OLT Class D+ is a tri-mode optical module. Its deployment extends the lifecycle of existing network technologies and significantly reduces the cost of broadband upgrades for users. However, due to its all-scenario coverage (-40℃ to +85℃), high-density scenario adaptation (1:128), and long-distance coverage (80km), it places extremely high demands on product performance, especially the sensitivity of the receiver's TO (Transmission Object). Currently, mature TO packaging solutions on the market are insufficient to meet the performance requirements of this product. Utility Model Content

[0003] The purpose of this invention is to improve the sensitivity performance of the receiver TO, so that optical module products can meet the application requirements of higher-end applications.

[0004] To address this, the present invention provides a receiver TO packaging structure, comprising a TO base, a TO cap, a detector, a bracket, and a converging lens; the TO cap is fastened to the TO base and together with the TO base forms an accommodating cavity; the top of the TO cap is provided with an optical window and an optical window plate for isolating the optical window from the accommodating cavity; the bracket is mounted on the cap; the converging lens is mounted on the bracket; the detector is mounted inside the accommodating cavity and is located on the converging optical path of the converging lens.

[0005] Specifically, the aforementioned optical window is fixed at the end of the optical window facing the TO base; the bracket is provided with a positioning post and an optical channel connected to the optical window; the positioning post is inserted into the optical window; and the converging lens is installed at the end of the optical channel away from the optical window.

[0006] Specifically, the bracket is provided with a mounting groove; the bottom of the mounting groove is provided with a light channel that connects to the light window; the converging lens is installed in the mounting groove.

[0007] Specifically, the aforementioned receiver TO package structure also includes a transimpedance amplifier; both the transimpedance amplifier and the detector are mounted on the TO base.

[0008] Specifically, the distance between the transimpedance amplifier and the detector is controlled between 70-130 μm.

[0009] Specifically, the aforementioned TO base is provided with a substrate; the detector is mounted on the substrate.

[0010] Specifically, the aforementioned substrate is a ceramic substrate.

[0011] Specifically, the aforementioned TO base is equipped with a cooler; the substrate is mounted on the cooler.

[0012] Specifically, the aforementioned TO base is provided with multiple TO pins; the multiple TO pins are respectively connected to the corresponding optical elements in the accommodating cavity by bonding wires.

[0013] This utility model also provides a Combo PON optical module, including the above-mentioned receiver TO packaging structure.

[0014] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0015] The receiver TO packaging structure provided by this utility model, without affecting the hermeticity of the TO packaging, features a large curvature lens designed outside the cap, which shortens the working distance of the optical path, reduces the light spot, ensures effective input of the light source, significantly improves sensitivity performance, effectively extends the life cycle of the existing network, and allows for a smooth upgrade to the next generation of PON.

[0016] The present invention will be further described in detail below with reference to the accompanying drawings. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the TO package structure of the receiver in one implementation method.

[0018] Figure 2 This is a schematic diagram of the support structure of the TO package structure of the receiving end in one implementation method.

[0019] Figure 3 This is a planar schematic diagram of a support in one implementation method.

[0020] Figure 4 This is a schematic diagram of the connection structure between the TO base and the TO cap of the receiving end TO packaging structure in one implementation method.

[0021] Figure 5 This is a schematic diagram of the installation of optical components on the TO base in one implementation method.

[0022] Figure 6 This is a schematic diagram of the optical path at the receiver end of a Combo PON optical module in one implementation method.

[0023] Explanation of reference numerals in the attached drawings: 1. TO base; 2. TO cap; 201. Optical window; 202. Optical window aperture; 3. Bracket; 301. Positioning post; 302. Optical channel; 303. Mounting slot; 4. Converging lens; 5. Detector; 6. Transimpedance amplifier; 7. Substrate; 8. TO pin; 9. Collimator; 10. 32° filter; 11. 13° filter; 12. 0° filter. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0025] In the description of this utility model, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0026] Reference Figure 1-6 This invention provides a receiver TO packaging structure, including a TO base 1, a TO cap 2, a detector 5, a bracket 3, and a converging lens 4. The TO cap 2 is fastened to the TO base 1, forming a cavity with the TO base 1. The top of the TO cap 2 is provided with an optical window 202 and an optical window 201 for isolating the optical window 202 from the cavity. The bracket 3 is mounted on the cap. The converging lens 4 is mounted on the bracket 3. The detector 5 is mounted inside the cavity and is located on the converging optical path of the converging lens 4. In use, the collimated parallel light received and converted by the optical module is converted into converged light by the converging lens 4, and then reaches the photosensitive surface of the detector 5 through the optical window 201. The detector 5 preferably includes an APD chip, and the converging lens 4 is preferably a large curvature convex lens (SR1.716), with the convex surface facing away from the detector 5, which can shorten the working distance of the optical path, making the converged light spot less than 40μm, smaller than the photosensitive surface of the chip, ensuring effective input of the light source, and effectively improving sensitivity. By controlling the sealing accuracy range of ±50um through the sealing electrode, and ensuring the chip accuracy range of detector 5 is ±30um through the placement machine, the TO packaging accuracy and batch consistency requirements are not high, and it is compatible with chips with poor performance, resulting in a significant cost advantage.

[0027] Specifically, refer to Figure 2The aforementioned optical window 201 is fixed to the end of the optical window hole 202 facing the TO base 1, that is, the optical window 201 is fixed to the inner side of the top wall of the TO cap 2, so that the optical window hole 202 and the optical window 201 form a positioning groove that can be used for mounting the bracket 3; the bracket 3 is provided with a positioning post 301 and an optical channel 302 communicating with the optical window 201; the positioning post 301 is inserted into the optical window hole 202; the converging lens 4 is installed at the end of the optical channel 302 away from the optical window 201. The foolproof positioning design composed of the positioning post 301 and the positioning groove ensures the consistency of lens assembly. Preferably, during assembly, the tolerance between the positioning post 301 and the TO cap 2 is ±50um, and the converging lens 4 and the bracket 3 are designed to slide together with a tolerance range of +0-50um to ensure the consistency of the incident light spot.

[0028] Furthermore, such as Figure 3 As shown, the bracket 3 has a mounting groove 303; the bottom of the mounting groove 303 has an optical channel 302 that connects to the optical window 201; the converging lens 4 is installed in the mounting groove 303. The converging lens 4 is generally fixed by adhesive. The mounting groove 303 reduces the bonding area between the converging lens 4 and the adhesive, thereby reducing the stress on the lens and effectively reducing the PDL caused by stress on the overall optical path.

[0029] In a more detailed implementation, such as Figure 5 As shown, the receiver TO package structure also includes a transimpedance amplifier 6 (TIA); both the transimpedance amplifier 6 and the detector 5 are mounted on the TO base 1.

[0030] To effectively reduce electrical crosstalk, the transimpedance amplifier 6 and the detector 5 are placed at a distance of 70-130μm.

[0031] Furthermore, a substrate 7 is provided on the TO base 1; the detector 5 is mounted on the substrate 7.

[0032] The substrate 7 is preferably a ceramic substrate with high thermal conductivity, high insulation, excellent mechanical strength and chemical stability to improve product stability.

[0033] Optionally, a cooler is provided on the TO base 1; the base plate 7 is mounted on the cooler.

[0034] In a more detailed embodiment, the TO base 1 is provided with multiple TO pins 8; the multiple TO pins 8 are respectively connected to corresponding optical elements in the accommodating cavity by bonding wires, which facilitates product performance debugging. The number of TO pins 8 is designed according to the number of optical elements on the TO base 1.

[0035] Example 1: This example provides a receiver TO package structure, including a TO base 1, a TO cap 2, an APD chip, a transimpedance amplifier 6, a ceramic substrate, a bracket 3, and a converging lens 4;

[0036] The TO cap 2 is fastened onto the TO base 1 and together with the TO base 1, they form a receiving cavity;

[0037] The top of the TO cap 2 is provided with a light window 202 and a light window plate 201 for separating the light window 202 from the accommodating cavity; the light window plate 201 is fixed to the inner side of the top wall of the TO cap 2.

[0038] The bottom of the bracket 3 is provided with a positioning post 301 that matches the light window 202; the upper surface of the bracket 3 is provided with a mounting groove 303; the bottom of the mounting groove 303 is provided with a light channel 302 that connects to the light window 201; the positioning post 301 is inserted into the light window 202.

[0039] The converging lens 4 is a large curvature convex lens (SR1.716), with one side being convex and the other side being flat. The converging lens 4 is installed in the mounting groove 303, with the flat side bonded to the bottom of the mounting groove 303.

[0040] The ceramic substrate and the transimpedance amplifier 6 are both mounted on the TO base 1; the APD chip is mounted on the ceramic substrate and located in the converging optical path of the converging lens 4; the placement distance between the transimpedance amplifier 6 and the APD chip is controlled at 100±30μm.

[0041] The TO base 1 is provided with multiple TO pins 8; the multiple TO pins 8 are respectively connected to the corresponding optical elements in the accommodating cavity by bonding wires.

[0042] The above-mentioned receiver TO package structure is assembled using the following steps:

[0043] Step 1: Visually align the ceramic substrate with the TO base 1, and fix the ceramic substrate to the TO base 1 by adhesive bonding.

[0044] Step 2: Align the APD chip with the ceramic substrate, and fix the APD chip to the ceramic substrate by adhesive bonding.

[0045] Step 3: The transimpedance amplifier 6 is fixed to the TO base 1 with the APD chip as the reference, and the distance between the amplifier and the APD chip is controlled at 100±30μm.

[0046] Step 4: Using a vacuum nitrogen-filling equipment, the TO cap 2 and the TO base 1 are welded together using resistance welding.

[0047] Step 5: Place the converging lens 4 with its convex surface facing up in the mounting slot 303 of the bracket 3 and fix it with glue.

[0048] Step 6: Insert the positioning post 301 of the bracket 3 into the light window 202 of the TO tube cap 2 and fix it with glue.

[0049] This embodiment also provides a Combo PON optical module, including the aforementioned receiver TO package structure, an optical coupling transmission device for reflecting the light returned from the optical fiber back to the receiver TO package structure, a collimator 9, a 32° filter 10, a 13° filter 11, and a 0° filter 12; the collimator 9 is disposed on the output optical path of the optical coupling transmission device; the 13° filter 11 is disposed on the output optical path of the collimator 9; the 32° filter 10 is disposed on the reflected optical path of the 13° filter 11; the 0° filter 12 is disposed on the reflected optical path of the 32° filter 10; and the converging lens 4 is disposed on the transmission optical path of the 0° filter 12.

[0050] Reference Figure 6 The light entering the optical coupling transmission device is converted into collimated parallel light of 1270nm by collimator 9, reflected by 13° filter 11 to 32° filter 10, and reflected again on 32° filter 10. The light passes through 0° filter 12 and then through converging lens 4. The converging lens 4 converts the collimated parallel light into focused light. The focused light passes through TO cap optical window 201 and reaches APD chip, where it is converted into an electrical signal. The signal is then amplified by transimpedance amplifier and output to the fiber optic sensing system through TO pin 8.

[0051] The above examples are merely illustrative of this utility model and do not constitute a limitation on the scope of protection of this utility model. All designs that are the same as or similar to this utility model are within the scope of protection of this utility model.

Claims

1. A receiving end TO package structure, characterized in that: The device includes a TO base (1), a TO cap (2), a detector (5), a bracket (3), and a converging lens (4); the TO cap (2) is fastened to the TO base (1) and together with the TO base (1) forms a receiving cavity; the top of the TO cap (2) is provided with a light window (202) and a light window plate (201) for separating the light window (202) from the receiving cavity; the bracket (3) is mounted on the cap; the converging lens (4) is mounted on the bracket (3); the detector (5) is mounted in the receiving cavity and is located on the converging light path of the converging lens (4).

2. The receiver TO packaging structure as described in claim 1, characterized in that: The light window (201) is fixed at one end of the light window hole (202) facing the TO base (1); the bracket (3) is provided with a positioning post (301) and a light channel (302) connected to the light window (201); the positioning post (301) is inserted into the light window hole (202); the converging lens (4) is installed at one end of the light channel (302) away from the light window (201).

3. The receiver TO packaging structure as described in claim 2, characterized in that: The bracket (3) has an installation groove (303); the bottom of the installation groove (303) has an optical channel (302) that connects to the optical window (201); the converging lens (4) is installed in the installation groove (303).

4. The receiver TO packaging structure as described in claim 1, characterized in that: It also includes a transimpedance amplifier (6); both the transimpedance amplifier (6) and the detector (5) are mounted on the TO base (1).

5. The receiver TO packaging structure as described in claim 4, characterized in that: The distance between the transimpedance amplifier (6) and the detector (5) is controlled to be 70-130 μm.

6. The receiver TO packaging structure as described in claim 1, characterized in that: The TO base (1) is provided with a substrate (7); the detector (5) is mounted on the substrate (7).

7. The receiver TO packaging structure as described in claim 6, characterized in that: The substrate (7) is a ceramic substrate.

8. The receiver TO packaging structure as described in claim 6, characterized in that: The TO base (1) is equipped with a cooler; the base plate (7) is mounted on the cooler.

9. The receiver TO packaging structure as described in claim 1, characterized in that: The TO base (1) is provided with multiple TO pins (8); the multiple TO pins (8) are respectively connected to the corresponding optical elements in the accommodating cavity by bonding wires.

10. A Combo PON optical module, characterized in that, Includes the receiver TO packaging structure as described in any one of claims 1-9.

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