Airtight packaging structure based on cob

Abstract

The utility model discloses a kind of airtight packaging structure based on COB, it includes circuit board, substrate assembly, photoelectric chip, lens assembly and optical transceiver interface;Circuit board middle part is equipped with mounting groove;Substrate assembly is embedded in mounting groove, and is connected with circuit board welding;Photoelectric chip is bonded and fixed at the reserved position on substrate assembly;Lens assembly covers photoelectric chip, and is sealed and set on substrate assembly, and photoelectric chip is located on the transmission light path of lens assembly;Optical transceiver interface is coupled and set on the end face of lens assembly;The utility model lens assembly and substrate assembly jointly constitute airtight packaging cavity, photoelectric chip is located in the cavity, to cover and protect the photosensitive area of photoelectric chip, under the premise of guaranteeing photoelectric chip performance, improve the reliability and service life of photoelectric chip, provide feasibility for optical module is applied to special scene.

Description

Technical Field

[0001] This utility model relates to the field of COB packaging technology, specifically to a COB-based hermetic packaging structure. Background Technology

[0002] With the development of cloud computing and 5G networks, optical modules need to support higher channel counts and higher speeds. Simultaneously, the increased speeds also place higher demands on module miniaturization and multi-channel parallel transmission. Parallel transmission optical modules transmit the speed of a single laser within a single optical fiber. Currently, COB-based non-hermetic-sealed optical modules typically experience mass failures after 4-5 years of use, which is insufficient for some specialized applications. Therefore, a demand has arisen for hermetic-sealed COB solutions.

[0003] Existing parallel multichannel solutions are mostly based on COB packaging, and most of them are non-hermetic. The bare chip is directly exposed to the environment and is susceptible to water vapor, dust and corrosive gases, which leads to a shortened device life and makes it difficult to meet the sealing requirements of high reliability fields such as military, aerospace and medical. Utility Model Content

[0004] To address the aforementioned problems in the prior art, this utility model provides a COB-based hermetic packaging structure, which solves the problem that existing COB-based packaging uses non-hermetic packaging, easily leading to product defects.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A COB-based hermetic packaging structure is provided, comprising a circuit board, a substrate assembly, a photoelectric chip, a lens assembly, and an optical transceiver interface; a mounting groove is provided in the middle of the circuit board; the substrate assembly is embedded in the mounting groove and soldered to the circuit board; the photoelectric chip is bonded and fixed at a reserved position on the substrate assembly; the lens assembly covers the photoelectric chip and is sealed on the substrate assembly, with the photoelectric chip located in the transmission light path of the lens assembly; the optical transceiver interface is coupled to the end face of the lens assembly.

[0006] The lens assembly and substrate assembly of this invention together form a hermetically sealed cavity, in which the photoelectric chip is located to cover and protect the photosensitive area of ​​the photoelectric chip. While ensuring the performance of the photoelectric chip, the reliability and service life of the photoelectric chip are improved, providing feasibility for the application of optical modules in special scenarios.

[0007] Furthermore, the substrate assembly includes a metal pad and a ceramic substrate, with the ceramic substrate welded and fixed to the central through-hole of the metal pad; the metal pad is embedded in the mounting groove and connected to the circuit board by reflow soldering.

[0008] Furthermore, the optoelectronic chip is bonded to the ceramic substrate using silver paste.

[0009] Furthermore, the lens assembly includes a metal housing and a collimating lens, the collimating lens being bonded and fixed to the central through-hole of the metal housing; the lens assembly is fixed to the substrate assembly by welding the metal housing to a metal pad.

[0010] Furthermore, the metal casing and the metal pad are made of the same material.

[0011] This utility model discloses a COB-based hermetic packaging structure, the advantages of which are: The lens assembly and substrate assembly of this invention together form a hermetically sealed cavity, in which the photoelectric chip is located to cover and protect the photosensitive area of ​​the photoelectric chip. While ensuring the performance of the photoelectric chip, the reliability and service life of the photoelectric chip are improved, providing feasibility for the application of optical modules in special scenarios. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a COB-based hermetic packaging structure according to this utility model.

[0013] Figure 2 This is a cross-sectional schematic diagram of a COB-based hermetic packaging structure according to this utility model.

[0014] Figure 3 This is a cross-sectional view of the circuit board of this utility model.

[0015] Figure 4 This is a cross-sectional structural diagram of the substrate assembly of this utility model.

[0016] Figure 5 This is a cross-sectional structural diagram of the lens assembly of this utility model.

[0017] Among them, 1. Circuit board; 11. Mounting slot; 2. Substrate assembly; 21. Metal pad; 22. Ceramic substrate; 3. Optoelectronic chip; 4. Lens assembly; 41. Metal housing; 42. Collimating lens; 5. Optical transceiver interface. Detailed Implementation The specific embodiments of this utility model are described below to enable those skilled in the art to understand this utility model. However, it should be understood that this utility model is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of this utility model as defined and determined by the appended claims, these changes are obvious. All utility model creations utilizing the concept of this utility model are within the scope of protection.

[0018] Example 1 refer toFigures 1-5 This embodiment provides a COB-based hermetic packaging structure, the purpose of which is to solve the problem that existing COB-based packaging uses non-hermetic packaging, which easily leads to product defects. The specific structure of this embodiment will be described in detail below.

[0019] A COB-based hermetic packaging structure includes a circuit board 1, a substrate assembly 2, a photoelectric chip 3, a lens assembly 4, and an optical transceiver interface 5.

[0020] The circuit board 1 has a mounting groove 11 in the middle; the substrate assembly 2 is embedded in the mounting groove 11 and is soldered to the circuit board 1; the optoelectronic chip 3 is bonded and fixed at a reserved position on the substrate assembly 2.

[0021] Specifically, the lens assembly 4 covers the photoelectric chip 3 and is sealed on the substrate assembly 2, and the photoelectric chip 3 is located in the transmission light path of the lens assembly 4; the optical transceiver interface 5 is coupled to the end face of the lens assembly 4.

[0022] In this embodiment, the lens assembly 4 is sealed on the substrate assembly 2, and together with the substrate assembly 2, they form a hermetically sealed cavity. The photoelectric chip 3 is located in this cavity to cover and protect the photosensitive area of ​​the photoelectric chip. While ensuring the performance of the photoelectric chip 3, the reliability and service life of the photoelectric chip 3 are improved, providing feasibility for the application of the optical module in special scenarios.

[0023] Optionally, the optoelectronic chip 3 can be one of four types: DriveT, TIA, VCSEL, or PD; and the optical transceiver interface 5 can be a PEI material lens.

[0024] Alternatively, high-speed lines and DC lines can be routed within the mounting slot 11 using a PCB layout design, with pads provided.

[0025] Specifically, the substrate assembly 2 includes a metal pad 21 and a ceramic substrate 22. The ceramic substrate 22 is welded and fixed to the central through-hole of the metal pad 21. The metal pad 21 is embedded in the mounting groove 11 and is welded to the circuit board 1 by reflow soldering.

[0026] Specifically, the optoelectronic chip 3 is bonded to the ceramic substrate 22 with silver paste.

[0027] In this embodiment, the size of the metal pad 21 matches the size of the mounting groove 11. A through mounting hole is provided in the middle of the metal pad 21. In an inert gas environment, the ceramic substrate 22 is embedded in the mounting hole of the metal pad 21 and welded together by a gold-tin solder joint welding method.

[0028] Then, the metal pad 21 with the ceramic substrate 22 soldered on it is embedded in the mounting groove 11, and the metal pad 21 is soldered to the circuit board 1 by reflow soldering.

[0029] The optoelectronic chip 3 is bonded to the ceramic substrate 22 with silver paste according to the patch size, and then heated and baked to fix it.

[0030] Alternatively, the ceramic substrate 22 can be made with gold-plated traces, and through holes can be made at the end of each trace segment and gold-plated in the through holes to make them conductive to the bottom pads. The spacing between the through holes of each adjacent trace segment is consistent with the pads reserved in the mounting groove 11. Solder paste is pre-applied on the pads of the mounting groove 11 to connect the through holes and the pads to achieve electrical connection.

[0031] Specifically, the lens assembly 4 includes a metal housing 41 and a collimating lens 42, which is bonded and fixed to the central through-hole of the metal housing 41; the lens assembly 4 is fixed to the substrate assembly 2 by welding the metal housing 41 to the metal pad 21.

[0032] Specifically, the metal casing 41 and the metal pad 21 are made of the same material.

[0033] In this embodiment, the bottom of the metal housing 41 is hollowed out, and a through mounting hole is provided in the middle of the metal housing 41. The collimating lens 42 is embedded in the mounting hole of the metal housing 41 and is bonded and fixed.

[0034] The metal housing 41 is aligned with the metal pad 21. In an inert gas environment, when the metal housing 41 is placed on the metal pad 21, the collimating lens 42 is visually aligned (ensuring that the collimating lens 42 is aligned with the photosensitive surface of the photoelectric chip 3, and the mounting accuracy is ±10µm). The metal housing 41 and the metal pad 21 are sealed and fixedly connected by parallel sealing welding. Finally, the optical transceiver interface 5 is coupled and set on the end face of the lens assembly 4 by active alignment. The light input and output are achieved by fixing with UV glue and structural adhesive, and finally the hermetically sealed assembly is achieved.

[0035] This allows the lens assembly 4 and the substrate assembly 2 to together form a hermetically sealed cavity, in which the photoelectric chip 3 is located to cover and protect the photosensitive area of ​​the photoelectric chip. While ensuring the performance of the photoelectric chip 3, this improves the reliability and lifespan of the photoelectric chip 3, providing feasibility for the application of optical modules in special scenarios.

[0036] The metal casing 41 and the metal pad 21 are made of the same material, which facilitates welding.

[0037] Although the specific embodiments of the utility model have been described in detail with reference to the accompanying drawings, this should not be construed as limiting the scope of protection of this patent. Various modifications and variations that can be made by those skilled in the art without inventive effort within the scope described in the claims still fall within the scope of protection of this patent.

Claims

1. A COB-based hermetic packaging structure, characterized in that, It includes a circuit board (1), a substrate assembly (2), an optoelectronic chip (3), a lens assembly (4), and an optical transceiver interface (5). The circuit board (1) has a mounting groove (11) in the middle; the substrate assembly (2) is embedded in the mounting groove (11) and soldered to the circuit board (1); the optoelectronic chip (3) is bonded and fixed at a reserved position on the substrate assembly (2); The lens assembly (4) covers the photoelectric chip (3) and is sealed on the substrate assembly (2), and the photoelectric chip (3) is located on the transmission light path of the lens assembly (4); the optical transceiver interface (5) is coupled to the end face of the lens assembly (4).

2. The COB-based hermetic packaging structure according to claim 1, characterized in that: The substrate assembly (2) includes a metal pad (21) and a ceramic substrate (22). The ceramic substrate (22) is welded and fixed to the middle through-hole of the metal pad (21). The metal pad (21) is embedded in the mounting groove (11) and is welded to the circuit board (1) by reflow soldering.

3. The COB-based hermetic packaging structure according to claim 2, characterized in that: The optoelectronic chip (3) is fixed on the ceramic substrate (22) by silver paste.

4. The COB-based hermetic packaging structure according to claim 2, characterized in that: The lens assembly (4) includes a metal housing (41) and a collimating lens (42), the collimating lens (42) being bonded and fixed to the middle through-hole of the metal housing (41); the lens assembly (4) is fixed to the substrate assembly (2) by welding the metal housing (41) to the metal pad (21).

5. The COB-based hermetic packaging structure according to claim 4, characterized in that: The metal shell (41) and the metal pad (21) are made of the same material.

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