A 100G LR4 TOSA high-speed optical module hermetic packaging structure

Abstract

The present invention provides a 100G LR4TOSA high-speed optical module airtight packaging structure, which relates to the field of optical communication technology, including: a metal tube shell, as a main frame box; a PCB metallized circuit substrate, located at the end side of the metal tube shell, and directly sintered with the metal tube shell into one; a PCB circuit substrate, which is a part of the PCB metallized circuit substrate, and its two ends are respectively provided with gold-plated pads and BGA pads for circuit connection; a PCB sealing shell, which is a part of the PCB metallized circuit substrate, is located outside the PCB circuit substrate, and is used to wrap and seal the PCB circuit substrate. The present invention realizes high-speed and stable transmission of optical signals, precise temperature control, reduces wavelength drift, improves stability, improves optical performance, optimizes signal integration and transmission, stabilizes airtight connections, prevents electromagnetic interference, ensures signal stability, and improves efficiency and electrical performance.

Description

Technical Field

[0001] The present invention relates to the field of optical communication technology, and in particular to a 100G LR4 TOSA high-speed optical module airtight packaging structure. Background Art

[0002] 100G LR4 TOSA is the core component of 100Gbps CFP2 / CFP4 / QSFP28 LR4 module. The maximum transmission distance of 100G LR4 module can reach 10KM. The main application scenarios are 100G data center switches, 100G high-end campus core switches, 5G mid-haul networks and metropolitan optical transmission networks. The 100G LR4 TOSA adopts 4X25Gbps DML Laser chip.

[0003] BOX hermetic packaging has been widely used in long-distance optical communications, data centers, industrial and commercial environments, high-performance computing and artificial intelligence due to its excellent environmental stability, protection performance and heat dissipation. The main application scenarios are data center switches, high-end campus core switches, 5G mid-haul networks and metropolitan optical transmission networks. These optical modules usually use ceramic circuit packaging shells, 4X25Gbps DML Laser chips, a total of 4 wavelengths, TEC to control chip temperature, single-channel Up to 25Gbps per l ane (NRZ modulation format), FPC flexible board connection circuit, and the packaging form uses a metal shell packaged with a ceramic circuit for hermetic packaging, which meets high airtightness, high reliability and excellent electrical insulation performance. However, this integration method has some significant disadvantages.

[0004] First, the commonly used ceramic circuit substrates are expensive: Compared with some lower-cost packaging materials, the production cost of ceramic packaging is higher, which may limit its application in large-scale production. Processing difficulty: Ceramic materials are difficult to process and require special technology and equipment, which increases the complexity and cost of production.

[0005] Secondly, due to the circuit connected by this FPC, once the FPC is damaged, the gold finger welding points on the PCB and the device need to be melted and removed. However, this integrated optical device has a large number of gold fingers, generally 14 to 18 gold fingers. If the operation is not done properly, it is easy to cause the entire circuit to be short-circuited, so the replacement of the entire optical module becomes complicated and costly. This design is not conducive to the later product maintenance, and is also not conducive to the high-frequency signal transmission of high-speed products.

[0006] In addition, the traditional flexible board circuit connection method increases the manufacturing cost of the optical module. If the internal thin film circuit is directly connected to the module's PCB circuit by BGA welding, the cost of a flexible board will be saved, and the flexible board welding process at one end will be saved in the manufacturing process. At the same time, the flexible board is welded twice, and the high temperature generated during welding will also cause certain proportion of damage to the flexible board circuit. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention provides a 100G LR4 TOSA high-speed optical module hermetic packaging structure, aiming to provide a simpler manufacturing process, a more convenient maintenance and upgrade path, and a lower-cost packaging solution.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A 100G LR4 TOSA high-speed optical module hermetic packaging structure, characterized by comprising:

[0010] Metal tube shell, serving as the main frame box;

[0011] The PCB metalized circuit substrate is located at the end side of the metal tube shell and is directly sintered with the metal tube shell into one body;

[0012] PCB circuit substrate is a part of PCB metallized circuit substrate, with gold-plated pads and BGA pads at both ends for circuit connection;

[0013] The PCB sealing shell is a part of the PCB metallized circuit substrate, located outside the PCB circuit substrate, and is used to wrap and seal the PCB circuit substrate.

[0014] The preferred technical solution, the 100G LR4 TOSA high-speed optical module hermetic packaging structure, is characterized by further comprising:

[0015] TEC temperature controller, located near the PCB metallized circuit substrate;

[0016] Ceramic circuit substrate, located directly above the TEC temperature controller;

[0017] The beam splitter lens is located in the metal tube shell and is used to combine multiple channels of light into one channel of light;

[0018] A chip is located above the ceramic circuit substrate and in the optical path of the beam splitter lens;

[0019] The plug-in optical fiber connection collimator is located outside the tube shell, coaxially opposite to the chip, and has an optical isolator inside;

[0020] A first collimating lens, located between the beam splitter lens and the pluggable optical fiber connection collimator;

[0021] The second array collimating lens is located at the light output front end of the chip;

[0022] and a tube shell cover plate, which is located directly above the metal tube shell and is welded and sealed into one piece by reflow soldering.

[0023] The preferred technical solution is that the chip is a 4X25Gbps DML Laser chip, which consists of 4 small high-speed optical modules evenly distributed and placed in their positions, and the spacing between the high-speed optical modules is a working distance of 1mm.

[0024] According to a preferred technical solution, the beam splitter lens is a beam splitter Z-BLOCK lens.

[0025] According to a preferred technical solution, the interior of the beam splitter lens is composed of a plurality of 13.5° glass sheets and is located between the second array collimating lens and the first collimating lens, so as to combine four channels of light into one channel of light.

[0026] According to a preferred technical solution, a ceramic thin film circuit is arranged on the TEC temperature controller, and the chip is arranged on the ceramic thin film circuit.

[0027] In a preferred technical solution, the chip is combined with the ceramic thin film circuit by high-temperature soldering.

[0028] According to a preferred technical solution, the pluggable optical fiber connection collimator and the metal tube shell are fixed by laser welding.

[0029] According to a preferred technical solution, the TEC temperature controller is attached to the bottom of the metal tube shell cavity.

[0030] According to a preferred technical solution, the PCB metallized circuit substrate is sintered into one body with the metal tube shell by glass solder.

[0031] The present invention provides a 100G LR4 TOSA high-speed optical module hermetic packaging structure. It has the following beneficial effects:

[0032] High-speed and stable optical signal transmission: Through precise design and advanced manufacturing technology, the hermetic packaging structure of the 100G LR4 TOSA high-speed optical module achieves high-speed, stable and reliable transmission of optical signals. The metal shell as the main frame provides the necessary mechanical support and protection. At the same time, the choice of metal material is also conducive to heat dissipation, maintaining the stability of the internal temperature of the optical module. This design ensures that the optical module can work normally in harsh environments, providing a solid foundation for the construction of modern high-speed communication networks.

[0033] High-precision temperature control: The patent uses a TEC temperature controller, which works through the Peltier effect to achieve high-precision temperature control of the laser chip, thereby stabilizing the operating wavelength. This design helps reduce the temperature drift of the DFB laser wavelength, which is particularly important for WDM systems with small wavelength intervals. It can prevent crosstalk between channels and help high-power devices dissipate heat, further improving the stability and reliability of the optical module.

[0034] Excellent optical performance: The use of the optical splitter Z-BLOCK lens makes the optical module have excellent performance such as flexible channel number, low insertion loss, low channel crosstalk, good temperature stability and passive assembly. These performance improvements not only optimize the integration and transmission of optical signals, but also improve the overall performance of the optical module.

[0035] Efficient fiber connection: The design of the plug-in fiber connection collimator has the characteristics of low insertion loss and high return loss, which can efficiently convert and transmit optical signals, reduce the loss of optical energy, and improve the overall transmission efficiency. At the same time, it is fixed to the metal shell by laser welding to ensure the stability and airtightness of the connection, further improving the stability and reliability of the optical module.

[0036] Electromagnetic interference protection: The metalized PCB circuit substrate design, whose metal layer can effectively block or absorb electromagnetic interference, improve the integrity of the signal and the overall anti-interference ability of the system. This is of great significance for ensuring the stability and reliability of high-speed signals during transmission.

[0037] Optimization of manufacturing cost and efficiency: The metallized PCB circuit substrate used in this patent is soldered to the module's PCB board through the SMT process platform. Due to the short connection path and uniform distribution of the solder balls, the BGA package has lower parasitic inductance and capacitance, which is conducive to high-speed signal transmission. At the same time, there are a large number of solder balls connected at the bottom of the BGA chip, so the heat can be distributed and conducted more evenly, effectively reducing the chip temperature. This design not only improves the electrical performance of electronic products, but also optimizes manufacturing costs and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the cross-sectional structure of the present invention;

[0039] Figure 2 It is a schematic diagram of the explosion structure of the present invention;

[0040] Figure 3 This is a schematic diagram of the structure after the PCB circuit substrate and the PCB sealing shell are separated from each other;

[0041] Figure 4 This is a schematic diagram of the structure of the tube shell after the cover plate of the present invention is opened;

[0042] In the figure: 1-metal tube shell, 2-PCB metallized circuit substrate, 4-PCB circuit substrate, 5-PCB sealing shell, 6-TEC temperature controller, 32-ceramic circuit substrate, 37-splitter lens, 40-chip, 51-optical isolator, 52-plug-in optical fiber connection collimator, 53-first collimating lens, 82-second array collimating lens, 84-circuit board, 85-tube shell cover. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] like Figure 1-Figure 4 As shown,

[0045] A 100G LR4 TOSA (Transmitter Optical Sub-Assembly) high-speed optical module hermetic packaging structure is designed to ensure the stability and reliability of high-speed data transmission. The specific structure includes the following key components:

[0046] First, the metal tube shell 1 is the main frame box of the entire packaging structure. It provides the necessary mechanical support and protection to ensure that the internal components are protected from the external environment. The choice of metal material not only enhances the robustness of the structure, but also facilitates heat dissipation and maintains the stability of the internal temperature of the optical module. A circuit board 84 is provided at the bottom of the metal tube shell 1.

[0047] The PCB metalized circuit substrate 2 is cleverly placed on the end side of the metal tube shell 1 and directly integrated with the metal tube shell 1 through an advanced sintering process. This design not only improves the integration of the circuit, but also enhances the electrical connection and thermal conduction between the circuit substrate and the tube shell.

[0048] The PCB circuit substrate 4 is a functional area of ​​the PCB metallized circuit substrate 2, and its importance is self-evident. Its two ends are respectively provided with gold-plated pads and BGA (Ball Grid Array) pads, which provide a reliable interface for the connection between circuits and ensure lossless transmission of high-speed signals.

[0049] The PCB sealing shell 5 is another key component of the PCB metallized circuit substrate 2. It is tightly wrapped around the outside of the PCB circuit substrate 4 to form an effective barrier to prevent the intrusion of pollutants such as moisture and dust, thereby ensuring the long-term stable operation of the optical module.

[0050] The hermetic packaging structure also integrates a TEC temperature controller 6, which is arranged close to the PCB metallized circuit substrate 2 and is used to accurately control the operating temperature of the optical module to prevent performance degradation or damage caused by overheating.

[0051] The ceramic circuit substrate 32 is located directly above the TEC temperature controller 6 , and provides an ideal mounting platform for the chip above it due to its excellent insulation performance and thermal stability.

[0052] The beam splitter lens 37 is a beam splitter Z-BLOCK lens, which is a specially designed optical element located inside the metal tube shell 1. Through the combination of multiple 13.5° glass slides inside, it can effectively synthesize multi-channel light into one light, thereby meeting the requirements of the 100G LR4 optical module for optical signal integration.

[0053] Chip 40 is a 4X25Gbps DML (Direct Modulated Laser) Laser chip, whose four small high-speed optical modules are evenly arranged with a precise spacing of 1mm. This layout not only optimizes space utilization, but also ensures stable and efficient transmission of optical signals.

[0054] The plug-in optical fiber connection collimator 52 is located outside the metal tube shell 1, coaxially opposite to the chip 40, and is equipped with an optical isolator 51 inside to prevent reflection interference of optical signals and improve communication quality. It is fixed to the metal tube shell 1 by laser welding to ensure the stability and airtightness of the connection.

[0055] The first collimating lens 53 and the second array collimating lens 82 are respectively located between the beam splitter lens 37 and the pluggable optical fiber connection collimator 52 and the light output front end of the chip 40, and they work together to accurately calibrate and focus the optical signal to ensure accurate transmission of the optical signal.

[0056] The tube shell cover plate 85 is sealed on the top of the metal tube shell 1 by reflow soldering technology, forming a final airtight packaging structure, providing all-round protection for the optical module.

[0057] It is particularly worth mentioning that a ceramic thin film circuit is provided on the TEC temperature controller 6, and the chip 40 is tightly combined with the ceramic thin film circuit by high-temperature soldering. This design not only improves the heat conduction efficiency, but also ensures the stable operation of the chip.

[0058] In summary, the hermetic packaging structure of this 100G LR4 TOSA high-speed optical module achieves high-speed, stable and reliable optical signal transmission through precise design and advanced manufacturing technology, providing a solid foundation for the construction of modern high-speed communication networks.

[0059] The present invention uses a TEC temperature controller 6 to work through its Peltier effect, which can achieve high-precision temperature control of the laser chip 40 and stabilize the operating wavelength. The TEC temperature controller 6 helps reduce the temperature drift of the DFB laser wavelength by maintaining a stable temperature. This is especially important for WDM systems (such as DWDM, LAN-WDM, MWDM) using small wavelength intervals, and can prevent crosstalk between channels and heat dissipation of high-power devices.

[0060] The optical splitter Z-BLOCK lens has the advantages of flexible channel number, low insertion loss, low channel crosstalk, good temperature stability and passive assembly.

[0061] Plug-in fiber optic connection collimator with low insertion loss and high return loss: Fiber optic collimator can efficiently convert and transmit optical signals, reduce the loss of optical energy and improve the overall transmission efficiency.

[0062] The metalized PCB circuit substrate design, its metal layer can effectively block or absorb electromagnetic interference, improve the integrity of the signal and the overall anti-interference ability of the system. It also has obvious advantages in manufacturing costs.

[0063] The metalized PCB circuit substrate is connected to the link of the module's PCB board, and the SMT process platform is used for BGA welding. Due to the short connection path and uniform distribution of the solder balls, the BGA package has lower parasitic inductance and capacitance, which is conducive to high-speed signal transmission and improves the electrical performance of electronic products. At the same time, there are a large number of solder balls connected at the bottom of the BGA chip, so the heat can be distributed and conducted more evenly, effectively reducing the chip temperature and improving the stability and reliability of the product.

[0064] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A 100G LR4 TOSA high-speed optical module hermetic packaging structure, characterized in that: include: A metal tube shell (1) serving as a main frame box; A PCB metalized circuit substrate (2) is located at the end side of the metal tube shell (1) and is directly sintered with the metal tube shell (1) to form an integral body; The PCB circuit substrate (4) is a part of the PCB metallized circuit substrate (2), and has gold-plated pads and BGA pads at both ends thereof for circuit connection; The PCB sealing shell (5) is a part of the PCB metallized circuit substrate (2), is located outside the PCB circuit substrate (4), and is used to wrap and seal the PCB circuit substrate (4).

2. The 100G LR4 TOSA high-speed optical module hermetic packaging structure according to claim 1, characterized in that: Also includes: A TEC temperature controller (6) is located near the PCB metallized circuit substrate (2); A ceramic circuit substrate (32) is located directly above the TEC temperature controller (6); A beam splitter lens (37), located in the metal tube shell (1), is used to combine multiple channels of light into one channel of light; A chip (40) is located above the ceramic circuit substrate (32) and on the optical path of the beam splitter lens (37); A plug-in optical fiber connection collimator (52) is located outside the tube shell (1) and is coaxially opposite to the chip (40), and has an optical isolator (51) installed inside; A first collimating lens (53) is located between the beam splitter lens (37) and the plug-in optical fiber connection collimator (52); A second array collimating lens (82) is located at the light-emitting front end of the chip (40); And a tube shell cover plate (85) is located directly above the metal tube shell (1) and is welded and sealed into one piece by reflow welding.

3. The 100G LR4 TOSA high-speed optical module hermetic packaging structure according to claim 1, characterized in that: The chip (40) is a 4X25Gbps DML Laser chip, which consists of four small high-speed optical modules that are evenly distributed and placed at their positions, and the spacing between the high-speed optical modules is a working distance of 1mm.

4. The 100G LR4 TOSA high-speed optical module hermetic packaging structure according to claim 3, characterized in that: The beam splitter lens (37) is a beam splitter Z-BLOCK lens.

5. The 100G LR4 TOSA high-speed optical module hermetic packaging structure according to claim 3, characterized in that: The beam splitter lens (37) is composed of a plurality of 13.5° glass sheets and is located between the second array collimating lens (82) and the first collimating lens (52) to combine four channels of light into one channel of light.

6. The 100G LR4 TOSA high-speed optical module hermetic packaging structure according to claim 3, characterized in that: The TEC temperature controller is provided with a ceramic thin film circuit, and the chip (40) is provided on the ceramic thin film circuit.

7. The 100G LR4 TOSA high-speed optical module hermetic packaging structure according to claim 6, characterized in that: The chip (40) is combined with the ceramic thin film circuit by high-temperature soldering.

8. The 100G LR4 TOSA high-speed optical module hermetic packaging structure according to claim 1, characterized in that: The plug-in optical fiber connection collimator (52) and the metal tube shell (1) are fixed by laser welding.

9. The 100G LR4 TOSA high-speed optical module hermetic packaging structure according to claim 1, characterized in that: The TEC temperature controller (6) is attached to the bottom of the metal tube shell (1) cavity.

10. The 100G LR4 TOSA high-speed optical module hermetic packaging structure according to claim 1, characterized in that: The PCB metallized circuit substrate (2) is sintered into one piece with the metal tube shell (1) through glass solder.

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