Optical module

Abstract

The invention discloses an optical module. The optical module provided by the invention comprises a shell which comprises a base and a cover body which are enclosed to form a mounting cavity; the circuit board is arranged in the mounting cavity and is provided with a through window along the thickness direction; the daughter board and the circuit board are stacked and electrically connected, and the daughter board is arranged on the side, facing the base, of the circuit board; the heat sink and the daughter board are located on the same side of the circuit board, and the heat sink is fixed to the circuit board and at least partially covers the window; the light emitting assembly is arranged on the heat sink, located in the open window and electrically connected with the circuit board. The silicon optical chip is arranged on the heat sink, located in the open window and electrically connected with the daughter board, and light emitted by the light emitting assembly enters the silicon optical chip and is emitted out of the silicon optical chip after being processed by the silicon optical chip. According to the optical module, the high-frequency performance of the optical module can be improved while the heat dissipation effect of the optical module is ensured.

Description

Technical Field

[0001] This application relates to the field of optical module technology, specifically to an optical module. Background Technology

[0002] A traditional optical module includes a housing and optoelectronic components housed within the housing. The optoelectronic components include a circuit board, a light-emitting component, and a silicon photonics chip. The light-emitting component includes a laser and a lens mounted on a heat sink. The silicon photonics chip is optically coupled to the light-emitting component to receive, process, and then emit the light emitted by the component. The silicon photonics chip is electrically connected to the circuit board.

[0003] However, if the silicon photonics chip is placed on the circuit board while the optical emitting component is placed on the heat sink, it will increase the difficulty of optical coupling between the silicon photonics chip and the optical emitting component. If both the silicon photonics chip and the optical emitting component are placed on the heat sink, both the laser and the silicon photonics chip need to be electrically connected to the same circuit board, increasing the routing complexity of the circuit board and reducing high-frequency performance. Summary of the Invention

[0004] This application provides an optical module that can solve the problem that existing optical modules cannot simultaneously achieve both heat dissipation and high-frequency performance.

[0005] To achieve the above objectives, the optical module provided in this application includes:

[0006] The housing includes a base and a cover that enclose and form the mounting cavity;

[0007] A circuit board is disposed in the mounting cavity, and a window extending through the thickness direction is provided on it;

[0008] A sub-board is stacked on top of the circuit board and electrically connected thereto, and the sub-board is located on the side of the circuit board facing the base;

[0009] A heat sink, located on the same side of the circuit board as the sub-board, is fixed to the circuit board and at least partially covers the opening;

[0010] A light-emitting component is disposed on the heat sink, located in the window, and electrically connected to the circuit board;

[0011] A silicon photonic chip is disposed on the heat sink, located in the window, and electrically connected to the sub-board. Light emitted by the light emitting component is incident on the silicon photonic chip, processed by the silicon photonic chip, and then emitted from the silicon photonic chip.

[0012] In some embodiments of this application, the sub-board includes a connecting portion and a protruding portion. The connecting portion is stacked with and electrically connected to the circuit board. The protruding portion covers the opening portion, and the silicon photonics chip is electrically connected to the protruding portion.

[0013] In some embodiments of this application, the side surface of the silicon photonic chip facing away from the base is electrically connected to the side surface of the protrusion facing away from the base via a conductive connection line.

[0014] or,

[0015] The silicon photonic chip has a first conductive connection portion protruding on the side of its surface opposite to the base, and a second conductive connection portion protruding on the side of its surface opposite to the base. The first conductive connection portion and the second conductive connection portion are electrically connected by leads.

[0016] In some embodiments of this application, the side surface of the silicon photonic chip facing away from the base is flush with the side surface of the protruding portion facing away from the base.

[0017] In some embodiments of this application, the light emitting component includes a laser and an optical device. Both the laser and the optical device are disposed on the heat sink and are located in the window along the length of the circuit board. The optical device is disposed between the laser and the silicon photonic chip to optically couple the laser and the silicon photonic chip. The laser is electrically connected to the circuit board.

[0018] In some embodiments of this application, the optical module further includes:

[0019] A digital signal processing chip is disposed on the side of the sub-board opposite to the circuit board and electrically connected thereto, with the heat dissipation surface of the digital signal processing chip facing the base.

[0020] In some embodiments of this application, the optical module further includes:

[0021] A thermal pad is disposed on the side of the digital signal processing chip facing the base, and thermally connects the digital signal processing chip and the base.

[0022] In some embodiments of this application, the heat sink is thermally connected to the base, and the outer surface of the base is the main heat dissipation surface.

[0023] In some embodiments of this application, the heat sink includes a mounting portion and a connecting portion. The mounting portion at least partially covers the opening. The connecting portion protrudes along the width direction of the circuit board on one side of the mounting portion. The connecting portion is connected to the side surface of the circuit board facing the base. The light emitting component and the silicon photonic chip are both disposed on the mounting portion, and / or, at least a portion of the sub-board is disposed on the mounting portion.

[0024] In some embodiments of this application, the connecting portion protrudes from the mounting portion along the thickness direction of the circuit board.

[0025] The technical solution provided in this application has at least the following beneficial effects: This application creates a window on the circuit board, and a sub-board is stacked below the circuit board. Simultaneously, both the silicon photonics chip and the light-emitting component are placed on a heat sink to ensure good heat dissipation for both. The heat sink and the sub-board are located on the same side of the circuit board, i.e., the heat sink is located below the circuit board and at least partially covers the window. This allows the silicon photonics chip and the light-emitting component on the heat sink to be located within the window, reserving more space on the side of the circuit board opposite to the sub-board for other components, ensuring a compact layout within the housing, and improving the space utilization of the optical module in the thickness direction. Furthermore, the light-emitting component is electrically connected to the circuit board, the silicon photonics chip is electrically connected to the sub-board, and the circuit board is electrically connected to the sub-board. By adjusting the routing of the light-emitting component and the silicon photonics chip, the routing space for their electrical connection is improved, thereby enhancing the high-frequency performance of the optical module. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a perspective view of the optical module in an embodiment of this application;

[0028] Figure 2 This is a cross-sectional view of the optical module in an embodiment of this application;

[0029] Figure 3 This is a partial enlarged view of the optical module in an embodiment of this application;

[0030] Figure 4 This is a schematic diagram of the structure of the heat sink and sub-board in the optical module in the embodiments of this application.

[0031] The main reference numerals in the drawings of this application are explained as follows:

[0032] 1-Housing; 11-Base; 2-Circuit board; 21-Window; 3-Sub-board; 31-Connecting part; 32-Protruding part; 321-Second conductive connection part; 4-Heat sink; 41-Mounting part; 42-Connecting part; 5-Light emitting assembly; 51-Laser; 52-Lens; 53-Isolator; 6-Silicon photonic chip; 61-First conductive connection part; 7-Solder ball array; 8-Conductive connecting line; 9-Digital signal processing chip; 10-Thermal pad; 101-Heat dissipation assembly; 20-Light receiving assembly; 201-Fiber optic array; 202-Transimpedance amplifier; 203-Receiver silicon photonic chip; 30-Padded block. Detailed Implementation

[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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. Therefore, they should not be construed as limitations on this application.

[0035] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0036] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0037] This application provides an optical module, which will be described in detail below. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments of this application. Furthermore, the descriptions of each embodiment have their own emphasis; parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments.

[0038] Reference Figure 1 and Figure 2 The optical module provided in this application includes a housing 1, a circuit board 2, a sub-board 3, a heat sink 4, a light emitting component 5, and a silicon photonic chip 6. The housing 1 includes a base 11 and a cover that enclose a mounting cavity. The circuit board 2 is disposed within the mounting cavity, and a window 21 extending through the circuit board 2 along its thickness direction is provided on the circuit board 2. The sub-board 3 is stacked on top of the circuit board 2 and electrically connected to it, and is located on the side of the circuit board 2 facing the base 11. The heat sink 4 is located on the same side of the circuit board 2 as the sub-board 3, and is fixed to the circuit board 2 and at least partially covers the window 21. The light emitting component 5 is disposed on the heat sink 4 and located within the window 21, and is electrically connected to the circuit board 2. The silicon photonic chip 6 is disposed on the heat sink 4 and located within the window 21, and is electrically connected to the sub-board 3. Light emitted by the light emitting component 5 is incident on the silicon photonic chip 6, processed by the silicon photonic chip 6, and then emitted from the silicon photonic chip 6.

[0039] This application incorporates a window 21 on the circuit board 2, with a sub-board 3 stacked beneath it. The silicon photonic chip 6 and the light-emitting component 5 are both mounted on a heat sink 4 to ensure good heat dissipation for both. The heat sink 4 and the sub-board 3 are located on the same side of the circuit board 2, i.e., the heat sink 4 is located below the circuit board 2 and at least partially covers the window 21. This allows the silicon photonic chip 6 and the light-emitting component 5 mounted on the heat sink 4 to be positioned within the window 21, reserving more space on the side of the circuit board 2 facing away from the sub-board 3 for other components. This ensures a compact layout within the housing 1 and improves the space utilization of the optical module in the thickness direction. Furthermore, the light-emitting component 5 is electrically connected to the circuit board 2, the silicon photonic chip 6 is electrically connected to the sub-board 3, and the circuit board 2 is electrically connected to the sub-board 3. By adjusting the routing of the light-emitting component 5 and the silicon photonic chip 6, the routing space for their electrical connection is improved, enhancing the high-frequency performance of the optical module.

[0040] like Figure 2As shown, the surface of circuit board 2 facing the cover is the upper surface of circuit board 2, and the surface of circuit board 2 facing the base 11 is the lower surface of circuit board 2. The upper and lower surfaces are arranged opposite to each other. Sub-board 3 is disposed on the lower surface of circuit board 2 and is electrically connected to circuit board 2 through solder ball array 7. To ensure the reliability of the electrical connection structure between sub-board 3 and circuit board 2, a protective adhesive layer is filled between sub-board 3 and circuit board 2. The protective adhesive layer fills between two adjacent solder balls in solder ball array 7 and wraps around the solder balls. The protective adhesive layer not only provides mechanical structural protection to solder ball array 7, but also provides electrical insulation to solder ball array 7.

[0041] Combination Figure 2 and Figure 3 To facilitate the electrical connection between the sub-board 3 and the silicon photonics chip 6, the sub-board 3 provided in this application includes a connecting portion 31 and a protruding portion 32. The connecting portion 31 of the sub-board 3 is stacked with and electrically connected to the circuit board 2, and the protruding portion 32 of the sub-board 3 covers a portion of the opening 21 in its thickness direction. The silicon photonics chip 6 is electrically connected to the protruding portion 32. That is, the electrical connection structure between the silicon photonics chip 6 and the protruding portion 32 is located within the opening 21, through which the silicon photonics chip 6 and the sub-board 3 can be easily electrically connected by gold wire bonding. This reduces the complexity of the electrical connection between the sub-board 3 and the silicon photonics chip 6.

[0042] Specifically, the surface of the silicon photonic chip 6 facing away from the base 11 is electrically connected to the surface of the protruding portion 32 of the daughter board 3 facing away from the base 11 via conductive connecting wires (here, gold wires). For example... Figure 3 As shown, the silicon photonic chip 6 has a first conductive connection portion 61 on its surface opposite to the base 11, and the protruding portion 32 of the daughter board 3 has a second conductive connection portion 321 on its surface opposite to the base 11. The first conductive connection portion 61 and the second conductive connection portion 321 are electrically connected by a conductive connection line 8. The conductive connection line 8 is typically made of a highly conductive material, such as gold wire or aluminum wire, which ensures stable current and signal transmission, reduces resistance and signal loss, and improves the reliability of the electrical connection. The first conductive connection portion 61 and the second conductive connection portion 321 can be solder pads. A solder pad is a metal structure located on both the daughter board 3 and the silicon photonic chip 6, providing an electrical connection point between them.

[0043] To shorten the length of the conductive connection line 8 between the silicon photonic chip 6 and the protruding portion 32 of the daughter board 3, the surface of the silicon photonic chip 6 facing away from the base 11 is flush with the surface of the protruding portion 32 facing away from the base 11, such as... Figure 2As shown. The surface of the silicon photonic chip 6 facing away from the base 11 is the upper surface of the silicon photonic chip 6, and the surface of the protruding portion 32 of the daughter board 3 facing away from the base 11 is the upper surface of the daughter board 3. The upper surfaces of the silicon photonic chip 6 and the daughter board 3 are flush, ensuring that their upper surfaces are in the same horizontal plane, so as to eliminate the height difference between them, ensure that the length of the conductive connection line 8 used to electrically connect the two is short, improve the transmission effect, and improve the high-frequency performance.

[0044] The light-emitting component 5 includes a laser 51 and optical components, both mounted on a heat sink 4 and located within a window 21. Along the length of the circuit board 2, the optical components are positioned between the laser 51 and the silicon photonic chip 6 to optically couple them. The laser 51 is electrically connected to the circuit board 2. As a high-heat-generating element, the laser 51 is mounted on the heat sink 4 to dissipate heat and ensure good heat dissipation. Specifically, the optical components include a lens 52 and an isolator 53, with the lens 52 positioned between the isolator 53 and the laser 51. Light emitted from the laser 51 is focused by the lens 52 and enters the isolator 53 before being incident on the silicon photonic chip 6. The isolator 53 prevents light from being reflected back into the laser 51, thus avoiding any impact on its performance. Meanwhile, by placing the laser 51, lens 52, isolator 53 and silicon photonic chip 6 on the heat sink 4, the circuit board 2 can obtain more layout space, which facilitates the layout of components.

[0045] In some embodiments of this application, the optical module further includes a digital signal processing chip 9. The digital signal processing chip 9 is disposed on the side of the daughter board 3 opposite to the circuit board 2 and is electrically connected to it. The heat dissipation surface of the digital signal processing chip 9 faces the base 11, thereby ensuring that the heat sink 4 and the digital signal processing chip 9 are on the same side of the circuit board 2, i.e., both are located close to the base 11, ensuring that their heat dissipation directions are consistent, so that most of the heat is conducted from the bottom of the circuit board 2 to the base 11, improving the heat dissipation effect.

[0046] To further improve the heat dissipation of the digital signal processing chip 9, a thermal pad 10 is provided on the side of the digital signal processing chip 9 facing the base 11. The thermal pad 10 thermally connects the digital signal processing chip 9 and the base 11 to form a heat conduction path between them, so as to better conduct the heat of the digital signal processing chip 9 to the outside of the housing 1 through the base 11.

[0047] In some embodiments, the heat sink 4 and the base 11 are thermally connected, and a heat dissipation pad or thermal paste is provided between the heat sink 4 and the base 11 to better conduct heat from the heat sink 4 to the base 11. For example, the heat dissipation pad or thermal paste is provided between the heat sink 4 and the base 11, which enables the conduction of the heat transfer path between the two, forming a complete heat conduction path and improving the heat dissipation effect of the optical module.

[0048] The housing 1 includes a base 11 and a cover connected to the base 11. The base 11 and the cover can be fixed together with screws. A heat sink 4 is located inside the base 11. The heat generated by the silicon photonic chip 6 is mainly transferred to the base 11. Therefore, in this application, the base 11 serves as the main heat dissipation surface of the housing 1, while the cover serves as the secondary heat dissipation surface. The base 11 has a special heat dissipation design to better dissipate heat to the outside of the housing 1. For example, the optical module also includes a heat dissipation component 101, which is located or formed outside the base 11 and is thermally connected to the base 11 to improve the heat transfer efficiency of the base 11, quickly transferring the heat generated by the devices inside the housing 1 to the outside of the housing 1, preventing the optical module from deteriorating due to excessive temperature.

[0049] Reference Figure 4 The heat sink 4 includes a mounting portion 41 and a connecting portion 42. At least a portion of the mounting portion 41 covers the opening 21. The connecting portion 42 protrudes along the width direction of the circuit board 2 on one side of the mounting portion 41. The side of the connecting portion 42 facing away from the mounting portion 41 is connected to the surface of the circuit board 2 facing the base 11. The light emitting component 5 and the silicon photonic chip 6 are both disposed on the mounting portion 41, and / or, at least a portion of the sub-board 3 is disposed on the mounting portion 41. Because the connecting portion 42 protrudes from the upper surface of the mounting portion 41, the upper surface of the mounting portion 41 is positioned away from the top of the connecting portion 42 from the circuit board 2, forming a recessed area to accommodate the light emitting component 5 and the silicon photonic chip 6. This lowers the position of the light emitting component 5 and the silicon photonic chip 6, facilitating electrical connection between the silicon photonic chip 6 and the sub-board 3. The opposing sides of the silicon photonic chip 6 and the sub-board 3 are close together, further shortening the length of the conductive connection line 8 used to electrically connect them and improving transmission efficiency.

[0050] The connecting portion 42 is disposed around the mounting portion 41 and protrudes from the mounting portion 41 along the thickness direction of the circuit board 2. This can be understood as the height of the connecting portion 42 being higher than the height of the mounting portion 41. Alternatively, the top wall of the connecting portion 42 (the wall of the connecting portion 42 facing the circuit board 2) is higher than the top wall of the mounting portion 41 (the wall of the mounting portion 41 facing the circuit board 2). Or, the top wall of the connecting portion 42 is attached to and in contact with the circuit board 2, while there is a gap between the top wall of the mounting portion 41 and the circuit board 2. This arrangement allows the surfaces of the silicon photonics chip 6 and the daughter board 3 to be flush, improving signal transmission performance. Simultaneously, the light emitting component 5 can be better coupled to the silicon photonics chip 6, reducing assembly difficulty.

[0051] By increasing the contact area between the sub-board 3 and the heat sink 4, the heat dissipation effect of the sub-board 3 is improved. The mounting portion 41 of the heat sink 4 includes a main body area and an overlapping area. The connecting portion 42 protrudes along the width direction of the circuit board 2 on at least one side of the main body area of ​​the mounting portion 41. The overlapping area is closer to the sub-board 3 than the main body area. At least a portion of the connecting portion 31 of the sub-board 3 overlaps with the overlapping area of ​​the mounting portion 41 near the protruding portion 32. The protruding portion 32 of the sub-board 3 overlaps with the overlapping area of ​​the mounting portion 41. The protruding portion 32 of the sub-board 3 is in contact with and electrically connected to the silicon photonic chip 6. There is no fixed connection structure between the sub-board 3 and the overlapping area of ​​the mounting portion 41.

[0052] For example, there are two connecting portions 42, which protrude along the width direction of the circuit board 2 on opposite sides of the main body area of ​​the mounting portion 41. The protruding portion 32 of the sub-board 3 overlaps the main body area and is located between the two connecting portions 42, thereby enabling the sub-board 3 to be limited in the width direction through the connecting portions 42. In order to achieve the installation limitation of the sub-board 3 in the length direction, the thickness of the portion (overlapping area) of the mounting portion 41 of the heat sink 4 used to support or place the sub-board 3 is less than the thickness of the main body area of ​​the mounting portion 41, so as to form a limiting step surface at the intersection of the overlapping area and the main body area, which is used to limit the relative position of the sub-board 3 and the mounting portion 41 of the heat sink 4 in the length direction of the circuit board 2.

[0053] Continue to refer to Figure 2 and Figure 3 The aforementioned optical module also includes an optical receiving component 20. The optical receiving component 20 includes an optical fiber array 201, a transimpedance amplifier 202, and a receiving silicon photonic chip 203. Both the transimpedance amplifier 202 and the receiving silicon photonic chip 203 are located on the side of the circuit board 2 opposite to the sub-board 3. The receiving silicon photonic chip 203 includes a photodetector and a waveguide. The optical fiber array 201 is optically connected to the waveguide and is fixedly supported above the silicon photonic chip 6 by a pad 30. The transimpedance amplifier 202 is electrically connected to the photodetector, and the photodetector is electrically connected to the circuit board 2 via gold wires.

[0054] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0055] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims. Furthermore, specific examples have been used in the specification to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application, and the content of this specification should not be construed as a limitation of this application.

Claims

1. An optical module characterized by comprising: The application relates to a shell, a circuit board, a sub-board, a heat sink, a light emitting assembly and a silicon optical chip. The shell comprises a base and a cover which enclose a mounting cavity. The circuit board is arranged in the mounting cavity and is provided with a window penetrating through the thickness direction. The sub-board is arranged in the same layer as the circuit board and is electrically connected to the circuit board. The heat sink is arranged on the same side of the circuit board as the sub-board. The heat sink is fixed to the circuit board and at least partially covers the window. The light emitting assembly is arranged on the heat sink, in the window and is electrically connected to the circuit board.

2. The optical module according to claim 1, characterized by The silicon optical chip is arranged on the heat sink, in the window and is electrically connected to the sub-board.

3. The optical module according to claim 2, characterized by The light emitted by the light emitting assembly is incident into the silicon optical chip and is emitted from the silicon optical chip after being processed by the silicon optical chip. The sub-board comprises a connecting part and a protruding part. The connecting part is arranged in the same layer as the circuit board and is electrically connected to the circuit board.

4. The optical module according to claim 2 or 3, characterized by The protruding part covers part of the window.

5. The optical module of claim 2, wherein, The silicon optical chip is electrically connected to the protruding part.

6. The optical module of claim 1, wherein, The side surface of the silicon optical chip opposite to the base is electrically connected to the side surface of the protruding part opposite to the base through a conductive connecting line. Alternatively, 7. The optical module according to claim 6, characterized by The side surface of the silicon optical chip opposite to the base is provided with a first conductive connecting part. The side surface of the protruding part opposite to the base is provided with a second conductive connecting part.

8. The optical module according to claim 1 or 6 or 7, characterized by, The first conductive connecting part and the second conductive connecting part are electrically connected through a lead.

9. The optical module of claim 1, wherein, The side surface of the silicon optical chip opposite to the base is flush with the side surface of the protruding part opposite to the base.

10. The optical module according to claim 9, characterized by The light emitting assembly comprises a laser and an optical device. Both the laser and the optical device are arranged on the heat sink and are located in the window. Along the length direction of the circuit board, the optical device is arranged between the laser and the silicon optical chip to optically couple the laser and the silicon optical chip. The laser is electrically connected to the circuit board. The application further comprises a digital signal processing chip. The digital signal processing chip is arranged on the side of the sub-board opposite to the circuit board and is electrically connected to the sub-board. The heat dissipation surface of the digital signal processing chip faces the base. The application further comprises a heat conductive pad. The heat conductive pad is arranged on the side of the digital signal processing chip facing the base and is heat conductively connected to the digital signal processing chip and the base. The heat sink is heat conductively connected to the base. The outer surface of the base is a main heat dissipation surface. The heat sink comprises a mounting part and a connecting part. At least part of the mounting part covers the window. The connecting part is protrudingly arranged on one side of the mounting part along the width direction of the circuit board. The connecting part is connected to the side surface of the circuit board facing the base. The light emitting assembly and the silicon optical chip are arranged on the mounting part. At least part of the sub-board is arranged on the mounting part. The connecting part is protrudingly arranged on the mounting part along the thickness direction of the circuit board.

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