CN114755765B

CN114755765B - Optical module

Info

Publication number: CN114755765B
Application number: CN202110024351.6A
Authority: CN
Inventors: 邵乾; 刘维伟; 姚建伟
Original assignee: Hisense Broadband Multimedia Technology Co Ltd
Current assignee: Hisense Broadband Multimedia Technology Co Ltd
Priority date: 2021-01-08
Filing date: 2021-01-08
Publication date: 2023-04-18
Anticipated expiration: 2041-01-08
Also published as: CN114755765A

Abstract

The application discloses an optical module, which comprises a tube shell, a circuit board and a cavity, wherein a cavity is arranged in the tube shell, and a photoelectric element is arranged in the cavity; a socket is arranged at one end of the tube shell, the surface of the socket is made of metal, the circuit board is inserted into the tube shell through the socket, a metal layer is arranged at the contact part of the circuit board and the socket, a soldering tin piece is filled in a gap between the metal layer and the socket, and the metal layer is welded and fixed with the socket through the soldering tin piece; the two ends of the circuit board are respectively provided with a first electric circuit and a second electric circuit, the electric element in the tube shell is electrically connected with the first electric circuit, and the first electric circuit is electrically connected with the second electric circuit through the internal circuit of the circuit board. The application provides an optical module is with circuit board disect insertion tube in, through soldering tin spare with the whole sealings in gap between circuit board and the tube, simple process to circuit switches on inside and outside the tube through circuit board inner line realization tube, and the gas tightness of keeping the tube when having realized the inside and outside electrical interconnection of tube.

Description

Optical module

Technical Field

The application relates to the technical field of optical communication, in particular to an optical module.

Background

With the development of new services and application modes such as cloud computing, mobile internet, video and the like, the development and progress of the optical communication technology become increasingly important. In the optical communication technology, an optical module is a tool for realizing the interconversion of optical signals and is one of key devices in optical communication equipment, and the transmission rate of the optical module is continuously increased along with the development requirement of the optical communication technology.

In order to realize the above photoelectric conversion function, a standard optical module includes a circuit board, and a tosa and a rosa connected to the circuit board, wherein, in the high-speed optical communication module, in order to ensure the airtightness of the tosa and the rosa, the tosa and the rosa usually adopt an airtight shell packaging structure. Traditional airtight tube mainly has ceramic circuit board and metal tube to constitute, after airtight tube was inside to be gone up different parts according to different product assembly and to realize the function, finally realized the inside airtight encapsulation of tube with the tube cover board through parallel seal welding technology.

However, the high-temperature ceramic sintering process adopted by the traditional airtight shell is complex, the technical difficulty is high, the cost is high, and in order to reduce the cost and improve the high-speed signal quality, a non-airtight shell has been introduced in the field of data centers at present, but the non-airtight shell can only be used in a data center machine room with a better environment, and cannot be applied in the field with severe environment such as wireless 5G.

Disclosure of Invention

The application provides an optical module to solve the technical problems of complex process and high cost of an airtight tube shell in the existing optical module.

In order to solve the technical problem, the embodiment of the application discloses the following technical scheme:

the embodiment of the application discloses an optical module, includes:

the device comprises a tube shell, a first electrode, a second electrode, a first electrode and a second electrode, wherein a cavity is arranged in the tube shell, and a photoelectric element is arranged in the cavity; one end of the tube shell is provided with an optical window, and light in the tube shell is transmitted through the optical window; the other end of the cavity is provided with a socket, the surface of the socket is metal, and the socket is communicated with the cavity;

one end of the circuit board is inserted into the tube shell through the socket, a metal layer is arranged at the contact position of the circuit board and the socket, a soldering tin piece is filled in a gap between the metal layer of the circuit board and the socket, and the metal layer is welded and fixed with the socket through the soldering tin piece so as to realize the airtight packaging of the tube shell and the circuit board; the circuit board comprises a circuit board and is characterized in that a first electric circuit is arranged at one end, inserted into the tube shell, of the circuit board, a second electric circuit is arranged at one end, far away from the tube shell, of the circuit board, an electric element in the tube shell is electrically connected with the first electric circuit, and the first electric circuit is electrically connected with the second electric circuit through an internal circuit of the circuit board.

The optical module comprises a tube shell and a circuit board, wherein a cavity is arranged in the tube shell, and a photoelectric element is arranged in the cavity; a socket is arranged at one end of the tube shell, the surface of the socket is made of metal, the socket is communicated with the cavity, one end of the circuit board is inserted into the tube shell through the socket, a metal layer is arranged at the contact position of the circuit board and the socket, a soldering tin piece is filled in a gap between the metal layer of the circuit board and the socket, the metal layer is welded and fixed with the socket through the soldering tin piece to realize airtight packaging of the tube shell and the circuit board, namely the circuit board and the tube shell are welded together through the soldering tin piece, and the gap between the circuit board and the tube shell is completely sealed through the soldering tin piece; the circuit board is provided with a first electric circuit at one end inserted into the tube shell, a second electric circuit at one end far away from the tube shell, an electric element in the tube shell is electrically connected with the first electric circuit, the first electric circuit is electrically connected with the second electric circuit through an internal circuit of the circuit board, and the electric element is communicated to the outside of the tube shell from the inside of the tube shell through the internal circuit of the circuit board, so that the internal and external electric interconnection of the tube shell can be realized; the other end of the tube shell is provided with an optical window, and light in the tube shell is transmitted through the optical window so as to realize the emission or the reception of the light. The application provides an optical module with the circuit board disect insertion tube in, through soldering tin spare with the whole sealings in gap between circuit board and the tube, simple process, it is with low costs, replaced the airtight tube of the ceramic technology is fired altogether to the high temperature that present technology is complicated, with high costs to realize that the interior outer circuit of tube switches on through the circuit board inner line, thereby can realize the inside and outside electric interconnection of tube and keep the gas tightness of tube.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

In order to more clearly explain the technical solution of the present application, the drawings needed to be used in the embodiments are briefly described below, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic diagram of a connection relationship of an optical communication terminal;

fig. 2 is a schematic structural diagram of an optical network terminal;

fig. 3 is a schematic structural diagram of an optical module provided in an embodiment of the present application;

fig. 4 is an exploded schematic view of an optical module according to an embodiment of the present disclosure;

FIG. 5 is a schematic diagram of a conventional hermetic package structure in an optical module;

FIG. 6 is an exploded view of a conventional hermetic enclosure in an optical module;

fig. 7 is a schematic structural diagram of an airtight package in an optical module according to an embodiment of the present disclosure;

fig. 8 is an exploded schematic view of an airtight package in an optical module according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of a circuit board in an optical module according to an embodiment of the present application;

fig. 10 is a schematic view of another angular structure of a circuit board in an optical module according to an embodiment of the present disclosure;

fig. 11 is a cross-sectional view of a circuit board in an optical module according to an embodiment of the present disclosure;

fig. 12 is a schematic diagram illustrating an assembling process of an airtight housing and a circuit board in an optical module according to an embodiment of the present disclosure;

fig. 13 is a partial assembly cross-sectional view of an air-tight package and a circuit board in an optical module according to an embodiment of the present application;

fig. 14 is a schematic diagram of a path of water vapor permeating from the inside of the circuit board into the hermetic package in the optical module according to the embodiment of the present application;

fig. 15 is a schematic structural diagram of a solder part in an optical module according to an embodiment of the present disclosure;

fig. 16 is another schematic structural diagram of a circuit board in an optical module according to an embodiment of the present disclosure;

fig. 17 is a schematic view illustrating an assembly of a hermetic package and a circuit board in an optical module according to an embodiment of the present application.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort shall fall within the protection scope of the present application.

One of the core links of optical fiber communication is the interconversion of optical and electrical signals. The optical fiber communication uses optical signals carrying information to transmit in information transmission equipment such as optical fibers/optical waveguides, and the information transmission with low cost and low loss can be realized by using the passive transmission characteristic of light in the optical fibers/optical waveguides; in order to establish information connection between information transmission devices such as optical fibers and optical waveguides and information processing devices such as computers, interconversion between electrical signals and optical signals is required.

The optical module realizes the function of interconversion of optical signals and electrical signals in the technical field of optical fiber communication, and the interconversion of the optical signals and the electrical signals is the core function of the optical module. The optical module is electrically connected with an external upper computer through a golden finger on an internal circuit board, and the main electrical connection comprises power supply, I2C signals, data information, grounding and the like; the electrical connection mode realized by the gold finger has become the mainstream connection mode of the optical module industry, and on the basis of the mainstream connection mode, the definition of the pin on the gold finger forms various industry protocols/specifications.

Fig. 1 is a schematic diagram of connection relationship of an optical communication terminal. As shown in fig. 1, the connection of the optical communication terminal mainly includes interconnection among the optical network terminal 100, the optical module 200, the optical fiber 101, and the network cable 103.

One end of the optical fiber 101 is connected with a far-end server, one end of the network cable 103 is connected with local information processing equipment, and the connection between the local information processing equipment and the far-end server is completed by the connection between the optical fiber 101 and the network cable 103; and the connection between the optical fiber 101 and the network cable 103 is completed by the optical network terminal 100 having the optical module 200.

An optical port of the optical module 200 is externally accessed to the optical fiber 101, and establishes bidirectional optical signal connection with the optical fiber 101; an electrical port of the optical module 200 is externally connected to the optical network terminal 100, and establishes bidirectional electrical signal connection with the optical network terminal 100; the optical module realizes the mutual conversion of optical signals and electric signals, thereby realizing the establishment of information connection between the optical fiber and the optical network terminal. Specifically, the optical signal from the optical fiber is converted into an electrical signal by the optical module and then input to the optical network terminal 100, and the electrical signal from the optical network terminal 100 is converted into an optical signal by the optical module and input to the optical fiber.

The optical network terminal is provided with an optical module interface 102, which is used for accessing an optical module 200 and establishing bidirectional electric signal connection with the optical module 200; the optical network terminal is provided with a network cable interface 104, which is used for accessing the network cable 103 and establishing bidirectional electric signal connection with the network cable 103; the optical module 200 is connected to the network cable 103 via the optical network terminal 100. Specifically, the optical network terminal transmits a signal from the optical module to the network cable and transmits the signal from the network cable to the optical module, and the optical network terminal serves as an upper computer of the optical module to monitor the operation of the optical module.

At this point, a bidirectional signal transmission channel is established between the remote server and the local information processing device through the optical fiber, the optical module, the optical network terminal and the network cable.

Common information processing apparatuses include routers, switches, electronic computers, and the like; the optical network terminal is an upper computer of the optical module, provides data signals for the optical module, and receives the data signals from the optical module.

Fig. 2 is a schematic diagram of an optical network terminal structure. As shown in fig. 2, the optical network terminal 100 has a circuit board 105, and a cage 106 is disposed on a surface of the circuit board 105; an electric connector is arranged in the cage 106 and used for connecting an electric port of an optical module such as a golden finger; the cage 106 is provided with a heat sink 107, and the heat sink 107 has a first boss portion such as a fin that increases a heat radiation area.

The optical module 200 is inserted into the onu 100, specifically, the electrical port of the optical module is inserted into the electrical connector inside the cage 106, and the optical port of the optical module is connected to the optical fiber 101.

The cage 106 is positioned on the circuit board, and the electrical connector on the circuit board is wrapped in the cage, so that the electrical connector is arranged in the cage; the optical module is inserted into the cage, held by the cage, and the heat generated by the optical module is conducted to the cage 106 and then diffused by the heat sink 107 on the cage.

Fig. 3 is a schematic structural diagram of an optical module according to an embodiment of the present application, and fig. 4 is an exploded schematic diagram of the optical module according to the embodiment of the present application. As shown in fig. 3 and 4, an optical module 200 provided in the embodiment of the present application includes an upper housing 201, a lower housing 202, an unlocking member 203, a circuit board 300, a tosa 400, and a tosa 500.

The upper shell 201 is covered on the lower shell 202 to form a wrapping cavity with two openings; the outer contour of the packaging cavity generally presents a square body. Specifically, the lower housing 202 includes a main board and two side boards located at two sides of the main board and disposed perpendicular to the main board; the upper shell comprises a cover plate, and the cover plate covers two side plates of the upper shell to form a wrapping cavity; the upper shell may further include two side walls disposed at two sides of the cover plate and perpendicular to the cover plate, and the two side walls are combined with the two side plates to cover the upper shell 201 on the lower shell 202.

The two openings can be two end openings (204, 205) located at the same end of the optical module, or two openings located at different ends of the optical module; one opening is an electric port 204, and a gold finger of the circuit board extends out of the electric port 204 and is inserted into an upper computer such as an optical network terminal; the other opening is an optical port 205 for external optical fiber access to connect the tosa 400 and the rosa 500 inside the optical module; the optoelectronic devices such as the circuit board 300, the tosa 400, the rosa 500, etc. are located in the package cavity.

The assembly mode of combining the upper shell and the lower shell is adopted, so that the circuit board 300, the transmitter sub-module 400, the receiver sub-module 500 and other devices can be conveniently installed in the shells, and the outermost packaging protection shell of the modules is formed by the upper shell and the lower shell; the upper shell and the lower shell are made of metal materials generally, electromagnetic shielding and heat dissipation are achieved, the shell of the optical module cannot be made into an integral component generally, and therefore when devices such as a circuit board are assembled, the positioning component, the heat dissipation component and the electromagnetic shielding component cannot be installed, and production automation is not facilitated.

The unlocking component 203 is located on the outer wall of the wrapping cavity/lower shell 202, and is used for realizing the fixed connection between the optical module and the upper computer or releasing the fixed connection between the optical module and the upper computer.

The unlocking component 203 is provided with a clamping component matched with the upper computer cage; the end of the unlocking member 203 is pulled to make the unlocking member 203 relatively move on the surface of the outer wall; the optical module is inserted into the cage of the upper computer, and the optical module is fixed in the cage of the upper computer by the clamping component of the unlocking component 203; by pulling the unlocking member 203, the engaging member of the unlocking member 203 moves along with it, and the connection relationship between the engaging member and the upper computer is changed to release the engagement relationship between the optical module and the upper computer, so that the optical module can be drawn out from the cage of the upper computer.

The circuit board 300 is provided with circuit traces, electronic components (such as capacitors, resistors, triodes, and MOS transistors), and chips (such as an MCU, a laser driver chip, a limiting amplifier chip, a clock data recovery CDR, a power management chip, and a data processing chip DSP).

The circuit board 300 is used to provide signal circuits for signal electrical connection, which can provide signals. The circuit board 300 connects the electrical devices in the optical module together according to circuit design through circuit wiring to realize power supply, electrical signal transmission, grounding and other electrical functions.

The circuit board is generally a rigid circuit board, and the rigid circuit board can also realize a bearing effect due to relatively hard materials of the rigid circuit board, for example, the rigid circuit board can stably bear a chip; when the optical transceiver component is positioned on the circuit board, the rigid circuit board can also provide stable bearing; the hard circuit board can also be inserted into an electric connector in the upper computer cage, and specifically, a metal pin/golden finger is formed on the surface of the tail end of one side of the hard circuit board and is used for being connected with the electric connector; these are not easily implemented with flexible circuit boards.

A flexible circuit board is also used in a part of the optical module to supplement the rigid circuit board; the flexible circuit board is generally used in combination with a rigid circuit board, for example, the rigid circuit board may be connected to the optical transceiver module by using the flexible circuit board.

In order to increase the transmission rate of the optical module and adapt to various severe environments, the tosa 400 and the rosa 500 of the optical module need to have air tightness, and therefore the tosa 400 and the rosa 500 usually adopt an air-tight shell package structure.

Fig. 5 is a schematic structural diagram of a conventional hermetic package in an optical module, and fig. 6 is an exploded schematic diagram of the conventional hermetic package in the optical module. As shown in fig. 5 and 6, the conventional hermetic package mainly includes a metal cover 410, a metal package 420 and a ceramic circuit board 430, wherein the metal package 420 has an opening at the top and is internally provided with a cavity, and devices such as an optical component (e.g., a light emitting device or a light receiving device) are disposed in the cavity; the metal cover plate 410 covers the opening above the metal package 420 to form a sealed cavity with the metal package 420 through the metal cover plate 410, so as to ensure the sealing performance of the optical components and the like in the metal package 420; one end of the ceramic circuit board 430 is inserted into the metal package 420, and the ceramic circuit board 430 and the metal package 420 are hermetically welded; the ceramic circuit board 430 is provided with a metal circuit, and optical components and the like in the package 420 are electrically interconnected with the circuit board 300 through the metal circuit on the ceramic circuit board 430.

Specifically, the ceramic circuit board 430 is inserted into the metal package 420, and then devices such as an optical component and the like are placed in a cavity inside the package 420, and after different devices of the optical component are electrically connected with the ceramic circuit board 430 to realize functions, the metal cover plate 410 is subjected to a parallel sealing and welding process to realize airtight packaging inside the package.

The traditional airtight tube shell design method is as follows: metallizing the Ceramic, adopting an HTCC (High Temperature Co-Fired Ceramic) process, manufacturing a pre-designed circuit on a green Ceramic chip by using metal slurry in the modes of punching, filling holes, printing and the like, and then finally manufacturing a Ceramic circuit board by processes of laminating, high-Temperature sintering and the like; and then sintering and welding the ceramic circuit board and the metal tube shell together at a high temperature, thereby realizing the electrical interconnection between the inside and the outside of the tube shell and maintaining the air tightness of the tube shell.

However, the high-temperature ceramic sintering process adopted by the ceramic circuit board of the traditional airtight envelope is complex, has great technical difficulty and high cost, the prior technical process is mainly mastered by foreign countries such as Japan, and especially no current supplier can provide a mature solution at home for realizing the speed of more than 10G on the ceramic circuit board. In order to reduce cost and improve high-speed signal quality, a non-airtight tube shell is introduced in the field of data centers at present, but the non-airtight tube shell can only be used in a data center machine room with a better environment and cannot meet the application in the field with severe environment such as wireless 5G.

In order to solve the above problem, an embodiment of the present application provides a novel airtight tube shell, which mainly comprises a circuit board (a ceramic co-fired circuit board replacing the conventional scheme), a tube shell and a soldering component, wherein the circuit board and the tube shell are welded together by using the soldering component, and a gap between the circuit board and the tube shell is completely sealed by the soldering component.

In the embodiment of the present application, the Circuit Board 300 is a (Printed Circuit Board) rigid PCB Circuit Board, which is a multi-layer PCB Circuit Board, and the boards and layers of the PCB are bonded together by an adhesive. The PCB circuit board is mainly made of a copper-clad plate, the copper-clad plate is composed of a substrate, a copper foil and an adhesive, the substrate is an insulating layer plate composed of high-molecular synthetic resin and a reinforcing material, the surface of the substrate is covered with a layer of pure copper foil with high conductivity and good weldability, the copper-clad plate with the copper foil covering one surface of the substrate is called a single-sided copper-clad plate, the copper-clad plate with the copper foil covering both surfaces of the substrate is called a double-sided copper-clad plate, and the copper foil can be firmly covered on the substrate and is completed by the adhesive. The conventional ceramic circuit board 430 is different from the circuit board 300 provided in the present application, and after it is sintered and soldered to the package 420 at a high temperature, it is connected to the circuit board 300 at one side of the package 420 directly or through a flexible circuit board, and the chip on the circuit board 300 drives the electric components in the package 420 to work.

Fig. 7 is a schematic structural diagram of an airtight tube shell in an optical module according to an embodiment of the present disclosure, and fig. 8 is an exploded schematic diagram of an airtight tube shell in an optical module according to an embodiment of the present disclosure. As shown in fig. 7 and 8, a cavity is disposed inside a package 420 in the hermetic package provided in the embodiment of the present application, and a photoelectric element, such as a laser chip or a photodetector, is disposed in the cavity; one end of the pipe shell 420 is provided with a socket 421, and the socket 421 is communicated with the cavity; one end of the circuit board 300 is inserted into the package 420 through the socket 421 to be electrically connected to the electrical components in the cavity, so as to drive the electrical components to perform corresponding functions, such as light emitting or light receiving; an optical port is provided on the side of cartridge 420 opposite to socket 421 through which light within cartridge 420 is transmitted. A fiber optic adapter is typically coupled to a side of package 420 remote from circuit board 300 and is coupled to the optical port of package 420 to facilitate transmission of light beams between the optical port and the fiber optic adapter.

When the light emitting module is disposed in the package 420, the light emitting module generally includes light emitting chips and other electrical components, and optical devices such as lenses, isolators and the like, and the light emitting chips are close to the circuit board 300 inserted into the package 420, so as to facilitate electrical connection between the light emitting chips and the circuit board 300 by wire bonding, thereby driving the light emitting chips to emit light beams; the lens sets up between the light mouth of transmitting chip and tube 420, and it is located the light path that transmits of transmitting chip, is close to the light mouth of tube 420 promptly, and the light beam that so transmits the chip transmission gets into lens, converts the beam that diverges into convergent beam through lens, and convergent beam is coupled to the optic fibre adapter through the light mouth of tube 420 in, has realized the transmission of light.

When the light receiving module is disposed in the tube case 420, the light receiving module generally includes optical devices such as a lens, and electrical components such as a light detector and a transimpedance amplifier, the lens, the light detector and the transimpedance amplifier are sequentially disposed in the tube case 420 along the optical path transmission direction, that is, the lens is close to the optical port of the tube case 420, the transimpedance amplifier is close to the socket 421 of the tube case 420, the light detector is disposed between the lens and the transimpedance amplifier, and the light detector and the transimpedance amplifier are electrically connected to the circuit board 300 through a wire bonding. The light beam transmitted by the optical fiber adapter is transmitted to the lens through the optical port of the tube shell 420, the divergent light beam is converted into the collimated light beam through the lens, the collimated light beam enters the optical detector, the collimated light beam is converted into the electric signal through the optical detector, the output electric signal enters the transimpedance amplifier and is amplified through the transimpedance amplifier, and the amplified electric signal is transmitted to the circuit board 300.

In the embodiment of the present application, in order to ensure the sealing performance of the package 420, a transparent optical window 450 is packaged at the optical port, and the optical window 450 is a glass sheet allowing light to pass through, so that the light beam emitted by the light emitting chip enters the lens, and is converted into a converging light beam by the lens, and the converging light beam is coupled into the fiber adapter through the optical window 450; alternatively, the light beam transmitted by the optical fiber adapter is transmitted to the lens through the optical window 450, the divergent light beam is converted into a collimated light beam through the lens, the collimated light beam enters the optical detector, and the collimated light beam is converted into an electrical signal through the optical detector.

In the embodiment of the present application, in order to enhance the transmittance of the light window 450 and prevent the light reflection phenomenon from affecting the performance of the light conversion element, the light window 450 is usually tilted by a predetermined angle (usually 8 °), and the surface of the glass sheet is coated with an anti-reflection film with a corresponding wavelength to enhance the transmittance of the light beam.

After the circuit board 300 is inserted into the package 420, the gap between the circuit board 300 and the package 420 is sealed by the soldering member 440, so that the surface of the socket 421 of the package 420 is metal to facilitate the soldering between the package 420 and the soldering member 440, and the package 420 and the soldering member 440 are directly soldered. In the embodiment of the present application, the surface metal of the package 420 is a metal that can be easily soldered to the solder 440, such as gold plating, nickel plating, etc.

In this embodiment, the soldering member 440 may be a structural member, that is, the soldering member 440 includes a first side plate, a second side plate and a third side plate, two ends of the second side plate are respectively connected to the first side plate and the third side plate, and the first side plate and the third side plate are disposed opposite to each other, so that the first side plate and the third side plate of the soldering member 440 are respectively welded to two sidewalls of the socket 421; a through hole is formed in the second side plate of the soldering member 440, the circuit board 300 is inserted into the package 420 through the through hole, and after the circuit board 300 is inserted into the through hole, the boundary between the circuit board 300 and the through hole is soldered, so that the gap between the circuit board 300 and the package 420 is completely sealed by the soldering member 440.

Solder 440 may also be a solder material, and after circuit board 300 is inserted into package 420 through socket 421 of package 420, solder is applied to the gap between the side of circuit board 300 and package 420, and then solder is soldered to package 420 and the gap between solder and the side of circuit board 300, respectively, so as to completely seal the gap between circuit board 300 and package 420.

In the present embodiment, the solder members 440 include, but are not limited to, solder paste, solder pads, solder wires, and the like.

Fig. 9 is a schematic structural diagram of a circuit board 300 in an optical module according to an embodiment of the present disclosure, and fig. 10 is a schematic structural diagram of another angle of the circuit board 300 in the optical module according to the embodiment of the present disclosure. As shown in fig. 9 and 10, a metal layer is disposed at a contact portion between the circuit board 300 and the socket 421, a solder member 440 is filled in a gap between the metal layer of the circuit board 300 and the socket 421, and the metal layer is fixed to the socket 421 by the solder member 440, so as to achieve airtight sealing between the package 420 and the circuit board 300.

In the embodiment of the present application, in order to conveniently provide metal layers on the sides of the circuit board 300, metal layers may be provided on all sides of the circuit board 300 inserted into the package 420, and the circuit board 300 is soldered to the soldering member 440 through the metal layers. That is, copper layers are laid on the sides of the circuit board 300, and gold layers are plated on the surfaces of the copper layers, so that the sides of the circuit board 300 can be conveniently welded and fixed with the soldering tin 440, and external water vapor can be prevented from permeating into the case 420 through the gap between the circuit board 300 and the case 420.

Specifically, the portion of the circuit board 300 inserted into the package 420 includes a first side 301, a second side 302, a third side 303, a fourth side 304, and a fifth side 305, where the first side 301 is an upper side of the circuit board 300 and is open toward an upper portion of the package 420; the fifth side 305 is a lower side of the circuit board 300, opposite to the first side 301; the second side 302 is a rear side of the circuit board 300, and upper and lower edges thereof are respectively connected with the first side 301 and the fifth side 305; the fourth side 304 is a front side of the circuit board 300, which is opposite to the second side 302; the third side 303 is a right side of the circuit board 300, and has upper and lower edges connected to the first side 301 and the fifth side 305, respectively, and front and rear edges connected to the second side 302 and the fourth side 304, respectively. The first side 301, the second side 302, the fourth side 304 and the fifth side 305 of the circuit board 300 are all laid with copper layers and plated with gold on the surfaces thereof inserted into the package 420, so that the soldering member 440 is used to plug and solder the gap between the circuit board 300 and the package 420, thereby preventing external moisture and the like from penetrating into the package 420 through the gap between the circuit board 300 and the package 420 and affecting the performance of the optical components in the package 420.

Although the circuit board 300 and the package 420 are sealed by the solder 440, the circuit board 300 is a multi-layer structure, and the board and the layer-to-layer joints of the circuit board are easily penetrated by water vapor, but the waterproof performance of the metal is very good, in order to prevent water vapor from penetrating into the package 420 through the inside of the circuit board 300, in addition to the first side 301, the second side 302, the fourth side 304 and the fifth side 305 of the circuit board 300, the side of the circuit board 300 inserted into the package 420 also requires to be covered with copper and plated with gold, i.e., the third side 303 of the circuit board 300 is covered with copper and plated with gold, so the metal layer of the third side 303 of the right side of the circuit board 300 plays a final defense against water vapor.

In the embodiment of the present application, no metal layer is disposed on the side of the first side 301, the second side 302, the fourth side 304, and the fifth side 305 of the circuit board 300 that is not inserted into the package 420, that is, no metal layer is disposed on the end surface of the circuit board 300 on which the second electrical circuit 320 is disposed, the distance between the metal layers disposed on the circuit board 300 is slightly greater than the distance between the third side 303 of the package 420 and the left side of the package 420 on which the circuit board 300 is inserted, and the metal layer is not disposed on the rest of the circuit board 300.

Fig. 11 is a cross-sectional view of a circuit board 300 in an optical module according to an embodiment of the present disclosure. As shown in fig. 11, since the upper and lower surfaces of circuit board 300 are plated with copper layers for airtight soldering and plated with gold, so that no trace can be routed on the surface of circuit board 300, a first electrical trace 311 is disposed at one end of circuit board 300 inserted into package 420, a second electrical trace 320 is disposed at one end of circuit board 300 far from package 420, the electrical components in package 420 are electrically connected to first electrical trace 311, and first electrical trace 311 is electrically connected to second electrical trace 320 through the internal trace of circuit board 300. Since the circuit board 300 is provided with a metal layer on each side surface inserted into the package 420, in order to provide the first electric wiring 311 on the end of the circuit board 300 inserted into the package 420, a recess 310 is required to be provided on the metal layer of the circuit board 300, the surface of the recess 310 is the surface of the circuit board 300, and the surface is not coated with the metal layer, and the first electric wiring 311 is provided in the recess 310. In the embodiment of the present application, the first electrical trace 311 and the second electrical trace 320 may be circuit pads, and a plurality of circuit pads are sequentially disposed along the width direction of the circuit board 300, and the first circuit pad and the second circuit pad may be electrically connected through the internal trace 350 of the circuit board 300.

Specifically, a first electrical trace 311 and a second electrical trace 320 are disposed on the first side 301 of the circuit board 300, the first electrical trace 311 is located in the cavity of the package 420, the second electrical trace 320 is located outside the package 420, since the circuit board 300 cannot be routed on the surface, in order to achieve electrical connection, an internal trace 350 is disposed inside the circuit board 300, one end of the internal trace 350 is electrically connected to the first electrical trace 311, and the other end of the internal trace 350 is connected to the second electrical trace 320, so as to lead the circuit to the internal trace 350 in the middle layer of the circuit board 300, and lead the circuit back to the surface of the circuit board 300 after the internal trace 350 is led to the outside of the package 420.

In order to electrically connect the first electrical line 311 and the second electrical line 320 with the internal line 350 of the circuit board 300, a first via hole 330 and a second via hole 340 are provided in the circuit board 300, the first via hole 330 is provided below the first electrical line 311, and the first electrical line 311 is electrically connected with the internal line 350 through the first via hole 330; the second via hole 340 is disposed below the second electrical line 320, and the second electrical line 320 is electrically connected to the internal line 350 through the second via hole 340. In the embodiment of the present application, the first via 330 and the second via 340 are both blind holes, the first via 330 communicates the first electrical trace 311 with the internal trace 350, and the second via 340 communicates the second electrical trace 320 with the internal trace 350.

In the present embodiment, the first electrical wiring 311 may include a plurality of first circuit pads, which are sequentially disposed in the width direction of the circuit board 300; the second electric line 320 may include a plurality of second circuit pads, which are sequentially disposed in a width direction of the circuit board 300. The first via 330 is disposed between the first circuit pad and the inner line 350, the second via 340 is disposed between the second circuit pad and the inner line 350, and one end of the inner line 350 is electrically connected to the first via 330 and the other end is electrically connected to the second via 340.

Since the first side 301 of the circuit board 300 is inserted into the end face of the package 420 and is provided with the first electrical trace 311, the surface of which cannot be laid with a copper layer, so that external moisture may permeate into the package 420 through the gap between the layers of the circuit board 300, a gap exists between the edge of the first electrical trace 311 close to the package 420 and the edge of the circuit board 300, that is, a gap exists between the edge of the recess 310 and the third side 303, and a metal layer is provided on the gap to block moisture permeation. In the embodiment of the present application, the gap between the edge of the first electrical trace 311 and the third side 303 of the circuit board 300 has a size of 0.1mm or more.

Specifically, on the first side 301 of the circuit board 300, a gap is left between the right edge of the recessed area 310 and the right edge of the first side 301, a copper layer is laid on the gap and a gold layer is plated on the surface of the gap, and the metal layer on the gap is connected with the metal layers on the first side 301 and the third side 303, so as to prevent external moisture and the like from penetrating into the inside of the package 420 through the gap between the circuit board 300 and the package 420 and affecting the performance of the optical component in the package 420.

Fig. 12 is a schematic view illustrating an assembly process of a circuit board 300 and a package 420 in an optical module according to an embodiment of the present disclosure. As shown in fig. 12, the circuit board 300 is inserted into the package 420, and copper layers are laid on each side of the package and gold-plated, and a first electrical line 311 and a second electrical line 320 are respectively disposed at two ends of the circuit board 300, an internal line 350 is disposed at the middle layer of the circuit board 300, a first via hole 330 is disposed below the first electrical line 311 to connect the internal line 350, a second via hole 340 is disposed below the second electrical line 320 to connect the internal line 350, and then the circuit board 300 and the package 420 are respectively cleaned by plasma cleaning or ultrasonic cleaning; then, the circuit board 300 is inserted into the case 420 through the socket 421 of the case 420, so that the first electrical trace 311 is located in the cavity of the case 420, the second electrical trace 320 is located outside the case of the case 420, and if necessary, the junction between the two may be pre-fixed by using glue; solder paste is then applied to the gap at the interface of package 420 and board 300, and package 420 and board 300 are soldered together by solder paste through reflow soldering.

After cartridge 420 and circuit board 300 are soldered together with solder paste, it is necessary for a worker to perform visual inspection and leak detection on the soldered airtight cartridge to detect the assembly sealability of circuit board 300 and cartridge 420, thereby preventing external moisture and the like from permeating into cartridge 420 through the gap between circuit board 300 and cartridge 420.

Fig. 13 is a partial assembly cross-sectional view of a circuit board 300 and a package 420 in an optical module according to an embodiment of the present disclosure. As shown in fig. 13, after the package 420 and the circuit board 300 are soldered together by solder paste, optical components (such as an optical transmitter or an optical receiver) are placed in the cavity of the package 420, and the electrical components in the package 420 are electrically connected to the first electrical traces 311 on the circuit board 300 by wire bonding, and then the electrical components are led back to the second electrical traces 320 on the surface of the circuit board 300 through the first via 330, the inner traces 350 and the second via 340, thereby achieving electrical interconnection between the inside and the outside of the package 420; in addition, light within the package 420 is transmitted through the optical window, thereby achieving electrical interconnection between the interior and exterior of the package while maintaining the hermeticity of the package.

Fig. 14 is a schematic diagram of a path of water vapor permeating from the inside of the circuit board into the hermetic package in the optical module according to the embodiment of the present disclosure. As shown in fig. 14, the package 420 and the circuit board 300 are soldered together by the solder 440, but there is a possibility that defects such as holes, bubbles, and cracks may occur during soldering of the solder 440, and the package 420 leaks gas at the soldered portion, so that moisture penetrates into the package 420 from the bubbles, cracks, and the like at the soldered portion, and the performance of the photoelectric element in the package 420 is affected.

Fig. 15 is another schematic structural diagram of a solder 440 in an optical module according to an embodiment of the present disclosure. As shown in fig. 15, in order to avoid water vapor infiltration caused by poor welding of the soldering tin member 440 with the package 420 and the circuit board 300 due to poor welding of bubbles and cracks, in the present application, after the gap between the package 420 and the circuit board 300 is welded together by the soldering tin member 440, the first waterproof layer 441 is coated on each outer side surface of the soldering tin member 440, and the first waterproof layer 441 can cover the bubbles and cracks of the soldering tin member 440, which are poor welding, so that the gas leakage phenomenon caused by the cracking of the soldering tin member 440 or the bubbles can be solved. In this embodiment, the first waterproof layer 441 may be a glue layer, and after the gap between the case 420 and the circuit board 300 is welded together by the soldering tin 440, a layer of glue is covered outside the soldering tin 440, so as to prevent the air leakage phenomenon of the case 420 at the welding position, and prevent water vapor from permeating into the inside of the case 420 from the welding bubble, crack, and the like.

Fig. 16 is another schematic structural diagram of a circuit board 300 in an optical module provided in the embodiment of the present application, and fig. 17 is an assembly top view of the circuit board 300 and a package 420 in an optical module provided in the embodiment of the present application. As shown in fig. 16 and 17, in the embodiment of the present application, a recessed area 310 is disposed at an end of the circuit board 300 inserted into the package 420, a bottom surface of the recessed area 310 is a surface of the circuit board, a top surface of the recessed area 310 is a surface of a metal layer of the circuit board, and a first electrical trace 311 is disposed in the recessed area 310, in order to dispose the first electrical trace 311, the surface of the recessed area 310 is not disposed with the metal layer, so that after water vapor enters the circuit board 300 through a gap between the multiple layers of the circuit board 300, the water vapor can enter the interior of the package 420 through the recessed area 310, which affects performance of the optoelectronic component in the package 420.

In order to prevent water vapor from penetrating into the package 420 from the inside of the circuit board 300, the circuit board 300 is entirely made of copper sheets around the first electrical traces 311 inside the package 420, so that a concave region 310 is formed between the first electrical traces 311 and the copper sheets around the first electrical traces, i.e. a cross-sectional line position in the figure, which is a position where water vapor penetrates. In the embodiment of the present application, a second waterproof layer is disposed on the surface of the recessed area 310. That is, the first electrical trace 311 is disposed in the recessed area 310, and after the first electrical trace 311 is electrically connected to the internal trace 350 of the circuit board 300 through the first via hole 330, a second waterproof layer is disposed in the gap between the first electrical trace 311 and the edge of the recessed area 310 and between the first electrical trace 311, so that even if there is water vapor in the circuit board 300, the second waterproof layer can block the water vapor, and the water vapor cannot enter the interior of the package 420 through the surface of the recessed area 310.

In this embodiment, the second waterproof layer may be a glue layer, in order to facilitate electrical connection between the electrical component in the case 420 and the first electrical line 311 through a wire bonding, after the end of the circuit board 300 provided with the first electrical line 311 is inserted into the case 420, the circuit board 300 is welded to the case 420 through the soldering member 440, the electrical component in the case 420 is electrically connected to the first electrical line 311 through the wire bonding, and then a layer of glue for releasing water vapor is added in the recessed area 310 of the circuit board 300, so that the glue does not flow around due to the recessed design, and the waterproof layer is formed after the glue is cured, thereby preventing water vapor from permeating from this position.

The optical module provided by the embodiment of the application comprises a tube shell, a circuit board and a soldering tin piece, wherein a cavity is arranged in the tube shell, and a photoelectric element is arranged in the cavity; the one end of tube is equipped with the socket, the socket is linked together with the cavity, the one end of circuit board inserts in the tube through the socket, and all be provided with the metal level on each side that the circuit board inserted the tube, the surface of socket is the metal, soldering tin spare sets up in the clearance between the socket of tube and the circuit board, thereby it is in the same place to weld circuit board and tube through soldering tin spare, and the outside of soldering tin spare is provided with first waterproof layer, cover the bubble that appears when soldering tin spare welding is not good through first waterproof layer, crackle etc. in order to realize the airtight encapsulation of tube and circuit board, thereby avoid soldering tin spare to open the material or the gas leakage phenomenon that factors such as bubble caused; the circuit board is characterized in that a sunken area is arranged at one end, inserted into the tube shell, of the circuit board, a first electric circuit is arranged in the sunken area, a second electric circuit is arranged at one end, far away from the tube shell, of the circuit board, an internal circuit is arranged in the middle layer of the circuit board, the first electric circuit is electrically connected with the internal circuit through a first via hole, the second electric circuit is electrically connected with the internal circuit through a second via hole, an electric element in the cavity is electrically connected with the first electric circuit on the circuit board through a routing mode, so that the circuit is led to the middle layer of the circuit board through the first via hole, and after the circuit is led to the outside of the tube shell through the internal circuit in the middle layer, the circuit is led back to the second electric circuit on the surface of the circuit board through the second via hole, so that the internal and external electric interconnection of the tube shell is realized; because the surface of the recessed area is not provided with the metal layer, the water vapor cannot be prevented from permeating into the tube shell 420 from the recessed area, a second waterproof layer is arranged in the area of the recessed area except the first electric circuit, and the bottom surface of the recessed area is covered by the second waterproof layer so as to prevent the water vapor from permeating from the recessed area; the other end of the tube shell is provided with an optical window, and light in the tube shell is transmitted through the optical window so as to realize the emission or the reception of the light. The application provides an optical module is with circuit board disect insertion tube in, the gap between with circuit board and the tube is whole sealed through soldering tin piece, the infiltration of steam that factors such as soldering tin piece welding fracture or bubble caused is avoided to the first waterproof layer in the soldering tin piece outside, avoid steam by the depressed area infiltration tube in the second waterproof layer through circuit board depressed area bottom surface, moreover, the steam generator is simple in process, low cost, the airtight tube of ceramic technology is fired altogether to the high temperature that has replaced present technology complicacy, with high costs, and optical component's electric component is direct to be connected through routing and circuit board electricity, high frequency performance is better, satisfy the open air application like the abominable field of environment such as 5G better.

It should be noted that, in the present specification, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a circuit structure, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such circuit structure, article, or apparatus. Without further limitation, having an element defined by the phrase "comprising a … …" does not exclude the presence of another like element in a circuit structure, article, or device that comprises the element.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

The above-described embodiments of the present application do not limit the scope of the present application.

Claims

1. A light module, comprising:

one end of the circuit board is inserted into the tube shell through the socket, metal layers are arranged on the side faces of the circuit board inserted into the tube shell, soldering tin pieces are filled in gaps between the metal layers of the circuit board and the socket, and the metal layers are welded and fixed with the socket through the soldering tin pieces so as to realize airtight packaging of the tube shell and the circuit board; a sunken area is arranged on the upper side surface of the shell, which is inserted into the shell, the surface of the sunken area is the surface of the circuit board, and the surface of the sunken area is not coated with a metal layer; a first electric circuit is arranged in the depressed area, a second electric circuit is arranged at one end of the circuit board far away from the tube shell, an electric element in the tube shell is electrically connected with the first electric circuit, and the first electric circuit is electrically connected with the second electric circuit through an internal circuit of the circuit board; waterproof layers are arranged in gaps between the first electric circuit and the edge of the depressed area and between the first electric circuits.

2. The optical module according to claim 1, wherein the circuit board includes a first side surface and a fourth side surface, a second side surface and a fifth side surface, which are disposed opposite to each other, and a metal layer is disposed on all of the first side surface, the second side surface, the fourth side surface and the fifth side surface that are inserted into the package, and no metal layer is disposed on the portion of the side surface that is not inserted into the package.

3. The optical module according to claim 2, wherein the circuit board further includes a third side surface connected to the first side surface, the second side surface, the fourth side surface, and the fifth side surface, the third side surface is inserted into the package, and a metal layer is disposed on the third side surface.

4. The optical module according to claim 3, wherein the first electrical trace and the second electrical trace are disposed on a first side of the circuit board, a left-right gap exists between an edge of the recessed area facing away from the second electrical trace and the third side, and a metal layer is disposed on the gap.

5. The optical module according to claim 4, wherein the gap has a size of 0.1mm or more.

6. The optical module according to claim 1, wherein a first via hole and a second via hole are provided in the circuit board, the first electrical wiring is electrically connected to the internal wiring through the first via hole, and the second electrical wiring is electrically connected to the internal wiring through the second via hole.

7. The optical module of claim 6, wherein the first via and the second via are blind vias.

8. The optical module of claim 1, wherein the metal of the socket is gold plating, nickel plating.

9. The optical module of claim 1, wherein the metal layer on the circuit board is a copper layer, and the copper layer is plated with a gold layer on a surface thereof.

10. The optical module as claimed in claim 1, wherein the solder members comprise solder paste, solder pieces and solder wires.