CN214795313U

CN214795313U - Optical module

Info

Publication number: CN214795313U
Application number: CN202121355472.0U
Authority: CN
Inventors: 邵乾; 韩继弘; 宿靖啟
Original assignee: Hisense Broadband Multimedia Technology Co Ltd
Current assignee: Hisense Broadband Multimedia Technology Co Ltd
Priority date: 2021-06-17
Filing date: 2021-06-17
Publication date: 2021-11-19
Anticipated expiration: 2031-06-17

Abstract

In the optical module provided by the application, a blind groove is formed in the upper surface of a circuit board, a copper layer is arranged on the surface of the blind groove, a signal pad, a first heat-conducting cushion block and a second heat-conducting cushion block are arranged on the surface of the copper layer, a silicon optical chip is arranged on the first heat-conducting cushion block and is in routing connection with the circuit board through the signal pad, a laser assembly is arranged on the second heat-conducting cushion block, and a metal upper cover covers the second heat-conducting cushion block; the blind groove is arranged, so that for the high transmission rate optical module with a large number of electronic elements, the electronic elements can be designed on the lower surface of the circuit board corresponding to the blind groove, and the space between the bottom of the blind groove and the lower surface of the circuit board can be used for routing lines between inner layers of the circuit board; meanwhile, the first heat conduction cushion block and the second heat conduction cushion block are arranged to transfer heat generated by the silicon optical chip and the laser assembly to the copper layer, and then the heat on the surface of the copper layer is transferred to the shell of the optical module through the metal upper cover, so that heat dissipation inside the optical module is facilitated.

Description

Optical module

Technical Field

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

Background

The optical communication technology can be applied to novel services and application modes such as cloud computing, mobile internet, video and the like. In optical communication, an optical module is a tool for realizing the interconversion of optical signals and is one of the key devices in optical communication equipment. The adoption of a silicon optical chip to realize a photoelectric conversion function has become a mainstream scheme adopted by a high-speed optical module.

In the silicon optical module, a silicon optical chip is arranged on a circuit board and is electrically connected with the circuit board through routing; the silicon optical chip is connected with the optical interface of the optical module through the optical fiber ribbon, so that optical signals can enter and exit the silicon optical chip. The silicon material used for the silicon optical chip is not an ideal laser chip luminescent material, and the luminescent unit cannot be integrated in the silicon optical chip manufacturing process, so the silicon optical chip needs to be provided with light by an external light source.

Therefore, the silicon optical module usually further includes Laser Boxes (LB), transimpedance amplifiers (TIA), DRIVERs (DRIVER), and other electronic devices. However, with the development of optical communication, the integration level of the optical module is higher and higher, and the power density of the optical module is also increased, so that a large amount of heat is generated inside the optical module in the working process. If the heat generated inside the optical module cannot be dissipated in time, the working performance of the optical module will be seriously affected.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides an optical module, which is convenient for realizing the internal heat dissipation of the optical module and avoiding the centralized accumulation of the internal heat of the optical module.

The application provides an optical module including:

the upper surface of the circuit board is provided with a blind groove, and the surface of the blind groove is plated with a copper layer, a signal bonding pad, a first heat conduction cushion block and a second heat conduction cushion block;

the laser assembly is arranged on the second heat conduction cushion block, embedded in the blind groove and used for emitting light which does not carry signals;

the silicon optical chip is electrically connected with the circuit board through the signal bonding pad, arranged on the first heat conduction cushion block, embedded in the blind groove and used for receiving light which is emitted by the laser assembly and does not carry signals;

the signal bonding pad is arranged on one side of the silicon optical chip, one end of the signal bonding pad is electrically connected with the silicon optical chip, and the other end of the signal bonding pad is electrically connected with the circuit board;

and the metal upper cover is covered above the second heat conduction cushion block, the bottom of the metal upper cover is in contact with the copper layer, and the metal upper cover is provided with a notch for avoiding the signal bonding pad and is used for transmitting heat generated by the laser assembly to the optical module shell.

Has the advantages that:

according to the scheme, the blind groove is formed in the upper surface of the circuit board, the copper layer is arranged on the surface of the blind groove, the signal bonding pad, the first heat conduction cushion block and the second heat conduction cushion block are arranged on the surface of the copper layer, the silicon optical chip is arranged on the first heat conduction cushion block and connected with the circuit board in a routing mode through the signal bonding pad, the laser assembly is arranged on the second heat conduction cushion block, and the metal upper cover is covered above the second heat conduction cushion block.

On one hand, the blind grooves are arranged, so that for the high transmission rate optical module with more electronic elements, the electronic elements can be designed on the lower surface of the circuit board corresponding to the blind grooves, and the space between the bottom of the blind grooves and the lower surface of the circuit board can be used for routing lines between inner layers of the circuit board; on the other hand, the first heat conduction cushion block and the second heat conduction cushion block are arranged to transfer heat generated by the silicon optical chip and the laser assembly to the copper layer, and then the heat on the surface of the copper layer is transferred to the shell of the optical module through the metal upper cover, so that heat dissipation inside the optical module is facilitated, and the heat inside the optical module is prevented from being accumulated in a centralized mode.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

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

FIG. 2 is a schematic diagram of an optical network unit;

fig. 3 is a schematic structural diagram of an optical module according to an embodiment of the present disclosure;

fig. 4 is an exploded structural schematic diagram of an optical module provided in an embodiment of the present application;

fig. 5 is a schematic structural diagram of the optical module provided in the embodiment of the present application, in which the upper shell and the lower shell are removed;

fig. 6 is a schematic structural diagram of a circuit board of an optical module provided in an embodiment of the present application;

fig. 7 is a schematic structural diagram of a heat conducting pad block disposed on a circuit board of an optical module according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of devices arranged on a circuit board heat-conducting cushion block of an optical module according to an embodiment of the present application;

fig. 9 is a schematic view showing a structure of each structure on a circuit board of an optical module according to an embodiment of the present application;

fig. 10 is a schematic diagram of a relative arrangement relationship between a metal upper cover and a circuit board of an optical module provided in the embodiment of the present application;

fig. 11 is a first schematic perspective view of a metal upper cover of an optical module according to an embodiment of the present application;

fig. 12 is a schematic perspective view of a metal upper cover of an optical module according to an embodiment of the present application;

fig. 13 is a first schematic diagram illustrating a relative relationship between a signal pad of an optical module and other structures according to an embodiment of the present application;

fig. 14 is a second schematic diagram illustrating a relative relationship between a signal pad of an optical module and other structures according to an embodiment of the present application;

fig. 15 is a third schematic diagram illustrating a relative relationship between a signal pad of an optical module and another structure according to an embodiment of the present application;

fig. 16 is a fourth schematic diagram illustrating a relative relationship between a signal pad of an optical module and other structures according to an embodiment of the present application;

fig. 17 is a schematic diagram illustrating a gold wire connection of a silicon optical chip of an optical module according to an embodiment of the present application.

Detailed Description

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 of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

One of the core links of optical communication is the interconversion of optical and electrical signals. Optical communication uses optical signals carrying information to transmit in information transmission equipment such as optical fiber/optical waveguide, and the information transmission with low cost and low loss can be realized by using the passive transmission characteristic of light in the optical fiber/optical waveguide; meanwhile, the information processing device such as a computer uses an electric signal, and in order to establish information connection between the information transmission device such as an optical fiber or an optical waveguide and the information processing device such as a computer, it is necessary to perform interconversion between the electric signal and the optical signal.

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 of the optical module, and the main electrical connection comprises power supply, I2C signals, data signals, 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 an optical network unit 100, an optical module 200, an optical fiber 101, and a 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 unit 100 having the optical module 200.

The optical port of the optical module 200 is connected to the optical fiber 101, and establishes a bidirectional optical signal connection with the optical fiber. The electrical port of the optical module 200 is connected to the optical network unit 100, and establishes bidirectional electrical signal connection with the optical network unit. The optical module realizes the interconversion between an optical signal and an electrical signal, thereby realizing the connection between the optical fiber 101 and the optical network unit 100.

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 unit 100, and the electrical signal from the optical network unit 100 is converted into an optical signal by the optical module and input to the optical fiber 101. The optical module 200 is a tool for realizing the mutual conversion of the photoelectric signals, and has no function of processing data, and in the photoelectric conversion process, the carrier of the information is converted between the light and the electricity, but the information itself is not changed.

The optical network unit 100 has an optical module interface 102 for accessing the optical module 200 and establishing a bidirectional electrical signal connection with the optical module 200. The optical network unit 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 through an optical network unit. Specifically, the optical network unit 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 unit serves as an upper computer of the optical module to monitor the operation of the optical module.

To this end, the remote server establishes a bidirectional signal transmission channel with the local information processing device sequentially through the optical fiber 101, the optical module 200, the optical network unit 100, and the network cable 103.

Common information processing apparatuses include routers, switches, electronic computers, and the like; the optical network unit is an upper computer of the optical module, provides data signals for the optical module, and receives the data signals from the optical module, and the common upper computer of the optical module also comprises an Optical Line Terminal (OLT) and the like.

Fig. 2 is a schematic diagram of an optical network unit structure. As shown in fig. 2, the optical network unit 100 includes a circuit board 105, and a cage 106 is disposed on a surface of the circuit board 105; an electrical connector connected to the circuit board 105 is provided in the cage 106, and is used for connecting an electrical port of an optical module such as a gold finger; the cage 106 is provided with a heat sink 107, and the heat sink 107 has a convex structure such as a fin for increasing a heat radiation area.

The optical module 200 is inserted into the optical network unit 100, specifically, an electrical port of the optical module is inserted into an electrical connector in the cage 106, and an optical port of the optical module is connected to the optical fiber 101.

The cage 106 is located on the circuit board 105 of the optical network unit 100, and the electrical connectors on the circuit board 105 are wrapped in the cage; the optical module is inserted into the cage, the cage fixes the optical module, and heat generated by the optical module is conducted to the cage through the optical module housing and finally diffused through 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 disclosure, fig. 4 is an exploded schematic structural diagram of the optical module, and fig. 5 is a schematic structural diagram of the optical module according to the embodiment of the present disclosure with an upper shell and a lower shell removed; the optical module in the optical communication terminal in the foregoing embodiment is described below with reference to fig. 3, 4, and 5. As shown in fig. 3, 4 and 5, an optical module 200 provided by an embodiment of the present invention includes an upper housing 201, a lower housing 202, an unlocking handle 203, an electrical port 204, an optical port 205, a circuit board 300, a silicon optical chip 500, a laser component (covered), a first optical fiber ribbon 600, a second optical fiber ribbon 700, and an optical fiber interface 400, wherein the silicon optical chip 500 and the laser component are disposed on the same side surface of the circuit board 300.

As shown in fig. 3, the upper housing 201 and the lower housing 202 form a two-opening package cavity, specifically, two ends (204, 205) in the same direction may be opened, or two openings in different directions may be opened; one of the openings is an electrical port 204 for inserting into an upper computer such as an optical network unit, the other opening is an optical port 205 for connecting an external optical fiber to an internal optical fiber, and the photoelectric devices such as the circuit board 300, the silicon optical chip 500 and the laser assembly are positioned in the packaging cavity.

The upper shell 201 and the lower shell 202 are generally made of metal materials, which is beneficial to realizing electromagnetic shielding and heat dissipation; the assembly mode of combining the upper shell and the lower shell is adopted, so that devices such as a circuit board and the like can be conveniently installed in the shell, the shell of the optical module can not be generally integrated, and therefore when the devices such as the circuit board and the like are assembled, the positioning component, the heat dissipation structure and the electromagnetic shielding structure cannot be installed, and production automation is not facilitated.

The unlocking handle 203 is positioned on the outer wall of the packaging cavity/lower shell 202, and the tail end of the unlocking handle is pulled to enable the unlocking handle to move relatively on the surface of the outer wall; when the optical module is inserted into the upper computer, the unlocking handle fixes the optical module in the cage of the upper computer, and the clamping relation between the optical module and the upper computer is released by pulling the unlocking handle, so that the optical module can be drawn out from the cage of the upper computer.

The circuit board 300 is generally a rigid circuit board, which can also perform a bearing function due to its relatively rigid material, for example, the rigid circuit board can stably bear a chip; when the optical transceiver 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 a 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 device through the flexible circuit board.

The surface of the end part of the circuit board 300 is provided with a golden finger, the golden finger is composed of mutually independent pins, the circuit board is inserted into the electric connection in the cage, the golden finger is in conductive connection with a clamping elastic sheet in the electric connector, the golden finger can be arranged on the surface of one side of the circuit board, and the golden finger is generally arranged on the upper surface and the lower surface of the circuit board in consideration of the large requirement on the number of the pins; the golden finger is used for establishing electrical connection with the upper computer, and the specific electrical connection can be power supply, grounding, I2C signals, communication data signals and the like.

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, a limiting amplifier chip, a clock data recovery CDR, a power management chip, and a data processing chip DSP).

The silicon photonics chip 500 itself has no light source, and the laser assembly serves as an external light source for the silicon photonics chip 500. The laser component can be selected from a laser box, a laser chip is packaged in the laser box, the laser chip emits light to generate laser beams, the laser component is used for providing emitted laser to the silicon optical chip 500, the laser becomes a preferred light source for optical modules and even optical fiber transmission by better single-wavelength characteristic and better wavelength tuning characteristic, other types of light such as LED light and the like are generally not adopted by common optical communication systems, even if the light source is adopted in a special optical communication system, the characteristics of the light source and the chip components are greatly different from the laser, so that the optical modules adopting the laser and the optical modules adopting other light sources have large technical difference, and the skilled person generally does not consider that the two types of optical modules can give technical inspiration each other.

The bottom surface of the silicon optical chip 500 and the bottom surface of the laser component are respectively arranged on the substrate, the silicon optical chip is optically connected with the light source, the light path is very sensitive to the position relation between the silicon optical chip and the light source, and materials with different expansion coefficients are deformed to different degrees, so that the realization of a preset light path is not facilitated; in the embodiment of the application, the silicon optical chip and the light source are arranged on the same substrate, and the substrate made of the same material deforms to equivalently influence the positions of the silicon optical chip and the light source, so that the relative position of the silicon optical chip and the light source is prevented from being greatly changed; it is preferable that the expansion coefficient of the substrate material is close to that of the silicon optical chip and/or the light source material, the main material of the silicon optical chip is silicon, the light source can be kovar metal, and the substrate is generally selected from silicon or glass.

There are many relations between the substrate and the circuit board 300, one of them is as shown in fig. 4, the circuit board 300 has an opening penetrating the upper and lower surfaces, the silicon optical chip and/or the light source is arranged in the opening, thus, the silicon optical chip and/or the light source can simultaneously fan heat to the upper surface of the circuit board and the lower surface of the circuit board, the substrate is arranged at one side of the circuit board, the silicon optical chip and/or the light source penetrates the opening of the circuit board and then is placed on the heat dissipation substrate, the substrate plays a role of bearing and heat dissipation; in another mode, the circuit board is not provided with an opening, the substrate is arranged on the circuit board, specifically, the substrate is arranged on the surface of the circuit board or embedded in the circuit board, and the silicon optical chip and the light source are arranged on the surface of the substrate.

The bottom surface of the laser assembly is disposed on the substrate, the laser assembly emits light through the side surface, and the emitted light enters the silicon optical chip 500. Silicon is used as a main substrate of the silicon optical chip, and silicon is not an ideal luminescent material, so that a light source cannot be integrated in the silicon optical chip 500, and an external light source such as a laser component is required to provide the light source. The light provided by the laser component to the silicon optical chip is emitted light with a single wavelength and stable power, and does not carry any data, and the emitted light is modulated by the silicon optical chip 500 to realize loading of data into the emitted light.

The bottom surface of the silicon photonics chip 500 is disposed on a substrate, and the side surface of the silicon photonics chip 500 receives emitted light from a light source; the modulation of the emitted light and the demodulation of the received light are completed by a silicon optical chip, and a bonding pad electrically connected with a circuit board in a routing way is arranged on the surface of the silicon optical chip; specifically, the circuit board provides a data signal from the upper computer to the silicon optical chip, the silicon optical chip modulates the data signal into emitted light, and received light from the outside is demodulated into an electric signal through the silicon optical chip and then is output to the upper computer through the circuit board.

As shown in fig. 4, each of the first optical fiber ribbon 600 and the second optical fiber ribbon 700 is formed by combining a plurality of optical fibers and is covered by an optical fiber array; in the present embodiment, the first fiber optic ribbon 600 is a transmitting fiber optic ribbon and the second fiber optic ribbon 700 is a receiving fiber optic ribbon; one end of the first optical fiber ribbon 600 is connected with the silicon optical chip 500, and the other end is connected with the optical fiber interface 400; one end of the second optical fiber ribbon 700 is connected with the silicon optical chip 500, and the other end is connected with the optical fiber interface 400; the optical fiber interface 400 is connected with an external optical fiber. It can be seen that the silicon optical chip 500 and the optical fiber interface 400 are optically connected through the first optical fiber ribbon 600 and the second optical fiber ribbon 700, and the optical fiber interface 400 is optically connected to the external optical fiber of the optical module.

The laser assembly will not carry the transmission light transmission of signal to silicon optical chip 500 in, silicon optical chip 500 modulates the transmission light that does not carry the signal, specifically load the transmission light that does not carry the signal with data, and then modulate the transmission light that does not carry the signal for the transmission light that carries data signal, this transmission light that carries data signal transmits to optical fiber interface 400 department through first optical fiber ribbon 600, transmit to outside optic fibre through optical fiber interface 400 in, thereby in the optical transmission to the outside optic fibre of optical module with the light transmission that carries data signal, the realization is converted the electrical signal into optical signal.

The optical signal from the external optical fiber is transmitted to the optical fiber interface 400, and then transmitted to the silicon optical chip 500 through the second optical fiber ribbon 700, and the silicon optical chip 500 demodulates the optical signal into an electrical signal, and outputs the electrical signal to the upper computer through the circuit board, so that the optical signal is converted into the electrical signal.

The design scheme provided by the embodiment of the application is not only suitable for a 400G optical module, but also suitable for high-rate transmission modules such as an 800G optical module.

Fig. 6 is a schematic structural diagram of a circuit board 300 according to an embodiment of the present disclosure, and as shown in fig. 6, a first blind groove 310 and a second blind groove 320 are disposed on an upper surface of the circuit board 300, a first signal pad 330 is disposed on a surface of the first blind groove 310, and a second signal pad 340 is disposed on a surface of the second blind groove 320, where the design scheme provided in the embodiment of the present disclosure is not only suitable for a 400G optical module but also suitable for a high-speed transmission module such as an 800G optical module, when the design scheme is suitable for the 400G optical module, a blind groove is disposed on a surface of the circuit board 300 adaptively, when the design scheme is suitable for the 800G optical module, the first blind groove 310 and the second blind groove 320 are disposed on a surface of the circuit board 300 adaptively, the first signal pad 330 is disposed on a surface of the first blind groove 310, and the second signal pad 340 is disposed on a surface of the second blind groove 320.

The blind groove in this application embodiment can hold silicon optical chip and laser assembly, and wherein the upper surface of silicon optical chip and the upper surface parallel and level of circuit board, the upper surface parallel and level of laser assembly and the upper surface of circuit board set up the routing length that can shorten silicon optical chip and laser assembly like this.

It should be noted that the blind slot mentioned in this application does not extend through the upper and lower surfaces of the circuit board, but only extends through a longitudinal portion of the circuit board, and the bottom end of the blind slot can be seen in a top view.

The surface of the circuit board 300 is provided with the blind groove to replace the existing scheme that the through groove is arranged on the surface of the circuit board 300, in the application, for the high transmission rate optical module with a large number of electronic elements, the blind groove is arranged, so that the electronic elements can be designed on the lower surface of the circuit board corresponding to the blind groove, and the bottom of the blind groove can be used for routing lines between inner layers of the circuit board to the lower surface of the circuit board.

Fig. 7 is a schematic structural view of disposing heat conducting pads on the surface of the circuit board 300 according to the embodiment of the present disclosure, specifically, as shown in fig. 7, copper layers are laid on the surfaces of the first blind groove 310 and the second blind groove 320, and a first heat conducting pad 311, a second heat conducting pad 312, a third heat conducting pad 313 and a fourth heat conducting pad 314 are adhered to the surface of the copper layer of the first blind groove 310 through a heat conducting adhesive; correspondingly, four corresponding heat-conducting pads, such as

pads

321, 322, 323, and 324 in fig. 7, are respectively adhered to the copper layer surface of the second blind groove 320 by heat-conducting glue.

The circuit board comprises a ground layer and a signal layer, the copper layer is connected with the ground layer through a via hole, and the signal pad is connected with the signal layer through a via hole.

The first, second, third and fourth heat-conducting

pads

311, 312, 313 and 314 will be described as examples; the surfaces of the first heat conduction pad 311, the second heat conduction pad 312, the third heat conduction pad 313 and the fourth heat conduction pad 314 are provided with corresponding structures, and heat generated by the structures during operation can be transferred to the copper layer through the heat conduction pads.

Fig. 8 is a schematic structural diagram of structures disposed on a heat conducting pad of a circuit board according to an embodiment of the present disclosure; as shown in fig. 8, a silicon optical chip 500 is disposed on a surface of the first thermal conductive pad 311, a TIA (transimpedance amplifier) chip 510 and a Driver chip 520 are disposed on a surface of the silicon optical chip 500, the Driver chip 520 is configured to drive the laser component to emit an optical signal, and the TIA chip 510 is configured to amplify the optical signal transmitted to the silicon optical chip 500; the second heat conducting cushion block 312 is sequentially provided with a laser assembly 801, a collimating lens 802, an isolator 803 and a converging lens 804; the third heat conduction cushion block 313 is provided with a first optical fiber array 610 for covering the first optical fiber ribbon 600, and the first optical fiber ribbon passes through the lower part of the optical fiber array; third thermally conductive spacer 313 also has a second optical fiber array 710 disposed thereon for housing a second optical fiber ribbon 700 that passes thereunder. For example, a lens, specifically a focusing lens, is disposed in the light-emitting direction of the laser assembly 801, and is located between the laser assembly 801 and the silicon optical chip 500, and is used for converging light emitted by the laser chip for subsequent coupling; or two lenses, specifically a collimating lens and a converging lens, are arranged in the light emitting direction of the laser chip, light emitted by the laser chip is changed into collimated light through the collimating lens, the collimated light can keep smaller optical power attenuation in the longer distance light transmission process, and the converging lens receives the collimated light so as to converge and couple the light into the silicon optical chip. The isolator is used for preventing light emitted by the laser chip from returning to the laser chip after being emitted, so that the isolator is arranged in the light emitting direction of the laser chip.

The surface of the first heat conducting cushion block 311 is provided with a silicon optical chip 500, the surface of the second heat conducting cushion block 312 is provided with a laser component 801, the third heat conducting cushion block is used for the first optical fiber ribbon 600 to pass through, and the fourth heat conducting cushion block is used for the second optical fiber ribbon 700 to pass through, so that the heat of the silicon optical chip 500, the laser component 801, the first optical fiber ribbon 600 and the second optical fiber ribbon 700 is transmitted to the copper layer through the corresponding heat conducting cushion blocks. Based on this, one of the functions of the first, second, third and fourth heat-conducting

pads

311, 312, 313 and 314 is heat conduction, so that the heat conductivity thereof is high, and heat generated by the corresponding devices can be transferred. Meanwhile, because the thermal expansion coefficients of the circuit board and the silicon optical chip 500, the laser component 801, the first optical fiber ribbon 600 and the second optical fiber ribbon 700 are not matched with each other, which results in poor stability of the optical path, in the embodiment of the present application, the thermal expansion coefficients of the first thermal conductive pad 311, the second thermal conductive pad 312, the third thermal conductive pad 313 and the fourth thermal conductive pad 314 are respectively matched with the thermal expansion coefficients of the silicon optical chip 500, the laser component 801, the first optical fiber ribbon 600 and the second optical fiber ribbon 700, so that stability of the optical path at different temperatures can be ensured. In the embodiment of the present application, the material of each thermal pad is preferably, but not limited to, aluminum nitride ceramic or tungsten copper.

In the embodiment of the present application, the silicon optical chip 500 is disposed on the heat conducting pad of the blind slot, rather than on the upper surface of the circuit board, so that the gold wire length between the high frequency signal of the silicon optical chip 500 and the circuit board 300 can be shortened, and the transmission performance of the high frequency signal can be optimized.

Fig. 9 is a schematic view showing a structure of each structure on a circuit board of an optical module according to an embodiment of the present application; heat transfer to the copper layer surface through each heat conduction cushion with corresponding device in this application embodiment, in order to avoid inside heat to concentrate to the optical module outside with the heat transfer on copper layer surface, the cover is equipped with metal upper cover 900 above second heat conduction cushion 312 in this application embodiment. Fig. 9 shows a schematic structural diagram finally appearing after the surface of the circuit board 300 is covered with the metal upper cover 900.

The bottom end of the metal upper cover 900 extends downward to the surface of the circuit board until contacting the copper layer, specifically, a first gap is formed between the second heat conduction cushion block and the third heat conduction cushion block, and a second gap is formed between the second heat conduction cushion block and the fourth heat conduction cushion block; the metal cap 900 extends down to the first gap and the second gap and contacts with the copper layer, and in order to achieve better heat dissipation effect, the larger the contact area between the metal cap 900 and the copper layer is, the better the heat dissipation is.

The metal top cover 900 is made of a high thermal conductivity metal material, including but not limited to tungsten copper, molybdenum copper, etc.

Meanwhile, the metal upper cover 900 may be used to protect the laser assembly 801, the collimating lens 802, the isolator 803, and the condensing lens 804 from being contaminated or damaged.

The first heat conduction cushion block and the second heat conduction cushion block are arranged to transfer heat generated by the silicon optical chip and the laser assembly to the copper layer, and then the heat on the surface of the copper layer is transferred to the shell of the optical module through the metal upper cover, so that the internal heat dissipation of the optical module is convenient to realize, and the internal heat of the optical module is prevented from being accumulated in a centralized mode.

The metal top cover 900 can prevent heat from being excessively concentrated on the copper layer and not being dissipated, and the heat inside the optical module can be transferred to the outside of the optical module through the metal top cover 900.

Fig. 10 is a schematic diagram illustrating a relative position relationship between the metal cover 900 and the circuit board 300; as shown in fig. 10, the protruding end 902 at one end of the metal top cover 900 is connected across the circuit board 300, so as to achieve a better fixed connection with the circuit board 300.

Fig. 11 and 12 are perspective views of the metal upper cover 900, and as can be seen from fig. 11 and 12, the metal upper cover 900 includes a notch 901, a protruding end 902, and a cavity 903.

The gap 901 is used for avoiding a signal pad, the protruding end 902 is bridged on the circuit board, that is, the circuit board 300 supports the protruding end 902 to further support the metal upper cover 900, and the cavity 903 is used for covering each device on the second heat conduction cushion block.

In the embodiment of the present application, in order to realize the electrical connection between the silicon optical chip 500 and the circuit board 300, the first signal pad 330 is disposed on the surface of the copper layer of the blind slot, and the first signal pad 330 is used for gold wire bonding connection between the silicon optical chip 500 and the circuit board 300.

In the embodiment of the present application, in order to avoid the first signal pad 330, a notch 901 is formed at one end of the metal upper cover 900 close to the first signal pad 330, and the notch 901 just exposes the first signal pad 330 without being covered, so that the gold wire bonding connection between the silicon optical chip 500 and the circuit board 300 is facilitated.

Fig. 13 is a first schematic diagram illustrating a relative relationship between a signal pad of an optical module and other structures according to an embodiment of the present application; fig. 14 is a second schematic diagram illustrating a relative relationship between a signal pad of an optical module and other structures according to an embodiment of the present application; fig. 15 is a third schematic diagram illustrating a relative relationship between a signal pad of an optical module and another structure according to an embodiment of the present application; fig. 16 is a fourth schematic diagram illustrating a relative relationship between a signal pad of an optical module and other structures according to an embodiment of the present application; FIGS. 14-16 are partial schematic views of selected structures corresponding to one of the blind grooves, i.e., 400 optical module structures; similarly, the 800G optical module structure adaptability is applicable.

As can be seen from fig. 13-16, the relative position relationship between the first signal pad 330 and the silicon optical chip 500, the metal upper cover 900, etc. each structure is designed such that the first signal pad 330 is exposed and not covered, which facilitates the gold wire bonding connection between the silicon optical chip 500 and the circuit board 300.

Fig. 17 is a schematic diagram illustrating a gold wire connection of a silicon optical chip of an optical module according to an embodiment of the present application; as shown in fig. 17, one end of the silicon optical chip 500 is directly connected to the circuit board 300 by wire bonding, and the other end is connected to the first signal pad 330 by wire bonding to realize gold wire bonding between the silicon optical chip 500 and the circuit board 300.

In summary, the first signal pad 330 is provided in the embodiment of the present application for electrical connection between the silicon optical chip 500 and the circuit board 300; the circuit board surface is equipped with blind groove in the embodiment of this application, blind groove surface is equipped with the copper layer, the copper layer surface is equipped with each heat conduction cushion, each heat conduction cushion surface is equipped with silicon optical chip, laser assembly isotructure, still be equipped with the metal upper cover simultaneously, silicon optical chip like this, the heat that laser assembly isotructure produced passes through heat conduction cushion and transmits to the copper layer surface at the during operation, the heat on copper layer surface passes through the outside that the metal upper cover transmitted to the optical module, and then distribute away the inside heat of optical module, thereby avoid thermal piling up the normal work of guaranteeing the optical module.

On the other hand, in the embodiment of the application, since the TIA chip 510 and the Driver chip 520 are flip-chip bonded on the silicon optical chip 500, namely, the side of the TIA chip 510 and the Driver chip 520 for placing electronic components faces the silicon optical chip 500, the side of the TIA chip 510 and the Driver chip 520 for placing electronic components is defined as the front side of the TIA chip 510 and the Driver chip 520, the side opposite to the front side is defined as the back side, the back surfaces of the TIA chip 510 and the Driver chip 520 are closely adjacent to the housing of the optical module, specifically, the upper housing of the optical module, in order to achieve heat dissipation of the TIA chip 510 and the Driver chip 520 in this embodiment of the present application, in this application, heat transfer may be performed between the TIA chip 510 and the upper housing of the optical module through a heat conduction column, heat transfer may also be performed by filling a heat conduction glue between the TIA chip 510 and the upper housing of the optical module, and the Driver chip 520 may also perform heat transfer through the heat conduction column or the heat conduction glue.

On the one hand, this application sets up the blind groove, to the more high transmission rate optical module of electronic component quantity like this, can be with the circuit board lower surface that electronic component design corresponds in blind groove department, and can be used for the circuit between the circuit board inlayer to walk the line between blind groove bottom to the circuit board lower surface.

Meanwhile, the first heat conduction cushion block and the second heat conduction cushion block are arranged to transfer heat generated by the silicon optical chip and the laser assembly to the copper layer, and then the heat on the surface of the copper layer is transferred to the shell of the optical module through the metal upper cover, so that heat dissipation inside the optical module is facilitated, and the heat inside the optical module is prevented from being accumulated in a centralized mode.

Simultaneously, can carry out heat transfer through the heat conduction post between TIA chip and the optical module upper housing in this application, also can fill heat-conducting glue and carry out heat transfer between TIA chip and the optical module upper housing gap, Driver chip can carry out heat transfer through heat conduction post or heat-conducting glue equally.

Meanwhile, in the embodiment of the present application, the thermal expansion coefficients of the first thermal conductive cushion block, the second thermal conductive cushion block, the third thermal conductive cushion block and the fourth thermal conductive cushion block are respectively matched with the thermal expansion coefficients of the silicon optical chip, the laser component, the first optical fiber ribbon and the second optical fiber ribbon, so that the stability of the optical path at different temperatures can be ensured.

Therefore, the light module heat dispersion and the light path stability that this application provided are all better.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.

Claims

1. A light module, comprising:

2. The optical module of claim 1, wherein the blind slot receives the silicon photonic chip and the laser assembly, an upper surface of the silicon photonic chip is flush with an upper surface of the circuit board, and an upper surface of the laser assembly is flush with an upper surface of the circuit board.

3. The optical module of claim 1, wherein the circuit board comprises a ground layer and a signal layer, the copper layer is connected to the ground layer by a via, and the signal pad is connected to the signal layer by a via.

4. The optical module of claim 1, wherein the blind slot surface is further provided with a third thermally conductive pad and a fourth thermally conductive pad, the third thermally conductive pad is provided with a first optical fiber array, and the fourth thermally conductive pad is provided with a second optical fiber array;

the light module further includes:

a first fiber optic ribbon traversing the first array of optical fibers;

a second fiber optic ribbon passing through the second array of optical fibers.

5. The optical module of claim 4, wherein the second thermally conductive pad has a first gap with the third thermally conductive pad and a second gap with the fourth thermally conductive pad;

the metal cap extends down to the first and second gaps and contacts the copper layer.

6. The optical module of claim 4, wherein the coefficients of thermal expansion of the first, second, third, and fourth thermally conductive spacers match the coefficients of thermal expansion of the silicon optical chip, the laser assembly, the first optical fiber ribbon, and the second optical fiber ribbon, respectively.

7. The optical module of claim 4, wherein the signal pad is located between the second and fourth thermal pads and near the silicon optical chip, and is configured for gold wire connection between the silicon optical chip and the circuit board.

8. The optical module of claim 1, wherein the metal upper cover comprises a notch, a protruding end, and a cavity;

the notch is used for avoiding the signal bonding pad, the protruding end is bridged on the circuit board, and the cavity is used for covering the devices on the second heat conduction cushion block.

9. The optical module of claim 1, wherein a TIA chip and a Driver chip are disposed on a surface of the silicon optical chip, a thermal conductive adhesive is filled between the TIA chip and a housing of the optical module, and a thermal conductive adhesive is filled between the Driver chip and the housing of the optical module.

10. The optical module of claim 1, wherein a collimating lens, an isolator and a converging lens are sequentially arranged between the laser component and the silicon optical chip.