optical module

Abstract

An optical module (200) includes a circuit board (300) and a laser chip (311). The laser chip (311) is disposed on the circuit board (300) and is used to emit optical signals. The surface of the circuit board (300) has a heating area (3311) located below the laser chip (311) for heating the laser chip (311). The heating area (3311) is formed by etching the surface of the circuit board (300). A heat-conducting layer (3003) is disposed on the circuit board (300) and is located between the laser chip (311) and the heating area (3311). The bottom surface of the heat-conducting layer (3003) is connected to the heating area (3311), and the top surface of the heat-conducting layer (3003) is connected to the laser chip (311) for transmitting optical signals. Thermal conduction; or, the circuit board (300) has a through hole (302), and a first copper cladding layer (303) is formed on the side of the through hole (302); a support portion (301) is provided in the through hole (302); the support portion (301) includes a first thermally conductive layer (3012) and a heating device (330), and the edge of the first thermally conductive layer (3012) is spaced from the edge of the first copper cladding layer (303); the laser chip (311) is disposed on the first thermally conductive layer (3012); the heating device (330) is disposed on the first thermally conductive layer (3012) and located on the side of the laser chip (311); the heating device (330) is electrically connected to the circuit board (300) for heating the laser chip (311) at low temperature to maintain the working performance of the laser chip (311).

Description

optical module

[0001] This application claims priority to Chinese Patent Application No. 202423198195.3, filed on December 24, 2024; and priority to Chinese Patent Application No. 202422976739.8, filed on December 3, 2024; the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of optical fiber communication technology, and in particular to an optical module. Background Technology

[0003] With the development of new business and application models such as cloud computing, mobile internet, and video, the advancement of optical communication technology has become increasingly important. In optical communication technology, the optical module is the tool for converting between photoelectric signals and signals, and it is one of the key components in optical communication equipment. Furthermore, with the evolving needs of optical communication technology, the transmission rate of optical modules is continuously increasing. Summary of the Invention

[0004] This disclosure provides an optical module, including:

[0005] A circuit board and a laser chip, wherein the laser chip is disposed on the circuit board for emitting optical signals;

[0006] The circuit board has a heating zone on its surface, located below the laser chip, for heating the laser chip; the heating zone is formed by etching the surface of the circuit board; a thermally conductive layer is disposed on the circuit board, located between the laser chip and the heating zone, with its bottom surface connected to the heating zone and its top surface connected to the laser chip, for conducting heat; or...

[0007] The circuit board has through holes, and a first copper plating layer is formed on the side of the through holes; a support portion is disposed in the through holes; the support portion includes a first thermally conductive layer and a heating device, and the edge of the first thermally conductive layer is spaced from the edge of the first copper plating layer; the laser chip is disposed on the first thermally conductive layer; the heating device of the laser chip is disposed on the first thermally conductive layer and located on the side of the laser chip; the heating device is electrically connected to the circuit board and is used to heat the laser chip at low temperatures.

[0008] This disclosure also provides an optical module, including:

[0009] A circuit board having through holes; a first copper plating layer is formed on the top surface of the circuit board, the first copper plating layer being located on the side of the through holes; a support portion is provided within the through holes; the support portion includes:

[0010] A heat-resistant layer, wherein the thermal conductivity of the heat-resistant layer is less than that of the circuit board;

[0011] A first thermally conductive layer is located above the thermally insulating layer, and the thermal conductivity of the first thermally conductive layer is greater than that of the thermally insulating layer; the edge of the first thermally conductive layer is spaced from the edge of the first copper-clad layer.

[0012] The laser is disposed on the first heat-conducting layer;

[0013] A driver chip is disposed on the first copper layer; the driver chip is electrically connected to the circuit board and electrically connected to the laser.

[0014] A heating device is disposed on the first thermally conductive layer and located on the side of the laser away from the driving chip; the heating device is electrically connected to the circuit board and is used to heat the laser at low temperatures.

[0015] This disclosure also provides an optical module, including:

[0016] Circuit board;

[0017] A laser chip, mounted on the circuit board, is used to emit optical signals;

[0018] The surface layer of the circuit board has:

[0019] A heating zone, located below the laser chip, is used to heat the laser chip; the heating zone is formed by etching the surface layer of the circuit board.

[0020] The circuit board is provided with:

[0021] A thermally conductive layer is located between the laser chip and the heating area, with its bottom surface connected to the heating area and its top surface connected to the laser chip, for conducting heat.

[0022] The heat-conducting layer is non-conductive and is directly connected to the heating zone; or, the heat-conducting layer is conductive and an insulating layer is provided between the heat-conducting layer and the heating zone, with the top surface of the insulating layer connected to the bottom surface of the heat-conducting layer and the bottom surface of the insulating layer connected to the heating zone. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments of this disclosure will be briefly introduced below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual flow of the method, the actual timing of the signals, etc. involved in the embodiments of this disclosure.

[0024] Figure 1 is a partial structural diagram of an optical communication system according to some embodiments;

[0025] Figure 2 is a partial structural diagram of a host computer according to some embodiments;

[0026] Figure 3A is a structural diagram of an optical module according to some embodiments;

[0027] Figure 3B is a structural diagram of an optical module according to some embodiments;

[0028] Figure 4A is an exploded view of an optical module according to some embodiments;

[0029] Figure 4B is an exploded view of an optical module according to some embodiments;

[0030] Figure 5 is a cross-sectional view of the internal structure of an optical module according to some embodiments;

[0031] Figure 6 is an exploded view of the internal structure of an optical module according to some embodiments;

[0032] Figure 7 is a partially enlarged view of the internal structure of an optical module according to some embodiments;

[0033] Figure 8 is a partial enlarged view of a circuit board of an optical module according to some embodiments;

[0034] Figure 9 is a structural diagram of a laser chip according to some embodiments;

[0035] Figure 10 is a partial cross-sectional view of the internal structure of an optical module according to some embodiments;

[0036] Figure 11 is another partial cross-sectional view of the internal structure of an optical module according to some embodiments;

[0037] Figure 12 is a schematic diagram of the internal structure of an optical module according to some embodiments;

[0038] Figure 13 is another schematic diagram of the internal structure of an optical module according to some embodiments;

[0039] Figure 14A is an exploded view of a lens assembly and circuit board according to some embodiments;

[0040] Figure 14B is a magnified view of a portion of point A in Figure 14A;

[0041] Figure 15A is a partial schematic diagram of an optical module according to some embodiments;

[0042] Figure 15B is a partial schematic diagram of an optical module according to some embodiments;

[0043] Figure 15C is a partial schematic diagram of an optical module according to some embodiments;

[0044] Figure 16 is a partial schematic diagram of the bottom surface of a circuit board according to some embodiments;

[0045] Figure 17 is a structural diagram of a heating device according to some embodiments;

[0046] Figure 18A is a diagram showing the usage state of a support according to some embodiments;

[0047] Figure 18B is a second usage diagram of a support portion according to some embodiments;

[0048] Figure 19A is a performance test diagram of a circuit board without a support and heating component according to some embodiments;

[0049] Figure 19B is a performance test diagram of a circuit board with a support and a heating element provided according to some embodiments. Detailed Implementation

[0050] The embodiments of this disclosure will now be described clearly and in detail with reference to the accompanying drawings. However, the described embodiments are merely some, and not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.

[0051] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open and inclusive, meaning "including, but not limited to"; the terms "first" and "second" should not be construed as indicating or implying relative importance or indicating an upper limit on the number; the term "multiple" means two or more; the term "connection" should be interpreted broadly, for example, "connection" can be a fixed connection, a detachable connection, or an integral part, and can be a direct connection or an indirect connection through an intermediate medium; the use of the terms "applicable to" or "configured to" implies open and inclusive language, which does not exclude applicability to or configuration to devices performing additional tasks or steps; descriptions such as "parallel," "perpendicular," "identical," "consistent," and "aligned" are not limited to absolute mathematical theoretical relationships, but also include acceptable error ranges arising in practice, and differences based on the same design concept but due to manufacturing reasons.

[0052] In optical communication technology, to establish information transmission between information processing devices, information is loaded onto light, and the speed of light propagation is used to transmit the information. This light carrying information is called an optical signal. When optical signals are transmitted in optical information transmission equipment, optical power loss can be reduced, enabling long-distance transmission of optical signals. At the same time, the cost of optical information transmission equipment such as optical fibers is lower than that of electrical information transmission equipment such as copper wires. Therefore, optical communication technology can achieve high-speed, long-distance, and low-cost information transmission.

[0053] Information processing equipment typically includes optical network units (ONUs), gateways, routers, switches, mobile phones, computers, servers, tablets, televisions, etc., while optical information transmission equipment typically includes optical fibers and optical waveguides. Information processing equipment can only recognize and process electrical signals, while optical communication technology uses optical signals for transmission, requiring optical modules to convert between optical and electrical signals.

[0054] An optical module enables the conversion between optical signals and electrical signals between information processing equipment and optical information transmission equipment. In some embodiments, at least one of the optical signal input or output terminals of the optical module is connected to an optical fiber, and at least one of the electrical signal input or output terminals of the optical module is connected to an optical network terminal. A first optical signal from the optical fiber is transmitted to the optical module, which converts the first optical signal into a first electrical signal and transmits the first electrical signal to the optical network terminal. A second electrical signal from the optical network terminal is transmitted to the optical module, which converts the second electrical signal into a second optical signal and transmits the second optical signal to the optical fiber.

[0055] Since multiple information processing devices can transmit information via electrical signals, at least one of these devices needs to be directly connected to the optical module, rather than all of them. Here, the information processing device directly connected to the optical module is also referred to as the host computer of the optical module. Furthermore, the optical signal input or output terminal of the optical module is called the optical port, and the electrical signal input or output terminal is called the electrical port.

[0056] Figure 1 is a partial structural diagram of an optical communication system according to some embodiments. As shown in Figure 1, the optical communication system mainly includes a remote information processing device 1000, a local information processing device 2000, a host computer 100 for optical modules, an optical module 200, an optical fiber 101, and a network cable 103, wherein the optical fiber 101 is an optical information transmission device, and the network cable 103 is an electrical information transmission device.

[0057] In some embodiments, one end of the optical fiber 101 extends toward the remote information processing device 1000, and the other end of the optical fiber 101 is connected to the optical module 200 through the optical port of the optical module 200. The optical signal can undergo total internal reflection in the optical fiber 101, and the propagation of the optical signal in the direction of total internal reflection can almost maintain the original optical power. The optical signal undergoes multiple total internal reflections in the optical fiber 101 to transmit the optical signal from the remote information processing device 1000 to the optical module 200, or to transmit the optical signal from the optical module 200 to the remote information processing device 1000, thereby realizing long-distance information transmission based on low power loss.

[0058] The optical communication system includes one or more optical fibers 101. In some embodiments, the optical fiber 101 is detachably connected to the optical module 200; in some embodiments, the optical fiber 101 is non-detachably connected to the optical module 200.

[0059] The host computer 100 is configured to provide data signals to the optical module 200, or receive data signals from the optical module 200, or monitor or control the working status of the optical module 200.

[0060] The host computer 100 includes a housing for accommodating the optical module 200, and an optical module interface 102 disposed on the housing. The optical module 200 is inserted into the housing through the optical module interface 102 to establish a unidirectional or bidirectional electrical signal connection between the host computer 100 and the optical module 200.

[0061] The host computer 100 also includes an external power interface that can connect to an electrical signal network. In some embodiments, the external power interface includes a Universal Serial Bus (USB) interface or a network cable interface 104. The network cable interface 104 is configured to connect a network cable 103 to establish a unidirectional or bidirectional electrical signal connection between the host computer 100 and the network cable 103.

[0062] One end of the network cable 103 is connected to the local information processing device 2000, and the other end is connected to the host computer 100, so as to establish an electrical signal connection between the local information processing device 2000 and the host computer 100 through the network cable 103. In some embodiments, a third electrical signal emitted by the local information processing device 2000 is transmitted to the host computer 100 through the network cable 103. The host computer 100 generates a second electrical signal based on the third electrical signal. The second electrical signal from the host computer 100 is transmitted to the optical module 200. The optical module 200 converts the second electrical signal into a second optical signal and transmits the second optical signal to the optical fiber 101. The second optical signal is transmitted in the optical fiber 101 to the remote information processing device 1000.

[0063] In some embodiments, a first optical signal from a remote information processing device 1000 is transmitted through an optical fiber 101, and the first optical signal from the optical fiber 101 is transmitted to an optical module 200. The optical module 200 converts the first optical signal into a first electrical signal, and transmits the first electrical signal to a host computer 100. The host computer 100 generates a fourth electrical signal based on the first electrical signal and transmits the fourth electrical signal to a local information processing device 2000.

[0064] In some embodiments, the optical module is a tool for converting optical signals to electrical signals. During the conversion process, the information does not change, but the encoding or decoding method of the information changes.

[0065] In addition to optical network terminals, the host computer 100 also includes optical line terminals (OLTs), optical network equipment (ONTs), or data center servers.

[0066] Figure 2 is a partial structural diagram of a host computer according to some embodiments. To clearly show the connection relationship between the optical module 200 and the host computer 100, Figure 2 only shows the structure of the host computer 100 related to the optical module 200. As shown in Figure 2, in some embodiments, the host computer 100 further includes a PCB circuit board 105 disposed in a receiving cavity, and a cage 106 disposed on the surface of the PCB circuit board 105; the optical module 200 is inserted into the cage 106 and fixed by the cage 106;

[0067] In some embodiments, a heat sink 107 is provided on the cage 106 to dissipate heat for the optical module; in some embodiments, the heat sink 107 has protruding structures such as fins to increase the heat dissipation area.

[0068] In some embodiments, an electrical connector is provided inside the cage 106, which is configured to connect to the electrical port of the optical module 200.

[0069] In some embodiments, the optical module 200 is inserted into the cage 106 of the host computer 100, and the cage 106 fixes the optical module 200. The heat generated by the optical module 200 is conducted to the cage 106 and then diffused through the heat sink 107.

[0070] In some embodiments, the optical module 200 is inserted into the cage 106 of the host computer 100, and the electrical port of the optical module 200 is connected to the electrical connector inside the cage 106, thereby establishing an electrical signal connection between the optical module 200 and the host computer 100.

[0071] In some embodiments, the optical port of the optical module 200 is connected to the optical fiber 101, thereby enabling the optical module 200 to establish an optical signal connection with the optical fiber 101.

[0072] Figure 3A is a structural diagram of an optical module according to some embodiments, and Figure 3B is a structural diagram of an optical module according to some embodiments. Figure 4A is an exploded view of an optical module according to some embodiments; Figure 4B is an exploded view of an optical module according to some embodiments. As shown in Figures 3A to 4B, in some embodiments, the optical module 200 includes a shell, which includes an upper shell 201 and a lower shell 202. The upper shell 201 covers the lower shell 202, forming two openings 204 and 205, one of which is an electrical port and the other is an optical port. In some embodiments, the shell forms one opening that serves as both an electrical port and an optical port.

[0073] In some embodiments, the upper housing 201 and the lower housing 202 are made of metal materials, which facilitates electromagnetic shielding and heat dissipation.

[0074] The assembly method of combining the upper housing 201 and the lower housing 202 facilitates the installation of the circuit board 300, lens assembly 400 and optical transceiver component 900 into the housing. The upper housing 201 and the lower housing 202 can encapsulate and protect the above-mentioned devices.

[0075] The direction of the line connecting the two openings 204 and 205 can be consistent with or inconsistent with the length direction of the optical module 200. For example, opening 204 is located at the end of the optical module 200 (right end in Figure 3), and opening 205 is also located at the end of the optical module 200 (left end in Figure 3). Alternatively, opening 204 is located at the end of the optical module 200, while opening 205 is located on the side of the optical module 200.

[0076] In some embodiments, the lower housing 202 includes a base plate 2021 and two lower side plates 2022 located on both sides of the base plate 2021 and perpendicular to the base plate 2021; the upper housing 201 includes a cover plate 2011, which covers the two lower side plates 2022 of the lower housing 202 to form the aforementioned housing.

[0077] In some embodiments, the lower housing 202 includes a base plate 2021 and two lower side plates 2022 located on both sides of the base plate 2021 and perpendicular to the base plate 2021; the upper housing 201 includes a cover plate 2011 and two upper side plates located on both sides of the cover plate 2011 and perpendicular to the cover plate 2011. The two upper side plates and the two lower side plates 2022 are combined to realize that the upper housing 201 covers the lower housing 202.

[0078] As shown in Figures 3A to 4B, in some embodiments, the optical module includes a circuit board 300 disposed within a housing. The circuit board 300 includes circuit traces, electronic components, and chips. The electronic components and chips are connected according to the circuit design through the circuit traces to achieve functions such as power supply, electrical signal transmission, and grounding. Electronic components may include, for example, capacitors, resistors, transistors, and metal-oxide-semiconductor field-effect transistors (MOSFETs). Chips may include microcontroller units (MCUs), laser driver chips, transimpedance amplifiers (TIAs), limiting amplifiers (LAs), clock and data recovery chips (CDRs), power management chips, and digital signal processing (DSP) chips.

[0079] In some embodiments, the circuit board includes a rigid circuit board, which, due to its relatively rigid material, can also serve a load-bearing function, such as being able to stably support the aforementioned electronic components and chips; the rigid circuit board can also be inserted into an electrical connector in the cage 106 of the host computer 100.

[0080] In some embodiments, the circuit board further includes a flexible circuit board, which can be used independently or in conjunction with a rigid circuit board.

[0081] In some embodiments, the circuit board further includes gold fingers formed on its end surface, the gold fingers consisting of a plurality of independent pins.

[0082] In some implementations, the gold fingers are located on one side of the surface of the circuit board 300 (e.g., the upper surface shown in Figure 4A or Figure 4B); in other implementations, the gold fingers are located on the upper and lower surfaces of the circuit board 300 to provide a greater number of pins, thereby adapting to applications with high pin count requirements.

[0083] In some implementations, the gold fingers of the circuit board extend from the electrical port and are inserted into the electrical connector of the host computer 100; the circuit board is inserted into the cage 106, and the gold fingers are connected to the electrical connector inside the cage 106. The gold fingers are configured to establish an electrical connection with the host computer, enabling electrical connection functions such as power supply, grounding, two-wire synchronous serial (Inter-Integrated Circuit, I2C) signal transmission, and data signal transmission.

[0084] In some embodiments, the optical module 200 further includes an unlocking component 600 located outside its housing. The unlocking component 600 is configured to establish a fixed connection between the optical module 200 and the host computer, or to release the fixed connection between the optical module 200 and the host computer.

[0085] For example, the unlocking component 600 is located on the outside of the two lower side plates 2022 of the lower housing 202, and includes a locking component that matches the cage 106 of the host computer 100. When the optical module 200 is inserted into the cage 106, the locking component of the unlocking component 600 fixes the optical module 200 in the cage 106; when the unlocking component 600 is pulled, the locking component of the unlocking component 600 moves accordingly, thereby changing the connection relationship between the locking component and the host computer, so as to release the fixation between the optical module 200 and the host computer, thereby allowing the optical module 200 to be pulled out of the cage 106.

[0086] In some embodiments, the optical module 200 further includes an optical transceiver 900 located within a housing. The optical transceiver 900 can be placed on the circuit board 300. The optical transceiver 900 has both transmitting and receiving functions to enable the transmission and reception of optical signals.

[0087] In some embodiments, the lens assembly 400 is connected to the circuit board 300 and covers devices such as a light emitting chip and / or a light receiving chip. The lens assembly 400 has a transmissive surface and a reflective surface, which, in combination, adjust the transmission direction of the emitted and / or received light signals, enabling the emitted light signal generated by the light emitting chip to be output from the optical module and the light signal input to the optical module to be transmitted to the light receiving chip. The light emitting chip is such as a laser, and the light receiving chip is such as a photodetector.

[0088] In some embodiments, the lens assembly 400 is connected to the optical fiber strip 410. The optical signal generated by the optical emitting chip is transmitted to the optical fiber strip 410 through the lens assembly 400, or the optical signal input through the optical fiber strip 410 is transmitted to the lens assembly 400 and then transmitted to the optical receiving chip through the lens assembly 400.

[0089] In some embodiments, the optical module 200 may include a lens assembly 400. Of course, in some embodiments, the number of lens assemblies 400 in the optical module 200 is not limited to one, and may also include two lens assemblies 400, with a light emitting chip and / or a light receiving chip disposed below each lens assembly 400.

[0090] Figure 5 is a cross-sectional view of the internal structure of an optical module according to some embodiments. Figure 6 is an exploded view of the internal structure of an optical module according to some embodiments. As shown in Figures 4, 5 and 6, in some embodiments, an optical chip 3001 may be disposed on the circuit board 300. The optical chip 3001 may be a laser chip 311 and / or an optical receiver chip 312, and the laser chip 311 and the optical receiver chip 312 may be fixed side by side on the circuit board 300.

[0091] A light matching chip 3002 can be disposed on the circuit board 300. The light matching chip 3002 can be a bare chip such as a laser driver chip 321 and / or a TIA chip 322. The bare chip is bonded to the circuit board 300 with silver paste, which serves to fix and dissipate heat. Then, the bare chip and the circuit board 300 are connected by gold wire bonding.

[0092] Since the optical chip 3001 is attached to the circuit board 300, its light-emitting or light-incident surface is located on the top surface of the optical chip 3001. Thus, the beam emitted by the laser chip is perpendicular to the circuit board 300, and the beam received by the optical receiving chip is also perpendicular to the circuit board 300. However, the optical fiber 101 connecting the optical module is parallel to the circuit board 300. It is necessary to change the transmission direction of the beam emitted by the laser chip and the external beam transmitted to the optical receiving chip. Therefore, the beam emitted by the laser chip can be changed by the optical transceiver component 900, so that the beam emitted by the laser chip is reflected by the lens assembly, and the reflected beam is parallel to the circuit board 300, so as to facilitate the coupling of the reflected beam into the optical fiber. The received beam transmitted by the external optical fiber is reflected by the lens assembly, and the reflected beam is perpendicular to the circuit board 300, so as to facilitate its reception by the optical receiving chip.

[0093] In some embodiments, the optical transceiver component 900 may include a lens assembly 901. The lens assembly 901 covers the optical matching chip 3002 and the optical chip 3001 on the circuit board 300, so as to place the optical matching chip 3002 and the optical chip 3001 within the covering cavity formed by the lens assembly 901 and the circuit board 300, thereby shortening the distance between the optical matching chip 3002 and the optical chip 3001, and further shortening the wire bonding distance between the optical matching chip 3002 and the optical chip 3001. For example, the lens assembly 901 covers the TIA 322 and the optical receiving chip 312, shortening the wire bonding distance between the TIA 322 and the optical receiving chip 312; the lens assembly 901 covers the laser driver chip 321 and the laser chip 311, shortening the wire bonding distance between the laser driver chip 321 and the laser chip 311.

[0094] The optical transceiver unit 900 may include an optical fiber support 902. The optical fiber support 902 may be connected to the side of the lens assembly 901 facing the optical port.

[0095] In some embodiments, the lens assembly 901 may be recessed inward toward the circuit board 300 to form a cover groove. The cover groove may be provided with a first lens 9121. The first lens 9121 may be located directly above the optical chip 3001 to achieve collimation or focusing of the light beam.

[0096] The lens assembly 901, with its side facing away from the circuit board 300 recessed inward, can form an optical aperture slot. The sidewall of the optical aperture slot can be a reflective surface 9131. The reflective surface 9131 can be located above the first lens 9121 to achieve the reflection of the light beam.

[0097] A second lens 9142 may be provided on the side of the lens assembly 901 facing the fiber optic bracket 902 to achieve beam focusing or collimation.

[0098] Laser chip 311 emits a diverging beam, which is then collimated by first lens 9121. The collimated beam is reflected by reflector 9131, and the reflected collimated beam is then converted into a converging beam by second lens 9142 and coupled to an optical fiber. The beam is then transmitted through the optical fiber to the outside of the optical module, thus transmitting the optical signal. The beam outside the optical module is transmitted through the optical fiber to second lens 9142, where it is collimated. The collimated beam is reflected by reflector 9131, and the reflected collimated beam is transmitted vertically downwards. After being coupled by first lens 9121, it is vertically incident on optical receiver chip 312, thus receiving the optical signal.

[0099] The luminescence performance of laser chips is highly sensitive to temperature, and its performance deteriorates at low temperatures. To address this issue, in some embodiments, heating resistors are placed around the laser chip and fixed to the surface of the circuit board using thermally conductive adhesive. The heat generated by the heating resistors is conducted through the thermally conductive silver paste to the surface of the circuit board, and then to the area around the laser chip, thus heating the laser chip and reducing the probability of it being at low temperatures, thereby ensuring its luminescence performance.

[0100] When the thermally conductive adhesive is conductive, direct contact between the adhesive and the electrodes can cause a short circuit. Therefore, in some embodiments, when the thermally conductive adhesive is conductive, electrodes are provided on the upper surface of the heating resistor, while other surfaces are free of electrodes, to reduce contact between the electrodes and the thermally conductive silver paste, thereby reducing electrode short circuits.

[0101] To heat the laser chip, in some embodiments, the surface of the circuit board has a heating zone, and the laser chip is disposed above the heating zone. The heating zone and the laser chip are connected by thermally conductive adhesive, which forms a thermally conductive layer. The heat generated by the heating zone is directly conducted to the laser chip through the thermally conductive layer. This not only heats the laser chip, reducing the probability of the laser chip being at a low temperature to ensure its light-emitting performance, but also reduces the heat transfer path and improves heating efficiency.

[0102] When the thermally conductive adhesive is conductive, direct contact between the thermally conductive adhesive and the heating area can cause a short circuit. Therefore, in some embodiments, when the thermally conductive adhesive is conductive, an insulating layer is provided between the heating area and the thermally conductive layer. The insulating layer can electrically isolate the heating area and the thermally conductive layer, reducing the current from the heating area entering the thermally conductive area, thereby reducing short circuits in the heating area.

[0103] Figure 7 is a partially enlarged view of the internal structure of an optical module according to some embodiments. Figure 8 is a partially enlarged view of a circuit board of an optical module according to some embodiments. As shown in Figures 7 and 8, in some embodiments, the circuit board 300 may include an upper surface layer 331. The upper surface layer 331 may have a heating area 3311. A laser chip 311 may be placed above the heating area 3311 so that the heating area 3311 can heat the laser chip 311.

[0104] In some embodiments, a reference ground 350 may be provided on the upper surface layer 331. One end of the heating area 3311 may be connected to the reference ground 350. The reference ground 350 may be a grounding area located on the upper surface layer 331, or it may be a grounding layer located on the middle layer of the circuit board 300.

[0105] In some embodiments, an adjustable voltage source 360 ​​may be provided on the upper surface layer 331. The adjustable voltage source 360 ​​may be connected to the other end of the heating zone 3311 to provide voltage to the heating zone 3311 so that the heating zone 3311 can generate heat.

[0106] When a voltage is applied to a resistor, current flows through the resistor, generating heat during the process. Since the heating zone 3311 also functions as a resistor, when a voltage is applied to the heating zone 3311, current flows through the heating zone 3311, generating heat during the process.

[0107] In some embodiments, the heating region 3311 can be formed by etching the metal region of the upper surface layer 331. The metal region of the upper surface layer 331 is etched along at least one etch line to give the metal region at least one insulating region, thereby changing the metal region from a single piece of metal into multiple pieces of metal to form the heating region 3311, resulting in a simple structure. Compared to the unetched metal region, the cross-sectional area of ​​the heating region 3311 is reduced, its length is increased, and its resistivity is increased. The resistivity of the heating region 3311 is greater than that of other regions surrounding the heating region 3311, causing the heating region 3311 to generate a large amount of heat when current passes through it, thus improving the heat generation efficiency.

[0108] As shown in Figure 8, the current moves in the direction indicated by the arrow (→) within the heating zone 3311, generating heat.

[0109] In some embodiments, the heating region 3311 is connected to the reference ground 350 and the adjustable voltage source 360. A gap may exist between the first region 3314 of the heating region 3311 and the body region 3312 of the upper surface layer 331, meaning the first region 3314 of the heating region 3311 is not connected to the body region 3312 of the upper surface layer 331. The first region 3314 is the region of the heating region 3311 excluding the region connected to the reference ground 350 and the adjustable voltage source 360. The gap between the first region 3314 and the body region 3312 of the upper surface layer 3311 separates the first region 3314 of the heating region 3311 from the body region 3312, reducing the current flowing from the heating region 3311 to the body region 3312 and preventing current crosstalk from affecting other devices on the circuit board 300.

[0110] In some embodiments, there may be a gap between the heating zone 3311 and the body region 3312 of the upper surface layer 331, and the heating zone 3311 and the body region 3312 are connected by wire bonding. This gap between the heating zone 3311 and the body region 3312 of the upper surface layer 331 can separate the heating zone 3311 from the body region 3312, reducing the current flowing from the heating zone 3311 to the body region 3312 and preventing current crosstalk from affecting other devices on the circuit board 300.

[0111] As shown in Figure 8, the heating zone 3311 may include a first sub-heating zone 33111 and a second sub-heating zone 33112. A first insulating zone 33114 may be provided between the first sub-heating zone 33111 and the second sub-heating zone 33112. The first insulating zone 33114 may extend from the first boundary of the heating zone 3311 to the second boundary of the heating zone 3311, but not to the second boundary of the heating zone 3311, so that one end of the first sub-heating zone 33111 and one end of the second sub-heating zone 33112 are connected. This can extend the length of the heating zone 3311, reduce the cross-sectional area of ​​the heating zone 3311, and increase the resistivity of the heating zone 3311.

[0112] The first boundary and the second boundary of the heating zone 3311 can be set relative to each other. For example, the first boundary of the heating zone 3311 can be the upper boundary of the heating zone 3311, and the second boundary of the heating zone 3311 can be the lower boundary of the heating zone 3311, with the upper boundary and the lower boundary of the heating zone 3311 set relative to each other.

[0113] Heating region 3311 may include a third sub-heating region 33113. A second insulating region 33115 may be provided between the third sub-heating region 33113 and the second sub-heating region 33112. The second insulating region 33115 may extend from the second boundary of heating region 3311 towards the first boundary of heating region 3311, but not to the first boundary of heating region 3311, so that the other end of the second sub-heating region 33112 is connected to one end of the third sub-heating region 33113, which can further extend the length of heating region 3311 and further improve the resistivity of heating region 3311.

[0114] The end of the first sub-heating zone 33111 that is not connected to the second sub-heating zone 33112 is the first end of the first sub-heating zone 33111, and the end of the first sub-heating zone 33111 that is connected to the second sub-heating zone 33112 is the second end of the first sub-heating zone 33111. The first end of the first sub-heating zone 33111 can be connected to an adjustable voltage source 360 ​​to provide voltage to the heating zone 33111. The first end of the first sub-heating zone 33111 refers to the area between the left boundary of the heating zone 33111 and the first insulating zone 33114.

[0115] The end of the third sub-heating region 33113 that is not connected to the second sub-heating region 33112 is the first end of the third sub-heating region 33113, and the end of the third sub-heating region 33113 that is not connected to the second sub-heating region 33112 is the second end of the third sub-heating region 33113. The second end of the third sub-heating region 33113 can be connected to the reference ground 350. The second end of the third sub-heating region 33113 refers to the area between the right boundary of the heating region 3311 and the second insulating region 33115.

[0116] Figure 9 is a structural diagram of a laser chip according to some embodiments. As shown in Figure 9, in some embodiments, the laser chip 311 may include a first top surface 3113. A first positive electrode 3111 may be disposed on the first top surface 3113. The first positive electrode 3111 may be connected to the second positive electrode 3211 of the laser driver chip 321 via a first wire bonding.

[0117] The laser chip 311 may include a second top surface 3114. A first negative electrode 3112 may be disposed on the second top surface 3114. The first negative electrode 3112 may be connected to the second negative electrode 3212 of the laser driver chip 321 via a second wire bonding.

[0118] The first top surface 3113 and the second top surface 3114 are the top surfaces of different substrates, so that the first positive electrode 3111 and the first negative electrode 3112 are disposed on different top surfaces of the laser chip 311.

[0119] The first top surface 3113 and the second top surface 3114 can be flush or not.

[0120] In some embodiments, the modulation current and bias current provided by the laser driver chip 321 can be transmitted to the laser chip 311 in the form of differential signals through the first and second bonding wires, so that the laser chip 311 emits optical signals under the action of the modulation current and bias current.

[0121] Figure 10 is a partial cross-sectional view of the internal structure of an optical module according to some embodiments. Figure 11 is another partial cross-sectional view of the internal structure of an optical module according to some embodiments. As shown in Figures 10 and 11, in some embodiments, there is a gap between the body region 3312 of the upper surface layer 331 and the first region 3314 of the heating region 3311, so that the first region 3314 of the heating region 3311 is separated from the body region 3312, thereby allowing current to flow from one end of the heating region 3311 (i.e., the end near the adjustable voltage source 360) to the other end of the heating region 3311 (i.e., the end near the reference ground 350).

[0122] Alternatively, there may be a gap between the body region 3312 and the heating region 3311 of the upper surface layer 331, so that the heating region 3311 is separated from the body region 3312, thereby allowing current to flow from one end of the heating region 3311 (i.e., the end near the adjustable voltage source 360) to the other end of the heating region 3311 (i.e., the end near the reference ground 350).

[0123] In some embodiments, a thermally conductive layer 3003 can be used to connect the laser chip 311 and the heating region 3311. The top surface of the thermally conductive layer 3003 can be connected to the laser chip 311. The bottom surface of the thermally conductive layer 3003 can be connected to the heating region 3311. The thermally conductive layer 3003 can conduct heat generated by the heating region 3311 to the laser chip 311, thereby heating the laser chip 311.

[0124] In some embodiments, the width of the heat-conducting layer 3003 is greater than or equal to the width of the laser chip 311, and the length of the heat-conducting layer 3003 is greater than or equal to the length of the laser chip 311, so that as much heat as possible is conducted from the heat-conducting layer 3003 to the laser chip 311.

[0125] The thermally conductive layer 3003 can be formed of thermally conductive adhesive. When the thermally conductive adhesive is non-conductive, i.e. has insulating properties, the thermally conductive layer 3003 is also insulating. The heating zone 3311 and the laser chip 311 are directly connected through the thermally conductive layer 3003. The current in the heating zone 3311 is conducted along the heating zone 3311 and will not enter the thermally conductive layer 3003, reducing the risk of short circuits in the heating zone 3311.

[0126] Thermally conductive adhesives can be epoxy thermally conductive adhesives, silicone rubber, and thermally conductive silicone rubber. All of these materials have thermal conductivity but not electrical conductivity, so the thermally conductive layer 3003 formed by epoxy thermally conductive adhesives, silicone rubber, and thermally conductive silicone rubber can conduct heat but not electricity.

[0127] When the thermally conductive adhesive is conductive, the thermally conductive layer 3003 is also conductive. An insulating layer 340 can be provided between the heating zone 3311 and the thermally conductive layer 3003. The top surface of the insulating layer 340 can be connected to the bottom surface of the thermally conductive layer 3003. The bottom surface of the insulating layer 340 can be connected to the heating zone 3311. The insulating layer 340 can electrically isolate the heating zone 3311 from the thermally conductive layer 3003, so that the current in the heating zone 3311 is conducted along the heating zone 3311 and will not enter the thermally conductive layer 3003, thereby reducing the short circuit of the heating zone 3311.

[0128] Thermally conductive adhesives can be silver paste, copper paste, and aluminum paste. All three types of adhesives have electrical and thermal conductivity, which allows the thermally conductive layer 3003 formed by them to conduct electricity and heat.

[0129] The insulating layer 340 may be an insulating board. The insulating layer 340 may be formed by plating a metal layer on the surface of the heating zone 3311. The insulating layer 340 may be formed by depositing a material layer on the surface of the heating zone 3311.

[0130] In some embodiments, the width of the insulating layer 340 is greater than or equal to the width of the heat-conducting layer 3003, and the length of the insulating layer 340 is greater than or equal to the length of the heat-conducting layer 3003, so that the heat on the insulating layer 340 is conducted to the heat-conducting layer as much as possible.

[0131] In some embodiments, the circuit board 300 may include a lower surface layer 333. The lower surface layer 333 may be disposed correspondingly to the upper surface layer 331.

[0132] In some embodiments, the circuit board 300 may include an intermediate layer 3004. The intermediate layer 3004 may be located between the upper surface layer 331 and the lower surface layer 333. The body region 3312 of the upper surface layer 331 and the heating region 3311 are both located above the intermediate layer 3004.

[0133] Figure 12 is a schematic diagram of the internal structure of an optical module according to some embodiments. Figure 13 is another schematic diagram of the internal structure of an optical module according to some embodiments. As shown in Figures 12 and 13, in some embodiments, the adjustable voltage source 360 ​​may include an input pin 361, which can be connected to an external power supply to receive a fixed power supply voltage. The adjustable voltage source 360 ​​may include a feedback pin 363 to provide a feedback voltage. The adjustable voltage source 360 ​​may include an output pin 362. The output pin 362 may be connected to a heating zone 3311 to provide voltage to the heating zone 3311. The adjustable voltage source 360 ​​can adjust the voltage of the output pin 362 according to the feedback voltage of the feedback pin 363, so that the heating zone 3311 can generate heat according to the voltage, thereby heating the laser chip 311.

[0134] In some embodiments, an MCU may be disposed on the surface of the circuit board 300. The MCU can acquire the temperature of the laser chip 311 and output a feedback voltage to the adjustable voltage source 360 ​​based on the temperature of the laser chip 311. The MCU may include a register 374. The register 374 may store a relationship table between temperature and feedback voltage. The MCU can read the feedback voltage corresponding to the temperature of the laser chip 311 from the register 374 and output the feedback voltage.

[0135] As shown in Figure 12, in some embodiments, a temperature detector 380 may be disposed on the surface of the circuit board 300. The temperature detector 380 may be disposed on the side of the laser chip 311. The temperature detector 380 is a temperature-sensitive element whose resistance value changes with temperature. Therefore, the temperature around the temperature detector can be determined by the resistance value of the temperature detector, thereby monitoring the temperature of the laser chip 311.

[0136] The MCU can be an MCU370a. The MCU370a may include an input pin 372, which is connected to a temperature detector 380 to obtain the resistance value of the temperature detector 380. The MCU370a can calculate the actual temperature of the temperature detector 380 based on its resistance value. The MCU370a may include a register 374. Register 374 may store a table showing the relationship between temperature and feedback voltage. The MCU370a can read the feedback voltage corresponding to the temperature of the laser chip 311 from register 374 and output the feedback voltage. The MCU370a may include an output pin 371. Output pin 371 can be connected to the feedback pin 363 of the adjustable voltage source 360 ​​to output a feedback voltage to the feedback pin 363 of the adjustable voltage source 360.

[0137] As shown in Figure 13, in some embodiments, the MCU may be MCU370b. MCU370b integrates a temperature sensor 373. MCU370b can obtain the temperature of the laser chip 311 through the temperature sensor 370. MCU370b may include a register 374. Register 374 may store a table showing the relationship between temperature and feedback voltage. MCU370b can read the feedback voltage corresponding to the temperature of the laser chip 311 from register 374 and output the feedback voltage. MCU370b may include an output pin 371. Output pin 371 can be connected to the feedback pin 363 of the adjustable voltage source 360 ​​to output a feedback voltage to the feedback pin 363 of the adjustable voltage source 360.

[0138] Optical modules contain optical chips such as lasers, which are used to generate optical signals. During use, it has been found that for high-speed lasers such as single-wavelength 100G, when the optical module is in a low-temperature environment, such as 0°C, the laser's performance often degrades due to the low temperature, resulting in phenomena such as a drop in optical power, spectral shift, and reduced laser bandwidth, ultimately causing the optical module to malfunction. It's understandable that the laser, also known as a laser chip, can be understood in this way: the laser is used to emit optical signals.

[0139] In view of the above problems, in the embodiments of this application, the heating device is selectively energized to facilitate the heating device to heat the laser in low-temperature environments, maintain the laser's operating temperature, reduce the adverse effects of low-temperature environments on laser performance, and ensure the laser's working performance.

[0140] Next, the structure and working principle of the heating device for maintaining the laser's operating temperature will be explained with reference to Figures 14A to 19B.

[0141] Figure 14A is an exploded view of a lens assembly and circuit board according to some embodiments, and Figure 14B is a partial enlarged view of point A in Figure 14A. As shown in Figures 14A and 14B, in some embodiments, a driver chip 320 is disposed below the lens assembly 400, and the driver chip 320 is disposed on the circuit board 300. The driver chip 320 is electrically connected to the circuit board 300.

[0142] In some embodiments, a laser 310 is disposed on the side of the driver chip 320, located below the lens assembly 400, and is used to generate optical signals. The laser 310 is close to the driver chip 320 to reduce the distance between the drive signal output by the driver chip 320 and the laser 310. The laser 310 can be wired to the driver chip 320. Exemplarily, the laser 310 can be a laser array capable of generating multiple optical signals.

[0143] Laser 310 can be a VCSEL (Vertical Cavity Surface Emitting Laser). VCSEL lasers are based on gallium arsenide semiconductor materials and have advantages such as small size, circular output spot, low threshold current, and easy integration into large-area arrays, making them widely used in optical communication. However, during continuous use, it has been found that VCSEL lasers generally experience severe performance degradation at low temperatures, which will seriously affect the normal operation of optical modules.

[0144] In some optical modules, the laser can be placed on a thermoelectric cooler via a COC substrate. The thermoelectric cooler is placed on the surface of a circuit board 300. The negative electrode of the laser is directly soldered to the pads on the surface of the COC substrate, and the positive electrode of the laser is connected to the COC substrate via wire bonding. Heat is conducted to the laser through the thermoelectric cooler. The laser 310 needs to be positioned below the lens assembly 400 and needs to be wire bonded to the driver chip 320, making it inconvenient to heat the laser 310 via the thermoelectric cooler.

[0145] In some embodiments, a heating device 330 is disposed on the side of the laser 310. When the optical module is in a low-temperature environment, the heating device 330 is energized and generates heat. The heat generated by the heating device 330 can heat the laser 310, reducing the adverse effects of the low-temperature environment on the laser 310. The heating device 330 can be a heating resistor, etc.

[0146] In some embodiments, the laser 310 and the heating device 330 are disposed on the circuit board 300. Since the circuit board 300 is composed of multiple layers of boards and adjacent boards are bonded together with resin, the heat conduction and heat dissipation performance of the circuit board 300 is poor. Therefore, when the laser 310 is bonded to the circuit board 300, the heat generated by the heating device 330 is conducted to the laser 310 only through the circuit board 300, which will result in low heat transfer efficiency and increased energy consumption of the heating device 330.

[0147] In some embodiments, to improve the efficiency of transferring heat generated by the heating device 330 to the laser 310, a copper layer and vias are provided on the circuit board 300, the heating device 330 is disposed on the copper layer, and the copper layer surrounds the side of the laser 310. However, in use, it has been found that the temperature of the laser 310 is prone to becoming too high under high temperature conditions.

[0148] In some embodiments, a support portion 301 is formed on the circuit board 300, which supports and connects the heating device 330 and the laser 310. Heat generated by the heating device 330 is transferred to the support portion 301, which then transfers this heat to the laser 310. The support portion 301 also reduces heat transfer to other parts of the circuit board 300, minimizing heat loss from the heating device 330 and improving its heating efficiency. This helps maintain the operating temperature of the laser 310 and reduces the adverse effects of low-temperature environments on the laser 310's performance. The support portion 301 can be formed by filling the circuit board 300 with a material with low thermal conductivity. The material with low thermal conductivity can be epoxy resin, polyethylene resin, etc., whose thermal conductivity is lower than that of the circuit board 300. Therefore, in high-temperature environments, the support portion 301 can prevent heat generated by other devices on the circuit board 300 from being conducted to the laser 310, thereby reducing the excessively high temperature of the laser 310 in high-temperature environments.

[0149] In some embodiments, a photodetector 3006 may be disposed below the lens assembly 400. The photodetector 3006 is used to receive optical signals. The photodetector 3006 is located on the side of the laser 310 and is not located on the support portion 301. The photodetector 3006 may be a photodetector array capable of receiving multiple optical signals.

[0150] In some embodiments, a TIA 350 may be disposed below the lens assembly 400, and the TIA 350 is located on the side of the photodetector 3006. Exemplarily, the TIA 350 may be located on the side of the driver chip 320.

[0151] Figure 15A is a partial schematic diagram of an optical module according to some embodiments. As shown in Figure 15A, a through-hole 302 is provided on the circuit board 300. The through-hole 302 is located on the side of the driver chip 320 and is spaced from the edge of the driver chip 320. A support portion 301 is formed by filling the through-hole 302 with a material with low thermal conductivity. Exemplarily, a material with low thermal conductivity and a material with high thermal conductivity can be stacked and filled in the through-hole 302. For example, a heat-resistant layer is formed by filling the through-hole 302 with a material with low thermal conductivity, and a heat-conducting layer is formed by filling the heat-resistant layer with a material with high thermal conductivity. The heat-conducting layer connects the laser 310 and the heating device 330. A metal layer or the like can be disposed above the heat-resistant layer, and the thermal conductivity of the metal layer or the like is greater than that of the heat-resistant layer.

[0152] In some embodiments, a first copper-clad layer 303 is provided on the circuit board 300. The first copper-clad layer 303 is located at the edge of the through-hole 302, and a gap is formed between the through-hole 302 and the first copper-clad layer 303. The driver chip 320 is mounted on the first copper-clad layer 303. When the optical module 200 is in a low-temperature environment, the heating device 330 operates to ensure the operating temperature of the laser 310. The gap can reduce the heat generated by the heating device 330 from being transferred to the first copper-clad layer 303. When the optical module 200 is in a high-temperature environment, the heating device 330 does not operate. The gap can reduce the heat generated by the driver chip 320 from being transferred to the support portion 301, thereby reducing the impact of the heat generated by the driver chip 320 on the laser 310.

[0153] Figure 15B is a partial schematic diagram of an optical module according to some embodiments, and Figure 15C is a partial schematic diagram of an optical module according to some embodiments. Figures 15B and 15C illustrate a support structure. As shown in Figures 15B and 15C, in some embodiments, the support 301 includes a heat-resistant layer 3011 located within a through-hole 302. The heat-resistant layer 3011 may be formed of a material with low thermal conductivity; the thermal conductivity of the heat-resistant layer 3011 is lower than that of the main material of the circuit board 300. Exemplarily, the through-hole 302 is filled with epoxy resin to form the heat-resistant layer 3011. The heat-insulating layer 3011 can block the heat generated by the heating device 330, reduce the heat generated by the heating device 330 from being transferred to the outside of the laser 310, and facilitate the improvement of the heating efficiency of the heating device 330. The heat-insulating layer 3011 can also block the heat generated by other devices on the circuit board 300 from being transferred to the laser 310, which can reduce the impact of the heat generated by other devices on the circuit board 300 on the laser 310 under high temperature environment, and thus facilitate the control of the operating temperature of the laser 310 within a relatively stable range.

[0154] In some embodiments, the support portion 301 may include a first thermally conductive layer 3012, which is located on top of the heat-insulating layer 3011. The first thermally conductive layer 3012 may be formed by covering the top of the heat-insulating layer 3011 with a metal, such as copper or gold, but the first thermally conductive layer 3012 is not limited to being formed with a metal. The first thermally conductive layer 3012 is not connected to the first copper-clad layer 303. The laser 310 and the heating device 330 are disposed on the first thermally conductive layer 3012, and the heat generated by the heating device 330 is transferred to the laser 310 through the first thermally conductive layer to heat the laser 310. Using a metal such as copper or gold in the first thermally conductive layer 3012 will accelerate the heat transfer efficiency.

[0155] In some embodiments, the top of the first thermally conductive layer 3012 is higher than the top surface of the circuit board 300, and the bottom of the first thermally conductive layer 3012 is lower than the top surface of the circuit board 300.

[0156] In some embodiments, the support portion 301 may include a second thermally conductive layer 3013, which is located at the bottom of the heat-insulating layer 3011. The second thermally conductive layer 3013 may be formed by covering the bottom of the heat-insulating layer 3011 with a metal, such as copper or gold.

[0157] In some embodiments, the top of the second thermal conductive layer 3013 is higher than the bottom surface of the circuit board 300, and the bottom of the second thermal conductive layer 3013 is lower than the bottom surface of the circuit board 300.

[0158] In some embodiments, a temperature sensor is disposed below the lens assembly 400, located on the circuit board 300 outside the first thermally conductive layer 3012 and the first copper-clad layer 303. The temperature sensor is used to collect the operating temperature of the laser within the optical module, facilitating the control of the heating device 330 to turn on or off. The temperature sensor transmits the collected laser operating temperature to the MCU, which compares the laser operating temperature with a preset temperature. If the laser operating temperature is lower than the preset temperature, it indicates that the optical module is in a low-temperature environment, and the MCU controls the heating device 330 to supply power for heating, thereby heating the laser 310 and increasing its operating temperature. If the laser operating temperature is not lower than the preset temperature, it indicates that the optical module is in a normal operating environment, and the heating device 330 does not operate.

[0159] In some embodiments, the temperature sensor may also be located within the MCU. The temperature sensor collects the operating temperature of the laser 310 in the optical module and stores the collected operating temperature of the laser in the register of the MCU. The MCU reads the operating temperature of the laser 310 and controls the start and stop of the heating device 330 based on the operating temperature of the laser 310.

[0160] Figure 16 is a partial schematic diagram of the bottom surface of a circuit board according to some embodiments. As shown in Figure 16, in some embodiments, a second copper-clad layer 304 is formed on the bottom surface of the circuit board 300. The second copper-clad layer 304 is located at the edge of the second thermally conductive layer 3013 and is connected to the second thermally conductive layer 3013. The second copper-clad layer 304 and the second thermally conductive layer 3013 can be connected to heat dissipation protrusions on the housing to ensure the heat dissipation effect of the heat dissipation protrusions. Exemplarily, the top of the second thermally conductive layer 3013 is flush with the top of the second copper-clad layer 304.

[0161] In some embodiments, a second copper-clad layer 304 is disposed opposite to a first copper-clad layer 303, and the second copper-clad layer 304 is disposed in the projection area of ​​the first copper-clad layer 303 in the bottom direction of the circuit board 300. A via 305 is disposed between the second copper-clad layer 304 and the first copper-clad layer 303, connecting the first copper-clad layer 303 and the second copper-clad layer 304. Heat generated by the driver chip 320 is radiated to the first copper-clad layer 303, conducted through the via 305 to the second copper-clad layer 304, and then conducted through the via 305 to the heat dissipation protrusions on the housing. Exemplarily, a plurality of vias 305 are disposed between the second copper-clad layer 304 and the first copper-clad layer 303.

[0162] Figure 17 is a structural diagram of a heating device according to some embodiments. As shown in Figure 17, in some embodiments, the heating device 330 includes a substrate 335, a heating layer 332, and a second pad 334. The heating layer 332, the first pad 336, and the second pad 334 are disposed on the substrate 335. One end of the heating layer 332 is connected to the first pad 336, and the other end of the heating layer 332 is connected to the second pad 334. The substrate 335 may be a ceramic substrate, but is not limited to a ceramic substrate; the heating layer 332 may optionally be a resistance wire. The first pad 336 and the second pad 334 are used to electrically connect to the circuit board 300 to energize the heating layer 332.

[0163] In some embodiments, the heating layer 332 extends from one end of the laser 310 to the other end of the laser 310, that is, the length of the heating layer 332 is greater than or equal to the length of the laser 310, so that the heat generated by the heating layer 332 can be transferred to the laser 310 more evenly.

[0164] In some embodiments, the first pad 336 and the second pad 334 are disposed on the top surface of the substrate 335 to facilitate the electrical connection between the heating device 330 and the circuit board 300.

[0165] Figure 18A is a first usage diagram of a support according to some embodiments, and Figure 18B is a second usage diagram of a support according to some embodiments; wherein, the solid arrows represent the heat generated by the heating device, and the dashed arrows represent the heat generated by the driving chip, etc. As shown in Figures 18A and 18B, in some embodiments, the laser 310 and the heating device 330 are disposed on the first heat-conducting layer 3012, and the laser 310 is located between the heating device 330 and the driving chip 320, so that the heating device 330 can be close to the laser 310 but far away from the driving chip 320, reducing the adverse effects of heat radiation from the heating device 330 to the driving chip 320.

[0166] When the optical module is in a low-temperature environment, the heating device 330 is powered on and generates heat. This heat radiates outwards from the heating device 330. Due to the high thermal conductivity of the first thermally conductive layer 3012, most of the heat is radiated to it. This radiated heat is then transferred to the laser 310. Since a heat-blocking layer 3011 lies beneath the first thermally conductive layer 3012, it prevents heat from being conducted downwards from the first thermally conductive layer 3012, facilitating more efficient heat transfer to the laser 310. When the optical module is in a non-low-temperature environment, the heating device 330 is not powered on and does not generate heat.

[0167] When the optical module is in a high-temperature environment, the heat-blocking layer 3011 can block the heat generated by the driver chip 320 and other devices on the circuit board 300, reduce the heat generated by the driver chip 320 and other devices from being conducted to the first heat-conducting layer 3012, and thus reduce the heat generated by the driver chip 320 and other devices from being transferred to the laser 310, so as to reduce the impact of the heat generated by the driver chip 320 and other devices on the laser 310.

[0168] Figure 19A shows a performance test diagram of a circuit board without a support and heating element according to some embodiments, and Figure 19B shows a performance test diagram of a circuit board with a support and heating element according to some embodiments; where BER is the Bit Error Rate (BER) and TEMP is the temperature. As shown in Figures 19A and 19B, when the circuit board 300 lacks a support and heating element, the performance of the laser 310 is relatively poor when the ambient temperature of the optical module is below 20°C. However, after the support 302 and heating element 330 are provided on the circuit board 300, the performance of the laser 310 is significantly improved. Comparing Figures 19A and 19B, it can be seen that providing the support 302 and heating element 330 on the circuit board 300 can significantly improve the performance of the laser 310 in low-temperature environments, while the performance of the laser 310 in high-temperature environments does not change significantly. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit them. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure.

Claims

1. An optical module, comprising: A circuit board and a laser chip, wherein the laser chip is disposed on the circuit board for emitting optical signals; The circuit board has a heating zone on its surface, located below the laser chip, for heating the laser chip; the heating zone is formed by etching the surface of the circuit board; a thermally conductive layer is disposed on the circuit board, located between the laser chip and the heating zone, with its bottom surface connected to the heating zone and its top surface connected to the laser chip, for conducting heat; or... The circuit board has through holes, and a first copper plating layer is formed on the side of the through holes; a support portion is disposed in the through holes; the support portion includes a first thermally conductive layer and a heating device, and the edge of the first thermally conductive layer is spaced from the edge of the first copper plating layer; the laser chip is disposed on the first thermally conductive layer; the heating device of the laser chip is disposed on the first thermally conductive layer and located on the side of the laser chip; the heating device is electrically connected to the circuit board and is used to heat the laser chip at low temperatures.

2. The optical module according to claim 1, wherein The heat-conducting layer is non-conductive and is directly connected to the heating zone; or, the heat-conducting layer is conductive and an insulating layer is provided between the heat-conducting layer and the heating zone, with the top surface of the insulating layer connected to the bottom surface of the heat-conducting layer and the bottom surface of the insulating layer connected to the heating zone.

3. The optical module according to claim 2, wherein The heating zone includes: First sub-heating zone; A second sub-heating zone is provided with a first insulating zone between it and the first sub-heating zone; the first insulating zone extends from the first boundary of the heating zone to the second boundary of the heating zone, but does not extend to the second boundary of the heating zone, so that one end of the second sub-heating zone is connected to one end of the first sub-heating zone. A third sub-heating zone is provided with a second insulating zone between it and the second sub-heating zone; the second insulating zone extends from the second boundary of the heating zone to the first boundary of the heating zone, but does not extend to the first boundary of the heating zone, so that one end of the third sub-heating zone is connected to the other end of the second sub-heating zone.

4. The optical module according to claim 3, wherein The circuit board is provided with: An adjustable voltage source, with its output pin connected to the end of the first sub-heating zone that is not connected to the second sub-heating zone, is used to provide voltage; For reference, it is connected to the end of the third sub-heating zone that is not connected to the second sub-heating zone; The surface layer of the circuit board also includes a body area, there is a gap between the body area and the heating area, and the heating area is connected to the reference ground and the adjustable voltage source by wire bonding.

5. The optical module according to claim 3, wherein, The circuit board is provided with: An adjustable voltage source, with its output pin connected to the end of the first sub-heating zone that is not connected to the second sub-heating zone, is used to provide voltage; For reference, it is connected to the end of the third sub-heating zone that is not connected to the second sub-heating zone; The surface layer of the circuit board also includes a body region, which has a gap with the first region of the heating zone. The body region is connected to the reference ground and the adjustable voltage source. The first region is the region of the heating zone other than the region connected to the reference ground and the adjustable voltage source.

6. The optical module according to claim 4 or 5, wherein the circuit board further comprises: Temperature detector, used to monitor temperature; The MCU has its input pin connected to the temperature detector and its output pin connected to the feedback pin of the adjustable voltage source to output a feedback voltage. The MCU integrates: A register is used to store a table showing the relationship between the temperature and the feedback voltage.

7. The optical module according to claim 4 or 5, wherein the circuit board further comprises: The MCU's output pin is connected to the feedback pin of the adjustable voltage source to output a feedback voltage; The MCU integrates: Temperature sensors are used to monitor temperature; A register is used to store a table showing the relationship between the temperature and the feedback voltage.

8. The optical module according to claim 2, wherein, The width of the insulating layer is greater than or equal to the width of the heat-conducting layer, and the length of the insulating layer is greater than or equal to the length of the heat-conducting layer.

9. [Correction 18.02.2025 according to Rule 91] The optical module according to claim 2, wherein, The laser chip includes: The first positive electrode is disposed on the first top surface; A first negative electrode is disposed on the second top surface; the first top surface and the second top surface are different top surfaces of the laser chip; A laser driver chip is disposed on the circuit board, and the laser driver chip includes: The second positive electrode is connected to the first positive electrode; The second negative electrode is connected to the first negative electrode; both the second positive electrode and the second negative electrode of the laser driver chip output modulation current and bias current, so that the modulation current and bias current are transmitted to the laser chip in the form of differential signals.

10. [Correction 18.02.2025 according to Rule 91] The optical module according to claim 9 further includes: A lens assembly, covering the laser chip and the laser driver chip, includes: The first lens is located on the side of the lens assembly facing the circuit board and is located in the light output path of the laser chip; The reflecting surface is located on the side of the lens assembly facing away from the circuit board and is located in the collimating optical path of the first lens; The second lens is located in the reflected light path of the reflecting surface, so that the second lens can converge the light signal reflected by the reflecting surface.

11. The optical module according to claim 10, wherein the circuit board further comprises: An optical receiver chip is used to receive optical signals; An optical matching chip is connected to the optical receiving chip via wire bonding; the lens assembly covers the optical receiving chip and the optical matching chip.

12. The optical module according to claim 1, further comprising a lens assembly for changing the transmission direction of the optical signal; the via and the first copper-clad layer are located below the lens assembly; The support portion further includes a heat-resistant layer and a driving chip. The thermal conductivity of the heat-resistant layer is less than that of the circuit board. The first thermally conductive layer is located above the heat-resistant layer, and the thermal conductivity of the first thermally conductive layer is greater than that of the heat-resistant layer. The laser chip driving chip is disposed on the first copper-clad layer. The driving chip is electrically connected to the circuit board and to the laser chip. The heating device is disposed on the side of the laser chip away from the driving chip.

13. The optical module according to claim 12, wherein the support portion further comprises a second thermally conductive layer, the second thermally conductive layer being located below the thermally insulating layer; the second thermally conductive layer is connected to the heat dissipation protrusion of the housing.

14. The optical module according to claim 13, wherein, A second copper-clad layer is formed on the back side of the circuit board, and the second copper-clad layer is connected to the second thermal conductive layer; a via is provided on the second copper-clad layer, and the via connects the first copper-clad layer and the second copper-clad layer; The second copper cladding layer connects to the heat dissipation protrusion.

15. The optical module according to claim 12, wherein, The heating device includes a substrate, on which a heating layer, a first pad, and a second pad are disposed. One end of the heating layer is connected to the first pad, and the other end of the heating layer is connected to the second pad. The heating layer extends from one end of the laser chip to the other end of the laser chip. The substrate is mounted on the first thermally conductive layer, and the first pad and the second pad are electrically connected to the circuit board.

16. The optical module according to claim 12, wherein, The bottom of the first thermal conductive layer is lower than the top surface of the circuit board, and the top of the first thermal conductive layer is higher than the top surface of the circuit board.

17. The optical module according to claim 12, wherein, The heat-insulating layer is an epoxy resin layer, and the through holes are filled with epoxy resin to form an epoxy resin layer.

18. The optical module according to claim 12 further includes a temperature sensor located below the lens assembly and close to the laser chip, the temperature sensor being located outside the first thermally conductive layer and the first copper-clad layer.

19. An optical module, comprising: The circuit board has through holes; A first copper plating layer is formed on the top surface of the circuit board, and the first copper plating layer is located on the side of the through hole; A support portion is provided inside the through hole; the support portion includes: A heat-resistant layer, wherein the thermal conductivity of the heat-resistant layer is less than that of the circuit board; A first thermally conductive layer is located above the thermally insulating layer, and the thermal conductivity of the first thermally conductive layer is greater than that of the thermally insulating layer; the edge of the first thermally conductive layer is spaced from the edge of the first copper-clad layer. The laser chip is disposed on the first heat-conducting layer; A driver chip is disposed on the first copper layer; the driver chip is electrically connected to the circuit board and electrically connected to the laser chip. A heating device is disposed on the first thermally conductive layer and located on the side of the laser chip away from the driving chip; the heating device is electrically connected to the circuit board and is used to heat the laser chip at low temperatures.

20. The optical module according to claim 19, wherein the support portion further comprises a second thermally conductive layer, the second thermally conductive layer being located below the thermally insulating layer; A second copper cladding layer is formed on the back side of the circuit board, and the second copper cladding layer is connected to the second thermal conductive layer; A via is provided on the second copper clad layer, and the via connects the second copper clad layer and the first copper clad layer; The second thermal conductive layer and the second copper-clad layer are connected to the heat dissipation protrusions on the optical module housing.

21. The optical module according to claim 19, wherein, The heating device includes a substrate, on which a heating layer, a first pad, and a second pad are disposed. One end of the heating layer is connected to the first pad, and the other end of the heating layer is connected to the second pad. The heating layer extends from one end of the laser chip to the other end of the laser chip. The substrate is mounted on the first thermally conductive layer, and the first pad and the second pad are electrically connected to the circuit board.

22. An optical module, comprising: Circuit board; A laser chip, mounted on the circuit board, is used to emit optical signals; The surface layer of the circuit board has: A heating zone, located below the laser chip, is used to heat the laser chip; the heating zone is formed by etching the surface layer of the circuit board. The circuit board is provided with: A thermally conductive layer is located between the laser chip and the heating area, with its bottom surface connected to the heating area and its top surface connected to the laser chip, for conducting heat. The heat-conducting layer is non-conductive and is directly connected to the heating zone; or, the heat-conducting layer is conductive and an insulating layer is provided between the heat-conducting layer and the heating zone, with the top surface of the insulating layer connected to the bottom surface of the heat-conducting layer and the bottom surface of the insulating layer connected to the heating zone.

23. The optical module according to claim 22, wherein, The heating zone includes: First sub-heating zone; A second sub-heating zone is provided with a first insulating zone between it and the first sub-heating zone; the first insulating zone extends from the first boundary of the heating zone to the second boundary of the heating zone, but does not extend to the second boundary of the heating zone, so that one end of the second sub-heating zone is connected to one end of the first sub-heating zone. A third sub-heating zone is provided with a second insulating zone between it and the second sub-heating zone; the second insulating zone extends from the second boundary of the heating zone to the first boundary of the heating zone, but does not extend to the first boundary of the heating zone, so that one end of the third sub-heating zone is connected to the other end of the second sub-heating zone.

24. The optical module according to claim 23, wherein, The circuit board is provided with: An adjustable voltage source, with its output pin connected to the end of the first sub-heating zone that is not connected to the second sub-heating zone, is used to provide voltage; For reference, it is connected to the end of the third sub-heating zone that is not connected to the second sub-heating zone; The surface layer of the circuit board also includes a body area, there is a gap between the body area and the heating area, and the heating area is connected to the reference ground and the adjustable voltage source by wire bonding.

25. The optical module according to claim 23, wherein, The circuit board is provided with: An adjustable voltage source, with its output pin connected to the end of the first sub-heating zone that is not connected to the second sub-heating zone, is used to provide voltage; For reference, it is connected to the end of the third sub-heating zone that is not connected to the second sub-heating zone; The surface layer of the circuit board also includes a body region, which has a gap with the first region of the heating zone. The body region is connected to the reference ground and the adjustable voltage source. The first region is the region of the heating zone other than the region connected to the reference ground and the adjustable voltage source.

26. The optical module according to claim 24 or 25, wherein the circuit board further comprises: Temperature detector, used to monitor temperature; The MCU has its input pin connected to the temperature detector and its output pin connected to the feedback pin of the adjustable voltage source to output a feedback voltage. The MCU integrates: A register is used to store a table showing the relationship between the temperature and the feedback voltage.

27. The optical module according to claim 24 or 25, further comprising: The MCU's output pin is connected to the feedback pin of the adjustable voltage source to output a feedback voltage; The MCU integrates: Temperature sensors are used to monitor temperature; A register is used to store a table showing the relationship between the temperature and the feedback voltage.

28. The optical module according to claim 22, wherein, The width of the insulating layer is greater than or equal to the width of the heat-conducting layer, and the length of the insulating layer is greater than or equal to the length of the heat-conducting layer.

29. The optical module according to claim 22, wherein, The laser chip includes: The first positive electrode is disposed on the first top surface; A first negative electrode is disposed on the second top surface; the first top surface and the second top surface are different top surfaces of the laser chip; A laser driver chip is disposed on the circuit board, and the laser driver chip includes: The second positive electrode is connected to the first positive electrode; The second negative electrode is connected to the first negative electrode; both the second positive electrode and the second negative electrode of the laser driver chip output modulation current and bias current, so that the modulation current and bias current are transmitted to the laser chip in the form of differential signals.

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