An optical module

Abstract

The application discloses an optical module, comprising a first substrate, the first substrate is provided with a first notch area, a second notch area, a first signal transmission area and a second signal transmission area. The first notch area and the second notch area are formed by the first side surface and the bottom surface of the first substrate being recessed inward. The first notch area is provided with a first pin. The second notch area is provided with a second pin. The first signal transmission area and the second signal transmission area are extended downward from the first side surface of the first substrate to the top surface of the corresponding notch area. The first signal transmission area and the second signal transmission area are respectively provided with a first signal line transmission layer and a second signal line transmission layer. The first pin is connected with the first signal line transmission layer. The second pin is connected with the second signal line transmission layer. The second signal line transmission layer is provided with a laser chip. In the application, the first substrate for fixing the laser chip is only provided in the optical emitting device, and the first substrate is a ceramic substrate, which reduces the impedance mismatching of the high-frequency signal line connected with the pin and improves the bandwidth of the high-frequency signal line.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical fiber communication technology, and in particular to an optical module. BACKGROUND

[0002] The optical module is a tool for converting optical signals and electrical signals, and is one of the key devices in optical communication equipment. The optical module usually includes optical transmitter devices, optical receiver devices, microprocessors and other devices. In addition, some optical modules encapsulate separate optical transmitter devices and optical receiver devices together in a metal shell to form an optical transceiver assembly.

[0003] Based on the TO (Through-hole) packaging technology, compared with other packaging technologies, it has the advantages of small parasitic parameters and low process cost. Therefore, the optical transmitter in the optical transceiver assembly often adopts a coaxial TO packaging method. The optical transmitter usually includes a cap and a socket. The cap is arranged on the socket. The socket is provided with a metal boss and a plurality of through holes for the pins to pass through. The bottom surface of the metal boss is fixed to the socket. The side surface of the metal boss is fixed with a laser chip. The pins are connected with the laser chip. The capacitive effect generated by the interaction between the metal boss and the pins causes the impedance of the high-frequency signal line connected with the pins to be mismatched, thereby affecting the bandwidth of the high-frequency signal line. SUMMARY

[0004] The present application provides an optical module to improve the bandwidth of the high-frequency signal line.

[0005] An optical module, comprising:

[0006] An optical transmitter device, comprising a socket and a pin;

[0007] The socket is provided with a first substrate on the top;

[0008] The pin includes a first pin and a second pin which extend into and out of the socket;

[0009] The first substrate is a ceramic substrate, and the first substrate is provided with a first notch area, a second notch area, a first signal transmission area and a second signal transmission area on the top;

[0010] The first notch area is formed by inwardly recessing the first side surface of the first substrate and the bottom surface of the first substrate, and the first pin is arranged inside the first notch area;

[0011] The second notch area is formed by inwardly recessing the first side surface of the first substrate and the bottom surface of the first substrate, and the second pin is arranged inside the second notch area;

[0012] The first signal transmission area is formed by extending the first side surface of the first substrate downwardly to the top surface of the first notch area, and the first high-frequency signal line is laid on the surface of the first signal transmission area to form a first signal line transmission layer;

[0013] The second signal transmission area is not connected with the first signal transmission area, extends from the first side of the first substrate to the top surface of the second notch area downward, and a second high-frequency signal line is laid on the surface to form a second signal line transmission layer;

[0014] The first pin is connected with the first signal line transmission layer located in the first notch area.

[0015] The second pin is connected with the second signal line transmission layer located in the second notch area.

[0016] The second signal line transmission layer is provided with a laser chip on the surface.

[0017] The laser chip is connected with the surface of the second signal line transmission layer through a negative pin and is connected with the surface of the first signal line transmission layer through a positive pin by wire bonding.

[0018] Beneficial effects: the application provides a light module, which comprises a light emitting device. The light emitting device comprises a socket and a pin. The socket is provided with a first substrate. The pin comprises a first pin and a second pin which extend into and out of the socket. The first substrate is provided with a first notch area, a second notch area, a first signal transmission area and a second signal transmission area. The first notch area and the second notch area are both formed by the inward recess of the first side surface of the first substrate and the bottom surface of the first substrate. The first pin is arranged in the first notch area. The second pin is arranged in the second notch area. The placement of the first pin in the first notch area and the placement of the second pin in the second notch area facilitate the determination of the placement position of the first substrate on the socket, thereby improving the coupling efficiency. The first signal transmission area extends downward from the first side surface of the first substrate to the top surface of the first notch area. The surface of the first signal transmission area is paved with a first high-frequency signal line to form a first signal line transmission layer. The second signal transmission area extends downward from the first side surface of the first substrate to the top surface of the second notch area. The surface of the second signal transmission area is paved with a second high-frequency signal line to form a second signal line transmission layer. The first pin is connected with the first signal line transmission layer located in the first notch area. The second pin is connected with the second signal line transmission layer located in the second notch area. The connection of the first pin with the first signal line transmission layer located in the first notch area increases the contact area of the first pin with the first signal line transmission layer, thereby improving the transmission rate of the high-frequency signal. Correspondingly, the connection of the second pin with the second signal line transmission layer located in the second notch area increases the contact area of the second pin with the second signal line transmission layer, thereby improving the transmission rate of the high-frequency signal. The surface of the second signal line transmission layer is provided with a laser chip. The negative pin of the laser chip is connected with the surface of the second signal line transmission layer, and the positive pin is wire-connected with the surface of the first signal line transmission layer. In the application, the light emitting device does not have a metal boss for fixing the laser chip, but only has the first substrate for fixing the laser chip, and the first substrate is a ceramic substrate, which avoids the capacitive effect caused by the interaction between the metal boss and the pin, reduces the impedance mismatch of the high-frequency signal line connected with the pin caused by the capacitive effect, thereby reducing the signal reflection phenomenon caused by the impedance mismatch of the high-frequency signal line, and improving the bandwidth of the high-frequency signal line. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0020] Figure 1 The connection relationship diagram of the optical communication system;

[0021] Figure 2 is a block diagram of an optical network terminal according to some embodiments;

[0022] Figure 3 is a block diagram of an optical module according to some embodiments;

[0023] Figure 4 is an exploded block diagram of an optical module according to some embodiments;

[0024] Figure 5 is a block diagram of an optical transceiver assembly according to some embodiments;

[0025] Figure 6 is an exploded diagram of an optical transceiver assembly according to some embodiments;

[0026] Figure 7 is a block diagram of an optical transmitter device according to some embodiments;

[0027] Figure 8 is a block diagram of an optical transmitter device according to some embodiments, excluding the cap;

[0028] Figure 9 is an exploded block diagram of an optical transmitter device according to some embodiments;

[0029] Figure 10 is a first angular cross-sectional view of an optical transmitter device according to some embodiments;

[0030] Figure 11 is a partial enlarged view of Figure 10

[0031] Figure 12 is a second angular cross-sectional view of an optical transmitter device according to some embodiments;

[0032] Figure 13 is a third angular cross-sectional view of an optical transmitter device according to some embodiments;

[0033] Figure 14 is a first angular block diagram of a cap according to some embodiments;

[0034] Figure 15 is a second angular block diagram of a cap according to some embodiments;

[0035] Figure 16 is a first angular block diagram of a tube shell according to some embodiments;

[0036] Figure 17 is a second angular block diagram of a tube shell according to some embodiments;

[0037] Figure 18 is a first angular block diagram of a first substrate, a laser chip, and a pin according to some embodiments; ​

[0038] Figure 19 A second angle view of the first substrate, the laser chip and the pin according to some embodiments;

[0039] Figure 20 A first angle view of the first substrate and the laser chip according to some embodiments;

[0040] Figure 21 A second angle view of the first substrate and the laser chip according to some embodiments;

[0041] Figure 22 A first angle view of the first substrate according to some embodiments;

[0042] Figure 23 A second angle view of the first substrate according to some embodiments. DETAILED DESCRIPTION

[0043] In an optical communication system, optical signals are used to carry information to be transmitted, and the optical signals carrying the information are transmitted to an information processing device such as a computer through an information transmission device such as an optical fiber or an optical waveguide, so as to complete the transmission of information. Since the light has a passive transmission characteristic when transmitted through the optical fiber or the optical waveguide, the information transmission can be realized at a low cost and low loss. In addition, the signal transmitted by the information transmission device such as the optical fiber or the optical waveguide is an optical signal, while the signal that can be recognized and processed by the information processing device such as the computer is an electrical signal. Therefore, in order to establish an information connection between the information transmission device such as the optical fiber or the optical waveguide and the information processing device such as the computer, it is necessary to realize the mutual conversion between the electrical signal and the optical signal.

[0044] An optical module realizes the mutual conversion function between the optical signal and the electrical signal in the field of optical communication technology. The optical module includes an optical port and an electrical port. The optical module realizes optical communication with the information transmission device such as the optical fiber or the optical waveguide through the optical port, and realizes electrical connection with the optical network terminal (for example, an optical modem) through the electrical port. The electrical connection is mainly used for power supply, I2C signal transmission, data information transmission, grounding and the like. The optical network terminal transmits the electrical signal to the information processing device such as the computer through a network cable or a wireless fidelity (Wi-Fi) technology.

[0045] Figure 1 A connection relationship diagram of an optical communication system. As shown in Figure 1 , the optical communication system includes a remote server 1000, a local information processing device 2000, an optical network terminal 100, an optical module 200, an optical fiber 101 and a network cable 103.

[0046] One end of the optical fiber 101 is connected to the remote server 1000, and the other end is connected to the optical network terminal 100 through the optical module 200. The optical fiber itself can support long-distance signal transmission, for example, signal transmission of thousands of meters (6-8 kilometers), and theoretically, unlimited distance transmission can be achieved if a repeater is used. Therefore, in a general optical communication system, the distance between the remote server 1000 and the optical network terminal 100 can usually reach thousands of meters, tens of kilometers, or hundreds of kilometers.

[0047] One end of the network cable 103 is connected to the local information processing device 2000, and the other end is connected to the optical network terminal 100. The local information processing device 2000 can be any one or several of the following devices: a router, a switch, a computer, a mobile phone, a tablet computer, a television, etc.

[0048] The physical distance between the remote server 1000 and the optical network terminal 100 is greater than the physical distance between the local information processing device 2000 and the optical network terminal 100. The connection between the local information processing device 2000 and the remote server 1000 is completed by 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 module 200 and the optical network terminal 100.

[0049] The optical module 200 includes an optical port and an electrical port. The optical port is configured to access the optical fiber 101, so that the optical module 200 and the optical fiber 101 establish a bidirectional optical signal connection; the electrical port is configured to access the optical network terminal 100, so that the optical module 200 and the optical network terminal 100 establish a bidirectional electrical signal connection. The optical module 200 realizes the mutual conversion of optical signals and electrical signals, thereby establishing an information connection between the optical fiber 101 and the optical network terminal 100. For example, the optical signal from the optical fiber 101 is converted into an electrical signal by the optical module 200 and then input into the optical network terminal 100, and the electrical signal from the optical network terminal 100 is converted into an optical signal by the optical module 200 and then input into the optical fiber 101. Since the optical module 200 is a tool for converting optical signals and electrical signals, it does not have the function of processing data, and in the above optical-electrical conversion process, the information does not change.

[0050] The optical network terminal 100 comprises a housing in the shape of a cuboid, and an optical module interface 102 and a network cable interface 104 arranged on the housing. The optical module interface 102 is configured to access the optical module 200, so that the optical network terminal 100 and the optical module 200 establish a bidirectional electrical signal connection. The network cable interface 104 is configured to access the network cable 103, so that the optical network terminal 100 and the network cable 103 establish a bidirectional electrical signal connection. The optical module 200 and the network cable 103 are connected through the optical network terminal 100. For example, the optical network terminal 100 transmits electrical signals from the optical module 200 to the network cable 103, and transmits electrical signals from the network cable 103 to the optical module 200, so that the optical network terminal 100, as a host of the optical module 200, can monitor the operation of the optical module 200. The host of the optical module 200 can also include an optical line terminal (OLT) in addition to the optical network terminal 100.

[0051] The remote server 1000 establishes a bidirectional signal transmission channel with the local information processing device 2000 through the optical fiber 101, the optical module 200, the optical network terminal 100, and the network cable 103.

[0052] Figure 2 The figure is a structural diagram of the optical network terminal, and the connection relationship between the optical module 200 and the optical network terminal 100 is clearly shown. Figure 2 Only the structure of the optical network terminal 100 related to the optical module 200 is shown. As Figure 2 The optical network terminal 100 further comprises a circuit board 105 arranged in the housing, a cage 106 arranged on the surface of the circuit board 105, a heat sink 107 arranged on the cage 106, and an electrical connector arranged inside the cage 106. The electrical connector is configured to access the electrical port of the optical module 200. The heat sink 107 has a fin or other protruding part to increase the heat dissipation area.

[0053] The optical module 200 is inserted into the cage 106 of the optical network terminal 100, and the optical module 200 is fixed by the cage 106. The heat generated by the optical module 200 is conducted to the cage 106, and then diffused through the heat sink 107. After the optical module 200 is inserted into the cage 106, the electrical port of the optical module 200 is connected to the electrical connector inside the cage 106, so that the optical module 200 and the optical network terminal 100 establish a bidirectional electrical signal connection. In addition, the optical port of the optical module 200 is connected to the optical fiber 101, so that the optical module 200 and the optical fiber 101 establish a bidirectional optical signal connection.

[0054] Figure 3 The figure is a structural diagram of an optical module according to some embodiments. Figure 4 The figure is an exploded structural diagram of the optical module according to some embodiments. As Figure 3and 4 As shown, the optical module 200 includes a shell, a circuit board 300 disposed inside the shell, and an optical transceiver assembly 400.

[0055] The housing includes an upper housing 201 and a lower housing 202, with the upper housing 201 covering the lower housing 202 to form the aforementioned housing with two openings; the outer contour of the housing is generally square.

[0056] In some embodiments of this disclosure, 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.

[0057] 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.

[0058] 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. Figure 3 The opening 205 is also located at the end of the optical module 200 (right end). Figure 3 (Left end). Alternatively, opening 204 is located at the end of optical module 200, while opening 205 is located on the side of optical module 200. Opening 204 is an electrical port, through which the gold fingers 301 of circuit board 300 extend and are inserted into a host computer (e.g., optical network terminal 100); opening 205 is an optical port, configured to connect to external optical fiber 101 so that external optical fiber 101 can connect to the optical transceiver assembly 400 inside optical module 200.

[0059] The assembly method using an upper housing 201 and a lower housing 202 facilitates the installation of components such as the circuit board 300 and the optical transceiver assembly 400 into the housing, with the upper housing 201 and lower housing 202 providing encapsulation and protection for these components. Furthermore, the assembly of the circuit board 300 and the optical transceiver assembly 400 facilitates the deployment of positioning components, heat dissipation components, and electromagnetic shielding components, which is beneficial for automated production.

[0060] In some embodiments, the upper housing 201 and the lower housing 202 are generally made of metal materials, which facilitates electromagnetic shielding and heat dissipation.

[0061] In some embodiments, the optical module 200 further comprises an unlocking component located outside the shell of the optical module 200, which is configured to realize the fixed connection between the optical module 200 and the host machine, or to release the fixed connection between the optical module 200 and the host machine.

[0062] For example, the unlocking component is located on the outer wall of the two lower side plates 2022 of the lower shell 202, and has a clamping component matched with the cage of the host machine (for example, the cage 106 of the optical network terminal 100). When the optical module 200 is inserted into the cage of the host machine, the optical module 200 is fixed in the cage of the host machine by the clamping component of the unlocking component; when the unlocking component is pulled, the clamping component of the unlocking component moves, thereby changing the connection relationship between the clamping component and the host machine, so as to release the clamping relationship between the optical module 200 and the host machine, and thus the optical module 200 can be pulled out of the cage of the host machine.

[0063] The circuit board 300 comprises circuit traces, electronic components and chips, and the electronic components and chips are connected together according to the circuit design through the circuit traces to realize the functions of power supply, electrical signal transmission and grounding. The electronic components include, for example, capacitors, resistors, transistors, metal oxide semiconductor field effect transistors (MOSFETs). The chips include, for example, microcontroller units (MCUs), laser drive chips, limiting amplifiers, clock and data recovery (CDR) chips, power management chips, digital signal processing (DSP) chips.

[0064] The circuit board 300 is generally a hard circuit board, and the hard circuit board can also realize the bearing function due to its relatively hard material, for example, the hard circuit board can stably bear the above-mentioned electronic components and chips; when the optical transceiver assembly is located on the circuit board, the hard circuit board can also provide stable bearing; the hard circuit board can also be inserted into the electrical connector in the cage of the host machine.

[0065] The circuit board 300 further comprises a gold finger 301 formed on the surface of the end thereof, and the gold finger 301 is composed of a plurality of pins independent of each other. The circuit board 300 is inserted into the cage 106, and the gold finger 301 is in conductive connection with the electrical connector in the cage 106. The gold finger 301 can be arranged only on the surface of one side of the circuit board 300 (for example, the surface of the lower shell 202), or can be arranged on the surfaces of both sides of the circuit board 300 (for example, the surfaces of the lower shell 202 and the upper shell 201). Figure 4The upper surface shown) can also be provided on the upper and lower surfaces of the circuit board 300 to accommodate occasions where the number of pins required is large. The gold finger 301 is configured to establish an electrical connection with the host computer to achieve power supply, grounding, I2C signal transmission, data signal transmission, etc.

[0066] Of course, flexible circuit boards are also used in some optical modules. Flexible circuit boards are generally used in conjunction with rigid circuit boards as a supplement to rigid circuit boards. For example, a flexible circuit board can be used to connect the rigid circuit board and the optical transceiver assembly.

[0067] The optical transceiver assembly 400 includes an optical transmitting device and an optical receiving device. The optical transmitting device is configured to implement optical signal transmission, and the optical receiving device is configured to implement optical signal reception. For example, the optical transmitting device and the optical receiving device are combined together to form an integrated optical transceiver assembly.

[0068] Figure 5 A structural schematic diagram of an optical transceiver assembly according to some embodiments. Figure 6 An exploded view of an optical transceiver assembly according to some embodiments. As shown in Figure 5-6 As can be seen, in the embodiments of the present application, the optical transceiver assembly 400 includes a round-square tube body 401, an optical transmitting device 402, an optical receiving device 403, an optical assembly 404, and a fiber adapter 405. Specifically,

[0069] The round-square tube body 401 is provided with a first port, a second port, and a third port for carrying and fixing the optical transmitting device 402, the optical receiving device 403, the optical assembly 404, and the fiber adapter 405. Specifically, the optical transmitting device 402 is inlaid in the first port, the optical receiving device 403 is inlaid in the second port, the optical assembly 404 is arranged in the inner cavity of the round-square tube body 401, and the fiber adapter 405 is inlaid in the third port.

[0070] Generally, the first port and the second port are arranged on adjacent side walls of the round-square tube body 401, respectively, the first port and the third port are arranged on the side walls in the length direction of the round-square tube body 401, respectively, and the second port is arranged on the side wall in the width direction of the round-square tube body 401.

[0071] The round-square tube body 401 is generally made of metal material, which is beneficial to electromagnetic shielding and heat dissipation. Specifically, the optical transmitting device 402 is in thermal contact with the round-square tube body 401 through the first port, and the optical receiving device 403 is in thermal contact with the round-square tube body 401 through the second port. The optical transmitting device 402 and the optical receiving device 403 are directly press-fitted into the round-square tube body 401, and the round-square tube body 401 is in contact with the optical transmitting device 402 and the optical receiving device 403 directly or through a thermal conductive medium. In this way, the round-square tube body 401 can be used for heat dissipation of the optical transmitting device 402 and the optical receiving device 403, thereby ensuring the heat dissipation effect of the optical transmitting device 402 and the optical receiving device 403.

[0072] The light emitting device 402 is connected to the circuit board 300 via a flexible circuit board and is used to emit data light.

[0073] The optical receiver 403 is connected to the circuit board 300 via a flexible circuit board and contains an optical receiver chip for receiving data light. Specifically, the optical receiver 403 includes a socket and a cap, with the cap covering the socket, forming a cavity between the cap and the socket. The optical receiver chip and a second lens are disposed on the socket. The data light emitted by the fiber optic adapter 405 is reflected by the optical component 404 to the second lens within the optical receiver 403, and then focused onto the optical receiver chip by the second lens.

[0074] Optical component 404 is disposed in the inner cavity of round-square tube 401 and is used to adjust the data light emitted by light emitting device 402 and the data light incident on light receiving device 403.

[0075] Fiber optic adapter 405 is used to connect optical fibers. Specifically, optical transmitter 402 is embedded in the first port of the round-square tube, optical receiver 403 is embedded in the second port of the round-square tube, and fiber optic adapter 405 is embedded in the third port of the round-square tube. Optical transmitter 402 and optical receiver 403 establish optical connections with fiber optic adapter 405 respectively. The data light emitted by optical transmitter 402 and the light received by optical receiver 403 are both transmitted through the same optical fiber in fiber optic adapter 405. That is, the same optical fiber in fiber optic adapter 405 is the transmission channel for light entering and exiting the optical transceiver assembly, enabling the optical transceiver assembly to achieve a single-fiber bidirectional optical transmission mode.

[0076] Figure 7 This is a structural diagram of a light emitting device according to some embodiments. Figure 8 This is a structural diagram of a light-emitting device excluding the cap, according to some embodiments. Figure 9 This is an exploded structural diagram of a light emitting device according to some embodiments. Figure 10 This is a first angular cross-sectional view of a light emitting device according to some embodiments. Figure 11 for Figure 10 A magnified view of a portion of the image. Figure 12 This is a second-angle cross-sectional view of a light-emitting device according to some embodiments. Figure 13 This is a third-angle cross-sectional view of a light-emitting device according to some embodiments. Figure 14 This is a first-angle structural diagram of a cap according to some embodiments. Figure 15 This is a second-angle structural diagram of a cap according to some embodiments. For example... Figure 7-15It can be seen that, in some embodiments, the light emitting device 402 comprises a tube base 4021 and a tube cap 4022, the tube cap 4022 is covered on the tube base 4021, and the tube cap 4022 and the tube base 4021 enclose a cavity. The first substrate 4025 is arranged in the cavity enclosed by the tube cap 4022 and the tube base 4021. The laser chip 4026 is arranged on the first substrate 4025. The positive electrode pin of the laser chip 4026 is connected with the laser drive chip on the circuit board 300, and the negative electrode pin of the laser chip 4026 is connected with the laser drive chip on the circuit board 300. The laser chip 4026 generates data light and monitoring light under the action of the driving current and the modulation current provided by the laser drive chip. The tube cap 4022 is provided with a through hole 40221, and the first lens 4024 is bonded on the through hole 40221. The first lens 4024 is a collimating lens. The data light emitted by the laser chip 4026 is collimated by the first lens 4024 on the tube cap 4022, enters the round-square tube body 401, and is coupled into the fiber adapter 405 after converging by the optical assembly 404 in the round-square tube body 401.

[0077] As Figure 7-15 It can be seen that, in some embodiments, the cavity enclosed by the tube cap 4022 and the tube base 4021 is further provided with a light detector 4027. The light detector 4027 is located at the back of the laser chip 4026. The light detector 4027 is used to receive the monitoring light emitted by the laser chip 4026 to generate a monitoring current. The connection relationship between the positive and negative electrode pins of the light detector 4027 and other devices is that the positive electrode pin of the light detector 4027 is grounded, and the negative electrode pin of the light detector 4027 is directly connected with the MCU; or, the positive electrode pin of the light detector 4027 is directly connected with the MCU, and the negative electrode pin of the light detector 4027 is wire-bonded with the positive electrode pin of the laser chip.

[0078] Figure 16 It is a first angle structure diagram of a tube shell according to some embodiments. Figure 17 It is a second angle structure diagram of a tube shell according to some embodiments. As Figure 7-17It can be seen that, in some embodiments, the light emitting device 402 includes the pin 4023. The first end of the pin 4023 is connected to the circuit board 300 through the flexible circuit board, and the second end of the pin 4023 extends into the socket 4021 and is connected to the devices on the socket 4021 in the cavity surrounded by the socket 4021 and the cap 4022; or the second end of the pin 4023 extends into the socket 4021 but does not extend into the cavity surrounded by the socket 4021 and the cap 4022. The pin 4023 includes a first pin 40231, a second pin 40232, a third pin 40233, and a fourth pin 40234. The first pin 40231 has a first end connected to the laser drive chip on the circuit board 300 through the flexible circuit board and a second end connected to the positive pin of the laser chip 4026 through a signal line. The second pin 40232 has a first end connected to the laser drive chip on the circuit board 300 through the flexible circuit board and a second end connected to the negative pin of the laser chip 4026 through a signal line. The third pin 40233 has a first end connected to the MCU on the circuit board 300 through the flexible circuit board and a second end wire-bonded to one pin of the light detector 4027. The fourth pin 40234 has a first end connected to the ground and a second end connected to the socket 4021.

[0079] Since the socket 4021 is grounded, when the light detector 4027 is directly placed on the socket 4021, the negative pin of the light detector 4027 is grounded. However, for this type of light detector 4027, the negative pin cannot be grounded and can only be connected to the positive pin of the laser chip or the MCU through the third pin 40233. Therefore, a first substrate for placing the light detector 4027 is provided on the socket 4021. The first substrate is provided with a pad area, and the negative pin of the light detector 4027 is connected to the pad area. Since the light detector 4027 can only be connected to the positive pin of the laser chip or the MCU through the third pin 40233, the pad area is wire-bonded to the positive pin of the laser chip or the third pin 40233 in addition to being connected to the negative pin of the light detector 4027. When the pad area is wire-bonded to the positive pin of the laser chip, the positive pin of the light detector 4027 is wire-bonded to the MCU through the third pin 40233. When the pad area is wire-bonded to the third pin 40233, the positive pin of the light detector 4027 is wire-bonded to the socket 4021.

[0080] In a conventional optical module, the cap is directly arranged on the top surface of the socket. Since the socket and the cap are connected by resistance welding, after the cap is removed, there will be residues on the surface of the socket, making the surface of the socket uneven. When the socket and the cap are connected again by resistance welding, there may be gaps between the cap and the socket, causing the light emitting device to have air leakage or light path deviation problems. In order to solve this problem, as shown in FIG. 1, the socket 4021 is provided with a second substrate 4025. The second substrate 4025 is arranged on the top surface of the socket 4021 and is provided with a plurality of through holes 40251. The through holes 40251 are arranged in a circular array. The cap 4022 is arranged on the second substrate 4025. The cap 4022 is provided with a plurality of through holes 40221 corresponding to the through holes 40251 of the second substrate 4025. The through holes 40221 of the cap 4022 are arranged in a circular array. The through holes 40251 of the second substrate 4025 and the through holes 40221 of the cap 4022 are arranged in a one-to-one correspondence. Figure 7-17It can be known that, in some embodiments, the tube seat 4021 comprises a tube seat body 40211 and a protrusion 40212, the top surface of the tube seat body 40211 is provided with the first substrate 4025, the side surface of the tube seat body 40211 is in contact with the inner side surface of the protrusion 40212, the bottom surface of the tube seat body 40211 is connected with the fourth pin 40234, the first pin 40231, the second pin 40232 and the third pin 40233 all extend from the bottom surface of the tube seat body 40211 to the top surface of the tube seat body 40211 and extend out of the top surface of the tube seat body 40211, the cap 4022 is in contact with the top surface of the protrusion 40212, and the top surface of the protrusion 40212 is higher than the top surface of the tube seat body 40211. Since the top surface of the protrusion 40212 is higher than the top surface of the tube seat body 40211, the cap 4022 is only in contact with the top surface of the protrusion 40212 and not in contact with the top surface of the tube seat body 40211, so that after the cap 4022 is removed, only the top surface of the protrusion 40212 has residues and the top surface of the tube seat body 40211 has no residues. Since the height of the top surface of the first substrate 4025 is higher than the height of the top surface of the protrusion 40212, the first substrate 4025 on the top surface of the tube seat body 40211 is removed before the cap 4022 and the protrusion 40212 are connected again by resistance welding, and then the top surface of the protrusion 40212 is polished. Before the cap 4022 and the protrusion 40212 are connected again by resistance welding, the top surface of the protrusion 40212 is polished to improve the flatness of the top surface of the protrusion 40212, avoid the existence of gaps between the top surface of the protrusion 40212 and the cap 4022, and further avoid the problems of gas leakage or light path deviation of the light emitting device 402.

[0081] In the above description, the top surface of the tube seat body 40211 refers to the surface of the tube seat body 40211 close to the cap 4022, the bottom surface of the tube seat body 40211 refers to the surface of the tube seat body 40211 away from the cap 4022, and the top surface of the protrusion 40212 refers to the surface of the protrusion 40212 close to the cap 4022.

[0082] When the height of the pin 4023 protruding from the tube seat 4021 is lower than the height difference between the top surface of the protrusion 40212 and the top surface of the tube seat body 40211, the top surface of the protrusion 40212 is polished to be easy to polish the pin 4023, so that the flatness of the top surface of the protrusion 40212 is lower. In order to improve the flatness of the top surface of the protrusion 40212, in some embodiments, the height difference between the top surface of the protrusion 40212 and the top surface of the tube seat body 40211 is greater than the height of the pin 4023 protruding from the tube seat 4021. The height of the pin 4023 protruding from the tube seat 4021 refers to the height difference between the part of the pin 4023 protruding from the tube seat 4021 and the tube seat body 40211.

[0083] The height difference between the top surface of the protrusion 40212 and the top surface of the socket body 40211 is greater than the height of the pin 4023 protruding from the socket 4021. When polishing the top surface of the protrusion 40212, the pin 4023 can be avoided, the flatness of the top surface of the protrusion 40212 is improved, and the gap between the top surface of the protrusion 40212 and the cap 4022 is avoided, thereby avoiding the problems of light emitting device 402 gas leakage or light path deviation.

[0084] The socket body 40211 and the protrusion 40212 can be two independent structural members or one integrally formed structural member. When the socket body 40211 and the protrusion 40212 are two independent structural members, the side surface of the socket body 40211 is in contact with part of the inner side surface of the protrusion 40212. When the socket body 40211 and the protrusion 40212 are one integrally formed structural member, the protrusion 40212 is obtained by extending from the edge of the socket body 40211 towards the cap 4022.

[0085] Since the top view of the socket body 40211 is circular, the top view of the protrusion 40212 in contact with the socket body 40211 is annular.

[0086] Figure 18 A first angle structure diagram of the first substrate, the laser chip and the pin according to some embodiments. Figure 19 A second angle structure diagram of the first substrate, the laser chip and the pin according to some embodiments. Figure 20 A first angle structure diagram of the first substrate and the laser chip according to some embodiments. Figure 21 A second angle structure diagram of the first substrate and the laser chip according to some embodiments. Figure 22 A first angle structure diagram of the first substrate according to some embodiments. Figure 23 A second angle structure diagram of the first substrate according to some embodiments. Figure 8-13 As can be seen from 18-23, in some embodiments, the first substrate 4025 is located on the top surface of the socket body 40211, the first substrate 4025 is provided with the laser chip 4026, and the first substrate 4025 is a ceramic substrate.

[0087] In a conventional optical module, the laser chip is located on a metal boss. Due to the capacitive effect caused by the interaction between the metal boss and the pin protruding from the socket, the impedance of the high-frequency signal line connected to the pin is not matched, thereby affecting the bandwidth of the high-frequency signal line.

[0088] In some embodiments, only the first substrate 4025 for fixing the laser chip is arranged on the top surface of the tube base body 40211, and no metal boss is arranged, and the first substrate 4025 is a ceramic substrate. Since there is no metal boss for fixing the laser chip in the light emitting device, only the first substrate 4025 for fixing the laser chip, and the first substrate 4025 is a ceramic substrate, the capacitive effect caused by the interaction between the metal boss and the pin 4023 is avoided, the impedance mismatch of the high-frequency signal line connected with the pin caused by the capacitive effect is reduced, and the signal reflection phenomenon caused by the impedance mismatch of the high-frequency signal line is reduced, and the bandwidth of the high-frequency signal line is improved.

[0089] As Figure 18-23 It can be seen that, in some embodiments, the first substrate 4025 is provided with a first signal transmission area 40251, a second signal transmission area 40252, a first notch area 40253, a second notch area 40254 and a third notch area 40255 at one end facing the light detector 4027. Specifically,

[0090] The first signal transmission area 40251 extends downward from the surface of the first substrate 4025 facing the light detector 4027 to the bottom surface of the first substrate 4025. Since the first substrate 4025 is a ceramic substrate, high-frequency signal lines can be laid on the surface to form a circuit pattern, and the first signal transmission area 40251 on the first substrate 4025 is laid with first high-frequency signal lines to form a first signal line transmission layer.

[0091] The first signal line transmission layer is welded to the first pin 40231 at the first end and wire-bonded to the positive pin of the laser chip 4026 at the second end, and is used for transmitting the first high-frequency signal.

[0092] The second signal transmission area 40252 extends downward from the surface of the first substrate 4025 facing the light detector 4027 to the bottom surface of the first substrate 4025. Since the first substrate 4025 is a ceramic substrate, high-frequency signal lines can be laid on the surface to form a circuit pattern, and the second signal transmission area 40252 on the first substrate 4025 is laid with second high-frequency signal lines to form a second signal line transmission layer. The surface of the first substrate 4025 facing the light detector 4027 is the first side surface of the first substrate 4025.

[0093] The second signal line transmission layer is welded to the second pin 40232 at the first end and wire-bonded to the negative pin of the laser chip 4026 at the second end, and is used for transmitting the second high-frequency signal.

[0094] The negative pin of the laser chip 4026 is connected to the surface of the second signal line transmission layer, and the positive pin of the laser chip 4026 is wire-bonded to the surface of the first signal line transmission layer.

[0095] The laser chip 4026 generates data light under the action of a first high-frequency signal and a second high-frequency signal. The first high-frequency signal is a first driving current and a first modulation current, and the second high-frequency signal is a second driving current and a second modulation current. The first driving current and the second driving current are opposite in phase, and the first modulation current and the second modulation current are opposite in phase.

[0096] The first notch area 40253 is formed by inwardly recessing the side of the first substrate 4025 facing the photodetector 4027 and the bottom surface of the first substrate 4025. The first pin 40231 is arranged in the first notch area 40253. Since the first signal line transmission layer extends downward from the side of the first substrate 4025 facing the photodetector 4027 to the bottom surface of the first substrate 4025, the first signal line transmission layer extends downward from the side of the first substrate 4025 facing the photodetector 4027 to the top surface of the first notch area 40253 of the first substrate 4025. Since the first signal line transmission layer extends downward from the side of the first substrate 4025 facing the photodetector 4027 to the top surface of the first notch area 40253 of the first substrate 4025, the first end of the first pin 40231 is connected to the first signal line transmission layer located on the top surface of the first notch area 40253, and the second end of the first pin 40231 is connected to the laser driving chip through the flexible circuit board.

[0097] The second notch area 40254 is formed by inwardly recessing the side of the first substrate 4025 facing the photodetector 4027 and the bottom surface of the first substrate 4025. The second pin 40232 is arranged in the second notch area 40254. Since the first signal line transmission layer extends downward from the side of the first substrate 4025 facing the photodetector 4027 to the bottom surface of the first substrate 4025, the first signal line transmission layer extends downward from the side of the first substrate 4025 facing the photodetector 4027 to the top surface of the second notch area 40254 of the first substrate 4025. Since the second signal line transmission layer extends downward from the side of the first substrate 4025 facing the photodetector 4027 to the top surface of the second notch area 40254 of the first substrate 4025, the first end of the second pin 40232 is connected to the second signal line transmission layer located on the top surface of the second notch area 40254, and the second end of the second pin 40232 is connected to the laser driving chip through the flexible circuit board.

[0098] The first pin 40231 is placed in the first notch area 40253, and the second pin 40232 is placed in the second notch area 40254. When the first substrate 4025 is placed on the top surface of the socket 4021, the placement position of the first substrate 4025 on the top surface of the socket 4021 can be determined according to the positions of the first pin 40231 and the second pin 40232. That is, the first pin 40231 is placed in the first notch area 40253, and the second pin 40232 is placed in the second notch area 40254, so that the placement position of the first substrate 4025 on the socket 4021 can be determined conveniently, thereby ensuring that the concentricity of the cap 4022 meets the production requirements (the concentricity of the cap meets the production requirements means that there is a partial deviation between the optical axis of the light emitted by the laser chip on the first substrate and the central axis of the first lens on the cap, but the deviation is within the preset deviation), and the coupling efficiency is improved.

[0099] The first pin 40231 is connected to the first signal line transmission layer located in the first notch area 40253, so that the contact area of the first pin and the first signal line transmission layer is increased, and the transmission rate of the high-frequency signal is improved. Correspondingly, the second pin is connected to the second signal line transmission layer located in the second notch area, so that the contact area of the second pin and the second signal line transmission layer is increased, and the transmission rate of the high-frequency signal is improved. The first pin 40231 is welded to the first signal line transmission layer located on the top surface of the first notch area 40253 by solder, and the second pin 40232 is welded to the second signal line transmission layer located on the top surface of the second notch area 40254 by solder.

[0100] The first pin 40231 is welded to the first signal line transmission layer located on the top surface of the first notch area 40253 by solder, and the second pin 40232 is welded to the second signal line transmission layer located on the top surface of the second notch area 40254 by solder. Different solder materials correspond to different dielectric constants. The shape of the top surface of the first notch area 40253 can be changed to adapt to the solder located between the top surface of the first notch area 40253 and the first pin 40231, so that the impedance of the solder is closer to the impedance of the first signal line transmission layer or the first pin. The shape of the top surface of the second notch area 40254 can also be changed to adapt to the solder located between the top surface of the second notch area 40254 and the second pin 40232, so that the impedance of the solder is closer to the impedance of the second signal line transmission layer or the second pin. Therefore, the first pin 40231 is placed in the first notch area 40253, and the second pin 40232 is placed in the second notch area 40254. The impedance matching between the first pin and the first signal line transmission layer and the impedance matching between the second pin and the second signal line transmission layer can also be realized by controlling the shapes of the first notch area 40253 and the second notch area 40254.

[0101] The third notch region 40255 is formed by inwardly recessing the side of the first substrate 4025 facing the photodetector 4027 and the bottom side of the first substrate 4025. The third notch region 40255 is located between the first notch region 40253 and the second notch region 40254, and the photodetector 4027 is located in the cavity surrounded by the top side of the tube base body 40211 and the third notch region 40255.

[0102] The laser chip 4026 is located on the first side of the first substrate 4025, and the distance between the laser chip 4026 and the first side of the first substrate 4025 is close. When the photodetector 4027 is not located in the cavity (i.e., without the third notch region), part of the monitoring light will be reflected through the first side of the first substrate 4025, so that the received monitoring light is limited, which may cause lower monitoring accuracy. In order to improve the monitoring accuracy, in some embodiments, the photodetector 4027 is placed in the cavity surrounded by the top side of the tube base body 40211 and the third notch region 40255. The photodetector 4027 located in the cavity can receive more monitoring light, thereby improving the monitoring accuracy.

[0103] The distance between the top side of the third notch region 40255 and the laser chip 4026 is 200-400 μm. The distance between the top side of the third notch region 40255 and the laser chip 4026 refers to the distance between the top side of the third notch region 40255 and the bottom side of the laser chip. The bottom side of the laser chip refers to the side of the laser chip close to the third notch region, not the side connected to the first side of the first substrate, nor the side away from the first side of the first substrate.

[0104] The application provides an optical module comprising an optical transmitter. The optical transmitter comprises a socket and a pin. The socket is provided with a first substrate. The pin comprises a first pin and a second pin which extend into and out of the socket. The first substrate is provided with a first notch area, a second notch area, a first signal transmission area and a second signal transmission area. The first notch area and the second notch area are both formed by the inward recess of the first side surface of the first substrate and the bottom surface of the first substrate. The first pin is arranged in the first notch area. The second pin is arranged in the second notch area. The arrangement of the first pin in the first notch area and the arrangement of the second pin in the second notch area facilitate the determination of the placement position of the first substrate on the socket, thereby improving the coupling efficiency. The first signal transmission area extends downward from the first side surface of the first substrate to the top surface of the first notch area. The surface of the first signal transmission area is paved with a first high-frequency signal line to form a first signal line transmission layer. The second signal transmission area extends downward from the first side surface of the first substrate to the top surface of the second notch area. The surface of the second signal transmission area is paved with a second high-frequency signal line to form a second signal line transmission layer. The first pin is connected with the first signal line transmission layer located in the first notch area. The second pin is connected with the second signal line transmission layer located in the second notch area. The connection of the first pin with the first signal line transmission layer located in the first notch area increases the contact area of the first pin with the first signal line transmission layer, thereby improving the transmission rate of the high-frequency signal. Correspondingly, the connection of the second pin with the second signal line transmission layer located in the second notch area increases the contact area of the second pin with the second signal line transmission layer, thereby improving the transmission rate of the high-frequency signal. The surface of the second signal line transmission layer is provided with a laser chip. The laser chip is connected with the surface of the second signal line transmission layer through a negative pin and is connected with the surface of the first signal line transmission layer through a positive pin. In the application, the optical transmitter does not have a metal boss for fixing the laser chip, but only has a first substrate for fixing the laser chip, and the first substrate is a ceramic substrate, thereby avoiding the capacitive effect caused by the interaction between the metal boss and the pin, reducing the impedance mismatch of the high-frequency signal line connected with the pin caused by the capacitive effect, thereby reducing the signal reflection phenomenon caused by the impedance mismatch of the high-frequency signal line, and improving the bandwidth of the high-frequency signal line.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application.

Claims

1. An optical module characterized by comprising: The application relates to a light emitting device, comprising a socket and a pin. The socket is provided with a first substrate. The pin comprises a first pin and a second pin which extend into and out of the socket. The first substrate is a ceramic substrate which is provided with a first notch area, a second notch area, a third notch area, a first signal transmission area and a second signal transmission area. The first notch area is formed by inwardly recessing the first side surface of the first substrate and the bottom surface of the first substrate, and the first pin is arranged in the first notch area. The second notch area is formed by inwardly recessing the first side surface of the first substrate and the bottom surface of the first substrate, and the second pin is arranged in the second notch area. The third notch area is located between the first notch area and the second notch area, and a light detector is arranged in the third notch area; the light detector is electrically connected with the first substrate. The first signal transmission area extends from the first side surface of the first substrate to the top surface of the first notch area, and a first high-frequency signal line is arranged on the surface of the first signal transmission area to form a first signal line transmission layer. The second signal transmission area is not connected with the first signal transmission area, extends from the first side surface of the first substrate to the top surface of the second notch area, and a second high-frequency signal line is arranged on the surface of the second signal transmission area to form a second signal line transmission layer. The first pin is connected with the first signal line transmission layer located in the first notch area. The second pin is connected with the second signal line transmission layer located in the second notch area. The second signal line transmission layer is provided with a laser chip. The negative pin of the laser chip is connected with the surface of the second signal line transmission layer, and the positive pin of the laser chip is wire-bonded with the surface of the first signal line transmission layer. The socket comprises:

2. The optical module according to claim 1, characterized by The socket body is provided with a first substrate on the top surface. The inner side surface of the protrusion is in contact with the side surface of the socket body, the top surface is in contact with the cap, and the height difference between the top surface of the socket body and the top surface of the protrusion is greater than the height of the pin protruding from the top surface of the socket body. The protrusion is obtained by extending the edge of the socket body towards the cap.

3. The optical module according to claim 2, characterized by The distance between the top surface of the third notch area and the laser chip is 200-400 mu m.

4. The optical module according to claim 1, characterized by The application further comprises a second substrate.

5. The optical module according to claim 2, characterized by The second substrate is fixed to the top surface of the socket body, and a pad area is arranged on the top surface of the second substrate. The pad area is wire-bonded with the positive pin of the laser chip. The light detector is located on the top surface of the second substrate, the negative pin is also connected with the pad area, and the positive pin is connected with the third pin of the pin. The application further comprises a second substrate.

6. The optical module according to claim 2, characterized by The second substrate is fixed to the top surface of the socket body, and a pad area is arranged on the top surface of the second substrate. The pad area is wire-bonded with the third pin of the pin. The light detector is located on the top surface of the second substrate, the negative pin is connected with the pad area, and the positive pin is connected with the socket. The pin further comprises a fourth pin.

7. The optical module of claim 1, wherein, The first end of the fourth pin is grounded, and the second end of the fourth pin is connected with the socket. The shape of the top view of the protrusion is annular.

8. The optical module according to claim 2, characterized by The application further comprises:

9. The optical module of claim 1, wherein, ​ The round-square tube body is provided with a first pipe orifice and a second pipe orifice, and the light emitter is inlaid in the first pipe orifice. The light receiving device is inlaid in the second pipe orifice. The optical assembly is arranged in the inner cavity of the round-square tube body, and is used for adjusting the data light emitted by the light emitting device and the data light incident to the light receiving device.

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