An optical module

Abstract

This application discloses an optical module, comprising: a circuit board, a packaging substrate, an optical chip, and a filler layer. The packaging substrate is electrically connected to the circuit board; the optical chip is disposed opposite to the packaging substrate, with bumps on the side of the optical chip facing the packaging substrate and pads on the side of the packaging substrate facing the optical chip, the bumps being soldered to the pads; a filler layer is disposed between the optical chip and the packaging substrate, and the filler layer at least covers the bumps and pads to improve the mechanical strength and electrical connection stability between the optical chip and the circuit board.

Description

Technical Field

[0001] This application relates to the field of optical communication technology, and in particular to an optical module. Background Technology

[0002] 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, optical modules are the tools for converting between photoelectric and electrical signals, and are one of the key components in optical communication equipment. Furthermore, with the evolving needs of optical communication technology, the transmission quality of optical modules is continuously improving.

[0003] An optical module consists of a circuit board and an optical chip. The optical chip is electrically connected to the circuit board via a packaging substrate. The mechanical strength between the optical chip and the packaging substrate is relatively low, resulting in poor electrical connection stability. Summary of the Invention

[0004] This application provides an optical module to solve the problems of low mechanical strength and poor electrical connection stability between the optical chip and the packaging substrate.

[0005] To address the aforementioned technical problems, the embodiments of this application disclose the following technical solutions:

[0006] In a first aspect, embodiments of this application disclose an optical module, including a circuit board;

[0007] The packaging substrate is electrically connected to the circuit board.

[0008] The optical chip is positioned opposite to the packaging substrate. The side of the optical chip facing the packaging substrate has a bump, and the side of the packaging substrate facing the optical chip has a pad. The bump is soldered to the pad.

[0009] A filler layer is provided between the optical chip and the packaging substrate, and the filler layer at least covers the bumps and pads.

[0010] The above technical solution has the following advantages: a filling layer is provided between the optical chip and the packaging substrate, and the filling layer at least covers the bumps and pads. The filling layer fills the gap between the optical chip and the packaging substrate, so that the optical chip, the packaging substrate and the filling layer together form a rigid junction; the number of contact points between the optical chip and the packaging substrate is increased. Based on the principle that the contact points between objects can disperse stress, the stress between the optical chip and the packaging substrate is effectively dispersed to multiple contact points, the stress on each contact point is reduced, and the stability and mechanical strength of the connection between the optical chip and the packaging substrate are improved.

[0011] In some embodiments, the optical chip includes a light emitting chip, the light emitting surface of which is exposed in the filler layer, wherein the light emitting surface is adjacent to a surface of the light emitting chip having bumps.

[0012] The above technical solution has the following advantages: the light-emitting surface of the light-emitting chip is exposed to the filling layer, so as to prevent glue from contaminating the light-emitting surface and improve the light-emitting quality of the light-emitting chip.

[0013] In some embodiments, the light-emitting surface is suspended relative to the sidewall of the packaging substrate.

[0014] The above technical solution has the following advantages: the light-emitting surface is suspended relative to the side wall of the packaging substrate, so that the light-emitting surface is exposed to the filling layer, thereby preventing glue from contaminating the light-emitting surface and improving the light emission quality of the light-emitting chip.

[0015] In some embodiments, the light-emitting surface extends beyond the sidewall of the packaging substrate.

[0016] The above technical solution has the following advantages: the light-emitting surface extends from the side wall of the packaging substrate. Since the adhesive will be subject to gravity, the overflowing adhesive will flow down the side wall of the packaging substrate under the action of gravity, so as to prevent the adhesive from contaminating the light-emitting surface.

[0017] In some embodiments, the packaging substrate is recessed inward to form a first recess, and the light-emitting surface is suspended above the first recess.

[0018] The above technical solution has the following advantages: the light-emitting surface is suspended in the first recess, which prevents glue from contaminating the light-emitting surface and improves the light emission quality, and enables the miniaturization of the light-emitting chip to improve the space utilization of the optical module.

[0019] In some embodiments, the first recess is configured as a first notch, which is formed by hollowing out from one side edge of the encapsulation substrate into the encapsulation substrate.

[0020] The above technical solution has the following advantages: the light-emitting surface is suspended above the first notch, so that the light emitted from the light-emitting surface can propagate unobstructed through the first notch, thereby improving the propagation quality of the emitted light.

[0021] In some embodiments, the light-emitting chip includes two sidewalls along the width direction, the light-emitting surface is connected between the two sidewalls, and the portions of the two sidewalls located on the first notch are suspended above the first notch.

[0022] The above technical solution has the following advantages: it prevents the emitted light from being reflected by the sidewall of the first notch along the width direction of the light emitting chip, thereby improving the light emission efficiency.

[0023] In some embodiments, the light emitting chip further includes a reflective surface configured to reflect light from inside the light emitting chip to the light emitting surface, and the reflective surface is exposed in the filler layer, wherein the reflective surface is adjacent to the surface of the light emitting chip facing the packaging substrate.

[0024] The above technical solution has the following advantages: exposing the reflective surface to the filler layer can effectively prevent the chlorine element in the adhesive from corroding the reflective film on the reflective surface, thus ensuring the reflective performance of the reflective film.

[0025] In some embodiments, the reflective surface is configured to be suspended relative to the sidewall of the encapsulation substrate.

[0026] The above technical solution has the following advantages: the reflective surface is suspended relative to the side wall of the packaging substrate, which can effectively prevent chlorine in the adhesive from corroding the reflective surface and ensure the reflective performance of the reflective surface.

[0027] In some embodiments, the optical chip further includes a waveguide disposed on the side of the optical chip with bumps, for transmitting light from the light emitting chip to a position close to the light emitting surface, and a filling layer covering the waveguide.

[0028] The above technical solution has the following advantages: the filling layer covers the waveguide to prevent moisture from causing damage to the waveguide surface or changes in refractive index, thereby ensuring the performance of the waveguide.

[0029] Compared with the prior art, the beneficial effects of this application are as follows:

[0030] This application discloses an optical module comprising: a circuit board, a packaging substrate, an optical chip, and a filler layer. The packaging substrate is electrically connected to the circuit board; the optical chip is disposed opposite to the packaging substrate, with bumps on the side of the optical chip facing the packaging substrate and pads on the side of the packaging substrate facing the optical chip, the bumps being soldered to the pads; a filler layer is disposed between the optical chip and the packaging substrate, and the filler layer at least covers the bumps and pads. By soldering the bumps to the pads, the packaging substrate is electrically connected to the circuit board, realizing the electrical connection between the optical chip and the circuit board. The filler layer between the optical chip and the packaging substrate increases the contact points between them. Based on the principle that contact points between objects can disperse stress, the stress between the optical chip and the packaging substrate is dispersed to multiple contact points, reducing the stress on the bumps and pads, thereby improving the mechanical strength and electrical connection stability of the bump-pad connection, i.e., improving the stability of the electrical connection between the optical chip and the circuit board, and also enhancing drop resistance. Thus, based on the cooperation between the optical chip and the circuit board to realize the function of the optical module, the stable electrical connection between the optical chip and the circuit board is beneficial to improving the performance of the optical module. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a partial structural diagram of an optical communication system according to some embodiments;

[0033] Figure 2 This is a partial structural diagram of a host computer according to some embodiments;

[0034] Figure 3 This is a structural diagram of an optical module according to some embodiments;

[0035] Figure 4 An exploded view of an optical module according to some embodiments;

[0036] Figure 5 A schematic diagram of the structure of an optical chip and a packaging substrate in an optical module provided in this application embodiment. Figure 1 ;

[0037] Figure 6 for Figure 5 Exploded view of the optical chip and packaging substrate;

[0038] Figure 7 for Figure 5 A schematic diagram of the structure of the optical chip;

[0039] Figure 8 for Figure 5 Schematic diagram of the structure of the intermediate packaging substrate;

[0040] Figure 9a for Figure 5 A flowchart illustrating the process of filling the intermediate filling layer between the optical chip and the packaging substrate;

[0041] Figure 9b for Figure 9a A schematic diagram of step S110;

[0042] Figure 9c for Figure 9a A schematic diagram of step S120;

[0043] Figure 9d for Figure 9a Schematic diagram of step S130 Figure 1 ;

[0044] Figure 9e for Figure 9a Schematic diagram of step S130 Figure 2 ;

[0045] Figure 9f for Figure 9e Another perspective on the structure;

[0046] Figure 9g for Figure 9a Schematic diagram of step S130 Figure 3 ;

[0047] Figure 9h for Figure 9a A schematic diagram of step S140;

[0048] Figure 9i for Figure 9a A schematic diagram of step S150;

[0049] Figure 10a A schematic diagram of the structure of an optical chip and a packaging substrate in an optical module provided in this application embodiment. Figure 2 ;

[0050] Figure 10b for Figure 10a Exploded view;

[0051] Figure 11a A schematic diagram of the structure of an optical chip and a packaging substrate in an optical module provided in this application embodiment. Figure 3 ;

[0052] Figure 11b for Figure 11a Exploded view;

[0053] Figure 11c A schematic diagram of the structure of an optical chip and a packaging substrate in an optical module provided in this application embodiment. Figure 4 ;

[0054] Figure 11d for Figure 11c Exploded view;

[0055] Figure 12a for Figure 9a Schematic diagram of step S130 Figure 4 ;

[0056] Figure 12b for Figure 9a Schematic diagram of step S130 Figure 5 . Detailed Implementation

[0057] 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.

[0058] 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.

[0059] In optical communication technology, to establish information transmission between information processing devices, information needs to be loaded onto light, and the propagation of light is used to transmit the information. Here, the light carrying the information is called an optical signal. When optical signals are transmitted in information transmission equipment, optical power loss can be reduced, thus enabling high-speed, long-distance, and low-cost information transmission. Information processing devices can recognize and process electrical signals. Information processing devices typically include optical network units (ONUs), gateways, routers, switches, mobile phones, computers, servers, tablets, televisions, etc., while information transmission equipment typically includes optical fibers and optical waveguides.

[0060] An optical module enables the conversion between optical and electrical signals between information processing and transmission devices. For example, at least one of the optical signal input or output ports of the optical module is connected to an optical fiber, and at least one of the electrical signal input or output ports is connected to an optical network terminal. A first optical signal from the optical fiber is transmitted to the optical module, which converts it into a first electrical signal and transmits it to the optical network terminal. A second electrical signal from the optical network terminal is transmitted to the optical module, which converts it into a second optical signal and transmits it back to the optical fiber. Since multiple information processing devices can transmit information via electrical signals, at least one of the devices needs to be directly connected to the optical module, rather than all devices. Here, the information processing device directly connected to the optical module is referred to as the host computer of the optical module. Furthermore, the optical signal input or output port of the optical module can be referred to as an optical port, and the electrical signal input or output port can be referred to as an electrical port.

[0061] Figure 1 This is a partial structural diagram of an optical communication system according to some embodiments. Figure 1 As shown, the optical communication system mainly includes a remote information processing device 1000, a local information processing device 2000, a host computer 100, an optical module 200, an optical fiber 101, and a network cable 103.

[0062] One end of optical fiber 101 extends toward the remote information processing device 1000, and the other end of optical fiber 101 is connected to optical module 200 through the optical port of optical module 200. The optical signal can undergo total internal reflection in 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 optical fiber 101 to transmit the optical signal from the remote information processing device 1000 to optical module 200, or to transmit the optical signal from optical module 200 to remote information processing device 1000, thereby realizing long-distance, low-power loss information transmission.

[0063] The optical communication system may include one or more optical fibers 101, and the optical fibers 101 may be detachably or fixedly connected to the optical module 200. The host computer 100 is configured to provide data signals to the optical module 200, receive data signals from the optical module 200, or monitor or control the operating status of the optical module 200.

[0064] The host computer 100 includes a generally rectangular housing and an optical module interface 102 disposed on the housing. The optical module interface 102 is configured to connect to the optical module 200 so that the host computer 100 and the optical module 200 can establish a one-way or two-way electrical signal connection.

[0065] The host computer 100 also includes an external power interface that can connect to an electrical signal network. For example, this external power interface includes a Universal Serial Bus (USB) interface or a network cable interface 104, which 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. One end of the network cable 103 is connected to the local information processing device 2000, and the other end of the network cable 103 is connected to the host computer 100, thereby establishing an electrical signal connection between the local information processing device 2000 and the host computer 100 via the network cable 103. For example, a third electrical signal emitted by the local information processing device 2000 is transmitted to the host computer 100 via the network cable 103. The host computer 100 generates a second electrical signal based on the third electrical signal. This second electrical signal from the host computer 100 is transmitted to the optical module 200, which converts the second electrical signal into a second optical signal and transmits it to the optical fiber 101. The second optical signal is then transmitted in the optical fiber 101 to the remote information processing device 1000. Alternatively, a first optical signal from the remote information processing device 1000 propagates through the optical fiber 101 and is transmitted to the optical module 200. The optical module 200 converts the first optical signal into a first electrical signal and transmits it to the 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 the local information processing device 2000. It should be noted that an optical module is a tool for converting optical signals to electrical signals. During the conversion process, the information itself does not change, but the encoding and decoding methods can change.

[0066] In addition to optical network terminals, the host computer 100 also includes optical line terminals (OLTs), optical network equipment (ONTs), or data center servers.

[0067] Figure 2 This 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 the structure of the host computer 100 related to the optical module 200 is shown. For example... Figure 2 As shown, the host computer 100 also includes a PCB circuit board 105 disposed within the housing, a cage 106 disposed on the surface of the PCB circuit board 105, a heat sink 107 disposed on the cage 106, and an electrical connector disposed inside the cage 106. The electrical connector is configured to connect to the electrical port of the optical module 200; the heat sink 107 has fins and other protruding structures to increase the heat dissipation area.

[0068] The optical module 200 is inserted into the cage 106 of the host computer 100, where it is secured. Heat generated by the optical module 200 is conducted to the cage 106 and then dissipated through the heat sink 107. After insertion into the cage 106, the optical module 200's electrical port connects to the electrical connector inside the cage 106, establishing a bidirectional electrical signal connection between the optical module 200 and the host computer 100. Furthermore, the optical port of the optical module 200 connects to the optical fiber 101, establishing a bidirectional optical signal connection between the optical module 200 and the optical fiber 101.

[0069] Figure 3 This is a structural diagram of an optical module according to some embodiments. Figure 4 This is an exploded view of an optical module according to some embodiments. Figure 3 and Figure 4 As shown, the optical module 200 includes a shell, a circuit board 300 disposed within the shell, a light emitting component 400, and a light receiving component 500. However, this disclosure is not limited thereto; in some embodiments, the optical module 200 includes one of the light emitting component 400 and the light receiving component 500.

[0070] 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 having two openings 204 and 205; the outer contour of the housing is generally square.

[0071] 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.

[0072] 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.

[0073] 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, from which the gold fingers of circuit board 300 extend and are inserted into the electrical connector of host computer 100; opening 205 is an optical port, configured to connect to external optical fiber 101 so that optical fiber 101 connects optical emitting component 400 and optical receiving component 500 in optical module 200.

[0074] The assembly method using an upper housing 201 and a lower housing 202 facilitates the installation of the circuit board 300, the light emitting component 400, the light receiving component 500, etc., into the aforementioned housings. The upper housing 201 and the lower housing 202 can encapsulate and protect these devices. Furthermore, the assembly of the circuit board 300, the light emitting component 400, and the light receiving component 500 facilitates the deployment of positioning components, heat dissipation components, and electromagnetic shielding components for these devices, which is beneficial for automated production.

[0075] In some embodiments, the upper housing 201 and the lower housing 202 are made of metal materials, which facilitates electromagnetic shielding and heat dissipation.

[0076] 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.

[0077] 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.

[0078] Circuit board 300 includes circuit traces, electronic components, and chips. The circuit traces connect the electronic components and chips according to the circuit design 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, for example, microcontroller units (MCUs), laser driver chips, transimpedance amplifiers (TIAs), limiting amplifiers (LIAs), clock and data recovery chips (CDRs), power management chips, and digital signal processing (DSP) chips.

[0079] Circuit board 300 is generally a rigid circuit board. Due to its relatively hard material, the rigid circuit board can also perform a load-bearing function. For example, the rigid circuit board can stably support the aforementioned electronic components and chips. The rigid circuit board can also be inserted into the electrical connector in the cage 106 of the host computer 100.

[0080] The circuit board 300 also includes gold fingers formed on its end surfaces, each gold finger consisting of a plurality of independent pins. The circuit board 300 is inserted into a cage 106 and is electrically connected to an electrical connector within the cage 106 by the gold fingers. The gold fingers may be located only on one side of the surface of the circuit board 300 (e.g., ...). Figure 4 The upper surface shown can also be positioned on the upper and lower surfaces of the circuit board 300 to provide a greater number of pins, thus adapting to applications with high pin count requirements. The gold fingers are configured to establish an electrical connection with the host computer to achieve power supply, grounding, two-wire synchronous serial (Inter-Integrated Circuit, I2C) signal transmission, and data signal transmission. 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.

[0081] At least one of the light emitting component 400 or the light receiving component 500 is located on the side of the circuit board 300 away from the gold fingers. The light emitting component 400 is used to emit light signals. The light receiving component 500 is used to receive light signals.

[0082] In some embodiments, the light emitting component 400 and the light receiving component 500 are physically separated from the circuit board 300, and then electrically connected to the circuit board 300 through corresponding flexible circuit boards or electrical connectors.

[0083] In some embodiments, at least one of the light emitting component or the light receiving component may be directly disposed on the circuit board 300. For example, at least one of the light emitting component or the light receiving component may be disposed on the surface of the circuit board 300 or the side of the circuit board 300.

[0084] Figure 5 A schematic diagram of the structure of an optical chip and a packaging substrate in an optical module provided in this application embodiment. Figure 1 ; Figure 6 for Figure 5 Exploded view of the optical chip and packaging substrate; Figure 7 for Figure 5 A schematic diagram of the structure of the optical chip; Figure 8 for Figure 5 A schematic diagram of the structure of the mid-packaging substrate. The following is a combination of... Figures 4 to 8 The structures of the optical chip 420 and the packaging substrate 410 in the optical module of this application are described below. Figures 4 to 8 As shown, the optical module 200 includes a circuit board 300, which can be disposed on the lower housing 202.

[0085] In some examples, circuit board 300 can be a printed circuit board (PCB).

[0086] In some embodiments, the optical module further includes a packaging substrate 410, which is electrically connected to the circuit board 300.

[0087] In some examples, the packaging substrate 410 can be connected to the circuit board 300 by bonding or soldering, and there are no restrictions on the connection method between the packaging substrate 410 and the circuit board 300.

[0088] In some examples, the packaging substrate 410 can be a chip on carrier substrate (COC SUB), also known as a chip on carrier carrier, and there is no limitation on the type of packaging substrate 410.

[0089] In some examples, the packaging substrate 410 may be made of ceramic material, glass material, organic material or silicon-based material, and there is no limitation on the material of the packaging substrate 410.

[0090] In some embodiments, the optical module 200 further includes an optical chip 420, which is disposed opposite to the packaging substrate 410 and is welded to the packaging substrate 410.

[0091] In some examples, the opposite sides of the packaging substrate 410 are connected to the optical chip 420 and the circuit board 300, respectively.

[0092] In some examples, the optical chip 420 is used to convert electrical signals into optical signals and transmit the optical signals through optical fibers; or to convert received optical signals into electrical signals and transmit them through network cables.

[0093] In some examples, the optical chip 420 used to convert electrical signals into optical signals is an optical emitting chip.

[0094] In some examples, the optical chip 420 used to convert optical signals into electrical signals is an optical receiver chip.

[0095] In some examples, the optical chip 420 can be a Group III-V chip such as an electro-absorption modulated laser (EML) or a distributed feedback laser (DFB), and there is no restriction on the type of optical chip.

[0096] In some examples, the optical chip 420 may include a substrate 423, which serves as the bottom base material of the optical chip.

[0097] In some examples, the optical chip 420 is electrically and mechanically connected to the packaging substrate 410 via an appropriate number of bumps 421 on its surface in a flip-chip manner. As a flip chip, it may contain circuit units.

[0098] In some examples, the packaging substrate 410 has a pad 411 on the side facing the optical chip 420, and the pad 411 is soldered to the bump 421.

[0099] In some examples, the optical emitting chip emits optical signals from one of its own surfaces, and the emitted optical signals are then transmitted to an optical fiber. This emitting surface is called the light-emitting surface.

[0100] In some examples, the light-emitting chip generates light from an internal surface, loads information onto the light to obtain a light signal, and the light signal is emitted from the light-emitting surface, which is the light-emitting surface.

[0101] In some examples, the light-emitting chip also includes electrodes (not shown).

[0102] In some examples, the light-emitting chip is mounted upright onto the packaging substrate. The light-emitting chip includes two opposing sides, with the emitting surface and electrodes located on the opposing sides of the light-emitting chip, respectively. After the light-emitting chip is mounted onto the packaging substrate, the electrodes are located between the emitting surface and the packaging substrate. In other words, the light-emitting chip is mounted on the packaging substrate with the emitting surface facing upwards, and the electrodes are located at the bottom of the light-emitting chip.

[0103] In some examples, the light-emitting chip is flip-chip mounted onto the packaging substrate, with electrodes formed on the surface of the light-emitting surface. After the light-emitting chip is mounted onto the packaging substrate, the electrodes are located between the light-emitting surface and the packaging substrate. In other words, the light-emitting surface of the light-emitting chip faces downwards, and the electrodes are located at the bottom of the light-emitting chip.

[0104] In some examples, the optical chip has bumps on the side facing the packaging substrate, and the bumps are soldered to the packaging substrate.

[0105] In some examples, the packaging substrate has pads on the side facing the optical chip, and the pads are soldered to bumps to form solder joints.

[0106] In some examples, the pads can be made of metal for transmitting electrical signals and conducting current, and also for carrying bumps to enable electrical connections with the bumps.

[0107] Because the coefficients of thermal expansion between the bumps and the packaging substrate differ significantly, substantial thermal stress is generated at the solder joints. This thermal stress affects the stability of the solder joint connection, thereby impacting the mechanical strength between the optical chip and the packaging substrate. Simultaneously, the optical chip and packaging substrate are electrically connected via solder joints; a decrease in the mechanical strength between the optical chip and the packaging substrate also leads to a deterioration in the stability of the electrical connection.

[0108] In addition, due to the large difference in thermal expansion coefficients between the bumps and the packaging substrate, as well as insufficient soldering, gaps may exist between the pads and the bumps, affecting the airtightness between the optical chip and the packaging substrate. Moisture may seep through these gaps into the electrical connection path between the optical chip or the packaging substrate, thereby affecting the working performance and lifespan of the optical module.

[0109] Therefore, by providing a filler layer 430 between the optical chip 420 and the packaging substrate 410, the filler layer 430 at least covers the bump 421 and the pad 411.

[0110] By using the filler layer 430 between the optical chip 420 and the packaging substrate 410, the optical chip 420, the packaging substrate 410, and the filler layer 430 together form a rigid structure, increasing the mechanical strength between the optical chip 420 and the packaging substrate 410. At the same time, the filler layer 430 wraps around the bump 421 and the pad 411, that is, the filler layer 430 contacts the bump 421 and the pad 411, increasing the contact points around the solder joint. Based on the principle that contact points between objects can disperse stress, the thermal stress generated between the optical chip 420 and the packaging substrate 410 is effectively dispersed to multiple contact points, reducing the stress on each contact point and improving the stability of the soldering between the optical chip 420 and the packaging substrate 410.

[0111] In addition, the filler layer 430 wraps around the bumps 421 and the pads 411, which can isolate the bumps 421 from the outside world and the pads 411 from the outside world, preventing external moisture from penetrating into the optical chip 420 and the packaging substrate 410. The effect of preventing moisture penetration is more obvious in non-airtight environments, thereby reducing the impact of moisture on the solder joints, increasing the stability of the solder joint connection and extending the service life of the optical chip 420 and the packaging substrate 410. The effect of extending the service life is even more significant at high temperatures.

[0112] In some examples, the filler layer 430 is constructed by forming an underfill adhesive.

[0113] In some examples, the filler layer 430 may be made of epoxy resin or optical adhesive.

[0114] In some examples, the filler layer 430 can be made of epoxy resin adhesive with silica (SiO2) particles, epoxy resin adhesive without SiO2 particles, or acrylic adhesive, etc., and there are no specific restrictions on the material of the filler layer.

[0115] The heat dissipation coefficient of the filling layer 430 is greater than that of air. By filling the space between the optical chip 420 and the packaging substrate 410 with the filling layer 430, and based on the principle that a higher heat dissipation coefficient leads to greater heat dissipation efficiency, the heat generated by the optical chip 420 is dissipated outwards through the bumps 421, pads 411, and the filling layer 430. Compared to related technologies where heat is dissipated outwards through the bumps 421, pads 411, and air in the gap between the optical chip 420 and the packaging substrate 410, this significantly improves the heat dissipation efficiency of the optical chip 420. This prevents the optical chip 420 from operating at high temperatures, ensuring its performance and thus improving the overall performance of the optical module 200. In some embodiments, the optical chip 420 also includes a waveguide 422, which confines light within the channel of the optical chip 420 through total internal reflection.

[0116] In some embodiments, waveguide 422 is configured as an optical waveguide.

[0117] In some embodiments, the light-emitting chip emits light from its own light-emitting surface, and the waveguide 422 is used to guide and transmit the light to a position close to the light-emitting surface 425, thereby playing the role of transmitting the light. In order to ensure that the optical signal can be transmitted efficiently from the waveguide to the light-emitting surface 425 with low loss, the waveguide needs to be optically coupled to the light-emitting surface 425. Therefore, the performance requirements of the waveguide 422 are relatively high.

[0118] In some examples, waveguide 422 is located on the side of optical chip 420 with bump 421; in order to ensure good performance of waveguide 422, filler layer 430 covers waveguide 422 to prevent moisture from penetrating into waveguide 422 through gaps, thereby causing damage to the surface of waveguide 422 or changes in refractive index, thus ensuring the performance of waveguide 422.

[0119] In some embodiments, the filler layer 430 is configured to be formed using capillary action, and at least one gap formed between the surfaces of the optical chip 420 and the package substrate 410 facing each other, the bump 421 and the pad 411 can serve as a capillary.

[0120] Figure 9a for Figure 5 A flowchart illustrating the process of filling the intermediate filling layer between the optical chip and the packaging substrate; Figure 9b for Figure 9a A schematic diagram of step S110; Figure 9c for Figure 9a A schematic diagram of step S120. (See diagram below.) Figure 9a As shown, filling the space between the optical chip and the packaging substrate with a filling layer may include at least steps S110 to S150.

[0121] Step S110: The bumps 421 of the optical chip 420 are soldered to the pads 411 of the packaging substrate 410 to form a carrier chip (COC).

[0122] Step S120: Place the carrier chip on the worktable 440, and the packaging substrate 410 is located between the optical chip 420 and the worktable 440.

[0123] Step S130: Apply adhesive to the dispensing area 443 of the packaging substrate 410 using the dispensing device 450, and heat the packaging substrate 410 at a first temperature using the worktable 440.

[0124] Specifically, the packaging substrate 410 is heated to a first temperature to make the adhesive flow, thereby accelerating the capillary action of the adhesive in the capillary and improving the efficiency of the adhesive filling between the optical chip 420 and the packaging substrate 410.

[0125] In some examples, the first temperature can be determined based on the flow characteristics of the adhesive, and the temperature corresponding to the high fluidity of the adhesive can be selected.

[0126] In some examples, if the adhesive used for the filler layer 430 is epoxy resin, the first temperature can be greater than or equal to 60 degrees Celsius and less than or equal to 90 degrees Celsius. At the first temperature, the intermolecular forces of the epoxy resin are weakened, and the intermolecular movement can easily overcome viscous resistance, thus exhibiting good flowability. If the first temperature is less than 60 degrees Celsius or greater than 90 degrees Celsius, the flowability of the epoxy resin will decrease, which is not conducive to its filling between the optical chip 420 and the packaging substrate 410.

[0127] In some examples, the fluidity of the adhesive at room temperature allows it to fill the space between the optical chip 420 and the packaging substrate 410, eliminating the need to heat the packaging substrate 410.

[0128] Figure 9d for Figure 9a Schematic diagram of step S130 Figure 1 ; Figure 9e for Figure 9a Schematic diagram of step S130 Figure 2 ; Figure 9f for Figure 9e Another perspective on the structure; Figure 9g for Figure 9a Schematic diagram of step S130 Figure 3 .like Figures 9d to 9f As shown, the dispensing area 443 may include a portion of the surface of the encapsulation substrate 410 facing the optical chip 420, corresponding to the periphery of the optical chip 420. For example... Figure 9e In the example, the dispensing area 443 is the periphery of one end of the optical chip 420 on the surface of the encapsulation substrate 410 facing the optical chip 420.

[0129] It is understandable that the dispensing area 443 can also be used to represent the area formed by the movement trajectory of the adhesive ejected from the dispensing device 450 on the encapsulation substrate 410.

[0130] like Figure 9d As shown, in some examples, the dispensing device 450 can be a contact pressure valve or a spiral pump valve.

[0131] and Figure 9g As shown, in some embodiments, the dispensing device 450 may be a non-contact jet pump valve.

[0132] In application, the type of dispensing device 450 can be selected based on the output pressure of the dispensing device 450, the viscosity of the adhesive, and the surface material of the optical chip 420 and the packaging substrate 410. This embodiment does not limit the type of dispensing device 450.

[0133] Figure 9h for Figure 9a A schematic diagram of step S140; Figure 9i for Figure 9aA schematic diagram of step S150.

[0134] Step S140: Heat the packaging substrate 410 at a second temperature using a worktable 440 or place the carrier chip in an oven.

[0135] In some embodiments, the packaging substrate 410 is heated at a second temperature, or the carrier chip is placed in an oven with a second temperature to heat and cure the adhesive, thereby forming a rigid structure together with the optical chip 420 and the packaging substrate 410 to increase the connection strength between the optical chip 420 and the packaging substrate 410.

[0136] For the same type of adhesive, the second temperature is higher than the first temperature.

[0137] For example, if the filler layer 430 uses epoxy resin adhesive, the second temperature can be greater than or equal to 90 degrees Celsius and less than or equal to 120 degrees Celsius. At the second temperature, the intermolecular interaction force of the epoxy resin adhesive increases, making it more difficult for the intermolecular movement to overcome viscous resistance, thereby reducing its fluidity. If the second temperature is less than 90 degrees Celsius, the epoxy resin adhesive has a high fluidity, which is not conducive to its curing; if the second temperature is greater than 120 degrees Celsius, the epoxy resin adhesive may denature and lose its adhesiveness, thus failing to form a rigid structure together with the optical chip 420 and the packaging substrate 410.

[0138] In some embodiments, the worktable used in step S140 can be distinguished from the worktable 440 used in step S140.

[0139] In step S130, the worktable 440 can be a work platform used for preheating (heating the packaging substrate 410 at a first temperature), carrying and fixing the carrier chip.

[0140] In step S140, the worktable 440 can be a heating platform, used to heat the packaging substrate 410 at a second temperature after the adhesive is filled into the optical chip 420 and the packaging substrate 410, so that the adhesive is cured by heat.

[0141] Step S150, End.

[0142] In some embodiments, after the adhesive is heated and cured, the bottom filling is completed, resulting in an overall structure of the optical chip 420 filled with the filling layer 430 and the encapsulation substrate 410.

[0143] The amount of adhesive applied, the application range, the arrangement of the bumps, and the distance between the optical chip 420 and the packaging substrate 410 all affect the flow rate of the adhesive. This makes it difficult to control the flow range of the adhesive during the process of filling the space between the optical chip 420 and the packaging substrate 410. Furthermore, to ensure that the cured adhesive can cover the bumps 421 and pads 11, adhesive may overflow between the packaging substrate 410 and the optical chip 420. Because the distance between the optical chip 420 and the packaging substrate 410 is small, the overflowing adhesive may contaminate the sidewalls of the optical chip 420, which are adjacent to the surface of the optical chip 420 facing the packaging substrate 410.

[0144] In some embodiments, the optical chip 420 includes a light emitting chip, and the sidewall of the light emitting chip includes a light-emitting surface 425.

[0145] In some examples, to prevent overflowing adhesive from contaminating the light-emitting surface and thus affecting the light emission quality of the light-emitting chip, the light-emitting surface 425 of the light-emitting chip is exposed to the filler layer 430. The light-emitting surface 425 is adjacent to the surface of the light-emitting chip with bumps 421 to prevent adhesive contamination of the light-emitting surface 425 and improve the light emission quality of the light-emitting chip.

[0146] As mentioned earlier, the light emitting chip emits light from the light emitting surface 425, and the emitted light propagates into the optical fiber.

[0147] In some examples, the light-emitting surface 425, also known as the AR surface, is coated with an anti-reflection film. The anti-reflection film is used to allow more light to pass through, thereby improving the light emission efficiency of the light-emitting chip and thus improving the working performance of the optical module 200.

[0148] like Figure 5 As shown, in some embodiments, the light-emitting surface 425 is suspended relative to the sidewall of the packaging substrate 410, so that the light-emitting surface 425 is exposed to the filler layer 430.

[0149] It should be noted that the side surface of the packaging substrate 410 facing the optical chip 420 is referred to as the first surface, and the sidewall of the packaging substrate 410 is used to represent the surface of the packaging substrate 410 adjacent to the first surface.

[0150] Here, the light-emitting surface 425 is suspended above the sidewall of the packaging substrate 410. Therefore, the light-emitting surface 425 and the sidewall of the packaging substrate 410 are not on the same plane, and the first surface of the light-emitting chip extends beyond the sidewall of the packaging substrate 410. Consequently, any overflowing adhesive flows down the sidewall of the packaging substrate 410 due to gravity, without contaminating the light-emitting surface. Even if the adhesive overflows quickly or in large quantities, it will only adhere to the portion of the first surface extending from the sidewall of the packaging substrate 410, without contaminating the light-emitting surface.

[0151] Figure 5 and Figure 6 As shown, in some embodiments, the light-emitting surface 425 can be suspended relative to the sidewall of the packaging substrate 410 in the following manner: the light-emitting surface 425 extends out of the sidewall of the packaging substrate 410, and the overflowing adhesive will flow down the sidewall of the packaging substrate 410 under the action of gravity, so as to prevent the adhesive from contaminating the light-emitting surface 425.

[0152] In some examples, the packaging substrate 410 is small in size, and the light-emitting surface 425 of the light-emitting chip can be designed to extend out of the sidewall of the packaging substrate 410.

[0153] In some examples, the packaging substrate 410 is relatively large. If the light-emitting surface 425 of the light-emitting chip is configured to extend beyond the sidewall of the packaging substrate 410, the overall structure of the light-emitting chip and the packaging substrate 410 will increase, thereby reducing the space utilization of the optical module 200. In this case, the light-emitting surface 425 can be suspended relative to the sidewall of the packaging substrate 410 in the following way:

[0154] like Figure 10a and Figure 10b As shown, Figure 10a A schematic diagram of the structure of an optical chip and a packaging substrate in an optical module provided in this application embodiment. Figure 2 , Figure 10b for Figure 10a An exploded view. For example, the packaging substrate 410 is recessed inward to form a first recess 426, and the light-emitting surface 425 is suspended on the first recess 426.

[0155] In this way, it is not necessary to design the length of the light-emitting chip to be longer in order to make the light-emitting surface 425 extend beyond the side wall of the packaging substrate 410; at the same time, the light-emitting surface 425 is suspended, so that the overflowing glue flows into the first recess 426 by gravity, reducing the overflowing glue from flowing to the outermost surface of the packaging substrate 410, thereby preventing the glue from contaminating the outermost surface of the packaging substrate 410 and occupying space, and ensuring the installation space for other devices attached to the packaging substrate 410.

[0156] The first recess 426 has a receiving cavity, and in particular, the opening of the receiving cavity is at least partially facing the light emitting chip.

[0157] In some examples, the light-emitting chip extends such that the light-emitting surface 425 is located at the opening of the receiving cavity, thereby suspending the light-emitting surface 425.

[0158] In some embodiments, the first recess 426 is configured as a first groove, which is formed by the first surface of the packaging substrate 410 extending away from the first surface of the packaging substrate 410. In this case, the opening of the first groove faces the light emitting chip, and the light emitting chip extends to the light emitting surface 425 located at the opening, so that the overflowing glue flows into the first groove based on the gravity it receives, preventing the glue from contaminating the light emitting surface 425 of the light emitting chip.

[0159] In other embodiments, the first recess 426 is configured as a first notch, which is formed by hollowing out from one side edge of the encapsulation substrate 410 into the encapsulation substrate 410.

[0160] To facilitate the description of the positional relationship, the direction in which the packaging substrate 410 and the light emitting chip overlap is called the thickness direction T1, the direction from the light emitting surface 425 of the light emitting chip to its opposite surface is called the length direction T2, and the direction on the light emitting surface 425 that faces the edge of the packaging substrate 410 is called the width direction T3.

[0161] like Figure 10a or Figure 10b As shown, in some examples, the receiving cavity of the first notch is surrounded by four sidewalls, wherein the first sidewall 4261 and the second sidewall 4262 are arranged opposite each other along the width direction T3 of the light emitting chip, and the third sidewall 4263 and the fourth sidewall 4264 both extend along the width direction T3 of the light emitting chip and connect the first sidewall 4261 and the second sidewall 4262. The third sidewall 4263 is also parallel to the first surface of the packaging substrate 410, and the plane of the fourth sidewall 4264 intersects the first surface of the packaging substrate 410. The third sidewall 4263 and the fourth sidewall 4264 should also ensure that the opening of the receiving cavity faces the light emitting chip and partially faces the light emission direction. The light emitting chip extends beyond the fourth sidewall 4264 to the light emission surface 425, so as to be suspended above the first notch.

[0162] In some examples, the light-emitting surface 425 of the light-emitting chip can extend beyond the fourth sidewall 4264 without protruding from the outermost surface of the packaging substrate 410. That is, the light-emitting chip extends to the opening of the light-emitting surface 425 at the first notch, and the overflowing adhesive can flow into the receiving cavity based on the gravity, which is convenient for subsequent cleaning of the overflowing adhesive.

[0163] It should be noted that, Figure 10a or Figure 10b The first notch is only an exemplary embodiment of the first notch. The receiving cavity of the first notch can also be constructed as an ellipsoid, a hemisphere, or other irregular polyhedron, as long as the opening of the receiving cavity faces the light emitting chip and the opening faces the light emission direction.

[0164] In some examples, the direction of light emission includes the direction of the light emitting surface 425 from the inside of the light emitting chip to its normal direction from the outside.

[0165] Therefore, the light-emitting chip extends to the light-emitting surface 425 and is suspended above the first notch, allowing the overflowing adhesive to flow into the receiving cavity due to gravity. This prevents the overflowing adhesive from contaminating the light-emitting surface. Furthermore, since the opening of the first notch faces the direction of light emission, the light emitted from the light-emitting surface 425 can be emitted unobstructed through the opening facing the direction of light emission and propagate to the optical fiber, thus improving the light emission efficiency and quality.

[0166] In some embodiments, the light-emitting chip includes two sidewalls along the width direction T3, and a light-emitting surface is connected between the two sidewalls. The portions of the two sidewalls located on the first notch are suspended above the first notch. However, light emitted from the light-emitting surface of the light chip will exhibit a certain degree of divergence. To prevent the light from being reflected by the sidewalls along the width direction T3 of the light-emitting chip during emission, thus affecting the light emission efficiency, the first width dimension d1 of the first notch of the packaging substrate 410 is larger than the second width dimension d2 of the light-emitting surface 425. This ensures that the emitted light will not strike the sidewalls along the width direction T3 of the light-emitting chip, thereby improving the light emission efficiency. Wherein, the first width dimension d1 is the dimension of the first notch along the width direction T3 of the light-emitting chip, and the second width dimension d2 is the dimension of the light-emitting surface 425 along the width direction T3 of the light-emitting chip. (Length direction;)

[0167] In some examples, the light-emitting surface 425 of the light-emitting chip is at a first position in the length direction T2, the first notch corresponds to the outermost surface of the packaging substrate 410 at a second position in the length direction T2, and the first width dimension d1 is greater than the second width dimension d2. That is, the width dimension of the first notch at each position between the first position and the second position is greater than the width dimension of the emitted light at that position.

[0168] In some embodiments, to ensure that the first width dimension d1 is greater than the second width dimension d2, the minimum width dimension of the first notch between the first and second positions can be configured to be greater than the width dimension of the emitted light at the second position. In this way, the light will not be reflected at the minimum width dimension of the first notch after emission, and therefore will not be reflected at other positions after passing through the first notch. This ensures that the light emitted from the light-emitting surface 425 is transmitted to the optical fiber with high quality, improving the quality of the optical signal received by the optical fiber.

[0169] exist Figure 10a and Figure 10b In the example, the first width dimension d1 is the distance between the third sidewall 4263 and the fourth sidewall 4264.

[0170] It is understandable that the size configuration of the first notch in the thickness direction T1 can also be configured with reference to the implementation method of the first width dimension of the first notch.

[0171] In some examples, the sidewall of the first notch in the thickness direction T1 can also be matched with the edge line of the outgoing light at the second position, so that the light exits from the first notch, improving the quality of the optical signal received by the optical fiber.

[0172] In some other embodiments, due to the limited space within the housing of the optical module 200, the light-emitting surface 425 is flush with the sidewall of the packaging substrate 410 so that the light-emitting surface 425 is exposed to the filler layer 430.

[0173] In some examples, when the adhesive forming the filler layer 430 has poor flowability or the gap between the packaging substrate 410 and the light-emitting chip is large, the light-emitting surface 425 can be configured to be flush with the sidewall of the packaging substrate 410. In this way, while preventing adhesive contamination of the light-emitting surface 425, the light-emitting chip can be miniaturized, improving the space utilization of the optical module 200.

[0174] Reference Figure 5 The illustration shows an embodiment where the light-emitting surface 425 extends beyond the sidewall of the packaging substrate 410. In some examples, the light-emitting surface 425 is flush with one sidewall of its corresponding packaging substrate 410, allowing excess adhesive to flow down the sidewall of the packaging substrate 410 under gravity without contaminating the light-emitting surface. The sidewall flush with the light-emitting surface 425 can be the same as the sidewall extending from the light-emitting surface 425 in the aforementioned embodiments, meaning the welding orientation of the light-emitting chip and the packaging substrate 410 remains unchanged.

[0175] It should be noted that the sidewall flush with the light-emitting surface 425 and the sidewall extending from the light-emitting surface 425 in the aforementioned embodiment are just examples. In fact, the orientation of the light-emitting chip on the packaging substrate 410 can also be adjusted according to the size of the light-emitting chip and the internal layout and size of the packaging substrate 410. This embodiment does not limit this.

[0176] Figure 11a A schematic diagram of the structure of an optical chip and a packaging substrate in an optical module provided in this application embodiment. Figure 3 , Figure 11b for Figure 11a Exploded view. (e.g.) Figure 11a and Figure 11bAs shown, in some embodiments, the light emitting chip further includes a reflective surface 428, also known as the HR surface. A reflective film is provided on the side of the reflective surface 428 facing the interior of the light emitting chip. The reflective film guides light out from the front cavity surface, i.e., the light-emitting surface 425, thereby increasing the power of the light emitting chip and reducing losses. In other words, the reflective surface 428 is configured to reflect light from inside the light emitting chip to the light-emitting surface 425.

[0177] During the process of filling the light-emitting chip and the packaging substrate 410 with adhesive, although the reflective film is disposed on the side of the reflective surface 428 facing the inside of the light-emitting chip, the adhesive may enter the inside of the light-emitting chip through tiny gaps in the reflective surface 428. For example, some volatile components in the adhesive may enter the inside of the light-emitting chip through tiny gaps in the reflective surface 428 and then condense on the reflective film, thereby contaminating the reflective surface 428. More seriously, the chlorine element in the adhesive will corrode the reflective film, thereby affecting the reflective performance of the reflective film.

[0178] In some embodiments, in order to prevent adhesive from contaminating the reflective surface 428, the reflective surface 428 is exposed to the filler layer 430, wherein the reflective surface 428 is adjacent to the surface of the light emitting chip facing the packaging substrate 410, so as to effectively prevent the chlorine element in the adhesive from corroding the reflective film, thereby ensuring the reflective performance of the reflective surface 428, and correspondingly improving the working performance of the optical module 200.

[0179] In some embodiments, the technical solution where the reflective surface 428 is exposed to the filler layer 430 can refer to the aforementioned implementation where the light-emitting surface 425 is exposed to the filler layer 430.

[0180] In some embodiments, the light-emitting surface 425 and the reflective surface 428 can be the opposite two ends of a light-emitting chip, and there is no restriction on the positional relationship between the reflective surface 428 and the light-emitting surface 425.

[0181] In some examples, the reflective surface 428 is configured to be suspended relative to the sidewall of the packaging substrate 410.

[0182] In some embodiments, the technical solution of the reflective surface 428 being suspended above the sidewall of the packaging substrate 410 can refer to the aforementioned embodiment in which the light-emitting surface 425 is exposed in the filling layer 430.

[0183] In some implementations, the light-emitting surface 425 and the reflective surface 428 of the light-emitting chip can be exposed together in the filler layer 430 to ensure that the overflowing adhesive does not contaminate the light-emitting surface 425 and the reflective surface 428, thereby ensuring the performance of the light-emitting surface 425 and the reflective surface 428 and improving the overall performance of the optical module 200.

[0184] In some examples, when the light emitting chip is a DFB chip, its light-emitting surface 425 and reflective surface 428 can be exposed together in the filling layer 430 to ensure the light emission performance of the DFB chip.

[0185] like Figure 11a and Figure 11b As shown, in some embodiments, the light-emitting surface 425 and the reflective surface 428 of the light-emitting chip both extend beyond the sidewall of the packaging substrate 410, so that the light-emitting surface 425 and the reflective surface 428 are suspended above the sidewall of the packaging substrate 410.

[0186] The light-emitting chip extends along the length direction T2 until both the light-emitting surface 425 and the reflective surface 428 extend out of the surface of the packaging substrate 410. It can be understood that the surfaces of the packaging substrate 410 to which the light-emitting surface 425 and the reflective surface 428 extend are not coplanar.

[0187] Figure 11c A schematic diagram of the structure of an optical chip and a packaging substrate in an optical module provided in this application embodiment. Figure 4 , Figure 11d for Figure 11c Exploded view. (e.g.) Figure 11c and Figure 11d As shown, in some embodiments, the encapsulation substrate 410 is recessed inward to form a second recess 427, and the reflective surface 428 is suspended on the second recess 427.

[0188] In some examples, the construction scheme of the second recess 427 can refer to the construction scheme of the first recess 416 described above.

[0189] In this way, it is not necessary to design the length of the light emitting chip to be longer in order to make the reflective surface 428 extend out of the side wall of the packaging substrate 410; at the same time, the reflective surface 428 is suspended, so that the overflowing glue flows into the second recess 427 by gravity, reducing the amount of overflowing glue flowing to the outermost surface of the packaging substrate 410, thereby preventing the glue from contaminating the outermost surface of the packaging substrate 410 and occupying space, and ensuring the installation space for other devices attached to the packaging substrate 410.

[0190] The second recess 427 has a receiving cavity, and in particular, the opening of the receiving cavity is at least partially facing the light emitting chip.

[0191] In some examples, the light-emitting chip extends to the opening of the receiving cavity where the reflective surface 428 is located, so that the reflective surface 428 is suspended.

[0192] In some embodiments, the second recess 427 is configured as a second groove, which is formed by the first surface of the packaging substrate 410 extending away from the first surface of the packaging substrate 410. In this case, the opening of the second groove faces the light emitting chip, and the light emitting chip extends to the reflective surface 428 located at the opening, so that the overflowing adhesive flows into the second groove based on the gravity it receives, preventing the adhesive from contaminating the reflective surface 428 of the light emitting chip.

[0193] In other embodiments, the second recess 427 is configured as a second notch, which is formed by hollowing out from one side edge of the encapsulation substrate 410 into the encapsulation substrate 410.

[0194] like Figure 11c or Figure 11d As shown, in some examples, the receiving cavity of the second notch is surrounded by four sidewalls. The first sidewall 4271 and the second sidewall 4272 of the second notch are positioned opposite each other along the width direction T3 of the light-emitting chip. The third sidewall 4273 and the fourth sidewall 4274 both extend along the width direction T3 of the light-emitting chip and connect the first sidewall 4271 and the second sidewall 4272. The third sidewall 4273 is also parallel to the first surface of the packaging substrate 410, and the plane containing the fourth sidewall 4274 intersects the first surface of the packaging substrate 410. The third sidewall 4273 and the fourth sidewall 4274 should also ensure that the opening of the receiving cavity partially faces the light-emitting chip and partially faces the opposite direction of light emission. The light-emitting chip extends beyond the fourth sidewall 4274 to the reflective surface 428, so that the reflective surface 428 is suspended above the second notch.

[0195] In some examples, the reflective surface 428 of the light-emitting chip can extend beyond the fourth sidewall 4274 without protruding from the outermost surface of the packaging substrate 410. That is, the light-emitting chip extends to the opening of the reflective surface 428 at the second notch, and the overflowing adhesive can flow into the receiving cavity based on the gravity, which facilitates the subsequent cleaning of the overflowing adhesive.

[0196] It should be noted that, Figure 11c or Figure 11d The second notch is merely an exemplary embodiment of the second notch, and the receiving cavity of the second notch may also be constructed as an ellipsoid, a hemisphere, or other irregular polyhedron.

[0197] In some other embodiments, due to the limited space within the housing of the optical module 200, the reflective surface 428 is flush with the sidewall of the encapsulation substrate 410 so that the reflective surface 428 is exposed to the filler layer 430.

[0198] In some examples, when the adhesive forming the filler layer 430 has poor flowability or the gap between the packaging substrate 410 and the light-emitting chip is large, the reflective surface 428 can be configured to be flush with the sidewall of the packaging substrate 410. In this way, while preventing adhesive from contaminating the reflective surface 428, the light-emitting chip can be miniaturized, improving the space utilization of the optical module 200.

[0199] Reference Figure 11a The illustration shows an embodiment where the reflective surface 428 extends beyond the sidewall of the packaging substrate 410. In some examples, the reflective surface 428 is flush with one sidewall of its corresponding packaging substrate 410, allowing excess adhesive to flow down the sidewall of the packaging substrate 410 under gravity without contaminating the reflective surface 428. The sidewall flush with the reflective surface 428 can be the same as the sidewall from which the reflective surface 428 extends in the aforementioned embodiments, meaning the welding orientation of the light-emitting chip and the packaging substrate 410 remains unchanged.

[0200] It should be noted that the sidewall flush with the reflective surface 428 and the sidewall protruding from the reflective surface 428 in the previous embodiment are just examples. In fact, the orientation of the light emitting chip on the packaging substrate 410 can also be adjusted according to the size of the light emitting chip and the internal layout and size of the packaging substrate 410. This embodiment does not limit this.

[0201] Figure 12a for Figure 9a Schematic diagram of step S130 Figure 4 , Figure 12b for Figure 9a Schematic diagram of step S130 Figure 5 .like Figure 12a and Figure 12b As shown, in some examples, the dispensing area 443 may be disposed in the peripheral area of ​​the optical chip 420 that does not correspond to the light-emitting surface 425 and / or the reflective surface 428.

[0202] Specifically, when the packaging substrate 410 has a first recess 426 at the corresponding light-emitting surface 425, the dispensing area 443 can be disposed in the peripheral area of ​​the optical chip 420 corresponding to the reflective surface 428, or in the peripheral area of ​​the optical chip 420 not corresponding to the light-emitting surface 425 and the reflective surface 428 (see reference). Figure 12a or Figure 12b (As shown).

[0203] Specifically, when the packaging substrate 410 has a second recess 427 at the corresponding reflective surface 428, the dispensing area 443 can be disposed in the peripheral area of ​​the optical chip 420 corresponding to the light-emitting surface 425, or in the peripheral area of ​​the optical chip 420 not corresponding to the light-emitting surface 425 and the reflective surface 428 (see reference). Figure 12a or Figure 12b(As shown).

[0204] Specifically, when the packaging substrate 410 has a first recess 426 at the corresponding light-emitting surface 425 and a second recess 427 at the corresponding reflective surface 428, the dispensing area 443 can be disposed in the peripheral area of ​​the optical chip 420 that does not correspond to the light-emitting surface 425 and the reflective surface 428 (e.g., Figure 12a or Figure 12b (As shown).

[0205] The optical module provided in this application embodiment utilizes a filling layer 430 to fill the gap between the optical chip 420 and the packaging substrate 410, forming a rigid structure with the optical chip 420, packaging substrate 410, and filling layer 430. This effectively disperses stress while improving the overall thermal stability and mechanical strength of the optical chip 420 and packaging substrate 410. Furthermore, in non-hermetic applications, the filling layer 430 wraps around the bumps 421 and pads 411 to prevent moisture penetration and reduce the impact of moisture on the solder joints. This is particularly beneficial at high temperatures, extending the lifespan of the optical chip 420 and packaging substrate 410. Additionally, exposing the light-emitting surface 425 or the reflective surface 428 to the filling layer 430 prevents adhesive contamination of the light-emitting surface 425 or the reflective surface 428, improving the performance of the light-emitting chip and thus optimizing the overall performance of the optical module 200.

[0206] 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 characterized by comprising: include: Circuit board; A packaging substrate, which is electrically connected to the circuit board; An optical chip is disposed opposite to the packaging substrate. The optical chip has a bump on the side facing the packaging substrate, and the packaging substrate has a pad on the side facing the optical chip. The bump is soldered to the pad. A filler layer is provided between the optical chip and the packaging substrate, and the filler layer at least covers the bumps and the pads.

2. The optical module according to claim 1, characterized by The optical chip includes a light emitting chip, the light emitting surface of which is exposed in the filling layer, wherein the light emitting surface is adjacent to the surface of the light emitting chip having the bumps.

3. The optical module according to claim 2, characterized in that, The light-emitting surface is suspended relative to the sidewall of the packaging substrate.

4. The optical module according to claim 3, characterized in that, The light-emitting surface extends from the sidewall of the packaging substrate.

5. The optical module according to claim 3, characterized in that, The packaging substrate is recessed inward to form a first recess, and the light-emitting surface is suspended above the first recess.

6. The optical module according to claim 5, characterized in that, The first recess is configured as a first notch, which is formed by hollowing out from one edge of the packaging substrate into the interior of the packaging substrate.

7. The optical module according to claim 6, characterized in that, The light-emitting chip includes two sidewalls along its width, and the light-emitting surface is connected between the two sidewalls. The portions of the two sidewalls located on the first notch are suspended above the first notch.

8. The optical module according to claim 2, characterized in that, The light emitting chip also includes a reflective surface, which is configured to reflect light from inside the light emitting chip to the light emitting surface, and the reflective surface is exposed on the filler layer, wherein the reflective surface is adjacent to the surface of the light emitting chip facing the packaging substrate.

9. The optical module according to claim 8, characterized in that, The reflective surface is configured to be suspended relative to the sidewall of the encapsulation substrate.

10. The optical module according to any one of claims 2-9, characterized in that, The optical chip also includes a waveguide, which is disposed on the side of the optical emitting chip having the bump, for transmitting light from the optical emitting chip to a position close to the light emitting surface, and the filling layer covers the waveguide.

Images