Optical engine and communication device

Abstract

An optical engine (1) and a communication device (100). The optical engine (1) comprises a first chip (4), a second chip (5), a glass substrate (3), an electrical fan-out structure (18) and an optical fan-out structure (16), wherein the first chip (4) is a photonic chip, and the second chip (5) is an electronic chip; the glass substrate (3) comprises a first surface (310) and a second surface (320) that are disposed opposite each other in a thickness direction; the electrical fan-out structure (18) comprises a first redistribution layer (19) disposed on the first surface (310) of the glass substrate (3), the first chip (4) and the second chip (5) both being disposed on the first redistribution layer (19), and the first redistribution layer (19) being configured for electrical connection between the first chip (4) and the second chip (5), and being configured to route external ports of the second chip (5); and the optical fan-out structure (16) comprises an optical waveguide (17) and a coupling structure (20) which are disposed in the glass substrate (3), the optical waveguide (17) extending in the glass substrate (3), and the coupling structure (20) being configured to couple the optical waveguide (17) to the first chip (4). The optical engine (1) is applied to the communication device (100).

Description

A light engine and communication device

[0001] This application claims priority to Chinese Patent Application No. 202510477115.8, filed with the State Intellectual Property Office of China on April 16, 2025, entitled "An optical engine and a communication device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of optical communication technology, and in particular to an optical engine and a communication device. Background Technology

[0003] In the field of optical communication, an optical engine is an integrated component used to transmit and receive optical signals. It includes photonic chips for photoelectric conversion, such as laser chips and photodetector chips, as well as electronic chips that work in conjunction with the photonic chips, such as driver chips and transimpedance amplifier chips.

[0004] In the aforementioned optical engine, the photonic chip needs to transmit optical signals to the outside via an optical signal connector, and the electronic chip needs to transmit electrical signals to the outside via an electrical signal connector. Therefore, it is necessary to fan out both the optical and electrical signal connectors simultaneously. Related technologies typically employ silicon adapter boards as an integrated optoelectronic adapter structure to achieve simultaneous fan-out of both the optical and electrical signal connectors.

[0005] The structure used to fan out optical signal connections in silicon interposers mainly includes optical waveguides formed within the silicon interposer using semiconductor fabrication processes. However, due to limitations in materials and processes, optical waveguides in silicon interposers can only transmit C-band and O-band optical signals, and their waveguide cross-sectional dimensions are relatively small, typically a maximum of 220 nm, limiting their use to single-mode signals. This significantly restricts their application and necessitates the use of more expensive single-mode light sources, increasing the cost of the optical engine. Summary of the Invention

[0006] This application provides an optical engine and a communication device to improve the problems of large application limitations and high costs.

[0007] To achieve the above objectives, this application adopts the following technical solution:

[0008] In one aspect, a light engine is provided, which includes a first chip, a second chip, a glass substrate, an electric fan-out structure, and a light fan-out structure, wherein the first chip is an electronic chip and the second chip is a photonic chip.

[0009] The glass substrate includes a first surface and a second surface disposed opposite to each other in the thickness direction; the fan-out structure includes a first redistribution layer disposed on the first surface of the glass substrate, and a first chip and a second chip are both disposed on the first redistribution layer; the first redistribution layer is used for electrical connection between the first chip and the second chip, and for leading out an external port of the second chip.

[0010] The optical fan-out structure includes an optical waveguide and a coupling structure disposed in a glass substrate. The optical waveguide extends in the glass substrate, and the coupling structure is used to couple the optical waveguide to a first chip.

[0011] In the optical engine provided in this application, both the first chip and the second chip are disposed on a glass substrate, and the optical signal connection end and the electrical signal connection end are fanned out through the optical fan-out structure and the electrical fan-out structure disposed on the glass substrate; that is, the glass substrate is used as an optoelectronic integrated adapter board in the optical engine. This design has the advantages of having a high glass transition temperature (Tg), which is conducive to the integration of redistribution layers on the glass substrate, and can withstand the high temperatures when the first chip and the second chip are packaged on the glass substrate, as well as the high temperatures when the optical engine is packaged on the circuit board, thus having fewer application limitations.

[0012] On the other hand, since the optical waveguide formed in the glass substrate has a large waveguide cross-sectional size and a large adjustment range, it can improve coupling tolerance, reduce coupling difficulty and improve coupling efficiency; it can also adapt to the application scenarios of multimode optical signals. In this case, multimode light sources, such as multimode VCSEL chips, can be used in the optical engine, which helps to reduce the cost of the optical engine.

[0013] On the other hand, the optical waveguide formed in the glass substrate can transmit a wide range of optical signal wavelengths, not limited to the traditional C-band and O-band, and has a wide range of applications.

[0014] In some possible implementations, the light engine also includes a packaging substrate, which includes a third surface and a fourth surface disposed opposite each other in the thickness direction.

[0015] The fan-out structure also includes a third redistribution layer, a fourth redistribution layer, a second connecting post, and a package interconnection structure. The third redistribution layer is disposed on the third surface of the package substrate, and the fourth redistribution layer is disposed on the fourth surface of the package substrate. The second connecting post penetrates the package substrate and connects the third redistribution layer and the fourth redistribution layer.

[0016] The glass substrate is disposed on the outer side of the third surface of the packaging substrate, and the third redistribution layer is electrically connected to the first redistribution layer; the packaging interconnect structure is disposed on the fourth redistribution layer for packaging connection.

[0017] In the optical engine provided in this application, the optical engine is packaged through a glass substrate and a packaging substrate, which is beneficial for the interconnection and packaging design of the optical engine and reduces the processing difficulty of the glass substrate.

[0018] In some possible implementations, the fan-out structure further includes a second redistribution layer and a second connecting post; the second redistribution layer is disposed on a second surface of the glass substrate, and the first connecting post penetrates the glass substrate and connects the second redistribution layer and the first redistribution layer; the second surface of the glass substrate is close to the third surface of the encapsulation substrate, and the second redistribution layer and the third redistribution layer are electrically connected.

[0019] In the optical engine provided in this application, the glass substrate uses through-glass via (TGV) technology to achieve electrical connection with the packaging substrate. This design is beneficial for improving interconnection density and packaging performance, and also for reducing packaging size.

[0020] In some possible implementations, the second surface of the glass substrate is close to the third surface of the packaging substrate; the first redistribution layer includes a first pad, and the third redistribution layer includes a second pad; the fan-out structure also includes leads connecting the first pad and the second pad.

[0021] In the optical engine provided in this application, the glass substrate and the packaging substrate are electrically connected by wire bonding, which reduces the difficulty and cost of connection.

[0022] In some possible implementations, the first surface of the glass substrate is close to the third surface of the packaging substrate; the first redistribution layer is electrically connected to the third redistribution layer.

[0023] In the optical engine provided in this application, the packaging substrate can be flip-chip mounted on the glass substrate. With this design, the first redistribution layer on the glass substrate can be directly connected to the packaging substrate, thereby simplifying the interconnection structure between the packaging substrate and the glass substrate and reducing the interconnection difficulty.

[0024] In some possible implementations, the packaging substrate has a through cavity exposing the first chip and the second chip. This design facilitates heat dissipation for both the first and second chips, and also makes it easier to install heat dissipation devices for cooling the first and second chips.

[0025] In some possible implementations, the encapsulation substrate is an organic substrate, a ceramic substrate, or a composite substrate. In the optical engine provided in this application, the encapsulation substrate can employ different types of substrates, offering a wide range of choices that are beneficial for adapting to different scenarios and controlling costs.

[0026] In some possible implementations, the optical engine further includes a third chip, which includes a microcontroller chip for controlling the operation of the optical engine; the third chip is disposed on a third redistribution layer of the packaging substrate. The optical engine provided in this application can also integrate a microcontroller chip. This design is beneficial for improving the integration of the optical engine; and placing the microcontroller chip on the packaging substrate helps reduce the wiring pressure on the glass substrate, thereby reducing processing difficulty and cost.

[0027] In some possible implementations, the glass substrate includes a glass core and a first organic layer and a second organic layer disposed on both sides of the glass core, and an optical waveguide and coupling structure are disposed in the glass core; the outer surface of the first organic layer away from the glass core is the first surface, and the outer surface of the second organic layer away from the glass core is the second surface.

[0028] The fan-out structure includes a second redistribution layer, a connection structure, and an encapsulation interconnect structure. The second redistribution layer is disposed on the second surface of the glass substrate. The connection structure penetrates the glass substrate and connects the first redistribution layer and the second redistribution layer. The encapsulation interconnect structure is disposed on the second redistribution layer and is used for encapsulation connection.

[0029] In the optical engine provided in this application, the glass substrate can adopt a design of glass core plus two organic layers, that is, the glass substrate and the encapsulation substrate are integrated into one, which is conducive to reducing the size of the optical engine and simplifying the fan-out structure.

[0030] In some possible implementations, the glass substrate includes a glass core and an organic layer disposed on one side of the glass core, and an optical waveguide and coupling structure disposed in the glass core; the outer surface of the glass core away from the organic layer is a first surface, and the outer surface of the organic layer away from the glass core is a second surface.

[0031] The fan-out structure includes a second redistribution layer, a connection structure, and an encapsulation interconnect structure. The second redistribution layer is disposed on the second surface of the glass substrate. The connection structure penetrates the glass substrate and connects the first redistribution layer and the second redistribution layer. The encapsulation interconnect structure is disposed on the second redistribution layer and is used for encapsulation connection.

[0032] In the optical engine provided in this application, the glass substrate can adopt a design of glass core plus single organic layer, that is, the glass substrate and the encapsulation substrate are integrated into one, which is conducive to reducing the size of the optical engine and simplifying the fan-out structure.

[0033] In some possible implementations, the optical engine further includes a third chip, which includes a microcontroller chip for controlling the operation of the optical engine; the third chip is disposed on a first redistribution layer of the glass substrate. The optical engine provided in this application can also integrate a microcontroller chip, which is beneficial for improving the integration of the optical engine.

[0034] In some possible implementations, the third chip may also include a switching chip, a central processing unit chip, a graphics processing unit chip, or a neural network processor chip. This design can further improve the integration of the optical engine, enabling it to perform more functions.

[0035] In some possible implementations, the package interconnect structure includes an array of solder ball bumps or an array of metal contacts. The optical engine provided in this application can be connected to a circuit board through different package interconnect structures, offering flexible connection methods suitable for various application scenarios.

[0036] In some possible implementations, the coupling structure includes a coupling groove and a coupling lens. The coupling groove is disposed on the glass substrate and serves to connect the first chip and the optical waveguide; the coupling lens is disposed in the coupling groove and serves to couple the first chip and the optical waveguide. This design can effectively achieve the coupling of optical signals between the first chip and the optical waveguide, and the structure is simple and easy to implement on a glass substrate.

[0037] In some possible implementations, the coupling structure includes a coupling groove and a reflective film. The coupling groove is disposed on the glass substrate and serves to connect the first chip and the optical waveguide; the reflective film is disposed on the groove wall of the coupling groove and serves to couple the first chip and the optical waveguide. This design can effectively achieve the coupling of optical signals between the first chip and the optical waveguide, and the structure is simple and easy to implement on a glass substrate.

[0038] In some possible implementations, the coupling structure includes a coupling groove and a reflective concave mirror. The coupling groove is disposed on the glass substrate and serves to connect the first chip and the optical waveguide; the reflective concave mirror is disposed in the coupling groove and serves to couple the first chip and the optical waveguide. This design can effectively achieve the coupling of optical signals between the first chip and the optical waveguide, and the structure is simple and easy to implement on a glass substrate.

[0039] In some possible implementations, the coupling structure includes a bent-extension coupling waveguide, one end of which is connected to an optical waveguide and the other end to a first chip, for coupling the first chip and the optical waveguide. This design allows for better coupling of optical signals between the first chip and the optical waveguide, and the structure is simple and easily implemented on a glass substrate.

[0040] In some possible implementations, the coupling waveguide includes a coupling groove and a solid glass structure. The coupling groove is disposed on a glass substrate and is used to connect the first chip and the optical waveguide. The solid glass structure is suspended in the coupling groove and its two ends are connected to the first chip and the optical waveguide, respectively.

[0041] In the optical engine provided in this application, the solid glass structure and the air around the coupling groove form a coupling waveguide. The large difference in refractive index between the air and the glass is beneficial for achieving large-angle bending, which in turn is beneficial for improving the interconnection density.

[0042] In some possible implementations, the optical waveguide extends in a direction parallel to the first surface in a glass substrate, the glass substrate having a coupling region, an external optical fiber connected to the coupling region being coupled to the optical waveguide; the coupling region is located in the side surface of the glass substrate, and the end of the optical waveguide away from the first chip extends into the coupling region.

[0043] Alternatively, the coupling region is located in the first or second surface, and the optical fan-out structure also includes a reflective structure disposed in the glass substrate. The end of the optical waveguide away from the first chip extends to the reflective structure, and the reflective structure is used to deflect the optical signal transmitted between the coupling region and the optical waveguide.

[0044] In the optical engine provided in this application, the external optical fiber can be coupled to the optical waveguide at different positions on the glass substrate, which is flexible in design and can adapt to different application scenarios.

[0045] In some possible implementations, the external optical fiber is connected to the glass substrate in the coupling region via an optical fiber connector; the optical fan-out structure also includes a positioning structure disposed at the edge of the coupling region of the glass substrate to limit the connection position of the optical fiber connector. This design, on the one hand, can adapt to scenarios where the external optical fiber is connected to the optical engine via an optical fiber connector; on the other hand, the positioning structure can improve the installation accuracy of the optical fiber connector, thereby improving the alignment accuracy between the external optical fiber and the optical waveguide, and ensuring the coupling quality of the two.

[0046] In some possible implementations, the fiber optic connector is pluggable to the optical engine; the fiber optic connector is a male connector and the positioning structure is a female connector that mates with the fiber optic connector; or, the fiber optic connector is a female connector and the positioning structure is a male connector that mates with the fiber optic connector.

[0047] In the optical engine provided in this application, a fiber optic connector enables pluggable and detachable mating between the external optical fiber and the optical engine, which simplifies the coupling difficulty with the external optical fiber, especially in multi-channel, multi-fiber application scenarios. Furthermore, it can be adapted to different types of connectors, offering good adaptability.

[0048] In some possible implementations, the optical waveguide is formed in a glass substrate using ion exchange or laser direct writing techniques. Compared to forming the optical waveguide in a silicon interposer, the aforementioned method of forming the optical waveguide in a glass substrate is less difficult, thus facilitating the formation of the optical waveguide.

[0049] In some possible implementations, the waveguide cross-sectional dimensions of the optical waveguide range from 10 μm to 80 μm. Optical waveguides with these dimensions are advantageous in two ways: firstly, they improve packaging tolerance and reduce packaging difficulty; secondly, they can transmit multimode optical signals, thus making them suitable for multimode optical signal transmission scenarios and consequently reducing the cost of the optical engine.

[0050] In some possible implementations, the optical waveguide is a multimode optical waveguide, and the first chip includes a multimode vertical-cavity surface-emitting laser chip; or, the optical waveguide is a single-mode optical waveguide, and the first chip includes a single-mode vertical-cavity surface-emitting laser chip.

[0051] The optical engine provided in this application can transmit both multimode and single-mode optical signals, and both can use a vertical-cavity surface-emitting laser chip, which helps to reduce the cost of the optical engine.

[0052] In some possible implementations, the first chip includes multiple photoelectric conversion units, and the optical fan-out structure includes multiple optical waveguides and multiple coupling structures disposed in the glass substrate, with the photoelectric conversion units, coupling structures, and optical waveguides coupled in a one-to-one correspondence. This design is beneficial for achieving high-density optical signal transmission.

[0053] In some possible implementations, the second chip includes multiple circuit units; one first chip is connected to one second chip; or at least two second chips are connected to one first chip; or one second chip is connected to at least two first chips.

[0054] In the first and second connected chips, the number of circuit units and photoelectric conversion units are the same, and they are connected in a one-to-one correspondence.

[0055] This design is beneficial for increasing the number of channels in the optical engine, thereby enabling high-density optical signal transmission.

[0056] In some possible implementations, the first chip includes two unit rows arranged in a first direction, each unit row including a plurality of photoelectric conversion units arranged in a second direction, the photoelectric conversion units in the two unit rows being staggered in the second direction; wherein the first direction is perpendicular to the second direction and both are parallel to the first surface; all optical waveguides coupled to the first chip are located on the same side of the first chip along the first direction, arranged side by side along the second direction, and extending along the first direction.

[0057] In the optical engine provided in this application, the multiple photoelectric conversion units in the first chip are arranged in a double-row staggered manner. This design is beneficial in two ways: firstly, it is advantageous to place the multi-channel optical waveguides connected to the first chip on the same side of the first chip, thereby facilitating fiber output from the same side and position; secondly, it is advantageous to integrate more channels of optical waveguides, thereby facilitating the realization of high-density optical signal transmission.

[0058] In some possible implementations, the first chip includes a laser chip, and the second chip includes a driver chip, which is electrically connected to the laser chip; and / or, the first chip includes a photodetector chip, and the second chip includes a transimpedance amplifier chip, which is electrically connected to the photodetector chip. The optical engine provided in this application can be a product that integrates optical signal transceiver, or a product that can only transmit or receive optical signals.

[0059] In a second aspect, a communication device is provided, the communication device including a circuit board and an optical engine as described in any one of the first aspects, the optical engine being electrically connected to the circuit board.

[0060] The technical effects achievable by the communication equipment provided in this application are the same as those achievable by the optical engine in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0061] Figure 1 is a schematic diagram of the structure of a light engine provided in an embodiment of this application;

[0062] Figure 2 is a structural schematic diagram of the light engine in Figure 1 from another angle;

[0063] Figure 3 is a schematic diagram of the optical engine structure on the glass substrate in Figure 1;

[0064] Figure 4 is a cross-sectional view of the light engine in Figure 1;

[0065] Figure 5 is a cross-sectional view of another optical engine provided in an embodiment of this application;

[0066] Figure 6 is a cross-sectional view of another light engine provided in an embodiment of this application;

[0067] Figure 7 is a cross-sectional view of another optical engine provided in an embodiment of this application;

[0068] Figure 8 is a cross-sectional view of another optical engine provided in an embodiment of this application;

[0069] Figure 9 is a schematic diagram of the working principle of the positioning structure in Figure 8;

[0070] Figure 10 is a schematic diagram of the extension of the optical waveguide in Figure 1;

[0071] Figure 11 is a diagram showing the arrangement of photoelectric conversion units in a first chip according to an embodiment of this application;

[0072] Figure 12 is a schematic diagram of another optical engine packaging interconnection structure provided in an embodiment of this application;

[0073] Figure 13 is a schematic diagram of another optical engine provided in an embodiment of this application;

[0074] Figure 14 is a schematic diagram of wire bonding of the optical engine in Figure 13;

[0075] Figure 15 is a schematic diagram of another optical engine provided in an embodiment of this application;

[0076] Figure 16 is a schematic diagram of another optical engine provided in an embodiment of this application;

[0077] Figure 17 is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0078] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them.

[0079] In the following embodiments of this application, the terms "first," "second," etc., are used for descriptive convenience only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0080] In the embodiments of this application, "upper", "lower", "left" and "right" are not limited to the orientation of the components in the accompanying drawings. It should be understood that these directional terms can be relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the components in the accompanying drawings.

[0081] In the embodiments of this application, unless the context otherwise requires, the term "comprising" is interpreted as open and encompassing throughout the specification and claims, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "exemplarily," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this application. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0082] As used herein, “about,” “approximately,” or “approximately” includes the stated value and the average value within an acceptable range of deviation from the given value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the given quantity (i.e., the limitations of the measurement system).

[0083] As used herein, “parallel,” “perpendicular,” and “equal” include the described situation and situations that are similar to the described situation, within an acceptable range of deviation, which is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, “parallel” includes absolute parallelism and approximate parallelism, where an acceptable range of deviation for approximate parallelism may be, for example, within 5°; “perpendicular” includes absolute perpendicularity and approximate perpendicularity, where an acceptable range of deviation for approximate perpendicularity may also be, for example, within 5°; “equal” includes absolute equality and approximate equality, where an acceptable range of deviation for approximate equality may be, for example, a difference between the two equals being less than or equal to 5% of either one.

[0084] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate.

[0085] Exemplary embodiments are described in this application with reference to cross-sectional views and / or plan views and / or equivalent circuit diagrams, which are idealized exemplary drawings. In the drawings, the thickness of layers and regions is enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as being limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched regions shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the regions of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0086] This application provides an optical engine 1, as shown in Figures 1 to 4. The optical engine 1 includes a glass substrate 3, a first chip 4, a second chip 5, a packaging substrate 2, an optical fan-out structure 16, and an electric fan-out structure 18. For ease of description, the structure of the optical engine 1 will be illustrated with reference to a first direction X, a second direction Y, and a third direction Z that are mutually perpendicular to each other.

[0087] As shown in Figure 4, the glass substrate 3 in the light engine 1 is a flat plate structure made of glass material. The thickness direction of the flat plate structure is parallel to the third direction Z, and includes a first surface 310 and a second surface 320 disposed opposite to each other in the thickness direction (i.e., the third direction Z). Both the first surface 310 and the second surface 320 are parallel to the first direction X and the second direction Y. The glass substrate 3 also includes a side surface connecting the first surface 310 and the second surface 320.

[0088] Please refer to Figures 1, 3, and 4. In the light engine 1, both the first chip 4 and the second chip 5 are disposed on the outer side of the first surface 310 of the glass substrate 3. The first chip 4 is a photonic integrated circuit (oIC), which is a chip that uses photons (light waves) as information carriers and has both electrical signal connection terminals and optical signal connection terminals. The second chip 5 is an electrical integrated circuit (eIC), which is a chip that uses electrons (charged particles) as information carriers and has electrical signal connection terminals.

[0089] In the optical engine 1 provided in this application embodiment, the first chip 4 uses a photonic chip to achieve photoelectric conversion. These can be divided into two categories: one is a laser chip that converts electrical signals into optical signals, and the other is a photodetector chip that converts optical signals into electrical signals. The electrical signal connection terminal of the laser chip is used to receive electrical signals controlling the operation of the laser chip, and the optical signal connection terminal is used to output the optical signals generated by the laser chip. The laser chip can be an edge-emitting laser (EEL) chip, a vertical-cavity surface-emitting laser (VCSEL) chip, a distributed feedback (DFB) laser chip, or a distributed Bragg reflector (DBR) laser chip, etc.

[0090] The optical signal connection terminal of the photodetector chip is used to receive optical signals, and the electrical signal connection terminal is used to output the current signal generated by the photodetector chip in response to the optical signal. The photodetector chip can be a photodiode (PD) chip, a PIN photodiode chip, an avalanche photodiode (APD) chip, or a single photon avalanche photodiode (SAPD) chip, etc.

[0091] The optical engine 1 provided in this application embodiment does not limit the type of laser chip or the type of photodetector chip, and can be selected according to the actual application scenario.

[0092] The second chip 5 uses an electronic chip of the same type as the first chip 4, and is used to work in conjunction with the first chip 4. Corresponding to the two types of first chips 4 mentioned above, the second chip 5 is also divided into two categories: one is a driver chip corresponding to the laser chip, and the other is a transimpedance amplifier (TIA) chip corresponding to the photodetector chip. The driver chip has an input terminal and an output terminal. Its input terminal receives the electrical signal controlling the driver chip's operation, and its output terminal is electrically connected to the laser chip's electrical signal connection terminal to output the electrical signal controlling the laser chip's operation, thereby controlling the laser chip to generate an optical signal. The transimpedance amplifier chip also has an input terminal and an output terminal. Its input terminal is connected to the photodetector chip to receive the current signal generated by the photodetector's detection of the optical signal; the transimpedance amplifier chip converts this current signal into a voltage signal, and its output terminal outputs the converted voltage signal.

[0093] As described above, the electrical signal connection terminals of the second chip 5 can be divided into interconnection ports and external ports. The interconnection ports are used for electrical connection with the electrical signal connection terminals of the first chip 4, transmitting electrical signals between the first chip 4 and the second chip 5. Examples of interconnection ports include the output terminal of a driver chip and the input terminal of a transimpedance amplifier chip. The external ports are used for electrical connection with other structures besides the first chip 4, transmitting electrical signals between the second chip 5 and other structures besides the first chip 4. Examples of external ports include the input terminal of a driver chip and the output terminal of a transimpedance amplifier chip.

[0094] In some embodiments, the first chip 4 may be a multi-channel photonic chip, meaning each first chip 4 includes multiple photoelectric conversion units, each photoelectric conversion unit having both an electrical signal connection terminal and an optical signal connection terminal. The multiple photoelectric conversion units are used to implement multi-channel photoelectric conversion functionality. Correspondingly, the second chip 5 also uses a multi-channel electronic chip, meaning each second chip 5 includes multiple circuit units, each circuit unit having an electrical signal connection terminal. The circuit units in the second chip 5 are connected one-to-one with the photoelectric conversion units in the first chip 4 to cooperate with the operation of the first chip 4.

[0095] In this application scenario where both the first chip 4 and the second chip 5 are multi-channel chips, the first chip 4 and the second chip 5 can adopt a 1-to-1 architecture, or a 1-to-X (X is a positive integer greater than 1) or X-to-1 architecture, as long as the circuit unit and the photoelectric conversion unit have a one-to-one correspondence.

[0096] In the optical engine 1 provided in this application embodiment, the type and number of the first chip 4, the number of channels of each first chip 4, and the cooperative architecture of the first chip 4 and the second chip 5 are related to the functions, costs, and processing requirements of the optical engine 1, and can be specifically selected according to the actual application scenario.

[0097] In some embodiments, as shown in FIG3, the optical engine 1 is provided with four first chips 4 and eight second chips 5. The four first chips 4 are two laser chips 12 and two photodetector chips 14, respectively, and the eight second chips 5 are four driver chips 11 and four transimpedance amplifier chips 13, respectively. The two laser chips 12, two photodetector chips 14, four driver chips 11, and four transimpedance amplifier chips 13 are formed in a transmitting module 10 and a receiving module 15 arranged at intervals in the second direction Y.

[0098] In the transmitting module 10, two laser chips 12 are arranged at intervals along the second direction Y. Each laser chip 12 includes 2N (N is a positive integer greater than 1) laser units to generate 2N channels of optical signals, which are output through 2N optical signal connection terminals. One laser chip 12 is connected to two driver chips 11, and the two connected driver chips 11 are placed on both sides of the laser chip 12 along the first direction X. Each driver chip 11 includes N driving units. The two driver chips 11 placed on both sides of the laser chip 12 have a total of 2N driving units. These 2N driving units are connected one-to-one with the 2N laser units in the laser chip 12, and the driving units control the connected laser units to generate optical signals.

[0099] Two photodetector chips 14 in the receiving module 15 are arranged at a distance along the second direction Y. Each photodetector chip 14 includes 2N detection units for detecting optical signals input through 2N channels via 2N optical signal connection terminals. One photodetector chip 14 is connected to two transimpedance amplifier chips 13, and the two connected transimpedance amplifier chips 13 are positioned on both sides of the photodetector chip 14 along the first direction X. Each transimpedance amplifier includes N transimpedance amplification units. The two transimpedance amplifier chips 13 positioned on both sides of the photodetector chip 14 have a total of 2N transimpedance amplification units. These 2N transimpedance amplification units are connected one-to-one with the 2N detection units in the photodetector chip 14, and the transimpedance amplification units are used to convert the current signals generated by the connected detection units into voltage signals.

[0100] The optical engine 1 in the above embodiment includes two laser chips 12 and two photodetector chips 14. Both the laser chips 12 and the photodetector chips 14 are multi-channel photonic chips, thus enabling simultaneous transmission and reception of multi-channel optical signals. Furthermore, the driver chip 11 and laser chip 12, as well as the transimpedance amplifier chip 13 and photodetector chip 14, all adopt a one-to-two architecture. This design is beneficial for fully utilizing the multi-channel performance of the photonic chips and maximizing the number of channels for transmitting and receiving optical signals in the optical engine 1.

[0101] In the optical engine 1 provided in this embodiment, the optical fan-out structure 16 is used to fan out the optical signal connection terminal in the first chip 4. As shown in Figures 3 and 4, the optical fan-out structure 16 includes an optical waveguide 17 and a coupling structure 20 disposed in the glass substrate 3. The optical waveguide 17 is an optical signal transmission channel extending in the glass substrate 3, which can be formed by methods such as ion exchange technology or laser direct writing technology. Ion exchange technology refers to using ions such as silver ions (Ag+), potassium ions (K+), or lithium ions (Li+) to exchange ions with alkali metal ions (e.g., sodium ions (Na+)) in the glass substrate 3 to form a specific refractive index distribution in the glass substrate 3, thereby forming the optical waveguide 17 in the glass substrate 3. Laser direct writing technology refers to using the nonlinear absorption effect of a femtosecond laser to induce microstructural changes inside the glass substrate 3 to form a specific refractive index distribution in the glass substrate 3, thereby forming the optical waveguide 17 in the glass substrate 3.

[0102] Compared to optical waveguides formed in silicon interposers (with a maximum waveguide cross-sectional area typically of 220 nm), optical waveguides 17 formed on glass substrates 3 can have larger waveguide cross-sectional areas and a wider adjustment range, typically ranging from 10 μm to 80 μm. Here, the waveguide cross-sectional area refers to the largest dimension in the cross-section of the optical waveguide 17. For example, for a circular cross-section optical waveguide 17, the waveguide cross-sectional area can be characterized by its diameter. Optical waveguides 17 with the aforementioned range of cross-sectional areas can be used as multimode waveguides to transmit multimode signals or as single-mode waveguides to transmit single-mode signals, thus adapting to different application scenarios.

[0103] Furthermore, since the silicon interposer is transparent to lasers with wavelengths greater than 1100nm, the optical waveguide formed in the silicon interposer can only be used to transmit optical signals with wavelengths above 1100nm. In other words, its application is limited to the O-band and C-band, which is quite restrictive. On the other hand, the glass substrate 3 is transparent to lasers with wavelengths greater than 200nm. Therefore, the optical waveguide 17 fabricated in the glass substrate 3 can transmit optical signals with wavelengths less than 1100nm, such as 850nm, 940nm, and 1060nm, as well as optical signals with wavelengths greater than 1100nm, such as the O-band and C-band, which has fewer application limitations.

[0104] For example, the waveguide cross-sectional size of the optical waveguide 17 in the glass substrate 3 can be 30μm to 50μm. In this case, it can be used as a multimode waveguide for transmitting multimode optical signals with a wavelength of 850nm, to adapt to scenarios where the laser chip 12 is selected as an 850nm multimode VCSEL. In the scenario of multimode optical signal transmission, the cost of the laser is relatively low, which helps to reduce the cost of the optical engine 1.

[0105] In another example, the waveguide cross-sectional area of ​​the optical waveguide 17 in the glass substrate 3 is 10μm to 15μm. In this case, it can be used as a single-mode waveguide for transmitting single-mode optical signals with wavelengths of 940nm and 1060nm, to adapt to scenarios where the laser chip 12 uses a 940nm or 1060nm single-mode VCSEL. In single-mode optical signal transmission scenarios, since there is no intermodal dispersion, the transmission distance is longer, making it suitable for long-distance applications.

[0106] In addition, the optical waveguide 17 with a larger waveguide cross-sectional size is beneficial to improving the packaging tolerance, which in turn helps to reduce the coupling difficulty of the optical waveguide 17 and improve the coupling efficiency of the optical waveguide 17.

[0107] In some embodiments, as shown in FIG4, the optical waveguide 17 in the optical fan-out structure 16 is a straight waveguide extending in the glass substrate 3 in a direction parallel to the first plane. One end of the straight waveguide extends to a position close to the first chip 4, and the other end extends to the side surface of the glass substrate 3. The end of the optical waveguide 17 close to the first chip 4 is coupled to the optical signal connection terminal of the first chip 4 through a coupling structure 20. The optical signal can be transmitted between the optical signal connection terminal of the first chip 4 and the optical waveguide 17 through the coupling structure 20. The end of the optical waveguide 17 extending to the side surface of the glass substrate 3 is used for coupling with an external optical fiber 61. The optical signal can be transmitted between the coupled external optical fiber 61 and the optical waveguide 17.

[0108] Therefore, it can be seen that when the external optical fiber 61 is coupled to the optical waveguide 17, an optical signal channel can be formed: external optical fiber 61 - optical waveguide 17 - coupling structure 20 - first chip 4. For example, the optical signal generated by the first chip 4 (laser chip 12) can be transmitted into the external optical fiber 61 through the coupling structure 20 and the optical waveguide 17. As another example, the first chip 4 (photodetector chip 14) can receive the optical signal transmitted in the external optical fiber 61 through the coupling structure 20 and the optical waveguide 17.

[0109] For ease of description, the region in the glass substrate 3 used for connecting the external optical fiber 61 is referred to as the coupling region, and the optical waveguide 17 in the glass substrate 3 extends into this coupling region. When the external optical fiber 61 is connected to this coupling region, the external optical fiber 61 is fixed to the coupling region through the optical fiber connector 62, and the external optical fiber 61 can be coupled with the optical waveguide 17. Exemplarily, in the above embodiment, the coupling region is located in the side surface of the glass substrate 3.

[0110] In some embodiments, referring to FIG4, the coupling structure 20 in the optical fan-out structure 16 is disposed at the end of the optical waveguide 17 near the first chip 4 and at the location of the first chip 4, including a coupling groove 21 and a coupling lens 22. The coupling groove 21 is formed on the first surface 310 and extends a certain depth from the first surface 310 toward the second surface 320. The opening of the coupling groove 21 faces the first chip 4, and the end of the optical waveguide 17 near the first chip 4 is exposed in one groove wall of the coupling groove 21. The coupling lens 22 is disposed in the coupling groove 21 and is an internally deflecting microlens, used to deflect the optical signal transmitted between the optical signal connection end coupled to the first chip 4 and the optical waveguide 17, thereby realizing the coupling effect between the first chip 4 and the optical waveguide 17. The coupling lens 22 can be formed by 3D printing with acrylic adhesive through two-photon polymerization effect.

[0111] In other embodiments, as shown in FIG5, the coupling structure 20 in the optical fan-out structure 16 includes a coupling groove 21 and a reflective film 28. The coupling groove 21 is formed on the first surface 310 and extends a certain depth from the first surface 310 toward the second surface 320. The opening of the coupling groove 21 faces the first chip 4, and the end of the optical waveguide 17 near the first chip 4 is exposed in one groove wall of the coupling groove 21. The reflective film 28 is attached to the other groove wall of the coupling groove 21. By controlling the morphological characteristics of the groove wall to which the reflective film 28 is attached, the reflective film 28 can have a specific morphology. The reflective film 28 with the specific morphology can deflect the optical signal transmitted between the optical signal connection end of the first chip 4 and the optical waveguide 17, thereby realizing the coupling function between the first chip 4 and the optical waveguide 17.

[0112] For example, the groove wall with the reflective film 28 attached forms a concave mirror that is tilted at 45 degrees relative to a third party in the Z direction. When the reflective film 28 is attached to the concave mirror, the functions of turning and coupling light signals are integrated into one.

[0113] In some embodiments, the coupling structure 20 includes a coupling groove 21 and a reflective concave mirror disposed in the coupling groove 21. The shape of the reflective concave mirror can be referred to as the coupling lens 22 in FIG4, and it is used to achieve the same function as the reflective film 28 with a specific morphology described above.

[0114] In some other embodiments, as shown in FIG6, the coupling structure 20 in the optical fan-out structure 16 employs a curved coupling waveguide. One end of the coupling waveguide is connected to the optical waveguide 17, and the other end is connected to the optical signal connection terminal of the first chip 4. The portion between the two ends has a smooth curved transition for coupling the first chip 4 and the optical waveguide 17. Exemplarily, the coupling waveguide can be an arc waveguide.

[0115] In some embodiments, the coupling waveguide includes a coupling groove 21 and a solid glass structure 29. The coupling groove 21 is formed on a first surface 310 and extends to a certain depth from the first surface 310 toward a second surface 320. The opening of the coupling groove 21 faces the first chip 4, and the end of the optical waveguide 17 near the first chip 4 is exposed in one wall of the coupling groove 21. The solid glass structure 29 is disposed in the coupling groove 21 and is in a suspended state. Its outer periphery is surrounded by air in the coupling groove 21. The refractive index difference between the air and the glass forms a waveguide structure that restricts the transmission of optical signals. This design can increase the refractive index difference of the coupling waveguide, enabling large-angle bending of the coupling waveguide, which is beneficial for reducing the coupling distance between the optical waveguide 17 and the first chip 4. For example, the refractive index difference between the solid glass structure 29 and air can reach 0.5%, and its bending radius can be tens of micrometers; in contrast, when the refractive index difference of the optical waveguide is 0.02%, its bending radius is on the order of millimeters.

[0116] In some embodiments, as shown in FIG7, the optical fan-out structure 16 further includes a reflective structure 30 disposed in the glass substrate 3. The end of the optical waveguide 17 away from the first chip 4 extends to a position close to the reflective structure 30. The reflective structure 30 is used to deflect and couple the optical signal transmitted between the optical waveguide 17 and the external optical fiber 61, thereby changing the transmission path of the optical signal when it is transmitted between the optical waveguide 17 and the external optical fiber 61, and thus changing the coupling position with the external optical fiber 61, that is, adjusting the position of the coupling region on the glass substrate 3. By adjusting the position of the coupling region on the glass substrate 3, the coupling position between the external optical fiber 61 and the glass substrate 3 can be flexible and diverse, thereby adapting to different application scenarios.

[0117] For example, as shown in FIG7, by setting the reflection structure 30, the coupling region can be located in the first surface 310. In this case, when the external optical fiber 61 is coupled to the optical engine 1, it is set on the first surface 310 in a vertical position relative to the glass substrate 3. This design helps to reduce the space occupied in the extension direction of the optical waveguide 17 when coupled to the external optical fiber 61.

[0118] Another example is that by setting the reflection structure 30, the coupling region can be located in the second surface 320. The effect is the same as if the coupling region were located in the first surface 310, and will not be described again here.

[0119] In some embodiments, as shown in Figures 8 and 9, the optical fan-out structure 16 further includes a positioning structure 31 disposed on the glass substrate 3 at the edge of the coupling region. This positioning structure 31 cooperates with the fiber optic connector 62 of the external optical fiber 61 to limit the coupling position of the external optical fiber 61 when coupling with the coupling region, thereby ensuring the accuracy of the coupling position and allowing the external optical fiber 61 to be better aligned with the optical waveguide 17, ensuring the coupling efficiency between the optical waveguide 17 and the external optical fiber 61. The positioning structure 31 can be a positioning protrusion, positioning post, positioning plate, positioning groove, or positioning hole, etc.

[0120] Depending on the type of fiber optic connector 62 in the external fiber optic cable 61, the positioning structure 31 can be designed in different ways. For example, the fiber optic connector 62 is a male connector, and the positioning structure 31 is a female connector that mates with the fiber optic connector 62. Yet another example, the fiber optic connector 62 is a female connector, and the positioning structure 31 is a male connector that mates with the fiber optic connector 62.

[0121] In some embodiments, the fiber optic connector 62 is selected from the female end of an MT (Mechanical Transfer) fiber optic connector, an MPO (Multi-fiber Push On) fiber optic connector, and an MTP (Multi-fiber Termination Push-on) fiber optic connector. Correspondingly, the positioning structure 31 includes a positioning pin that mates with the positioning groove in the aforementioned fiber optic connector.

[0122] In other embodiments, the fiber optic connector 62 is selected from the male connectors of MT fiber optic connectors, MPO fiber optic connectors and MTP fiber optic connectors, and correspondingly, the positioning structure 31 includes positioning holes that mate with the positioning pins in the aforementioned fiber optic connectors.

[0123] With the above-mentioned positioning structure 31, the fiber optic connector 62 and the optical engine 1 can be plugged and detached, which helps to reduce the coupling difficulty between the external fiber 61 and the optical waveguide 17. Especially in multi-channel and multi-fiber application scenarios, multiple external fibers 61 can be plugged and detached with the optical engine 1 through one fiber optic connector 62.

[0124] In an embodiment where the first chip 4 employs a multi-channel photonic chip, the optical fan-out structure 16 includes a corresponding number of optical waveguides 17 and coupling structures 20 disposed in the glass substrate 3. The multi-channel optical waveguides 17 can extend to one, two, or more coupling regions. The end faces of the multi-channel optical waveguides 17 are exposed in the coupling regions. Correspondingly, a fiber array (FA) 6 with multiple external optical fibers 61 and fiber optic connectors 62 can be used to interface with the glass substrate 3 in the coupling regions. When the fiber array 6 is connected to the coupling region of the glass substrate 3 via the fiber optic connectors 62, the multiple external optical fibers 61 in the fiber array 6 are simultaneously coupled one-to-one with the multi-channel optical waveguides 17 in the coupling regions. In cases where there is more than one coupling region, a fiber array 6 with the same number of coupling regions can be used to couple one-to-one with each coupling region.

[0125] For example, in the optical engine 1 shown in Figures 1 to 4, there are a transmitting module 10 and a receiving module 15. The transmitting module 10 includes two laser chips 12, and the receiving module 15 includes two photodetector chips 14. Both the laser chips 12 and the photodetector chips 14 are 2N-channel photonic chips. Therefore, the two laser chips 12 in the transmitting module 10 have 4N laser units and 4N optical signal connection terminals, and the two photodetector chips 14 in the receiving module 15 have 4N detection units and 4N optical signal connection terminals.

[0126] In this case, as shown in Figure 10, the optical fan-out structure 16 includes an 8N-channel optical waveguide 17 and 8N coupling structures 20. Among them, the 4N-channel optical waveguide 17 is set to the transmitting module 10 and is called the transmitting (Tx) optical waveguide 17A; the other 4N-channel optical waveguide 17 is set to the receiving module 15 and is called the receiving (Rx) optical waveguide 17B.

[0127] The 4N-channel transmitting waveguide 17A is coupled one-to-one with 4N optical signal connection terminals in the two laser chips 12 through 4N coupling structures 20, and is used to transmit the 4N-channel optical signals generated by the 4N laser units. The 4N-channel receiving waveguide 17B is coupled one-to-one with 4N optical signal connection terminals in the two photodetector chips 14 through 4N coupling structures 20. The optical signals transmitted by the 4N-channel receiving waveguide 17B are input to the 4N detection units in the two photodetector chips 14 through the 4N coupling structures 20 and the 4N optical signal connection terminals. The 4N detection units are used to receive and detect the optical signals transmitted through the receiving waveguide 17B.

[0128] The 4N channel transmitting waveguides 17A are arranged side-by-side in the second direction Y and extend to the same coupling region along the first direction X, which is called the transmitting coupling region. The 4N channel receiving waveguides 17B are arranged side-by-side in the second direction Y and extend to the same coupling region along the first direction X, which is called the receiving coupling region. The transmitting and receiving coupling regions are located on the same side of the glass substrate 3 and are close to each other. The transmitting fiber array 6A with 4N external optical fibers 61 is connected to the glass substrate 3 in the transmitting coupling region, and the receiving fiber array 6B with 4N external optical fibers 61 is connected to the glass substrate 3 in the receiving coupling region, thereby realizing the connection between the optical engine 1 and the external optical fibers 61.

[0129] In the embodiment where the first chip 4 employs a multi-channel photonic chip, the multiple photoelectric conversion units in the first chip 4 can be arranged in a double-row staggered configuration.

[0130] For example, as shown in Figure 11, the first chip 4 includes 2N photoelectric conversion units 41, which are arranged in two unit rows 42. The two unit rows 42 are arranged in a first direction X, and each includes N photoelectric conversion units 41 arranged in a second direction Y. The N photoelectric conversion units 41 in the two unit rows 42 are staggered in the second direction Y. In this case, the 2N-channel optical waveguide 17 coupled to the 2N photoelectric conversion units 41 can be disposed on the same side of the first chip 4 along the first direction X. The N-channel optical waveguide 17 is coupled one-to-one with the N photoelectric conversion units 41 in the near-end unit row 42. Furthermore, after passing through the side gaps of the photoelectric conversion units 41 in the near-end unit row 42, the N-channel optical waveguide 17 is coupled one-to-one with the N photoelectric conversion units 41 in the far-end unit row 42. The 2N-channel optical waveguide 17 extends along the first direction X to the same coupling region. When connecting external optical fibers 61, an optical fiber array 6 with 2N external optical fibers 61 can be used to interface with the glass substrate 3 in the coupling region. When the optical fiber array 6 is connected to the coupling region of the glass substrate 3 through the optical fiber connector 62, the 2N external optical fibers 61 in the optical fiber array 6 are simultaneously coupled one-to-one with the multi-channel optical waveguide 17 in the coupling region, realizing one-to-one coupling of 2N optical fibers with 2N channels of optical waveguide 17 in one go.

[0131] It can be seen that the first chip 4 adopts a double-row staggered arrangement design, which is conducive to the concentrated placement of the optical waveguide 17 in the same area and to the coupling with the external optical fiber 61 in the same position, thereby facilitating the fabrication of the optical waveguide 17 and simplifying the coupling method between the optical engine 1 and the external optical fiber 61.

[0132] As described above, the light fan-out structure 16 provided in the glass substrate 3 can fan out the optical signal connection end of the first chip 4, which is beneficial for setting the first chip 4 on the glass substrate 3 and for connecting the optical signal connection end of the first chip 4 to the external optical fiber 61.

[0133] In the optical engine 1 provided in this application embodiment, the fan-out structure 18 is electrically connected to the electrical signal connection terminals in the first chip 4 and the second chip 5. On the one hand, it is used to realize the electrical connection between the first chip 4 and the second chip 5 and establish an electrical signal transmission channel between the first chip 4 and the second chip 5; on the other hand, it is used to fan out the electrical signal connection terminals in the optical engine 1 to realize the encapsulation connection of the optical engine 1 and establish an electrical signal transmission channel between the optical engine 1 and the outside.

[0134] As shown in Figure 4, the fan-out structure 18 includes a redistribution layer (RDL) disposed on the first surface 310 of the glass substrate 3. The redistribution layer comprises stacked dielectric and circuit layers. The dielectric layer can be made of materials such as polyimide (PI), ABF (Ajinomoto Build-up Film), or silicon oxide (SiO2) to achieve insulation between the circuit layers. The circuit layers can be made of materials such as copper (Cu), aluminum (Al), or silver (Ag) to enable the transmission and rerouting of electrical signals. The redistribution layer is mainly used to redistribute the chip's input / output (I / O) signal connection points to adapt to packaging requirements, while improving interconnect density and electrical performance.

[0135] For ease of distinction, the redistribution layer disposed on the first surface 310 of the glass substrate 3 is referred to as the first redistribution layer 19. The electrical signal connection terminals of the first chip 4 and the second chip 5 are both electrically connected to the first redistribution layer 19. The first redistribution layer 19 is used to realize the electrical connection between the first chip 4 and the second chip 5, and also to realize the function of bringing out the external ports in the second chip 5, so as to facilitate the fan-out and encapsulation connection of the external electrical signal connection terminals.

[0136] In the above-described embodiment comprising a laser chip 12, a photodetector chip 14, a driver chip 11, and a transimpedance amplifier chip 13, the laser chip 12, the photodetector chip 14, the driver chip 11, and the transimpedance amplifier chip 13 can be disposed on the first redistribution layer 19 using flip-chip bonding technology. The first redistribution layer 19, through its circuit layer design, can achieve electrical connections between the laser chip 12 and the driver chip 11, and between the photodetector chip 14 and the transimpedance amplifier chip 13. It can also facilitate the routing of the input terminal of the driver chip 11 and the output terminal of the transimpedance amplifier chip 13.

[0137] Referring to Figure 4, the fan-out structure 18 also includes a first connecting post 23 and a second redistribution layer 24. The first connecting post 23 is disposed in a through-glass via (TGV) that penetrates the glass substrate 3 in a third direction Z. The second redistribution layer 24 is disposed on the second surface 320 of the glass substrate 3. The first connecting post 23 is used to connect the second portion of the first redistribution layer 19 and the second redistribution layer 24. By using the first redistribution layer 19, the first connecting post 23, and the second redistribution layer 24 disposed on the glass substrate 3, the purpose of fanning out the external port of the second chip 5 to the second surface 320 of the glass substrate 3 can be achieved.

[0138] As shown in Figures 1, 2, and 4, the optical engine 1 provided in this embodiment further includes an encapsulation substrate 2. The encapsulation substrate 2 is a flat plate structure made of organic materials, ceramic materials, or composite materials. The thickness direction of this plate structure is parallel to the third direction Z, and it includes a third surface 210 and a fourth surface 220 disposed opposite to each other in the thickness direction (i.e., the third direction Z). Both the third surface 210 and the fourth surface 220 are parallel to the first direction X and the second direction Y. A glass substrate 3 is disposed outside the third surface 210 in the encapsulation substrate 2, and the second surface 320 in the glass substrate 3 is closer to the encapsulation substrate 2 than the first surface 310, that is, the second surface 320 and the third surface 210 are close to each other.

[0139] The fan-out structure 18 also includes a third redistribution layer 25, a fourth redistribution layer 27, a second connecting post 26, and a package interconnect structure 8. The third redistribution layer 25 is disposed on the third surface 210 of the package substrate 2 and is electrically connected to the second redistribution layer 24 disposed on the second surface 320 of the glass substrate 3. The fourth redistribution layer 27 is disposed on the fourth surface 220 of the package substrate 2. The second connecting post 26 is disposed in a through-hole extending Z through the package substrate 2 in a third direction, for connecting the third redistribution layer 25 and the fourth redistribution layer 27. The package interconnect structure 8 is disposed outside the fourth redistribution layer 27 and is electrically connected to the fourth redistribution layer 27.

[0140] It can be seen that the fan-out structure 18, designed as described above, can fan out the external ports of the second chip 5 to the package interconnect structure 8. The package interconnect structure 8 is used for packaging the optical engine 1 and the circuit board. Depending on the packaging method, the package interconnect structure 8 can adopt different designs.

[0141] As an example, as shown in Figure 2, the optical engine 1 and the circuit board are packaged using a Land Grid Array (LGA), and the package interconnect structure 8 includes multiple metal contacts 9. As another example, as shown in Figure 12, the optical engine 1 and the circuit board are packaged using a Ball Grid Array (BGA), and the package interconnect structure 8 includes multiple solder bumps 32, i.e., BGA solder balls.

[0142] As shown in Figures 1 and 4, the optical engine 1 provided in this embodiment further includes a third chip 7, which is also an electronic chip with electrical signal connection terminals. The third chip 7 includes a microcontroller unit (MCU) for controlling the normal operation of the optical engine 1. The third chip 7 is disposed outside the third surface 210 of the package substrate 2, and its electrical signal connection terminals are electrically connected to the third redistribution layer 25. Exemplarily, the third chip 7 can be disposed on the third redistribution layer 25 using flip-chip interconnect technology. The external electrical signal connection terminals of the third chip 7 can also be fanned out to the package interconnect structure 8 through the fan-out structure 18.

[0143] In some embodiments, the third chip 7 is disposed on the outer side of the first surface 310 of the glass substrate 3, and its electrical signal connection terminal is electrically connected to the first redistribution layer 19. Exemplarily, the third chip 7 can be disposed on the first redistribution layer 19 using flip-chip interconnect technology. The external electrical signal connection terminals of the third chip 7 can also be fanned out to the package interconnect structure 8 via the fan-out structure 18.

[0144] In some embodiments, the third chip 7 further includes a switching chip, which enables the optical engine 1 and the switching chip to be co-packaged (CPO) in optoelectronics. The switching chip may be, for example, an application-specific integrated circuit (ASIC) chip.

[0145] In other embodiments, the third chip 7 further includes an xPU chip, which can be a central processing unit (CPU) chip, a graphics processing unit (GPU) chip, or a neural network processing unit (NPU) chip. Integrating the xPU chip achieves an OIO (Optical I / O) package for the optical engine 1 and the xPU chip.

[0146] In the optical engine 1 provided in the above embodiments of this application, the first chip 4 and the second chip 5 are both disposed on the glass substrate 3, and the optical signal connection end and the electrical signal connection end are fanned out through the optical fan-out structure 16 and the electrical fan-out structure 18 disposed on the glass substrate 3; that is, the glass substrate 3 is used as the optoelectronic integrated adapter board in the optical engine 1. This design has several advantages. Firstly, the glass substrate 3 has a high glass transition temperature Tg, which facilitates the integration of a redistribution layer on the glass substrate 3. It can also withstand the high temperatures when the first chip 4 and the second chip 5 are packaged on the glass substrate 3, as well as the high temperatures when the optical engine 1 is packaged on the circuit board, thus reducing application limitations. Secondly, the optical waveguide 17 formed in the glass substrate 3 has a large waveguide cross-sectional size and a large adjustment range, which can improve coupling tolerance, reduce coupling difficulty, and improve coupling efficiency. It can also adapt to multimode optical signal application scenarios. In this case, a multimode light source, such as a multimode VCSEL chip, can be used in the optical engine 1, thereby helping to reduce the cost of the optical engine 1. On the other hand, the optical waveguide 17 formed in the glass substrate 3 can transmit a wide range of optical signal wavelengths, not limited to the traditional C-band and O-band, and has a wide range of applications.

[0147] This application also provides another optical engine 1, which differs from the optical engine 1 in the above embodiment in that it has a fan-out structure 18. As shown in Figures 13 and 14, in this embodiment, the fan-out structure 18 includes a first redistribution layer 19, a third redistribution layer 25, a second connecting post 26, a fourth redistribution layer 27, and a package interconnect structure 8. The first redistribution layer 19 includes a first pad 33, and the third redistribution layer 25 includes a second pad 35. The fan-out structure 18 also includes leads 34 for connecting the first pad 33 and the second pad 35.

[0148] It can be seen that in this embodiment, the glass substrate 3 and the packaging substrate 2 are electrically connected by wire bonding, which reduces the difficulty and cost of connection.

[0149] This application also provides another optical engine 1, which differs from the optical engine 1 in the positional relationship between the glass substrate 3 and the encapsulation substrate 2, as well as the fan-out structure 18. As shown in FIG15, in this embodiment, the encapsulation substrate 2 is disposed outside the first surface 310 of the glass substrate 3, and the third surface 210 of the encapsulation substrate 2 is closer to the glass substrate 3 than the fourth surface 220. The fan-out structure 18 includes a first redistribution layer 19, a third redistribution layer 25, a second connecting post 26, a fourth redistribution layer 27, and an encapsulation interconnect structure 8; the first redistribution layer 19 and the third redistribution layer 25 are electrically connected.

[0150] In some embodiments, the packaging substrate 2 is provided with a through cavity 36 exposing the first chip 4 and the second chip 5. This design is beneficial for heat dissipation of the first chip 4 and the second chip 5, as well as for providing a heat dissipation structure for heat dissipation of the first chip 4 and the second chip 5.

[0151] This application also provides another optical engine 1, which differs from the optical engine 1 in the relationship between the glass substrate 3 and the encapsulation substrate 2, as well as the fan-out structure 18. As shown in FIG16, the glass substrate 3 includes a glass core 301 and a first organic layer 302 and a second organic layer 303 disposed on both sides of the glass core 301, that is, the glass substrate 3 and the encapsulation substrate 2 are integrated into one unit. The first organic layer 302 and the second organic layer 303 are formed using organic materials, such as polyimide. The outer surface of the first organic layer 302 away from the glass core 301 is the first surface 310, and the outer surface of the second organic layer 303 away from the glass core 301 is the second surface 320.

[0152] The optical fan-out structure 16 includes an optical waveguide 17 and a coupling structure 20 disposed in the glass core 301. The electric fan-out structure 18 includes a first redistribution layer 19, a connection structure, a second redistribution layer 24, and an encapsulation interconnect structure 8. The first redistribution layer 19 is disposed on a first surface 310 of the glass substrate 3, the second redistribution layer 24 is disposed on a second surface 320 of the glass substrate 3, and the connection structure penetrates the glass substrate 3, connecting the first redistribution layer 19 and the second redistribution layer 24. The encapsulation interconnect structure 8 is disposed on the second redistribution layer 24. The connection structure may include a connecting pillar structure penetrating the glass substrate 3, and may also include a redistribution layer disposed between the first organic layer 302 and the glass core 301, and / or, between the second organic layer 303 and the glass core 301.

[0153] In some embodiments, only the second organic layer 303 may be retained, that is, the glass substrate 3 includes a glass core 301 and an organic layer, the organic layer is disposed on one side of the glass core 301, the outer surface of the glass core 301 away from the organic layer is the first surface 310, and the surface of the organic layer away from the glass core 301 is the second surface 320. Other details can be found in the above embodiments, and will not be repeated here.

[0154] In the above embodiments, the optical engine 1 has the function of both transmitting and receiving optical signals. However, the embodiments of this application are not limited to this. For example, the optical engine 1 may only have the function of transmitting or receiving optical signals. That is, only one of the transmitting module and the receiving module is provided.

[0155] This application also provides a communication device that is used in the field of optical communication. It can be a device such as an optical module, switch, and server that exchange information via optical signals. As shown in FIG17, the communication device 100 includes a printed circuit board (PCB) 110 and an optical engine 1 provided in any of the above embodiments. The optical engine 1 is encapsulated on the PCB 110 and electrically connected to the PCB 110.

[0156] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

A light engine, characterized in that, The optical engine includes a first chip, a second chip, a glass substrate, an electric fan-out structure, and an optical fan-out structure; The first chip is an electronic chip, and the second chip is a photonic chip. The glass substrate includes a first surface and a second surface disposed opposite to each other in the thickness direction; the fan-out structure includes a first redistribution layer disposed on the first surface of the glass substrate, and both the first chip and the second chip are disposed on the first redistribution layer; the first redistribution layer is used for electrical connection between the first chip and the second chip, and for leading out the external port of the second chip; The optical fan-out structure includes an optical waveguide and a coupling structure disposed in the glass substrate. The optical waveguide extends in the glass substrate, and the coupling structure is used to couple the optical waveguide to the first chip. The light engine according to claim 1 is characterized in that, The optical engine also includes a packaging substrate, which includes a third surface and a fourth surface disposed opposite to each other in the thickness direction; The fan-out structure further includes a third redistribution layer, a fourth redistribution layer, a second connecting post, and a package interconnection structure. The third redistribution layer is disposed on the third surface of the package substrate, and the fourth redistribution layer is disposed on the fourth surface of the package substrate. The second connecting post penetrates the package substrate and connects the third redistribution layer and the fourth redistribution layer. The glass substrate is disposed on the outer side of the third surface in the packaging substrate, and the third redistribution layer is electrically connected to the first redistribution layer. The encapsulated interconnect structure is disposed on the fourth redistribution layer and is used for encapsulating connections. The light engine according to claim 2 is characterized in that, The fan-out structure further includes a second redistribution layer and a second connecting post; the second redistribution layer is disposed on the second surface of the glass substrate, and the first connecting post penetrates the glass substrate and connects the second redistribution layer and the first redistribution layer; The second surface of the glass substrate is close to the third surface of the packaging substrate, and the second redistribution layer is electrically connected to the third redistribution layer. The light engine according to claim 2 is characterized in that, The second surface of the glass substrate is close to the third surface of the encapsulation substrate; The first redistribution layer includes a first pad, and the third redistribution layer includes a second pad; The fan-out structure also includes leads connecting the first pad and the second pad. The light engine according to claim 2 is characterized in that, The first surface of the glass substrate is close to the third surface of the encapsulation substrate; The first redistribution layer is electrically connected to the third redistribution layer. The light engine according to claim 5 is characterized in that, The packaging substrate has a through cavity that exposes the first chip and the second chip. The light engine according to any one of claims 2 to 6 is characterized in that, The packaging substrate is an organic substrate, a ceramic substrate, or a composite substrate. The light engine according to any one of claims 2 to 7 is characterized in that, The light engine also includes a third chip, which includes a microcontroller chip for controlling the operation of the light engine. The third chip is disposed on the third redistribution layer of the packaging substrate. The light engine according to claim 1 is characterized in that, The glass substrate includes a glass core and a first organic layer and a second organic layer disposed on both sides of the glass core, and the optical waveguide and the coupling structure are disposed in the glass core; The outer surface of the first organic layer away from the glass core is the first surface, and the outer surface of the second organic layer away from the glass core is the second surface; The fan-out structure includes a second redistribution layer, a connection structure, and an encapsulation interconnection structure. The second redistribution layer is disposed on the second surface of the glass substrate, and the connection structure penetrates the glass substrate and connects the first redistribution layer and the second redistribution layer. The encapsulation interconnect structure is disposed on the second redistribution layer and is used for encapsulating connections. The light engine according to claim 1 is characterized in that, The glass substrate includes a glass core and an organic layer disposed on one side of the glass core, and the optical waveguide and the coupling structure are disposed in the glass core; The outer surface of the glass core away from the organic layer is the first surface, and the outer surface of the organic layer away from the glass core is the second surface; The fan-out structure includes a second redistribution layer, a connection structure, and an encapsulation interconnection structure. The second redistribution layer is disposed on the second surface of the glass substrate, and the connection structure penetrates the glass substrate and connects the first redistribution layer and the second redistribution layer. The encapsulation interconnect structure is disposed on the second redistribution layer and is used for encapsulating connections. The light engine according to claim 9 or 10 is characterized in that, The light engine also includes a third chip, which includes a microcontroller chip for controlling the operation of the light engine. The third chip is disposed on the first redistribution layer of the glass substrate. The light engine according to any one of claims 8 to 11 is characterized in that, The third chip also includes a switching chip, a central processing unit chip, a graphics processing unit chip, or a neural network processor chip. The light engine according to any one of claims 2 to 12 is characterized in that, The packaged interconnect structure includes an array of solder ball bumps or an array of metal contacts. The light engine according to any one of claims 1 to 13 is characterized in that, The coupling structure includes a coupling groove and a coupling lens. The coupling groove is disposed on the glass substrate and is used to connect the first chip and the optical waveguide. The coupling lens is disposed in the coupling groove and is used to couple the first chip and the optical waveguide. The light engine according to any one of claims 1 to 13 is characterized in that, The coupling structure includes a coupling groove and a reflective film. The coupling groove is disposed on the glass substrate and is used to connect the first chip and the optical waveguide. The reflective film is disposed on the groove wall of the coupling groove and is used to couple the first chip and the optical waveguide. The light engine according to any one of claims 1 to 13 is characterized in that, The coupling structure includes a coupling groove and a reflective concave mirror. The coupling groove is disposed on the glass substrate and is used to connect the first chip and the optical waveguide. The reflective concave mirror is disposed in the coupling groove and is used to couple the first chip and the optical waveguide. The light engine according to any one of claims 1 to 13 is characterized in that, The coupling structure includes a curved and extended coupling waveguide, one end of which is connected to the optical waveguide and the other end of which is connected to the first chip, for coupling the first chip and the optical waveguide. The light engine according to claim 17 is characterized in that, The coupling waveguide includes a coupling groove and a solid glass structure. The coupling groove is disposed on the glass substrate and is used to connect the first chip and the optical waveguide. The solid glass structure is suspended in the coupling groove and its two ends are respectively connected to the first chip and the optical waveguide. The light engine according to any one of claims 1 to 18 is characterized in that, The optical waveguide extends in the glass substrate in a direction parallel to the first surface, and the glass substrate has a coupling region, wherein an external optical fiber connected to the coupling region is coupled to the optical waveguide. The coupling region is located in the side surface of the glass substrate, and the end of the optical waveguide away from the first chip extends into the coupling region; Alternatively, the coupling region is located in the first surface or the second surface, and the optical fan-out structure further includes a reflective structure disposed in the glass substrate. The end of the optical waveguide away from the first chip extends to the reflective structure, and the reflective structure is used to deflect the optical signal transmitted between the coupling region and the optical waveguide. The light engine according to claim 19 is characterized in that, The external optical fiber is connected to the glass substrate in the coupling region via an optical fiber connector; The optical fan-out structure further includes a positioning structure disposed at the edge of the coupling region on the glass substrate to limit the connection position of the optical fiber connector. The light engine according to claim 20 is characterized in that, The fiber optic connector is pluggable and detachable from the optical engine; The fiber optic connector is a male connector, and the positioning structure is a female connector that mates with the fiber optic connector. Alternatively, the fiber optic connector may be a female connector, and the positioning structure may be a male connector that mates with the fiber optic connector. The light engine according to any one of claims 1 to 21 is characterized in that, The optical waveguide is formed in the glass substrate using ion exchange technology or laser direct writing technology. The light engine according to any one of claims 1 to 22 is characterized in that, The waveguide cross-sectional dimensions of the optical waveguide range from 10 μm to 80 μm. The light engine according to any one of claims 1 to 23 is characterized in that, The optical waveguide is a multimode optical waveguide, and the first chip includes a multimode vertical cavity surface-emitting laser chip. Alternatively, the optical waveguide is a single-mode optical waveguide, and the first chip includes a single-mode vertical-cavity surface-emitting laser chip. The light engine according to any one of claims 1 to 24 is characterized in that, The first chip includes multiple photoelectric conversion units, and the light fan-out structure includes multiple optical waveguides and multiple coupling structures disposed in the glass substrate, wherein the photoelectric conversion units, the coupling structures and the optical waveguides are coupled in a one-to-one correspondence. The light engine according to claim 25 is characterized in that, The second chip includes multiple circuit units; One of the first chips is connected to one of the second chips; Alternatively, at least two of the second chips are connected to one of the first chips; Alternatively, one second chip may be connected to at least two first chips; In the connected first chip and second chip, the number of circuit units and the number of photoelectric conversion units are the same, and they are connected in a one-to-one correspondence. The light engine according to claim 25 or 26 is characterized in that, The first chip includes two unit rows arranged in a first direction, each unit row including a plurality of photoelectric conversion units arranged in a second direction, and the photoelectric conversion units in the two unit rows are staggered in the second direction; Wherein, the first direction is perpendicular to the second direction, and both are parallel to the first surface; All the optical waveguides coupled to the first chip are located on the same side of the first chip along the first direction, arranged side by side along the second direction, and extending along the first direction. The light engine according to any one of claims 1 to 27 is characterized in that, The first chip includes a laser chip, and the second chip includes a driver chip, wherein the driver chip is electrically connected to the laser chip; And / or, the first chip includes a photodetector chip, and the second chip includes a transimpedance amplifier chip, the transimpedance amplifier chip being electrically connected to the photodetector chip. A communication device, characterized in that, The communication device includes: Circuit board; And, the light engine as described in any one of claims 1 to 28, wherein the light engine is electrically connected to the circuit board.

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