A carrier board with in-board optical waveguide and optoelectronic integrated system, hermetic chip

Abstract

The application discloses a carrier plate with in-plate optical waveguide and an optoelectronic integrated system and a hermetically sealed chip, and relates to the fields of optoelectronic integration and chip packaging. The carrier plate comprises a carrier plate body and an optical waveguide layer. The surface of the carrier plate body is provided with a mounting area, and the mounting area is provided with a plate-end coupling structure. The optical waveguide layer is embedded in the carrier plate body and used for transmitting optical signals. The plate-end coupling structure is a micro-mirror coupling structure, a vertical coupling grating or a tapered waveguide coupler, and is used for converting the transmission direction of the optical signals in the optical waveguide layer and the direction perpendicular to the surface of the carrier plate body. The carrier plate with in-plate optical waveguide and the optoelectronic integrated system and the hermetically sealed chip have the following advantages: an optical window is arranged on the bottom surface of the hermetically sealed chip and is non-contactly optically coupled with the embedded optical waveguide in the carrier plate, the heat dissipation path and the optical signal transmission path are spatially separated, the in-plate high-speed optical interconnection is realized, the optical isolation structure is simplified, and the thermal stability of the system is improved.

Description

Technical Field

[0001] This invention relates to optoelectronic integration and chip packaging technology, specifically to a carrier board with an in-board optical waveguide, an optoelectronic integration system, and a packaged chip. Background Technology

[0002] With the rapid growth in bandwidth demands from data centers and artificial intelligence computing, traditional optical module interconnect solutions face significant bottlenecks in terms of bandwidth density and power consumption. Co-packaged optics technology, by encapsulating the switching chip and photoelectric conversion engine in the same package, significantly shortens the electrical signal transmission distance, thereby reducing power consumption and improving signal integrity, and is considered one of the key paths to solve the aforementioned bottlenecks.

[0003] US Patent Publication No. US20240310578A1 discloses an optoelectronic component, relating to a CPO optoelectronic component and a circuit board-level optical interconnect. The solution includes a module and a circuit board: the module comprises a module substrate and a module waveguide disposed thereon, and the circuit board comprises a circuit board substrate and a circuit board waveguide disposed thereon; the module is assembled onto the circuit board, aligning the circuit board waveguide with the module waveguide to achieve optical coupling, which can be evanescent coupling or edge coupling. The document also describes an architecture where a CPO transceiver and a Switch ASIC are co-packaged, and points out that fiber optic fly-through interconnects suffer from problems such as high assembly precision requirements, high cost, and large size, proposing that integrated waveguides can replace optical fibers for optical transmission between two substrates.

[0004] In existing co-packaged optical solutions, besides the aforementioned substrate waveguide coupling method, another mainstream approach for extracting optical signals is to directly insert the optical fiber into the package, allowing direct coupling between the fiber and the optical engine inside the package. However, this direct fiber insertion method requires extremely high alignment precision between the fiber and the chip, typically at the micrometer level. Furthermore, the difference in thermal expansion coefficients between the fiber and package materials can easily lead to long-term reliability issues, such as fiber displacement and coupling efficiency drift. In addition, this method involves complex assembly processes at the packaging end, hindering large-scale automated production. While US20240310578A1 proposes a substrate-to-substrate waveguide coupling solution to avoid the fiber fly-through interconnect problem, it employs a direct alignment and coupling method between the module waveguide and the circuit board waveguide. It does not disclose the creation of an optical window at the bottom of the optoelectronic co-packaged chip, nor does it disclose a technical solution for alignment and coupling with the embedded optical waveguide on the printed circuit board via a micromirror coupling structure. At the board-level interconnection level, on-board optics technology achieves high-speed optical interconnection between chips within the board by embedding polymer optical waveguides within the printed circuit board. However, how to efficiently and reliably couple the co-packaged optical chip with the on-board optical waveguide remains a key challenge that restricts the practical application of this technology.

[0005] In terms of optical crosstalk isolation, traditional solutions typically use a metal shield to physically block the photoelectric conversion area to prevent stray light from interfering with adjacent optical channels. However, metal shields are bulky, occupying packaging space and requiring separate mounting and fixing processes, increasing manufacturing costs and process complexity. Furthermore, the mismatch in thermal expansion coefficients between the metal shield and the chip material can introduce stress issues, affecting system reliability.

[0006] Furthermore, in existing co-packaged optical structures, the heat dissipation path and optical path of the photoelectric conversion chip are usually not optimized and separated. The heat generated by the chip during operation may cause local deformation of the package, which in turn causes a drift in optical coupling efficiency, affecting the thermal stability and long-term operational reliability of the system.

[0007] In summary, how to avoid the high-precision coupling and reliability challenges caused by directly inserting optical fibers into the package, and how to simplify the optical crosstalk isolation structure to reduce assembly complexity, are technical problems that urgently need to be solved in this field. Summary of the Invention

[0008] The purpose of this invention is to provide a carrier board with an in-board optical waveguide and an optoelectronic integrated system and a packaged chip to solve the problems of poor coupling reliability caused by fiber insertion into the package and thermal coupling drift caused by the lack of separation between the heat dissipation path and the optical path in the existing CPO solution.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a carrier plate having an in-plate optical waveguide, comprising:

[0010] Carrier board body;

[0011] An optical waveguide layer, embedded inside the substrate, is used to transmit optical signals;

[0012] The surface of the carrier board body is provided with a mounting area, and the mounting area has a board end coupling structure.

[0013] Furthermore, the board-end coupling structure is a micromirror coupling structure, a vertical coupling grating, or a tapered waveguide coupler, used to convert the transmission direction of the optical signal in the optical waveguide layer between the direction perpendicular to the surface of the carrier board.

[0014] Furthermore, the substrate also includes a copper trace layer for transmitting electrical signals, and the optical waveguide layer is layered with the copper trace layer. The optical waveguide layer is made of polymer material, glass material or silicon nitride material.

[0015] Furthermore, the carrier board is also provided with an optical fiber connector port, which is connected to the optical waveguide layer and is used to connect with external optical fiber patch cords to realize inter-board optical interconnection.

[0016] An optoelectronic integrated system with an in-plate optical waveguide includes:

[0017] Co-packaged chips;

[0018] And the aforementioned carrier plate with an in-plate optical waveguide;

[0019] The packaged chip is mounted in the mounting area of ​​the carrier board.

[0020] Furthermore, the optoelectronic integrated system also includes a heat sink disposed on the top surface of the packaged chip; the optical window of the packaged chip is located on its bottom surface, so that the heat dissipation path where the heat sink is located is spatially separated from the optical signal transmission path where the optical window is located.

[0021] A packaged chip with an in-board optical waveguide is mounted on a carrier board with an in-board optical waveguide to form an optoelectronic integrated system. The packaged chip includes a molding compound and a switching processing chip, a laser emitting chip, and an optical interposer encapsulated within the molding compound. The molding compound has opposing top and bottom surfaces. The optical interposer integrates an optical modulator, a photodetector, and an internal optical waveguide for converting electrical signals to optical signals in cooperation with the switching processing chip and the laser emitting chip. The bottom surface of the molding compound has an optical window aligned with the end coupling structure of the carrier board to output optical signals generated by the optical interposer downwards to the optical waveguide layer of the carrier board, or to receive optical signals transmitted from the optical waveguide layer upwards to the optical interposer.

[0022] Furthermore, the encapsulated chip also includes a light-blocking component, which is independently attached to the periphery of the encapsulation or the optical window to prevent optical signal crosstalk. The light-blocking component is made of a material that absorbs or reflects optical signals of the working wavelength. The light-blocking component is fixed to the encapsulation or carrier plate of the encapsulated chip by means of snap-fit, adhesive, plug-in, magnetic attraction, or bolt connection. In specific implementations, the light-blocking component can be a light-blocking strip or a light-blocking frame, and is made of black light-absorbing plastic, metal material, or composite material containing light-absorbing filler.

[0023] Furthermore, the encapsulated chip includes multiple parallel photoelectric conversion channels, and the light-blocking components are configured in a strip or grid shape, which are disposed between adjacent photoelectric conversion channels to isolate optical crosstalk between channels.

[0024] Furthermore, the switching processing chip and the laser emitting chip are both mounted on the same surface of the optical interposer; or the switching processing chip is mounted on the first surface of the optical interposer by flip-chip bonding, and the laser emitting chip is mounted on the second surface or sidewall of the optical interposer.

[0025] Compared with existing technologies, the present invention provides a carrier board with an in-board optical waveguide, an optoelectronic integrated system, and a packaged chip. At the optical signal transmission architecture level, by opening an optical window on the bottom surface of the packaged chip and using a micromirror coupling structure to align and couple it with the optical waveguide embedded in the carrier board, non-contact optical signal transmission between the packaged chip and the carrier board is achieved. This fundamentally avoids the high-precision alignment and long-term reliability challenges required for direct insertion of optical fibers into the package. At the optical crosstalk isolation level, light-blocking components independently attached around the plastic package or the optical window replace the traditional metal shielding cover, resulting in a smaller size. The assembly is simpler and does not cover the heat dissipation surface, thus not affecting the system's thermal management performance. At the same time, the present invention places the heat sink on the top surface of the encapsulated chip and the optical window on the bottom surface, so that the heat dissipation path and the optical signal transmission path are spatially separated. The main direction of thermal deformation is orthogonal to the sensitive direction of the optical path alignment, which effectively reduces thermal coupling efficiency drift and improves the thermal stability of the system. In particular, high-speed signals are transmitted within the board through optical waveguides, flexible interconnection is achieved between boards through optical fiber ports, and low-speed signals are transmitted through copper traces, forming a hierarchical optical interconnection system, realizing optimized transmission of signals of different rates and distances. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0027] Figure 1 This is a schematic diagram of the overall structure of the carrier board, the encapsulated chip, and the optoelectronic integrated system in an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure in an embodiment of the present invention, in which both the switching processing chip and the laser emitting chip are mounted on the same surface of the optical interposer.

[0029] Figure 3 This is a top view schematic diagram showing that, in an embodiment of the present invention, both the switching processing chip and the laser emitting chip are mounted on the same surface of the optical interposer;

[0030] Figure 4 This is a bottom view schematic diagram showing that, in an embodiment of the present invention, both the switching processing chip and the laser emitting chip are mounted on the same surface of the optical interposer;

[0031] Figure 5 This is a schematic diagram of the structure in an embodiment of the present invention, in which the switching processing chip is flip-chip mounted on the first surface of the optical interposer and the laser emitting chip is mounted on the second surface or sidewall of the optical interposer.

[0032] Figure 6This is a top view schematic diagram of an embodiment of the present invention, in which the switching processing chip is mounted on the first surface of the optical interposer by flip-chip bonding and the laser emitting chip is mounted on the second surface or sidewall of the optical interposer.

[0033] Figure 7 This is a bottom view schematic diagram of an embodiment of the present invention, in which the switching processing chip is mounted on the first surface of the optical interposer by flip-chip bonding, and the laser emitting chip is mounted on the second surface or sidewall of the optical interposer.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. Carrier board body; 2. Fiber optic connector port; 3. Molded enclosure; 4. Switching processing chip; 5. Laser emitting chip; 6. Optical interposer layer; 7. Optical window; 8. Heat sink. Detailed Implementation

[0036] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0037] As attached Figure 1 As shown:

[0038] Example 1:

[0039] This invention provides an optoelectronic integrated system with an in-plate optical waveguide, comprising:

[0040] A carrier plate with an in-plate optical waveguide;

[0041] The chip is encapsulated and mounted on the mounting area of ​​the carrier board;

[0042] And a heat sink 8 is located on the top surface of the sealed chip.

[0043] As attached Figure 1 As shown:

[0044] Example 2:

[0045] The present invention provides a carrier board with an in-board optical waveguide, comprising a carrier board body 1 and an optical waveguide layer, wherein the surface of the carrier board body 1 is provided with a mounting area and the mounting area has a board end coupling structure, and the optical waveguide layer is embedded in the interior of the carrier board body 1 for transmitting optical signals.

[0046] In one embodiment of the present invention, the plate-end coupling structure is a micromirror coupling structure, a vertical coupling grating, or a tapered waveguide coupler, used to convert the transmission direction of the optical signal in the optical waveguide layer between the direction perpendicular to the surface of the carrier plate 1.

[0047] In one embodiment of the present invention, the carrier body 1 is further provided with a copper trace layer for transmitting electrical signals, and the optical waveguide layer and the copper trace layer are arranged in layers. The optical waveguide layer is made of polymer material, glass material or silicon nitride material.

[0048] In one embodiment of the present invention, the carrier board body 1 is further provided with an optical fiber connector port 2, which is connected to the optical waveguide layer optical path and is used to connect with external optical fiber patch cords to realize inter-board optical interconnection.

[0049] Working principle: The optical signal propagates horizontally within the optical waveguide layer of the carrier board. Upon reaching the mounting area, the board-end coupling structure converts the signal transmission direction to be perpendicular to the carrier board surface, allowing the signal to be emitted from the carrier board surface or received from the encapsulated chip. After the encapsulated chip is mounted, its bottom optical window 7 aligns with the board-end coupling structure. The optical signal passes through the optical window 7 into the optical interposer layer 6 inside the encapsulated chip, where it is converted into an electrical signal by a photodetector. Alternatively, the optical signal generated by the laser emitting chip 5 inside the encapsulated chip and modulated by an optical modulator is output downwards from the optical window 7 and coupled into the carrier board's optical waveguide layer via the board-end coupling structure, achieving high-speed optical interconnection within the board. Optical interconnection between boards is accomplished by connecting external fiber optic patch cords through fiber optic connector ports 2 on the carrier board. Low-speed control signals and power signals are transmitted through the copper trace layer, thus forming a hierarchical optical interconnection system.

[0050] As attached Figure 1 As shown:

[0051] Example 3:

[0052] This invention provides a packaged chip with an in-board optical waveguide, which is mounted on a carrier board in Embodiment 2 to form the optoelectronic integrated system in Embodiment 1. The packaged chip includes: a molding compound 3 and a switching processing chip 4, a laser emitting chip 5, and an optical interposer 6 encapsulated within the molding compound 3. The molding compound 3 has opposing top and bottom surfaces. The optical interposer 6 integrates an optical modulator, a photodetector, and an internal optical waveguide for converting electrical signals to optical signals in cooperation with the switching processing chip 4 and the laser emitting chip 5. The bottom surface of the molding compound 3 is provided with an optical window 7, which is aligned with the end coupling structure of the carrier board to output the optical signal generated by the optical interposer 6 downward to the optical waveguide layer of the carrier board, or to receive the optical signal transmitted from the optical waveguide layer upward to the optical interposer 6.

[0053] In one embodiment of the present invention, the encapsulated chip further includes a light-blocking component. The light-blocking component is independently attached to the periphery of the encapsulation body 3 or the periphery of the optical window 7 to prevent optical signal crosstalk. The light-blocking component is made of a material that absorbs or reflects optical signals of the working wavelength. The light-blocking component is fixed to the encapsulation body 3 or the carrier plate of the encapsulated chip by means of snap-fit, adhesive, plug-in, magnetic attraction or bolt connection. In specific implementations, the light-blocking component can be a light-blocking strip or a light-blocking frame, and is made of black light-absorbing plastic, metal material or composite material containing light-absorbing filler.

[0054] In one embodiment of the present invention, the encapsulated chip includes multiple parallel photoelectric conversion channels, and the light-blocking component is configured as a strip or grid, which is disposed between adjacent photoelectric conversion channels to isolate light crosstalk between channels.

[0055] As attached Figure 2 To be continued Figure 4 As shown, the switching processing chip 4 and the laser emitting chip 5 are both mounted on the same surface of the optical interposer 6, that is, they are arranged side by side on the optical interposer 6 in the same direction. The optical modulator and the internal optical waveguide integrated in the optical interposer 6 are electrically connected and optically connected to the switching processing chip 4 and the laser emitting chip 5, respectively. The high-speed electrical signal output by the switching processing chip 4 is directly transmitted to the optical interposer 6 for modulation. The optical carrier provided by the laser emitting chip 5 is coupled into the optical modulator through the internal optical waveguide. The modulated optical signal is transmitted through the internal optical waveguide of the optical interposer 6 to the optical window 7 on the bottom surface of the encapsulation 3 and output downwards.

[0056] As attached Figure 5 To be continued Figure 7 As shown, the switching processing chip 4 is flip-chip bonded to the first surface of the optical interposer 6, and the laser emitting chip 5 is bonded to the second surface or sidewall of the optical interposer 6. That is, the switching processing chip 4 and the laser emitting chip 5 are located on different surfaces or in different orientations of the optical interposer 6. The switching processing chip 4 is electrically connected to the first surface of the optical interposer 6 via flip-chip bonding bumps. The laser emitting chip 5 is bonded to the second surface of the optical interposer 6 opposite to the first surface or to the sidewall of the optical interposer 6. The optical carrier generated by the laser emitting chip 5 is transmitted to the optical modulator via an internal optical waveguide within the optical interposer 6. The electrical signal output by the switching processing chip 4 is transmitted to the optical interposer 6 via flip-chip bonding to drive the optical modulator to complete the electro-optical conversion.

[0057] In one embodiment of the present invention, the optical window 7 of the encapsulated chip is located on its bottom surface, so that the heat dissipation path where the heat sink 8 is located is spatially separated from the optical signal transmission path where the optical window 7 is located.

[0058] Working principle: After the packaged chip is mounted on the carrier board, the high-speed electrical signal output by the switching processing chip 4 is transmitted to the optical interposer layer 6. The optical modulator within the optical interposer layer 6 modulates the electrical signal into an optical signal based on the optical carrier provided by the laser emitting chip 5. The optical signal is transmitted through the internal optical waveguide to the optical window 7 on the bottom surface of the molding compound 3, output downwards, and coupled into the optical waveguide layer via the board-end coupling structure of the carrier board. Conversely, the receiving direction is reversed; the optical signal from the optical waveguide layer of the carrier board enters the optical interposer layer 6 via the board-end coupling structure and the optical window 7, is converted into an electrical signal by the photodetector, and then transmitted to the switching processing chip 4. During this process, light-blocking components attached around the molding compound 3 or the optical window 7 physically block stray light, preventing optical crosstalk to adjacent channels or the external environment. Heat sink 8 is attached to the top surface of the encapsulated chip. The heat generated by the chip during operation is conducted upward in the vertical direction to the heat sink 8 for dissipation, while the optical signal is transmitted downward in the vertical direction. The heat dissipation path and the optical signal transmission path are spatially separated. The thermal deformation is mainly along the vertical direction, which is orthogonal to the horizontal direction that is sensitive to the optical path alignment, thereby reducing thermal coupling efficiency drift.

[0059] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A carrier plate having an in-plate optical waveguide, characterized in that, include: Carrier board body (1); An optical waveguide layer is embedded inside the substrate (1) to transmit optical signals; The surface of the carrier board body (1) is provided with a mounting area, and the mounting area has a board end coupling structure.

2. A carrier plate with an in-plate optical waveguide according to claim 1, characterized in that, The plate-end coupling structure is a micromirror coupling structure, a vertical coupling grating, or a tapered waveguide coupler, used to convert the transmission direction of the optical signal in the optical waveguide layer between the direction perpendicular to the surface of the carrier plate (1).

3. A carrier plate with an in-plate optical waveguide according to claim 1, characterized in that, The carrier board body (1) is also provided with a copper trace layer for transmitting electrical signals. The optical waveguide layer and the copper trace layer are arranged in layers. The optical waveguide layer is made of polymer material, glass material or silicon nitride material.

4. A carrier plate with an in-plate optical waveguide according to claim 1, characterized in that, The carrier plate body (1) is also provided with an optical fiber connector port (2), which is connected to the optical waveguide layer optical path.

5. An optoelectronic integrated system with an in-plate optical waveguide, characterized in that, include: Co-packaged chips; And, the carrier plate having an in-plate optical waveguide as described in any one of claims 1-4; The packaged chip is mounted in the mounting area of ​​the carrier board.

6. The optoelectronic integrated system with an in-plate optical waveguide according to claim 5, characterized in that, It also includes a heat sink (8) located on the top surface of the encapsulated chip.

7. A packaged chip with an in-board optical waveguide, mounted on a carrier board with an in-board optical waveguide as described in any one of claims 1-4, to constitute the optoelectronic integrated system as described in any one of claims 5-6, characterized in that, The package includes a molding compound (3) and a switching processing chip (4), a laser emitting chip (5), and an optical interposer (6) encapsulated within the molding compound (3). The molding compound (3) has a top surface and a bottom surface. The optical interposer (6) integrates an optical modulator, a photodetector, and an internal optical waveguide. The bottom surface of the molding compound (3) is provided with an optical window (7), which is aligned with the end coupling structure of the substrate.

8. A packaged chip with an in-board optical waveguide according to claim 7, characterized in that, It also includes light-blocking parts, which are independently attached to the periphery of the encapsulation body (3) or the periphery of the optical window (7). The light-blocking parts are made of materials that absorb or reflect working wavelength light signals. The light-blocking parts are fixed to the carrier plate or the encapsulation body (3) of the encapsulated chip by means of snap-fit, adhesive, plug-in, magnetic attraction or bolt connection.

9. A packaged chip with an in-board optical waveguide according to claim 7, characterized in that, The encapsulated chip includes multiple parallel photoelectric conversion channels, and the light-blocking components are configured in a strip or grid shape, which are disposed between adjacent photoelectric conversion channels.

10. A packaged chip with an in-board optical waveguide according to claim 7, characterized in that, The switching processing chip (4) and the laser emitting chip (5) are configured in either of the following two packaging methods: The switching processing chip (4) and the laser emitting chip (5) are both mounted on the same surface of the optical interposer (6); The switching processing chip (4) is flip-chip bonded to the first surface of the optical interposer (6), and the laser emitting chip (5) is bonded to the second surface or sidewall of the optical interposer (6) opposite to the first surface.

Images