On-chip integrated interconnection structure

Abstract

The invention provides an on-chip integrated interconnection structure which comprises a calculation module integrated on the same substrate, a plurality of photoelectric co-packaging modules and coarse wavelength division multiplexers, the photoelectric co-packaging modules and the coarse wavelength division multiplexers are stacked around the calculation module, and the calculation module and the photoelectric co-packaging modules are electrically interconnected through a rewiring layer. And the photoelectric co-packaging module and the coarse wavelength division multiplexer realize optical interconnection through a polymer waveguide. According to the on-chip integrated interconnection structure provided by the invention, the photoelectric co-packaging module, the coarse wavelength division multiplexer and the calculation module are interconnected and packaged and integrated together, so that an optical in-out integrated optical communication module is realized; moreover, the photoelectric co-packaging module and the coarse wavelength division multiplexer are connected through the polymer waveguide, the problem that the packaging density is limited due to the size limitation of existing optical fiber interconnection is solved through the small size of the polymer waveguide, and the packaging density is effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic chip packaging technology, and specifically relates to an on-chip integrated interconnect structure, which has the characteristics of high integration and miniaturization. Background Technology

[0002] Currently, most optical communication components and interconnection solutions use a single module for a single task, severely limiting the number of modules that can be accommodated per unit area. While the integration of optical and electrical chips has increased the number of chips that can be integrated per unit area in recent years, these interconnection carriers, such as optical fibers and copper cables, still occupy a considerable amount of space. With increasingly stringent requirements for optical modules in terms of transmission rate, bandwidth, and energy efficiency, the need for higher integration and higher-density packaging for multi-channel optical transceivers remains a key focus in the field of optical communication.

[0003] Because the on-chip package area is fixed, all modules and interconnections must be routed within a limited space. Many solutions employ optical fibers as interconnects for optical signals. For example, patent document CN115542478A discloses an external optical fiber on the surface of an optoelectronic chip for optical interconnection between the three-dimensional package structure and external devices; patent document CN118938408A discloses the use of optical fibers as optical waveguides, and so on. However, in solutions using optical fibers for interconnection, the arrangement and routing of the fibers occupy a considerable amount of space, resulting in an inherent physical limit to the number of interconnectable modules, leading to lower integration density and overall integration. Using other small-sized optical waveguides for interconnection is more difficult to manufacture and more prone to damage, making it unsuitable for large-scale integration scenarios. Summary of the Invention

[0004] The purpose of this invention is to provide an on-chip integrated interconnect structure that enables optical input and output and achieves high integration.

[0005] To achieve the above objectives, the present invention provides an on-chip integrated interconnect structure, including a computing module integrated on the same substrate, a plurality of optoelectronic co-packaged modules and a coarse wavelength division multiplexer stacked around the computing module, wherein the computing module and the optoelectronic co-packaged modules are electrically interconnected through a rewiring layer, and the optoelectronic co-packaged modules and the coarse wavelength division multiplexer are optically interconnected through a polymer waveguide.

[0006] Furthermore, each of the optoelectronic co-packaged modules has a plurality of waveguide ports arranged vertically relative to the substrate, and the coarse wavelength division multiplexer has a multi-layer structure, the number of layers being equal to the number of waveguide ports in each of the optoelectronic co-packaged modules.

[0007] Furthermore, the polymer waveguide has a multilayer structure, with each layer connected to the waveguide port of the optoelectronic co-packaged module located on the same layer, and each layer also connected to the port of the coarse wavelength division multiplexer located on the same layer.

[0008] Furthermore, a focusing lens is provided between the polymer waveguide and the waveguide port of the optoelectronic co-package module.

[0009] Furthermore, a focusing lens is also provided between the polymer waveguide and the port of the coarse wavelength division multiplexer.

[0010] Furthermore, the focusing lens is formed by two-photon 3D printing, and the size of the focusing lens is 10μm~20μm.

[0011] Furthermore, each layer of the polymer waveguide is formed by etching on a single layer of polymer, or by laser induction, or by two-photon 3D printing.

[0012] Furthermore, the plurality of optoelectronic co-package modules are divided into multiple groups, and the stacking direction of each group of optoelectronic co-package modules is parallel to the surface of the substrate, and the plane of each optoelectronic co-package module is perpendicular to the surface of the substrate.

[0013] Furthermore, the substrate is provided with a fixed slot, and the optoelectronic co-package module is inserted into the slot to be mounted on the substrate.

[0014] Furthermore, the plurality of optoelectronic co-package modules are divided into multiple groups, and the stacking direction of each group of optoelectronic co-package modules is perpendicular to the surface of the substrate, and the plane of each optoelectronic co-package module is parallel to the surface of the substrate.

[0015] Beneficial effects:

[0016] The on-chip integrated interconnect structure of the present invention interconnects and integrates optoelectronic co-packaged modules, coarse wavelength division multiplexers, and computing modules together, solving the problem of single-module single-function and complex connection of most existing chips, and realizing an integrated optical communication module with optical input and output.

[0017] The optoelectronic co-packaged module and coarse wavelength division multiplexer of this invention are connected by polymer waveguides. The small size of the polymer waveguides solves the problem of limited packaging density caused by the volume limitations of existing optical fiber interconnects, effectively improving the packaging density. Typically, the average diameter of optical fiber is 125 μm, which is difficult to integrate in a limited space. The polymer waveguides of this application are smaller in size, thereby achieving higher integration density without changing the on-chip area. By increasing the number of interconnect channels, the bandwidth of simultaneous transmission is greatly increased.

[0018] The dense arrangement of optoelectronic co-packaged modules surrounding the computing unit in the on-chip integrated interconnect structure of the present invention increases the number of data streams that can be processed simultaneously.

[0019] The light source module of the on-chip integrated interconnect structure of the present invention is external, thereby allowing flexible modulation of parameters such as wavelength band, wavelength division number, and wavelength division interval. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of an on-chip integrated interconnect structure according to a first embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of an on-chip integrated interconnect structure according to a third embodiment of the present invention.

[0022] Figure label:

[0023] 1-Computing module; 2-Optics co-packaged module; 3-Slot; 4-Coarse wavelength division multiplexer; 5-Polymer waveguide; 6-Rewiring layer; 7-Substrate. Detailed Implementation

[0024] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0025] First embodiment: An on-chip integrated interconnect structure

[0026] like Figure 1 The diagram illustrates an on-chip integrated interconnect structure according to a first embodiment of the present invention. This structure is suitable for interconnecting optoelectronic co-packaged modules with computing modules and coarse wavelength division multiplexers (CWDMs) within a chip. It includes a single computing module 1, multiple optoelectronic co-packaged modules 2, and a CWDM 4 integrated and packaged on the same substrate 7. The computing module 1 and the optoelectronic co-packaged modules 2 are electrically interconnected via a redistribution layer 6, and the optoelectronic co-packaged modules 2 and the CWDM 4 are optically interconnected via a polymer waveguide 5.

[0027] The coarse wavelength division multiplexer 4 has a single first-type port for connecting to an external light source in the integrated interconnect structure and multiple second-type ports for optical interconnection with the optoelectronic co-packaged module 2. It performs wavelength division multiplexing on a single transmitted optical signal from the external light source, so that during communication, after light enters the coarse wavelength division multiplexer 4 via the first-type port, it is split into multiple paths via the multiple second-type ports, each path corresponding to one waveguide port of one optoelectronic co-packaged module 2. The number of second-type ports in the coarse wavelength division multiplexer 4 is equal to the total number of waveguide ports in all optoelectronic co-packaged modules 2.

[0028] The core layer size of the polymer waveguide 5 is determined according to the wavelength of light. For visible light, the core layer size of the polymer waveguide 5 is 100nm~500nm. Furthermore, if the polymer waveguide 5 is a multilayer structure, the thickness of a single polymer waveguide 5 layer matches the size of the waveguide port of the optoelectronic co-packaged module 2. Therefore, this invention uses the polymer waveguide 5 to replace traditional optical fibers for connection, thus requiring less physical space and achieving higher integration, allowing the coarse wavelength division multiplexer 4 to be integrated with the optoelectronic co-packaged module 2. In this embodiment, the overall chip size is approximately 1×2cm.

[0029] In this embodiment, each optoelectronic co-package module 2 has three waveguide ports arranged vertically relative to the substrate 7, and the coarse wavelength division multiplexer 4 and polymer waveguide 5 have three layers. All waveguide ports of the optoelectronic co-package modules 2 on the same horizontal plane are connected to the coarse wavelength division multiplexer 4 on the same layer via the polymer waveguide 5, making the polymer waveguide 5 a multi-layer structure. Each layer of the polymer waveguide 5 connects to the waveguide ports of the optoelectronic co-package modules 2 on the same layer, and each layer also connects to the ports of the coarse wavelength division multiplexer 4 on the same layer. In other embodiments, the number of optoelectronic co-package modules 2 and the number of waveguide ports in each optoelectronic co-package module 2 can be changed according to the wavelength division multiplexing requirements. That is, there can be multiple optoelectronic co-package modules 2, each optoelectronic co-package module 2 having several waveguide ports arranged vertically relative to the substrate 7, and the coarse wavelength division multiplexer 4 having a multi-layer structure with the number of layers equal to the number of waveguide ports in each optoelectronic co-package module 2.

[0030] In this embodiment, the polymer waveguide 5 has a multilayer structure. Each layer is connected to the waveguide port of the optoelectronic co-encapsulation module 2 located on the same layer, and each layer is also connected to the port of the coarse wavelength division multiplexer 4 located on the same layer. Each layer of polymer waveguide 5 is formed by etching on a single layer of polymer or by laser induction. Etching or laser induction are existing technologies and will not be described in detail here.

[0031] All optoelectronic co-packaged modules 2 are arranged around the computing module 1 to achieve stacking of the optoelectronic co-packaged modules 2. Thus, when each optoelectronic co-packaged module 2 is interconnected with the computing module 1 via an electrical interface, the number of optoelectronic co-packaged modules 2 around the computing module 1 is maximized, and the effect of each optoelectronic co-packaged module 2 is independent of its own position. In this embodiment, the multiple optoelectronic co-packaged modules 2 are divided into 4 groups (or any number of groups), the stacking direction of each group of optoelectronic co-packaged modules 2 is parallel to the surface of the substrate 7, and the plane of each optoelectronic co-packaged module 2 is perpendicular to the surface of the substrate 7.

[0032] When the polymer waveguide is a multilayer structure, preferably, the multilayer polymer waveguide 5 is fabricated by the following method: all layers of polymer waveguide 5 are pre-formed by etching or laser induction, then the bottom layer of polymer waveguide is laid first, followed by the stacking of the second layer of polymer waveguide 5, and then the stacking of the third layer of polymer waveguide 5. Alternatively, the bottom layer of polymer waveguide is formed by laying the bottom layer of polymer and etching or laser induction, then the second layer of polymer is stacked and etched or laser induction is used to form the second layer of polymer waveguide 5, and finally the third layer of polymer is stacked and etched or laser induction is used to form the third layer of polymer waveguide 5. Therefore, the polymer waveguide is not suspended and does not require a structure to fix or support it.

[0033] In summary, compared to traditional fiber optic structures, the multilayer polymer waveguide 5 has a higher integration density, enabling the coarse wavelength division multiplexer 4 to be packaged together with other modules. Furthermore, compared to waveguides manufactured using pure two-photon 3D printing, its fabrication technology is more mature, with lower manufacturing difficulty and cost, thus improving the stability of the finished product. Moreover, the multilayer structure of the polymer waveguide 5 enhances the scalability of the entire device. Therefore, the number of optoelectronic co-packaged modules 2 and the number of waveguide ports in each optoelectronic co-packaged module 2 can be adjusted according to the requirements of wavelength division multiplexing, thereby improving the overall scalability of the chip.

[0034] In this embodiment, a fixed slot 3 is provided on the substrate 7, and the optoelectronic co-package module 2 is inserted into the slot 3 to be mounted on the substrate 7. Therefore, the optoelectronic co-package module 2 is pluggable. The computing module 1 and the optoelectronic co-package module 2 are electrically interconnected through the slot 3 and the redistribution layer (RDL) 6. The redistribution layer 6 connects the bottom of the slot 3 and the computing module 1.

[0035] In this embodiment, a focusing lens is provided between the polymer waveguide 5 and the waveguide port of the optoelectronic co-package module 2 to converge the light transmitted in the polymer waveguide 5 into the optoelectronic co-package module. This focusing lens is located at least at one of the end face of the polymer waveguide 5 facing the optoelectronic co-package module 2 and the waveguide port of the optoelectronic co-package module 2. The focusing lens is preferably obtained by two-photon laser 3D printing and can be a microlens, preferably with a size of 10μm to 20μm.

[0036] The purpose of placing a focusing lens between the polymer waveguide 5 and the waveguide port of the optoelectronic co-package module 2 includes:

[0037] 1) There may be positional errors during the installation of polymer waveguide 5, which may cause the emitted light from polymer waveguide 5 to be unable to be fully aligned with the waveguide port of optoelectronic co-package module 2. By setting a focusing lens, the focused beam can be more aligned with the waveguide port of optoelectronic co-package module 2.

[0038] 2) A gap is left between the polymer waveguide 5 and the waveguide port of the optoelectronic co-package module 2. This is because if there is no gap between the waveguide outlet of the polymer waveguide and the waveguide port of the optoelectronic co-package module, the waveguide part of the polymer waveguide is easily deformed or the waveguide port of the optoelectronic co-package module is damaged by squeezing when installing the polymer waveguide 5 and plugging and unplugging the optoelectronic co-package module 2. Therefore, the gap between the waveguide port of the polymer waveguide 5 and the optoelectronic co-package module 2 and the focusing lens are used to replace the waveguide that should be set to avoid deformation or damage.

[0039] In this embodiment, the polymer waveguide 5 is directly connected to the coarse wavelength division multiplexer 4 (i.e., without a gap). In other embodiments, when there are large process errors, a gap may be left between the polymer waveguide 5 and the coarse wavelength division multiplexer 4, and a focusing lens may be provided.

[0040] The optoelectronic co-package module 2 is used for on-chip optoelectronic modulation and conversion. In this embodiment, the optoelectronic co-package module 2 is for visible light optoelectronic modulation and conversion. The specific structure of the optoelectronic co-package module 2 is not limited in the entire integrated device. For example, it may include any one or more of optical components such as dense wavelength division multiplexing chips, modulators, and photodetectors packaged together to achieve high-density integration, as well as electronic chips such as ASICs and GPUs, as long as it is an optoelectronic co-package module capable of achieving optoelectronic modulation and demodulation functions. In this embodiment, the substrate used for the optoelectronic co-package module 2 is a substrate-like plate (SLP).

[0041] In this embodiment, the computing module 1 is a CPU / GPU or other computing module with the same function. The substrate 7 is a glass substrate or a PCB board. When selecting a glass substrate, the characteristics of low dielectric constant, easy fine processing, and adjustable thermal stability of the glass substrate are utilized to simplify the structure and ensure the stability of the device.

[0042] Second embodiment: An on-chip integrated interconnect structure

[0043] According to a second embodiment of the present invention, the present invention provides an on-chip integrated interconnect structure suitable for interconnection between computing modules and other optical modules in a chip, including a single computing module 1, multiple optoelectronic co-packaged modules 2, and a single coarse wavelength division multiplexer (CWDM) 4 integrated and packaged on the same substrate 7. The computing module 1 and the optoelectronic co-packaged modules 2 are electrically interconnected via a redistribution layer 6, and the optoelectronic co-packaged modules 2 and the CWDM 4 are optically interconnected via a polymer waveguide 5.

[0044] The difference between this embodiment and the first embodiment is that the polymer waveguide 5 is formed by two-photon 3D printing.

[0045] This embodiment is consistent with the first embodiment in that: there are multiple optoelectronic co-package modules 2, each optoelectronic co-package module 2 has several waveguide ports arranged vertically relative to the substrate 7, and the coarse wavelength division multiplexer 4 has a multi-layer structure with the number of layers equal to the number of waveguide ports of each optoelectronic co-package module 2. The polymer waveguide 5 has a multi-layer structure, with each layer connected to the waveguide ports of the optoelectronic co-package module 2 on the same layer, and each layer also connected to the ports of the coarse wavelength division multiplexer 4 on the same layer. This setting, where the number of layers of the coarse wavelength division multiplexer 4 is equal to the number of waveguide ports of each optoelectronic co-package module 2, makes it easier to fabricate the polymer waveguide 5 using two-photon 3D printing.

[0046] In other embodiments, the coarse wavelength division multiplexer 4 can also be a structure with any number of layers, such as a single-layer structure, and the number of layers is not necessarily equal to the number of vertically arranged waveguide ports in each optoelectronic co-package module 2. Correspondingly, the number of layers in the polymer waveguide 5 can also be equal to the number of layers in the coarse wavelength division multiplexer 4. The polymer waveguide 5 can also be a single-layer structure when the coarse wavelength division multiplexer 4 is a single-layer structure. If the number of layers in the coarse wavelength division multiplexer 4 is different from the number of waveguide ports in each optoelectronic co-package module 2, the fabrication difficulty of the polymer waveguide 5 is relatively high.

[0047] Third embodiment: An on-chip integrated interconnect structure

[0048] like Figure 2 The diagram illustrates an on-chip integrated interconnect structure according to a second embodiment of the present invention. This structure is suitable for interconnecting computing modules and coarse wavelength division multiplexers (CWDMs) within a chip. It includes a single computing module 1, multiple optoelectronic co-packaged modules 2, and a single CWDM 4, all integrated and packaged on the same substrate 7. The computing module 1 and the optoelectronic co-packaged modules 2 are electrically interconnected via a redistribution layer (not shown), and the optoelectronic co-packaged modules 2 and the CWDM 4 are optically interconnected via a polymer waveguide 5.

[0049] The coarse wavelength division multiplexer 4 has a single first-type port for external connection to the integrated interconnect structure and multiple second-type ports for optical interconnection with the optoelectronic co-packaged module 2. It performs wavelength division multiplexing on a single-path transmitted optical signal from an external light source, so that during communication, light enters the coarse wavelength division multiplexer 4 via the first-type port and is then split into multiple paths via the multiple second-type ports, each path corresponding to one waveguide port of one optoelectronic co-packaged module 2. The number of second-type ports in the coarse wavelength division multiplexer 4 is equal to the total number of waveguide ports in all optoelectronic co-packaged modules 2. In this embodiment, the coarse wavelength division multiplexer 4 has a multi-layer structure, thereby achieving higher integration; however, in other embodiments, the coarse wavelength division multiplexer 4 can also be a single-layer structure.

[0050] The core size of polymer waveguide 5 is determined according to the wavelength of light. For visible light, the core size of polymer waveguide 5 is 100nm~500nm. Therefore, this invention achieves higher integration by replacing traditional optical fiber with polymer waveguide 5 for connection, allowing the coarse wavelength division multiplexer 4 to be packaged together with other modules.

[0051] All optoelectronic co-packaged modules 2 are arranged around the computing module 1. In this embodiment, the plane of each optoelectronic co-packaged module 2 is parallel to the surface of the substrate 7 and has three waveguide ports arranged parallel to the substrate 7. The coarse wavelength division multiplexer 4 has a multi-layer structure, although not all layers are shown in the figure. In other embodiments, the number of optoelectronic co-packaged modules 2 and the number of ports can be changed according to the requirements of wavelength division multiplexing.

[0052] The multiple optoelectronic co-packaged modules 2 are divided into multiple groups. The stacking direction of each group of optoelectronic co-packaged modules 2 is perpendicular to the surface of the substrate 7, and the plane of each optoelectronic co-packaged module 2 is parallel to the surface of the substrate 7. Adjacent optoelectronic co-packaged modules 2 are electrically interconnected, typically through TSV or TGV, similar to an interposer. The bottom is electrically interconnected with the redistribution layer via pads or copper pillars, and bonded using a hybrid bonding process. The polymer waveguide 5 is fabricated using two-photon 3D printing to achieve arrangement in three-dimensional space, with more flexible connection methods. Theoretically, this stacking method can achieve infinite stacking. The diameter of the two-photon 3D printed polymer waveguide 5 is 500nm~2000nm, resulting in a smaller overall volume, better arrangement, and higher integration.

[0053] Compared with the prior art, the on-chip integrated interconnect structure of the present invention has the following advantages:

[0054] 1. By interconnecting and integrating optoelectronic co-packaged modules, coarse wavelength division multiplexers, and computing modules, the problem of single-module single-function and complex connection of most existing chips is solved, realizing an integrated optical communication module with optical input and output.

[0055] 2. The optoelectronic co-packaged module and the coarse wavelength division multiplexer are connected by polymer waveguides. The small size of the polymer waveguides solves the problem of limited packaging density caused by the volume limitations of existing fiber optic interconnects, effectively improving the packaging density. Typically, the average diameter of optical fiber is 125µm, which is difficult to integrate in a limited space. The polymer waveguides in this application are smaller in size, thus achieving higher integration density without changing the on-chip area. By increasing the number of interconnect channels, the bandwidth of simultaneous transmission is greatly increased.

[0056] 3. The dense arrangement of optoelectronic co-packaged modules around the computing unit increases the number of data streams that can be processed simultaneously.

[0057] 4. The light source module is external, which allows for flexible modulation of parameters such as wavelength band, wavelength division number, and wavelength division interval.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. Various variations can be made to the above embodiments of the present invention. All simple and equivalent changes and modifications made in accordance with the claims and description of this application fall within the protection scope of the claims of this patent. All aspects not described in detail in this invention are conventional technical content.

Claims

1. An on-chip integrated interconnect structure, characterized in that, The device includes a computing module integrated on the same substrate, several optoelectronic co-packaged modules stacked around the computing module, and a coarse wavelength division multiplexer. The computing module and the optoelectronic co-packaged modules are electrically interconnected through a rewiring layer, and the optoelectronic co-packaged modules and the coarse wavelength division multiplexer are optically interconnected through a polymer waveguide.

2. The on-chip integrated interconnect structure according to claim 1, characterized in that, Each of the optoelectronic co-packaged modules has a number of waveguide ports arranged vertically relative to the substrate. The coarse wavelength division multiplexer has a multi-layer structure, and the number of layers is equal to the number of waveguide ports in each optoelectronic co-packaged module.

3. The on-chip integrated interconnect structure according to claim 2, characterized in that, The polymer waveguide has a multilayer structure, with each layer connected to the waveguide port of the optoelectronic co-packaged module located on the same layer, and each layer also connected to the port of the coarse wavelength division multiplexer located on the same layer.

4. The on-chip integrated interconnect structure according to claim 2, characterized in that, A focusing lens is provided between the polymer waveguide and the waveguide port of the optoelectronic co-package module.

5. The on-chip integrated interconnect structure according to claim 4, characterized in that, A focusing lens is also provided between the polymer waveguide and the port of the coarse wavelength division multiplexer.

6. The on-chip integrated interconnect structure according to claim 4 or 5, characterized in that, The focusing lens is formed by two-photon 3D printing, and the size of the focusing lens is 10μm~20μm.

7. The on-chip integrated interconnect structure according to claim 3, characterized in that, Each layer of the polymer waveguide is formed by etching on a single layer of polymer, or by laser induction, or by two-photon 3D printing.

8. The on-chip integrated interconnect structure according to claim 1, characterized in that, The plurality of optoelectronic co-package modules are divided into multiple groups, and the stacking direction of each group of optoelectronic co-package modules is parallel to the surface of the substrate, and the plane of each optoelectronic co-package module is perpendicular to the surface of the substrate.

9. The on-chip integrated interconnect structure according to claim 8, characterized in that, The substrate has a fixed slot, and the optoelectronic co-package module is inserted into the slot to be mounted on the substrate.

10. The on-chip integrated interconnect structure according to claim 1, characterized in that, The plurality of optoelectronic co-package modules are divided into multiple groups, and the stacking direction of each group of optoelectronic co-package modules is perpendicular to the surface of the substrate, and the plane of each optoelectronic co-package module is parallel to the surface of the substrate.

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