An integrated photonics package structure and method of forming the same

Abstract

The application provides an integrated photon package structure and a forming method thereof. The integrated photon package structure comprises an electrical signal module, a silicon photon unit, a light emitting unit and a micro optical coupler which are packaged in a plastic package layer. The electrical signal module is electrically connected with the silicon photon unit and the light emitting unit respectively and is used for providing electrical signals to the silicon photon unit and the light emitting unit. The silicon photon unit, the light emitting unit and the micro optical coupler are arranged at intervals. The silicon photon unit is located between the light emitting unit and the micro optical coupler. The light emitting unit is used for providing horizontal light rays. The horizontal light rays are vertically transmitted through the silicon photon unit and the micro optical coupler and are emitted out of the integrated photon package structure, so as to realize optical interconnection in the package.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit technology, and in particular to an integrated photonic packaging structure and its formation method. Background Technology

[0002] Current photonic packaging methods mainly include chip-on-substrate (CoS) integration and off-chip light source (such as laser diode) integration. CoS packaging lacks moisture protection (MSL) and mechanical handling protection, its back-end assembly method is not surface-mount (SMT), and it is unsuitable for integration with optical platforms. Off-chip light source packaging lacks heat dissipation and internal optical interconnects (e.g., z-axis control of the light source). Summary of the Invention

[0003] One of the objectives of this invention is to provide an integrated photonic packaging structure and a method for forming the same, which can realize optical interconnection within the package.

[0004] Another objective of this invention is to provide an integrated photonic packaging structure and a method for forming the same, which can achieve heat dissipation of the light source within the package.

[0005] To address the above problems, this invention provides an integrated photonic packaging structure, comprising an electrical signal module, a silicon photonic unit, a light-emitting unit, and a micro-optical coupler encapsulated in a molding compound.

[0006] The electrical signal module is electrically connected to the silicon photonic unit and the light-emitting unit respectively, and is used to provide electrical signals to the silicon photonic unit and the light-emitting unit. The silicon photonic unit, the light-emitting unit and the micro-optical coupler are arranged at intervals, and the silicon photonic unit is located between the light-emitting unit and the micro-optical coupler. The light-emitting unit is used to provide horizontal light rays, and the horizontal light rays are vertically transmitted and emitted from the integrated photonic packaging structure through the silicon photonic unit and the micro-optical coupler.

[0007] Optionally, the micro-optical coupler has multiple waveguides, each waveguide having a mutually perpendicular and optically connected input end and output end, wherein the horizontal light rays are processed by the silicon photonic unit and enter the waveguide horizontally from the input end and exit vertically from the output end.

[0008] Furthermore, the waveguide includes a first segment and a second segment, which are arranged perpendicularly. A reflector is provided at the intersection of the first segment and the second segment. The acute angle between the reflector and the first segment and the second segment is 45°. The end of the first segment away from the reflector is the input end, and the end of the second segment away from the reflector is the output end. This allows the horizontal light rays to enter the waveguide from the input end, be reflected by the reflector and changed into vertical light rays, and exit from the output end.

[0009] Furthermore, the input end is matched with the mode and phase of the silicon photonic unit, and the output end is matched with the mode and phase of the optical fiber, so that the horizontal light rays can enter the waveguide horizontally and exit the waveguide vertically.

[0010] Furthermore, the output terminal is located on the upper surface of the micro-optical coupler, and a recessed region is formed on the upper surface of the encapsulation layer. The recessed region exposes the output terminal, and the micro-optical coupler is connected to the optical fiber in the recessed region.

[0011] Furthermore, the electrical signal module includes a first electrical signal unit and a second electrical signal unit. The first electrical signal unit is located on the silicon photonic unit and is electrically connected to the silicon photonic unit. The second electrical signal unit is spaced apart and disposed outside the silicon photonic unit, the micro-optical coupler, and the light-emitting unit.

[0012] Furthermore, it also includes an optical interface structure encapsulated in a molding layer. The optical interface structure is disposed between the input terminal and the silicon photonic unit, and between the silicon photonic unit and the light-emitting area, so as to conduct the horizontal light emitted by the optical unit to the silicon photonic unit, and conduct the horizontal light processed by the silicon photonic unit to the input terminal.

[0013] Optionally, it also includes a first base and a second base encapsulated in a molding compound, the first base being located below the silicon photonic unit and the second base being located below the light-emitting unit, the lower surface of the molding compound exposing the lower surface of the first base and the lower surface of the second base.

[0014] Optionally, the system may also include a heat dissipation structure encapsulated in the molding compound, the heat dissipation structure being located on the light-emitting unit, and the molding compound exposing the upper surface of the heat dissipation structure, the heat dissipation structure being connected to an external system-level heat sink at the upper surface.

[0015] Furthermore, the heat dissipation structure includes a silicon plug, which is mounted on the light-emitting unit via a thermal interface material layer.

[0016] Furthermore, the heat sink has heat dissipation holes that extend through the heat sink in the thickness direction and are filled with metal material.

[0017] Furthermore, the heat sink is made of silicon, the metal is made of copper, and the encapsulation layer is made of opaque resin.

[0018] Furthermore, the lower surfaces of the second electrical signal unit, the silicon photonic unit, and the light-emitting unit all have electrical connection regions, and the molding layer exposes the electrical connection regions of the second electrical signal unit, the silicon photonic unit, and the light-emitting unit.

[0019] Furthermore, it also includes an interconnect structure on the lower surface of the molding layer, and the interconnect structure is electrically connected to the second electrical signal unit, the silicon photonic unit and the light-emitting unit respectively.

[0020] Furthermore, the lower surface of the interconnect structure has a plurality of solder pads, on which solder balls are formed.

[0021] Optionally, the light-emitting unit has a light-emitting area, which is disposed facing the light-emitting unit and the micro-optical coupler.

[0022] On the other hand, the present invention provides a method for forming an integrated photonic packaging structure, the method comprising the following steps:

[0023] An electrical signal module, a silicon photonic unit, a light-emitting unit, a blocking model, and a micro-optical coupler are fixed on a temporary carrier plate. The electrical signal module is electrically connected to the silicon photonic unit and the light-emitting unit, respectively, and is used to provide electrical signals to the silicon photonic unit and the light-emitting unit. The silicon photonic unit, the light-emitting unit, and the micro-optical coupler are spaced apart, with the silicon photonic unit located between the light-emitting unit and the micro-optical coupler. The light-emitting unit is used to provide horizontal light rays, and the horizontal light rays are vertically transmitted and emitted out of the integrated photonic packaging structure through the silicon photonic unit and the micro-optical coupler.

[0024] A molding compound is filled between the electrical signal module, silicon photonic unit, light-emitting unit, blocking model, and micro-optical coupler, and the molding compound is cured to form a molding layer.

[0025] Optionally, the step of fixing the electrical signal module, silicon photonic unit, light-emitting unit, and micro-optical coupler onto a temporary carrier specifically includes:

[0026] A temporary carrier plate is provided, one side of which has an adhesive layer formed;

[0027] The first base and the second base are spaced apart on the temporary carrier plate;

[0028] The silicon photonic unit is assembled on the first base, and the light-emitting unit is assembled on the second base, wherein the silicon photonic unit and the light-emitting unit are arranged at intervals and adjacent to each other;

[0029] The electrical signal module, micro-optical coupler, blocking model and heat dissipation structure are placed on the temporary carrier, silicon photonic unit and light-emitting unit;

[0030] An index-matched epoxy resin is distributed and cured between the silicon photonic unit and the input end of the micro-optical coupler, and between the light-emitting regions of the silicon photonic unit and the light-emitting unit, to form an optical interface structure.

[0031] Furthermore, the electrical signal module includes a first electrical signal unit and a second electrical signal unit. Placing the electrical signal module, the micro-optical coupler, and the heat dissipation structure on the temporary carrier, the silicon photonic unit, and the light-emitting unit includes:

[0032] The first electrical signal unit is packaged on the silicon photonic unit using a three-dimensional integrated packaging method, so that the first electrical signal unit is electrically connected to the silicon photonic unit;

[0033] The second electrical signal unit and the micro-optical coupler are placed outside the silicon photonic unit and the light-emitting unit, and the silicon photonic unit is located between the micro-optical coupler and the light-emitting unit. The light-emitting unit is located between the silicon photonic unit and the second electrical signal unit, and the output end of the micro-optical coupler is oriented towards the silicon photonic unit, and the light-emitting area of ​​the light-emitting unit is oriented towards the silicon photonic unit.

[0034] The blocking model is placed on the upper surface of the micro-optical coupler;

[0035] The heat dissipation structure is assembled onto the upper surface of the light-emitting unit through a thermal interface material layer.

[0036] Optionally, methods for forming the molding compound include:

[0037] A molding compound is filled between the electrical signal module, the silicon photonic unit, the light-emitting unit, the blocking model, and the micro-optical coupler, and the molding compound is cured to form a molding layer, wherein the molding layer covers the upper surface of the micro-optical coupler and exposes the lower surface of the micro-optical coupler;

[0038] Remove the blocking model and temporary carrier plate, and form a recessed region on the upper surface of the micro-optical coupler, the recessed region exposing the upper surface of the micro-optical coupler.

[0039] Optionally, after forming the molding compound, the following may also be included:

[0040] From the lower surface side of the molding layer, a trench is formed in the molding layer, the trench exposing the electrical connection area of ​​the light-emitting unit and the silicon photonic unit, and the trench is filled with a conductive material;

[0041] An interconnect structure is formed on the lower surface of the molding compound. The interconnect structure is electrically connected to the electrical connection area of ​​the conductive material and the second electrical signal unit, respectively. The lower surface of the interconnect structure has solder pads on which solder beads are formed.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] This invention provides an integrated photonic packaging structure and its formation method. The integrated photonic packaging structure includes an electrical signal module, a silicon photonic unit, a light-emitting unit, and a micro-optical coupler encapsulated in a molding compound. The electrical signal module is electrically connected to the silicon photonic unit and the light-emitting unit, respectively, and is used to provide electrical signals to the silicon photonic unit and the light-emitting unit. The silicon photonic unit, the light-emitting unit, and the micro-optical coupler are spaced apart, with the silicon photonic unit located between the light-emitting unit and the micro-optical coupler. The light-emitting unit is used to provide horizontal light rays, and the horizontal light rays are vertically transmitted and emitted out of the integrated photonic packaging structure through the silicon photonic unit and the micro-optical coupler to achieve optical interconnection within the package. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of an integrated photonic packaging structure provided in an embodiment of the present invention.

[0045] Explanation of reference numerals in the attached figures:

[0046] 10- Molding layer; 11- Recessed area; 21- First electrical signal unit; 22- Second electrical signal unit; 23- Silicon photonic unit; 24- Light emission unit; 25- Heat dissipation structure; 26- Micro-optical coupler; 27- First base; 28- Second base; 29- Optical interface structure; 30- Interconnect structure; 31- Passivation layer; 32- Metal interconnect layer; 33- Solder pad; 40- Solder ball. Detailed Implementation

[0047] The following will provide a more detailed description of an integrated photonic packaging structure and its formation method according to the present invention. The invention will now be described in more detail with reference to the accompanying drawings, which illustrate preferred embodiments of the invention. It should be understood that those skilled in the art can modify the invention described herein while still achieving its advantageous effects. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit the invention.

[0048] For clarity, not all features of the actual embodiments are described. In the following description, well-known functions and structures are not detailed in detail, as they would obscure the invention with unnecessary detail. It should be understood that in the development of any actual embodiment, numerous implementation details must be made to achieve the developer's specific objectives, such as changes from one embodiment to another according to limitations related to the system or business. Furthermore, it should be understood that such development work may be complex and time-consuming, but is merely routine work for those skilled in the art.

[0049] To make the objectives and features of the present invention more apparent and understandable, the specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise ratios, and are only used to conveniently and clearly assist in illustrating the objectives of the embodiments of the present invention.

[0050] It should be noted that the upper surface of the molding compound is defined as the surface of the molding compound that is furthest away from the interconnect structure along the thickness direction. Figure 1 The surface located vertically at the top of the molding compound is defined as the "top surface," and the surface of the molding compound closest to the interconnect structure along its thickness direction is defined as the "bottom surface." Figure 1 The surface located vertically below the center is called the "lower surface".

[0051] Figure 1 This is a schematic diagram of an integrated photonic packaging structure provided in this embodiment. Figure 1 As shown, this embodiment provides an integrated photonic packaging structure, including an electrical signal module, a silicon photonic unit 23, a light-emitting unit 24, and a micro-optical coupler 26 encapsulated in a molding compound 10. In this embodiment, the molding compound 10 encapsulates the electrical signal module, the silicon photonic unit 23, the light-emitting unit 24, and the micro-optical coupler 26, providing moisture protection and mechanical handling protection for the integrated photonic packaging structure, and facilitating subsequent assembly of the integrated photonic packaging structure.

[0052] The electrical signal module is electrically connected to the silicon photonic unit 23 and the light-emitting unit 24 respectively, and is used to provide electrical signals to the silicon photonic unit 23 and the light-emitting unit 24. The silicon photonic unit 23, the light-emitting unit 24 and the micro-optical coupler 26 are arranged at intervals, and the silicon photonic unit 23 is located between the light-emitting unit 24 and the micro-optical coupler 26. The light-emitting unit 24 is used to provide horizontal light rays, and the horizontal light rays are emitted vertically out of the integrated photonic packaging structure through the silicon photonic unit 23 and the micro-optical coupler 26.

[0053] The light-emitting unit 24 has a light-emitting area, which is disposed facing the light-emitting unit 24 and the micro-optical coupler 26.

[0054] The micro-optical coupler 26 has multiple waveguides, each serving as an optical path. All waveguides can convert at least one horizontal light ray processed by the silicon photonic unit 23 into a vertical light ray and emit it vertically. Specifically, each waveguide has mutually perpendicular and optically connected input and output ends, such that horizontal light rays enter the waveguide horizontally from the input end, undergo a direction change, and then exit vertically from the output end. The output end is used to connect an external optical fiber. All waveguides can be arranged at intervals; preferably, the centers of all waveguides in sections perpendicular to the input and output ends are collinear. The upper surface of the micro-optical coupler 26 has two alignment holes for connecting an MPO connector. The two alignment holes are spaced apart on both sides of the output end of all waveguides to achieve compatibility of the micro-optical coupler 26 with a pluggable MPO (multi-push-on) connector.

[0055] In one embodiment, the waveguide includes a first segment and a second segment, which are arranged perpendicularly. A reflector is disposed at the intersection of the first segment and the second segment. The acute angle between the reflector and the first segment and the second segment is 45°. The end of the first segment away from the reflector is the input end, and the end of the second segment away from the reflector is the output end. This allows horizontal light rays to enter the waveguide from the input end, be reflected at the reflector and changed into vertical light rays, and exit from the output end.

[0056] In another embodiment, the input end is matched with the mode and phase of the silicon photonic unit 23, and the output end is matched with the mode and phase of the optical fiber, so that horizontal light rays can enter horizontally and exit vertically from the waveguide.

[0057] The upper surface of the molding compound 10 exposes the upper surface of the micro-optical coupler 26, and the lower surface of the molding compound 10 exposes the lower surface of the micro-optical coupler 26. The upper surface of the molding compound 10 is higher than the upper surface of the micro-optical coupler 26, such that the molding compound 10 forms a recessed region 11 above the micro-optical coupler 26. The output terminal of the micro-optical coupler 26 is located on the upper surface of the micro-optical coupler 26, and the micro-optical coupler 26 is connected to an optical fiber in the recessed region 11 to allow the optical fiber to be attached from the top of the integrated photonic package structure.

[0058] The silicon photonic unit 23 is, for example, a silicon photonic integrated circuit chip (Si-PIC), and the light-emitting unit 24 includes, but is not limited to, a laser diode. The material of the micro-optical coupler 26 includes, but is not limited to, silicon dioxide, and the reflector can be a reflector that has undergone surface polishing and aluminum film coating finishing. The material of the molding layer 10 is an opaque resin material (e.g., a black opaque resin material) to prevent the light transmitted within the integrated photonic packaging structure from being affected by the external environment.

[0059] The electrical signal module includes a first electrical signal unit 21 and a second electrical signal unit 22. The first electrical signal unit 21 is located on and electrically connected to the silicon photonic unit 23 to provide electrical signals to the silicon photonic unit 23. Preferably, the first electrical signal unit 21 and the silicon photonic unit 23 are electrically connected through a three-dimensional integrated packaging method. The second electrical signal unit 22 is spaced apart on the outside of the silicon photonic unit 23, the micro-optical coupler 26, and the light-emitting unit 24. The upper surface of the molding compound 10 exposes the upper surfaces of the first electrical signal unit 21 and the second electrical signal unit 22, and the lower surface of the molding compound 10 exposes the lower surface of the second electrical signal unit 22. The second electrical signal unit 22 can be electrically connected to the silicon photonic unit 23, for example, for power management, and can also be electrically connected to the light-emitting unit 24, for example, for monitoring the temperature of the light-emitting unit 24.

[0060] In this embodiment, the lower surfaces of the silicon photonic unit 23, the light-emitting unit 24, the first electrical signal unit 21, and the second electrical signal unit 22 all have electrical connection regions. The first electrical signal unit 21 is electrically connected to the silicon photonic unit 23 through the electrical connection region. The electrical connection regions of the silicon photonic unit 23, the light-emitting unit 24, and the second electrical signal unit 22 are all electrically connected to the interconnect structure 30. The first electrical signal unit 21 and the second electrical signal unit 22 are, for example, electronic integrated circuit chips (i.e., EICs).

[0061] The integrated photonic packaging structure further includes an optical interface structure 29 and a base encapsulated in a molding layer 10. The optical interface structure 29 is disposed between the input end and the silicon photonic unit 23 and between the silicon photonic unit 23 and the light-emitting area, so as to conduct the horizontal light emitted by the optical unit to the silicon photonic unit 23 and conduct the horizontal light processed by the silicon photonic unit 23 to the input end.

[0062] The base includes a first base 27 and a second base 28. The first base 27 is located below the silicon photonic unit 23, and the second base 28 is located below the light-emitting unit 24. The lower surface of the molding compound 10 exposes the lower surface of both the first base 27 and the second base 28. During the fabrication of the integrated photonic packaging structure, the first base 27 and the second base 28 respectively support the silicon photonic unit 23 and the light-emitting unit 24, and their height is adjusted to control the vertical axis (i.e., the z-axis) of the optical coupling between the light-emitting unit 24 and the silicon photonic unit 23.

[0063] The heights of the first base 27 and the second base 28 can be designed according to the actual structure of each structure (i.e., the light-emitting unit 24, the silicon photonic unit 23, and the micro-optical coupler 26). In this embodiment, the bases are installed on the light-emitting unit 24 and the silicon photonic unit 23 by electroplating to precisely control the heights of the first base 27 and the second base 28. This ensures that the optical axes between the light-emitting unit 24 and the silicon photonic unit 23 remain the same in the vertical direction (i.e., the thickness direction of the molding layer 10), thereby achieving alignment of the light-emitting unit 24 and the silicon photonic unit 23, and thus enabling precise optical z-axis control of the light-emitting unit 24.

[0064] In this embodiment, the materials of the first base 27 and the second base 28 include, but are not limited to, metals. Preferably, the materials of the first base 27 and the second base 28 are copper. Furthermore, in order to reduce weight, the first base 27 and the second base 28 can be patterned copper bases.

[0065] The integrated photonic packaging structure further includes a heat dissipation structure 25 encapsulated in the molding compound 10. The heat dissipation structure 25 is located on the light-emitting unit 24, and the molding compound 10 exposes the upper surface of the heat dissipation structure 25. The heat dissipation structure 25 is connected to an external system-level heat sink at its upper surface to dissipate heat from the light-emitting unit 24 and the electrical signal module in the integrated photonic packaging structure to the system-level heat sink, thereby facilitating heat dissipation within the integrated photonic packaging structure. The molding compound 10 exposes the surface of the heat dissipation structure 25 away from the light-emitting unit 24.

[0066] In this embodiment, the heat dissipation structure 25 includes a silicon plug, which is mounted on the light-emitting unit 24 through a thermal interface material (TIM) layer. The material of the heat dissipation block is, for example, silicon. The heat dissipation block has heat dissipation holes that extend through the thickness direction of the heat dissipation block and are filled with a metal material (e.g., copper) to enhance heat dissipation capacity.

[0067] The integrated photonic packaging structure further includes an interconnect structure 30, which is located on the lower surface of the molding layer 10, and is electrically connected to the electrical signal module and the light-emitting unit 24.

[0068] In detail, the interconnect structure 30 includes a passivation layer 31 and a metal interconnect layer 32 embedded in the passivation layer 31. The upper surface of the passivation layer 31 covers the lower surface of the molding compound 10. The metal interconnect layer 32 is connected to the second electrical signal unit 22, the light-emitting unit 24, and the silicon photonic unit 23 on the upper surface of the passivation layer 31, respectively. In detail, the metal interconnect layer 32 is electrically connected to the second electrical signal unit 22 on the upper surface of the passivation layer 31. The metal interconnect layer 32 extends into the molding compound 10 on the upper surface of the passivation layer 31 and is electrically connected to the light-emitting unit 24 and the silicon photonic unit 23, respectively.

[0069] The interconnect structure 30 has a plurality of solder pads 33 on the lower surface side of the passivation layer 31, and the passivation layer 31 exposes the plurality of solder pads 33. Solder balls are formed on the plurality of solder pads 33 to facilitate subsequent soldering of the integrated photonic package structure to other devices (e.g., circuit boards). The solder balls can be used to solder the integrated photonic package structure to the devices (e.g., circuit boards) to which it is to be soldered, so that the integrated photonic package structure can be assembled onto the system circuit board via SMT.

[0070] In this embodiment, the passivation layer 31 is an insulating material, such as a polymer, and more specifically, one or a combination of polyimides, benzocyclobutene (BCB), or poly(p-dioxazolebenzene) (PBO). The metal interconnect layer 32 can be a metallic material such as Cu, Ag, W, or Au, a conductive alloy, a conductive oxide (e.g., ITO), or a conductive organic material such as a conductive polymer.

[0071] Please continue reading. Figure 1 This embodiment also provides a method for forming an integrated photonic packaging structure, including the following steps:

[0072] Step S1: Fix the electrical signal module, silicon photonic unit 23, light-emitting unit 24, blocking model, and micro-optical coupler 26 onto a temporary carrier plate. The electrical signal module is electrically connected to both the silicon photonic unit 23 and the light-emitting unit 24, and provides electrical signals to them. The silicon photonic unit 23, the light-emitting unit 24, and the micro-optical coupler 26 are spaced apart, with the silicon photonic unit 23 located between the light-emitting unit 24 and the micro-optical coupler 26. The light-emitting unit 24 provides horizontal light rays, which are then vertically transmitted and emitted from the integrated photonic packaging structure via the silicon photonic unit 23 and the micro-optical coupler 26. The blocking model is made of a non-adhesive material.

[0073] This step specifically includes: First, providing a temporary carrier plate, one side of which has an adhesive layer formed, wherein the shape of the carrier plate is, for example, circular or square.

[0074] Next, the base is placed on the temporary carrier plate. Specifically, the base includes a first base 27 and a second base 28, which are spaced apart on the temporary carrier plate.

[0075] Next, the silicon photonic unit 23 is assembled on the first base 27, and the light-emitting unit 24 is assembled on the second base 28. At this time, the silicon photonic unit 23 and the light-emitting unit 24 are arranged at intervals and adjacent to each other.

[0076] Next, the electrical signal module, micro-optical coupler 26, blocking model and heat dissipation structure 25 are placed on the temporary carrier, silicon photonic unit 23 and light-emitting unit 24. In detail, the electrical signal module includes a first electrical signal unit 21 and a second electrical signal unit 22. The first electrical signal unit 21 is packaged on the silicon photonic unit 23 using a three-dimensional integrated packaging method, so that the first electrical signal unit 21 is electrically connected to the silicon photonic unit 23. The second electrical signal unit 22 and the micro-optical coupler 26 are placed outside the silicon photonic unit 23 and the light-emitting unit 24, with the silicon photonic unit 23 located between the micro-optical coupler 26 and the light-emitting unit 24, and the light-emitting unit 24 located between the silicon photonic unit 23 and the second electrical signal unit 22. The output end of the micro-optical coupler 26 is oriented towards the silicon photonic unit 23, and the light-emitting area of ​​the light-emitting unit 24 is oriented towards the silicon photonic unit 23. The blocking model is located on the upper surface of the micro-optical coupler 26. The heat dissipation structure 25 is assembled on the upper surface of the light-emitting unit 24 through a thermal interface material layer.

[0077] Next, an index-matched epoxy resin is distributed and cured between the silicon photonic unit 23 and the input end of the micro-optical coupler 26, and between the light-emitting regions of the silicon photonic unit 23 and the light-emitting unit 24, to form an optical interface structure 29.

[0078] Step S2: Fill the space between the electrical signal module, silicon photonic unit 23, light-emitting unit 24, blocking model and micro-optical coupler 26 with encapsulating material, and cure the encapsulating material to form encapsulation layer 10.

[0079] In detail, a molding compound is first filled between the electrical signal module, silicon photonic unit 23, light-emitting unit 24, blocking model and micro-optical coupler 26, and the molding compound is cured to form a molding layer 10, wherein the molding layer 10 covers the upper surface of the micro-optical coupler 26 and exposes the lower surface of the micro-optical coupler 26.

[0080] Then remove the blocking model and temporary carrier plate, and form a recessed area on the upper surface of the micro-optical coupler 26, the recessed area exposing the upper surface of the micro-optical coupler 26.

[0081] The process after step S2 also includes:

[0082] Step S3: From the lower surface side of the molding layer 10, a trench is formed in the molding layer 10, the trench exposing the electrical connection area of ​​the light-emitting unit 24 and the silicon photonic unit 23, and the trench is filled with conductive material.

[0083] Step S4: An interconnect structure 30 is formed on the lower surface of the molding compound 10. The interconnect structure 30 is electrically connected to the conductive material and the electrical connection area of ​​the second electrical signal unit 22. The lower surface of the interconnect structure 30 has a solder pad 33, and solder beads 40 are formed on the solder pad 33.

[0084] This step specifically includes:

[0085] First, a first passivation layer is formed on the lower surface of the molding layer 10. The first passivation layer has a first trench, which exposes the electrical connection area of ​​the second electrical signal unit 22 and the conductive material.

[0086] Next, a first metal layer is formed on the first passivation layer, and the first metal layer also fills the first trench, so that the first metal layer is electrically connected to the second electrical signal unit 22, the light-emitting unit 24 and the silicon photonic unit 23.

[0087] Next, a second passivation layer is formed on the first passivation layer and the first metal layer, and a second trench is formed in the second passivation layer, the second trench exposing a portion of the first metal layer;

[0088] Next, a second metal layer is formed in the second trench, the second metal layer being electrically connected to the first metal layer, and the lower surface of the second metal layer having a solder pad 33, the second passivation layer 31 exposing the solder pad 33.

[0089] Next, solder balls 40 are formed on the solder pads 33 using a BGA (Ball Array Package) packaging method.

[0090] In summary, this invention provides an integrated photonic packaging structure and its formation method. The integrated photonic packaging structure includes an electrical signal module, a silicon photonic unit, a light-emitting unit, and a micro-optical coupler encapsulated in a molding compound. The electrical signal module is electrically connected to the silicon photonic unit and the light-emitting unit, respectively, and is used to provide electrical signals to the silicon photonic unit and the light-emitting unit. The silicon photonic unit, the light-emitting unit, and the micro-optical coupler are spaced apart, with the silicon photonic unit located between the light-emitting unit and the micro-optical coupler. The light-emitting unit provides horizontal light rays, which are vertically transmitted and emitted from the integrated photonic packaging structure through the silicon photonic unit and the micro-optical coupler, thereby achieving optical interconnection within the package. This invention provides an integrated photonic packaging structure that achieves higher data rates (e.g., exceeding 800G).

[0091] Furthermore, it should be noted that, unless otherwise specified or indicated, the terms "first" and "second" in the specification are used only to distinguish the various components, elements, steps, etc. in the specification, and are not used to indicate the logical or sequential relationships between the various components, elements, steps, etc.

[0092] It is understood that although the present invention has been disclosed above with reference to preferred embodiments, these embodiments are not intended to limit the present invention. For any person skilled in the art, many possible variations and modifications can be made to the technical solutions of the present invention based on the disclosed technical content, or equivalent embodiments can be modified accordingly, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention shall still fall within the protection scope of the present invention.

Claims

1. An integrated photonics package structure, comprising: This includes an electrical signal module, a silicon photonic unit, a light-emitting unit, and a micro-optical coupler, all encapsulated in a plastic encapsulation layer. The electrical signal module is electrically connected to the silicon photonic unit and the light-emitting unit respectively, and is used to provide electrical signals to the silicon photonic unit and the light-emitting unit. The silicon photonic unit, the light-emitting unit and the micro-optical coupler are arranged at intervals, and the silicon photonic unit is located between the light-emitting unit and the micro-optical coupler. The light-emitting unit is used to provide horizontal light rays, and the horizontal light rays are vertically transmitted and emitted out of the integrated photonic packaging structure through the silicon photonic unit and the micro-optical coupler. The electrical signal module includes a first electrical signal unit and a second electrical signal unit. The first electrical signal unit is located on the silicon photonic unit and is electrically connected to the silicon photonic unit. The second electrical signal unit is spaced apart on the outside of the silicon photonic unit, the micro-optical coupler, and the light-emitting unit. The integrated photonic packaging structure further includes a first base and a second base encapsulated in a molding compound. The first base is located below the silicon photonic unit, and the second base is located below the light-emitting unit. The lower surface of the molding compound exposes the lower surface of the first base and also exposes the lower surface of the second base.

2. The integrated photonic package structure of claim 1, wherein, The micro-optical coupler has multiple waveguides, each waveguide having a mutually perpendicular and optically connected input end and output end. The horizontal light rays are processed by the silicon photonic unit and enter the waveguide horizontally from the input end and exit vertically from the output end.

3. The integrated photonic package structure of claim 2, wherein, The waveguide includes a first segment and a second segment, which are arranged perpendicularly. A reflector is provided at the intersection of the first segment and the second segment. The acute angle between the reflector and the first segment and the second segment is 45°. The end of the first segment away from the reflector is the input end, and the end of the second segment away from the reflector is the output end. This allows horizontal light rays to enter the waveguide from the input end, be reflected by the reflector and changed into vertical light rays, and exit from the output end.

4. The integrated photonic package structure of claim 2, wherein, The input end is matched with the mode and phase of the silicon photonic unit, and the output end is matched with the mode and phase of the optical fiber, so that the horizontal light rays can enter the waveguide horizontally and exit the waveguide vertically.

5. The integrated photonic package structure of claim 2, wherein, The output terminal is located on the upper surface of the micro-optical coupler. A recessed area is formed on the upper surface of the encapsulation layer, the recessed area exposes the output terminal, and the micro-optical coupler is connected to the optical fiber in the recessed area.

6. The integrated photonic package structure of claim 2, wherein, It also includes an optical interface structure encapsulated in a plastic encapsulation layer. The optical interface structure is disposed between the input terminal and the silicon photonic unit, and between the silicon photonic unit and the light-emitting area, so as to conduct the horizontal light emitted by the optical unit to the silicon photonic unit, and conduct the horizontal light processed by the silicon photonic unit to the input terminal.

7. The integrated photonic packaging structure as described in claim 1, characterized in that, It also includes a heat dissipation structure encapsulated in the molding compound, the heat dissipation structure being located on the light-emitting unit, and the molding compound exposing the upper surface of the heat dissipation structure, the heat dissipation structure being connected to an external system-level heat sink at the upper surface.

8. The integrated photonic packaging structure as described in claim 7, characterized in that, The heat dissipation structure includes a silicon plug, which is mounted on the light-emitting unit through a thermal interface material layer.

9. The integrated photonic packaging structure as described in claim 8, characterized in that, The silicon plug has heat dissipation holes that extend through the silicon plug in the thickness direction and are filled with metal material.

10. The integrated photonic packaging structure as described in claim 9, characterized in that, The silicon plug is made of silicon, the metal is made of copper, and the encapsulation layer is made of opaque resin.

11. The integrated photonic packaging structure as described in claim 1, characterized in that, The lower surfaces of the second electrical signal unit, the silicon photonic unit, and the light-emitting unit all have electrical connection regions, and the molding layer exposes the electrical connection regions of the second electrical signal unit, the silicon photonic unit, and the light-emitting unit.

12. The integrated photonic packaging structure as described in claim 1, characterized in that, It also includes an interconnect structure on the lower surface of the molding layer, and the interconnect structure is electrically connected to the second electrical signal unit, the silicon photonics unit and the light-emitting unit respectively.

13. The integrated photonic packaging structure as described in claim 12, characterized in that, The lower surface of the interconnect structure has multiple solder pads, on which solder balls are formed.

14. The integrated photonic packaging structure as described in claim 1, characterized in that, The light-emitting unit has a light-emitting area, which is positioned facing the light-emitting unit and the micro-optical coupler.

15. A method for forming an integrated photonic packaging structure, comprising preparing an integrated photonic packaging structure as described in any one of claims 1 to 14, characterized in that, Includes the following steps: An electrical signal module, a silicon photonic unit, a light-emitting unit, a blocking model, and a micro-optical coupler are fixed on a temporary carrier plate. The electrical signal module is electrically connected to the silicon photonic unit and the light-emitting unit, respectively, and is used to provide electrical signals to the silicon photonic unit and the light-emitting unit. The silicon photonic unit, the light-emitting unit, and the micro-optical coupler are spaced apart, with the silicon photonic unit located between the light-emitting unit and the micro-optical coupler. The light-emitting unit is used to provide horizontal light rays, and the horizontal light rays are vertically transmitted and emitted out of the integrated photonic packaging structure through the silicon photonic unit and the micro-optical coupler. A molding compound is filled between the electrical signal module, the silicon photonic unit, the light-emitting unit, the blocking model, and the micro-optical coupler, and the molding compound is cured to form a molding layer; The steps of fixing the electrical signal module, silicon photonic unit, light-emitting unit, and micro-optical coupler onto a temporary carrier specifically include: A temporary carrier plate is provided, one side of which has an adhesive layer formed; The first base and the second base are spaced apart on the temporary carrier plate; The silicon photonic unit is assembled on the first base, and the light-emitting unit is assembled on the second base, wherein the silicon photonic unit and the light-emitting unit are arranged at intervals and adjacent to each other; The electrical signal module, micro-optical coupler, blocking model and heat dissipation structure are placed on the temporary carrier, silicon photonic unit and light-emitting unit; An exponentially matched epoxy resin is distributed and cured between the silicon photonic unit and the input end of the micro-optical coupler, and between the light-emitting regions of the silicon photonic unit and the light-emitting unit, to form an optical interface structure. The electrical signal module includes a first electrical signal unit and a second electrical signal unit. Placing the electrical signal module, the micro-optical coupler, and the heat dissipation structure on the temporary carrier, the silicon photonic unit, and the light-emitting unit includes: The first electrical signal unit is packaged on the silicon photonic unit using a three-dimensional integrated packaging method, so that the first electrical signal unit is electrically connected to the silicon photonic unit; The second electrical signal unit and the micro-optical coupler are placed outside the silicon photonic unit and the light-emitting unit, and the silicon photonic unit is located between the micro-optical coupler and the light-emitting unit. The light-emitting unit is located between the silicon photonic unit and the second electrical signal unit, and the output end of the micro-optical coupler is oriented towards the silicon photonic unit, and the light-emitting area of ​​the light-emitting unit is oriented towards the silicon photonic unit. The blocking model is placed on the upper surface of the micro-optical coupler; The heat dissipation structure is assembled onto the upper surface of the light-emitting unit through a thermal interface material layer.

16. The method for forming the integrated photonic packaging structure as described in claim 15, characterized in that, Methods for forming a molding compound include: A molding compound is filled between the electrical signal module, the silicon photonic unit, the light-emitting unit, the blocking model, and the micro-optical coupler, and the molding compound is cured to form a molding layer, wherein the molding layer covers the upper surface of the micro-optical coupler and exposes the lower surface of the micro-optical coupler; Remove the blocking model and temporary carrier plate, and form a recessed region on the upper surface of the micro-optical coupler, the recessed region exposing the upper surface of the micro-optical coupler.

17. The method for forming the integrated photonic packaging structure as described in claim 15, characterized in that, Following the formation of the molding compound layer are: From the lower surface side of the molding layer, a trench is formed in the molding layer, the trench exposing the electrical connection area of ​​the light-emitting unit and the silicon photonic unit, and the trench is filled with a conductive material; An interconnect structure is formed on the lower surface of the molding compound. The interconnect structure is electrically connected to the electrical connection area of ​​the conductive material and the second electrical signal unit, respectively. The lower surface of the interconnect structure has solder pads on which solder beads are formed.

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