Photoelectric interconnection packaging structure and preparation method thereof

Abstract

According to the photoelectric interconnection packaging structure and the preparation method thereof provided by the invention, the TGV metal columns and the optical waveguide layers are prepared in the glass substrate based on a laser method, and the composite optical waveguide substrate with the interconnected TGV metal columns and the laminated optical waveguide layers is prepared after stacking and bonding, so that the layout of multiple layers of optical waveguides can be realized based on the TGV adapter plate; high-density and high-performance integration of an electric chip and an optical chip is realized, the packaging size is reduced, the power consumption is reduced, the reliability is improved, and good photoelectric signal transmission is realized.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor technology and relates to an optoelectronic interconnect packaging structure and its fabrication method. Background Technology

[0002] Light has excellent properties such as low signal attenuation, low power consumption, high bandwidth and compatibility with CMOS. It is generally believed in the industry that introducing optical technology into semiconductor manufacturing processes can reduce chip size, reduce cost and power consumption, and improve reliability. Thus, functional chips can be connected by optical fiber through edge coupling.

[0003] In semiconductor 2.5D / 3D packaging, organic interposers, through-silicon via (TSV) interposers, and through-glass via (TGV) interposers are the mainstream interposer materials. The main purpose of setting up interposers is to solve some challenges in semiconductor packaging, such as improving integration, reducing costs, and improving electrical performance.

[0004] Most existing optoelectronic interconnect packaging structures directly bond optical and electrical chips to a substrate, electrically connecting them via wire bonding or flip-chip bonding. However, these existing structures struggle to meet the demands of high-density, high-performance product packaging. Glass, being an insulating material with a low dielectric constant (approximately one-third that of silicon) and a small loss factor (about 2-3 orders of magnitude lower than silicon), exhibits excellent high-frequency performance. This allows glass to significantly reduce insertion loss and crosstalk at high frequencies.

[0005] Therefore, it is necessary to provide an optoelectronic interconnect packaging structure and its fabrication method. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide an optoelectronic interconnect packaging structure and its preparation method, so as to solve the problem that the optoelectronic interconnect packaging structure in the prior art is difficult to meet the requirements of high-density and high-performance products.

[0007] To achieve the above and other related objectives, the present invention provides a method for fabricating an optoelectronic interconnect packaging structure, comprising the following steps:

[0008] Fabricating a composite optical waveguide substrate, wherein the steps for fabricating the composite optical waveguide substrate include:

[0009] A glass substrate is provided, the glass substrate including a first surface and a second surface disposed opposite to each other;

[0010] A through-hole is formed from top to bottom through the glass substrate using a first laser method.

[0011] A TGV metal pillar is formed inside the through hole to fill the through hole;

[0012] A second laser method is used to form a first groove with its bottom located in the glass substrate from the first surface of the glass substrate;

[0013] A first optical waveguide layer is formed in the first groove to complete the fabrication of a single optical waveguide substrate;

[0014] The optical waveguide substrates are stacked and bonded from bottom to top to form the composite optical waveguide substrate, and the TGV metal pillars located in each optical waveguide substrate are electrically connected to form interconnected TGV metal pillars.

[0015] A first redistribution layer is formed on a first surface of the composite optical waveguide substrate, and a second redistribution layer is formed on a second surface of the composite optical waveguide substrate. The first redistribution layer is electrically connected to a first end of the interconnect TGV metal pillar, and the second redistribution layer is electrically connected to a second end of the interconnect TGV metal pillar.

[0016] The first redistribution layer and the composite optical waveguide substrate are patterned to form a second groove, and each second groove exposes the corresponding first optical waveguide layer.

[0017] A second optical waveguide layer is formed in the second groove, and the second optical waveguide layer is connected to the corresponding first optical waveguide layer;

[0018] An electrical chip and an optical chip with a photosensitive area are provided. The electrical chip and the optical chip are bonded to a first redistribution layer. Both the electrical chip and the optical chip are electrically connected to the first redistribution layer, and the photosensitive area of ​​the optical chip is correspondingly disposed with respect to the second optical waveguide layer.

[0019] Optionally, the first laser method includes laser ablation or laser-induced denaturation etching; the second laser method includes laser ablation or laser-induced denaturation etching; and the method for forming the TGV metal pillar includes electroless plating or electroplating.

[0020] Optionally, the method for forming the first redistribution layer on the first surface of the glass substrate includes a semiconductor process or a substrate bonding method; the method for forming the second redistribution layer on the second surface of the glass substrate includes a semiconductor process or a substrate bonding method.

[0021] Optionally, the composite optical waveguide substrate includes N optical waveguide substrates stacked and bonded from bottom to top, wherein the value of N is 2≤N≤5 and N is an integer.

[0022] Optionally, in the composite optical waveguide substrate, the vertical projection of the upper first optical waveguide layer is completely located within the lower first optical waveguide layer.

[0023] Optionally, the thickness of the glass substrate is 100–300 μm.

[0024] The present invention also provides an optoelectronic interconnect packaging structure, the optoelectronic interconnect packaging structure comprising:

[0025] A composite optical waveguide substrate, the composite optical waveguide substrate comprising optical waveguide substrates stacked and bonded from bottom to top, the optical waveguide substrate comprising:

[0026] A glass substrate, the glass substrate comprising a first surface and a second surface disposed opposite to each other;

[0027] A through-hole, which extends from top to bottom through the first surface of the glass substrate;

[0028] TGV metal pillars, wherein the TGV metal pillars fill the through holes;

[0029] A first groove extends from a first surface of the glass substrate into the glass substrate;

[0030] A first optical waveguide layer is located in the first groove;

[0031] The TGV metal pillars in each of the optical waveguide substrates are electrically connected vertically to form the interconnecting TGV metal pillars of the composite optical waveguide substrate.

[0032] A first redistribution layer is located on a first surface of the composite optical waveguide substrate and is electrically connected to a first end of the interconnecting TGV metal pillar.

[0033] The second redistribution layer is located on the second surface of the composite optical waveguide substrate and is electrically connected to the second end of the interconnecting TGV metal pillar.

[0034] The second groove penetrates the first rewiring layer and exposes the corresponding first optical waveguide layer;

[0035] The second optical waveguide layer is located in the second groove and is connected to the corresponding first optical waveguide layer.

[0036] An electrical chip and an optical chip with a photosensitive area are provided. The electrical chip and the optical chip are bonded to the first redistribution layer. Both the electrical chip and the optical chip are electrically connected to the first redistribution layer, and the photosensitive area of ​​the optical chip is correspondingly disposed with the second optical waveguide layer.

[0037] Optionally, the composite optical waveguide substrate includes N layers of optical waveguide substrates stacked and bonded from bottom to top, wherein the value of N is 2≤N≤5.

[0038] Optionally, in the composite optical waveguide substrate, the vertical projection of the upper first optical waveguide layer is completely located within the lower first optical waveguide layer.

[0039] Optionally, it also includes a metal reflector located on the sidewall of the first groove; a convex lens located on the second optical waveguide layer; and a metal bump located on the second redistribution layer.

[0040] As described above, the optoelectronic interconnect packaging structure and its fabrication method of the present invention are based on the laser method to prepare TGV metal pillars and optical waveguide layers in a glass substrate, and after stacking and bonding, a composite optical waveguide substrate with interconnected TGV metal pillars and stacked optical waveguide layers is prepared. Thus, a multi-layer optical waveguide layout can be realized based on the TGV adapter board, realizing high-density and high-performance integration of electrical chips and optical chips, reducing package size, reducing power consumption, improving reliability, and achieving good optoelectronic signal transmission. Attached Figure Description

[0041] Figure 1 The diagram shown is a schematic flowchart of the process for preparing the optoelectronic interconnect packaging structure in an embodiment of the present invention.

[0042] Figure 2 The diagram shown is a schematic representation of the structure after the through-hole is formed in an embodiment of the present invention.

[0043] Figure 3 The diagram shown is a schematic representation of the structure after the formation of the TGV metal column in an embodiment of the present invention.

[0044] Figure 4 The diagram shown is a schematic representation of the structure after the first groove is formed in an embodiment of the present invention.

[0045] Figure 5 The diagram shown is a structural schematic of the metal reflector and the first optical waveguide layer after they are formed in an embodiment of the present invention.

[0046] Figure 6 The diagram shown is a structural schematic of the bonding of an optical waveguide substrate in an embodiment of the present invention.

[0047] Figure 7 The diagram shown is a schematic representation of the structure of the composite optical waveguide substrate after its formation in an embodiment of the present invention.

[0048] Figure 8 The diagram shown is a structural schematic of the first and second redistribution layers after they have been formed in an embodiment of the present invention.

[0049] Figure 9 The diagram shown is a schematic representation of the structure after the second groove is formed in an embodiment of the present invention.

[0050] Figure 10 The diagram shown is a schematic representation of the structure after the formation of the second optical waveguide layer and the convex lens in an embodiment of the present invention.

[0051] Figure 11 The diagram shows the structure of the bonding electrical chip, optical chip, and metal bumps in an embodiment of the present invention.

[0052] Explanation of reference numerals in the attached figures

[0053] 100 glass substrate

[0054] 101 Through Hole

[0055] 102 TGV metal column

[0056] 103 First Groove

[0057] 104 First optical waveguide layer

[0058] 105 Metal Reflector

[0059] 106 Second Groove

[0060] 107 Second optical waveguide layer

[0061] 110 Optical waveguide substrate

[0062] 120 Composite Optical Waveguide Substrate

[0063] 121 Interconnected TGV Metal Pillars

[0064] 210 First Rerouting Layer

[0065] 220 Second Rerouting Layer

[0066] 300° convex lens

[0067] 401 electrical chip

[0068] 402 optical chip

[0069] 412 Photosensitive area

[0070] 500 metal bumps Detailed Implementation

[0071] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0072] In the detailed description of embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged and not to scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0073] For ease of description, spatial relation terms such as “below,” “under,” “lower than,” “below,” “above,” and “upper” may be used herein to describe the relationship between one element or feature shown in the accompanying drawings and other elements or features. It will be understood that these spatial relation terms are intended to include orientations of the device in use or operation other than those depicted in the drawings, and may include embodiments in which the first and second features are formed in direct contact, or embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact. Furthermore, when a layer is referred to as “between” two layers, it may be the only layer between the two layers, or there may be one or more layers in between.

[0074] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0075] See Figure 1 This embodiment provides a method for fabricating an optoelectronic interconnect packaging structure. It can fabricate TGV metal pillars and optical waveguide layers in a glass substrate using a laser method, and fabricate a composite optical waveguide substrate with interconnected TGV metal pillars and stacked optical waveguide layers after stacking and bonding. This allows for the layout of multi-layer optical waveguides based on a TGV adapter board, achieving high-density, high-performance integration of electrical and optical chips, reducing package size, lowering power consumption, improving reliability, and achieving good optoelectronic signal transmission.

[0076] The following is in conjunction with the appendix Figures 2 to 11 The fabrication of the aforementioned optoelectronic interconnect packaging structure is further described, specifically including:

[0077] First, refer to Figure 1 and Figure 2Step S1 is executed, providing a glass substrate 100, the glass substrate 100 including a first surface and a second surface disposed opposite to each other.

[0078] Specifically, the glass substrate 100 may include a wafer-level glass substrate, such as 4-inch, 6-inch, 8-inch, 12-inch, etc. The thickness of the glass substrate 100 may be 100-300μm, such as 100μm, 200μm, 300μm, etc. However, the size of the glass substrate 100 is not limited to this and can be set as needed. No excessive restrictions are imposed here.

[0079] Next, refer to Figure 1 and Figure 2 In step S2, a through hole 101 is formed from top to bottom through the glass substrate 100 using a first laser method.

[0080] The first laser method may include laser ablation or laser-induced denaturation etching. Specific operations of laser ablation and laser-induced denaturation etching are not detailed here, but can be found in existing fabrication methods. Since the through-hole 101 is formed using a laser method, the opening width is greater than the bottom width. The specific dimensions of the through-hole 101 are not excessively limited here.

[0081] Furthermore, after forming the via 101, the glass substrate 100 can be subjected to a thinning process, such as chemical mechanical polishing (CMP), to further reduce the thickness of the glass substrate 100, reduce the size of the packaging structure, and remove the wider area of ​​the via 101, thereby further reducing the critical dimension of the via 101. The thickness of the thinned glass substrate 100 can be 100–200 μm, such as 100 μm, 150 μm, or 200 μm, and the critical dimension (CD) of the thinned via 101 can be 40–50 μm, such as 40 μm, 45 μm, or 50 μm.

[0082] Next, refer to Figure 1 and Figure 3 Step S3 is executed, in which a TGV metal pillar 102 is formed to fill the through hole 101, and a second TGV metal pillar 202 is formed to fill the through hole 101.

[0083] The method for forming the TGV metal column 102 may include chemical plating or electroplating. The specific operations of chemical plating or electroplating will not be described here, but can be referred to existing preparation methods.

[0084] In this embodiment, the TGV metal pillar 102 is made of copper, but the material of the TGV metal pillar 102 is not limited to this, and other conductive metal materials can also be used.

[0085] Furthermore, after the through hole 101 is prepared by laser method, in order to facilitate the formation of the TGV metal pillar 102 that fills the through hole 101, the through hole 101 can be surface treated, such as by wet etching, so that the through hole 101 has a smooth inner surface. The method of surface treatment is not limited here.

[0086] Furthermore, after the TGV metal pillars 102 are formed, the glass substrate 100 can be surface treated, such as by grinding or wet etching, to facilitate the subsequent preparation of the redistribution layer and obtain a flat surface.

[0087] Next, refer to Figure 1 and Figure 4 In step S4, a second laser method is used to form a first groove 103 with its bottom located in the glass substrate 100 from the first surface of the glass substrate 100.

[0088] The second laser method may include laser ablation or laser-induced denaturation etching, and preferably the first laser method and the second laser method use the same preparation method to reduce process complexity and facilitate process management and operation. However, it is not limited to this. As needed, the first laser method and the second laser method may also use different preparation methods.

[0089] Since the first groove 103 is prepared by laser method, the opening width of the first groove 103 is greater than the bottom width, that is, the side wall of the first groove 103 has an inclined surface. The inclined surface is beneficial to the subsequent transmission of optical signals. The inclination angle of the inclined surface can be set according to specific needs and is not limited here.

[0090] Next, refer to Figure 1 and Figure 5 Step S5 is executed to form a first optical waveguide layer 104 in the first groove 103 to complete the fabrication of a single optical waveguide substrate 110.

[0091] Among them, see Figure 5 To reduce light loss and improve light transmission efficiency, in this embodiment, it is preferable to form a metal reflector 105 on the sidewall of the first groove 103, such as a titanium metal reflector prepared by sputtering and etching. The metal reflector 105 formed can also cover the bottom of the first groove 103, which is not limited here.

[0092] When the first optical waveguide layer 104 is prepared, a semiconductor process method can be used, that is, it is prepared by steps such as coating, exposure, development and etching. The first optical waveguide layer 104 formed may include an organic polymer optical waveguide wiring layer, a silicon-based optical waveguide wiring layer, a lithium niobate optical waveguide wiring layer or a lithium borate optical waveguide wiring layer, etc.

[0093] Next, refer to Figure 1 , Figure 6 and Figure 7 In step S6, the optical waveguide substrates 110 are stacked and bonded from bottom to top to form the composite optical waveguide substrate 120. In the composite optical waveguide substrate 120, the TGV metal pillars 102 located in each of the optical waveguide substrates 110 are electrically connected to form interconnecting TGV metal pillars 121.

[0094] Thus far, from steps S1 to S6, the fabrication of the composite optical waveguide substrate 120 is completed. The method for bonding the optical waveguide substrate 110 is not limited here and can be selected as needed.

[0095] As an example, the composite optical waveguide substrate 120 may include N optical waveguide substrates 110 stacked and bonded from bottom to top, wherein the value of N is preferably 2≤N≤5, and N is an integer, but the value of N is not limited to this; see [reference]. Figure 6 and Figure 7 In this embodiment, the composite optical waveguide substrate 120 formed by bonding includes three optical waveguide substrates 110 stacked and bonded from bottom to top, i.e., N is 3. However, as needed, N can also be 2, 4, 5, 8, etc., which is not limited here.

[0096] As an example, in the composite optical waveguide substrate 120, the vertical projection of the upper first optical waveguide layer 105 is completely located within the lower first optical waveguide layer 105.

[0097] For details, please refer to Figure 7 In this embodiment, the vertical projection of the first optical waveguide layer 105 in the upper optical waveguide substrate 110 is completely located in the first optical waveguide layer 105 in the lower optical waveguide substrate 110, thereby effectively reducing the space occupied by the composite optical waveguide substrate 120 and reducing the size of the packaging structure.

[0098] Of course, as needed, the vertical projection of the upper first optical waveguide layer 105 may also be partially located in the lower first optical waveguide layer 105, or the upper first optical waveguide layer 105 and the lower first optical waveguide layer 105 may be staggered, that is, the vertical projections have no overlapping area, which is not limited here.

[0099] The optical waveguide substrate 110 to be bonded may have the same structure and morphology, or it may have different structures and / or morphologies. The specific configuration can be set as needed and is not limited here.

[0100] Next, refer to Figure 1 and Figure 8 In step S7, a first redistribution layer 210 is formed on the first surface of the composite optical waveguide substrate 120, and a second redistribution layer 220 is formed on the second surface of the composite optical waveguide substrate 120. The first redistribution layer 210 is electrically connected to the first end of the interconnect TGV metal pillar 121, and the second redistribution layer 220 is electrically connected to the second end of the interconnect TGV metal pillar 121.

[0101] Specifically, the method for forming the first redistribution layer 210 on the first surface of the composite optical waveguide substrate 120 may include a semiconductor process method or a substrate bonding method. Similarly, the method for forming the second redistribution layer 220 on the second surface of the composite optical waveguide substrate 120 may include a semiconductor process method or a substrate bonding method.

[0102] The semiconductor manufacturing process is a method of preparing the first redistribution layer 210 and the second redistribution layer 220 on the composite optical waveguide substrate 120 through steps such as coating, exposure, development, deposition, and etching. The substrate bonding method is a method of preparing the required first redistribution layer 210 and second redistribution layer 220 in advance, and then directly bonding the first redistribution layer 210 and the second redistribution layer 220 to the composite optical waveguide substrate 120.

[0103] The specific fabrication methods for the first redistribution layer 210 and the second redistribution layer 220 are not excessively limited here; they can be fabricated using the same method, or different methods can be used. The specific materials and structures of the first redistribution layer 210 and the second redistribution layer 220 are also not excessively limited here and can be selected as needed.

[0104] Next, refer to Figure 1 and Figure 9 In step S8, the first redistribution layer 210 and the composite optical waveguide substrate 120 are graphically patterned to form a second groove 106, and each second groove 106 exposes the corresponding first optical waveguide layer 104.

[0105] Specifically, the etching methods for the first redistribution layer 210 and the composite optical waveguide substrate 120 can be selected as needed, and the morphology of the second groove 106 is not limited here.

[0106] like Figure 9 In this embodiment, since the composite optical waveguide substrate 120 has three stacked first optical waveguide layers 104, when the second groove 106 is formed, three sets of second grooves 106 corresponding to the first optical waveguide layers 104 are formed to expose the corresponding first optical waveguide layers 104, which facilitates the subsequent fabrication of optical waveguide layers.

[0107] Next, refer to Figure 1 and Figure 10 In step S9, a second optical waveguide layer 107 is formed in the second groove 106, and the second optical waveguide layer 107 is connected to the corresponding first optical waveguide layer 104.

[0108] Specifically, the second optical waveguide layer 107 can be fabricated using semiconductor processing methods, i.e., through steps such as coating, exposure, development, and etching. The resulting second optical waveguide layer 107 may include an organic polymer optical waveguide wiring layer, a silicon-based optical waveguide wiring layer, a lithium niobate optical waveguide wiring layer, or a lithium borate optical waveguide wiring layer, etc. Preferably, the fabrication and material of the second optical waveguide layer 107 are the same as those of the first optical waveguide layer 104 to reduce process complexity.

[0109] See Figure 10 Furthermore, it is preferable to form a convex lens 300 on the second optical waveguide layer 107, so as to concentrate light and further reduce light loss. The method of fabricating the convex lens 300 is not limited here; bonding method can be used, but it is not limited to this.

[0110] Next, refer to Figure 1 and Figure 11 In step S10, an electrical chip 401 and an optical chip 402 with a photosensitive area 412 are provided. The electrical chip 401 and the optical chip 402 are bonded to the first redistribution layer 210. Both the electrical chip 401 and the optical chip 402 are electrically connected to the first redistribution layer 210, and the photosensitive area 412 of the optical chip 402 is correspondingly disposed with the second optical waveguide layer 107.

[0111] For details, please refer to Figure 11 The electrical leads of the electrical chip 401 and the optical chip 402 are electrically connected to the first redistribution layer 210 via metal bumps. The photosensitive area 412 of the optical chip 402 is correspondingly disposed with the second optical waveguide layer 107, so as to form an optical transmission path in conjunction with the first optical waveguide layer 104. Figure 11 The dashed line with an arrow is shown in the image.

[0112] For further details, please refer to [link / reference]. Figure 11Metal bumps 500 can also be formed on the surface of the second redistribution layer 220 to facilitate subsequent electrical connections.

[0113] Understandably, in order to increase production capacity, Figure 11 The optoelectronic interconnect packaging structure described herein can be considered as a single-unit structure formed after a cutting process. Of course, depending on the needs, Figure 11 The optoelectronic interconnect packaging structure described herein can also be a monolithic structure directly prepared without a cutting process; no excessive restrictions are imposed here.

[0114] See Figures 2 to 11 This embodiment also provides an optoelectronic interconnect packaging structure, wherein the optoelectronic interconnect packaging structure can be directly prepared using the above-described preparation process. Therefore, the materials, structure, etc. of the optoelectronic interconnect packaging structure can be referred to the above content. Of course, the optoelectronic interconnect packaging structure can also be prepared using other preparation processes as needed.

[0115] In this embodiment, the optoelectronic interconnect packaging structure includes:

[0116] Composite optical waveguide substrate 120, the composite optical waveguide substrate 120 including optical waveguide substrates 110 stacked and bonded from bottom to top, the optical waveguide substrate 110 including:

[0117] A glass substrate 100, the glass substrate 100 including a first surface and a second surface disposed opposite to each other;

[0118] Through hole 101, the through hole 101 is prepared by a first laser method, and the through hole 101 penetrates the glass substrate 100 from top to bottom through the first surface of the glass substrate 100;

[0119] TGV metal pillar 102, the TGV metal pillar 102 filling the through hole 101;

[0120] A first groove 103 extends from a first surface of the glass substrate 100 into the glass substrate 100;

[0121] The first optical waveguide layer 104 is located in the first groove 103;

[0122] The TGV metal pillars 102 in each of the optical waveguide substrates 110 are electrically connected to form the interconnecting TGV metal pillars 121 of the composite optical waveguide substrate 120.

[0123] A first redistribution layer 210 is located on a first surface of the composite optical waveguide substrate 120 and is electrically connected to a first end of the interconnect TGV metal pillar 121.

[0124] The second redistribution layer 220 is located on the second surface of the composite optical waveguide substrate 120 and is electrically connected to the second end of the interconnect TGV metal pillar 121.

[0125] The second groove 106 penetrates the first rewiring layer 210 and exposes the corresponding first optical waveguide layer 104.

[0126] The second optical waveguide layer 107 is located in the second groove 106 and is connected to the corresponding first optical waveguide layer 104.

[0127] An electrical chip 401 and an optical chip 402 having a photosensitive area 412 are bonded to the first redistribution layer 210. Both the electrical chip 401 and the optical chip 402 are electrically connected to the first redistribution layer 210, and the photosensitive area 412 of the optical chip 402 is correspondingly disposed with the second optical waveguide layer 107.

[0128] The glass substrate 100 may include a wafer-level glass substrate, such as 4-inch, 6-inch, 8-inch, 12-inch, etc. The thickness of the glass substrate 100 may be 100-300μm, such as 100μm, 200μm, 300μm, etc. However, the size of the glass substrate 100 is not limited to this and can be set as needed. No excessive restrictions are imposed here.

[0129] The TGV metal column 102 may be a tapered shape with a wider top and a narrower bottom, prepared by laser method, but is not limited to this. The shape and size of the TGV metal column 102 are not limited here.

[0130] As an example, the composite optical waveguide substrate 120 may include N optical waveguide substrates 110 stacked and bonded from bottom to top, wherein the value of N is preferably 2≤N≤5, and N is an integer, but the value of N is not limited to this; see [reference]. Figure 6 , Figure 7 and Figure 11 In this embodiment, the composite optical waveguide substrate 120 formed by bonding includes three optical waveguide substrates 110 stacked and bonded from bottom to top, i.e., N is 3. However, as needed, N can also be 2, 4, 5, 8, etc., which is not limited here.

[0131] As an example, in the composite optical waveguide substrate 120, the vertical projection of the upper first optical waveguide layer 105 is completely located within the lower first optical waveguide layer 105.

[0132] For details, please refer to Figure 11In this embodiment, the vertical projection of the first optical waveguide layer 105 in the upper optical waveguide substrate 110 is completely located in the first optical waveguide layer 105 in the lower optical waveguide substrate 110, thereby effectively reducing the space occupied by the composite optical waveguide substrate 120 and reducing the size of the packaging structure.

[0133] Of course, depending on the needs, the vertical projection of the upper first optical waveguide layer 105 can also be partially located in the lower first optical waveguide layer 105, or the upper first optical waveguide layer 105 and the lower first optical waveguide layer 105 can be staggered, that is, the vertical projections have no overlapping area, which is not limited here.

[0134] The optical waveguide substrate 110 to be bonded may have the same structure and morphology, or it may have different structures and / or morphologies. The specific configuration can be set as needed and is not limited here.

[0135] See Figure 11 In order to reduce light loss and improve light transmission efficiency, in this embodiment, a metal reflector 105 is preferably provided on the side wall of the first groove 103. Of course, the metal reflector 105 may also cover the bottom of the first groove 103 as needed, which is not limited here.

[0136] For further details, please refer to [link / reference]. Figure 11 Preferably, a convex lens 300 is provided on the second optical waveguide layer 107 to concentrate light and further reduce light loss.

[0137] For further details, please refer to [link / reference]. Figure 11 Metal bumps 500 or similar materials can also be provided on the surface of the second redistribution layer 220 to facilitate subsequent electrical connections.

[0138] In summary, the optoelectronic interconnect packaging structure and its fabrication method of the present invention are based on the laser method to prepare TGV metal pillars and optical waveguide layers in a glass substrate, and after stacking and bonding, a composite optical waveguide substrate with interconnected TGV metal pillars and stacked optical waveguide layers is prepared. Thus, a multi-layer optical waveguide layout can be realized based on the TGV adapter board, realizing high-density and high-performance integration of electrical chips and optical chips, reducing package size, reducing power consumption, improving reliability, and achieving good optoelectronic signal transmission.

[0139] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for fabricating an optoelectronic interconnect packaging structure, characterized in that, Includes the following steps: Fabricating a composite optical waveguide substrate, wherein the steps for fabricating the composite optical waveguide substrate include: A glass substrate is provided, the glass substrate including a first surface and a second surface disposed opposite to each other; A through-hole is formed from top to bottom through the glass substrate using a first laser method. A TGV metal pillar is formed inside the through hole to fill the through hole; A second laser method is used to form a first groove with its bottom located in the glass substrate from the first surface of the glass substrate; A first optical waveguide layer is formed in the first groove to complete the fabrication of a single optical waveguide substrate; The optical waveguide substrates are stacked and bonded from bottom to top to form the composite optical waveguide substrate, and the TGV metal pillars located in each optical waveguide substrate are electrically connected to form interconnected TGV metal pillars. A first redistribution layer is formed on a first surface of the composite optical waveguide substrate, and a second redistribution layer is formed on a second surface of the composite optical waveguide substrate. The first redistribution layer is electrically connected to a first end of the interconnect TGV metal pillar, and the second redistribution layer is electrically connected to a second end of the interconnect TGV metal pillar. The first redistribution layer and the composite optical waveguide substrate are patterned to form a second groove, and each second groove exposes the corresponding first optical waveguide layer. A second optical waveguide layer is formed in the second groove, and the second optical waveguide layer is connected to the corresponding first optical waveguide layer; An electrical chip and an optical chip with a photosensitive area are provided. The electrical chip and the optical chip are bonded to a first redistribution layer. Both the electrical chip and the optical chip are electrically connected to the first redistribution layer, and the photosensitive area of ​​the optical chip is correspondingly disposed with respect to the second optical waveguide layer.

2. The method for fabricating the optoelectronic interconnect packaging structure according to claim 1, characterized in that: The first laser method includes laser ablation or laser-induced denaturation etching; the second laser method includes laser ablation or laser-induced denaturation etching; the method for forming the TGV metal pillar includes electroless plating or electroplating.

3. The method for fabricating the optoelectronic interconnect packaging structure according to claim 1, characterized in that: The method for forming the first redistribution layer on the first surface of the glass substrate includes a semiconductor process or a substrate bonding method; the method for forming the second redistribution layer on the second surface of the glass substrate includes a semiconductor process or a substrate bonding method.

4. The method for fabricating the optoelectronic interconnect packaging structure according to claim 1, characterized in that: The composite optical waveguide substrate includes N optical waveguide substrates stacked and bonded from bottom to top, wherein the value of N is 2≤N≤5 and N is an integer.

5. The method for fabricating the optoelectronic interconnect packaging structure according to claim 1, characterized in that: In the composite optical waveguide substrate, the vertical projection of the upper first optical waveguide layer is completely located within the lower first optical waveguide layer.

6. The method for fabricating the optoelectronic interconnect packaging structure according to claim 1, characterized in that: The thickness of the glass substrate is 100–300 μm.

7. A photoelectric interconnect packaging structure, characterized in that, The optoelectronic interconnect packaging structure includes: A composite optical waveguide substrate, the composite optical waveguide substrate comprising optical waveguide substrates stacked and bonded from bottom to top, the optical waveguide substrate comprising: A glass substrate, the glass substrate comprising a first surface and a second surface disposed opposite to each other; A through-hole, which extends from top to bottom through the first surface of the glass substrate; TGV metal pillars, wherein the TGV metal pillars fill the through holes; A first groove extends from a first surface of the glass substrate into the glass substrate; A first optical waveguide layer is located in the first groove; The TGV metal pillars in each of the optical waveguide substrates are electrically connected vertically to form the interconnecting TGV metal pillars of the composite optical waveguide substrate. A first redistribution layer is located on a first surface of the composite optical waveguide substrate and is electrically connected to a first end of the interconnecting TGV metal pillar. The second redistribution layer is located on the second surface of the composite optical waveguide substrate and is electrically connected to the second end of the interconnecting TGV metal pillar. The second groove penetrates the first rewiring layer and exposes the corresponding first optical waveguide layer; The second optical waveguide layer is located in the second groove and is connected to the corresponding first optical waveguide layer. An electrical chip and an optical chip with a photosensitive area are provided. The electrical chip and the optical chip are bonded to the first redistribution layer. Both the electrical chip and the optical chip are electrically connected to the first redistribution layer, and the photosensitive area of ​​the optical chip is correspondingly disposed with the second optical waveguide layer.

8. The optoelectronic interconnect packaging structure according to claim 7, characterized in that: The composite optical waveguide substrate comprises N layers of optical waveguide substrates stacked and bonded from bottom to top, wherein the value of N is 2≤N≤5.

9. The optoelectronic interconnect packaging structure according to claim 7, characterized in that: In the composite optical waveguide substrate, the vertical projection of the upper first optical waveguide layer is completely located within the lower first optical waveguide layer.

10. The optoelectronic interconnect packaging structure according to claim 7, characterized in that: It also includes a metal reflector located on the sidewall of the first groove; a convex lens located on the second optical waveguide layer; and a metal bump located on the second redistribution layer.

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