Substrate and method for manufacturing the same

Abstract

The application discloses a substrate and a manufacturing method thereof. The substrate comprises: a substrate, which has a through hole; and a conductive connection structure, which is filled in the through hole. The conductive connection structure comprises a three-dimensional conductive mesh structure and a conductive filler. The three-dimensional conductive mesh structure is distributed in the through hole, and the conductive filler is filled in the gaps of the three-dimensional conductive mesh structure in the through hole.

Description

Technical Field

[0001] This invention relates to the fields of semiconductor packaging and microelectronics technology, and in particular to a substrate and its fabrication method. Background Technology

[0002] In the semiconductor packaging field, the mainstream process for through-glass via (TGV) metallization is to form a conductive seed layer inside the hole and then electroplate it for filling.

[0003] Existing glass-through-via (TGV) metallization technologies typically involve first forming a seed layer on the inner surface of the glass via, followed by electroplating to deposit metal onto the seed layer. Physical vapor deposition (PVD) or chemical deposition can be used to form the seed layer. However, PVD seed layer formation suffers from uneven coverage within high aspect ratio (>5:1) vias, with a weak or discontinuous seed layer at the bottom, leading to unbalanced current distribution during subsequent electroplating, making it prone to voids within the via. Furthermore, the electroplated film exhibits poor adhesion to the glass and is susceptible to failure under thermal stress. Chemical deposition seed layer formation, on the other hand, is complex, faces significant environmental challenges, and suffers from high resistivity and weak adhesion of the coating itself, making it difficult to guarantee the uniformity and reliability of deep via filling. Summary of the Invention

[0004] This invention provides a substrate and a method for manufacturing the same, in order to solve the aforementioned technical problems existing in the prior art.

[0005] In a first aspect, to solve the above-mentioned technical problems, embodiments of the present invention provide a substrate, comprising: A substrate having a through-hole extending through the substrate; A conductive connection structure is filled within the through hole; The conductive connection structure includes a three-dimensional conductive mesh structure and a conductive filler; the three-dimensional conductive mesh structure is distributed within the through hole, and the conductive filler fills the gaps in the three-dimensional conductive mesh structure within the through hole.

[0006] In one possible implementation, the conductive connection structure further includes: Activated particles are located on the surface of the three-dimensional conductive mesh structure; the conductive filler covers the activated particles.

[0007] In one possible implementation, the three-dimensional conductive mesh structure is composed of at least one nanomaterial.

[0008] One possible implementation, a nanoconductive material, includes: Carbon nanotubes, metal nanowires, MXene, two-dimensional materials that are conductors or semiconductors, graphene, graphene foam, and carbon derived from metal-organic frameworks.

[0009] In one possible implementation, the conductive connection structure further includes: A catalyst anchoring layer is located between the inner wall of the through-hole and the three-dimensional conductive connection structure, the three-dimensional conductive connection structure including the carbon nanotubes.

[0010] One possible implementation is that the carbon nanotubes include multi-walled carbon nanotubes.

[0011] One possible implementation, the catalyst anchoring layer, includes: Silane coupling agents and metal complexes.

[0012] One possible implementation of the three-dimensional conductive mesh structure includes: A conductive transition layer is located on the surface of the three-dimensional conductive mesh structure.

[0013] Secondly, embodiments of the present invention provide a method for manufacturing a substrate, comprising: A substrate is provided, the substrate having a through-hole extending through the substrate; A three-dimensional conductive mesh structure is formed within the through-hole; The three-dimensional conductive mesh structure is electroplated to fill the through holes with conductive filler; wherein the conductive filler fills the gaps in the three-dimensional conductive mesh structure within the through holes, and the conductive connection structure includes the three-dimensional conductive mesh structure and the conductive filler.

[0014] One possible implementation involves forming a three-dimensional conductive mesh structure within the through-hole, comprising: A catalyst anchoring layer is formed on the inner wall surface of the through hole in the substrate. The substrate having the catalyst anchoring layer is placed in a plasma reaction chamber, and acetylene, hydrogen and ammonia are introduced into the reaction chamber, so that carbon nanotubes grow from the inner wall of the through hole to the center of the through hole, thus obtaining the three-dimensional conductive network structure.

[0015] One possible implementation further includes, before forming a catalyst anchoring layer on the inner wall surface of the through-hole in the substrate, the following: The inner wall of the through hole is activated using oxygen plasma.

[0016] One possible implementation involves forming a three-dimensional conductive mesh structure within the through-hole, comprising: A foam conductive block with a three-dimensional network structure is formed by using a dispersion containing at least one nano-conductive material and a pore-forming agent. The conductive foam block is ground or cut into micron-sized particles and mixed with a preset solution to form a slurry. The slurry is dropped onto the surface of the substrate and placed in a vacuum chamber, so that the slurry fills the through-hole; The solution is removed to obtain a three-dimensional conductive mesh structure formed by the bonding of at least one nano-conductive material.

[0017] One possible implementation further includes electroplating the three-dimensional conductive mesh structure before filling the through-holes with conductive filler, and then: The three-dimensional conductive network structure is sensitized and activated to attach palladium nanoparticles to the surface of the three-dimensional conductive network structure. The three-dimensional conductive network structure with palladium nanoparticles attached is placed together with the substrate in a conductive transition layer solution to form a transition layer on the surface of the three-dimensional conductive network structure and the palladium nanoparticles.

[0018] One possible implementation involves electroplating the three-dimensional conductive mesh structure to fill the through-holes with a conductive filler, including: A three-dimensional conductive mesh structure having the conductive transition layer and the substrate are placed in an electroplating solution, so that the conductive filler material in the electroplating solution grows from the surface of the conductive transition layer until it protrudes outside the through hole.

[0019] One possible implementation involves placing a three-dimensional conductive mesh structure having the conductive transition layer and the substrate in an electroplating solution, allowing the conductive filler material in the electroplating solution to grow from the surface of the conductive transition layer until it protrudes beyond the via, further comprising: The conductive connection structure metal is annealed. Remove the portion of the conductive connection structure that protrudes from the through hole. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the through-hole metallization process in related technologies. Figure 2 This is a schematic diagram of the structure of a substrate provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of another substrate structure provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of another substrate structure provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of another substrate structure provided in an embodiment of the present invention; Figure 6 A method for manufacturing a substrate provided in an embodiment of the present invention; Figure 7This is a schematic diagram of forming a three-dimensional conductive mesh structure according to an embodiment of the present invention.

[0021] Explanation of reference numerals in the attached figures: 1-Substrate, 2-Conductive connection structure, 21-Seed layer, 22-Copper plating, H-Through hole, 23-Three-dimensional conductive mesh structure, 24-Conductive filler, 25-Activated particles, 26-Catalyst anchoring layer, 27-Conductive transition layer. Detailed Implementation

[0022] This invention provides a substrate and a method for manufacturing the same, in order to solve the aforementioned technical problems existing in the prior art.

[0023] It should be understood that the specific structural and functional details disclosed in the embodiments of the present invention are merely representative and are intended to describe exemplary embodiments of this application. However, this application can be implemented in many alternative or combined forms and should not be construed as being limited solely to the embodiments set forth herein.

[0024] In the description of this application, it should be understood that the terms "center," "lateral," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more. Additionally, the term "comprising" and any variations thereof are intended to cover non-exclusive inclusion.

[0025] This document describes exemplary embodiments with reference to sectional views and / or plan views, which are idealized exemplary drawings.

[0026] In the accompanying drawings, the thickness of layers and regions has been enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to factors such as manufacturing techniques and / or tolerances. Consequently, exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include shape deviations caused, for example, by manufacturing processes. For instance, etched areas shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of areas of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0027] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the figures denote the same or similar structures, and therefore repeated descriptions of them will be omitted. Terms describing position and direction in the present invention are illustrative based on the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of the present invention. The accompanying drawings of the present invention are for illustrative purposes only and do not represent actual proportions.

[0028] It should be noted that specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below. The following description is a preferred embodiment for carrying out the present application; however, the description is for the purpose of illustrating the general principles of the application and is not intended to limit the scope of the application. The scope of protection of this application shall be determined by the appended claims.

[0029] Please refer to Figure 1 This is a flowchart of the through-hole metallization process in related technologies.

[0030] S10. A through-hole H is formed on the substrate 1 using TGV technology; S11. A seed layer 21 is formed on the surface of the through hole H; The seed layer 21 can be formed by physical vapor deposition or chemical deposition; however, when the seed layer 21 is formed by physical vapor deposition, there is uneven coverage of the seed layer 21 in the via H, especially in via H with a high aspect ratio (>5:1).

[0031] S12-S14, electroplating is performed on the seed layer 21, so that the copper plating 22 grows along the surface of the seed layer 21 until the through hole H is filled, thus obtaining the conductive connection structure 2.

[0032] S12 is a schematic diagram of electroplating the seed layer 21 for a short period of time, S13 is a schematic diagram of electroplating the seed layer 21 for a longer period of time, and S14 is a schematic diagram of the seed layer 21 after electroplating is completed.

[0033] Because the seed layer 21 formed by physical vapor deposition has uneven coverage in the via H with a high aspect ratio (>5:1), the seed layer 21 at the bottom of the via H is weak or discontinuous, which leads to an unbalanced current distribution during subsequent electroplating, easily forming voids in the hole. In addition, the adhesion between the electroplated film and the glass is poor, and it is prone to failure under thermal stress. On the other hand, the seed layer 21 formed by chemical plating is complex, faces great environmental pressure, and has high resistivity and weak adhesion, making it difficult to guarantee the uniformity and reliability of filling deep holes.

[0034] To address the aforementioned problems, embodiments of the present invention provide a substrate and a method for manufacturing the same, which will be described in detail below with reference to the accompanying drawings.

[0035] Please refer to Figure 2 This is a schematic diagram of a substrate provided in an embodiment of the present invention. The substrate includes: Substrate 1, substrate 1 having a through hole H penetrating substrate 1; Conductive connection structure 2 is filled inside the through hole H; The conductive connection structure 2 includes a three-dimensional conductive mesh structure 23 and a conductive filler 24; the three-dimensional conductive mesh structure 23 is distributed in the through hole H, and the conductive filler 24 fills the gaps in the three-dimensional conductive mesh structure 23 in the through hole H.

[0036] In some embodiments, the substrate 1 includes: Glass substrate, ceramic substrate, quartz substrate, polymer substrate. For example, substrate 1 can be a wafer made of glass substrate.

[0037] In some embodiments, the aspect ratio of the via H is greater than 5:1. For example, the aspect ratio of the via H can be greater than 20:1. By having the aspect ratio of the via H greater than 5:1, vias H with a high aspect ratio can be formed in the substrate 1, thereby enabling the fabrication of high-performance passive devices by utilizing the characteristics of the substrate 1 and the high aspect ratio vias H when the substrate 1 is a glass substrate, ceramic substrate, or quartz substrate.

[0038] In some embodiments, the three-dimensional conductive mesh structure 23 is composed of at least one nano-conductive material, which provides a much stronger active interface than the traditional seed layer 21 composed of a single thin film. This significantly increases the number of electroplating nucleation sites, effectively reduces local current density, significantly improves the initial shrinkage rate of electroplating filling, and promotes void-free filling of the through-hole H from the bottom up. Furthermore, the three-dimensional conductive mesh structure 23 can be composed of multiple nano-conductive materials, allowing for the combination of materials of different dimensions. This synergistically improves the conductivity, mechanical interlocking, and thermal conductivity of the three-dimensional conductive mesh structure 23, resulting in a conductive connection structure 2 with lower resistance, higher reliability, and better thermal management capabilities.

[0039] In other embodiments, the nanoconductive material includes: Carbon nanotubes, metal nanowires, MXene, two-dimensional materials that are conductors or semiconductors, graphene, graphene foam, and carbon derived from metal-organic frameworks.

[0040] For example, the three-dimensional conductive network structure 23 can be composed of any one of carbon nanotubes, metal nanowires, MXene, two-dimensional conductive or semiconductor materials, graphene, graphene foam, or metal-organic framework-derived carbon. It can also be composed of carbon nanotubes and graphene, or metal nanowires and two-dimensional conductive or semiconductor materials. Of course, it can also be other combinations, which are not limited here.

[0041] In some embodiments, the metal nanowires include one-dimensional metal nanomaterials such as copper nanowires and silver nanowires.

[0042] In the embodiments provided by the present invention, by making the three-dimensional conductive mesh structure 23 composed of carbon nanotubes and graphene, the connectivity and mechanical strength of the three-dimensional conductive mesh structure 23 can be enhanced.

[0043] In some embodiments, the conductive filler 24 can be a conductive material with good conductivity, such as copper, silver, or gold, which can reduce the resistance of the conductive connection structure 2.

[0044] In the embodiments provided by the present invention, the conductive connection structure 2 filled in the via H of the substrate includes a three-dimensional conductive mesh structure 23 and a conductive filler 24; the three-dimensional conductive mesh structure 23 is distributed in the via H, and the conductive filler 24 fills the gaps in the three-dimensional conductive mesh structure 23 in the via H. The three-dimensional conductive mesh structure 23 can provide uniformly distributed chemical electroplating initiation sites, and combined with pulse electroplating, the conductive filler 24 is synergistically filled from top to bottom, so that the conductive connection structure 2 has lower resistance, higher reliability and two-row thermal management capability; and the nanoscale fibers or sheets of the three-dimensional conductive mesh structure 23 itself will entwine, interweave and overlap to form a physical interpenetrating structure, so that the three-dimensional conductive mesh structure 23 as a whole and the interior of the via H, as well as the units inside the three-dimensional conductive mesh structure 23, are not only bound by chemical bonds or van der Waals forces, but also by geometric interlocking, generating an additional mechanical anchoring effect, thereby significantly enhancing the integrity and anti-peeling ability of the three-dimensional conductive mesh structure 23. By filling the voids in the three-dimensional conductive network structure with conductive filler 24, a strong bonding interface is expected to be formed between the three-dimensional conductive mesh structure 23 and the conductive filler 24, thereby significantly enhancing the adhesion and thermomechanical reliability of the conductive connection structure 2. Furthermore, the three-dimensional conductive mesh structure 23 provides a large electrochemically active surface area, which can promote the uniform distribution of electroplating current and the rapid deposition of metal ions, thus achieving more efficient and void-free filling of the conductive filler 24.

[0045] Please refer to Figure 3 This is a schematic diagram of another substrate structure provided in an embodiment of the present invention.

[0046] The conductive connection structure 2 also includes: Activated particles 25 are located on the surface of the three-dimensional conductive mesh structure 23; conductive filler 24 covers the activated particles 25.

[0047] Activated particle 25 can be palladium nanoparticles.

[0048] In the embodiments provided by the present invention, by setting activation particles 25 on the surface of the three-dimensional conductive mesh structure 23, the surface activity of the three-dimensional mesh structure can be improved, so that a dense and continuous conductive filler 24 film can be pre-formed on the surface of the three-dimensional conductive mesh structure 23, which facilitates the transformation of the three-dimensional conductive mesh structure 23 into a three-dimensional electrode with a fully metallized surface and excellent conductivity, and facilitates the implementation of subsequent chemical electroplating processes.

[0049] Please refer to Figure 4 This is a schematic diagram of another substrate structure provided in an embodiment of the present invention. The conductive connection structure 2 further includes: The catalyst anchoring layer 26 is located between the inner wall of the through hole H and the three-dimensional conductive connection structure 2, which includes carbon nanotubes.

[0050] In some embodiments, the carbon nanotubes can be multi-walled carbon nanotubes, which facilitates the direct growth of a three-dimensional conductive network structure 23 composed of multi-walled carbon nanotubes within the through-hole H, reducing the complexity of the process.

[0051] In some embodiments, the outer diameter of the multi-walled carbon nanotube ranges from 20 nm to 40 nm, and the length of the multi-walled carbon nanotube ranges from 10 μm to 20 μm.

[0052] In some embodiments, the chemical anchoring layer includes: Silane coupling agents and metal complexes.

[0053] Silane coupling agents can be 3-glycidyl etheroxypropyltrimethoxysilane (abbreviated as GPTMS), 3-mercaptopropyltrimethoxysilane (abbreviated as MPTMS), etc., and the metal complex can be Co²⁻. + Ni² + wait.

[0054] By forming a catalyst anchoring layer 26 on the inner wall surface of the through hole H, it is easier to grow carbon nanotubes on the inner wall surface of the through hole H.

[0055] Please refer to Figure 5 This is a schematic diagram of another substrate structure provided in an embodiment of the present invention. The conductive connection structure 2 further includes: The conductive transition layer 27 is located on the surface of the three-dimensional conductive mesh structure 23, which is a non-metallic material.

[0056] By providing a conductive transition layer 27 on the surface of the non-metallic three-dimensional conductive mesh structure 23, it is convenient to use the unit mesh conductive structure together with the conductive transition layer 27 as the anode for electroplating of the electroplating filler 24.

[0057] In some embodiments, signal lines, passive devices, active devices, etc., can be fabricated on the surface of the substrate 1 having the above-described connection structure.

[0058] Based on the same inventive concept, embodiments of the present invention provide a method for manufacturing a substrate, please refer to... Figure 6 A method for manufacturing a substrate provided in an embodiment of the present invention includes: S21. A substrate 1 is provided, the substrate 1 having a through hole H through the substrate 1; For example, a 300 μm thick borosilicate glass wafer can be provided as substrate 1, and a through-hole H can be fabricated using a combination of laser drilling and wet etching. The through-hole H is cylindrical, with a diameter of 30 μm, a depth of 300 μm, and an aspect ratio of 10:1.

[0059] S22. A three-dimensional conductive mesh structure is formed in the through hole H; 23. Please refer to Figure 7 This is a schematic diagram of a three-dimensional conductive mesh structure provided in an embodiment of the present invention. A three-dimensional conductive mesh structure 23 is formed within the through-hole H, comprising: S221. A catalyst anchoring layer 26 is formed on the inner wall surface of the through hole H in the substrate 1. In some embodiments, before forming the catalyst anchoring layer 26 on the inner wall surface of the through hole H in the substrate 1, the method further includes: The inner wall of the through hole H is activated by oxygen plasma, which can better form the catalyst anchoring layer 26 on the inner wall surface of the through hole H on the substrate 1.

[0060] A catalyst anchoring layer 26 is formed on the inner wall surface of the through hole H of the substrate 1, which allows the catalyst anchoring layer 26 to simultaneously perform the dual functions of interface bonding and catalyst precursor, so that the conductive filling layer (such as chemical copper plating 22) grows in situ from the surface of the three-dimensional conductive network structure 23, so that there is no independent interface between the two.

[0061] S222. The substrate 1 with the catalyst anchoring layer 26 is placed in the plasma reaction chamber, and acetylene, hydrogen and ammonia are introduced into the reaction chamber, so that carbon nanotubes grow from the inner wall of the through hole H to the center of the through hole H, and a three-dimensional conductive network structure 23 is obtained.

[0062] For example, substrate 1 in S21 can be immersed in an ethanol solution containing 3-aminopropyltriethoxysilane-ferric chloride complex (APTES-FeCl) and reacted at 80°C for 3 hours. The silane groups form Si-O-Si covalent bonds with the hydroxyl groups on the glass surface, and Fe³⁺… + The complex end serves as a catalyst precursor, thereby forming a catalyst anchoring layer 26 on the inner wall surface of the through-hole H of the substrate 1. The substrate 1 with the catalyst anchoring layer 26 is then subjected to a reduction treatment at 300°C for 30 minutes in a hydrogen / argon mixed atmosphere, resulting in Fe³⁺. + It is reduced to Fe nanoparticle catalyst with a particle size of approximately 5 nm.

[0063] The substrate 1 containing the iron (Fe) nanoparticle catalyst was transferred to a plasma-enhanced chemical vapor deposition (PECVD) reaction chamber and heated to 400°C. Acetylene (50 sccm), hydrogen (200 sccm), and ammonia (150 sccm) were introduced, and the plasma was turned on (power 100 W) for 30 minutes. Under the action of the iron nanoparticle catalyst, carbon nanotubes grew from the inner wall of the through-hole H along the center of the through-hole H, forming a multi-walled carbon nanotube as a three-dimensional conductive network structure 23. The outer diameter of the carbon nanotubes was approximately 20-40 nm, and the length was approximately 10-20 μm.

[0064] In other embodiments, a three-dimensional conductive mesh structure is formed within the via, including: A foam conductive block with a three-dimensional network structure is formed by using a dispersion containing at least one nano-conductive material and a pore-forming agent. The conductive foam block is ground or cut into micron-sized particles and mixed with a pre-set solution to form a slurry. The slurry is dropped onto the surface of the substrate and placed in a vacuum chamber, so that the slurry fills the through-holes; The solution is removed to obtain a three-dimensional conductive mesh structure formed by the bonding of at least one nano-conductive material.

[0065] For example, taking a dispersion containing graphene as an example, an aqueous dispersion of graphene oxide (GO) with a concentration of 2 mg / mL was prepared. Using the above graphene oxide dispersion as a precursor, a certain mass of naphthalene was added as a pore-forming agent, and sodium ascorbate was added as a reducing agent. The solution was transferred to a high-pressure reactor lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at 200°C for 12 hours. During this process, the graphene oxide was partially reduced and self-assembled into a gel, while the pore-forming agent sublimated to generate gas, forming a porous structure. After the reaction, the resulting graphene hydrogel was freeze-dried to finally obtain a graphene foam block (i.e., a foam conductor block with a three-dimensional network structure) with a three-dimensional continuous network structure and extremely low density (below 10 mg / cm³). This material has abundant pores and an extremely high specific surface area.

[0066] The prepared graphene foam blocks are ground or sheared into micron-sized particles and redispersed in a suitable pre-set solution (such as N-methylpyrrolidone, NMP) to form a uniform slurry. The slurry is dropped onto the surface of a substrate 1 (glass substrate) with through-holes H. The entire system is placed in a vacuum chamber, and a low pressure (e.g., 10 Pa) is slowly evacuated and maintained for several minutes. The pressure difference drives the slurry to completely penetrate and fill all through-holes H. The vacuum is released, and the substrate is allowed to stand at atmospheric pressure to allow the slurry to remain stable within the pores. The substrate 1 containing the slurry in the through-holes H is subjected to programmed temperature drying and heat treatment (e.g., heated to 300-400°C under nitrogen protection) to completely remove the pre-set solution and allow the graphene sheets to interlock within the through-holes through π-π conjugation and van der Waals forces, forming a stable, three-dimensional interconnected graphene foam network framework (i.e., a three-dimensional conductive mesh structure 23) that completely fills the through-holes.

[0067] The dispersion can also include other nano-conductive materials or multiple nano-conductive materials, such as a dispersion of carbon nanotubes and graphene supported in a certain proportion. This allows one-dimensional carbon nanotubes to bridge two-dimensional graphene, thereby enhancing the connectivity and mechanical strength of the three-dimensional conductive network structure.

[0068] In addition to the vacuum injection and freeze-drying processes mentioned above, the three-dimensional conductive mesh structure can also be formed by electrophoretic deposition, spin coating, spraying, centrifugal filling, and external field (electric field, magnetic field) assisted assembly, etc., without any restrictions.

[0069] S23. Electroplating is performed on the three-dimensional conductive mesh structure 23 to fill the through hole H with conductive filler 24; wherein, the conductive filler 24 fills the gaps in the three-dimensional conductive mesh structure 23 in the through hole H, and the conductive connection structure 2 includes the three-dimensional conductive mesh structure 23 and the conductive filler 24.

[0070] In some embodiments, before electroplating the three-dimensional conductive mesh structure to fill the through-holes with conductive filler, the method further includes: A three-dimensional conductive network structure is sensitized and activated to attach palladium nanoparticles to its surface. The three-dimensional conductive network structure with attached palladium nanoparticles is then placed together with a substrate in a conductive transition layer solution to form a conductive transition layer on the surface of the three-dimensional conductive network structure and the palladium nanoparticles.

[0071] For example, the three-dimensional conductive network structure is the aforementioned multi-walled carbon nanotubes. First, a substrate with multi-walled carbon nanotubes can be sequentially immersed in a dilute hydrochloric acid solution of stannous chloride (sensitization solution) and a dilute hydrochloric acid solution of palladium chloride (activation solution) for 5 minutes each, allowing activated particles (such as palladium nanoparticles) to adsorb onto the carbon nanotube surface. Then, it is thoroughly rinsed with deionized water. Next, the substrate 1 with multi-walled carbon nanotubes is immersed in a commercially available alkaline electroless copper plating solution (i.e., a conductive transition solution), maintaining the solution temperature at 40°C. After reacting for approximately 15-20 minutes, a dense, continuous metallic copper film (i.e., a conductive transition layer) with a thickness of approximately 100-200 nm can be uniformly deposited on the surface of the multi-walled carbon nanotubes. This step transforms the three-dimensional carbon nanotube network into a three-dimensional composite electrode with a fully metallized surface and excellent bulk conductivity. Using this three-dimensional composite electrode as the cathode and high-purity phosphorus copper spheres as the anode, pulse electroplating with copper is performed. The electroplating solution used is an acidic copper sulfate solution, mainly composed of copper sulfate, sulfuric acid, and a small amount of organic additives (leveling agents, inhibitors, and accelerators). A pulsed current mode is employed, and the electroplating process is carried out at room temperature with gentle mechanical stirring. Due to the uniform current distribution and large active surface area provided by the three-dimensional composite electrode, copper deposition begins simultaneously and uniformly from the bottom and sidewalls of the multi-walled carbon nanotubes within the vias. The synergistic effect of palladium nanoparticles helps achieve a "superfilling" effect, where the deposition rate inside the via is slightly higher than that at the via opening, effectively preventing void formation. Electroplating is stopped when the via is completely filled with dense copper and a moderate protrusion forms at the opening, ensuring complete filling of the voids within the via and the three-dimensional conductive network structure.

[0072] If the three-dimensional conductive network structure is a metal nanowire, such as a copper nanowire, then there is no need to form a conductive transition layer.

[0073] For example, a three-dimensional conductive mesh structure, such as the aforementioned graphene foam network framework, can be sensitized by immersing a substrate with the through-holes filled with the graphene foam network framework in an acidic stannous chloride (SnCl) solution for a period of time, causing the graphene surface to adsorb reducing Sn²⁺. + Then, after cleaning, the substrate is immersed in a palladium chloride solution, Sn² + Pd² + The process reduces the material to highly catalytically active palladium nanoparticles, which then firmly adhere to the graphene surface. Subsequently, the substrate with the palladium nanoparticles attached to the graphene surface in the through-hole H can be immersed in an alkaline electroless copper plating solution (typically composed of copper sulfate providing Cu²⁺). +In a system where disodium EDTA is used as a complexing agent and formaldehyde as a reducing agent, with the pH maintained at 12-13, copper ions are reduced and preferentially deposited around the palladium nanoparticles under the catalysis of palladium nanoparticles. The newly deposited copper itself also has catalytic activity, allowing the copper layer to grow continuously. Ultimately, a uniform, dense, and well-bonded metallic copper film (i.e., a conductive transition layer) is formed on the entire surface of the graphene foam network skeleton, thus transforming the graphene foam network skeleton into a uniformly covered three-dimensional composite electrode. The three-dimensional composite electrode is used as the cathode and electroplated using a conventional acidic copper sulfate electroplating solution. Due to the excellent conductivity and huge surface area provided by the three-dimensional composite electrode, the current distribution is uniform, enabling bottom-up, void-free super-filling. Finally, pure copper is used to completely fill the voids in the through-holes and the three-dimensional conductive network structure.

[0074] In addition to electroless plating to form a conductive transition layer (such as a copper layer) on the surface of a three-dimensional conductive network structure, low-temperature methods such as atomic layer deposition, molecular layer deposition, and sputtering (for via openings) can also be used to deposit metals or conductive oxides as conductive transition layers.

[0075] By sensitizing and activating a three-dimensional conductive network structure, palladium nanoparticles are attached to its surface. The three-dimensional conductive network structure with attached palladium nanoparticles is then placed together with a substrate in a conductive transition layer solution. A conductive transition layer is formed on the surface of the three-dimensional conductive network structure and the palladium nanoparticles, which can reduce the contact resistance between different units within the three-dimensional conductive network structure and form a continuous conductive transition layer on the surface of the three-dimensional conductive network structure that can form a strong metallurgical bond with subsequent copper electroplating, thus implementing an electroless pretreatment.

[0076] In some embodiments, electroplating the three-dimensional conductive mesh structure to fill the through-holes with a conductive filler includes: A three-dimensional conductive mesh structure with a conductive transition layer and a substrate are placed in an electroplating solution, allowing the conductive filler material in the electroplating solution to grow from the surface of the conductive transition layer until it protrudes out of the through-hole.

[0077] In some embodiments, the three-dimensional conductive mesh structure having a conductive transition layer and the substrate are placed in an electroplating solution, and the conductive filler material in the electroplating solution is grown from the surface of the conductive transition layer until it protrudes outside the via, further comprising: Annealing treatment of conductive connection structure metals; Remove the portion of the conductive connection structure that protrudes from the through hole.

[0078] For example, annealing at 200°C for 30 minutes in a nitrogen / hydrogen mixed atmosphere can eliminate electroplating stress, refine grains, reduce resistivity, and further enhance the bonding strength between copper and the underlying metallization layer. Subsequently, chemical mechanical polishing / planarization (CMP) is used to remove excess copper protrusions at the orifices, planarizing the substrate surface to meet the requirements of subsequent photolithography and wiring processes.

[0079] In the embodiments provided by this invention, a three-dimensional conductive mesh structure is formed within a through-hole of a substrate; the three-dimensional conductive mesh structure is electroplated to fill the through-hole with a conductive filler; wherein the conductive filler fills the voids in the three-dimensional conductive mesh structure within the through-hole, and the conductive connection structure includes the three-dimensional conductive mesh structure and the conductive filler. Through-holes with high aspect ratios can be filled using a solution / precursor method, overcoming the limitations of physical properties, resulting in a three-dimensional conductive mesh structure with low resistance, high reliability, and good thermal management capabilities, achieving void-free through-hole filling.

[0080] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0081] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A substrate, characterized in that, include: A substrate having a through-hole extending through the substrate; A conductive connection structure is filled within the through hole; The conductive connection structure includes a three-dimensional conductive mesh structure and a conductive filler; The three-dimensional conductive mesh structure is distributed within the through holes, and the conductive filler fills the gaps in the three-dimensional conductive mesh structure within the through holes.

2. The substrate as described in claim 1, characterized in that, The conductive connection structure further includes: Activated particles are located on the surface of the three-dimensional conductive mesh structure; the conductive filler covers the activated particles.

3. The substrate as described in claim 1 or 2, characterized in that, The three-dimensional conductive mesh structure is composed of at least one nano-conductive material.

4. The substrate as described in claim 3, characterized in that, Nanomaterials that conduct electricity, including: Carbon nanotubes, metal nanowires, MXene, two-dimensional materials that are conductors or semiconductors, graphene, graphene foam, and carbon derived from metal-organic frameworks.

5. The substrate as described in claim 4, characterized in that, The conductive connection structure further includes: A catalyst anchoring layer is located between the inner wall of the through-hole and the three-dimensional conductive connection structure, the three-dimensional conductive connection structure including the carbon nanotubes.

6. The substrate as claimed in claim 5, characterized in that, The carbon nanotubes include multi-walled carbon nanotubes.

7. The substrate as claimed in claim 5, characterized in that, The catalyst anchoring layer includes: Silane coupling agents and metal complexes.

8. The substrate as described in claim 1 or 2, characterized in that, The three-dimensional conductive mesh structure includes: A conductive transition layer is located on the surface of the three-dimensional conductive mesh structure.

9. A method for manufacturing a substrate, characterized in that, include: A substrate is provided, the substrate having a through-hole extending through the substrate; A three-dimensional conductive mesh structure is formed within the through-hole; The three-dimensional conductive mesh structure is electroplated to fill the through holes with conductive filler; wherein the conductive filler fills the gaps in the three-dimensional conductive mesh structure within the through holes, and the conductive connection structure includes the three-dimensional conductive mesh structure and the conductive filler.

10. The manufacturing method as described in claim 9, characterized in that, A three-dimensional conductive mesh structure is formed within the through-hole, including: A catalyst anchoring layer is formed on the inner wall surface of the through hole in the substrate. The substrate having the catalyst anchoring layer is placed in a plasma reaction chamber, and acetylene, hydrogen and ammonia are introduced into the reaction chamber, so that carbon nanotubes grow from the inner wall of the through hole to the center of the through hole, thus obtaining the three-dimensional conductive network structure.

11. The manufacturing method as described in claim 10, characterized in that, Before forming the catalyst anchoring layer on the inner wall surface of the through-hole of the substrate, the method further includes: The inner wall of the through hole is activated using oxygen plasma.

12. The manufacturing method as described in claim 9, characterized in that, A three-dimensional conductive mesh structure is formed within the through-hole, including: A foam conductive block with a three-dimensional network structure is formed by using a dispersion containing at least one nano-conductive material and a pore-forming agent. The conductive foam block is ground or cut into micron-sized particles and mixed with a preset solution to form a slurry. The slurry is dropped onto the surface of the substrate and placed in a vacuum chamber, so that the slurry fills the through-hole; The solution is removed to obtain a three-dimensional conductive mesh structure formed by the bonding of at least one nano-conductive material.

13. The manufacturing method according to any one of claims 9-12, characterized in that, Before electroplating the three-dimensional conductive mesh structure to fill the through holes with conductive filler, the process further includes: The three-dimensional conductive network structure is sensitized and activated to attach palladium nanoparticles to the surface of the three-dimensional conductive network structure. The three-dimensional conductive network structure with palladium nanoparticles attached is placed together with the substrate in a conductive transition layer solution to form a transition layer on the surface of the three-dimensional conductive network structure and the palladium nanoparticles.

14. The manufacturing method as described in claim 13, characterized in that, Electroplating the three-dimensional conductive mesh structure to fill the through-holes with a conductive filler includes: A three-dimensional conductive mesh structure having the conductive transition layer and the substrate are placed in an electroplating solution, so that the conductive filler material in the electroplating solution grows from the surface of the conductive transition layer until it protrudes outside the through hole.

15. The manufacturing method as described in claim 14, characterized in that, The three-dimensional conductive mesh structure having the conductive transition layer and the substrate are placed in an electroplating solution, and the conductive filler material in the electroplating solution is grown from the surface of the conductive transition layer until it protrudes outside the through-hole, further comprising: The conductive connection structure metal is annealed. Remove the portion of the conductive connection structure that protrudes from the through hole.

Images