Glass sheet and method of making the same, microelectronic device

Abstract

A glass plate and its preparation method, as well as a microelectronic device, are disclosed. The glass plate preparation method includes: using titanium metal alkoxide as a titanium source and forming a titanium dioxide layer on the surface of a glass substrate through a preset process. This helps to prepare a titanium dioxide buffer layer on the glass substrate that is pure in composition, dense in structure, uniform in thickness, and has strong bonding. This allows the glass plate of this application to buffer CTE mismatch by utilizing the inherent properties of titanium dioxide material, and also to construct a continuous stress transmission path through the good bonding between the glass substrate and the titanium dioxide layer and the dense and uniform structure of the titanium dioxide layer, thereby promoting stress transmission and synergistically reducing the risk of interfacial microcracks and solving the reliability defects caused by the mismatch of thermal expansion coefficients between glass and metal.

Description

Technical Field

[0001] This application relates to the field of microelectronic packaging technology, specifically to a glass plate and its preparation method, and microelectronic devices. Background Technology

[0002] With the development of integrated circuits towards higher density and higher performance, advanced packaging technologies such as 2.5D / 3D packaging are widely used. Glass substrates, due to their excellent electrical properties (such as low dielectric constant and low loss), good high-frequency characteristics, adjustable coefficient of thermal expansion, and high flatness, have become one of the ideal materials for high-end packaging interposers or core boards. Forming through-glass vias (TGVs) in glass substrates is a key technology for achieving vertical interconnects, improving packaging density, and enhancing signal transmission efficiency.

[0003] Currently, the manufacturing process for TGVs and their circuits typically involves: laser drilling to form TGVs on a glass substrate, followed by physical vapor deposition (PVD) to deposit a thin metal layer (such as copper) on the glass substrate surface and the TGV hole walls as a seed layer, and finally electroplating to fill the TGVs and form surface copper circuitry. However, in actual product reliability testing (such as thermal shock testing), this process path suffers from limitations due to the thermal expansion coefficient of the glass material (such as Schott BF33 glass, which has a coefficient of thermal expansion of approximately 3-4 × 10⁻⁴). -6 (°C) and the commonly used conductive metal copper (thermal expansion coefficient is approximately 16 × 10⁻⁶). -6 There is a significant mismatch in the coefficient of thermal expansion (CTE) between the copper trace and the glass substrate. During subsequent processing or temperature cycling in the product's operating environment, the difference in the degree of thermal expansion and contraction between the two will lead to a large thermal stress at the interface. This can easily cause microcracks or even macrocracks on the brittle glass substrate, especially in stress concentration areas such as the edges of TGV holes. This seriously affects the mechanical integrity and long-term reliability of the structure. It may also lead to a decrease in the interfacial bonding force between the copper trace and the glass substrate. Under repeated stress, interface delamination, copper layer wrinkling or even peeling may occur, resulting in electrical connection failure. Summary of the Invention

[0004] In view of this, this application provides a glass plate and its preparation method, as well as a microelectronic device, to solve the above-mentioned technical problems.

[0005] To achieve the above objectives, in a first aspect, this application provides a method for preparing a glass plate, comprising: providing a precursor sol, the precursor sol comprising a titanium source and an organic solvent, the titanium source comprising a titanium metal alkoxide; atomizing the precursor sol to obtain droplets, and contacting the droplets with at least one surface of a glass substrate, the surface temperature being 150 °C to 500 °C, thereby forming a titanium dioxide layer on the surface through thermal decomposition of the titanium source; and forming a metallic conductive layer on the titanium dioxide layer to obtain a glass plate.

[0006] Based on the first aspect, in some possible implementations, the diameter of the droplets is between 10 μm and 100 μm.

[0007] Based on the first aspect, in some possible implementations, providing the precursor sol includes the following steps: mixing a titanium source and a solvent to obtain a precursor sol, wherein the concentration of the titanium metal alkoxide in the precursor sol is from 0.1 mol / L to 1 mol / L.

[0008] Based on the first aspect, in some possible implementations, the precursor sol also includes acetylacetone, with a molar ratio of acetylacetone to titanium alkoxide of (2~20):1.

[0009] Based on the first aspect, in some possible implementations, before the droplets come into contact with at least one surface of the glass substrate, the preparation method further includes: forming hydrophilic groups on the surface of the glass substrate by a plasma activation process.

[0010] Based on the first aspect, in some possible implementations, the preparation method further includes: heat-treating the glass substrate on which the titanium dioxide layer is formed, wherein the heat treatment temperature is 400°C to 500°C and the time is 0.5 h to 1 h.

[0011] Secondly, this application provides a glass plate prepared by the above-described preparation method, comprising: a glass substrate, a titanium dioxide layer on at least one surface of the glass substrate, and a metal conductive layer on the titanium dioxide layer.

[0012] Based on the first aspect, in some possible implementations, the glass substrate has at least one through hole, and the titanium dioxide layer also covers the sidewalls of the through hole.

[0013] Based on the first aspect, in some possible implementations, the thickness of the titanium dioxide layer is 500 nm to 700 nm.

[0014] Thirdly, this application provides a microelectronic device including the aforementioned glass plate.

[0015] In the glass plate preparation method of this application, titanium metal alkoxide is used as the titanium source and a titanium dioxide layer is formed on the surface of the glass substrate through a preset process. This helps to prepare a titanium dioxide buffer layer with pure composition, dense structure, uniform thickness and strong bonding on the glass substrate. This allows the glass plate of this application to buffer CTE mismatch by utilizing the inherent properties of titanium dioxide material, and also to build a continuous stress transmission path through the good bonding between the glass substrate and the titanium dioxide layer and the dense and uniform structure of the titanium dioxide layer, thereby promoting stress transmission and synergistically reducing the risk of interfacial microcracks and solving the reliability defects caused by the mismatch of thermal expansion coefficients between glass and metal.

[0016] In the glass plate of this application, a pure titanium dioxide layer is provided between the glass substrate and the metal conductive layer to construct a gradient thermomechanical interface. This helps to build a stable and reliable stress buffer transition zone between the glass and metal interfaces, thereby reducing microcracks, interface delamination and decreased bonding strength caused by CTE mismatch, and thus improving the long-term reliability of the glass plate under temperature cycling. Detailed Implementation

[0017] To facilitate understanding of the technical solutions of this application, a more comprehensive description of the technical solutions will be provided below. The technical solutions of this application can be implemented in many different forms and are not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the technical solutions of this application more thorough and comprehensive.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0019] In related technologies, to address the CTE mismatch between materials, an intermediate or buffer layer is typically introduced between the two materials. For example, some solutions propose using organic dielectric materials as buffer layers, which have a low modulus and facilitate stress release. However, organic materials generally lack sufficient heat resistance and long-term stability, and their adhesion to glass and metals may be unsatisfactory, potentially introducing new reliability risks in high-temperature processes or harsh environments. Alternatively, other technologies employ other inorganic materials as transition layers. However, selecting a suitable material system and employing a fabrication process capable of uniformly covering complex three-dimensional surfaces, including the walls of TGV pores with large depth-to-width ratios, while ensuring good adhesion between the buffer layer and both upper and lower layers and effectively mitigating thermal stress, remains a pressing technical challenge in this field.

[0020] Based on this, one embodiment of this application provides a method for preparing a glass plate, comprising:

[0021] Step 1: Provide a precursor sol, which contains a titanium source and an organic solvent. The titanium source includes a titanium alkoxide. For example, the titanium alkoxide can be tetrabutyl titanate, isopropyl titanate, or a mixture thereof, and the organic solvent can be ethanol, isopropanol, or a mixture thereof.

[0022] The above steps use titanium metal alkoxide as the titanium source. Titanium metal alkoxide can form a uniform and stable true solution in organic solvents, which meets the stringent requirements of the subsequent spraying process for the stability of the precursor and the uniformity of atomization. At the same time, it can undergo a clear and rapid thermal decomposition reaction under heating conditions to generate high-purity titanium dioxide and release gaseous organic matter, which is beneficial to the subsequent formation of a dense inorganic film layer with few impurities.

[0023] In some embodiments, providing the precursor sol includes the following steps: mixing a titanium source and a solvent to obtain a precursor sol, wherein the concentration of the titanium alkoxide in the precursor sol is from 0.1 mol / L to 1 mol / L. For example, the concentration of the titanium alkoxide in the precursor sol can be 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1 mol / L, or any value within the range of any two of the above values. Controlling the concentration of the titanium alkoxide within the above range helps to balance the chemical reactivity and transport characteristics of the precursor sol. At this concentration, the solution provides sufficient titanium source to accumulate at a reasonable deposition rate and film thickness, reducing the problems of increased solution viscosity, difficulty in atomization, and excessive byproducts during thermal decomposition that may cause loose film or impurity residues when the concentration is high. This is conducive to further improving the deposition efficiency, film purity, and overall compactness of the titanium dioxide layer, and optimizing the formation quality of the buffer layer.

[0024] In some embodiments, the precursor sol further includes acetylacetone, with a molar ratio of acetylacetone to titanium alkoxide of (2~20):1. For example, the molar ratio of acetylacetone to titanium alkoxide can be 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, or any value within the range of any two of the above values. Using acetylacetone as a structural stabilizer for titanium alkoxide and controlling its molar ratio to titanium alkoxide within the above range helps to reduce premature hydrolysis and condensation of titanium alkoxide in solution, thus extending the process window of the precursor sol. Meanwhile, this ratio ensures that the stabilizer can decompose in a timely manner without leaving too much carbon impurity during the spray pyrolysis process, which is conducive to further improving the chemical stability and process repeatability of the precursor sol during atomization and deposition, and ultimately obtaining a more uniform, dense and less defective titanium dioxide buffer layer.

[0025] In some embodiments, the molar ratio of acetylacetone to titanium alkoxide is (5-6):1. For example, the molar ratio of acetylacetone to titanium alkoxide can be 5:1, 5.1:1, 5.2:1, 5.3:1, 5.4:1, 5.5:1, 5.6:1, 5.7:1, 5.8:1, 5.9:1, 6:1, or any value within the range of any two of the above values. Further controlling the molar ratio of acetylacetone to titanium alkoxide within the above range helps to further regulate the thermal decomposition behavior of the titanium source complex, reducing the risk of increased organic residue or insufficient pyrolysis in the film layer when there is a large amount of stabilizer. This is beneficial for further promoting the formation of a titanium dioxide film with fewer impurities and a more dense and uniform structure, improving its insulation and mechanical integrity as a buffer layer, and optimizing the final stress buffering performance.

[0026] In some embodiments, before contacting the droplets with at least one surface of the glass substrate, the preparation method further includes forming hydrophilic groups on the surface of the glass substrate using a plasma activation process. This pretreatment of the glass substrate surface allows the subsequently impacting droplet precursors to spread and adhere better on the substrate, promoting close contact and potential chemical bonding between the interfaces. This, in turn, helps to further enhance the interfacial bonding strength between the titanium dioxide layer and the glass substrate, thereby strengthening the adhesion reliability of the buffer layer under thermal stress from the source.

[0027] In some embodiments, the plasma activation process includes activating a glass substrate in an oxygen atmosphere, wherein the oxygen flow rate is 30 sccm to 60 sccm, the activation power is 50 W to 150 W, and the activation time is 2 min to 10 min, thereby forming hydrophilic groups on the glass surface. For example, the oxygen flow rate can be 30 sccm, 35 sccm, 40 sccm, 45 sccm, 50 sccm, 55 sccm, 60 sccm, or any value within any two of the above values; the activation power can be 50 W, 70 W, 90 W, 110 W, 130 W, 150 W, or any value within any two of the above values; and the activation time can be 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, or any value within any two of the above values. The hydrophilic groups include hydroxyl groups, etc.

[0028] Understandably, the pretreatment of the glass substrate may also include surface cleaning, such as ultrasonic cleaning with ethanol and acetone sequentially at room temperature, with the ultrasonic power controlled at 50 W to 100 W and the frequency at 40 Hz to 60 Hz, and the cleaning time for each cycle being 5 min to 20 min. After cleaning, residual reagents are rinsed with distilled water, and then the substrate is dried to remove surface moisture.

[0029] Step 2: Atomize the precursor sol to obtain droplets, and bring the droplets into contact with at least one surface of the glass substrate. The surface temperature is between 150°C and 500°C, allowing the titanium source to form a titanium dioxide layer on the surface through thermal decomposition. For example, the surface temperature can be 150°C, 180°C, 210°C, 240°C, 270°C, 300°C, 330°C, 360°C, 400°C, 420°C, 450°C, 480°C, 500°C, or any value within a range of any two of the above values. Understandably, the surface can be preheated to the preset temperature by preheating the glass substrate.

[0030] The above steps mainly promote the formation of titanium dioxide layer through an improved spray pyrolysis process. In this process, the precursor sol is atomized into micron-sized droplets and sprayed onto the preheated substrate. After the droplets hit the substrate, the solvent evaporates rapidly. Titanium metal alkoxide molecules undergo instantaneous solid-phase reactions of thermal decomposition and oxidation on the substrate surface, directly generating and depositing titanium dioxide grains. This allows titanium dioxide to be generated in situ and densely stacked, rather than physically attached, which helps to improve the bonding force between the titanium dioxide layer and the glass substrate.

[0031] In some embodiments, the surface temperature is between 400 °C and 500 °C. For example, the surface temperature can be 400 °C, 410 °C, 420 °C, 430 °C, 440 °C, 450 °C, 460 °C, 470 °C, 480 °C, 490 °C, 500 °C, or any value within the range of any two of the above values. Further controlling the surface temperature within the above range helps to provide better energy conditions for the thermal decomposition and oxidation reaction of titanium alkoxide, enabling the precursor to achieve a rapid and sufficient pyrolysis-oxidation reaction, promoting the formation and dense stacking of highly crystalline titanium dioxide microcrystals, while reducing the risk of thermal damage to the glass substrate at higher temperatures or incomplete reaction and loose film at lower temperatures. This is beneficial for further enhancing the crystal quality, density, and adhesion between the formed titanium dioxide layer and the substrate, giving it better long-term thermomechanical stability and stress buffering capacity.

[0032] In some embodiments, the droplet diameter is from 10 μm to 100 μm. For example, the droplet diameter can be 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, or any value within the range of any two of the above values. Controlling the droplet diameter within the micrometer range helps the droplets obtain a suitable kinetic energy to surface area-to-volume ratio when impacting the substrate, thereby facilitating better spreading uniformity, controllable evaporation rate, and sufficient heat exchange. This promotes more uniform decomposition and deposition of the precursor on the substrate surface, reduces sputtering and agglomeration due to larger droplets or rapid drying due to smaller droplets, and further improves the surface smoothness, internal density, and thickness uniformity of the formed titanium dioxide layer, enhancing its mechanical consistency and stress dispersion effect as a buffer layer.

[0033] In some embodiments, the preparation method further includes: heat-treating the glass substrate with the titanium dioxide layer formed thereon at a temperature of 400 °C to 500 °C for a time of 0.5 h to 1 h. For example, the heat treatment temperature can be 400 °C, 410 °C, 420 °C, 430 °C, 440 °C, 450 °C, 460 °C, 470 °C, 480 °C, 490 °C, 500 °C, or any value within the range of any two of the above values. The heat treatment time can be 0.5 h, 0.6 h, 0.7 h, 0.8 h, 0.9 h, 1 h, or any value within the range of any two of the above values. Further heat-treating the glass substrate with the deposited titanium dioxide layer helps to further promote the decomposition or volatilization of residual organic matter within the titanium dioxide layer, thereby promoting further growth and crystal transformation of titanium dioxide grains. Meanwhile, this heat treatment process can further eliminate the internal stress generated during the deposition process, which helps to improve the crystallinity, densification degree and interfacial interdiffusion bonding between the obtained titanium dioxide layer and the glass substrate. This is conducive to further improving the mechanical strength, thermal stability and long-term stress buffering capacity of the titanium dioxide buffer layer, and consolidating its effect in solving the CTE mismatch problem.

[0034] Step 3: Form a conductive metal layer on the titanium dioxide layer to obtain a glass plate. For example, the conductive metal layer may include copper.

[0035] Therefore, in the glass plate preparation method of this application, titanium metal alkoxide is used as the titanium source and a titanium dioxide layer is formed on the surface of the glass substrate through a preset process. This helps to prepare a titanium dioxide buffer layer with pure composition, dense structure, uniform thickness and strong bonding on the glass substrate. This allows the glass plate of this application to buffer CTE mismatch by utilizing the properties of titanium dioxide itself, and also to build a continuous stress transmission path through the good bonding between the glass substrate and the titanium dioxide layer and the dense and uniform structure of the titanium dioxide layer, thereby promoting stress transmission and synergistically reducing the risk of interfacial microcracks and solving the reliability defects caused by the mismatch of thermal expansion coefficients between glass and metal.

[0036] One embodiment of this application provides a glass plate, comprising: a glass substrate, a titanium dioxide layer located on at least one surface of the glass substrate, and a metal conductive layer located on the titanium dioxide layer.

[0037] In the glass plate of this application, a pure titanium dioxide layer is provided between the glass substrate and the metal conductive layer to construct a gradient thermomechanical interface. This helps to build a stable and reliable stress buffer transition zone between the glass and metal interfaces, thereby reducing microcracks, interface delamination and decreased bonding strength caused by CTE mismatch, and thus improving the long-term reliability of the glass plate under temperature cycling.

[0038] Among them, titanium dioxide material itself has an octane rating of approximately 8.6 × 10⁻⁶. -6 The coefficient of thermal expansion at / ℃ is exactly between that of the glass substrate (approximately 3-4×10⁻⁶). -6 / ℃) and a conductive layer of metals such as copper (approximately 16×10) -6 Between 0.5°C and 0.6°C. During temperature cycling, this intermediate layer decomposes and transitions the abrupt, concentrated thermal strain caused by the large CTE difference between the glass and metal into two smaller and gradual strain stages, thereby effectively reducing the peak shear stress at the interface. Simultaneously, the pre-set thickness of the titanium dioxide layer ensures sufficient mechanical integrity for effective stress gradient transition and reduces the risk of increased internal stress or weakened interfacial bonding due to excessive titanium dioxide layer thickness. It also mitigates problems such as insufficient buffering and uneven coverage when the titanium dioxide layer is too thin. Therefore, placing a pre-set thickness of pure titanium dioxide layer between the glass substrate and the metal conductive layer helps to construct a stable and reliable stress buffer transition zone at the glass-metal interface, thereby reducing microcracks, interfacial delamination, and decreased bonding caused by CTE mismatch, and ultimately improving the long-term reliability of the glass plate under temperature cycling.

[0039] In some embodiments, the glass substrate has at least one through-hole, and a titanium dioxide layer further covers the sidewalls of the through-hole. In related technologies, the sidewalls of glass through-holes (such as the edge of the hole) are areas of relatively concentrated thermal stress during temperature cycling and are also regions prone to microcracks. Controlling the titanium dioxide layer to further cover the sidewalls of the glass through-hole helps to extend stress buffering and transition protection from a two-dimensional plane to the critical stress concentration areas of the three-dimensional hole structure. This facilitates the direct construction of a buffer barrier in high-risk areas for crack initiation, more comprehensively reducing the risk of peri-hole cracks caused by CTE mismatch, and further improving the mechanical integrity and long-term reliability of the entire glass plate under temperature cycling.

[0040] In some embodiments, the thickness of the titanium dioxide layer is 500 nm to 700 nm. For example, the thickness of the titanium dioxide layer can be 500 nm, 510 nm, 520 nm, 530 nm, 540 nm, 550 nm, 560 nm, 570 nm, 580 nm, 590 nm, 600 nm, 610 nm, 620 nm, 630 nm, 640 nm, 650 nm, 660 nm, 670 nm, 680 nm, 690 nm, 700 nm, or any value within the range of any two of the above values. This application has found that controlling the thickness of the titanium dioxide layer within the above range helps to achieve a better balance between the functional requirements of effective thermal stress buffering and gradient transition and process controllability, cost, and the internal stress of the film itself. This specific thickness ensures that the buffer layer has sufficient mechanical strength to effectively disperse and absorb thermal strain, while avoiding the increased deposition stress, potential decrease in adhesion to the substrate, and excessive consumption of materials and time costs that may result from an excessively thick film layer. It also prevents problems such as uneven coverage, insufficient buffering capacity, or easy damage in subsequent processes that may occur due to an excessively thin film layer. This is conducive to obtaining a buffer interface with stable performance and high repeatability, further improving the effect of suppressing microcracks and enhancing interfacial adhesion.

[0041] One embodiment of this application also provides a microelectronic device, including the glass plate described above.

[0042] The microelectronic device of this application includes a glass plate with a pure, dense, strongly bonded, and optimized-thickness titanium dioxide buffer layer between the glass and the metal conductive layer. This effectively buffers and redistributes the thermomechanical stress borne by the critical interconnect interfaces (especially high-stress areas such as the sidewalls of glass vias) when the device experiences temperature fluctuations during the packaging process or operating environment. This helps reduce the risk of microcracks, interface delamination, or conductive line breakage caused by stress concentration inside the device, thereby improving the overall long-term reliability and service life of the microelectronic device.

[0043] The present application will be described below through specific embodiments and comparative examples. Those skilled in the art should understand that the preparation methods described in this application are merely examples, and any other suitable preparation methods are within the scope of this application.

[0044] Example 1:

[0045] A glass plate, the preparation method of which includes:

[0046] Step 1: Add tetrabutyl titanate to the organic solvent isopropanol to dissolve it, and obtain the precursor sol, wherein the concentration of tetrabutyl titanate is 0.5 mol / L.

[0047] Step 2: The glass substrate is ultrasonically cleaned sequentially with ethanol and acetone at room temperature. The ultrasonic power is controlled at 50 W to 100 W and the frequency is 40 Hz to 60 Hz. The cleaning time for each cleaning session is 5 min to 20 min. After cleaning, the residual reagent is rinsed with distilled water and then dried to remove surface moisture, resulting in a clean glass substrate for later use. This glass substrate has TGV holes.

[0048] Step 3: Film deposition was performed using an ultrasonic spray pyrolysis system. An integrated ultrasonic atomizing nozzle (ultrasonic frequency 60 kHz) was used to atomize the precursor sol into uniform droplets with a diameter of 50 μm ± 10 μm. During film deposition, the temperature of the glass substrate surface was controlled at 150 ℃, the nozzle-substrate distance was maintained at 20 cm, and the liquid flow rate was adjusted to 100 mL / h. Two-dimensional scanning was performed by the nozzle along a toothed wave trajectory: reciprocating along the X-axis at a rate of 80 mm / s to increase the film thickness, and slowly moving along the Y-axis at a rate of 2 mm / s to achieve large-area coverage. According to the required thickness of the target titanium dioxide layer, deposition was completed through multi-layer stacking. After each layer scan, the substrate temperature was kept stable to ensure film uniformity, ultimately achieving a titanium dioxide layer thickness of 500 nm.

[0049] Step 4: A copper conductive layer is formed on the titanium dioxide layer using the PVD process to obtain the glass plate.

[0050] Example 2:

[0051] The difference from Example 1 is that in the third step, the thickness of the titanium dioxide layer reaches 600 nm.

[0052] Example 3:

[0053] The difference from Example 1 is that in the third step, the thickness of the titanium dioxide layer reaches 700 nm.

[0054] Example 4:

[0055] The difference from Example 1 is that in the third step, the temperature of the glass substrate film surface is controlled at 400°C during film formation.

[0056] Example 5:

[0057] The difference from Example 1 is that in the third step, the temperature of the glass substrate film surface is controlled at 500°C during film formation.

[0058] Example 6:

[0059] The difference from Example 1 is that in the first step, after the titanium source is dissolved in an organic solvent, acetylacetone is also added to obtain a precursor sol, and the molar ratio of the added acetylacetone to the titanium source is 5.

[0060] Example 7:

[0061] The difference from Example 1 is that, in the second step, oxygen plasma activation is added to the clean glass substrate. This is performed at room temperature with an oxygen flow rate of 40 sccm and a power of 80 W for 8 minutes to form hydrophilic groups on the glass surface. Furthermore, before the fourth step, a heat treatment is added to the glass substrate with the titanium dioxide layer formed. The heat treatment temperature is 500 °C, and the time is 0.5 h.

[0062] Comparative Example 1:

[0063] A conventional glass plate is provided, including a glass substrate and a copper conductive layer disposed on the surface of the glass substrate.

[0064] Comparative Example 2:

[0065] The difference from Example 1 is that a titanium dioxide layer is formed between the glass substrate and the copper conductive layer by a PVD deposition process, and the thickness of the titanium dioxide layer is 300 nm.

[0066] Comparative Example 3:

[0067] The difference from Comparative Example 2 is that the thickness of the titanium dioxide layer is controlled to be above 700 nm.

[0068] Comparative Example 4: A titanium dioxide layer with a thickness of 300 nm was formed between a glass substrate and a copper conductive layer by a chemical plating process.

[0069] This application conducted thermal shock reliability tests on the glass plates provided in the above embodiments and comparative examples, and tested the crack condition and interlayer bonding strength of each glass plate. The test methods are as follows, and the test results are shown in Table 1.

[0070] 1. Thermal shock reliability test: After the copper conductive layer process is completed, the glass plate product is placed in a thermal cycling equipment to conduct a high temperature of 125℃ and a low temperature of -45℃ cycle reliability test, which is maintained for 30 minutes in turn. After 500 cycles, the initial TGV hole is observed to see if there are microcracks.

[0071] 2. Crack test of glass plate: Cracks in glass plate are observed and counted using an optical microscope at X20 magnification.

[0072] 3. Adhesion Test: A cross-cut adhesion test is used to determine whether the copper layer adhesion meets the requirements. A result of 4B or higher is acceptable. A cross-cut adhesion test is performed on the glass substrate using a cross-cut tool to evenly cut a grid of a specific size. The blade width is approximately 10 mm to 12 mm, with intervals of 1 mm to 1.2 mm, for a total of 10 grids. When cutting straight lines, 10 equally spaced straight lines will appear. Cutting perpendicular to these straight lines creates a 10x10 square. The cross-cut tool should cut to the substrate, not just the coating; otherwise, the test is invalid. The adhesion performance of the surface coating is verified using the cross-cut method or the tape method.

[0073] Table 1. Test results of glass plates from Examples 1-7 and Comparative Examples 1-4 of this application

[0074]

[0075] Examples 1-7 of this application use titanium alkoxide as the titanium source and form a titanium dioxide layer on the surface of a glass substrate through a predetermined process. This helps to prepare a pure, dense, uniformly thick, and strongly bonded titanium dioxide buffer layer on the glass substrate. This allows the glass plate of this application to buffer CTE mismatch by utilizing the inherent properties of titanium dioxide, and also to construct a continuous stress transmission path through the good bonding between the glass substrate and the titanium dioxide layer, as well as the dense and uniform structure of the titanium dioxide layer. This promotes stress transmission and synergistically reduces the risk of interfacial microcracks, thus solving reliability defects caused by the mismatch of thermal expansion coefficients between glass and metal. Furthermore, in the glass plates of Examples 1-7 of this application, a pure titanium dioxide layer is placed between the glass substrate and the metal conductive layer, thereby constructing a gradient thermomechanical interface. This helps to build a stable and reliable stress buffer transition zone between the glass and metal interfaces, which is beneficial for reducing microcracks, interfacial delamination, and decreased bonding strength caused by CTE mismatch, thereby improving the long-term reliability of the glass plate under temperature cycling.

[0076] In Examples 1-3, Example 2 controls the thickness of the titanium dioxide layer to 600 nm. This specific thickness can achieve a better balance between the functional requirements of effective thermal stress buffering and gradient transition and process controllability, cost and internal stress of the film itself, which is conducive to obtaining a buffer interface with stable performance and high repeatability, and further improves the effect of suppressing microcracks and enhancing interfacial bonding.

[0077] In Examples 1 and 4-5, Examples 4-5 further control the temperature of the glass substrate film surface within a preset range during film formation. This helps to provide better energy conditions for the thermal decomposition and oxidation reaction of titanium metal alkoxide, enabling the precursor to achieve rapid and sufficient pyrolysis-oxidation reaction. This promotes the formation and dense stacking of highly crystalline titanium dioxide microcrystals, thereby further enhancing the crystal quality, density, and bonding force between the formed titanium dioxide layer and the substrate, giving it superior long-term thermomechanical stability and stress buffering ability.

[0078] Based on Example 1, Example 6 also adds a predetermined amount of acetylacetone to the precursor sol. As a structural stabilizer of the titanium source, acetylacetone helps to reduce premature hydrolysis and condensation of titanium alkoxides in solution, and extends the process window of the precursor sol. The predetermined amount of acetylacetone can decompose in time without leaving too much carbon impurity, which is conducive to further improving the chemical stability and process repeatability of the precursor sol during atomization and deposition, and finally obtaining a more uniform, dense and less defective titanium dioxide buffer layer.

[0079] Based on Example 1, Example 7 adds pretreatment and subsequent heat treatment of the glass substrate: On the one hand, the pretreatment introduces hydrophilic groups on the corresponding surface of the glass substrate, which is beneficial for the better spreading and adhesion of the droplet precursor on the substrate, promoting close contact and possible chemical bonding between the interfaces, thereby further improving the interfacial bonding strength between the titanium dioxide layer and the glass substrate. On the other hand, the subsequent heat treatment helps to further promote the decomposition or volatilization of residual organic matter in the titanium dioxide layer, thereby promoting the further growth and crystal transformation of titanium dioxide grains. At the same time, this heat treatment process can also further eliminate the internal stress generated during the deposition process, which helps to improve the crystallinity, densification degree and interfacial interdiffusion bonding between the obtained titanium dioxide layer and the glass substrate, thereby further improving the mechanical strength, thermal stability and long-term stress buffering capacity of the titanium dioxide buffer layer, consolidating its effect in solving the CTE mismatch problem.

[0080] Compared to Examples 1-7 of this application, the conventional glass substrate-copper conductive layer structure provided in Comparative Example 1 has a large CTE mismatch between the glass material and the commonly used conductive metal copper, resulting in a large difference in the degree of thermal expansion and contraction between the two. This will generate huge thermal stress at the interface, which is prone to microcracks or even macrocracks on the brittle glass substrate, especially in stress concentration areas such as the edge of the TGV hole.

[0081] Compared to Examples 1-7 of this application, Comparative Examples 2 and 3 form titanium dioxide layers of appropriate thickness between the glass substrate and the copper conductive layer using PVD deposition, and Comparative Example 4 forms titanium dioxide layers of appropriate thickness between the glass substrate and the copper conductive layer using electroless plating. On the one hand, a titanium dioxide layer that is too thin has insufficient buffering effect, resulting in poor stress transfer between the glass substrate and the copper conductive layer. On the other hand, a titanium dioxide layer that is too thick has large internal stress and is difficult to form a good interface, resulting in more cracks in the resulting glass plate. On the other hand, the bonding strength between the titanium dioxide layer formed by PVD deposition or electroless plating and the glass substrate or the copper conductive layer is not as good as that of the embodiments of this application, indicating that the titanium dioxide layer formation process of this application can improve the bonding strength of the obtained titanium dioxide layer compared with the conventional processes in related technologies.

[0082] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] The embodiments described above are merely illustrative of several implementations of the technical solution of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the technical solution of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for preparing a glass plate, characterized in that, include: A precursor sol is provided, the precursor sol comprising a titanium source and an organic solvent, the titanium source comprising a titanium metal alkoxide; The precursor sol is atomized to obtain droplets, and the droplets are brought into contact with at least one surface of a glass substrate, the temperature of which is 150 °C to 500 °C, so that the titanium source forms a titanium dioxide layer on the surface through thermal decomposition. as well as A conductive metal layer is formed on the titanium dioxide layer to obtain the glass plate.

2. The preparation method according to claim 1, characterized in that, The diameter of the droplets is 10 μm to 100 μm.

3. The preparation method according to claim 1, characterized in that, Providing the precursor sol includes the following steps: The titanium source and the solvent are mixed to obtain a precursor sol, wherein the concentration of the titanium metal alkoxide in the precursor sol is 0.1 mol / L to 1 mol / L.

4. The preparation method according to claim 3, characterized in that, The precursor sol also includes acetylacetone, and the molar ratio of acetylacetone to the titanium metal alkoxide is (2~20):

1.

5. The preparation method according to claim 1, characterized in that, Before bringing the droplets into contact with at least one surface of the glass substrate, the preparation method further includes: Hydrophilic groups are formed on the surface of the glass substrate by a plasma activation process.

6. The preparation method according to claim 1, characterized in that, The preparation method further includes: The glass substrate on which the titanium dioxide layer is formed is subjected to heat treatment at a temperature of 400 °C to 500 °C for a time of 0.5 h to 1 h.

7. A glass plate prepared by the preparation method according to any one of claims 1-6, characterized in that, The glass plate includes: Glass substrate; A titanium dioxide layer located on at least one surface of the glass substrate; and A conductive metal layer located on the titanium dioxide layer.

8. The glass plate as described in claim 7, characterized in that, The glass substrate has at least one through hole, and the titanium dioxide layer also covers the sidewall of the through hole.

9. The glass plate as described in claim 7, characterized in that, The thickness of the titanium dioxide layer is 500 nm to 700 nm.

10. A microelectronic device, characterized in that, Includes the glass plate as described in any one of claims 7 to 9.

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